> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandrine
> Bailleux via TF-A
> Sent: 16 June 2020 13:09
> To: Alexei Fedorov <Alexei.Fedorov(a)arm.com>; Madhukar Pappireddy
> <Madhukar.Pappireddy(a)arm.com>; Varun Wadekar <vwadekar(a)nvidia.com>
> Cc: tf-a(a)lists.trustedfirmware.org
> Subject: Re: [TF-A] Upgrading libfdt library
>
> Hi Alexei,
>
> On 6/16/20 1:51 PM, Alexei Fedorov wrote:
> > Thanks for your very detailed explanation of the reason behind this
> > solution.
> > This brings the question on how do we monitor libfdt bug fixes, code
> > cleanup, etc. (which Madhukar pointed out) and integrate these changes
> > in TF-A source tree.
>
> Right now, it is a manual process and not only for libfdt but for all projects TF-A
> depends on. We keep an eye on them and aim at updating them when
> necessary. Unfortunately, like any manual process, it is error-prone and things
> might slip through the cracks. The TF-A release tick is usually a good reminder
> to update all dependencies but unfortunately libfdt has been left behind for
> some time (about 2 years)...
As I recall, when we tried to update libfdt last time, there was significant code bloat in generated binary (feature creep?) and we abandoned the update. The policy was to stick to a stable version and only update if there are any bugfixes or new feature we would want to make use of.
Generally speaking, we might have done several fixes in the imported 3rd party library by running static checks like for MISRA compliance etc and this has to be repeated when the library is updated. Also, for security audits, it is important to be sure of the "security status" of the imported library and hence we tended to not update for every release.
But I agree that we do have to be on top of bug fixes and hence we need to update but not sure how we can balance this with concerns above.
Regarding MbedTLS, being a security critical project, we would like to encourage platform integrators to take ownership of staying upto date rather than relying on update from TF-A repo. Hence the motivation to keep it separate.
Best Regards
Soby Mathew
>
> Regards,
> Sandrine
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi,
I've tested the libfdt update on STM32MP1.
I can see a boot time increase by ~6%, thanks to U-Boot 'bootstage
report' command. But I don't think this should block the lib upgrade.
I've some comments about the patch, I'll send that on gerrit.
Regards,
Yann
On 6/17/20 1:03 AM, Madhukar Pappireddy via TF-A wrote:
> Hi Varun,
>
> I have pushed the draft patch here [1] to upgrade the libfdt source
> files. I have tested this patch by running all tests that we usually run
> before merging a patch to TF-A repo. I am looking forward to receiving
> feedback from platform owners.
>
> However, I am not convinced why this effort needs an exhaustive
> evaluation with various criteria as you mentioned below. I am upgrading
> source files and I am not introducing a new project to TF-A. Let me know
> your thoughts.
>
> [1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4596
>
> Thanks,
>
> Madhukar
>
> *From:* Varun Wadekar <vwadekar(a)nvidia.com>
> *Sent:* Monday, June 15, 2020 2:12 PM
> *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com>
> *Cc:* tf-a(a)lists.trustedfirmware.org
> *Subject:* RE: Upgrading libfdt library
>
> Thanks, Madhukar.
>
> I think this needs a broader discussion where we form a list evaluation
> criteria of features, API, metrics, KPIs etc by pooling them from the
> platform owners.
>
> If we don’t receive any inputs, then it makes sense to execute the
> current tests and make sure that they work as expected.
>
> Thoughts?
>
> -Varun
>
> *From:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com
> <mailto:Madhukar.Pappireddy@arm.com>>
> *Sent:* Monday, June 15, 2020 8:30 AM
> *To:* Varun Wadekar <vwadekar(a)nvidia.com <mailto:vwadekar@nvidia.com>>
> *Cc:* tf-a(a)lists.trustedfirmware.org <mailto:tf-a@lists.trustedfirmware.org>
> *Subject:* RE: Upgrading libfdt library
>
> *External email: Use caution opening links or attachments*
>
> Hi Varun,
>
> Please find my replies inline.
>
> Thanks,
>
> Madhu
>
> *From:* Varun Wadekar <vwadekar(a)nvidia.com <mailto:vwadekar@nvidia.com>>
> *Sent:* Friday, June 12, 2020 7:04 PM
> *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com
> <mailto:Madhukar.Pappireddy@arm.com>>
> *Cc:* tf-a(a)lists.trustedfirmware.org <mailto:tf-a@lists.trustedfirmware.org>
> *Subject:* RE: Upgrading libfdt library
>
> Hi Madhukar,
>
> Before we merge this change, can you please explain how we arrived at
> this specific version? Are we tracking the stable version of the library?
>
> >> I was told by Andre that the releases(tags) by themselves don’t mean
> much in the libfdt project and it is better to upgrade directly to the
> recent commit(the latest HEAD was 85e5d83 when I started this
> investigation).
>
> What would be the testing criteria before merging the library? Does tftf
> provide any tests that can act as a smoking gun?
>
> >> Given that we rely more on libfdt APIs now, I plan to run all the
> existing tests in our CI (includes tftf and Linux boot tests) to verify
> if the libfdt library has any issues when integrating with TF-A. I
> believe these tests are thorough enough.
>
> Does it make sense to ask platform owners to test the specific version
> you plan to merge? This way we would have more confidence in the library.
>
> >> Yes, I wanted to take the feedback from platform owners and hence I
> sent this email before actually pushing the patch to tf.org for review.
> There was a performance concern in the past when upgrading libfdt source
> files [1].
>
> [1] https://github.com/ARM-software/tf-issues/issues/643
>
> -Varun
>
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org
> <mailto:tf-a-bounces@lists.trustedfirmware.org>> *On Behalf Of *Madhukar
> Pappireddy via TF-A
> *Sent:* Friday, June 12, 2020 4:48 PM
> *To:* tf-a(a)lists.trustedfirmware.org <mailto:tf-a@lists.trustedfirmware.org>
> *Subject:* [TF-A] Upgrading libfdt library
>
> *External email: Use caution opening links or attachments*
>
> Hello,
>
> I am planning to upgrade libfdt library source files in TF-A. They
> haven’t been updated for a while. As the project moves towards improving
> the fconf framework and adding more properties in device tree source
> files, we rely more on libfdt APIs. I have done some preliminary
> investigation to check if there is any performance penalty in upgrading
> the libfdt source files integrated into TF-A from the current
> version(which corresponds to commit aadd0b6 in the dtc repo [1]) to
> master commit (85e5d83). I have run some basics tests on both x86 and
> aarch64 machines and I have not seen any performance degradation. I plan
> to push a patch shortly to integrate the latest version of libfdt files
> in TF-A.
>
> Please let me know if you are aware of any performance issues or have
> other concerns.
>
> [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git
>
> Thanks,
>
> Madhu
>
Hi Madhukar,
Before we merge this change, can you please explain how we arrived at this specific version? Are we tracking the stable version of the library?
What would be the testing criteria before merging the library? Does tftf provide any tests that can act as a smoking gun?
Does it make sense to ask platform owners to test the specific version you plan to merge? This way we would have more confidence in the library.
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Madhukar Pappireddy via TF-A
Sent: Friday, June 12, 2020 4:48 PM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Upgrading libfdt library
External email: Use caution opening links or attachments
Hello,
I am planning to upgrade libfdt library source files in TF-A. They haven't been updated for a while. As the project moves towards improving the fconf framework and adding more properties in device tree source files, we rely more on libfdt APIs. I have done some preliminary investigation to check if there is any performance penalty in upgrading the libfdt source files integrated into TF-A from the current version(which corresponds to commit aadd0b6 in the dtc repo [1]) to master commit (85e5d83). I have run some basics tests on both x86 and aarch64 machines and I have not seen any performance degradation. I plan to push a patch shortly to integrate the latest version of libfdt files in TF-A.
Please let me know if you are aware of any performance issues or have other concerns.
[1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git
Thanks,
Madhu
Hi Alexei,
On 6/15/20 2:18 PM, Alexei Fedorov via TF-A wrote:
> I'm wondering why we need to integrate libfdt sources in TF-A? Why
> cannot we use the same option as for MbedTls when the build system gets
> the path to the preloaded source tree?
As far as I know, the question is the other way around: why is mbed TLS
not integrated in the TF-A source tree? If you look at the other
external libraries used by TF-A (not just libfdt, but also compiler-rt
library, zlib, ...), they all are integrated.
As far as I am aware, there are several reasons for keeping these
projects in the TF-A tree:
1) It is more developer-friendly. Whenever you clone the TF-A repo, you
get all required dependencies at the same time, no need to pull them
yourself.
2) It allows us to keep local modifications on top of mainline. Such
modifications are sometimes necessary or make our life easier to
integrate/interface the project with the rest of the TF-A code base.
3) We don't depend on the library project infrastructure. For example if
their git server is down, this would not affect us, as we've got our own
copy hosted on tf.org. Not sure this third reason was actually
considered at the time the decision was made but I see this as a tiny bonus.
Now 1) could be achieved some other way, for example we could add the
dependent projects as git submodules and have a setup script that pulls
them in. We did not go for this option at the time and I don't recall
exactly why. It might just be because of the infrastructure/setup
required to work with git submodules.
So having these projects integrated in the TF-A source tree is the
common practice in our project. As far as I am aware, the reason why we
treat mbed TLS differently is because it is very security sensitive,
thus it's important that people keep up to date with the latest version
to get all latest vulnerability fixes. If we had imported it in the TF-A
project, this would have put the onus on us to monitor mbed TLS for
security fixes and push updates as soon as they become available. This
was deemed impractical and too much responsibility for us at the time.
Regards,
Sandrine
Hello all,
I am glad to announce that Raghu Krishnamurthy has been appointed
maintainer for the TF-A project. The maintainers list has been updated
accordingly in the following patch:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4582
Best regards,
Sandrine
Hi Raghu,
We had a discussion internally about handling the mandatory and optional properties in fconf and we believe we can use the following approach. Please let us know if it is acceptable to you.
As agreed over the mailing list, we treat the scenarios of a missing/incorrect mandatory property or a structurally bad dtb as an integration error and must lead to panic in runtime. It is the responsibility of the developer providing the populate callback to detect and return an error code in such scenarios. It will be treated as an unrecoverable error and further escalated to panic() by the fconf framework itself. An incorrect or missing optional property in a dtb should lead to a warning message and the boot loader should continue after assigning a default value to the specific property.
Further, every property accessed by a populate callback should be clearly defined as either mandatory or optional in a fconf based binding document such as the one shown here [1]. This must be enforced in spirit as part of the code review process. We believe the callbacks can be categorized into two: Generic vs platform-specific. Generic callbacks are the ones that are required to support a standard component supported by platforms running TF-A such as TBBR, SDEI, IO Policy, GICv3, etc. Platform-specific callbacks are provided by platform developers to work with non-standard components such as a Proprietary Hardware IP.
The binding document for generic populate callbacks should be provided by the TF-A project. The generic binding will become a contract for the platforms to implement the support for integrating standard components and hence, will be platform agnostic. Correspondingly, it is the responsibility of the platform developer to provide the binding for platform-specific populate callbacks.
Any thoughts?
[1] https://trustedfirmware-a.readthedocs.io/en/latest/components/fconf/fconf_p…
Thanks,
Madhukar
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Manish Badarkhe via TF-A
Sent: Wednesday, May 20, 2020 6:00 AM
To: Raghu K <raghu.ncstate(a)icloud.com>; Sandrine Bailleux <Sandrine.Bailleux(a)arm.com>; tf-a(a)lists.trustedfirmware.org; Louis Mayencourt <Louis.Mayencourt(a)arm.com>
Cc: nd <nd(a)arm.com>
Subject: Re: [TF-A] fconf: Validating config data
Hi Raghu
We have plan to work on this and come up with some design which handles mandatory/critical properties.
On 13/05/2020, 22:18, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi All,
Since the 2.3 release is done, can we revisit this topic? I think we
left this with finalizing on how to handle bad/incorrect DTB's.
Sandrine's latest proposal below:
"A bad DTB seems more like an integration error than a
programming error to me, and thus should be handled with runtime checks
according to the current guidelines. Incorrect values for mandatory
properties should probably be treated as unrecoverable errors (causing a
panic) and incorrect/missing optional properties as recoverable errors
(issuing a warning message)."
I agree with this proposal and think we should follow this. This
addresses my original concern of handling errors consistently and being
safe by verifying mandatory/critical properties at run-time.
Thoughts ?
Thanks
Raghu
On 4/13/20 10:27 AM, Raghu Krishnamurthy wrote:
> Thanks Sandrine. Revisiting after v2.3 is sounds fine.
>
> -Raghu
>
> On 4/10/20 2:25 AM, Sandrine Bailleux wrote:
>> Hi Raghu,
>>
>> On 4/8/20 12:50 AM, Raghu Krishnamurthy wrote:
>>> Thanks Sandrine, Louis,
>>>
>>> Agree with both of you. I'm fine with using asserts or panics, as
>>> long as we uniformly use it. The change i sent out(review 3845) was
>>> because i noticed inconsistency in handling errors. If we do use
>>> asserts, all code that checks for mandatory properties, should be
>>> changed to assert as opposed to return error code. For optional
>>> properties, we can continue to return an error code or print
>>> warnings etc.
>>
>> Yes, I too think consistency is key here. As you said, we need to
>> settle on the expected behaviour and enforce it uniformly across the
>> fconf code. Let's revisit this code after the v2.3 release.
>>
>>> I would like to point out that using asserts here is different from
>>> what is documented in the coding guidelines. The guidelines
>>> explicitly spells out using asserts for "programming errors".
>>> Now, is having a bad DTB considered a programming error? ;) The DTB
>>> is platform data as opposed to code. The guidelines might need to be
>>> updated based on the conclusion here.
>>
>> Now that you point it out, and after taking a closer look at [1], I
>> think I was wrong. A bad DTB seems more like an integration error
>> than a programming error to me, and thus should be handled with
>> runtime checks according to the current guidelines. Incorrect values
>> for mandatory properties should probably be treated as unrecoverable
>> errors (causing a panic) and incorrect/missing optional properties as
>> recoverable errors (issuing a warning message).
>>
>> [1]
>> https://trustedfirmware-a.readthedocs.io/en/latest/process/coding-guideline…
>>
>>
>>> Also note the couple of scenarios i mentioned in an earlier email.
>>> Platforms like RPI4 don't generally enable TBBR and the DTB image
>>> could get corrupt or be modified on purpose. On a release build,
>>> this could cause silent corruption. Panic() would avoid this.
>>>
>>> In any case, it would be good to settle on the expected behavior for
>>> each of these abnormal cases. I don't have a strong preference for
>>> asserts or panics here, since each has its pros and cons as both of
>>> you called out.
>>>
>>> Thanks
>>> Raghu
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi All,
The next TF-A Tech Forum is scheduled for Thu 18th June 2020 16:00 – 17:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know. Note the new time that is an hour earlier then previous sessions.
Agenda:
* TF-A Unit Level Testing - Presented by Lauren Wehrmeister
* General explanation of the new approach for Unit Testing in TF-A.
* Optional TF-A Mailing List Topic Discussions
If TF-A contributors have anything they wish to present at any future TF-A tech forum please contact me to have that scheduled.
Thanks
Joanna
Hi Alexei,
To be clear, my current effort is to upgrade the libfdt source files in TF-A. I am not sure why the libfdt source was not integrated into TF-A as a preloaded source tree similar to MbedTLS. Perhaps, any TF-A veteran can help answer this question?
Since there is an ongoing effort in the TF-A project to move to CMake build framework, I did not plan to integrate libfdt Makefile into TF-A.
Hi Yann,
Between commits aadd0b6 (the current version in TF-A for libfdt files) and 85e5d83, I have noticed bug fixes, code cleanups. I am not familiar with the dtc project. I can push a WIP patch with libfdt source files picked from commit 85e5d83. Please let me know if you see any issues with ST platforms.
Thanks,
Madhukar
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Yann GAUTIER via TF-A
Sent: Monday, June 15, 2020 10:26 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] Upgrading libfdt library
Hi Madhukar,
We had seen some issue on STM32MP1 with the previous libfdt rebase, that led to the ticket [1]. And then a partial revert [2].
I'll then try this new version to check if boot time doesn't increase too much.
Do you expect other changes than the one changing __ASSEMBLY__ to __ASSEMBLER__? And maybe some updates in libfdt.mk file?
If you push this new version to gerrit, it will be easier to fetch and test, as a WIP if it is better for you?
Regards,
Yann
[1] https://github.com/ARM-software/tf-issues/issues/643
[2]
https://github.com/ARM-software/arm-trusted-firmware/commit/00f588bf2cc5298…
On 6/15/20 2:18 PM, Alexei Fedorov via TF-A wrote:
> Hi Madhukar,
>
> I'm wondering why we need to integrate libfdt sources in TF-A? Why
> cannot we use the same option as for MbedTls when the build system
> gets the path to the preloaded source tree?
>
> Regards.
>
> Alexei
>
> ----------------------------------------------------------------------
> --
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of
> Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org>
> *Sent:* 13 June 2020 01:04
> *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com>
> *Cc:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
> *Subject:* Re: [TF-A] Upgrading libfdt library
>
> Hi Madhukar,
>
> Before we merge this change, can you please explain how we arrived at
> this specific version? Are we tracking the stable version of the library?
>
> What would be the testing criteria before merging the library? Does
> tftf provide any tests that can act as a smoking gun?
>
> Does it make sense to ask platform owners to test the specific version
> you plan to merge? This way we would have more confidence in the library.
>
> -Varun
>
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> *On Behalf Of
> *Madhukar Pappireddy via TF-A
> *Sent:* Friday, June 12, 2020 4:48 PM
> *To:* tf-a(a)lists.trustedfirmware.org
> *Subject:* [TF-A] Upgrading libfdt library
>
> *External email: Use caution opening links or attachments*
>
> Hello,
>
> I am planning to upgrade libfdt library source files in TF-A. They
> haven’t been updated for a while. As the project moves towards
> improving the fconf framework and adding more properties in device
> tree source files, we rely more on libfdt APIs. I have done some
> preliminary investigation to check if there is any performance penalty
> in upgrading the libfdt source files integrated into TF-A from the
> current version(which corresponds to commit aadd0b6 in the dtc repo
> [1]) to master commit (85e5d83). I have run some basics tests on both
> x86 and
> aarch64 machines and I have not seen any performance degradation. I
> plan to push a patch shortly to integrate the latest version of libfdt
> files in TF-A.
>
> Please let me know if you are aware of any performance issues or have
> other concerns.
>
> [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git
>
> Thanks,
>
> Madhu
>
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Madhukar,
We had seen some issue on STM32MP1 with the previous libfdt rebase, that
led to the ticket [1]. And then a partial revert [2].
I'll then try this new version to check if boot time doesn't increase
too much.
Do you expect other changes than the one changing __ASSEMBLY__ to
__ASSEMBLER__? And maybe some updates in libfdt.mk file?
If you push this new version to gerrit, it will be easier to fetch and
test, as a WIP if it is better for you?
Regards,
Yann
[1] https://github.com/ARM-software/tf-issues/issues/643
[2]
https://github.com/ARM-software/arm-trusted-firmware/commit/00f588bf2cc5298…
On 6/15/20 2:18 PM, Alexei Fedorov via TF-A wrote:
> Hi Madhukar,
>
> I'm wondering why we need to integrate libfdt sources in TF-A? Why
> cannot we use the same option as for MbedTls when the build system gets
> the path to the preloaded source tree?
>
> Regards.
>
> Alexei
>
> ------------------------------------------------------------------------
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun
> Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org>
> *Sent:* 13 June 2020 01:04
> *To:* Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com>
> *Cc:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
> *Subject:* Re: [TF-A] Upgrading libfdt library
>
> Hi Madhukar,
>
> Before we merge this change, can you please explain how we arrived at
> this specific version? Are we tracking the stable version of the library?
>
> What would be the testing criteria before merging the library? Does tftf
> provide any tests that can act as a smoking gun?
>
> Does it make sense to ask platform owners to test the specific version
> you plan to merge? This way we would have more confidence in the library.
>
> -Varun
>
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> *On Behalf Of
> *Madhukar Pappireddy via TF-A
> *Sent:* Friday, June 12, 2020 4:48 PM
> *To:* tf-a(a)lists.trustedfirmware.org
> *Subject:* [TF-A] Upgrading libfdt library
>
> *External email: Use caution opening links or attachments*
>
> Hello,
>
> I am planning to upgrade libfdt library source files in TF-A. They
> haven’t been updated for a while. As the project moves towards improving
> the fconf framework and adding more properties in device tree source
> files, we rely more on libfdt APIs. I have done some preliminary
> investigation to check if there is any performance penalty in upgrading
> the libfdt source files integrated into TF-A from the current
> version(which corresponds to commit aadd0b6 in the dtc repo [1]) to
> master commit (85e5d83). I have run some basics tests on both x86 and
> aarch64 machines and I have not seen any performance degradation. I plan
> to push a patch shortly to integrate the latest version of libfdt files
> in TF-A.
>
> Please let me know if you are aware of any performance issues or have
> other concerns.
>
> [1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git
>
> Thanks,
>
> Madhu
>
>
Hi Madhukar,
I'm wondering why we need to integrate libfdt sources in TF-A? Why cannot we use the same option as for MbedTls when the build system gets the path to the preloaded source tree?
Regards.
Alexei
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 13 June 2020 01:04
To: Madhukar Pappireddy <Madhukar.Pappireddy(a)arm.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Upgrading libfdt library
Hi Madhukar,
Before we merge this change, can you please explain how we arrived at this specific version? Are we tracking the stable version of the library?
What would be the testing criteria before merging the library? Does tftf provide any tests that can act as a smoking gun?
Does it make sense to ask platform owners to test the specific version you plan to merge? This way we would have more confidence in the library.
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Madhukar Pappireddy via TF-A
Sent: Friday, June 12, 2020 4:48 PM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Upgrading libfdt library
External email: Use caution opening links or attachments
Hello,
I am planning to upgrade libfdt library source files in TF-A. They haven’t been updated for a while. As the project moves towards improving the fconf framework and adding more properties in device tree source files, we rely more on libfdt APIs. I have done some preliminary investigation to check if there is any performance penalty in upgrading the libfdt source files integrated into TF-A from the current version(which corresponds to commit aadd0b6 in the dtc repo [1]) to master commit (85e5d83). I have run some basics tests on both x86 and aarch64 machines and I have not seen any performance degradation. I plan to push a patch shortly to integrate the latest version of libfdt files in TF-A.
Please let me know if you are aware of any performance issues or have other concerns.
[1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git
Thanks,
Madhu
Hello Etienne,
On 6/10/20 1:19 PM, Etienne Carriere via TF-A wrote:
> Dear all,
>
> As part of a patchset series review (topic scmi-msg), change [1]
> imports confine_array_index.h header file from OP-TEE OS repository.
> The file originates from the open source Fuschia project, see link in
> commit message of [1].
>
> As being imported for external packages, the header file inherits
> Fushca and OP-TEE notices.
> The helper function can protect some data structure from side channel
> attacks leveraging index indirect access overflows during speculative
> execution.
> It is not Arm copyright. It is BSD-3-Clause license.
> I'll add an entry in the docs/license.rst for the file.
>
> Where to locate the file?
> It is ok to add such a file in include/common?
> Does it deserve a specific lib path, like
> include/lib/speculconfie_array_index.h?
> Maybe add as include/lib/cpus/confine_array_index.h as it is CPU
> speculative matters?
Before we discuss the location of this header file, have we considered
using the compiler support for speculative execution mitigations
instead? I am referring to the __builtin_speculation_safe_value() macro,
which I believe achieves the same goal as the code you propose to
introduce here, i.e. protecting against Spectre v1 bounds-check bypass
attacks.
TF-A already uses this compiler builtin today and provides a wrapper
macro around it, see SPECULATION_SAFE_VALUE() in include/lib/utils_def.f
(although I would argue this is not the best location one could think
of...). For reference, this was introduced by commit [1].
According to Arm's whitepaper [2], the support for this compiler builtin
was added in GCC 9 and LLVM/Clang was to follow shortly.
If these versions are too recent for you, then I believe the official
location to get equivalent code is [3]. As stated there:
The header file provided here allows a migration path to using the
builtin function for users who are unable to immediately upgrade to a
compiler which supports the builtin.
So I would prefer we get the code from there rather than from the OP-TEE
project, which got it from the Fuschia project ;) This is licensed under
the Boost Software License 1.0, which we've never used in TF-A so I
would need to check with our legal department whether this is OK, but I
don't expect any issues there as this is described as a permissive
license only requiring preservation of copyright and license notices.
This is assuming that both header files (the one from OP-TEE and the one
from the Arm software Github repo) are equivalent... Is this the case?
Is the code provided in OP-TEE perhaps more optimized?
Regards,
Sandrine
[1]
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=9edd…
[2]
https://developer.arm.com/support/arm-security-updates/speculative-processo…
[3] https://github.com/ARM-software/speculation-barrier
You have been invited to the following event.
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558
8656 US (New York) +1 669 900
9128 US (San Jose) 877 853 5247 US
Toll-free 888 788 0099 US Toll-freeMeeting ID:
915 970 4974Find your local
number: https://zoom.us/u/ad27hc6t7h
When: Every 2 weeks from 16:00 to 17:00 on Thursday United Kingdom Time
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
* Bill Fletcher- creator
* tf-a(a)lists.trustedfirmware.org
Event details:
https://www.google.com/calendar/event?action=VIEW&eid=NWlub3Ewdm1tMmk1cTJrM…
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
Hello,
I am planning to upgrade libfdt library source files in TF-A. They haven't been updated for a while. As the project moves towards improving the fconf framework and adding more properties in device tree source files, we rely more on libfdt APIs. I have done some preliminary investigation to check if there is any performance penalty in upgrading the libfdt source files integrated into TF-A from the current version(which corresponds to commit aadd0b6 in the dtc repo [1]) to master commit (85e5d83). I have run some basics tests on both x86 and aarch64 machines and I have not seen any performance degradation. I plan to push a patch shortly to integrate the latest version of libfdt files in TF-A.
Please let me know if you are aware of any performance issues or have other concerns.
[1] https://git.kernel.org/pub/scm/utils/dtc/dtc.git
Thanks,
Madhu
Hello Matteo,
Apologies for still using an outdated term. I have trained myself to get used to "TF-A" - looks like I am still not there.
>> The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers
That is good to hear. For the exact scope, I think we can assume the usual expectations from any LTS software stack - stability, performance, security, bug fixes along with maintenance support. We are open to discussing the cadence and any other operational commitments.
@Francois, from the description of Trusted Substrate looks like you also expect the sub-projects to provide LTS versions for the project as a whole to succeed (?)
-Varun
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Matteo Carlini via TF-A
Sent: Thursday, June 11, 2020 4:25 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] ATF LTS version
External email: Use caution opening links or attachments
Hi Francois,
> I'd be happy to know more about what you see as TFA LTS: exact scope, number of versions, duration, operational commitments (zero-day...).
> Do you have other firmware LTS needs?
Agree. That’s precisely what I was hinting to Varun, when mentioning concrete requirements for the LTS scheme.
> Trusted Substrate is the aggregation of { TFA, OP-TEE, some TEE apps such as firmwareTPM, U-Boot }.
> Trusted Substrate effort is led by Linaro members and is going to be set up as a more open project.
First time I heard about it. Good to know, but I guess we'll need to discuss the intersection and collaboration with the Trusted Firmware project at some point.
Having a LTS versioning scheme for the Trusted Firmware hosted projects should be theoretically either in the scope of the Project itself or, if the Board agrees, appointed to some other project/entity.
> Our end goal is to enable unified, transactional, robust (anti-bricking, anti rollback) UEFI OTA on both U-Boot and EDK2.
Fair, but IMHO this has little to do with Arm Secure world software LTS releases (TF-A/Hafnium/OP-TEE/TAs, TF-M)...probably best to discuss aside, this is not in scope of what Varun is raising.
Thanks
Matteo
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
I should also mention the Release processes we follow and the attempt to indicated the deprecation of interfaces in advance in the effort to maintain compatibility https://trustedfirmware-a.readthedocs.io/en/latest/about/release-informatio…
On 11/06/2020, 14:47, "TF-A on behalf of Joanna Farley via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Varun,
I guess this suggestion came in response to last weeks Tech Forum discussion from a question about experiences people had from migrating to different TF-A tagged releases. In general we try and keep the tip of Master at tagged release quality through an extensive CI system ran on each patch. I appreciate this CI is currently a little opaque to many contributors as this is still in the process of being transitioned to the OpenCI hosted by Trustedfirmware.org servers which will be visible to all. As mentioned in the recent "Overview of the TF-A v2.3 Release" presentation on https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ the additional testing done for a 6 monthly tagged release is quite minimal and the larger work is ensuring all documentation is up to date. Additionally all new features are generally behind their own build flags but I appreciate it is some work for a tagged release to be absorbed into product offerings.
I asked at the tech forum last week what more we could do to allow releases to be integrated more easily. On the call it was requested if we could disable weak bindings to symbols so it could be more easily seen where platform decisions may need to be made and we will look into this. If there are any more adjustments to the way tagged releases are produced please let us know.
One thing that had been considered briefly was the production of a security bug only branch that was maintained only between 6 month tagged releases before being replaced by the next security bug only branch based on the next 6 month release but that has not progressed very far as a proposal as until your email here it was perceived to not be in demand. A LTS branch is a larger endeavour as it sounds like something that includes more than security fixes and I look forward to you elaborating more as Matteo requests.
Thanks
Joanna
On 11/06/2020, 12:19, "Matteo Carlini via TF-A" <tf-a(a)lists.trustedfirmware.org> wrote:
Hi Varun,
Thanks for raising this topic (but please do embrace the official terminology “TF-A”…we never really promoted ATF and it's also absolutely outdated now 😉 ).
Arm has received different queries over time on supporting Trusted Firmware LTS releases, but the effort to sustain them is something that the Arm engineering team alone cannot really afford and commit to (either in the TF-A or TF-M space).
The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers, so to evaluate the possibility of a more concrete proposal to be carried on within the community Project.
I guess it will also be good to start by elaborating more concretely on the requirements that you would like to see in an hypothetical LTS versioning scheme.
Thanks
Matteo
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A
> Sent: 10 June 2020 22:47
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] ATF LTS version
>
> Hello team,
>
> To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain.
>
> For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won’t have to upgrade the entire firmware to get these goodies.
>
> It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally?
>
> -Varun
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Varun,
I guess this suggestion came in response to last weeks Tech Forum discussion from a question about experiences people had from migrating to different TF-A tagged releases. In general we try and keep the tip of Master at tagged release quality through an extensive CI system ran on each patch. I appreciate this CI is currently a little opaque to many contributors as this is still in the process of being transitioned to the OpenCI hosted by Trustedfirmware.org servers which will be visible to all. As mentioned in the recent "Overview of the TF-A v2.3 Release" presentation on https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ the additional testing done for a 6 monthly tagged release is quite minimal and the larger work is ensuring all documentation is up to date. Additionally all new features are generally behind their own build flags but I appreciate it is some work for a tagged release to be absorbed into product offerings.
I asked at the tech forum last week what more we could do to allow releases to be integrated more easily. On the call it was requested if we could disable weak bindings to symbols so it could be more easily seen where platform decisions may need to be made and we will look into this. If there are any more adjustments to the way tagged releases are produced please let us know.
One thing that had been considered briefly was the production of a security bug only branch that was maintained only between 6 month tagged releases before being replaced by the next security bug only branch based on the next 6 month release but that has not progressed very far as a proposal as until your email here it was perceived to not be in demand. A LTS branch is a larger endeavour as it sounds like something that includes more than security fixes and I look forward to you elaborating more as Matteo requests.
Thanks
Joanna
On 11/06/2020, 12:19, "Matteo Carlini via TF-A" <tf-a(a)lists.trustedfirmware.org> wrote:
Hi Varun,
Thanks for raising this topic (but please do embrace the official terminology “TF-A”…we never really promoted ATF and it's also absolutely outdated now 😉 ).
Arm has received different queries over time on supporting Trusted Firmware LTS releases, but the effort to sustain them is something that the Arm engineering team alone cannot really afford and commit to (either in the TF-A or TF-M space).
The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers, so to evaluate the possibility of a more concrete proposal to be carried on within the community Project.
I guess it will also be good to start by elaborating more concretely on the requirements that you would like to see in an hypothetical LTS versioning scheme.
Thanks
Matteo
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A
> Sent: 10 June 2020 22:47
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] ATF LTS version
>
> Hello team,
>
> To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain.
>
> For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won’t have to upgrade the entire firmware to get these goodies.
>
> It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally?
>
> -Varun
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Francois,
> I'd be happy to know more about what you see as TFA LTS: exact scope, number of versions, duration, operational commitments (zero-day...).
> Do you have other firmware LTS needs?
Agree. That’s precisely what I was hinting to Varun, when mentioning concrete requirements for the LTS scheme.
> Trusted Substrate is the aggregation of { TFA, OP-TEE, some TEE apps such as firmwareTPM, U-Boot }.
> Trusted Substrate effort is led by Linaro members and is going to be set up as a more open project.
First time I heard about it. Good to know, but I guess we'll need to discuss the intersection and collaboration with the Trusted Firmware project at some point.
Having a LTS versioning scheme for the Trusted Firmware hosted projects should be theoretically either in the scope of the Project itself or, if the Board agrees, appointed to some other project/entity.
> Our end goal is to enable unified, transactional, robust (anti-bricking, anti rollback) UEFI OTA on both U-Boot and EDK2.
Fair, but IMHO this has little to do with Arm Secure world software LTS releases (TF-A/Hafnium/OP-TEE/TAs, TF-M)...probably best to discuss aside, this is not in scope of what Varun is raising.
Thanks
Matteo
Hi Varun,
Thanks for raising this topic (but please do embrace the official terminology “TF-A”…we never really promoted ATF and it's also absolutely outdated now 😉 ).
Arm has received different queries over time on supporting Trusted Firmware LTS releases, but the effort to sustain them is something that the Arm engineering team alone cannot really afford and commit to (either in the TF-A or TF-M space).
The idea has also been just raised to the Trusted Firmware project Board for initial consideration and we will be all very keen to understand how much interest there is from the wider TF-A community of adopters and external (non-Arm) maintainers, so to evaluate the possibility of a more concrete proposal to be carried on within the community Project.
I guess it will also be good to start by elaborating more concretely on the requirements that you would like to see in an hypothetical LTS versioning scheme.
Thanks
Matteo
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A
> Sent: 10 June 2020 22:47
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] ATF LTS version
>
> Hello team,
>
> To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain.
>
> For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won’t have to upgrade the entire firmware to get these goodies.
>
> It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally?
>
> -Varun
Hi Varun,
There are early discussions in Linaro on what would mean setting up
"Collaborative LTS" for what we call Trusted Substrate (see below
signature).
I'd be happy to know more about what you see as TFA LTS: exact scope,
number of versions, duration, operational commitments (zero-day...).
Do you have other firmware LTS needs?
Cheers
François-Frédéric Ozog
Linaro
Trusted Substrate is the aggregation of { TFA, OP-TEE, some TEE apps such
as firmwareTPM, U-Boot }.
Trusted Substrate effort is led by Linaro members and is going to be set up
as a more open project.
Our end goal is to enable unified, transactional, robust (anti-bricking,
anti rollback) UEFI OTA on both U-Boot and EDK2.
On Wed, 10 Jun 2020 at 23:47, Varun Wadekar via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> Hello team,
>
>
>
> To extend the discussion around version upgrades from our last call, I
> would like to understand if there is enough interest around generating a
> LTS version of the TF-A to alleviate the pain.
>
>
>
> For NVIDIA, this would be helpful as it streamlines the upgrade path for
> our devices in the field. The LTS version will guarantee security fixes,
> bug fixes, stability fixes for the longer term and we won’t have to upgrade
> the entire firmware to get these goodies.
>
>
>
> It would be interesting to see what OEMs and maintainers think about this?
> Has this been discussed at tf.org or Arm internally?
>
>
>
> -Varun
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
François-Frédéric Ozog | *Director Linaro Edge & Fog Computing Group*
T: +33.67221.6485
francois.ozog(a)linaro.org | Skype: ffozog
This event has been changed with this note:
"Starting 18th June, the TF-A Tech Forum will be moved earlier by 1 hour to
1600 UK time (1500 UTC). This change is to avoid overlapping the TF
Technical Steering Committee call.
A new invite will be posted to the TF-A mailing list and on the
trustedfirmware.org website."
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558 8656
US (New York) +1 669 900 9128 US (San
Jose) 877 853 5247 US Toll-free
888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your
local number: https://zoom.us/u/ad27hc6t7h
When: Every 2 weeks from 17:00 to 18:00 on Thursday from Thu 26 Mar to Wed
17 Jun United Kingdom Time (changed)
Where: Zoom
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
(Guest list has been hidden at organiser's request)
Event details:
https://www.google.com/calendar/event?action=VIEW&eid=N3ZoNDBuZzZnM2k4cGszY…
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
This event has been changed with this note:
"Starting 18th June, the TF-A Tech Forum will be moved earlier by 1 hour to
1600 UK time (1500 UTC). This change is to avoid overlapping the TF
Technical Steering Committee call.
A new invite will be posted to the TF-A mailing list and on the
trustedfirmware.org website."
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558 8656
US (New York) +1 669 900 9128 US (San
Jose) 877 853 5247 US Toll-free
888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your
local number: https://zoom.us/u/ad27hc6t7h
When: Every 2 weeks from 17:00 to 18:00 on Thursday from Thu 7 May to Wed
17 Jun United Kingdom Time (changed)
Where: Zoom
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
(Guest list has been hidden at organiser's request)
Event details:
https://www.google.com/calendar/event?action=VIEW&eid=N3ZoNDBuZzZnM2k4cGszY…
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
This event has been cancelled.
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558 8656
US (New York) +1 669 900 9128 US (San
Jose) 877 853 5247 US Toll-free
888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your
local number: https://zoom.us/u/ad27hc6t7h
When: United Kingdom Time
Where: Zoom
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
(Guest list has been hidden at organiser's request)
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
Hi all,
Starting 18th June, the TF-A Tech Forum will be moved earlier by 1 hour to
1600 UK time (1500 UTC). This change is to avoid overlapping with the TF
Technical Steering Committee call.
We'll delete the existing invite and send a new one to this list.
Regards
Bill
--
[image: Linaro] <http://www.linaro.org/>
*Bill Fletcher* | *Field Engineering*
T: +44 7833 498336 <+44+7833+498336>
bill.fletcher(a)linaro.org | Skype: billfletcher2020
Hello team,
To extend the discussion around version upgrades from our last call, I would like to understand if there is enough interest around generating a LTS version of the TF-A to alleviate the pain.
For NVIDIA, this would be helpful as it streamlines the upgrade path for our devices in the field. The LTS version will guarantee security fixes, bug fixes, stability fixes for the longer term and we won't have to upgrade the entire firmware to get these goodies.
It would be interesting to see what OEMs and maintainers think about this? Has this been discussed at tf.org or Arm internally?
-Varun
Dear all,
As part of a patchset series review (topic scmi-msg), change [1]
imports confine_array_index.h header file from OP-TEE OS repository.
The file originates from the open source Fuschia project, see link in
commit message of [1].
As being imported for external packages, the header file inherits
Fushca and OP-TEE notices.
The helper function can protect some data structure from side channel
attacks leveraging index indirect access overflows during speculative
execution.
It is not Arm copyright. It is BSD-3-Clause license.
I'll add an entry in the docs/license.rst for the file.
Where to locate the file?
It is ok to add such a file in include/common?
Does it deserve a specific lib path, like
include/lib/speculconfie_array_index.h?
Maybe add as include/lib/cpus/confine_array_index.h as it is CPU
speculative matters?
Could you help [1] review to progress?
[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4055
Regards,
Etienne
> On 6 Jun 2020, at 17:52, Heiko Stübner via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Walter,
>
> Am Freitag, 5. Juni 2020, 22:45:25 CEST schrieb Walter Lozano via TF-A:
>> I have noticed that default baudrate for rk3399 board RK3399_BAUDRATE
>> defined in plat/rockchip/rk3399/rk3399_def.h is 115200 while U-boot
>> default value and most documentation points to a value of 1500000 for
>> console.
>
> console baudrate on rk3399 differ a lot between boards. There are a
> number using the 1.5MHz and another big number using 115200
> (including but not limited to the ChromeOS devices from the Gru line).
>
> Hence we have the code that selects the actual baudrate from the
> devicetree attached by u-boot when calling TF-A.
>
> So I guess it should stay as it is right now.
On the RK3399 there are currently a couple of roadblocks preventing
this selection of the baudrate from the devicetree from working.
Firstly in U-Boot, SPL_ATF_NO_PLATFORM_PARAM is forced on when
selecting ROCKCHIP_RK3399 in Kconfig [1].
Secondly in TF-A the 64K buffer used to store the passed devicetree
isn't large enough to fit some of the RK3399 device tree blobs, as I
found when removing SPL_ATF_NO_PLATFORM_PARAM from U-Boot.
I guess the issue in TF-A needs to be fixed first before passing the
platform parameter can be enabled in U-Boot, I've submitted a TF-A
patch to increase the buffer size [2].
[1]: https://gitlab.denx.de/u-boot/u-boot/-/blob/61853a7ac7e167d90899ec4e99d2e07…
[2]: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4512
> Heiko
>
>
>> This of course means that messages printed by ATF are not visible by
>> default in this context.
>>
>> The change from 1500000 to 115200 was introduced in
>> 0c05748bdebfad9fa43a80962186438bb8fbce62,
>>
>> https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=0c05…
>>
>> with the following message
>>
>> commit 0c05748bdebfad9fa43a80962186438bb8fbce62
>> Author: Caesar Wang <wxt(a)rock-chips.com>
>> Date: Tue Apr 19 20:42:17 2016 +0800
>>
>> rockchip: fixes for the required
>>
>> This patch has the following change for rk3399.
>>
>> * Set the uart to 115200 since the loader decide to set
>> uart baud to 115200Hz. So the ATF also should set uart baud to 115200.
>> [..]
>>
>> However, I'm not sure it this still applies.
>>
>> I'll be happy to submit a patch to update the value if it is OK.
>>
>> Regards,
>>
>> Walter
>>
>>
>
>
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hello,
Sorry for chiming in late. Are we sure that the msr/mrs to the GICv3 EOI
register is not a context synchronizing event or ensures ordering itself
? Also did the addition of DSB() fix the issue ? If yes, can you try
adding a delay or a few NOP's/dummy instructions or an ISB to see if the
issue goes away?
We need to know the right thing to do architecturally and confirm that
the issue is really due to reordering at the core before adding the DSB.
Adding a DSB might be masking a timing issue.
-Raghu
On 6/8/20 4:47 AM, Sandeep Tripathy via TF-A wrote:
>> -----Original Message-----
>> From: Soby Mathew [mailto:Soby.Mathew@arm.com]
>> Sent: Monday, June 08, 2020 3:36 PM
>> To: Sandeep Tripathy; Olivier Deprez; tf-a(a)lists.trustedfirmware.org
>> Cc: nd
>> Subject: RE: [TF-A] GICV3: system interface EOI ordering RFC
>>
>> Just some inputs from my side:
>> I agree we need at least a dsb() after the write to MMIO region to silence
>> the
>> peripheral and before the EOI at GIC sysreg interface. Adding it to the
>> GIC EOI
>
> Thanks for the confirmation. Now it’s about choosing the right place.
>
>> API seems the logical thing to do but as Olivier mentions, there are
>> interrupt
>> handler which do not deal with MMIO (eg: the Systimer interrupt) so adding
>> it
>> to GICv3 API might be arduous for such handlers.
>>
>> So there is a choice here to let the interrupt handlers to deal with
>> ensuring
>> completeness before EOI at sysreg interface or adding it to GICv3 EOI API
>> and
>> take the overhead for interrupt handlers which do not have to deal with
>> MMIO.
>>
>
> Yes I feel either of these is a must to guarantee functionality
> architecturally though
> both approach end up with some unnecessary overhead.
>
> If GICv3 api takes care then it is an overhead for some ISRs dealing with
> non-MMIO.
> At present I do not see an active use case in reference implementation where
> sys timer
> ISR is in a performance intensive path where one additional DSB will be
> perceivable.
> But there may be some I could be totally wrong in this assumption (pmu/debug
> or.. not sure).
> Whereas I can certainly imagine some MMIO ISRs in performance critical path
> where unnecessary
> DSB is not acceptable at all.
>
> If the interrupt handler needs to ensure then it will generically add 'DSB'
> as I think
> the driver cannot and should not make assumptions about how EOI is done
> afterwards.
> That will be overhead for the ISRs dealing with MMIO peripherals and non
> GIC-v3.
> If we consider only GICv3+ then good. Otherwise I would prefer the
> 'plat_ic_end_of_interrupt'
> like Olivier mentioned with a #if GICv3 instead of each ISRs dealing with
> it.
>
>> The GICv3 legacy MMIO CPU interface is deprecated for TF-A and the sys
>> interface is the only one GICv3 driver in TF-A supports.
>
> Right we can ignore the GICv3 legacy mode but GICv2 will still remain ?
>
>>
>> Best Regards
>> Soby Mathew
>>
>
> Thanks
> Sandeep
>
>>> -----Original Message-----
>>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep
>>> Tripathy via TF-A
>>> Sent: 08 June 2020 10:34
>>> To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf-
>> a(a)lists.trustedfirmware.org
>>> Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC
>>>
>>> Hi Olivier,
>>>> -----Original Message-----
>>>> From: Olivier Deprez [mailto:Olivier.Deprez@arm.com]
>>>> Sent: Monday, June 08, 2020 1:14 PM
>>>> To: tf-a(a)lists.trustedfirmware.org; Sandeep Tripathy
>>>> Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC
>>>>
>>>> Hi Sandeep,
>>>>
>>>> gicv3_end_of_interrupt_sel1 is a static access helper macro. Its
>>>> naming precisely tells what it does at gicv3 module level. It is
>>>> called from
>>> the weak
>>>> plat_ic_end_of_interrupt function for BL32 image.
>>>>
>>>> I tend to think it is the driver responsibility to ensure the module
>>> interrupt
>>>> acknowledge register write is reaching HW in order (or "be visible to
>>> all
>>>> observers").
>>>
>>> The driver should be agnostic of what interrupt controller is used and
>>> its
>>> behavior.
>>> And since 'all' writes were to mmio ranges mapped Device(nGnRE)
>>> /strongly-ordered(nGnRnE)
>>> there was no such need. This is a special case for GICv3 system
>>> interface only.
>>> Adding at driver level a DSB is unnecessary for other interrupt
>>> controllers.
>>>
>>>> Also I suspect adding a dsb might not be required generically for all
>>> kind of IP.
>>>
>>> Here are you referring to the peripheral IP or interrupt controller IP ?
>>> The issue is reordering at arm core itself (STR to device address Vs
>>> msr(sysreg
>>> write)).
>>> So I think Its applicable for all IP.
>>>
>>>> Adding a barrier in generic code might incur an unnecessary
>>>> bottleneck.
>>>
>>> But if there is a need to *ensure* presence of at least one DSB between
>>> the
>>> write transfer from core to device clear and gicv3 eoi icc register
>>> write in a
>>> generic way then what other option we have.
>>>>
>>>> Thus wouldn't it be better to add the barrier to the overridden
>>>> platform function rather than in generic gicv3 code?
>>>
>>> That can be done but I feel this is more to do with gicv3 system
>>> interface only.
>>> Inside plat_xxx one has to check #if GICV3 ...and system interface.
>>>>
>>>> I have a put a comment in the review, we can continue the discussion
>>> there.
>>>>
>>>> Regards,
>>>> Olivier.
>>>>
>>> Thanks
>>> Sandeep
>>>> ________________________________________
>>>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of
>>>> Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org>
>>>> Sent: 05 June 2020 19:43
>>>> To: tf-a(a)lists.trustedfirmware.org
>>>> Subject: [TF-A] GICV3: system interface EOI ordering RFC
>>>>
>>>> Hi,
>>>> In a typical interrupt handling sequence we do 1-Read IAR
>>>> 2-Do interrupt handling
>>>> 3-Clear the interrupt at source , so that the device de-asserts IRQ
>>> request to
>>>> GIC
>>>> >> I am suggesting a need of DSB here in case of GICv3 +.
>>>> 4-Write to GIC cpu interface to do EOI.
>>>>
>>>> Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write
>>>> over
>>> AMBA
>>>> interface. The
>>>> Addresses are mapped with (nR) attribute. Hence the write transfers
>>> from the
>>>> core will be
>>>> generated at step 3 and 4 in order. Please ignore the additional
>>> buffers/bridges
>>>> in path from
>>>> core till peripheral which has to be dealt separately as per SOC.
>>>>
>>>> Query: I understand GICv3 system interface accesses are not over this
>>> protocol
>>>> and core will not
>>>> follow the ordering rule ?
>>>>
>>>> I have observed spurious interrupt issue/manifestation ( I don't have
>>> the
>>>> transfers probed) in
>>>> RTOS environment where I have a primitive GICv3 driver but I wonder
>>>> why things does not fail in Linux or tf-a. If it is working because
>>>> from step(3) to
>>> step(4) we have
>>>> barriers by chace
>>>> due to other device register writes then I would suggest to have one
>>>> in
>>> the EOI
>>>> clearing API itself.
>>>>
>>>> RFC:
>>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454
>>>>
>>>> Thanks
>>>> Sandeep
>>> --
>>> TF-A mailing list
>>> TF-A(a)lists.trustedfirmware.org
>>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> -----Original Message-----
> From: Soby Mathew [mailto:Soby.Mathew@arm.com]
> Sent: Monday, June 08, 2020 3:36 PM
> To: Sandeep Tripathy; Olivier Deprez; tf-a(a)lists.trustedfirmware.org
> Cc: nd
> Subject: RE: [TF-A] GICV3: system interface EOI ordering RFC
>
> Just some inputs from my side:
> I agree we need at least a dsb() after the write to MMIO region to silence
> the
> peripheral and before the EOI at GIC sysreg interface. Adding it to the
> GIC EOI
Thanks for the confirmation. Now it’s about choosing the right place.
> API seems the logical thing to do but as Olivier mentions, there are
> interrupt
> handler which do not deal with MMIO (eg: the Systimer interrupt) so adding
> it
> to GICv3 API might be arduous for such handlers.
>
> So there is a choice here to let the interrupt handlers to deal with
> ensuring
> completeness before EOI at sysreg interface or adding it to GICv3 EOI API
> and
> take the overhead for interrupt handlers which do not have to deal with
> MMIO.
>
Yes I feel either of these is a must to guarantee functionality
architecturally though
both approach end up with some unnecessary overhead.
If GICv3 api takes care then it is an overhead for some ISRs dealing with
non-MMIO.
At present I do not see an active use case in reference implementation where
sys timer
ISR is in a performance intensive path where one additional DSB will be
perceivable.
But there may be some I could be totally wrong in this assumption (pmu/debug
or.. not sure).
Whereas I can certainly imagine some MMIO ISRs in performance critical path
where unnecessary
DSB is not acceptable at all.
If the interrupt handler needs to ensure then it will generically add 'DSB'
as I think
the driver cannot and should not make assumptions about how EOI is done
afterwards.
That will be overhead for the ISRs dealing with MMIO peripherals and non
GIC-v3.
If we consider only GICv3+ then good. Otherwise I would prefer the
'plat_ic_end_of_interrupt'
like Olivier mentioned with a #if GICv3 instead of each ISRs dealing with
it.
> The GICv3 legacy MMIO CPU interface is deprecated for TF-A and the sys
> interface is the only one GICv3 driver in TF-A supports.
Right we can ignore the GICv3 legacy mode but GICv2 will still remain ?
>
> Best Regards
> Soby Mathew
>
Thanks
Sandeep
> > -----Original Message-----
> > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep
> > Tripathy via TF-A
> > Sent: 08 June 2020 10:34
> > To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf-
> a(a)lists.trustedfirmware.org
> > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC
> >
> > Hi Olivier,
> > > -----Original Message-----
> > > From: Olivier Deprez [mailto:Olivier.Deprez@arm.com]
> > > Sent: Monday, June 08, 2020 1:14 PM
> > > To: tf-a(a)lists.trustedfirmware.org; Sandeep Tripathy
> > > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC
> > >
> > > Hi Sandeep,
> > >
> > > gicv3_end_of_interrupt_sel1 is a static access helper macro. Its
> > > naming precisely tells what it does at gicv3 module level. It is
> > > called from
> > the weak
> > > plat_ic_end_of_interrupt function for BL32 image.
> > >
> > > I tend to think it is the driver responsibility to ensure the module
> > interrupt
> > > acknowledge register write is reaching HW in order (or "be visible to
> > all
> > > observers").
> >
> > The driver should be agnostic of what interrupt controller is used and
> > its
> > behavior.
> > And since 'all' writes were to mmio ranges mapped Device(nGnRE)
> > /strongly-ordered(nGnRnE)
> > there was no such need. This is a special case for GICv3 system
> > interface only.
> > Adding at driver level a DSB is unnecessary for other interrupt
> > controllers.
> >
> > > Also I suspect adding a dsb might not be required generically for all
> > kind of IP.
> >
> > Here are you referring to the peripheral IP or interrupt controller IP ?
> > The issue is reordering at arm core itself (STR to device address Vs
> > msr(sysreg
> > write)).
> > So I think Its applicable for all IP.
> >
> > > Adding a barrier in generic code might incur an unnecessary
> > > bottleneck.
> >
> > But if there is a need to *ensure* presence of at least one DSB between
> > the
> > write transfer from core to device clear and gicv3 eoi icc register
> > write in a
> > generic way then what other option we have.
> > >
> > > Thus wouldn't it be better to add the barrier to the overridden
> > > platform function rather than in generic gicv3 code?
> >
> > That can be done but I feel this is more to do with gicv3 system
> > interface only.
> > Inside plat_xxx one has to check #if GICV3 ...and system interface.
> > >
> > > I have a put a comment in the review, we can continue the discussion
> > there.
> > >
> > > Regards,
> > > Olivier.
> > >
> > Thanks
> > Sandeep
> > > ________________________________________
> > > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of
> > > Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org>
> > > Sent: 05 June 2020 19:43
> > > To: tf-a(a)lists.trustedfirmware.org
> > > Subject: [TF-A] GICV3: system interface EOI ordering RFC
> > >
> > > Hi,
> > > In a typical interrupt handling sequence we do 1-Read IAR
> > > 2-Do interrupt handling
> > > 3-Clear the interrupt at source , so that the device de-asserts IRQ
> > request to
> > > GIC
> > > >> I am suggesting a need of DSB here in case of GICv3 +.
> > > 4-Write to GIC cpu interface to do EOI.
> > >
> > > Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write
> > > over
> > AMBA
> > > interface. The
> > > Addresses are mapped with (nR) attribute. Hence the write transfers
> > from the
> > > core will be
> > > generated at step 3 and 4 in order. Please ignore the additional
> > buffers/bridges
> > > in path from
> > > core till peripheral which has to be dealt separately as per SOC.
> > >
> > > Query: I understand GICv3 system interface accesses are not over this
> > protocol
> > > and core will not
> > > follow the ordering rule ?
> > >
> > > I have observed spurious interrupt issue/manifestation ( I don't have
> > the
> > > transfers probed) in
> > > RTOS environment where I have a primitive GICv3 driver but I wonder
> > > why things does not fail in Linux or tf-a. If it is working because
> > > from step(3) to
> > step(4) we have
> > > barriers by chace
> > > due to other device register writes then I would suggest to have one
> > > in
> > the EOI
> > > clearing API itself.
> > >
> > > RFC:
> > https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454
> > >
> > > Thanks
> > > Sandeep
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Just some inputs from my side:
I agree we need atleast a dsb() after the write to MMIO region to silence the peripheral and before the EOI at GIC sysreg interface. Adding it to the GIC EOI API seems the logical thing to do but as Olivier mentions, there are interrupt handler which do not deal with MMIO (eg: the Systimer interrupt) so adding it to GICv3 API might be arduous for such handlers.
So there is a choice here to let the interrupt handlers to deal with ensuring completeness before EOI at sysreg interface or adding it to GICv3 EOI API and take the overhead for interrupt handlers which do not have to deal with MMIO.
The GICv3 legacy MMIO CPU interface is deprecated for TF-A and the sys interface is the only one GICv3 driver in TF-A supports.
Best Regards
Soby Mathew
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandeep
> Tripathy via TF-A
> Sent: 08 June 2020 10:34
> To: Olivier Deprez <Olivier.Deprez(a)arm.com>; tf-a(a)lists.trustedfirmware.org
> Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC
>
> Hi Olivier,
> > -----Original Message-----
> > From: Olivier Deprez [mailto:Olivier.Deprez@arm.com]
> > Sent: Monday, June 08, 2020 1:14 PM
> > To: tf-a(a)lists.trustedfirmware.org; Sandeep Tripathy
> > Subject: Re: [TF-A] GICV3: system interface EOI ordering RFC
> >
> > Hi Sandeep,
> >
> > gicv3_end_of_interrupt_sel1 is a static access helper macro. Its
> > naming precisely tells what it does at gicv3 module level. It is
> > called from
> the weak
> > plat_ic_end_of_interrupt function for BL32 image.
> >
> > I tend to think it is the driver responsibility to ensure the module
> interrupt
> > acknowledge register write is reaching HW in order (or "be visible to
> all
> > observers").
>
> The driver should be agnostic of what interrupt controller is used and its
> behavior.
> And since 'all' writes were to mmio ranges mapped Device(nGnRE)
> /strongly-ordered(nGnRnE)
> there was no such need. This is a special case for GICv3 system interface only.
> Adding at driver level a DSB is unnecessary for other interrupt controllers.
>
> > Also I suspect adding a dsb might not be required generically for all
> kind of IP.
>
> Here are you referring to the peripheral IP or interrupt controller IP ?
> The issue is reordering at arm core itself (STR to device address Vs msr(sysreg
> write)).
> So I think Its applicable for all IP.
>
> > Adding a barrier in generic code might incur an unnecessary bottleneck.
>
> But if there is a need to *ensure* presence of at least one DSB between the
> write transfer from core to device clear and gicv3 eoi icc register write in a
> generic way then what other option we have.
> >
> > Thus wouldn't it be better to add the barrier to the overridden
> > platform function rather than in generic gicv3 code?
>
> That can be done but I feel this is more to do with gicv3 system interface only.
> Inside plat_xxx one has to check #if GICV3 ...and system interface.
> >
> > I have a put a comment in the review, we can continue the discussion
> there.
> >
> > Regards,
> > Olivier.
> >
> Thanks
> Sandeep
> > ________________________________________
> > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of
> > Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org>
> > Sent: 05 June 2020 19:43
> > To: tf-a(a)lists.trustedfirmware.org
> > Subject: [TF-A] GICV3: system interface EOI ordering RFC
> >
> > Hi,
> > In a typical interrupt handling sequence we do 1-Read IAR
> > 2-Do interrupt handling
> > 3-Clear the interrupt at source , so that the device de-asserts IRQ
> request to
> > GIC
> > >> I am suggesting a need of DSB here in case of GICv3 +.
> > 4-Write to GIC cpu interface to do EOI.
> >
> > Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write
> > over
> AMBA
> > interface. The
> > Addresses are mapped with (nR) attribute. Hence the write transfers
> from the
> > core will be
> > generated at step 3 and 4 in order. Please ignore the additional
> buffers/bridges
> > in path from
> > core till peripheral which has to be dealt separately as per SOC.
> >
> > Query: I understand GICv3 system interface accesses are not over this
> protocol
> > and core will not
> > follow the ordering rule ?
> >
> > I have observed spurious interrupt issue/manifestation ( I don't have
> the
> > transfers probed) in
> > RTOS environment where I have a primitive GICv3 driver but I wonder
> > why things does not fail in Linux or tf-a. If it is working because
> > from step(3) to
> step(4) we have
> > barriers by chace
> > due to other device register writes then I would suggest to have one
> > in
> the EOI
> > clearing API itself.
> >
> > RFC:
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454
> >
> > Thanks
> > Sandeep
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Sandeep,
gicv3_end_of_interrupt_sel1 is a static access helper macro. Its naming precisely tells what it does at gicv3 module level. It is called from the weak plat_ic_end_of_interrupt function for BL32 image.
I tend to think it is the driver responsibility to ensure the module interrupt acknowledge register write is reaching HW in order (or "be visible to all observers").
Also I suspect adding a dsb might not be required generically for all kind of IP. Adding a barrier in generic code might incur an unnecessary bottleneck.
Thus wouldn't it be better to add the barrier to the overridden platform function rather than in generic gicv3 code?
I have a put a comment in the review, we can continue the discussion there.
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Sandeep Tripathy via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 05 June 2020 19:43
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] GICV3: system interface EOI ordering RFC
Hi,
In a typical interrupt handling sequence we do
1-Read IAR
2-Do interrupt handling
3-Clear the interrupt at source , so that the device de-asserts IRQ request to GIC
>> I am suggesting a need of DSB here in case of GICv3 +.
4-Write to GIC cpu interface to do EOI.
Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write over AMBA interface. The
Addresses are mapped with (nR) attribute. Hence the write transfers from the core will be
generated at step 3 and 4 in order. Please ignore the additional buffers/bridges in path from
core till peripheral which has to be dealt separately as per SOC.
Query: I understand GICv3 system interface accesses are not over this protocol and core will not
follow the ordering rule ?
I have observed spurious interrupt issue/manifestation ( I don’t have the transfers probed) in
RTOS environment where I have a primitive GICv3 driver but I wonder why things does
not fail in Linux or tf-a. If it is working because from step(3) to step(4) we have barriers by chace
due to other device register writes then I would suggest to have one in the EOI clearing API itself.
RFC: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454
Thanks
Sandeep
Hi Walter,
Am Freitag, 5. Juni 2020, 22:45:25 CEST schrieb Walter Lozano via TF-A:
> I have noticed that default baudrate for rk3399 board RK3399_BAUDRATE
> defined in plat/rockchip/rk3399/rk3399_def.h is 115200 while U-boot
> default value and most documentation points to a value of 1500000 for
> console.
console baudrate on rk3399 differ a lot between boards. There are a
number using the 1.5MHz and another big number using 115200
(including but not limited to the ChromeOS devices from the Gru line).
Hence we have the code that selects the actual baudrate from the
devicetree attached by u-boot when calling TF-A.
So I guess it should stay as it is right now.
Heiko
> This of course means that messages printed by ATF are not visible by
> default in this context.
>
> The change from 1500000 to 115200 was introduced in
> 0c05748bdebfad9fa43a80962186438bb8fbce62,
>
> https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=0c05…
>
> with the following message
>
> commit 0c05748bdebfad9fa43a80962186438bb8fbce62
> Author: Caesar Wang <wxt(a)rock-chips.com>
> Date: Tue Apr 19 20:42:17 2016 +0800
>
> rockchip: fixes for the required
>
> This patch has the following change for rk3399.
>
> * Set the uart to 115200 since the loader decide to set
> uart baud to 115200Hz. So the ATF also should set uart baud to 115200.
> [..]
>
> However, I'm not sure it this still applies.
>
> I'll be happy to submit a patch to update the value if it is OK.
>
> Regards,
>
> Walter
>
>
I have noticed that default baudrate for rk3399 board RK3399_BAUDRATE
defined in plat/rockchip/rk3399/rk3399_def.h is 115200 while U-boot
default value and most documentation points to a value of 1500000 for
console.
This of course means that messages printed by ATF are not visible by
default in this context.
The change from 1500000 to 115200 was introduced in
0c05748bdebfad9fa43a80962186438bb8fbce62,
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=0c05…
with the following message
commit 0c05748bdebfad9fa43a80962186438bb8fbce62
Author: Caesar Wang <wxt(a)rock-chips.com>
Date: Tue Apr 19 20:42:17 2016 +0800
rockchip: fixes for the required
This patch has the following change for rk3399.
* Set the uart to 115200 since the loader decide to set
uart baud to 115200Hz. So the ATF also should set uart baud to 115200.
[..]
However, I'm not sure it this still applies.
I'll be happy to submit a patch to update the value if it is OK.
Regards,
Walter
Hi,
In a typical interrupt handling sequence we do
1-Read IAR
2-Do interrupt handling
3-Clear the interrupt at source , so that the device de-asserts IRQ
request to GIC
>> I am suggesting a need of DSB here in case of GICv3 +.
4-Write to GIC cpu interface to do EOI.
Till GICv2 and with GICv3 legacy interface ICC_EOI write is a write over
AMBA interface. The
Addresses are mapped with (nR) attribute. Hence the write transfers from
the core will be
generated at step 3 and 4 in order. Please ignore the additional
buffers/bridges in path from
core till peripheral which has to be dealt separately as per SOC.
Query: I understand GICv3 system interface accesses are not over this
protocol and core will not
follow the ordering rule ?
I have observed spurious interrupt issue/manifestation ( I don’t have the
transfers probed) in
RTOS environment where I have a primitive GICv3 driver but I wonder why
things does
not fail in Linux or tf-a. If it is working because from step(3) to step(4)
we have barriers by chace
due to other device register writes then I would suggest to have one in the
EOI clearing API itself.
RFC: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4454
Thanks
Sandeep
Hi Okash,
These are generally provided on https://www.trustedfirmware.org/meetings/tf-a-technical-forum/ however they are missing from 7th May onwards at the moment. I have an update pending approval on tf.org for adding the details of that session and then I need to add the information from the session on 21st May and the session yesterday.
Joanna
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Okash Khawaja via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Okash Khawaja <okash.khawaja(a)gmail.com>
Date: Friday, 5 June 2020 at 11:29
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Slides for recent TF-A Forums
Hi,
Where can I find slides for recent TF-A Forum presentations?
Thanks,
Okash
Hi Bill,
I continue to the error while trying to invoke “Allow-CI” or other votes as part of gerrit review. I tried multiple browsers as well and logged out before attempting again.
Thanks,
Madhu
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Bill Fletcher via TF-A
Sent: Tuesday, June 2, 2020 12:13 PM
To: Varun Wadekar <vwadekar(a)nvidia.com>
Cc: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] Gerrit seems to be broken
Hi Varun,
Do you still see the problem? It has been reported before.
Regards
Bill
On Tue, 2 Jun 2020 at 18:01, Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>> wrote:
Hello,
The TF gerrit review dashboard seems to be broken this morning. I see “Server error” and it does not allow me to post scores or comments. Tried different browsers, but same issue persists.
Anyone else seeing the same problem? Is this is a known issue? If yes, is anyone working on it?
-Varun
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
[Image removed by sender. Linaro]<http://www.linaro.org/>
Bill Fletcher | Field Engineering
T: +44 7833 498336<tel:+44+7833+498336>
bill.fletcher(a)linaro.org<mailto:bill.fletcher@linaro.org> | Skype: billfletcher2020
Hi Varun,
Do you still see the problem? It has been reported before.
Regards
Bill
On Tue, 2 Jun 2020 at 18:01, Varun Wadekar via TF-A <
tf-a(a)lists.trustedfirmware.org> wrote:
> Hello,
>
>
>
> The TF gerrit review dashboard seems to be broken this morning. I see
> “Server error” and it does not allow me to post scores or comments. Tried
> different browsers, but same issue persists.
>
>
>
> Anyone else seeing the same problem? Is this is a known issue? If yes, is
> anyone working on it?
>
>
>
> -Varun
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
--
[image: Linaro] <http://www.linaro.org/>
*Bill Fletcher* | *Field Engineering*
T: +44 7833 498336 <+44+7833+498336>
bill.fletcher(a)linaro.org | Skype: billfletcher2020
Working for me, the main and additional dashboards.
https://review.trustedfirmware.org/admin/repos/TF-A/trusted-firmware-a,dash…
I posted comments earlier ok as well.
Joanna
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Varun Wadekar <vwadekar(a)nvidia.com>
Date: Tuesday, 2 June 2020 at 18:02
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Gerrit seems to be broken
Hello,
The TF gerrit review dashboard seems to be broken this morning. I see “Server error” and it does not allow me to post scores or comments. Tried different browsers, but same issue persists.
Anyone else seeing the same problem? Is this is a known issue? If yes, is anyone working on it?
-Varun
Hello,
The TF gerrit review dashboard seems to be broken this morning. I see "Server error" and it does not allow me to post scores or comments. Tried different browsers, but same issue persists.
Anyone else seeing the same problem? Is this is a known issue? If yes, is anyone working on it?
-Varun
Hi All,
The next TF-A Tech Forum is scheduled for Thu 4th June 2020 17:00 - 18:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know.
Agenda:
* TF-A SMC fuzzing module overview - Presented by Mark Dykes
* General explanation of the approach taken to randomize the type and timing of the SMC calls in TF-A to provide a Fuzz testing capability.
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
Hi Andrzej
I think recent patch: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3493 which is currently in review may be solution for your issue where SCU presence is being checked before accessing CLUSTERCFR_EL1 register.
Thanks
Manish Badarkhe
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of "Witkowski, Andrzej via TF-A" <tf-a(a)lists.trustedfirmware.org>
Reply to: "Witkowski, Andrzej" <andrzej.witkowski(a)intel.com>
Date: Monday, 1 June 2020 at 19:38
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>
Cc: "Witkowski, Andrzej" <andrzej.witkowski(a)intel.com>, "Lessnau, Adam" <adam.lessnau(a)intel.com>
Subject: [TF-A] Unhandled Exception at EL3 in BL31 for Neoverse N1 with direct connect of DSU
Hi,
I work on project which uses ARM CPU Neoverse N1 with direct connect of DSU.
I noticed the following error “Unhandled Exception at EL3” in BL31 bootloader after switching from ATF 2.1 to 2.2.
The root cause is that after invoking neoverse_n1_errata-report function in lib/cpus/aarch64/neoverse_n1.S file and reaching the line 525, the function check_errata_dsu_934 in lib/cpus/aarch64/dsu_helpers.S file is always invoked regardless of whether ERRATA_DSU_936184 is set to 0 or to 1.
In our case, ERRATA_DSU_936184 := 0.
[cid:image001.png@01D6384E.C183C050]
[cid:image002.png@01D6384E.C183C050]
Neoverse N1 with direct connect version of DSU doesn’t contain SCU/L3 cache and CLUSTERCFR_EL1 register.
The error “Unhandled Exception at EL3” appears in BL31 bootloader during attempt to read the CLUSTERCFR_EL1 register which doesn’t exist in our RTL HW.
Andrzej Witkowskie
Intel Technology Poland
---------------------------------------------------------------------
Intel Technology Poland sp. z o.o.
ul. Słowackiego 173 | 80-298 Gdańsk | Sąd Rejonowy Gdańsk Północ | VII Wydział Gospodarczy Krajowego Rejestru Sądowego - KRS 101882 | NIP 957-07-52-316 | Kapitał zakładowy 200.000 PLN.
Ta wiadomość wraz z załącznikami jest przeznaczona dla określonego adresata i może zawierać informacje poufne. W razie przypadkowego otrzymania tej wiadomości, prosimy o powiadomienie nadawcy oraz trwałe jej usunięcie; jakiekolwiek przeglądanie lub rozpowszechnianie jest zabronione.
