| Message ID | 1389593524-1676-1-git-send-email-m.chehab@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Tested-by: Antti Palosaari <crope@iki.fi> regards Antti On 13.01.2014 08:12, Mauro Carvalho Chehab wrote: > Avoid circular mutex lock by pushing the dev->lock to the .fini > callback on each extension. > > As em28xx-dvb, em28xx-alsa and em28xx-rc have their own data > structures, and don't touch at the common structure during .fini, > only em28xx-v4l needs to be locked. > > [ 90.994317] ====================================================== > [ 90.994356] [ INFO: possible circular locking dependency detected ] > [ 90.994395] 3.13.0-rc1+ #24 Not tainted > [ 90.994427] ------------------------------------------------------- > [ 90.994458] khubd/54 is trying to acquire lock: > [ 90.994490] (&card->controls_rwsem){++++.+}, at: [<ffffffffa0177b08>] snd_ctl_dev_free+0x28/0x60 [snd] > [ 90.994656] > [ 90.994656] but task is already holding lock: > [ 90.994688] (&dev->lock){+.+.+.}, at: [<ffffffffa040db81>] em28xx_close_extension+0x31/0x90 [em28xx] > [ 90.994843] > [ 90.994843] which lock already depends on the new lock. > [ 90.994843] > [ 90.994874] > [ 90.994874] the existing dependency chain (in reverse order) is: > [ 90.994905] > -> #1 (&dev->lock){+.+.+.}: > [ 90.995057] [<ffffffff810b8fa3>] __lock_acquire+0xb43/0x1330 > [ 90.995121] [<ffffffff810b9f82>] lock_acquire+0xa2/0x120 > [ 90.995182] [<ffffffff816a5b6c>] mutex_lock_nested+0x5c/0x3c0 > [ 90.995245] [<ffffffffa0422cca>] em28xx_vol_put_mute+0x1ba/0x1d0 [em28xx_alsa] > [ 90.995309] [<ffffffffa017813d>] snd_ctl_elem_write+0xfd/0x140 [snd] > [ 90.995376] [<ffffffffa01791c2>] snd_ctl_ioctl+0xe2/0x810 [snd] > [ 90.995442] [<ffffffff811db8b0>] do_vfs_ioctl+0x300/0x520 > [ 90.995504] [<ffffffff811dbb51>] SyS_ioctl+0x81/0xa0 > [ 90.995568] [<ffffffff816b1929>] system_call_fastpath+0x16/0x1b > [ 90.995630] > -> #0 (&card->controls_rwsem){++++.+}: > [ 90.995780] [<ffffffff810b7a47>] check_prevs_add+0x947/0x950 > [ 90.995841] [<ffffffff810b8fa3>] __lock_acquire+0xb43/0x1330 > [ 90.995901] [<ffffffff810b9f82>] lock_acquire+0xa2/0x120 > [ 90.995962] [<ffffffff816a762b>] down_write+0x3b/0xa0 > [ 90.996022] [<ffffffffa0177b08>] snd_ctl_dev_free+0x28/0x60 [snd] > [ 90.996088] [<ffffffffa017a255>] snd_device_free+0x65/0x140 [snd] > [ 90.996154] [<ffffffffa017a751>] snd_device_free_all+0x61/0xa0 [snd] > [ 90.996219] [<ffffffffa0173af4>] snd_card_do_free+0x14/0x130 [snd] > [ 90.996283] [<ffffffffa0173f14>] snd_card_free+0x84/0x90 [snd] > [ 90.996349] [<ffffffffa0423397>] em28xx_audio_fini+0x97/0xb0 [em28xx_alsa] > [ 90.996411] [<ffffffffa040dba6>] em28xx_close_extension+0x56/0x90 [em28xx] > [ 90.996475] [<ffffffffa040f639>] em28xx_usb_disconnect+0x79/0x90 [em28xx] > [ 90.996539] [<ffffffff814a06e7>] usb_unbind_interface+0x67/0x1d0 > [ 90.996620] [<ffffffff8142920f>] __device_release_driver+0x7f/0xf0 > [ 