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Thomas Gleixner 60a0c1a612 tick: Prevent uncontrolled switch to oneshot mode 
commit 1f73a9806b upstream.

When the system switches from periodic to oneshot mode, the broadcast
logic causes a possibility that a CPU which has not yet switched to
oneshot mode puts its own clock event device into oneshot mode without
updating the state and the timer handler.

CPU0				CPU1
				per cpu tickdev is in periodic mode
				and switched to broadcast

Switch to oneshot mode
 tick_broadcast_switch_to_oneshot()
  cpumask_copy(tick_oneshot_broacast_mask,
	       tick_broadcast_mask);

  broadcast device mode = oneshot

				Timer interrupt

				irq_enter()
				 tick_check_oneshot_broadcast()
				  dev->set_mode(ONESHOT);

				tick_handle_periodic()
				 if (dev->mode == ONESHOT)
				   dev->next_event += period;
				   FAIL.

We fail, because dev->next_event contains KTIME_MAX, if the device was
in periodic mode before the uncontrolled switch to oneshot happened.

We must copy the broadcast bits over to the oneshot mask, because
otherwise a CPU which relies on the broadcast would not been woken up
anymore after the broadcast device switched to oneshot mode.

So we need to verify in tick_check_oneshot_broadcast() whether the CPU
has already switched to oneshot mode. If not, leave the device
untouched and let the CPU switch controlled into oneshot mode.

This is a long standing bug, which was never noticed, because the main
user of the broadcast x86 cannot run into that scenario, AFAICT. The
nonarchitected timer mess of ARM creates a gazillion of differently
broken abominations which trigger the shortcomings of that broadcast
code, which better had never been necessary in the first place.