This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.
Hi,
I work on project which uses ARM CPU Neoverse N1 with direct connect of DSU.
I noticed the following error "Unhandled Exception at EL3" in BL31 bootloader after switching from ATF 2.1 to 2.2.
The root cause is that after invoking neoverse_n1_errata-report function in lib/cpus/aarch64/neoverse_n1.S file and reaching the line 525, the function check_errata_dsu_934 in lib/cpus/aarch64/dsu_helpers.S file is always invoked regardless of whether ERRATA_DSU_936184 is set to 0 or to 1.
In our case, ERRATA_DSU_936184 := 0.
[cid:image001.png@01D63828.FA4B1440]
[cid:image002.png@01D6382A.B84A0950]
Neoverse N1 with direct connect version of DSU doesn't contain SCU/L3 cache and CLUSTERCFR_EL1 register.
The error "Unhandled Exception at EL3" appears in BL31 bootloader during attempt to read the CLUSTERCFR_EL1 register which doesn't exist in our RTL HW.
Andrzej Witkowskie
Intel Technology Poland
---------------------------------------------------------------------
Intel Technology Poland sp. z o.o.
ul. Sowackiego 173 | 80-298 Gdask | Sd Rejonowy Gdask Pnoc | VII Wydzia Gospodarczy Krajowego Rejestru Sdowego - KRS 101882 | NIP 957-07-52-316 | Kapita zakadowy 200.000 PLN.
Ta wiadomo wraz z zacznikami jest przeznaczona dla okrelonego adresata i moe zawiera informacje poufne. W razie przypadkowego otrzymania tej wiadomoci, prosimy o powiadomienie nadawcy oraz trwae jej usunicie; jakiekolwiek przegldanie lub rozpowszechnianie jest zabronione.
This e-mail and any attachments may contain confidential material for the sole use of the intended recipient(s). If you are not the intended recipient, please contact the sender and delete all copies; any review or distribution by others is strictly prohibited.
Hi all,
Now that the tf.org project maintenance process [1] has been finalized,
it is time to think about electing new maintainers for the project. We
are delighted to announce that the following contributors have been
appointed maintainers by their peers:
- Julius Werner (Google)
- Varun Wadekar (NVIDIA)
- Andre Przywara (Arm)
- Lauren Wehrmeister (Arm)
- Madhukar Pappireddy (Arm)
As outlined in [1], here is the definition and responsibilities of
maintainers:
------------8<------------
There are a number of maintainers assigned to the project. The project
keeps a list of them along with their contact information. Maintainers
don't necessarily need a deep domain expertise of all areas of the
project, instead they look at the project from a high level perspective.
They are expected to ensure that changes adhere to the project's quality
criteria, to its architectural direction, to its threat model and so on.
Code owners and maintainers are complementary roles.
Unlike code owners, maintainers can approve any patch, no matter what
module it concerns. They are responsible for ensuring patches have had
enough overall review and adding their own approval in a timely manner.
They also have merge rights, i.e. the ability to merge a patch in the
tree once it has received all required approvals.
------------8<------------
These people have been granted Code-Review -2/+2 rights in Gerrit and
have been added in the maintainers.rst file as part of this patch:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/4298
Congratulations to them!
Best regards,
Sandrine
[1]
https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…
Hi Pankaj,
Can you please send the specific NOTICE messages which are missing, may be sending 1.5 and 2.3 logs will help.
thanks
Manish
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Pankaj Gupta via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 27 May 2020 09:36
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs.
Hi
After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs.
Any pointers on how to fix this issue.
Thanks.
Regards
Pankaj
Hi
After migrating from TFA-1.5 to TFA2.3, parts of NOTICE messages are missed, which comes as part of boot-up logs.
Any pointers on how to fix this issue.
Thanks.
Regards
Pankaj
Hi Raghu
We have plan to work on this and come up with some design which handles
mandatory/critical properties.
On 13/05/2020, 22:18, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi All,
Since the 2.3 release is done, can we revisit this topic? I think we
left this with finalizing on how to handle bad/incorrect DTB's.
Sandrine's latest proposal below:
"A bad DTB seems more like an integration error than a
programming error to me, and thus should be handled with runtime checks
according to the current guidelines. Incorrect values for mandatory
properties should probably be treated as unrecoverable errors (causing a
panic) and incorrect/missing optional properties as recoverable errors
(issuing a warning message)."
I agree with this proposal and think we should follow this. This
addresses my original concern of handling errors consistently and being
safe by verifying mandatory/critical properties at run-time.
Thoughts ?
Thanks
Raghu
On 4/13/20 10:27 AM, Raghu Krishnamurthy wrote:
> Thanks Sandrine. Revisiting after v2.3 is sounds fine.
>
> -Raghu
>
> On 4/10/20 2:25 AM, Sandrine Bailleux wrote:
>> Hi Raghu,
>>
>> On 4/8/20 12:50 AM, Raghu Krishnamurthy wrote:
>>> Thanks Sandrine, Louis,
>>>
>>> Agree with both of you. I'm fine with using asserts or panics, as
>>> long as we uniformly use it. The change i sent out(review 3845) was
>>> because i noticed inconsistency in handling errors. If we do use
>>> asserts, all code that checks for mandatory properties, should be
>>> changed to assert as opposed to return error code. For optional
>>> properties, we can continue to return an error code or print
>>> warnings etc.
>>
>> Yes, I too think consistency is key here. As you said, we need to
>> settle on the expected behaviour and enforce it uniformly across the
>> fconf code. Let's revisit this code after the v2.3 release.
>>
>>> I would like to point out that using asserts here is different from
>>> what is documented in the coding guidelines. The guidelines
>>> explicitly spells out using asserts for "programming errors".
>>> Now, is having a bad DTB considered a programming error? ;) The DTB
>>> is platform data as opposed to code. The guidelines might need to be
>>> updated based on the conclusion here.
>>
>> Now that you point it out, and after taking a closer look at [1], I
>> think I was wrong. A bad DTB seems more like an integration error
>> than a programming error to me, and thus should be handled with
>> runtime checks according to the current guidelines. Incorrect values
>> for mandatory properties should probably be treated as unrecoverable
>> errors (causing a panic) and incorrect/missing optional properties as
>> recoverable errors (issuing a warning message).
>>
>> [1]
>> https://trustedfirmware-a.readthedocs.io/en/latest/process/coding-guideline…
>>
>>
>>> Also note the couple of scenarios i mentioned in an earlier email.
>>> Platforms like RPI4 don't generally enable TBBR and the DTB image
>>> could get corrupt or be modified on purpose. On a release build,
>>> this could cause silent corruption. Panic() would avoid this.
>>>
>>> In any case, it would be good to settle on the expected behavior for
>>> each of these abnormal cases. I don't have a strong preference for
>>> asserts or panics here, since each has its pros and cons as both of
>>> you called out.
>>>
>>> Thanks
>>> Raghu
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi All,
The next TF-A Tech Forum is scheduled for Thu 21st May 2020 17:00 - 18:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know.
Agenda:
* Firmware Configuration Framework (FConf) Update - Presented by Manish Badarkhe and Madhukar Pappireddy
* Discussion on how we have leveraged FConf framework in making statically configured components of TF-A to be dynamic.
A number of such components have already been identified which potentially use FConf framework. Patches for such
components are either merged or in-review
* Design discussion on CoT descriptors movement to device tree using FConf framework.
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
Hi Florian,
I can give some general answers to your questions and hopefully get to
answering your real questions with further discussion. Please feel free
to ask more questions if this does not help.
>> I noticed that TF-A is designed to load FIP Image but the U-Boot
Environment have a different format. How to access the QSPI NOR memory?
NXP specific driver?
[RK] TF-A generally provides frameworks to do most things and does not
provide device specific drivers but for SPI NOR, there are drivers under
drivers/mtd/nor that could potentially be used. You will likely need to
implement the appropriate platform hooks for the SPI bus itself to use
it. The TF-A IO framework has the io_mtd layer that can be hooked into a
nor device. drivers/st/spi/stm32_qspi.c seems to use all of this and
should be a good example(perhaps some one from ST can chime in too). if
you hook you SPI driver to the TF-A layers correctly, there should be
nothing preventing you from accessing the uboot environment partition.
Also, TF-A's primary/default format for firmware images is FIP but
definitely does not preclude a platform from using it's own format.
>>The bl2 is designed to load only one FIP image, is it possible to add
an additional entry ?
[RK] Not really. BL2 is fairly generic and you should be able to hook
any image format to it. If you must use the FIP format, you can map your
images to existing image id's to create a FIP with any image that you
have. Once again, FIP is fairly flexible and generally treats firmware
images in the package as blob's.
>>if we want to use a secure boot in the future
[RK] Like with the above things, the Trusted Board Boot framework is
flexible and you should be able to implement secure boot on FIP and
other formats. TF-A provides an implementation of the TBBR specification
for secure boot.
It should be possible to implement the algorithm below, if you have an
appropriate platform port, from what i gather in your question below.
Thanks
-Raghu
On 5/13/20 5:40 AM, florian.manoel--- via TF-A wrote:
>
> Hello TF-A mail list,
>
> I’m new here, so I quickly introduce myself.
> I am Florian Manoel, working as firmware developer at Siemens in
> Karlsruhe, Germany. Recently, we decided to start some development
> based on ARM processor, the theme TF-A is new for us.
>
> Currently, we have a custom board equipped with the processor NXP
> Layerscape LS1043a. So far, everything is working as planned, the
> PreBootLoader (TF-A) boots the bootloader (U-Boot) that’s boots linux
> on top.
> However, we want to have the possibility to boot an alternative u-boot
> FIP image, I explain:
> We use as boot source a QSPI NOR memory. In this memory are stored
> ‘bl2_qspi.pbl’, 2 times ‘fip.bin’, the u-boot environment and some
> micro-code.
> We want to select the u-boot image to be booted according to the value
> of a specific variable stored in the u-boot environment ‘u-boot-select’.
> The algo is, for my eye, relatively simple :
>
> Start
> - Check value of the u-boot variable ‘u-boot-select’
>
> - Check if the corresponding u-boot image is valid, if not select the
> alternative one
> - Boot selected u-boot image
> End
>
>
> We want this functionality in case an u-boot image is broken (ex:
> power OFF during U-Boot update).
>
> I already went through the source code and it rose more question than
> it answered. For example:
> I noticed that TF-A is designed to load FIP Image but the U-Boot
> Environment have a different format. How to access the QSPI NOR
> memory? NXP specific driver?
> The bl2 is designed to load only one FIP image, is it possible to add
> an additional entry ?
> On top of it come the question of the reliability and what will happen
> if we want to use a secure boot in the future..
>
> I am looking for advice and support on this specific topic.
> Thanks for your support,
>
> Mit freundlichen Grüßen
> Florian Manoël
>
> Siemens AG
> Digital Industries
> Process Automation
> Software House Khe
> DI PA CI R&D 2
> Östliche Rheinbrückenstr. 50
> 76187 Karlsruhe, Deutschland
> Tel.: +49 721 595-1433
> mailto:florian.manoel@siemens.com
> www.siemens.com/ingenuityforlife <https://siemens.com/ingenuityforlife>
>
> Siemens Aktiengesellschaft: Vorsitzender des Aufsichtsrats: Jim
> Hagemann Snabe; Vorstand: Joe Kaeser, Vorsitzender; Roland Busch,
> Klaus Helmrich, Cedrik Neike, Ralf P. Thomas; Sitz der Gesellschaft:
> Berlin und München, Deutschland; Registergericht: Berlin
> Charlottenburg, HRB 12300, München, HRB 6684; WEEE-Reg.-Nr. DE 23691322
>
>
Hi Raghu and Louis,
On 4/7/20 12:14 PM, Louis Mayencourt via TF-A wrote:
> I do agree with you: case 2 and 3 are similar (wrongly formed DTB) and
> should lead to the same behavior.
>
> A mandatory property miss or a hit with a structurally incorrect node
> means that the DTB doesn't follow the provided binding document. Such a
> DTB shouldn't be considered as valid and should trigger a build failure
> and/or a code panic.
That's what still confuses me... Agree on cases 2 and 3 triggering a
build failure if possible, but not a code panic. A code panic stays in a
release build. With what we've been discussing so far, it would seem
more appropriate to me to have debug assertions to catch cases 2 and 3.
These debug assertions can help catching structural problems in the DTB
during the development phase and can be eliminated for a production
build, leaving no checks whatsoever in the code.
This is the strategy we've been using so far in TF-A. For lots of
platform interfaces, the generic code includes debug assertions to check
the correct implementation of these interfaces by platform integrators.
For example, checking the range of their return values. I would say this
is deeply embedded into the threat model TF-A uses today. See
https://trustedfirmware-a.readthedocs.io/en/latest/process/coding-guideline…
On one hand, it makes sense to me. On the other hand, I take Raghu's
point that it would be unrealistic to assume that 100% of code has been
covered by tests. This is very hard to achieve in practice, especially
to cover all error cases ; thus, it seems utopian to assume that all
debug assertions have been exercised during development and can be
safely removed.
TF-A does provide a way to keep debug assertions in a release build
(using the ENABLE_ASSERTIONS build flag) if platform integrators judge
they would rather keep them but this is not the default behaviour.
Regards,
Sandrine
Hello TF-A mail list,
I'm new here, so I quickly introduce myself.
I am Florian Manoel, working as firmware developer at Siemens in Karlsruhe, Germany. Recently, we decided to start some development based on ARM processor, the theme TF-A is new for us.
Currently, we have a custom board equipped with the processor NXP Layerscape LS1043a. So far, everything is working as planned, the PreBootLoader (TF-A) boots the bootloader (U-Boot) that's boots linux on top.
However, we want to have the possibility to boot an alternative u-boot FIP image, I explain:
We use as boot source a QSPI NOR memory. In this memory are stored 'bl2_qspi.pbl', 2 times 'fip.bin', the u-boot environment and some micro-code.
We want to select the u-boot image to be booted according to the value of a specific variable stored in the u-boot environment 'u-boot-select'.
The algo is, for my eye, relatively simple :
Start
- Check value of the u-boot variable 'u-boot-select'
- Check if the corresponding u-boot image is valid, if not select the alternative one
- Boot selected u-boot image
End
We want this functionality in case an u-boot image is broken (ex: power OFF during U-Boot update).
I already went through the source code and it rose more question than it answered. For example:
I noticed that TF-A is designed to load FIP Image but the U-Boot Environment have a different format. How to access the QSPI NOR memory? NXP specific driver?
The bl2 is designed to load only one FIP image, is it possible to add an additional entry ?
On top of it come the question of the reliability and what will happen if we want to use a secure boot in the future..
I am looking for advice and support on this specific topic.
Thanks for your support,
Mit freundlichen Grüßen
Florian Manoël
Siemens AG
Digital Industries
Process Automation
Software House Khe
DI PA CI R&D 2
Östliche Rheinbrückenstr. 50
76187 Karlsruhe, Deutschland
Tel.: +49 721 595-1433
mailto:florian.manoel@siemens.com
www.siemens.com/ingenuityforlife<https://siemens.com/ingenuityforlife>
Siemens Aktiengesellschaft: Vorsitzender des Aufsichtsrats: Jim Hagemann Snabe; Vorstand: Joe Kaeser, Vorsitzender; Roland Busch, Klaus Helmrich, Cedrik Neike, Ralf P. Thomas; Sitz der Gesellschaft: Berlin und München, Deutschland; Registergericht: Berlin Charlottenburg, HRB 12300, München, HRB 6684; WEEE-Reg.-Nr. DE 23691322
Hello all,
As the trustedfirmware.org project maintenance process [1] is now live,
it would be good if we start adopting it in our development flow for TF-A.
I would like to highlight the main changes that will have an impact on
our day-to-day work on the project.
1. Patch submitters to explicit choose their reviewers
------------------------------------------------------
All patches should now have dedicated reviewers. The patch submitter is
responsible for adding them in the reviewers field of their Gerrit review.
Each patch should have 2 types of reviewers:
- Code owners.
- Maintainers.
There needs to be 1 code owner per module modified by the patch as well
as 1 maintainer.
The maintainers and code owners are listed here:
https://trustedfirmware-a.readthedocs.io/en/latest/about/maintainers.html
Ideally, we would have at least 2 code owners per module so that they
can review each other's patches. Unfortunately we're not there yet
(especially for platform ports) so we need a work around for patches
submitted by the sole code owner of a module itself.
In this scenario, I would like to suggest we leave it to the patch
submitter to decide on a case by case basis whether they want to
nominate someone to do the detailed technical review or skip it
entirely. In any case, a maintainer will still need to review and
approve the patch.
If this proves not to be working well over time (either because it
creates unnecessary review bottlenecks or lowers the code quality too
much), we can revisit that in the future.
If you've got patches in review right now, may I please request you to
add reviewers accordingly? The sooner we start adopting this process the
better, as it will allow us to see how this works in practice and come
up with adjustments if need be.
2. Reviewers to provide feedback in a timely manner
---------------------------------------------------
If someone asks you to do a review, please try to do it in a timely
manner. There is no timeline guidelines set just yet for TF-A but I
think a good rule of thumb would be to aim to provide feedback in a
week's time. This does not mean that the review has to be completed in a
week (complex patches might need a lot of discussion and/or rounds of
review & rework), just that there's some progress and activity at least
once per week.
If for some reason, you know you won't be able to honour a review
request, please say so on Gerrit ASAP so that the patch submitter can
choose another reviewer.
3. What's next?
---------------
In the coming weeks or months, we'd like to:
- Extend the list of code owners.
- Extend the list of maintainers.
- Come up with TF-A specific contribution guidelines that complement the
tf.org process [1]. We already have some here [2] but would like to
expand them and possibly revisit some of them. Obviously, this will be a
community effort, much like the tf.org process was, and all TF-A
contributors will have a say in defining this so that we end up with
something that works for everyone (as much as possible).
Best regards,
Sandrine
[1]
https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…
[2]
https://trustedfirmware-a.readthedocs.io/en/latest/process/contributing.html
Hello,
While reviewing all the compiler flags used by TF-A, we couldn't find information for the following options in the GCC manual [1]
* --fatal-warnings (https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…)
* -fno-stack-protector (https://review.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a/…)
Can someone please help me understand if these options are still valid?
Thanks.
[1] https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/Option-Index.html#Option-Index
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
Hi all,
On 5/5/20 9:04 AM, Sandrine Bailleux via TF-A wrote:
> I've received very little feedback on version 2 of the proposal, which
> hints that we are reaching an agreement. Thus, I plan to finalize the
> proposal this week. This can then become part of our development flow
> for all trustedfirmware.org projects.
>
> Thanks again for all the inputs!
The project maintenance process is now live. The document has been moved
here (with a few minor edits to turn it from a proposal to an effective
process):
https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…
Thanks!
Regards,
Sandrine
Hi,
Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
1 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
New defect(s) Reported-by: Coverity Scan
Showing 1 of 1 defect(s)
** CID 358027: Insecure data handling (TAINTED_SCALAR)
________________________________________________________________________________________________________
*** CID 358027: Insecure data handling (TAINTED_SCALAR)
/common/fdt_wrappers.c: 295 in fdt_get_reg_props_by_name()
289
290 index = fdt_stringlist_search(dtb, node, "reg-names", name);
291 if (index < 0) {
292 return index;
293 }
294
>>> CID 358027: Insecure data handling (TAINTED_SCALAR)
>>> Passing tainted variable "index" to a tainted sink.
295 return fdt_get_reg_props_by_index(dtb, node, index, base, size);
296 }
297
298 /*******************************************************************************
299 * This function gets the stdout path node.
300 * It reads the value indicated inside the device tree.
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/ls/click?upn=nJaKvJSIH-2FPAfmty-2BK5tYpPkl…
Hello Stuart, Alexei,
Chiming-in here on Ampere's behalf...
We analysed this proposal internally. And we see a number issues with this, some of which was already raised by Raghu in the previous threads.
Here is a summary of the main issues that we see.
* Only supporting mbedtls, and this is fixed config at compile time.
* We propose that there should be a variable for the algorithm to be used, which can be setup at initialization time.
* This solution relies on taking the hash directly from the digest as the measurement, instead of the computed hash. This is not safe, especially considering measured boot may use a different hash bank, so digest hash may not be correct/valid.
* Only measuring the BL2 image, per the ARM SBSG we must be measuring and logging *all* images/boot phases
* BL31
* BL32 (all secure partitions)
* BL33 (UEFI or any other non-secure boot loader)
* Once we ERET into BL33, the measure boot flow continues and is owned by that boot loader
* Only see support for PCR0, any/all unsigned config data must be logged to PCR1.
* Passing PCRs to non-secure software before logging is not compliant with TCG Static-Root-of-Trust Measurement (SRTM) requirements
* It was discussed before in separate conversations… especially in systems where you are talked about two different signing domains where BL33 is a different trust/signing domain.
* BL33 should only do hash-log-extend… there is no need for BL33 to be aware of the current PCR value (beyond what is provided in the boot event log).
* Based on comments on the mail thread, there seem to be bad assumptions/expectations around TPM accessibility from non-secure world.
* Expecting SPI/I2C TPMs to be directly accessed from non-secure world instead of abstracting hardware details via the TCG CRB interface (which has been already standardized as the defacto mechanism for ARM on past mobile, client, and server solutions).
* CRB will "just work" for Aptio/EDK2/Linux/Windows/Hyper-V/VMWare
* NOTE: This goes back to what is a “productizable” TPM solution. We want it to be turn-key solution for customers without having to support/develop proprietary drivers.
-Vivek/Harb
Hi All,
The next TF-A Tech Forum is scheduled for Thu 7th May 2020 17:00 - 18:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know.
This meeting will be chaired by Bipin Ravi.
Agenda:
* Overview of a new TF-A Build System based on Cmake by Javier Almansa Sobrino
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu
> Krishnamurthy via TF-A
> Sent: 30 April 2020 02:33
> To: Manish Badarkhe <Manish.Badarkhe(a)arm.com>; tf-
> a(a)lists.trustedfirmware.org
> Cc: nd <nd(a)arm.com>
> Subject: Re: [TF-A] Need input on Errata implementation
>
> Hi Manish,
>
> Really appreciate you for taking time to respond to my concerns/questions.
>
> What about this situation? NS-EL2 makes an SMC call to EL3 to get some basic
> information like GET_SOC_INFORMATION. This is a simple SMC and there is no
> call to context save or context restore. During the SMC call, if there is a
> speculative AT instruction on a lower EL(say NS-EL2), there could be a bad
> cached translation. Do you not need to apply the errata in this situation ? If
> not, why?
>
> >>We can't simply apply this errata on reset and just leave the system.
>
> [RK]Totally agree. See CPU_E_HANDLER_FUNC. It is not necessary that
> cpu_ops are only called during reset and power down.
> CPU_E_HANDLER_FUNC is called at runtime due EA's.
>
> >>We thought of taking different approach for this errata
> implementation >>where anybody disable this workaround using macro as
> this errata is >>applicable for most of the CPUs (by default enabled) and can't
> be >>placed in cpu_ops.
>
> [RK]This is a poor approach in my view. Most CPU's is not all CPU's. The reason
> the errata framework exists is to apply CPU specific erratas by checking for
> them dynamically. Different stepping's of the same CPU's may or may not have
> the errata and typically you check the MIDR to know if the errata applies or
> not. Linux does not apply the errata to all CPU's since "most" CPU's have the
> issue. They check for its existence at runtime and only then apply it. TF-A
> should not hold itself to a lower standard.
Hi Raghu
I guess this depends on what the errata workaround involves. Since this workaround applies bit setting on an out of context register, it was not expected to affect the EL3 execution performance (or the lower level EL because the bits are restored on return). Also it was thought that the act of searching through the list of compiled CPUs and checking if the workaround is applicable might be more detrimental than the unilateral application of the workaround for this case (assuming no extra barriers are added since the code path it is inserted in have them already later in the sequence).
But I agree it is more elegant to have this coupled into CPU_OPS framework. I think Manish has some ideas for this.
Best Regards
Soby Mathew
>
> -Raghu
>
> On 4/29/20 1:35 AM, Manish Badarkhe wrote:
> > Hi Raghu
> >
> > Just to add/correct one more thing from my previous emails that this errata
> workaround proposed is
> > applied to both normal and secure world switches to EL3.
> >
> > Thanks
> > Manish Badarkhe
> >
> > On 29/04/2020, 12:25, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-
> bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org>
> wrote:
> >
> > Hi Raghu
> >
> > On 29/04/2020, 02:00, "Raghu K" <raghu.ncstate(a)icloud.com> wrote:
> >
> > Hi Manish,
> >
> > Thanks.
> >
> > >> we don’t have any AT instances in minimum execution window after
> context switching from S-EL(1/2)
> > >> to EL3 and before updating TCR register.
> >
> > 1) What is the minimum execution window? Does that not change based
> on micro-architecture?
> > Not sure about exact minimum execution window. IMO, it really depend
> upon when "context_save" gets called after
> > entering into EL3 from S-EL1/2. It may changed upon micro-architecture.
> Need some experts comment here.
> >
> > 2) Do we know that the "execution window" is exactly the same for all
> the CPU's this errata applies to?
> > It may be but we should not worry on that if we don’t have any AT
> instruction execution in that window.
> >
> > Also, it appears we are only talking about switching from S-EL1/2 to EL3.
> The same issue can happen when you go from NS-EL1/EL2 to EL3 as well. There
> also seems to be an assumption in the patch you submitted that this errata
> happens only during a so called context-switch. From my reading, the cortex-
> Ax errata notices don't limit the errata to occur only during "context-switches"
> in the "conditions" section and can occur while executing ANY code, although
> the work around section does muddy the waters a bit.
> >
> > In Linux, at NS-EL2 this workaround is already in place. Hence we just
> thought of considering cases from Secure EL side to put this workaround.
> > Yes, errata should not limit to particular conditional section but this
> particular errata is not straight-forward like another errata placed in the code
> currently. We can't simply apply this errata on reset and just leave the system.
> >
> > Back to problem, AT instruction speculative execution using out-of-
> context regime that results in page table walk and generate the incorrect
> > translation which are cached in TLB. To avoid this issue we thought of
> disabling PTW for that particular EL.
> > for e.g. If AT instruction execution for EL1 present in EL3 then we have to
> make sure speculative behaviour of this AT should not result in incorrect
> translation cached in TLB. If system is always in EL3 (if we loop-in in EL3 always
> without going back and forth to/from lower EL) then in that case
> > there is no need of this workaround.
> > Hence we thought to put this workaround over boundary context of
> context switches. When "context save" (close to EL3 entry) happened we
> meticulously save all EL system registers (S-EL1/S-EL2) with PTW disabled and
> continue EL3 execution with PTW disabled ensuring we should not cache any
> incorrect translation for (S-EL1/S-EL2) and during "context restore" (i.e. close
> to EL3 exit) again we disabled PTW, restore all system registers for EL (S-EL1/S-
> EL2) except TCR and then restore TCR.
> >
> > 3) Has there been any work done to actually reproduce this issue and
> also to see that this actually fixes the issue?
> > No this issue is hard to reproduce.
> >
> > 4) Has the CPU errata framework(cpu_ops etc.) been considered to
> possibly implement the errata? Sprinkling erratas through common framework
> code does not seem like a good idea.
> > We thought of taking different approach for this errata implementation
> where anybody disable this workaround using macro as this errata is
> applicable for most of the CPUs (by default enabled) and can't be placed in
> cpu_ops.
> >
> > Thanks
> > Raghu
> >
> > Thanks
> > Manish Badarkhe
> >
> > On 4/28/20 1:44 AM, Manish Badarkhe wrote:
> > > Hi Raghu
> > >
> > > Please see my replies inline.
> > >
> > > Regards
> > > Manish Badarkhe
> > >
> > > On 28/04/2020, 11:29, "Raghu Krishnamurthy"
> <raghu.ncstate(a)icloud.com> wrote:
> > >
> > > Hi Manish,
> > >
> > > Understood.
> > >
> > > >>Hence before entering in EL3, we ensured that PTW is disabled
> (at
> > > context save)
> > >
> > > The context save and restore functions are executed in EL3. So how
> are
> > > you disabling PTW before entering EL3 ?
> > >
> > > Yes, I put it wrongly. We thought "context_save/restore" is best place
> to disable PTW without much affecting the
> > > code because we don’t have any AT instances in minimum execution
> window after context switching from S-EL(1/2)
> > > to EL3 and before updating TCR register.
> > >
> > > -Raghu
> > >
> > > Thanks
> > > Manish Badarkhe
> > >
> > > On 4/27/20 10:53 PM, Manish Badarkhe wrote:
> > > > Hi Raghu
> > > >
> > > > This workaround is specifically need for speculative AT instruction
> behaviour in out of context regime.
> > > > That means executing AT instruction for lower ELs (S-EL1/S-EL2) in
> higher EL i.e. EL3.
> > > >
> > > > Behaviour of AT instruction is unaltered when it get executed in
> same regime (when AT instruction executed for same EL
> > > > where it is executing) and there is no possibility to execute AT
> instruction for higher EL in lower EL.
> > > >
> > > > Hence before entering in EL3, we ensured that PTW is disabled (at
> context save) and restore PTW back during
> > > > exit of EL3. (at context restore).
> > > >
> > > > Thanks
> > > > Manish Badarkhe
> > > >
> > > > On 28/04/2020, 01:23, "Raghu K" <raghu.ncstate(a)icloud.com>
> wrote:
> > > >
> > > > Hi Manish,
> > > >
> > > > >>Hence proposed solution will work as it is
> > > >
> > > > [RK]If you are sure go ahead. I'm not convinced, but that may
> be because
> > > > i don't understand the errata fully/correctly.
> > > >
> > > > >>This workaround is very specific during context switching
> > > >
> > > > [RK] Context switching has many meanings depending on the
> context(OS,
> > > > hypervisor, TF-A world switch etc). The errata document i saw
> does not
> > > > elaborate on this. Perhaps clarifying this will help understand
> why the
> > > > solution you proposed will work.
> > > >
> > > > The solution below in points 2 and 3 have the same problem on
> entry and
> > > > exit, mentioned in my first email. Before you call
> > > > el1_sysregs_context_save, an AT instruction could have
> speculatively
> > > > executed through speculation of branches that occur BEFORE
> you call this
> > > > function, when TCR still has the enable bit set. The fact that you
> don't
> > > > have an AT instruction in the context save routine or any
> routine for
> > > > that matter, does not guarantee that the hardware did not
> speculate
> > > > through some other means to reach an AT instruction. The
> same applies to
> > > > the context_restore routines. There is no guarantee right after
> you
> > > > finish the restore routing(and hence TCR has the enable bit set),
> that
> > > > the CPU cannot speculate to an AT instruction.
> > > > So i'm not clear how you can say for certain that there was no
> > > > speculative AT instruction with the proposal below.
> > > >
> > > > Thanks
> > > > Raghu
> > > >
> > > > On 4/27/20 10:08 AM, Manish Badarkhe wrote:
> > > > > Hi All,
> > > > >
> > > > > Just update/correct details.
> > > > >
> > > > > Thanks
> > > > > Manish Badarkhe
> > > > >
> > > > > On 27/04/2020, 22:13, "TF-A on behalf of Manish Badarkhe
> via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-
> a(a)lists.trustedfirmware.org> wrote:
> > > > >
> > > > > Hi Raghu
> > > > >
> > > > > Please ignore my answer on question 2.
> > > > >
> > > > > With internal discussion came to below conclusion:
> > > > > 1. This workaround is very specific during context
> switching.
> > > > > 2 . If you check in context save routine
> (el1_sysregs_context_save or el2_sysregs_context_save),
> > > > > As per proposed solution, First step performed is to
> disable page table walk and we don’t have
> > > > > any AT instruction execution in context save routine.
> > > > > This ensures that there will be no possibility of
> speculative AT instruction execution without TCR update.
> > > > > 3. If you check in context restore routine
> (el1_sysregs_context_restore or el2_sysregs_context_restore),
> > > > > As per proposed solution, first step performed is to
> disable page table walk and we don’t have any
> > > > > AT instruction execution in context restore routine.
> > > > > This ensures that there will be no possibility of
> speculative AT instruction execution without TCR update.
> > > > >
> > > > > Hence proposed solution will work as it is ensuring no
> caching of translations in TLB while speculative AT instruction execution.
> > > > >
> > > > > Thanks
> > > > > Manish Badarkhe
> > > > >
> > > > > On 27/04/2020, 13:38, "TF-A on behalf of Manish Badarkhe
> via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-
> a(a)lists.trustedfirmware.org> wrote:
> > > > >
> > > > > Hi Raghu
> > > > >
> > > > > Please see my answers inline
> > > > >
> > > > > On 25/04/2020, 06:38, "TF-A on behalf of Raghu K via TF-
> A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-
> a(a)lists.trustedfirmware.org> wrote:
> > > > >
> > > > > Hi Manish,
> > > > >
> > > > > Before I agree or disagree with the suggested fix, the
> following would
> > > > > be interesting to know/discuss. Please feel free to
> correct me if i've
> > > > > misunderstood something.
> > > > >
> > > > > 1) Are "speculative" AT instructions subject to TCR_ELx
> control bits for
> > > > > all the listed CPU's? I imagine the answer is yes but
> would be good to
> > > > > get confirmation. I could not find any evidence in the
> instruction
> > > > > description or psuedocode in the ARMv8 ARM. It is
> possible to play many
> > > > > tricks on speculative execution of instructions such as
> skipping checks
> > > > > and doing them only when the CPU knows the
> instruction will be
> > > > > committed. If this is the case, changing TCR_ELx bits
> may not work. The
> > > > > errata document is vague about how to fix it.
> > > > >
> > > > > The speculative AT instruction may behave as you
> mentioned. We need more
> > > > > opinion on this.
> > > > > Proposed fix I mentioned by referring linux workaround
> for the same errata.
> > > > > Linux workaround is available in mainline kernel as
> below:
> > > > >
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?…
> v5.7-rc3&id=bd227553ad5077f21ddb382dcd910ba46181805a
> > > > >
> > > > > 2) Assuming the answer to question 1 is yes, your
> proposal may not work
> > > > > as is. In the worst case, as soon as you enter EL3, the
> very first thing
> > > > > that may happen, before you ever operate/write to
> TCR_ELx, is a
> > > > > speculative AT instruction that caches a bad translation
> in the TLB's.
> > > > > The same thing can happen on the exit path. As soon as
> you restore the
> > > > > TCR_ELx register, the first thing that can happen is a
> speculative AT
> > > > > that caches a bad translation. However, the el3_exit
> path does have DSB
> > > > > before ERET, so we will not speculate to an AT
> instruction if there are
> > > > > no branches between the instruction that sets TCR_ELx
> and the ERET.
> > > > > Somewhere in between, it looks like we will need a
> TLBI NSH to be
> > > > > certain there are no bad translation cached. This
> obviously has a
> > > > > potential performance cost on the lower EL's. Every
> entry into EL3
> > > > > flushes the TLB for lower EL's.
> > > > >
> > > > > Yes, this seems to be valid case during entry and exit path.
> > > > > I am not quite sure in that case where we need to avoid
> PTW.
> > > > > Also "TLBI NSH" works but it may cause performance
> issue.
> > > > > Need some more opinion/thoughts on this.
> > > > >
> > > > > Just thinking, can sequence mentioned for context save
> does not ensure that
> > > > > PTW is disabled?
> > > > > Something as below as last step in ELx(1/2) context save
> (elaborated more):
> > > > > > ·Save TCR register with PTW enable (EPD=0). (Just to
> enable PTW during
> > > > > > restore context). Do not operate TCR_EL1x register
> here just save its value to restore.
> > > > > > This ensures that during entry in EL3 there will be no
> chance of PTW
> > > > > >. while executing AT instruction.
> > > > >
> > > > > Thanks
> > > > >
> > > > > Raghu
> > > > >
> > > > > Thanks
> > > > > Manish Badarkhe
> > > > >
> > > > > On 4/24/20 2:56 AM, Manish Badarkhe via TF-A wrote:
> > > > > >
> > > > > > Hi All
> > > > > >
> > > > > > We are trying to implement errata which is applicable
> for below CPUs:
> > > > > >
> > > > > > <CPUs> : <Errata No.>
> > > > > >
> > > > > > Cortex-A53: 1530924
> > > > > >
> > > > > > Cortex-A76: 1165522
> > > > > > Cortex-A72: 1319367
> > > > > > Cortex-A57: 1319537
> > > > > > Cortex-A55: 1530923
> > > > > >
> > > > > > *Errata Description:*
> > > > > >
> > > > > > A speculative Address Translation (AT) instruction
> translates using
> > > > > > registers that are associated with an out-of-context
> translation
> > > > > > regime and caches the resulting translation in the TLB.
> A subsequent
> > > > > > translation request that is generated when the out-
> of-context
> > > > > > translation regime is current uses the previous cached
> TLB entry
> > > > > > producing an incorrect virtual to physical mapping.
> > > > > >
> > > > > > *Probable solution is to implement below fix in
> context.S file:*
> > > > > >
> > > > > > *During ELx (1 or 2) context save:*
> > > > > >
> > > > > > ·Operate TCR_ELx(1/2) to disable page table walk by
> operating EPD bits
> > > > > >
> > > > > > oThis will avoid any page table walk for S-EL1 or S-EL2.
> This will
> > > > > > help in avoiding caching of translations in TLB
> > > > > >
> > > > > > for S-EL1/S-EL2 in EL3.
> > > > > >
> > > > > > ·Save all system registers (which is already available)
> except TCR
> > > > > >
> > > > > > ·Clear EPD bits of TCR and then save. (Just to enable
> PTW during
> > > > > > restore context).
> > > > > >
> > > > > > *During ELx (1 or 2) context restore:*
> > > > > >
> > > > > > * Operate TCR_ELx(1/2) to disable page table walk
> by operating EPD bits
> > > > > > * Restore all system registers (which are saved
> during context save)
> > > > > > except TCR register.
> > > > > > * Restore TCR_ELx(1/2) register (which enable back
> PTW).
> > > > > >
> > > > > > With above we ensured that there will be no page
> table walk for S-EL1
> > > > > > and S-EL2 in EL3.
> > > > > >
> > > > > > is this proper other way to fix this problem? Need
> some suggestion/use
> > > > > > cases where and all we need this workaround in TF-A
> code.
> > > > > >
> > > > > > Thanks
> > > > > >
> > > > > > Manish Badarkhe
> > > > > >
> > > > > > IMPORTANT NOTICE: The contents of this email and
> any attachments are
> > > > > > confidential and may also be privileged. If you are not
> the intended
> > > > > > recipient, please notify the sender immediately and
> do not disclose
> > > > > > the contents to any other person, use it for any
> purpose, or store or
> > > > > > copy the information in any medium. Thank you.
> > > > > >
> > > > >
> > > > > --
> > > > > TF-A mailing list
> > > > > TF-A(a)lists.trustedfirmware.org
> > > > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > > > >
> > > > > IMPORTANT NOTICE: The contents of this email and any
> attachments are confidential and may also be privileged. If you are not the
> intended recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
> > > > > --
> > > > > TF-A mailing list
> > > > > TF-A(a)lists.trustedfirmware.org
> > > > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > > > >
> > > > > IMPORTANT NOTICE: The contents of this email and any
> attachments are confidential and may also be privileged. If you are not the
> intended recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
> > > > > --
> > > > > TF-A mailing list
> > > > > TF-A(a)lists.trustedfirmware.org
> > > > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > > > >
> > > > > IMPORTANT NOTICE: The contents of this email and any
> attachments are confidential and may also be privileged. If you are not the
> intended recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
> > > >
> > > >
> > > > IMPORTANT NOTICE: The contents of this email and any
> attachments are confidential and may also be privileged. If you are not the
> intended recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
> > > >
> > >
> > > IMPORTANT NOTICE: The contents of this email and any attachments
> are confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
> >
> >
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi all,
I've received very little feedback on version 2 of the proposal, which
hints that we are reaching an agreement. Thus, I plan to finalize the
proposal this week. This can then become part of our development flow
for all trustedfirmware.org projects.
Thanks again for all the inputs!
Regards,
Sandrine Bailleux
Hi Francois,
On Mon, Apr 20, 2020 at 11:45:02AM +0000, François Ozog via TF-A wrote:
> Hi,
>
> I am trying to identify a mechanism to enforce a form of two-way
> isolation between BL33 runtime services in OS, for instance:
> - a pair of 2MB areas that could be RO by one entity and RW by the other
> - an execute only BL33 2MB area?
Stupid Q! Are you referring to isolation between EFI runtime services and the
OS?
It is not clear what you mean by BL33 runtime services?
cheers,
Achin
>
> This is similar to hypervisor except it only deals with memory, no
> vCPU, no GIC virtualization...
>
> Could EL3 or EL2 install protective mappings ? BL33 could ask either
> EL2 hypervisor or SecureMonitor to actually install them.
>
> Cordially,
>
> FF
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Raghu
Just to add/correct one more thing from my previous emails that this errata workaround proposed is
applied to both normal and secure world switches to EL3.
Thanks
Manish Badarkhe
On 29/04/2020, 12:25, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Raghu
On 29/04/2020, 02:00, "Raghu K" <raghu.ncstate(a)icloud.com> wrote:
Hi Manish,
Thanks.
>> we don’t have any AT instances in minimum execution window after context switching from S-EL(1/2)
>> to EL3 and before updating TCR register.
1) What is the minimum execution window? Does that not change based on micro-architecture?
Not sure about exact minimum execution window. IMO, it really depend upon when "context_save" gets called after
entering into EL3 from S-EL1/2. It may changed upon micro-architecture. Need some experts comment here.
2) Do we know that the "execution window" is exactly the same for all the CPU's this errata applies to?
It may be but we should not worry on that if we don’t have any AT instruction execution in that window.
Also, it appears we are only talking about switching from S-EL1/2 to EL3. The same issue can happen when you go from NS-EL1/EL2 to EL3 as well. There also seems to be an assumption in the patch you submitted that this errata happens only during a so called context-switch. From my reading, the cortex-Ax errata notices don't limit the errata to occur only during "context-switches" in the "conditions" section and can occur while executing ANY code, although the work around section does muddy the waters a bit.
In Linux, at NS-EL2 this workaround is already in place. Hence we just thought of considering cases from Secure EL side to put this workaround.
Yes, errata should not limit to particular conditional section but this particular errata is not straight-forward like another errata placed in the code currently. We can't simply apply this errata on reset and just leave the system.
Back to problem, AT instruction speculative execution using out-of-context regime that results in page table walk and generate the incorrect
translation which are cached in TLB. To avoid this issue we thought of disabling PTW for that particular EL.
for e.g. If AT instruction execution for EL1 present in EL3 then we have to make sure speculative behaviour of this AT should not result in incorrect translation cached in TLB. If system is always in EL3 (if we loop-in in EL3 always without going back and forth to/from lower EL) then in that case
there is no need of this workaround.
Hence we thought to put this workaround over boundary context of context switches. When "context save" (close to EL3 entry) happened we meticulously save all EL system registers (S-EL1/S-EL2) with PTW disabled and continue EL3 execution with PTW disabled ensuring we should not cache any incorrect translation for (S-EL1/S-EL2) and during "context restore" (i.e. close to EL3 exit) again we disabled PTW, restore all system registers for EL (S-EL1/S-EL2) except TCR and then restore TCR.
3) Has there been any work done to actually reproduce this issue and also to see that this actually fixes the issue?
No this issue is hard to reproduce.
4) Has the CPU errata framework(cpu_ops etc.) been considered to possibly implement the errata? Sprinkling erratas through common framework code does not seem like a good idea.
We thought of taking different approach for this errata implementation where anybody disable this workaround using macro as this errata is applicable for most of the CPUs (by default enabled) and can't be placed in cpu_ops.
Thanks
Raghu
Thanks
Manish Badarkhe
On 4/28/20 1:44 AM, Manish Badarkhe wrote:
> Hi Raghu
>
> Please see my replies inline.
>
> Regards
> Manish Badarkhe
>
> On 28/04/2020, 11:29, "Raghu Krishnamurthy" <raghu.ncstate(a)icloud.com> wrote:
>
> Hi Manish,
>
> Understood.
>
> >>Hence before entering in EL3, we ensured that PTW is disabled (at
> context save)
>
> The context save and restore functions are executed in EL3. So how are
> you disabling PTW before entering EL3 ?
>
> Yes, I put it wrongly. We thought "context_save/restore" is best place to disable PTW without much affecting the
> code because we don’t have any AT instances in minimum execution window after context switching from S-EL(1/2)
> to EL3 and before updating TCR register.
>
> -Raghu
>
> Thanks
> Manish Badarkhe
>
> On 4/27/20 10:53 PM, Manish Badarkhe wrote:
> > Hi Raghu
> >
> > This workaround is specifically need for speculative AT instruction behaviour in out of context regime.
> > That means executing AT instruction for lower ELs (S-EL1/S-EL2) in higher EL i.e. EL3.
> >
> > Behaviour of AT instruction is unaltered when it get executed in same regime (when AT instruction executed for same EL
> > where it is executing) and there is no possibility to execute AT instruction for higher EL in lower EL.
> >
> > Hence before entering in EL3, we ensured that PTW is disabled (at context save) and restore PTW back during
> > exit of EL3. (at context restore).
> >
> > Thanks
> > Manish Badarkhe
> >
> > On 28/04/2020, 01:23, "Raghu K" <raghu.ncstate(a)icloud.com> wrote:
> >
> > Hi Manish,
> >
> > >>Hence proposed solution will work as it is
> >
> > [RK]If you are sure go ahead. I'm not convinced, but that may be because
> > i don't understand the errata fully/correctly.
> >
> > >>This workaround is very specific during context switching
> >
> > [RK] Context switching has many meanings depending on the context(OS,
> > hypervisor, TF-A world switch etc). The errata document i saw does not
> > elaborate on this. Perhaps clarifying this will help understand why the
> > solution you proposed will work.
> >
> > The solution below in points 2 and 3 have the same problem on entry and
> > exit, mentioned in my first email. Before you call
> > el1_sysregs_context_save, an AT instruction could have speculatively
> > executed through speculation of branches that occur BEFORE you call this
> > function, when TCR still has the enable bit set. The fact that you don't
> > have an AT instruction in the context save routine or any routine for
> > that matter, does not guarantee that the hardware did not speculate
> > through some other means to reach an AT instruction. The same applies to
> > the context_restore routines. There is no guarantee right after you
> > finish the restore routing(and hence TCR has the enable bit set), that
> > the CPU cannot speculate to an AT instruction.
> > So i'm not clear how you can say for certain that there was no
> > speculative AT instruction with the proposal below.
> >
> > Thanks
> > Raghu
> >
> > On 4/27/20 10:08 AM, Manish Badarkhe wrote:
> > > Hi All,
> > >
> > > Just update/correct details.
> > >
> > > Thanks
> > > Manish Badarkhe
> > >
> > > On 27/04/2020, 22:13, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
> > >
> > > Hi Raghu
> > >
> > > Please ignore my answer on question 2.
> > >
> > > With internal discussion came to below conclusion:
> > > 1. This workaround is very specific during context switching.
> > > 2 . If you check in context save routine (el1_sysregs_context_save or el2_sysregs_context_save),
> > > As per proposed solution, First step performed is to disable page table walk and we don’t have
> > > any AT instruction execution in context save routine.
> > > This ensures that there will be no possibility of speculative AT instruction execution without TCR update.
> > > 3. If you check in context restore routine (el1_sysregs_context_restore or el2_sysregs_context_restore),
> > > As per proposed solution, first step performed is to disable page table walk and we don’t have any
> > > AT instruction execution in context restore routine.
> > > This ensures that there will be no possibility of speculative AT instruction execution without TCR update.
> > >
> > > Hence proposed solution will work as it is ensuring no caching of translations in TLB while speculative AT instruction execution.
> > >
> > > Thanks
> > > Manish Badarkhe
> > >
> > > On 27/04/2020, 13:38, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
> > >
> > > Hi Raghu
> > >
> > > Please see my answers inline
> > >
> > > On 25/04/2020, 06:38, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
> > >
> > > Hi Manish,
> > >
> > > Before I agree or disagree with the suggested fix, the following would
> > > be interesting to know/discuss. Please feel free to correct me if i've
> > > misunderstood something.
> > >
> > > 1) Are "speculative" AT instructions subject to TCR_ELx control bits for
> > > all the listed CPU's? I imagine the answer is yes but would be good to
> > > get confirmation. I could not find any evidence in the instruction
> > > description or psuedocode in the ARMv8 ARM. It is possible to play many
> > > tricks on speculative execution of instructions such as skipping checks
> > > and doing them only when the CPU knows the instruction will be
> > > committed. If this is the case, changing TCR_ELx bits may not work. The
> > > errata document is vague about how to fix it.
> > >
> > > The speculative AT instruction may behave as you mentioned. We need more
> > > opinion on this.
> > > Proposed fix I mentioned by referring linux workaround for the same errata.
> > > Linux workaround is available in mainline kernel as below:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?…
> > >
> > > 2) Assuming the answer to question 1 is yes, your proposal may not work
> > > as is. In the worst case, as soon as you enter EL3, the very first thing
> > > that may happen, before you ever operate/write to TCR_ELx, is a
> > > speculative AT instruction that caches a bad translation in the TLB's.
> > > The same thing can happen on the exit path. As soon as you restore the
> > > TCR_ELx register, the first thing that can happen is a speculative AT
> > > that caches a bad translation. However, the el3_exit path does have DSB
> > > before ERET, so we will not speculate to an AT instruction if there are
> > > no branches between the instruction that sets TCR_ELx and the ERET.
> > > Somewhere in between, it looks like we will need a TLBI NSH to be
> > > certain there are no bad translation cached. This obviously has a
> > > potential performance cost on the lower EL's. Every entry into EL3
> > > flushes the TLB for lower EL's.
> > >
> > > Yes, this seems to be valid case during entry and exit path.
> > > I am not quite sure in that case where we need to avoid PTW.
> > > Also "TLBI NSH" works but it may cause performance issue.
> > > Need some more opinion/thoughts on this.
> > >
> > > Just thinking, can sequence mentioned for context save does not ensure that
> > > PTW is disabled?
> > > Something as below as last step in ELx(1/2) context save (elaborated more):
> > > > ·Save TCR register with PTW enable (EPD=0). (Just to enable PTW during
> > > > restore context). Do not operate TCR_EL1x register here just save its value to restore.
> > > > This ensures that during entry in EL3 there will be no chance of PTW
> > > >. while executing AT instruction.
> > >
> > > Thanks
> > >
> > > Raghu
> > >
> > > Thanks
> > > Manish Badarkhe
> > >
> > > On 4/24/20 2:56 AM, Manish Badarkhe via TF-A wrote:
> > > >
> > > > Hi All
> > > >
> > > > We are trying to implement errata which is applicable for below CPUs:
> > > >
> > > > <CPUs> : <Errata No.>
> > > >
> > > > Cortex-A53: 1530924
> > > >
> > > > Cortex-A76: 1165522
> > > > Cortex-A72: 1319367
> > > > Cortex-A57: 1319537
> > > > Cortex-A55: 1530923
> > > >
> > > > *Errata Description:*
> > > >
> > > > A speculative Address Translation (AT) instruction translates using
> > > > registers that are associated with an out-of-context translation
> > > > regime and caches the resulting translation in the TLB. A subsequent
> > > > translation request that is generated when the out-of-context
> > > > translation regime is current uses the previous cached TLB entry
> > > > producing an incorrect virtual to physical mapping.
> > > >
> > > > *Probable solution is to implement below fix in context.S file:*
> > > >
> > > > *During ELx (1 or 2) context save:*
> > > >
> > > > ·Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
> > > >
> > > > oThis will avoid any page table walk for S-EL1 or S-EL2. This will
> > > > help in avoiding caching of translations in TLB
> > > >
> > > > for S-EL1/S-EL2 in EL3.
> > > >
> > > > ·Save all system registers (which is already available) except TCR
> > > >
> > > > ·Clear EPD bits of TCR and then save. (Just to enable PTW during
> > > > restore context).
> > > >
> > > > *During ELx (1 or 2) context restore:*
> > > >
> > > > * Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
> > > > * Restore all system registers (which are saved during context save)
> > > > except TCR register.
> > > > * Restore TCR_ELx(1/2) register (which enable back PTW).
> > > >
> > > > With above we ensured that there will be no page table walk for S-EL1
> > > > and S-EL2 in EL3.
> > > >
> > > > is this proper other way to fix this problem? Need some suggestion/use
> > > > cases where and all we need this workaround in TF-A code.
> > > >
> > > > Thanks
> > > >
> > > > Manish Badarkhe
> > > >
> > > > IMPORTANT NOTICE: The contents of this email and any attachments are
> > > > confidential and may also be privileged. If you are not the intended
> > > > recipient, please notify the sender immediately and do not disclose
> > > > the contents to any other person, use it for any purpose, or store or
> > > > copy the information in any medium. Thank you.
> > > >
> > >
> > > --
> > > TF-A mailing list
> > > TF-A(a)lists.trustedfirmware.org
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >
> > > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> > > --
> > > TF-A mailing list
> > > TF-A(a)lists.trustedfirmware.org
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >
> > > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> > > --
> > > TF-A mailing list
> > > TF-A(a)lists.trustedfirmware.org
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > >
> > > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> >
> >
> > IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> >
>
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
This event has been changed.
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558 8656
US (New York) +1 669 900 9128 US (San
Jose) 877 853 5247 US Toll-free
888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your
local number: https://zoom.us/u/ad27hc6t7h
When: Every 2 weeks from 18:00 to 19:00 on Thursday from Thu 7 May to Thu
30 Jul Central European Time - Paris (changed)
Where: Zoom
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
(Guest list has been hidden at organiser's request)
Event details:
https://www.google.com/calendar/event?action=VIEW&eid=N3ZoNDBuZzZnM2k4cGszY…
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
Hi Bin Wu,
Glad if this helped!
Hi Thomas,
Thanks for the heads up!
Regards,
Olivier.
________________________________________
From: 吴斌(郅隆) <zhilong.wb(a)alibaba-inc.com>
Sent: 21 April 2020 13:52
To: Thomas Abraham; Olivier Deprez; TF-A
Subject: 回复:RE: [TF-A] 回复:Re: 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Dear All,
Thanks all your help again. Your professionalism and assistance impressed me.
BRs,
Bin Wu
------------------原始邮件 ------------------
发件人:Thomas Abraham <thomas.abraham(a)arm.com>
发送时间:Tue Apr 21 19:38:38 2020
收件人:Olivier Deprez <Olivier.Deprez(a)arm.com>, TF-A <tf-a-bounces(a)lists.trustedfirmware.org>, 吴斌(郅隆) <zhilong.wb(a)alibaba-inc.com>
主题:RE: [TF-A] 回复:Re: 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Hi,
Looking into the mail chain below, this is probably being tested on RD-N1-Edge platform. There was regression noticed in the dmc620 ras error handling in the code pushed to Linaro for RD-N1-Edge platform. This will be fixed later today and patches will be merged into Linaro repos. It should then be accessible using the usual repo init/sync commands.
Thanks,
Thomas.
> -----Original Message-----
> From: TF-A On Behalf Of Olivier
> Deprez via TF-A
> Sent: Tuesday, April 21, 2020 4:45 PM
> To: TF-A ; Raghu K via TF-A
> a(a)lists.trustedfirmware.org>; 吴斌(郅隆)
> Subject: Re: [TF-A] 回复:Re: 回复:Re: [RAS] BL32 UnRecognized Event -
> 0xC4000061 and BL31 Crashed
>
> Hi Raghu,
>
> Yes you're right, we probably need few return code checks here and here. I
> may submit a patch and verify it doesn't break anything else.
>
> Hi Bin Wu,
>
> I had noticed the following sequence originating from linux sdei driver init
> down to TF-A:
>
> INFO: SDEI: Private events initialized on 81000100
> INFO: SDEI: Private events initialized on 81000200
> INFO: SDEI: Private events initialized on 81000300
> INFO: SDEI: Private events initialized on 81010000
> INFO: SDEI: Private events initialized on 81010100
> INFO: SDEI: Private events initialized on 81010200
> INFO: SDEI: Private events initialized on 81010300
> INFO: SDEI: > VER
> INFO: SDEI: < VER:1000000000000
> INFO: SDEI: > P_RESET():81000000
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81000200
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81000300
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010000
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010100
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010200
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010300
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81000100
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > S_RESET():81000100
> INFO: SDEI: < S_RESET:0
> INFO: SDEI: > UNMASK:81000000
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81000100
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81000200
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81000300
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010000
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010100
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010200
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010300
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > INFO(n:804, 0)
> INFO: SDEI: < INFO:0
> INFO: SDEI: > INFO(n:805, 0)
> INFO: SDEI: < INFO:0
>
> There is an Sdei Info request about events 804 and 805.
> Although I don't see any register or enable event service call, so I wonder if
> this demo code is missing something or expects that the platform
> implements such event definition natively.
>
> This does not look like flows described in https://trustedfirmware-
> a.readthedocs.io/en/latest/components/sdei.html
> for regular SDEI usage or explicit dispatch of events.
>
> Maybe we should involve Linaro ppl on the expected init sequence and
> dependency to TF-A (platform files).
>
> Regards,
> Olivier.
>
>
> ________________________________________
> From: TF-A on behalf of 吴斌(郅
> 隆) via TF-A
> Sent: 21 April 2020 08:45
> To: TF-A; Raghu K via TF-A
> Subject: [TF-A] 回复:Re: 回复:Re: [RAS] BL32 UnRecognized Event -
> 0xC4000061 and BL31 Crashed
>
> Hi Olivier and All,
>
> Thank you so much for your help. It makes me understand the internals.
> The next step, I need to check this event_num(804) register flow in kernel
> side, am I right?
>
>
> BRs,
> Bin Wu
> ------------------原始邮件 ------------------
> 发件人:TF-A
> 发送时间:Tue Apr 21 09:51:49 2020
> 收件人:Raghu K via TF-A
> 主题:Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and
> BL31 Crashed
> Nice debug! Apart from the issue you pointed out, there is also the
> issue with not checking the return code. The ras handler should really
> be checking or panic'ing if there is an unexpected error code from
> spm_sp_call and sdei_dispatch_event.
>
> -Raghu
>
> On 4/20/20 2:37 PM, Olivier Deprez via TF-A wrote:
> > Hi Bin Wu,
> >
> > Here's an early observation. On receiving the RAS fiq interrupt the
> following occurs:
> >
> > ehf_el3_interrupt_handler => sgi_ras_intr_handler => spm_sp_call
> (enters/exit the SP to handle the injected RAS error) => sdei_dispatch_event
> >
> > se = get_event_entry(map);
> > if (!can_sdei_state_trans(se, DO_DISPATCH))
> > return -1;
> >
> > p *map
> > $6 = {ev_num = 804, intr = 0, map_flags = 112, reg_count = 0, lock = {lock =
> 0}}
> > p *se
> > $4 = {ep = 0, arg = 0, affinity = 0, reg_flags = 0, state = 0 '\0'}
> >
> > sdei_dispatch_event exits in error at this stage, this does not seem a
> correct behavior.
> > The SDEI handler is not called in NS world and context remains unchanged.
> > The interrupt handler blindly returns to S-EL1 SP context at same location
> where it last exited.
> > sgi_ras_intr_handler => ehf_el3_interrupt_handler => vector_entry
> fiq_aarch64 => el3_exit => re-enters the SP with X0=0xC4000061
> > SP then exits but the EL3 context has not been setup for SP entry leading
> to crash.
> >
> > IMO there is an issue around mapping SDEI event number to RAS interrupt
> number leading to sdei_dispatch_event exiting early.
> >
> > Regards,
> > Olivier.
> >
> >
> > ________________________________________
> > From: TF-A on behalf of Matteo Carlini via TF-A
> > Sent: 14 April 2020 10:41
> > To: 吴斌(郅隆); tf-a(a)lists.trustedfirmware.org; Thomas Abraham; Deepak
> Pandey
> > Cc: nd
> > Subject: Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061
> and BL31 Crashed
> >
> > Looping-in Thomas & Deepak, responsible for the RD-N1 landing team
> platforms releases. They might be able to help.
> >
> > Thanks
> > Matteo
> >
> > From: TF-A On Behalf Of ??(??) via TF-A
> > Sent: 14 April 2020 06:47
> > To: TF-A ; Raghu Krishnamurthy via TF-A
> > Subject: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061
> and BL31 Crashed
> >
> > Hi RagHu,
> >
> > Really appreciate your help.
> >
> > I was downloaded this software stack from git.linaro.org. This software
> stack include ATF, kernel, edk2 and so on.
> > The user guide i used from linaro is:https://git.linaro.org/landing-
> teams/working/arm/arm-reference-
> platforms.git/about/docs/rdn1edge/user-guide.rst#obtaining-the-rd-n1-
> edge-and-rd-n1-edge-dual-fast-model
> >
> > 1) What platform you are running on? Can this issue be reproduced
> > outside your testing environment, perhaps on FVP or QEMU?
> > A: I am running on ARM N1-Edge FVP platform. It can reproduced on this
> FVP platform.
> >
> > 2) What version of TF-A and StandaloneMM is being used? Preferably the
> > commit-id, so that we can be sure we are looking at the same code.
> > A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git
> tag:RD-INFRA-20191024-RC0
> > StandloneMM seems build from edk2 & edk2-platform. so i just put edk2
> and edk2-platform version information. if anything i missed, please let me
> know.
> > edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git tag:RD-
> INFRA-20191024-RC0
> > edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-
> platforms.git tag:RD-INFRA-20191024-RC0
> >
> > 3) What version of the kernel and sdei driver is being used?
> > A: kernel-release: https://git.linaro.org/landing-
> teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
> > The sdei driver was included in kernel, do i need to provide sdei driver
> version? If need please let me know.
> > 4) I can't tell from looking at the log but do you know if writing 0x123
> > to sde_ras_poison causes a DMC620 interrupt or an SError or external
> > abort through memory access ?
> > A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error.
> So I am also not sure which exception type it will trigger.
> >
> > BRs,
> > Bin Wu
> >
> > ------------------原始邮件 ------------------
> > 发件人:TF-A >
> > 发送时间:Tue Apr 14 01:25:47 2020
> > 收件人:Raghu Krishnamurthy via TF-A >
> > 主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31
> Crashed
> > Hello,
> >
> > >>Does BL31 need to send 0xC4000061 event to BL32 again?
> >
> > I don't think it will. It is really odd that
> > 0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM
> handler.
> > This is from looking at the upstream code quickly but it definitely
> > depends on the platform you are running, what version of TF-A you are
> > using, build options used. Is it possible that the unhandled exception
> > is occurring after successful handling of the DMC620 error but there is
> > a following issue that occurs right after, causing the crash?
> > From the register dump it looks like there was an Instruction abort
> > exception at address 0 while running in EL3. Something seems to have
> > gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
> > an instruction abort at address 0.
> >
> > >>Does current TF-A support to run RAS test? It seems BL31 will crash.
> > See above. The answer really depends on the factors mentioned above.
> >
> > The following would be helpful to know:
> > 1) What platform you are running on? Can this issue be reproduced
> > outside your testing environment, perhaps on FVP or QEMU?
> > 2) What version of TF-A and StandaloneMM is being used? Preferably the
> > commit-id, so that we can be sure we are looking at the same code.
> > 3) What version of the kernel and sdei driver is being used?
> > 4) I can't tell from looking at the log but do you know if writing 0x123
> > to sde_ras_poison causes a DMC620 interrupt or an SError or external
> > abort through memory access ?
> >
> > Thanks
> > Raghu
> >
> >
> > On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
> >> Dear Friends,
> >>
> >> I am using TF-A to test RAS feature.
> >> When I triggered DMC620 RAS error in Linux(echo 0x123 >
> >> /sys/kernel/debug/sdei_ras_poison).
> >> BL32 will recieve
> >> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and
> finally
> >> BL31 crashed.
> >>
> >> In my understanding, this 0xC4000061 should consumed by BL31, not
> send
> >> it to BL32 again.
> >>
> >> A piece of error log as below:
> >>
> >> *************************************
> >>
> >> CperWrite - CperAddress@0xFF610064
> >> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
> >> CperWrite - Got Error Section: Platform Memory.
> >> MmEntryPoint Done
> >> Received delegated event
> >> X0 : 0xC4000061
> >> X1 : 0x0
> >> X2 : 0x0
> >> X3 : 0x0
> >> Received event - 0xC4000061 on cpu 0
> >> UnRecognized Event - 0xC4000061
> >> Failed delegated event 0xC4000061, Status 0x2
> >> Unhandled Exception in EL3.
> >> x30 = 0x0000000000000000
> >> x0 = 0x00000000ff007e00
> >> x1 = 0xfffffffffffffffe
> >> x2 = 0x00000000600003c0
> >> x3 = 0x0000000000000000
> >> x4 = 0x0000000000000000
> >> x5 = 0x0000000000000000
> >> x6 = 0x00000000ff015080
> >> x7 = 0x0000000000000000
> >> x8 = 0x00000000c4000061
> >> x9 = 0x0000000000000021
> >> x10 = 0x0000000000000040
> >> x11 = 0x00000000ff00f2b0
> >> x12 = 0x00000000ff0118c0
> >> x13 = 0x0000000000000002
> >> x14 = 0x00000000ff016b70
> >> x15 = 0x00000000ff003f20
> >> x16 = 0x0000000000000044
> >> x17 = 0x00000000ff010430
> >> x18 = 0x0000000000000e3c
> >> x19 = 0x0000000000000000
> >> More error log please refer to attachment.
> >>
> >> My question is,
> >> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
> >> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
> >>
> >> Appreciate your help.
> >>
> >> BRs,
> >> Bin Wu
> >>
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi All,
Just update/correct details.
Thanks
Manish Badarkhe
On 27/04/2020, 22:13, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Raghu
Please ignore my answer on question 2.
With internal discussion came to below conclusion:
1. This workaround is very specific during context switching.
2 . If you check in context save routine (el1_sysregs_context_save or el2_sysregs_context_save),
As per proposed solution, First step performed is to disable page table walk and we don’t have
any AT instruction execution in context save routine.
This ensures that there will be no possibility of speculative AT instruction execution without TCR update.
3. If you check in context restore routine (el1_sysregs_context_restore or el2_sysregs_context_restore),
As per proposed solution, first step performed is to disable page table walk and we don’t have any
AT instruction execution in context restore routine.
This ensures that there will be no possibility of speculative AT instruction execution without TCR update.
Hence proposed solution will work as it is ensuring no caching of translations in TLB while speculative AT instruction execution.
Thanks
Manish Badarkhe
On 27/04/2020, 13:38, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Raghu
Please see my answers inline
On 25/04/2020, 06:38, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Manish,
Before I agree or disagree with the suggested fix, the following would
be interesting to know/discuss. Please feel free to correct me if i've
misunderstood something.
1) Are "speculative" AT instructions subject to TCR_ELx control bits for
all the listed CPU's? I imagine the answer is yes but would be good to
get confirmation. I could not find any evidence in the instruction
description or psuedocode in the ARMv8 ARM. It is possible to play many
tricks on speculative execution of instructions such as skipping checks
and doing them only when the CPU knows the instruction will be
committed. If this is the case, changing TCR_ELx bits may not work. The
errata document is vague about how to fix it.
The speculative AT instruction may behave as you mentioned. We need more
opinion on this.
Proposed fix I mentioned by referring linux workaround for the same errata.
Linux workaround is available in mainline kernel as below:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?…
2) Assuming the answer to question 1 is yes, your proposal may not work
as is. In the worst case, as soon as you enter EL3, the very first thing
that may happen, before you ever operate/write to TCR_ELx, is a
speculative AT instruction that caches a bad translation in the TLB's.
The same thing can happen on the exit path. As soon as you restore the
TCR_ELx register, the first thing that can happen is a speculative AT
that caches a bad translation. However, the el3_exit path does have DSB
before ERET, so we will not speculate to an AT instruction if there are
no branches between the instruction that sets TCR_ELx and the ERET.
Somewhere in between, it looks like we will need a TLBI NSH to be
certain there are no bad translation cached. This obviously has a
potential performance cost on the lower EL's. Every entry into EL3
flushes the TLB for lower EL's.
Yes, this seems to be valid case during entry and exit path.
I am not quite sure in that case where we need to avoid PTW.
Also "TLBI NSH" works but it may cause performance issue.
Need some more opinion/thoughts on this.
Just thinking, can sequence mentioned for context save does not ensure that
PTW is disabled?
Something as below as last step in ELx(1/2) context save (elaborated more):
> ·Save TCR register with PTW enable (EPD=0). (Just to enable PTW during
> restore context). Do not operate TCR_EL1x register here just save its value to restore.
> This ensures that during entry in EL3 there will be no chance of PTW
>. while executing AT instruction.
Thanks
Raghu
Thanks
Manish Badarkhe
On 4/24/20 2:56 AM, Manish Badarkhe via TF-A wrote:
>
> Hi All
>
> We are trying to implement errata which is applicable for below CPUs:
>
> <CPUs> : <Errata No.>
>
> Cortex-A53: 1530924
>
> Cortex-A76: 1165522
> Cortex-A72: 1319367
> Cortex-A57: 1319537
> Cortex-A55: 1530923
>
> *Errata Description:*
>
> A speculative Address Translation (AT) instruction translates using
> registers that are associated with an out-of-context translation
> regime and caches the resulting translation in the TLB. A subsequent
> translation request that is generated when the out-of-context
> translation regime is current uses the previous cached TLB entry
> producing an incorrect virtual to physical mapping.
>
> *Probable solution is to implement below fix in context.S file:*
>
> *During ELx (1 or 2) context save:*
>
> ·Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
>
> oThis will avoid any page table walk for S-EL1 or S-EL2. This will
> help in avoiding caching of translations in TLB
>
> for S-EL1/S-EL2 in EL3.
>
> ·Save all system registers (which is already available) except TCR
>
> ·Clear EPD bits of TCR and then save. (Just to enable PTW during
> restore context).
>
> *During ELx (1 or 2) context restore:*
>
> * Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
> * Restore all system registers (which are saved during context save)
> except TCR register.
> * Restore TCR_ELx(1/2) register (which enable back PTW).
>
> With above we ensured that there will be no page table walk for S-EL1
> and S-EL2 in EL3.
>
> is this proper other way to fix this problem? Need some suggestion/use
> cases where and all we need this workaround in TF-A code.
>
> Thanks
>
> Manish Badarkhe
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or
> copy the information in any medium. Thank you.
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Raghu
Please ignore my answer on question 2.
With internal discussion came to below conclusion:
1. This workaround is very specific during context switching.
2 . If you check in context save routine (el1_sysregs_context_save or el2_sysregs_context_save),
First step performed is to disable page table walk and Also, we don’t have any AT instruction execution in that context save routing.
This ensures that there will be no possibility of speculative AT instruction execution without TCR update.
