Re: [PATCH] tee: optee: Add SMC for loading OP-TEE image

Is there more I need to do to get this kernel patch reviewed?

Thanks, Jeff

On Mon, Feb 6, 2023 at 12:11 PM Jeffrey Kardatzke jkardatzke@google.com wrote:

v2 update where we check the system_state before returning EPROBE_DEFER so the SMC hole won't stay open if the FW isn't present in the rootfs.

From ff8990ca1568139c8c0bab4512aef3cc35a26466 Mon Sep 17 00:00:00 2001 From: Jeffrey Kardatzke jkardatzke@google.com Date: Fri, 3 Feb 2023 11:33:17 -0800 Subject: [PATCH v2] tee: optee: Add SMC for loading OP-TEE image

Adds an SMC call that will pass an OP-TEE binary image to EL3 and instruct it to load it as the BL32 payload. This works in conjunction with a feature added to Trusted Firmware for ARM that supports this.

Signed-off-by: Jeffrey Kardatzke jkardatzke@google.com

drivers/tee/optee/Kconfig | 9 ++++ drivers/tee/optee/optee_msg.h | 14 +++++++ drivers/tee/optee/optee_smc.h | 22 ++++++++++ drivers/tee/optee/smc_abi.c | 77 +++++++++++++++++++++++++++++++++++ 4 files changed, 122 insertions(+)

diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig index f121c224e682..b96b5db52b37 100644 --- a/drivers/tee/optee/Kconfig +++ b/drivers/tee/optee/Kconfig @@ -7,3 +7,12 @@ config OPTEE help This implements the OP-TEE Trusted Execution Environment (TEE) driver.

+config OPTEE_LOAD_IMAGE

• bool "Load Op-Tee image as firmware"
• default n
• depends on OPTEE
• help
• This loads the BL32 image for OP-TEE as firmware when the driver is probed.
• This returns -EPROBE_DEFER until the firmware is loadable from the
• filesystem.

diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h index 70e9cc2ee96b..84c1b15032a9 100644 --- a/drivers/tee/optee/optee_msg.h +++ b/drivers/tee/optee/optee_msg.h @@ -284,6 +284,20 @@ struct optee_msg_arg { */ #define OPTEE_MSG_FUNCID_GET_OS_REVISION 0x0001

+/*

• • Load Trusted OS from optee/tee.bin in the Linux firmware.
• • WARNING: Use this cautiously as it could lead to insecure loading of the
• • Trusted OS.
• • This SMC instructs EL3 to load a binary and excute it as the Trusted OS.
• • The first two params are the high and low 32 bits of the size of the payload
• • and the third and fourth params are the high and low 32 bits of the physical
• • address of the payload. The payload is in the OP-TEE image format.
• • Returns 0 on success and an error code otherwise.
• */

+#define OPTEE_MSG_FUNCID_LOAD_IMAGE 0x0002

/*

• Do a secure call with struct optee_msg_arg as argument
• The OPTEE_MSG_CMD_* below defines what goes in struct optee_msg_arg::cmd

diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h index 73b5e7760d10..908b1005e9db 100644 --- a/drivers/tee/optee/optee_smc.h +++ b/drivers/tee/optee/optee_smc.h @@ -104,6 +104,28 @@ struct optee_smc_call_get_os_revision_result { unsigned long reserved1; };

+/*

• • Load Trusted OS from optee/tee.bin in the Linux firmware.
• • WARNING: Use this cautiously as it could lead to insecure loading of the
• • Trusted OS.
• • This SMC instructs EL3 to load a binary and excute it as the Trusted OS.
• • Call register usage:
• • a0 SMC Function ID, OPTEE_SMC_CALL_LOAD_IMAGE
• • a1 Upper 32bit of a 64bit size for the payload
• • a2 Lower 32bit of a 64bit size for the payload
• • a3 Upper 32bit of the physical address for the payload
• • a4 Lower 32bit of the physical address for the payload
• • The payload is in the OP-TEE image format.
• • Returns result in a0, 0 on success and an error code otherwise.
• */

