V4L/DVB (13413): introduce missing kfree

Error handling code following a kzalloc should free the allocated data.
Similarly for usb-alloc urb.

The semantic match that finds the first 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@diku.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/hdpvr/hdpvr-video.c b/drivers/media/video/hdpvr/hdpvr-video.c
index 2eb9dc2ebe59797a9ffeac30eea0dbbd7eeae504..b5439cabb381e9bac7ca61ce5e18782be45f6ee8 100644 (file)
--- a/drivers/media/video/hdpvr/hdpvr-video.c
+++ b/drivers/media/video/hdpvr/hdpvr-video.c
@@ -139,7 +139,7 @@ int hdpvr_alloc_buffers(struct hdpvr_device *dev, uint count)
                urb = usb_alloc_urb(0, GFP_KERNEL);
                if (!urb) {
                        v4l2_err(&dev->v4l2_dev, "cannot allocate urb\n");
-                       goto exit;
+                       goto exit_urb;
                }
                buf->urb = urb;
 
@@ -148,7 +148,7 @@ int hdpvr_alloc_buffers(struct hdpvr_device *dev, uint count)
                if (!mem) {
                        v4l2_err(&dev->v4l2_dev,
                                 "cannot allocate usb transfer buffer\n");
-                       goto exit;
+                       goto exit_urb_buffer;
                }
 
                usb_fill_bulk_urb(buf->urb, dev->udev,
@@ -161,6 +161,10 @@ int hdpvr_alloc_buffers(struct hdpvr_device *dev, uint count)
                list_add_tail(&buf->buff_list, &dev->free_buff_list);
        }
        return 0;
+exit_urb_buffer:
+       usb_free_urb(urb);
+exit_urb:
+       kfree(buf);
 exit:
        hdpvr_free_buffers(dev);
        return retval;