Re: [PATCH] compat: Mark expected switch fall-throughs

From: Kees Cook
Date: Mon Oct 15 2018 - 17:30:12 EST


On Sat, Oct 13, 2018 at 4:50 AM, Gustavo A. R. Silva
<gustavo@xxxxxxxxxxxxxx> wrote:
> In preparation to enabling -Wimplicit-fallthrough, mark switch cases
> where we are expecting to fall through.
>
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Acked-by: Kees Cook <keescook@xxxxxxxxxxxx>

-Kees

> ---
> include/linux/compat.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/include/linux/compat.h b/include/linux/compat.h
> index d30e4db..06e7747 100644
> --- a/include/linux/compat.h
> +++ b/include/linux/compat.h
> @@ -488,8 +488,11 @@ put_compat_sigset(compat_sigset_t __user *compat, const sigset_t *set,
> compat_sigset_t v;
> switch (_NSIG_WORDS) {
> case 4: v.sig[7] = (set->sig[3] >> 32); v.sig[6] = set->sig[3];
> + /* fall through */
> case 3: v.sig[5] = (set->sig[2] >> 32); v.sig[4] = set->sig[2];
> + /* fall through */
> case 2: v.sig[3] = (set->sig[1] >> 32); v.sig[2] = set->sig[1];
> + /* fall through */
> case 1: v.sig[1] = (set->sig[0] >> 32); v.sig[0] = set->sig[0];
> }
> return copy_to_user(compat, &v, size) ? -EFAULT : 0;
> --
> 2.7.4
>



--
Kees Cook
Pixel Security