From: CAI Qian <caiqian@redhat.com>
To: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Dave Chinner <david@fromorbit.com>,
linux-xfs <linux-xfs@vger.kernel.org>,
Jens Axboe <axboe@kernel.dk>, Nick Piggin <npiggin@gmail.com>,
linux-fsdevel@vger.kernel.org, tj <tj@kernel.org>
Subject: local DoS - systemd hang or timeout (WAS: Re: [RFC][CFT] splice_read reworked)
Date: Tue, 4 Oct 2016 13:39:11 -0400 (EDT) [thread overview]
Message-ID: <1812816839.401734.1475602751170.JavaMail.zimbra@redhat.com> (raw)
In-Reply-To: <1937480340.100083.1475516965286.JavaMail.zimbra@redhat.com>
> ----- Original Message -----
> > From: "Al Viro" <viro@ZenIV.linux.org.uk>
> > To: "CAI Qian" <caiqian@redhat.com>
> > Cc: "Linus Torvalds" <torvalds@linux-foundation.org>, "Dave Chinner"
> > <david@fromorbit.com>, "linux-xfs"
> > <linux-xfs@vger.kernel.org>, xfs@oss.sgi.com, "Jens Axboe"
> > <axboe@kernel.dk>, "Nick Piggin" <npiggin@gmail.com>,
> > linux-fsdevel@vger.kernel.org
> > Sent: Sunday, October 2, 2016 9:37:37 PM
> > Subject: Re: [RFC][CFT] splice_read reworked
> >
> > On Fri, Sep 30, 2016 at 02:33:23PM -0400, CAI Qian wrote:
> >
> > OK, the immeditate trigger is
> > * sendfile() from something that uses seq_read to a regular file.
> > Does sb_start_write() around the call of do_splice_direct() (as always),
> > which ends up calling default_file_splice_read() (again, as usual), which
> > ends up calling ->read() of the source, i.e. seq_read(). No changes there.
> >
> > * sb_start_write() can be called under ->i_mutex. The latter is
> > on overlayfs inode, the former is done to upper layer in that overlayfs.
> > Nothing new, again.
> >
> > * ->i_mutex can be taken under ->cred_guard_mutex. Yes, it can -
> > in open_exec(). Again, no changes.
> >
> > * ->cred_guard_mutex can be taken in ->show() of a seq_file,
> > namely /proc/*/auxv... Argh, ->cred_guard_mutex whack-a-mole strikes
> > again...
> >
> > OK, I think essentially the same warning had been triggerable since _way_
> > back. All changes around splice have no effect on it.
> >
> > Look: to get a deadlock we need
> > (1) sendfile from /proc/<pid>/auxv to a regular file on upper layer of
> > overlayfs requesting not to freeze the target.
> > (2) attempt to freeze it blocking until (1) is done.
> > (3) directory modification on overlayfs trying to request not to freeze
> > the upper layer and blocking until (2) is done.
> > (4) execve() in <pid> holding ->cred_guard_mutex, trying to open
> > something in overlayfs and getting blocked on directory lock, held by (3).
> >
> > Now (1) gets around to reading from /proc/<pid>/auxv, which blocks on
> > ->cred_guard_mutex. Mentioning of seq_read itself holding locks is
> > irrelevant;
> > what matters is that ->read() grabs ->cred_guard_mutex.
> >
> > We used to have similar problems in /proc/*/environ and /proc/*/mem; looks
> > like /proc/*/environ needs to get the treatment similar to e268337dfe26 and
> > b409e578d9a4.
> >
> You are right. This is also reproducible on v4.8 mainline.
Not sure if related, but right after this lockdep happened and trinity running by a
non-privileged user finished inside the container. The host's systemctl command just
hang or timeout which renders the whole system unusable.
# systemctl status docker
Failed to get properties: Connection timed out
# systemctl reboot (hang)
[ 5535.596651] INFO: task systemd-journal:1165 blocked for more than 120 seconds.
