[PATCH 6/9] arch/powerpc/platforms/pseries/iommu.c: add missing kfree

[PATCH 6/9] arch/powerpc/platforms/pseries/iommu.c: add missing kfree

[Julia Lawall]

From: Julia Lawall <julia@diku.dk>

At this point, window has not been stored anywhere, so it has to be freed
before leaving the function.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@exists@
local idexpression x;
statement S,S1;
expression E;
identifier fl;
expression *ptr != NULL;
@@

x = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
     when != if (...) { <+...kfree(x)...+> }
     when any
     when != true x == NULL
x->fl
...>
(
if (x == NULL) S1
|
if (...) { ... when != x
               when forall
(
 return \(0\|<+...x...+>\|ptr\);
|
* return ...;
)
}
)
// </smpl>

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

---
 arch/powerpc/platforms/pseries/iommu.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c
index 2b20b05..6351af8 100644
--- a/arch/powerpc/platforms/pseries/iommu.c
+++ b/arch/powerpc/platforms/pseries/iommu.c
@@ -940,14 +940,14 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
 	if (ret) {
 		dev_info(&dev->dev, "failed to map direct window for %s: %d\n",
 			 dn->full_name, ret);
-		goto out_clear_window;
+		goto out_free_window;
 	}
 
 	ret = prom_add_property(pdn, win64);
 	if (ret) {
 		dev_err(&dev->dev, "unable to add dma window property for %s: %d",
 			 pdn->full_name, ret);
-		goto out_clear_window;
+		goto out_free_window;
 	}
 
 	window->device = pdn;
@@ -959,6 +959,9 @@ static u64 enable_ddw(struct pci_dev *dev, struct device_node *pdn)
 	dma_addr = of_read_number(&create.addr_hi, 2);
 	goto out_unlock;
 
+out_free_window:
+	kfree(window);
+
 out_clear_window:
 	remove_ddw(pdn);
 

Re: [PATCH 6/9] arch/powerpc/platforms/pseries/iommu.c: add missing kfree

[Nishanth Aravamudan]

On 08.08.2011 [13:18:00 +0200], Julia Lawall wrote:
> From: Julia Lawall <julia@diku.dk>
> 
> At this point, window has not been stored anywhere, so it has to be freed
> before leaving the function.
> 
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
> 
> // <smpl>
> @exists@
> local idexpression x;
> statement S,S1;
> expression E;
> identifier fl;
> expression *ptr != NULL;
> @@
> 
> x = \(kmalloc\|kzalloc\|kcalloc\)(...);
> ...
> if (x == NULL) S
> <... when != x
>      when != if (...) { <+...kfree(x)...+> }
>      when any
>      when != true x == NULL
> x->fl
> ...>
> (
> if (x == NULL) S1
> |
> if (...) { ... when != x
>                when forall
> (
>  return \(0\|<+...x...+>\|ptr\);
> |
> * return ...;
> )
> }
> )
> // </smpl>
> 
> Signed-off-by: Julia Lawall <julia@diku.dk>

Acked-by: Nishanth Aravamudan <nacc@us.ibm.com>

Thanks,
Nish

-- 
Nishanth Aravamudan <nacc@us.ibm.com>
IBM Linux Technology Center