Re: [PATCH 7/9] drm/virtio: Annotate struct virtio_gpu_object_array with __counted_by

["Gustavo A. R. Silva" <gustavo@embeddedor.com>]

On 9/22/23 11:32, Kees Cook wrote:
> Prepare for the coming implementation by GCC and Clang of the __counted_by
> attribute. Flexible array members annotated with __counted_by can have
> their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
> (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
> functions).
> 
> As found with Coccinelle[1], add __counted_by for struct virtio_gpu_object_array.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: David Airlie <airlied@redhat.com>
> Cc: Gerd Hoffmann <kraxel@redhat.com>
> Cc: Gurchetan Singh <gurchetansingh@chromium.org>
> Cc: Chia-I Wu <olvaffe@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: dri-devel@lists.freedesktop.org
> Cc: virtualization@lists.linux-foundation.org
> Signed-off-by: Kees Cook <keescook@chromium.org>

Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thanks
-- 
Gustavo

> ---
>   drivers/gpu/drm/virtio/virtgpu_drv.h | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/virtio/virtgpu_drv.h b/drivers/gpu/drm/virtio/virtgpu_drv.h
> index 8513b671f871..96365a772f77 100644
> --- a/drivers/gpu/drm/virtio/virtgpu_drv.h
> +++ b/drivers/gpu/drm/virtio/virtgpu_drv.h
> @@ -119,7 +119,7 @@ struct virtio_gpu_object_array {
>   	struct ww_acquire_ctx ticket;
>   	struct list_head next;
>   	u32 nents, total;
> -	struct drm_gem_object *objs[];
> +	struct drm_gem_object *objs[] __counted_by(total);
>   };
>   
>   struct virtio_gpu_vbuffer;