Re: [PATCH 4/4] drivers/hid: introduce missing kfree

[Jiri Kosina]

On Tue, 1 Jun 2010, Julia Lawall wrote:

> From: Julia Lawall <julia@xxxxxxx>
> 
> Error handling code following a kmalloc should free the allocated data.
> 
> The semantic match that finds the problem is as follows:
> (http://www.emn.fr/x-info/coccinelle/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> statement S;
> expression E;
> identifier f,f1,l;
> position p1,p2;
> expression *ptr != NULL;
> @@
> 
> x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x == NULL) S
> <... when != x
>      when != if (...) { <+...x...+> }
> (
> x->f1 = E
> |
>  (x->f1 == NULL || ...)
> |
>  f(...,x->f1,...)
> )
> ...>
> (
>  return \(0\|<+...x...+>\|ptr\);
> |
>  return@p2 ...;
> )
> 
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
> 
> print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@xxxxxxx>
> ---
>  drivers/hid/hid-roccat.c |    9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/hid/hid-roccat.c b/drivers/hid/hid-roccat.c
> index e05d48e..f6e80c7 100644
> --- a/drivers/hid/hid-roccat.c
> +++ b/drivers/hid/hid-roccat.c
> @@ -168,7 +168,7 @@ static int roccat_open(struct inode *inode, struct file *file)
>  		printk(KERN_EMERG "roccat device with minor %d doesn't exist\n",
>  				minor);
>  		error = -ENODEV;
> -		goto exit_unlock;
> +		goto exit_err;
>  	}
>  
>  	if (!device->open++) {
> @@ -178,7 +178,7 @@ static int roccat_open(struct inode *inode, struct file *file)
>  					PM_HINT_FULLON);
>  			if (error < 0) {
>  				--device->open;
> -				goto exit_unlock;
> +				goto exit_err;
>  			}
>  		}
>  		error = device->hid->ll_driver->open(device->hid);
> @@ -187,7 +187,7 @@ static int roccat_open(struct inode *inode, struct file *file)
>  				device->hid->ll_driver->power(device->hid,
>  						PM_HINT_NORMAL);
>  			--device->open;
> -			goto exit_unlock;
> +			goto exit_err;
>  		}
>  	}
>  
> @@ -202,6 +202,9 @@ exit_unlock:
>  	mutex_unlock(&device->readers_lock);
>  	mutex_unlock(&devices_lock);
>  	return error;
> +exit_err:
> +	kfree(reader);
> +	goto exit_unlock;
>  }
>  
>  static int roccat_release(struct inode *inode, struct file *file)

Applied, thank you Julia.

-- 
Jiri Kosina
SUSE Labs, Novell Inc.
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