simpleperf: prepare recording etm data for kernel.

1. Use property to lower kptr_restrict in Android >= 12.
2. Add memory addr of kernel modules in etm recording file.

Bug: 183135316
Test: run simpleperf_unit_test
Change-Id: Ieeb7eee00bf0278ba0028397896b8bcb79165fa5

6 files changed, 49 insertions, 18 deletions

diff --git a/simpleperf/cmd_record.cpp b/simpleperf/cmd_record.cpp
index 1aec064a..cc87881e 100644
--- a/simpleperf/cmd_record.cpp
+++ b/simpleperf/cmd_record.cpp
@@ -1863,7 +1863,16 @@ bool RecordCommand::DumpBuildIdFeature() {
 }
 
 bool RecordCommand::DumpFileFeature() {
-  return record_file_writer_->WriteFileFeatures(thread_tree_.GetAllDsos());
+  std::vector<Dso*> dso_v = thread_tree_.GetAllDsos();
+  // To parse ETM data for kernel modules, we need to dump memory address for kernel modules.
+  if (event_selection_set_.HasAuxTrace() && !event_selection_set_.ExcludeKernel()) {
+    for (Dso* dso : dso_v) {
+      if (dso->type() == DSO_KERNEL_MODULE) {
+        dso->CreateDumpId();
+      }
+    }
+  }
+  return record_file_writer_->WriteFileFeatures(dso_v);
 }
 
 bool RecordCommand::DumpMetaInfoFeature(bool kernel_symbols_available) {
diff --git a/simpleperf/cmd_record_test.cpp b/simpleperf/cmd_record_test.cpp
index b0e4e553..00b6463f 100644
--- a/simpleperf/cmd_record_test.cpp
+++ b/simpleperf/cmd_record_test.cpp
@@ -924,6 +924,15 @@ TEST(record_cmd, cs_etm_event) {
   ASSERT_TRUE(has_aux);
 }
 
+TEST(record_cmd, cs_etm_system_wide) {
+  TEST_REQUIRE_ROOT();
+  if (!ETMRecorder::GetInstance().CheckEtmSupport()) {
+    GTEST_LOG_(INFO) << "Omit this test since etm isn't supported on this device";
+    return;
+  }
+  ASSERT_TRUE(RunRecordCmd({"-e", "cs-etm", "-a"}));
+}
+
 TEST(record_cmd, aux_buffer_size_option) {
   if (!ETMRecorder::GetInstance().CheckEtmSupport()) {
     GTEST_LOG_(INFO) << "Omit this test since etm isn't supported on this device";
diff --git a/simpleperf/environment.cpp b/simpleperf/environment.cpp
index 98933581..fff0177d 100644
--- a/simpleperf/environment.cpp
+++ b/simpleperf/environment.cpp
@@ -181,11 +181,10 @@ std::vector<pid_t> GetAllProcesses() {
 
 bool GetThreadMmapsInProcess(pid_t pid, std::vector<ThreadMmap>* thread_mmaps) {
   thread_mmaps->clear();
-  return android::procinfo::ReadProcessMaps(
-      pid, [&](const android::procinfo::MapInfo& mapinfo) {
-        thread_mmaps->emplace_back(mapinfo.start, mapinfo.end - mapinfo.start, mapinfo.pgoff,
-                                   mapinfo.name.c_str(), mapinfo.flags);
-      });
+  return android::procinfo::ReadProcessMaps(pid, [&](const android::procinfo::MapInfo& mapinfo) {
+    thread_mmaps->emplace_back(mapinfo.start, mapinfo.end - mapinfo.start, mapinfo.pgoff,
+                               mapinfo.name.c_str(), mapinfo.flags);
+  });
 }
 
 bool GetKernelBuildId(BuildId* build_id) {
@@ -841,7 +840,10 @@ int GetAndroidVersion() {
   static int android_version = -1;
   if (android_version == -1) {
     android_version = 0;
-    std::string s = android::base::GetProperty("ro.build.version.release", "");
+    std::string s = android::base::GetProperty("ro.build.version.codename", "REL");
+    if (s == "REL") {
+      s = android::base::GetProperty("ro.build.version.release", "");
+    }
     // The release string can be a list of numbers (like 8.1.0), a character (like Q)
     // or many characters (like OMR1).
     if (!s.empty()) {
diff --git a/simpleperf/kallsyms.cpp b/simpleperf/kallsyms.cpp
index ecea9fc4..8fd3d306 100644
--- a/simpleperf/kallsyms.cpp
+++ b/simpleperf/kallsyms.cpp
@@ -65,8 +65,8 @@ bool CanReadKernelSymbolAddresses() {
 // This is based on the Perfetto implementation.
 class ScopedKptrUnrestrict {
  public:
-  ScopedKptrUnrestrict(bool use_property = false);  // Lowers kptr_restrict if necessary.
-  ~ScopedKptrUnrestrict();                          // Restores the initial kptr_restrict.
+  ScopedKptrUnrestrict();   // Lowers kptr_restrict if necessary.
+  ~ScopedKptrUnrestrict();  // Restores the initial kptr_restrict.
 
