Re: [Tee-dev] [RESEND PATCH] tee: add kernel internal client interface

On Fri, 13 Jul 2018 at 14:54, Jens Wiklander jens.wiklander@linaro.org wrote:

[+Sumit]

On Mon, Jul 09, 2018 at 08:15:49AM +0200, Jens Wiklander wrote:

...

Adds a kernel internal TEE client interface to be used by other drivers.

Signed-off-by: Jens Wiklander jens.wiklander@linaro.org

Thanks Jens for this patch. I have reviewed and tested this patch on Developerbox [1]. Following is brief description of my test-case:

Developerbox doesn't have support for hardware based TRNG. But it does have 7 on-chip thermal sensors accessible from Secure world only. So I wrote OP-TEE static TA to collect Entropy using thermal noise from these sensors. After using the interface provided by this patch, I am able to write "hw_random" char driver for Developerbox to get Entropy from OP-TEE static TA which could be further used by user-space daemon (rngd).

Reviewed-by: Sumit Garg sumit.garg@linaro.org Tested-by: Sumit Garg sumit.garg@linaro.org

[1] https://www.96boards.org/product/developerbox/

-Sumit

...

drivers/tee/tee_core.c | 113 +++++++++++++++++++++++++++++++++++++--- include/linux/tee_drv.h | 73 ++++++++++++++++++++++++++ 2 files changed, 179 insertions(+), 7 deletions(-)

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index dd46b758852a..7b2bb4c50058 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -38,15 +38,13 @@ static DEFINE_SPINLOCK(driver_lock); static struct class *tee_class; static dev_t tee_devt;

-static int tee_open(struct inode *inode, struct file *filp) +static struct tee_context *teedev_open(struct tee_device *teedev) { int rc;

• struct tee_device *teedev;
  struct tee_context *ctx;
  
  

• teedev = container_of(inode->i_cdev, struct tee_device, cdev);
  if (!tee_device_get(teedev))
  

•         return -EINVAL;
  

•         return ERR_PTR(-EINVAL);
  
  ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
  if (!ctx) {
  

@@ -57,16 +55,16 @@ static int tee_open(struct inode *inode, struct file *filp) kref_init(&ctx->refcount); ctx->teedev = teedev; INIT_LIST_HEAD(&ctx->list_shm);

• filp->private_data = ctx;
  rc = teedev->desc->ops->open(ctx);
  if (rc)
          goto err;
  
  

• return 0;
  

• return ctx;
  

err: kfree(ctx); tee_device_put(teedev);

• return rc;
  

• return ERR_PTR(rc);
  

}

void teedev_ctx_get(struct tee_context *ctx) @@ -100,6 +98,18 @@ static void teedev_close_context(struct tee_context *ctx) teedev_ctx_put(ctx); }

+static int tee_open(struct inode *inode, struct file *filp) +{

• struct tee_context *ctx;
  

• ctx = teedev_open(container_of(inode->i_cdev, struct tee_device, cdev));
  

• if (IS_ERR(ctx))
  

•         return PTR_ERR(ctx);
  

• filp->private_data = ctx;
  

• return 0;
  

+}

static int tee_release(struct inode *inode, struct file *filp) { teedev_close_context(filp->private_data); @@ -928,6 +938,95 @@ void *tee_get_drvdata(struct tee_device *teedev) } EXPORT_SYMBOL_GPL(tee_get_drvdata);

+struct match_dev_data {

• struct tee_ioctl_version_data *vers;
  

• const void *data;
  

• int (*match)(struct tee_ioctl_version_data *, const void *);
  

+};

+static int match_dev(struct device *dev, const void *data) +{

• const struct match_dev_data *match_data = data;
  

• struct tee_device *teedev = container_of(dev, struct tee_device, dev);
  

• teedev->desc->ops->get_version(teedev, match_data->vers);
  

• return match_data->match(match_data->vers, match_data->data);
  

+}

+struct tee_context * +tee_client_open_context(struct tee_context *start,

•                 int (*match)(struct tee_ioctl_version_data *,
  

•                              const void *),
  

•                 const void *data, struct tee_ioctl_version_data *vers)
  

+{

• struct device *dev = NULL;
  

• struct device *put_dev = NULL;
  

• struct tee_context *ctx = NULL;
  

• struct tee_ioctl_version_data v;
  

• struct match_dev_data match_data = { vers ? vers : &v, data, match };
  

• if (start)
  

•         dev = &start->teedev->dev;
  

• do {
  

•         dev = class_find_device(tee_class, dev, &match_data, match_dev);
  

•         if (!dev) {
  

•                 ctx = ERR_PTR(-ENOENT);
  

•                 break;
  

•         }
  

•         put_device(put_dev);
  

•         put_dev = dev;
  

•         ctx = teedev_open(container_of(dev, struct tee_device, dev));
  

