Re: [PATCH 2/2] tee: remove flags TEE_IOCTL_SHM_MAPPED and TEE_IOCTL_SHM_DMA_BUF

From: Sumit Garg
Date: Mon Apr 25 2022 - 02:47:00 EST


On Fri, 22 Apr 2022 at 23:31, Andrew Davis <afd@xxxxxx> wrote:
>
> These look to be leftover from an early edition of this driver. Userspace
> does not need this information. Checking all users of this that I have
> access to I have verified no one is using them.
>
> They leak internal use flags out to userspace. Even more they are not
> correct anymore after a45ea4efa358. Lets drop these flags before
> someone does try to use them for something and they become ABI.
>

Sounds reasonable to me.

> Signed-off-by: Andrew Davis <afd@xxxxxx>
> ---
> drivers/tee/tee_core.c | 1 -
> include/uapi/linux/tee.h | 4 ----
> 2 files changed, 5 deletions(-)
>
> diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
> index 8aa1a4836b92f..650dd87a38e77 100644
> --- a/drivers/tee/tee_core.c
> +++ b/drivers/tee/tee_core.c
> @@ -339,7 +339,6 @@ tee_ioctl_shm_register(struct tee_context *ctx,
> return PTR_ERR(shm);
>
> data.id = shm->id;
> - data.flags = shm->flags;
> data.length = shm->size;
>

This change is required for tee_ioctl_shm_alloc() as well.

-Sumit

> if (copy_to_user(udata, &data, sizeof(data)))
> diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h
> index 25a6c534beb1b..23e57164693c4 100644
> --- a/include/uapi/linux/tee.h
> +++ b/include/uapi/linux/tee.h
> @@ -42,10 +42,6 @@
> #define TEE_IOC_MAGIC 0xa4
> #define TEE_IOC_BASE 0
>
> -/* Flags relating to shared memory */
> -#define TEE_IOCTL_SHM_MAPPED 0x1 /* memory mapped in normal world */
> -#define TEE_IOCTL_SHM_DMA_BUF 0x2 /* dma-buf handle on shared memory */
> -
> #define TEE_MAX_ARG_SIZE 1024
>
> #define TEE_GEN_CAP_GP (1 << 0)/* GlobalPlatform compliant TEE */
> --
> 2.17.1
>