Re: [PATCH] gcov: Annotate struct gcov_iterator with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:52, 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 gcov_iterator.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Peter Oberparleiter <oberpar@xxxxxxxxxxxxx>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>   kernel/gcov/fs.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/kernel/gcov/fs.c b/kernel/gcov/fs.c
> index 5c3086cad8f9..01520689b57c 100644
> --- a/kernel/gcov/fs.c
> +++ b/kernel/gcov/fs.c
> @@ -99,7 +99,7 @@ struct gcov_iterator {
>   	struct gcov_info *info;
>   	size_t size;
>   	loff_t pos;
> -	char buffer[];
> +	char buffer[] __counted_by(size);
>   };
>   
>   /**