3. If you check in context save routine (el1_sysregs_context_restore or el2_sysregs_context_restore),
first step performed is to disable page table walk and Also, we don’t have any AT instruction execution in that path.
This ensures that there will be no possibility of speculative AT instruction execution without TCR update.
Hence proposed solution will work as it is ensuring no caching of translations in TLB while speculative AT instruction execution.
Thanks
Manish Badarkhe
On 27/04/2020, 13:38, "TF-A on behalf of Manish Badarkhe via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Raghu
Please see my answers inline
On 25/04/2020, 06:38, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Manish,
Before I agree or disagree with the suggested fix, the following would
be interesting to know/discuss. Please feel free to correct me if i've
misunderstood something.
1) Are "speculative" AT instructions subject to TCR_ELx control bits for
all the listed CPU's? I imagine the answer is yes but would be good to
get confirmation. I could not find any evidence in the instruction
description or psuedocode in the ARMv8 ARM. It is possible to play many
tricks on speculative execution of instructions such as skipping checks
and doing them only when the CPU knows the instruction will be
committed. If this is the case, changing TCR_ELx bits may not work. The
errata document is vague about how to fix it.
The speculative AT instruction may behave as you mentioned. We need more
opinion on this.
Proposed fix I mentioned by referring linux workaround for the same errata.
Linux workaround is available in mainline kernel as below:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?…
2) Assuming the answer to question 1 is yes, your proposal may not work
as is. In the worst case, as soon as you enter EL3, the very first thing
that may happen, before you ever operate/write to TCR_ELx, is a
speculative AT instruction that caches a bad translation in the TLB's.
The same thing can happen on the exit path. As soon as you restore the
TCR_ELx register, the first thing that can happen is a speculative AT
that caches a bad translation. However, the el3_exit path does have DSB
before ERET, so we will not speculate to an AT instruction if there are
no branches between the instruction that sets TCR_ELx and the ERET.
Somewhere in between, it looks like we will need a TLBI NSH to be
certain there are no bad translation cached. This obviously has a
potential performance cost on the lower EL's. Every entry into EL3
flushes the TLB for lower EL's.
Yes, this seems to be valid case during entry and exit path.
I am not quite sure in that case where we need to avoid PTW.
Also "TLBI NSH" works but it may cause performance issue.
Need some more opinion/thoughts on this.
Just thinking, can sequence mentioned for context save does not ensure that
PTW is disabled?
Something as below as last step in ELx(1/2) context save (elaborated more):
> ·Save TCR register with PTW enable (EPD=0). (Just to enable PTW during
> restore context). Do not operate TCR_EL1x register here just save its value to restore.
> This ensures that during entry in EL3 there will be no chance of PTW
>. while executing AT instruction.
Thanks
Raghu
Thanks
Manish Badarkhe
On 4/24/20 2:56 AM, Manish Badarkhe via TF-A wrote:
>
> Hi All
>
> We are trying to implement errata which is applicable for below CPUs:
>
> <CPUs> : <Errata No.>
>
> Cortex-A53: 1530924
>
> Cortex-A76: 1165522
> Cortex-A72: 1319367
> Cortex-A57: 1319537
> Cortex-A55: 1530923
>
> *Errata Description:*
>
> A speculative Address Translation (AT) instruction translates using
> registers that are associated with an out-of-context translation
> regime and caches the resulting translation in the TLB. A subsequent
> translation request that is generated when the out-of-context
> translation regime is current uses the previous cached TLB entry
> producing an incorrect virtual to physical mapping.
>
> *Probable solution is to implement below fix in context.S file:*
>
> *During ELx (1 or 2) context save:*
>
> ·Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
>
> oThis will avoid any page table walk for S-EL1 or S-EL2. This will
> help in avoiding caching of translations in TLB
>
> for S-EL1/S-EL2 in EL3.
>
> ·Save all system registers (which is already available) except TCR
>
> ·Clear EPD bits of TCR and then save. (Just to enable PTW during
> restore context).
>
> *During ELx (1 or 2) context restore:*
>
> * Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
> * Restore all system registers (which are saved during context save)
> except TCR register.
> * Restore TCR_ELx(1/2) register (which enable back PTW).
>
> With above we ensured that there will be no page table walk for S-EL1
> and S-EL2 in EL3.
>
> is this proper other way to fix this problem? Need some suggestion/use
> cases where and all we need this workaround in TF-A code.
>
> Thanks
>
> Manish Badarkhe
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or
> copy the information in any medium. Thank you.
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Raghu
Please see my answers inline
On 25/04/2020, 06:38, "TF-A on behalf of Raghu K via TF-A" <tf-a-bounces(a)lists.trustedfirmware.org on behalf of tf-a(a)lists.trustedfirmware.org> wrote:
Hi Manish,
Before I agree or disagree with the suggested fix, the following would
be interesting to know/discuss. Please feel free to correct me if i've
misunderstood something.
1) Are "speculative" AT instructions subject to TCR_ELx control bits for
all the listed CPU's? I imagine the answer is yes but would be good to
get confirmation. I could not find any evidence in the instruction
description or psuedocode in the ARMv8 ARM. It is possible to play many
tricks on speculative execution of instructions such as skipping checks
and doing them only when the CPU knows the instruction will be
committed. If this is the case, changing TCR_ELx bits may not work. The
errata document is vague about how to fix it.
The speculative AT instruction may behave as you mentioned. We need more
opinion on this.
Proposed fix I mentioned by referring linux workaround for the same errata.
Linux workaround is available in mainline kernel as below:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?…
2) Assuming the answer to question 1 is yes, your proposal may not work
as is. In the worst case, as soon as you enter EL3, the very first thing
that may happen, before you ever operate/write to TCR_ELx, is a
speculative AT instruction that caches a bad translation in the TLB's.
The same thing can happen on the exit path. As soon as you restore the
TCR_ELx register, the first thing that can happen is a speculative AT
that caches a bad translation. However, the el3_exit path does have DSB
before ERET, so we will not speculate to an AT instruction if there are
no branches between the instruction that sets TCR_ELx and the ERET.
Somewhere in between, it looks like we will need a TLBI NSH to be
certain there are no bad translation cached. This obviously has a
potential performance cost on the lower EL's. Every entry into EL3
flushes the TLB for lower EL's.
Yes, this seems to be valid case during entry and exit path.
I am not quite sure in that case where we need to avoid PTW.
Also "TLBI NSH" works but it may cause performance issue.
Need some more opinion/thoughts on this.
Just thinking, can sequence mentioned for context save does not ensure that
PTW is disabled?
Something as below as last step in ELx(1/2) context save (elaborated more):
> ·Save TCR register with PTW enable (EPD=0). (Just to enable PTW during
> restore context). Do not operate TCR_EL1x register here just save its value to restore.
> This ensures that during entry in EL3 there will be no chance of PTW
>. while executing AT instruction.
Thanks
Raghu
Thanks
Manish Badarkhe
On 4/24/20 2:56 AM, Manish Badarkhe via TF-A wrote:
>
> Hi All
>
> We are trying to implement errata which is applicable for below CPUs:
>
> <CPUs> : <Errata No.>
>
> Cortex-A53: 1530924
>
> Cortex-A76: 1165522
> Cortex-A72: 1319367
> Cortex-A57: 1319537
> Cortex-A55: 1530923
>
> *Errata Description:*
>
> A speculative Address Translation (AT) instruction translates using
> registers that are associated with an out-of-context translation
> regime and caches the resulting translation in the TLB. A subsequent
> translation request that is generated when the out-of-context
> translation regime is current uses the previous cached TLB entry
> producing an incorrect virtual to physical mapping.
>
> *Probable solution is to implement below fix in context.S file:*
>
> *During ELx (1 or 2) context save:*
>
> ·Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
>
> oThis will avoid any page table walk for S-EL1 or S-EL2. This will
> help in avoiding caching of translations in TLB
>
> for S-EL1/S-EL2 in EL3.
>
> ·Save all system registers (which is already available) except TCR
>
> ·Clear EPD bits of TCR and then save. (Just to enable PTW during
> restore context).
>
> *During ELx (1 or 2) context restore:*
>
> * Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
> * Restore all system registers (which are saved during context save)
> except TCR register.
> * Restore TCR_ELx(1/2) register (which enable back PTW).
>
> With above we ensured that there will be no page table walk for S-EL1
> and S-EL2 in EL3.
>
> is this proper other way to fix this problem? Need some suggestion/use
> cases where and all we need this workaround in TF-A code.
>
> Thanks
>
> Manish Badarkhe
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or
> copy the information in any medium. Thank you.
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Manish,
Before I agree or disagree with the suggested fix, the following would
be interesting to know/discuss. Please feel free to correct me if i've
misunderstood something.
1) Are "speculative" AT instructions subject to TCR_ELx control bits for
all the listed CPU's? I imagine the answer is yes but would be good to
get confirmation. I could not find any evidence in the instruction
description or psuedocode in the ARMv8 ARM. It is possible to play many
tricks on speculative execution of instructions such as skipping checks
and doing them only when the CPU knows the instruction will be
committed. If this is the case, changing TCR_ELx bits may not work. The
errata document is vague about how to fix it.
2) Assuming the answer to question 1 is yes, your proposal may not work
as is. In the worst case, as soon as you enter EL3, the very first thing
that may happen, before you ever operate/write to TCR_ELx, is a
speculative AT instruction that caches a bad translation in the TLB's.
The same thing can happen on the exit path. As soon as you restore the
TCR_ELx register, the first thing that can happen is a speculative AT
that caches a bad translation. However, the el3_exit path does have DSB
before ERET, so we will not speculate to an AT instruction if there are
no branches between the instruction that sets TCR_ELx and the ERET.
Somewhere in between, it looks like we will need a TLBI NSH to be
certain there are no bad translation cached. This obviously has a
potential performance cost on the lower EL's. Every entry into EL3
flushes the TLB for lower EL's.
Thanks
Raghu
On 4/24/20 2:56 AM, Manish Badarkhe via TF-A wrote:
>
> Hi All
>
> We are trying to implement errata which is applicable for below CPUs:
>
> <CPUs> : <Errata No.>
>
> Cortex-A53: 1530924
>
> Cortex-A76: 1165522
> Cortex-A72: 1319367
> Cortex-A57: 1319537
> Cortex-A55: 1530923
>
> *Errata Description:*
>
> A speculative Address Translation (AT) instruction translates using
> registers that are associated with an out-of-context translation
> regime and caches the resulting translation in the TLB. A subsequent
> translation request that is generated when the out-of-context
> translation regime is current uses the previous cached TLB entry
> producing an incorrect virtual to physical mapping.
>
> *Probable solution is to implement below fix in context.S file:*
>
> *During ELx (1 or 2) context save:*
>
> ·Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
>
> oThis will avoid any page table walk for S-EL1 or S-EL2. This will
> help in avoiding caching of translations in TLB
>
> for S-EL1/S-EL2 in EL3.
>
> ·Save all system registers (which is already available) except TCR
>
> ·Clear EPD bits of TCR and then save. (Just to enable PTW during
> restore context).
>
> *During ELx (1 or 2) context restore:*
>
> * Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
> * Restore all system registers (which are saved during context save)
> except TCR register.
> * Restore TCR_ELx(1/2) register (which enable back PTW).
>
> With above we ensured that there will be no page table walk for S-EL1
> and S-EL2 in EL3.
>
> is this proper other way to fix this problem? Need some suggestion/use
> cases where and all we need this workaround in TF-A code.
>
> Thanks
>
> Manish Badarkhe
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose
> the contents to any other person, use it for any purpose, or store or
> copy the information in any medium. Thank you.
>
Hi All
We are trying to implement errata which is applicable for below CPUs:
<CPUs> : <Errata No.>
Cortex-A53: 1530924
Cortex-A76: 1165522
Cortex-A72: 1319367
Cortex-A57: 1319537
Cortex-A55: 1530923
Errata Description:
A speculative Address Translation (AT) instruction translates using registers that are associated with an out-of-context translation regime and caches the resulting translation in the TLB. A subsequent translation request that is generated when the out-of-context translation regime is current uses the previous cached TLB entry producing an incorrect virtual to physical mapping.
Probable solution is to implement below fix in context.S file:
During ELx (1 or 2) context save:
· Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
o This will avoid any page table walk for S-EL1 or S-EL2. This will help in avoiding caching of translations in TLB
for S-EL1/S-EL2 in EL3.
· Save all system registers (which is already available) except TCR
· Clear EPD bits of TCR and then save. (Just to enable PTW during restore context).
During ELx (1 or 2) context restore:
* Operate TCR_ELx(1/2) to disable page table walk by operating EPD bits
* Restore all system registers (which are saved during context save) except TCR register.
* Restore TCR_ELx(1/2) register (which enable back PTW).
With above we ensured that there will be no page table walk for S-EL1 and S-EL2 in EL3.
is this proper other way to fix this problem? Need some suggestion/use cases where and all we need this workaround in TF-A code.
Thanks
Manish Badarkhe
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi,
On 4/21/20 7:23 AM, Soby Mathew via TF-A wrote:
> My view is that smaller patches are easier to review and we should try to break up the patches to logical chucks where possible. I haven't taken a look at the patches myself but I am sure there will be ways to break it up for ease of review.
I would like to strongly echo this. I find big patches so hard to
review. There is only so much things the human brain can comprehend in
one go. Smaller patches are just easier to reason about, they focus on
one thing and it is easier to get your head around them because the
entire patch and the interaction it may have with other components
"fits" in one's head. Thus, it is much easier to reach a good level of
confidence at review time.
Also, I believe there is a natural tendency of getting discouraged at
the sight of big patches, smaller patches have a much better chance of
getting reviewed quickly. They can also be dealt with incrementally. Say
in a 10 patch stack, it may happen that the 5 first are good to go,
while the sixth is more controversial and requires more discussion. In
this case, being able to merge the 5 patches is a first step in the
right direction.
Ideally, one should think about how to split the patches in a logical,
manageable way early during development. It is true that if it is an
afterthought, breaking up a huge patch down into smaller ones is a lot
of work. This is why it needs doing upfront IMO.
Cheers,
Sandrine
[resending as the previous email was sent to the wrong address]
Hi,
Looking into the mail chain below, this is probably being tested on RD-N1-Edge platform. There was regression noticed in the dmc620 ras error handling in the code pushed to Linaro for RD-N1-Edge platform. This will be fixed later today and patches will be merged into Linaro repos. It should then be accessible using the usual repo init/sync commands.
Thanks,
Thomas.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Olivier
> Deprez via TF-A
> Sent: Tuesday, April 21, 2020 4:45 PM
> To: TF-A <tf-a-bounces(a)lists.trustedfirmware.org>; Raghu K via TF-A <tf-
> a(a)lists.trustedfirmware.org>; 吴斌(郅隆) <zhilong.wb(a)alibaba-inc.com>
> Subject: Re: [TF-A] 回复:Re: 回复:Re: [RAS] BL32 UnRecognized Event -
> 0xC4000061 and BL31 Crashed
>
> Hi Raghu,
>
> Yes you're right, we probably need few return code checks here and here. I
> may submit a patch and verify it doesn't break anything else.
>
> Hi Bin Wu,
>
> I had noticed the following sequence originating from linux sdei driver init
> down to TF-A:
>
> INFO: SDEI: Private events initialized on 81000100
> INFO: SDEI: Private events initialized on 81000200
> INFO: SDEI: Private events initialized on 81000300
> INFO: SDEI: Private events initialized on 81010000
> INFO: SDEI: Private events initialized on 81010100
> INFO: SDEI: Private events initialized on 81010200
> INFO: SDEI: Private events initialized on 81010300
> INFO: SDEI: > VER
> INFO: SDEI: < VER:1000000000000
> INFO: SDEI: > P_RESET():81000000
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81000200
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81000300
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010000
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010100
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010200
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81010300
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > P_RESET():81000100
> INFO: SDEI: < P_RESET:0
> INFO: SDEI: > S_RESET():81000100
> INFO: SDEI: < S_RESET:0
> INFO: SDEI: > UNMASK:81000000
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81000100
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81000200
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81000300
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010000
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010100
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010200
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > UNMASK:81010300
> INFO: SDEI: < UNMASK:0
> INFO: SDEI: > INFO(n:804, 0)
> INFO: SDEI: < INFO:0
> INFO: SDEI: > INFO(n:805, 0)
> INFO: SDEI: < INFO:0
>
> There is an Sdei Info request about events 804 and 805.
> Although I don't see any register or enable event service call, so I wonder if
> this demo code is missing something or expects that the platform
> implements such event definition natively.
>
> This does not look like flows described in https://trustedfirmware-
> a.readthedocs.io/en/latest/components/sdei.html
> for regular SDEI usage or explicit dispatch of events.
>
> Maybe we should involve Linaro ppl on the expected init sequence and
> dependency to TF-A (platform files).
>
> Regards,
> Olivier.
>
>
> ________________________________________
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of 吴斌(郅
> 隆) via TF-A <tf-a(a)lists.trustedfirmware.org>
> Sent: 21 April 2020 08:45
> To: TF-A; Raghu K via TF-A
> Subject: [TF-A] 回复:Re: 回复:Re: [RAS] BL32 UnRecognized Event -
> 0xC4000061 and BL31 Crashed
>
> Hi Olivier and All,
>
> Thank you so much for your help. It makes me understand the internals.
> The next step, I need to check this event_num(804) register flow in kernel
> side, am I right?
>
>
> BRs,
> Bin Wu
> ------------------原始邮件 ------------------
> 发件人:TF-A <tf-a-bounces(a)lists.trustedfirmware.org>
> 发送时间:Tue Apr 21 09:51:49 2020
> 收件人:Raghu K via TF-A <tf-a(a)lists.trustedfirmware.org>
> 主题:Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and
> BL31 Crashed
> Nice debug! Apart from the issue you pointed out, there is also the
> issue with not checking the return code. The ras handler should really
> be checking or panic'ing if there is an unexpected error code from
> spm_sp_call and sdei_dispatch_event.
>
> -Raghu
>
> On 4/20/20 2:37 PM, Olivier Deprez via TF-A wrote:
> > Hi Bin Wu,
> >
> > Here's an early observation. On receiving the RAS fiq interrupt the
> following occurs:
> >
> > ehf_el3_interrupt_handler => sgi_ras_intr_handler => spm_sp_call
> (enters/exit the SP to handle the injected RAS error) => sdei_dispatch_event
> >
> > se = get_event_entry(map);
> > if (!can_sdei_state_trans(se, DO_DISPATCH))
> > return -1;
> >
> > p *map
> > $6 = {ev_num = 804, intr = 0, map_flags = 112, reg_count = 0, lock = {lock =
> 0}}
> > p *se
> > $4 = {ep = 0, arg = 0, affinity = 0, reg_flags = 0, state = 0 '\0'}
> >
> > sdei_dispatch_event exits in error at this stage, this does not seem a
> correct behavior.
> > The SDEI handler is not called in NS world and context remains unchanged.
> > The interrupt handler blindly returns to S-EL1 SP context at same location
> where it last exited.
> > sgi_ras_intr_handler => ehf_el3_interrupt_handler => vector_entry
> fiq_aarch64 => el3_exit => re-enters the SP with X0=0xC4000061
> > SP then exits but the EL3 context has not been setup for SP entry leading
> to crash.
> >
> > IMO there is an issue around mapping SDEI event number to RAS interrupt
> number leading to sdei_dispatch_event exiting early.
> >
> > Regards,
> > Olivier.
> >
> >
> > ________________________________________
> > From: TF-A on behalf of Matteo Carlini via TF-A
> > Sent: 14 April 2020 10:41
> > To: 吴斌(郅隆); tf-a(a)lists.trustedfirmware.org; Thomas Abraham; Deepak
> Pandey
> > Cc: nd
> > Subject: Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061
> and BL31 Crashed
> >
> > Looping-in Thomas & Deepak, responsible for the RD-N1 landing team
> platforms releases. They might be able to help.
> >
> > Thanks
> > Matteo
> >
> > From: TF-A On Behalf Of ??(??) via TF-A
> > Sent: 14 April 2020 06:47
> > To: TF-A ; Raghu Krishnamurthy via TF-A
> > Subject: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061
> and BL31 Crashed
> >
> > Hi RagHu,
> >
> > Really appreciate your help.
> >
> > I was downloaded this software stack from git.linaro.org. This software
> stack include ATF, kernel, edk2 and so on.
> > The user guide i used from linaro is:https://git.linaro.org/landing-
> teams/working/arm/arm-reference-
> platforms.git/about/docs/rdn1edge/user-guide.rst#obtaining-the-rd-n1-
> edge-and-rd-n1-edge-dual-fast-model
> >
> > 1) What platform you are running on? Can this issue be reproduced
> > outside your testing environment, perhaps on FVP or QEMU?
> > A: I am running on ARM N1-Edge FVP platform. It can reproduced on this
> FVP platform.
> >
> > 2) What version of TF-A and StandaloneMM is being used? Preferably the
> > commit-id, so that we can be sure we are looking at the same code.
> > A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git
> tag:RD-INFRA-20191024-RC0
> > StandloneMM seems build from edk2 & edk2-platform. so i just put edk2
> and edk2-platform version information. if anything i missed, please let me
> know.
> > edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git tag:RD-
> INFRA-20191024-RC0
> > edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-
> platforms.git tag:RD-INFRA-20191024-RC0
> >
> > 3) What version of the kernel and sdei driver is being used?
> > A: kernel-release: https://git.linaro.org/landing-
> teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
> > The sdei driver was included in kernel, do i need to provide sdei driver
> version? If need please let me know.
> > 4) I can't tell from looking at the log but do you know if writing 0x123
> > to sde_ras_poison causes a DMC620 interrupt or an SError or external
> > abort through memory access ?
> > A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error.
> So I am also not sure which exception type it will trigger.
> >
> > BRs,
> > Bin Wu
> >
> > ------------------原始邮件 ------------------
> > 发件人:TF-A >
> > 发送时间:Tue Apr 14 01:25:47 2020
> > 收件人:Raghu Krishnamurthy via TF-A >
> > 主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31
> Crashed
> > Hello,
> >
> > >>Does BL31 need to send 0xC4000061 event to BL32 again?
> >
> > I don't think it will. It is really odd that
> > 0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM
> handler.
> > This is from looking at the upstream code quickly but it definitely
> > depends on the platform you are running, what version of TF-A you are
> > using, build options used. Is it possible that the unhandled exception
> > is occurring after successful handling of the DMC620 error but there is
> > a following issue that occurs right after, causing the crash?
> > From the register dump it looks like there was an Instruction abort
> > exception at address 0 while running in EL3. Something seems to have
> > gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
> > an instruction abort at address 0.
> >
> > >>Does current TF-A support to run RAS test? It seems BL31 will crash.
> > See above. The answer really depends on the factors mentioned above.
> >
> > The following would be helpful to know:
> > 1) What platform you are running on? Can this issue be reproduced
> > outside your testing environment, perhaps on FVP or QEMU?
> > 2) What version of TF-A and StandaloneMM is being used? Preferably the
> > commit-id, so that we can be sure we are looking at the same code.
> > 3) What version of the kernel and sdei driver is being used?
> > 4) I can't tell from looking at the log but do you know if writing 0x123
> > to sde_ras_poison causes a DMC620 interrupt or an SError or external
> > abort through memory access ?
> >
> > Thanks
> > Raghu
> >
> >
> > On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
> >> Dear Friends,
> >>
> >> I am using TF-A to test RAS feature.
> >> When I triggered DMC620 RAS error in Linux(echo 0x123 >
> >> /sys/kernel/debug/sdei_ras_poison).
> >> BL32 will recieve
> >> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and
> finally
> >> BL31 crashed.
> >>
> >> In my understanding, this 0xC4000061 should consumed by BL31, not
> send
> >> it to BL32 again.
> >>
> >> A piece of error log as below:
> >>
> >> *************************************
> >>
> >> CperWrite - CperAddress@0xFF610064
> >> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
> >> CperWrite - Got Error Section: Platform Memory.
> >> MmEntryPoint Done
> >> Received delegated event
> >> X0 : 0xC4000061
> >> X1 : 0x0
> >> X2 : 0x0
> >> X3 : 0x0
> >> Received event - 0xC4000061 on cpu 0
> >> UnRecognized Event - 0xC4000061
> >> Failed delegated event 0xC4000061, Status 0x2
> >> Unhandled Exception in EL3.
> >> x30 = 0x0000000000000000
> >> x0 = 0x00000000ff007e00
> >> x1 = 0xfffffffffffffffe
> >> x2 = 0x00000000600003c0
> >> x3 = 0x0000000000000000
> >> x4 = 0x0000000000000000
> >> x5 = 0x0000000000000000
> >> x6 = 0x00000000ff015080
> >> x7 = 0x0000000000000000
> >> x8 = 0x00000000c4000061
> >> x9 = 0x0000000000000021
> >> x10 = 0x0000000000000040
> >> x11 = 0x00000000ff00f2b0
> >> x12 = 0x00000000ff0118c0
> >> x13 = 0x0000000000000002
> >> x14 = 0x00000000ff016b70
> >> x15 = 0x00000000ff003f20
> >> x16 = 0x0000000000000044
> >> x17 = 0x00000000ff010430
> >> x18 = 0x0000000000000e3c
> >> x19 = 0x0000000000000000
> >> More error log please refer to attachment.
> >>
> >> My question is,
> >> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
> >> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
> >>
> >> Appreciate your help.
> >>
> >> BRs,
> >> Bin Wu
> >>
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy the
> information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Raghu,
Yes you're right, we probably need few return code checks here and here. I may submit a patch and verify it doesn't break anything else.
Hi Bin Wu,
I had noticed the following sequence originating from linux sdei driver init down to TF-A:
INFO: SDEI: Private events initialized on 81000100
INFO: SDEI: Private events initialized on 81000200
INFO: SDEI: Private events initialized on 81000300
INFO: SDEI: Private events initialized on 81010000
INFO: SDEI: Private events initialized on 81010100
INFO: SDEI: Private events initialized on 81010200
INFO: SDEI: Private events initialized on 81010300
INFO: SDEI: > VER
INFO: SDEI: < VER:1000000000000
INFO: SDEI: > P_RESET():81000000
INFO: SDEI: < P_RESET:0
INFO: SDEI: > P_RESET():81000200
INFO: SDEI: < P_RESET:0
INFO: SDEI: > P_RESET():81000300
INFO: SDEI: < P_RESET:0
INFO: SDEI: > P_RESET():81010000
INFO: SDEI: < P_RESET:0
INFO: SDEI: > P_RESET():81010100
INFO: SDEI: < P_RESET:0
INFO: SDEI: > P_RESET():81010200
INFO: SDEI: < P_RESET:0
INFO: SDEI: > P_RESET():81010300
INFO: SDEI: < P_RESET:0
INFO: SDEI: > P_RESET():81000100
INFO: SDEI: < P_RESET:0
INFO: SDEI: > S_RESET():81000100
INFO: SDEI: < S_RESET:0
INFO: SDEI: > UNMASK:81000000
INFO: SDEI: < UNMASK:0
INFO: SDEI: > UNMASK:81000100
INFO: SDEI: < UNMASK:0
INFO: SDEI: > UNMASK:81000200
INFO: SDEI: < UNMASK:0
INFO: SDEI: > UNMASK:81000300
INFO: SDEI: < UNMASK:0
INFO: SDEI: > UNMASK:81010000
INFO: SDEI: < UNMASK:0
INFO: SDEI: > UNMASK:81010100
INFO: SDEI: < UNMASK:0
INFO: SDEI: > UNMASK:81010200
INFO: SDEI: < UNMASK:0
INFO: SDEI: > UNMASK:81010300
INFO: SDEI: < UNMASK:0
INFO: SDEI: > INFO(n:804, 0)
INFO: SDEI: < INFO:0
INFO: SDEI: > INFO(n:805, 0)
INFO: SDEI: < INFO:0
There is an Sdei Info request about events 804 and 805.
Although I don't see any register or enable event service call, so I wonder if this demo code is missing something or expects that the platform implements such event definition natively.
This does not look like flows described in https://trustedfirmware-a.readthedocs.io/en/latest/components/sdei.html
for regular SDEI usage or explicit dispatch of events.
Maybe we should involve Linaro ppl on the expected init sequence and dependency to TF-A (platform files).
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of 吴斌(郅隆) via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 21 April 2020 08:45
To: TF-A; Raghu K via TF-A
Subject: [TF-A] 回复:Re: 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Hi Olivier and All,
Thank you so much for your help. It makes me understand the internals.
The next step, I need to check this event_num(804) register flow in kernel side, am I right?
BRs,
Bin Wu
------------------原始邮件 ------------------
发件人:TF-A <tf-a-bounces(a)lists.trustedfirmware.org>
发送时间:Tue Apr 21 09:51:49 2020
收件人:Raghu K via TF-A <tf-a(a)lists.trustedfirmware.org>
主题:Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Nice debug! Apart from the issue you pointed out, there is also the
issue with not checking the return code. The ras handler should really
be checking or panic'ing if there is an unexpected error code from
spm_sp_call and sdei_dispatch_event.
-Raghu
On 4/20/20 2:37 PM, Olivier Deprez via TF-A wrote:
> Hi Bin Wu,
>
> Here's an early observation. On receiving the RAS fiq interrupt the following occurs:
>
> ehf_el3_interrupt_handler => sgi_ras_intr_handler => spm_sp_call (enters/exit the SP to handle the injected RAS error) => sdei_dispatch_event
>
> se = get_event_entry(map);
> if (!can_sdei_state_trans(se, DO_DISPATCH))
> return -1;
>
> p *map
> $6 = {ev_num = 804, intr = 0, map_flags = 112, reg_count = 0, lock = {lock = 0}}
> p *se
> $4 = {ep = 0, arg = 0, affinity = 0, reg_flags = 0, state = 0 '\0'}
>
> sdei_dispatch_event exits in error at this stage, this does not seem a correct behavior.
> The SDEI handler is not called in NS world and context remains unchanged.
> The interrupt handler blindly returns to S-EL1 SP context at same location where it last exited.
> sgi_ras_intr_handler => ehf_el3_interrupt_handler => vector_entry fiq_aarch64 => el3_exit => re-enters the SP with X0=0xC4000061
> SP then exits but the EL3 context has not been setup for SP entry leading to crash.
>
> IMO there is an issue around mapping SDEI event number to RAS interrupt number leading to sdei_dispatch_event exiting early.
>
> Regards,
> Olivier.
>
>
> ________________________________________
> From: TF-A on behalf of Matteo Carlini via TF-A
> Sent: 14 April 2020 10:41
> To: 吴斌(郅隆); tf-a(a)lists.trustedfirmware.org; Thomas Abraham; Deepak Pandey
> Cc: nd
> Subject: Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
>
> Looping-in Thomas & Deepak, responsible for the RD-N1 landing team platforms releases. They might be able to help.
>
> Thanks
> Matteo
>
> From: TF-A On Behalf Of ??(??) via TF-A
> Sent: 14 April 2020 06:47
> To: TF-A ; Raghu Krishnamurthy via TF-A
> Subject: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
>
> Hi RagHu,
>
> Really appreciate your help.
>
> I was downloaded this software stack from git.linaro.org. This software stack include ATF, kernel, edk2 and so on.
> The user guide i used from linaro is:https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms…
>
> 1) What platform you are running on? Can this issue be reproduced
> outside your testing environment, perhaps on FVP or QEMU?
> A: I am running on ARM N1-Edge FVP platform. It can reproduced on this FVP platform.
>
> 2) What version of TF-A and StandaloneMM is being used? Preferably the
> commit-id, so that we can be sure we are looking at the same code.
> A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git tag:RD-INFRA-20191024-RC0
> StandloneMM seems build from edk2 & edk2-platform. so i just put edk2 and edk2-platform version information. if anything i missed, please let me know.
> edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git tag:RD-INFRA-20191024-RC0
> edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git tag:RD-INFRA-20191024-RC0
>
> 3) What version of the kernel and sdei driver is being used?
> A: kernel-release: https://git.linaro.org/landing-teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
> The sdei driver was included in kernel, do i need to provide sdei driver version? If need please let me know.
> 4) I can't tell from looking at the log but do you know if writing 0x123
> to sde_ras_poison causes a DMC620 interrupt or an SError or external
> abort through memory access ?
> A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error. So I am also not sure which exception type it will trigger.
>
> BRs,
> Bin Wu
>
> ------------------原始邮件 ------------------
> 发件人:TF-A >
> 发送时间:Tue Apr 14 01:25:47 2020
> 收件人:Raghu Krishnamurthy via TF-A >
> 主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
> Hello,
>
> >>Does BL31 need to send 0xC4000061 event to BL32 again?
>
> I don't think it will. It is really odd that
> 0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM handler.
> This is from looking at the upstream code quickly but it definitely
> depends on the platform you are running, what version of TF-A you are
> using, build options used. Is it possible that the unhandled exception
> is occurring after successful handling of the DMC620 error but there is
> a following issue that occurs right after, causing the crash?
> From the register dump it looks like there was an Instruction abort
> exception at address 0 while running in EL3. Something seems to have
> gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
> an instruction abort at address 0.
>
> >>Does current TF-A support to run RAS test? It seems BL31 will crash.
> See above. The answer really depends on the factors mentioned above.
>
> The following would be helpful to know:
> 1) What platform you are running on? Can this issue be reproduced
> outside your testing environment, perhaps on FVP or QEMU?
> 2) What version of TF-A and StandaloneMM is being used? Preferably the
> commit-id, so that we can be sure we are looking at the same code.
> 3) What version of the kernel and sdei driver is being used?
> 4) I can't tell from looking at the log but do you know if writing 0x123
> to sde_ras_poison causes a DMC620 interrupt or an SError or external
> abort through memory access ?
>
> Thanks
> Raghu
>
>
> On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
>> Dear Friends,
>>
>> I am using TF-A to test RAS feature.
>> When I triggered DMC620 RAS error in Linux(echo 0x123 >
>> /sys/kernel/debug/sdei_ras_poison).
>> BL32 will recieve
>> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally
>> BL31 crashed.
>>
>> In my understanding, this 0xC4000061 should consumed by BL31, not send
>> it to BL32 again.
>>
>> A piece of error log as below:
>>
>> *************************************
>>
>> CperWrite - CperAddress@0xFF610064
>> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
>> CperWrite - Got Error Section: Platform Memory.
>> MmEntryPoint Done
>> Received delegated event
>> X0 : 0xC4000061
>> X1 : 0x0
>> X2 : 0x0
>> X3 : 0x0
>> Received event - 0xC4000061 on cpu 0
>> UnRecognized Event - 0xC4000061
>> Failed delegated event 0xC4000061, Status 0x2
>> Unhandled Exception in EL3.
>> x30 = 0x0000000000000000
>> x0 = 0x00000000ff007e00
>> x1 = 0xfffffffffffffffe
>> x2 = 0x00000000600003c0
>> x3 = 0x0000000000000000
>> x4 = 0x0000000000000000
>> x5 = 0x0000000000000000
>> x6 = 0x00000000ff015080
>> x7 = 0x0000000000000000
>> x8 = 0x00000000c4000061
>> x9 = 0x0000000000000021
>> x10 = 0x0000000000000040
>> x11 = 0x00000000ff00f2b0
>> x12 = 0x00000000ff0118c0
>> x13 = 0x0000000000000002
>> x14 = 0x00000000ff016b70
>> x15 = 0x00000000ff003f20
>> x16 = 0x0000000000000044
>> x17 = 0x00000000ff010430
>> x18 = 0x0000000000000e3c
>> x19 = 0x0000000000000000
>> More error log please refer to attachment.
>>
>> My question is,
>> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
>> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
>>
>> Appreciate your help.
>>
>> BRs,
>> Bin Wu
>>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi All,
The next TF-A Tech Forum is scheduled for Thu 23rd Apr 2020 17:00 - 18:00 (BST). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know.
Agenda:
* Overview of the TF-A v2.3 Release by Bipin Ravi and Mark Dykes
* Project Maintenance Proposal for tf.org Projects discussion
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of François
> Ozog via TF-A
> Sent: 20 April 2020 16:25
> To: Achin Gupta <Achin.Gupta(a)arm.com>
> Cc: tf-a(a)lists.trustedfirmware.org
> Subject: Re: [TF-A] [RFC] isolation between runtime BL33 services and OS
>
> On Mon, 20 Apr 2020 at 15:50, Achin Gupta <achin.gupta(a)arm.com> wrote:
> >
> > On Mon, Apr 20, 2020 at 03:37:23PM +0200, François Ozog wrote:
> > > On Mon, 20 Apr 2020 at 15:27, Achin Gupta <[1]achin.gupta(a)arm.com>
> > > wrote:
> > >
> > > Hi Francois,
> > > On Mon, Apr 20, 2020 at 11:45:02AM +0000, Fran ois Ozog via TF-A
> > > wrote:
> > > > Hi,
> > > >
> > > > I am trying to identify a mechanism to enforce a form of two-way
> > > > isolation between BL33 runtime services in OS, for instance:
> > > > - a pair of 2MB areas that could be RO by one entity and RW by the
> > > other
> > > > - an execute only BL33 2MB area?
> > > Stupid Q! Are you referring to isolation between EFI runtime
> > > services and the
> > > OS?
> > > It is not clear what you mean by BL33 runtime services?
> > >
> > > Not a stupid Q. I concentrate effectively on EFI runtime but more
> > > generally this is the non-trusted firmware component that delivers
> > > runtime services to OS.
> > > (My flow is somewhat convoluted: TFA loads minimal Linux as BL33, Linux
> > > kexecs a UEFI reduced U-Boot (without drivers) which bootefi the
> > > distro).
> >
> > Thanks! I see and IIUC, this is about two separately provisioned SW
> > components that share an EL (EL1 in this case) at the same time in the
> > same image. We want component A to have permission X on a memory
> > region and component B to have permission Y on the same memory region.
> > If so, then this would require a cooperation between the two components?
> >
> Yes. Well cooperation is what happens today: Component A (UEFI compliant
> FW) tells component B not to use memory it occupies.
> I wish an EL(+n) component to make that a guarantee. Yet I don't want to
> have "virtualization".
>
> > I might be still missing the obvious but I am wondering how a SW
> > entity at a higher EL (Hypervisor in EL2 or TF-A in EL3) could create
> > and enforce the separation between the two components. It would not
> > have visibility of what is happening inside the EL at the very least.
>
> I hoped that by installing a page mapping "power play", we could enforce
> some policy.
> Performance here is not important because those data and context changes
> seldomly happen.
> I assume components A and B have a different mapping for the same "physical
> page":
> - EL1_A(VA)-> IA1; EL1_B(VA)->IA2
> - EL2(IA1) -> PA (RW), EL2(IA2)->PA(RO) or "not present"
> A collaboration between UEFI FW and EL2/3 would allow that to happen.
> A call to UEFI runtime service from SystemTable would result in a swap of
> TTBR1 (from EL1_B to EL1_A) so that execution can continue in UEFI.
> (I have no solution, just trying to check if we can find one).
>
HI Francois,
What you suggest is possible AFAICS, as you suggest, if you create 2 IPAs with corresponding VAs. Communication between the 2 would involve some shared memory and invoking EL2 to trigger the switch between the VAs. This is suited more for an EL2 design I think rather than EL3.
Best Regards
Soby Mathew
> >
> > cheers,
> > Achin
> >
> > >
> > > cheers,
> > > Achin
> > > >
> > > > This is similar to hypervisor except it only deals with memory, no
> > > > vCPU, no GIC virtualization...
> > > >
> > > > Could EL3 or EL2 install protective mappings ? BL33 could ask
> > > either
> > > > EL2 hypervisor or SecureMonitor to actually install them.
> > > >
> > > > Cordially,
> > > >
> > > > FF
> > > > --
> > > > TF-A mailing list
> > > > [2]TF-A(a)lists.trustedfirmware.org
> > > > [3]https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > > IMPORTANT NOTICE: The contents of this email and any attachments
> are
> > > confidential and may also be privileged. If you are not the intended
> > > recipient, please notify the sender immediately and do not disclose
> > > the contents to any other person, use it for any purpose, or store
> > > or copy the information in any medium. Thank you.
> > >
> > > --
> > > [uc?id=0BxTAygkus3RgQVhuNHMwUi1mYWc&export=download]
> > > Fran ois-Fr d ric Ozog | Director Linaro Edge & Fog Computing Group
> > > T: +33.67221.6485
> > > [4]francois.ozog(a)linaro.org | Skype: ffozog
> > >
> > > References
> > >
> > > 1. mailto:achin.gupta@arm.com
> > > 2. mailto:TF-A@lists.trustedfirmware.org
> > > 3. https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > > 4. mailto:francois.ozog@linaro.org
> > IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended recipient,
> please notify the sender immediately and do not disclose the contents to any
> other person, use it for any purpose, or store or copy the information in any
> medium. Thank you.
>
>
>
> --
> François-Frédéric Ozog | Director Linaro Edge & Fog Computing Group
> T: +33.67221.6485
> francois.ozog(a)linaro.org | Skype: ffozog
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Olivier and All,
Thank you so much for your help. It makes me understand the internals.
The next step, I need to check this event_num(804) register flow in kernel side, am I right?
BRs,
Bin Wu
------------------原始邮件 ------------------
发件人:TF-A <tf-a-bounces(a)lists.trustedfirmware.org>
发送时间:Tue Apr 21 09:51:49 2020
收件人:Raghu K via TF-A <tf-a(a)lists.trustedfirmware.org>
主题:Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Nice debug! Apart from the issue you pointed out, there is also the
issue with not checking the return code. The ras handler should really
be checking or panic'ing if there is an unexpected error code from
spm_sp_call and sdei_dispatch_event.
-Raghu
On 4/20/20 2:37 PM, Olivier Deprez via TF-A wrote:
> Hi Bin Wu,
>
> Here's an early observation. On receiving the RAS fiq interrupt the following occurs:
>
> ehf_el3_interrupt_handler => sgi_ras_intr_handler => spm_sp_call (enters/exit the SP to handle the injected RAS error) => sdei_dispatch_event
>
> se = get_event_entry(map);
> if (!can_sdei_state_trans(se, DO_DISPATCH))
> return -1;
>
> p *map
> $6 = {ev_num = 804, intr = 0, map_flags = 112, reg_count = 0, lock = {lock = 0}}
> p *se
> $4 = {ep = 0, arg = 0, affinity = 0, reg_flags = 0, state = 0 '\0'}
>
> sdei_dispatch_event exits in error at this stage, this does not seem a correct behavior.
> The SDEI handler is not called in NS world and context remains unchanged.
> The interrupt handler blindly returns to S-EL1 SP context at same location where it last exited.
> sgi_ras_intr_handler => ehf_el3_interrupt_handler => vector_entry fiq_aarch64 => el3_exit => re-enters the SP with X0=0xC4000061
> SP then exits but the EL3 context has not been setup for SP entry leading to crash.
>
> IMO there is an issue around mapping SDEI event number to RAS interrupt number leading to sdei_dispatch_event exiting early.
>
> Regards,
> Olivier.
>
>
> ________________________________________
> From: TF-A on behalf of Matteo Carlini via TF-A
> Sent: 14 April 2020 10:41
> To: 吴斌(郅隆); tf-a(a)lists.trustedfirmware.org; Thomas Abraham; Deepak Pandey
> Cc: nd
> Subject: Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
>
> Looping-in Thomas & Deepak, responsible for the RD-N1 landing team platforms releases. They might be able to help.
>
> Thanks
> Matteo
>
> From: TF-A On Behalf Of ??(??) via TF-A
> Sent: 14 April 2020 06:47
> To: TF-A ; Raghu Krishnamurthy via TF-A
> Subject: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
>
> Hi RagHu,
>
> Really appreciate your help.
>
> I was downloaded this software stack from git.linaro.org. This software stack include ATF, kernel, edk2 and so on.
> The user guide i used from linaro is:https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms…
>
> 1) What platform you are running on? Can this issue be reproduced
> outside your testing environment, perhaps on FVP or QEMU?
> A: I am running on ARM N1-Edge FVP platform. It can reproduced on this FVP platform.
>
> 2) What version of TF-A and StandaloneMM is being used? Preferably the
> commit-id, so that we can be sure we are looking at the same code.
> A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git tag:RD-INFRA-20191024-RC0
> StandloneMM seems build from edk2 & edk2-platform. so i just put edk2 and edk2-platform version information. if anything i missed, please let me know.
> edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git tag:RD-INFRA-20191024-RC0
> edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git tag:RD-INFRA-20191024-RC0
>
> 3) What version of the kernel and sdei driver is being used?
> A: kernel-release: https://git.linaro.org/landing-teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
> The sdei driver was included in kernel, do i need to provide sdei driver version? If need please let me know.
> 4) I can't tell from looking at the log but do you know if writing 0x123
> to sde_ras_poison causes a DMC620 interrupt or an SError or external
> abort through memory access ?
> A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error. So I am also not sure which exception type it will trigger.
>
> BRs,
> Bin Wu
>
> ------------------原始邮件 ------------------
> 发件人:TF-A >
> 发送时间:Tue Apr 14 01:25:47 2020
> 收件人:Raghu Krishnamurthy via TF-A >
> 主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
> Hello,
>
> >>Does BL31 need to send 0xC4000061 event to BL32 again?
>
> I don't think it will. It is really odd that
> 0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM handler.
> This is from looking at the upstream code quickly but it definitely
> depends on the platform you are running, what version of TF-A you are
> using, build options used. Is it possible that the unhandled exception
> is occurring after successful handling of the DMC620 error but there is
> a following issue that occurs right after, causing the crash?
> From the register dump it looks like there was an Instruction abort
> exception at address 0 while running in EL3. Something seems to have
> gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
> an instruction abort at address 0.
>
> >>Does current TF-A support to run RAS test? It seems BL31 will crash.
> See above. The answer really depends on the factors mentioned above.
>
> The following would be helpful to know:
> 1) What platform you are running on? Can this issue be reproduced
> outside your testing environment, perhaps on FVP or QEMU?
> 2) What version of TF-A and StandaloneMM is being used? Preferably the
> commit-id, so that we can be sure we are looking at the same code.
> 3) What version of the kernel and sdei driver is being used?
> 4) I can't tell from looking at the log but do you know if writing 0x123
> to sde_ras_poison causes a DMC620 interrupt or an SError or external
> abort through memory access ?
>
> Thanks
> Raghu
>
>
> On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
>> Dear Friends,
>>
>> I am using TF-A to test RAS feature.
>> When I triggered DMC620 RAS error in Linux(echo 0x123 >
>> /sys/kernel/debug/sdei_ras_poison).
>> BL32 will recieve
>> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally
>> BL31 crashed.
>>
>> In my understanding, this 0xC4000061 should consumed by BL31, not send
>> it to BL32 again.
>>
>> A piece of error log as below:
>>
>> *************************************
>>
>> CperWrite - CperAddress@0xFF610064
>> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
>> CperWrite - Got Error Section: Platform Memory.
>> MmEntryPoint Done
>> Received delegated event
>> X0 : 0xC4000061
>> X1 : 0x0
>> X2 : 0x0
>> X3 : 0x0
>> Received event - 0xC4000061 on cpu 0
>> UnRecognized Event - 0xC4000061
>> Failed delegated event 0xC4000061, Status 0x2
>> Unhandled Exception in EL3.
>> x30 = 0x0000000000000000
>> x0 = 0x00000000ff007e00
>> x1 = 0xfffffffffffffffe
>> x2 = 0x00000000600003c0
>> x3 = 0x0000000000000000
>> x4 = 0x0000000000000000
>> x5 = 0x0000000000000000
>> x6 = 0x00000000ff015080
>> x7 = 0x0000000000000000
>> x8 = 0x00000000c4000061
>> x9 = 0x0000000000000021
>> x10 = 0x0000000000000040
>> x11 = 0x00000000ff00f2b0
>> x12 = 0x00000000ff0118c0
>> x13 = 0x0000000000000002
>> x14 = 0x00000000ff016b70
>> x15 = 0x00000000ff003f20
>> x16 = 0x0000000000000044
>> x17 = 0x00000000ff010430
>> x18 = 0x0000000000000e3c
>> x19 = 0x0000000000000000
>> More error log please refer to attachment.
>>
>> My question is,
>> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
>> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
>>
>> Appreciate your help.
>>
>> BRs,
>> Bin Wu
>>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
My view is that smaller patches are easier to review and we should try to break up the patches to logical chucks where possible. I haven't taken a look at the patches myself but I am sure there will be ways to break it up for ease of review.
Best Regards
Soby Mathew
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu
> Krishnamurthy via TF-A
> Sent: 20 April 2020 18:09
> To: Alexei Fedorov <Alexei.Fedorov(a)arm.com>; tf-a(a)lists.trustedfirmware.org
> Subject: Re: [TF-A] Event Log for Measured Boot
>
> Fair enough. I have no doubt it was tested. It is just extremely difficult to review
> such patches and I disagree with your statement.
> There is almost always a way to split patches up by using feature flags for
> example, that will help with not breaking the build. You can test them all
> together once you have all the patches. I also think it is perfectly reasonable to
> say measured boot cannot be turned on until a certain commit id present.
> However, if you think this is the right approach, i have no issues.
>
> Thanks
> Raghu
>
> On 4/20/20 8:44 AM, Alexei Fedorov wrote:
> > Hi Raghu and Varun,
> >
> > This patch is a complete, tested and verified reference implementation
> > for FVP platform.
> > Splitting it will create a set of separate non-buildable patches
> > causing more complexity in following and understanding the code
> > changes and dependencies.
> > The whole patch with all the code present in it should be reviewed
> > anyway, and the time spent will be less than the time used for
> > reviewing separate patches (mass defect).
> >
> > Alexei
> >
> > ----------------------------------------------------------------------
> > --
> > *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of
> > Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
> > *Sent:* 02 April 2020 05:11
> > *To:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
> > *Subject:* Re: [TF-A] Event Log for Measured Boot Hi Alexei,
> >
> > I second Varun on this. The patch is huge. I recommend breaking it up
> > into multiple commits. I've reviewed it but since it is a large patch,
> > it might require a few more sittings to grasp all the changes(which
> > also means there may be some stupid review comments :)).
> >
> > -Raghu
> >
> > On 3/31/20 10:28 AM, Varun Wadekar via TF-A wrote:
> >> Hello Alexei,
> >>
> >> Just curious, the patch is huge and will take some time to review. Do
> >> you expect this change to be merged before the v2.3 release?
> >>
> >> -Varun
> >>
> >> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> *On Behalf Of
> >> *Alexei Fedorov via TF-A
> >> *Sent:* Tuesday, March 31, 2020 7:19 AM
> >> *To:* tf-a(a)lists.trustedfirmware.org
> >> *Subject:* [TF-A] Event Log for Measured Boot
> >>
> >> *External email: Use caution opening links or attachments*
> >>
> >> Hi,
> >>
> >> Please review and provide your comments for the patch which adds
> >>
> >> Event Log generation for the Measured Boot.
> >>
> >> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3806
> >>
> >> Thanks.
> >>
> >> Alexei
> >>
> >> IMPORTANT NOTICE: The contents of this email and any attachments are
> >> confidential and may also be privileged. If you are not the intended
> >> recipient, please notify the sender immediately and do not disclose
> >> the contents to any other person, use it for any purpose, or store or
> >> copy the information in any medium. Thank you.
> >>
> >> ---------------------------------------------------------------------
> >> --- This email message is for the sole use of the intended
> >> recipient(s) and may contain confidential information. Any
> >> unauthorized review, use, disclosure or distribution is prohibited.
> >> If you are not the intended recipient, please contact the sender by
> >> reply email and destroy all copies of the original message.
> >> ---------------------------------------------------------------------
> >> ---
> >>
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > IMPORTANT NOTICE: The contents of this email and any attachments are
> > confidential and may also be privileged. If you are not the intended
> > recipient, please notify the sender immediately and do not disclose
> > the contents to any other person, use it for any purpose, or store or
> > copy the information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Nice debug! Apart from the issue you pointed out, there is also the
issue with not checking the return code. The ras handler should really
be checking or panic'ing if there is an unexpected error code from
spm_sp_call and sdei_dispatch_event.
-Raghu
On 4/20/20 2:37 PM, Olivier Deprez via TF-A wrote:
> Hi Bin Wu,
>
> Here's an early observation. On receiving the RAS fiq interrupt the following occurs:
>
> ehf_el3_interrupt_handler => sgi_ras_intr_handler => spm_sp_call (enters/exit the SP to handle the injected RAS error) => sdei_dispatch_event
>
> se = get_event_entry(map);
> if (!can_sdei_state_trans(se, DO_DISPATCH))
> return -1;
>
> p *map
> $6 = {ev_num = 804, intr = 0, map_flags = 112, reg_count = 0, lock = {lock = 0}}
> p *se
> $4 = {ep = 0, arg = 0, affinity = 0, reg_flags = 0, state = 0 '\0'}
>
> sdei_dispatch_event exits in error at this stage, this does not seem a correct behavior.
> The SDEI handler is not called in NS world and context remains unchanged.
> The interrupt handler blindly returns to S-EL1 SP context at same location where it last exited.
> sgi_ras_intr_handler => ehf_el3_interrupt_handler => vector_entry fiq_aarch64 => el3_exit => re-enters the SP with X0=0xC4000061
> SP then exits but the EL3 context has not been setup for SP entry leading to crash.
>
> IMO there is an issue around mapping SDEI event number to RAS interrupt number leading to sdei_dispatch_event exiting early.
>
> Regards,
> Olivier.
>
>
> ________________________________________
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Matteo Carlini via TF-A <tf-a(a)lists.trustedfirmware.org>
> Sent: 14 April 2020 10:41
> To: 吴斌(郅隆); tf-a(a)lists.trustedfirmware.org; Thomas Abraham; Deepak Pandey
> Cc: nd
> Subject: Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
>
> Looping-in Thomas & Deepak, responsible for the RD-N1 landing team platforms releases. They might be able to help.
>
> Thanks
> Matteo
>
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of ??(??) via TF-A
> Sent: 14 April 2020 06:47
> To: TF-A <tf-a-bounces(a)lists.trustedfirmware.org>; Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
> Subject: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
>
> Hi RagHu,
>
> Really appreciate your help.
>
> I was downloaded this software stack from git.linaro.org. This software stack include ATF, kernel, edk2 and so on.
> The user guide i used from linaro is:https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms…
>
> 1) What platform you are running on? Can this issue be reproduced
> outside your testing environment, perhaps on FVP or QEMU?
> A: I am running on ARM N1-Edge FVP platform. It can reproduced on this FVP platform.
>
> 2) What version of TF-A and StandaloneMM is being used? Preferably the
> commit-id, so that we can be sure we are looking at the same code.
> A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git tag:RD-INFRA-20191024-RC0
> StandloneMM seems build from edk2 & edk2-platform. so i just put edk2 and edk2-platform version information. if anything i missed, please let me know.
> edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git<https://git.linaro.org/landing-teams/working/arm/edk2.git/> tag:RD-INFRA-20191024-RC0
> edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git<https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git/> tag:RD-INFRA-20191024-RC0
>
> 3) What version of the kernel and sdei driver is being used?
> A: kernel-release: https://git.linaro.org/landing-teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
> The sdei driver was included in kernel, do i need to provide sdei driver version? If need please let me know.
> 4) I can't tell from looking at the log but do you know if writing 0x123
> to sde_ras_poison causes a DMC620 interrupt or an SError or external
> abort through memory access ?
> A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error. So I am also not sure which exception type it will trigger.
>
> BRs,
> Bin Wu
>
> ------------------原始邮件 ------------------
> 发件人:TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>>
> 发送时间:Tue Apr 14 01:25:47 2020
> 收件人:Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
> 主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
> Hello,
>
> >>Does BL31 need to send 0xC4000061 event to BL32 again?
>
> I don't think it will. It is really odd that
> 0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM handler.
> This is from looking at the upstream code quickly but it definitely
> depends on the platform you are running, what version of TF-A you are
> using, build options used. Is it possible that the unhandled exception
> is occurring after successful handling of the DMC620 error but there is
> a following issue that occurs right after, causing the crash?
> From the register dump it looks like there was an Instruction abort
> exception at address 0 while running in EL3. Something seems to have
> gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
> an instruction abort at address 0.
>
> >>Does current TF-A support to run RAS test? It seems BL31 will crash.
> See above. The answer really depends on the factors mentioned above.
>
> The following would be helpful to know:
> 1) What platform you are running on? Can this issue be reproduced
> outside your testing environment, perhaps on FVP or QEMU?
> 2) What version of TF-A and StandaloneMM is being used? Preferably the
> commit-id, so that we can be sure we are looking at the same code.
> 3) What version of the kernel and sdei driver is being used?
> 4) I can't tell from looking at the log but do you know if writing 0x123
> to sde_ras_poison causes a DMC620 interrupt or an SError or external
> abort through memory access ?
>
> Thanks
> Raghu
>
>
> On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
>> Dear Friends,
>>
>> I am using TF-A to test RAS feature.
>> When I triggered DMC620 RAS error in Linux(echo 0x123 >
>> /sys/kernel/debug/sdei_ras_poison).
>> BL32 will recieve
>> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally
>> BL31 crashed.
>>
>> In my understanding, this 0xC4000061 should consumed by BL31, not send
>> it to BL32 again.
>>
>> A piece of error log as below:
>>
>> *************************************
>>
>> CperWrite - CperAddress@0xFF610064
>> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
>> CperWrite - Got Error Section: Platform Memory.
>> MmEntryPoint Done
>> Received delegated event
>> X0 : 0xC4000061
>> X1 : 0x0
>> X2 : 0x0
>> X3 : 0x0
>> Received event - 0xC4000061 on cpu 0
>> UnRecognized Event - 0xC4000061
>> Failed delegated event 0xC4000061, Status 0x2
>> Unhandled Exception in EL3.
>> x30 = 0x0000000000000000
>> x0 = 0x00000000ff007e00
>> x1 = 0xfffffffffffffffe
>> x2 = 0x00000000600003c0
>> x3 = 0x0000000000000000
>> x4 = 0x0000000000000000
>> x5 = 0x0000000000000000
>> x6 = 0x00000000ff015080
>> x7 = 0x0000000000000000
>> x8 = 0x00000000c4000061
>> x9 = 0x0000000000000021
>> x10 = 0x0000000000000040
>> x11 = 0x00000000ff00f2b0
>> x12 = 0x00000000ff0118c0
>> x13 = 0x0000000000000002
>> x14 = 0x00000000ff016b70
>> x15 = 0x00000000ff003f20
>> x16 = 0x0000000000000044
>> x17 = 0x00000000ff010430
>> x18 = 0x0000000000000e3c
>> x19 = 0x0000000000000000
>> More error log please refer to attachment.
>>
>> My question is,
>> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
>> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
>>
>> Appreciate your help.
>>
>> BRs,
>> Bin Wu
>>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Bin Wu,
Here's an early observation. On receiving the RAS fiq interrupt the following occurs:
ehf_el3_interrupt_handler => sgi_ras_intr_handler => spm_sp_call (enters/exit the SP to handle the injected RAS error) => sdei_dispatch_event
se = get_event_entry(map);
if (!can_sdei_state_trans(se, DO_DISPATCH))
return -1;
p *map
$6 = {ev_num = 804, intr = 0, map_flags = 112, reg_count = 0, lock = {lock = 0}}
p *se
$4 = {ep = 0, arg = 0, affinity = 0, reg_flags = 0, state = 0 '\0'}
sdei_dispatch_event exits in error at this stage, this does not seem a correct behavior.
The SDEI handler is not called in NS world and context remains unchanged.
The interrupt handler blindly returns to S-EL1 SP context at same location where it last exited.
sgi_ras_intr_handler => ehf_el3_interrupt_handler => vector_entry fiq_aarch64 => el3_exit => re-enters the SP with X0=0xC4000061
SP then exits but the EL3 context has not been setup for SP entry leading to crash.
IMO there is an issue around mapping SDEI event number to RAS interrupt number leading to sdei_dispatch_event exiting early.
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Matteo Carlini via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 14 April 2020 10:41
To: 吴斌(郅隆); tf-a(a)lists.trustedfirmware.org; Thomas Abraham; Deepak Pandey
Cc: nd
Subject: Re: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Looping-in Thomas & Deepak, responsible for the RD-N1 landing team platforms releases. They might be able to help.
Thanks
Matteo
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of ??(??) via TF-A
Sent: 14 April 2020 06:47
To: TF-A <tf-a-bounces(a)lists.trustedfirmware.org>; Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Hi RagHu,
Really appreciate your help.
I was downloaded this software stack from git.linaro.org. This software stack include ATF, kernel, edk2 and so on.
The user guide i used from linaro is:https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms…
1) What platform you are running on? Can this issue be reproduced
outside your testing environment, perhaps on FVP or QEMU?
A: I am running on ARM N1-Edge FVP platform. It can reproduced on this FVP platform.
2) What version of TF-A and StandaloneMM is being used? Preferably the
commit-id, so that we can be sure we are looking at the same code.
A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git tag:RD-INFRA-20191024-RC0
StandloneMM seems build from edk2 & edk2-platform. so i just put edk2 and edk2-platform version information. if anything i missed, please let me know.
edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git<https://git.linaro.org/landing-teams/working/arm/edk2.git/> tag:RD-INFRA-20191024-RC0
edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git<https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git/> tag:RD-INFRA-20191024-RC0
3) What version of the kernel and sdei driver is being used?
A: kernel-release: https://git.linaro.org/landing-teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
The sdei driver was included in kernel, do i need to provide sdei driver version? If need please let me know.
4) I can't tell from looking at the log but do you know if writing 0x123
to sde_ras_poison causes a DMC620 interrupt or an SError or external
abort through memory access ?
A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error. So I am also not sure which exception type it will trigger.
BRs,
Bin Wu
------------------原始邮件 ------------------
发件人:TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>>
发送时间:Tue Apr 14 01:25:47 2020
收件人:Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Hello,
>>Does BL31 need to send 0xC4000061 event to BL32 again?
I don't think it will. It is really odd that
0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM handler.
This is from looking at the upstream code quickly but it definitely
depends on the platform you are running, what version of TF-A you are
using, build options used. Is it possible that the unhandled exception
is occurring after successful handling of the DMC620 error but there is
a following issue that occurs right after, causing the crash?
From the register dump it looks like there was an Instruction abort
exception at address 0 while running in EL3. Something seems to have
gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
an instruction abort at address 0.
>>Does current TF-A support to run RAS test? It seems BL31 will crash.
See above. The answer really depends on the factors mentioned above.
The following would be helpful to know:
1) What platform you are running on? Can this issue be reproduced
outside your testing environment, perhaps on FVP or QEMU?
2) What version of TF-A and StandaloneMM is being used? Preferably the
commit-id, so that we can be sure we are looking at the same code.
3) What version of the kernel and sdei driver is being used?
4) I can't tell from looking at the log but do you know if writing 0x123
to sde_ras_poison causes a DMC620 interrupt or an SError or external
abort through memory access ?
Thanks
Raghu
On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
> Dear Friends,
>
> I am using TF-A to test RAS feature.
> When I triggered DMC620 RAS error in Linux(echo 0x123 >
> /sys/kernel/debug/sdei_ras_poison).
> BL32 will recieve
> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally
> BL31 crashed.
>
> In my understanding, this 0xC4000061 should consumed by BL31, not send
> it to BL32 again.
>
> A piece of error log as below:
>
> *************************************
>
> CperWrite - CperAddress@0xFF610064
> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
> CperWrite - Got Error Section: Platform Memory.
> MmEntryPoint Done
> Received delegated event
> X0 : 0xC4000061
> X1 : 0x0
> X2 : 0x0
> X3 : 0x0
> Received event - 0xC4000061 on cpu 0
> UnRecognized Event - 0xC4000061
> Failed delegated event 0xC4000061, Status 0x2
> Unhandled Exception in EL3.
> x30 = 0x0000000000000000
> x0 = 0x00000000ff007e00
> x1 = 0xfffffffffffffffe
> x2 = 0x00000000600003c0
> x3 = 0x0000000000000000
> x4 = 0x0000000000000000
> x5 = 0x0000000000000000
> x6 = 0x00000000ff015080
> x7 = 0x0000000000000000
> x8 = 0x00000000c4000061
> x9 = 0x0000000000000021
> x10 = 0x0000000000000040
> x11 = 0x00000000ff00f2b0
> x12 = 0x00000000ff0118c0
> x13 = 0x0000000000000002
> x14 = 0x00000000ff016b70
> x15 = 0x00000000ff003f20
> x16 = 0x0000000000000044
> x17 = 0x00000000ff010430
> x18 = 0x0000000000000e3c
> x19 = 0x0000000000000000
> More error log please refer to attachment.
>
> My question is,
> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
>
> Appreciate your help.
>
> BRs,
> Bin Wu
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi all,
Trusted Firmware-A and TF-A tests version 2.3 is now available and can be found here:
TF-A:
https://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/tag/?h=v2.3
TF-A-tests:
https://git.trustedfirmware.org/TF-A/tf-a-tests.git/tag/?h=v2.3
Please refer to the readme and change log for further information.
Thanks & best regards,
[cid:image001.jpg@01D6170F.64702DF0]
Bipin Ravi | Principal Design Engineer
Bipin.Ravi(a)arm.com<mailto:Bipin.Ravi@arm.com> | Mobile: +1-214-212-0794
5707 Southwest Parkway, Suite 100, Austin, TX 78735
Hi Raghu and Varun,
This patch is a complete, tested and verified reference implementation for FVP platform.
Splitting it will create a set of separate non-buildable patches causing more complexity in following
and understanding the code changes and dependencies.
The whole patch with all the code present in it should be reviewed anyway, and the time spent will be less
than the time used for reviewing separate patches (mass defect).
Alexei
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 02 April 2020 05:11
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Event Log for Measured Boot
Hi Alexei,
I second Varun on this. The patch is huge. I recommend breaking it up
into multiple commits. I've reviewed it but since it is a large patch,
it might require a few more sittings to grasp all the changes(which also
means there may be some stupid review comments :)).
-Raghu
On 3/31/20 10:28 AM, Varun Wadekar via TF-A wrote:
> Hello Alexei,
>
> Just curious, the patch is huge and will take some time to review. Do
> you expect this change to be merged before the v2.3 release?
>
> -Varun
>
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> *On Behalf Of
> *Alexei Fedorov via TF-A
> *Sent:* Tuesday, March 31, 2020 7:19 AM
> *To:* tf-a(a)lists.trustedfirmware.org
> *Subject:* [TF-A] Event Log for Measured Boot
>
> *External email: Use caution opening links or attachments*
>
> Hi,
>
> Please review and provide your comments for the patch which adds
>
> Event Log generation for the Measured Boot.
>
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3806
>
> Thanks.
>
> Alexei
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy
> the information in any medium. Thank you.
>
> ------------------------------------------------------------------------
> This email message is for the sole use of the intended recipient(s) and
> may contain confidential information. Any unauthorized review, use,
> disclosure or distribution is prohibited. If you are not the intended
> recipient, please contact the sender by reply email and destroy all
> copies of the original message.
> ------------------------------------------------------------------------
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi,
If buffers are to be consumed by NWd only, it's probably better to contain the isolation at NS-EL2 (through Stage-2 MMU mapping).
Though from your statements I'm not clear if you wish to use an hypervisor, or not?
If yes, which implementation or kind do you want to use?
If not, I wonder if you could re-use OS facilities like shared mem with different permissions for two child processes (might be tricky)?
I don't think execute-only regions exist in Cortex-A (unless implementing additional hardware). If executable it's probably also readable. Maybe you meant execute-never?
Regards,
Olivier.
________________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 20 April 2020 13:45
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] [RFC] isolation between runtime BL33 services and OS
Hi,
I am trying to identify a mechanism to enforce a form of two-way
isolation between BL33 runtime services in OS, for instance:
- a pair of 2MB areas that could be RO by one entity and RW by the other
- an execute only BL33 2MB area?
This is similar to hypervisor except it only deals with memory, no
vCPU, no GIC virtualization...
Could EL3 or EL2 install protective mappings ? BL33 could ask either
EL2 hypervisor or SecureMonitor to actually install them.
Cordially,
FF
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi,
I am trying to identify a mechanism to enforce a form of two-way
isolation between BL33 runtime services in OS, for instance:
- a pair of 2MB areas that could be RO by one entity and RW by the other
- an execute only BL33 2MB area?
This is similar to hypervisor except it only deals with memory, no
vCPU, no GIC virtualization...
Could EL3 or EL2 install protective mappings ? BL33 could ask either
EL2 hypervisor or SecureMonitor to actually install them.
Cordially,
FF
Hi,
As part of integrating Hafnium within Trusted Firmware projects, a new mailing list has been created:
https://lists.trustedfirmware.org/mailman/listinfo/hafnium
You can register this list to participate to Hafnium in general, and coming S-EL2 firmware design discussions.
Regards,
Olivier.
Hi @François<mailto:francois.ozog@linaro.org>,
<quote>
Now, I changed U-Boot to Image, added code to ensure arg0 is 0 (DTB) but Linux does not start (zero printk visible).
I don't find kernel text base anymore, may be it disappeared: any suggestion to get the kernel start when loaded at 64KB offset?
the kernel image with embedded initrd is 10MB, SRAM is at 64MB so there should be enough space to decompress initrd...
</quote>
I recommend reading through the arm64 Linux booting requirements if you haven’t already; you’ll need to ensure all of those conditions are met before entering the kernel [1].
For example have you correctly set text_offset in the image header?
<quote>
u32 code0; /* Executable code */
u32 code1; /* Executable code */
u64 text_offset; /* Image load offset, little endian */
u64 image_size; /* Effective Image size, little endian */
u64 flags; /* kernel flags, little endian */
u64 res2 = 0; /* reserved */
u64 res3 = 0; /* reserved */
u64 res4 = 0; /* reserved */
u32 magic = 0x644d5241; /* Magic number, little endian, "ARM\x64" */
u32 res5; /* reserved (used for PE COFF offset) */
</quote>
<quote>
The Image must be placed text_offset bytes from a 2MB aligned base address anywhere in usable system RAM and called there.
</quote>
Kind regards,
Ash.
[1] https://elixir.bootlin.com/linux/latest/source/Documentation/arm64/booting.…
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Feng,
This is standard practice for operating systems, hypervisors, and firmware running on Armv8-A systems. A key distinction between SPSel,#0 and SPSel,#1 is that you can tell which stack pointer you were using when you took an exception as they correspond to different offsets in the vector table. Often times, taking an exception from the same EL when using SPSel,#0 is non-terminal whereas taking an exception from the same EL when already using SPSel,#1 is considered terminal.
Take for example the scenario where your operating system, hypervisor, or firmware is running some task/thread code at EL1/EL2/EL3 and runs out of stack space, triggering a translation fault and attempting to stack some data (we’ll probably be using unmapped guard pages at the stack boundaries). The first thing the exception handler will try to do is stack the GPRs. If the reason you took the exception is because the stack pointed to by SP_EL1/2/3 has itself overflowed, this attempt to stack the GPRs will itself cause a translation fault and you’ll get stuck in a recursive exception.
