Re: [PATCH v3 1/1] tee: optee: expose OS revision via sysfs

Hi Aristo,

On Fri, Dec 26, 2025 at 09:19:13PM +0800, Aristo Chen wrote:

Today the only way to read the OP-TEE OS version is from dmesg/journal logs, which can be lost as buffers roll over. Capture the OS revision (major/minor/build_id) from secure world for both SMC and FF-A ABIs, store it in the OP-TEE driver, and expose a stable userspace readout via /sys/class/tee/tee*/revision.

Signed-off-by: Aristo Chen aristo.chen@canonical.com

Documentation/ABI/testing/sysfs-class-tee | 10 +++++ drivers/tee/optee/core.c | 22 ++++++++++ drivers/tee/optee/ffa_abi.c | 25 ++++++++++- drivers/tee/optee/optee_private.h | 19 +++++++++ drivers/tee/optee/smc_abi.c | 25 ++++++++++- drivers/tee/tee_core.c | 52 ++++++++++++++++++++++- include/linux/tee_core.h | 5 +++ include/linux/tee_drv.h | 3 ++ 8 files changed, 156 insertions(+), 5 deletions(-)

Please split up this patch properly as to what goes into the generic TEE driver vs the OP-TEE changes.

diff --git a/Documentation/ABI/testing/sysfs-class-tee b/Documentation/ABI/testing/sysfs-class-tee index c9144d16003e..6e783210104e 100644 --- a/Documentation/ABI/testing/sysfs-class-tee +++ b/Documentation/ABI/testing/sysfs-class-tee @@ -13,3 +13,13 @@ Description: space if the variable is absent. The primary purpose of this variable is to let systemd know whether tee-supplicant is needed in the early boot with initramfs.

+What: /sys/class/tee/tee{,priv}X/revision +Date: Dec 2025 +KernelVersion: 6.18 +Contact: op-tee@lists.trustedfirmware.org +Description:

• Read-only revision string reported by the TEE driver. This is
  

• for diagnostics only and must not be used to infer feature
  

• support. Use TEE_IOC_VERSION for capability and compatibility
  

• checks.
  

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 5b62139714ce..58ee9ac0e467 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -63,6 +63,28 @@ int optee_set_dma_mask(struct optee *optee, u_int pa_width) return dma_coerce_mask_and_coherent(&optee->teedev->dev, mask); } +int optee_get_revision(struct optee *optee, char *buf, size_t len) +{

• u64 build_id;
• if (!optee)

• return -ENODEV;
  

• if (!buf || !len)

• return -EINVAL;
  

• build_id = optee->revision.os_build_id;
• if (build_id)

• scnprintf(buf, len, "%u.%u (%016llx)",
  

• 	  optee->revision.os_major,
  

• 	  optee->revision.os_minor,
  

• 	  (unsigned long long)build_id);
  

• else

• scnprintf(buf, len, "%u.%u", optee->revision.os_major,
  

• 	  optee->revision.os_minor);
  

• return 0;

+}

static void optee_bus_scan(struct work_struct *work) { WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP)); diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index bf8390789ecf..0a2990c2491e 100644 --- a/drivers/tee/optee/ffa_abi.c +++ b/drivers/tee/optee/ffa_abi.c @@ -776,7 +776,8 @@ static int optee_ffa_reclaim_protmem(struct optee *optee, */ static bool optee_ffa_api_is_compatible(struct ffa_device *ffa_dev,

• 			const struct ffa_ops *ops)
  

• 			const struct ffa_ops *ops,
  

• 			struct optee_revision *revision)
  

{ const struct ffa_msg_ops *msg_ops = ops->msg_ops; struct ffa_send_direct_data data = { @@ -806,6 +807,12 @@ static bool optee_ffa_api_is_compatible(struct ffa_device *ffa_dev, pr_err("Unexpected error %d\n", rc); return false; }

• if (revision) {

• revision->os_major = data.data0;
  

• revision->os_minor = data.data1;
  

• revision->os_build_id = data.data2;
  

• }
• if (data.data2) pr_info("revision %lu.%lu (%08lx)", data.data0, data.data1, data.data2);

@@ -898,8 +905,12 @@ static int optee_ffa_open(struct tee_context *ctx) return optee_open(ctx, true); } +static int optee_ffa_get_tee_revision(struct tee_device *teedev,

• 		      char *buf, size_t len);
  

I don't think you need a wrapper here but insted you can just use the generic optee_get_revision() callback.

static const struct tee_driver_ops optee_ffa_clnt_ops = { .get_version = optee_ffa_get_version,

• .get_tee_revision = optee_ffa_get_tee_revision,

This will then become:

.get_tee_revision = optee_get_revision,

.open = optee_ffa_open, .release = optee_release, .open_session = optee_open_session, @@ -918,6 +929,7 @@ static const struct tee_desc optee_ffa_clnt_desc = { static const struct tee_driver_ops optee_ffa_supp_ops = { .get_version = optee_ffa_get_version,

• .get_tee_revision = optee_ffa_get_tee_revision,

ditto.

