The patch titled
dvb-core: fix several locking related problems
has been removed from the -mm tree. Its filename was
dvb-core-fix-several-locking-related-problems.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
Subject: dvb-core: fix several locking related problems
From: Simon Arlott <simon@xxxxxxxxxxx>
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@xxxxxxxxxxx>
Cc: Andreas Oberritter <obi@xxxxxxxxxxx>
Cc: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxx>a
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/media/dvb/dvb-core/dmxdev.c | 12 +++---------
drivers/media/dvb/dvb-core/dvb_demux.c | 21 +++++++--------------
drivers/media/dvb/dvb-core/dvbdev.c | 9 +++------
3 files changed, 13 insertions(+), 29 deletions(-)
diff -puN drivers/media/dvb/dvb-core/dmxdev.c~dvb-core-fix-several-locking-related-problems drivers/media/dvb/dvb-core/dmxdev.c
--- a/drivers/media/dvb/dvb-core/dmxdev.c~dvb-core-fix-several-locking-related-problems
+++ a/drivers/media/dvb/dvb-core/dmxdev.c
@@ -180,8 +180,7 @@ static int dvb_dvr_release(struct inode
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 *
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);
diff -puN drivers/media/dvb/dvb-core/dvb_demux.c~dvb-core-fix-several-locking-related-problems drivers/media/dvb/dvb-core/dvb_demux.c
--- a/drivers/media/dvb/dvb-core/dvb_demux.c~dvb-core-fix-several-locking-related-problems
+++ a/drivers/media/dvb/dvb-core/dvb_demux.c
@@ -673,8 +673,7 @@ static int dmx_ts_feed_stop_filtering(st
struct dvb_demux *demux = feed->demux;
int ret;
- if (mutex_lock_interruptible(&demux->mutex))
- return -ERESTARTSYS;
+ mutex_lock(&demux->mutex);
if (feed->state < DMX_STATE_GO) {
mutex_unlock(&demux->mutex);
@@ -748,8 +747,7 @@ static int dvbdmx_release_ts_feed(struct
struct dvb_demux *demux = (struct dvb_demux *)dmx;
struct dvb_demux_feed *feed = (struct dvb_demux_feed *)ts_feed;
- if (mutex_lock_interruptible(&demux->mutex))
- return -ERESTARTSYS;
+ mutex_lock(&demux->mutex);
if (feed->state == DMX_STATE_FREE) {
mutex_unlock(&demux->mutex);
@@ -916,8 +914,7 @@ static int dmx_section_feed_stop_filteri
struct dvb_demux *dvbdmx = dvbdmxfeed->demux;
int ret;
- if (mutex_lock_interruptible(&dvbdmx->mutex))
- return -ERESTARTSYS;
+ mutex_lock(&dvbdmx->mutex);
if (!dvbdmx->stop_feed) {
mutex_unlock(&dvbdmx->mutex);
@@ -942,8 +939,7 @@ static int dmx_section_feed_release_filt
struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
struct dvb_demux *dvbdmx = dvbdmxfeed->demux;
- if (mutex_lock_interruptible(&dvbdmx->mutex))
- return -ERESTARTSYS;
+ mutex_lock(&dvbdmx->mutex);
if (dvbdmxfilter->feed != dvbdmxfeed) {
mutex_unlock(&dvbdmx->mutex);
@@ -1016,8 +1012,7 @@ static int dvbdmx_release_section_feed(s
struct dvb_demux_feed *dvbdmxfeed = (struct dvb_demux_feed *)feed;
struct dvb_demux *dvbdmx = (struct dvb_demux *)demux;
- if (mutex_lock_interruptible(&dvbdmx->mutex))
- return -ERESTARTSYS;
+ mutex_lock(&dvbdmx->mutex);
if (dvbdmxfeed->state == DMX_STATE_FREE) {
mutex_unlock(&dvbdmx->mutex);
@@ -1126,8 +1121,7 @@ static int dvbdmx_connect_frontend(struc
if (demux->frontend)
return -EINVAL;
- if (mutex_lock_interruptible(&dvbdemux->mutex))
- return -ERESTARTSYS;
+ mutex_lock(&dvbdemux->mutex);
demux->frontend = frontend;
mutex_unlock(&dvbdemux->mutex);
@@ -1138,8 +1132,7 @@ static int dvbdmx_disconnect_frontend(st
{
struct dvb_demux *dvbdemux = (struct dvb_demux *)demux;
- if (mutex_lock_interruptible(&dvbdemux->mutex))
- return -ERESTARTSYS;
+ mutex_lock(&dvbdemux->mutex);
demux->frontend = NULL;
mutex_unlock(&dvbdemux->mutex);
diff -puN drivers/media/dvb/dvb-core/dvbdev.c~dvb-core-fix-several-locking-related-problems drivers/media/dvb/dvb-core/dvbdev.c
--- a/drivers/media/dvb/dvb-core/dvbdev.c~dvb-core-fix-several-locking-related-problems
+++ a/drivers/media/dvb/dvb-core/dvbdev.c
@@ -203,8 +203,7 @@ int dvb_register_device(struct dvb_adapt
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_adap
{
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;
_
Patches currently in -mm which might be from simon@xxxxxxxxxxx are
git-dvb.patch
-
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