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

@@ -94,6 +94,7 @@ cc_library {
                 "libcutils",
                 "libdl",
                 "liblog",
+                "libvndksupport",
             ],
 
             sanitize: {

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

libvndksupport/Android.bp

@@ -1,6 +1,6 @@
 subdirs = ["tests"]
 
-cc_library_shared {
+cc_library {
     name: "libvndksupport",
     srcs: ["linker.c"],
     local_include_dirs: ["include/vndksupport"],