From ff5860f5088e9076ebcccf05a6ca709d5935cfa9 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sat, 20 Dec 2025 14:14:41 +0100 Subject: 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 Tested-by: CyberUnicorns Debugged-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) --- kernel/events/core.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'kernel') diff --git a/kernel/events/core.c b/kernel/events/core.c index dad0d3d2e85f..e3d8338fd51c 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -11906,6 +11906,11 @@ 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; @@ -11914,6 +11919,7 @@ 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 -- cgit v1.2.3