arm64: perf: reject CHAIN events at creation time

[linux-block.git] / arch / arm64 / kernel / perf_event.c

diff --git a/arch/arm64/kernel/perf_event.c b/arch/arm64/kernel/perf_event.c
index a5193f2146a689b2621c5ea548039de353c656c3..dde06c0f97f3ee5a3d0fdc9a6b1c517fe3f98045 100644 (file)
--- a/arch/arm64/kernel/perf_event.c
+++ b/arch/arm64/kernel/perf_event.c
@@ -1023,12 +1023,6 @@ static int armv8pmu_set_event_filter(struct hw_perf_event *event,
        return 0;
 }
 
-static bool armv8pmu_filter(struct pmu *pmu, int cpu)
-{
-       struct arm_pmu *armpmu = to_arm_pmu(pmu);
-       return !cpumask_test_cpu(smp_processor_id(), &armpmu->supported_cpus);
-}
-
 static void armv8pmu_reset(void *info)
 {
        struct arm_pmu *cpu_pmu = (struct arm_pmu *)info;
@@ -1069,6 +1063,14 @@ static int __armv8_pmuv3_map_event(struct perf_event *event,
                                       &armv8_pmuv3_perf_cache_map,
                                       ARMV8_PMU_EVTYPE_EVENT);
 
+       /*
+        * CHAIN events only work when paired with an adjacent counter, and it
+        * never makes sense for a user to open one in isolation, as they'll be
+        * rotated arbitrarily.
+        */
+       if (hw_event_id == ARMV8_PMUV3_PERFCTR_CHAIN)
+               return -EINVAL;
+
        if (armv8pmu_event_is_64bit(event))
                event->hw.flags |= ARMPMU_EVT_64BIT;
 
@@ -1258,7 +1260,6 @@ static int armv8_pmu_init(struct arm_pmu *cpu_pmu, char *name,
        cpu_pmu->stop                   = armv8pmu_stop;
        cpu_pmu->reset                  = armv8pmu_reset;
        cpu_pmu->set_event_filter       = armv8pmu_set_event_filter;
-       cpu_pmu->filter                 = armv8pmu_filter;
 
        cpu_pmu->pmu.event_idx          = armv8pmu_user_event_idx;