90.996682] [<ffffffff814292a5>] device_release_driver+0x25/0x40 > [ 90.996742] [<ffffffff81428b0c>] bus_remove_device+0x11c/0x1a0 > [ 90.996801] [<ffffffff81425536>] device_del+0x136/0x1d0 > [ 90.996863] [<ffffffff8149e0c0>] usb_disable_device+0xb0/0x290 > [ 90.996923] [<ffffffff814930c5>] usb_disconnect+0xb5/0x1d0 > [ 90.996984] [<ffffffff81495ab6>] hub_port_connect_change+0xd6/0xad0 > [ 90.997044] [<ffffffff814967c3>] hub_events+0x313/0x9b0 > [ 90.997105] [<ffffffff81496e95>] hub_thread+0x35/0x170 > [ 90.997165] [<ffffffff8108ea2f>] kthread+0xff/0x120 > [ 90.997226] [<ffffffff816b187c>] ret_from_fork+0x7c/0xb0 > [ 90.997287] > [ 90.997287] other info that might help us debug this: > [ 90.997287] > [ 90.997318] Possible unsafe locking scenario: > [ 90.997318] > [ 90.997348] CPU0 CPU1 > [ 90.997378] ---- ---- > [ 90.997408] lock(&dev->lock); > [ 90.997497] lock(&card->controls_rwsem); > [ 90.997607] lock(&dev->lock); > [ 90.997697] lock(&card->controls_rwsem); > [ 90.997786] > [ 90.997786] *** DEADLOCK *** > [ 90.997786] > [ 90.997817] 5 locks held by khubd/54: > [ 90.997847] #0: (&__lockdep_no_validate__){......}, at: [<ffffffff81496564>] hub_events+0xb4/0x9b0 > [ 90.998025] #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81493076>] usb_disconnect+0x66/0x1d0 > [ 90.998204] #2: (&__lockdep_no_validate__){......}, at: [<ffffffff8142929d>] device_release_driver+0x1d/0x40 > [ 90.998383] #3: (em28xx_devlist_mutex){+.+.+.}, at: [<ffffffffa040db77>] em28xx_close_extension+0x27/0x90 [em28xx] > [ 90.998567] #4: (&dev->lock){+.+.+.}, at: [<ffffffffa040db81>] em28xx_close_extension+0x31/0x90 [em28xx] > > Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com> > --- > drivers/media/usb/em28xx/em28xx-core.c | 2 -- > drivers/media/usb/em28xx/em28xx-video.c | 4 ++++ > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c > index b6dc3327c51c..898fb9bd88a2 100644 > --- a/drivers/media/usb/em28xx/em28xx-core.c > +++ b/drivers/media/usb/em28xx/em28xx-core.c > @@ -1099,12 +1099,10 @@ void em28xx_close_extension(struct em28xx *dev) > const struct em28xx_ops *ops = NULL; > > mutex_lock(&em28xx_devlist_mutex); > - mutex_lock(&dev->lock); > list_for_each_entry(ops, &em28xx_extension_devlist, next) { > if (ops->fini) > ops->fini(dev); > } > - mutex_unlock(&dev->lock); > list_del(&dev->devlist); > mutex_unlock(&em28xx_devlist_mutex); > } > diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c > index 004fe12ceec7..258628877951 100644 > --- a/drivers/media/usb/em28xx/em28xx-video.c > +++ b/drivers/media/usb/em28xx/em28xx-video.c > @@ -1896,6 +1896,8 @@ static int em28xx_v4l2_fini(struct em28xx *dev) > > em28xx_info("Disconnecting video extension"); > > + mutex_lock(&dev->lock); > + > v4l2_device_disconnect(&dev->v4l2_dev); > > em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE); > @@ -1924,6 +1926,8 @@ static int em28xx_v4l2_fini(struct em28xx *dev) > v4l2_ctrl_handler_free(&dev->ctrl_handler); > v4l2_device_unregister(&dev->v4l2_dev); > > + mutex_unlock(&dev->lock); > + > kref_put(&dev->ref, em28xx_free_device); > > return 0; >
