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

Pull perf fixes from Ingo Molnar:
"Two kernel side fixes:

- an Intel uncore PMU driver potential crash fix
- a kprobes/perf-call-graph interaction fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU
kprobes/x86: Fix page-fault handling logic

arch/x86/kernel/cpu/perf_event_intel_rapl.c

···
 	struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu);
 	int phys_id = topology_physical_package_id(cpu);
 	u64 ms;
+	u64 msr_rapl_power_unit_bits;
 
 	if (pmu)
 		return 0;
 
 	if (phys_id < 0)
+		return -1;
+
+	if (!rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits))
 		return -1;
 
 	pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu));
···
 	 *
 	 * we cache in local PMU instance
 	 */
-	rdmsrl(MSR_RAPL_POWER_UNIT, pmu->hw_unit);
-	pmu->hw_unit = (pmu->hw_unit >> 8) & 0x1FULL;
+	pmu->hw_unit = (msr_rapl_power_unit_bits >> 8) & 0x1FULL;
 	pmu->pmu = &rapl_pmu_class;
 
 	/*
···
 	cpu_notifier_register_begin();
 
 	for_each_online_cpu(cpu) {
-		rapl_cpu_prepare(cpu);
+		ret = rapl_cpu_prepare(cpu);
+		if (ret)
+			goto out;
 		rapl_cpu_init(cpu);
 	}
 
···
 		hweight32(rapl_cntr_mask),
 		ktime_to_ms(pmu->timer_interval));
 
+out:
 	cpu_notifier_register_done();
 
 	return 0;

arch/x86/kernel/kprobes/core.c

···
 	struct kprobe *cur = kprobe_running();
 	struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
 
-	switch (kcb->kprobe_status) {
-	case KPROBE_HIT_SS:
-	case KPROBE_REENTER:
+	if (unlikely(regs->ip == (unsigned long)cur->ainsn.insn)) {
+		/* This must happen on single-stepping */
+		WARN_ON(kcb->kprobe_status != KPROBE_HIT_SS &&
+			kcb->kprobe_status != KPROBE_REENTER);
 		/*
 		 * We are here because the instruction being single
 		 * stepped caused a page fault. We reset the current
···
 		else
 			reset_current_kprobe();
 		preempt_enable_no_resched();
-		break;
-	case KPROBE_HIT_ACTIVE:
-	case KPROBE_HIT_SSDONE:
+	} else if (kcb->kprobe_status == KPROBE_HIT_ACTIVE ||
+		   kcb->kprobe_status == KPROBE_HIT_SSDONE) {
 		/*
 		 * We increment the nmissed count for accounting,
 		 * we can also use npre/npostfault count for accounting
···
 		 * fixup routine could not handle it,
 		 * Let do_page_fault() fix it.
 		 */
-		break;
-	default:
-		break;
 	}
+
 	return 0;
 }