Thomas Gleixner 6bad6bccf2 timers: Prevent base clock corruption when forwarding ... When a timer is enqueued we try to forward the timer base clock. This mechanism has two issues: 1) Forwarding a remote base unlocked The forwarding function is called from get_target_base() with the current timer base lock held. But if the new target base is a different base than the current base (can happen with NOHZ, sigh!) then the forwarding is done on an unlocked base. This can lead to corruption of base->clk. Solution is simple: Invoke the forwarding after the target base is locked. 2) Possible corruption due to jiffies advancing This is similar to the issue in get_net_timer_interrupt() which was fixed in the previous patch. jiffies can advance between check and assignement and therefore advancing base->clk beyond the next expiry value. So we need to read jiffies into a local variable once and do the checks and assignment with the local copy. Fixes: a683f390b93f("timers: Forward the wheel clock whenever possible") Reported-by: Ashton Holmes <scoopta@gmail.com> Reported-by: Michael Thayer <michael.thayer@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Michal Necasek <michal.necasek@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: knut.osmundsen@oracle.com Cc: stable@vger.kernel.org Cc: stern@rowland.harvard.edu Cc: rt@linutronix.de Link: http://lkml.kernel.org/r/20161022110552.253640125@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>		2016-10-25 16:32:50 +02:00
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alarmtimer.c
clockevents.c
clocksource.c
hrtimer.c
itimer.c
jiffies.c
Kconfig
Makefile
ntp_internal.h
ntp.c
posix-clock.c
posix-cpu-timers.c
posix-timers.c
sched_clock.c
test_udelay.c
tick-broadcast-hrtimer.c
tick-broadcast.c
tick-common.c
tick-internal.h
tick-oneshot.c
tick-sched.c
tick-sched.h
time.c
timeconst.bc
timeconv.c
timecounter.c
timekeeping_debug.c
timekeeping_internal.h
timekeeping.c
timekeeping.h
timer_list.c
timer_stats.c
timer.c