6 files changed, 22 insertions, 9 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel_ds.c b/arch/x86/kernel/cpu/perf_event_intel_ds.c
index 73da6b64f5b..d6bd49faa40 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_ds.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_ds.c
@@ -439,7 +439,6 @@ void intel_pmu_pebs_enable(struct perf_event *event)
         hwc->config &= ~ARCH_PERFMON_EVENTSEL_INT;
 
         cpuc->pebs_enabled |= 1ULL << hwc->idx;
-        WARN_ON_ONCE(cpuc->enabled);
 
         if (x86_pmu.intel_cap.pebs_trap && event->attr.precise_ip > 1)
                 intel_pmu_lbr_enable(event);
diff --git a/arch/x86/kernel/cpu/perf_event_intel_lbr.c b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
index 3fab3de3ce9..47a7e63bfe5 100644
--- a/arch/x86/kernel/cpu/perf_event_intel_lbr.c
+++ b/arch/x86/kernel/cpu/perf_event_intel_lbr.c
@@ -72,8 +72,6 @@ void intel_pmu_lbr_enable(struct perf_event *event)
         if (!x86_pmu.lbr_nr)
                 return;
 
-        WARN_ON_ONCE(cpuc->enabled);
-
         /*
          * Reset the LBR stack if we changed task context to
          * avoid data leaks.
diff --git a/kernel/events/core.c b/kernel/events/core.c
index ba36013cfb2..1b5c081d8b9 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -2303,7 +2303,7 @@ do {					\
 static DEFINE_PER_CPU(int, perf_throttled_count);
 static DEFINE_PER_CPU(u64, perf_throttled_seq);
 
-static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count)
+static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count, bool disable)
 {
         struct hw_perf_event *hwc = &event->hw;
         s64 period, sample_period;
@@ -2322,9 +2322,13 @@ static void perf_adjust_period(struct perf_event *event, u64 nsec, u64 count)
         hwc->sample_period = sample_period;
 
         if (local64_read(&hwc->period_left) > 8*sample_period) {
-                event->pmu->stop(event, PERF_EF_UPDATE);
+                if (disable)
+                        event->pmu->stop(event, PERF_EF_UPDATE);
+
                 local64_set(&hwc->period_left, 0);
-                event->pmu->start(event, PERF_EF_RELOAD);
+
+                if (disable)
+                        event->pmu->start(event, PERF_EF_RELOAD);
         }
 }
 
@@ -2350,6 +2354,7 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
                 return;
 
         raw_spin_lock(&ctx->lock);
+        perf_pmu_disable(ctx->pmu);
 
         list_for_each_entry_rcu(event, &ctx->event_list, event_entry) {
                 if (event->state != PERF_EVENT_STATE_ACTIVE)
@@ -2381,13 +2386,17 @@ static void perf_adjust_freq_unthr_context(struct perf_event_context *ctx,
                 /*
                  * restart the event
                  * reload only if value has changed
+                 * we have stopped the event so tell that
+                 * to perf_adjust_period() to avoid stopping it
+                 * twice.
                  */
                 if (delta > 0)
-                        perf_adjust_period(event, period, delta);
+                        perf_adjust_period(event, period, delta, false);
 
                 event->pmu->start(event, delta > 0 ? PERF_EF_RELOAD : 0);
         }
 
+        perf_pmu_enable(ctx->pmu);
         raw_spin_unlock(&ctx->lock);
 }
 
@@ -4562,7 +4571,7 @@ static int __perf_event_overflow(struct perf_event *event,
                 hwc->freq_time_stamp = now;
 
                 if (delta > 0 && delta < 2*TICK_NSEC)
-                        perf_adjust_period(event, delta, hwc->last_period);
+                        perf_adjust_period(event, delta, hwc->last_period, true);
         }
 
         /*
diff --git a/tools/perf/bench/mem-memcpy-x86-64-asm.S b/tools/perf/bench/mem-memcpy-x86-64-asm.S
index a57b66e853c..185a96d66dd 100644
--- a/tools/perf/bench/mem-memcpy-x86-64-asm.S
+++ b/tools/perf/bench/mem-memcpy-x86-64-asm.S
@@ -1,2 +1,8 @@
 
 #include "../../../arch/x86/lib/memcpy_64.S"
+/*
+ * We need to provide note.GNU-stack section, saying that we want
+ * NOT executable stack. Otherwise the final linking will assume that
+ * the ELF stack should not be restricted at all and set it RWX.
+ */
+.section .note.GNU-stack,"",@progbits
diff --git a/tools/perf/util/event.c b/tools/perf/util/event.c
index 73ddaf06b8e..2044324b755 100644
--- a/tools/perf/util/event.c
+++ b/tools/perf/util/event.c
@@ -554,7 +554,7 @@ static int perf_event__process_kernel_mmap(struct perf_tool *tool __used,
 
         is_kernel_mmap = memcmp(event->mmap.filename,
                                 kmmap_prefix,
-                                strlen(kmmap_prefix)) == 0;
+                                strlen(kmmap_prefix) - 1) == 0;
         if (event->mmap.filename[0] == '/' ||
             (!is_kernel_mmap && event->mmap.filename[0] == '[')) {
 
diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c
index 667f3b78bb2..7132ee834e0 100644
--- a/tools/perf/util/evsel.c
+++ b/tools/perf/util/evsel.c
@@ -463,6 +463,7 @@ int perf_event__parse_sample(const union perf_event *event, u64 type,
         memset(data, 0, sizeof(*data));
         data->cpu = data->pid = data->tid = -1;
         data->stream_id = data->id = data->time = -1ULL;
+        data->period = 1;
 
         if (event->header.type != PERF_RECORD_SAMPLE) {
                 if (!sample_id_all)