linux/kernel
Thomas Gleixner 746976a301 NTP: remove clock_was_set() call to prevent deadlock
The clock_was_set() call in seconds_overflow() which happens only when
leap seconds are inserted / deleted is wrong in two aspects:

1. it results in a call to on_each_cpu() with interrupts disabled
2. it is potential deadlock source vs. call_lock in smp_call_function()

The only possible side effect of the removal might be, that an absolute
CLOCK_REALTIME timer fires 1 second too late, in the rare case of leap
second deletion and an absolute CLOCK_REALTIME timer which expires in
the affected time frame. It will never fire too early.

This was probably observed by the reporter of a June 30th -> July 1st
hang: http://lkml.org/lkml/2007/7/3/103

A similar problem was observed by Dave Jones, who provided a screen shot
with a lockdep back trace, which allowed to analyse the problem.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2007-07-03 13:54:27 -07:00
..
irq Fix crash with irqpoll due to the IRQF_IRQPOLL flag testing 2007-05-24 08:37:14 -07:00
power PM: introduce set_target method in pm_ops 2007-07-01 12:29:44 -07:00
time NTP: remove clock_was_set() call to prevent deadlock 2007-07-03 13:54:27 -07:00
.gitignore gitignore: ignore more generated files 2006-01-03 11:35:26 +01:00
acct.c [PATCH] kernel: change uses of f_{dentry, vfsmnt} to use f_path 2006-12-08 08:28:42 -08:00
audit.c audit: add spaces on either side of case "..." operator. 2007-05-08 11:15:09 -07:00
audit.h [PATCH] audit signal recipients 2007-05-11 05:38:25 -04:00
auditfilter.c audit: fix oops removing watch if audit disabled 2007-06-24 08:59:12 -07:00
auditsc.c [PATCH] Abnormal End of Processes 2007-05-11 05:38:26 -04:00
capability.c [PATCH] pid: replace do/while_each_task_pid with do/while_each_pid_task 2007-02-12 09:48:32 -08:00
compat.c signal/timer/event: timerfd compat code 2007-05-11 08:29:36 -07:00
configs.c use simple_read_from_buffer in kernel/ 2007-05-09 12:30:49 -07:00
cpu.c microcode: use suspend-related CPU hotplug notifications 2007-05-09 12:30:56 -07:00
cpuset.c cpuset: zero malloc - fix for old cpusets 2007-06-16 13:16:15 -07:00
delayacct.c KMEM_CACHE(): simplify slab cache creation 2007-05-07 12:12:55 -07:00
die_notifier.c move die notifier handling to common code 2007-05-08 11:15:04 -07:00
dma.c [PATCH] struct seq_operations and struct file_operations constification 2006-12-07 08:39:46 -08:00
exec_domain.c Remove obsolete #include <linux/config.h> 2006-06-30 19:25:36 +02:00
exit.c pi-futex: fix exit races and locking problems 2007-06-08 17:23:34 -07:00
extable.c [PATCH] symbol_put_addr() locks kernel 2006-05-15 11:20:55 -07:00
fork.c freezer: fix vfork problem 2007-05-23 20:14:11 -07:00
futex_compat.c Revert "futex_requeue_pi optimization" 2007-06-18 09:48:41 -07:00
futex.c FUTEX: Restore the dropped ERSCH fix 2007-06-24 12:08:53 -07:00
hrtimer.c Add suspend-related notifications for CPU hotplug 2007-05-09 12:30:56 -07:00
itimer.c The scheduled -EINVAL for invalid timevals in setitimer 2007-05-08 11:15:13 -07:00
kallsyms.c fix possible null ptr deref in kallsyms_lookup 2007-05-30 10:51:38 -07:00
Kconfig.hz [PATCH] HZ: 300Hz support 2006-12-07 08:39:36 -08:00
Kconfig.preempt Fix trivial typos in Kconfig* files 2007-05-09 07:12:20 +02:00
kexec.c kdump/kexec: calculate note size at compile time 2007-05-08 11:15:07 -07:00
kfifo.c [PATCH] Numerous fixes to kernel-doc info in source files. 2007-02-11 10:51:32 -08:00
kmod.c wait_for_helper: remove unneeded do_sigaction() 2007-05-09 12:30:53 -07:00
kprobes.c Kprobes: The ON/OFF knob thru debugfs 2007-05-08 11:15:19 -07:00
ksysfs.c remove "struct subsystem" as it is no longer needed 2007-05-02 18:57:59 -07:00
kthread.c freezer: fix kthread_create vs freezer theoretical race 2007-05-23 20:14:11 -07:00
latency.c [PATCH] severing module.h->sched.h 2006-12-04 02:00:22 -05:00
lockdep_internals.h [PATCH] lockdep: more chains 2006-12-07 08:39:43 -08:00
lockdep_proc.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
