From 6a879b25d9cab14e4fd2880f711ab26c6aa99e1c Mon Sep 17 00:00:00 2001
From: Hridya Valsaraju <hridya@google.com>
Date: Thu, 30 Jan 2020 17:34:46 -0800
Subject: [PATCH] Check /sys/kernel/tracing for tracefs

When debugfs is not mounted, atrace should look for
tracefs in /sys/kernel/tracing.

Test: CtsAtraceHostTestCases
Bug: 148436518
Change-Id: I45c0e664892bcda277fd9612106ad5216aea0a1b
---
 libcutils/trace-dev.cpp | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libcutils/trace-dev.cpp b/libcutils/trace-dev.cpp
index 2ee39d328..9ca172973 100644
--- a/libcutils/trace-dev.cpp
+++ b/libcutils/trace-dev.cpp
@@ -31,6 +31,10 @@ void atrace_set_tracing_enabled(bool enabled)
 static void atrace_init_once()
 {
     atrace_marker_fd = open("/sys/kernel/debug/tracing/trace_marker", O_WRONLY | O_CLOEXEC);
+    if (atrace_marker_fd == -1) {
+        atrace_marker_fd = open("/sys/kernel/tracing/trace_marker", O_WRONLY | O_CLOEXEC);
+    }
+
     if (atrace_marker_fd == -1) {
         ALOGE("Error opening trace file: %s (%d)", strerror(errno), errno);
         atrace_enabled_tags = 0;