Hi Hans,
On Tuesday 06 August 2013 12:39:27 Hans Verkuil wrote:
> On Mon 5 August 2013 19:53:23 Laurent Pinchart wrote:
> > The vb2_fop_mmap() function is a plug-in implementation of the mmap()
> > file operation that calls vb2_mmap() on the queue associated with the
> > video device. Neither the vb2_fop_mmap() function nor the v4l2_mmap()
> > mmap handler in the V4L2 core take any lock, leading to race conditions
> > between mmap() and other buffer-related ioctls such as VIDIOC_REQBUFS.
> >
> > Fix it by taking the queue or device lock around the vb2_mmap() call.
>
> Hi Laurent,
>
> Can you do the same for vb2_fop_get_unmapped_area()?
Sure. I'll repost a v7 of this patch that fixes both mmap and
get_unmapped_area.
> > Signed-off-by: Laurent Pinchart
> > <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
> > ---
> >
> > drivers/media/v4l2-core/videobuf2-core.c | 9 ++++++++-
> > 1 file changed, 8 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/media/v4l2-core/videobuf2-core.c
> > b/drivers/media/v4l2-core/videobuf2-core.c index 9fc4bab..bd4bade 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);
--
Regards,
Laurent Pinchart
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