Re: [PATCH -next] media: use struct_size() helper

[Tomasz Figa <tfiga@xxxxxxxxxxxx>]

Hi Yu,


On Wed, Aug 16, 2023 at 10:52 AM Yu Liao <liaoyu15@xxxxxxxxxx> wrote:
>
> Prefer struct_size_t() over open-coded versions of idiom:
>
> sizeof(struct-with-flex-array) + sizeof(typeof-flex-array-elements) * count
>
> where count is the max number of items the flexible array is supposed to
> contain.

Thanks for the patch. Please see my comment inline.

>
> Signed-off-by: Yu Liao <liaoyu15@xxxxxxxxxx>
> ---
>  drivers/media/common/videobuf2/frame_vector.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/media/common/videobuf2/frame_vector.c b/drivers/media/common/videobuf2/frame_vector.c
> index 0f430ddc1f67..c6bb88859e2a 100644
> --- a/drivers/media/common/videobuf2/frame_vector.c
> +++ b/drivers/media/common/videobuf2/frame_vector.c
> @@ -157,7 +157,7 @@ EXPORT_SYMBOL(frame_vector_to_pfns);
>  struct frame_vector *frame_vector_create(unsigned int nr_frames)
>  {
>         struct frame_vector *vec;
> -       int size = sizeof(struct frame_vector) + sizeof(void *) * nr_frames;
> +       int size = struct_size_t(struct frame_vector, ptrs, nr_frames);

Would struct_size() be more appropriate here, since we have vec declared above?

Best regards,
Tomasz

>
>         if (WARN_ON_ONCE(nr_frames == 0))
>                 return NULL;
> --
> 2.25.1
>