[ 5535.604728] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5535.611536] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5535.620285] systemd-journal D ffff880466167ca8 12672 1165 1 0x00000000
[ 5535.628182] ffff880466167ca8 ffff880466167cd0 0000000000000000 ffff88086c6e2000
[ 5535.636504] ffff88045deb0000 ffff880466168000 ffffffff81deb380 ffff88045deb0000
[ 5535.644817] 0000000000000246 00000000ffffffff ffff880466167cc0 ffffffff817cdaaf
[ 5535.653131] Call Trace:
[ 5535.655874] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5535.661425] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5535.668617] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5535.675237] [<ffffffff81161d7e>] ? proc_cgroup_show+0x4e/0x300
[ 5535.681857] [<ffffffff81252b01>] ? kmem_cache_alloc_trace+0x1d1/0x2e0
[ 5535.689162] [<ffffffff81161d7e>] proc_cgroup_show+0x4e/0x300
[ 5535.695592] [<ffffffff81302d40>] proc_single_show+0x50/0x90
[ 5535.701925] [<ffffffff812ac983>] seq_read+0x113/0x3e0
[ 5535.707672] [<ffffffff81280407>] __vfs_read+0x37/0x150
[ 5535.713521] [<ffffffff81349ded>] ? security_file_permission+0x9d/0xc0
[ 5535.720819] [<ffffffff812815ac>] vfs_read+0x8c/0x130
[ 5535.726472] [<ffffffff81282ac8>] SyS_read+0x58/0xc0
[ 5535.732024] [<ffffffff817d497c>] entry_SYSCALL_64_fastpath+0x1f/0xbd
[ 5535.739221] INFO: lockdep is turned off.
[ 5535.743649] INFO: task kworker/3:1:52401 blocked for more than 120 seconds.
[ 5535.751429] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5535.758239] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5535.766989] kworker/3:1 D ffff8803b25bbca8 13368 52401 2 0x00000080
[ 5535.774904] Workqueue: cgroup_destroy css_release_work_fn
[ 5535.780940] ffff8803b25bbca8 ffff8803b25bbcd0 0000000000000000 ffff88046ded2000
[ 5535.789254] ffff88046af8a000 ffff8803b25bc000 ffffffff81deb380 ffff88046af8a000
[ 5535.797562] 0000000000000246 00000000ffffffff ffff8803b25bbcc0 ffffffff817cdaaf
[ 5535.805877] Call Trace:
[ 5535.808621] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5535.814177] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5535.821379] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5535.828001] [<ffffffff811586af>] ? css_release_work_fn+0x2f/0x110
[ 5535.834911] [<ffffffff811586af>] css_release_work_fn+0x2f/0x110
[ 5535.841629] [<ffffffff810bc83f>] process_one_work+0x1df/0x710
[ 5535.848159] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710
[ 5535.854876] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0
[ 5535.861119] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710
[ 5535.867847] [<ffffffff810c3f7e>] kthread+0xfe/0x120
[ 5535.873404] [<ffffffff817d40ec>] ? _raw_spin_unlock_irq+0x2c/0x60
[ 5535.880320] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40
[ 5535.886369] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230
[ 5535.893675] INFO: lockdep is turned off.
[ 5535.898085] INFO: task kworker/45:4:146035 blocked for more than 120 seconds.
