From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail00d.mail.t-online.hu ([84.2.42.5]:55534 "EHLO mail00d.mail.t-online.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751230AbZDZE4Z (ORCPT ); Sun, 26 Apr 2009 00:56:25 -0400 Message-ID: <49F3E951.30607@freemail.hu> Date: Sun, 26 Apr 2009 06:55:45 +0200 From: =?UTF-8?B?TsOpbWV0aCBNw6FydG9u?= MIME-Version: 1.0 To: Trent Piepho CC: Mauro Carvalho Chehab , linux-media@vger.kernel.org, LKML Subject: Re: [PATCH] v4l2: fill the unused fields with zeros in case of VIDIOC_S_FMT References: <49F2C59A.9010703@freemail.hu> <49F3E917.70604@freemail.hu> In-Reply-To: <49F3E917.70604@freemail.hu> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org List-ID: The VIDIOC_S_FMT is a write-read ioctl: it sets the format and returns the current format in case of success. The parameter of VIDIOC_S_FMT ioctl is a pointer to struct v4l2_format. [1] This structure contains a fmt union so there are some padding bytes which are not used depending on the .type value. These unused bytes are filled with zeros with this patch. The patch was tested with v4l-test 0.12 [2] with vivi and with gspca_sunplus driver together with Trust 610 LCD POWERC@M ZOOM. References: [1] V4L2 API specification, revision 0.24 http://v4l2spec.bytesex.org/spec/r10944.htm [2] v4l-test: Test environment for Video For Linux Two API http://v4l-test.sourceforge.net/ Signed-off-by: Márton Németh --- --- linux/drivers/media/video/v4l2-ioctl.c.orig 2009-04-22 05:07:00.000000000 +0200 +++ linux/drivers/media/video/v4l2-ioctl.c 2009-04-26 06:29:20.000000000 +0200 @@ -777,44 +777,61 @@ static long __video_do_ioctl(struct file { struct v4l2_format *f = (struct v4l2_format *)arg; +#define CLEAR_UNUSED_FIELDS(data, last_member) \ + memset(((u8 *)data)+ \ + offsetof(struct v4l2_format, fmt)+ \ + sizeof(struct v4l2_ ## last_member), \ + 0, \ + sizeof(*(data))- \ + (offsetof(struct v4l2_format, fmt)+ \ + sizeof(struct v4l2_ ## last_member))) + /* FIXME: Should be one dump per type */ dbgarg(cmd, "type=%s\n", prt_names(f->type, v4l2_type_names)); switch (f->type) { case V4L2_BUF_TYPE_VIDEO_CAPTURE: + CLEAR_UNUSED_FIELDS(f, pix_format); v4l_print_pix_fmt(vfd, &f->fmt.pix); if (ops->vidioc_s_fmt_vid_cap) ret = ops->vidioc_s_fmt_vid_cap(file, fh, f); break; case V4L2_BUF_TYPE_VIDEO_OVERLAY: + CLEAR_UNUSED_FIELDS(f, window); if (ops->vidioc_s_fmt_vid_overlay) ret = ops->vidioc_s_fmt_vid_overlay(file, fh, f); break; case V4L2_BUF_TYPE_VIDEO_OUTPUT: + CLEAR_UNUSED_FIELDS(f, pix_format); v4l_print_pix_fmt(vfd, &f->fmt.pix); if (ops->vidioc_s_fmt_vid_out) ret = ops->vidioc_s_fmt_vid_out(file, fh, f); break; case V4L2_BUF_TYPE_VIDEO_OUTPUT_OVERLAY: + CLEAR_UNUSED_FIELDS(f, window); if (ops->vidioc_s_fmt_vid_out_overlay) ret = ops->vidioc_s_fmt_vid_out_overlay(file, fh, f); break; case V4L2_BUF_TYPE_VBI_CAPTURE: + CLEAR_UNUSED_FIELDS(f, vbi_format); if (ops->vidioc_s_fmt_vbi_cap) ret = ops->vidioc_s_fmt_vbi_cap(file, fh, f); break; case V4L2_BUF_TYPE_VBI_OUTPUT: + CLEAR_UNUSED_FIELDS(f, vbi_format); if (ops->vidioc_s_fmt_vbi_out) ret = ops->vidioc_s_fmt_vbi_out(file, fh, f); break; case V4L2_BUF_TYPE_SLICED_VBI_CAPTURE: + CLEAR_UNUSED_FIELDS(f, sliced_vbi_format); if (ops->vidioc_s_fmt_sliced_vbi_cap) ret = ops->vidioc_s_fmt_sliced_vbi_cap(file, fh, f); break; case V4L2_BUF_TYPE_SLICED_VBI_OUTPUT: + CLEAR_UNUSED_FIELDS(f, sliced_vbi_format); if (ops->vidioc_s_fmt_sliced_vbi_out) ret = ops->vidioc_s_fmt_sliced_vbi_out(file, fh, f);