Re: [PATCH 2/8] drivers/media/video/uvc: introduce missing kfree

From: Laurent Pinchart
Date: Tue Sep 15 2009 - 05:57:39 EST


On Tuesday 15 September 2009 11:54:36 Julia Lawall wrote:
> From: Julia Lawall <julia@xxxxxxx>
>
> 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@xxxxxxx>

Acked-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>

I'll apply and submit a pull request.

Thanks for the patch.

> ---
> drivers/media/video/uvc/uvc_video.c | 6 +++---
> 1 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/video/uvc/uvc_video.c
> b/drivers/media/video/uvc/uvc_video.c index 5b757f3..2f2971a 100644
> --- a/drivers/media/video/uvc/uvc_video.c
> +++ b/drivers/media/video/uvc/uvc_video.c
> @@ -124,13 +124,13 @@ 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);
>

--
Laurent Pinchart
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/