In contrast, if the reason you took the exception is because the stack pointed to by SP_EL0 has overflowed, the exception handler will successfully stack the GPRs to the SP_EL1/2/3 stack and be able to diagnose + log what went wrong before rebooting gracefully.
Hope that helps,
Ash.
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Chen Feng via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Chen Feng <puck.chen(a)hisilicon.com>
Date: Friday, 17 April 2020 at 09:02
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>, Alexei Fedorov <Alexei.Fedorov(a)arm.com>, Yatharth Kochar <Yatharth.Kochar(a)arm.com>, Sandrine Bailleux <Sandrine.Bailleux(a)arm.com>
Cc: "puck.chen(a)hisilicon.com" <puck.chen(a)hisilicon.com>, "lizhong11(a)hisilicon.com" <lizhong11(a)hisilicon.com>
Subject: [TF-A] sp select in atf
Hello all,
I see the atf use different sp, and special for smc64 it use the sp_el0.
So for the unhandled-exception handler, it must switch to sp_el0 to do
the back-trace-dump. Since it default used sp_el3 when exception happen.
My question here is why using different sp in atf code? Just use the
sp_el3 for all scenes seems more simpler.
Cheers,
- feng
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hello all,
I see the atf use different sp, and special for smc64 it use the sp_el0.
So for the unhandled-exception handler, it must switch to sp_el0 to do
the back-trace-dump. Since it default used sp_el3 when exception happen.
My question here is why using different sp in atf code? Just use the
sp_el3 for all scenes seems more simpler.
Cheers,
- feng
As of now ARM_LINUX_KERNEL_AS_BL33 is only supported when RESET_TO_BL31=1, along with it you need to pass PRELOADED_BL33_BASE as well as ARM_PRELOADED_DTB_BASE.
AFAIK This feature is not tested for platforms which uses all the BL(1/2/31) stages from TF-A . The most likely reason for this is loading and authentication of Linux Image.
BL2 which is responsible for loading of various images, does not have support to load linux image.
With platforms having RESET_TO_BL31, TF-A relies on prior loader which loads kernel and device tree blobs at respective address.
In short, if your platform has RESET_TO_BL31=1, it will be quite easy else you need to understand the BL2 loading mechanism and see if you can extend it for loading Linux and DTB.
Kernel Output format zImage/Image should work.
Hope this helps!
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of François Ozog via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 15 April 2020 13:31
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Linux as BL33
I want to use Linux as BL33 on a Marvell Macchiatobin.
Currently I have the successful boot flow:
TFA (mainline v2.2) -> U-Boot (Mainline 2020.04rc5) -> Kernel (5.6.3)
with U-root initrd (6.0.0, https://github.com/u-root/u-root ) ->
Ubuntu 19.10
The 5.6.3 "intermediary" kernel is 5.5MB uncompressed , u-root initrd
is 3.5MB compressed (some form of golang based busybox).
I was pointed to the ARM_LINUX_KERNEL_AS_BL33 option which is not
supported on the Macchiatobin.
It does not look too difficult to add, but I'd like to have some
feedback/guidance on how to do it:
- how to add the option to the TFA platform
- how to generate a usable kernel (compile options? non relocatable
kernel? output format, i.e. Image, zImage, uImage...)
Thanks for your help
-FF
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
+Harb
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Vivek Prasad via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: Thursday, April 16, 2020 10:19 AM
To: Stuart Yoder <stuart.yoder(a)arm.com>; Alexei Fedorov <Alexei.Fedorov(a)arm.com>; tf-a <tf-a(a)lists.trustedfirmware.org>; Raghu Krishnamurthy <raghu.ncstate(a)icloud.com>
Cc: Loc Ho <loc.ho(a)amperecomputing.com>; Vivek Kumar <vivek(a)amperecomputing.com>; Benjamin Chaffin <bchaffin(a)amperecomputing.com>; Ard Biesheuvel <Ard.Biesheuvel(a)arm.com>; Mohamad Ammar <moe(a)amperecomputing.com>; Charles Garcia-Tobin <Charles.Garcia-Tobin(a)arm.com>
Subject: Re: [TF-A] Proposal for Measured Boot Implementation
Hello Stuart, Alexei,
Chiming-in here on Ampere's behalf...
We analysed this proposal internally. And we see a number issues with this, some of which was already raised by Raghu in the previous threads.
Here is a summary of the main issues that we see.
* Only supporting mbedtls, and this is fixed config at compile time.
* We propose that there should be a variable for the algorithm to be used, which can be setup at initialization time.
* This solution relies on taking the hash directly from the digest as the measurement, instead of the computed hash. This is not safe, especially considering measured boot may use a different hash bank, so digest hash may not be correct/valid.
* Only measuring the BL2 image, per the ARM SBSG we must be measuring and logging *all* images/boot phases
* BL31
* BL32 (all secure partitions)
* BL33 (UEFI or any other non-secure boot loader)
* Once we ERET into BL33, the measure boot flow continues and is owned by that boot loader
* Only see support for PCR0, any/all unsigned config data must be logged to PCR1.
* Passing PCRs to non-secure software before logging is not compliant with TCG Static-Root-of-Trust Measurement (SRTM) requirements
* It was discussed before in separate conversations… especially in systems where you are talked about two different signing domains where BL33 is a different trust/signing domain.
* BL33 should only do hash-log-extend… there is no need for BL33 to be aware of the current PCR value (beyond what is provided in the boot event log).
* Based on comments on the mail thread, there seem to be bad assumptions/expectations around TPM accessibility from non-secure world.
* Expecting SPI/I2C TPMs to be directly accessed from non-secure world instead of abstracting hardware details via the TCG CRB interface (which has been already standardized as the defacto mechanism for ARM on past mobile, client, and server solutions).
* CRB will "just work" for Aptio/EDK2/Linux/Windows/Hyper-V/VMWare
* NOTE: This goes back to what is a “productizable” TPM solution. We want it to be turn-key solution for customers without having to support/develop proprietary drivers.
-Vivek/Harb
Hi all,
Thanks to all who have commented on this proposal so far. I've edited
the original document to try and incorporate all feedback gathered so
far (through the TSC meeting, this email thread and the TF-A tech call).
Please have another look and flag anything I might have missed:
https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…
The major changes are:
== Removed concept of self-review ==
This is proving too controversial, several people do not want to allow
self-review.
Roles of maintainer and code owner are still cumulative but cannot be
both exercised for the same patch.
The exact method of dealing with review bottleneck is still to be
decided. In addition to the current proposal of increasing the
maintainers pool, the most popular alternatives mentioned so far are:
- Set a minimum wait time for feedback before a patch can be merged
without any further delay.
- Mandate distinct reviewers for a patch.
== Enhanced the section "Patch contribution Guidelines" ==
Mentioned that patches should be small, on-topic, with comprehensive
commit messages.
== Added a note about how to deal with disagreement ==
If reviewers cannot find a common ground, the proposal is to call out a
3rd-party maintainer.
== Removed "out-of-date" platform state ==
Squashed it into "limited support" to reduce the number of states.
== Removed "orphan" state from platform support life cycle ==
This concept is orthogonal to the level of functionality.
Added a note in the "Code Owner" section instead.
== Per-project guidelines as a complementary document ==
Added a list of things that it would typically cover.
== Added requirement on fully supported platforms to document the
features they support ==
== Added todo mentioning that the proposal might cover branching
strategies in the future ==
The full diff may be seen here:
https://developer.trustedfirmware.org/phriction/diff/73/?l=4&r=5
This proposal is still open for discussion at this stage and further
feedback is most welcome!
Regards,
Sandrine
I want to use Linux as BL33 on a Marvell Macchiatobin.
Currently I have the successful boot flow:
TFA (mainline v2.2) -> U-Boot (Mainline 2020.04rc5) -> Kernel (5.6.3)
with U-root initrd (6.0.0, https://github.com/u-root/u-root ) ->
Ubuntu 19.10
The 5.6.3 "intermediary" kernel is 5.5MB uncompressed , u-root initrd
is 3.5MB compressed (some form of golang based busybox).
I was pointed to the ARM_LINUX_KERNEL_AS_BL33 option which is not
supported on the Macchiatobin.
It does not look too difficult to add, but I'd like to have some
feedback/guidance on how to do it:
- how to add the option to the TFA platform
- how to generate a usable kernel (compile options? non relocatable
kernel? output format, i.e. Image, zImage, uImage...)
Thanks for your help
-FF
Looping-in Thomas & Deepak, responsible for the RD-N1 landing team platforms releases. They might be able to help.
Thanks
Matteo
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of ??(??) via TF-A
Sent: 14 April 2020 06:47
To: TF-A <tf-a-bounces(a)lists.trustedfirmware.org>; Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] 回复:Re: [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Hi RagHu,
Really appreciate your help.
I was downloaded this software stack from git.linaro.org. This software stack include ATF, kernel, edk2 and so on.
The user guide i used from linaro is:https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms…
1) What platform you are running on? Can this issue be reproduced
outside your testing environment, perhaps on FVP or QEMU?
A: I am running on ARM N1-Edge FVP platform. It can reproduced on this FVP platform.
2) What version of TF-A and StandaloneMM is being used? Preferably the
commit-id, so that we can be sure we are looking at the same code.
A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git tag:RD-INFRA-20191024-RC0
StandloneMM seems build from edk2 & edk2-platform. so i just put edk2 and edk2-platform version information. if anything i missed, please let me know.
edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git<https://git.linaro.org/landing-teams/working/arm/edk2.git/> tag:RD-INFRA-20191024-RC0
edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git<https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git/> tag:RD-INFRA-20191024-RC0
3) What version of the kernel and sdei driver is being used?
A: kernel-release: https://git.linaro.org/landing-teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
The sdei driver was included in kernel, do i need to provide sdei driver version? If need please let me know.
4) I can't tell from looking at the log but do you know if writing 0x123
to sde_ras_poison causes a DMC620 interrupt or an SError or external
abort through memory access ?
A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error. So I am also not sure which exception type it will trigger.
BRs,
Bin Wu
------------------原始邮件 ------------------
发件人:TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>>
发送时间:Tue Apr 14 01:25:47 2020
收件人:Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Hello,
>>Does BL31 need to send 0xC4000061 event to BL32 again?
I don't think it will. It is really odd that
0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM handler.
This is from looking at the upstream code quickly but it definitely
depends on the platform you are running, what version of TF-A you are
using, build options used. Is it possible that the unhandled exception
is occurring after successful handling of the DMC620 error but there is
a following issue that occurs right after, causing the crash?
From the register dump it looks like there was an Instruction abort
exception at address 0 while running in EL3. Something seems to have
gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
an instruction abort at address 0.
>>Does current TF-A support to run RAS test? It seems BL31 will crash.
See above. The answer really depends on the factors mentioned above.
The following would be helpful to know:
1) What platform you are running on? Can this issue be reproduced
outside your testing environment, perhaps on FVP or QEMU?
2) What version of TF-A and StandaloneMM is being used? Preferably the
commit-id, so that we can be sure we are looking at the same code.
3) What version of the kernel and sdei driver is being used?
4) I can't tell from looking at the log but do you know if writing 0x123
to sde_ras_poison causes a DMC620 interrupt or an SError or external
abort through memory access ?
Thanks
Raghu
On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
> Dear Friends,
>
> I am using TF-A to test RAS feature.
> When I triggered DMC620 RAS error in Linux(echo 0x123 >
> /sys/kernel/debug/sdei_ras_poison).
> BL32 will recieve
> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally
> BL31 crashed.
>
> In my understanding, this 0xC4000061 should consumed by BL31, not send
> it to BL32 again.
>
> A piece of error log as below:
>
> *************************************
>
> CperWrite - CperAddress@0xFF610064
> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
> CperWrite - Got Error Section: Platform Memory.
> MmEntryPoint Done
> Received delegated event
> X0 : 0xC4000061
> X1 : 0x0
> X2 : 0x0
> X3 : 0x0
> Received event - 0xC4000061 on cpu 0
> UnRecognized Event - 0xC4000061
> Failed delegated event 0xC4000061, Status 0x2
> Unhandled Exception in EL3.
> x30 = 0x0000000000000000
> x0 = 0x00000000ff007e00
> x1 = 0xfffffffffffffffe
> x2 = 0x00000000600003c0
> x3 = 0x0000000000000000
> x4 = 0x0000000000000000
> x5 = 0x0000000000000000
> x6 = 0x00000000ff015080
> x7 = 0x0000000000000000
> x8 = 0x00000000c4000061
> x9 = 0x0000000000000021
> x10 = 0x0000000000000040
> x11 = 0x00000000ff00f2b0
> x12 = 0x00000000ff0118c0
> x13 = 0x0000000000000002
> x14 = 0x00000000ff016b70
> x15 = 0x00000000ff003f20
> x16 = 0x0000000000000044
> x17 = 0x00000000ff010430
> x18 = 0x0000000000000e3c
> x19 = 0x0000000000000000
> More error log please refer to attachment.
>
> My question is,
> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
>
> Appreciate your help.
>
> BRs,
> Bin Wu
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org<mailto:TF-A@lists.trustedfirmware.org>
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi RagHu,
Really appreciate your help.
I was downloaded this software stack from git.linaro.org. This software stack include ATF, kernel, edk2 and so on.
The user guide i used from linaro is:https://git.linaro.org/landing-teams/working/arm/arm-reference-platforms…
1) What platform you are running on? Can this issue be reproduced
outside your testing environment, perhaps on FVP or QEMU?
A: I am running on ARM N1-Edge FVP platform. It can reproduced on this FVP platform.
2) What version of TF-A and StandaloneMM is being used? Preferably the
commit-id, so that we can be sure we are looking at the same code.
A: TF-A: https://git.linaro.org/landing-teams/working/arm/arm-tf.git tag:RD-INFRA-20191024-RC0
StandloneMM seems build from edk2 & edk2-platform. so i just put edk2 and edk2-platform version information. if anything i missed, please let me know.
edk2: https://git.linaro.org/landing-teams/working/arm/edk2.git tag:RD-INFRA-20191024-RC0
edk2-platform: https://git.linaro.org/landing-teams/working/arm/edk2-platforms.git tag:RD-INFRA-20191024-RC0
3) What version of the kernel and sdei driver is being used?
A: kernel-release: https://git.linaro.org/landing-teams/working/arm/kernel-release.git tag:RD-INFRA-20191024-RC0
The sdei driver was included in kernel, do i need to provide sdei driver version? If need please let me know.
4) I can't tell from looking at the log but do you know if writing 0x123
to sde_ras_poison causes a DMC620 interrupt or an SError or external
abort through memory access ?
A: Sorry, linaro only refered it will inject the DMC-620 single-bit RAS error. So I am also not sure which exception type it will trigger.
BRs,
Bin Wu
------------------原始邮件 ------------------
发件人:TF-A <tf-a-bounces(a)lists.trustedfirmware.org>
发送时间:Tue Apr 14 01:25:47 2020
收件人:Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
主题:Re: [TF-A] [RAS] BL32 UnRecognized Event - 0xC4000061 and BL31 Crashed
Hello,
>>Does BL31 need to send 0xC4000061 event to BL32 again?
I don't think it will. It is really odd that
0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM handler.
This is from looking at the upstream code quickly but it definitely
depends on the platform you are running, what version of TF-A you are
using, build options used. Is it possible that the unhandled exception
is occurring after successful handling of the DMC620 error but there is
a following issue that occurs right after, causing the crash?
From the register dump it looks like there was an Instruction abort
exception at address 0 while running in EL3. Something seems to have
gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
an instruction abort at address 0.
>>Does current TF-A support to run RAS test? It seems BL31 will crash.
See above. The answer really depends on the factors mentioned above.
The following would be helpful to know:
1) What platform you are running on? Can this issue be reproduced
outside your testing environment, perhaps on FVP or QEMU?
2) What version of TF-A and StandaloneMM is being used? Preferably the
commit-id, so that we can be sure we are looking at the same code.
3) What version of the kernel and sdei driver is being used?
4) I can't tell from looking at the log but do you know if writing 0x123
to sde_ras_poison causes a DMC620 interrupt or an SError or external
abort through memory access ?
Thanks
Raghu
On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
> Dear Friends,
>
> I am using TF-A to test RAS feature.
> When I triggered DMC620 RAS error in Linux(echo 0x123 >
> /sys/kernel/debug/sdei_ras_poison).
> BL32 will recieve
> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally
> BL31 crashed.
>
> In my understanding, this 0xC4000061 should consumed by BL31, not send
> it to BL32 again.
>
> A piece of error log as below:
>
> *************************************
>
> CperWrite - CperAddress@0xFF610064
> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
> CperWrite - Got Error Section: Platform Memory.
> MmEntryPoint Done
> Received delegated event
> X0 : 0xC4000061
> X1 : 0x0
> X2 : 0x0
> X3 : 0x0
> Received event - 0xC4000061 on cpu 0
> UnRecognized Event - 0xC4000061
> Failed delegated event 0xC4000061, Status 0x2
> Unhandled Exception in EL3.
> x30 = 0x0000000000000000
> x0 = 0x00000000ff007e00
> x1 = 0xfffffffffffffffe
> x2 = 0x00000000600003c0
> x3 = 0x0000000000000000
> x4 = 0x0000000000000000
> x5 = 0x0000000000000000
> x6 = 0x00000000ff015080
> x7 = 0x0000000000000000
> x8 = 0x00000000c4000061
> x9 = 0x0000000000000021
> x10 = 0x0000000000000040
> x11 = 0x00000000ff00f2b0
> x12 = 0x00000000ff0118c0
> x13 = 0x0000000000000002
> x14 = 0x00000000ff016b70
> x15 = 0x00000000ff003f20
> x16 = 0x0000000000000044
> x17 = 0x00000000ff010430
> x18 = 0x0000000000000e3c
> x19 = 0x0000000000000000
> More error log please refer to attachment.
>
> My question is,
> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
>
> Appreciate your help.
>
> BRs,
> Bin Wu
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Varun,
1. The value of '1' sets ‘standard’ type of BP which according to GCC documentation:
"turns on all types of branch protection features. If a feature has additional tuning options, then ‘standard’ sets it to its standard level. "
It equals to "bti+pac-ret".
2. Yes. See above and use option value of '1'.
Regards.
Alexei
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 10 April 2020 19:28
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Cc: Kalyani Chidambaram Vaidyanathan <kalyanic(a)nvidia.com>; Anthony Zhou <anzhou(a)nvidia.com>
Subject: Re: [TF-A] BRANCH_PROTECTION
Hello,
Can someone please help clarify?
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A
Sent: Tuesday, April 7, 2020 9:58 PM
To: tf-a(a)lists.trustedfirmware.org
Cc: Kalyani Chidambaram Vaidyanathan <kalyanic(a)nvidia.com>; Anthony Zhou <anzhou(a)nvidia.com>
Subject: [TF-A] BRANCH_PROTECTION
External email: Use caution opening links or attachments
Hello,
Can someone please help me understand if
1. a ‘value’ of ‘1’ for BRANCH_PROTECTION covers the PAuth protection provided by a value of ‘2’ and/or ‘3’?
2. there is a way to enable BTI and “pac-ret” at the same time?
The docs provide this information.
<snip>
- ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication
and ARMv8.5 Branch Target Identification support for TF-A BL images themselves.
If enabled, it is needed to use a compiler that supports the option
``-mbranch-protection``. Selects the branch protection features to use:
- 0: Default value turns off all types of branch protection
- 1: Enables all types of branch protection features
- 2: Return address signing to its standard level
- 3: Extend the signing to include leaf functions
The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options
and resulting PAuth/BTI<https://tegra-sw-opengrok.nvidia.com/source/s?path=PAuth/BTI&project=stage-…> features.
+-------+--------------+-------+-----+
| Value | GCC option | PAuth | BTI |
+=======+==============+=======+=====+
| 0 | none | N | N |
+-------+--------------+-------+-----+
| 1 | standard | Y | Y |
+-------+--------------+-------+-----+
| 2 | pac-ret | Y | N |
+-------+--------------+-------+-----+
| 3 | pac-ret+leaf | Y | N |
+-------+--------------+-------+-----+
This option defaults to 0 and this is an experimental feature.
Note that Pointer Authentication is enabled for Non-secure world
irrespective of the value of this option if the CPU supports it.
<snip>
Thanks,
Varun
________________________________
This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message.
________________________________
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hello,
>>Does BL31 need to send 0xC4000061 event to BL32 again?
I don't think it will. It is really odd that
0xC4000061(SP_EVENT_COMPLETE_AARCH64) ever reaches the BL32/MM handler.
This is from looking at the upstream code quickly but it definitely
depends on the platform you are running, what version of TF-A you are
using, build options used. Is it possible that the unhandled exception
is occurring after successful handling of the DMC620 error but there is
a following issue that occurs right after, causing the crash?
From the register dump it looks like there was an Instruction abort
exception at address 0 while running in EL3. Something seems to have
gone seriously wrong to have 0xC4000061 ever go back to BL32 and to get
an instruction abort at address 0.
>>Does current TF-A support to run RAS test? It seems BL31 will crash.
See above. The answer really depends on the factors mentioned above.
The following would be helpful to know:
1) What platform you are running on? Can this issue be reproduced
outside your testing environment, perhaps on FVP or QEMU?
2) What version of TF-A and StandaloneMM is being used? Preferably the
commit-id, so that we can be sure we are looking at the same code.
3) What version of the kernel and sdei driver is being used?
4) I can't tell from looking at the log but do you know if writing 0x123
to sde_ras_poison causes a DMC620 interrupt or an SError or external
abort through memory access ?
Thanks
Raghu
On 4/13/20 12:16 AM, 吴斌(郅隆) via TF-A wrote:
> Dear Friends,
>
> I am using TF-A to test RAS feature.
> When I triggered DMC620 RAS error in Linux(echo 0x123 >
> /sys/kernel/debug/sdei_ras_poison).
> BL32 will recieve
> UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally
> BL31 crashed.
>
> In my understanding, this 0xC4000061 should consumed by BL31, not send
> it to BL32 again.
>
> A piece of error log as below:
>
> *************************************
>
> CperWrite - CperAddress@0xFF610064
> CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
> CperWrite - Got Error Section: Platform Memory.
> MmEntryPoint Done
> Received delegated event
> X0 : 0xC4000061
> X1 : 0x0
> X2 : 0x0
> X3 : 0x0
> Received event - 0xC4000061 on cpu 0
> UnRecognized Event - 0xC4000061
> Failed delegated event 0xC4000061, Status 0x2
> Unhandled Exception in EL3.
> x30 = 0x0000000000000000
> x0 = 0x00000000ff007e00
> x1 = 0xfffffffffffffffe
> x2 = 0x00000000600003c0
> x3 = 0x0000000000000000
> x4 = 0x0000000000000000
> x5 = 0x0000000000000000
> x6 = 0x00000000ff015080
> x7 = 0x0000000000000000
> x8 = 0x00000000c4000061
> x9 = 0x0000000000000021
> x10 = 0x0000000000000040
> x11 = 0x00000000ff00f2b0
> x12 = 0x00000000ff0118c0
> x13 = 0x0000000000000002
> x14 = 0x00000000ff016b70
> x15 = 0x00000000ff003f20
> x16 = 0x0000000000000044
> x17 = 0x00000000ff010430
> x18 = 0x0000000000000e3c
> x19 = 0x0000000000000000
> More error log please refer to attachment.
>
> My question is,
> 1. Does BL31 need to send 0xC4000061 event to BL32 again?
> 2. Does current TF-A support to run RAS test? It seems BL31 will crash.
>
> Appreciate your help.
>
> BRs,
> Bin Wu
>
Dear Friends,
I am using TF-A to test RAS feature.
When I triggered DMC620 RAS error in Linux(echo 0x123 > /sys/kernel/debug/sdei_ras_poison).
BL32 will recieve UnRecognized Event - 0xC4000061(SP_EVENT_COMPLETE_AARCH64) and finally BL31 crashed.
In my understanding, this 0xC4000061 should consumed by BL31, not send it to BL32 again.
A piece of error log as below:
*************************************
CperWrite - CperAddress@0xFF610064
CperWrite - 1 Section@FFBE91A8, Length 80, SectionType@FFBE9138
CperWrite - Got Error Section: Platform Memory.
MmEntryPoint Done
Received delegated event
X0 : 0xC4000061
X1 : 0x0
X2 : 0x0
X3 : 0x0
Received event - 0xC4000061 on cpu 0
UnRecognized Event - 0xC4000061
Failed delegated event 0xC4000061, Status 0x2
Unhandled Exception in EL3.
x30 = 0x0000000000000000
x0 = 0x00000000ff007e00
x1 = 0xfffffffffffffffe
x2 = 0x00000000600003c0
x3 = 0x0000000000000000
x4 = 0x0000000000000000
x5 = 0x0000000000000000
x6 = 0x00000000ff015080
x7 = 0x0000000000000000
x8 = 0x00000000c4000061
x9 = 0x0000000000000021
x10 = 0x0000000000000040
x11 = 0x00000000ff00f2b0
x12 = 0x00000000ff0118c0
x13 = 0x0000000000000002
x14 = 0x00000000ff016b70
x15 = 0x00000000ff003f20
x16 = 0x0000000000000044
x17 = 0x00000000ff010430
x18 = 0x0000000000000e3c
x19 = 0x0000000000000000
More error log please refer to attachment.
My question is,
1. Does BL31 need to send 0xC4000061 event to BL32 again?
2. Does current TF-A support to run RAS test? It seems BL31 will crash.
Appreciate your help.
BRs,
Bin Wu
Hello,
Can someone please help clarify?
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A
Sent: Tuesday, April 7, 2020 9:58 PM
To: tf-a(a)lists.trustedfirmware.org
Cc: Kalyani Chidambaram Vaidyanathan <kalyanic(a)nvidia.com>; Anthony Zhou <anzhou(a)nvidia.com>
Subject: [TF-A] BRANCH_PROTECTION
External email: Use caution opening links or attachments
Hello,
Can someone please help me understand if
1. a 'value' of '1' for BRANCH_PROTECTION covers the PAuth protection provided by a value of '2' and/or '3'?
2. there is a way to enable BTI and "pac-ret" at the same time?
The docs provide this information.
<snip>
- ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication
and ARMv8.5 Branch Target Identification support for TF-A BL images themselves.
If enabled, it is needed to use a compiler that supports the option
``-mbranch-protection``. Selects the branch protection features to use:
- 0: Default value turns off all types of branch protection
- 1: Enables all types of branch protection features
- 2: Return address signing to its standard level
- 3: Extend the signing to include leaf functions
The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options
and resulting PAuth/BTI<https://tegra-sw-opengrok.nvidia.com/source/s?path=PAuth/BTI&project=stage-…> features.
+-------+--------------+-------+-----+
| Value | GCC option | PAuth | BTI |
+=======+==============+=======+=====+
| 0 | none | N | N |
+-------+--------------+-------+-----+
| 1 | standard | Y | Y |
+-------+--------------+-------+-----+
| 2 | pac-ret | Y | N |
+-------+--------------+-------+-----+
| 3 | pac-ret+leaf | Y | N |
+-------+--------------+-------+-----+
This option defaults to 0 and this is an experimental feature.
Note that Pointer Authentication is enabled for Non-secure world
irrespective of the value of this option if the CPU supports it.
<snip>
Thanks,
Varun
________________________________
This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message.
________________________________
Hi,
Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
3 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
New defect(s) Reported-by: Coverity Scan
Showing 3 of 3 defect(s)
** CID 355490: Uninitialized variables (UNINIT)
/plat/brcm/board/stingray/src/paxb.c: 516 in pcie_cores_init()
________________________________________________________________________________________________________
*** CID 355490: Uninitialized variables (UNINIT)
/plat/brcm/board/stingray/src/paxb.c: 516 in pcie_cores_init()
510
511 pcie_core_soft_reset(core_idx);
512
513 VERBOSE("PCIe core %u is powered up\n", core_idx);
514 }
515
>>> CID 355490: Uninitialized variables (UNINIT)
>>> Using uninitialized value "ret".
516 return ret;
517 }
518
519 void paxb_rc_cfg_write(unsigned int core_idx, unsigned int where,
520 uint32_t val)
521 {
** CID 355489: Control flow issues (NO_EFFECT)
/plat/brcm/board/stingray/src/bl2_setup.c: 685 in plat_bcm_bl2_plat_arch_setup()
________________________________________________________________________________________________________
*** CID 355489: Control flow issues (NO_EFFECT)
/plat/brcm/board/stingray/src/bl2_setup.c: 685 in plat_bcm_bl2_plat_arch_setup()
679 EMMC_ERASE_PARTITION);
680 #endif
681
682 bcm_board_detect();
683 #ifdef DRIVER_EMMC_ENABLE
684 /* Initialize the card, if it is not */
>>> CID 355489: Control flow issues (NO_EFFECT)
>>> This less-than-zero comparison of an unsigned value is never true. "bcm_emmc_init(true) < 0U".
685 if (bcm_emmc_init(true) < 0)
686 WARN("eMMC Card Initialization Failed!!!\n");
687 #endif
688
689 #if BL2_TEST_I2C
690 i2c_test();
** CID 355488: (VARARGS)
/plat/brcm/board/common/bcm_elog.c: 251 in bcm_elog()
/plat/brcm/board/common/bcm_elog.c: 253 in bcm_elog()
/plat/brcm/board/common/bcm_elog.c: 241 in bcm_elog()
/plat/brcm/board/common/bcm_elog.c: 234 in bcm_elog()
/plat/brcm/board/common/bcm_elog.c: 223 in bcm_elog()
/plat/brcm/board/common/bcm_elog.c: 239 in bcm_elog()
________________________________________________________________________________________________________
*** CID 355488: (VARARGS)
/plat/brcm/board/common/bcm_elog.c: 251 in bcm_elog()
245 case 'l':
246 bit64 = 1;
247 fmt++;
248 goto loop;
249 case 'u':
250 if (bit64)
>>> CID 355488: (VARARGS)
>>> Calling va_arg on va_list "args", which has not been prepared with va_start().
251 unum = va_arg(args, uint64_t);
252 else
253 unum = va_arg(args, uint32_t);
254
255 elog_unsigned_num(elog, unum, 10);
256 break;
/plat/brcm/board/common/bcm_elog.c: 253 in bcm_elog()
247 fmt++;
248 goto loop;
249 case 'u':
250 if (bit64)
251 unum = va_arg(args, uint64_t);
252 else
>>> CID 355488: (VARARGS)
>>> Calling va_arg on va_list "args", which has not been prepared with va_start().
253 unum = va_arg(args, uint32_t);
254
255 elog_unsigned_num(elog, unum, 10);
256 break;
257 default:
258 /* Exit on any other format specifier */
/plat/brcm/board/common/bcm_elog.c: 241 in bcm_elog()
235 elog_string(elog, str);
236 break;
237 case 'x':
238 if (bit64)
239 unum = va_arg(args, uint64_t);
240 else
>>> CID 355488: (VARARGS)
>>> Calling va_arg on va_list "args", which has not been prepared with va_start().
241 unum = va_arg(args, uint32_t);
242
243 elog_unsigned_num(elog, unum, 16);
244 break;
245 case 'l':
246 bit64 = 1;
/plat/brcm/board/common/bcm_elog.c: 234 in bcm_elog()
228 } else
229 unum = (unsigned long)num;
230
231 elog_unsigned_num(elog, unum, 10);
232 break;
233 case 's':
>>> CID 355488: (VARARGS)
>>> Calling va_arg on va_list "args", which has not been prepared with va_start().
234 str = va_arg(args, char *);
235 elog_string(elog, str);
236 break;
237 case 'x':
238 if (bit64)
239 unum = va_arg(args, uint64_t);
/plat/brcm/board/common/bcm_elog.c: 223 in bcm_elog()
217 switch (*fmt) {
218 case 'i': /* Fall through to next one */
219 case 'd':
220 if (bit64)
221 num = va_arg(args, int64_t);
222 else
>>> CID 355488: (VARARGS)
>>> Calling va_arg on va_list "args", which has not been prepared with va_start().
223 num = va_arg(args, int32_t);
224
225 if (num < 0) {
226 elog_putchar(elog, '-');
227 unum = (unsigned long)-num;
228 } else
/plat/brcm/board/common/bcm_elog.c: 239 in bcm_elog()
233 case 's':
234 str = va_arg(args, char *);
235 elog_string(elog, str);
236 break;
237 case 'x':
238 if (bit64)
>>> CID 355488: (VARARGS)
>>> Calling va_arg on va_list "args", which has not been prepared with va_start().
239 unum = va_arg(args, uint64_t);
240 else
241 unum = va_arg(args, uint32_t);
242
243 elog_unsigned_num(elog, unum, 16);
244 break;
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/ls/click?upn=nJaKvJSIH-2FPAfmty-2BK5tYpPkl…
Hello,
Can someone please help me understand if
1. a 'value' of '1' for BRANCH_PROTECTION covers the PAuth protection provided by a value of '2' and/or '3'?
2. there is a way to enable BTI and "pac-ret" at the same time?
The docs provide this information.
<snip>
- ``BRANCH_PROTECTION``: Numeric value to enable ARMv8.3 Pointer Authentication
and ARMv8.5 Branch Target Identification support for TF-A BL images themselves.
If enabled, it is needed to use a compiler that supports the option
``-mbranch-protection``. Selects the branch protection features to use:
- 0: Default value turns off all types of branch protection
- 1: Enables all types of branch protection features
- 2: Return address signing to its standard level
- 3: Extend the signing to include leaf functions
The table below summarizes ``BRANCH_PROTECTION`` values, GCC compilation options
and resulting PAuth/BTI<https://tegra-sw-opengrok.nvidia.com/source/s?path=PAuth/BTI&project=stage-…> features.
+-------+--------------+-------+-----+
| Value | GCC option | PAuth | BTI |
+=======+==============+=======+=====+
| 0 | none | N | N |
+-------+--------------+-------+-----+
| 1 | standard | Y | Y |
+-------+--------------+-------+-----+
| 2 | pac-ret | Y | N |
+-------+--------------+-------+-----+
| 3 | pac-ret+leaf | Y | N |
+-------+--------------+-------+-----+
This option defaults to 0 and this is an experimental feature.
Note that Pointer Authentication is enabled for Non-secure world
irrespective of the value of this option if the CPU supports it.
<snip>
Thanks,
Varun
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
I realise non TF-A people may not have access to session conference details. These can be found here:
https://lists.trustedfirmware.org/pipermail/tf-a/2020-March/000330.html
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Joanna Farley via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Joanna Farley <Joanna.Farley(a)arm.com>
Date: Tuesday, 7 April 2020 at 18:10
To: tf-a <tf-a(a)lists.trustedfirmware.org>
Cc: "tsc(a)lists.trustedfirmware.org" <tsc(a)lists.trustedfirmware.org>, "tf-m(a)lists.trustedfirmware.org" <tf-m(a)lists.trustedfirmware.org>, "op-tee(a)linaro.org" <op-tee(a)linaro.org>
Subject: [TF-A] TF-A Tech Forum @ Thu 9 Apr 2020 17:00 - 18:00 (GMT) - Special session on Project Maintenance Proposal for tf.org
Hi All,
The third TF-A Tech Forum is scheduled for Thu 9th Apr 2020 17:00 - 18:00 (GMT). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know.
For this special session I have also copied the TF-M, TSC and OPTEE mailing lists as the subject may interest the people subscribed to those lists as there is a cross mailing list discussion currently ongoing.
Agenda:
* Overview of the Project Maintenance Proposal for tf.org Projects by Sandrine Bailleux
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi All,
The third TF-A Tech Forum is scheduled for Thu 9th Apr 2020 17:00 - 18:00 (GMT). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know.
For this special session I have also copied the TF-M, TSC and OPTEE mailing lists as the subject may interest the people subscribed to those lists as there is a cross mailing list discussion currently ongoing.
Agenda:
* Overview of the Project Maintenance Proposal for tf.org Projects by Sandrine Bailleux
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Joakim,
On 4/2/20 10:18 AM, Joakim Bech via TF-A wrote:
> Hi Sandrine,
>
> On Wed, Apr 01, 2020 at 11:46:20AM +0200, Sandrine Bailleux wrote:
>> Hi Joakim,
>>
>> On 4/1/20 10:08 AM, Joakim Bech via TSC wrote:
>>> How that works in practice is that all OP-TEE maintainers are adding
>>> their "Tested-by" (see example [2]) tag for the platform they maintain
>>> when we're doing a release. If there are platforms with no "Tested-by"
>>> tag, then they simply end up with the "last known version".
>>
>> I think that's a very good idea!
>>
> The "Tested-by" part for OP-TEE releases has been working pretty good,
> not sure how scalable it is the long run though. To give some more
> info regarding the "last known version", we even at one point had some
> stop-light for that. I.e. if a maintainer missed testing a release once,
> then it became "orange". If missed twice, then it became "red" and we
> showed last know supported version. But we dropped that idea a short
> while after introducing it.
May I know why you dropped the idea? Was it too much maintenance? If
that's the reason I guess again this could be addressed with some
automation work (generating the stop-light status from the commit
message info).
>>> However, to keep that up-to-date, it requires some discipline from the
>>> people maintaining such a table ... something that we in the OP-TEE
>>> project haven't been very good at :)
>>
>> Can't this be automated, such that it doesn't need to be manually kept
>> up-to-date? I imagine we could have some tools generating the platform
>> support table out of such a commit message.
>>
> Indeed it could, it's just a matter of doing some scripting if one
> doesn't want to do it manually. I already have Python scripts pulling
> all tags from GitHub pull requests. But there are of course several
> other ways how one could pull that kind of information.
Regards,
Sandrine
Hi Erik,
On 4/1/20 9:24 PM, Shreve, Erik via TF-A wrote:
> Sandrine,
>
> To clarify on functionality vs. support. I listed out a support life cycle consisting of the following states:
> Fully Supported
> Orphan
> Out of Date
> Deprecated
> These states are intended to have nothing to do with functionality, but only the support offered for the functionality that currently exists for a platform.
>
> I think I may have confused things when I listed "Functional Support" as the heading to represent "Functionality."
> I'm proposing that the supported "Functionality" should be documented in a standard way (within a project) for every platform.
>
> I do agree this could be burdensome to keep up with. But that is why I suggested that the project's feature list be versioned. The platform's supported feature list document would reference the version of the project feature list used. Platform maintainers then don' t have to continuously update the document. But it will be clear how long it has been since they did update and thus what information may be missing. Versioning the feature list document is also why I mentioned that the project version number may want to adopt a version number scheme where feature changes are represented by a certain part of the version number. For example Semantic Versioning 2.0.0: https://semver.org/. Hope that clarifies the intent? For implementation of this I'm imagining each project could create a supported_feature_list.rst file and each platform would copy that file into their platform doc folder and fill it in. I'm not saying that approach would be required at tf.org level, just sharing to further illustrate.
>
> That said, perhaps the implementation details for a project would not warrant such a document per platform? My primary concern around this is misuse/misconfiguration. If a platform doesn't support a feature or configuration it may not be obvious to a user unless an error is generated at build or run-time.
OK, I think I get the idea now, thanks for the explanations. This looks
reasonable to me. The idea of keeping a project's feature list being
mirrored and filled in per platform sounds like something we would want
to enforce at the tf.org level IMO.
At the same time, this could also be handled at the build system level
as you pointed out, or more precisely by the configuration manager. I am
thinking about the Linux kernel, where support for a particular feature
is handled (and documented) through the KConfig system. This might be a
more scalable approach. And it doesn't prevent us from also
auto-generating some feature list out of the Kconfig files for making
this information more accessible to users.
> My secondary concern is being able to consistently track tickets/bugs with features. Thus, I'm recommending that the features on that list be used with the ticket/issue system by feature name. This would allow users to find all bugs for Feature X on Platform Y in Project Z.
> Related to that, when I mentioned "tags." I wasn't thinking of Git tags, but "labels" in the ticket/issue tracking system(s). Different systems work differently for labeling/categorizing issues, but the goal is to provide a consistent way (per project) to find issues related to a feature on a platform.
>
> If requiring a feature list it is too much at the tf.org level then I'll be satisfied to push for that kind of documentation in the projects or platforms I'm involved in if/as appropriate.
Yes, good point, I think it would be desirable to be able to tie tickets
to some specific platform/feature/version. And I think it makes sense to
unify this across tf.org projects.
> Regarding the other conversational tidbits:
>
> Thanks for pointing out that the original proposal does say "builds all configurations supported by this platform" under "Fully Supported." I can see the intention here now. Substituting "features" for "configurations" would broaden the meaning a bit.
OK, I will change the wording, thanks for the suggestion.
> You said: "I am starting to think that we need a list of items to be defined per project."
> Yes, this sounds like a great idea.
>
> My original mention of wanting a "stronger standard put forth for platform documentation" was a response to seeing "Limited Support" in the original proposal allowing documentation to fall out of date.
>
>
> Hope that clarifies some of my thoughts. If not, I'm happy to continue the discussion. Thanks again for taking feedback!
>
> Erik Shreve, PSEM
> Software Security Engineer & Architect (CMCU Platform Development)
>
> -----Original Message-----
> From: Sandrine Bailleux [mailto:sandrine.bailleux@arm.com]
> Sent: Wednesday, April 01, 2020 4:18 AM
> To: Shreve, Erik; tf-a; tf-m(a)lists.trustedfirmware.org; tsc(a)lists.trustedfirmware.org; op-tee(a)linaro.org
> Cc: nd(a)arm.com
> Subject: Re: [EXTERNAL] [TF-M] Project Maintenance Proposal for tf.org Projects
>
> Hello Erik,
>
> Thanks for the feedback.
>
> On 3/26/20 3:37 PM, Shreve, Erik wrote:
>> Sandrine,
>>
>> Really glad to see this being pulled together. A couple of areas of feedback around the Platform Support Life Cycle.
>>
>> As previously mentioned there are two orthogonal concerns captured in the current life cycle: Support and Functionality.
>> I'd like to see these split out.
>
> Yes, you are the second person to mention that and I agree with you
> both. Unless someone disagrees, I intend to update the proposal and
> separate these 2 concepts in the next version of the document.
>
>> For functionality, chip vendors may not have a business case for supporting all features on a given platform but they may provide full support for the features they have chosen to include.
>> A simple example would be supporting PSA FF Isolation Level 1 only due to lack of HW isolation support needed to achieve Isolation Level 2 or greater.
>
> I completely agree. It would not make sense to support all features on
> all platforms just for the sake of completeness. Each platform ought to
> implement what is relevant in its case.
>
> That's what the current proposal tried to convey: a fully supported
> platform must "build all configurations *supported by this platform*"
> and "All *supported* configurations are tested in the CI". The key word
> here is supported and that would be defined by the platform itself. But
> I can see that maybe this wasn't clear enough. Your proposal below makes
> that a lot clearer.
>
>> Also, I'd like to see a stronger standard put forth for platform documentation. If a platform is "supported," I believe the documentation should be complete and accurate. A lack of complete and clear documentation leaves open a wide door for misuse/misconfiguration which could result in a vulnerable system.
>
> Fair point.
>
> But is it something we should include in this proposal or should we push
> it to a separate document setting expectations for the project's
> documentation, which the current general proposal could refer to (as in,
> "the platform should provide quality documentation up to the project's
> criteria defined in document XXX')?
>
> This is definitely an important topic but I am wary of keeping the
> tf.org proposal concise and focused at this point. I am worried that if
> we put too much stuff in it discussions will diverge too much and we
> might never reach an agreement.
>
> The same applies to testing standards for example, we could detail that
> in the proposal or simply leave it to projects to define it separately.
>
>> Here is a more concrete proposal:
>>
>> Functional Support:
>> Each project shall provide a standard feature or functionality list.
>> Each platform shall include in its documentation a copy of this list with the supported functionality marked as supported.
>> The platform documentation may reference a ticket if support is planned but not yet present.
>> The platform documentation shall explicitly state if a feature or function has no plans for support.
>
> Regarding the last item, this would require all platform maintainers to
> update their documentation every time a new feature is added to the
> project's global list of features. This seems too much of a constraint
> and unnecessary maintenance burden to me.
>
> I think a better, more lightweight alternative might be to let platform
> maintainers list what's supported and if some feature is not listed, it
> implies that it is not supported. This does not prevent platform
> maintainers from indicating their future plans of supporting a feature
> if they want to.
>
>> The feature/functionality list shall be versioned, with the version tied to the release version(s) of the project.
>> In this way, it will be clear if a platform was last officially updated for version X but the project is currently at version Y > X.
>
> I can see that Joakim Bech proposed something similar, with more details
> about how this was implemented for OP-TEE.
>
>> Note: projects will need to adopt (if they have not already) a version scheme that distinguishes between feature updates and bug fixes.
>
> Sorry I didn't get this, could you please elaborate?
>
>> Each project and platform shall use tags or similar functionality on tickets to associate tickets to features/functionality and platforms.
>> If the names of tags can't match the name of the feature or platform exactly then a mapping shall be provided in the appropriate document(s).
>
> If there's no appropriate tag in some cases, I guess we could always use
> a git SHA1 of a specific commit.
>
>> Life Cycle State
>>
>> Fully Supported
>> There is (at least) one active code owner for this platform.
>> All supported features build and either all tests pass or failures are associated with tracked known issues.
>> Other (not associated to a test) Known Issues are tracked
>> Documentation is up to date
>>
>> Note: Projects should document standards on how "active" code ownership is measured and
>> further document standards on how code owners are warned about impending life cycle state changes.
>
> Yes, good point, that is currently undefined in the proposal but I agree
> that it needs defining per project. I will add an item in the last
> section of the document.
>
> I am starting to think that we need a list of items to be defined per
> project. This list would complement the general tf.org proposal. Things
> like code owners/maintainers activity, code review timelines, and so on.
>
>>
>> Orphan
>> There is no active code owner
>> All supported features build and either all tests pass or failures are associated with tracked known issues.
>> Other (not associated to a test) Known Issues may not have been maintained (as there is no active code owner)
>> Documentation status is unclear since there is no active code owner.
>> There has been no change to the feature/functionality list in the project since the platform was last "Fully Supported"
>
> I am confused, you said earlier that you would like to see the concepts
> of support and functionality split out, but here you're listing 'orphan'
> as one of the possible states... Did I miss your point?
>
>> Out of date
>> Same as orphan, but either:
>> there have been changes to the feature/functionality list, or
>> there are failing tests without tracked tickets, or
>> there are known documentation issues.
>>
>> Deprecated
>> Same as Out of Date, but the build is broken. Platform may be removed from the project codebase in the future.
>>
>> Erik Shreve, PSEM
>> Software Security Engineer & Architect (CMCU Platform Development)
Hi Raghu,
I do agree with you: case 2 and 3 are similar (wrongly formed DTB) and should lead to the same behavior.
A mandatory property miss or a hit with a structurally incorrect node means that the DTB doesn't follow the provided binding document. Such a DTB shouldn't be considered as valid and should trigger a build failure and/or a code panic.
With the current implementation, case 2 and 3 are similar. The property_getter() functions expect a specific format of the node. If a node is not found or structurally incorrect, the function will return an error code, which will lead to a panic().
regards,
Louis
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 06 April 2020 19:51
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] fconf: Validating config data
Thanks Louis. This new terminology helps. Let me spell this out again
just to make sure we're on the same page. The following are the cases:
1) Mandatory Property hit, nodes are structurally correct - Works normally.
2) Mandatory Property hit, nodes are structurally *incorrect* - Asserts
should catch structural issues during development because system
integrator expected to not make mistakes with number of nodes etc.
3) Mandatory Property miss - Panic(). Why is this case causing a panic,
but not case 2? You are allowing for some one to make the mistake of not
having a mandatory property, but assume that if a mandatory property is
present, it is always structurally sound. This is the part i have a
problem with. In my view case 2 and case 3 should panic and code should
not just assert on mandatory properties and must ALWAYS check for
structural soundness of an FDT property.
Similarly there are 3 cases for optional properties.
My question: Why does case 3 panic, but not case 2 ? It sounds like your
assumption is that case 2 cannot happen. If case 2 cannot happen, i
claim that case 3 cannot happen either.
Let me know what you think!
Thanks
Raghu
On 4/6/20 3:57 AM, Louis Mayencourt via TF-A wrote:
> Hi Raghu,
>
> Let me try to clarify/reword my idea:
>
> We complete the fconf documentation with a binding document, which
> defines the nodes that should be present in the config DTB to consider
> it as valid/well-formed. The document contains two kinds of node:
>
> * mandatory (critical): the firmware can't proceed without this
> information (example: load address, image UUID, ...). If this node
> is not present in the DTS, the build fails and/or the code panic.
>
> * optional (no-critical): the firmware can assume or assign a default
> value and proceed (example: uart config, enable authentication flag,
> ...). Such a property is used to influence the default behavior of
> the firmware.
>
> />> This is non-deterministic failure./
> The miss of a mandatory (critical) node will always lead to a build
> failure / code panic.
> The miss of an optional (no-critical) node should not influence the
> default behavior of the firmware.
>
> />> Is it not confusing to make the assumption that a DTB is "well
> formed",i.e expect the build process/integrator to not mess up the
>>> structure or number of nodes but allow the same integrator to miss a critical property in the DTB?/
> A DTB with a missing mandatory (critical) property should not be
> considered well formed.
>
> />> If there is a missing critical property, is that not a badly formed
> DTB?/
> With the above definition, it is.
>
> />> And if so, why not check for badly formed DTB's uniformly in code
> and why only check for missing "critical" properties?/
> With the rewording of "critical" / "no-critical" to "mandatory" /
> "optional", I think the situation is clearer: A DTB with a missing
> "optional" node/property is is still considered well-formed.
>
> I hope I answered your questions and clarify the idea behind the design.
>
> regards,
> Louis
>
> ------------------------------------------------------------------------
> *From:* Raghu Krishnamurthy <raghu.ncstate(a)icloud.com>
> *Sent:* 05 April 2020 00:06
> *To:* Louis Mayencourt <Louis.Mayencourt(a)arm.com>
> *Subject:* Re: [TF-A] fconf: Validating config data
> Thanks Louis.
> >>you can imagine a well-formed DTB which contain a
> >>critical set of properties and can contain some optional properties.
>
> This makes things even more confusing. The assumption we are asking code
> to make is that the DTB is always "well formed", ie don't check for
> structural issues such as extra nodes etc, but we are still making the
> distinctions between critical and non-critical properties, that may or
> may not exist in the DTB, which may or may not cause a panic. This is
> non-deterministic failure.
> Is it not confusing to make the assumption that a DTB is "well
> formed",i.e expect the build process/integrator to not mess up the
> structure or number of nodes but allow the same integrator to miss a
> critical property in the DTB? If there is a missing critical property,
> is that not a badly formed DTB ? And if so, why not check for badly
> formed DTB's uniformly in code and why only check for missing "critical"
> properties?
>
> -Raghu
>
> On 4/3/20 3:16 AM, Louis Mayencourt wrote:
>> Hi Raghu,
>>
>> I do agree that we need something similar to a binding document for
>> fconf properties. (similar to
>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3694/2/docs/…).
>
>> At least for the common properties.
>>
>> The main idea behind the return code of the populator function was to
>> allow the code to handle no-critical property misses or to handle
>> critical failure by calling a platform hook.
>> With this in mind, you can imagine a well-formed DTB which contain a
>> critical set of properties and can contain some optional properties. The
>> return code and the populator "name" / "config" can be used to handle
>> this two cases.
>>
>> I tried to keep the design of fconf really simple, to leave room for
>> improvement according to feedbacks. Thanks for helping improving it!
>>
>> Regards,
>> Louis
>> ------------------------------------------------------------------------
>> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu
>> Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
>> *Sent:* 03 April 2020 10:15
>> *To:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
>> *Subject:* Re: [TF-A] fconf: Validating config data
>> A further point is that the fconf populators return an error code and
>> panics on error today. But if we are making the assumption that the
>> DTB's are well formed, do we really need to fail or even return an error
>> code?
>>
>> -Raghu
>>
>> On 4/3/20 1:51 AM, Raghu Krishnamurthy via TF-A wrote:
>>> Hi All, (Sorry for the long email)
>>>
>>> The review
>>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3845
>>> attempts to fix bounds check in the fconf populator code for the
>>> topology and SP's. During review, Sandrine thoughtfully pointed out that
>>> there were discussions around bounds check along the same lines in the
>>> review
>>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492 and
>>> it was deemed sufficient to have assertions in code and it was safe to
>>> make the assumption that the DTB is always well formed and contains
>>> valid values. I think this email mostly echoes Sandrine's concern from
>>> review 3492.
>>>
>>> While i agree with the assumptions, I am generally of the opinion that
>>> we should validate/range-check any data, even if it is signed. Being
>>> signed does not necessarily mean the data is well formed/valid. If there
>>> is a mistake in the build process and it is validly signed, it is
>>> possible that we silently corrupt state/data that could later be used to
>>> exploit firmware and/or make debugging hard. This is probably far
>>> fetched, but the cost of adding the check is trivial to avoid this
>>> possibility.
>>>
>>> I imagine the case where you have secure partitions signed by different
>>> entity other than the silicon provider(dual root-of-trust). A silicon
>>> provider provides a dev system for the SP provider to test and validate
>>> the SP's on silicon. The silicon has production firmware(and hence no
>>> assertions), but loads signed data from the SP provider which has some
>>> invalid values. There could be silent corruption without any indication
>>> whatsoever about what went wrong and it may be hard to debug if/when
>>> there are issues.
>>> Also, testing does not necessarily catch all invalid values since you
>>> will likely not get 100% coverage, given the number of config options
>>> available. Moreover, the code today, is not consistent in asserting on
>>> every property for valid values and the failure mode is not
>>> consistent/deterministic. It seems like every config option should have
>>> a list of valid values or a range of acceptable values that must be at a
>>> minimum asserted on.
>>> I also wouldn't discount platforms such as RPI, where TRUSTED_BOARD_BOOT
>>> is likely to be turned off since it really does not provide any
>>> security, so assuming we always have signed data might not be valid.
>>>
>>> Anyway, is this decision worth revisiting? Too paranoid perhaps? :P
>>>
>>>
>>> Thanks
>>> Raghu
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> IMPORTANT NOTICE: The contents of this email and any attachments are
>> confidential and may also be privileged. If you are not the intended
>> recipient, please notify the sender immediately and do not disclose the
>> contents to any other person, use it for any purpose, or store or copy
>> the information in any medium. Thank you.
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy
> the information in any medium. Thank you.
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Thanks Louis. This new terminology helps. Let me spell this out again
just to make sure we're on the same page. The following are the cases:
1) Mandatory Property hit, nodes are structurally correct - Works normally.
2) Mandatory Property hit, nodes are structurally *incorrect* - Asserts
should catch structural issues during development because system
integrator expected to not make mistakes with number of nodes etc.
3) Mandatory Property miss - Panic(). Why is this case causing a panic,
but not case 2? You are allowing for some one to make the mistake of not
having a mandatory property, but assume that if a mandatory property is
present, it is always structurally sound. This is the part i have a
problem with. In my view case 2 and case 3 should panic and code should
not just assert on mandatory properties and must ALWAYS check for
structural soundness of an FDT property.
Similarly there are 3 cases for optional properties.
My question: Why does case 3 panic, but not case 2 ? It sounds like your
assumption is that case 2 cannot happen. If case 2 cannot happen, i
claim that case 3 cannot happen either.
Let me know what you think!
Thanks
Raghu
On 4/6/20 3:57 AM, Louis Mayencourt via TF-A wrote:
> Hi Raghu,
>
> Let me try to clarify/reword my idea:
>
> We complete the fconf documentation with a binding document, which
> defines the nodes that should be present in the config DTB to consider
> it as valid/well-formed. The document contains two kinds of node:
>
> * mandatory (critical): the firmware can't proceed without this
> information (example: load address, image UUID, ...). If this node
> is not present in the DTS, the build fails and/or the code panic.
>
> * optional (no-critical): the firmware can assume or assign a default
> value and proceed (example: uart config, enable authentication flag,
> ...). Such a property is used to influence the default behavior of
> the firmware.
>
> />> This is non-deterministic failure./
> The miss of a mandatory (critical) node will always lead to a build
> failure / code panic.
> The miss of an optional (no-critical) node should not influence the
> default behavior of the firmware.
>
> />> Is it not confusing to make the assumption that a DTB is "well
> formed",i.e expect the build process/integrator to not mess up the
>>> structure or number of nodes but allow the same integrator to miss a critical property in the DTB?/
> A DTB with a missing mandatory (critical) property should not be
> considered well formed.
>
> />> If there is a missing critical property, is that not a badly formed
> DTB?/
> With the above definition, it is.
>
> />> And if so, why not check for badly formed DTB's uniformly in code
> and why only check for missing "critical" properties?/
> With the rewording of "critical" / "no-critical" to "mandatory" /
> "optional", I think the situation is clearer: A DTB with a missing
> "optional" node/property is is still considered well-formed.
>
> I hope I answered your questions and clarify the idea behind the design.
>
> regards,
> Louis
>
> ------------------------------------------------------------------------
> *From:* Raghu Krishnamurthy <raghu.ncstate(a)icloud.com>
> *Sent:* 05 April 2020 00:06
> *To:* Louis Mayencourt <Louis.Mayencourt(a)arm.com>
> *Subject:* Re: [TF-A] fconf: Validating config data
> Thanks Louis.
> >>you can imagine a well-formed DTB which contain a
> >>critical set of properties and can contain some optional properties.
>
> This makes things even more confusing. The assumption we are asking code
> to make is that the DTB is always "well formed", ie don't check for
> structural issues such as extra nodes etc, but we are still making the
> distinctions between critical and non-critical properties, that may or
> may not exist in the DTB, which may or may not cause a panic. This is
> non-deterministic failure.
> Is it not confusing to make the assumption that a DTB is "well
> formed",i.e expect the build process/integrator to not mess up the
> structure or number of nodes but allow the same integrator to miss a
> critical property in the DTB? If there is a missing critical property,
> is that not a badly formed DTB ? And if so, why not check for badly
> formed DTB's uniformly in code and why only check for missing "critical"
> properties?
>
> -Raghu
>
> On 4/3/20 3:16 AM, Louis Mayencourt wrote:
>> Hi Raghu,
>>
>> I do agree that we need something similar to a binding document for
>> fconf properties. (similar to
>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3694/2/docs/…).
>
>> At least for the common properties.
>>
>> The main idea behind the return code of the populator function was to
>> allow the code to handle no-critical property misses or to handle
>> critical failure by calling a platform hook.
>> With this in mind, you can imagine a well-formed DTB which contain a
>> critical set of properties and can contain some optional properties. The
>> return code and the populator "name" / "config" can be used to handle
>> this two cases.
>>
>> I tried to keep the design of fconf really simple, to leave room for
>> improvement according to feedbacks. Thanks for helping improving it!
>>
>> Regards,
>> Louis
>> ------------------------------------------------------------------------
>> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu
>> Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
>> *Sent:* 03 April 2020 10:15
>> *To:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
>> *Subject:* Re: [TF-A] fconf: Validating config data
>> A further point is that the fconf populators return an error code and
>> panics on error today. But if we are making the assumption that the
>> DTB's are well formed, do we really need to fail or even return an error
>> code?
>>
>> -Raghu
>>
>> On 4/3/20 1:51 AM, Raghu Krishnamurthy via TF-A wrote:
>>> Hi All, (Sorry for the long email)
>>>
>>> The review
>>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3845
>>> attempts to fix bounds check in the fconf populator code for the
>>> topology and SP's. During review, Sandrine thoughtfully pointed out that
>>> there were discussions around bounds check along the same lines in the
>>> review
>>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492 and
>>> it was deemed sufficient to have assertions in code and it was safe to
>>> make the assumption that the DTB is always well formed and contains
>>> valid values. I think this email mostly echoes Sandrine's concern from
>>> review 3492.
>>>
>>> While i agree with the assumptions, I am generally of the opinion that
>>> we should validate/range-check any data, even if it is signed. Being
>>> signed does not necessarily mean the data is well formed/valid. If there
>>> is a mistake in the build process and it is validly signed, it is
>>> possible that we silently corrupt state/data that could later be used to
>>> exploit firmware and/or make debugging hard. This is probably far
>>> fetched, but the cost of adding the check is trivial to avoid this
>>> possibility.
>>>
>>> I imagine the case where you have secure partitions signed by different
>>> entity other than the silicon provider(dual root-of-trust). A silicon
>>> provider provides a dev system for the SP provider to test and validate
>>> the SP's on silicon. The silicon has production firmware(and hence no
>>> assertions), but loads signed data from the SP provider which has some
>>> invalid values. There could be silent corruption without any indication
>>> whatsoever about what went wrong and it may be hard to debug if/when
>>> there are issues.
>>> Also, testing does not necessarily catch all invalid values since you
>>> will likely not get 100% coverage, given the number of config options
>>> available. Moreover, the code today, is not consistent in asserting on
>>> every property for valid values and the failure mode is not
>>> consistent/deterministic. It seems like every config option should have
>>> a list of valid values or a range of acceptable values that must be at a
>>> minimum asserted on.
>>> I also wouldn't discount platforms such as RPI, where TRUSTED_BOARD_BOOT
>>> is likely to be turned off since it really does not provide any
>>> security, so assuming we always have signed data might not be valid.
>>>
>>> Anyway, is this decision worth revisiting? Too paranoid perhaps? :P
>>>
>>>
>>> Thanks
>>> Raghu
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> IMPORTANT NOTICE: The contents of this email and any attachments are
>> confidential and may also be privileged. If you are not the intended
>> recipient, please notify the sender immediately and do not disclose the
>> contents to any other person, use it for any purpose, or store or copy
>> the information in any medium. Thank you.
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy
> the information in any medium. Thank you.
>
Hi Raghu,
Let me try to clarify/reword my idea:
We complete the fconf documentation with a binding document, which defines the nodes that should be present in the config DTB to consider it as valid/well-formed. The document contains two kinds of node:
* mandatory (critical): the firmware can't proceed without this information (example: load address, image UUID, ...). If this node is not present in the DTS, the build fails and/or the code panic.
* optional (no-critical): the firmware can assume or assign a default value and proceed (example: uart config, enable authentication flag, ...). Such a property is used to influence the default behavior of the firmware.
>> This is non-deterministic failure.
The miss of a mandatory (critical) node will always lead to a build failure / code panic.
The miss of an optional (no-critical) node should not influence the default behavior of the firmware.
>> Is it not confusing to make the assumption that a DTB is "well formed",i.e expect the build process/integrator to not mess up the
>> structure or number of nodes but allow the same integrator to miss a critical property in the DTB?
A DTB with a missing mandatory (critical) property should not be considered well formed.
>> If there is a missing critical property, is that not a badly formed DTB?
With the above definition, it is.
>> And if so, why not check for badly formed DTB's uniformly in code and why only check for missing "critical" properties?
With the rewording of "critical" / "no-critical" to "mandatory" / "optional", I think the situation is clearer: A DTB with a missing "optional" node/property is is still considered well-formed.
I hope I answered your questions and clarify the idea behind the design.
regards,
Louis
________________________________
From: Raghu Krishnamurthy <raghu.ncstate(a)icloud.com>
Sent: 05 April 2020 00:06
To: Louis Mayencourt <Louis.Mayencourt(a)arm.com>
Subject: Re: [TF-A] fconf: Validating config data
Thanks Louis.
>>you can imagine a well-formed DTB which contain a
>>critical set of properties and can contain some optional properties.
This makes things even more confusing. The assumption we are asking code
to make is that the DTB is always "well formed", ie don't check for
structural issues such as extra nodes etc, but we are still making the
distinctions between critical and non-critical properties, that may or
may not exist in the DTB, which may or may not cause a panic. This is
non-deterministic failure.
Is it not confusing to make the assumption that a DTB is "well
formed",i.e expect the build process/integrator to not mess up the
structure or number of nodes but allow the same integrator to miss a
critical property in the DTB? If there is a missing critical property,
is that not a badly formed DTB ? And if so, why not check for badly
formed DTB's uniformly in code and why only check for missing "critical"
properties?
-Raghu
On 4/3/20 3:16 AM, Louis Mayencourt wrote:
> Hi Raghu,
>
> I do agree that we need something similar to a binding document for
> fconf properties. (similar to
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3694/2/docs/…).
> At least for the common properties.
>
> The main idea behind the return code of the populator function was to
> allow the code to handle no-critical property misses or to handle
> critical failure by calling a platform hook.
> With this in mind, you can imagine a well-formed DTB which contain a
> critical set of properties and can contain some optional properties. The
> return code and the populator "name" / "config" can be used to handle
> this two cases.
>
> I tried to keep the design of fconf really simple, to leave room for
> improvement according to feedbacks. Thanks for helping improving it!
>
> Regards,
> Louis
> ------------------------------------------------------------------------
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu
> Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
> *Sent:* 03 April 2020 10:15
> *To:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
> *Subject:* Re: [TF-A] fconf: Validating config data
> A further point is that the fconf populators return an error code and
> panics on error today. But if we are making the assumption that the
> DTB's are well formed, do we really need to fail or even return an error
> code?
>
> -Raghu
>
> On 4/3/20 1:51 AM, Raghu Krishnamurthy via TF-A wrote:
>> Hi All, (Sorry for the long email)
>>
>> The review
>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3845
>> attempts to fix bounds check in the fconf populator code for the
>> topology and SP's. During review, Sandrine thoughtfully pointed out that
>> there were discussions around bounds check along the same lines in the
>> review
>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492 and
>> it was deemed sufficient to have assertions in code and it was safe to
>> make the assumption that the DTB is always well formed and contains
>> valid values. I think this email mostly echoes Sandrine's concern from
>> review 3492.
>>
>> While i agree with the assumptions, I am generally of the opinion that
>> we should validate/range-check any data, even if it is signed. Being
>> signed does not necessarily mean the data is well formed/valid. If there
>> is a mistake in the build process and it is validly signed, it is
>> possible that we silently corrupt state/data that could later be used to
>> exploit firmware and/or make debugging hard. This is probably far
>> fetched, but the cost of adding the check is trivial to avoid this
>> possibility.
>>
>> I imagine the case where you have secure partitions signed by different
>> entity other than the silicon provider(dual root-of-trust). A silicon
>> provider provides a dev system for the SP provider to test and validate
>> the SP's on silicon. The silicon has production firmware(and hence no
>> assertions), but loads signed data from the SP provider which has some
>> invalid values. There could be silent corruption without any indication
>> whatsoever about what went wrong and it may be hard to debug if/when
>> there are issues.
>> Also, testing does not necessarily catch all invalid values since you
>> will likely not get 100% coverage, given the number of config options
>> available. Moreover, the code today, is not consistent in asserting on
>> every property for valid values and the failure mode is not
>> consistent/deterministic. It seems like every config option should have
>> a list of valid values or a range of acceptable values that must be at a
>> minimum asserted on.
>> I also wouldn't discount platforms such as RPI, where TRUSTED_BOARD_BOOT
>> is likely to be turned off since it really does not provide any
>> security, so assuming we always have signed data might not be valid.
>>
>> Anyway, is this decision worth revisiting? Too paranoid perhaps? :P
>>
>>
>> Thanks
>> Raghu
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy
> the information in any medium. Thank you.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
+tf-a list
On 4/4/20 4:06 PM, Raghu Krishnamurthy wrote:
> Thanks Louis.
> >>you can imagine a well-formed DTB which contain a
> >>critical set of properties and can contain some optional properties.
>
> This makes things even more confusing. The assumption we are asking code
> to make is that the DTB is always "well formed", ie don't check for
> structural issues such as extra nodes etc, but we are still making the
> distinctions between critical and non-critical properties, that may or
> may not exist in the DTB, which may or may not cause a panic. This is
> non-deterministic failure.
> Is it not confusing to make the assumption that a DTB is "well
> formed",i.e expect the build process/integrator to not mess up the
> structure or number of nodes but allow the same integrator to miss a
> critical property in the DTB? If there is a missing critical property,
> is that not a badly formed DTB ? And if so, why not check for badly
> formed DTB's uniformly in code and why only check for missing "critical"
> properties?
>
> -Raghu
>
> On 4/3/20 3:16 AM, Louis Mayencourt wrote:
>> Hi Raghu,
>>
>> I do agree that we need something similar to a binding document for
>> fconf properties. (similar to
>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3694/2/docs/…).
>> At least for the common properties.
>>
>> The main idea behind the return code of the populator function was to
>> allow the code to handle no-critical property misses or to handle
>> critical failure by calling a platform hook.
>> With this in mind, you can imagine a well-formed DTB which contain a
>> critical set of properties and can contain some optional properties.
>> The return code and the populator "name" / "config" can be used to
>> handle this two cases.
>>
>> I tried to keep the design of fconf really simple, to leave room for
>> improvement according to feedbacks. Thanks for helping improving it!
>>
>> Regards,
>> Louis
>> ------------------------------------------------------------------------
>> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of
>> Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
>> *Sent:* 03 April 2020 10:15
>> *To:* tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
>> *Subject:* Re: [TF-A] fconf: Validating config data
>> A further point is that the fconf populators return an error code and
>> panics on error today. But if we are making the assumption that the
>> DTB's are well formed, do we really need to fail or even return an error
>> code?
>>
>> -Raghu
>>
>> On 4/3/20 1:51 AM, Raghu Krishnamurthy via TF-A wrote:
>>> Hi All, (Sorry for the long email)
>>>
>>> The review
>>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3845
>>> attempts to fix bounds check in the fconf populator code for the
>>> topology and SP's. During review, Sandrine thoughtfully pointed out
>>> that there were discussions around bounds check along the same lines
>>> in the review
>>> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492 and
>>> it was deemed sufficient to have assertions in code and it was safe
>>> to make the assumption that the DTB is always well formed and
>>> contains valid values. I think this email mostly echoes Sandrine's
>>> concern from review 3492.
>>>
>>> While i agree with the assumptions, I am generally of the opinion
>>> that we should validate/range-check any data, even if it is signed.
>>> Being signed does not necessarily mean the data is well formed/valid.
>>> If there is a mistake in the build process and it is validly signed,
>>> it is possible that we silently corrupt state/data that could later
>>> be used to exploit firmware and/or make debugging hard. This is
>>> probably far fetched, but the cost of adding the check is trivial to
>>> avoid this possibility.
>>>
>>> I imagine the case where you have secure partitions signed by
>>> different entity other than the silicon provider(dual root-of-trust).
>>> A silicon provider provides a dev system for the SP provider to test
>>> and validate the SP's on silicon. The silicon has production
>>> firmware(and hence no assertions), but loads signed data from the SP
>>> provider which has some invalid values. There could be silent
>>> corruption without any indication whatsoever about what went wrong
>>> and it may be hard to debug if/when there are issues.
>>> Also, testing does not necessarily catch all invalid values since you
>>> will likely not get 100% coverage, given the number of config options
>>> available. Moreover, the code today, is not consistent in asserting
>>> on every property for valid values and the failure mode is not
>>> consistent/deterministic. It seems like every config option should
>>> have a list of valid values or a range of acceptable values that must
>>> be at a minimum asserted on.
>>> I also wouldn't discount platforms such as RPI, where
>>> TRUSTED_BOARD_BOOT is likely to be turned off since it really does
>>> not provide any security, so assuming we always have signed data
>>> might not be valid.