+#define OPTEE_SMC_FUNCID_LOAD_IMAGE OPTEE_MSG_FUNCID_LOAD_IMAGE +#define OPTEE_SMC_CALL_LOAD_IMAGE \

• OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_LOAD_IMAGE)

/*

• Call with struct optee_msg_arg as argument

diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index a1c1fa1a9c28..c1abbee86b39 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -8,9 +8,11 @@

#include <linux/arm-smccc.h> #include <linux/errno.h> +#include <linux/firmware.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irqdomain.h> +#include <linux/kernel.h> #include <linux/mm.h> #include <linux/module.h> #include <linux/of.h> @@ -1354,6 +1356,77 @@ static void optee_shutdown(struct platform_device *pdev) optee_disable_shm_cache(optee); }

+#ifdef CONFIG_OPTEE_LOAD_IMAGE

+#define OPTEE_FW_IMAGE "optee/tee.bin"

+static int optee_load_fw(struct platform_device *pdev,

• optee_invoke_fn *invoke_fn)

+{

• const struct firmware *fw = NULL;
• struct arm_smccc_res res;
• phys_addr_t data_pa;
• u8 *data_buf = NULL;
• u64 data_size;
• u32 data_pa_high, data_pa_low;
• u32 data_size_high, data_size_low;
• int rc;
• rc = request_firmware(&fw, OPTEE_FW_IMAGE, &pdev->dev);
• if (rc) {
• /*
• • The firmware in the rootfs will not be accessible until we
• • are in the SYSTEM_RUNNING state, so return EPROBE_DEFER until
• • that point.
• */
• if (system_state < SYSTEM_RUNNING)
• return -EPROBE_DEFER;
• goto fw_err;
• }
• data_size = fw->size;
• /*
• • This uses the GFP_DMA flag to ensure we are allocated memory in the
• • 32-bit space since TF-A cannot map memory beyond the 32-bit boundary.
• */
• data_buf = kmalloc(fw->size, GFP_KERNEL | GFP_DMA);
• if (!data_buf) {
• rc = -ENOMEM;
• goto fw_err;
• }
• memcpy(data_buf, fw->data, fw->size);
• data_pa = virt_to_phys(data_buf);
• reg_pair_from_64(&data_pa_high, &data_pa_low, data_pa);
• reg_pair_from_64(&data_size_high, &data_size_low, data_size);
• goto fw_load;

+fw_err:

• pr_warn("image loading failed\n");
• data_pa_high = data_pa_low = data_size_high = data_size_low = 0;

+fw_load:

• /*
• • Always invoke the SMC, even if loading the image fails, to indicate
• • to EL3 that we have passed the point where it should allow invoking
• • this SMC.
• */
• invoke_fn(OPTEE_SMC_CALL_LOAD_IMAGE, data_size_high, data_size_low,
• data_pa_high, data_pa_low, 0, 0, 0, &res);
• if (!rc)
• rc = res.a0;
• if (fw)
• release_firmware(fw);
• kfree(data_buf);
• return rc;

+} +#else +static inline int optee_load_fw(struct platform_device *__unused,

• optee_invoke_fn *__unused) {
• return 0;

+} +#endif

static int optee_probe(struct platform_device *pdev) { optee_invoke_fn *invoke_fn; @@ -1372,6 +1445,10 @@ static int optee_probe(struct platform_device *pdev) if (IS_ERR(invoke_fn)) return PTR_ERR(invoke_fn);

• rc = optee_load_fw(pdev, invoke_fn);
• if (rc)
• return rc;
• if (!optee_msg_api_uid_is_optee_api(invoke_fn)) { pr_warn("api uid mismatch\n"); return -EINVAL;

-- 2.39.1.519.gcb327c4b5f-goog

On Fri, Feb 3, 2023 at 1:43 PM Jeffrey Kardatzke jkardatzke@google.com wrote:

...