[ 5535.906059] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5535.912865] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5535.921613] kworker/45:4 D ffff880853e9b950 14048 146035 2 0x00000080
[ 5535.929630] Workqueue: cgroup_destroy css_killed_work_fn
[ 5535.935582] ffff880853e9b950 0000000000000000 0000000000000000 ffff88086c6da000
[ 5535.943882] ffff88086c9e2000 ffff880853e9c000 ffff880853e9baa0 ffff88086c9e2000
[ 5535.952205] ffff880853e9ba98 0000000000000001 ffff880853e9b968 ffffffff817cdaaf
[ 5535.960522] Call Trace:
[ 5535.963265] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5535.968817] [<ffffffff817d33fb>] schedule_timeout+0x3db/0x6f0
[ 5535.975346] [<ffffffff817cf055>] ? wait_for_completion+0x45/0x130
[ 5535.982256] [<ffffffff817cf0d3>] wait_for_completion+0xc3/0x130
[ 5535.988972] [<ffffffff810d1fd0>] ? wake_up_q+0x80/0x80
[ 5535.994804] [<ffffffff8130de64>] drop_sysctl_table+0xc4/0xe0
[ 5536.001227] [<ffffffff8130de17>] drop_sysctl_table+0x77/0xe0
[ 5536.007648] [<ffffffff8130decd>] unregister_sysctl_table+0x4d/0xa0
[ 5536.014654] [<ffffffff8130deff>] unregister_sysctl_table+0x7f/0xa0
[ 5536.021657] [<ffffffff810f57f5>] unregister_sched_domain_sysctl+0x15/0x40
[ 5536.029344] [<ffffffff810d7704>] partition_sched_domains+0x44/0x450
[ 5536.036447] [<ffffffff817d0761>] ? __mutex_unlock_slowpath+0x111/0x1f0
[ 5536.043844] [<ffffffff81167684>] rebuild_sched_domains_locked+0x64/0xb0
[ 5536.051336] [<ffffffff8116789d>] update_flag+0x11d/0x210
[ 5536.057373] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450
[ 5536.064186] [<ffffffff81167acb>] ? cpuset_css_offline+0x1b/0x60
[ 5536.070899] [<ffffffff810fce3d>] ? trace_hardirqs_on+0xd/0x10
[ 5536.077420] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450
[ 5536.084234] [<ffffffff8115a9f5>] ? css_killed_work_fn+0x25/0x220
[ 5536.091049] [<ffffffff81167ae5>] cpuset_css_offline+0x35/0x60
[ 5536.097571] [<ffffffff8115aa2c>] css_killed_work_fn+0x5c/0x220
[ 5536.104207] [<ffffffff810bc83f>] process_one_work+0x1df/0x710
[ 5536.110736] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710
[ 5536.117461] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0
[ 5536.123697] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710
[ 5536.130426] [<ffffffff810c3f7e>] kthread+0xfe/0x120
[ 5536.135991] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40
[ 5536.142041] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230
[ 5536.149345] INFO: lockdep is turned off.
[ 5585.148183] perf: interrupt took too long (3146 > 3136), lowering kernel.perf_event_max_sample_rate to 63000
[ 5658.479538] INFO: task systemd:1 blocked for more than 120 seconds.
[ 5658.486551] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5658.493352] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5658.502095] systemd D ffff880468ccfca8 11952 1 0 0x00000000
[ 5658.509995] ffff880468ccfca8 ffff880468ccfcd0 0000000000000000 ffff88046aa24000
[ 5658.518297] ffff880468cd0000 ffff880468cd0000 ffffffff81deb380 ffff880468cd0000
[ 5658.526602] 0000000000000246 00000000ffffffff ffff880468ccfcc0 ffffffff817cdaaf
[ 5658.534909] Call Trace:
[ 5658.537645] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5658.543188] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5658.550375] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5658.556987] [<ffffffff81161d7e>] ? proc_cgroup_show+0x4e/0x300
[ 5658.563600] [<ffffffff81252b01>] ? kmem_cache_alloc_trace+0x1d1/0x2e0
[ 5658.570887] [<ffffffff81161d7e>] proc_cgroup_show+0x4e/0x300
[ 5658.577304] [<ffffffff81302d40>] proc_single_show+0x50/0x90
[ 5658.583620] [<ffffffff812ac983>] seq_read+0x113/0x3e0
[ 5658.589355] [<ffffffff81280407>] __vfs_read+0x37/0x150
[ 5658.595189] [<ffffffff81349ded>] ? security_file_permission+0x9d/0xc0
[ 5658.602480] [<ffffffff812815ac>] vfs_read+0x8c/0x130
[ 5658.608117] [<ffffffff81282ac8>] SyS_read+0x58/0xc0
[ 5658.613661] [<ffffffff817d497c>] entry_SYSCALL_64_fastpath+0x1f/0xbd
[ 5658.620849] INFO: lockdep is turned off.
[ 5658.625282] INFO: task systemd-journal:1165 blocked for more than 120 seconds.
