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Commit 3c135050 authored by Hans Verkuil's avatar Hans Verkuil Committed by Mauro Carvalho Chehab
Browse files

media: v4l2-dev/ioctl: require non-zero device_caps, verify sane querycap results 



Now that all V4L2 drivers set device_caps in struct video_device, we can add
a check for this to ensure all future drivers fill this in.

Also verify that when the querycap ioctl is called the driver didn't mess
with the device_caps value and that capabilities is a superset of device_caps.

Signed-off-by: default avatarHans Verkuil <hverkuil-cisco@xs4all.nl>
Reviewed-by: default avatarSakari Ailus <sakari.ailus@linux.intel.com>
[hverkuil-cisco@xs4all.nl: fix too-long line]
Signed-off-by: default avatarMauro Carvalho Chehab <mchehab+samsung@kernel.org>
parent 08aac0e3

drivers/media/v4l2-core/v4l2-dev.c

+3 −0
Original line number Diff line number Diff line
@@ -859,6 +859,9 @@ int __video_register_device(struct video_device *vdev, 
	/* the v4l2_dev pointer MUST be present */

	if (WARN_ON(!vdev->v4l2_dev))

		return -EINVAL;

	/* the device_caps field MUST be set */

	if (WARN_ON(!vdev->device_caps))

		return -EINVAL;



	/* v4l2_fh support */

	spin_lock_init(&vdev->fh_lock);

drivers/media/v4l2-core/v4l2-ioctl.c

+11 −6
Original line number Diff line number Diff line
@@ -1057,14 +1057,19 @@ static int v4l_querycap(const struct v4l2_ioctl_ops *ops, 


	ret = ops->vidioc_querycap(file, fh, cap);



	cap->capabilities |= V4L2_CAP_EXT_PIX_FORMAT;

	/*

	 * Drivers MUST fill in device_caps, so check for this and

	 * warn if it was forgotten.

	 * Drivers must not change device_caps, so check for this and

	 * warn if this happened.

	 */

	WARN_ON(cap->device_caps != vfd->device_caps);

	/*

	 * Check that capabilities is a superset of

	 * vfd->device_caps | V4L2_CAP_DEVICE_CAPS

	 */

	WARN(!(cap->capabilities & V4L2_CAP_DEVICE_CAPS) ||

		!cap->device_caps, "Bad caps for driver %s, %x %x",

		cap->driver, cap->capabilities, cap->device_caps);

	WARN_ON((cap->capabilities &

		 (vfd->device_caps | V4L2_CAP_DEVICE_CAPS)) !=

		(vfd->device_caps | V4L2_CAP_DEVICE_CAPS));

	cap->capabilities |= V4L2_CAP_EXT_PIX_FORMAT;

	cap->device_caps |= V4L2_CAP_EXT_PIX_FORMAT;



	return ret;