This is the kernel patch corresponding to the change landed in TF-A here: https://review.trustedfirmware.org/c/TF-A/trusted-firmware-a/+/18635

This appears to be the right place to post this, let me know if not please.

From 81d97a06a48d01eb53661b41905768271f07b870 Mon Sep 17 00:00:00 2001 From: Jeffrey Kardatzke jkardatzke@google.com Date: Fri, 3 Feb 2023 11:33:17 -0800 Subject: [PATCH] tee: optee: Add SMC for loading OP-TEE image

Adds an SMC call that will pass an OP-TEE binary image to EL3 and instruct it to load it as the BL32 payload. This works in conjunction with a feature added to Trusted Firmware for ARM that supports this.

Signed-off-by: Jeffrey Kardatzke jkardatzke@google.com

drivers/tee/optee/Kconfig | 9 +++++ drivers/tee/optee/optee_msg.h | 14 +++++++ drivers/tee/optee/optee_smc.h | 22 +++++++++++ drivers/tee/optee/smc_abi.c | 70 +++++++++++++++++++++++++++++++++++ 4 files changed, 115 insertions(+)

diff --git a/drivers/tee/optee/Kconfig b/drivers/tee/optee/Kconfig index f121c224e682..b96b5db52b37 100644 --- a/drivers/tee/optee/Kconfig +++ b/drivers/tee/optee/Kconfig @@ -7,3 +7,12 @@ config OPTEE help This implements the OP-TEE Trusted Execution Environment (TEE) driver.

+config OPTEE_LOAD_IMAGE

• bool "Load Op-Tee image as firmware"
• default n
• depends on OPTEE
• help
• This loads the BL32 image for OP-TEE as firmware when the driver is probed.
• This returns -EPROBE_DEFER until the firmware is loadable from the
• filesystem.

diff --git a/drivers/tee/optee/optee_msg.h b/drivers/tee/optee/optee_msg.h index 70e9cc2ee96b..84c1b15032a9 100644 --- a/drivers/tee/optee/optee_msg.h +++ b/drivers/tee/optee/optee_msg.h @@ -284,6 +284,20 @@ struct optee_msg_arg { */ #define OPTEE_MSG_FUNCID_GET_OS_REVISION 0x0001

+/*

• • Load Trusted OS from optee/tee.bin in the Linux firmware.
• • WARNING: Use this cautiously as it could lead to insecure loading of the
• • Trusted OS.
• • This SMC instructs EL3 to load a binary and excute it as the Trusted OS.
• • The first two params are the high and low 32 bits of the size of the payload
• • and the third and fourth params are the high and low 32 bits of the physical
• • address of the payload. The payload is in the OP-TEE image format.
• • Returns 0 on success and an error code otherwise.
• */

+#define OPTEE_MSG_FUNCID_LOAD_IMAGE 0x0002

/*

• Do a secure call with struct optee_msg_arg as argument
• The OPTEE_MSG_CMD_* below defines what goes in struct optee_msg_arg::cmd

diff --git a/drivers/tee/optee/optee_smc.h b/drivers/tee/optee/optee_smc.h index 73b5e7760d10..908b1005e9db 100644 --- a/drivers/tee/optee/optee_smc.h +++ b/drivers/tee/optee/optee_smc.h @@ -104,6 +104,28 @@ struct optee_smc_call_get_os_revision_result { unsigned long reserved1; };