lockdep.c lockdep: removed unused ip argument in mark_lock & mark_held_locks 2007-05-08 11:15:13 -07:00
Makefile move die notifier handling to common code 2007-05-08 11:15:04 -07:00
module.c Fix minor typoes in kernel/module.c 2007-05-09 07:26:28 +02:00
mutex-debug.c [PATCH] remove many unneeded #includes of sched.h 2007-02-14 08:09:54 -08:00
mutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
mutex.c wrap access to thread_info 2007-05-09 12:30:56 -07:00
mutex.h [PATCH] lockdep: prove mutex locking correctness 2006-07-03 15:27:04 -07:00
nsproxy.c fix refcounting of nsproxy object when unshared 2007-06-24 08:59:10 -07:00
panic.c [PATCH] Add TAINT_USER and ability to set taint flags from userspace 2007-02-11 10:51:29 -08:00
params.c kernel/params.c: fix lying comment for param_array() 2007-05-08 11:15:08 -07:00
pid.c statically initialize struct pid for swapper 2007-05-11 08:29:35 -07:00
posix-cpu-timers.c Introduce a handy list_first_entry macro 2007-05-08 11:15:11 -07:00
posix-timers.c posix-timers: Prevent softirq starvation by small intervals and SIG_IGN 2007-06-21 15:57:04 -07:00
printk.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
profile.c Detach sched.h from mm.h 2007-05-21 09:18:19 -07:00
ptrace.c [PATCH] auditing ptrace 2007-05-11 05:38:25 -04:00
rcupdate.c Add suspend-related notifications for CPU hotplug 2007-05-09 12:30:56 -07:00
rcutorture.c rcutorture: Remove redundant assignment to cur_ops in for loop 2007-05-08 11:15:17 -07:00
relay.c relayfs: fix overwrites 2007-06-28 11:38:18 -07:00
resource.c libata/IDE: remove combined mode quirk 2007-04-28 14:15:59 -04:00
rtmutex_common.h Revert "futex_requeue_pi optimization" 2007-06-18 09:48:41 -07:00
rtmutex-debug.c Remove all inclusions of <linux/config.h> 2006-10-04 03:38:54 -04:00
rtmutex-debug.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rtmutex-tester.c [PATCH] Add include/linux/freezer.h and move definitions from sched.h 2006-12-07 08:39:27 -08:00
rtmutex.c Revert "futex_requeue_pi optimization" 2007-06-18 09:48:41 -07:00
rtmutex.h [PATCH] lockdep: better lock debugging 2006-07-03 15:27:01 -07:00
rwsem.c Lockdep treats down_write_trylock like regular down_write 2007-05-08 11:15:09 -07:00
sched.c sched: fix next_interval determination in idle_balance() 2007-06-24 08:59:11 -07:00
seccomp.c Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00
signal.c Fix signalfd interaction with thread-private signals 2007-06-18 10:18:32 -07:00
softirq.c Add suspend-related notifications for CPU hotplug 2007-05-09 12:30:56 -07:00
softlockup.c Add suspend-related notifications for CPU hotplug 2007-05-09 12:30:56 -07:00
spinlock.c [PATCH] lockdep: spin_lock_irqsave_nested() 2006-11-25 13:28:34 -08:00
srcu.c [PATCH] SRCU: report out-of-memory errors 2006-10-04 07:55:30 -07:00
stacktrace.c [PATCH] lockdep: stacktrace subsystem, core 2006-07-03 15:27:02 -07:00
stop_machine.c stop_machine() now uses hard_irq_disable 2007-05-11 08:29:34 -07:00
sys_ni.c compat signalfd and timerfd are cond syscalls 2007-05-12 10:55:40 -07:00
sys.c attach_pid() with struct pid parameter 2007-05-11 08:29:35 -07:00
sysctl.c make sysctl/kernel/core_pattern and fs/exec.c agree on maximum core filename size 2007-05-17 05:23:05 -07:00
taskstats.c KMEM_CACHE(): simplify slab cache creation 2007-05-07 12:12:55 -07:00
time.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
timer.c NOHZ: prevent multiplication overflow - stop timer for huge timeouts 2007-05-29 18:11:10 -07:00
tsacct.c [PATCH] time: x86_64: split x86_64/kernel/time.c up 2007-02-16 08:14:00 -08:00
uid16.c header cleaning: don't include smp_lock.h when not used 2007-05-08 11:15:07 -07:00
user.c [PATCH] slab: remove kmem_cache_t 2006-12-07 08:39:25 -08:00
utsname_sysctl.c [PATCH] sysctl: remove insert_at_head from register_sysctl 2007-02-14 08:09:59 -08:00
utsname.c Merge sys_clone()/sys_unshare() nsproxy and namespace handling 2007-05-08 11:15:00 -07:00
wait.c Fix occurrences of "the the " 2007-05-09 08:57:56 +02:00
workqueue.c simplify cleanup_workqueue_thread() 2007-05-23 20:14:13 -07:00