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perf: Ensure swevent hrtimer is properly destroyed 

[ Upstream commit ff5860f5088e9076ebcccf05a6ca709d5935cfa9 ]

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: eb3182ef04 ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Peter Zijlstra 2025-12-20 14:14:41 +01:00 committed by Greg Kroah-Hartman
parent 088ca99dbb
commit deee9dfb11
1 changed files with 6 additions and 0 deletions
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6
kernel/events/core.c
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@ -11835,6 +11835,11 @@ static void perf_swevent_cancel_hrtimer(struct perf_event *event)
}
}
static void perf_swevent_destroy_hrtimer(struct perf_event *event)
{
hrtimer_cancel(&event->hw.hrtimer);
}
static void perf_swevent_init_hrtimer(struct perf_event *event)
{
struct hw_perf_event *hwc = &event->hw;
@ -11843,6 +11848,7 @@ static void perf_swevent_init_hrtimer(struct perf_event *event)
return;
hrtimer_setup(&hwc->hrtimer, perf_swevent_hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD);
event->destroy = perf_swevent_destroy_hrtimer;
/*
* Since hrtimers have a fixed rate, we can do a static freq->period