diff options
| author | Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com> | 2013-08-02 20:55:21 +0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <m.chehab@samsung.com> | 2013-08-18 14:22:07 +0400 |
| commit | 8a90f1a61c9b31bd0c89b8456fa4dce91ad69c57 (patch) | |
| tree | 04e4cb64f0f3213d2e0102ad7a7be4546c781090 | |
| parent | 5548a382508f1f76320e1ed55524dda73234299d (diff) | |
| download | linux-8a90f1a61c9b31bd0c89b8456fa4dce91ad69c57.tar.xz | |
[media] media: vb2: Take queue or device lock in mmap-related vb2 ioctl handlers
The vb2_fop_mmap() and vb2_fop_get_unmapped_area() functions are plug-in
implementation of the mmap() and get_unmapped_area() file operations
that calls vb2_mmap() and vb2_get_unmapped_area() on the queue
associated with the video device. Neither the
vb2_fop_mmap/vb2_fop_get_unmapped_area nor the
v4l2_mmap/vb2_get_unmapped_area functions in the V4L2 core take any
lock, leading to race conditions between mmap/get_unmapped_area and
other buffer-related ioctls such as VIDIOC_REQBUFS.
Fix it by taking the queue or device lock around the vb2_mmap() and
vb2_get_unmapped_area() calls.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-core.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 9fc4bab2da97..c9b50c7665de 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -2578,8 +2578,15 @@ EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf); int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) { struct video_device *vdev = video_devdata(file); + struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; + int err; - return vb2_mmap(vdev->queue, vma); + if (lock && mutex_lock_interruptible(lock)) + return -ERESTARTSYS; + err = vb2_mmap(vdev->queue, vma); + if (lock) + mutex_unlock(lock); + return err; } EXPORT_SYMBOL_GPL(vb2_fop_mmap); @@ -2685,8 +2692,15 @@ unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct video_device *vdev = video_devdata(file); + struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; + int ret; - return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); + if (lock && mutex_lock_interruptible(lock)) + return -ERESTARTSYS; + ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); + if (lock) + mutex_unlock(lock); + return ret; } EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area); #endif |