[PATCH 2/4] sound/soc/fsl/p1022_ds.c: Add of_node_put to avoid memory leak

[PATCH 2/4] sound/soc/fsl/p1022_ds.c: Add of_node_put to avoid memory leak

[Julia Lawall]

Add a call to of_node_put in the error handling code following a call to
of_parse_phandle.

This patch also moves the existing call to of_node_put tothe end of the
error handling code, to make it possible to jump to of_node_put without
doing the other cleanup operations.  These appear to be disjoint
operations, so the ordering doesn't matter.

The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
local idexpression x;
expression E,E1,E2;
statement S;
@@

*x = 
(of_find_node_by_path
|of_find_node_by_name
|of_find_node_by_phandle
|of_get_parent
|of_get_next_parent
|of_get_next_child
|of_find_compatible_node
|of_match_node
|of_find_node_by_type
|of_find_node_with_property
|of_find_matching_node
|of_parse_phandle
)(...);
...
if (x == NULL) S
<... when != x = E
*if (...) {
  ... when != of_node_put(x)
      when != if (...) { ... of_node_put(x); ... }
(
  return <+...x...+>;
|
*  return ...;
)
}
...>
(
E2 = x;
|
of_node_put(x);
)
// </smpl>

Signed-off-by: Julia Lawall <julia@diku.dk>

---
 sound/soc/fsl/p1022_ds.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/sound/soc/fsl/p1022_ds.c b/sound/soc/fsl/p1022_ds.c
index f8176e8..63b9eaa 100644
--- a/sound/soc/fsl/p1022_ds.c
+++ b/sound/soc/fsl/p1022_ds.c
@@ -346,8 +346,10 @@ static int p1022_ds_probe(struct platform_device *pdev)
 	}
 
 	mdata = kzalloc(sizeof(struct machine_data), GFP_KERNEL);
-	if (!mdata)
-		return -ENOMEM;
+	if (!mdata) {
+		ret = -ENOMEM;
+		goto error_put;
+	}
 
 	mdata->dai[0].cpu_dai_name = dev_name(&ssi_pdev->dev);
 	mdata->dai[0].ops = &p1022_ds_ops;
@@ -502,13 +504,12 @@ static int p1022_ds_probe(struct platform_device *pdev)
 	return 0;
 
 error:
-	of_node_put(codec_np);
-
 	if (sound_device)
 		platform_device_unregister(sound_device);
 
 	kfree(mdata);
-
+error_put:
+	of_node_put(codec_np);
 	return ret;
 }

Re: [PATCH 2/4] sound/soc/fsl/p1022_ds.c: Add of_node_put to avoid memory leak

[Mark Brown]

On Tue, Aug 31, 2010 at 05:48:56PM +0200, Julia Lawall wrote:
> Add a call to of_node_put in the error handling code following a call to
> of_parse_phandle.
> 
> This patch also moves the existing call to of_node_put tothe end of the
> error handling code, to make it possible to jump to of_node_put without
> doing the other cleanup operations.  These appear to be disjoint
> operations, so the ordering doesn't matter.

CCing in Timur who wrote and maintains that driver - looks OK to me.

> 
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> expression E,E1,E2;
> statement S;
> @@
> 
> *x = 
> (of_find_node_by_path
> |of_find_node_by_name
> |of_find_node_by_phandle
> |of_get_parent
> |of_get_next_parent
> |of_get_next_child
> |of_find_compatible_node
> |of_match_node
> |of_find_node_by_type
> |of_find_node_with_property
> |of_find_matching_node
> |of_parse_phandle
> )(...);
> ...
> if (x == NULL) S
> <... when != x = E
> *if (...) {
>   ... when != of_node_put(x)
>       when != if (...) { ... of_node_put(x); ... }
> (
>   return <+...x...+>;
> |
> *  return ...;
> )
> }
> ...>
> (
> E2 = x;
> |
> of_node_put(x);
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
>  sound/soc/fsl/p1022_ds.c |   11 ++++++-----
>  1 file changed, 6 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/soc/fsl/p1022_ds.c b/sound/soc/fsl/p1022_ds.c
> index f8176e8..63b9eaa 100644
> --- a/sound/soc/fsl/p1022_ds.c
> +++ b/sound/soc/fsl/p1022_ds.c
> @@ -346,8 +346,10 @@ static int p1022_ds_probe(struct platform_device *pdev)
>  	}
>  
>  	mdata = kzalloc(sizeof(struct machine_data), GFP_KERNEL);
> -	if (!mdata)
> -		return -ENOMEM;
> +	if (!mdata) {
> +		ret = -ENOMEM;
> +		goto error_put;
> +	}
>  
>  	mdata->dai[0].cpu_dai_name = dev_name(&ssi_pdev->dev);
>  	mdata->dai[0].ops = &p1022_ds_ops;
> @@ -502,13 +504,12 @@ static int p1022_ds_probe(struct platform_device *pdev)
>  	return 0;
>  
>  error:
> -	of_node_put(codec_np);
> -
>  	if (sound_device)
>  		platform_device_unregister(sound_device);
>  
>  	kfree(mdata);
> -
> +error_put:
> +	of_node_put(codec_np);
>  	return ret;
>  }
>  
> 

Re: [alsa-devel] [PATCH 2/4] sound/soc/fsl/p1022_ds.c: Add of_node_put to avoid memory leak

[Timur Tabi]

On Tue, Aug 31, 2010 at 10:48 AM, Julia Lawall <julia@diku.dk> wrote:
> Add a call to of_node_put in the error handling code following a call to
> of_parse_phandle.
>
> This patch also moves the existing call to of_node_put tothe end of the
> error handling code, to make it possible to jump to of_node_put without
> doing the other cleanup operations.  These appear to be disjoint
> operations, so the ordering doesn't matter.

Acked-by: Timur Tabi <timur@freescale.com>

Thanks, Julia.

-- 
Timur Tabi
Linux kernel developer at Freescale

Re: [PATCH 2/4] sound/soc/fsl/p1022_ds.c: Add of_node_put to avoid memory leak

[Liam Girdwood]

On Wed, 2010-09-01 at 13:39 -0500, Timur Tabi wrote:
> On Tue, Aug 31, 2010 at 10:48 AM, Julia Lawall <julia@diku.dk> wrote:
> > Add a call to of_node_put in the error handling code following a call to
> > of_parse_phandle.
> >
> > This patch also moves the existing call to of_node_put tothe end of the
> > error handling code, to make it possible to jump to of_node_put without
> > doing the other cleanup operations.  These appear to be disjoint
> > operations, so the ordering doesn't matter.
> 
> Acked-by: Timur Tabi <timur@freescale.com>

Acked-by: Liam Girdwood <lrg@slimlogic.uo.uk>
-- 
Freelance Developer, SlimLogic Ltd
ASoC and Voltage Regulator Maintainer.
http://www.slimlogic.co.uk

Re: [PATCH 2/4] sound/soc/fsl/p1022_ds.c: Add of_node_put to avoid memory leak

[Mark Brown]

On Tue, Aug 31, 2010 at 05:48:56PM +0200, Julia Lawall wrote:
> Add a call to of_node_put in the error handling code following a call to
> of_parse_phandle.

Applied, thanks.