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| 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/dvbdev.c | |
| parent | b10fece583fdfdb3d2f29b0da3896ec58b8fe122 (diff) | |
| download | linux-c278850206fd9df0bb62a72ca0b277fe20c5a452.tar.gz linux-c278850206fd9df0bb62a72ca0b277fe20c5a452.tar.bz2 linux-c278850206fd9df0bb62a72ca0b277fe20c5a452.zip | |
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/dvbdev.c')
| -rw-r--r-- | drivers/media/dvb/dvb-core/dvbdev.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/drivers/media/dvb/dvb-core/dvbdev.c b/drivers/media/dvb/dvb-core/dvbdev.c index 490337b5ee3e..14a372a0fe8b 100644 --- a/drivers/media/dvb/dvb-core/dvbdev.c +++ b/drivers/media/dvb/dvb-core/dvbdev.c @@ -203,8 +203,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev, int id; - if (mutex_lock_interruptible(&dvbdev_register_lock)) - return -ERESTARTSYS; + mutex_lock(&dvbdev_register_lock); if ((id = dvbdev_get_free_id (adap, type)) < 0){ mutex_unlock(&dvbdev_register_lock); @@ -294,8 +293,7 @@ int dvb_register_adapter(struct dvb_adapter *adap, const char *name, struct modu { int num; - if (mutex_lock_interruptible(&dvbdev_register_lock)) - return -ERESTARTSYS; + mutex_lock(&dvbdev_register_lock); if ((num = dvbdev_get_free_adapter_num ()) < 0) { mutex_unlock(&dvbdev_register_lock); @@ -323,8 +321,7 @@ EXPORT_SYMBOL(dvb_register_adapter); int dvb_unregister_adapter(struct dvb_adapter *adap) { - if (mutex_lock_interruptible(&dvbdev_register_lock)) - return -ERESTARTSYS; + mutex_lock(&dvbdev_register_lock); list_del (&adap->list_head); mutex_unlock(&dvbdev_register_lock); return 0; |