From: Andy Walls <awalls@md.metrocast.net>
To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Ezequiel Garcia <elezegarcia@gmail.com>
Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
Julia.Lawall@lip6.fr, kernel-janitors@vger.kernel.org,
Peter Senna Tschudin <peter.senna@gmail.com>
Subject: Re: [PATCH 01/23] uvc: Replace memcpy with struct assignment
Date: Wed, 24 Oct 2012 19:10:45 -0400 [thread overview]
Message-ID: <e8dd9233-589d-4e57-8a58-593789c8eae1@email.android.com> (raw)
In-Reply-To: <2776796.95QghSKdPW@avalon>
Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote:
>Hi Ezequiel,
>
>Thanks for the patch.
>
>On Tuesday 23 October 2012 16:57:04 Ezequiel Garcia 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.
>
>This looks good, but there's one more memcpy that can be replaced by a
>direct
>structure assignment in uvc_ctrl_add_info()
>(drivers/media/usb/uvc/uvc_ctrl.c). You might want to check why it
>hasn't been
>caught by the semantic patch.
>
>> 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. */
>
>--
>Regards,
>
>Laurent Pinchart
>
>--
>To unsubscribe from this list: send the line "unsubscribe linux-media"
>in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html
Maybe because there is no '&' operator on the second argument.
Regards,
Andy
next prev parent reply other threads:[~2012-10-24 23:10 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-23 19:57 [PATCH 01/23] uvc: Replace memcpy with struct assignment Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 02/23] cx231xx: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 03/23] usbvision: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 04/23] sn9c102: " Ezequiel Garcia
2012-10-24 0:50 ` Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 05/23] pwc: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 06/23] pvrusb2: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 07/23] hdpvr: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 08/23] cx25840: " Ezequiel Garcia
2012-10-23 22:20 ` Andy Walls
2012-10-23 19:57 ` [PATCH 09/23] zr36067: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 10/23] dvb-usb/friio-fe: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 11/23] au0828: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 12/23] tuners/xc4000: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 13/23] tuners/xc2028: " Ezequiel Garcia
2012-10-23 22:36 ` Andy Walls
2012-10-23 19:57 ` [PATCH 14/23] tuners/tda18271: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 15/23] ivtv: " Ezequiel Garcia
2012-10-23 22:08 ` Andy Walls
2012-10-24 0:28 ` Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 16/23] cx88: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 17/23] cx23885: " Ezequiel Garcia
2012-10-23 22:16 ` Andy Walls
2012-10-24 0:52 ` Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 18/23] cx18: " Ezequiel Garcia
2012-10-23 22:17 ` Andy Walls
2012-10-23 19:57 ` [PATCH 19/23] bttv: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 20/23] dvb-core: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 21/23] dvb-frontends: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 22/23] radio-wl1273: " Ezequiel Garcia
2012-10-23 19:57 ` [PATCH 23/23] wl128x: " Ezequiel Garcia
2012-10-24 22:35 ` [PATCH 01/23] uvc: " Laurent Pinchart
2012-10-24 23:10 ` Andy Walls [this message]
2012-12-27 21:12 ` Ezequiel Garcia
2012-12-27 23:49 ` Mauro Carvalho Chehab
2013-01-10 0:19 ` Laurent Pinchart
2013-01-12 17:44 ` Ezequiel Garcia
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