diff options
| author | Simon Arlott <simon@fire.lp0.eu> | 2007-03-10 06:21:25 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2007-03-27 08:45:54 -0300 |
| commit | c278850206fd9df0bb62a72ca0b277fe20c5a452 (patch) | |
| tree | 439ae68737b5bcb5d473b3d12c3d5417f697ccb3 /drivers/media/dvb/dvb-core/dmxdev.c | |
| parent | b10fece583fdfdb3d2f29b0da3896ec58b8fe122 (diff) | |
V4L/DVB (5400): Core: fix several locking related problems
Fix several instances of dvb-core functions using mutex_lock_interruptible
and returning -ERESTARTSYS where the calling function will either never
retry or never check the return value.
These cause a race condition with dvb_dmxdev_filter_free and
dvb_dvr_release, both of which are filesystem release functions whose
return value is ignored and will never be retried. When this happens it
becomes impossible to open dvr0 again (-EBUSY) since it has not been
released properly.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-By: Johannes Stezenbach <js@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>
Diffstat (limited to 'drivers/media/dvb/dvb-core/dmxdev.c')
| -rw-r--r-- | drivers/media/dvb/dvb-core/dmxdev.c | 12 |
1 files changed, 3 insertions, 9 deletions
diff --git a/drivers/media/dvb/dvb-core/dmxdev.c b/drivers/media/dvb/dvb-core/dmxdev.c index fc77de45ca4d..a5c0e1a3e6d1 100644 --- a/drivers/media/dvb/dvb-core/dmxdev.c +++ b/drivers/media/dvb/dvb-core/dmxdev.c @@ -180,8 +180,7 @@ static int dvb_dvr_release(struct inode *inode, struct file *file) struct dvb_device *dvbdev = file->private_data; struct dmxdev *dmxdev = dvbdev->priv; - if (mutex_lock_interruptible(&dmxdev->mutex)) - return -ERESTARTSYS; + mutex_lock(&dmxdev->mutex); if ((file->f_flags & O_ACCMODE) == O_WRONLY) { dmxdev->demux->disconnect_frontend(dmxdev->demux); @@ -673,13 +672,8 @@ static int dvb_demux_open(struct inode *inode, struct file *file) static int dvb_dmxdev_filter_free(struct dmxdev *dmxdev, struct dmxdev_filter *dmxdevfilter) { - if (mutex_lock_interruptible(&dmxdev->mutex)) - return -ERESTARTSYS; - - if (mutex_lock_interruptible(&dmxdevfilter->mutex)) { - mutex_unlock(&dmxdev->mutex); - return -ERESTARTSYS; - } + mutex_lock(&dmxdev->mutex); + mutex_lock(&dmxdevfilter->mutex); dvb_dmxdev_filter_stop(dmxdevfilter); dvb_dmxdev_filter_reset(dmxdevfilter); |