From: Rob Herring Date: Fri, 8 Apr 2022 20:33:30 +0000 (-0500) Subject: arm_pmu: Validate single/group leader events X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=e5c23779f93d45e39a52758ca593bd7e62e9b4be;p=linux.git 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 Cc: Will Deacon Cc: Mark Rutland Signed-off-by: Rob Herring Acked-by: Mark Rutland Link: https://lore.kernel.org/r/20220408203330.4014015-1-robh@kernel.org Cc: Signed-off-by: Will Deacon --- diff --git a/drivers/perf/arm_pmu.c b/drivers/perf/arm_pmu.c index 9694370651fa..59d3980b8ca2 100644 --- a/drivers/perf/arm_pmu.c +++ b/drivers/perf/arm_pmu.c @@ -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)