   bool KallsymsAvailable();  // Indicates if access to kallsyms should be successful.
 
@@ -79,7 +79,8 @@ class ScopedKptrUnrestrict {
   bool kallsyms_available_ = false;
 };
 
-ScopedKptrUnrestrict::ScopedKptrUnrestrict(bool use_property) : use_property_(use_property) {
+ScopedKptrUnrestrict::ScopedKptrUnrestrict() {
+  use_property_ = GetAndroidVersion() >= 12;
   if (CanReadKernelSymbolAddresses()) {
     // Everything seems to work (e.g., we are running as root and kptr_restrict
     // is < 2). Don't touching anything.
@@ -214,8 +215,8 @@ uint64_t GetKernelStartAddress() {
   return 0;
 }
 
-bool LoadKernelSymbols(std::string* kallsyms, bool use_property /* = false */) {
-  ScopedKptrUnrestrict kptr_unrestrict(use_property);
+bool LoadKernelSymbols(std::string* kallsyms) {
+  ScopedKptrUnrestrict kptr_unrestrict;
   if (kptr_unrestrict.KallsymsAvailable()) {
     return android::base::ReadFileToString(kKallsymsPath, kallsyms);
   }
diff --git a/simpleperf/kallsyms.h b/simpleperf/kallsyms.h
index ed097d29..cb1b5a6a 100644
--- a/simpleperf/kallsyms.h
+++ b/simpleperf/kallsyms.h
@@ -47,11 +47,7 @@ uint64_t GetKernelStartAddress();
 // Loads the /proc/kallsyms file, requesting access if required. The value of
 // kptr_restrict might be modified during the process. Its original value will
 // be restored. This usually requires root privileges.
-// In some cases, the process might have enough permission to send a request to
-// init to change the value of kptr_restrict, using the system property
-// security.lower_kptr_restrict. For this scenario, the use_property
-// argument should be set to true.
-bool LoadKernelSymbols(std::string* kallsyms, bool use_property = false);
+bool LoadKernelSymbols(std::string* kallsyms);
 
 #endif  // defined(__linux__)
 
diff --git a/simpleperf/kallsyms_test.cpp b/simpleperf/kallsyms_test.cpp
index 12aefbc4..e97327c6 100644
--- a/simpleperf/kallsyms_test.cpp
+++ b/simpleperf/kallsyms_test.cpp
@@ -18,6 +18,7 @@
 
 #include "get_test_data.h"
 #include "kallsyms.h"
+#include "test_util.h"
 
 using namespace simpleperf;
 
@@ -36,7 +37,7 @@ static bool KernelSymbolsMatch(const KernelSymbol& sym1, const KernelSymbol& sym
          ModulesMatch(sym1.module, sym2.module);
 }
 
-TEST(utils, ProcessKernelSymbols) {
+TEST(kallsyms, ProcessKernelSymbols) {
   std::string data =
       "ffffffffa005c4e4 d __warned.41698   [libsas]\n"
       "aaaaaaaaaaaaaaaa T _text\n"
@@ -60,3 +61,16 @@ TEST(utils, ProcessKernelSymbols) {
   ASSERT_FALSE(ProcessKernelSymbols(
       data, std::bind(&KernelSymbolsMatch, std::placeholders::_1, expected_symbol)));
 }
+
+#if defined(__ANDROID__)
+TEST(kallsyms, GetKernelStartAddress) {
+  TEST_REQUIRE_ROOT();
+  ASSERT_NE(GetKernelStartAddress(), 0u);
+}
+
+TEST(kallsyms, LoadKernelSymbols) {
+  TEST_REQUIRE_ROOT();
+  std::string kallsyms;
+  ASSERT_TRUE(LoadKernelSymbols(&kallsyms));
+}
+#endif  // defined(__ANDROID__)