Re: [PATCH] platform/chrome: wilco_ec: Annotate struct ec_event_queue with __counted_by

[Gustavo A. R. Silva]

On 9/22/23 11:51, 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 ec_event_queue.
>
> [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci
>
> Cc: Benson Leung <bleung@xxxxxxxxxxxx>
> Cc: Tzung-Bi Shih <tzungbi@xxxxxxxxxx>
> Cc: Dawei Li <set_pte_at@xxxxxxxxxxx>
> Cc: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> Cc: Maximilian Luz <luzmaximilian@xxxxxxxxx>
> Cc: "Uwe Kleine-König" <u.kleine-koenig@xxxxxxxxxxxxxx>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Jiang Jian <jiangjian@xxxxxxxxxx>
> Cc: chrome-platform@xxxxxxxxxxxxxxx
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>

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

Thanks
--
Gustavo

> ---
>   drivers/platform/chrome/wilco_ec/event.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/platform/chrome/wilco_ec/event.c b/drivers/platform/chrome/wilco_ec/event.c
> index a40f60bcefb6..f80a7c83cfba 100644
> --- a/drivers/platform/chrome/wilco_ec/event.c
> +++ b/drivers/platform/chrome/wilco_ec/event.c
> @@ -95,7 +95,7 @@ struct ec_event_queue {
>   	int capacity;
>   	int head;
>   	int tail;
> -	struct ec_event *entries[];
> +	struct ec_event *entries[] __counted_by(capacity);
>   };
>   
>   /* Maximum number of events to store in ec_event_queue */