Reported-and-tested-by: Stehle Vincent-B46079 <B46079@freescale.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Cc: John Stultz <john.stultz@linaro.org>,
Cc: Mark Rutland <mark.rutland@arm.com>
Link: http://lkml.kernel.org/r/alpine.DEB.2.02.1307012153060.4013@ionos.tec.linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-07-28 16:25:44 -07:00
..
debug kdb,vt_console: Fix missed data due to pager overruns 2012-10-21 09:27:59 -07:00
events perf: Fix mmap() accounting hole 2013-07-03 10:59:06 -07:00
gcov gcov: disable CONSTRUCTORS for UML 2011-07-26 16:49:45 -07:00
irq genirq: Fix can_request_irq() for IRQs without an action 2013-07-21 18:19:01 -07:00
power ftrace: Disable function tracing during suspend/resume and hibernation, again 2012-08-09 08:31:29 -07:00
sched sched: Convert BUG_ON()s in try_to_wake_up_local() to WARN_ON_ONCE()s 2013-04-25 21:19:55 -07:00
time tick: Prevent uncontrolled switch to oneshot mode 2013-07-28 16:25:44 -07:00
trace ftrace: Move ftrace_filter_lseek out of CONFIG_DYNAMIC_FTRACE section 2013-06-13 09:45:03 -07:00
.gitignore
acct.c Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2012-01-08 12:19:57 -08:00
async.c Fix a dead loop in async_synchronize_full() 2012-10-02 10:30:35 -07:00
audit_tree.c kernel/audit_tree.c: tree will leak memory when failure occurs in audit_trim_trees() 2013-05-11 13:48:14 -07:00
audit_watch.c kill path_lookup() 2011-03-14 09:15:23 -04:00
audit.c constify path argument of audit_log_d_path() 2012-03-20 21:29:40 -04:00
audit.h audit: remove AUDIT_SETUP_CONTEXT as it isn't used 2012-01-17 16:16:57 -05:00
auditfilter.c audit: allow interfield comparison in audit rules 2012-01-17 16:17:01 -05:00
auditsc.c kernel-doc: fix new warnings in auditsc.c 2012-01-23 08:44:53 -08:00
backtracetest.c
bounds.c memcg: remove direct page_cgroup-to-page pointer 2011-03-23 19:46:28 -07:00
capability.c Revert "capabitlies: ns_capable can use the cap helpers rather than lsm call" 2012-01-17 10:19:41 -08:00
cgroup_freezer.c cgroup: remove cgroup_subsys argument from callbacks 2012-02-02 09:20:22 -08:00
cgroup.c cgroup: fix an off-by-one bug which may trigger BUG_ON() 2013-05-07 19:51:56 -07:00
compat.c compat: Fix RT signal mask corruption via sigprocmask 2012-05-10 08:58:33 -07:00
configs.c kernel/configs.c: include MODULE_*() when CONFIG_IKCONFIG_PROC=n 2011-07-25 20:57:15 -07:00
cpu_pm.c cpu_pm: call notifiers during suspend 2011-09-23 12:05:29 +05:30
cpu.c CPU hotplug: provide a generic helper to disable/enable CPU hotplug 2013-06-20 11:58:44 -07:00
cpuset.c cpuset: fix cpuset_print_task_mems_allowed() vs rename() race 2013-03-04 06:06:44 +08:00
crash_dump.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
cred.c cred: copy_process() should clear child->replacement_session_keyring 2012-04-11 08:20:11 -07:00
delayacct.c KVM: Steal time implementation 2011-07-14 12:59:14 +03:00
dma.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
elfcore.c
exec_domain.c
exit.c posix_types.h: Cleanup stale __NFDBITS and related definitions 2012-08-09 08:31:39 -07:00
extable.c extable, core_kernel_data(): Make sure all archs define _sdata 2011-05-20 08:56:56 +02:00
fork.c mm/fork: fix overflow in vma length when copying mmap on clone 2012-06-10 00:36:06 +09:00
freezer.c PM / Freezer: Remove references to TIF_FREEZE in comments 2012-03-04 23:08:54 +01:00
futex_compat.c futex: Revert "futex: Mark get_robust_list as deprecated" 2013-02-28 06:59:01 -08:00
futex.c futex: Revert "futex: Mark get_robust_list as deprecated" 2013-02-28 06:59:01 -08:00
groups.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
hrtimer.c hrtimer: Add expiry time overflow check in hrtimer_interrupt 2013-05-07 19:51:55 -07:00
hung_task.c hung_task: fix the broken rcu_lock_break() logic 2012-03-05 15:49:42 -08:00
irq_work.c irq_work: fix compile failure on tile from missing include 2012-04-13 13:15:16 -04:00
itimer.c itimer: Use printk_once instead of WARN_ONCE 2012-04-10 11:00:30 +02:00
jump_label.c static keys: Inline the static_key_enabled() function 2012-02-28 20:01:08 +01:00
kallsyms.c Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2011-03-25 17:52:22 -07:00
Kconfig.freezer
Kconfig.hz
Kconfig.locks locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
Kconfig.preempt locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
kexec.c Merge branch 'akpm' (Andrew's patch-bomb) 2012-03-28 17:19:28 -07:00
kfifo.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
kmod.c usermodehelper: check subprocess_info->path != NULL 2013-05-19 10:54:50 -07:00
kprobes.c kprobes: return proper error code from register_kprobe() 2012-03-05 15:49:42 -08:00
ksysfs.c kernel: ksysfs.c is implicitly using stat.h 2011-10-31 09:20:13 -04:00
kthread.c kthread_worker: reimplement flush_kthread_work() to allow freeing the work item being executed 2012-10-02 10:30:40 -07:00
latencytop.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
lockdep_internals.h
lockdep_proc.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
lockdep_states.h
lockdep.c lockdep: Add CPU-idle/offline warning to lockdep-RCU splat 2012-02-21 09:06:06 -08:00
Makefile sysctl: Move the implementation into fs/proc/proc_sysctl.c 2012-01-24 16:37:54 -08:00
module.c module: fix out-by-one error in kallsyms 2012-11-26 11:37:41 -08:00
mutex-debug.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