[ 5658.633346] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5658.640147] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5658.648887] systemd-journal D ffff880466167ca8 12672 1165 1 0x00000000
[ 5658.656788] ffff880466167ca8 ffff880466167cd0 0000000000000000 ffff88086c6e2000
[ 5658.665092] ffff88045deb0000 ffff880466168000 ffffffff81deb380 ffff88045deb0000
[ 5658.673394] 0000000000000246 00000000ffffffff ffff880466167cc0 ffffffff817cdaaf
[ 5658.681690] Call Trace:
[ 5658.684419] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5658.689961] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5658.697143] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5658.703766] [<ffffffff81161d7e>] ? proc_cgroup_show+0x4e/0x300
[ 5658.710373] [<ffffffff81252b01>] ? kmem_cache_alloc_trace+0x1d1/0x2e0
[ 5658.717661] [<ffffffff81161d7e>] proc_cgroup_show+0x4e/0x300
[ 5658.724067] [<ffffffff81302d40>] proc_single_show+0x50/0x90
[ 5658.730386] [<ffffffff812ac983>] seq_read+0x113/0x3e0
[ 5658.736123] [<ffffffff81280407>] __vfs_read+0x37/0x150
[ 5658.741957] [<ffffffff81349ded>] ? security_file_permission+0x9d/0xc0
[ 5658.749244] [<ffffffff812815ac>] vfs_read+0x8c/0x130
[ 5658.754884] [<ffffffff81282ac8>] SyS_read+0x58/0xc0
[ 5658.760417] [<ffffffff817d497c>] entry_SYSCALL_64_fastpath+0x1f/0xbd
[ 5658.767607] INFO: lockdep is turned off.
[ 5658.772016] INFO: task kworker/3:1:52401 blocked for more than 120 seconds.
[ 5658.779789] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5658.786582] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5658.795322] kworker/3:1 D ffff8803b25bbca8 13368 52401 2 0x00000080
[ 5658.803224] Workqueue: cgroup_destroy css_release_work_fn
[ 5658.809261] ffff8803b25bbca8 ffff8803b25bbcd0 0000000000000000 ffff88046ded2000
[ 5658.817567] ffff88046af8a000 ffff8803b25bc000 ffffffff81deb380 ffff88046af8a000
[ 5658.825871] 0000000000000246 00000000ffffffff ffff8803b25bbcc0 ffffffff817cdaaf
[ 5658.834173] Call Trace:
[ 5658.836904] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5658.842447] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5658.849638] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5658.856246] [<ffffffff811586af>] ? css_release_work_fn+0x2f/0x110
[ 5658.863146] [<ffffffff811586af>] css_release_work_fn+0x2f/0x110
[ 5658.869858] [<ffffffff810bc83f>] process_one_work+0x1df/0x710
[ 5658.876370] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710
[ 5658.883067] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0
[ 5658.889287] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710
[ 5658.895991] [<ffffffff810c3f7e>] kthread+0xfe/0x120
[ 5658.901538] [<ffffffff817d40ec>] ? _raw_spin_unlock_irq+0x2c/0x60
[ 5658.908438] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40
[ 5658.914466] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230
[ 5658.921745] INFO: lockdep is turned off.
[ 5658.926133] INFO: task kworker/45:4:146035 blocked for more than 120 seconds.
