diff options
| author | Hans Verkuil <hverkuil@xs4all.nl> | 2014-08-25 15:57:59 +0400 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2014-09-22 03:12:49 +0400 |
| commit | 12561ad622de254d69ec1baaf6734afc602a2c30 (patch) | |
| tree | 32c93ebb4cf508eaf4fe1b19a26379b683fdcd34 /drivers/media/v4l2-core | |
| parent | 825fd08dbbd830b3f42e0f014f4c9f6eba5c434c (diff) | |
| download | linux-12561ad622de254d69ec1baaf6734afc602a2c30.tar.xz | |
[media] videobuf2-core: take mmap_sem before calling __qbuf_userptr
(Changes since v2: dropped local variable as suggested by Laurent)
Commit f035eb4e976ef5a059e30bc91cfd310ff030a7d3 (videobuf2: fix lockdep warning)
unfortunately removed the mmap_sem lock that is needed around the call to
__qbuf_userptr. Amazingly nobody noticed this (especially me as the author)
until Jan Kara pointed this out to me.
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Jan Kara <jack@suse.cz>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'drivers/media/v4l2-core')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-core.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c index 7e6aff673a5a..15b02f940ced 100644 --- a/drivers/media/v4l2-core/videobuf2-core.c +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -1627,7 +1627,9 @@ static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) ret = __qbuf_mmap(vb, b); break; case V4L2_MEMORY_USERPTR: + down_read(¤t->mm->mmap_sem); ret = __qbuf_userptr(vb, b); + up_read(¤t->mm->mmap_sem); break; case V4L2_MEMORY_DMABUF: ret = __qbuf_dmabuf(vb, b); |