Re: [RESEND PATCH] alpha: Replace one-element array with flexible array member

[Kees Cook <kees@kernel.org>]

On Fri, Dec 20, 2024 at 08:20:20PM +0100, Thorsten Blum wrote:
> Replace the deprecated one-element array with a modern flexible array
> member in the struct crb_struct.
> 
> Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
> ---
>  arch/alpha/include/asm/hwrpb.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/arch/alpha/include/asm/hwrpb.h b/arch/alpha/include/asm/hwrpb.h
> index fc76f36265ad..db831cf8de10 100644
> --- a/arch/alpha/include/asm/hwrpb.h
> +++ b/arch/alpha/include/asm/hwrpb.h
> @@ -135,7 +135,7 @@ struct crb_struct {
>  	/* virtual->physical map */
>  	unsigned long map_entries;
>  	unsigned long map_pages;
> -	struct vf_map_struct map[1];
> +	struct vf_map_struct map[];
>  };

Seems like this could use __counted_by(map_entries) as well?

...
                for (i = 0; i < crb->map_entries; ++i) {
                        unsigned long pfn = crb->map[i].pa >> PAGE_SHIFT;
...

But yes, this appears to be used as a flexible array and should be
adjusted. I see no sizeof() uses that would change. So:

Reviewed-by: Kees Cook <kees@kernel.org>

-Kees

-- 
Kees Cook