On 13.01.2014 07:12, Mauro Carvalho Chehab wrote: > Avoid circular mutex lock by pushing the dev->lock to the .fini > callback on each extension. > > As em28xx-dvb, em28xx-alsa and em28xx-rc have their own data > structures, and don't touch at the common structure during .fini, > only em28xx-v4l needs to be locked. > > [ 90.994317] ====================================================== > [ 90.994356] [ INFO: possible circular locking dependency detected ] > [ 90.994395] 3.13.0-rc1+ #24 Not tainted > [ 90.994427] ------------------------------------------------------- > [ 90.994458] khubd/54 is trying to acquire lock: > [ 90.994490] (&card->controls_rwsem){++++.+}, at: [<ffffffffa0177b08>] snd_ctl_dev_free+0x28/0x60 [snd] > [ 90.994656] > [ 90.994656] but task is already holding lock: > [ 90.994688] (&dev->lock){+.+.+.}, at: [<ffffffffa040db81>] em28xx_close_extension+0x31/0x90 [em28xx] > [ 90.994843] > [ 90.994843] which lock already depends on the new lock. > [ 90.994843] > [ 90.994874] > [ 90.994874] the existing dependency chain (in reverse order) is: > [ 90.994905] > -> #1 (&dev->lock){+.+.+.}: > [ 90.995057] [<ffffffff810b8fa3>] __lock_acquire+0xb43/0x1330 > [ 90.995121] [<ffffffff810b9f82>] lock_acquire+0xa2/0x120 > [ 90.995182] [<ffffffff816a5b6c>] mutex_lock_nested+0x5c/0x3c0 > [ 90.995245] [<ffffffffa0422cca>] em28xx_vol_put_mute+0x1ba/0x1d0 [em28xx_alsa] > [ 90.995309] [<ffffffffa017813d>] snd_ctl_elem_write+0xfd/0x140 [snd] > [ 90.995376] [<ffffffffa01791c2>] snd_ctl_ioctl+0xe2/0x810 [snd] > [ 90.995442] [<ffffffff811db8b0>] do_vfs_ioctl+0x300/0x520 > [ 90.995504] [<ffffffff811dbb51>] SyS_ioctl+0x81/0xa0 > [ 90.995568] [<ffffffff816b1929>] system_call_fastpath+0x16/0x1b > [ 90.995630] > -> #0 (&card->controls_rwsem){++++.+}: > [ 90.995780] [<ffffffff810b7a47>] check_prevs_add+0x947/0x950 > [ 90.995841] [<ffffffff810b8fa3>] __lock_acquire+0xb43/0x1330 > [ 90.995901] [<ffffffff810b9f82>] lock_acquire+0xa2/0x120 > [ 90.995962] [<ffffffff816a762b>] down_write+0x3b/0xa0 > [ 90.996022] [<ffffffffa0177b08>] snd_ctl_dev_free+0x28/0x60 [snd] > [ 90.996088] [<ffffffffa017a255>] snd_device_free+0x65/0x140 [snd] > [ 90.996154] [<ffffffffa017a751>] snd_device_free_all+0x61/0xa0 [snd] > [ 90.996219] [<ffffffffa0173af4>] snd_card_do_free+0x14/0x130 [snd] > [ 90.996283] [<ffffffffa0173f14>] snd_card_free+0x84/0x90 [snd] > [ 90.996349] [<ffffffffa0423397>] em28xx_audio_fini+0x97/0xb0 [em28xx_alsa] > [ 90.996411] [<ffffffffa040dba6>] em28xx_close_extension+0x56/0x90 [em28xx] > [ 90.996475] [<ffffffffa040f639>] em28xx_usb_disconnect+0x79/0x90 [em28xx] > [ 90.996539] [<ffffffff814a06e7>] usb_unbind_interface+0x67/0x1d0 > [ 90.996620] [<ffffffff8142920f>] __device_release_driver+0x7f/0xf0 > [ 90.996682] [<ffffffff814292a5>] device_release_driver+0x25/0x40 > [ 90.996742] [<ffffffff81428b0c>] bus_remove_device+0x11c/0x1a0 > [ 90.996801] [<ffffffff81425536>] device_del+0x136/0x1d0 > [ 90.996863] [<ffffffff8149e0c0>] usb_disable_device+0xb0/0x290 > [ 90.996923] [<ffffffff814930c5>] usb_disconnect+0xb5/0x1d0 > [ 90.996984] [<ffffffff81495ab6>] hub_port_connect_change+0xd6/0xad0 > [ 90.997044] [<ffffffff814967c3>] hub_events+0x313/0x9b0 > [ 90.997105] [<ffffffff81496e95>] hub_thread+0x35/0x170 > [ 90.997165] [<ffffffff8108ea2f>] kthread+0xff/0x120 > [ 90.997226] [<ffffffff816b187c>] ret_from_fork+0x7c/0xb0 > [ 90.997287] > [ 90.997287] other info that might help us debug this: > [ 90.997287] > [ 90.997318] Possible unsafe locking scenario: > [ 90.997318] > [ 90.997348] CPU0 CPU1 > [ 90.997378] ---- ---- > [ 90.997408] lock(&dev->lock); > [ 90.997497] lock(&card->controls_rwsem); > [ 90.997607] lock(&dev->lock); > [ 90.997697] lock(&card->controls_rwsem); > [ 90.997786] > [ 90.997786] *** DEADLOCK *** > [ 90.997786] > [ 90.997817] 5 locks held by khubd/54: > [ 90.997847] #0: (&__lockdep_no_validate__){......}, at: [<ffffffff81496564>] hub_events+0xb4/0x9b0 > [ 90.998025] #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81493076>] usb_disconnect+0x66/0x1d0 > [ 90.998204] #2: (&__lockdep_no_validate__){......}, at: [<ffffffff8142929d>] device_release_driver+0x1d/0x40 > [ 90.998383] #3: (em28xx_devlist_mutex){+.+.+.}, at: [<ffffffffa040db77>] em28xx_close_extension+0x27/0x90 [em28xx] > [ 90.998567] #4: (&dev->lock){+.+.+.}, at: [<ffffffffa040db81>] em28xx_close_extension+0x31/0x90 [em28xx] > > Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com> > --- > drivers/media/usb/em28xx/em28xx-core.c | 2 -- > drivers/media/usb/em28xx/em28xx-video.c | 4 ++++ > 2 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c > index b6dc3327c51c..898fb9bd88a2 100644 > --- a/drivers/media/usb/em28xx/em28xx-core.c > +++ b/drivers/media/usb/em28xx/em28xx-core.c > @@ -1099,12 +1099,10 @@ void em28xx_close_extension(struct em28xx *dev) > const struct em28xx_ops *ops = NULL; > > mutex_lock(&em28xx_devlist_mutex); > - mutex_lock(&dev->lock); > list_for_each_entry(ops, &em28xx_extension_devlist, next) { > if (ops->fini) > ops->fini(dev); > } > - mutex_unlock(&dev->lock); > list_del(&dev->devlist); > mutex_unlock(&em28xx_devlist_mutex); > } > diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c > index 004fe12ceec7..258628877951 100644 > --- a/drivers/media/usb/em28xx/em28xx-video.c > +++ b/drivers/media/usb/em28xx/em28xx-video.c > @@ -1896,6 +1896,8 @@ static int em28xx_v4l2_fini(struct em28xx *dev) > > em28xx_info("Disconnecting video extension"); > > + mutex_lock(&dev->lock); > + > v4l2_device_disconnect(&dev->v4l2_dev); > > em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE); > @@ -1924,6 +1926,8 @@ static int em28xx_v4l2_fini(struct em28xx *dev) > v4l2_ctrl_handler_free(&dev->ctrl_handler); > v4l2_device_unregister(&dev->v4l2_dev); > > + mutex_unlock(&dev->lock); > + > kref_put(&dev->ref, em28xx_free_device); > > return 0; Looks sane. Reviewed-by: Frank Schäfer <fschaefer.oss@googlemail.com> -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c index b6dc3327c51c..898fb9bd88a2 100644 --- a/drivers/media/usb/em28xx/em28xx-core.c +++ b/drivers/media/usb/em28xx/em28xx-core.c @@ -1099,12 +1099,10 @@ void em28xx_close_extension(struct em28xx *dev) const struct em28xx_ops *ops = NULL; mutex_lock(&em28xx_devlist_mutex); - mutex_lock(&dev->lock); list_for_each_entry(ops, &em28xx_extension_devlist, next) { if (ops->fini) ops->fini(dev); } - mutex_unlock(&dev->lock); list_del(&dev->devlist); mutex_unlock(&em28xx_devlist_mutex); } diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c index 004fe12ceec7..258628877951 100644 --- a/drivers/media/usb/em28xx/em28xx-video.c +++ b/drivers/media/usb/em28xx/em28xx-video.c @@ -1896,6 +1896,8 @@ static int em28xx_v4l2_fini(struct em28xx *dev) em28xx_info("Disconnecting video extension"); + mutex_lock(&dev->lock); + v4l2_device_disconnect(&dev->v4l2_dev); em28xx_uninit_usb_xfer(dev, EM28XX_ANALOG_MODE); @@ -1924,6 +1926,8 @@ static int em28xx_v4l2_fini(struct em28xx *dev) v4l2_ctrl_handler_free(&dev->ctrl_handler); v4l2_device_unregister(&dev->v4l2_dev); + mutex_unlock(&dev->lock); + kref_put(&dev->ref, em28xx_free_device); return 0;
Avoid circular mutex lock by pushing the dev->lock to the .fini callback on each extension. As em28xx-dvb, em28xx-alsa and em28xx-rc have their own data structures, and don't touch at the common structure during .fini, only em28xx-v4l needs to be locked. [ 90.994317] ====================================================== [ 90.994356] [ INFO: possible circular locking dependency detected ] [ 90.994395] 3.13.0-rc1+ #24 Not tainted [ 90.994427] ------------------------------------------------------- [ 90.994458] khubd/54 is trying to acquire lock: [ 90.994490] (&card->controls_rwsem){++++.+}, at: [<ffffffffa0177b08>] snd_ctl_dev_free+0x28/0x60 [snd] [ 90.994656] [ 90.994656] but task is already holding lock: [ 90.994688] (&dev->lock){+.+.+.}, at: [<ffffffffa040db81>] em28xx_close_extension+0x31/0x90 [em28xx] [ 90.994843] [ 90.994843] which lock already depends on the new lock. [ 90.994843] [ 90.994874] [ 90.994874] the existing dependency chain (in reverse order) is: [ 90.994905] -> #1 (&dev->lock){+.+.+.}: [ 90.995057] [<ffffffff810b8fa3>] __lock_acquire+0xb43/0x1330 [ 90.995121] [<ffffffff810b9f82>] lock_acquire+0xa2/0x120 [ 90.995182] [<ffffffff816a5b6c>] mutex_lock_nested+0x5c/0x3c0 [ 90.995245] [<ffffffffa0422cca>] em28xx_vol_put_mute+0x1ba/0x1d0 [em28xx_alsa] [ 90.995309] [<ffffffffa017813d>] snd_ctl_elem_write+0xfd/0x140 [snd] [ 90.995376] [<ffffffffa01791c2>] snd_ctl_ioctl+0xe2/0x810 [snd] [ 90.995442] [<ffffffff811db8b0>] do_vfs_ioctl+0x300/0x520 [ 90.995504] [<ffffffff811dbb51>] SyS_ioctl+0x81/0xa0 [ 90.995568] [<ffffffff816b1929>] system_call_fastpath+0x16/0x1b [ 90.995630] -> #0 (&card->controls_rwsem){++++.