* [PATCH] sound/soc/fsl/fsl_dma.c: add missing of_node_put
@ 2011-08-20 7:23 Julia Lawall
2011-08-22 10:18 ` Liam Girdwood
2011-08-22 14:03 ` Timur Tabi
0 siblings, 2 replies; 4+ messages in thread
From: Julia Lawall @ 2011-08-20 7:23 UTC (permalink / raw)
To: Timur Tabi
Cc: alsa-devel, Takashi Iwai, devicetree-discuss, Mark Brown,
kernel-janitors, linux-kernel, Grant Likely, linuxppc-dev,
Liam Girdwood
From: Julia Lawall <julia@diku.dk>
of_parse_phandle increments the reference count of np, so this should be
decremented before trying the next possibility.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@@
expression e,e1,e2;
@@
*e = of_parse_phandle(...)
... when != of_node_put(e)
when != true e == NULL
when != e2 = e
e = e1
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
---
sound/soc/fsl/fsl_dma.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
index 0efc04a..b33271b 100644
--- a/sound/soc/fsl/fsl_dma.c
+++ b/sound/soc/fsl/fsl_dma.c
@@ -880,10 +880,12 @@ static struct device_node *find_ssi_node(struct device_node *dma_channel_np)
np = of_parse_phandle(ssi_np, "fsl,playback-dma", 0);
if (np == dma_channel_np)
return ssi_np;
+ of_node_put(np);
np = of_parse_phandle(ssi_np, "fsl,capture-dma", 0);
if (np == dma_channel_np)
return ssi_np;
+ of_node_put(np);
}
return NULL;
^ permalink raw reply related [flat|nested] 4+ messages in thread* Re: [PATCH] sound/soc/fsl/fsl_dma.c: add missing of_node_put
2011-08-20 7:23 [PATCH] sound/soc/fsl/fsl_dma.c: add missing of_node_put Julia Lawall
@ 2011-08-22 10:18 ` Liam Girdwood
2011-08-22 14:03 ` Timur Tabi
1 sibling, 0 replies; 4+ messages in thread
From: Liam Girdwood @ 2011-08-22 10:18 UTC (permalink / raw)
To: Julia Lawall
Cc: alsa-devel@alsa-project.org, Takashi Iwai,
devicetree-discuss@lists.ozlabs.org, Mark Brown,
kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org,
Grant Likely, linuxppc-dev@lists.ozlabs.org, Timur Tabi
On 20/08/11 08:23, Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
>
> of_parse_phandle increments the reference count of np, so this should be
> decremented before trying the next possibility.
>
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> expression e,e1,e2;
> @@
>
> *e = of_parse_phandle(...)
> ... when != of_node_put(e)
> when != true e == NULL
> when != e2 = e
> e = e1
> // </smpl>
>
> Signed-off-by: Julia Lawall <julia@diku.dk>
>
> ---
> sound/soc/fsl/fsl_dma.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
> index 0efc04a..b33271b 100644
> --- a/sound/soc/fsl/fsl_dma.c
> +++ b/sound/soc/fsl/fsl_dma.c
> @@ -880,10 +880,12 @@ static struct device_node *find_ssi_node(struct device_node *dma_channel_np)
> np = of_parse_phandle(ssi_np, "fsl,playback-dma", 0);
> if (np == dma_channel_np)
> return ssi_np;
> + of_node_put(np);
>
> np = of_parse_phandle(ssi_np, "fsl,capture-dma", 0);
> if (np == dma_channel_np)
> return ssi_np;
> + of_node_put(np);
> }
>
> return NULL;
>
Acked-by: Liam Girdwood <lrg@ti.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] sound/soc/fsl/fsl_dma.c: add missing of_node_put
2011-08-20 7:23 [PATCH] sound/soc/fsl/fsl_dma.c: add missing of_node_put Julia Lawall
2011-08-22 10:18 ` Liam Girdwood
@ 2011-08-22 14:03 ` Timur Tabi
[not found] ` <4E5261A5.5050608-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
1 sibling, 1 reply; 4+ messages in thread
From: Timur Tabi @ 2011-08-22 14:03 UTC (permalink / raw)
To: Julia Lawall
Cc: alsa-devel, Takashi Iwai, devicetree-discuss, Mark Brown,
kernel-janitors, linux-kernel, Grant Likely, linuxppc-dev,
Liam Girdwood
Julia Lawall wrote:
> diff --git a/sound/soc/fsl/fsl_dma.c b/sound/soc/fsl/fsl_dma.c
> index 0efc04a..b33271b 100644
> --- a/sound/soc/fsl/fsl_dma.c
> +++ b/sound/soc/fsl/fsl_dma.c
> @@ -880,10 +880,12 @@ static struct device_node *find_ssi_node(struct device_node *dma_channel_np)
> np = of_parse_phandle(ssi_np, "fsl,playback-dma", 0);
> if (np == dma_channel_np)
> return ssi_np;
> + of_node_put(np);
>
> np = of_parse_phandle(ssi_np, "fsl,capture-dma", 0);
> if (np == dma_channel_np)
> return ssi_np;
> + of_node_put(np);
> }
Thanks for catching the problem, Julia, but the fix is not quite correct. My
code assumes that of_parse_phandle() doesn't claim the node, but it doesn't
actually use the node pointer, either. All I care about is whether 'np' is
equal to dma_channel_np. I'm not going to use 'np'. So I think the real fix is
this:
@@ -880,10 +880,12 @@ static struct device_node *find_ssi_node(struct
device_node *dma_channel_np)
np = of_parse_phandle(ssi_np, "fsl,playback-dma", 0);
+ of_node_put(np);
if (np == dma_channel_np)
return ssi_np;
np = of_parse_phandle(ssi_np, "fsl,capture-dma", 0);
+ of_node_put(np);
if (np == dma_channel_np)
return ssi_np;
}
return NULL;
--
Timur Tabi
Linux kernel developer at Freescale
^ permalink raw reply [flat|nested] 4+ messages in thread
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2011-08-20 7:23 [PATCH] sound/soc/fsl/fsl_dma.c: add missing of_node_put Julia Lawall
2011-08-22 10:18 ` Liam Girdwood
2011-08-22 14:03 ` Timur Tabi
[not found] ` <4E5261A5.5050608-KZfg59tc24xl57MIdRCFDg@public.gmane.org>
2011-08-22 14:06 ` Julia Lawall
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