.open = optee_ffa_open, .release = optee_release_supp, .supp_recv = optee_supp_recv, @@ -1034,6 +1046,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) { const struct ffa_notifier_ops *notif_ops; const struct ffa_ops *ffa_ops;

• struct optee_revision revision = { }; unsigned int max_notif_value; unsigned int rpc_param_count; struct tee_shm_pool *pool;

@@ -1047,7 +1060,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) ffa_ops = ffa_dev->ops; notif_ops = ffa_ops->notifier_ops;

• if (!optee_ffa_api_is_compatible(ffa_dev, ffa_ops))

• if (!optee_ffa_api_is_compatible(ffa_dev, ffa_ops, &revision)) return -EINVAL;

if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps, @@ -1059,6 +1072,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) optee = kzalloc(sizeof(*optee), GFP_KERNEL); if (!optee) return -ENOMEM;

• optee->revision = revision;

pool = optee_ffa_shm_pool_alloc_pages(); if (IS_ERR(pool)) { @@ -1194,3 +1208,10 @@ void optee_ffa_abi_unregister(void) if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT)) ffa_unregister(&optee_ffa_driver); } +static int optee_ffa_get_tee_revision(struct tee_device *teedev,

• 		      char *buf, size_t len)
  

+{

• struct optee *optee = tee_get_drvdata(teedev);
• return optee_get_revision(optee, buf, len);

+} diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index db9ea673fbca..8d65f8b16b4a 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -171,6 +171,24 @@ struct optee_ffa { struct optee; +/**

• • struct optee_revision - OP-TEE OS revision reported by secure world
• • @os_major: OP-TEE OS major version
• • @os_minor: OP-TEE OS minor version
• • @os_build_id: OP-TEE OS build identifier (0 if unspecified)
• • Values come from OPTEE_SMC_CALL_GET_OS_REVISION (SMC ABI) or
• • OPTEE_FFA_GET_OS_VERSION (FF-A ABI); this is the trusted OS revision, not an
• • FF-A ABI version.
• */

+struct optee_revision {

• u32 os_major;
• u32 os_minor;
• u64 os_build_id;

+};

+int optee_get_revision(struct optee *optee, char *buf, size_t len);

/**

• struct optee_ops - OP-TEE driver internal operations
• @do_call_with_arg: enters OP-TEE in secure world

@@ -249,6 +267,7 @@ struct optee { bool in_kernel_rpmb_routing; struct work_struct scan_bus_work; struct work_struct rpmb_scan_bus_work;

• struct optee_revision revision;

}; struct optee_session { diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index 0be663fcd52b..4dc2c16147ee 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -1240,8 +1240,12 @@ static int optee_smc_open(struct tee_context *ctx) return optee_open(ctx, sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL); } +static int optee_get_tee_revision(struct tee_device *teedev,

• 		  char *buf, size_t len);
  

static const struct tee_driver_ops optee_clnt_ops = { .get_version = optee_get_version,

• .get_tee_revision = optee_get_tee_revision, .open = optee_smc_open, .release = optee_release, .open_session = optee_open_session,

@@ -1261,6 +1265,7 @@ static const struct tee_desc optee_clnt_desc = { static const struct tee_driver_ops optee_supp_ops = { .get_version = optee_get_version,

• .get_tee_revision = optee_get_tee_revision, .open = optee_smc_open, .release = optee_release_supp, .supp_recv = optee_supp_recv,

@@ -1323,7 +1328,8 @@ static bool optee_msg_api_uid_is_optee_image_load(optee_invoke_fn *invoke_fn) } #endif -static void optee_msg_get_os_revision(optee_invoke_fn *invoke_fn) +static void optee_msg_get_os_revision(optee_invoke_fn *invoke_fn,

• 		      struct optee_revision *revision)
  

{ union { struct arm_smccc_res smccc; @@ -1337,6 +1343,12 @@ static void optee_msg_get_os_revision(optee_invoke_fn *invoke_fn) invoke_fn(OPTEE_SMC_CALL_GET_OS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);

• if (revision) {

• revision->os_major = res.result.major;
  

• revision->os_minor = res.result.minor;
  

• revision->os_build_id = res.result.build_id;
  

• }
• if (res.result.build_id) pr_info("revision %lu.%lu (%0*lx)", res.result.major, res.result.minor, (int)sizeof(res.result.build_id) * 2,

@@ -1727,6 +1739,7 @@ static int optee_probe(struct platform_device *pdev) unsigned int thread_count; struct tee_device *teedev; struct tee_context *ctx;