[ 5658.934099] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5658.940902] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5658.949636] kworker/45:4 D ffff880853e9b950 14048 146035 2 0x00000080
[ 5658.957632] Workqueue: cgroup_destroy css_killed_work_fn
[ 5658.963574] ffff880853e9b950 0000000000000000 0000000000000000 ffff88086c6da000
[ 5658.971877] ffff88086c9e2000 ffff880853e9c000 ffff880853e9baa0 ffff88086c9e2000
[ 5658.980179] ffff880853e9ba98 0000000000000001 ffff880853e9b968 ffffffff817cdaaf
[ 5658.988498] Call Trace:
[ 5658.991225] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5658.996768] [<ffffffff817d33fb>] schedule_timeout+0x3db/0x6f0
[ 5659.003271] [<ffffffff817cf055>] ? wait_for_completion+0x45/0x130
[ 5659.010161] [<ffffffff817cf0d3>] wait_for_completion+0xc3/0x130
[ 5659.016871] [<ffffffff810d1fd0>] ? wake_up_q+0x80/0x80
[ 5659.022706] [<ffffffff8130de64>] drop_sysctl_table+0xc4/0xe0
[ 5659.029120] [<ffffffff8130de17>] drop_sysctl_table+0x77/0xe0
[ 5659.035535] [<ffffffff8130decd>] unregister_sysctl_table+0x4d/0xa0
[ 5659.042529] [<ffffffff8130deff>] unregister_sysctl_table+0x7f/0xa0
[ 5659.049528] [<ffffffff810f57f5>] unregister_sched_domain_sysctl+0x15/0x40
[ 5659.057203] [<ffffffff810d7704>] partition_sched_domains+0x44/0x450
[ 5659.064297] [<ffffffff817d0761>] ? __mutex_unlock_slowpath+0x111/0x1f0
[ 5659.071673] [<ffffffff81167684>] rebuild_sched_domains_locked+0x64/0xb0
[ 5659.079144] [<ffffffff8116789d>] update_flag+0x11d/0x210
[ 5659.085172] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450
[ 5659.091964] [<ffffffff81167acb>] ? cpuset_css_offline+0x1b/0x60
[ 5659.098668] [<ffffffff810fce3d>] ? trace_hardirqs_on+0xd/0x10
[ 5659.105179] [<ffffffff817cf61f>] ? mutex_lock_nested+0x2df/0x450
[ 5659.111982] [<ffffffff8115a9f5>] ? css_killed_work_fn+0x25/0x220
[ 5659.118783] [<ffffffff81167ae5>] cpuset_css_offline+0x35/0x60
[ 5659.125296] [<ffffffff8115aa2c>] css_killed_work_fn+0x5c/0x220
[ 5659.131906] [<ffffffff810bc83f>] process_one_work+0x1df/0x710
[ 5659.138417] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710
[ 5659.145124] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0
[ 5659.151345] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710
[ 5659.158044] [<ffffffff810c3f7e>] kthread+0xfe/0x120
[ 5659.163586] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40
[ 5659.169605] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230
[ 5659.176892] INFO: lockdep is turned off.
[ 5781.364367] INFO: task systemd:1 blocked for more than 120 seconds.
[ 5781.371373] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5781.378177] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5781.386918] systemd D ffff880468ccfca8 11952 1 0 0x00000000
[ 5781.394818] ffff880468ccfca8 ffff880468ccfcd0 0000000000000000 ffff88046aa24000
[ 5781.403121] ffff880468cd0000 ffff880468cd0000 ffffffff81deb380 ffff880468cd0000
[ 5781.411421] 0000000000000246 00000000ffffffff ffff880468ccfcc0 ffffffff817cdaaf
[ 5781.419725] Call Trace:
[ 5781.422460] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5781.428003] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5781.435192] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5781.441801] [<ffffffff81161d7e>] ? proc_cgroup_show+0x4e/0x300
[ 5781.448404] [<ffffffff81252b01>] ? kmem_cache_alloc_trace+0x1d1/0x2e0
[ 5781.455691] [<ffffffff81161d7e>] proc_cgroup_show+0x4e/0x300
[ 5781.462109] [<ffffffff81302d40>] proc_single_show+0x50/0x90
[ 5781.468428] [<ffffffff812ac983>] seq_read+0x113/0x3e0
[ 5781.474165] [<ffffffff81280407>] __vfs_read+0x37/0x150
[ 5781.479991] [<ffffffff81349ded>] ? security_file_permission+0x9d/0xc0
[ 5781.487277] [<ffffffff812815ac>] vfs_read+0x8c/0x130
[ 5781.492914] [<ffffffff81282ac8>] SyS_read+0x58/0xc0
[ 5781.498455] [<ffffffff817d497c>] entry_SYSCALL_64_fastpath+0x1f/0xbd
[ 5781.505646] INFO: lockdep is turned off.
[ 5781.510085] INFO: task systemd-journal:1165 blocked for more than 120 seconds.
