From 0b3c24bd4fb29ff48150c03104658af902a0e137 Mon Sep 17 00:00:00 2001
From: Jiyong Park <jiyong@google.com>
Date: Fri, 26 May 2017 17:57:18 +0900
Subject: [PATCH] fix: ATRACE does not work for libs loaded in sphal namespace

From O, libutils.so is loaded twice. Once in the default namespace and
once in the sphal namespace for vendor libs. However, since the
framework only communicates with the instance loaded in the default
namespace, report_sysprop_change() event is not notified to the instance
in sphal namespace. This causes ATRACE to not work for vendor libs
loaded in sphal namespace.

So, the instance loaded in default namespace now explicitly redirects
the event to the other instance.

Bug: 62084107
Test: start an app, run 'adb shell atrace gfx --stream'. atrace from the
graphics driver are visible.

Change-Id: Ia6c2ca6bcb9a8849ebb09b5c38d60480c92d4571
---
 libutils/Android.bp       |  1 +
 libutils/misc.cpp         | 38 ++++++++++++++++++++++++++++++++++++--
 libvndksupport/Android.bp |  2 +-
 3 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/libutils/Android.bp b/libutils/Android.bp
index 696db3bdc..5e76279df 100644
--- a/libutils/Android.bp
+++ b/libutils/Android.bp
@@ -94,6 +94,7 @@ cc_library {
                 "libcutils",
                 "libdl",
                 "liblog",
+                "libvndksupport",
             ],
 
             sanitize: {
diff --git a/libutils/misc.cpp b/libutils/misc.cpp
index ab72fe6ed..d95fd056b 100644
--- a/libutils/misc.cpp
+++ b/libutils/misc.cpp
@@ -23,6 +23,13 @@
 #include <utils/Log.h>
 #include <utils/Vector.h>
 
+#if defined(__ANDROID__)
+#include <dlfcn.h>
+#include <vndksupport/linker.h>
+#endif
+
+extern "C" void do_report_sysprop_change();
+
 using namespace android;
 
 namespace android {
@@ -61,7 +68,36 @@ void add_sysprop_change_callback(sysprop_change_callback cb, int priority) {
 #endif
 }
 
+#if defined(__ANDROID__)
+void (*get_report_sysprop_change_func())() {
+    void (*func)() = nullptr;
+    void* handle = android_load_sphal_library("libutils.so", RTLD_NOW);
+    if (handle != nullptr) {
+        func = reinterpret_cast<decltype(func)>(dlsym(handle, "do_report_sysprop_change"));
+    }
+
+    return func;
+}
+#endif
+
 void report_sysprop_change() {
+    do_report_sysprop_change();
+
+#if defined(__ANDROID__)
+    // libutils.so is double loaded; from the default namespace and from the
+    // 'sphal' namespace. Redirect the sysprop change event to the other instance
+    // of libutils.so loaded in the 'sphal' namespace so that listeners attached
+    // to that instance is also notified with this event.
+    static auto func = get_report_sysprop_change_func();
+    if (func != nullptr) {
+        (*func)();
+    }
+#endif
+}
+
+};  // namespace android
+
+void do_report_sysprop_change() {
 #if !defined(_WIN32)
     pthread_mutex_lock(&gSyspropMutex);
     Vector<sysprop_change_callback_info> listeners;
@@ -76,5 +112,3 @@ void report_sysprop_change() {
     }
 #endif
 }
-
-}; // namespace android
diff --git a/libvndksupport/Android.bp b/libvndksupport/Android.bp
index ab9e26fe4..b62422323 100644
--- a/libvndksupport/Android.bp
+++ b/libvndksupport/Android.bp
@@ -1,6 +1,6 @@
 subdirs = ["tests"]
 
-cc_library_shared {
+cc_library {
     name: "libvndksupport",
     srcs: ["linker.c"],
     local_include_dirs: ["include/vndksupport"],