+}: [ 90.995780] [<ffffffff810b7a47>] check_prevs_add+0x947/0x950 [ 90.995841] [<ffffffff810b8fa3>] __lock_acquire+0xb43/0x1330 [ 90.995901] [<ffffffff810b9f82>] lock_acquire+0xa2/0x120 [ 90.995962] [<ffffffff816a762b>] down_write+0x3b/0xa0 [ 90.996022] [<ffffffffa0177b08>] snd_ctl_dev_free+0x28/0x60 [snd] [ 90.996088] [<ffffffffa017a255>] snd_device_free+0x65/0x140 [snd] [ 90.996154] [<ffffffffa017a751>] snd_device_free_all+0x61/0xa0 [snd] [ 90.996219] [<ffffffffa0173af4>] snd_card_do_free+0x14/0x130 [snd] [ 90.996283] [<ffffffffa0173f14>] snd_card_free+0x84/0x90 [snd] [ 90.996349] [<ffffffffa0423397>] em28xx_audio_fini+0x97/0xb0 [em28xx_alsa] [ 90.996411] [<ffffffffa040dba6>] em28xx_close_extension+0x56/0x90 [em28xx] [ 90.996475] [<ffffffffa040f639>] em28xx_usb_disconnect+0x79/0x90 [em28xx] [ 90.996539] [<ffffffff814a06e7>] usb_unbind_interface+0x67/0x1d0 [ 90.996620] [<ffffffff8142920f>] __device_release_driver+0x7f/0xf0 [ 90.996682] [<ffffffff814292a5>] device_release_driver+0x25/0x40 [ 90.996742] [<ffffffff81428b0c>] bus_remove_device+0x11c/0x1a0 [ 90.996801] [<ffffffff81425536>] device_del+0x136/0x1d0 [ 90.996863] [<ffffffff8149e0c0>] usb_disable_device+0xb0/0x290 [ 90.996923] [<ffffffff814930c5>] usb_disconnect+0xb5/0x1d0 [ 90.996984] [<ffffffff81495ab6>] hub_port_connect_change+0xd6/0xad0 [ 90.997044] [<ffffffff814967c3>] hub_events+0x313/0x9b0 [ 90.997105] [<ffffffff81496e95>] hub_thread+0x35/0x170 [ 90.997165] [<ffffffff8108ea2f>] kthread+0xff/0x120 [ 90.997226] [<ffffffff816b187c>] ret_from_fork+0x7c/0xb0 [ 90.997287] [ 90.997287] other info that might help us debug this: [ 90.997287] [ 90.997318] Possible unsafe locking scenario: [ 90.997318] [ 90.997348] CPU0 CPU1 [ 90.997378] ---- ---- [ 90.997408] lock(&dev->lock); [ 90.997497] lock(&card->controls_rwsem); [ 90.997607] lock(&dev->lock); [ 90.997697] lock(&card->controls_rwsem); [ 90.997786] [ 90.997786] *** DEADLOCK *** [ 90.997786] [ 90.997817] 5 locks held by khubd/54: [ 90.997847] #0: (&__lockdep_no_validate__){......}, at: [<ffffffff81496564>] hub_events+0xb4/0x9b0 [ 90.998025] #1: (&__lockdep_no_validate__){......}, at: [<ffffffff81493076>] usb_disconnect+0x66/0x1d0 [ 90.998204] #2: (&__lockdep_no_validate__){......}, at: [<ffffffff8142929d>] device_release_driver+0x1d/0x40 [ 90.998383] #3: (em28xx_devlist_mutex){+.+.+.}, at: [<ffffffffa040db77>] em28xx_close_extension+0x27/0x90 [em28xx] [ 90.998567] #4: (&dev->lock){+.+.+.}, at: [<ffffffffa040db81>] em28xx_close_extension+0x31/0x90 [em28xx] Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com> --- drivers/media/usb/em28xx/em28xx-core.c | 2 -- drivers/media/usb/em28xx/em28xx-video.c | 4 ++++ 2 files changed, 4 insertions(+), 2 deletions(-)