Re: [PATCH 2/9] drm/amdgpu/discovery: Annotate struct ip_hw_instance with __counted_by

[Alex Deucher]

On Fri, Sep 22, 2023 at 1:33 PM Kees Cook <keescook@xxxxxxxxxxxx> 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 ip_hw_instance.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> Cc: "Christian König" <christian.koenig@xxxxxxx>
> Cc: "Pan, Xinhui" <Xinhui.Pan@xxxxxxx>
> Cc: David Airlie <airlied@xxxxxxxxx>
> Cc: Daniel Vetter <daniel@xxxxxxxx>
> Cc: Hawking Zhang <Hawking.Zhang@xxxxxxx>
> Cc: amd-gfx@xxxxxxxxxxxxxxxxxxxxx
> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

Acked-by: Alex Deucher <alexander.deucher@xxxxxxx>

> ---
>  drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> index d1bc7b212520..be4c97a3d7bf 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_discovery.c
> @@ -662,7 +662,7 @@ struct ip_hw_instance {
>         u8  harvest;
>
>         int num_base_addresses;
> -       u32 base_addr[];
> +       u32 base_addr[] __counted_by(num_base_addresses);
>  };
>
>  struct ip_hw_id {
> --
> 2.34.1
>