1 files changed, 39 insertions, 7 deletions

diff --git a/src/traced/probes/ftrace/atrace_wrapper.cc b/src/traced/probes/ftrace/atrace_wrapper.cc
index 2522e472b..632c13137 100644
--- a/src/traced/probes/ftrace/atrace_wrapper.cc
+++ b/src/traced/probes/ftrace/atrace_wrapper.cc
@@ -25,9 +25,13 @@
 #include <sys/wait.h>
 #include <unistd.h>
 
+#include "perfetto/base/build_config.h"
 #include "perfetto/base/logging.h"
 #include "perfetto/base/time.h"
+#include "perfetto/ext/base/android_utils.h"
+#include "perfetto/ext/base/optional.h"
 #include "perfetto/ext/base/pipe.h"
+#include "perfetto/ext/base/string_utils.h"
 #include "perfetto/ext/base/utils.h"
 
 namespace perfetto {
@@ -35,10 +39,12 @@ namespace perfetto {
 namespace {
 
 RunAtraceFunction g_run_atrace_for_testing = nullptr;
+base::Optional<bool> g_is_old_atrace_for_testing{};
 
 #if PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID)
 // Args should include "atrace" for argv[0].
-bool ExecvAtrace(const std::vector<std::string>& args) {
+bool ExecvAtrace(const std::vector<std::string>& args,
+                 std::string* atrace_errors) {
   int status = 1;
 
   std::vector<char*> argv;
@@ -158,21 +164,22 @@ bool ExecvAtrace(const std::vector<std::string>& args) {
   PERFETTO_EINTR(waitpid(pid, &status, 0));
 
   bool ok = WIFEXITED(status) && WEXITSTATUS(status) == 0;
-  if (!ok) {
-    // TODO(lalitm): use the stderr result from atrace.
+  if (!ok)
     PERFETTO_ELOG("%s", error.c_str());
-  }
+  if (atrace_errors)
+    atrace_errors->append(error);
   return ok;
 }
 #endif
 
 }  // namespace
 
-bool RunAtrace(const std::vector<std::string>& args) {
+bool RunAtrace(const std::vector<std::string>& args,
+               std::string* atrace_errors) {
   if (g_run_atrace_for_testing)
-    return g_run_atrace_for_testing(args);
+    return g_run_atrace_for_testing(args, atrace_errors);
 #if PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID)
-  return ExecvAtrace(args);
+  return ExecvAtrace(args, atrace_errors);
 #else
   PERFETTO_LOG("Atrace only supported on Android.");
   return false;
@@ -183,4 +190,29 @@ void SetRunAtraceForTesting(RunAtraceFunction f) {
   g_run_atrace_for_testing = f;
 }
 
+bool IsOldAtrace() {
+  if (g_is_old_atrace_for_testing.has_value())
+    return *g_is_old_atrace_for_testing;
+#if PERFETTO_BUILDFLAG(PERFETTO_OS_ANDROID) && \
+    !PERFETTO_BUILDFLAG(PERFETTO_ANDROID_BUILD)
+  // Sideloaded case. We could be sideloaded on a modern device or an older one.
+  std::string str_value = base::GetAndroidProp("ro.build.version.sdk");
+  if (str_value.empty())
+    return false;
+  auto opt_value = base::CStringToUInt32(str_value.c_str());
+  return opt_value.has_value() && *opt_value < 28;  // 28 == Android P.
+#else
+  // In in-tree builds we know that atrace is current, no runtime checks needed.
+  return false;
+#endif
+}
+
+void SetIsOldAtraceForTesting(bool value) {
+  g_is_old_atrace_for_testing = value;
+}
+
+void ClearIsOldAtraceForTesting() {
+  g_is_old_atrace_for_testing.reset();
+}
+
 }  // namespace perfetto