[ 5781.518146] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5781.524946] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5781.533686] systemd-journal D ffff880466167ca8 12672 1165 1 0x00000000
[ 5781.541581] ffff880466167ca8 ffff880466167cd0 0000000000000000 ffff88086c6e2000
[ 5781.549880] ffff88045deb0000 ffff880466168000 ffffffff81deb380 ffff88045deb0000
[ 5781.558186] 0000000000000246 00000000ffffffff ffff880466167cc0 ffffffff817cdaaf
[ 5781.566493] Call Trace:
[ 5781.569222] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5781.574764] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5781.581953] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5781.588559] [<ffffffff81161d7e>] ? proc_cgroup_show+0x4e/0x300
[ 5781.595166] [<ffffffff81252b01>] ? kmem_cache_alloc_trace+0x1d1/0x2e0
[ 5781.602451] [<ffffffff81161d7e>] proc_cgroup_show+0x4e/0x300
[ 5781.608864] [<ffffffff81302d40>] proc_single_show+0x50/0x90
[ 5781.615182] [<ffffffff812ac983>] seq_read+0x113/0x3e0
[ 5781.620916] [<ffffffff81280407>] __vfs_read+0x37/0x150
[ 5781.626749] [<ffffffff81349ded>] ? security_file_permission+0x9d/0xc0
[ 5781.634035] [<ffffffff812815ac>] vfs_read+0x8c/0x130
[ 5781.639673] [<ffffffff81282ac8>] SyS_read+0x58/0xc0
[ 5781.645215] [<ffffffff817d497c>] entry_SYSCALL_64_fastpath+0x1f/0xbd
[ 5781.652403] INFO: lockdep is turned off.
[ 5781.656811] INFO: task kworker/3:1:52401 blocked for more than 120 seconds.
[ 5781.664583] Tainted: G W 4.8.0-rc8-fornext+ #1
[ 5781.671383] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 5781.680121] kworker/3:1 D ffff8803b25bbca8 13368 52401 2 0x00000080
[ 5781.688021] Workqueue: cgroup_destroy css_release_work_fn
[ 5781.694057] ffff8803b25bbca8 ffff8803b25bbcd0 0000000000000000 ffff88046ded2000
[ 5781.702356] ffff88046af8a000 ffff8803b25bc000 ffffffff81deb380 ffff88046af8a000
[ 5781.710656] 0000000000000246 00000000ffffffff ffff8803b25bbcc0 ffffffff817cdaaf
[ 5781.718954] Call Trace:
[ 5781.721684] [<ffffffff817cdaaf>] schedule+0x3f/0xa0
[ 5781.727224] [<ffffffff817cdf18>] schedule_preempt_disabled+0x18/0x30
[ 5781.734414] [<ffffffff817cf4df>] mutex_lock_nested+0x19f/0x450
[ 5781.741021] [<ffffffff811586af>] ? css_release_work_fn+0x2f/0x110
[ 5781.747919] [<ffffffff811586af>] css_release_work_fn+0x2f/0x110
[ 5781.754626] [<ffffffff810bc83f>] process_one_work+0x1df/0x710
[ 5781.761137] [<ffffffff810bc7c0>] ? process_one_work+0x160/0x710
[ 5781.767841] [<ffffffff810bce9b>] worker_thread+0x12b/0x4a0
[ 5781.774061] [<ffffffff810bcd70>] ? process_one_work+0x710/0x710
[ 5781.780765] [<ffffffff810c3f7e>] kthread+0xfe/0x120
[ 5781.786304] [<ffffffff817d40ec>] ? _raw_spin_unlock_irq+0x2c/0x60
[ 5781.793203] [<ffffffff817d4baf>] ret_from_fork+0x1f/0x40
[ 5781.799229] [<ffffffff810c3e80>] ? kthread_create_on_node+0x230/0x230
[ 5781.806514] INFO: lockdep is turned off.
