Re: [PATCH] hpet: Annotate struct hpets with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:53, 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 hpets.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Clemens Ladisch <clemens@xxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>   drivers/char/hpet.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
> index 3b2159416e62..807c389510de 100644
> --- a/drivers/char/hpet.c
> +++ b/drivers/char/hpet.c
> @@ -92,7 +92,7 @@ struct hpets {
>   	unsigned long hp_delta;
>   	unsigned int hp_ntimer;
>   	unsigned int hp_which;
> -	struct hpet_dev hp_dev[];
> +	struct hpet_dev hp_dev[] __counted_by(hp_ntimer);
>   };
>   
>   static struct hpets *hpets;