[PATCH] usb: misc: chaoskey: remove useless else

[PATCH] usb: misc: chaoskey: remove useless else

[Salah Triki]

Remove useless else in order to make the code cleaner.

Signed-off-by: Salah Triki <salah.triki@gmail.com>
---
 drivers/usb/misc/chaoskey.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
index 87067c3d6109..9814ac2201d5 100644
--- a/drivers/usb/misc/chaoskey.c
+++ b/drivers/usb/misc/chaoskey.c
@@ -299,14 +299,11 @@ static int chaoskey_release(struct inode *inode, struct file *file)
 
 	--dev->open;
 
-	if (!dev->present) {
-		if (dev->open == 0) {
-			mutex_unlock(&dev->lock);
+	mutex_unlock(&dev->lock);
+
+	if (!dev->present)
+		if (dev->open == 0)
 			chaoskey_free(dev);
-		} else
-			mutex_unlock(&dev->lock);
-	} else
-		mutex_unlock(&dev->lock);
 
 	usb_dbg(interface, "release success");
 	return 0;
-- 
2.25.1

Re: [PATCH] usb: misc: chaoskey: remove useless else

[Keith Packard]

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Salah Triki <salah.triki@gmail.com> writes:

> Remove useless else in order to make the code cleaner.

> -	if (!dev->present) {
> -		if (dev->open == 0) {
> -			mutex_unlock(&dev->lock);
> +	mutex_unlock(&dev->lock);
> +
> +	if (!dev->present)
> +		if (dev->open == 0)
>  			chaoskey_free(dev);
> -		} else
> -			mutex_unlock(&dev->lock);
> -	} else
> -		mutex_unlock(&dev->lock);

This accesses dev->present outside of the lock region introducing a
potential race condition.

-- 
-keith

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Re: [PATCH] usb: misc: chaoskey: remove useless else

[Greg Kroah-Hartman]

On Fri, Aug 13, 2021 at 05:40:49PM +0100, Salah Triki wrote:
> Remove useless else in order to make the code cleaner.
> 
> Signed-off-by: Salah Triki <salah.triki@gmail.com>
> ---
>  drivers/usb/misc/chaoskey.c | 11 ++++-------
>  1 file changed, 4 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/usb/misc/chaoskey.c b/drivers/usb/misc/chaoskey.c
> index 87067c3d6109..9814ac2201d5 100644
> --- a/drivers/usb/misc/chaoskey.c
> +++ b/drivers/usb/misc/chaoskey.c
> @@ -299,14 +299,11 @@ static int chaoskey_release(struct inode *inode, struct file *file)
>  
>  	--dev->open;
>  
> -	if (!dev->present) {
> -		if (dev->open == 0) {
> -			mutex_unlock(&dev->lock);
> +	mutex_unlock(&dev->lock);
> +
> +	if (!dev->present)
> +		if (dev->open == 0)
>  			chaoskey_free(dev);
> -		} else
> -			mutex_unlock(&dev->lock);
> -	} else
> -		mutex_unlock(&dev->lock);
>  
>  	usb_dbg(interface, "release success");
>  	return 0;
> -- 
> 2.25.1
> 

Please fix whatever tool "found" this code to be changed so that it does
not introduce bugs again, that's a broken tool.

thanks,

greg k-h