next prev parent reply other threads:[~2016-10-04 17:39 UTC|newest]
Thread overview: 104+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20160908235521.GL2356@ZenIV.linux.org.uk>
[not found] ` <20160909015324.GD30056@dastard>
[not found] ` <CA+55aFzohsUXj_3BeFNr2t50Wm=G+7toRDEz=Tk7VJqP3n1hXQ@mail.gmail.com>
[not found] ` <CA+55aFxrqCng2Qxasc9pyMrKUGFjo==fEaFT1vkH9Lncte3RgQ@mail.gmail.com>
[not found] ` <20160909023452.GO2356@ZenIV.linux.org.uk>
[not found] ` <CA+55aFwHQMjO4-vtfB9-ytc=o+DRo-HXVGckvXLboUxgpwb7_g@mail.gmail.com>
[not found] ` <20160909221945.GQ2356@ZenIV.linux.org.uk>
[not found] ` <CA+55aFzTOOB6oEVaaGD0N7Uznk-W9+ULPwzsxS_L_oZqGVSeLA@mail.gmail.com>
[not found] ` <20160914031648.GB2356@ZenIV.linux.org.uk>
[not found] ` <20160914133925.2fba4629@roar.ozlabs.ibm.com>
2016-09-18 5:33 ` xfs_file_splice_read: possible circular locking dependency detected Al Viro
2016-09-19 3:08 ` Nicholas Piggin
2016-09-19 6:11 ` Al Viro
2016-09-19 7:26 ` Nicholas Piggin
[not found] ` <CA+55aFznQaOWoSMNphgGJJWZ=8-odrc0DAUMzfGPQe+_N4UgNA@mail.gmail.com>
[not found] ` <20160914042559.GC2356@ZenIV.linux.org.uk>
[not found] ` <20160917082007.GA6489@ZenIV.linux.org.uk>
[not found] ` <20160917190023.GA8039@ZenIV.linux.org.uk>
2016-09-18 19:31 ` skb_splice_bits() and large chunks in pipe (was " Al Viro
2016-09-18 20:12 ` Linus Torvalds
2016-09-18 22:31 ` Al Viro
2016-09-19 0:18 ` Linus Torvalds
2016-09-19 0:22 ` Al Viro
2016-09-20 9:51 ` Herbert Xu
2016-09-23 19:00 ` [RFC][CFT] splice_read reworked Al Viro
2016-09-23 19:01 ` [PATCH 01/11] fix memory leaks in tracing_buffers_splice_read() Al Viro
2016-09-23 19:02 ` [PATCH 02/11] splice_to_pipe(): don't open-code wakeup_pipe_readers() Al Viro
2016-09-23 19:02 ` [PATCH 03/11] splice: switch get_iovec_page_array() to iov_iter Al Viro
2016-09-23 19:03 ` [PATCH 04/11] splice: lift pipe_lock out of splice_to_pipe() Al Viro
2016-09-23 19:45 ` Linus Torvalds
2016-09-23 20:10 ` Al Viro
2016-09-23 20:36 ` Linus Torvalds
2016-09-24 3:59 ` Al Viro
2016-09-24 17:29 ` Al Viro
2016-09-27 15:38 ` Nicholas Piggin
2016-09-27 15:53 ` Chuck Lever
2016-09-24 3:59 ` [PATCH 04/12] " Al Viro
2016-09-26 13:35 ` Miklos Szeredi
2016-09-27 4:14 ` Al Viro
2016-12-17 19:54 ` Andreas Schwab
2016-12-18 19:28 ` Linus Torvalds
2016-12-18 19:57 ` Andreas Schwab
2016-12-18 20:12 ` Al Viro
2016-12-18 20:30 ` Al Viro
2016-12-18 22:10 ` Linus Torvalds
2016-12-18 22:18 ` Al Viro
2016-12-18 22:22 ` Linus Torvalds
2016-12-18 22:49 ` Andreas Schwab
2016-12-21 18:56 ` Andreas Schwab
2016-12-21 19:12 ` Linus Torvalds
2016-09-24 4:00 ` [PATCH 06/12] new helper: add_to_pipe() Al Viro
2016-09-26 13:49 ` Miklos Szeredi
2016-09-24 4:01 ` [PATCH 10/12] new iov_iter flavour: pipe-backed Al Viro
2016-09-29 20:53 ` Miklos Szeredi
2016-09-29 22:50 ` Al Viro
