[PATCH 3/8] drivers/media/video/hdpvr: introduce missing kfree

From: Julia Lawall
Date: Fri Sep 11 2009 - 12:21:43 EST


From: Julia Lawall <julia@xxxxxxx>

Error handling code following a kzalloc 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,f1,l;
position p1,p2;
expression *ptr != NULL;
@@

x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
when != if (...) { <+...x...+> }
(
x->f1 = E
|
(x->f1 == NULL || ...)
|
f(...,x->f1,...)
)
...>
(
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>
---
drivers/media/video/hdpvr/hdpvr-video.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/hdpvr/hdpvr-video.c b/drivers/media/video/hdpvr/hdpvr-video.c
index 2eb9dc2..0d17ce5 100644
--- a/drivers/media/video/hdpvr/hdpvr-video.c
+++ b/drivers/media/video/hdpvr/hdpvr-video.c
@@ -132,7 +132,7 @@ int hdpvr_alloc_buffers(struct hdpvr_device *dev, uint count)
buf = kzalloc(sizeof(struct hdpvr_buffer), GFP_KERNEL);
if (!buf) {
v4l2_err(&dev->v4l2_dev, "cannot allocate buffer\n");
- goto exit;
+ goto exit_nobuf;
}
buf->dev = dev;

@@ -162,6 +162,8 @@ int hdpvr_alloc_buffers(struct hdpvr_device *dev, uint count)
}
return 0;
exit:
+ kfree(buf);
+exit_nobuf:
hdpvr_free_buffers(dev);
return retval;
}
--
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