Re: [PATCH v3 09/12] tee: add tee_shm_register_{user,kernel}_buf()

[Sumit Garg]

On Tue, 25 Jan 2022 at 21:59, Jens Wiklander <jens.wiklander@xxxxxxxxxx> wrote:
>
> Adds the two new functions tee_shm_register_user_buf() and
> tee_shm_register_kernel_buf() which should be used instead of the old
> tee_shm_register().
>
> This avoids having the caller supplying the flags parameter which
> exposes a bit more than desired of the internals of the TEE subsystem.
>
> Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>
> ---
>  drivers/tee/tee_core.c    |  3 +--
>  drivers/tee/tee_private.h |  2 ++
>  drivers/tee/tee_shm.c     | 33 +++++++++++++++++++++++++++++++++
>  include/linux/tee_drv.h   |  2 ++
>  4 files changed, 38 insertions(+), 2 deletions(-)
>

Reviewed-by: Sumit Garg <sumit.garg@xxxxxxxxxx>

-Sumit

> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> index a15812baaeb1..8aa1a4836b92 100644
> --- a/drivers/tee/tee_core.c
> +++ b/drivers/tee/tee_core.c
> @@ -334,8 +334,7 @@ tee_ioctl_shm_register(struct tee_context *ctx,
>         if (data.flags)
>                 return -EINVAL;
>
> -       shm = tee_shm_register(ctx, data.addr, data.length,
> -                              TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
> +       shm = tee_shm_register_user_buf(ctx, data.addr, data.length);
>         if (IS_ERR(shm))
>                 return PTR_ERR(shm);
>
> diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
> index 7265f47c6d8e..409cadcc1cff 100644
> --- a/drivers/tee/tee_private.h
> +++ b/drivers/tee/tee_private.h
> @@ -58,5 +58,7 @@ void teedev_ctx_get(struct tee_context *ctx);
>  void teedev_ctx_put(struct tee_context *ctx);
>
>  struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
> +struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> +                                         unsigned long addr, size_t length);
>
>  #endif /*TEE_PRIVATE_H*/
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index dc02afd7b5c9..0b6f7aabbf88 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -299,6 +299,39 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
>  }
>  EXPORT_SYMBOL_GPL(tee_shm_register);
>
> +/**
> + * tee_shm_register_user_buf() - Register a userspace shared memory buffer
> + * @ctx:       Context that registers the shared memory
> + * @addr:      The userspace address of the shared buffer
> + * @length:    Length of the shared buffer
> + *
> + * @returns a pointer to 'struct tee_shm'
> + */
> +struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
> +                                         unsigned long addr, size_t length)
> +{
> +       return tee_shm_register(ctx, addr, length,
> +                               TEE_SHM_DMA_BUF | TEE_SHM_USER_MAPPED);
> +}
> +
> +/**
> + * tee_shm_register_kernel_buf() - Register kernel memory to be shared with
> + *                                secure world
> + * @ctx:       Context that registers the shared memory
> + * @addr:      The buffer
> + * @length:    Length of the buffer
> + *
> + * @returns a pointer to 'struct tee_shm'
> + */
> +
> +struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> +                                           void *addr, size_t length)
> +{
> +       return tee_shm_register(ctx, (unsigned long)addr, length,
> +                               TEE_SHM_DMA_BUF | TEE_SHM_KERNEL_MAPPED);
> +}
> +EXPORT_SYMBOL_GPL(tee_shm_register_kernel_buf);
> +
>  static int tee_shm_fop_release(struct inode *inode, struct file *filp)
>  {
>         tee_shm_put(filp->private_data);
> diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> index 7f038f8787c7..c9d2cc32a5ed 100644
> --- a/include/linux/tee_drv.h
> +++ b/include/linux/tee_drv.h
> @@ -287,6 +287,8 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
>   */
>  struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
>                                  size_t length, u32 flags);
> +struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
> +                                           void *addr, size_t length);
>
>  /**
>   * tee_shm_is_registered() - Check if shared memory object in registered in TEE
> --
> 2.31.1
>