[PATCH] arch/powerpc/platforms/52xx/efika.c: Add of_node_put to avoid memory leak

[PATCH] arch/powerpc/platforms/52xx/efika.c: Add of_node_put to avoid memory leak

[Julia Lawall]

This function is implemented as though the function of_get_next_child does
not increment the reference count of its result, but actually it does.
Thus the patch adds of_node_put in error handling code and drops a call to
of_node_get.

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

// <smpl>
@r exists@
local idexpression x;
expression E1;
position p1,p2;
@@

x@p1 = of_get_next_child(...);
... when != x = E1
of_node_get@p2(x)

@script:python@
p1 << r.p1;
p2 << r.p2;
@@

cocci.print_main("call",p1)
cocci.print_secs("get",p2)
// </smpl>

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

---
 arch/powerpc/platforms/52xx/efika.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/arch/powerpc/platforms/52xx/efika.c b/arch/powerpc/platforms/52xx/efika.c
index 45c0cb9..18c1048 100644
--- a/arch/powerpc/platforms/52xx/efika.c
+++ b/arch/powerpc/platforms/52xx/efika.c
@@ -99,7 +99,7 @@ static void __init efika_pcisetup(void)
 	if (bus_range = NULL || len < 2 * sizeof(int)) {
 		printk(KERN_WARNING EFIKA_PLATFORM_NAME
 		       ": Can't get bus-range for %s\n", pcictrl->full_name);
-		return;
+		goto out_put;
 	}
 
 	if (bus_range[1] = bus_range[0])
@@ -111,12 +111,12 @@ static void __init efika_pcisetup(void)
 	printk(" controlled by %s\n", pcictrl->full_name);
 	printk("\n");
 
-	hose = pcibios_alloc_controller(of_node_get(pcictrl));
+	hose = pcibios_alloc_controller(pcictrl);
 	if (!hose) {
 		printk(KERN_WARNING EFIKA_PLATFORM_NAME
 		       ": Can't allocate PCI controller structure for %s\n",
 		       pcictrl->full_name);
-		return;
+		goto out_put;
 	}
 
 	hose->first_busno = bus_range[0];
@@ -124,6 +124,9 @@ static void __init efika_pcisetup(void)
 	hose->ops = &rtas_pci_ops;
 
 	pci_process_bridge_OF_ranges(hose, pcictrl, 0);
+	return;
+out_put:
+	of_node_put(pcictrl);
 }
 
 #else

Re: [PATCH] arch/powerpc/platforms/52xx/efika.c: Add of_node_put

[Grant Likely]

On Sat, Sep 04, 2010 at 09:13:17AM +0200, Julia Lawall wrote:
> This function is implemented as though the function of_get_next_child does
> not increment the reference count of its result, but actually it does.
> Thus the patch adds of_node_put in error handling code and drops a call to
> of_node_get.

applied, thanks.

g.

> 
> The semantic match that finds this problem is as follows:
> (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @r exists@
> local idexpression x;
> expression E1;
> position p1,p2;
> @@
> 
> x@p1 = of_get_next_child(...);
> ... when != x = E1
> of_node_get@p2(x)
> 
> @script:python@
> p1 << r.p1;
> p2 << r.p2;
> @@
> 
> cocci.print_main("call",p1)
> cocci.print_secs("get",p2)
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>
> 
> ---
>  arch/powerpc/platforms/52xx/efika.c |    9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/arch/powerpc/platforms/52xx/efika.c b/arch/powerpc/platforms/52xx/efika.c
> index 45c0cb9..18c1048 100644
> --- a/arch/powerpc/platforms/52xx/efika.c
> +++ b/arch/powerpc/platforms/52xx/efika.c
> @@ -99,7 +99,7 @@ static void __init efika_pcisetup(void)
>  	if (bus_range = NULL || len < 2 * sizeof(int)) {
>  		printk(KERN_WARNING EFIKA_PLATFORM_NAME
>  		       ": Can't get bus-range for %s\n", pcictrl->full_name);
> -		return;
> +		goto out_put;
>  	}
>  
>  	if (bus_range[1] = bus_range[0])
> @@ -111,12 +111,12 @@ static void __init efika_pcisetup(void)
>  	printk(" controlled by %s\n", pcictrl->full_name);
>  	printk("\n");
>  
> -	hose = pcibios_alloc_controller(of_node_get(pcictrl));
> +	hose = pcibios_alloc_controller(pcictrl);
>  	if (!hose) {
>  		printk(KERN_WARNING EFIKA_PLATFORM_NAME
>  		       ": Can't allocate PCI controller structure for %s\n",
>  		       pcictrl->full_name);
> -		return;
> +		goto out_put;
>  	}
>  
>  	hose->first_busno = bus_range[0];
> @@ -124,6 +124,9 @@ static void __init efika_pcisetup(void)
>  	hose->ops = &rtas_pci_ops;
>  
>  	pci_process_bridge_OF_ranges(hose, pcictrl, 0);
> +	return;
> +out_put:
> +	of_node_put(pcictrl);
>  }
>  
>  #else
>