diff options
| author | Arjan van de Ven <arjan@linux.intel.com> | 2008-05-20 09:53:52 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2008-06-16 13:20:06 -0700 |
| commit | 69f24455cf25d776f8b19d06c7a43a8185fc633d (patch) | |
| tree | 6bc8f3832dfe5274bbc1c7ff51aed893f119e255 | |
| parent | c7559a1531958785bdc25363f8cde154011c0f9d (diff) | |
bttv: Fix a deadlock in the bttv driver
commit 81b2dbcad86732ffc02bad87aa25c4651199fc77 in mainline.
vidiocgmbuf() does this:
mutex_lock(&fh->cap.vb_lock);
retval = videobuf_mmap_setup(&fh->cap, gbuffers, gbufsize,
V4L2_MEMORY_MMAP);
and videobuf_mmap_setup() then just does
mutex_lock(&q->vb_lock);
ret = __videobuf_mmap_setup(q, bcount, bsize, memory);
mutex_unlock(&q->vb_lock);
which is an obvious double-take deadlock.
This patch fixes this by having vidiocgmbuf() just call the
__videobuf_mmap_setup function instead.
Acked-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Reported-by: Koos Vriezen <koos.vriezen@gmail.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | drivers/media/video/bt8xx/bttv-driver.c | 2 | ||||
| -rw-r--r-- | drivers/media/video/videobuf-core.c | 3 | ||||
| -rw-r--r-- | include/media/videobuf-core.h | 3 |
3 files changed, 6 insertions, 2 deletions
diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c index fcf8f2d208a..594522a155e 100644 --- a/drivers/media/video/bt8xx/bttv-driver.c +++ b/drivers/media/video/bt8xx/bttv-driver.c @@ -2613,7 +2613,7 @@ static int vidiocgmbuf(struct file *file, void *priv, struct video_mbuf *mbuf) struct bttv_fh *fh = priv; mutex_lock(&fh->cap.vb_lock); - retval = videobuf_mmap_setup(&fh->cap, gbuffers, gbufsize, + retval = __videobuf_mmap_setup(&fh->cap, gbuffers, gbufsize, V4L2_MEMORY_MMAP); if (retval < 0) { mutex_unlock(&fh->cap.vb_lock); diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c index eab79ffdf56..57a9de4b041 100644 --- a/drivers/media/video/videobuf-core.c +++ b/drivers/media/video/videobuf-core.c @@ -335,7 +335,7 @@ int videobuf_mmap_free(struct videobuf_queue *q) } /* Locking: Caller holds q->vb_lock */ -static int __videobuf_mmap_setup(struct videobuf_queue *q, +int __videobuf_mmap_setup(struct videobuf_queue *q, unsigned int bcount, unsigned int bsize, enum v4l2_memory memory) { @@ -1093,6 +1093,7 @@ EXPORT_SYMBOL_GPL(videobuf_read_stream); EXPORT_SYMBOL_GPL(videobuf_read_one); EXPORT_SYMBOL_GPL(videobuf_poll_stream); +EXPORT_SYMBOL_GPL(__videobuf_mmap_setup); EXPORT_SYMBOL_GPL(videobuf_mmap_setup); EXPORT_SYMBOL_GPL(videobuf_mmap_free); EXPORT_SYMBOL_GPL(videobuf_mmap_mapper); diff --git a/include/media/videobuf-core.h b/include/media/videobuf-core.h index 99033945cde..75527313760 100644 --- a/include/media/videobuf-core.h +++ b/include/media/videobuf-core.h @@ -227,6 +227,9 @@ unsigned int videobuf_poll_stream(struct file *file, int videobuf_mmap_setup(struct videobuf_queue *q, unsigned int bcount, unsigned int bsize, enum v4l2_memory memory); +int __videobuf_mmap_setup(struct videobuf_queue *q, + unsigned int bcount, unsigned int bsize, + enum v4l2_memory memory); int videobuf_mmap_free(struct videobuf_queue *q); int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma); |