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authorHans Verkuil <hansverk@cisco.com>2018-05-11 12:32:24 +0300
committerMauro Carvalho Chehab <mchehab+samsung@kernel.org>2018-05-28 23:31:44 +0300
commit73a110623e7b7592defea69f028cccae495d69a4 (patch)
tree9b1c21779d0317c9d18715cb9ce7197e8f2e0117 /drivers/media
parenteba09b5b3dfb1b79db4428b6f379f68db4b62056 (diff)
downloadlinux-73a110623e7b7592defea69f028cccae495d69a4.tar.xz
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')
-rw-r--r--drivers/media/v4l2-core/v4l2-dev.c6
-rw-r--r--drivers/media/v4l2-core/v4l2-ioctl.c20
-rw-r--r--drivers/media/v4l2-core/v4l2-subdev.c17
3 files changed, 33 insertions, 10 deletions
diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
index c4f4357e9ca4..4ffd7d60a901 100644
--- a/drivers/media/v4l2-core/v4l2-dev.c
+++ b/drivers/media/v4l2-core/v4l2-dev.c
@@ -360,14 +360,8 @@ static long v4l2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
int ret = -ENODEV;
if (vdev->fops->unlocked_ioctl) {
- struct mutex *lock = v4l2_ioctl_get_lock(vdev, cmd);
-
- if (lock && mutex_lock_interruptible(lock))
- return -ERESTARTSYS;
if (video_is_registered(vdev))
ret = vdev->fops->unlocked_ioctl(filp, cmd, arg);
- if (lock)
- mutex_unlock(lock);
} else
ret = -ENOTTY;
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index c23fbfe90a9e..965fd301f617 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -2655,14 +2655,15 @@ static struct v4l2_ioctl_info v4l2_ioctls[] = {
};
#define V4L2_IOCTLS ARRAY_SIZE(v4l2_ioctls)
-bool v4l2_is_known_ioctl(unsigned int cmd)
+static bool v4l2_is_known_ioctl(unsigned int cmd)
{
if (_IOC_NR(cmd) >= V4L2_IOCTLS)
return false;
return v4l2_ioctls[_IOC_NR(cmd)].ioctl == cmd;
}
-struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev, unsigned cmd)
+static struct mutex *v4l2_ioctl_get_lock(struct video_device *vdev,
+ unsigned int cmd)
{
if (_IOC_NR(cmd) >= V4L2_IOCTLS)
return vdev->lock;
@@ -2713,6 +2714,7 @@ static long __video_do_ioctl(struct file *file,
unsigned int cmd, void *arg)
{
struct video_device *vfd = video_devdata(file);
+ struct mutex *lock; /* ioctl serialization mutex */
const struct v4l2_ioctl_ops *ops = vfd->ioctl_ops;
bool write_only = false;
struct v4l2_ioctl_info default_info;
@@ -2731,6 +2733,16 @@ static long __video_do_ioctl(struct file *file,
if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags))
vfh = file->private_data;
+ lock = v4l2_ioctl_get_lock(vfd, cmd);
+
+ if (lock && mutex_lock_interruptible(lock))
+ return -ERESTARTSYS;
+
+ if (!video_is_registered(vfd)) {
+ ret = -ENODEV;
+ goto unlock;
+ }
+
if (v4l2_is_known_ioctl(cmd)) {
info = &v4l2_ioctls[_IOC_NR(cmd)];
@@ -2780,6 +2792,9 @@ done:
}
}
+unlock:
+ if (lock)
+ mutex_unlock(lock);
return ret;
}
@@ -2969,7 +2984,6 @@ out:
kvfree(mbuf);
return err;
}
-EXPORT_SYMBOL(video_usercopy);
long video_ioctl2(struct file *file,
unsigned int cmd, unsigned long arg)
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