• } while (IS_ERR(ctx) && PTR_ERR(ctx) != -ENOMEM);
  

• put_device(put_dev);
  

• return ctx;
  

+} +EXPORT_SYMBOL_GPL(tee_client_open_context);

+void tee_client_close_context(struct tee_context *ctx) +{

• teedev_close_context(ctx);
  

+} +EXPORT_SYMBOL_GPL(tee_client_close_context);

+void tee_client_get_version(struct tee_context *ctx,

•                     struct tee_ioctl_version_data *vers)
  

+{

• ctx->teedev->desc->ops->get_version(ctx->teedev, vers);
  

+} +EXPORT_SYMBOL_GPL(tee_client_get_version);

+int tee_client_open_session(struct tee_context *ctx,

•                     struct tee_ioctl_open_session_arg *arg,
  

•                     struct tee_param *param)
  

+{

• if (!ctx->teedev->desc->ops->open_session)
  

•         return -EINVAL;
  

• return ctx->teedev->desc->ops->open_session(ctx, arg, param);
  

+} +EXPORT_SYMBOL_GPL(tee_client_open_session);

+int tee_client_close_session(struct tee_context *ctx, u32 session) +{

• if (!ctx->teedev->desc->ops->close_session)
  

•         return -EINVAL;
  

• return ctx->teedev->desc->ops->close_session(ctx, session);
  

+} +EXPORT_SYMBOL_GPL(tee_client_close_session);

+int tee_client_invoke_func(struct tee_context *ctx,

•                    struct tee_ioctl_invoke_arg *arg,
  

•                    struct tee_param *param)
  

+{

• if (!ctx->teedev->desc->ops->invoke_func)
  

•         return -EINVAL;
  

• return ctx->teedev->desc->ops->invoke_func(ctx, arg, param);
  

+} +EXPORT_SYMBOL_GPL(tee_client_invoke_func);

static int __init tee_init(void) { int rc; diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index a2b3dfcee0b5..6cfe05893a76 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -453,6 +453,79 @@ static inline int tee_shm_get_id(struct tee_shm *shm) */ struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id);

+/**

• • tee_client_open_context() - Open a TEE context
• • @start: if not NULL, continue search after this context
• • @match: function to check TEE device
• • @data: data for match function
• • @vers: if not NULL, version data of TEE device of the context returned
• • This function does an operation similar to open("/dev/teeX") in user space.
• • A returned context must be released with tee_client_close_context().
• • Returns a TEE context of the first TEE device matched by the match()
• • callback or an ERR_PTR.
• */

+struct tee_context * +tee_client_open_context(struct tee_context *start,

•                 int (*match)(struct tee_ioctl_version_data *,
  

•                              const void *),
  

•                 const void *data, struct tee_ioctl_version_data *vers);
  

+/**

• • tee_client_close_context() - Close a TEE context
• • @ctx: TEE context to close
• • Note that all sessions previously opened with this context will be
• • closed when this function is called.
• */

+void tee_client_close_context(struct tee_context *ctx);

+/**

• • tee_client_get_version() - Query version of TEE
• • @ctx: TEE context to TEE to query
• • @vers: Pointer to version data
• */

+void tee_client_get_version(struct tee_context *ctx,

•                     struct tee_ioctl_version_data *vers);
  

+/**

• • tee_client_open_session() - Open a session to a Trusted Application
• • @ctx: TEE context
• • @arg: Open session arguments, see description of

• •       struct tee_ioctl_open_session_arg
    

• • @param: Parameters passed to the Trusted Application
• • Returns < 0 on error else see @arg->ret for result. If @arg->ret
• • is TEEC_SUCCESS the session identifier is available in @arg->session.
• */

+int tee_client_open_session(struct tee_context *ctx,

•                     struct tee_ioctl_open_session_arg *arg,
  

•                     struct tee_param *param);
  

+/**

• • tee_client_close_session() - Close a session to a Trusted Application
• • @ctx: TEE Context
• • @session: Session id
• • Return < 0 on error else 0, regardless the session will not be
• • valid after this function has returned.
• */

+int tee_client_close_session(struct tee_context *ctx, u32 session);

+/**

• • tee_client_invoke_func() - Invoke a function in a Trusted Application
• • @ctx: TEE Context
• • @arg: Invoke arguments, see description of

• •       struct tee_ioctl_invoke_arg
    

• • @param: Parameters passed to the Trusted Application
• • Returns < 0 on error else see @arg->ret for result.
• */

+int tee_client_invoke_func(struct tee_context *ctx,

•                    struct tee_ioctl_invoke_arg *arg,
  

•                    struct tee_param *param);
  

static inline bool tee_param_is_memref(struct tee_param *param) { switch (param->attr & TEE_IOCTL_PARAM_ATTR_TYPE_MASK) { -- 2.17.1