lkml.org 
[lkml]   [2012]   [Dec]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH 01/23] uvc: Replace memcpy with struct assignment
From
Mauro,

On Tue, Oct 23, 2012 at 4:57 PM, Ezequiel Garcia <elezegarcia@gmail.com> wrote:
> This kind of memcpy() is error-prone. Its replacement with a struct
> assignment is prefered because it's type-safe and much easier to read.
>
> Found by coccinelle. Hand patched and reviewed.
> Tested by compilation only.
>
> A simplified version of the semantic match that finds this problem is as
> follows: (http://coccinelle.lip6.fr/)
>
> // <smpl>
> @@
> identifier struct_name;
> struct struct_name to;
> struct struct_name from;
> expression E;
> @@
> -memcpy(&(to), &(from), E);
> +to = from;
> // </smpl>
>
> Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
> Signed-off-by: Ezequiel Garcia <elezegarcia@gmail.com>
> ---
> drivers/media/usb/uvc/uvc_v4l2.c | 6 +++---
> 1 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
> index f00db30..4fc8737 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -314,7 +314,7 @@ static int uvc_v4l2_set_format(struct uvc_streaming *stream,
> goto done;
> }
>
> - memcpy(&stream->ctrl, &probe, sizeof probe);
> + stream->ctrl = probe;
> stream->cur_format = format;
> stream->cur_frame = frame;
>
> @@ -386,7 +386,7 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
> return -EBUSY;
> }
>
> - memcpy(&probe, &stream->ctrl, sizeof probe);
> + probe = stream->ctrl;
> probe.dwFrameInterval =
> uvc_try_frame_interval(stream->cur_frame, interval);
>
> @@ -397,7 +397,7 @@ static int uvc_v4l2_set_streamparm(struct uvc_streaming *stream,
> return ret;
> }
>
> - memcpy(&stream->ctrl, &probe, sizeof probe);
> + stream->ctrl = probe;
> mutex_unlock(&stream->mutex);
>
> /* Return the actual frame period. */
> --
> 1.7.4.4
>

It seems you've marked this one as "Changes requested" [1].
However, Laurent didn't request any change,
but just pointed out we missed one memcpy replacement candidate.

I believe it's safe to apply the patch (together with the other 20 patches)
and we can fix the missing spot in another patch.

Thanks,

--
Ezequiel

[1] http://patchwork.linuxtv.org/patch/15142/


\
 
 \ /
  Last update: 2012-12-27 23:01    [W:1.662 / U:0.012 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site