From 45fe4fe19120a22f7339f5bb110447170c25fca9 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Wed, 30 Jan 2008 13:30:03 +0100 Subject: [PATCH] x86: make clockevents more robust detect zero event-device multiplicators - they then cause division-by-zero crashes if a clockevent has been initialized incorrectly. Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/time/clockevents.c | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 5fb139fef9fa..3e59fce6dd43 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -41,6 +41,11 @@ unsigned long clockevent_delta2ns(unsigned long latch, { u64 clc = ((u64) latch << evt->shift); + if (unlikely(!evt->mult)) { + evt->mult = 1; + WARN_ON(1); + } + do_div(clc, evt->mult); if (clc < 1000) clc = 1000; @@ -151,6 +156,14 @@ static void clockevents_notify_released(void) void clockevents_register_device(struct clock_event_device *dev) { BUG_ON(dev->mode != CLOCK_EVT_MODE_UNUSED); + /* + * A nsec2cyc multiplicator of 0 is invalid and we'd crash + * on it, so fix it up and emit a warning: + */ + if (unlikely(!dev->mult)) { + dev->mult = 1; + WARN_ON(1); + } spin_lock(&clockevents_lock); -- 2.20.1