[PATCH] drm/amdgpu: disallow multiple BO_HANDLES chunks in one submit

[Christian König]

Am 02.07.24 um 15:23 schrieb Pierre-Eric Pelloux-Prayer:
> Before this commit, only submits with both a BO_HANDLES chunk and a
> 'bo_list_handle' would be rejected (by amdgpu_cs_parser_bos).
>
> But if UMD sent a multiple BO_HANDLES, what would happen is:
> * only the last one would be really used
> * all the others would leak memory as amdgpu_cs_p1_bo_handles would
>    overwrite the previous p->bo_list value
>
> This commit rejects submissions with multiple BO_HANDLES chunks to
> match the implementation of the parser.
>
> Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer at amd.com>
> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> index c08dfffae262..69d168d6f35a 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
> @@ -154,6 +154,10 @@ static int amdgpu_cs_p1_bo_handles(struct amdgpu_cs_parser *p,
>   	struct drm_amdgpu_bo_list_entry *info;
>   	int r;
>   
> +	/* Disallow multiple BO_HANDLES chunks. */

Describe why you do something, instead of what you do since that should 
be obvious from the code.

E.g. something like /* Only allow a single BO list to avoid memory leak. */

With that fixed Reviewed-by: Christian König <christian.koenig at amd.com>

Regards,
Christian.


> +	if (p->bo_list)
> +		return -EINVAL;
> +
>   	r = amdgpu_bo_create_list_entry_array(data, &info);
>   	if (r)
>   		return r;