From: Rob Herring robh@kernel.org
commit e5c23779f93d45e39a52758ca593bd7e62e9b4be upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/perf/arm_pmu.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-)
--- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -321,6 +321,9 @@ 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; @@ -418,12 +421,7 @@ __hw_perf_event_init(struct perf_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)