linux-stable/kernel
Vegard Nossum b2d4c2edb2 locking/hung_task: Show all locks
When we get a hung task it can often be valuable to see _all_ the held
locks on the system (in case we are being blocked on trying to acquire
one), e.g. with this patch we can immediately see where the problem is
below:

    INFO: task trinity-c3:14933 blocked for more than 120 seconds.
	  Not tainted 4.8.0-rc1+ #135
    "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
    trinity-c3      D ffff88010c16fc88     0 14933      1 0x00080004
     ffff88010c16fc88 000000003b9aca00 0000000000000000 0000000000000296
     00000000776cdf88 ffff88011a520ae0 ffff88011a520b08 ffff88011a520198
     ffffffff867d7f00 ffff88011942c080 ffff880116841580 ffff88010c168000
    Call Trace:
     [<ffffffff845e9d37>] schedule+0x77/0x230
     [<ffffffff833cb8b9>] __lock_sock+0x129/0x250
     [<ffffffff833cb790>] ? __sk_destruct+0x450/0x450
     [<ffffffff81408ac0>] ? wake_bit_function+0x2e0/0x2e0
     [<ffffffff833d832b>] lock_sock_nested+0xeb/0x120
     [<ffffffff83bad815>] irda_setsockopt+0x65/0xb40
     [<ffffffff833c6c09>] SyS_setsockopt+0x139/0x230
     [<ffffffff833c6ad0>] ? SyS_recv+0x20/0x20
     [<ffffffff81004660>] ? trace_event_raw_event_sys_enter+0xb90/0xb90
     [<ffffffff823c7023>] ? __this_cpu_preempt_check+0x13/0x20
     [<ffffffff8162ee60>] ? __context_tracking_exit.part.3+0x30/0x1b0
     [<ffffffff833c6ad0>] ? SyS_recv+0x20/0x20
     [<ffffffff81007bd3>] do_syscall_64+0x1b3/0x4b0
     [<ffffffff845f84aa>] entry_SYSCALL64_slow_path+0x25/0x25

    Showing all locks held in the system:
    2 locks held by khungtaskd/563:
     #0:  (rcu_read_lock){......}, at: [<ffffffff81534ce6>] watchdog+0x106/0x910
     #1:  (tasklist_lock){......}, at: [<ffffffff8141b3c4>] debug_show_all_locks+0x74/0x360
    1 lock held by trinity-c0/19280:
     #0:  (sk_lock-AF_IRDA){......}, at: [<ffffffff83bab7c6>] irda_accept+0x176/0x10f0
    1 lock held by trinity-c0/12865:
     #0:  (sk_lock-AF_IRDA){......}, at: [<ffffffff83bab7c6>] irda_accept+0x176/0x10f0

Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mandeep Singh Baines <msb@chromium.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1471538460-7505-1-git-send-email-vegard.nossum@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-08-24 12:16:13 +02:00
..
bpf Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2016-07-27 12:03:20 -07:00
configs config: add android config fragments 2016-08-02 19:35:42 -04:00
debug
events perf/core: Change log level for duration warning to KERN_INFO 2016-08-02 10:23:57 +02:00
gcov gcov: add support for gcc version >= 6 2016-07-15 14:54:27 +09:00
irq genirq: Fix missing irq allocation affinity hint 2016-07-19 10:49:47 +02:00
livepatch modules: add ro_after_init support 2016-08-04 10:16:55 +09:30
locking locking/rwsem: Scan the wait_list for readers only once 2016-08-18 15:37:11 +02:00
power mm, vmscan: move LRU lists to node 2016-07-28 16:07:41 -07:00
printk Revert "printk: create pr_<level> functions" 2016-08-09 10:48:18 -07:00
rcu locking, rcu, cgroup: Avoid synchronize_sched() in __cgroup_procs_write() 2016-08-18 15:36:59 +02:00
sched xen: features and fixes for 4.8-rc0 2016-07-27 11:35:37 -07:00
time Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-29 13:55:30 -07:00
trace block: rename bio bi_rw to bi_opf 2016-08-07 14:41:02 -06:00
.gitignore
acct.c
async.c
audit.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit 2016-07-29 17:54:17 -07:00
audit.h Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit 2016-07-29 17:54:17 -07:00
audit_fsnotify.c
audit_tree.c audit: cleanup prune_tree_thread 2016-04-04 09:46:47 -04:00
audit_watch.c don't bother with ->d_inode->i_sb - it's always equal to ->d_sb 2016-04-10 17:11:51 -04:00
auditfilter.c audit: add fields to exclude filter by reusing user filter 2016-06-27 11:01:00 -04:00
auditsc.c Merge branch 'stable-4.8' of git://git.infradead.org/users/pcmoore/audit 2016-07-29 17:54:17 -07:00
backtracetest.c
bounds.c
capability.c kernel: Add noaudit variant of ns_capable() 2016-06-06 20:16:18 +10:00
cgroup.c locking, rcu, cgroup: Avoid synchronize_sched() in __cgroup_procs_write() 2016-08-18 15:36:59 +02:00
cgroup_freezer.c
cgroup_pids.c cgroup: Use lld instead of ld when printing pids controller events_limit 2016-06-21 15:03:36 -04:00
compat.c
configs.c
context_tracking.c
cpu.c timers/core: Correct callback order during CPU hot plug 2016-07-28 18:56:22 +02:00
cpu_pm.c
cpuset.c cpuset, mm: fix TIF_MEMDIE check in cpuset_change_task_nodemask 2016-07-28 16:07:41 -07:00
crash_dump.c
cred.c cred: Reject inodes with invalid ids in set_create_file_as() 2016-06-30 18:05:09 -05:00
delayacct.c
dma.c
elfcore.c
exec_domain.c
exit.c kernel/exit.c: quieten greatest stack depth printk 2016-08-02 19:35:23 -04:00
extable.c
fork.c mm: fix memcg stack accounting for sub-page stacks 2016-07-28 16:07:41 -07:00
freezer.c freezer, oom: check TIF_MEMDIE on the correct task 2016-07-28 16:07:41 -07:00
futex.c futex: Assume all mappings are private on !MMU systems 2016-07-29 18:44:14 +02:00
futex_compat.c
groups.c
hung_task.c locking/hung_task: Show all locks 2016-08-24 12:16:13 +02:00
irq_work.c
jump_label.c powerpc updates for 4.8 #2 2016-08-05 09:00:54 -04:00
kallsyms.c kallsyms: add support for relative offsets in kallsyms address table 2016-03-15 16:55:16 -07:00
kcmp.c
Kconfig.freezer
Kconfig.hz
Kconfig.locks
Kconfig.preempt
kcov.c kernel/kcov: unproxify debugfs file's fops 2016-06-15 04:56:35 -07:00
kexec.c kexec: allow architectures to override boot mapping 2016-08-02 19:35:27 -04:00
kexec_core.c kexec: add restriction on kexec_load() segment sizes 2016-08-02 19:35:31 -04:00
kexec_file.c kexec: introduce a protection mechanism for the crashkernel reserved memory 2016-05-23 17:04:14 -07:00
kexec_internal.h
kmod.c
kprobes.c
ksysfs.c kexec: add a kexec_crash_loaded() function 2016-08-02 19:35:30 -04:00
kthread.c
latencytop.c
Makefile ELF/MIPS build fix 2016-05-23 17:04:14 -07:00
membarrier.c
memremap.c libnvdimm for 4.8 2016-07-28 17:38:16 -07:00
module-internal.h
module.c Removed the MODULE_SIG_FORCE-means-no-MODULE_FORCE_LOAD patch. 2016-08-04 09:14:38 -04:00
module_signing.c KEYS: Move the point of trust determination to __key_link() 2016-04-11 22:43:43 +01:00
notifier.c
nsproxy.c
padata.c kernel/padata.c: hide unused functions 2016-05-19 19:12:14 -07:00
panic.c kexec: use core_param for crash_kexec_post_notifiers boot option 2016-08-02 19:35:29 -04:00
params.c
pid.c remove lots of IS_ERR_VALUE abuses 2016-05-27 15:26:11 -07:00
pid_namespace.c
profile.c profile: Convert to hotplug state machine 2016-07-15 10:41:42 +02:00
ptrace.c tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
range.c
reboot.c
relay.c relay: add global mode support for buffer-only channels 2016-08-02 19:35:41 -04:00
resource.c /proc/iomem: only expose physical resource addresses to privileged users 2016-04-14 12:56:09 -07:00
seccomp.c tree-wide: replace config_enabled() with IS_ENABLED() 2016-08-04 08:50:07 -04:00
signal.c signals: Use hrtimer for sigtimedwait() 2016-07-07 10:35:07 +02:00
smp.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-29 13:55:30 -07:00
smpboot.c
smpboot.h
softirq.c arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections 2016-03-25 16:37:42 -07:00
stacktrace.c
stop_machine.c stop_machine: Touch_nmi_watchdog() after MULTI_STOP_PREPARE 2016-07-27 11:12:11 +02:00
sys.c prctl: make PR_SET_THP_DISABLE wait for mmap_sem killable 2016-05-23 17:04:14 -07:00
sys_ni.c
sysctl.c printk: add kernel parameter to control writes to /dev/kmsg 2016-08-02 19:35:06 -04:00
sysctl_binary.c kernel/sysctl_binary.c: use generic UUID library 2016-05-20 17:58:30 -07:00
task_work.c task_work: use READ_ONCE/lockless_dereference, avoid pi_lock if !task_works 2016-08-02 19:35:02 -04:00
taskstats.c taskstats: use the libnl API to align nlattr on 64-bit 2016-04-23 20:13:25 -04:00
test_kprobes.c
torture.c torture: Stop onoff task if there is only one cpu 2016-06-14 16:03:28 -07:00
tracepoint.c kernel/...: convert pr_warning to pr_warn 2016-03-22 15:36:02 -07:00
tsacct.c
uid16.c
up.c
user-return-notifier.c
user.c
user_namespace.c fs: Limit file caps to the user namespace of the super block 2016-06-24 10:40:31 -05:00
utsname.c
utsname_sysctl.c
watchdog.c Revert "perf/x86/intel, watchdog: Switch NMI watchdog to ref cycles on x86" 2016-07-10 20:58:36 +02:00
workqueue.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-07-29 13:55:30 -07:00
workqueue_internal.h