Re: [PATCH 5/9] drm/nouveau/pm: Annotate struct nvkm_perfdom with __counted_by

[Lyude Paul <lyude@redhat.com>]

Reviewed-by: Lyude Paul <lyude@redhat.com>

Thanks!

On Fri, 2023-09-22 at 10:32 -0700, 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 nvkm_perfdom.
> 
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
> 
> Cc: Ben Skeggs <bskeggs@redhat.com>
> Cc: Karol Herbst <kherbst@redhat.com>
> Cc: Lyude Paul <lyude@redhat.com>
> Cc: David Airlie <airlied@gmail.com>
> Cc: Daniel Vetter <daniel@ffwll.ch>
> Cc: dri-devel@lists.freedesktop.org
> Cc: nouveau@lists.freedesktop.org
> Signed-off-by: Kees Cook <keescook@chromium.org>
> ---
>  drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h b/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h
> index 6ae25d3e7f45..c011227f7052 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h
> +++ b/drivers/gpu/drm/nouveau/nvkm/engine/pm/priv.h
> @@ -82,7 +82,7 @@ struct nvkm_perfdom {
>  	u8  mode;
>  	u32 clk;
>  	u16 signal_nr;
> -	struct nvkm_perfsig signal[];
> +	struct nvkm_perfsig signal[] __counted_by(signal_nr);
>  };
>  
>  struct nvkm_funcdom {

-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat