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authorArjan van de Ven <arjan@linux.intel.com>2008-05-20 09:53:52 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-05-20 10:12:26 -0700
commit81b2dbcad86732ffc02bad87aa25c4651199fc77 (patch)
tree6c956c561fbaaa7e04ef612695bf5d3d0b5faef2 /drivers
parentbabd90b274e6b43a7dc7bb08562bf566cbabdbf8 (diff)
downloadlinux-81b2dbcad86732ffc02bad87aa25c4651199fc77.tar.bz2
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')
-rw-r--r--drivers/media/video/bt8xx/bttv-driver.c2
-rw-r--r--drivers/media/video/videobuf-core.c3
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);