2 files changed, 16 insertions, 12 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel_rapl.c b/arch/x86/kernel/cpu/perf_event_intel_rapl.c
index 4b9a9e9466bd..7c87424d4140 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c
@@ -535,6 +535,7 @@ static int rapl_cpu_prepare(int cpu)
         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;
@@ -542,6 +543,9 @@ static int rapl_cpu_prepare(int cpu)
         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));
         if (!pmu)
                 return -1;
@@ -555,8 +559,7 @@ static int rapl_cpu_prepare(int 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;
 
         /*
@@ -677,7 +680,9 @@ static int __init rapl_pmu_init(void)
         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);
         }
 
@@ -700,6 +705,7 @@ static int __init rapl_pmu_init(void)
                 hweight32(rapl_cntr_mask),
                 ktime_to_ms(pmu->timer_interval));
 
+out:
         cpu_notifier_register_done();
 
         return 0;
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index 79a3f9682871..61b17dc2c277 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -897,9 +897,10 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
         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
@@ -914,9 +915,8 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
                 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
@@ -945,10 +945,8 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
                  * fixup routine could not handle it,
                  * Let do_page_fault() fix it.
                  */
-                break;
-        default:
-                break;
         }
+
         return 0;
 }