V4L/DVB (7491): vivi: make vivi openable only once
vivi currently doesn't have the infrastructure to handle being opened more than
one time and will crash if it is. So, make it openable only once.
Signed-off-by: Brandon Philips <bphilips@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c
index 0e62317..02a2327 100644
--- a/drivers/media/video/vivi.c
+++ b/drivers/media/video/vivi.c
@@ -164,6 +164,7 @@
struct mutex lock;
spinlock_t slock;
+ struct mutex mutex;
int users;
@@ -1036,6 +1037,7 @@
struct vivi_dev *dev;
struct vivi_fh *fh;
int i;
+ int retval = 0;
printk(KERN_DEBUG "vivi: open called (minor=%d)\n", minor);
@@ -1045,9 +1047,15 @@
return -ENODEV;
found:
- /* If more than one user, mutex should be added */
+ mutex_lock(&dev->mutex);
dev->users++;
+ if (dev->users > 1) {
+ dev->users--;
+ retval = -EBUSY;
+ goto unlock;
+ }
+
dprintk(dev, 1, "open minor=%d type=%s users=%d\n", minor,
v4l2_type_names[V4L2_BUF_TYPE_VIDEO_CAPTURE], dev->users);
@@ -1055,8 +1063,13 @@
fh = kzalloc(sizeof(*fh), GFP_KERNEL);
if (NULL == fh) {
dev->users--;
- return -ENOMEM;
+ retval = -ENOMEM;
+ goto unlock;
}
+unlock:
+ mutex_unlock(&dev->mutex);
+ if (retval)
+ return retval;
file->private_data = fh;
fh->dev = dev;
@@ -1128,7 +1141,9 @@
kfree(fh);
+ mutex_lock(&dev->mutex);
dev->users--;
+ mutex_unlock(&dev->mutex);
dprintk(dev, 1, "close called (minor=%d, users=%d)\n",
minor, dev->users);
@@ -1243,6 +1258,7 @@
/* initialize locks */
mutex_init(&dev->lock);
spin_lock_init(&dev->slock);
+ mutex_init(&dev->mutex);
dev->vidq.timeout.function = vivi_vid_timeout;
dev->vidq.timeout.data = (unsigned long)dev;