Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Thomas Gleixner:
 "Three fixlets for perf:

   - add a missing NULL pointer check in the intel BTS driver

   - make BTS an exclusive PMU because BTS can only handle one event at
     a time

   - ensure that exclusive events are limited to one PMU so that several
     exclusive events can be scheduled on different PMU instances"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/core: Limit matching exclusive events to one PMU
  perf/x86/intel/bts: Make it an exclusive PMU
  perf/x86/intel/bts: Make sure debug store is valid

Author: torvalds

arch/x86/events/intel/bts.c

@@ -455,7 +455,7 @@ int intel_bts_interrupt(void)
 	 * The only surefire way of knowing if this NMI is ours is by checking
 	 * the write ptr against the PMI threshold.
 	 */
-	if (ds->bts_index >= ds->bts_interrupt_threshold)
+	if (ds && (ds->bts_index >= ds->bts_interrupt_threshold))
 		handled = 1;
 
 	/*
@@ -584,7 +584,8 @@ static __init int bts_init(void)
 	if (!boot_cpu_has(X86_FEATURE_DTES64) || !x86_pmu.bts)
 		return -ENODEV;
 
-	bts_pmu.capabilities	= PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_ITRACE;
+	bts_pmu.capabilities	= PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_ITRACE |
+				  PERF_PMU_CAP_EXCLUSIVE;
 	bts_pmu.task_ctx_nr	= perf_sw_context;
 	bts_pmu.event_init	= bts_event_init;
 	bts_pmu.add		= bts_event_add;

kernel/events/core.c

@@ -3929,7 +3929,7 @@ static void exclusive_event_destroy(struct perf_event *event)
 
 static bool exclusive_event_match(struct perf_event *e1, struct perf_event *e2)
 {
-	if ((e1->pmu->capabilities & PERF_PMU_CAP_EXCLUSIVE) &&
+	if ((e1->pmu == e2->pmu) &&
 	    (e1->cpu == e2->cpu ||
 	     e1->cpu == -1 ||
 	     e2->cpu == -1))