Re: [PATCH] watchdog: scx200_wdt: Mark expected switch fall-through

[Kees Cook <keescook@chromium.org>]

On Mon, Jul 29, 2019 at 03:06:02PM -0500, Gustavo A. R. Silva wrote:
> Mark switch cases where we are expecting to fall through.
> 
> This patch fixes the following warning (Building: i386):
> 
> drivers/watchdog/scx200_wdt.c: In function ‘scx200_wdt_ioctl’:
> drivers/watchdog/scx200_wdt.c:188:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
>    scx200_wdt_ping();
>    ^~~~~~~~~~~~~~~~~
> drivers/watchdog/scx200_wdt.c:189:2: note: here
>   case WDIOC_GETTIMEOUT:
>   ^~~~
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Reviewed-by: Kees Cook <keescook@chromium.org>

-Kees

> ---
>  drivers/watchdog/scx200_wdt.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/watchdog/scx200_wdt.c b/drivers/watchdog/scx200_wdt.c
> index efd7996694de..46268309ee9b 100644
> --- a/drivers/watchdog/scx200_wdt.c
> +++ b/drivers/watchdog/scx200_wdt.c
> @@ -186,6 +186,7 @@ static long scx200_wdt_ioctl(struct file *file, unsigned int cmd,
>  		margin = new_margin;
>  		scx200_wdt_update_margin();
>  		scx200_wdt_ping();
> +		/* Fall through */
>  	case WDIOC_GETTIMEOUT:
>  		if (put_user(margin, p))
>  			return -EFAULT;
> -- 
> 2.22.0
> 

-- 
Kees Cook