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| author | Arjan van de Ven <arjan@linux.intel.com> | 2008-05-20 09:53:52 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-05-20 10:12:26 -0700 |
| commit | 81b2dbcad86732ffc02bad87aa25c4651199fc77 (patch) | |
| tree | 6c956c561fbaaa7e04ef612695bf5d3d0b5faef2 /drivers/media | |
| parent | babd90b274e6b43a7dc7bb08562bf566cbabdbf8 (diff) | |
| download | linux-81b2dbcad86732ffc02bad87aa25c4651199fc77.tar.gz linux-81b2dbcad86732ffc02bad87aa25c4651199fc77.tar.bz2 linux-81b2dbcad86732ffc02bad87aa25c4651199fc77.zip | |
Fix a deadlock in the bttv driver
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>
Diffstat (limited to 'drivers/media')
| -rw-r--r-- | drivers/media/video/bt8xx/bttv-driver.c | 2 | ||||
| -rw-r--r-- | drivers/media/video/videobuf-core.c | 3 |
2 files changed, 3 insertions, 2 deletions
diff --git a/drivers/media/video/bt8xx/bttv-driver.c b/drivers/media/video/bt8xx/bttv-driver.c index 2ca3e9cfb2bb..0165aac533bf 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 982f4463896c..0a88c44ace00 100644 --- a/drivers/media/video/videobuf-core.c +++ b/drivers/media/video/videobuf-core.c @@ -331,7 +331,7 @@ 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) { @@ -1129,6 +1129,7 @@ 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); |