>>>
>>> Anyway, is this decision worth revisiting? Too paranoid perhaps? :P
>>>
>>>
>>> Thanks
>>> Raghu
>> --
>> TF-A mailing list
>> TF-A(a)lists.trustedfirmware.org
>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>> IMPORTANT NOTICE: The contents of this email and any attachments are
>> confidential and may also be privileged. If you are not the intended
>> recipient, please notify the sender immediately and do not disclose
>> the contents to any other person, use it for any purpose, or store or
>> copy the information in any medium. Thank you.
>
Hi Raghu,
On 4/3/20 1:38 AM, Raghu Krishnamurthy via TF-A wrote:
> Thanks Sandrine. Patches look good.
Thanks for the review!
> I realized after looking at things a little closer that i had
> misunderstood how fconf works for io policies. I thought the image id's
> themselves came from the config files and not just the UUID's, which is
> why i was worried about bounds check, since the id was coming from an
> external source(trusted or untrusted, depending on if it is signed data
> or not).
> This also made me realize that we are using another table built into
> code, to convert from image id to UUID for io policies. Is there a
> reason image id's also can't be discovered from the config file?
I remember some internal discussions around this topic a few weeks ago.
If I recall correctly, the current thinking is that down the line, we
would like to move image IDs to DTBs but this looks complicated to
achieve today because image IDs are used by several components in TF-A
to tie things together. More work would be needed to abstract this
properly everywhere.
I think other folks in the team (Olivier? Manish? Louis?) might be able
to comment further on this.
Regards,
Sandrine
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
A further point is that the fconf populators return an error code and
panics on error today. But if we are making the assumption that the
DTB's are well formed, do we really need to fail or even return an error
code?
-Raghu
On 4/3/20 1:51 AM, Raghu Krishnamurthy via TF-A wrote:
> Hi All, (Sorry for the long email)
>
> The review
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3845
> attempts to fix bounds check in the fconf populator code for the
> topology and SP's. During review, Sandrine thoughtfully pointed out that
> there were discussions around bounds check along the same lines in the
> review
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492 and
> it was deemed sufficient to have assertions in code and it was safe to
> make the assumption that the DTB is always well formed and contains
> valid values. I think this email mostly echoes Sandrine's concern from
> review 3492.
>
> While i agree with the assumptions, I am generally of the opinion that
> we should validate/range-check any data, even if it is signed. Being
> signed does not necessarily mean the data is well formed/valid. If there
> is a mistake in the build process and it is validly signed, it is
> possible that we silently corrupt state/data that could later be used to
> exploit firmware and/or make debugging hard. This is probably far
> fetched, but the cost of adding the check is trivial to avoid this
> possibility.
>
> I imagine the case where you have secure partitions signed by different
> entity other than the silicon provider(dual root-of-trust). A silicon
> provider provides a dev system for the SP provider to test and validate
> the SP's on silicon. The silicon has production firmware(and hence no
> assertions), but loads signed data from the SP provider which has some
> invalid values. There could be silent corruption without any indication
> whatsoever about what went wrong and it may be hard to debug if/when
> there are issues.
> Also, testing does not necessarily catch all invalid values since you
> will likely not get 100% coverage, given the number of config options
> available. Moreover, the code today, is not consistent in asserting on
> every property for valid values and the failure mode is not
> consistent/deterministic. It seems like every config option should have
> a list of valid values or a range of acceptable values that must be at a
> minimum asserted on.
> I also wouldn't discount platforms such as RPI, where TRUSTED_BOARD_BOOT
> is likely to be turned off since it really does not provide any
> security, so assuming we always have signed data might not be valid.
>
> Anyway, is this decision worth revisiting? Too paranoid perhaps? :P
>
>
> Thanks
> Raghu
Hi All, (Sorry for the long email)
The review
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3845
attempts to fix bounds check in the fconf populator code for the
topology and SP's. During review, Sandrine thoughtfully pointed out that
there were discussions around bounds check along the same lines in the
review
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3492 and
it was deemed sufficient to have assertions in code and it was safe to
make the assumption that the DTB is always well formed and contains
valid values. I think this email mostly echoes Sandrine's concern from
review 3492.
While i agree with the assumptions, I am generally of the opinion that
we should validate/range-check any data, even if it is signed. Being
signed does not necessarily mean the data is well formed/valid. If there
is a mistake in the build process and it is validly signed, it is
possible that we silently corrupt state/data that could later be used to
exploit firmware and/or make debugging hard. This is probably far
fetched, but the cost of adding the check is trivial to avoid this
possibility.
I imagine the case where you have secure partitions signed by different
entity other than the silicon provider(dual root-of-trust). A silicon
provider provides a dev system for the SP provider to test and validate
the SP's on silicon. The silicon has production firmware(and hence no
assertions), but loads signed data from the SP provider which has some
invalid values. There could be silent corruption without any indication
whatsoever about what went wrong and it may be hard to debug if/when
there are issues.
Also, testing does not necessarily catch all invalid values since you
will likely not get 100% coverage, given the number of config options
available. Moreover, the code today, is not consistent in asserting on
every property for valid values and the failure mode is not
consistent/deterministic. It seems like every config option should have
a list of valid values or a range of acceptable values that must be at a
minimum asserted on.
I also wouldn't discount platforms such as RPI, where TRUSTED_BOARD_BOOT
is likely to be turned off since it really does not provide any
security, so assuming we always have signed data might not be valid.
Anyway, is this decision worth revisiting? Too paranoid perhaps? :P
Thanks
Raghu
Thanks Sandrine. Patches look good.
I realized after looking at things a little closer that i had
misunderstood how fconf works for io policies. I thought the image id's
themselves came from the config files and not just the UUID's, which is
why i was worried about bounds check, since the id was coming from an
external source(trusted or untrusted, depending on if it is signed data
or not).
This also made me realize that we are using another table built into
code, to convert from image id to UUID for io policies. Is there a
reason image id's also can't be discovered from the config file?
-Raghu
On 4/2/20 7:17 AM, Sandrine Bailleux (Code Review) wrote:
> Hi guys,
>
> This is the patch I mentioned last Thursday at the TF-A tech call. Sorry
> it took me so long to post it.
>
> View Change
> <https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3836>
>
> To view, visit change 3836
> <https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3836>.
> To unsubscribe, or for help writing mail filters, visit settings
> <https://review.trustedfirmware.org/settings>.
>
> Gerrit-Project: TF-A/trusted-firmware-a
> Gerrit-Branch: integration
> Gerrit-Change-Id: Ic5ea20e43cf8ca959bb7f9b60de7c0839b390add
> Gerrit-Change-Number: 3836
> Gerrit-PatchSet: 1
> Gerrit-Owner: Sandrine Bailleux <sandrine.bailleux(a)arm.com>
> Gerrit-Reviewer: Louis Mayencourt <louis.mayencourt(a)arm.com>
> Gerrit-Reviewer: Raghu K <raghu.ncstate(a)icloud.com>
> Gerrit-Reviewer: Sandrine Bailleux <sandrine.bailleux(a)arm.com>
> Gerrit-Comment-Date: Thu, 02 Apr 2020 14:17:12 +0000
> Gerrit-HasComments: No
> Gerrit-Has-Labels: No
> Gerrit-MessageType: comment
Hi Joakim,
On 4/1/20 10:08 AM, Joakim Bech via TSC wrote:
> Hi Christian, Sandrine, all,
>
> On Thu, Mar 26, 2020 at 10:27:14AM +0100, Sandrine Bailleux wrote:
>> Hi Christian,
>>
>> Thanks a lot for the read and the comments!
>>
>> On 3/25/20 7:05 PM, Christian Daudt wrote:
>>> �The maintenance proposal looks great ! I have some feedback on
>>> specific portions:
>>> �1. maintainer/owner/author patches. " Note that roles can be
>>> cumulative, in particular the same individual can be both a code owner
>>> and a maintainer. In such a scenario, the individual would be able to
>>> self-merge a patch solely affecting his module, having the authority to
>>> approve it from both a code owner and maintainer's point of view.": I'm
>>> always leery of people self-approving their patches. At a minimum, all
>>> self-patches should be published and a minimum wait time provided for
>>> feedback. Or preferably that another maintainer does the merge (it does
>>> not need to be mandated but should be suggested).
>>
>> Yes, actually this is something that generated some disagreement inside Arm
>> as well and I am glad you're bringing this up here, as I'd like to hear more
>> opinions on this.
>>
>> I too have concerns about allowing self-reviewing. I am not so much
>> concerned about people potentially abusing of this situation to silently
>> merge patches, as I think we should trust our maintainers. But I am worried
>> that a self-review is rarely as good as a peer review, simply because it is
>> so easy to miss things when it's your own work. I believe several pair of
>> eyes is always better, as different people think differently, have different
>> perspectives and backgrounds, and are able to catch different issues.
>>
>> But to pull this off, we need enough people to do all these reviews. The
>> proposal currently allows self-review because some of us feared that
>> mandating 2 reviewers for every patch (especially pure platform patches)
>> would be impractical and too heavyweight, especially for the TF-M project in
>> its current contributors organization, as I understand. It would be great to
>> get more feedback from the TF-M community as to whether they think it could
>> work in the end.
>>
>> It's a difficult balance between having the best possible code review
>> practices, and realistically getting all the review work done in a timely
>> manner, avoiding bottlenecks on specific people and keeping the flow of
>> patches smooth.
>>
>> I like your idea of a minimum wait time provided for feedback. I think it
>> could be a good middle ground solution.
>>
> +1 for that, after silence for X weeks it should be OK to merge the
> patch. X would need to be number that is high enough for people to have
> a chance to find it and look into it, but shouldn't be too high, since
> there is a risk that it'll force the contributor to pile up things that
> might be dependent on this patch. To throw something out, I'd say ~2
> weeks sounds like a good number to me.
>
>> Your other suggestion of having a different maintainer doing the merge would
>> work as well IMO but requires more workforce. Again this comes down to
>> whether this can realistically be achieved for each project. This solution
>> was actually suggested within Arm as well (and even called out at the end of
>> the proposal ;) ).
>>
>> Bottom line is, in an ideal world I would like to condemn self-review
>> because I consider this as bad practice
> +1
>
>> , but I do not know whether this will
>> be practical and will work for TF-M as well.
>>
>>> �2. 'timely manner': This expectation should be more explicit - when
>>> the author can start requesting other maintainers to merge on assumption
>>> that silence == approval (or not). Such timeliness expectations are
>>> probably best set per project however.
>>
>> Yes, "timely manner" is definitely too vague and was actually left that way
>> on purpose at this stage to avoid touching upon what I think is a sensitive
>> subject! I am aware that some patches sometimes spend a long time in review,
>> definitely longer than they should and it understandably generates some
>> frustration. This is something we absolutely need to improve on IMO and
>> hopefully a bigger pool of maintainers will help solve this issue. But I
>> agree that the expected review timeline should be clearly established and it
>> is probably best to let each project decides theirs.
>>
>>> �3. The proposal does not address branching strategies. i.e. will
>>> there be separate maintainers for dev/master/stable branches? I don't
>>> think it needs to address it yet - keep it simpler for a start. But a
>>> todo saying something like "in the future this project maintenance
>>> proposal might be expanded to address multi-branch maintainership" would
>>> be good.
>>
>> Good point. A todo sounds good, I will add one in the last section of the
>> document.
>>
>>> �4. The platform lifecycle state machine has too many transitions.
>>> "Fully maintained" <-> "orphan" -> "out" seems sufficient to me.
>>
>> Hmm OK. There might be too many transitions but I feel we need something
>> between fully maintained and out, i.e. the limited support one.
>>
>> Julius Werner also pointed out on Thursday that orphan might be misplaced,
>> as all these other stages deal with some degrees of feature support (what's
>> known to work), whereas orphan is an orthogonal topic that is not directly
>> related to the level of supported features. For example, a platform could
>> have recently become orphan but all features and tests still work for some
>> time.
>>
> At one point in time in the OP-TEE project we tried to keep track of
> maintained platforms, by simply saying maintained "Yes" if they are
> maintained. However they're not maintained, we indicated that by stating
> the last known version where a platform was maintained. People can still
> find that information here [1] (not up-to-date). The intention was to
> give future users of an old platform a chance to know if it ever has
> been supported and what version that was. That could serve as a starting
> point in case someone is interested in bring a device/platform back to
> life.
Yes, I think such information can be very useful. It saves some "git
archeology" effort to try and dig this information afterwards. Also,
when someone starts looking at a project, I would expect this to be one
of the first thing they look up, they would want to know in which shape
the project is for the particular platform they are interested in.
That's almost as important in my eyes as a "getting started" guide.
We could have such a high-level table that just says whether a platform
is supported or not (just a yes/no) and have complementary, per-platform
documentation that goes into the details of what features are supported
exactly.
> How that works in practice is that all OP-TEE maintainers are adding
> their "Tested-by" (see example [2]) tag for the platform they maintain
> when we're doing a release. If there are platforms with no "Tested-by"
> tag, then they simply end up with the "last known version".
I think that's a very good idea!
> However, to keep that up-to-date, it requires some discipline from the
> people maintaining such a table ... something that we in the OP-TEE
> project haven't been very good at :)
Can't this be automated, such that it doesn't need to be manually kept
up-to-date? I imagine we could have some tools generating the platform
support table out of such a commit message.
> So, I'm not proposing something, it's just that I wanted to share what
> we've tried and it "works", but not easy to maintain (a release
> checklist could fix that).
>
> [1] https://optee.readthedocs.io/en/latest/general/platforms.html
> [2] https://github.com/OP-TEE/optee_os/pull/3309/commits/765b92604459240bed7fcf…
>
Hi Alexei,
I second Varun on this. The patch is huge. I recommend breaking it up
into multiple commits. I've reviewed it but since it is a large patch,
it might require a few more sittings to grasp all the changes(which also
means there may be some stupid review comments :)).
-Raghu
On 3/31/20 10:28 AM, Varun Wadekar via TF-A wrote:
> Hello Alexei,
>
> Just curious, the patch is huge and will take some time to review. Do
> you expect this change to be merged before the v2.3 release?
>
> -Varun
>
> *From:* TF-A <tf-a-bounces(a)lists.trustedfirmware.org> *On Behalf Of
> *Alexei Fedorov via TF-A
> *Sent:* Tuesday, March 31, 2020 7:19 AM
> *To:* tf-a(a)lists.trustedfirmware.org
> *Subject:* [TF-A] Event Log for Measured Boot
>
> *External email: Use caution opening links or attachments*
>
> Hi,
>
> Please review and provide your comments for the patch which adds
>
> Event Log generation for the Measured Boot.
>
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3806
>
> Thanks.
>
> Alexei
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy
> the information in any medium. Thank you.
>
> ------------------------------------------------------------------------
> This email message is for the sole use of the intended recipient(s) and
> may contain confidential information. Any unauthorized review, use,
> disclosure or distribution is prohibited. If you are not the intended
> recipient, please contact the sender by reply email and destroy all
> copies of the original message.
> ------------------------------------------------------------------------
>
Hello TF-A,
I understand most devs/reviewers will be busy working towards code freeze,
but if its possible can this patch-set be reviewed.
The patch-set is about "Add support for Broadcom platform".
Patch-set link
https://review.trustedfirmware.org/q/topic:%2522brcm_initial_support%2522
Thanks
Sheetal
Sandrine,
Really glad to see this being pulled together. A couple of areas of feedback around the Platform Support Life Cycle.
As previously mentioned there are two orthogonal concerns captured in the current life cycle: Support and Functionality.
I'd like to see these split out. For functionality, chip vendors may not have a business case for supporting all features on a given platform but they may provide full support for the features they have chosen to include.
A simple example would be supporting PSA FF Isolation Level 1 only due to lack of HW isolation support needed to achieve Isolation Level 2 or greater.
Also, I'd like to see a stronger standard put forth for platform documentation. If a platform is "supported," I believe the documentation should be complete and accurate. A lack of complete and clear documentation leaves open a wide door for misuse/misconfiguration which could result in a vulnerable system.
Here is a more concrete proposal:
Functional Support:
Each project shall provide a standard feature or functionality list.
Each platform shall include in its documentation a copy of this list with the supported functionality marked as supported.
The platform documentation may reference a ticket if support is planned but not yet present.
The platform documentation shall explicitly state if a feature or function has no plans for support.
The feature/functionality list shall be versioned, with the version tied to the release version(s) of the project.
In this way, it will be clear if a platform was last officially updated for version X but the project is currently at version Y > X.
Note: projects will need to adopt (if they have not already) a version scheme that distinguishes between feature updates and bug fixes.
Each project and platform shall use tags or similar functionality on tickets to associate tickets to features/functionality and platforms.
If the names of tags can't match the name of the feature or platform exactly then a mapping shall be provided in the appropriate document(s).
Life Cycle State
Fully Supported
There is (at least) one active code owner for this platform.
All supported features build and either all tests pass or failures are associated with tracked known issues.
Other (not associated to a test) Known Issues are tracked
Documentation is up to date
Note: Projects should document standards on how "active" code ownership is measured and
further document standards on how code owners are warned about impending life cycle state changes.
Orphan
There is no active code owner
All supported features build and either all tests pass or failures are associated with tracked known issues.
Other (not associated to a test) Known Issues may not have been maintained (as there is no active code owner)
Documentation status is unclear since there is no active code owner.
There has been no change to the feature/functionality list in the project since the platform was last "Fully Supported"
Out of date
Same as orphan, but either:
there have been changes to the feature/functionality list, or
there are failing tests without tracked tickets, or
there are known documentation issues.
Deprecated
Same as Out of Date, but the build is broken. Platform may be removed from the project codebase in the future.
Erik Shreve, PSEM
Software Security Engineer & Architect (CMCU Platform Development)
-----Original Message-----
From: TF-M [mailto:tf-m-bounces@lists.trustedfirmware.org] On Behalf Of Sandrine Bailleux via TF-M
Sent: Tuesday, March 24, 2020 4:42 AM
To: tf-a; tf-m(a)lists.trustedfirmware.org; tsc(a)lists.trustedfirmware.org; op-tee(a)linaro.org
Cc: nd(a)arm.com
Subject: [EXTERNAL] [TF-M] Project Maintenance Proposal for tf.org Projects
Hello all,
As the developers community at trustedfirmware.org is growing, there is
an increasing need to have work processes that are clearly documented,
feel smooth and scale well. We think that there is an opportunity to
improve the way the trustedfirmware.org projects are managed today.
That's why we are sharing a project maintenance proposal, focusing on
the TF-A and TF-M projects initially. The aim of this document is to
propose a set of rules, guidelines and processes to try and improve the
way we work together as a community today.
Note that this is an early draft at this stage. This is put up for
further discussion within the trustedfirmware.org community. Nothing is
set in stone yet and it is expected to go under change as feedback from
the community is incorporated.
Please find the initial proposal here:
https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…
Please provide any feedback you may have by replying to this email
thread, keeping all 4 mailing lists in the recipients list.
I will collate comments from the community and try to incorporate them
in the document, keeping you updated on changes made between revisions.
Regards,
Sandrine
--
TF-M mailing list
TF-M(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-m
Hi Andrej,
On 3/26/20 10:54 AM, Andrej Butok via TF-A wrote:
>> But I am worried that a self-review is rarely as good as a peer review
>
> On practice, unfortunately, some TF-M tasks are waiting weeks and even months for review and following approvals.
> If I were a maintainer & owner of my own TFM area, I do not want to wait & push & remind somebody else.
> Better to have a post-merge review for these cases, which does not limit and slow down the development.
Thanks for the feedback. That's not good, patches can't realistically
stay in review for weeks and even months, that's just not workable.
Worse, it might discourage developers to contribute to the project.
I can see that cumulating maintainer & owner roles would solve the
problem here but perhaps enlarging the pool of maintainers would as
well? Presumably, the situation is like that today because the current
maintainers of the project are overloaded and cannot get all reviews
done in a timely manner?
I am skeptical about a post-merge review process... Once a patch is
merged there is less urge and motivation (if any) for people to take a
look at it. I am worried that patches might never get reviewed that way.
Regards,
Sandrine
Hi Sandrine,
> Please find the initial proposal here:
>
> https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…
>
> Please provide any feedback you may have by replying to this email
> thread, keeping all 4 mailing lists in the recipients list.
>
> I will collate comments from the community and try to incorporate them
> in the document, keeping you updated on changes made between revisions.
The maintenance proposal looks great ! I have some feedback on specific portions:
1. maintainer/owner/author patches. " Note that roles can be cumulative, in particular the same individual can be both a code owner and a maintainer. In such a scenario, the individual would be able to self-merge a patch solely affecting his module, having the authority to approve it from both a code owner and maintainer's point of view.": I'm always leery of people self-approving their patches. At a minimum, all self-patches should be published and a minimum wait time provided for feedback. Or preferably that another maintainer does the merge (it does not need to be mandated but should be suggested).
2. 'timely manner': This expectation should be more explicit - when the author can start requesting other maintainers to merge on assumption that silence == approval (or not). Such timeliness expectations are probably best set per project however.
3. The proposal does not address branching strategies. i.e. will there be separate maintainers for dev/master/stable branches? I don't think it needs to address it yet - keep it simpler for a start. But a todo saying something like "in the future this project maintenance proposal might be expanded to address multi-branch maintainership" would be good.
4. The platform lifecycle state machine has too many transitions. "Fully maintained" <-> "orphan" -> "out" seems sufficient to me.
Thanks,
Christian.
This message and any attachments may contain confidential information from Cypress or its subsidiaries. If it has been received in error, please advise the sender and immediately delete this message.
Hello Pankaj,
Hope you are doing well.
The initial email point to one change, but I see that as the tip of a patch series. I reviewed https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3370
and left some comments, but did not review the complete patch series.
Are you requesting a review of the entire patch series?
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Joanna Farley via TF-A
Sent: Tuesday, March 31, 2020 9:37 AM
To: Pankaj Gupta <pankaj.gupta(a)nxp.com>; tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] [EXT] Patch-set review request: New NXP Platform LX2120ARDB support on TFA
External email: Use caution opening links or attachments
Hi Pankaj,
We will try, one of the arm team has done some +1 reviews and I have just kicked of a CI+2 run on the top of the patch stack. As you can imagine the Arm team is pressed for time the closer to the freeze date.
Other TF-A contributors you all have +1 rights so if folks have time assistance with further +1 reviews would be appreciated as that would help in accelerating confidence is getting +2 and merging.
Traditionally the project has relied on Arm folks but for some time now all contributors have had +1 rights on each other patches and the new project maintenance proposal is set up to take us in the direction of enabling all contributors helping each other.
Thanks
Joanna
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org<mailto:tf-a-bounces@lists.trustedfirmware.org>> on behalf of Pankaj Gupta via TF-A <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
Reply to: Pankaj Gupta <pankaj.gupta(a)nxp.com<mailto:pankaj.gupta@nxp.com>>
Date: Monday, 30 March 2020 at 20:48
To: "tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>" <tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>>
Subject: Re: [TF-A] [EXT] Patch-set review request: New NXP Platform LX2120ARDB support on TFA
Please find the link to the review request.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3370
Regards
Pankaj
From: Pankaj Gupta via TF-A
Sent: Monday, 30 March, 22:57
Subject: [EXT] [TF-A] Patch-set review request: New NXP Platform LX2120ARDB support on TFA
To: tf-a(a)lists.trustedfirmware.org<mailto:tf-a@lists.trustedfirmware.org>
Caution: EXT Email
Hi All,
Please pick this review request so that code changes can be merged before code freeze.
Thanks.
Regards
Pankaj
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
Hello team,
Please help review and merge the following bug fixes before v2.3 is released.
* https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3819: include: context_mgmt: include ep_info.h
* https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3820: Tegra: enable EHF for watchdog timer interrupts
* https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3818: Tegra: remove ENABLE_SVE_FOR_NS = 0
Thanks.
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Varun Wadekar via TF-A
Sent: Monday, March 30, 2020 10:02 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] RFR: Tegra fixes for v2.3
External email: Use caution opening links or attachments
Hello team,
Please help review and merge the following bug fixes before v2.3 is released.
* https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3731: Tegra: fixup GIC init from the 'on_finish' handler
* https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3770: Tegra186: increase memory mapped regions
Thanks.
________________________________
This email message is for the sole use of the intended recipient(s) and may contain confidential information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply email and destroy all copies of the original message.
________________________________
Hello Alexei,
Just curious, the patch is huge and will take some time to review. Do you expect this change to be merged before the v2.3 release?
-Varun
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Alexei Fedorov via TF-A
Sent: Tuesday, March 31, 2020 7:19 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Event Log for Measured Boot
External email: Use caution opening links or attachments
Hi,
Please review and provide your comments for the patch which adds
Event Log generation for the Measured Boot.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3806
Thanks.
Alexei
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
Hi Pankaj,
We will try, one of the arm team has done some +1 reviews and I have just kicked of a CI+2 run on the top of the patch stack. As you can imagine the Arm team is pressed for time the closer to the freeze date.
Other TF-A contributors you all have +1 rights so if folks have time assistance with further +1 reviews would be appreciated as that would help in accelerating confidence is getting +2 and merging.
Traditionally the project has relied on Arm folks but for some time now all contributors have had +1 rights on each other patches and the new project maintenance proposal is set up to take us in the direction of enabling all contributors helping each other.
Thanks
Joanna
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Pankaj Gupta via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Pankaj Gupta <pankaj.gupta(a)nxp.com>
Date: Monday, 30 March 2020 at 20:48
To: "tf-a(a)lists.trustedfirmware.org" <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] [EXT] Patch-set review request: New NXP Platform LX2120ARDB support on TFA
Please find the link to the review request.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3370
Regards
Pankaj
From: Pankaj Gupta via TF-A
Sent: Monday, 30 March, 22:57
Subject: [EXT] [TF-A] Patch-set review request: New NXP Platform LX2120ARDB support on TFA
To: tf-a(a)lists.trustedfirmware.org
Caution: EXT Email
Hi All,
Please pick this review request so that code changes can be merged before code freeze.
Thanks.
Regards
Pankaj
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi,
Please review and provide your comments for the patch which adds
Event Log generation for the Measured Boot.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3806
Thanks.
Alexei
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Please find the link to the review request.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3370
Regards
Pankaj
From: Pankaj Gupta via TF-A
Sent: Monday, 30 March, 22:57
Subject: [EXT] [TF-A] Patch-set review request: New NXP Platform LX2120ARDB support on TFA
To: tf-a(a)lists.trustedfirmware.org
Caution: EXT Email
Hi All,
Please pick this review request so that code changes can be merged before code freeze.
Thanks.
Regards
Pankaj
Hello team,
Please help review and merge the following bug fixes before v2.3 is released.
* https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3731: Tegra: fixup GIC init from the 'on_finish' handler
* https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3770: Tegra186: increase memory mapped regions
Thanks.
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
Hello,
As the prepartion for the series of patches for adding GICv3.1 and GICv4 support,
please review and provide your comments for the patch which introduces GICv3 makefile
and adds configuration options for the driver.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3754
Regards.
Alexei
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Raghu,
Thanks for reviewing the proposal. Please find my answers below.
1) The idea was to use the same hash algorithm throughout all TF-A
code for consistency and not introduce any new build flags. One of the
initial implementations even didn't calculate the hash itself but was
reading verified data provided by the Chain of Trust (CoT) for the
purpose of optimisation.
Existing definition of TF_MBEDTLS_HASH_ALG_ID in
'drivers\auth\mbedtls\mbedtls_common.mk' at line #76:
ifeq (${HASH_ALG}, sha384)
TF_MBEDTLS_HASH_ALG_ID := TF_MBEDTLS_SHA384
else ifeq (${HASH_ALG}, sha512)
TF_MBEDTLS_HASH_ALG_ID := TF_MBEDTLS_SHA512
else
TF_MBEDTLS_HASH_ALG_ID := TF_MBEDTLS_SHA256
endif
passed to 'include\drivers\auth\mbedtls\mbedtls_config.h', line #72
#define MBEDTLS_SHA256_C
#if (TF_MBEDTLS_HASH_ALG_ID != TF_MBEDTLS_SHA256)
#define MBEDTLS_SHA512_C
#endif
and used in Mbed TLS to define MBEDTLS_MD_MAX_SIZE in 'include\mbedtls\md.h':
#if defined(MBEDTLS_SHA512_C)
#define MBEDTLS_MD_MAX_SIZE 64 /* longest known is SHA512 */
#else
#define MBEDTLS_MD_MAX_SIZE 32 /* longest known is SHA256 or less */
#endif
makes impossible usage HASH_ALG=sha256 for TF-A and sha512 for Measured Boot
calculations, because the following chain of function calls
arm_bl1_set_bl2_hash() ->
crypto_mod_calc_hash() ->
crypto_lib_desc.calc_hash() ->
calc_hash() ->
mbedtls_md_info_from_type()
returns CRYPTO_ERR_HASH error caused by insufficient space in internal Mbed TLS
buffers and fixing this issue needs extra modifications in make and header files.
Upgrading/changing the hash algorithm will require re-building of TF-A and
re-flashing BL1 in ROM, so please explain what you mean by
"potentially break measured boot on old devices in case a hash algorithm is broken"
The functionality for getting the hash algorithm from the platform (e.g. eFuses)
can be added later as a platform build option and requires fixing the issue described
above.
2) Yes, Measured Boot requires TF-A built with TRUSTED_BOARD_BOOT option enabled,
and as BL2 image is a part of CoT it is verified by BL1.
3) Yes. Event Log implementation is based on TCG Specifications.
BL2 loads images, calculates their hashes and writes data into Event Log stored
in Secure memory.
4) It is planned to add fTPM service implementation to TF-A, see Javier's message:
https://lists.trustedfirmware.org/pipermail/tf-a/2020-March/000339.html
Stuart could also comment on the naming convention.
5) N/A
6) Event Log is a complex structure with entries of different lengths, and
TFTF test checks the length of each field against the remaining size of the Event Log's
data to be processed before accessing and printing the actual data.
Thanks.
Alexei.
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 21 March 2020 05:53
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Proposal for Measured Boot Implementation
Hi Alexei,
Thanks. This looks good at first glance. However, i do have some
questions that aren't obvious to me by reading the description below and
looking at code. Questions are numbered based on your original email.
Perhaps these can be discussed in the TF-A forum if it is inconvenient
over email.
1) Would be good if the hash alg comes from the config file. This will
make the implementation "crypto agile" from the very beginning. It is
common to want to upgrade/change the hash algorithm and since BL1 is in
ROM, you potentially break measured boot on old devices in case a hash
algorithm is broken. The other option is to get the hash algorithm from
the platform, perhaps a platform gets it from eFuses as opposed to
config files.
2) It looks like you are using memory allocated in the loaded DTB as the
equivalent of a TPM "PCR". How is this protected from direct
modification by BL2? Or is it not protected because BL2 forms a part of
the Root-of-Trust for Measurement(RTM)?(since it's signature is verified
by BL1?)
3) What does "Event Log" refer to? Is it the same event log proposed by
TCG in the platform firmware profile ? As a general question, how close
is the measured boot in TF-A/PSA going to be to TCG ? Will BL2 extend
measurements for other images ?
4) Would be great not to refer to "TPM" in the measured boot
implementation. Here we are implementing measured boot without a TPM,
but it could be implemented with a TPM. Maybe it should be tcg event log?
5) OK.
6) What does validate event log mean here? More details ?
Thanks
-Raghu
On 3/20/20 7:15 AM, Alexei Fedorov via TF-A wrote:
> Hello,
>
> I'm preparing the next set of patches for Measured Boot support in TF-A,
> please find some details on design and implementation below.
>
> 1. SHA256/384/512 hash algorithm for Measured Boot related hash calculations
> is passed as an existing build 'HASH_ALG' build parameter.
>
> 2. BL1 calculates BL2 image hash and passes these data to BL2 via
> FW_CONFIG/TB_FW_CONFIG device tree in new 'bl2_hash_data' byte array
> added
> in 'fvp_fw_config.dts'.
>
> These changes are part of the patch under review, please see
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3555
>
> 3. Event Log is calculated by BL2 in Secure Memory and copied to
> Non-secure memory. Address in Non-secure memory is calculated as:
>
> "nt_fw_config_addr + nt_fw_config_max_size"
>
> with values obtained from 'tb_fw_config':
>
> nt_fw_config_addr = <0x0 0x80000000>;
> nt_fw_config_max_size = <0x200>;
>
> 4. Event Log address and size is passed by TOS_FW_CONFIG and NT_FW_CONFIG
> device tree in 2 new added properties:
>
> Property name: 'tpm_event_log_addr'
> Value type is an unsigned 64-bit integer specifying the physical address
> of the Event Log.
>
> Property name: 'tpm_event_log_size'
> Value type is an unsigned 32-bit integer specifying the size of the
> Event Log.
>
> /* TPM Event Log Config */
> tpm_event_log {
> compatible = "arm,nt_fw";
> tpm_event_log_addr = <0x0 0x0>;
> tpm_event_log_size = <0x0>;
> };
>
> 5. TF-A provides Event Log to the BL33 (TFTF/UEFI/U-boot) in 'nt_fw_config'
> device tree, which address is passed by BL31 as 'arg0' parameter,
> see TFTF patch:
>
> https://review.trustedfirmware.org/c/TF-A/tf-a-tests/+/3327
>
> 6. A new test which validates and prints Event Log data passed
> in 'nt_fw_config' to BL33 will be added to TFTF.
>
> Please review and provide your comments on the proposed design.
>
> Regards.
> Alexei.
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy
> the information in any medium. Thank you.
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hello,
>But I am worried that a self-review is rarely as good as a peer review
On practice, unfortunately, some TF-M tasks are waiting weeks and even months for review and following approvals.
If I were a maintainer & owner of my own TFM area, I do not want to wait & push & remind somebody else.
Better to have a post-merge review for these cases, which does not limit and slow down the development.
Thanks,
Andrej Butok
-----Original Message-----
From: TF-M <tf-m-bounces(a)lists.trustedfirmware.org> On Behalf Of Sandrine Bailleux via TF-M
Sent: Thursday, March 26, 2020 10:28 AM
To: Christian Daudt <Christian.Daudt(a)cypress.com>; tf-a <tf-a(a)lists.trustedfirmware.org>; tf-m(a)lists.trustedfirmware.org; tsc(a)lists.trustedfirmware.org; op-tee(a)linaro.org
Cc: nd(a)arm.com
Subject: Re: [TF-M] Project Maintenance Proposal for tf.org Projects
Hi Christian,
Thanks a lot for the read and the comments!
On 3/25/20 7:05 PM, Christian Daudt wrote:
> �The maintenance proposal looks great ! I have some feedback on
> specific portions:
> �1. maintainer/owner/author patches. " Note that roles can be
> cumulative, in particular the same individual can be both a code owner
> and a maintainer. In such a scenario, the individual would be able to
> self-merge a patch solely affecting his module, having the authority
> to approve it from both a code owner and maintainer's point of view.":
> I'm always leery of people self-approving their patches. At a minimum,
> all self-patches should be published and a minimum wait time provided
> for feedback. Or preferably that another maintainer does the merge (it
> does not need to be mandated but should be suggested).
Yes, actually this is something that generated some disagreement inside Arm as well and I am glad you're bringing this up here, as I'd like to hear more opinions on this.
I too have concerns about allowing self-reviewing. I am not so much concerned about people potentially abusing of this situation to silently merge patches, as I think we should trust our maintainers. But I am worried that a self-review is rarely as good as a peer review, simply because it is so easy to miss things when it's your own work. I believe several pair of eyes is always better, as different people think differently, have different perspectives and backgrounds, and are able to catch different issues.
But to pull this off, we need enough people to do all these reviews. The proposal currently allows self-review because some of us feared that mandating 2 reviewers for every patch (especially pure platform patches) would be impractical and too heavyweight, especially for the TF-M project in its current contributors organization, as I understand. It would be great to get more feedback from the TF-M community as to whether they think it could work in the end.
It's a difficult balance between having the best possible code review practices, and realistically getting all the review work done in a timely manner, avoiding bottlenecks on specific people and keeping the flow of patches smooth.
I like your idea of a minimum wait time provided for feedback. I think it could be a good middle ground solution.
Your other suggestion of having a different maintainer doing the merge would work as well IMO but requires more workforce. Again this comes down to whether this can realistically be achieved for each project.
This solution was actually suggested within Arm as well (and even called out at the end of the proposal ;) ).
Bottom line is, in an ideal world I would like to condemn self-review because I consider this as bad practice, but I do not know whether this will be practical and will work for TF-M as well.
> �2. 'timely manner': This expectation should be more explicit -
> when the author can start requesting other maintainers to merge on
> assumption that silence == approval (or not). Such timeliness
> expectations are probably best set per project however.
Yes, "timely manner" is definitely too vague and was actually left that way on purpose at this stage to avoid touching upon what I think is a sensitive subject! I am aware that some patches sometimes spend a long time in review, definitely longer than they should and it understandably generates some frustration. This is something we absolutely need to improve on IMO and hopefully a bigger pool of maintainers will help solve this issue. But I agree that the expected review timeline should be clearly established and it is probably best to let each project decides theirs.
> �3. The proposal does not address branching strategies. i.e. will
> there be separate maintainers for dev/master/stable branches? I don't
> think it needs to address it yet - keep it simpler for a start. But a
> todo saying something like "in the future this project maintenance
> proposal might be expanded to address multi-branch maintainership" would be good.
Good point. A todo sounds good, I will add one in the last section of the document.
> �4. The platform lifecycle state machine has too many transitions.
> "Fully maintained" <-> "orphan" -> "out" seems sufficient to me.
Hmm OK. There might be too many transitions but I feel we need something between fully maintained and out, i.e. the limited support one.
Julius Werner also pointed out on Thursday that orphan might be misplaced, as all these other stages deal with some degrees of feature support (what's known to work), whereas orphan is an orthogonal topic that is not directly related to the level of supported features. For example, a platform could have recently become orphan but all features and tests still work for some time.
Regards,
Sandrine
--
TF-M mailing list
TF-M(a)lists.trustedfirmware.org
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.tru…
Hello,
Following up with the Proposal for Measured Boot Implementation
described in
https://lists.trustedfirmware.org/pipermail/tf-a/2020-March/000332.html
, I am working on the implementation of a test fTPM service to exercise
Measured Boot on TF-A.
Some details about the implementation can be found below:
1.- The service will be based on Microsoft's reference implementation
of the TPM 2.0 Specification by TCG. It will be implemented as an OP-
TEE TA.
2.- During service initialisation, the fTPM service will read the TPM
Event Log stored by Measured Boot in Secure Memory and it will extend
it into the PCR specified by the log header.
3.- Alongside with the fTPM service, a test framework based on OP-TEE
Toolkit is being implemented as well. This test framework will generate
and run a Linux/Buildroot environment over a Foundation Model so the
fTPM's PCRs can be accessed to verify its content.
It is important here to highlight that this fTPM service and the
related test framework are meant to be used only for demonstration
purposes, it is not meant to be used as a production implementation.
Please, let me know any comment or query you might have with regards
this.
Best regards,
Javier
Hi,
This is to notify that we are planning to target the Trusted Firmware-A 2.3 release during the third week of April as part of the regular 6 month cadence. The aim is to consolidate all TF-A work since the 2.2 release. As part of this, a release candidate tag will be created and release activities will commence from Monday April 6th. Essentially we will not merge any major enhancements from this date until the release is made. Please ensure any Pull Requests (PR's) desired to make the 2.2 release are submitted in good time to be complete by Friday April 3rd. Any major enhancement PR's still open after that date will not be merged until after the release.
Thanks & best regards,
[cid:image001.jpg@01D5F78C.8108B010]
Bipin Ravi | Principal Design Enginee
Bipin.ravi(a)arm.com<mailto:Bipin.ravi@arm.com> | Skype: Bipin.Ravi.ARM
Direct: +1-512-225 -1071 | Mobile: +1-214-212-0794
5707 Southwest Parkway, Suite 100, Austin, TX 78735
Hello all,
As the developers community at trustedfirmware.org is growing, there is
an increasing need to have work processes that are clearly documented,
feel smooth and scale well. We think that there is an opportunity to
improve the way the trustedfirmware.org projects are managed today.
That's why we are sharing a project maintenance proposal, focusing on
the TF-A and TF-M projects initially. The aim of this document is to
propose a set of rules, guidelines and processes to try and improve the
way we work together as a community today.
Note that this is an early draft at this stage. This is put up for
further discussion within the trustedfirmware.org community. Nothing is
set in stone yet and it is expected to go under change as feedback from
the community is incorporated.
Please find the initial proposal here:
https://developer.trustedfirmware.org/w/collaboration/project-maintenance-p…
Please provide any feedback you may have by replying to this email
thread, keeping all 4 mailing lists in the recipients list.
I will collate comments from the community and try to incorporate them
in the document, keeping you updated on changes made between revisions.
Regards,
Sandrine
Hi Victor,
There's currently no plan to support Trusted Debug Control, primarily for the lack of an available platform IP component requiring it.
Are you aware of a specific need for a real platform, that could also be available for testing the implementation?
Thanks
Matteo
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Victor Duan via TF-A
Sent: 18 March 2020 01:35
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Trusted Debug Control
Trusted Debug Control specified by TBBR CLIENT is as not supported in the current TF-A v2.2. Is there any plan to support it in the future?
Thank you!
Hi Alexei,
Thanks. This looks good at first glance. However, i do have some
questions that aren't obvious to me by reading the description below and
looking at code. Questions are numbered based on your original email.
Perhaps these can be discussed in the TF-A forum if it is inconvenient
over email.
1) Would be good if the hash alg comes from the config file. This will
make the implementation "crypto agile" from the very beginning. It is
common to want to upgrade/change the hash algorithm and since BL1 is in
ROM, you potentially break measured boot on old devices in case a hash
algorithm is broken. The other option is to get the hash algorithm from
the platform, perhaps a platform gets it from eFuses as opposed to
config files.
2) It looks like you are using memory allocated in the loaded DTB as the
equivalent of a TPM "PCR". How is this protected from direct
modification by BL2? Or is it not protected because BL2 forms a part of
the Root-of-Trust for Measurement(RTM)?(since it's signature is verified
by BL1?)
3) What does "Event Log" refer to? Is it the same event log proposed by
TCG in the platform firmware profile ? As a general question, how close
is the measured boot in TF-A/PSA going to be to TCG ? Will BL2 extend
measurements for other images ?
4) Would be great not to refer to "TPM" in the measured boot
implementation. Here we are implementing measured boot without a TPM,
but it could be implemented with a TPM. Maybe it should be tcg event log?
5) OK.
6) What does validate event log mean here? More details ?
Thanks
-Raghu
On 3/20/20 7:15 AM, Alexei Fedorov via TF-A wrote:
> Hello,
>
> I'm preparing the next set of patches for Measured Boot support in TF-A,
> please find some details on design and implementation below.
>
> 1. SHA256/384/512 hash algorithm for Measured Boot related hash calculations
> is passed as an existing build 'HASH_ALG' build parameter.
>
> 2. BL1 calculates BL2 image hash and passes these data to BL2 via
> FW_CONFIG/TB_FW_CONFIG device tree in new 'bl2_hash_data' byte array
> added
> in 'fvp_fw_config.dts'.
>
> These changes are part of the patch under review, please see
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3555
>
> 3. Event Log is calculated by BL2 in Secure Memory and copied to
> Non-secure memory. Address in Non-secure memory is calculated as:
>
> "nt_fw_config_addr + nt_fw_config_max_size"
>
> with values obtained from 'tb_fw_config':
>
> nt_fw_config_addr = <0x0 0x80000000>;
> nt_fw_config_max_size = <0x200>;
>
> 4. Event Log address and size is passed by TOS_FW_CONFIG and NT_FW_CONFIG
> device tree in 2 new added properties:
>
> Property name: 'tpm_event_log_addr'
> Value type is an unsigned 64-bit integer specifying the physical address
> of the Event Log.
>
> Property name: 'tpm_event_log_size'
> Value type is an unsigned 32-bit integer specifying the size of the
> Event Log.
>
> /* TPM Event Log Config */
> tpm_event_log {
> compatible = "arm,nt_fw";
> tpm_event_log_addr = <0x0 0x0>;
> tpm_event_log_size = <0x0>;
> };
>
> 5. TF-A provides Event Log to the BL33 (TFTF/UEFI/U-boot) in 'nt_fw_config'
> device tree, which address is passed by BL31 as 'arg0' parameter,
> see TFTF patch:
>
> https://review.trustedfirmware.org/c/TF-A/tf-a-tests/+/3327
>
> 6. A new test which validates and prints Event Log data passed
> in 'nt_fw_config' to BL33 will be added to TFTF.
>
> Please review and provide your comments on the proposed design.
>
> Regards.
> Alexei.
>
> IMPORTANT NOTICE: The contents of this email and any attachments are
> confidential and may also be privileged. If you are not the intended
> recipient, please notify the sender immediately and do not disclose the
> contents to any other person, use it for any purpose, or store or copy
> the information in any medium. Thank you.
>
>> As a general reminder, it is up to the developer to document changes in common TF-A code that is relevant in the "Upcoming Change Log" file.
Thanks for highlighting this. For Tegra platforms, we will provide up to date information to the platform change log after 2.3. We will have to live with the current state of the log for 2.3.
>> Reviewers please continue to help determine if documentation is required for a given patch.
Curious, have there been discussions around automating this somehow? E.g. add a tag to the commit message for a script to pick later.
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Lauren Wehrmeister via TF-A
Sent: Tuesday, March 17, 2020 10:51 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Platforms to maintain their own Change Log files following 2.3 Release
External email: Use caution opening links or attachments
Hi All,
Following the TF-A release planned for April, platforms will be expected to maintain their own Change Log files to document relevant changes in platform specific code. The common TF-A Change Log will no longer document Platform specific updates after the 2.3 release.
As a general reminder, it is up to the developer to document changes in common TF-A code that is relevant in the "Upcoming Change Log" file. Reviewers please continue to help determine if documentation is required for a given patch. During each code freeze for a release the documentation in the upcoming change log will be moved to the change log corresponding to the release.
Thanks,
Lauren Wehrmeister
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
Hello,
I'm preparing the next set of patches for Measured Boot support in TF-A,
please find some details on design and implementation below.
1. SHA256/384/512 hash algorithm for Measured Boot related hash calculations
is passed as an existing build 'HASH_ALG' build parameter.
2. BL1 calculates BL2 image hash and passes these data to BL2 via
FW_CONFIG/TB_FW_CONFIG device tree in new 'bl2_hash_data' byte array added
in 'fvp_fw_config.dts'.
These changes are part of the patch under review, please see
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3555
3. Event Log is calculated by BL2 in Secure Memory and copied to
Non-secure memory. Address in Non-secure memory is calculated as:
"nt_fw_config_addr + nt_fw_config_max_size"
with values obtained from 'tb_fw_config':
nt_fw_config_addr = <0x0 0x80000000>;
nt_fw_config_max_size = <0x200>;
4. Event Log address and size is passed by TOS_FW_CONFIG and NT_FW_CONFIG
device tree in 2 new added properties:
Property name: 'tpm_event_log_addr'
Value type is an unsigned 64-bit integer specifying the physical address
of the Event Log.
Property name: 'tpm_event_log_size'
Value type is an unsigned 32-bit integer specifying the size of the Event Log.
/* TPM Event Log Config */
tpm_event_log {
compatible = "arm,nt_fw";
tpm_event_log_addr = <0x0 0x0>;
tpm_event_log_size = <0x0>;
};
5. TF-A provides Event Log to the BL33 (TFTF/UEFI/U-boot) in 'nt_fw_config'
device tree, which address is passed by BL31 as 'arg0' parameter, see TFTF patch:
https://review.trustedfirmware.org/c/TF-A/tf-a-tests/+/3327
6. A new test which validates and prints Event Log data passed
in 'nt_fw_config' to BL33 will be added to TFTF.
Please review and provide your comments on the proposed design.
Regards.
Alexei.
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi All,
The second TF-A Tech Forum is scheduled for next week for Thu 26 Mar 2020 17:00 - 18:00 (GMT). A reoccurring meeting invite has been sent out to the subscribers of this TF-A mailing list. If you don’t have this please let me know.
I have an agenda for next week however for future meetings if other project contributors would also like to present on topics please reach out to me and I will look to schedule.
Agenda:
* Technical Overview of the Fconf (Firmware Configuration) Feature by Louis Mayencourt
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
You have been invited to the following event.
Title: TF-A Tech Forum
We run an open technical forum call for anyone to participate and it is not
restricted to Trusted Firmware project members. It will operate under the
guidance of the TF TSC. Feel free to forward this invite to
colleagues. Invites are via the TF-A mailing list and also published on the
Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558 8656
US (New York) +1 669 900 9128 US (San
Jose) 877 853 5247 US Toll-free
888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your
local number: https://zoom.us/u/ad27hc6t7h
When: Every 2 weeks from 17:00 to 18:00 on Thursday United Kingdom Time
Where: Zoom
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
(Guest list has been hidden at organiser's request)
Event details:
https://www.google.com/calendar/event?action=VIEW&eid=N3ZoNDBuZzZnM2k4cGszY…
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
Hi All,
Following the TF-A release planned for April, platforms will be expected to maintain their own Change Log files to document relevant changes in platform specific code. The common TF-A Change Log will no longer document Platform specific updates after the 2.3 release.
As a general reminder, it is up to the developer to document changes in common TF-A code that is relevant in the "Upcoming Change Log" file. Reviewers please continue to help determine if documentation is required for a given patch. During each code freeze for a release the documentation in the upcoming change log will be moved to the change log corresponding to the release.
Thanks,
Lauren Wehrmeister
Hello team,
This is an email requesting reviews for the latest Tegra platform changes [1] from our downstream branch.
Please review these changes at the earliest and help us get them merged before the release candidate tag is generated. We hope to push one more batch for v2.3, after [1] gets merged.
Thanks in advance.
Varun
[1] https://review.trustedfirmware.org/q/topic:%22tegra-downstream-03122020%22+…
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
Hi Sumit,
On 3/4/20 4:55 PM, Sumit Garg via TF-A wrote:
>> The last remaining item would be to address the MISRA violations
>> that Coverity found, which I've copied & pasted for you on Gerrit in the
>> top patch.
>
> I have tried to address most of MISRA violations and updated the
> patch-set. But since I don't have access to Coverity tool you are
> using, so can you please check if there is any relevant MISRA
> violation that I missed?
Sure, I will re-run the tool in our internal CI and let you know the
results.
>> Also, this feature is only used on QEMU right now and I am not aware of
>> anyone trying to enable it for their platforms just yet. Thus there is a
>> risk we might have overlooked some issues that we'll discover at that time.
>
> Socionext being a silicon vendor is actively looking for this feature
> and I think they will build upon this feature to enable firmware
> encryption on their platforms to meet DRM robustness rules.
Interesting, thanks for sharing this information.
>> Furthermore, I know that you've done some testing of this feature on
>> QEMU but this is not integrated into the CI loop right now. Thus, there
>> is a risk that we might break it in the future and this will go
>> unnoticed, unless you plan to test it regularly on your end.
>
> Yeah we should plan to enable testing for this feature in CI loop.
For now, I've added in our internal CI a simple build test based on the
build instructions you've provided in the patch set. This will at least
make sure we do not break the build inadvertently in the future.
But as you say, going forward, we should plan for proper testing on
QEMU. I am hoping we will soon be able to extend the OpenCI [1] and add
this support there.
[1]
https://lists.trustedfirmware.org/pipermail/tf-a/2020-February/000264.html
>> * Saying so in the (upcoming) change log.
>
> I hope you can take care of this.
Actually this is something you have access to, it's a matter of adding a
line in docs/change-log-upcoming.rst in the TF-A source tree.
Regards,
Sandrine
Hi Everyone,
I have tried to address most of the implementation concerns with updated
patch-set [1] as follows:
*Concern*: Firmware encryption bit needs to be signed
*Address*: Moved the firmware encryption bit from FIP ToC header to
"io_uuid_spec_t" struct which is part of "plat_io_policy" that is embedded
in the boot-loader (BL1 or BL2) and hence firmware encryption bit is signed.
Also, with this implementation fip_tool is no longer aware of encryption
and just encrypted binaries are piped to fip_tool.
*Concern*: Capability to encrypt with different keys for different images
*Address*: Passed "img_id" buffer reference as an argument of
"plat_get_enc_key_info()" API. So that platforms may choose to either
provide a unique key per firmware image or just derive a key from HUK per
firmware using "img_id" buffer as a salt.
*Concern*: Coupling of FIP and encryption layer
*Address*: Firstly I think we all can agree that encryption layer provides
confidentiality protection specific to IO storage. Secondly FIP is actually
a packaging layer that sits over actual IO layer and having the encryption
layer coupled with FIP provides an abstraction layer for any FIP payload
which in turn provides the following features:
1. Allows the firmware certificates to be encrypted as well to protect
against cloning satisfying R050_TBBR_PROTECTION requirement.
2. Allows the firmware configuration data to be encrypted as well.
3. Provides a capability to have a secure key store as FIP payload which is
protected using HUK.
*Concern*: Allow usage of alternative verify-then-decrypt method
*Address*: A platform could disable this encryption layer and implement
decryption as part of "bl2_plat_handle_post_image_load()".
Please let me know in case I missed any implementation concerns and feel
free to provide your feedback on updated patch-set [1].
[1]
https://review.trustedfirmware.org/q/topic:%22tbbr%252Ffw_enc%22+(status:op…
Regards,
Sumit
Hi Masahiro,
That warning is expected. GCC complains about this, since tf_base_xlat_table is not constant and we are asking it to be put in a read-only section (see the REGISTER_XLAT_CONTEXT_RO_BASE_TABLE macro). This is fine since:
* We only want the base table to be read-only after the tables have been initialized. The only time we change tf_base_xlat_table is when we initialize it, and at that point in the platform setup sequence the MMU is off, so permissions have no effect.
* We never write to this with the MMU on (it's the level 1 translation table), so there is no danger of generating MMU faults.
I hope this answers your question.
Thanks
Petre
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Masahiro Yamada via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 06 March 2020 12:30
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Incorrect section attributes with ALLOW_RO_XLAT_TABLES=1
Hi.
If I build TF-A with ALLOW_RO_XLAT_TABLES=1,
the base xlat table goes into .rodata section
instead of .bss section.
Then, I see a warning like:
/tmp/ccswitLr.s: Assembler messages:
/tmp/ccswitLr.s:297: Warning: setting incorrect section attributes for .rodata
Is this a know issue?
[Reproduce Command]
make PLAT=fvp CROSS_COMPILE=aarch64-linux-gnu- ALLOW_RO_XLAT_TABLES=1
The full build log is below:
masahiro@pug:~/ref/trusted-firmware-a$ make PLAT=fvp
CROSS_COMPILE=aarch64-linux-gnu- ALLOW_RO_XLAT_TABLES=1
CC lib/libfdt/fdt.c
CC lib/libfdt/fdt_addresses.c
CC lib/libfdt/fdt_empty_tree.c
CC lib/libfdt/fdt_ro.c
CC lib/libfdt/fdt_rw.c
CC lib/libfdt/fdt_strerror.c
CC lib/libfdt/fdt_sw.c
CC lib/libfdt/fdt_wip.c
AR build/fvp/release/lib/libfdt.a
Building fvp
CC lib/libc/abort.c
CC lib/libc/assert.c
CC lib/libc/exit.c
CC lib/libc/memchr.c
CC lib/libc/memcmp.c
CC lib/libc/memcpy.c
CC lib/libc/memmove.c
CC lib/libc/memrchr.c
CC lib/libc/memset.c
CC lib/libc/printf.c
CC lib/libc/putchar.c
CC lib/libc/puts.c
CC lib/libc/snprintf.c
CC lib/libc/strchr.c
CC lib/libc/strcmp.c
CC lib/libc/strlcpy.c
CC lib/libc/strlen.c
CC lib/libc/strncmp.c
CC lib/libc/strnlen.c
CC lib/libc/strrchr.c
AS lib/libc/aarch64/setjmp.S
AR build/fvp/release/lib/libc.a
CC drivers/arm/smmu/smmu_v3.c
CC drivers/arm/sp805/sp805.c
CC drivers/delay_timer/delay_timer.c
CC drivers/io/io_semihosting.c
CC lib/semihosting/semihosting.c
CC plat/arm/board/fvp/fvp_bl1_setup.c
CC plat/arm/board/fvp/fvp_err.c
CC plat/arm/board/fvp/fvp_io_storage.c
CC drivers/arm/cci/cci.c
CC drivers/delay_timer/generic_delay_timer.c
CC drivers/cfi/v2m/v2m_flash.c
CC drivers/io/io_fip.c
CC drivers/io/io_memmap.c
CC drivers/io/io_storage.c
CC plat/arm/common/arm_bl1_setup.c
CC plat/arm/common/arm_err.c
CC plat/arm/common/arm_fconf_io_storage.c
CC plat/arm/common/fconf/arm_fconf_io.c
CC lib/fconf/fconf.c
CC lib/fconf/fconf_dyn_cfg_getter.c
CC plat/arm/common/arm_dyn_cfg.c
CC plat/arm/common/arm_dyn_cfg_helpers.c
CC common/fdt_wrappers.c
CC bl1/bl1_main.c
CC bl1/aarch64/bl1_arch_setup.c
CC bl1/aarch64/bl1_context_mgmt.c
CC lib/cpus/errata_report.c
CC lib/el3_runtime/aarch64/context_mgmt.c
CC plat/common/plat_bl1_common.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS lib/semihosting/aarch64/semihosting_call.S
AS plat/arm/board/fvp/aarch64/fvp_helpers.S
AS lib/cpus/aarch64/aem_generic.S
AS lib/cpus/aarch64/cortex_a35.S
AS lib/cpus/aarch64/cortex_a53.S
AS lib/cpus/aarch64/cortex_a57.S
AS lib/cpus/aarch64/cortex_a72.S
AS lib/cpus/aarch64/cortex_a73.S
AS bl1/aarch64/bl1_entrypoint.S
AS bl1/aarch64/bl1_exceptions.S
AS lib/cpus/aarch64/cpu_helpers.S
AS plat/common/aarch64/platform_up_stack.S
AS lib/cpus/aarch64/dsu_helpers.S
AS lib/el3_runtime/aarch64/context.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl1/bl1.ld.S
LD build/fvp/release/bl1/bl1.elf
BIN build/fvp/release/bl1.bin
Built build/fvp/release/bl1.bin successfully
OD build/fvp/release/bl1/bl1.dump
CC drivers/arm/sp805/sp805.c
CC drivers/io/io_semihosting.c
CC lib/utils/mem_region.c
CC lib/semihosting/semihosting.c
CC plat/arm/board/fvp/fvp_bl2_setup.c
CC plat/arm/board/fvp/fvp_err.c
CC plat/arm/board/fvp/fvp_io_storage.c
CC plat/arm/common/arm_nor_psci_mem_protect.c
CC drivers/arm/tzc/tzc400.c
CC plat/arm/board/fvp/fvp_security.c
CC plat/arm/common/arm_tzc400.c
CC drivers/cfi/v2m/v2m_flash.c
CC drivers/delay_timer/delay_timer.c
CC drivers/delay_timer/generic_delay_timer.c
CC drivers/io/io_fip.c
CC drivers/io/io_memmap.c
CC drivers/io/io_storage.c
CC plat/arm/common/arm_bl2_setup.c
CC plat/arm/common/arm_err.c
CC plat/arm/common/arm_fconf_io_storage.c
CC plat/arm/common/fconf/arm_fconf_io.c
CC lib/fconf/fconf.c
CC lib/fconf/fconf_dyn_cfg_getter.c
CC plat/arm/common/arm_dyn_cfg.c
CC plat/arm/common/arm_dyn_cfg_helpers.c
CC common/fdt_wrappers.c
CC plat/arm/common/aarch64/arm_bl2_mem_params_desc.c
CC plat/arm/common/arm_image_load.c
CC common/desc_image_load.c
CC bl2/bl2_image_load_v2.c
CC bl2/bl2_main.c
CC bl2/aarch64/bl2_arch_setup.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS lib/semihosting/aarch64/semihosting_call.S
AS lib/locks/exclusive/aarch64/spinlock.S
AS plat/common/aarch64/platform_up_stack.S
AS common/aarch64/early_exceptions.S
AS bl2/aarch64/bl2_entrypoint.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl2/bl2.ld.S
LD build/fvp/release/bl2/bl2.elf
BIN build/fvp/release/bl2.bin
Built build/fvp/release/bl2.bin successfully
OD build/fvp/release/bl2/bl2.dump
CC drivers/arm/fvp/fvp_pwrc.c
CC drivers/arm/smmu/smmu_v3.c
CC drivers/delay_timer/delay_timer.c
CC drivers/cfi/v2m/v2m_flash.c
CC lib/utils/mem_region.c
CC plat/arm/board/fvp/fvp_bl31_setup.c
CC plat/arm/board/fvp/fvp_pm.c
CC plat/arm/board/fvp/fvp_topology.c
CC plat/arm/common/arm_nor_psci_mem_protect.c
CC drivers/arm/gic/common/gic_common.c
CC drivers/arm/gic/v3/gicv3_main.c
CC drivers/arm/gic/v3/gicv3_helpers.c
CC plat/common/plat_gicv3.c
CC plat/arm/common/arm_gicv3.c
CC drivers/arm/gic/v3/gic500.c
CC drivers/arm/cci/cci.c
CC drivers/arm/tzc/tzc400.c
CC plat/arm/board/fvp/fvp_security.c
CC plat/arm/common/arm_tzc400.c
CC drivers/delay_timer/generic_delay_timer.c
CC lib/cpus/aarch64/cpuamu.c
CC plat/arm/common/arm_bl31_setup.c
CC plat/arm/common/arm_pm.c
CC plat/arm/common/arm_topology.c
CC plat/common/plat_psci_common.c
CC plat/arm/common/aarch64/execution_state_switch.c
CC plat/arm/common/arm_sip_svc.c
CC lib/pmf/pmf_smc.c
CC bl31/bl31_main.c
CC bl31/interrupt_mgmt.c
CC bl31/bl31_context_mgmt.c
CC common/runtime_svc.c
CC services/arm_arch_svc/arm_arch_svc_setup.c
CC services/std_svc/std_svc_setup.c
CC lib/el3_runtime/cpu_data_array.c
CC lib/el3_runtime/aarch64/context_mgmt.c
CC lib/cpus/errata_report.c
CC lib/psci/psci_off.c
CC lib/psci/psci_on.c
CC lib/psci/psci_suspend.c
CC lib/psci/psci_common.c
CC lib/psci/psci_main.c
CC lib/psci/psci_setup.c
CC lib/psci/psci_system_off.c
CC lib/psci/psci_mem_protect.c
CC lib/locks/bakery/bakery_lock_coherent.c
CC lib/psci/psci_stat.c
CC lib/pmf/pmf_main.c
CC lib/extensions/spe/spe.c
CC lib/extensions/amu/aarch64/amu.c
CC lib/extensions/sve/sve.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
/tmp/ccswitLr.s: Assembler messages:
/tmp/ccswitLr.s:297: Warning: setting incorrect section attributes for .rodata
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS plat/arm/board/fvp/aarch64/fvp_helpers.S
AS lib/cpus/aarch64/aem_generic.S
AS lib/cpus/aarch64/cortex_a35.S
AS lib/cpus/aarch64/cortex_a53.S
AS lib/cpus/aarch64/cortex_a57.S
AS lib/cpus/aarch64/cortex_a72.S
AS lib/cpus/aarch64/cortex_a73.S
AS lib/cpus/aarch64/cpuamu_helpers.S
AS bl31/aarch64/bl31_entrypoint.S
AS bl31/aarch64/crash_reporting.S
AS bl31/aarch64/ea_delegate.S
AS bl31/aarch64/runtime_exceptions.S
AS lib/cpus/aarch64/dsu_helpers.S
AS plat/common/aarch64/platform_mp_stack.S
AS lib/el3_runtime/aarch64/cpu_data.S
AS lib/cpus/aarch64/cpu_helpers.S
AS lib/locks/exclusive/aarch64/spinlock.S
AS lib/psci/aarch64/psci_helpers.S
AS lib/el3_runtime/aarch64/context.S
AS lib/extensions/amu/aarch64/amu_helpers.S
AS lib/cpus/aarch64/wa_cve_2017_5715_bpiall.S
AS lib/cpus/aarch64/wa_cve_2017_5715_mmu.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl31/bl31.ld.S
LD build/fvp/release/bl31/bl31.elf
BIN build/fvp/release/bl31.bin
Built build/fvp/release/bl31.bin successfully
OD build/fvp/release/bl31/bl31.dump
CC plat/arm/board/fvp/fvp_bl2u_setup.c
CC drivers/arm/tzc/tzc400.c
CC plat/arm/board/fvp/fvp_security.c
CC plat/arm/common/arm_tzc400.c
CC drivers/delay_timer/delay_timer.c
CC drivers/delay_timer/generic_delay_timer.c
CC plat/arm/common/arm_bl2u_setup.c
CC bl2u/bl2u_main.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS bl2u/aarch64/bl2u_entrypoint.S
AS plat/common/aarch64/platform_up_stack.S
AS common/aarch64/early_exceptions.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl2u/bl2u.ld.S
LD build/fvp/release/bl2u/bl2u.elf
BIN build/fvp/release/bl2u.bin
Built build/fvp/release/bl2u.bin successfully
OD build/fvp/release/bl2u/bl2u.dump
CPP plat/arm/board/fvp/fdts/fvp_fw_config.dts
DTC plat/arm/board/fvp/fdts/fvp_fw_config.dts
CPP plat/arm/board/fvp/fdts/fvp_soc_fw_config.dts
DTC plat/arm/board/fvp/fdts/fvp_soc_fw_config.dts
CPP plat/arm/board/fvp/fdts/fvp_nt_fw_config.dts
DTC plat/arm/board/fvp/fdts/fvp_nt_fw_config.dts
CPP fdts/fvp-base-gicv3-psci.dts
DTC fdts/fvp-base-gicv3-psci.dts
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:215.20-220.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/flash@0,00000000:
simple-bus unit address format error, expected "0"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:221.19-224.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/vram@2,00000000:
simple-bus unit address format error, expected "200000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:225.23-229.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/ethernet@2,02000000:
simple-bus unit address format error, expected "202000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:230.26-235.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/clk24mhz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:236.30-241.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/refclk1mhz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:242.32-247.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/refclk32khz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:248.21-370.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/iofpga@3,00000000:
simple-bus unit address format error, expected "300000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:371.33-377.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/fixedregulator: missing
or empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:381.21-387.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/osc: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:388.12-391.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/muxfpga: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:392.12-395.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/dvimode: missing or
empty reg/ranges property
--
Best Regards
Masahiro Yamada
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi.
If I build TF-A with ALLOW_RO_XLAT_TABLES=1,
the base xlat table goes into .rodata section
instead of .bss section.
Then, I see a warning like:
/tmp/ccswitLr.s: Assembler messages:
/tmp/ccswitLr.s:297: Warning: setting incorrect section attributes for .rodata
Is this a know issue?
