V4L/DVB (13012): uvc: introduce missing kfree
Julia Lawall [Fri, 18 Sep 2009 02:44:01 +0000 (23:44 -0300)]
Move the kzalloc and associated test after the stream/query test, to avoid
the need to free the allocated if the stream/query test fails.

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@diku.dk>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Douglas Schilling Landgraf <dougsland@redhat.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/uvc/uvc_video.c

index 5b757f3..f960e8e 100644 (file)
@@ -124,13 +124,14 @@ static int uvc_get_video_ctrl(struct uvc_streaming *stream,
        int ret;
 
        size = stream->dev->uvc_version >= 0x0110 ? 34 : 26;
+       if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) &&
+                       query == UVC_GET_DEF)
+               return -EIO;
+
        data = kmalloc(size, GFP_KERNEL);
        if (data == NULL)
                return -ENOMEM;
 
-       if ((stream->dev->quirks & UVC_QUIRK_PROBE_DEF) && query == UVC_GET_DEF)
-               return -EIO;
-
        ret = __uvc_query_ctrl(stream->dev, query, 0, stream->intfnum,
                probe ? UVC_VS_PROBE_CONTROL : UVC_VS_COMMIT_CONTROL, data,
                size, UVC_CTRL_STREAMING_TIMEOUT);