linux-stable/kernel/time
Chang-An Chen cd37fd46b4 timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze()
commit 3f2552f7e9 upstream.

tick_freeze() introduced by suspend-to-idle in commit 124cf9117c ("PM /
sleep: Make it possible to quiesce timers during suspend-to-idle") uses
timekeeping_suspend() instead of syscore_suspend() during
suspend-to-idle. As a consequence generic sched_clock will keep going
because sched_clock_suspend() and sched_clock_resume() are not invoked
during suspend-to-idle which can result in a generic sched_clock wrap.

On a ARM system with suspend-to-idle enabled, sched_clock is registered
as "56 bits at 13MHz, resolution 76ns, wraps every 4398046511101ns", which
means the real wrapping duration is 8796093022202ns.

[  134.551779] suspend-to-idle suspend (timekeeping_suspend())
[ 1204.912239] suspend-to-idle resume (timekeeping_resume())
......
[ 1206.912239] suspend-to-idle suspend (timekeeping_suspend())
[ 5880.502807] suspend-to-idle resume (timekeeping_resume())
......
[ 6000.403724] suspend-to-idle suspend (timekeeping_suspend())
[ 8035.753167] suspend-to-idle resume  (timekeeping_resume())
......
[ 8795.786684] (2)[321:charger_thread]......
[ 8795.788387] (2)[321:charger_thread]......
[    0.057226] (0)[0:swapper/0]......
[    0.061447] (2)[0:swapper/2]......

sched_clock was not stopped during suspend-to-idle, and sched_clock_poll
hrtimer was not expired because timekeeping_suspend() was invoked during
suspend-to-idle. It makes sched_clock wrap at kernel time 8796s.

To prevent this, invoke sched_clock_suspend() and sched_clock_resume() in
tick_freeze() together with timekeeping_suspend() and timekeeping_resume().

Fixes: 124cf9117c (PM / sleep: Make it possible to quiesce timers during suspend-to-idle)
Signed-off-by: Chang-An Chen <chang-an.chen@mediatek.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Matthias Brugger <matthias.bgg@gmail.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Corey Minyard <cminyard@mvista.com>
Cc: <linux-mediatek@lists.infradead.org>
Cc: <linux-arm-kernel@lists.infradead.org>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: <kuohong.wang@mediatek.com>
Cc: <freddy.hsin@mediatek.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/1553828349-8914-1-git-send-email-chang-an.chen@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-04-27 09:36:38 +02:00
..
alarmtimer.c alarmtimer: Return correct remaining time 2019-04-17 08:38:50 +02:00
clockevents.c clockevents: Warn if cpu_all_mask is used as cpumask 2018-08-02 14:55:53 +02:00
clocksource.c clocksource: Revert "Remove kthread" 2018-09-06 23:38:35 +02:00
hrtimer.c Merge branch 'fortglx/4.19/time' of https://git.linaro.org/people/john.stultz/linux into timers/core 2018-07-12 22:19:58 +02:00
itimer.c pid: Implement PIDTYPE_TGID 2018-07-21 10:43:12 -05:00
jiffies.c jiffies: Revert bogus conversion of NSEC_PER_SEC to TICK_NSEC 2017-03-07 11:03:28 +01:00
Kconfig sched/isolation: Eliminate NO_HZ_FULL_ALL 2018-02-15 15:40:37 -08:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ntp.c timekeeping/ntp: Constify some function arguments 2018-07-19 17:08:05 -07:00
ntp_internal.h timekeeping/ntp: Constify some function arguments 2018-07-19 17:08:05 -07:00
posix-clock.c vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
posix-cpu-timers.c posix-cpu-timers: Unbreak timer rearming 2019-01-31 08:14:39 +01:00
posix-stubs.c posix-timers: Use new ktime_get_*_ts64() helpers 2018-06-19 09:56:27 +02:00
posix-timers.c posix-timers: Fix division by zero bug 2018-12-29 13:37:56 +01:00
posix-timers.h posix-timers: Make forward callback return s64 2018-07-02 11:33:25 +02:00
sched_clock.c timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze() 2019-04-27 09:36:38 +02:00
test_udelay.c
tick-broadcast-hrtimer.c tick/broadcast-hrtimer: Use cpu_possible_mask for ce_broadcast_hrtimer 2018-08-02 14:55:52 +02:00
tick-broadcast.c tick/broadcast: Use for_each_cpu() specially on UP kernels 2018-05-15 22:45:54 +02:00
tick-common.c timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze() 2019-04-27 09:36:38 +02:00
tick-internal.h Revert: Unify CLOCK_MONOTONIC and CLOCK_BOOTTIME 2018-04-26 14:53:32 +02:00
tick-oneshot.c clockevents: Fix kernel messages split across multiple lines 2018-04-17 17:18:04 +02:00
tick-sched.c nohz: Fix local_timer_softirq_pending() 2018-07-31 22:08:44 +02:00
tick-sched.h nohz: Gather tick_sched booleans under a common flag field 2018-04-09 11:54:57 +02:00
time.c Merge branch 'fortglx/4.19/time' of https://git.linaro.org/people/john.stultz/linux into timers/core 2018-07-12 22:19:58 +02:00
timeconst.bc time: Introduce jiffies64_to_nsecs() 2017-02-01 09:13:45 +01:00
timeconv.c
timecounter.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
timekeeping.c timekeeping: Use proper seqcount initializer 2019-02-12 19:47:05 +01:00
timekeeping.h timers/sched_clock: Prevent generic sched_clock wrap caused by tick_freeze() 2019-04-27 09:36:38 +02:00
timekeeping_debug.c timekeeping/ntp: Constify some function arguments 2018-07-19 17:08:05 -07:00
timekeeping_internal.h timekeeping/ntp: Constify some function arguments 2018-07-19 17:08:05 -07:00
timer.c timers: Clear timer_base::must_forward_clk with timer_base::lock held 2018-08-02 12:52:38 +02:00
timer_list.c Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-06-04 20:27:54 -07:00