[Reproduce Command]
make PLAT=fvp CROSS_COMPILE=aarch64-linux-gnu- ALLOW_RO_XLAT_TABLES=1
The full build log is below:
masahiro@pug:~/ref/trusted-firmware-a$ make PLAT=fvp
CROSS_COMPILE=aarch64-linux-gnu- ALLOW_RO_XLAT_TABLES=1
CC lib/libfdt/fdt.c
CC lib/libfdt/fdt_addresses.c
CC lib/libfdt/fdt_empty_tree.c
CC lib/libfdt/fdt_ro.c
CC lib/libfdt/fdt_rw.c
CC lib/libfdt/fdt_strerror.c
CC lib/libfdt/fdt_sw.c
CC lib/libfdt/fdt_wip.c
AR build/fvp/release/lib/libfdt.a
Building fvp
CC lib/libc/abort.c
CC lib/libc/assert.c
CC lib/libc/exit.c
CC lib/libc/memchr.c
CC lib/libc/memcmp.c
CC lib/libc/memcpy.c
CC lib/libc/memmove.c
CC lib/libc/memrchr.c
CC lib/libc/memset.c
CC lib/libc/printf.c
CC lib/libc/putchar.c
CC lib/libc/puts.c
CC lib/libc/snprintf.c
CC lib/libc/strchr.c
CC lib/libc/strcmp.c
CC lib/libc/strlcpy.c
CC lib/libc/strlen.c
CC lib/libc/strncmp.c
CC lib/libc/strnlen.c
CC lib/libc/strrchr.c
AS lib/libc/aarch64/setjmp.S
AR build/fvp/release/lib/libc.a
CC drivers/arm/smmu/smmu_v3.c
CC drivers/arm/sp805/sp805.c
CC drivers/delay_timer/delay_timer.c
CC drivers/io/io_semihosting.c
CC lib/semihosting/semihosting.c
CC plat/arm/board/fvp/fvp_bl1_setup.c
CC plat/arm/board/fvp/fvp_err.c
CC plat/arm/board/fvp/fvp_io_storage.c
CC drivers/arm/cci/cci.c
CC drivers/delay_timer/generic_delay_timer.c
CC drivers/cfi/v2m/v2m_flash.c
CC drivers/io/io_fip.c
CC drivers/io/io_memmap.c
CC drivers/io/io_storage.c
CC plat/arm/common/arm_bl1_setup.c
CC plat/arm/common/arm_err.c
CC plat/arm/common/arm_fconf_io_storage.c
CC plat/arm/common/fconf/arm_fconf_io.c
CC lib/fconf/fconf.c
CC lib/fconf/fconf_dyn_cfg_getter.c
CC plat/arm/common/arm_dyn_cfg.c
CC plat/arm/common/arm_dyn_cfg_helpers.c
CC common/fdt_wrappers.c
CC bl1/bl1_main.c
CC bl1/aarch64/bl1_arch_setup.c
CC bl1/aarch64/bl1_context_mgmt.c
CC lib/cpus/errata_report.c
CC lib/el3_runtime/aarch64/context_mgmt.c
CC plat/common/plat_bl1_common.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS lib/semihosting/aarch64/semihosting_call.S
AS plat/arm/board/fvp/aarch64/fvp_helpers.S
AS lib/cpus/aarch64/aem_generic.S
AS lib/cpus/aarch64/cortex_a35.S
AS lib/cpus/aarch64/cortex_a53.S
AS lib/cpus/aarch64/cortex_a57.S
AS lib/cpus/aarch64/cortex_a72.S
AS lib/cpus/aarch64/cortex_a73.S
AS bl1/aarch64/bl1_entrypoint.S
AS bl1/aarch64/bl1_exceptions.S
AS lib/cpus/aarch64/cpu_helpers.S
AS plat/common/aarch64/platform_up_stack.S
AS lib/cpus/aarch64/dsu_helpers.S
AS lib/el3_runtime/aarch64/context.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl1/bl1.ld.S
LD build/fvp/release/bl1/bl1.elf
BIN build/fvp/release/bl1.bin
Built build/fvp/release/bl1.bin successfully
OD build/fvp/release/bl1/bl1.dump
CC drivers/arm/sp805/sp805.c
CC drivers/io/io_semihosting.c
CC lib/utils/mem_region.c
CC lib/semihosting/semihosting.c
CC plat/arm/board/fvp/fvp_bl2_setup.c
CC plat/arm/board/fvp/fvp_err.c
CC plat/arm/board/fvp/fvp_io_storage.c
CC plat/arm/common/arm_nor_psci_mem_protect.c
CC drivers/arm/tzc/tzc400.c
CC plat/arm/board/fvp/fvp_security.c
CC plat/arm/common/arm_tzc400.c
CC drivers/cfi/v2m/v2m_flash.c
CC drivers/delay_timer/delay_timer.c
CC drivers/delay_timer/generic_delay_timer.c
CC drivers/io/io_fip.c
CC drivers/io/io_memmap.c
CC drivers/io/io_storage.c
CC plat/arm/common/arm_bl2_setup.c
CC plat/arm/common/arm_err.c
CC plat/arm/common/arm_fconf_io_storage.c
CC plat/arm/common/fconf/arm_fconf_io.c
CC lib/fconf/fconf.c
CC lib/fconf/fconf_dyn_cfg_getter.c
CC plat/arm/common/arm_dyn_cfg.c
CC plat/arm/common/arm_dyn_cfg_helpers.c
CC common/fdt_wrappers.c
CC plat/arm/common/aarch64/arm_bl2_mem_params_desc.c
CC plat/arm/common/arm_image_load.c
CC common/desc_image_load.c
CC bl2/bl2_image_load_v2.c
CC bl2/bl2_main.c
CC bl2/aarch64/bl2_arch_setup.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS lib/semihosting/aarch64/semihosting_call.S
AS lib/locks/exclusive/aarch64/spinlock.S
AS plat/common/aarch64/platform_up_stack.S
AS common/aarch64/early_exceptions.S
AS bl2/aarch64/bl2_entrypoint.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl2/bl2.ld.S
LD build/fvp/release/bl2/bl2.elf
BIN build/fvp/release/bl2.bin
Built build/fvp/release/bl2.bin successfully
OD build/fvp/release/bl2/bl2.dump
CC drivers/arm/fvp/fvp_pwrc.c
CC drivers/arm/smmu/smmu_v3.c
CC drivers/delay_timer/delay_timer.c
CC drivers/cfi/v2m/v2m_flash.c
CC lib/utils/mem_region.c
CC plat/arm/board/fvp/fvp_bl31_setup.c
CC plat/arm/board/fvp/fvp_pm.c
CC plat/arm/board/fvp/fvp_topology.c
CC plat/arm/common/arm_nor_psci_mem_protect.c
CC drivers/arm/gic/common/gic_common.c
CC drivers/arm/gic/v3/gicv3_main.c
CC drivers/arm/gic/v3/gicv3_helpers.c
CC plat/common/plat_gicv3.c
CC plat/arm/common/arm_gicv3.c
CC drivers/arm/gic/v3/gic500.c
CC drivers/arm/cci/cci.c
CC drivers/arm/tzc/tzc400.c
CC plat/arm/board/fvp/fvp_security.c
CC plat/arm/common/arm_tzc400.c
CC drivers/delay_timer/generic_delay_timer.c
CC lib/cpus/aarch64/cpuamu.c
CC plat/arm/common/arm_bl31_setup.c
CC plat/arm/common/arm_pm.c
CC plat/arm/common/arm_topology.c
CC plat/common/plat_psci_common.c
CC plat/arm/common/aarch64/execution_state_switch.c
CC plat/arm/common/arm_sip_svc.c
CC lib/pmf/pmf_smc.c
CC bl31/bl31_main.c
CC bl31/interrupt_mgmt.c
CC bl31/bl31_context_mgmt.c
CC common/runtime_svc.c
CC services/arm_arch_svc/arm_arch_svc_setup.c
CC services/std_svc/std_svc_setup.c
CC lib/el3_runtime/cpu_data_array.c
CC lib/el3_runtime/aarch64/context_mgmt.c
CC lib/cpus/errata_report.c
CC lib/psci/psci_off.c
CC lib/psci/psci_on.c
CC lib/psci/psci_suspend.c
CC lib/psci/psci_common.c
CC lib/psci/psci_main.c
CC lib/psci/psci_setup.c
CC lib/psci/psci_system_off.c
CC lib/psci/psci_mem_protect.c
CC lib/locks/bakery/bakery_lock_coherent.c
CC lib/psci/psci_stat.c
CC lib/pmf/pmf_main.c
CC lib/extensions/spe/spe.c
CC lib/extensions/amu/aarch64/amu.c
CC lib/extensions/sve/sve.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
/tmp/ccswitLr.s: Assembler messages:
/tmp/ccswitLr.s:297: Warning: setting incorrect section attributes for .rodata
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS plat/arm/board/fvp/aarch64/fvp_helpers.S
AS lib/cpus/aarch64/aem_generic.S
AS lib/cpus/aarch64/cortex_a35.S
AS lib/cpus/aarch64/cortex_a53.S
AS lib/cpus/aarch64/cortex_a57.S
AS lib/cpus/aarch64/cortex_a72.S
AS lib/cpus/aarch64/cortex_a73.S
AS lib/cpus/aarch64/cpuamu_helpers.S
AS bl31/aarch64/bl31_entrypoint.S
AS bl31/aarch64/crash_reporting.S
AS bl31/aarch64/ea_delegate.S
AS bl31/aarch64/runtime_exceptions.S
AS lib/cpus/aarch64/dsu_helpers.S
AS plat/common/aarch64/platform_mp_stack.S
AS lib/el3_runtime/aarch64/cpu_data.S
AS lib/cpus/aarch64/cpu_helpers.S
AS lib/locks/exclusive/aarch64/spinlock.S
AS lib/psci/aarch64/psci_helpers.S
AS lib/el3_runtime/aarch64/context.S
AS lib/extensions/amu/aarch64/amu_helpers.S
AS lib/cpus/aarch64/wa_cve_2017_5715_bpiall.S
AS lib/cpus/aarch64/wa_cve_2017_5715_mmu.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl31/bl31.ld.S
LD build/fvp/release/bl31/bl31.elf
BIN build/fvp/release/bl31.bin
Built build/fvp/release/bl31.bin successfully
OD build/fvp/release/bl31/bl31.dump
CC plat/arm/board/fvp/fvp_bl2u_setup.c
CC drivers/arm/tzc/tzc400.c
CC plat/arm/board/fvp/fvp_security.c
CC plat/arm/common/arm_tzc400.c
CC drivers/delay_timer/delay_timer.c
CC drivers/delay_timer/generic_delay_timer.c
CC plat/arm/common/arm_bl2u_setup.c
CC bl2u/bl2u_main.c
CC common/bl_common.c
CC common/tf_log.c
CC drivers/console/multi_console.c
CC plat/common/plat_bl_common.c
CC plat/common/plat_log_common.c
CC plat/common/aarch64/plat_common.c
CC lib/compiler-rt/builtins/popcountdi2.c
CC lib/compiler-rt/builtins/popcountsi2.c
CC plat/arm/board/fvp/fvp_common.c
CC plat/arm/common/arm_common.c
CC plat/arm/common/arm_console.c
CC lib/xlat_tables_v2/aarch64/xlat_tables_arch.c
CC lib/xlat_tables_v2/xlat_tables_context.c
CC lib/xlat_tables_v2/xlat_tables_core.c
CC lib/xlat_tables_v2/xlat_tables_utils.c
AS bl2u/aarch64/bl2u_entrypoint.S
AS plat/common/aarch64/platform_up_stack.S
AS common/aarch64/early_exceptions.S
AS common/aarch64/debug.S
AS lib/aarch64/cache_helpers.S
AS lib/aarch64/misc_helpers.S
AS plat/common/aarch64/platform_helpers.S
AS drivers/arm/pl011/aarch64/pl011_console.S
AS plat/arm/board/common/aarch64/board_arm_helpers.S
AS plat/arm/common/aarch64/arm_helpers.S
AS lib/xlat_tables_v2/aarch64/enable_mmu.S
PP bl2u/bl2u.ld.S
LD build/fvp/release/bl2u/bl2u.elf
BIN build/fvp/release/bl2u.bin
Built build/fvp/release/bl2u.bin successfully
OD build/fvp/release/bl2u/bl2u.dump
CPP plat/arm/board/fvp/fdts/fvp_fw_config.dts
DTC plat/arm/board/fvp/fdts/fvp_fw_config.dts
CPP plat/arm/board/fvp/fdts/fvp_soc_fw_config.dts
DTC plat/arm/board/fvp/fdts/fvp_soc_fw_config.dts
CPP plat/arm/board/fvp/fdts/fvp_nt_fw_config.dts
DTC plat/arm/board/fvp/fdts/fvp_nt_fw_config.dts
CPP fdts/fvp-base-gicv3-psci.dts
DTC fdts/fvp-base-gicv3-psci.dts
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:215.20-220.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/flash@0,00000000:
simple-bus unit address format error, expected "0"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:221.19-224.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/vram@2,00000000:
simple-bus unit address format error, expected "200000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:225.23-229.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/ethernet@2,02000000:
simple-bus unit address format error, expected "202000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:230.26-235.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/clk24mhz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:236.30-241.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/refclk1mhz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:242.32-247.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/refclk32khz: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:248.21-370.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/iofpga@3,00000000:
simple-bus unit address format error, expected "300000000"
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:371.33-377.5:
Warning (simple_bus_reg): /smb@0,0/motherboard/fixedregulator: missing
or empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:381.21-387.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/osc: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:388.12-391.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/muxfpga: missing or
empty reg/ranges property
./build/fvp/release/fdts/fvp-base-gicv3-psci.pre.dts:392.12-395.6:
Warning (simple_bus_reg): /smb@0,0/motherboard/mcc/dvimode: missing or
empty reg/ranges property
--
Best Regards
Masahiro Yamada
Hi All,
I’ll be running the TF-A Tech Forum next week and I wanted to give an idea of what to expect in this inaugural meeting.
While in future meetings I will want to seek input of what the agenda will be before the meeting with the option for other project contributors to present on topics in this first one I have a set agenda which is influenced by the format used in the counterpart TF-M Tech Forum.
Agenda:
* Introduction to the TF-A Technical Forum Meeting
* Technical Overview of the Debug-FS Feature
* Optional TF-A Mailing List Topic Discussions
Thanks
Joanna
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Bill Fletcher via TF-A <tf-a(a)lists.trustedfirmware.org>
Reply to: Bill Fletcher <bill.fletcher(a)linaro.org>
Date: Friday, 28 February 2020 at 15:25
To: <tf-a(a)lists.trustedfirmware.org>
Subject: [TF-A] Updated invitation: TF-A Tech Forum @ Thu 12 Mar 2020 17:00 - 18:00 (GMT) (tf-a(a)lists.trustedfirmware.org)
This event has been changed.
TF-A Tech Forum
When
Thu 12 Mar 2020 17:00 – 18:00 United Kingdom Time
Calendar
tf-a(a)lists.trustedfirmware.org
Who
(Guest list has been hidden at organiser's request)
more details »<https://www.google.com/calendar/event?action=VIEW&eid=MGVhNDdsMGVqNnEzZ3BpY…>
Changed:
We are starting an open technical forum call for anyone to participate and it is not restricted to Trusted Firmware project members. It will operate under the guidance of the TF TSC.
Feel free to forward this invite to colleagues. Future invites will be via the TF-A mailing list and also published on the Trusted Firmware website. Details are here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/<https://www.google.com/url?q=https%3A%2F%2Fwww.trustedfirmware.org%2Fmeetin…>
Trusted Firmware is inviting you to a scheduled Zoom meeting.
Join Zoom Meeting
https://zoom.us/j/9159704974<https://www.google.com/url?q=https%3A%2F%2Fzoom.us%2Fj%2F9159704974&sa=D&us…>
Meeting ID: 915 970 4974
One tap mobile
+16465588656,,9159704974# US (New York)
+16699009128,,9159704974# US (San Jose)
Dial by your location
+1 646 558 8656 US (New York)
+1 669 900 9128 US (San Jose)
877 853 5247 US Toll-free
888 788 0099 US Toll-free
Meeting ID: 915 970 4974
Find your local number: https://zoom.us/u/ad27hc6t7h<https://www.google.com/url?q=https%3A%2F%2Fzoom.us%2Fu%2Fad27hc6t7h&sa=D&us…>
(updated due to content filtering issues)
Going (tf-a(a)lists.trustedfirmware.org)? Yes<https://www.google.com/calendar/event?action=RESPOND&eid=MGVhNDdsMGVqNnEzZ3…> - Maybe<https://www.google.com/calendar/event?action=RESPOND&eid=MGVhNDdsMGVqNnEzZ3…> - No<https://www.google.com/calendar/event?action=RESPOND&eid=MGVhNDdsMGVqNnEzZ3…> more options »<https://www.google.com/calendar/event?action=VIEW&eid=MGVhNDdsMGVqNnEzZ3BpY…>
Invitation from Google Calendar<https://www.google.com/calendar/>
You are receiving this courtesy email at the account tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event. Alternatively, you can sign up for a Google Account at https://www.google.com/calendar/ and control your notification settings for your entire calendar.
Forwarding this invitation could allow any recipient to send a response to the organiser and be added to the guest list, invite others regardless of their own invitation status or to modify your RSVP. Learn more<https://support.google.com/calendar/answer/37135#forwarding>.
-- TF-A mailing list TF-A(a)lists.trustedfirmware.org https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hello,
I'm preparing a set of patches for GICv3 driver for GICv3.1 and GICv4 support.
Please review and provide your comments for the 1st patch which separates GICD and GICR accessor functions and adds new macros for GICv3 registers access.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3550
Regards.
Alexei
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
sandeep.tripathy(a)broadcom.com has replied "Maybe" to this invitation.
Title: TF-A Tech Forum
This meeting originally contained an attachment. Please contact your
organizer for the attachment.
This event has been changed.
TF-A Tech Forum
When
Thu 12 Mar 2020 17:00 – 18:00 United Kingdom Time
Calendar
tf-a(a)lists.trustedfirmware.org
Who
(Guest list has been hidden at organiser's request)
more details »
Changed:
We are starting an open technical forum call for anyone to participate and
it is not restricted to Trusted Firmware project members. It will operate
under the guidance of the TF TSC.
Feel free to forward this invite to colleagues. Future invites will be via
the TF-A mailing list and also published on the Trusted Firmware website.
Details are here:
https://www.trustedfirmware.org/meetings/tf-a-technical-forum/
Trusted Firmware is inviting you to a scheduled Zoom meeting.
Join Zoom Meeting
https://zoom.us/j/9159704974
Meeting ID: 915 970 4974
One tap mobile
+16465588656,,9159704974# US (New York)
+16699009128,,9159704974# US (San Jose)
Dial by your location
+1 646 558 8656 US (New York)
+1 669 900 9128 US (San Jose)
877 853 5247 US Toll-free
888 788 0099 US Toll-free
Meeting ID: 915 970 4974
Find your local number: https://zoom.us/u/ad27hc6t7h
(updated due to content filtering issues)
Going (tf-a(a)lists.trustedfirmware.org)?
Yes -
Maybe -
No more options »
Invitation from Google Calendar
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more .
When: Thu Mar 12, 2020 10:30pm – 11:30pm India Standard Time - Kolkata
Calendar: Bill Fletcher via TF-A
Who:
* Bill Fletcher via TF-A - organizer
* sandeep.tripathy(a)broadcom.com - creator
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively you can sign up for a Google account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organizer and be added to the guest list, or invite others regardless
of their own invitation status, or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
This event has been changed.
Title: TF-A Tech Forum
We are starting an open technical forum call for anyone to participate and
it is not restricted to Trusted Firmware project members. It will operate
under the guidance of the TF TSC. Feel free to forward this invite to
colleagues. Future invites will be via the TF-A mailing list and also
published on the Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558 8656
US (New York) +1 669 900 9128 US (San
Jose) 877 853 5247 US Toll-free
888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your
local number: https://zoom.us/u/ad27hc6t7h (updated due to
content filtering issues) (changed)
When: Thu 12 Mar 2020 17:00 – 18:00 United Kingdom Time
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
(Guest list has been hidden at organiser's request)
Event details:
https://www.google.com/calendar/event?action=VIEW&eid=MGVhNDdsMGVqNnEzZ3BpY…
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
You have been invited to the following event.
Title: TF-A Tech Forum
We are starting an open technical forum call for anyone to participate and
it is not restricted to Trusted Firmware project members. It will operate
under the guidance of the TF TSC. Feel free to forward this invite to
colleagues. Future invites will be via the TF-A mailing list and also
published on the Trusted Firmware website. Details are
here: https://www.trustedfirmware.org/meetings/tf-a-technical-forum/Tr…
Firmware is inviting you to a scheduled Zoom meeting.Join Zoom
Meetinghttps://zoom.us/j/9159704974Meeting ID: 915 970 4974One tap
mobile+16465588656,,9159704974# US (New York)+16699009128,,9159704974# US
(San Jose)Dial by your location +1 646 558 8656
US (New York) +1 669 900 9128 US (San
Jose) 877 853 5247 US Toll-free
888 788 0099 US Toll-freeMeeting ID: 915 970 4974Find your
local number: https://zoom.us/u/ad27hc6t7h
When: Thu 12 Mar 2020 17:00 – 18:00 United Kingdom Time
Calendar: tf-a(a)lists.trustedfirmware.org
Who:
(Guest list has been hidden at organiser's request)
Event details:
https://www.google.com/calendar/event?action=VIEW&eid=MGVhNDdsMGVqNnEzZ3BpY…
Invitation from Google Calendar: https://www.google.com/calendar/
You are receiving this courtesy email at the account
tf-a(a)lists.trustedfirmware.org because you are an attendee of this event.
To stop receiving future updates for this event, decline this event.
Alternatively, you can sign up for a Google Account at
https://www.google.com/calendar/ and control your notification settings for
your entire calendar.
Forwarding this invitation could allow any recipient to send a response to
the organiser and be added to the guest list, invite others regardless of
their own invitation status or to modify your RSVP. Learn more at
https://support.google.com/calendar/answer/37135#forwarding
Hi Scott
Please add the platform specific flags as a field in fip_dev_state_t.
typedef struct {
uintptr_t dev_spec;
uint32_t plat_toc_flag;
} fip_dev_state_t;
Then this field can be updated as part of verifying the FIP header. This header needs to be cleared when the device is closed.
Introduce a helper in fip driver to query the flags:
int fip_dev_get_plat_toc_flag(io_dev_info_t *dev_info, uint32_t *plat_toc_flag);
That should satisfy your requirement.
Best Regards
Soby Mathew
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Scott
> Branden via TF-A
> Sent: 07 February 2020 18:57
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] FIP header flags available for feature selection
>
> Hello,
>
> The fip header has reserved fields available for platform specific use.
> The fiptool allows these header fields to be filled in using the --plat-toc-flags.
>
> A call needs to be available in the ATF framework to get these flags without
> accessing the FIP file again to get these flags.
> We have a solution we've used for ATF for quite some time to access these
> flags.
>
> It's finally being upstreamed here:
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2839
>
> If there are any other efficient methods to access these flags or a better
> proposal please suggest.
>
> Thanks,
> Scott
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Raghu,
Thanks a lot for the review comments and feedback!
On 2/25/20 3:45 AM, Raghu Krishnamurthy via TF-A wrote:
> The patch stack looks great! I do have a suggestion for the long term
> evolution/future work on root's of trust and cert_create. It would be
> great to generalize "dual-root" to "multi-root". It is conceivable that
> firmware supporting secure partitions/SPCI etc, could move to having
> multiple root's of trust. Here we have the silicon provider, and the
> platform owner as two roots, but a more complex system could contain
> silicon firmware, platform firmware and multiple secure partitions, each
> signed by different entities. To remove the signing dependencies between
> each of these entities, we could have a ROTPK for each of these entities
> and the same solution used here, can be applied to solve multiple root's
> of trust and is summarized very well by your statement -"As long as
> there is a defined contract between BL2 and the (P)(*)ROTK-rooted images
> as to how/where to securely get this key or hash, there should not be
> any need for the two vendors to do any cross-signing."
>> To do this, If possible, we should start moving away from tables such as
> the ones in cert_create/src/dualroot/cot.c and have platforms provide
> the certificate dependencies and keys used to sign them in a config
> file. This achieves two things: it makes cert_create independent of the
> cert chain a platform wants to use and the number of roots of trust,
> and, makes cert_create more usable by reducing the number of command
> line arguments to be provided, which is a long list today. You could
> potentially use the config file provided to auto generate the tbbr_cot.c
> file being linked into the firmware too.
>
> Let me know what you think.
I agree with everything you said above. Indeed, there's no reason to
stop at 2 roots of trust and as you pointed out there are real use cases
to enable more. The dualroot chain of trust is only the first step in
that direction and is a useful way to experiment with extending the TBBR
implementation and chain of trust, while addressing a real use case.
Also completely agree with the lack of flexibility of the hard-coded
chain of trust in cert_create/src/dualroot/cot.c and
drivers/auth/dualroot/cot.c for that matter. In fact, we (at Arm) are
thinking along the same lines as you and have had similar ideas boiling
for some time. We are making gradual changes to introduce more
flexibility into TF-A, not just for the chain of trust, but for any
platform-specific data.
Maybe you've seen the recent FConf framework patches, which is a key
piece into enabling platform layers to move platform-specific data into
configuration files. There is still work to do but down the line we are
already thinking about moving the chain of trust description into such a
configuration file.
Moving the CoT into a configuration file has many advantages:
- It could constitute the single input source for the chain of trust,
serving both the cert_create tool and the firmware. Today, the CoT is
described and duplicated in both places and there is really no good
reason to keep things like that IMO. As you said, we could auto-generate
the tbbr_cot.c file and build into the firmware, or even have the
firmware dynamically parse the configuration file at runtime and extract
its CoT.
- It could simplify the description of the CoT. Today, I think that the
C data structures in tbbr_cot.c are quite complex and not
straight-forward to understand at first. If we described them using some
configuration language, I believe we could abstract some of these
details away or at least organize them in a more intuitive way.
Regards,
Sandrine
Hi Sandrine,
The patch stack looks great! I do have a suggestion for the long term
evolution/future work on root's of trust and cert_create. It would be
great to generalize "dual-root" to "multi-root". It is conceivable that
firmware supporting secure partitions/SPCI etc, could move to having
multiple root's of trust. Here we have the silicon provider, and the
platform owner as two roots, but a more complex system could contain
silicon firmware, platform firmware and multiple secure partitions, each
signed by different entities. To remove the signing dependencies between
each of these entities, we could have a ROTPK for each of these entities
and the same solution used here, can be applied to solve multiple root's
of trust and is summarized very well by your statement -"As long as
there is a defined contract between BL2 and the (P)(*)ROTK-rooted images
as to how/where to securely get this key or hash, there should not be
any need for the two vendors to do any cross-signing."
To do this, If possible, we should start moving away from tables such as
the ones in cert_create/src/dualroot/cot.c and have platforms provide
the certificate dependencies and keys used to sign them in a config
file. This achieves two things: it makes cert_create independent of the
cert chain a platform wants to use and the number of roots of trust,
and, makes cert_create more usable by reducing the number of command
line arguments to be provided, which is a long list today. You could
potentially use the config file provided to auto generate the tbbr_cot.c
file being linked into the firmware too.
Let me know what you think.
Thanks
Raghu
On 2/24/20 3:43 AM, Sandrine Bailleux via TF-A wrote:
> Hi,
>
> Following up on my email sent in November 2019:
> https://lists.trustedfirmware.org/pipermail/tf-a/2019-November/000124.html
>
> and the proof-of-concept code and documentation shared at that time:
> [1]
> https://developer.trustedfirmware.org/w/tf_a/poc-multiple-signing-domains/
> [2] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2443
>
> I've made a number of improvements and cleanups in the code. I am
> posting a new version that introduces this new chain of trust (called
> "dualroot", as it has 2 roots of trust) as an alternative to the default
> TBBR one. Right now, it is only enabled on some Arm platforms but it
> should be pretty straight-forward to extend this to other platforms.
>
> The code is available there:
> https://review.trustedfirmware.org/q/topic:%22sb%252Fdualroot%22
>
> and is comprised of the following patches:
> - Introduce a new "dualroot" chain of trust
> - cert_create: Define the dualroot CoT
> - Build system: Changes to drive cert_create for dualroot CoT
> - plat/arm: Provide some PROTK files for development
> - plat/arm: Add support for dualroot CoT
> - plat/arm: Pass cookie argument down to arm_get_rotpk_info()
> - plat/arm: Retrieve the right ROTPK when using the dualroot CoT
>
> This patch stack is based on preparatory work (which has already been
> merged) to select a different CoT. This patch stack:
> - Did some build system refactoring.
> - Introduced a new 'COT' build option to select the chosen chain of trust.
> - Made no functional change.
> See
> http://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=dcd03…
>
> Note that I've not updated the TF-A documentation just yet to reflect
> these changes. I will do that once I've had some initial feedback from
> the community and feel that we're reaching a consensus (in the interest
> of saving time keeping documentation aligned with code going under rework).
>
>
> Changes Compared to the Proof-of-Concept Patch [2]
> --------------------------------------------------
>
> - Introduced a proper, separate chain of trust rather than hijacking the
> TBBR one. It also has its own header file for certificate extensions
> OIDs now.
>
> - NS-ROTPK has been renamed into "Platform ROTPK", or PROTPK for short.
> Going forward, this key would sign both non-trusted images (such as
> BL33) and secure partitions. The NS- prefix did not fit well this use
> case. The "Platform" prefix instead refers to the owner of this key,
> i.e. the platform owner, as opposed to the Silicon Provider.
>
> - Removed Non-Trusted World Bootloader Key Certificate.
> This didn't seem needed in this context and simplifies the CoT.
>
> - Removed the Non-Trusted Key from the Trusted Key Certificate, as it's
> not used in this CoT (the PROTPK signs all non-trusted images instead).
>
> - As a consequence, the corresponding option for feeding the PROTPK to
> the cert_create tool has been renamed into --prot-key (was --ns-rot-key).
>
> - The hash of the PROTPK is now provided in a file rather than being
> hard-coded into the code. This is cleaner than polluting the code with a
> byte array.
>
> - Proper integration in the build system.
> Using the dualroot chain of trust is achieved through the COT build
> option:
>
> make <usual trusted boot build options> COT=dualroot
>
> - plat_get_rotpk_info() is unchanged if using the TBBR CoT.
> The alternative implementation managing both ROTPK or PROTPK is
> selected only if the dualroot CoT has been chosen at build time.
>
>
> Testing and Supported Platforms
> -------------------------------
>
> Tested on AEMv8-A Base Platform (AArch32 and AArch64 execution states),
> rde1edge, rdn1edge, SGI-575 and SGM-775 FVPs (all available on
> https://developer.arm.com/tools-and-software/simulation-models/fixed-virtua…).
>
> Arm Juno is not supported right now because it has its own
> implementation of plat_get_arm_rotpk_info() instead of piggy-backing on
> the Arm common one.
>
> Ran the standard set of tests available in the TF-A-Tests repository:
> http://git.trustedfirmware.org/TF-A/tf-a-tests.git/about/
>
> Also ran the firmware update tests available in the same repository. See
>
> https://trustedfirmware-a-tests.readthedocs.io/en/latest/user-guide.html#ns…
> for more information.
>
> Finally, performed some end-to-end boot tests to Linux.
>
> And of course, ran our regression tests to make sure that existing
> configurations using the TBBR chain of trust are still working as expected.
>
>
> Caveats
> -------
>
> The PROTPK hash is embedded into the firmware. It's unlikely that a real
> system would like to do that. The use case targeted here is to remove
> the need for the primary ROTPK owner to interact with the PROTPK owner.
> If BL2 embeds the hash, this defeats the purpose, as now the BL2 owner
> (which is expected to be the primary ROTPK owner) has to get the PROTPK
> from the other vendor.
>
> In a real system, we would expect the PROTPK to be provisioned in such a
> way that BL2 is able to retrieve it. For example, the PROTPK owner might
> burn it (or a hash of it) in some OTP memory. As long as there is a
> defined contract between BL2 and the PROTK-rooted images as to how/where
> to securely get this key or hash, there should not be any need for the
> two vendors to do any cross-signing.
>
> This caveat was already present in the proof-of-concept [2] and stays
> out of the scope for this work, as this ties into broader topics such as
> key provisioning. Right now, the onus is on the platform layer to handle
> this appropriately.
>
>
> Future work
> -----------
>
> We have plans to change the "dualroot" CoT further and extend the PROTPK
> signing domain with a secure partition. This would demonstrate the use
> of several secure partitions, some owned by the silicon provider, others
> owned by the platform owner.
>
>
> Regards,
> Sandrine
>
Hi,
Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
1 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
3 defect(s), reported by Coverity Scan earlier, were marked fixed in the recent build analyzed by Coverity Scan.
New defect(s) Reported-by: Coverity Scan
Showing 1 of 1 defect(s)
** CID 354288: Memory - corruptions (OVERRUN)
________________________________________________________________________________________________________
*** CID 354288: Memory - corruptions (OVERRUN)
/plat/intel/soc/common/socfpga_psci.c: 138 in socfpga_system_reset()
132
133 extern uint64_t intel_rsu_update_address;
134
135 static void __dead2 socfpga_system_reset(void)
136 {
137 if (intel_rsu_update_address)
>>> CID 354288: Memory - corruptions (OVERRUN)
>>> Overrunning buffer pointed to by "&intel_rsu_update_address" of 8 bytes by passing it to a function which accesses it at byte offset 15.
138 mailbox_rsu_update(&intel_rsu_update_address);
139 else
140 mailbox_reset_cold();
141
142 while (1)
143 wfi();
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/ls/click?upn=nJaKvJSIH-2FPAfmty-2BK5tYpPkl…
Hi,
Following up on my email sent in November 2019:
https://lists.trustedfirmware.org/pipermail/tf-a/2019-November/000124.html
and the proof-of-concept code and documentation shared at that time:
[1]
https://developer.trustedfirmware.org/w/tf_a/poc-multiple-signing-domains/
[2] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2443
I've made a number of improvements and cleanups in the code. I am
posting a new version that introduces this new chain of trust (called
"dualroot", as it has 2 roots of trust) as an alternative to the default
TBBR one. Right now, it is only enabled on some Arm platforms but it
should be pretty straight-forward to extend this to other platforms.
The code is available there:
https://review.trustedfirmware.org/q/topic:%22sb%252Fdualroot%22
and is comprised of the following patches:
- Introduce a new "dualroot" chain of trust
- cert_create: Define the dualroot CoT
- Build system: Changes to drive cert_create for dualroot CoT
- plat/arm: Provide some PROTK files for development
- plat/arm: Add support for dualroot CoT
- plat/arm: Pass cookie argument down to arm_get_rotpk_info()
- plat/arm: Retrieve the right ROTPK when using the dualroot CoT
This patch stack is based on preparatory work (which has already been
merged) to select a different CoT. This patch stack:
- Did some build system refactoring.
- Introduced a new 'COT' build option to select the chosen chain of trust.
- Made no functional change.
See
http://git.trustedfirmware.org/TF-A/trusted-firmware-a.git/commit/?id=dcd03…
Note that I've not updated the TF-A documentation just yet to reflect
these changes. I will do that once I've had some initial feedback from
the community and feel that we're reaching a consensus (in the interest
of saving time keeping documentation aligned with code going under rework).
Changes Compared to the Proof-of-Concept Patch [2]
--------------------------------------------------
- Introduced a proper, separate chain of trust rather than hijacking the
TBBR one. It also has its own header file for certificate extensions
OIDs now.
- NS-ROTPK has been renamed into "Platform ROTPK", or PROTPK for short.
Going forward, this key would sign both non-trusted images (such as
BL33) and secure partitions. The NS- prefix did not fit well this use
case. The "Platform" prefix instead refers to the owner of this key,
i.e. the platform owner, as opposed to the Silicon Provider.
- Removed Non-Trusted World Bootloader Key Certificate.
This didn't seem needed in this context and simplifies the CoT.
- Removed the Non-Trusted Key from the Trusted Key Certificate, as it's
not used in this CoT (the PROTPK signs all non-trusted images instead).
- As a consequence, the corresponding option for feeding the PROTPK to
the cert_create tool has been renamed into --prot-key (was --ns-rot-key).
- The hash of the PROTPK is now provided in a file rather than being
hard-coded into the code. This is cleaner than polluting the code with a
byte array.
- Proper integration in the build system.
Using the dualroot chain of trust is achieved through the COT build
option:
make <usual trusted boot build options> COT=dualroot
- plat_get_rotpk_info() is unchanged if using the TBBR CoT.
The alternative implementation managing both ROTPK or PROTPK is
selected only if the dualroot CoT has been chosen at build time.
Testing and Supported Platforms
-------------------------------
Tested on AEMv8-A Base Platform (AArch32 and AArch64 execution states),
rde1edge, rdn1edge, SGI-575 and SGM-775 FVPs (all available on
https://developer.arm.com/tools-and-software/simulation-models/fixed-virtua…).
Arm Juno is not supported right now because it has its own
implementation of plat_get_arm_rotpk_info() instead of piggy-backing on
the Arm common one.
Ran the standard set of tests available in the TF-A-Tests repository:
http://git.trustedfirmware.org/TF-A/tf-a-tests.git/about/
Also ran the firmware update tests available in the same repository. See
https://trustedfirmware-a-tests.readthedocs.io/en/latest/user-guide.html#ns…
for more information.
Finally, performed some end-to-end boot tests to Linux.
And of course, ran our regression tests to make sure that existing
configurations using the TBBR chain of trust are still working as expected.
Caveats
-------
The PROTPK hash is embedded into the firmware. It's unlikely that a real
system would like to do that. The use case targeted here is to remove
the need for the primary ROTPK owner to interact with the PROTPK owner.
If BL2 embeds the hash, this defeats the purpose, as now the BL2 owner
(which is expected to be the primary ROTPK owner) has to get the PROTPK
from the other vendor.
In a real system, we would expect the PROTPK to be provisioned in such a
way that BL2 is able to retrieve it. For example, the PROTPK owner might
burn it (or a hash of it) in some OTP memory. As long as there is a
defined contract between BL2 and the PROTK-rooted images as to how/where
to securely get this key or hash, there should not be any need for the
two vendors to do any cross-signing.
This caveat was already present in the proof-of-concept [2] and stays
out of the scope for this work, as this ties into broader topics such as
key provisioning. Right now, the onus is on the platform layer to handle
this appropriately.
Future work
-----------
We have plans to change the "dualroot" CoT further and extend the PROTPK
signing domain with a secure partition. This would demonstrate the use
of several secure partitions, some owned by the silicon provider, others
owned by the platform owner.
Regards,
Sandrine
Hi,
I have pushed a patch [1] to use a barrier to synchronize pending EA at the entry and exit of exception handlers in BL31(EL3S). There is an interesting discussion as seen in the gerrit review comments of the patch. It looks like this patch is just enabling early panic/crash of the system in the event of SErrors but it does come with performance penalty (due to DSBs) for common exceptions like SMC calls. We believe this needs broader discussion to understand the practical approach to handle SErrors, especially in SoCs without RAS support. Please let us know your thoughts on this patch.
[1] https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3440
Thanks,
Madhukar
Hi Raghu,
Thank you for your comments. My own comments are inline.
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Raghu Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 18 February 2020 00:16
To: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Protecting Secure World Translation Tables
I think it is worth implementing this to raise the bar for successful
attacks. To Varun's point, in today's systems without S-EL2(<v8.4), it
would be less effective as pointed out, since EL3 memory can be
completely accessed by SEL1 and SEL1 code tends to have a larger code
base on mobile devices(OPTEE, tlk etc). However, on systems with very
thin SEL1 shims(typically servers), this would definitely raise the bar
for attacks, since you effectively only have SEL0 and EL3. SEL1 cannot
be exploited practically.
For new SoCs with SEL2, this mitigation can still be very effective if
we can ensure future SEL2 implementations have much smaller code bases
and implements this mitigation itself. Effectively, i view SEL2 and EL3
as being equally privileged(it is no different than SEL1 because SEL2
can barf all over EL3 memory and TZ resources if exploited). SEL2
extensions, however, gives EL3 protection from SEL1 and can prevent SEL1
from accessing ALL TZ resources. If you view SEL2 and EL3 as equally
privileged and view both together as a single entity, v8.4 systems
effectively have EL3, SEL1, SEL0 AND the ability for EL3 to protect
itself and other TZ resources from SEL1. In such a system, EL3(and SEL2)
having this mitigation will definitely raise the bar for successful attacks.
Also, the cost to implement this mitigation is relatively low for a
fairly significant raise in the bar for successful attacks.
PS - I say significantly raise the bar since an attacker will
potentially require gadgets to modify TTBRx, invalidate TLB's, and
enough gadgets in the code base to have a successful attack. If code in
TF-A EL3 is fairly small, and code that writes to TTBR_EL3 can be in
some section of the image that can be reclaimed/erased after initial
setup, the attacker would have no gadget to modify TTBR_EL3, so there
would be virtually no way to change TTBR_EL3. On a default build of FVP,
there is a grand total of 1 instruction that writes to TTBR0_EL3 in
enable_mmu_direct_el3. This might be a nice follow up change to this
mitigation, if others think it is worth it. The same could be extended
to other system registers that don't ever need to be changed(VBAR_EL3?
SCTLR_EL3?).
Petre: enable_mmu_direct_el3 is also used in the read-only xlat tables API, because the change
is made while the MMU is on (so it must be disabled first). I decided to implement it this way
in order to allow a platform to make any changes it needs to the translation tables (e.g. for
reclaiming initialization code) before calling this API. So, it is kind of "dynamic"...but after
it is called nothing can be done to the tables from that EL. This means that we have to reclaim
before using this API (otherwise we would have to choose between reclaiming and this feature
since RO tables won't allow changing the memory map). I was afraid the change might impose
too much rigidity on the initialization of platform BL images, so I went with this approach
instead of making the tables read-only at creation by the init_xlat_tables* functions.
Thanks
Raghu
On 2/17/20 12:35 PM, Varun Wadekar via TF-A wrote:
> Hello Petre,
>
> Thanks for the patch. Before I review the actual code, would like to understand how effective this patch will be and if you have seen a real world attack that this patch mitigates.
>
> AFAIU, the ARM architecture provides the TZ bit as the only protection to create "partitions" on a CPU core. So, potentially S-EL1 can access almost all TZ resources that EL3 can access. Thus, creating a silo inside EL3 exception mode is not an effective mitigation against any other TZ component writing to the physical memory where the page tables are stored. For the scope of this attack vector, are we assuming that the system cannot be compromised by attacking other TZ software components in the system?
>
> I feel until we have a way to distinguish between CPU realms (EL3 v S-EL2 v S-EL1) at the hardware bus level (ARM v9?), these mitigations are not that effective.
>
> Thoughts?
>
> -Varun
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Petre-Ionut Tudor via TF-A
> Sent: Monday, February 17, 2020 9:40 AM
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] Protecting Secure World Translation Tables
>
> External email: Use caution opening links or attachments
>
>
> Hello Everyone,
>
> For quite some time I have been working on a security hardening feature that offers extra protection against tampering with the Secure world translation tables. An example would be using a gadget that can perform writes to arbitrary Secure memory locations to change memory attributes and/or the memory map.
>
> A real world exploit that uses read/write gadgets to tamper with translation tables can be found here: https://vimeo.com/335948808. If you only want the slide deck, it's available here: https://speakerdeck.com/hhj4ck/el3-tour-get-the-ultimate-privilege-of-andro….
>
> A patch implementing this feature has been recently pushed upstream here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3349. It extends v2 of the translation tables library with an API that can be called by a BL image any time after the initialization of the xlat tables to make them read-only.
>
> It would be great to hear your opinions about this, particularly whether or not it is a desirable feature to have in TF-A and what extra work needs to be done for it to meet the use cases that you consider most relevant.
>
> Best wishes
> Petre
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> -----------------------------------------------------------------------------------
> This email message is for the sole use of the intended recipient(s) and may contain
> confidential information. Any unauthorized review, use, disclosure or distribution
> is prohibited. If you are not the intended recipient, please contact the sender by
> reply email and destroy all copies of the original message.
> -----------------------------------------------------------------------------------
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Varun,
Thank you for the suggestions. My comments are inline.
Petre
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Varun Wadekar via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 18 February 2020 05:44
To: Raghu Krishnamurthy <raghu.ncstate(a)icloud.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>
Subject: Re: [TF-A] Protecting Secure World Translation Tables
Thanks Raghu.
I agree that this patch reduces the attack surface and would be a good addition, if we consider use cases where EL3 code runs in a silo. Since S-EL1 can contain any third party code, there is an opportunity to change memory contents without EL3 ever noticing the change. A hash for the RO page tables would improve this change immensely IMO.
> Petre: Thank you for the suggestion. Sounds like an interesting improvement to make (maybe in a follow-up to this change?, since my rotation in the TF-A team is nearing its end).
This change is not effective for platforms that use dynamic page tables e.g. Tegra platforms, so we won't be enabling it. But if other maintainers think this is a good addition to their platforms, I don’t have any objection.
> Petre: Do you think it would be worth making this feature play more nicely with the dynamic translation library? I'm thinking providing a counter-API to make tables writable again. So that, every time a dynamic API is needed, since the translation context will be aware of the tables being RO, it first calls a make_tables_writable API before doing whatever it needs to and after it completes (whether successfully or not) calls make_tables_readonly. Essentially, it would act like a wrapper around the dynamic library functions.
What do you think of this? Is the disable MMU + cache flush penalty too severe (incurred twice for each dynamic xlat API call)?
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu Krishnamurthy via TF-A
Sent: Monday, February 17, 2020 4:16 PM
To: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] Protecting Secure World Translation Tables
External email: Use caution opening links or attachments
I think it is worth implementing this to raise the bar for successful attacks. To Varun's point, in today's systems without S-EL2(<v8.4), it would be less effective as pointed out, since EL3 memory can be completely accessed by SEL1 and SEL1 code tends to have a larger code base on mobile devices(OPTEE, tlk etc). However, on systems with very thin SEL1 shims(typically servers), this would definitely raise the bar for attacks, since you effectively only have SEL0 and EL3. SEL1 cannot be exploited practically.
For new SoCs with SEL2, this mitigation can still be very effective if we can ensure future SEL2 implementations have much smaller code bases and implements this mitigation itself. Effectively, i view SEL2 and EL3 as being equally privileged(it is no different than SEL1 because SEL2 can barf all over EL3 memory and TZ resources if exploited). SEL2 extensions, however, gives EL3 protection from SEL1 and can prevent SEL1 from accessing ALL TZ resources. If you view SEL2 and EL3 as equally privileged and view both together as a single entity, v8.4 systems effectively have EL3, SEL1, SEL0 AND the ability for EL3 to protect itself and other TZ resources from SEL1. In such a system, EL3(and SEL2) having this mitigation will definitely raise the bar for successful attacks.
Also, the cost to implement this mitigation is relatively low for a fairly significant raise in the bar for successful attacks.
PS - I say significantly raise the bar since an attacker will potentially require gadgets to modify TTBRx, invalidate TLB's, and enough gadgets in the code base to have a successful attack. If code in TF-A EL3 is fairly small, and code that writes to TTBR_EL3 can be in some section of the image that can be reclaimed/erased after initial setup, the attacker would have no gadget to modify TTBR_EL3, so there would be virtually no way to change TTBR_EL3. On a default build of FVP, there is a grand total of 1 instruction that writes to TTBR0_EL3 in enable_mmu_direct_el3. This might be a nice follow up change to this mitigation, if others think it is worth it. The same could be extended to other system registers that don't ever need to be changed(VBAR_EL3?
SCTLR_EL3?).
Thanks
Raghu
On 2/17/20 12:35 PM, Varun Wadekar via TF-A wrote:
> Hello Petre,
>
> Thanks for the patch. Before I review the actual code, would like to understand how effective this patch will be and if you have seen a real world attack that this patch mitigates.
>
> AFAIU, the ARM architecture provides the TZ bit as the only protection to create "partitions" on a CPU core. So, potentially S-EL1 can access almost all TZ resources that EL3 can access. Thus, creating a silo inside EL3 exception mode is not an effective mitigation against any other TZ component writing to the physical memory where the page tables are stored. For the scope of this attack vector, are we assuming that the system cannot be compromised by attacking other TZ software components in the system?
>
> I feel until we have a way to distinguish between CPU realms (EL3 v S-EL2 v S-EL1) at the hardware bus level (ARM v9?), these mitigations are not that effective.
>
> Thoughts?
>
> -Varun
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of
> Petre-Ionut Tudor via TF-A
> Sent: Monday, February 17, 2020 9:40 AM
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] Protecting Secure World Translation Tables
>
> External email: Use caution opening links or attachments
>
>
> Hello Everyone,
>
> For quite some time I have been working on a security hardening feature that offers extra protection against tampering with the Secure world translation tables. An example would be using a gadget that can perform writes to arbitrary Secure memory locations to change memory attributes and/or the memory map.
>
> A real world exploit that uses read/write gadgets to tamper with translation tables can be found here: https://vimeo.com/335948808. If you only want the slide deck, it's available here: https://speakerdeck.com/hhj4ck/el3-tour-get-the-ultimate-privilege-of-andro….
>
> A patch implementing this feature has been recently pushed upstream here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3349. It extends v2 of the translation tables library with an API that can be called by a BL image any time after the initialization of the xlat tables to make them read-only.
>
> It would be great to hear your opinions about this, particularly whether or not it is a desirable feature to have in TF-A and what extra work needs to be done for it to meet the use cases that you consider most relevant.
>
> Best wishes
> Petre
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> ----------------------------------------------------------------------
> ------------- This email message is for the sole use of the intended
> recipient(s) and may contain confidential information. Any
> unauthorized review, use, disclosure or distribution is prohibited.
> If you are not the intended recipient, please contact the sender by
> reply email and destroy all copies of the original message.
> ----------------------------------------------------------------------
> -------------
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hello Petre,
Thanks for the patch. Before I review the actual code, would like to understand how effective this patch will be and if you have seen a real world attack that this patch mitigates.
AFAIU, the ARM architecture provides the TZ bit as the only protection to create "partitions" on a CPU core. So, potentially S-EL1 can access almost all TZ resources that EL3 can access. Thus, creating a silo inside EL3 exception mode is not an effective mitigation against any other TZ component writing to the physical memory where the page tables are stored. For the scope of this attack vector, are we assuming that the system cannot be compromised by attacking other TZ software components in the system?
I feel until we have a way to distinguish between CPU realms (EL3 v S-EL2 v S-EL1) at the hardware bus level (ARM v9?), these mitigations are not that effective.
Thoughts?
-Varun
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Petre-Ionut Tudor via TF-A
Sent: Monday, February 17, 2020 9:40 AM
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Protecting Secure World Translation Tables
External email: Use caution opening links or attachments
Hello Everyone,
For quite some time I have been working on a security hardening feature that offers extra protection against tampering with the Secure world translation tables. An example would be using a gadget that can perform writes to arbitrary Secure memory locations to change memory attributes and/or the memory map.
A real world exploit that uses read/write gadgets to tamper with translation tables can be found here: https://vimeo.com/335948808. If you only want the slide deck, it's available here: https://speakerdeck.com/hhj4ck/el3-tour-get-the-ultimate-privilege-of-andro….
A patch implementing this feature has been recently pushed upstream here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3349. It extends v2 of the translation tables library with an API that can be called by a BL image any time after the initialization of the xlat tables to make them read-only.
It would be great to hear your opinions about this, particularly whether or not it is a desirable feature to have in TF-A and what extra work needs to be done for it to meet the use cases that you consider most relevant.
Best wishes
Petre
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
-----------------------------------------------------------------------------------
This email message is for the sole use of the intended recipient(s) and may contain
confidential information. Any unauthorized review, use, disclosure or distribution
is prohibited. If you are not the intended recipient, please contact the sender by
reply email and destroy all copies of the original message.
-----------------------------------------------------------------------------------
On 18/02/2020 05:52, Sumit Garg wrote:
> On Tue, 18 Feb 2020 at 00:44, Soby Mathew <Soby.Mathew(a)arm.com> wrote:
>>
>> Hi Everyone,
>> I have confirmation from the TBFU architect that both decrypt-then-verify and verify-then-decrypt is acceptable and neither case affects boot integrity.
>
> Thanks for this confirmation.
>
>> So I think the flexibility should be given to the platform to choose this.
>>
>> @Sumit Garg, could you please rework the patches as I mentioned in my previous feedback and submit again?
>
> Sure I will try to address implementation specific concerns. Actually
> earlier I was waiting for above design specific confirmation.
>
> -Sumit
[Adding back the tf-a list]
OK, Thanks Sumit.
>>
>> Best Regards
>> Soby Mathew
>>
>>> -----Original Message-----
>>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghupathy
>>> Krishnamurthy via TF-A
>>> Sent: 28 January 2020 14:58
>>> To: Sumit Garg <sumit.garg(a)linaro.org>
>>> Cc: Daniel Thompson <daniel.thompson(a)linaro.org>; Miklos Balint
>>> <Miklos.Balint(a)arm.com>; Kiyoshi Owada <owada.kiyoshi(a)socionext.com>; tf-
>>> a(a)lists.trustedfirmware.org; Joakim Bech <joakim.bech(a)linaro.org>; nd
>>> <nd(a)arm.com>; Sandrine Bailleux <Sandrine.Bailleux(a)arm.com>
>>> Subject: Re: [TF-A] [RFC] New feature in TF-A to load encrypted FIP payloads
>>>
>>> Hi Sumit,
>>>
>>>
>>> I completely agree with you! All i'm asking for is that what you are proposing is
>>> ratified in the spec clearly, without any ambiguities and that we don't
>>> implement what we *think* is correct, but implement the spec. If the spec
>>> specifies encryption, we should implement encryption, not authenticated
>>> encryption. One is not a direct substitute for the other and requires careful
>>> thinking. Similarly, the order of signing, encryption, decryption and
>>> authentication must be specified and explained clearly, specifically to avoid
>>> these kinds of discussions.
>>>
>>>
>>> Thanks
>>> -Raghu
>>>
>>> On January 27, 2020 at 10:49 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>>>
>>>
>>> On Mon, 27 Jan 2020 at 22:54, Raghupathy Krishnamurthy
>>> <raghu.ncstate(a)icloud.com> wrote:
>>>
>>>
>>>
>>> Sumit,
>>>
>>>
>>> Great point. This perhaps needs to be added to the list of things that need
>>> clarification(Sandrine can you help with this too?) in the PSA-TBFU . I believe
>>> the answer to your concern lies in the PSA-TBFU in section 3.5, where it talks
>>> about optimizing the trusted boot process. To overcome the problem you're
>>> talking about, you would:
>>> 1) Verify asymmetric signature.
>>> 2) Decrypt firmware using SSK on successful signature verification.
>>> 3) Rekey the firmware using BSSK(or as the PSA specifies, a key derived from
>>> the HUK using a KDF).
>>> You will only verify the asymmetric signature on every firmware update, and
>>> use the rekeyed firmware(encrypted and mac;d with device specific key) on
>>> normal boot.
>>>
>>>
>>>
>>> Following is the quote from PSA-TBFU spec:
>>>
>>> "An implementation **can** optimize the trusted boot process at the expense
>>> of **simplicity**"
>>>
>>> It doesn't seems to be a recommended practice from spec. And especially for
>>> DRM use-cases, this approach is NOT recommended due to following concerns
>>> raised by DRM vendors (original concerns were with respect to TAs but will
>>> equally apply for firmware as well):
>>> - allows the device to self sign code authorized to run on the device.
>>> - increase the attack surface by having two different ways to load firmware.
>>> - allow a break once break forever situation, if you defeat the RSA 'install' once,
>>> no matter how hard it is, now your firmware is nicely transformed in a secure
>>> firmware and can be reused.
>>>
>>> Whereas on the other hand, considering
>>> "sign-then-encrypt-then-authenticate", it provides two mutually exclusive
>>> crypto layers (signature layer and authenticated encryption
>>> layer) which in turns provides implementation flexibility as follows:
>>>
>>> Firmware update:
>>> - Require both layers.
>>>
>>> Normal boot:
>>> - DRM use-case, require both layers.
>>> - Boot time optimization required, can use only authenticated encryption.
>>> - Platform provides secure on-chip NVM and boot time optimization required,
>>> can use only signature verification (or simply hash stored in secure on-chip
>>> NVM memory).
>>>
>>> -Sumit
>>>
>>>
>>> Thanks
>>> Raghu
>>>
>>>
>>> On January 26, 2020 at 10:34 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>>>
>>>
>>> On Fri, 24 Jan 2020 at 16:36, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>>>
>>>
>>>
>>>
>>> On Fri, 24 Jan 2020 at 04:02, Raghupathy Krishnamurthy
>>>
>>>
>>> <raghu.ncstate(a)icloud.com> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>> I also just realized that both the TBBR and ARM PSA only talk about
>>> encryption of the image, and not authenticated encryption. The guarantees
>>> provided by both are completely different. Your
>>> review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/)
>>> talks about the requirement R060_TBBR_FUNCTION being implemented, which
>>> is technically not true(and potentially misleading). We must make a note of this
>>> difference and use the appropriate terminology, without mixing the two, in the
>>> documentation, commit messages, source code comments and error prints.
>>> The tool is also called 'encrypt_fw ' but should maybe be named appropriately
>>> to indicate it is doing authenticated encryption.
>>>
>>>
>>>
>>>
>>> I wouldn't call it misleading. Since firmware encryption feature
>>>
>>>
>>> essentially provides confidentiality protection and authenticated
>>>
>>>
>>> encryption is the type of crypto algorithm which we have used to
>>>
>>>
>>> implement it.
>>>
>>>
>>>
>>>
>>>>
>>>
>>>
>>>> BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-
>>> REL.pdf) expects that the image manifest(X509 certificate) contain the hash of
>>> the ENCRYPTED image(Table 2 and as described in my answer to your question
>>> "How would this ensure integrity of ciphertext"). The TBBR spec completely
>>> misses this fact, and is a crucial detail if we only implement encryption(as
>>> opposed to authenticated encryption).Build_macros.mk, in your change, passes
>>> the un-encrypted image to cert-tool. You can get away with it in your
>>> implementation, since you are using authenticated encryption, not if you were
>>> only implementing firmware encryption.
>>>
>>>
>>>
>>>
>>> I have already highlighted the issue with signing the ciphertext in my
>>>
>>>
>>> previous reply which deviates from security properties provided by
>>>
>>>
>>> signature verification of plain firmware. So I think we need to
>>>
>>>
>>> revisit ARM PSA TBFU spec.
>>>
>>>
>>>
>>>
>>>
>>>
>>> In addition to this, there are implementation specific issues with "signing the
>>> ciphertext" too. It simply makes the ciphertext immutable for device and
>>> disallows meeting following firmware re-encryption requirement as per TBBR
>>> spec:
>>>
>>>
>>> R070_TBBR_PROTECTION. The Trusted boot firmware may do the binding of
>>> software image updates at run- time by decrypting the updated SoC certificates
>>> and software images using the OTP/Fuse Secret Symmetric Key (SSK), followed
>>> by the re-encrypting these SoC certificates and software images using a
>>> reproducible secret unique per device symmetric key (BSSK), and then updating
>>> the ToC correspondingly.
>>>
>>>
>>> Also, externally signing every firmware image encrypted with BSSK doesn't
>>> seem scalable as well. It also hampers the case where encryption key is never
>>> exposed out from device eg. encryption key is only accessible to hardware
>>> crypto engine etc.
>>>
>>>
>>> -Sumit
>>>
>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Is it possible for somebody from ARM to have the TBBR spec updated to
>>> reflect this? Also perhaps talk to the spec writers about incorporating
>>> authenticated encryption into TBBR and PSA? This patch set is somewhat
>>> trailblazing in this regard.
>>>
>>>
>>>>
>>>
>>>
>>>> -Raghu
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A <tf-
>>> a(a)lists.trustedfirmware.org> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>> Hi Sumit,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thanks for your response.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> So firstly I would suggest you to revisit TBBR spec [1],
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] I'm very familiar with the TBBR spec and the requirements. Note
>>>> that not all SoC's adhere perfectly to the TBBR spec, since it does
>>>> not apply to devices in all market segments. However, these devices do
>>>> use arm trusted firmware and TBBR CoT in a slightly modified form,
>>>> which is still perfectly valid. Also, the TBBR spec can be changed if
>>>> required :)
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one use authenticated decryption only to establish TBBR
>>>
>>>
>>>>
>>>
>>>
>>>> Chain of Trust providing device the capability to self sign its firmware?
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] Fair point. However, you may have devices that don't have the
>>> processing power or hardware budget or cost factors(paying for HSM's to store
>>> private asymmetric keys), to implement asymmetric verification, in which case
>>> using authenticated decryption to verify firmware authenticity and integrity is
>>> perfectly valid. The attacks on devices that use symmetric keys to verify
>>> firmware authenticity and integrity are usually related to exploiting firmware
>>> flaws that leak the key or insiders leaking keys, but that is a different problem
>>> and requires different solutions. Fundamentally, there is nothing wrong with
>>> using symmetric keys for this purpose, so long as the key is well protected. Also
>>> note, security requirements and guarantees are different for different systems.
>>> The risk is taken by the system designer and should not be imposed by
>>> framework code. I don't advocate doing this but it is an option that your
>>> implementation does not provide(and perhaps rightly so).
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> How would this ensure integrity of ciphertext?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to
>>> cert_tool to sign. You don't decrypt the encrypted cipher text until you have
>>> verified the asymmetric signature(which provides integrity). As far as signature
>>> verification is concerned, whether you sign the plain text or ciphertext is
>>> immaterial, since you are simply verifying that the absolute bits you loaded
>>> have not been modified(assuming you use a secure signature scheme).
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Have a look at some defective sign and encrypt techniques here [2]
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] Again, very familiar with [2]. In the S/MIME case, you have multiple
>>> parties. With secure boot, you have one party, effectively verifying its own
>>> messages across time. There is only one key used to verify signatures. 1.1 and
>>> 1.2 does not apply. Also you are encrypting and signing with completely
>>> different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal
>>> encryption. Here you use symmetric encryption and asymmetric signing.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one not use TBBR CoT here?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] see above. Not all systems are designed equal.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> and why would one like to hardcode in a device during
>>>
>>>
>>>>
>>>
>>>
>>>> provisioning to boot only either an encrypted or a plain firmware
>>>
>>>
>>>> image?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] Why would you not? You typically want to have the same security policy
>>> for a class of devices and not be modifiable by an attacker. It isn't common for
>>> the same class of devices to use encrypted firmware some times, and un-
>>> encrypted firmware other times. If it is common, there is no problem with
>>> setting the bit in the FIP header, as long as verified boot is mandatory. The only
>>> concern(as my original email said) is the coupling of the FIP layer and the
>>> crypto module, in the implementation. I still don't like that fact that the bit
>>> saying the file is encrypted is not signed and this may require talking to the
>>> TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of
>>> Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity
>>> is verified by some means! R010_TBBR_TOC should perhaps be mandatory
>>> then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by
>>> hardware in readable registers. This requirement seems contradictory to
>>> R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM
>>> by ROM or some boot stage and then ROM'd or loaded into registers. I may be
>>> misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header
>>> in ATF implementation of TBBR) as being in ROM or integrity verified.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> How would one handle a case where BL31 is in plain format and BL32 is in
>>> encrypted format?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK]TBBR CoT is equipped to do this. The table is defined on a per image
>>> basis.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> If you are really paranoid about authentication of FIP header...
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] I don't mean to pontificate but there are real world customers buying
>>> real hardware, running ATF code, who care about such details and ask about
>>> such things routinely. It is not just me being paranoid and is definitely not a
>>> minor matter to think of such details. We should discuss more and consider the
>>> implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different
>>> thread, without blocking your code review. Can somebody from ARM clarify
>>> these requirements with the spec writers?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thanks
>>>
>>>
>>>> -Raghu
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org>
>>> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hi Raghu,
>>>
>>>
>>>>
>>>
>>>
>>>> I guess you have completely misunderstood this feature. This is an
>>>
>>>
>>>> optional feature which allows to load encrypted FIP payloads using
>>>
>>>
>>>> authenticated decryption which MUST be used along with signature
>>>
>>>
>>>> verification (or TBBR CoT).
>>>
>>>
>>>>
>>>
>>>
>>>> So firstly I would suggest you to revisit TBBR spec [1], especially
>>>
>>>
>>>> requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
>>>
>>>
>>>>
>>>
>>>
>>>> On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
>>>
>>>
>>>> <raghu.ncstate(a)icloud.com> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hello,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> The patch stack looks good. The only comment i have is that the FIP layer has
>>> now become security aware and supports authenticated decryption(only). This
>>> is a deviation from the secure/signed/verified boot design, where we use the
>>> TBBR COT to dictate the security operations on the file. This is nice, because
>>> file IO is decoupled from the security policy. This may be a big deviation(i
>>> apologize if this was considered and shot down for some other reason), but it
>>> may be worthwhile to consider making authenticated decryption a part of the
>>> authentication framework as opposed to coupling it with the FIP layer.
>>>
>>>
>>>>
>>>
>>>
>>>> It looks like you have mixed both TBBR CoT and this authenticated
>>>
>>>
>>>> decryption feature. They both are completely different and rather
>>>
>>>
>>>> complement each other where TBBR CoT establishes
>>>
>>>
>>>> secure/signed/verified boot and this authenticated decryption feature
>>>
>>>
>>>> provides confidentiality protection for FIP payloads.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> At a high level, this would mean adding a new authentication
>>> method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having
>>> the platform specify that the image is using authenticated encryption in the
>>> TBBR COT.
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one use authenticated decryption only to establish TBBR
>>>
>>>
>>>> Chain of Trust providing device the capability to self sign its
>>>
>>>
>>>> firmwares? We must use signature verification for TBBR CoT (see
>>>
>>>
>>>> section: 2.1 Authentication of Code Images by Certificate in TBBR spec
>>>
>>>
>>>> [1]).
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> The authentication framework is already well designed and well equipped to
>>> handle these types of extensions.
>>>
>>>
>>>> 1) This would make the change simpler, since you would not require changes
>>> to the FIP tool and the FIP layer.
>>>
>>>
>>>> 2) This would also allow for future cases where a platform may want to only
>>> encrypt the file and use public key authentication on the encrypted file(for ex.
>>> the soc does not have a crypto accelerator for aes-gcm but only for AES and
>>> public key verification, for whatever reason).
>>>
>>>
>>>>
>>>
>>>
>>>> How would this ensure integrity of ciphertext? This approach may be
>>>
>>>
>>>> vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
>>>
>>>
>>>> part of AES-GCM provides integrity protection for ciphertext.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> 3) This would let you choose the order in which you want to do the
>>> authenticated decryption(or just decryption) and signature verification, if you
>>> use both, one or the other.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Have a look at some defective sign and encrypt techniques here [2].
>>>
>>>
>>>> The order can't be any arbitrary one, we need to be careful about
>>>
>>>
>>>> this.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> One other thing i'm not entirely comfortable with is that the flag indicating if
>>> there are encrypted files or not in the FIP, is in the *unsigned* portion of the
>>> FIP header. An attacker could simply flip bits that dictate security policy in the
>>> header and avoid detection(in this case, the indication that the file needs
>>> authenticated decryption). If a platform only uses authenticated encryption, but
>>> not verified boot, an attacker could flip the bit in the FIP header and have any
>>> image loaded on the platform.
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one not use TBBR CoT here?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> If authenticated encryption cannot be used without verified boot(which
>>> requires build time flags), having a flag to indicate that there are encrypted
>>> files in the FIP header is moot, since this can come at build time through the
>>> TBBR COT. In any case, it seems like the security policy that firmware images
>>> need to be decrypted or authenticated with authenticated decryption, seems
>>> like a firmware build time or manufacturing time decision(perhaps a bit set in
>>> the e-fuses).
>>>
>>>
>>>>
>>>
>>>
>>>> Again you are confusing TBBR CoT with authenticated decryption
>>>
>>>
>>>> feature. And why would one like to hardcode in a device during
>>>
>>>
>>>> provisioning to boot only either an encrypted or a plain firmware
>>>
>>>
>>>> image?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> There seems to be no benefit to having a flag in the FIP header.
>>>
>>>
>>>>
>>>
>>>
>>>> How would one handle a case where BL31 is in plain format and BL32 is
>>>
>>>
>>>> in encrypted format?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Otherwise, I cant think of any attacks due to this and it may be completely
>>> okay, but generally, consuming data that dictates security policy/operations
>>> before verifying its integrity seems like a recipe for disaster.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> If you are really paranoid about authentication of FIP header then you
>>>
>>>
>>>> should look at implementing optional requirement: R010_TBBR_TOC as per
>>>
>>>
>>>> TBBR spec [1].
>>>
>>>
>>>>
>>>
>>>
>>>> [1]
>>>> https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requi
>>>> rements-client-tbbr-client-armv8-a
>>>
>>>
>>>> [2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
>>>
>>>
>>>>
>>>
>>>
>>>> -Sumit
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> -Raghu
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-
>>> a(a)lists.trustedfirmware.org> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hi Sandrine,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
>>>
>>>
>>>> <Sandrine.Bailleux(a)arm.com> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hello Sumit,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thank you for reworking the patches and addressing all of my review
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> comments. I am happy with the latest version of these and consider
>>>> them
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> ready to go. I plan to leave them in Gerrit for another week to give
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> extra time for other potential reviewers to have a look and comment.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thanks for your review.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> To everyone on the list: Please raise any concerns you may have about
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> these patches in the coming week. If I don't hear anything by 29th
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> January 2020, I will merge these patches.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> @Sumit: One of the next actions for this patch stack would be to have
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> some level of testing in the CI system to detect any potential
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> regressions. We (at Arm) can quite easily add a few build tests but
>>>> then
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> testing the software stack on QEMU is a bit more involved for various
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> ...) so this might have to wait for some time.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Okay, will wait for CI testing.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> -Sumit
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Regards,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Sandrine
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> --
>>>
>>>
>>>> TF-A mailing list
>>>
>>>
>>>> TF-A(a)lists.trustedfirmware.org
>>>
>>>
>>>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>>
>>>
>>>> --
>>>
>>>
>>>> TF-A mailing list
>>>
>>>
>>>> TF-A(a)lists.trustedfirmware.org
>>>
>>>
>>>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>> --
>>> TF-A mailing list
>>> TF-A(a)lists.trustedfirmware.org
>>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
On 17/02/2020 23:25, Raghu Krishnamurthy wrote:
> Thanks Soby. Couple of questions:
> 1) Is this going to be clarified in the PSA-TBFU ?
Hi Raghu,
Yes, this clarification will added to the spec.
> 2) Is authenticated encryption/decryption going to be addressed ? One of
> the issues i had was the fact that AES-GCM was being used here instead
> of just encryption such as aes-cbc/ctr etc. I think it is worth adding a
> note in the spec stating that it can be used safely instead of
> encryption, and probably preferred.
Yes, clarification regarding using AEAD algorithms/AES-GCM will be
provided as I understand.
Best Regards
Soby Mathew
>
> Thanks
> Raghu
>
> On 2/17/20 11:14 AM, Soby Mathew wrote:
>> Hi Everyone,
>> I have confirmation from the TBFU architect that both decrypt-then-verify and verify-then-decrypt is acceptable and neither case affects boot integrity. So I think the flexibility should be given to the platform to choose this.
>>
>> @Sumit Garg, could you please rework the patches as I mentioned in my previous feedback and submit again?
>>
>> Best Regards
>> Soby Mathew
>>
>>> -----Original Message-----
>>> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghupathy
>>> Krishnamurthy via TF-A
>>> Sent: 28 January 2020 14:58
>>> To: Sumit Garg <sumit.garg(a)linaro.org>
>>> Cc: Daniel Thompson <daniel.thompson(a)linaro.org>; Miklos Balint
>>> <Miklos.Balint(a)arm.com>; Kiyoshi Owada <owada.kiyoshi(a)socionext.com>; tf-
>>> a(a)lists.trustedfirmware.org; Joakim Bech <joakim.bech(a)linaro.org>; nd
>>> <nd(a)arm.com>; Sandrine Bailleux <Sandrine.Bailleux(a)arm.com>
>>> Subject: Re: [TF-A] [RFC] New feature in TF-A to load encrypted FIP payloads
>>>
>>> Hi Sumit,
>>>
>>>
>>> I completely agree with you! All i'm asking for is that what you are proposing is
>>> ratified in the spec clearly, without any ambiguities and that we don't
>>> implement what we *think* is correct, but implement the spec. If the spec
>>> specifies encryption, we should implement encryption, not authenticated
>>> encryption. One is not a direct substitute for the other and requires careful
>>> thinking. Similarly, the order of signing, encryption, decryption and
>>> authentication must be specified and explained clearly, specifically to avoid
>>> these kinds of discussions.
>>>
>>>
>>> Thanks
>>> -Raghu
>>>
>>> On January 27, 2020 at 10:49 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>>>
>>>
>>> On Mon, 27 Jan 2020 at 22:54, Raghupathy Krishnamurthy
>>> <raghu.ncstate(a)icloud.com> wrote:
>>>
>>>
>>>
>>> Sumit,
>>>
>>>
>>> Great point. This perhaps needs to be added to the list of things that need
>>> clarification(Sandrine can you help with this too?) in the PSA-TBFU . I believe
>>> the answer to your concern lies in the PSA-TBFU in section 3.5, where it talks
>>> about optimizing the trusted boot process. To overcome the problem you're
>>> talking about, you would:
>>> 1) Verify asymmetric signature.
>>> 2) Decrypt firmware using SSK on successful signature verification.
>>> 3) Rekey the firmware using BSSK(or as the PSA specifies, a key derived from
>>> the HUK using a KDF).
>>> You will only verify the asymmetric signature on every firmware update, and
>>> use the rekeyed firmware(encrypted and mac;d with device specific key) on
>>> normal boot.
>>>
>>>
>>>
>>> Following is the quote from PSA-TBFU spec:
>>>
>>> "An implementation **can** optimize the trusted boot process at the expense
>>> of **simplicity**"
>>>
>>> It doesn't seems to be a recommended practice from spec. And especially for
>>> DRM use-cases, this approach is NOT recommended due to following concerns
>>> raised by DRM vendors (original concerns were with respect to TAs but will
>>> equally apply for firmware as well):
>>> - allows the device to self sign code authorized to run on the device.
>>> - increase the attack surface by having two different ways to load firmware.
>>> - allow a break once break forever situation, if you defeat the RSA 'install' once,
>>> no matter how hard it is, now your firmware is nicely transformed in a secure
>>> firmware and can be reused.
>>>
>>> Whereas on the other hand, considering
>>> "sign-then-encrypt-then-authenticate", it provides two mutually exclusive
>>> crypto layers (signature layer and authenticated encryption
>>> layer) which in turns provides implementation flexibility as follows:
>>>
>>> Firmware update:
>>> - Require both layers.
