[PATCH 1/4] arch/ia64/sn/pci/tioca_provider.c: introduce missingkfree

From: Julia Lawall
Date: Wed Sep 10 2008 - 07:58:06 EST


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,l;
position p1,p2;
expression *ptr != NULL;
@@

(
if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) == NULL) S
|
x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
)
<... when != x
when != if (...) { <+...x...+> }
x->f = E
...>
(
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>
---
arch/ia64/sn/pci/tioca_provider.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/arch/ia64/sn/pci/tioca_provider.c b/arch/ia64/sn/pci/tioca_provider.c
index 529462c..7916512 100644
--- a/arch/ia64/sn/pci/tioca_provider.c
+++ b/arch/ia64/sn/pci/tioca_provider.c
@@ -420,8 +420,10 @@ tioca_dma_mapped(struct pci_dev *pdev, u64 paddr, size_t req_size)
entry = find_next_zero_bit(map, mapsize, last_entry);
}

- if (entry > mapsize)
+ if (entry > mapsize) {
+ kfree(ca_dmamap);
goto map_return;
+ }

for (i = 0; i < entries; i++)
set_bit(entry + i, map);
--
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