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| author |   Hans Verkuil <hverkuil@xs4all.nl> | 2016-01-27 10:08:42 -0200 |
|---|---|---|
| committer |   Mauro Carvalho Chehab <mchehab@osg.samsung.com> | 2016-02-04 09:13:46 -0200 |
| commit | fac710e45d0b12443acd4d905c9acec27ab4ca14 (patch) | |
| tree | f2c04c4a2e2fad5dae41bcb05e015a4ea6df2f7e /include | |
| parent | [media] tda1004x: only update the frontend properties if locked (diff) | |
| download | linux-dev-fac710e45d0b12443acd4d905c9acec27ab4ca14.tar.xz linux-dev-fac710e45d0b12443acd4d905c9acec27ab4ca14.zip | |
[media] vb2: fix nasty vb2_thread regression
The vb2_thread implementation was made generic and was moved from
videobuf2-v4l2.c to videobuf2-core.c in commit af3bac1a. Unfortunately
that clearly was never tested since it broke read() causing NULL address
references.
The root cause was confused handling of vb2_buffer vs v4l2_buffer (the pb
pointer in various core functions).
The v4l2_buffer no longer exists after moving the code into the core and
it is no longer needed. However, the vb2_thread code passed a pointer to
a vb2_buffer to the core functions were a v4l2_buffer pointer was expected
and vb2_thread expected that the vb2_buffer fields would be filled in
correctly.
This is obviously wrong since v4l2_buffer != vb2_buffer. Note that the
pb pointer is a void pointer, so no type-checking took place.
This patch fixes this problem:
1) allow pb to be NULL for vb2_core_(d)qbuf. The vb2_thread code will use
a NULL pointer here since they don't care about v4l2_buffer anyway.
2) let vb2_core_dqbuf pass back the index of the received buffer. This is
all vb2_thread needs: this index is the index into the q->bufs array
and vb2_thread just gets the vb2_buffer from there.
3) the fileio->b pointer (that originally contained a v4l2_buffer) is
removed altogether since it is no longer needed.
Tested with vivid and the cobalt driver.
Cc: stable@vger.kernel.org # Kernel >= 4.3
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Matthias Schwarzott <zzam@gentoo.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/media/videobuf2-core.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index ef03ae56b1c1..8a0f55b6c2ba 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -533,7 +533,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, const unsigned int requested_sizes[]); int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb); int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb); -int vb2_core_dqbuf(struct vb2_queue *q, void *pb, bool nonblocking); +int vb2_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, + bool nonblocking); int vb2_core_streamon(struct vb2_queue *q, unsigned int type); int vb2_core_streamoff(struct vb2_queue *q, unsigned int type); |