>>>
>>> Normal boot:
>>> - DRM use-case, require both layers.
>>> - Boot time optimization required, can use only authenticated encryption.
>>> - Platform provides secure on-chip NVM and boot time optimization required,
>>> can use only signature verification (or simply hash stored in secure on-chip
>>> NVM memory).
>>>
>>> -Sumit
>>>
>>>
>>> Thanks
>>> Raghu
>>>
>>>
>>> On January 26, 2020 at 10:34 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>>>
>>>
>>> On Fri, 24 Jan 2020 at 16:36, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>>>
>>>
>>>
>>>
>>> On Fri, 24 Jan 2020 at 04:02, Raghupathy Krishnamurthy
>>>
>>>
>>> <raghu.ncstate(a)icloud.com> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>> I also just realized that both the TBBR and ARM PSA only talk about
>>> encryption of the image, and not authenticated encryption. The guarantees
>>> provided by both are completely different. Your
>>> review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/)
>>> talks about the requirement R060_TBBR_FUNCTION being implemented, which
>>> is technically not true(and potentially misleading). We must make a note of this
>>> difference and use the appropriate terminology, without mixing the two, in the
>>> documentation, commit messages, source code comments and error prints.
>>> The tool is also called 'encrypt_fw ' but should maybe be named appropriately
>>> to indicate it is doing authenticated encryption.
>>>
>>>
>>>
>>>
>>> I wouldn't call it misleading. Since firmware encryption feature
>>>
>>>
>>> essentially provides confidentiality protection and authenticated
>>>
>>>
>>> encryption is the type of crypto algorithm which we have used to
>>>
>>>
>>> implement it.
>>>
>>>
>>>
>>>
>>>>
>>>
>>>
>>>> BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-
>>> REL.pdf) expects that the image manifest(X509 certificate) contain the hash of
>>> the ENCRYPTED image(Table 2 and as described in my answer to your question
>>> "How would this ensure integrity of ciphertext"). The TBBR spec completely
>>> misses this fact, and is a crucial detail if we only implement encryption(as
>>> opposed to authenticated encryption).Build_macros.mk, in your change, passes
>>> the un-encrypted image to cert-tool. You can get away with it in your
>>> implementation, since you are using authenticated encryption, not if you were
>>> only implementing firmware encryption.
>>>
>>>
>>>
>>>
>>> I have already highlighted the issue with signing the ciphertext in my
>>>
>>>
>>> previous reply which deviates from security properties provided by
>>>
>>>
>>> signature verification of plain firmware. So I think we need to
>>>
>>>
>>> revisit ARM PSA TBFU spec.
>>>
>>>
>>>
>>>
>>>
>>>
>>> In addition to this, there are implementation specific issues with "signing the
>>> ciphertext" too. It simply makes the ciphertext immutable for device and
>>> disallows meeting following firmware re-encryption requirement as per TBBR
>>> spec:
>>>
>>>
>>> R070_TBBR_PROTECTION. The Trusted boot firmware may do the binding of
>>> software image updates at run- time by decrypting the updated SoC certificates
>>> and software images using the OTP/Fuse Secret Symmetric Key (SSK), followed
>>> by the re-encrypting these SoC certificates and software images using a
>>> reproducible secret unique per device symmetric key (BSSK), and then updating
>>> the ToC correspondingly.
>>>
>>>
>>> Also, externally signing every firmware image encrypted with BSSK doesn't
>>> seem scalable as well. It also hampers the case where encryption key is never
>>> exposed out from device eg. encryption key is only accessible to hardware
>>> crypto engine etc.
>>>
>>>
>>> -Sumit
>>>
>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Is it possible for somebody from ARM to have the TBBR spec updated to
>>> reflect this? Also perhaps talk to the spec writers about incorporating
>>> authenticated encryption into TBBR and PSA? This patch set is somewhat
>>> trailblazing in this regard.
>>>
>>>
>>>>
>>>
>>>
>>>> -Raghu
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A <tf-
>>> a(a)lists.trustedfirmware.org> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>> Hi Sumit,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thanks for your response.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> So firstly I would suggest you to revisit TBBR spec [1],
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] I'm very familiar with the TBBR spec and the requirements. Note
>>>> that not all SoC's adhere perfectly to the TBBR spec, since it does
>>>> not apply to devices in all market segments. However, these devices do
>>>> use arm trusted firmware and TBBR CoT in a slightly modified form,
>>>> which is still perfectly valid. Also, the TBBR spec can be changed if
>>>> required :)
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one use authenticated decryption only to establish TBBR
>>>
>>>
>>>>
>>>
>>>
>>>> Chain of Trust providing device the capability to self sign its firmware?
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] Fair point. However, you may have devices that don't have the
>>> processing power or hardware budget or cost factors(paying for HSM's to store
>>> private asymmetric keys), to implement asymmetric verification, in which case
>>> using authenticated decryption to verify firmware authenticity and integrity is
>>> perfectly valid. The attacks on devices that use symmetric keys to verify
>>> firmware authenticity and integrity are usually related to exploiting firmware
>>> flaws that leak the key or insiders leaking keys, but that is a different problem
>>> and requires different solutions. Fundamentally, there is nothing wrong with
>>> using symmetric keys for this purpose, so long as the key is well protected. Also
>>> note, security requirements and guarantees are different for different systems.
>>> The risk is taken by the system designer and should not be imposed by
>>> framework code. I don't advocate doing this but it is an option that your
>>> implementation does not provide(and perhaps rightly so).
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> How would this ensure integrity of ciphertext?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to
>>> cert_tool to sign. You don't decrypt the encrypted cipher text until you have
>>> verified the asymmetric signature(which provides integrity). As far as signature
>>> verification is concerned, whether you sign the plain text or ciphertext is
>>> immaterial, since you are simply verifying that the absolute bits you loaded
>>> have not been modified(assuming you use a secure signature scheme).
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Have a look at some defective sign and encrypt techniques here [2]
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] Again, very familiar with [2]. In the S/MIME case, you have multiple
>>> parties. With secure boot, you have one party, effectively verifying its own
>>> messages across time. There is only one key used to verify signatures. 1.1 and
>>> 1.2 does not apply. Also you are encrypting and signing with completely
>>> different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal
>>> encryption. Here you use symmetric encryption and asymmetric signing.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one not use TBBR CoT here?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] see above. Not all systems are designed equal.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> and why would one like to hardcode in a device during
>>>
>>>
>>>>
>>>
>>>
>>>> provisioning to boot only either an encrypted or a plain firmware
>>>
>>>
>>>> image?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] Why would you not? You typically want to have the same security policy
>>> for a class of devices and not be modifiable by an attacker. It isn't common for
>>> the same class of devices to use encrypted firmware some times, and un-
>>> encrypted firmware other times. If it is common, there is no problem with
>>> setting the bit in the FIP header, as long as verified boot is mandatory. The only
>>> concern(as my original email said) is the coupling of the FIP layer and the
>>> crypto module, in the implementation. I still don't like that fact that the bit
>>> saying the file is encrypted is not signed and this may require talking to the
>>> TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of
>>> Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity
>>> is verified by some means! R010_TBBR_TOC should perhaps be mandatory
>>> then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by
>>> hardware in readable registers. This requirement seems contradictory to
>>> R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM
>>> by ROM or some boot stage and then ROM'd or loaded into registers. I may be
>>> misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header
>>> in ATF implementation of TBBR) as being in ROM or integrity verified.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> How would one handle a case where BL31 is in plain format and BL32 is in
>>> encrypted format?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> [RK]TBBR CoT is equipped to do this. The table is defined on a per image
>>> basis.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> If you are really paranoid about authentication of FIP header...
>>>
>>>
>>>>
>>>
>>>
>>>> [RK] I don't mean to pontificate but there are real world customers buying
>>> real hardware, running ATF code, who care about such details and ask about
>>> such things routinely. It is not just me being paranoid and is definitely not a
>>> minor matter to think of such details. We should discuss more and consider the
>>> implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different
>>> thread, without blocking your code review. Can somebody from ARM clarify
>>> these requirements with the spec writers?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thanks
>>>
>>>
>>>> -Raghu
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org>
>>> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hi Raghu,
>>>
>>>
>>>>
>>>
>>>
>>>> I guess you have completely misunderstood this feature. This is an
>>>
>>>
>>>> optional feature which allows to load encrypted FIP payloads using
>>>
>>>
>>>> authenticated decryption which MUST be used along with signature
>>>
>>>
>>>> verification (or TBBR CoT).
>>>
>>>
>>>>
>>>
>>>
>>>> So firstly I would suggest you to revisit TBBR spec [1], especially
>>>
>>>
>>>> requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
>>>
>>>
>>>>
>>>
>>>
>>>> On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
>>>
>>>
>>>> <raghu.ncstate(a)icloud.com> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hello,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> The patch stack looks good. The only comment i have is that the FIP layer has
>>> now become security aware and supports authenticated decryption(only). This
>>> is a deviation from the secure/signed/verified boot design, where we use the
>>> TBBR COT to dictate the security operations on the file. This is nice, because
>>> file IO is decoupled from the security policy. This may be a big deviation(i
>>> apologize if this was considered and shot down for some other reason), but it
>>> may be worthwhile to consider making authenticated decryption a part of the
>>> authentication framework as opposed to coupling it with the FIP layer.
>>>
>>>
>>>>
>>>
>>>
>>>> It looks like you have mixed both TBBR CoT and this authenticated
>>>
>>>
>>>> decryption feature. They both are completely different and rather
>>>
>>>
>>>> complement each other where TBBR CoT establishes
>>>
>>>
>>>> secure/signed/verified boot and this authenticated decryption feature
>>>
>>>
>>>> provides confidentiality protection for FIP payloads.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> At a high level, this would mean adding a new authentication
>>> method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having
>>> the platform specify that the image is using authenticated encryption in the
>>> TBBR COT.
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one use authenticated decryption only to establish TBBR
>>>
>>>
>>>> Chain of Trust providing device the capability to self sign its
>>>
>>>
>>>> firmwares? We must use signature verification for TBBR CoT (see
>>>
>>>
>>>> section: 2.1 Authentication of Code Images by Certificate in TBBR spec
>>>
>>>
>>>> [1]).
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> The authentication framework is already well designed and well equipped to
>>> handle these types of extensions.
>>>
>>>
>>>> 1) This would make the change simpler, since you would not require changes
>>> to the FIP tool and the FIP layer.
>>>
>>>
>>>> 2) This would also allow for future cases where a platform may want to only
>>> encrypt the file and use public key authentication on the encrypted file(for ex.
>>> the soc does not have a crypto accelerator for aes-gcm but only for AES and
>>> public key verification, for whatever reason).
>>>
>>>
>>>>
>>>
>>>
>>>> How would this ensure integrity of ciphertext? This approach may be
>>>
>>>
>>>> vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
>>>
>>>
>>>> part of AES-GCM provides integrity protection for ciphertext.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> 3) This would let you choose the order in which you want to do the
>>> authenticated decryption(or just decryption) and signature verification, if you
>>> use both, one or the other.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Have a look at some defective sign and encrypt techniques here [2].
>>>
>>>
>>>> The order can't be any arbitrary one, we need to be careful about
>>>
>>>
>>>> this.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> One other thing i'm not entirely comfortable with is that the flag indicating if
>>> there are encrypted files or not in the FIP, is in the *unsigned* portion of the
>>> FIP header. An attacker could simply flip bits that dictate security policy in the
>>> header and avoid detection(in this case, the indication that the file needs
>>> authenticated decryption). If a platform only uses authenticated encryption, but
>>> not verified boot, an attacker could flip the bit in the FIP header and have any
>>> image loaded on the platform.
>>>
>>>
>>>>
>>>
>>>
>>>> Why would one not use TBBR CoT here?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> If authenticated encryption cannot be used without verified boot(which
>>> requires build time flags), having a flag to indicate that there are encrypted
>>> files in the FIP header is moot, since this can come at build time through the
>>> TBBR COT. In any case, it seems like the security policy that firmware images
>>> need to be decrypted or authenticated with authenticated decryption, seems
>>> like a firmware build time or manufacturing time decision(perhaps a bit set in
>>> the e-fuses).
>>>
>>>
>>>>
>>>
>>>
>>>> Again you are confusing TBBR CoT with authenticated decryption
>>>
>>>
>>>> feature. And why would one like to hardcode in a device during
>>>
>>>
>>>> provisioning to boot only either an encrypted or a plain firmware
>>>
>>>
>>>> image?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> There seems to be no benefit to having a flag in the FIP header.
>>>
>>>
>>>>
>>>
>>>
>>>> How would one handle a case where BL31 is in plain format and BL32 is
>>>
>>>
>>>> in encrypted format?
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Otherwise, I cant think of any attacks due to this and it may be completely
>>> okay, but generally, consuming data that dictates security policy/operations
>>> before verifying its integrity seems like a recipe for disaster.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> If you are really paranoid about authentication of FIP header then you
>>>
>>>
>>>> should look at implementing optional requirement: R010_TBBR_TOC as per
>>>
>>>
>>>> TBBR spec [1].
>>>
>>>
>>>>
>>>
>>>
>>>> [1]
>>>> https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requi
>>>> rements-client-tbbr-client-armv8-a
>>>
>>>
>>>> [2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
>>>
>>>
>>>>
>>>
>>>
>>>> -Sumit
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> -Raghu
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-
>>> a(a)lists.trustedfirmware.org> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hi Sandrine,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
>>>
>>>
>>>> <Sandrine.Bailleux(a)arm.com> wrote:
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Hello Sumit,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thank you for reworking the patches and addressing all of my review
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> comments. I am happy with the latest version of these and consider
>>>> them
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> ready to go. I plan to leave them in Gerrit for another week to give
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> extra time for other potential reviewers to have a look and comment.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Thanks for your review.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> To everyone on the list: Please raise any concerns you may have about
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> these patches in the coming week. If I don't hear anything by 29th
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> January 2020, I will merge these patches.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> @Sumit: One of the next actions for this patch stack would be to have
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> some level of testing in the CI system to detect any potential
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> regressions. We (at Arm) can quite easily add a few build tests but
>>>> then
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> testing the software stack on QEMU is a bit more involved for various
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> ...) so this might have to wait for some time.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Okay, will wait for CI testing.
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> -Sumit
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Regards,
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> Sandrine
>>>
>>>
>>>>
>>>
>>>
>>>>
>>>
>>>
>>>> --
>>>
>>>
>>>> TF-A mailing list
>>>
>>>
>>>> TF-A(a)lists.trustedfirmware.org
>>>
>>>
>>>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>>
>>>
>>>> --
>>>
>>>
>>>> TF-A mailing list
>>>
>>>
>>>> TF-A(a)lists.trustedfirmware.org
>>>
>>>
>>>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>>> --
>>> TF-A mailing list
>>> TF-A(a)lists.trustedfirmware.org
>>> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Adding back tf-a list,
> Hi Everyone,
> I have confirmation from the TBFU architect that both decrypt-then-verify and
> verify-then-decrypt is acceptable and neither case affects boot integrity. So I
> think the flexibility should be given to the platform to choose this.
>
> @Sumit Garg, could you please rework the patches as I mentioned in my
> previous feedback and submit again?
>
> Best Regards
> Soby Mathew
>
> > -----Original Message-----
> > From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of
> > Raghupathy Krishnamurthy via TF-A
> > Sent: 28 January 2020 14:58
> > To: Sumit Garg <sumit.garg(a)linaro.org>
> > Cc: Daniel Thompson <daniel.thompson(a)linaro.org>; Miklos Balint
> > <Miklos.Balint(a)arm.com>; Kiyoshi Owada <owada.kiyoshi(a)socionext.com>;
> > tf- a(a)lists.trustedfirmware.org; Joakim Bech <joakim.bech(a)linaro.org>;
> > nd <nd(a)arm.com>; Sandrine Bailleux <Sandrine.Bailleux(a)arm.com>
> > Subject: Re: [TF-A] [RFC] New feature in TF-A to load encrypted FIP
> > payloads
> >
> > Hi Sumit,
> >
> >
> > I completely agree with you! All i'm asking for is that what you are
> > proposing is ratified in the spec clearly, without any ambiguities and
> > that we don't implement what we *think* is correct, but implement the
> > spec. If the spec specifies encryption, we should implement
> > encryption, not authenticated encryption. One is not a direct
> > substitute for the other and requires careful thinking. Similarly, the
> > order of signing, encryption, decryption and authentication must be
> > specified and explained clearly, specifically to avoid these kinds of discussions.
> >
> >
> > Thanks
> > -Raghu
> >
> > On January 27, 2020 at 10:49 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
> >
> >
> > On Mon, 27 Jan 2020 at 22:54, Raghupathy Krishnamurthy
> > <raghu.ncstate(a)icloud.com> wrote:
> >
> >
> >
> > Sumit,
> >
> >
> > Great point. This perhaps needs to be added to the list of things that
> > need clarification(Sandrine can you help with this too?) in the
> > PSA-TBFU . I believe the answer to your concern lies in the PSA-TBFU
> > in section 3.5, where it talks about optimizing the trusted boot
> > process. To overcome the problem you're talking about, you would:
> > 1) Verify asymmetric signature.
> > 2) Decrypt firmware using SSK on successful signature verification.
> > 3) Rekey the firmware using BSSK(or as the PSA specifies, a key
> > derived from the HUK using a KDF).
> > You will only verify the asymmetric signature on every firmware
> > update, and use the rekeyed firmware(encrypted and mac;d with device
> > specific key) on normal boot.
> >
> >
> >
> > Following is the quote from PSA-TBFU spec:
> >
> > "An implementation **can** optimize the trusted boot process at the
> > expense of **simplicity**"
> >
> > It doesn't seems to be a recommended practice from spec. And
> > especially for DRM use-cases, this approach is NOT recommended due to
> > following concerns raised by DRM vendors (original concerns were with
> > respect to TAs but will equally apply for firmware as well):
> > - allows the device to self sign code authorized to run on the device.
> > - increase the attack surface by having two different ways to load firmware.
> > - allow a break once break forever situation, if you defeat the RSA
> > 'install' once, no matter how hard it is, now your firmware is nicely
> > transformed in a secure firmware and can be reused.
> >
> > Whereas on the other hand, considering
> > "sign-then-encrypt-then-authenticate", it provides two mutually
> > exclusive crypto layers (signature layer and authenticated encryption
> > layer) which in turns provides implementation flexibility as follows:
> >
> > Firmware update:
> > - Require both layers.
> >
> > Normal boot:
> > - DRM use-case, require both layers.
> > - Boot time optimization required, can use only authenticated encryption.
> > - Platform provides secure on-chip NVM and boot time optimization
> > required, can use only signature verification (or simply hash stored
> > in secure on-chip NVM memory).
> >
> > -Sumit
> >
> >
> > Thanks
> > Raghu
> >
> >
> > On January 26, 2020 at 10:34 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
> >
> >
> > On Fri, 24 Jan 2020 at 16:36, Sumit Garg <sumit.garg(a)linaro.org> wrote:
> >
> >
> >
> >
> > On Fri, 24 Jan 2020 at 04:02, Raghupathy Krishnamurthy
> >
> >
> > <raghu.ncstate(a)icloud.com> wrote:
> >
> >
> > >
> >
> >
> > > I also just realized that both the TBBR and ARM PSA only talk about
> > encryption of the image, and not authenticated encryption. The
> > guarantees provided by both are completely different. Your
> > review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/
> > 2495/) talks about the requirement R060_TBBR_FUNCTION being
> > implemented, which is technically not true(and potentially
> > misleading). We must make a note of this difference and use the
> > appropriate terminology, without mixing the two, in the documentation,
> > commit messages, source code comments and error prints.
> > The tool is also called 'encrypt_fw ' but should maybe be named
> > appropriately to indicate it is doing authenticated encryption.
> >
> >
> >
> >
> > I wouldn't call it misleading. Since firmware encryption feature
> >
> >
> > essentially provides confidentiality protection and authenticated
> >
> >
> > encryption is the type of crypto algorithm which we have used to
> >
> >
> > implement it.
> >
> >
> >
> >
> > >
> >
> >
> > > BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-
> > REL.pdf) expects that the image manifest(X509 certificate) contain the
> > hash of the ENCRYPTED image(Table 2 and as described in my answer to
> > your question "How would this ensure integrity of ciphertext"). The
> > TBBR spec completely misses this fact, and is a crucial detail if we
> > only implement encryption(as opposed to authenticated
> > encryption).Build_macros.mk, in your change, passes the un-encrypted
> > image to cert-tool. You can get away with it in your implementation,
> > since you are using authenticated encryption, not if you were only
> implementing firmware encryption.
> >
> >
> >
> >
> > I have already highlighted the issue with signing the ciphertext in my
> >
> >
> > previous reply which deviates from security properties provided by
> >
> >
> > signature verification of plain firmware. So I think we need to
> >
> >
> > revisit ARM PSA TBFU spec.
> >
> >
> >
> >
> >
> >
> > In addition to this, there are implementation specific issues with
> > "signing the ciphertext" too. It simply makes the ciphertext immutable
> > for device and disallows meeting following firmware re-encryption
> > requirement as per TBBR
> > spec:
> >
> >
> > R070_TBBR_PROTECTION. The Trusted boot firmware may do the binding of
> > software image updates at run- time by decrypting the updated SoC
> > certificates and software images using the OTP/Fuse Secret Symmetric
> > Key (SSK), followed by the re-encrypting these SoC certificates and
> > software images using a reproducible secret unique per device
> > symmetric key (BSSK), and then updating the ToC correspondingly.
> >
> >
> > Also, externally signing every firmware image encrypted with BSSK
> > doesn't seem scalable as well. It also hampers the case where
> > encryption key is never exposed out from device eg. encryption key is
> > only accessible to hardware crypto engine etc.
> >
> >
> > -Sumit
> >
> >
> >
> >
> > >
> >
> >
> > > Is it possible for somebody from ARM to have the TBBR spec updated
> > > to
> > reflect this? Also perhaps talk to the spec writers about
> > incorporating authenticated encryption into TBBR and PSA? This patch
> > set is somewhat trailblazing in this regard.
> >
> >
> > >
> >
> >
> > > -Raghu
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A
> > > <tf-
> > a(a)lists.trustedfirmware.org> wrote:
> >
> >
> > >
> >
> >
> > > Hi Sumit,
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Thanks for your response.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > So firstly I would suggest you to revisit TBBR spec [1],
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > [RK] I'm very familiar with the TBBR spec and the requirements. Note
> > > that not all SoC's adhere perfectly to the TBBR spec, since it does
> > > not apply to devices in all market segments. However, these devices
> > > do use arm trusted firmware and TBBR CoT in a slightly modified
> > > form, which is still perfectly valid. Also, the TBBR spec can be
> > > changed if required :)
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Why would one use authenticated decryption only to establish TBBR
> >
> >
> > >
> >
> >
> > > Chain of Trust providing device the capability to self sign its firmware?
> >
> >
> > >
> >
> >
> > > [RK] Fair point. However, you may have devices that don't have the
> > processing power or hardware budget or cost factors(paying for HSM's
> > to store private asymmetric keys), to implement asymmetric
> > verification, in which case using authenticated decryption to verify
> > firmware authenticity and integrity is perfectly valid. The attacks on
> > devices that use symmetric keys to verify firmware authenticity and
> > integrity are usually related to exploiting firmware flaws that leak
> > the key or insiders leaking keys, but that is a different problem and
> > requires different solutions. Fundamentally, there is nothing wrong
> > with using symmetric keys for this purpose, so long as the key is well
> protected. Also note, security requirements and guarantees are different for
> different systems.
> > The risk is taken by the system designer and should not be imposed by
> > framework code. I don't advocate doing this but it is an option that
> > your implementation does not provide(and perhaps rightly so).
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > How would this ensure integrity of ciphertext?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > [RK] You sign the ciphertext. In your design, you pass bl31_enc.bin
> > > to
> > cert_tool to sign. You don't decrypt the encrypted cipher text until
> > you have verified the asymmetric signature(which provides integrity).
> > As far as signature verification is concerned, whether you sign the
> > plain text or ciphertext is immaterial, since you are simply verifying
> > that the absolute bits you loaded have not been modified(assuming you use a
> secure signature scheme).
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Have a look at some defective sign and encrypt techniques here [2]
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > [RK] Again, very familiar with [2]. In the S/MIME case, you have
> > > multiple
> > parties. With secure boot, you have one party, effectively verifying
> > its own messages across time. There is only one key used to verify
> > signatures. 1.1 and
> > 1.2 does not apply. Also you are encrypting and signing with
> > completely different keys and algorithms. Section 1.2 applies when you
> > use RSA/El-gamal encryption. Here you use symmetric encryption and
> asymmetric signing.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Why would one not use TBBR CoT here?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > [RK] see above. Not all systems are designed equal.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > and why would one like to hardcode in a device during
> >
> >
> > >
> >
> >
> > > provisioning to boot only either an encrypted or a plain firmware
> >
> >
> > > image?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > [RK] Why would you not? You typically want to have the same security
> > > policy
> > for a class of devices and not be modifiable by an attacker. It isn't
> > common for the same class of devices to use encrypted firmware some
> > times, and un- encrypted firmware other times. If it is common, there
> > is no problem with setting the bit in the FIP header, as long as
> > verified boot is mandatory. The only concern(as my original email
> > said) is the coupling of the FIP layer and the crypto module, in the
> > implementation. I still don't like that fact that the bit saying the
> > file is encrypted is not signed and this may require talking to the
> > TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted
> > Table of Contents". The FIP header cannot be "trusted", if it is not
> > in ROM or its integrity is verified by some means! R010_TBBR_TOC
> > should perhaps be mandatory then. Also see R080_TBBR_TOC that says the
> > TOC MUST be ROM'ed or tied by hardware in readable registers. This
> > requirement seems contradictory to R010_TBBR_TOC, given that the FIP
> > header(TOC) is copied from mutable NVM by ROM or some boot stage and
> > then ROM'd or loaded into registers. I may be misunderstanding
> R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header in ATF
> implementation of TBBR) as being in ROM or integrity verified.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > How would one handle a case where BL31 is in plain format and BL32
> > > is in
> > encrypted format?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > [RK]TBBR CoT is equipped to do this. The table is defined on a per
> > > image
> > basis.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > If you are really paranoid about authentication of FIP header...
> >
> >
> > >
> >
> >
> > > [RK] I don't mean to pontificate but there are real world customers
> > > buying
> > real hardware, running ATF code, who care about such details and ask
> > about such things routinely. It is not just me being paranoid and is
> > definitely not a minor matter to think of such details. We should
> > discuss more and consider the implications of R080_TBBR_TOC and
> > R010_TBBR_TOC, perhaps on a different thread, without blocking your
> > code review. Can somebody from ARM clarify these requirements with the
> spec writers?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Thanks
> >
> >
> > > -Raghu
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org>
> > wrote:
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Hi Raghu,
> >
> >
> > >
> >
> >
> > > I guess you have completely misunderstood this feature. This is an
> >
> >
> > > optional feature which allows to load encrypted FIP payloads using
> >
> >
> > > authenticated decryption which MUST be used along with signature
> >
> >
> > > verification (or TBBR CoT).
> >
> >
> > >
> >
> >
> > > So firstly I would suggest you to revisit TBBR spec [1], especially
> >
> >
> > > requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
> >
> >
> > >
> >
> >
> > > On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
> >
> >
> > > <raghu.ncstate(a)icloud.com> wrote:
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Hello,
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > The patch stack looks good. The only comment i have is that the FIP
> > > layer has
> > now become security aware and supports authenticated decryption(only).
> > This is a deviation from the secure/signed/verified boot design, where
> > we use the TBBR COT to dictate the security operations on the file.
> > This is nice, because file IO is decoupled from the security policy.
> > This may be a big deviation(i apologize if this was considered and
> > shot down for some other reason), but it may be worthwhile to consider
> > making authenticated decryption a part of the authentication framework as
> opposed to coupling it with the FIP layer.
> >
> >
> > >
> >
> >
> > > It looks like you have mixed both TBBR CoT and this authenticated
> >
> >
> > > decryption feature. They both are completely different and rather
> >
> >
> > > complement each other where TBBR CoT establishes
> >
> >
> > > secure/signed/verified boot and this authenticated decryption
> > > feature
> >
> >
> > > provides confidentiality protection for FIP payloads.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > At a high level, this would mean adding a new authentication
> > method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and
> having the
> > platform specify that the image is using authenticated encryption in
> > the TBBR COT.
> >
> >
> > >
> >
> >
> > > Why would one use authenticated decryption only to establish TBBR
> >
> >
> > > Chain of Trust providing device the capability to self sign its
> >
> >
> > > firmwares? We must use signature verification for TBBR CoT (see
> >
> >
> > > section: 2.1 Authentication of Code Images by Certificate in TBBR
> > > spec
> >
> >
> > > [1]).
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > The authentication framework is already well designed and well
> > > equipped to
> > handle these types of extensions.
> >
> >
> > > 1) This would make the change simpler, since you would not require
> > > changes
> > to the FIP tool and the FIP layer.
> >
> >
> > > 2) This would also allow for future cases where a platform may want
> > > to only
> > encrypt the file and use public key authentication on the encrypted file(for ex.
> > the soc does not have a crypto accelerator for aes-gcm but only for
> > AES and public key verification, for whatever reason).
> >
> >
> > >
> >
> >
> > > How would this ensure integrity of ciphertext? This approach may be
> >
> >
> > > vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag
> > > as
> >
> >
> > > part of AES-GCM provides integrity protection for ciphertext.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > 3) This would let you choose the order in which you want to do the
> > authenticated decryption(or just decryption) and signature
> > verification, if you use both, one or the other.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Have a look at some defective sign and encrypt techniques here [2].
> >
> >
> > > The order can't be any arbitrary one, we need to be careful about
> >
> >
> > > this.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > One other thing i'm not entirely comfortable with is that the flag
> > > indicating if
> > there are encrypted files or not in the FIP, is in the *unsigned*
> > portion of the FIP header. An attacker could simply flip bits that
> > dictate security policy in the header and avoid detection(in this
> > case, the indication that the file needs authenticated decryption). If
> > a platform only uses authenticated encryption, but not verified boot,
> > an attacker could flip the bit in the FIP header and have any image loaded on
> the platform.
> >
> >
> > >
> >
> >
> > > Why would one not use TBBR CoT here?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > If authenticated encryption cannot be used without verified
> > > boot(which
> > requires build time flags), having a flag to indicate that there are
> > encrypted files in the FIP header is moot, since this can come at
> > build time through the TBBR COT. In any case, it seems like the
> > security policy that firmware images need to be decrypted or
> > authenticated with authenticated decryption, seems like a firmware
> > build time or manufacturing time decision(perhaps a bit set in the e-fuses).
> >
> >
> > >
> >
> >
> > > Again you are confusing TBBR CoT with authenticated decryption
> >
> >
> > > feature. And why would one like to hardcode in a device during
> >
> >
> > > provisioning to boot only either an encrypted or a plain firmware
> >
> >
> > > image?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > There seems to be no benefit to having a flag in the FIP header.
> >
> >
> > >
> >
> >
> > > How would one handle a case where BL31 is in plain format and BL32
> > > is
> >
> >
> > > in encrypted format?
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Otherwise, I cant think of any attacks due to this and it may be
> > > completely
> > okay, but generally, consuming data that dictates security
> > policy/operations before verifying its integrity seems like a recipe for disaster.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > If you are really paranoid about authentication of FIP header then
> > > you
> >
> >
> > > should look at implementing optional requirement: R010_TBBR_TOC as
> > > per
> >
> >
> > > TBBR spec [1].
> >
> >
> > >
> >
> >
> > > [1]
> > > https://developer.arm.com/docs/den0006/latest/trusted-board-boot-req
> > > ui
> > > rements-client-tbbr-client-armv8-a
> >
> >
> > > [2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
> >
> >
> > >
> >
> >
> > > -Sumit
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > -Raghu
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-
> > a(a)lists.trustedfirmware.org> wrote:
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Hi Sandrine,
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
> >
> >
> > > <Sandrine.Bailleux(a)arm.com> wrote:
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Hello Sumit,
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Thank you for reworking the patches and addressing all of my review
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > comments. I am happy with the latest version of these and consider
> > > them
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > ready to go. I plan to leave them in Gerrit for another week to give
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > extra time for other potential reviewers to have a look and comment.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Thanks for your review.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > To everyone on the list: Please raise any concerns you may have
> > > about
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > these patches in the coming week. If I don't hear anything by 29th
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > January 2020, I will merge these patches.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > @Sumit: One of the next actions for this patch stack would be to
> > > have
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > some level of testing in the CI system to detect any potential
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > regressions. We (at Arm) can quite easily add a few build tests but
> > > then
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > testing the software stack on QEMU is a bit more involved for
> > > various
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > reasons (first instance of QEMU testing, dependencies on OPTEE,
> > > UEFI,
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > ...) so this might have to wait for some time.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Okay, will wait for CI testing.
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > -Sumit
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Regards,
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > Sandrine
> >
> >
> > >
> >
> >
> > >
> >
> >
> > > --
> >
> >
> > > TF-A mailing list
> >
> >
> > > TF-A(a)lists.trustedfirmware.org
> >
> >
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> >
> >
> > > --
> >
> >
> > > TF-A mailing list
> >
> >
> > > TF-A(a)lists.trustedfirmware.org
> >
> >
> > > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> > --
> > TF-A mailing list
> > TF-A(a)lists.trustedfirmware.org
> > https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Thanks Raghu.
I agree that this patch reduces the attack surface and would be a good addition, if we consider use cases where EL3 code runs in a silo. Since S-EL1 can contain any third party code, there is an opportunity to change memory contents without EL3 ever noticing the change. A hash for the RO page tables would improve this change immensely IMO.
This change is not effective for platforms that use dynamic page tables e.g. Tegra platforms, so we won't be enabling it. But if other maintainers think this is a good addition to their platforms, I don’t have any objection.
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Raghu Krishnamurthy via TF-A
Sent: Monday, February 17, 2020 4:16 PM
To: tf-a(a)lists.trustedfirmware.org
Subject: Re: [TF-A] Protecting Secure World Translation Tables
External email: Use caution opening links or attachments
I think it is worth implementing this to raise the bar for successful attacks. To Varun's point, in today's systems without S-EL2(<v8.4), it would be less effective as pointed out, since EL3 memory can be completely accessed by SEL1 and SEL1 code tends to have a larger code base on mobile devices(OPTEE, tlk etc). However, on systems with very thin SEL1 shims(typically servers), this would definitely raise the bar for attacks, since you effectively only have SEL0 and EL3. SEL1 cannot be exploited practically.
For new SoCs with SEL2, this mitigation can still be very effective if we can ensure future SEL2 implementations have much smaller code bases and implements this mitigation itself. Effectively, i view SEL2 and EL3 as being equally privileged(it is no different than SEL1 because SEL2 can barf all over EL3 memory and TZ resources if exploited). SEL2 extensions, however, gives EL3 protection from SEL1 and can prevent SEL1 from accessing ALL TZ resources. If you view SEL2 and EL3 as equally privileged and view both together as a single entity, v8.4 systems effectively have EL3, SEL1, SEL0 AND the ability for EL3 to protect itself and other TZ resources from SEL1. In such a system, EL3(and SEL2) having this mitigation will definitely raise the bar for successful attacks.
Also, the cost to implement this mitigation is relatively low for a fairly significant raise in the bar for successful attacks.
PS - I say significantly raise the bar since an attacker will potentially require gadgets to modify TTBRx, invalidate TLB's, and enough gadgets in the code base to have a successful attack. If code in TF-A EL3 is fairly small, and code that writes to TTBR_EL3 can be in some section of the image that can be reclaimed/erased after initial setup, the attacker would have no gadget to modify TTBR_EL3, so there would be virtually no way to change TTBR_EL3. On a default build of FVP, there is a grand total of 1 instruction that writes to TTBR0_EL3 in enable_mmu_direct_el3. This might be a nice follow up change to this mitigation, if others think it is worth it. The same could be extended to other system registers that don't ever need to be changed(VBAR_EL3?
SCTLR_EL3?).
Thanks
Raghu
On 2/17/20 12:35 PM, Varun Wadekar via TF-A wrote:
> Hello Petre,
>
> Thanks for the patch. Before I review the actual code, would like to understand how effective this patch will be and if you have seen a real world attack that this patch mitigates.
>
> AFAIU, the ARM architecture provides the TZ bit as the only protection to create "partitions" on a CPU core. So, potentially S-EL1 can access almost all TZ resources that EL3 can access. Thus, creating a silo inside EL3 exception mode is not an effective mitigation against any other TZ component writing to the physical memory where the page tables are stored. For the scope of this attack vector, are we assuming that the system cannot be compromised by attacking other TZ software components in the system?
>
> I feel until we have a way to distinguish between CPU realms (EL3 v S-EL2 v S-EL1) at the hardware bus level (ARM v9?), these mitigations are not that effective.
>
> Thoughts?
>
> -Varun
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of
> Petre-Ionut Tudor via TF-A
> Sent: Monday, February 17, 2020 9:40 AM
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] Protecting Secure World Translation Tables
>
> External email: Use caution opening links or attachments
>
>
> Hello Everyone,
>
> For quite some time I have been working on a security hardening feature that offers extra protection against tampering with the Secure world translation tables. An example would be using a gadget that can perform writes to arbitrary Secure memory locations to change memory attributes and/or the memory map.
>
> A real world exploit that uses read/write gadgets to tamper with translation tables can be found here: https://vimeo.com/335948808. If you only want the slide deck, it's available here: https://speakerdeck.com/hhj4ck/el3-tour-get-the-ultimate-privilege-of-andro….
>
> A patch implementing this feature has been recently pushed upstream here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3349. It extends v2 of the translation tables library with an API that can be called by a BL image any time after the initialization of the xlat tables to make them read-only.
>
> It would be great to hear your opinions about this, particularly whether or not it is a desirable feature to have in TF-A and what extra work needs to be done for it to meet the use cases that you consider most relevant.
>
> Best wishes
> Petre
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> ----------------------------------------------------------------------
> ------------- This email message is for the sole use of the intended
> recipient(s) and may contain confidential information. Any
> unauthorized review, use, disclosure or distribution is prohibited.
> If you are not the intended recipient, please contact the sender by
> reply email and destroy all copies of the original message.
> ----------------------------------------------------------------------
> -------------
>
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
I think it is worth implementing this to raise the bar for successful
attacks. To Varun's point, in today's systems without S-EL2(<v8.4), it
would be less effective as pointed out, since EL3 memory can be
completely accessed by SEL1 and SEL1 code tends to have a larger code
base on mobile devices(OPTEE, tlk etc). However, on systems with very
thin SEL1 shims(typically servers), this would definitely raise the bar
for attacks, since you effectively only have SEL0 and EL3. SEL1 cannot
be exploited practically.
For new SoCs with SEL2, this mitigation can still be very effective if
we can ensure future SEL2 implementations have much smaller code bases
and implements this mitigation itself. Effectively, i view SEL2 and EL3
as being equally privileged(it is no different than SEL1 because SEL2
can barf all over EL3 memory and TZ resources if exploited). SEL2
extensions, however, gives EL3 protection from SEL1 and can prevent SEL1
from accessing ALL TZ resources. If you view SEL2 and EL3 as equally
privileged and view both together as a single entity, v8.4 systems
effectively have EL3, SEL1, SEL0 AND the ability for EL3 to protect
itself and other TZ resources from SEL1. In such a system, EL3(and SEL2)
having this mitigation will definitely raise the bar for successful attacks.
Also, the cost to implement this mitigation is relatively low for a
fairly significant raise in the bar for successful attacks.
PS - I say significantly raise the bar since an attacker will
potentially require gadgets to modify TTBRx, invalidate TLB's, and
enough gadgets in the code base to have a successful attack. If code in
TF-A EL3 is fairly small, and code that writes to TTBR_EL3 can be in
some section of the image that can be reclaimed/erased after initial
setup, the attacker would have no gadget to modify TTBR_EL3, so there
would be virtually no way to change TTBR_EL3. On a default build of FVP,
there is a grand total of 1 instruction that writes to TTBR0_EL3 in
enable_mmu_direct_el3. This might be a nice follow up change to this
mitigation, if others think it is worth it. The same could be extended
to other system registers that don't ever need to be changed(VBAR_EL3?
SCTLR_EL3?).
Thanks
Raghu
On 2/17/20 12:35 PM, Varun Wadekar via TF-A wrote:
> Hello Petre,
>
> Thanks for the patch. Before I review the actual code, would like to understand how effective this patch will be and if you have seen a real world attack that this patch mitigates.
>
> AFAIU, the ARM architecture provides the TZ bit as the only protection to create "partitions" on a CPU core. So, potentially S-EL1 can access almost all TZ resources that EL3 can access. Thus, creating a silo inside EL3 exception mode is not an effective mitigation against any other TZ component writing to the physical memory where the page tables are stored. For the scope of this attack vector, are we assuming that the system cannot be compromised by attacking other TZ software components in the system?
>
> I feel until we have a way to distinguish between CPU realms (EL3 v S-EL2 v S-EL1) at the hardware bus level (ARM v9?), these mitigations are not that effective.
>
> Thoughts?
>
> -Varun
>
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Petre-Ionut Tudor via TF-A
> Sent: Monday, February 17, 2020 9:40 AM
> To: tf-a(a)lists.trustedfirmware.org
> Subject: [TF-A] Protecting Secure World Translation Tables
>
> External email: Use caution opening links or attachments
>
>
> Hello Everyone,
>
> For quite some time I have been working on a security hardening feature that offers extra protection against tampering with the Secure world translation tables. An example would be using a gadget that can perform writes to arbitrary Secure memory locations to change memory attributes and/or the memory map.
>
> A real world exploit that uses read/write gadgets to tamper with translation tables can be found here: https://vimeo.com/335948808. If you only want the slide deck, it's available here: https://speakerdeck.com/hhj4ck/el3-tour-get-the-ultimate-privilege-of-andro….
>
> A patch implementing this feature has been recently pushed upstream here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3349. It extends v2 of the translation tables library with an API that can be called by a BL image any time after the initialization of the xlat tables to make them read-only.
>
> It would be great to hear your opinions about this, particularly whether or not it is a desirable feature to have in TF-A and what extra work needs to be done for it to meet the use cases that you consider most relevant.
>
> Best wishes
> Petre
> IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
>
> -----------------------------------------------------------------------------------
> This email message is for the sole use of the intended recipient(s) and may contain
> confidential information. Any unauthorized review, use, disclosure or distribution
> is prohibited. If you are not the intended recipient, please contact the sender by
> reply email and destroy all copies of the original message.
> -----------------------------------------------------------------------------------
>
Hello Everyone,
For quite some time I have been working on a security hardening feature that offers extra protection against tampering with the Secure world translation tables. An example would be using a gadget that can perform writes to arbitrary Secure memory locations to change memory attributes and/or the memory map.
A real world exploit that uses read/write gadgets to tamper with translation tables can be found here: https://vimeo.com/335948808. If you only want the slide deck, it's available here: https://speakerdeck.com/hhj4ck/el3-tour-get-the-ultimate-privilege-of-andro….
A patch implementing this feature has been recently pushed upstream here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3349. It extends v2 of the translation tables library with an API that can be called by a BL image any time after the initialization of the xlat tables to make them read-only.
It would be great to hear your opinions about this, particularly whether or not it is a desirable feature to have in TF-A and what extra work needs to be done for it to meet the use cases that you consider most relevant.
Best wishes
Petre
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi,
I am using an iMX8M mini, I have flashed the image with uuu.auto of
L4.14.98_2.0.0_ga_images_MX8MMEVK and I have a Linux image with OP-TEE. Now
I want to use TF-A but I don't know the steps to continue. I am reading
this document (
https://source.codeaurora.org/external/imx/uboot-imx/tree/doc/imx/habv4/gui…
and https : //trustedfirmware-a.readthedocs.io/en/latest/plat/imx8m.html
<https://trustedfirmware-a.readthedocs.io/en/latest/plat/imx8m.html>) but I
don't know how to get these files: u-boot.bin, u-boot-nodtb.bin,
u-boot-spl.bin , DTB U-Boot file (for example, fsl-imx8mq-evk.dtb).
Can anyone tell me the steps to follow?
Thanks, best regards
Iñigo.
Hi,
Please find the latest report on new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
2 new defect(s) introduced to ARM-software/arm-trusted-firmware found with Coverity Scan.
New defect(s) Reported-by: Coverity Scan
Showing 2 of 2 defect(s)
** CID 353989: Integer handling issues (INCOMPATIBLE_CAST)
________________________________________________________________________________________________________
*** CID 353989: Integer handling issues (INCOMPATIBLE_CAST)
/plat/intel/soc/common/socfpga_psci.c: 138 in socfpga_system_reset()
132
133 extern uint64_t intel_rsu_update_address;
134
135 static void __dead2 socfpga_system_reset(void)
136 {
137 if (intel_rsu_update_address)
>>> CID 353989: Integer handling issues (INCOMPATIBLE_CAST)
>>> Pointer "&intel_rsu_update_address" points to an object whose effective type is "unsigned long long" (64 bits, unsigned) but is dereferenced as a narrower "unsigned int" (32 bits, unsigned). This may lead to unexpected results depending on machine endianness.
138 mailbox_rsu_update((uint32_t *)&intel_rsu_update_address);
139 else
140 mailbox_reset_cold();
141
142 while (1)
143 wfi();
** CID 353988: Integer handling issues (INCOMPATIBLE_CAST)
________________________________________________________________________________________________________
*** CID 353988: Integer handling issues (INCOMPATIBLE_CAST)
/plat/intel/soc/common/socfpga_sip_svc.c: 526 in sip_smc_handler()
520
521 case INTEL_SIP_SMC_RSU_NOTIFY:
522 status = intel_rsu_notify(x1);
523 SMC_RET1(handle, status);
524
525 case INTEL_SIP_SMC_RSU_RETRY_COUNTER:
>>> CID 353988: Integer handling issues (INCOMPATIBLE_CAST)
>>> Pointer "rsu_respbuf" points to an object whose effective type is "unsigned long long" (64 bits, unsigned) but is dereferenced as a narrower "unsigned int" (32 bits, unsigned). This may lead to unexpected results depending on machine endianness.
526 status = intel_rsu_retry_counter((uint32_t *)rsu_respbuf,
527 ARRAY_SIZE(rsu_respbuf), &val);
528 if (status) {
529 SMC_RET1(handle, status);
530 } else {
531 SMC_RET2(handle, status, val);
________________________________________________________________________________________________________
To view the defects in Coverity Scan visit, https://u2389337.ct.sendgrid.net/ls/click?upn=nJaKvJSIH-2FPAfmty-2BK5tYpPkl…
Hello,
The fip header has reserved fields available for platform specific use.
The fiptool allows these header fields to be filled in using the
--plat-toc-flags.
A call needs to be available in the ATF framework to get these flags
without accessing the FIP file again to get these flags.
We have a solution we've used for ATF for quite some time to access
these flags.
It's finally being upstreamed here:
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2839
If there are any other efficient methods to access these flags or a
better proposal please suggest.
Thanks,
Scott
Hi Pankaj,
Would it be possible to provide more information on your platform (what CPU, its revision, number of clusters/CPUs per cluster, etc.)?
Is your platform code publically available?
Regards.
Alexei
________________________________
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> on behalf of Pankaj Gupta via TF-A <tf-a(a)lists.trustedfirmware.org>
Sent: 07 February 2020 10:57
To: Olivier Deprez <Olivier.Deprez(a)arm.com>
Cc: tf-a(a)lists.trustedfirmware.org <tf-a(a)lists.trustedfirmware.org>; nd <nd(a)arm.com>
Subject: Re: [TF-A] [EXT] RE: Issue with addition of NXP Platform support on TFA v2.2
Hi,
Please find the comments in-line.
Regards
Pankaj
-----Original Message-----
From: Olivier Deprez <Olivier.Deprez(a)arm.com>
Sent: Wednesday, February 5, 2020 6:54 PM
To: Pankaj Gupta <pankaj.gupta(a)nxp.com>
Cc: nd <nd(a)arm.com>; tf-a(a)lists.trustedfirmware.org
Subject: [EXT] RE: Issue with addition of NXP Platform support on TFA v2.2
>Caution: EXT Email
>Hi Pankaj,
>Can you pls provide a bit more background:
>Which boot stage (BL1/BL2/BL31...) get affected?
BL2
>Is there any crash report to console?
No. But, using the external debugger, it is found that core gets to non-responding.
>Is this an aarch64/or aarch32 platform?
aarch64
>There can be different root causes to this e.g.
>1. a stale translation in TLB, or a dirty cache line remnant from earlier boot stages. If this is the case, it would need invalidating TLB and/or caches on BL entry.
>2. the empty table ptr given by xlat_table_get_empty is pointing nowhere sensible because of this specific platform layout
>There are multiple calls to xlat_clean_dcache_range in this file, do you confirm the crash happen within xlat_tables_map_region?
Yes.
Basis of saying 'yes' is: if this function is commented, the BL2 comes up successfully.
Flow in the code base is :
mmap_add_dynamic_region -> mmap_add_dynamic_region_ctx ->
xlat_tables_map_region-> xlat_table_get_empty //....issue is seen.
>Can you try one or both statements below after the call to xlat_table_get_empty (and uncomment calls to clean_dcache_range):
>
> inv_dcache_range((uintptr_t)subtable, XLAT_TABLE_SIZE);
>
> xlat_arch_tlbi_va((uintptr_t)subtable, ctx->xlat_regime);
> xlat_arch_tlbi_va_sync();
mmap_add_dynamic_region -> mmap_add_dynamic_region_ctx ->
xlat_tables_map_region-> xlat_table_get_empty-> xlat_arch_tlbi_va //issue is resolved.
The root cause of this issue is race condition.
Please correct me if I am wrong.
Another observation:
mmap_add_dynamic_region -> mmap_add_dynamic_region_ctx (Putting console debug logs in this function)->
xlat_tables_map_region-> xlat_table_get_empty //issue is resolved.
Please share your view for this observation as well.
Regards,
Olivier.
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Pankaj Gupta via TF-A
Sent: 05 February 2020 11:45
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Issue with addition of NXP Platform support on TFA v2.2
Hi,
In the TFA v2.2 code base, the file "lib/xlat_tables_v2/xlat_tables_core.c" has the implementation for function "xlat_tables_map_region()".
The implementation for this function is changed in TFAv2.2 (compared TFAv1.5), with addition of function "xlat_clean_dcache_range()".
Due to this addition, my earlier* working platform on TFAv1.5, is hanging here.
If the function call for the function "xlat_clean_dcache_range()", is comment, then the platform works well.
Code snippet:
static inline __attribute__((unused)) void xlat_clean_dcache_range(uintptr_t addr, size_t size) {
if (is_dcache_enabled())
clean_dcache_range(addr, size); // On commenting this line, my platform works fine with TFAv2.2
}
Please share your views on what could I be missing here.
Thanks.
Regards
Pankaj
*Earlier raised patch for this platform was not merged due to review comments are not disposed-off in time; and TF-A got migrated from github to gerrit.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://eur01.safelinks.protection.outlook.com/?url=https%3A%2F%2Flists.tru…
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.
Hi Pankaj,
Can you pls provide a bit more background:
Which boot stage (BL1/BL2/BL31...) get affected?
Is there any crash report to console?
Is this an aarch64/or aarch32 platform?
There can be different root causes to this e.g.
1. a stale translation in TLB, or a dirty cache line remnant from earlier boot stages. If this is the case, it would need invalidating TLB and/or caches on BL entry.
2. the empty table ptr given by xlat_table_get_empty is pointing nowhere sensible because of this specific platform layout
There are multiple calls to xlat_clean_dcache_range in this file, do you confirm the crash happen within xlat_tables_map_region?
Can you try one or both statements below after the call to xlat_table_get_empty (and uncomment calls to clean_dcache_range):
inv_dcache_range((uintptr_t)subtable, XLAT_TABLE_SIZE);
xlat_arch_tlbi_va((uintptr_t)subtable, ctx->xlat_regime);
xlat_arch_tlbi_va_sync();
Regards,
Olivier.
-----Original Message-----
From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Pankaj Gupta via TF-A
Sent: 05 February 2020 11:45
To: tf-a(a)lists.trustedfirmware.org
Subject: [TF-A] Issue with addition of NXP Platform support on TFA v2.2
Hi,
In the TFA v2.2 code base, the file "lib/xlat_tables_v2/xlat_tables_core.c" has the implementation for function "xlat_tables_map_region()".
The implementation for this function is changed in TFAv2.2 (compared TFAv1.5), with addition of function "xlat_clean_dcache_range()".
Due to this addition, my earlier* working platform on TFAv1.5, is hanging here.
If the function call for the function "xlat_clean_dcache_range()", is comment, then the platform works well.
Code snippet:
static inline __attribute__((unused)) void xlat_clean_dcache_range(uintptr_t addr, size_t size) {
if (is_dcache_enabled())
clean_dcache_range(addr, size); // On commenting this line, my platform works fine with TFAv2.2
}
Please share your views on what could I be missing here.
Thanks.
Regards
Pankaj
*Earlier raised patch for this platform was not merged due to review comments are not disposed-off in time; and TF-A got migrated from github to gerrit.
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi Fathi,
Thanks for the below write-up, this is really great news!
> Note: this is in silent mode (links to the build job are currently disabled,
> and will be re-enableb today).
Please go ahead in re-enabling those jobs, so that people can see the results of the build jobs (while we work on propagating back to Gerrit also the results of the LAVA boot jobs).
Thanks
Matteo
> -----Original Message-----
> From: TF-A <tf-a-bounces(a)lists.trustedfirmware.org> On Behalf Of Fathi
> Boudra via TF-A
> Sent: 05 February 2020 12:45
> To: TF-A(a)lists.trustedfirmware.org
> Cc: Ryan Arnold <ryan.arnold(a)linaro.org>
> Subject: [TF-A] CI status update - end to end boot testing on Juno
>
> Hi,
>
> The end-to-end testing prototype is now completed and enabled.
> This encompases an end-to-end testing pipeline whereby TF-A code
> submission to gerrit results in a TF build (based on the code submission)
> being injected into a file system (recovery image) and booted on a Juno
> device in the Linaro TF LAVA instance with the results of the boot test
> available in the LAVA instance.
>
> Here's the explanation of the CI pipeline:
> 1. Trigger - capture gerrit events:
> https://ci.trustedfirmware.org/job/trigger-tf-a-builder/
> All changes made to the trusted-firmware A repository are captured by
> the trigger event and result in a build.
> e.g., triggering commit:
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/3100
> Note: this is in silent mode (links to the build job are currently disabled,
> and will be re-enableb today).
> 2. Build Binary Artifacts - Binary artifacts built via:
> https://ci.trustedfirmware.org/job/tf-a-builder/
> e.g., https://ci.trustedfirmware.org/job/tf-a-builder/631/
> (with a link to the accompanying LAVA job and a link to the trigger job in
> gerrit) 3. Recovery/Flash submission to LAVA - Used to flash the binary to the
> board:
> https://ci.trustedfirmware.org/job/post-build-lava/
> 4. LAVA tests results
> e.g., Specific example of the template applied to a specific build
> (631 above)
> https://tf.validation.linaro.org/scheduler/job/895/definition
> Results: https://tf.validation.linaro.org/results/895
> Link to all jobs: https://tf.validation.linaro.org/scheduler/alljobs
>
> Some additional information:
> * tf-a-ci-scripts git repository has been set up and contains the CI scripts for
> TF-A.
> https://git.trustedfirmware.org/ci/tf-a-ci-scripts.git/
> * tf-a-job-configs git repository has been set up and contains the Jenkins jobs
> configurations automatically deployed on https://ci.trustedfirmware.org
> Jenkins instance.
> https://git.trustedfirmware.org/ci/tf-a-job-configs.git/
>
> Cheers,
> --
> Fathi Boudra
> Linaro.org | Open source software for ARM SoCs
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Hi,
In the TFA v2.2 code base, the file "lib/xlat_tables_v2/xlat_tables_core.c" has the implementation for function "xlat_tables_map_region()".
The implementation for this function is changed in TFAv2.2 (compared TFAv1.5), with addition of function "xlat_clean_dcache_range()".
Due to this addition, my earlier* working platform on TFAv1.5, is hanging here.
If the function call for the function "xlat_clean_dcache_range()", is comment, then the platform works well.
Code snippet:
static inline __attribute__((unused)) void xlat_clean_dcache_range(uintptr_t addr, size_t size)
{
if (is_dcache_enabled())
clean_dcache_range(addr, size); // On commenting this line, my platform works fine with TFAv2.2
}
Please share your views on what could I be missing here.
Thanks.
Regards
Pankaj
*Earlier raised patch for this platform was not merged due to review comments are not disposed-off in time; and TF-A got migrated from github to gerrit.
Hi all,
On Tue, 2020-01-28 at 14:57 +0000, Raghupathy Krishnamurthy via TF-A
wrote:
> I completely agree with you! All i'm asking for is that what you are
> proposing is ratified in the spec clearly, without any ambiguities
> and that we don't implement what we *think* is correct, but implement
> the spec. If the spec specifies encryption, we should implement
> encryption, not authenticated encryption. One is not a direct
> substitute for the other and requires careful thinking. Similarly,
> the order of signing, encryption, decryption and authentication must
> be specified and explained clearly, specifically to avoid these kinds
> of discussions.
Just to keep everyone in the loop, we are currently having some
internal discussions within Arm about TBBR/TBFU and all the
questions/concerns that have been raised in this thread.
I will update you ASAP.
Best regards,
Sandrine
Hi Sumit,
I completely agree with you! All i'm asking for is that what you are proposing is ratified in the spec clearly, without any ambiguities and that we don't implement what we *think* is correct, but implement the spec. If the spec specifies encryption, we should implement encryption, not authenticated encryption. One is not a direct substitute for the other and requires careful thinking. Similarly, the order of signing, encryption, decryption and authentication must be specified and explained clearly, specifically to avoid these kinds of discussions.
Thanks
-Raghu
On January 27, 2020 at 10:49 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
On Mon, 27 Jan 2020 at 22:54, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
Sumit,
Great point. This perhaps needs to be added to the list of things that need clarification(Sandrine can you help with this too?) in the PSA-TBFU . I believe the answer to your concern lies in the PSA-TBFU in section 3.5, where it talks about optimizing the trusted boot process. To overcome the problem you're talking about, you would:
1) Verify asymmetric signature.
2) Decrypt firmware using SSK on successful signature verification.
3) Rekey the firmware using BSSK(or as the PSA specifies, a key derived from the HUK using a KDF).
You will only verify the asymmetric signature on every firmware update, and use the rekeyed firmware(encrypted and mac;d with device specific key) on normal boot.
Following is the quote from PSA-TBFU spec:
"An implementation **can** optimize the trusted boot process at the
expense of **simplicity**"
It doesn't seems to be a recommended practice from spec. And
especially for DRM use-cases, this approach is NOT recommended due to
following concerns raised by DRM vendors (original concerns were with
respect to TAs but will equally apply for firmware as well):
- allows the device to self sign code authorized to run on the device.
- increase the attack surface by having two different ways to load firmware.
- allow a break once break forever situation, if you defeat the RSA
'install' once, no matter how hard it is, now your firmware is nicely
transformed in a secure firmware and can be reused.
Whereas on the other hand, considering
"sign-then-encrypt-then-authenticate", it provides two mutually
exclusive crypto layers (signature layer and authenticated encryption
layer) which in turns provides implementation flexibility as follows:
Firmware update:
- Require both layers.
Normal boot:
- DRM use-case, require both layers.
- Boot time optimization required, can use only authenticated encryption.
- Platform provides secure on-chip NVM and boot time optimization
required, can use only signature verification (or simply hash stored
in secure on-chip NVM memory).
-Sumit
Thanks
Raghu
On January 26, 2020 at 10:34 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
On Fri, 24 Jan 2020 at 16:36, Sumit Garg <sumit.garg(a)linaro.org> wrote:
On Fri, 24 Jan 2020 at 04:02, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
>
> I also just realized that both the TBBR and ARM PSA only talk about encryption of the image, and not authenticated encryption. The guarantees provided by both are completely different. Your review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/) talks about the requirement R060_TBBR_FUNCTION being implemented, which is technically not true(and potentially misleading). We must make a note of this difference and use the appropriate terminology, without mixing the two, in the documentation, commit messages, source code comments and error prints. The tool is also called 'encrypt_fw ' but should maybe be named appropriately to indicate it is doing authenticated encryption.
I wouldn't call it misleading. Since firmware encryption feature
essentially provides confidentiality protection and authenticated
encryption is the type of crypto algorithm which we have used to
implement it.
>
> BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-REL.pdf) expects that the image manifest(X509 certificate) contain the hash of the ENCRYPTED image(Table 2 and as described in my answer to your question "How would this ensure integrity of ciphertext"). The TBBR spec completely misses this fact, and is a crucial detail if we only implement encryption(as opposed to authenticated encryption).Build_macros.mk, in your change, passes the un-encrypted image to cert-tool. You can get away with it in your implementation, since you are using authenticated encryption, not if you were only implementing firmware encryption.
I have already highlighted the issue with signing the ciphertext in my
previous reply which deviates from security properties provided by
signature verification of plain firmware. So I think we need to
revisit ARM PSA TBFU spec.
In addition to this, there are implementation specific issues with
"signing the ciphertext" too. It simply makes the ciphertext immutable
for device and disallows meeting following firmware re-encryption
requirement as per TBBR spec:
R070_TBBR_PROTECTION. The Trusted boot firmware may do the binding of
software image updates at run-
time by decrypting the updated SoC certificates and software images
using the OTP/Fuse Secret
Symmetric Key (SSK), followed by the re-encrypting these SoC
certificates and software images using a
reproducible secret unique per device symmetric key (BSSK), and then
updating the ToC correspondingly.
Also, externally signing every firmware image encrypted with BSSK
doesn't seem scalable as well. It also hampers the case where
encryption key is never exposed out from device eg. encryption key is
only accessible to hardware crypto engine etc.
-Sumit
>
> Is it possible for somebody from ARM to have the TBBR spec updated to reflect this? Also perhaps talk to the spec writers about incorporating authenticated encryption into TBBR and PSA? This patch set is somewhat trailblazing in this regard.
>
> -Raghu
>
>
> On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Sumit,
>
>
> Thanks for your response.
>
>
> So firstly I would suggest you to revisit TBBR spec [1],
>
>
>
> [RK] I'm very familiar with the TBBR spec and the requirements. Note that not all SoC's adhere perfectly to the TBBR spec, since it does not apply to devices in all market segments. However, these devices do use arm trusted firmware and TBBR CoT in a slightly modified form, which is still perfectly valid. Also, the TBBR spec can be changed if required :)
>
>
> Why would one use authenticated decryption only to establish TBBR
>
> Chain of Trust providing device the capability to self sign its firmware?
>
> [RK] Fair point. However, you may have devices that don't have the processing power or hardware budget or cost factors(paying for HSM's to store private asymmetric keys), to implement asymmetric verification, in which case using authenticated decryption to verify firmware authenticity and integrity is perfectly valid. The attacks on devices that use symmetric keys to verify firmware authenticity and integrity are usually related to exploiting firmware flaws that leak the key or insiders leaking keys, but that is a different problem and requires different solutions. Fundamentally, there is nothing wrong with using symmetric keys for this purpose, so long as the key is well protected. Also note, security requirements and guarantees are different for different systems. The risk is taken by the system designer and should not be imposed by framework code. I don't advocate doing this but it is an option that your implementation does not provide(and perhaps rightly so).
>
>
> How would this ensure integrity of ciphertext?
>
>
>
> [RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to cert_tool to sign. You don't decrypt the encrypted cipher text until you have verified the asymmetric signature(which provides integrity). As far as signature verification is concerned, whether you sign the plain text or ciphertext is immaterial, since you are simply verifying that the absolute bits you loaded have not been modified(assuming you use a secure signature scheme).
>
>
> Have a look at some defective sign and encrypt techniques here [2]
>
>
>
> [RK] Again, very familiar with [2]. In the S/MIME case, you have multiple parties. With secure boot, you have one party, effectively verifying its own messages across time. There is only one key used to verify signatures. 1.1 and 1.2 does not apply. Also you are encrypting and signing with completely different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal encryption. Here you use symmetric encryption and asymmetric signing.
>
>
> Why would one not use TBBR CoT here?
>
>
>
> [RK] see above. Not all systems are designed equal.
>
>
>
> and why would one like to hardcode in a device during
>
> provisioning to boot only either an encrypted or a plain firmware
> image?
>
>
> [RK] Why would you not? You typically want to have the same security policy for a class of devices and not be modifiable by an attacker. It isn't common for the same class of devices to use encrypted firmware some times, and un-encrypted firmware other times. If it is common, there is no problem with setting the bit in the FIP header, as long as verified boot is mandatory. The only concern(as my original email said) is the coupling of the FIP layer and the crypto module, in the implementation. I still don't like that fact that the bit saying the file is encrypted is not signed and this may require talking to the TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity is verified by some means! R010_TBBR_TOC should perhaps be mandatory then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by hardware in readable registers. This requirement seems contradictory to R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM by ROM or some boot stage and then ROM'd or loaded into registers. I may be misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header in ATF implementation of TBBR) as being in ROM or integrity verified.
>
>
> How would one handle a case where BL31 is in plain format and BL32 is in encrypted format?
>
>
>
> [RK]TBBR CoT is equipped to do this. The table is defined on a per image basis.
>
>
> If you are really paranoid about authentication of FIP header...
>
> [RK] I don't mean to pontificate but there are real world customers buying real hardware, running ATF code, who care about such details and ask about such things routinely. It is not just me being paranoid and is definitely not a minor matter to think of such details. We should discuss more and consider the implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different thread, without blocking your code review. Can somebody from ARM clarify these requirements with the spec writers?
>
>
> Thanks
> -Raghu
>
>
> On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>
>
> Hi Raghu,
>
> I guess you have completely misunderstood this feature. This is an
> optional feature which allows to load encrypted FIP payloads using
> authenticated decryption which MUST be used along with signature
> verification (or TBBR CoT).
>
> So firstly I would suggest you to revisit TBBR spec [1], especially
> requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
>
> On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
> <raghu.ncstate(a)icloud.com> wrote:
>
>
>
> Hello,
>
>
> The patch stack looks good. The only comment i have is that the FIP layer has now become security aware and supports authenticated decryption(only). This is a deviation from the secure/signed/verified boot design, where we use the TBBR COT to dictate the security operations on the file. This is nice, because file IO is decoupled from the security policy. This may be a big deviation(i apologize if this was considered and shot down for some other reason), but it may be worthwhile to consider making authenticated decryption a part of the authentication framework as opposed to coupling it with the FIP layer.
>
> It looks like you have mixed both TBBR CoT and this authenticated
> decryption feature. They both are completely different and rather
> complement each other where TBBR CoT establishes
> secure/signed/verified boot and this authenticated decryption feature
> provides confidentiality protection for FIP payloads.
>
>
> At a high level, this would mean adding a new authentication method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having the platform specify that the image is using authenticated encryption in the TBBR COT.
>
> Why would one use authenticated decryption only to establish TBBR
> Chain of Trust providing device the capability to self sign its
> firmwares? We must use signature verification for TBBR CoT (see
> section: 2.1 Authentication of Code Images by Certificate in TBBR spec
> [1]).
>
>
> The authentication framework is already well designed and well equipped to handle these types of extensions.
> 1) This would make the change simpler, since you would not require changes to the FIP tool and the FIP layer.
> 2) This would also allow for future cases where a platform may want to only encrypt the file and use public key authentication on the encrypted file(for ex. the soc does not have a crypto accelerator for aes-gcm but only for AES and public key verification, for whatever reason).
>
> How would this ensure integrity of ciphertext? This approach may be
> vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
> part of AES-GCM provides integrity protection for ciphertext.
>
>
> 3) This would let you choose the order in which you want to do the authenticated decryption(or just decryption) and signature verification, if you use both, one or the other.
>
>
>
> Have a look at some defective sign and encrypt techniques here [2].
> The order can't be any arbitrary one, we need to be careful about
> this.
>
>
> One other thing i'm not entirely comfortable with is that the flag indicating if there are encrypted files or not in the FIP, is in the *unsigned* portion of the FIP header. An attacker could simply flip bits that dictate security policy in the header and avoid detection(in this case, the indication that the file needs authenticated decryption). If a platform only uses authenticated encryption, but not verified boot, an attacker could flip the bit in the FIP header and have any image loaded on the platform.
>
> Why would one not use TBBR CoT here?
>
>
> If authenticated encryption cannot be used without verified boot(which requires build time flags), having a flag to indicate that there are encrypted files in the FIP header is moot, since this can come at build time through the TBBR COT. In any case, it seems like the security policy that firmware images need to be decrypted or authenticated with authenticated decryption, seems like a firmware build time or manufacturing time decision(perhaps a bit set in the e-fuses).
>
> Again you are confusing TBBR CoT with authenticated decryption
> feature. And why would one like to hardcode in a device during
> provisioning to boot only either an encrypted or a plain firmware
> image?
>
>
> There seems to be no benefit to having a flag in the FIP header.
>
> How would one handle a case where BL31 is in plain format and BL32 is
> in encrypted format?
>
>
> Otherwise, I cant think of any attacks due to this and it may be completely okay, but generally, consuming data that dictates security policy/operations before verifying its integrity seems like a recipe for disaster.
>
>
>
> If you are really paranoid about authentication of FIP header then you
> should look at implementing optional requirement: R010_TBBR_TOC as per
> TBBR spec [1].
>
> [1] https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requiremen…
> [2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
>
> -Sumit
>
>
> -Raghu
>
>
> On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>
>
> Hi Sandrine,
>
>
> On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
> <Sandrine.Bailleux(a)arm.com> wrote:
>
>
>
>
> Hello Sumit,
>
>
>
>
> Thank you for reworking the patches and addressing all of my review
>
>
> comments. I am happy with the latest version of these and consider them
>
>
> ready to go. I plan to leave them in Gerrit for another week to give
>
>
> extra time for other potential reviewers to have a look and comment.
>
>
>
>
>
>
> Thanks for your review.
>
>
> To everyone on the list: Please raise any concerns you may have about
>
>
> these patches in the coming week. If I don't hear anything by 29th
>
>
> January 2020, I will merge these patches.
>
>
>
>
> @Sumit: One of the next actions for this patch stack would be to have
>
>
> some level of testing in the CI system to detect any potential
>
>
> regressions. We (at Arm) can quite easily add a few build tests but then
>
>
> testing the software stack on QEMU is a bit more involved for various
>
>
> reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
>
>
> ...) so this might have to wait for some time.
>
>
>
>
>
>
> Okay, will wait for CI testing.
>
>
> -Sumit
>
>
> Regards,
>
>
> Sandrine
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
On Mon, 27 Jan 2020 at 22:43, Raghupathy Krishnamurthy via TF-A
<tf-a(a)lists.trustedfirmware.org> wrote:
>
> Thanks Soby, Sumit, Sandrine and Joakim!
