Re: [PATCH v2 1/1] tee: optee: expose OS revision via sysfs

Hi,

Sumit Garg sumit.garg@kernel.org 於 2025年11月25日週二 下午3:55寫道：

On Tue, Nov 25, 2025 at 01:23:22PM +0530, Sumit Garg via OP-TEE wrote:

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On Mon, Nov 24, 2025 at 08:15:04AM +0100, Jens Wiklander wrote:

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Hi,

On Sat, Nov 22, 2025 at 4:00 PM Wei Ming Chen jj251510319013@gmail.com wrote:

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From: Aristo Chen aristo.chen@canonical.com

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*/optee_os_revision.

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

drivers/tee/optee/core.c | 19 +++++++++++++++++++ drivers/tee/optee/ffa_abi.c | 13 +++++++++++-- drivers/tee/optee/optee_private.h | 17 +++++++++++++++++ drivers/tee/optee/smc_abi.c | 13 +++++++++++-- 4 files changed, 58 insertions(+), 4 deletions(-)

This appears to be a feature that could be useful for all TEEs.

True, it is something that TEE core should support. Although I would have preferred to extend TEE_IOC_VERSION since that's the common way the user-space library get's TEE implementation specific information. But since it being already a user-space ABI which doesn't offer extension. Maybe we can consider adding TEE_IOC_REVERSION instead of sysfs.

Ah, typo here:

s/TEE_IOC_REVERSION/TEE_IOC_REVISION/

-Sumit

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But before doing that we need to know who is the actual consumer here from user-space perspective? Will the client applications also depend on the TEE implementation revision?

My current thinking is that if the TEE revision is exposed, users can write a script to capture the platform state and record the exact secure OS revision even after the dmesg/journalctl logs have rolled over. This would significantly improve bug triage and regression tracking.

In my case, I have a package with precompiled xtest binaries for multiple releases (from 3.14 to 4.6), and I work with different platforms that run different OP-TEE OS versions. Having a reliable way to obtain the TEE revision would help a lot, as it would allow me to select the correct xtest version when running tests.

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If so, let's take a step back to see what's needed. We can add the sysfs attribute from drivers/tee/tee_core.c and add another optional callback to struct tee_driver_ops, such as get_tee_revision(). For OP-TEE, the specific information we want to share is clear, but other TEEs might have additional or different data. What do others think?

Implementation wise, this sounds like a reasonable approach.

-Sumit

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Cheers, Jens

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diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 5b62139714ce..66409cf5da1c 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -83,8 +83,27 @@ static ssize_t rpmb_routing_model_show(struct device *dev, } static DEVICE_ATTR_RO(rpmb_routing_model);

+static ssize_t optee_os_revision_show(struct device *dev,

•                                 struct device_attribute *attr, char *buf)
  

+{

•   struct optee *optee = dev_get_drvdata(dev);
  

•   struct optee_version_info *v;
  

•   if (!optee)
  

•           return -ENODEV;
  

•   v = &optee->version_info;
  

•   if (v->os_build_id)
  

•           return sysfs_emit(buf, "%u.%u (%016llx)\n", v->os_major,
  

•                             v->os_minor, (unsigned long long)v->os_build_id);
  

•   return sysfs_emit(buf, "%u.%u\n", v->os_major, v->os_minor);
  

+} +static DEVICE_ATTR_RO(optee_os_revision);

static struct attribute *optee_dev_attrs[] = { &dev_attr_rpmb_routing_model.attr,

•   &dev_attr_optee_os_revision.attr,
    NULL
  

};

diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c index bf8390789ecf..3d4f35599dd1 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_version_info *version_info)
  

{ 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 (version_info) {
  

•           version_info->os_major = data.data0;
  

•           version_info->os_minor = data.data1;
  

•           version_info->os_build_id = data.data2;
  

•   }
  

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

@@ -1034,6 +1041,7 @@ 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_version_info version_info = { };
    unsigned int max_notif_value;
    unsigned int rpc_param_count;
    struct tee_shm_pool *pool;
  

@@ -1047,7 +1055,7 @@ 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, &version_info))
            return -EINVAL;
  
    if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps,
  

@@ -1059,6 +1067,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev) optee = kzalloc(sizeof(*optee), GFP_KERNEL); if (!optee) return -ENOMEM;

•   optee->version_info = version_info;
  
    pool = optee_ffa_shm_pool_alloc_pages();
    if (IS_ERR(pool)) {
  

diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index db9ea673fbca..3e7bcd44976b 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -19,6 +19,22 @@

#define OPTEE_MAX_ARG_SIZE 1024

+/**

• • struct optee_version_info - 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_version_info {

•   u32 os_major;
  

•   u32 os_minor;
  

•   u64 os_build_id;
  

+};

/* Some Global Platform error codes used in this driver */ #define TEEC_SUCCESS 0x00000000 #define TEEC_ERROR_BAD_PARAMETERS 0xFFFF0006 @@ -249,6 +265,7 @@ struct optee { bool in_kernel_rpmb_routing; struct work_struct scan_bus_work; struct work_struct rpmb_scan_bus_work;

•   struct optee_version_info version_info;
  

};

struct optee_session { diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c index 0be663fcd52b..07c703609320 100644 --- a/drivers/tee/optee/smc_abi.c +++ b/drivers/tee/optee/smc_abi.c @@ -1323,7 +1323,8 @@ 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_version_info *version_info)
  

{ union { struct arm_smccc_res smccc; @@ -1337,6 +1338,12 @@ 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 (version_info) {
  

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

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

•           version_info->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 +1734,7 @@ static int optee_probe(struct platform_device *pdev) unsigned int thread_count; struct tee_device *teedev; struct tee_context *ctx;

•   struct optee_version_info version_info = { };
    u32 max_notif_value;
    u32 arg_cache_flags;
    u32 sec_caps;
  

@@ -1745,7 +1753,7 @@ static int optee_probe(struct platform_device *pdev) return -EINVAL; }

•   optee_msg_get_os_revision(invoke_fn);
  

•   optee_msg_get_os_revision(invoke_fn, &version_info);
  
    if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
            pr_warn("api revision mismatch\n");
  

@@ -1814,6 +1822,7 @@ static int optee_probe(struct platform_device *pdev) rc = -ENOMEM; goto err_free_shm_pool; }

•   optee->version_info = version_info;
  
    optee->ops = &optee_ops;
    optee->smc.invoke_fn = invoke_fn;
  

-- 2.43.0