simpleperf: support recording etm data in perf.data.

1. In event_fd.cpp, add functions to create aux buffer and read etm
data.
2. In record.h, Add AuxTraceRecord.
2. In RecordReadThread.cpp, wrap etm data into AuxTraceRecords.
3. Add logic to read and write AuxTraceRecords in perf.data.
4. Show recorded etm data size after recording.

Bug: 135204414
Test: run simpleperf_unit_test.
Change-Id: I3b20fe8f3c786f130f38e34962ca9f86a31fc584

1 files changed, 16 insertions, 6 deletions

diff --git a/simpleperf/record_file_reader.cpp b/simpleperf/record_file_reader.cpp
index d57d3d8d..88617007 100644
--- a/simpleperf/record_file_reader.cpp
+++ b/simpleperf/record_file_reader.cpp
@@ -240,7 +240,7 @@ bool RecordFileReader::ReadRecord(std::unique_ptr<Record>& record) {
   }
   record = nullptr;
   if (read_record_size_ < header_.data.size) {
-    record = ReadRecord(&read_record_size_);
+    record = ReadRecord();
     if (record == nullptr) {
       return false;
     }
@@ -251,7 +251,7 @@ bool RecordFileReader::ReadRecord(std::unique_ptr<Record>& record) {
   return true;
 }
 
-std::unique_ptr<Record> RecordFileReader::ReadRecord(uint64_t* nbytes_read) {
+std::unique_ptr<Record> RecordFileReader::ReadRecord() {
   char header_buf[Record::header_size()];
   if (!Read(header_buf, Record::header_size())) {
     return nullptr;
@@ -270,7 +270,7 @@ std::unique_ptr<Record> RecordFileReader::ReadRecord(uint64_t* nbytes_read) {
         return nullptr;
       }
       cur_size += bytes_to_read;
-      *nbytes_read += header.size;
+      read_record_size_ += header.size;
       if (!Read(header_buf, Record::header_size())) {
         return nullptr;
       }
@@ -280,7 +280,7 @@ std::unique_ptr<Record> RecordFileReader::ReadRecord(uint64_t* nbytes_read) {
       LOG(ERROR) << "SPLIT records are not followed by a SPLIT_END record.";
       return nullptr;
     }
-    *nbytes_read += header.size;
+    read_record_size_ += header.size;
     header = RecordHeader(buf.data());
     p.reset(new char[header.size]);
     memcpy(p.get(), buf.data(), buf.size());
@@ -292,7 +292,7 @@ std::unique_ptr<Record> RecordFileReader::ReadRecord(uint64_t* nbytes_read) {
         return nullptr;
       }
     }
-    *nbytes_read += header.size;
+    read_record_size_ += header.size;
   }
 
   const perf_event_attr* attr = &file_attrs_[0].attr;
@@ -317,7 +317,17 @@ std::unique_ptr<Record> RecordFileReader::ReadRecord(uint64_t* nbytes_read) {
       }
     }
   }
-  return ReadRecordFromOwnedBuffer(*attr, header.type, p.release());
+  auto r = ReadRecordFromOwnedBuffer(*attr, header.type, p.release());
+  if (r->type() == PERF_RECORD_AUXTRACE) {
+    auto auxtrace = static_cast<AuxTraceRecord*>(r.get());
+    auxtrace->location.file_offset = header_.data.offset + read_record_size_;
+    read_record_size_ += auxtrace->data->aux_size;
+    if (fseek(record_fp_, auxtrace->data->aux_size, SEEK_CUR) != 0) {
+      PLOG(ERROR) << "fseek() failed";
+      return nullptr;
+    }
+  }
+  return r;
 }
 
 bool RecordFileReader::Read(void* buf, size_t len) {