>
>
> Agree with Joakim/Soby about encrypt then sign and sign then encrypt being okay, when authenticated encryption is used. I'd like to point out again, that the link provided by Sumit talks about encrypt-then-sign and sign-then-encrypt, using asymmetric encryption and asymmetric signing only, and as Joakim rightly pointed out(and as i did in my earlier email), does not necessarily apply here. They are not talking about symmetric encryption with asymmetric signing, which is what PSA-TBFU and TBBR are talking about.
> I usually don't like signing plain text and encrypt(not authenticated encryption, just encryption like aes-cbc etc) plain text due to https://moxie.org/blog/the-cryptographic-doom-principle/(written by the creator of the the WhatsApp end-to-end encryption protocol, this applies to symmetric encryption and symmetric signing/MAC's, but it applies to any ciphertext that is decrypted without verifying its integrity). If we were to sign the plain text then encrypt the firmware, the size of the encrypted file needs to be integrity protected as well, not just the bit that indicates that the file is encrypted. If not, when we decrypt the firmware image, we can perform some creative attacks on symmetric encryption, as specified in the link, and requires careful implementation of error handling/reporting on decryption errors.
Just to clarify here further that authenticated encryption (aes-gcm)
follows “encrypt-then-authenticate” principal only, which is mentioned
optimal as per https://moxie.org/blog/the-cryptographic-doom-principle/.
-Sumit
>
>
> I also like Soby's approach of having an attribute EP_ENCRYPTED and relying on platform_pre_image_load() and platform_post_image_load() to do the decryption and that addresses my non-spec related concerns. It also allows for decrypt-then-authenticate(which i wouldn't use) and authenticate-then-decrypt. It also puts the attribute that indicates firmware encryption in the image descriptor table which is integrity protected by virtue of it being in the ROM or being signed, and also leaves the FIP layer unaltered.
>
>
> Thanks
> -Raghu
>
> On January 27, 2020 at 6:42 AM, Soby Mathew <Soby.Mathew(a)arm.com> wrote:
>
>
> On 27/01/2020 12:34, Joakim Bech via TF-A wrote:
>
> on raw binaries are there so we can be sure that
> we're loading unmodified firmware coming from the one owning a private key
> corresponding to the public key hardcoded into the device (or via a hash of
> the public key). I think we all can agree
>
> OK, I have finally managed to catch up on this thread. Apologies for the
> delayed response.
>
> As Joakim mentions, I think both the mentioned cases ie. encrypt plain
> text -> sign and sign -> encrypt are valid and it depend on the threat
> model and security requirement.
>
> I have had a brief look at the patch stack and coupling the feature to
> the FIP does not seem like a good idea to me( + the added complexity
> protecting the ToC). Currently meta data of the firmware images is
> passed OOB via the `bl_mem_params_node_t` descriptor to the BL images
> whereas this patch breaks that convention. It is better to follow the
> set convention and avoid dependency on FIP format (btw platforms need
> not use FIP format and can use other packaging formats).
>
> The iv data to decrypt seems to be prepended to the encrypted file in
> the fip which is making custom manipulations file pointer manipulations
> which is raising some red flags.
>
> https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/8/drive…
>
> IMO, this should not visible to be FIP driver. I am not sure of the best
> practice for sending iv data but if it has to be prepended, it should be
> FIP agnostic.
>
> The TBBR assumes a single owner for all images whereas the TBFU
> supercedes this spec by allowing multiple owners for different images.
> We are in the process of enhancing the CoT for different Root of Trusts
> for different images and there needs to be capability to encrypt with
> different keys for different images based on ownership. The current
> implementation has some limitations like introducing a platform API
> invocation within the driver layer to get the single key which is not
> ideal IMO.
>
> I haven't fully flushed out my ideas, but thoughts are based on
> enhancements done by Masahiro for adding decompression support for BL
> images. See https://github.com/ARM-software/arm-trusted-firmware/pull/1224 .
>
> Basically, this patch series allows any filter to be setup before/after
> the images are loaded. It relies on pre-load and post load hooks which
> are platform specific to perform the filter operation. So, if a new
> image attribute `EP_ENCRYPTED` is added ep_info_exp.h, then BL2 needs to
> do the following in bl2_plat_handle_pre_image_load()
> {
> if EP_ENCRYPTED is set :
> load the image to SRAM and decrypt using crypto module
> }
>
> This will cater for `decrypt-then-authenticate` flow.
>
> The fip_tool no longer needs to be aware of encryption and the build
> process just needs to pipe the encrypted binaries to the fip_tool.
>
> Similarly if `authenticate-then-decrypt` needs to be supported, then all
> that the platform needs to do is implement decrypt in
> bl2_plat_handle_post_image_load().
>
> The platform can now use different keys to use for different BL images
> if it needs to do so.
>
> Some usecases require the firmware images to be re-encrypted using HUK
> after firmware update (aka firmware binding) and following this design
> will allow this to be done as well.
>
>
> Best Regards
> Soby Mathew
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Sumit,
Great point. This perhaps needs to be added to the list of things that need clarification(Sandrine can you help with this too?) in the PSA-TBFU . I believe the answer to your concern lies in the PSA-TBFU in section 3.5, where it talks about optimizing the trusted boot process. To overcome the problem you're talking about, you would:
1) Verify asymmetric signature.
2) Decrypt firmware using SSK on successful signature verification.
3) Rekey the firmware using BSSK(or as the PSA specifies, a key derived from the HUK using a KDF).
You will only verify the asymmetric signature on every firmware update, and use the rekeyed firmware(encrypted and mac;d with device specific key) on normal boot.
Thanks
Raghu
On January 26, 2020 at 10:34 PM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
On Fri, 24 Jan 2020 at 16:36, Sumit Garg <sumit.garg(a)linaro.org> wrote:
On Fri, 24 Jan 2020 at 04:02, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
>
> I also just realized that both the TBBR and ARM PSA only talk about encryption of the image, and not authenticated encryption. The guarantees provided by both are completely different. Your review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/) talks about the requirement R060_TBBR_FUNCTION being implemented, which is technically not true(and potentially misleading). We must make a note of this difference and use the appropriate terminology, without mixing the two, in the documentation, commit messages, source code comments and error prints. The tool is also called 'encrypt_fw ' but should maybe be named appropriately to indicate it is doing authenticated encryption.
I wouldn't call it misleading. Since firmware encryption feature
essentially provides confidentiality protection and authenticated
encryption is the type of crypto algorithm which we have used to
implement it.
>
> BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-REL.pdf) expects that the image manifest(X509 certificate) contain the hash of the ENCRYPTED image(Table 2 and as described in my answer to your question "How would this ensure integrity of ciphertext"). The TBBR spec completely misses this fact, and is a crucial detail if we only implement encryption(as opposed to authenticated encryption).Build_macros.mk, in your change, passes the un-encrypted image to cert-tool. You can get away with it in your implementation, since you are using authenticated encryption, not if you were only implementing firmware encryption.
I have already highlighted the issue with signing the ciphertext in my
previous reply which deviates from security properties provided by
signature verification of plain firmware. So I think we need to
revisit ARM PSA TBFU spec.
In addition to this, there are implementation specific issues with
"signing the ciphertext" too. It simply makes the ciphertext immutable
for device and disallows meeting following firmware re-encryption
requirement as per TBBR spec:
R070_TBBR_PROTECTION. The Trusted boot firmware may do the binding of
software image updates at run-
time by decrypting the updated SoC certificates and software images
using the OTP/Fuse Secret
Symmetric Key (SSK), followed by the re-encrypting these SoC
certificates and software images using a
reproducible secret unique per device symmetric key (BSSK), and then
updating the ToC correspondingly.
Also, externally signing every firmware image encrypted with BSSK
doesn't seem scalable as well. It also hampers the case where
encryption key is never exposed out from device eg. encryption key is
only accessible to hardware crypto engine etc.
-Sumit
>
> Is it possible for somebody from ARM to have the TBBR spec updated to reflect this? Also perhaps talk to the spec writers about incorporating authenticated encryption into TBBR and PSA? This patch set is somewhat trailblazing in this regard.
>
> -Raghu
>
>
> On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Sumit,
>
>
> Thanks for your response.
>
>
> So firstly I would suggest you to revisit TBBR spec [1],
>
>
>
> [RK] I'm very familiar with the TBBR spec and the requirements. Note that not all SoC's adhere perfectly to the TBBR spec, since it does not apply to devices in all market segments. However, these devices do use arm trusted firmware and TBBR CoT in a slightly modified form, which is still perfectly valid. Also, the TBBR spec can be changed if required :)
>
>
> Why would one use authenticated decryption only to establish TBBR
>
> Chain of Trust providing device the capability to self sign its firmware?
>
> [RK] Fair point. However, you may have devices that don't have the processing power or hardware budget or cost factors(paying for HSM's to store private asymmetric keys), to implement asymmetric verification, in which case using authenticated decryption to verify firmware authenticity and integrity is perfectly valid. The attacks on devices that use symmetric keys to verify firmware authenticity and integrity are usually related to exploiting firmware flaws that leak the key or insiders leaking keys, but that is a different problem and requires different solutions. Fundamentally, there is nothing wrong with using symmetric keys for this purpose, so long as the key is well protected. Also note, security requirements and guarantees are different for different systems. The risk is taken by the system designer and should not be imposed by framework code. I don't advocate doing this but it is an option that your implementation does not provide(and perhaps rightly so).
>
>
> How would this ensure integrity of ciphertext?
>
>
>
> [RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to cert_tool to sign. You don't decrypt the encrypted cipher text until you have verified the asymmetric signature(which provides integrity). As far as signature verification is concerned, whether you sign the plain text or ciphertext is immaterial, since you are simply verifying that the absolute bits you loaded have not been modified(assuming you use a secure signature scheme).
>
>
> Have a look at some defective sign and encrypt techniques here [2]
>
>
>
> [RK] Again, very familiar with [2]. In the S/MIME case, you have multiple parties. With secure boot, you have one party, effectively verifying its own messages across time. There is only one key used to verify signatures. 1.1 and 1.2 does not apply. Also you are encrypting and signing with completely different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal encryption. Here you use symmetric encryption and asymmetric signing.
>
>
> Why would one not use TBBR CoT here?
>
>
>
> [RK] see above. Not all systems are designed equal.
>
>
>
> and why would one like to hardcode in a device during
>
> provisioning to boot only either an encrypted or a plain firmware
> image?
>
>
> [RK] Why would you not? You typically want to have the same security policy for a class of devices and not be modifiable by an attacker. It isn't common for the same class of devices to use encrypted firmware some times, and un-encrypted firmware other times. If it is common, there is no problem with setting the bit in the FIP header, as long as verified boot is mandatory. The only concern(as my original email said) is the coupling of the FIP layer and the crypto module, in the implementation. I still don't like that fact that the bit saying the file is encrypted is not signed and this may require talking to the TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity is verified by some means! R010_TBBR_TOC should perhaps be mandatory then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by hardware in readable registers. This requirement seems contradictory to R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM by ROM or some boot stage and then ROM'd or loaded into registers. I may be misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header in ATF implementation of TBBR) as being in ROM or integrity verified.
>
>
> How would one handle a case where BL31 is in plain format and BL32 is in encrypted format?
>
>
>
> [RK]TBBR CoT is equipped to do this. The table is defined on a per image basis.
>
>
> If you are really paranoid about authentication of FIP header...
>
> [RK] I don't mean to pontificate but there are real world customers buying real hardware, running ATF code, who care about such details and ask about such things routinely. It is not just me being paranoid and is definitely not a minor matter to think of such details. We should discuss more and consider the implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different thread, without blocking your code review. Can somebody from ARM clarify these requirements with the spec writers?
>
>
> Thanks
> -Raghu
>
>
> On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>
>
> Hi Raghu,
>
> I guess you have completely misunderstood this feature. This is an
> optional feature which allows to load encrypted FIP payloads using
> authenticated decryption which MUST be used along with signature
> verification (or TBBR CoT).
>
> So firstly I would suggest you to revisit TBBR spec [1], especially
> requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
>
> On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
> <raghu.ncstate(a)icloud.com> wrote:
>
>
>
> Hello,
>
>
> The patch stack looks good. The only comment i have is that the FIP layer has now become security aware and supports authenticated decryption(only). This is a deviation from the secure/signed/verified boot design, where we use the TBBR COT to dictate the security operations on the file. This is nice, because file IO is decoupled from the security policy. This may be a big deviation(i apologize if this was considered and shot down for some other reason), but it may be worthwhile to consider making authenticated decryption a part of the authentication framework as opposed to coupling it with the FIP layer.
>
> It looks like you have mixed both TBBR CoT and this authenticated
> decryption feature. They both are completely different and rather
> complement each other where TBBR CoT establishes
> secure/signed/verified boot and this authenticated decryption feature
> provides confidentiality protection for FIP payloads.
>
>
> At a high level, this would mean adding a new authentication method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having the platform specify that the image is using authenticated encryption in the TBBR COT.
>
> Why would one use authenticated decryption only to establish TBBR
> Chain of Trust providing device the capability to self sign its
> firmwares? We must use signature verification for TBBR CoT (see
> section: 2.1 Authentication of Code Images by Certificate in TBBR spec
> [1]).
>
>
> The authentication framework is already well designed and well equipped to handle these types of extensions.
> 1) This would make the change simpler, since you would not require changes to the FIP tool and the FIP layer.
> 2) This would also allow for future cases where a platform may want to only encrypt the file and use public key authentication on the encrypted file(for ex. the soc does not have a crypto accelerator for aes-gcm but only for AES and public key verification, for whatever reason).
>
> How would this ensure integrity of ciphertext? This approach may be
> vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
> part of AES-GCM provides integrity protection for ciphertext.
>
>
> 3) This would let you choose the order in which you want to do the authenticated decryption(or just decryption) and signature verification, if you use both, one or the other.
>
>
>
> Have a look at some defective sign and encrypt techniques here [2].
> The order can't be any arbitrary one, we need to be careful about
> this.
>
>
> One other thing i'm not entirely comfortable with is that the flag indicating if there are encrypted files or not in the FIP, is in the *unsigned* portion of the FIP header. An attacker could simply flip bits that dictate security policy in the header and avoid detection(in this case, the indication that the file needs authenticated decryption). If a platform only uses authenticated encryption, but not verified boot, an attacker could flip the bit in the FIP header and have any image loaded on the platform.
>
> Why would one not use TBBR CoT here?
>
>
> If authenticated encryption cannot be used without verified boot(which requires build time flags), having a flag to indicate that there are encrypted files in the FIP header is moot, since this can come at build time through the TBBR COT. In any case, it seems like the security policy that firmware images need to be decrypted or authenticated with authenticated decryption, seems like a firmware build time or manufacturing time decision(perhaps a bit set in the e-fuses).
>
> Again you are confusing TBBR CoT with authenticated decryption
> feature. And why would one like to hardcode in a device during
> provisioning to boot only either an encrypted or a plain firmware
> image?
>
>
> There seems to be no benefit to having a flag in the FIP header.
>
> How would one handle a case where BL31 is in plain format and BL32 is
> in encrypted format?
>
>
> Otherwise, I cant think of any attacks due to this and it may be completely okay, but generally, consuming data that dictates security policy/operations before verifying its integrity seems like a recipe for disaster.
>
>
>
> If you are really paranoid about authentication of FIP header then you
> should look at implementing optional requirement: R010_TBBR_TOC as per
> TBBR spec [1].
>
> [1] https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requiremen…
> [2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
>
> -Sumit
>
>
> -Raghu
>
>
> On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>
>
> Hi Sandrine,
>
>
> On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
> <Sandrine.Bailleux(a)arm.com> wrote:
>
>
>
>
> Hello Sumit,
>
>
>
>
> Thank you for reworking the patches and addressing all of my review
>
>
> comments. I am happy with the latest version of these and consider them
>
>
> ready to go. I plan to leave them in Gerrit for another week to give
>
>
> extra time for other potential reviewers to have a look and comment.
>
>
>
>
>
>
> Thanks for your review.
>
>
> To everyone on the list: Please raise any concerns you may have about
>
>
> these patches in the coming week. If I don't hear anything by 29th
>
>
> January 2020, I will merge these patches.
>
>
>
>
> @Sumit: One of the next actions for this patch stack would be to have
>
>
> some level of testing in the CI system to detect any potential
>
>
> regressions. We (at Arm) can quite easily add a few build tests but then
>
>
> testing the software stack on QEMU is a bit more involved for various
>
>
> reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
>
>
> ...) so this might have to wait for some time.
>
>
>
>
>
>
> Okay, will wait for CI testing.
>
>
> -Sumit
>
>
> Regards,
>
>
> Sandrine
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Thanks Soby, Sumit, Sandrine and Joakim!
Agree with Joakim/Soby about encrypt then sign and sign then encrypt being okay, when authenticated encryption is used. I'd like to point out again, that the link provided by Sumit talks about encrypt-then-sign and sign-then-encrypt, using asymmetric encryption and asymmetric signing only, and as Joakim rightly pointed out(and as i did in my earlier email), does not necessarily apply here. They are not talking about symmetric encryption with asymmetric signing, which is what PSA-TBFU and TBBR are talking about.
I usually don't like signing plain text and encrypt(not authenticated encryption, just encryption like aes-cbc etc) plain text due to https://moxie.org/blog/the-cryptographic-doom-principle/(written by the creator of the the WhatsApp end-to-end encryption protocol, this applies to symmetric encryption and symmetric signing/MAC's, but it applies to any ciphertext that is decrypted without verifying its integrity). If we were to sign the plain text then encrypt the firmware, the size of the encrypted file needs to be integrity protected as well, not just the bit that indicates that the file is encrypted. If not, when we decrypt the firmware image, we can perform some creative attacks on symmetric encryption, as specified in the link, and requires careful implementation of error handling/reporting on decryption errors.
I also like Soby's approach of having an attribute EP_ENCRYPTED and relying on platform_pre_image_load() and platform_post_image_load() to do the decryption and that addresses my non-spec related concerns. It also allows for decrypt-then-authenticate(which i wouldn't use) and authenticate-then-decrypt. It also puts the attribute that indicates firmware encryption in the image descriptor table which is integrity protected by virtue of it being in the ROM or being signed, and also leaves the FIP layer unaltered.
Thanks
-Raghu
On January 27, 2020 at 6:42 AM, Soby Mathew <Soby.Mathew(a)arm.com> wrote:
On 27/01/2020 12:34, Joakim Bech via TF-A wrote:
on raw binaries are there so we can be sure that
we're loading unmodified firmware coming from the one owning a private key
corresponding to the public key hardcoded into the device (or via a hash of
the public key). I think we all can agree
OK, I have finally managed to catch up on this thread. Apologies for the
delayed response.
As Joakim mentions, I think both the mentioned cases ie. encrypt plain
text -> sign and sign -> encrypt are valid and it depend on the threat
model and security requirement.
I have had a brief look at the patch stack and coupling the feature to
the FIP does not seem like a good idea to me( + the added complexity
protecting the ToC). Currently meta data of the firmware images is
passed OOB via the `bl_mem_params_node_t` descriptor to the BL images
whereas this patch breaks that convention. It is better to follow the
set convention and avoid dependency on FIP format (btw platforms need
not use FIP format and can use other packaging formats).
The iv data to decrypt seems to be prepended to the encrypted file in
the fip which is making custom manipulations file pointer manipulations
which is raising some red flags.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/8/drive…
IMO, this should not visible to be FIP driver. I am not sure of the best
practice for sending iv data but if it has to be prepended, it should be
FIP agnostic.
The TBBR assumes a single owner for all images whereas the TBFU
supercedes this spec by allowing multiple owners for different images.
We are in the process of enhancing the CoT for different Root of Trusts
for different images and there needs to be capability to encrypt with
different keys for different images based on ownership. The current
implementation has some limitations like introducing a platform API
invocation within the driver layer to get the single key which is not
ideal IMO.
I haven't fully flushed out my ideas, but thoughts are based on
enhancements done by Masahiro for adding decompression support for BL
images. See https://github.com/ARM-software/arm-trusted-firmware/pull/1224 .
Basically, this patch series allows any filter to be setup before/after
the images are loaded. It relies on pre-load and post load hooks which
are platform specific to perform the filter operation. So, if a new
image attribute `EP_ENCRYPTED` is added ep_info_exp.h, then BL2 needs to
do the following in bl2_plat_handle_pre_image_load()
{
if EP_ENCRYPTED is set :
load the image to SRAM and decrypt using crypto module
}
This will cater for `decrypt-then-authenticate` flow.
The fip_tool no longer needs to be aware of encryption and the build
process just needs to pipe the encrypted binaries to the fip_tool.
Similarly if `authenticate-then-decrypt` needs to be supported, then all
that the platform needs to do is implement decrypt in
bl2_plat_handle_post_image_load().
The platform can now use different keys to use for different BL images
if it needs to do so.
Some usecases require the firmware images to be re-encrypted using HUK
after firmware update (aka firmware binding) and following this design
will allow this to be done as well.
Best Regards
Soby Mathew
On 24/01/2020 20:20, Raghupathy Krishnamurthy via TF-A wrote:
> It appears that the BL1 FWU SMC's are written under the assumption that only one core can call the SMC's at any given time but i don't see anything enforcing it. What prevent's this ?
>
>
> -Raghu
>
Hi Raghu
The BL1 itself is uni-processor [except the early assembly code which
differentiates primary core from secondaries]. Hence it makes no attempt
to provide protection for the SMCs from multiple cores.
Best Regards
Soby Mathew
Thanks Sumit. We are beginning to go off topic and i don't think you and i agree entirely. I'll lay out my concerns, to see if others on the list share my opinion/concerns, so i hope you can let them respond. If nobody else shares my concerns or responds, the patch will be merged soon anyway, so no point dragging this out :) I apologize for the long email. I don't know how to keep this topic short and detailed. :)
Here are my concerns:
1) The patch set claims to implement R060_TBBR_FUNCTION from the TBBR spec. I don't agree with this. The patch is using authenticated encryption(which does provide confidentiality) but is different from implementing firmware encryption as described in the TBBR(and PSA) in my view. If we are implementing R060_TBBR_FUNCTION, in my view, this should be implemented such that the firmware is first encrypted(symmetric), and the encrypted firmware should be asymmetrically signed(as per PSA). Also, the order for verification should be asymmetric signature verification and then decryption(symmetric). In this patch, plain text firmware is asymmetrically signed, plain text firmware is encrypted and authenticated with a symmetric key using authenticated encryption. The order for verification in this patch is authenticate and decrypt using the symmetric key and THEN asymmetric signature verification on the decryted(and now plain text) firmware. The ordering of verification and decryption are subtly different from what the spec(TBBR and PSA) expects. Security does not *seem* to be broken as far as i can tell, but the patch is not strictly an implementation of the spec, as it claims. This can throw off people reading the spec and trying to match code to spec. This is not good when someone wants to audit and gain confidence in the security of the implementation. At a minimum, we need someone writing the spec to address this.
2) The TBBR spec does not talk about authenticated encryption of firmware and only talks about encryption of firmware. It also does not specify if the encrypted firmware needs to be signed or the plain text need to be signed. This is critical detail. It also does not specify the order in which encryption and signing, decryption and verification must be done. These are important details and need to be addressed explicitly(perhaps in both TBBR and PSA). Use of authenticated encryption needs to be explicitly discussed as well.
3) TBBR specifies that the TOC(table of contents) *may* be authenticated. The TOC contains bits that dictate security policy, in this case, if the firmware is encrypted or not. I don't think it is good to consume security policy from unauthenticated data. In my view, this information must be in the signed image manifest(certificate in ATF) since an attacker can at-least cause simple DoS attacks by flipping bits in the FIP header, undetected. If the bit is flipped, a firmware image going out to a million devices may not boot, since an attacker decided to flip a bit, and signature verification fails, since the boot loader decided not decrypt the firmware based in an unsigned bit of information. PSA appears to have a better approach and makes no provision such data to be outside the image manifest, which is always signed.
4) This last one is a matter of opinion and can live with the current design. The FIP layer is now aware of the crypto module. FIP has also become coupled with authenticated encryption(If we do this, why not have the FIP layer call auth_mod_verify_img() and why stop at cyrpto_mod_auth_decrypt()) . FIP is security aware. I'd like to keep things the way they are today, where IO and security are separate modules and glued together by another layer(load_auth_image() for example). This is cleaner in my view since security policy(should i decrypt? should i verify signatures? should i apply any security at all?) is separate from IO.
Thanks
Raghu
On January 24, 2020 at 3:06 AM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
On Fri, 24 Jan 2020 at 04:02, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
I also just realized that both the TBBR and ARM PSA only talk about encryption of the image, and not authenticated encryption. The guarantees provided by both are completely different. Your review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/) talks about the requirement R060_TBBR_FUNCTION being implemented, which is technically not true(and potentially misleading). We must make a note of this difference and use the appropriate terminology, without mixing the two, in the documentation, commit messages, source code comments and error prints. The tool is also called 'encrypt_fw ' but should maybe be named appropriately to indicate it is doing authenticated encryption.
I wouldn't call it misleading. Since firmware encryption feature
essentially provides confidentiality protection and authenticated
encryption is the type of crypto algorithm which we have used to
implement it.
BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-REL.pdf) expects that the image manifest(X509 certificate) contain the hash of the ENCRYPTED image(Table 2 and as described in my answer to your question "How would this ensure integrity of ciphertext"). The TBBR spec completely misses this fact, and is a crucial detail if we only implement encryption(as opposed to authenticated encryption).Build_macros.mk, in your change, passes the un-encrypted image to cert-tool. You can get away with it in your implementation, since you are using authenticated encryption, not if you were only implementing firmware encryption.
I have already highlighted the issue with signing the ciphertext in my
previous reply which deviates from security properties provided by
signature verification of plain firmware. So I think we need to
revisit ARM PSA TBFU spec.
-Sumit
Is it possible for somebody from ARM to have the TBBR spec updated to reflect this? Also perhaps talk to the spec writers about incorporating authenticated encryption into TBBR and PSA? This patch set is somewhat trailblazing in this regard.
-Raghu
On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
Hi Sumit,
Thanks for your response.
So firstly I would suggest you to revisit TBBR spec [1],
[RK] I'm very familiar with the TBBR spec and the requirements. Note that not all SoC's adhere perfectly to the TBBR spec, since it does not apply to devices in all market segments. However, these devices do use arm trusted firmware and TBBR CoT in a slightly modified form, which is still perfectly valid. Also, the TBBR spec can be changed if required :)
Why would one use authenticated decryption only to establish TBBR
Chain of Trust providing device the capability to self sign its firmware?
[RK] Fair point. However, you may have devices that don't have the processing power or hardware budget or cost factors(paying for HSM's to store private asymmetric keys), to implement asymmetric verification, in which case using authenticated decryption to verify firmware authenticity and integrity is perfectly valid. The attacks on devices that use symmetric keys to verify firmware authenticity and integrity are usually related to exploiting firmware flaws that leak the key or insiders leaking keys, but that is a different problem and requires different solutions. Fundamentally, there is nothing wrong with using symmetric keys for this purpose, so long as the key is well protected. Also note, security requirements and guarantees are different for different systems. The risk is taken by the system designer and should not be imposed by framework code. I don't advocate doing this but it is an option that your implementation does not provide(and perhaps rightly so).
How would this ensure integrity of ciphertext?
[RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to cert_tool to sign. You don't decrypt the encrypted cipher text until you have verified the asymmetric signature(which provides integrity). As far as signature verification is concerned, whether you sign the plain text or ciphertext is immaterial, since you are simply verifying that the absolute bits you loaded have not been modified(assuming you use a secure signature scheme).
Have a look at some defective sign and encrypt techniques here [2]
[RK] Again, very familiar with [2]. In the S/MIME case, you have multiple parties. With secure boot, you have one party, effectively verifying its own messages across time. There is only one key used to verify signatures. 1.1 and 1.2 does not apply. Also you are encrypting and signing with completely different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal encryption. Here you use symmetric encryption and asymmetric signing.
Why would one not use TBBR CoT here?
[RK] see above. Not all systems are designed equal.
and why would one like to hardcode in a device during
provisioning to boot only either an encrypted or a plain firmware
image?
[RK] Why would you not? You typically want to have the same security policy for a class of devices and not be modifiable by an attacker. It isn't common for the same class of devices to use encrypted firmware some times, and un-encrypted firmware other times. If it is common, there is no problem with setting the bit in the FIP header, as long as verified boot is mandatory. The only concern(as my original email said) is the coupling of the FIP layer and the crypto module, in the implementation. I still don't like that fact that the bit saying the file is encrypted is not signed and this may require talking to the TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity is verified by some means! R010_TBBR_TOC should perhaps be mandatory then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by hardware in readable registers. This requirement seems contradictory to R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM by ROM or some boot stage and then ROM'd or loaded into registers. I may be misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header in ATF implementation of TBBR) as being in ROM or integrity verified.
How would one handle a case where BL31 is in plain format and BL32 is in encrypted format?
[RK]TBBR CoT is equipped to do this. The table is defined on a per image basis.
If you are really paranoid about authentication of FIP header...
[RK] I don't mean to pontificate but there are real world customers buying real hardware, running ATF code, who care about such details and ask about such things routinely. It is not just me being paranoid and is definitely not a minor matter to think of such details. We should discuss more and consider the implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different thread, without blocking your code review. Can somebody from ARM clarify these requirements with the spec writers?
Thanks
-Raghu
On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
Hi Raghu,
I guess you have completely misunderstood this feature. This is an
optional feature which allows to load encrypted FIP payloads using
authenticated decryption which MUST be used along with signature
verification (or TBBR CoT).
So firstly I would suggest you to revisit TBBR spec [1], especially
requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
Hello,
The patch stack looks good. The only comment i have is that the FIP layer has now become security aware and supports authenticated decryption(only). This is a deviation from the secure/signed/verified boot design, where we use the TBBR COT to dictate the security operations on the file. This is nice, because file IO is decoupled from the security policy. This may be a big deviation(i apologize if this was considered and shot down for some other reason), but it may be worthwhile to consider making authenticated decryption a part of the authentication framework as opposed to coupling it with the FIP layer.
It looks like you have mixed both TBBR CoT and this authenticated
decryption feature. They both are completely different and rather
complement each other where TBBR CoT establishes
secure/signed/verified boot and this authenticated decryption feature
provides confidentiality protection for FIP payloads.
At a high level, this would mean adding a new authentication method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having the platform specify that the image is using authenticated encryption in the TBBR COT.
Why would one use authenticated decryption only to establish TBBR
Chain of Trust providing device the capability to self sign its
firmwares? We must use signature verification for TBBR CoT (see
section: 2.1 Authentication of Code Images by Certificate in TBBR spec
[1]).
The authentication framework is already well designed and well equipped to handle these types of extensions.
1) This would make the change simpler, since you would not require changes to the FIP tool and the FIP layer.
2) This would also allow for future cases where a platform may want to only encrypt the file and use public key authentication on the encrypted file(for ex. the soc does not have a crypto accelerator for aes-gcm but only for AES and public key verification, for whatever reason).
How would this ensure integrity of ciphertext? This approach may be
vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
part of AES-GCM provides integrity protection for ciphertext.
3) This would let you choose the order in which you want to do the authenticated decryption(or just decryption) and signature verification, if you use both, one or the other.
Have a look at some defective sign and encrypt techniques here [2].
The order can't be any arbitrary one, we need to be careful about
this.
One other thing i'm not entirely comfortable with is that the flag indicating if there are encrypted files or not in the FIP, is in the *unsigned* portion of the FIP header. An attacker could simply flip bits that dictate security policy in the header and avoid detection(in this case, the indication that the file needs authenticated decryption). If a platform only uses authenticated encryption, but not verified boot, an attacker could flip the bit in the FIP header and have any image loaded on the platform.
Why would one not use TBBR CoT here?
If authenticated encryption cannot be used without verified boot(which requires build time flags), having a flag to indicate that there are encrypted files in the FIP header is moot, since this can come at build time through the TBBR COT. In any case, it seems like the security policy that firmware images need to be decrypted or authenticated with authenticated decryption, seems like a firmware build time or manufacturing time decision(perhaps a bit set in the e-fuses).
Again you are confusing TBBR CoT with authenticated decryption
feature. And why would one like to hardcode in a device during
provisioning to boot only either an encrypted or a plain firmware
image?
There seems to be no benefit to having a flag in the FIP header.
How would one handle a case where BL31 is in plain format and BL32 is
in encrypted format?
Otherwise, I cant think of any attacks due to this and it may be completely okay, but generally, consuming data that dictates security policy/operations before verifying its integrity seems like a recipe for disaster.
If you are really paranoid about authentication of FIP header then you
should look at implementing optional requirement: R010_TBBR_TOC as per
TBBR spec [1].
[1] https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requiremen…
[2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
-Sumit
-Raghu
On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
Hi Sandrine,
On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
<Sandrine.Bailleux(a)arm.com> wrote:
Hello Sumit,
Thank you for reworking the patches and addressing all of my review
comments. I am happy with the latest version of these and consider them
ready to go. I plan to leave them in Gerrit for another week to give
extra time for other potential reviewers to have a look and comment.
Thanks for your review.
To everyone on the list: Please raise any concerns you may have about
these patches in the coming week. If I don't hear anything by 29th
January 2020, I will merge these patches.
@Sumit: One of the next actions for this patch stack would be to have
some level of testing in the CI system to detect any potential
regressions. We (at Arm) can quite easily add a few build tests but then
testing the software stack on QEMU is a bit more involved for various
reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
...) so this might have to wait for some time.
Okay, will wait for CI testing.
-Sumit
Regards,
Sandrine
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
On 27/01/2020 12:34, Joakim Bech via TF-A wrote:
> on raw binaries are there so we can be sure that
> we're loading unmodified firmware coming from the one owning a private key
> corresponding to the public key hardcoded into the device (or via a hash of
> the public key). I think we all can agree
OK, I have finally managed to catch up on this thread. Apologies for the
delayed response.
As Joakim mentions, I think both the mentioned cases ie. encrypt plain
text -> sign and sign -> encrypt are valid and it depend on the threat
model and security requirement.
I have had a brief look at the patch stack and coupling the feature to
the FIP does not seem like a good idea to me( + the added complexity
protecting the ToC). Currently meta data of the firmware images is
passed OOB via the `bl_mem_params_node_t` descriptor to the BL images
whereas this patch breaks that convention. It is better to follow the
set convention and avoid dependency on FIP format (btw platforms need
not use FIP format and can use other packaging formats).
The iv data to decrypt seems to be prepended to the encrypted file in
the fip which is making custom manipulations file pointer manipulations
which is raising some red flags.
https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/8/drive…
IMO, this should not visible to be FIP driver. I am not sure of the best
practice for sending iv data but if it has to be prepended, it should be
FIP agnostic.
The TBBR assumes a single owner for all images whereas the TBFU
supercedes this spec by allowing multiple owners for different images.
We are in the process of enhancing the CoT for different Root of Trusts
for different images and there needs to be capability to encrypt with
different keys for different images based on ownership. The current
implementation has some limitations like introducing a platform API
invocation within the driver layer to get the single key which is not
ideal IMO.
I haven't fully flushed out my ideas, but thoughts are based on
enhancements done by Masahiro for adding decompression support for BL
images. See https://github.com/ARM-software/arm-trusted-firmware/pull/1224 .
Basically, this patch series allows any filter to be setup before/after
the images are loaded. It relies on pre-load and post load hooks which
are platform specific to perform the filter operation. So, if a new
image attribute `EP_ENCRYPTED` is added ep_info_exp.h, then BL2 needs to
do the following in bl2_plat_handle_pre_image_load()
{
if EP_ENCRYPTED is set :
load the image to SRAM and decrypt using crypto module
}
This will cater for `decrypt-then-authenticate` flow.
The fip_tool no longer needs to be aware of encryption and the build
process just needs to pipe the encrypted binaries to the fip_tool.
Similarly if `authenticate-then-decrypt` needs to be supported, then all
that the platform needs to do is implement decrypt in
bl2_plat_handle_post_image_load().
The platform can now use different keys to use for different BL images
if it needs to do so.
Some usecases require the firmware images to be re-encrypted using HUK
after firmware update (aka firmware binding) and following this design
will allow this to be done as well.
Best Regards
Soby Mathew
On Mon, 2020-01-27 at 12:04 +0000, Sandrine Bailleux via TF-A wrote:
> I share this concern. I was actually surprised to see that the TBBR
> specification advocates putting this security policy bit in the
> unencrypted part of the FIP, I do not know the rationale for that.
Sorry, I meant: in the *unsigned* part of the FIP. This bit itself
cannot be encrypted, as it indicates how to decrypt data!
Hi,
On Fri, 2020-01-24 at 18:39 +0000, Raghupathy Krishnamurthy via TF-A
wrote:
> Here are my concerns:
> 1) The patch set claims to implement R060_TBBR_FUNCTION from the TBBR
> spec. I don't agree with this. The patch is using authenticated
> encryption(which does provide confidentiality) but is different from
> implementing firmware encryption as described in the TBBR(and PSA) in
> my view. If we are implementing R060_TBBR_FUNCTION, in my view, this
> should be implemented such that the firmware is first
> encrypted(symmetric), and the encrypted firmware should be
> asymmetrically signed(as per PSA). Also, the order for verification
> should be asymmetric signature verification and then
> decryption(symmetric). In this patch, plain text firmware is
> asymmetrically signed, plain text firmware is encrypted and
> authenticated with a symmetric key using authenticated encryption.
> The order for verification in this patch is authenticate and decrypt
> using the symmetric key and THEN asymmetric signature verification on
> the decryted(and now plain text) firmware. The ordering of
> verification and decryption are subtly different from what the
> spec(TBBR and PSA) expects. Security does not *seem* to be broken as
> far as i can tell, but the patch is not strictly an implementation of
> the spec, as it claims. This can throw off people reading the spec
> and trying to match code to spec. This is not good when someone wants
> to audit and gain confidence in the security of the implementation.
> At a minimum, we need someone writing the spec to address this.
I do not have a strong opinion on this one. As I mentioned at the start
of this email thread, I am quite new to the concept of authenticated
decryption and naively thought this would not differ too much from
using decryption + signature verification separately. However, if these
are fundamentally different things like you say, I get your point and I
too am worried about the confusion this could create.
> 2) The TBBR spec does not talk about authenticated encryption of
> firmware and only talks about encryption of firmware. It also does
> not specify if the encrypted firmware needs to be signed or the plain
> text need to be signed. This is critical detail. It also does not
> specify the order in which encryption and signing, decryption and
> verification must be done. These are important details and need to be
> addressed explicitly(perhaps in both TBBR and PSA). Use of
> authenticated encryption needs to be explicitly discussed as well.
TBBR is quite an old specification and it is unlikely that it will ever
be updated. PSA-TBFU is meant to supersede it so I think any
update/clarification/addition would only apply to TBFU.
I agree that it would be good for PSA-TBFU to provide some guidance
around encryption and signature together, in which order they should be
done and what security properties they bring together. I can raise this
to the PSA architects.
> 3) TBBR specifies that the TOC(table of contents) *may* be
> authenticated. The TOC contains bits that dictate security policy, in
> this case, if the firmware is encrypted or not. I don't think it is
> good to consume security policy from unauthenticated data. In my
> view, this information must be in the signed image
> manifest(certificate in ATF) since an attacker can at-least cause
> simple DoS attacks by flipping bits in the FIP header, undetected. If
> the bit is flipped, a firmware image going out to a million devices
> may not boot, since an attacker decided to flip a bit, and signature
> verification fails, since the boot loader decided not decrypt the
> firmware based in an unsigned bit of information. PSA appears to have
> a better approach and makes no provision such data to be outside the
> image manifest, which is always signed.
I share this concern. I was actually surprised to see that the TBBR
specification advocates putting this security policy bit in the
unencrypted part of the FIP, I do not know the rationale for that.
Given that TBBR will be deprecated in the future, I wonder whether it
would be better to adopt PSA's approach here and move this security
policy bit in the signed part of the FIP. This will make this part of
the implementation non-TBBR compliant but again, I don't see that as a
big concern, as we should look at PSA-TBFU as the future and not worry
too much about TBBR if we have good reasons to diverge.
> 4) This last one is a matter of opinion and can live with the current
> design. The FIP layer is now aware of the crypto module. FIP has also
> become coupled with authenticated encryption(If we do this, why not
> have the FIP layer call auth_mod_verify_img() and why stop at
> cyrpto_mod_auth_decrypt()) . FIP is security aware. I'd like to keep
> things the way they are today, where IO and security are separate
> modules and glued together by another layer(load_auth_image() for
> example). This is cleaner in my view since security policy(should i
> decrypt? should i verify signatures? should i apply any security at
> all?) is separate from IO.
I agree with you. I too found it more elegant and cleaner to have the
FIP layer and crypto layer as 2 independent modules. I too feel
slightly uncomfortable about introducing such a dependency. But I
could not think of a way to avoid it while keeping the security policy
bit in the FIP ToC header. That said, if the latter is something we're
considering to redesign then we might be able to remove this dependency and keep the design as it is.
Regards,
Sandrine
On Fri, 24 Jan 2020 at 04:02, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
>
> I also just realized that both the TBBR and ARM PSA only talk about encryption of the image, and not authenticated encryption. The guarantees provided by both are completely different. Your review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/) talks about the requirement R060_TBBR_FUNCTION being implemented, which is technically not true(and potentially misleading). We must make a note of this difference and use the appropriate terminology, without mixing the two, in the documentation, commit messages, source code comments and error prints. The tool is also called 'encrypt_fw ' but should maybe be named appropriately to indicate it is doing authenticated encryption.
I wouldn't call it misleading. Since firmware encryption feature
essentially provides confidentiality protection and authenticated
encryption is the type of crypto algorithm which we have used to
implement it.
>
> BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-REL.pdf) expects that the image manifest(X509 certificate) contain the hash of the ENCRYPTED image(Table 2 and as described in my answer to your question "How would this ensure integrity of ciphertext"). The TBBR spec completely misses this fact, and is a crucial detail if we only implement encryption(as opposed to authenticated encryption).Build_macros.mk, in your change, passes the un-encrypted image to cert-tool. You can get away with it in your implementation, since you are using authenticated encryption, not if you were only implementing firmware encryption.
I have already highlighted the issue with signing the ciphertext in my
previous reply which deviates from security properties provided by
signature verification of plain firmware. So I think we need to
revisit ARM PSA TBFU spec.
-Sumit
>
> Is it possible for somebody from ARM to have the TBBR spec updated to reflect this? Also perhaps talk to the spec writers about incorporating authenticated encryption into TBBR and PSA? This patch set is somewhat trailblazing in this regard.
>
> -Raghu
>
>
> On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>
> Hi Sumit,
>
>
> Thanks for your response.
>
>
> So firstly I would suggest you to revisit TBBR spec [1],
>
>
>
> [RK] I'm very familiar with the TBBR spec and the requirements. Note that not all SoC's adhere perfectly to the TBBR spec, since it does not apply to devices in all market segments. However, these devices do use arm trusted firmware and TBBR CoT in a slightly modified form, which is still perfectly valid. Also, the TBBR spec can be changed if required :)
>
>
> Why would one use authenticated decryption only to establish TBBR
>
> Chain of Trust providing device the capability to self sign its firmware?
>
> [RK] Fair point. However, you may have devices that don't have the processing power or hardware budget or cost factors(paying for HSM's to store private asymmetric keys), to implement asymmetric verification, in which case using authenticated decryption to verify firmware authenticity and integrity is perfectly valid. The attacks on devices that use symmetric keys to verify firmware authenticity and integrity are usually related to exploiting firmware flaws that leak the key or insiders leaking keys, but that is a different problem and requires different solutions. Fundamentally, there is nothing wrong with using symmetric keys for this purpose, so long as the key is well protected. Also note, security requirements and guarantees are different for different systems. The risk is taken by the system designer and should not be imposed by framework code. I don't advocate doing this but it is an option that your implementation does not provide(and perhaps rightly so).
>
>
> How would this ensure integrity of ciphertext?
>
>
>
> [RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to cert_tool to sign. You don't decrypt the encrypted cipher text until you have verified the asymmetric signature(which provides integrity). As far as signature verification is concerned, whether you sign the plain text or ciphertext is immaterial, since you are simply verifying that the absolute bits you loaded have not been modified(assuming you use a secure signature scheme).
>
>
> Have a look at some defective sign and encrypt techniques here [2]
>
>
>
> [RK] Again, very familiar with [2]. In the S/MIME case, you have multiple parties. With secure boot, you have one party, effectively verifying its own messages across time. There is only one key used to verify signatures. 1.1 and 1.2 does not apply. Also you are encrypting and signing with completely different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal encryption. Here you use symmetric encryption and asymmetric signing.
>
>
> Why would one not use TBBR CoT here?
>
>
>
> [RK] see above. Not all systems are designed equal.
>
>
>
> and why would one like to hardcode in a device during
>
> provisioning to boot only either an encrypted or a plain firmware
> image?
>
>
> [RK] Why would you not? You typically want to have the same security policy for a class of devices and not be modifiable by an attacker. It isn't common for the same class of devices to use encrypted firmware some times, and un-encrypted firmware other times. If it is common, there is no problem with setting the bit in the FIP header, as long as verified boot is mandatory. The only concern(as my original email said) is the coupling of the FIP layer and the crypto module, in the implementation. I still don't like that fact that the bit saying the file is encrypted is not signed and this may require talking to the TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity is verified by some means! R010_TBBR_TOC should perhaps be mandatory then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by hardware in readable registers. This requirement seems contradictory to R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM by ROM or some boot stage and then ROM'd or loaded into registers. I may be misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header in ATF implementation of TBBR) as being in ROM or integrity verified.
>
>
> How would one handle a case where BL31 is in plain format and BL32 is in encrypted format?
>
>
>
> [RK]TBBR CoT is equipped to do this. The table is defined on a per image basis.
>
>
> If you are really paranoid about authentication of FIP header...
>
> [RK] I don't mean to pontificate but there are real world customers buying real hardware, running ATF code, who care about such details and ask about such things routinely. It is not just me being paranoid and is definitely not a minor matter to think of such details. We should discuss more and consider the implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different thread, without blocking your code review. Can somebody from ARM clarify these requirements with the spec writers?
>
>
> Thanks
> -Raghu
>
>
> On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
>
>
> Hi Raghu,
>
> I guess you have completely misunderstood this feature. This is an
> optional feature which allows to load encrypted FIP payloads using
> authenticated decryption which MUST be used along with signature
> verification (or TBBR CoT).
>
> So firstly I would suggest you to revisit TBBR spec [1], especially
> requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
>
> On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
> <raghu.ncstate(a)icloud.com> wrote:
>
>
>
> Hello,
>
>
> The patch stack looks good. The only comment i have is that the FIP layer has now become security aware and supports authenticated decryption(only). This is a deviation from the secure/signed/verified boot design, where we use the TBBR COT to dictate the security operations on the file. This is nice, because file IO is decoupled from the security policy. This may be a big deviation(i apologize if this was considered and shot down for some other reason), but it may be worthwhile to consider making authenticated decryption a part of the authentication framework as opposed to coupling it with the FIP layer.
>
> It looks like you have mixed both TBBR CoT and this authenticated
> decryption feature. They both are completely different and rather
> complement each other where TBBR CoT establishes
> secure/signed/verified boot and this authenticated decryption feature
> provides confidentiality protection for FIP payloads.
>
>
> At a high level, this would mean adding a new authentication method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having the platform specify that the image is using authenticated encryption in the TBBR COT.
>
> Why would one use authenticated decryption only to establish TBBR
> Chain of Trust providing device the capability to self sign its
> firmwares? We must use signature verification for TBBR CoT (see
> section: 2.1 Authentication of Code Images by Certificate in TBBR spec
> [1]).
>
>
> The authentication framework is already well designed and well equipped to handle these types of extensions.
> 1) This would make the change simpler, since you would not require changes to the FIP tool and the FIP layer.
> 2) This would also allow for future cases where a platform may want to only encrypt the file and use public key authentication on the encrypted file(for ex. the soc does not have a crypto accelerator for aes-gcm but only for AES and public key verification, for whatever reason).
>
> How would this ensure integrity of ciphertext? This approach may be
> vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
> part of AES-GCM provides integrity protection for ciphertext.
>
>
> 3) This would let you choose the order in which you want to do the authenticated decryption(or just decryption) and signature verification, if you use both, one or the other.
>
>
>
> Have a look at some defective sign and encrypt techniques here [2].
> The order can't be any arbitrary one, we need to be careful about
> this.
>
>
> One other thing i'm not entirely comfortable with is that the flag indicating if there are encrypted files or not in the FIP, is in the *unsigned* portion of the FIP header. An attacker could simply flip bits that dictate security policy in the header and avoid detection(in this case, the indication that the file needs authenticated decryption). If a platform only uses authenticated encryption, but not verified boot, an attacker could flip the bit in the FIP header and have any image loaded on the platform.
>
> Why would one not use TBBR CoT here?
>
>
> If authenticated encryption cannot be used without verified boot(which requires build time flags), having a flag to indicate that there are encrypted files in the FIP header is moot, since this can come at build time through the TBBR COT. In any case, it seems like the security policy that firmware images need to be decrypted or authenticated with authenticated decryption, seems like a firmware build time or manufacturing time decision(perhaps a bit set in the e-fuses).
>
> Again you are confusing TBBR CoT with authenticated decryption
> feature. And why would one like to hardcode in a device during
> provisioning to boot only either an encrypted or a plain firmware
> image?
>
>
> There seems to be no benefit to having a flag in the FIP header.
>
> How would one handle a case where BL31 is in plain format and BL32 is
> in encrypted format?
>
>
> Otherwise, I cant think of any attacks due to this and it may be completely okay, but generally, consuming data that dictates security policy/operations before verifying its integrity seems like a recipe for disaster.
>
>
>
> If you are really paranoid about authentication of FIP header then you
> should look at implementing optional requirement: R010_TBBR_TOC as per
> TBBR spec [1].
>
> [1] https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requiremen…
> [2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
>
> -Sumit
>
>
> -Raghu
>
>
> On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
>
>
> Hi Sandrine,
>
>
> On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
> <Sandrine.Bailleux(a)arm.com> wrote:
>
>
>
>
> Hello Sumit,
>
>
>
>
> Thank you for reworking the patches and addressing all of my review
>
>
> comments. I am happy with the latest version of these and consider them
>
>
> ready to go. I plan to leave them in Gerrit for another week to give
>
>
> extra time for other potential reviewers to have a look and comment.
>
>
>
>
>
>
> Thanks for your review.
>
>
> To everyone on the list: Please raise any concerns you may have about
>
>
> these patches in the coming week. If I don't hear anything by 29th
>
>
> January 2020, I will merge these patches.
>
>
>
>
> @Sumit: One of the next actions for this patch stack would be to have
>
>
> some level of testing in the CI system to detect any potential
>
>
> regressions. We (at Arm) can quite easily add a few build tests but then
>
>
> testing the software stack on QEMU is a bit more involved for various
>
>
> reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
>
>
> ...) so this might have to wait for some time.
>
>
>
>
>
>
> Okay, will wait for CI testing.
>
>
> -Sumit
>
>
> Regards,
>
>
> Sandrine
>
>
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
> --
> TF-A mailing list
> TF-A(a)lists.trustedfirmware.org
> https://lists.trustedfirmware.org/mailman/listinfo/tf-a
Never mind. No PSCI SMC's will be available.
On January 24, 2020 at 12:20 PM, Raghupathy Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
It appears that the BL1 FWU SMC's are written under the assumption that only one core can call the SMC's at any given time but i don't see anything enforcing it. What prevent's this ?
-Raghu
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
It appears that the BL1 FWU SMC's are written under the assumption that only one core can call the SMC's at any given time but i don't see anything enforcing it. What prevent's this ?
-Raghu
On 22/01/2020 12:29, Scott Branden via TF-A wrote:
> Please revert the removal of RSA PKCS#1 v1.5 support from cert_tool:
>
> https://github.com/ARM-software/arm-trusted-firmware/commit/6a415a508ea6ace…
>
> We have products shipping with such support. I think this problem came
> up before when somebody tried removing such support.
> They still need to run with the latest yocto codebase.
>
> Regards,
> Scott
>
Hi Scott,
It is untenable for us as maintainers to keep supporting deprecated
features in the tree. We need to be able to move the codebase forward.
As the commit message says, the RSA PKCS#1.5 support was removed from
BL1/BL2 images before this patch, and it no longer made sense to keep
the support for just the cert_tool.
Seems that you are not using the latest TF-A code for your platform
(since PKCS#1.5 is not supported), it does not make sense to pull the
latest master just for the tool. So my suggestion would be pin your
yocto scripts to a TF-A release that had the support for PKCS#1.5.
Best Regards
Soby Mathew
Hi Sumit,
Thanks for your response.
>>So firstly I would suggest you to revisit TBBR spec [1],
[RK] I'm very familiar with the TBBR spec and the requirements. Note that not all SoC's adhere perfectly to the TBBR spec, since it does not apply to devices in all market segments. However, these devices do use arm trusted firmware and TBBR CoT in a slightly modified form, which is still perfectly valid. Also, the TBBR spec can be changed if required :)
>>Why would one use authenticated decryption only to establish TBBR
Chain of Trust providing device the capability to self sign its firmware?
[RK] Fair point. However, you may have devices that don't have the processing power or hardware budget or cost factors(paying for HSM's to store private asymmetric keys), to implement asymmetric verification, in which case using authenticated decryption to verify firmware authenticity and integrity is perfectly valid. The attacks on devices that use symmetric keys to verify firmware authenticity and integrity are usually related to exploiting firmware flaws that leak the key or insiders leaking keys, but that is a different problem and requires different solutions. Fundamentally, there is nothing wrong with using symmetric keys for this purpose, so long as the key is well protected. Also note, security requirements and guarantees are different for different systems. The risk is taken by the system designer and should not be imposed by framework code. I don't advocate doing this but it is an option that your implementation does not provide(and perhaps rightly so).
>>How would this ensure integrity of ciphertext?
[RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to cert_tool to sign. You don't decrypt the encrypted cipher text until you have verified the asymmetric signature(which provides integrity). As far as signature verification is concerned, whether you sign the plain text or ciphertext is immaterial, since you are simply verifying that the absolute bits you loaded have not been modified(assuming you use a secure signature scheme).
>>Have a look at some defective sign and encrypt techniques here [2]
[RK] Again, very familiar with [2]. In the S/MIME case, you have multiple parties. With secure boot, you have one party, effectively verifying its own messages across time. There is only one key used to verify signatures. 1.1 and 1.2 does not apply. Also you are encrypting and signing with completely different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal encryption. Here you use symmetric encryption and asymmetric signing.
>>Why would one not use TBBR CoT here?
[RK] see above. Not all systems are designed equal.
>>and why would one like to hardcode in a device during
provisioning to boot only either an encrypted or a plain firmware
image?
[RK] Why would you not? You typically want to have the same security policy for a class of devices and not be modifiable by an attacker. It isn't common for the same class of devices to use encrypted firmware some times, and un-encrypted firmware other times. If it is common, there is no problem with setting the bit in the FIP header, as long as verified boot is mandatory. The only concern(as my original email said) is the coupling of the FIP layer and the crypto module, in the implementation. I still don't like that fact that the bit saying the file is encrypted is not signed and this may require talking to the TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity is verified by some means! R010_TBBR_TOC should perhaps be mandatory then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by hardware in readable registers. This requirement seems contradictory to R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM by ROM or some boot stage and then ROM'd or loaded into registers. I may be misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header in ATF implementation of TBBR) as being in ROM or integrity verified.
>>How would one handle a case where BL31 is in plain format and BL32 is in encrypted format?
[RK]TBBR CoT is equipped to do this. The table is defined on a per image basis.
>>If you are really paranoid about authentication of FIP header...
[RK] I don't mean to pontificate but there are real world customers buying real hardware, running ATF code, who care about such details and ask about such things routinely. It is not just me being paranoid and is definitely not a minor matter to think of such details. We should discuss more and consider the implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different thread, without blocking your code review. Can somebody from ARM clarify these requirements with the spec writers?
Thanks
-Raghu
On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
Hi Raghu,
I guess you have completely misunderstood this feature. This is an
optional feature which allows to load encrypted FIP payloads using
authenticated decryption which MUST be used along with signature
verification (or TBBR CoT).
So firstly I would suggest you to revisit TBBR spec [1], especially
requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
Hello,
The patch stack looks good. The only comment i have is that the FIP layer has now become security aware and supports authenticated decryption(only). This is a deviation from the secure/signed/verified boot design, where we use the TBBR COT to dictate the security operations on the file. This is nice, because file IO is decoupled from the security policy. This may be a big deviation(i apologize if this was considered and shot down for some other reason), but it may be worthwhile to consider making authenticated decryption a part of the authentication framework as opposed to coupling it with the FIP layer.
It looks like you have mixed both TBBR CoT and this authenticated
decryption feature. They both are completely different and rather
complement each other where TBBR CoT establishes
secure/signed/verified boot and this authenticated decryption feature
provides confidentiality protection for FIP payloads.
At a high level, this would mean adding a new authentication method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having the platform specify that the image is using authenticated encryption in the TBBR COT.
Why would one use authenticated decryption only to establish TBBR
Chain of Trust providing device the capability to self sign its
firmwares? We must use signature verification for TBBR CoT (see
section: 2.1 Authentication of Code Images by Certificate in TBBR spec
[1]).
The authentication framework is already well designed and well equipped to handle these types of extensions.
1) This would make the change simpler, since you would not require changes to the FIP tool and the FIP layer.
2) This would also allow for future cases where a platform may want to only encrypt the file and use public key authentication on the encrypted file(for ex. the soc does not have a crypto accelerator for aes-gcm but only for AES and public key verification, for whatever reason).
How would this ensure integrity of ciphertext? This approach may be
vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
part of AES-GCM provides integrity protection for ciphertext.
3) This would let you choose the order in which you want to do the authenticated decryption(or just decryption) and signature verification, if you use both, one or the other.
Have a look at some defective sign and encrypt techniques here [2].
The order can't be any arbitrary one, we need to be careful about
this.
One other thing i'm not entirely comfortable with is that the flag indicating if there are encrypted files or not in the FIP, is in the *unsigned* portion of the FIP header. An attacker could simply flip bits that dictate security policy in the header and avoid detection(in this case, the indication that the file needs authenticated decryption). If a platform only uses authenticated encryption, but not verified boot, an attacker could flip the bit in the FIP header and have any image loaded on the platform.
Why would one not use TBBR CoT here?
If authenticated encryption cannot be used without verified boot(which requires build time flags), having a flag to indicate that there are encrypted files in the FIP header is moot, since this can come at build time through the TBBR COT. In any case, it seems like the security policy that firmware images need to be decrypted or authenticated with authenticated decryption, seems like a firmware build time or manufacturing time decision(perhaps a bit set in the e-fuses).
Again you are confusing TBBR CoT with authenticated decryption
feature. And why would one like to hardcode in a device during
provisioning to boot only either an encrypted or a plain firmware
image?
There seems to be no benefit to having a flag in the FIP header.
How would one handle a case where BL31 is in plain format and BL32 is
in encrypted format?
Otherwise, I cant think of any attacks due to this and it may be completely okay, but generally, consuming data that dictates security policy/operations before verifying its integrity seems like a recipe for disaster.
If you are really paranoid about authentication of FIP header then you
should look at implementing optional requirement: R010_TBBR_TOC as per
TBBR spec [1].
[1] https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requiremen…
[2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
-Sumit
-Raghu
On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
Hi Sandrine,
On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
<Sandrine.Bailleux(a)arm.com> wrote:
Hello Sumit,
Thank you for reworking the patches and addressing all of my review
comments. I am happy with the latest version of these and consider them
ready to go. I plan to leave them in Gerrit for another week to give
extra time for other potential reviewers to have a look and comment.
Thanks for your review.
To everyone on the list: Please raise any concerns you may have about
these patches in the coming week. If I don't hear anything by 29th
January 2020, I will merge these patches.
@Sumit: One of the next actions for this patch stack would be to have
some level of testing in the CI system to detect any potential
regressions. We (at Arm) can quite easily add a few build tests but then
testing the software stack on QEMU is a bit more involved for various
reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
...) so this might have to wait for some time.
Okay, will wait for CI testing.
-Sumit
Regards,
Sandrine
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
+tf a list
On January 23, 2020 at 2:32 PM, Raghupathy Krishnamurthy <raghu.ncstate(a)icloud.com> wrote:
I also just realized that both the TBBR and ARM PSA only talk about encryption of the image, and not authenticated encryption. The guarantees provided by both are completely different. Your review(https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/2495/) talks about the requirement R060_TBBR_FUNCTION being implemented, which is technically not true(and potentially misleading). We must make a note of this difference and use the appropriate terminology, without mixing the two, in the documentation, commit messages, source code comments and error prints. The tool is also called 'encrypt_fw ' but should maybe be named appropriately to indicate it is doing authenticated encryption.
BTW, ARM PSA(file:///home/raghu/repos/fvp/DEN0072-PSA_TBFU_1-0-REL.pdf) expects that the image manifest(X509 certificate) contain the hash of the ENCRYPTED image(Table 2 and as described in my answer to your question "How would this ensure integrity of ciphertext"). The TBBR spec completely misses this fact, and is a crucial detail if we only implement encryption(as opposed to authenticated encryption).Build_macros.mk, in your change, passes the un-encrypted image to cert-tool. You can get away with it in your implementation, since you are using authenticated encryption, not if you were only implementing firmware encryption.
Is it possible for somebody from ARM to have the TBBR spec updated to reflect this? Also perhaps talk to the spec writers about incorporating authenticated encryption into TBBR and PSA? This patch set is somewhat trailblazing in this regard.
-Raghu
On January 23, 2020 at 12:08 PM, Raghupathy Krishnamurthy via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
Hi Sumit,
Thanks for your response.
So firstly I would suggest you to revisit TBBR spec [1],
[RK] I'm very familiar with the TBBR spec and the requirements. Note that not all SoC's adhere perfectly to the TBBR spec, since it does not apply to devices in all market segments. However, these devices do use arm trusted firmware and TBBR CoT in a slightly modified form, which is still perfectly valid. Also, the TBBR spec can be changed if required :)
Why would one use authenticated decryption only to establish TBBR
Chain of Trust providing device the capability to self sign its firmware?
[RK] Fair point. However, you may have devices that don't have the processing power or hardware budget or cost factors(paying for HSM's to store private asymmetric keys), to implement asymmetric verification, in which case using authenticated decryption to verify firmware authenticity and integrity is perfectly valid. The attacks on devices that use symmetric keys to verify firmware authenticity and integrity are usually related to exploiting firmware flaws that leak the key or insiders leaking keys, but that is a different problem and requires different solutions. Fundamentally, there is nothing wrong with using symmetric keys for this purpose, so long as the key is well protected. Also note, security requirements and guarantees are different for different systems. The risk is taken by the system designer and should not be imposed by framework code. I don't advocate doing this but it is an option that your implementation does not provide(and perhaps rightly so).
How would this ensure integrity of ciphertext?
[RK] You sign the ciphertext. In your design, you pass bl31_enc.bin to cert_tool to sign. You don't decrypt the encrypted cipher text until you have verified the asymmetric signature(which provides integrity). As far as signature verification is concerned, whether you sign the plain text or ciphertext is immaterial, since you are simply verifying that the absolute bits you loaded have not been modified(assuming you use a secure signature scheme).
Have a look at some defective sign and encrypt techniques here [2]
[RK] Again, very familiar with [2]. In the S/MIME case, you have multiple parties. With secure boot, you have one party, effectively verifying its own messages across time. There is only one key used to verify signatures. 1.1 and 1.2 does not apply. Also you are encrypting and signing with completely different keys and algorithms. Section 1.2 applies when you use RSA/El-gamal encryption. Here you use symmetric encryption and asymmetric signing.
Why would one not use TBBR CoT here?
[RK] see above. Not all systems are designed equal.
and why would one like to hardcode in a device during
provisioning to boot only either an encrypted or a plain firmware
image?
[RK] Why would you not? You typically want to have the same security policy for a class of devices and not be modifiable by an attacker. It isn't common for the same class of devices to use encrypted firmware some times, and un-encrypted firmware other times. If it is common, there is no problem with setting the bit in the FIP header, as long as verified boot is mandatory. The only concern(as my original email said) is the coupling of the FIP layer and the crypto module, in the implementation. I still don't like that fact that the bit saying the file is encrypted is not signed and this may require talking to the TBBR spec writers. Page 22 of the TBBR spec calls out ToC as "Trusted Table of Contents". The FIP header cannot be "trusted", if it is not in ROM or its integrity is verified by some means! R010_TBBR_TOC should perhaps be mandatory then. Also see R080_TBBR_TOC that says the TOC MUST be ROM'ed or tied by hardware in readable registers. This requirement seems contradictory to R010_TBBR_TOC, given that the FIP header(TOC) is copied from mutable NVM by ROM or some boot stage and then ROM'd or loaded into registers. I may be misunderstanding R080_TBBR_TOC, but i'd interpret it as the TOC(FIP header in ATF implementation of TBBR) as being in ROM or integrity verified.
How would one handle a case where BL31 is in plain format and BL32 is in encrypted format?
[RK]TBBR CoT is equipped to do this. The table is defined on a per image basis.
If you are really paranoid about authentication of FIP header...
[RK] I don't mean to pontificate but there are real world customers buying real hardware, running ATF code, who care about such details and ask about such things routinely. It is not just me being paranoid and is definitely not a minor matter to think of such details. We should discuss more and consider the implications of R080_TBBR_TOC and R010_TBBR_TOC, perhaps on a different thread, without blocking your code review. Can somebody from ARM clarify these requirements with the spec writers?
Thanks
-Raghu
On January 23, 2020 at 12:38 AM, Sumit Garg <sumit.garg(a)linaro.org> wrote:
Hi Raghu,
I guess you have completely misunderstood this feature. This is an
optional feature which allows to load encrypted FIP payloads using
authenticated decryption which MUST be used along with signature
verification (or TBBR CoT).
So firstly I would suggest you to revisit TBBR spec [1], especially
requirements: R040_TBBR_TOC, R060_TBBR_FUNCTION etc.
On Thu, 23 Jan 2020 at 00:14, Raghupathy Krishnamurthy
<raghu.ncstate(a)icloud.com> wrote:
Hello,
The patch stack looks good. The only comment i have is that the FIP layer has now become security aware and supports authenticated decryption(only). This is a deviation from the secure/signed/verified boot design, where we use the TBBR COT to dictate the security operations on the file. This is nice, because file IO is decoupled from the security policy. This may be a big deviation(i apologize if this was considered and shot down for some other reason), but it may be worthwhile to consider making authenticated decryption a part of the authentication framework as opposed to coupling it with the FIP layer.
It looks like you have mixed both TBBR CoT and this authenticated
decryption feature. They both are completely different and rather
complement each other where TBBR CoT establishes
secure/signed/verified boot and this authenticated decryption feature
provides confidentiality protection for FIP payloads.
At a high level, this would mean adding a new authentication method(perhaps AUTH_METHOD_AUTHENTICATED_DECRYPTION), and having the platform specify that the image is using authenticated encryption in the TBBR COT.
Why would one use authenticated decryption only to establish TBBR
Chain of Trust providing device the capability to self sign its
firmwares? We must use signature verification for TBBR CoT (see
section: 2.1 Authentication of Code Images by Certificate in TBBR spec
[1]).
The authentication framework is already well designed and well equipped to handle these types of extensions.
1) This would make the change simpler, since you would not require changes to the FIP tool and the FIP layer.
2) This would also allow for future cases where a platform may want to only encrypt the file and use public key authentication on the encrypted file(for ex. the soc does not have a crypto accelerator for aes-gcm but only for AES and public key verification, for whatever reason).
How would this ensure integrity of ciphertext? This approach may be
vulnerable to Chosen Ciphertext Attacks (CCAs). Authentication tag as
part of AES-GCM provides integrity protection for ciphertext.
3) This would let you choose the order in which you want to do the authenticated decryption(or just decryption) and signature verification, if you use both, one or the other.
Have a look at some defective sign and encrypt techniques here [2].
The order can't be any arbitrary one, we need to be careful about
this.
One other thing i'm not entirely comfortable with is that the flag indicating if there are encrypted files or not in the FIP, is in the *unsigned* portion of the FIP header. An attacker could simply flip bits that dictate security policy in the header and avoid detection(in this case, the indication that the file needs authenticated decryption). If a platform only uses authenticated encryption, but not verified boot, an attacker could flip the bit in the FIP header and have any image loaded on the platform.
Why would one not use TBBR CoT here?
If authenticated encryption cannot be used without verified boot(which requires build time flags), having a flag to indicate that there are encrypted files in the FIP header is moot, since this can come at build time through the TBBR COT. In any case, it seems like the security policy that firmware images need to be decrypted or authenticated with authenticated decryption, seems like a firmware build time or manufacturing time decision(perhaps a bit set in the e-fuses).
Again you are confusing TBBR CoT with authenticated decryption
feature. And why would one like to hardcode in a device during
provisioning to boot only either an encrypted or a plain firmware
image?
There seems to be no benefit to having a flag in the FIP header.
How would one handle a case where BL31 is in plain format and BL32 is
in encrypted format?
Otherwise, I cant think of any attacks due to this and it may be completely okay, but generally, consuming data that dictates security policy/operations before verifying its integrity seems like a recipe for disaster.
If you are really paranoid about authentication of FIP header then you
should look at implementing optional requirement: R010_TBBR_TOC as per
TBBR spec [1].
[1] https://developer.arm.com/docs/den0006/latest/trusted-board-boot-requiremen…
[2] http://world.std.com/~dtd/sign_encrypt/sign_encrypt7.html
-Sumit
-Raghu
On January 22, 2020 at 3:51 AM, Sumit Garg via TF-A <tf-a(a)lists.trustedfirmware.org> wrote:
Hi Sandrine,
On Wed, 22 Jan 2020 at 15:43, Sandrine Bailleux
<Sandrine.Bailleux(a)arm.com> wrote:
Hello Sumit,
Thank you for reworking the patches and addressing all of my review
comments. I am happy with the latest version of these and consider them
ready to go. I plan to leave them in Gerrit for another week to give
extra time for other potential reviewers to have a look and comment.
Thanks for your review.
To everyone on the list: Please raise any concerns you may have about
these patches in the coming week. If I don't hear anything by 29th
January 2020, I will merge these patches.
@Sumit: One of the next actions for this patch stack would be to have
some level of testing in the CI system to detect any potential
regressions. We (at Arm) can quite easily add a few build tests but then
testing the software stack on QEMU is a bit more involved for various
reasons (first instance of QEMU testing, dependencies on OPTEE, UEFI,
...) so this might have to wait for some time.
Okay, will wait for CI testing.
-Sumit
Regards,
Sandrine
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a
--
TF-A mailing list
TF-A(a)lists.trustedfirmware.org
https://lists.trustedfirmware.org/mailman/listinfo/tf-a