Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
perf: Ensure swevent hrtimer is properly destroyed
With the change to hrtimer_try_to_cancel() in
perf_swevent_cancel_hrtimer() it appears possible for the hrtimer to
still be active by the time the event gets freed.
Make sure the event does a full hrtimer_cancel() on the free path by
installing a perf_event::destroy handler.
Fixes: eb3182ef0405 ("perf/core: Fix system hang caused by cpu-clock usage")
Reported-by: CyberUnicorns <a101e_iotvul@163.com>
Tested-by: CyberUnicorns <a101e_iotvul@163.com>
Debugged-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
+6
+6
kernel/events/core.c
+6
kernel/events/core.c
···
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}
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}
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+
static void perf_swevent_destroy_hrtimer(struct perf_event *event)
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+
{
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+
hrtimer_cancel(&event->hw.hrtimer);
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+
}
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+
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static void perf_swevent_init_hrtimer(struct perf_event *event)
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{
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struct hw_perf_event *hwc = &event->hw;
···
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return;
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hrtimer_setup(&hwc->hrtimer, perf_swevent_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
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+
event->destroy = perf_swevent_destroy_hrtimer;
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/*
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* Since hrtimers have a fixed rate, we can do a static freq->period