diff options
| author | Mauro Carvalho Chehab <mchehab@infradead.org> | 2007-03-10 07:21:25 -0200 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@infradead.org> | 2007-03-10 07:21:25 -0200 |
| commit | 941a74c8fd1971768d96e37511be63853fddf0a0 (patch) | |
| tree | f03ec3ae3d43810887617e4d5f3d09edee2f1a45 /linux/drivers/media/dvb/dvb-core/dvbdev.c | |
| parent | b57241d11bd12a147c53051dcd943aef49f905f2 (diff) | |
| download | mediapointer-dvb-s2-941a74c8fd1971768d96e37511be63853fddf0a0.tar.gz mediapointer-dvb-s2-941a74c8fd1971768d96e37511be63853fddf0a0.tar.bz2 | |
Core: fix several locking related problems
From: Simon Arlott <simon@fire.lp0.eu>
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 'linux/drivers/media/dvb/dvb-core/dvbdev.c')
| -rw-r--r-- | linux/drivers/media/dvb/dvb-core/dvbdev.c | 9 |
1 files changed, 3 insertions, 6 deletions
diff --git a/linux/drivers/media/dvb/dvb-core/dvbdev.c b/linux/drivers/media/dvb/dvb-core/dvbdev.c index 5c7512a84..9c8e9c3f4 100644 --- a/linux/drivers/media/dvb/dvb-core/dvbdev.c +++ b/linux/drivers/media/dvb/dvb-core/dvbdev.c @@ -214,8 +214,7 @@ 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); @@ -305,8 +304,7 @@ 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); @@ -334,8 +332,7 @@ 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; |