[PATCH] rtc: Move variable into switch case statement

[PATCH] rtc: Move variable into switch case statement

[Kees Cook]

When building with automatic stack variable initialization, GCC 12
complains about variables defined outside of switch case statements.
Move the variable into the case that uses it, which silences the warning:

drivers/rtc/dev.c: In function 'rtc_dev_ioctl':
drivers/rtc/dev.c:394:30: warning: statement will never be executed [-Wswitch-unreachable]
  394 |                         long offset;
      |                              ^~~~~~

Fixes: 6a8af1b6568a ("rtc: add parameter ioctl")
Signed-off-by: Kees Cook <keescook@chromium.org>
---
 drivers/rtc/dev.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
index e104972a28fd..69325aeede1a 100644
--- a/drivers/rtc/dev.c
+++ b/drivers/rtc/dev.c
@@ -391,14 +391,14 @@ static long rtc_dev_ioctl(struct file *file,
 		}
 
 		switch(param.param) {
-			long offset;
 		case RTC_PARAM_FEATURES:
 			if (param.index != 0)
 				err = -EINVAL;
 			param.uvalue = rtc->features[0];
 			break;
 
-		case RTC_PARAM_CORRECTION:
+		case RTC_PARAM_CORRECTION: {
+			long offset;
 			mutex_unlock(&rtc->ops_lock);
 			if (param.index != 0)
 				return -EINVAL;
@@ -407,7 +407,7 @@ static long rtc_dev_ioctl(struct file *file,
 			if (err == 0)
 				param.svalue = offset;
 			break;
-
+		}
 		default:
 			if (rtc->ops->param_get)
 				err = rtc->ops->param_get(rtc->dev.parent, &param);
-- 
2.30.2

Re: [PATCH] rtc: Move variable into switch case statement

[Gustavo A. R. Silva]

On Wed, Dec 08, 2021 at 08:39:15PM -0800, Kees Cook wrote:
> When building with automatic stack variable initialization, GCC 12
> complains about variables defined outside of switch case statements.
> Move the variable into the case that uses it, which silences the warning:
> 
> drivers/rtc/dev.c: In function 'rtc_dev_ioctl':
> drivers/rtc/dev.c:394:30: warning: statement will never be executed [-Wswitch-unreachable]
>   394 |                         long offset;
>       |                              ^~~~~~
> 
> Fixes: 6a8af1b6568a ("rtc: add parameter ioctl")
> Signed-off-by: Kees Cook <keescook@chromium.org>

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

Thanks
--
Gustavo

> ---
>  drivers/rtc/dev.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/rtc/dev.c b/drivers/rtc/dev.c
> index e104972a28fd..69325aeede1a 100644
> --- a/drivers/rtc/dev.c
> +++ b/drivers/rtc/dev.c
> @@ -391,14 +391,14 @@ static long rtc_dev_ioctl(struct file *file,
>  		}
>  
>  		switch(param.param) {
> -			long offset;
>  		case RTC_PARAM_FEATURES:
>  			if (param.index != 0)
>  				err = -EINVAL;
>  			param.uvalue = rtc->features[0];
>  			break;
>  
> -		case RTC_PARAM_CORRECTION:
> +		case RTC_PARAM_CORRECTION: {
> +			long offset;
>  			mutex_unlock(&rtc->ops_lock);
>  			if (param.index != 0)
>  				return -EINVAL;
> @@ -407,7 +407,7 @@ static long rtc_dev_ioctl(struct file *file,
>  			if (err == 0)
>  				param.svalue = offset;
>  			break;
> -
> +		}
>  		default:
>  			if (rtc->ops->param_get)
>  				err = rtc->ops->param_get(rtc->dev.parent, &param);
> -- 
> 2.30.2
> 
> 
> 
> 

Re: [PATCH] rtc: Move variable into switch case statement

[Alexandre Belloni]

On Wed, 8 Dec 2021 20:39:15 -0800, Kees Cook wrote:
> When building with automatic stack variable initialization, GCC 12
> complains about variables defined outside of switch case statements.
> Move the variable into the case that uses it, which silences the warning:
> 
> drivers/rtc/dev.c: In function 'rtc_dev_ioctl':
> drivers/rtc/dev.c:394:30: warning: statement will never be executed [-Wswitch-unreachable]
>   394 |                         long offset;
>       |                              ^~~~~~
> 
> [...]

Applied, thanks!

[1/1] rtc: Move variable into switch case statement
      commit: ba52eac083e1598e748811ff58d259f77e4c5c4d

Best regards,
-- 
Alexandre Belloni <alexandre.belloni@bootlin.com>