Let the default Atrace HAL support /sys/kernel/tracing

With this change, atrace HAL will look for tracefs in
/sys/kernel/tracing first and /sys/kernel/debug/tracing second.

Test: systrace
Bug: 185427606
Change-Id: Iccc5af92db222dc422a527c14b1f2fb7bc4e7746

3 files changed, 34 insertions, 11 deletions

diff --git a/atrace/1.0/default/AtraceDevice.cpp b/atrace/1.0/default/AtraceDevice.cpp
index 4e82b0adf3..9f0c4c4c36 100644
--- a/atrace/1.0/default/AtraceDevice.cpp
+++ b/atrace/1.0/default/AtraceDevice.cpp
@@ -16,6 +16,7 @@
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <android-base/stringprintf.h>
 
 #include "AtraceDevice.h"
 
@@ -39,15 +40,11 @@ const std::map<std::string, TracingConfig> kTracingMap = {
         // gfx
         {
                 "gfx",
-                {"Graphics",
-                 {{"/sys/kernel/debug/tracing/events/mdss/enable", false},
-                  {"/sys/kernel/debug/tracing/events/sde/enable", false},
-                  {"/sys/kernel/debug/tracing/events/mali_systrace/enable", false}}},
+                {"Graphics", {{"mdss", false}, {"sde", false}, {"mali_systrace", false}}},
         },
         {
                 "ion",
-                {"ION allocation",
-                 {{"/sys/kernel/debug/tracing/events/kmem/ion_alloc_buffer_start/enable", false}}},
+                {"ION allocation", {{"kmem/ion_alloc_buffer_start", false}}},
         },
 };
 
@@ -65,16 +62,31 @@ Return<void> AtraceDevice::listCategories(listCategories_cb _hidl_cb) {
     return Void();
 }
 
+AtraceDevice::AtraceDevice() {
+    struct stat st;
+
+    tracefs_event_root_ = "/sys/kernel/tracing/events/";
+    if (stat(tracefs_event_root_.c_str(), &st) != 0) {
+        tracefs_event_root_ = "/sys/kernel/debug/tracing/events/";
+        CHECK(stat(tracefs_event_root_.c_str(), &st) == 0) << "tracefs must be mounted at either"
+                                                              "/sys/kernel/tracing or "
+                                                              "/sys/kernel/debug/tracing";
+    }
+}
+
 Return<::android::hardware::atrace::V1_0::Status> AtraceDevice::enableCategories(
-    const hidl_vec<hidl_string>& categories) {
+        const hidl_vec<hidl_string>& categories) {
     if (!categories.size()) {
         return Status::ERROR_INVALID_ARGUMENT;
     }
+
     for (auto& c : categories) {
         if (kTracingMap.count(c)) {
             for (auto& p : kTracingMap.at(c).paths) {
-                if (!android::base::WriteStringToFile("1", p.first)) {
-                    LOG(ERROR) << "Failed to enable tracing on: " << p.first;
+                std::string tracefs_event_enable_path = android::base::StringPrintf(
+                        "%s%s/enable", tracefs_event_root_.c_str(), p.first.c_str());
+                if (!android::base::WriteStringToFile("1", tracefs_event_enable_path)) {
+                    LOG(ERROR) << "Failed to enable tracing on: " << tracefs_event_enable_path;
                     if (p.second) {
                         // disable before return
                         disableAllCategories();
@@ -91,10 +103,13 @@ Return<::android::hardware::atrace::V1_0::Status> AtraceDevice::enableCategories
 
 Return<::android::hardware::atrace::V1_0::Status> AtraceDevice::disableAllCategories() {
     auto ret = Status::SUCCESS;
+
     for (auto& c : kTracingMap) {
         for (auto& p : c.second.paths) {
-            if (!android::base::WriteStringToFile("0", p.first)) {
-                LOG(ERROR) << "Failed to disable tracing on: " << p.first;
+            std::string tracefs_event_enable_path = android::base::StringPrintf(
+                    "%s%s/enable", tracefs_event_root_.c_str(), p.first.c_str());
+            if (!android::base::WriteStringToFile("0", tracefs_event_enable_path)) {
+                LOG(ERROR) << "Failed to disable tracing on: " << tracefs_event_enable_path;
                 if (p.second) {
                     ret = Status::ERROR_TRACING_POINT;
                 }
diff --git a/atrace/1.0/default/AtraceDevice.h b/atrace/1.0/default/AtraceDevice.h
index e700f89129..ab87c65123 100644
--- a/atrace/1.0/default/AtraceDevice.h
+++ b/atrace/1.0/default/AtraceDevice.h
@@ -36,12 +36,16 @@ using ::android::hardware::Return;
 using ::android::hardware::Void;
 
 struct AtraceDevice : public IAtraceDevice {
+    AtraceDevice();
     // Methods from ::android::hardware::atrace::V1_0::IAtraceDevice follow.
     Return<void> listCategories(listCategories_cb _hidl_cb) override;
     Return<::android::hardware::atrace::V1_0::Status> enableCategories(
         const hidl_vec<hidl_string>& categories) override;
     Return<::android::hardware::atrace::V1_0::Status> disableAllCategories() override;
 
+  private:
+    std::string tracefs_event_root_;
+
     // Methods from ::android::hidl::base::V1_0::IBase follow.
 };
 
diff --git a/atrace/1.0/default/android.hardware.atrace@1.0-service.rc b/atrace/1.0/default/android.hardware.atrace@1.0-service.rc
index eb54c39a61..7110b45c9f 100644
--- a/atrace/1.0/default/android.hardware.atrace@1.0-service.rc
+++ b/atrace/1.0/default/android.hardware.atrace@1.0-service.rc
@@ -1,10 +1,14 @@
 on late-init
     # vendor graphics trace points
     chmod 0666 /sys/kernel/debug/tracing/events/sde/enable
+    chmod 0666 /sys/kernel/tracing/events/sde/enable
     chmod 0666 /sys/kernel/debug/tracing/events/mdss/enable
+    chmod 0666 /sys/kernel/tracing/events/mdss/enable
     chmod 0666 /sys/kernel/debug/tracing/events/mali_systrace/enable
+    chmod 0666 /sys/kernel/tracing/events/mali_systrace/enable
     # ion allocation trace point
     chmod 0666 /sys/kernel/debug/tracing/events/kmem/ion_alloc_buffer_start/enable
+    chmod 0666 /sys/kernel/tracing/events/kmem/ion_alloc_buffer_start/enable
 
 service vendor.atrace-hal-1-0 /vendor/bin/hw/android.hardware.atrace@1.0-service
     interface android.hardware.atrace@1.0::IAtraceDevice default