From fac710e45d0b12443acd4d905c9acec27ab4ca14 Mon Sep 17 00:00:00 2001 From: Hans Verkuil <hverkuil@xs4all.nl> Date: Wed, 27 Jan 2016 10:08:42 -0200 Subject: [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> --- include/media/videobuf2-core.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'include/media') 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); -- cgit v1.2.3-70-g09d2