Re: [Tee-dev] [PATCHv3 1/3] optee: do drivers initialization before and after tee-supplicant run

On Wed, 27 May 2020 at 22:56, Jarkko Sakkinen jarkko.sakkinen@linux.intel.com wrote:

On Mon, 2020-05-25 at 14:52 +0300, Maxim Uvarov wrote:

...

Some drivers (like ftpm) can operate only after tee-supplicant runs becase of tee-supplicant provides things like storage services. This patch splits probe of non tee-supplicant dependable drivers to early stage, and after tee-supplicant run probe other drivers.

Fix the typos and remove extra spaces (one space after '.').

Why "tee-supplicant" and not "TEE-supplicant"?

...

Signed-off-by: Maxim Uvarov maxim.uvarov@linaro.org Suggested-by: Sumit Garg sumit.garg@linaro.org Suggested-by: Arnd Bergmann arnd@linaro.org

---

drivers/tee/optee/core.c | 28 +++++++++++++++++++++++++--- drivers/tee/optee/device.c | 17 +++++++++++------ drivers/tee/optee/optee_private.h | 10 +++++++++- 3 files changed, 45 insertions(+), 10 deletions(-)

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c index 99698b8a3a74..d059e3ac491c 100644 --- a/drivers/tee/optee/core.c +++ b/drivers/tee/optee/core.c @@ -17,6 +17,7 @@ #include <linux/tee_drv.h> #include <linux/types.h> #include <linux/uaccess.h> +#include <linux/workqueue.h> #include "optee_private.h" #include "optee_smc.h" #include "shm_pool.h" @@ -218,6 +219,15 @@ static void optee_get_version(struct tee_device *teedev, *vers = v; }

+static void optee_bus_scan(struct work_struct *work) +{

• int rc;
  

• rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP);
  

• if (rc)
  

•         pr_err("optee_enumerate_devices failed %d\n", rc);
  

+}

Is pr_err() required really here? Why not just pr_info()?

Why have it all and not just ftrace when needed? There is series going on to add CONFIG_FTRACE_FUNC_PROTOTYPE to that to get return values and arguments.

Actually if optee_enumerate_devices() fail then I would say there is something wrong with memory or Secure OS and more likely we should stop execution. I think something line WARN_ON might be more suitable here. What do you think?

...

static int optee_open(struct tee_context *ctx) { struct optee_context_data *ctxdata; @@ -241,8 +251,18 @@ static int optee_open(struct tee_context *ctx) kfree(ctxdata); return -EBUSY; }

• }
  
  

•         if (!optee->scan_bus_done) {
  

•                 INIT_WORK(&optee->scan_bus_work, optee_bus_scan);
  

•                 optee->scan_bus_wq = create_workqueue("optee_bus_scan");
  

•                 if (!optee->scan_bus_wq) {
  

•                         pr_err("optee: couldn't create workqueue\n");
  

Neither get pr_err() here. Please remove this one completely.

What is the benefit of removing print here? Kernel binary size?

...

•                         return -ECHILD;
  

•                 }
  

•                 queue_work(optee->scan_bus_wq, &optee->scan_bus_work);
  

•                 optee->scan_bus_done = true;
  

•         }
  

• }
  mutex_init(&ctxdata->mutex);
  INIT_LIST_HEAD(&ctxdata->sess_list);
  
  

@@ -296,8 +316,10 @@ static void optee_release(struct tee_context *ctx)

  ctx->data = NULL;

• if (teedev == optee->supp_teedev)
  

• if (teedev == optee->supp_teedev) {
  

•         destroy_workqueue(optee->scan_bus_wq);
          optee_supp_release(&optee->supp);
  

• }
  

}

static const struct tee_driver_ops optee_ops = { @@ -675,7 +697,7 @@ static int optee_probe(struct platform_device *pdev)

  platform_set_drvdata(pdev, optee);

• rc = optee_enumerate_devices();
  

• rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
  if (rc) {
          optee_remove(pdev);
          return rc;
  

diff --git a/drivers/tee/optee/device.c b/drivers/tee/optee/device.c index e3a148521ec1..d4931dad07aa 100644 --- a/drivers/tee/optee/device.c +++ b/drivers/tee/optee/device.c @@ -21,7 +21,6 @@

• TEE_ERROR_BAD_PARAMETERS - Incorrect input param
• TEE_ERROR_SHORT_BUFFER - Output buffer size less than required

*/ -#define PTA_CMD_GET_DEVICES 0x0

static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) { @@ -32,7 +31,8 @@ static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data) }

static int get_devices(struct tee_context *ctx, u32 session,

•                struct tee_shm *device_shm, u32 *shm_size)
  

•                struct tee_shm *device_shm, u32 *shm_size,
  

•                u32 func)
  

{ int ret = 0; struct tee_ioctl_invoke_arg inv_arg; @@ -42,7 +42,7 @@ static int get_devices(struct tee_context *ctx, u32 session, memset(&param, 0, sizeof(param));

  /* Invoke PTA_CMD_GET_DEVICES function */

• inv_arg.func = PTA_CMD_GET_DEVICES;
  

• inv_arg.func = func;
  inv_arg.session = session;
  inv_arg.num_params = 4;
  
  

@@ -87,7 +87,7 @@ static int optee_register_device(const uuid_t *device_uuid, u32 device_id) return rc; }

-int optee_enumerate_devices(void) +static int __optee_enumerate_devices(u32 func) { const uuid_t pta_uuid = UUID_INIT(0x7011a688, 0xddde, 0x4053, @@ -118,7 +118,7 @@ int optee_enumerate_devices(void) goto out_ctx; }

• rc = get_devices(ctx, sess_arg.session, NULL, &shm_size);
  

• rc = get_devices(ctx, sess_arg.session, NULL, &shm_size, func);
  if (rc < 0 || !shm_size)
          goto out_sess;
  
  

@@ -130,7 +130,7 @@ int optee_enumerate_devices(void) goto out_sess; }

• rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size);
  

• rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
  if (rc < 0)
          goto out_shm;
  
  

@@ -158,3 +158,8 @@ int optee_enumerate_devices(void)

  return rc;

}

+int optee_enumerate_devices(u32 func) +{

• return  __optee_enumerate_devices(func);
  

+} diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h index d9c5037b4e03..8b71839a357e 100644 --- a/drivers/tee/optee/optee_private.h +++ b/drivers/tee/optee/optee_private.h @@ -78,6 +78,9 @@ struct optee_supp {

• @memremaped_shm virtual address of memory in shared memory pool
• @sec_caps: secure world capabilities defined by

•               OPTEE_SMC_SEC_CAP_* in optee_smc.h
  

• • @scan_bus_done flag if device registation was already done.
• • @scan_bus_wq workqueue to scan optee bus and register optee drivers
• • @scan_bus_work workq to scan optee bus and register optee drivers
  */

struct optee { struct tee_device *supp_teedev; @@ -89,6 +92,9 @@ struct optee { struct tee_shm_pool *pool; void *memremaped_shm; u32 sec_caps;

• bool   scan_bus_done;
  

• struct workqueue_struct *scan_bus_wq;
  

• struct work_struct scan_bus_work;
  

};

struct optee_session { @@ -173,7 +179,9 @@ void optee_free_pages_list(void *array, size_t num_entries); void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages, size_t page_offset);

-int optee_enumerate_devices(void); +#define PTA_CMD_GET_DEVICES 0x0 +#define PTA_CMD_GET_DEVICES_SUPP 0x1 +int optee_enumerate_devices(u32 func);

/*

• Small helpers

No exalanation of "scan bus" neither in the comments nor in the code.

Idea was when tee-supplicant opens /dev/tee-priv0 then we run workqueue (to not hold current open()) and do bus scan for TA applications which require tee-supplicant run. There is no "scan bus" as API. The is optee_enumerate_devices() is split up on 2 stages.

Maxim.

/Jarkko