simpleperf: Enable ETM events after create aux buffer

Otherwise, ETM events can't be enabled successfully.

Bug: 336375740
Test: run simpleperf manually
Change-Id: I6583aebced57d739f98769cc39dab862569ec8ad

3 files changed, 56 insertions, 3 deletions

diff --git a/simpleperf/cmd_record.cpp b/simpleperf/cmd_record.cpp
index 40582045..ee93e1ea 100644
--- a/simpleperf/cmd_record.cpp
+++ b/simpleperf/cmd_record.cpp
@@ -631,7 +631,7 @@ bool RecordCommand::PrepareRecording(Workload* workload) {
   } else {
     need_to_check_targets = true;
   }
-  if (delay_in_ms_ != 0) {
+  if (delay_in_ms_ != 0 || event_selection_set_.HasAuxTrace()) {
     event_selection_set_.SetEnableCondition(false, false);
   }
 
@@ -755,6 +755,12 @@ bool RecordCommand::PrepareRecording(Workload* workload) {
     }
   }
   if (event_selection_set_.HasAuxTrace()) {
+    // ETM events can only be enabled successfully after MmapEventFiles().
+    if (delay_in_ms_ == 0 && !event_selection_set_.IsEnabledOnExec()) {
+      if (!event_selection_set_.EnableETMEvents()) {
+        return false;
+      }
+    }
     // ETM data is dumped to kernel buffer only when there is no thread traced by ETM. It happens
     // either when all monitored threads are scheduled off cpu, or when all etm perf events are
     // disabled.
@@ -762,8 +768,7 @@ bool RecordCommand::PrepareRecording(Workload* workload) {
     // makes less than expected data, especially in system wide recording. So add a periodic event
     // to flush etm data by temporarily disable all perf events.
     auto etm_flush = [this]() {
-      return event_selection_set_.SetEnableEvents(false) &&
-             event_selection_set_.SetEnableEvents(true);
+      return event_selection_set_.DisableETMEvents() && event_selection_set_.EnableETMEvents();
     };
     if (!loop->AddPeriodicEvent(SecondToTimeval(kDefaultEtmDataFlushPeriodInSec), etm_flush)) {
       return false;
diff --git a/simpleperf/event_selection_set.cpp b/simpleperf/event_selection_set.cpp
index c75f8049..6a1e5a9e 100644
--- a/simpleperf/event_selection_set.cpp
+++ b/simpleperf/event_selection_set.cpp
@@ -233,6 +233,8 @@ bool EventSelectionSet::BuildAndCheckEventSelection(const std::string& event_nam
       // enabling/disabling etm devices. So don't adjust frequency by default.
       selection->event_attr.freq = 0;
       selection->event_attr.sample_period = 1;
+      // An ETM event can't be enabled without mmap aux buffer. So disable it by default.
+      selection->event_attr.disabled = 1;
     } else {
       selection->event_attr.freq = 1;
       // Set default sample freq here may print msg "Adjust sample freq to max allowed sample
@@ -461,6 +463,17 @@ void EventSelectionSet::SetEnableCondition(bool enable_on_open, bool enable_on_e
   }
 }
 
+bool EventSelectionSet::IsEnabledOnExec() const {
+  for (const auto& group : groups_) {
+    for (const auto& selection : group.selections) {
+      if (!selection.event_attr.enable_on_exec) {
+        return false;
+      }
+    }
+  }
+  return true;
+}
+
 void EventSelectionSet::SampleIdAll() {
   for (auto& group : groups_) {
     for (auto& selection : group.selections) {
@@ -939,4 +952,36 @@ bool EventSelectionSet::SetEnableEvents(bool enable) {
   return true;
 }
 
+bool EventSelectionSet::EnableETMEvents() {
+  for (auto& group : groups_) {
+    for (auto& sel : group.selections) {
+      if (!sel.event_type_modifier.event_type.IsEtmEvent()) {
+        continue;
+      }
+      for (auto& fd : sel.event_fds) {
+        if (!fd->SetEnableEvent(true)) {
+          return false;
+        }
+      }
+    }
+  }
+  return true;
+}
+
+bool EventSelectionSet::DisableETMEvents() {
+  for (auto& group : groups_) {
+    for (auto& sel : group.selections) {
+      if (!sel.event_type_modifier.event_type.IsEtmEvent()) {
+        continue;
+      }
+      for (auto& fd : sel.event_fds) {
+        if (!fd->SetEnableEvent(false)) {
+          return false;
+        }
+      }
+    }
+  }
+  return true;
+}
+
 }  // namespace simpleperf
diff --git a/simpleperf/event_selection_set.h b/simpleperf/event_selection_set.h
index e046035b..1b3d6b4e 100644
--- a/simpleperf/event_selection_set.h
+++ b/simpleperf/event_selection_set.h
@@ -122,6 +122,7 @@ class EventSelectionSet {
   std::map<int, size_t> GetHardwareCountersForCpus() const;
 
   void SetEnableCondition(bool enable_on_open, bool enable_on_exec);
+  bool IsEnabledOnExec() const;
   void SampleIdAll();
   // Only set sample rate for events that haven't set sample rate.
   void SetSampleRateForNewEvents(const SampleRate& rate);
@@ -179,6 +180,8 @@ class EventSelectionSet {
       double check_interval_in_sec = DEFAULT_PERIOD_TO_CHECK_MONITORED_TARGETS_IN_SEC);
 
   bool SetEnableEvents(bool enable);
+  bool EnableETMEvents();
+  bool DisableETMEvents();
 
  private:
   struct EventSelection {