mutex-debug.h mutex: Use p->on_cpu for the adaptive spin 2011-04-14 08:52:33 +02:00
mutex.c sched/rt: Use schedule_preempt_disabled() 2012-03-01 10:28:03 +01:00
mutex.h mutex: Use p->on_cpu for the adaptive spin 2011-04-14 08:52:33 +02:00
notifier.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
nsproxy.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
padata.c padata: Fix cpu hotplug 2012-03-29 19:52:46 +08:00
panic.c panic: fix a possible deadlock in panic() 2013-04-12 09:38:47 -07:00
params.c params: <level>_initcall-like kernel parameters 2012-03-26 12:50:51 +10:30
pid_namespace.c pidns: add reboot_pid_ns() to handle the reboot syscall 2012-03-28 17:14:36 -07:00
pid.c vfs: fix panic in __d_lookup() with high dentry hashtable counts 2012-02-13 20:45:38 -05:00
posix-cpu-timers.c posix-cpu-timers: Fix nanosleep task_struct leak 2013-02-28 06:58:59 -08:00
posix-timers.c posix-timer: Don't call idr_find() with out-of-range ID 2013-03-04 06:06:38 +08:00
printk.c printk: fix buffer overflow when calling log_prefix function from call_console_drivers 2013-02-21 10:04:57 -08:00
profile.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
ptrace.c ptrace: ensure arch_ptrace/ptrace_request can never race with SIGKILL 2013-01-27 20:47:43 -08:00
range.c range: fix bogus misuse of module.h to get printk() 2011-10-31 09:20:11 -04:00
rcu.h rcu: Allow nesting of rcu_idle_enter() and rcu_idle_exit() 2012-02-21 09:06:12 -08:00
rcupdate.c rcu: Check for illegal use of RCU from offlined CPUs 2012-02-21 09:06:03 -08:00
rcutiny_plugin.h rcu: Simplify unboosting checks 2012-02-21 09:03:43 -08:00
rcutiny.c rcu: Add RCU_NONIDLE() for idle-loop RCU read-side critical sections 2012-02-21 09:06:13 -08:00
rcutorture.c PTR_ERR should be called before its argument is cleared. 2012-02-21 09:06:10 -08:00
rcutree_plugin.h rcu: Hold off RCU_FAST_NO_HZ after timer posted 2012-02-21 09:42:30 -08:00
rcutree_trace.c rcu: Rework detection of use of RCU by offline CPUs 2012-02-21 09:06:07 -08:00
rcutree.c rcu: Fix batch-limit size problem 2012-12-17 10:37:46 -08:00
rcutree.h rcu: Rework detection of use of RCU by offline CPUs 2012-02-21 09:06:07 -08:00
relay.c splice: fix racy pipe->buffers uses 2012-07-16 09:04:42 -07:00
res_counter.c net: introduce res_counter_charge_nofail() for socket allocations 2012-01-22 15:08:46 -05:00
resource.c kernel/resource.c: fix stack overflow in __reserve_region_with_split() 2013-02-14 10:48:53 -08:00
rtmutex_common.h
rtmutex-debug.c lockdep, rtmutex, bug: Show taint flags on error 2011-12-06 08:16:49 +01:00
rtmutex-debug.h
rtmutex-tester.c rtmutex-tester: convert sysdev_class to a regular subsystem 2011-12-14 14:54:22 -08:00
rtmutex.c Revert "rcu: Permit rt_mutex_unlock() with irqs disabled" 2011-12-11 10:33:18 -08:00
rtmutex.h
rwsem.c Remove all #inclusions of asm/system.h 2012-03-28 18:30:03 +01:00
seccomp.c seccomp: audit abnormal end to a process due to seccomp 2012-01-17 16:16:55 -05:00
semaphore.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
signal.c kernel/signal.c: stop info leak via the tkill and the tgkill syscalls 2013-04-25 21:19:54 -07:00
smp.c smp: Fix SMP function call empty cpu mask race 2013-02-03 18:24:42 -06:00
softirq.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2012-03-20 10:32:09 -07:00
spinlock.c locking/kconfig: Simplify INLINE_SPIN_UNLOCK usage 2012-03-23 13:18:57 +01:00
srcu.c rcu: Call out dangers of expedited RCU primitives 2012-02-21 09:06:08 -08:00
stacktrace.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
stop_machine.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
sys_ni.c Cross Memory Attach 2011-10-31 17:30:44 -07:00
sys.c reboot: rigrate shutdown/reboot to boot cpu 2013-06-20 11:58:45 -07:00
sysctl_binary.c sysctl: fix null checking in bin_dn_node_address() 2013-03-04 06:06:41 +08:00
sysctl.c sysctl: fix write access to dmesg_restrict/kptr_restrict 2012-04-05 14:51:43 +10:00
taskstats.c Make TASKSTATS require root access 2011-09-19 17:04:37 -07:00
test_kprobes.c
time.c time: Remove bogus comments 2012-03-15 18:17:55 -07:00
timeconst.pl timeconst.pl: Eliminate Perl warning 2013-02-28 06:58:58 -08:00
timer.c timer: Fix jiffies wrap behavior of round_jiffies_common() 2013-07-21 18:19:01 -07:00
tracepoint.c static keys: Introduce 'struct static_key', static_key_true()/false() and static_key_slow_[inc|dec]() 2012-02-24 10:05:59 +01:00
tsacct.c [S390] cputime: add sparse checking and cleanup 2011-12-15 14:56:19 +01:00
uid16.c userns: user namespaces: convert several capable() calls 2011-03-23 19:47:08 -07:00
up.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
user_namespace.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
user-return-notifier.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
user.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
utsname_sysctl.c Merge branch 'modsplit-Oct31_2011' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux 2011-11-06 19:44:47 -08:00
utsname.c kernel: Map most files to use export.h instead of module.h 2011-10-31 09:20:12 -04:00
wait.c lockdep/waitqueues: Add better annotation 2011-12-21 10:07:39 +01:00
watchdog.c watchdog: using u64 in get_sample_period() 2012-12-03 11:47:17 -08:00
workqueue_sched.h
workqueue.c workqueue: convert BUG_ON()s in __queue_delayed_work() to WARN_ON_ONCE()s 2012-12-17 10:37:43 -08:00