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| author | Thomas Gleixner <tglx@linutronix.de> | 2015-07-05 22:53:17 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2015-07-07 18:46:48 +0200 |
| commit | c4288334818c81c946acb23d2319881f58c3d497 (patch) | |
| tree | 77b3e765201a4d673d130e169becc0211f69f161 /kernel/time/tick-broadcast.c | |
| parent | tick/broadcast: Check for hrtimer broadcast active early (diff) | |
| download | linux-c4288334818c81c946acb23d2319881f58c3d497.tar.xz linux-c4288334818c81c946acb23d2319881f58c3d497.zip | |
tick/broadcast: Handle spurious interrupts gracefully
Andriy reported that on a virtual machine the warning about negative
expiry time in the clock events programming code triggered:
hpet: hpet0 irq 40 for MSI
hpet: hpet1 irq 41 for MSI
Switching to clocksource hpet
WARNING: at kernel/time/clockevents.c:239
[<ffffffff810ce6eb>] clockevents_program_event+0xdb/0xf0
[<ffffffff810cf211>] tick_handle_periodic_broadcast+0x41/0x50
[<ffffffff81016525>] timer_interrupt+0x15/0x20
When the second hpet is installed as a per cpu timer the broadcast
event is not longer required and stopped, which sets the next_evt of
the broadcast device to KTIME_MAX.
If after that a spurious interrupt happens on the broadcast device,
then the current code blindly handles it and tries to reprogram the
broadcast device afterwards, which adds the period to
next_evt. KTIME_MAX + period results in a negative expiry value
causing the WARN_ON in the clockevents code to trigger.
Add a proper check for the state of the broadcast device into the
interrupt handler and return if the interrupt is spurious.
[ Folded in pointer fix from Sudeep ]
Reported-by: Andriy Gapon <avg@FreeBSD.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Sudeep Holla <sudeep.holla@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Preeti U Murthy <preeti@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20150705205221.802094647@linutronix.de
Diffstat (limited to 'kernel/time/tick-broadcast.c')
| -rw-r--r-- | kernel/time/tick-broadcast.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index c8d731ac9563..ee3cf942d6eb 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -316,6 +316,13 @@ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) bool bc_local; raw_spin_lock(&tick_broadcast_lock); + + /* Handle spurious interrupts gracefully */ + if (clockevent_state_shutdown(tick_broadcast_device.evtdev)) { + raw_spin_unlock(&tick_broadcast_lock); + return; + } + bc_local = tick_do_periodic_broadcast(); if (clockevent_state_oneshot(dev)) { |