+/*

• • Load Trusted OS from optee/tee.bin in the Linux firmware.
• • WARNING: Use this cautiously as it could lead to insecure loading of the
• • Trusted OS.
• • This SMC instructs EL3 to load a binary and excute it as the Trusted OS.
• • Call register usage:
• • a0 SMC Function ID, OPTEE_SMC_CALL_LOAD_IMAGE
• • a1 Upper 32bit of a 64bit size for the payload
• • a2 Lower 32bit of a 64bit size for the payload
• • a3 Upper 32bit of the physical address for the payload
• • a4 Lower 32bit of the physical address for the payload
• • The payload is in the OP-TEE image format.
• • Returns result in a0, 0 on success and an error code otherwise.
• */

+#define OPTEE_SMC_FUNCID_LOAD_IMAGE OPTEE_MSG_FUNCID_LOAD_IMAGE +#define OPTEE_SMC_CALL_LOAD_IMAGE \

• OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_LOAD_IMAGE)

/*

• Call with struct optee_msg_arg as argument

diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index a1c1fa1a9c28..b1e6c4a807db 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -8,6 +8,7 @@

#include <linux/arm-smccc.h> #include <linux/errno.h> +#include <linux/firmware.h> #include <linux/interrupt.h> #include <linux/io.h> #include <linux/irqdomain.h> @@ -1354,6 +1355,69 @@ static void optee_shutdown(struct platform_device *pdev) optee_disable_shm_cache(optee); }

+#ifdef CONFIG_OPTEE_LOAD_IMAGE

+#define OPTEE_FW_IMAGE "optee/tee.bin"

+static int optee_load_fw(struct platform_device *pdev,

• optee_invoke_fn *invoke_fn)

+{

• const struct firmware *fw = NULL;
• struct arm_smccc_res res;
• phys_addr_t data_pa;
• u8 *data_buf = NULL;
• u64 data_size;
• u32 data_pa_high, data_pa_low;
• u32 data_size_high, data_size_low;
• int rc;
• rc = request_firmware(&fw, OPTEE_FW_IMAGE, &pdev->dev);
• if (rc)
• return -EPROBE_DEFER;
• data_size = fw->size;
• /*
• • This uses the GFP_DMA flag to ensure we are allocated memory in the
• • 32-bit space since TF-A cannot map memory beyond the 32-bit boundary.
• */
• data_buf = kmalloc(fw->size, GFP_KERNEL | GFP_DMA);
• if (!data_buf) {
• rc = -ENOMEM;
• goto fw_err;
• }
• memcpy(data_buf, fw->data, fw->size);
• data_pa = virt_to_phys(data_buf);
• reg_pair_from_64(&data_pa_high, &data_pa_low, data_pa);
• reg_pair_from_64(&data_size_high, &data_size_low, data_size);
• goto fw_load;

+fw_err:

• pr_warn("image loading failed\n");
• data_pa_high = data_pa_low = data_size_high = data_size_low = 0;

+fw_load:

• /*
• • Always invoke the SMC, even if loading the image fails, to indicate
• • to EL3 that we have passed the point where it should allow invoking
• • this SMC.
• */
• invoke_fn(OPTEE_SMC_CALL_LOAD_IMAGE, data_size_high, data_size_low,
• data_pa_high, data_pa_low, 0, 0, 0, &res);
• if (!rc)
• rc = res.a0;
• if (fw)
• release_firmware(fw);
• kfree(data_buf);
• return rc;

+} +#else +static inline int optee_load_fw(struct platform_device *__unused,

• optee_invoke_fn *__unused) {
• return 0;

+} +#endif

static int optee_probe(struct platform_device *pdev) { optee_invoke_fn *invoke_fn; @@ -1372,6 +1436,12 @@ static int optee_probe(struct platform_device *pdev) if (IS_ERR(invoke_fn)) return PTR_ERR(invoke_fn);

• rc = optee_load_fw(pdev, invoke_fn);
• if (rc) {
• pr_warn("image loading failed\n");
• return rc;
• }
• if (!optee_msg_api_uid_is_optee_api(invoke_fn)) { pr_warn("api uid mismatch\n"); return -EINVAL;

-- 2.39.1.519.gcb327c4b5f-goog