• struct optee_revision revision = { }; u32 max_notif_value; u32 arg_cache_flags; u32 sec_caps;

@@ -1745,7 +1758,7 @@ static int optee_probe(struct platform_device *pdev) return -EINVAL; }

• optee_msg_get_os_revision(invoke_fn);

• optee_msg_get_os_revision(invoke_fn, &revision);

if (!optee_msg_api_revision_is_compatible(invoke_fn)) { pr_warn("api revision mismatch\n"); @@ -1814,6 +1827,7 @@ static int optee_probe(struct platform_device *pdev) rc = -ENOMEM; goto err_free_shm_pool; }

• optee->revision = revision;

optee->ops = &optee_ops; optee->smc.invoke_fn = invoke_fn; @@ -1971,3 +1985,10 @@ void optee_smc_abi_unregister(void) { platform_driver_unregister(&optee_driver); } +static int optee_get_tee_revision(struct tee_device *teedev,

• 		  char *buf, size_t len)
  

Ditto here, you don't need this extra wrapper here.

+{

• struct optee *optee = tee_get_drvdata(teedev);
• return optee_get_revision(optee, buf, len);

+} diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index d65d47cc154e..0ba0e16462b9 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -13,6 +13,7 @@ #include <linux/overflow.h> #include <linux/slab.h> #include <linux/tee_core.h> +#include <linux/tee_drv.h>

This include is rather meant for TEE client drivers, don't include it here. Instead use linux/tee_core.h.

#include <linux/uaccess.h> #include <crypto/sha1.h> #include "tee_private.h" @@ -1146,7 +1147,56 @@ static struct attribute *tee_dev_attrs[] = { NULL }; -ATTRIBUTE_GROUPS(tee_dev); +static const struct attribute_group tee_dev_group = {

• .attrs = tee_dev_attrs,

+};

+static ssize_t revision_show(struct device *dev,

• 	     struct device_attribute *attr, char *buf)
  

+{

• struct tee_device *teedev = container_of(dev, struct tee_device, dev);
• char version[TEE_REVISION_STR_SIZE];
• int ret;
• if (!teedev->desc->ops->get_tee_revision)

• return -ENODEV;
  

• ret = teedev->desc->ops->get_tee_revision(teedev, version,

• 				  sizeof(version));
  

• if (ret)

• return ret;
  

• return sysfs_emit(buf, "%s\n", version);

+} +static DEVICE_ATTR_RO(revision);

+static struct attribute *tee_revision_attrs[] = {

• &dev_attr_revision.attr,
• NULL

+};

+static umode_t tee_revision_attr_is_visible(struct kobject *kobj,

• 			    struct attribute *attr, int n)
  

+{

• struct device *dev = kobj_to_dev(kobj);
• struct tee_device *teedev = container_of(dev, struct tee_device, dev);
• if (teedev->desc->ops->get_tee_revision)

• return attr->mode;
  

• return 0;

+}

+static const struct attribute_group tee_revision_group = {

• .attrs = tee_revision_attrs,
• .is_visible = tee_revision_attr_is_visible,

+};

+static const struct attribute_group *tee_dev_groups[] = {

• &tee_dev_group,
• &tee_revision_group,
• NULL

+}; static const struct class tee_class = { .name = "tee", diff --git a/include/linux/tee_core.h b/include/linux/tee_core.h index 1f3e5dad6d0d..de11612afa62 100644 --- a/include/linux/tee_core.h +++ b/include/linux/tee_core.h @@ -76,6 +76,9 @@ struct tee_device { /**

• struct tee_driver_ops - driver operations vtable
• @get_version: returns version of driver

• • @get_tee_revision: returns revision string (diagnostic only);

• • 	do not infer feature support from this, use
    

• • 	TEE_IOC_VERSION instead
    

  • @open: called for a context when the device file is opened
  • @close_context: called when the device file is closed
  • @release: called to release the context

@@ -98,6 +101,8 @@ struct tee_device { struct tee_driver_ops { void (*get_version)(struct tee_device *teedev, struct tee_ioctl_version_data *vers);

• int (*get_tee_revision)(struct tee_device *teedev,

• 		char *buf, size_t len);
  

  int (*open)(struct tee_context *ctx); void (*close_context)(struct tee_context *ctx); void (*release)(struct tee_context *ctx);

diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 88a6f9697c89..e76238d435ce 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -322,4 +322,7 @@ struct tee_client_driver { #define to_tee_client_driver(d) \ container_of_const(d, struct tee_client_driver, driver) +/* Size for TEE revision string buffer used by get_tee_revision(). */ +#define TEE_REVISION_STR_SIZE 128

This should rather go to linux/tee_core.h.

-Sumit

#endif /*__TEE_DRV_H*/

2.43.0