Commit e5c23779 authored Apr 08, 2022 by Rob Herring Committed by Will Deacon Apr 13, 2022

arm_pmu: Validate single/group leader events



In the case where there is only a cycle counter available (i.e.
PMCR_EL0.N is 0) and an event other than CPU cycles is opened, the open
should fail as the event can never possibly be scheduled. However, the
event validation when an event is opened is skipped when the group
leader is opened. Fix this by always validating the group leader events.

Reported-by: Al Grant <al.grant@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220408203330.4014015-1-robh@kernel.org


Cc: <stable@vger.kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>

parent d02b4dd8

drivers/perf/arm_pmu.c

+4 −6

Original line number	Diff line number	Diff line
		@@ -400,6 +400,9 @@ validate_group(struct perf_event *event)
		if (!validate_event(event->pmu, &fake_pmu, leader))
		return -EINVAL;

		if (event == leader)
		return 0;

		for_each_sibling_event(sibling, leader) {
		if (!validate_event(event->pmu, &fake_pmu, sibling))
		return -EINVAL;
		@@ -489,12 +492,7 @@ __hw_perf_event_init(struct perf_event *event)
		local64_set(&hwc->period_left, hwc->sample_period);
		}

		if (event->group_leader != event) {
		if (validate_group(event) != 0)
		return -EINVAL;
		}

		return 0;
		return validate_group(event);
		}

		static int armpmu_event_init(struct perf_event *event)