2016-09-30 7:30 ` Miklos Szeredi
2016-10-03 3:34 ` [RFC] O_DIRECT vs EFAULT (was Re: [PATCH 10/12] new iov_iter flavour: pipe-backed) Al Viro
2016-10-03 17:07 ` Linus Torvalds
2016-10-03 18:54 ` Al Viro
2016-09-24 4:01 ` [PATCH 11/12] switch generic_file_splice_read() to use of ->read_iter() Al Viro
2016-09-24 4:02 ` [PATCH 12/12] switch default_file_splice_read() to use of pipe-backed iov_iter Al Viro
2016-09-23 19:03 ` [PATCH 05/11] skb_splice_bits(): get rid of callback Al Viro
2016-09-23 19:04 ` [PATCH 06/11] new helper: add_to_pipe() Al Viro
2016-09-23 19:04 ` [PATCH 07/11] fuse_dev_splice_read(): switch to add_to_pipe() Al Viro
2016-09-23 19:06 ` [PATCH 08/11] cifs: don't use memcpy() to copy struct iov_iter Al Viro
2016-09-23 19:08 ` [PATCH 09/11] fuse_ioctl_copy_user(): don't open-code copy_page_{to,from}_iter() Al Viro
2016-09-26 9:31 ` Miklos Szeredi
2016-09-23 19:09 ` [PATCH 10/11] new iov_iter flavour: pipe-backed Al Viro
2016-09-23 19:10 ` [PATCH 11/11] switch generic_file_splice_read() to use of ->read_iter() Al Viro
2016-09-30 13:32 ` [RFC][CFT] splice_read reworked CAI Qian
2016-09-30 17:42 ` CAI Qian
2016-09-30 18:33 ` CAI Qian
2016-10-03 1:37 ` Al Viro
2016-10-03 17:49 ` CAI Qian
2016-10-04 17:39 ` CAI Qian [this message]
2016-10-04 21:42 ` local DoS - systemd hang or timeout (WAS: Re: [RFC][CFT] splice_read reworked) tj
2016-10-05 14:09 ` CAI Qian
2016-10-05 15:30 ` tj
2016-10-05 15:54 ` CAI Qian
2016-10-05 18:57 ` CAI Qian
2016-10-05 20:05 ` Al Viro
2016-10-06 12:20 ` CAI Qian
2016-10-06 12:25 ` CAI Qian
2016-10-06 16:11 ` CAI Qian
2016-10-06 17:00 ` Linus Torvalds
2016-10-06 18:12 ` CAI Qian
2016-10-07 9:57 ` Dave Chinner
2016-10-07 15:25 ` Linus Torvalds
2016-10-07 7:08 ` Jan Kara
2016-10-07 14:43 ` CAI Qian
2016-10-07 15:27 ` CAI Qian
2016-10-07 18:56 ` CAI Qian
2016-10-09 21:54 ` Dave Chinner
2016-10-10 14:10 ` CAI Qian
2016-10-10 20:14 ` CAI Qian
2016-10-10 21:57 ` Dave Chinner
2016-10-12 19:50 ` [bisected] " CAI Qian
2016-10-12 20:59 ` Dave Chinner
2016-10-13 16:25 ` CAI Qian
2016-10-13 20:49 ` Dave Chinner
2016-10-13 20:56 ` CAI Qian
2016-10-09 21:51 ` Dave Chinner
2016-10-21 15:38 ` [4.9-rc1+] overlayfs lockdep CAI Qian
2016-10-24 12:57 ` Miklos Szeredi
2016-10-07 9:27 ` local DoS - systemd hang or timeout (WAS: Re: [RFC][CFT] splice_read reworked) Dave Chinner
2016-10-03 1:42 ` [RFC][CFT] splice_read reworked Al Viro
2016-10-03 14:06 ` CAI Qian
2016-10-03 15:20 ` CAI Qian
2016-10-03 21:12 ` Dave Chinner
2016-10-04 13:57 ` CAI Qian
2016-10-03 20:32 ` CAI Qian
2016-10-03 20:35 ` Al Viro
2016-10-04 13:29 ` CAI Qian
2016-10-04 14:28 ` Al Viro
2016-10-04 16:21 ` CAI Qian
2016-10-04 20:12 ` Al Viro
2016-10-05 14:30 ` CAI Qian
2016-10-05 16:07 ` Al Viro
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