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| author | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:03 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-01-30 13:30:03 +0100 |
| commit | 45fe4fe19120a22f7339f5bb110447170c25fca9 (patch) | |
| tree | 06639135ca5bc60e952670dd7df40e195edb2ad9 /kernel | |
| parent | 1a0c009ac53de4a7664a1239936f0bc258133156 (diff) | |
| download | kernel-common-45fe4fe19120a22f7339f5bb110447170c25fca9.tar.gz kernel-common-45fe4fe19120a22f7339f5bb110447170c25fca9.tar.bz2 kernel-common-45fe4fe19120a22f7339f5bb110447170c25fca9.zip | |
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 <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/clockevents.c | 13 |
1 files changed, 13 insertions, 0 deletions
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); |