diff options
| author | Hans Verkuil <hansverk@cisco.com> | 2018-05-11 05:32:24 -0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab+samsung@kernel.org> | 2018-05-28 16:31:44 -0400 |
| commit | 73a110623e7b7592defea69f028cccae495d69a4 (patch) | |
| tree | 9b1c21779d0317c9d18715cb9ce7197e8f2e0117 /drivers/media/v4l2-core/v4l2-subdev.c | |
| parent | eba09b5b3dfb1b79db4428b6f379f68db4b62056 (diff) | |
media: v4l2-core: push taking ioctl mutex down to ioctl handler
The ioctl serialization mutex (vdev->lock or q->lock for vb2 queues)
was taken at the highest level in v4l2-dev.c. This prevents more
fine-grained locking since at that level we cannot examine the ioctl
arguments, we can only do that after video_usercopy is called.
So push the locking down to __video_do_ioctl() and subdev_do_ioctl_lock().
This also allows us to make a few functions in v4l2-ioctl.c static and
video_usercopy() is no longer exported.
The locking scheme is not changed by this patch, just pushed down.
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Diffstat (limited to 'drivers/media/v4l2-core/v4l2-subdev.c')
| -rw-r--r-- | drivers/media/v4l2-core/v4l2-subdev.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c index f9eed938d348..6a7f7f75dfd7 100644 --- a/drivers/media/v4l2-core/v4l2-subdev.c +++ b/drivers/media/v4l2-core/v4l2-subdev.c @@ -502,10 +502,25 @@ static long subdev_do_ioctl(struct file *file, unsigned int cmd, void *arg) return 0; } +static long subdev_do_ioctl_lock(struct file *file, unsigned int cmd, void *arg) +{ + struct video_device *vdev = video_devdata(file); + struct mutex *lock = vdev->lock; + long ret = -ENODEV; + + if (lock && mutex_lock_interruptible(lock)) + return -ERESTARTSYS; + if (video_is_registered(vdev)) + ret = subdev_do_ioctl(file, cmd, arg); + if (lock) + mutex_unlock(lock); + return ret; +} + static long subdev_ioctl(struct file *file, unsigned int cmd, unsigned long arg) { - return video_usercopy(file, cmd, arg, subdev_do_ioctl); + return video_usercopy(file, cmd, arg, subdev_do_ioctl_lock); } #ifdef CONFIG_COMPAT |