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

[Kees Cook <keescook@chromium.org>]

On Mon, Jul 29, 2019 at 10:10:33AM -0500, Gustavo A. R. Silva wrote:
> Mark switch cases where we are expecting to fall through.
> 
> This patch fixes the following warnings:
> 
> drivers/watchdog/ar7_wdt.c: warning: this statement may fall
> through [-Wimplicit-fallthrough=]:  => 237:3
> drivers/watchdog/pcwd.c: warning: this statement may fall
> through [-Wimplicit-fallthrough=]:  => 653:3
> drivers/watchdog/sb_wdog.c: warning: this statement may fall
> through [-Wimplicit-fallthrough=]:  => 204:3
> drivers/watchdog/wdt.c: warning: this statement may fall
> through [-Wimplicit-fallthrough=]:  => 391:3
> 
> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

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

-Kees

> ---
>  drivers/watchdog/ar7_wdt.c | 1 +
>  drivers/watchdog/pcwd.c    | 2 +-
>  drivers/watchdog/sb_wdog.c | 1 +
>  drivers/watchdog/wdt.c     | 2 +-
>  4 files changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/watchdog/ar7_wdt.c b/drivers/watchdog/ar7_wdt.c
> index b9b2d06b3879..668a1c704f28 100644
> --- a/drivers/watchdog/ar7_wdt.c
> +++ b/drivers/watchdog/ar7_wdt.c
> @@ -235,6 +235,7 @@ static long ar7_wdt_ioctl(struct file *file,
>  		ar7_wdt_update_margin(new_margin);
>  		ar7_wdt_kick(1);
>  		spin_unlock(&wdt_lock);
> +		/* Fall through */
>  
>  	case WDIOC_GETTIMEOUT:
>  		if (put_user(margin, (int *)arg))
> diff --git a/drivers/watchdog/pcwd.c b/drivers/watchdog/pcwd.c
> index 1b2cf5b95a89..c3c93e00b320 100644
> --- a/drivers/watchdog/pcwd.c
> +++ b/drivers/watchdog/pcwd.c
> @@ -651,7 +651,7 @@ static long pcwd_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  			return -EINVAL;
>  
>  		pcwd_keepalive();
> -		/* Fall */
> +		/* Fall through */
>  
>  	case WDIOC_GETTIMEOUT:
>  		return put_user(heartbeat, argp);
> diff --git a/drivers/watchdog/sb_wdog.c b/drivers/watchdog/sb_wdog.c
> index 5a6ced7a7e8f..202fc8d8ca5f 100644
> --- a/drivers/watchdog/sb_wdog.c
> +++ b/drivers/watchdog/sb_wdog.c
> @@ -202,6 +202,7 @@ static long sbwdog_ioctl(struct file *file, unsigned int cmd,
>  		timeout = time;
>  		sbwdog_set(user_dog, timeout);
>  		sbwdog_pet(user_dog);
> +		/* Fall through */
>  
>  	case WDIOC_GETTIMEOUT:
>  		/*
> diff --git a/drivers/watchdog/wdt.c b/drivers/watchdog/wdt.c
> index 0650100fad00..7d278b37e083 100644
> --- a/drivers/watchdog/wdt.c
> +++ b/drivers/watchdog/wdt.c
> @@ -389,7 +389,7 @@ static long wdt_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
>  		if (wdt_set_heartbeat(new_heartbeat))
>  			return -EINVAL;
>  		wdt_ping();
> -		/* Fall */
> +		/* Fall through */
>  	case WDIOC_GETTIMEOUT:
>  		return put_user(heartbeat, p);
>  	default:
> -- 
> 2.22.0
> 

-- 
Kees Cook