From 61bd7277244c1b5d5b9eedbe953cfb1ed1965f41 Mon Sep 17 00:00:00 2001
From: Kalesh Singh <kaleshsingh@google.com>
Date: Mon, 29 Mar 2021 17:03:19 -0400
Subject: [PATCH] Add memtrackproxy system server service

Serve memtrackproxy service from system server.

This service enforces access control on requests for memory usage stats
to the memtrack HAL based on the call context's PID and UID.

Bug: 177664629
Test: memtrackproxy_test
Change-Id: I10829ffcf4e5b2813d4c622268b0b59da6f171b6
Merged-In: I10829ffcf4e5b2813d4c622268b0b59da6f171b6
---
 services/core/jni/Android.bp                  |  3 +++
 .../jni/com_android_server_SystemServer.cpp   | 20 +++++++++++++++++++
 .../java/com/android/server/SystemServer.java | 11 ++++++++++
 3 files changed, 34 insertions(+)

diff --git a/services/core/jni/Android.bp b/services/core/jni/Android.bp
index 24bb1b12305e3..d0bd8b3e1ae29 100644
--- a/services/core/jni/Android.bp
+++ b/services/core/jni/Android.bp
@@ -102,6 +102,7 @@ cc_defaults {
         "libaudioclient",
         "libbase",
         "libappfuse",
+        "libbinder_ndk",
         "libbinder",
         "libcutils",
         "libcrypto",
@@ -110,6 +111,7 @@ cc_defaults {
         "libhardware",
         "libhardware_legacy",
         "libhidlbase",
+        "libmemtrackproxy",
         "libmtp",
         "libnativehelper",
         "libprocessgroup",
@@ -154,6 +156,7 @@ cc_defaults {
         "android.hardware.input.classifier@1.0",
         "android.hardware.ir@1.0",
         "android.hardware.light@2.0",
+        "android.hardware.memtrack-V1-ndk_platform",
         "android.hardware.power@1.0",
         "android.hardware.power@1.1",
         "android.hardware.power-V1-cpp",
diff --git a/services/core/jni/com_android_server_SystemServer.cpp b/services/core/jni/com_android_server_SystemServer.cpp
index d18043f6b3e9f..b93b8ab034f86 100644
--- a/services/core/jni/com_android_server_SystemServer.cpp
+++ b/services/core/jni/com_android_server_SystemServer.cpp
@@ -23,11 +23,14 @@
 #include <jni.h>
 #include <nativehelper/JNIHelp.h>
 
+#include <android/binder_manager.h>
+#include <android/binder_stability.h>
 #include <android/hidl/manager/1.2/IServiceManager.h>
 #include <binder/IServiceManager.h>
 #include <hidl/HidlTransportSupport.h>
 #include <incremental_service.h>
 
+#include <memtrackproxy/MemtrackProxy.h>
 #include <schedulerservice/SchedulingPolicyService.h>
 #include <sensorservice/SensorService.h>
 #include <sensorservicehidl/SensorManager.h>
@@ -57,6 +60,21 @@ static void android_server_SystemServer_startSensorService(JNIEnv* /* env */, jo
 
 }
 
+static void android_server_SystemServer_startMemtrackProxyService(JNIEnv* env,
+                                                                  jobject /* clazz */) {
+    using aidl::android::hardware::memtrack::MemtrackProxy;
+
+    const char* memtrackProxyService = "memtrack.proxy";
+
+    std::shared_ptr<MemtrackProxy> memtrack_proxy = ndk::SharedRefBase::make<MemtrackProxy>();
+    auto binder = memtrack_proxy->asBinder();
+
+    AIBinder_forceDowngradeToLocalStability(binder.get());
+
+    const binder_exception_t err = AServiceManager_addService(binder.get(), memtrackProxyService);
+    LOG_ALWAYS_FATAL_IF(err != EX_NONE, "Cannot register %s: %d", memtrackProxyService, err);
+}
+
 static void android_server_SystemServer_startHidlServices(JNIEnv* env, jobject /* clazz */) {
     using ::android::frameworks::schedulerservice::V1_0::ISchedulingPolicyService;
     using ::android::frameworks::schedulerservice::V1_0::implementation::SchedulingPolicyService;
@@ -121,6 +139,8 @@ static void android_server_SystemServer_setIncrementalServiceSystemReady(JNIEnv*
 static const JNINativeMethod gMethods[] = {
         /* name, signature, funcPtr */
         {"startSensorService", "()V", (void*)android_server_SystemServer_startSensorService},
+        {"startMemtrackProxyService", "()V",
+         (void*)android_server_SystemServer_startMemtrackProxyService},
         {"startHidlServices", "()V", (void*)android_server_SystemServer_startHidlServices},
         {"initZygoteChildHeapProfiling", "()V",
          (void*)android_server_SystemServer_initZygoteChildHeapProfiling},
diff --git a/services/java/com/android/server/SystemServer.java b/services/java/com/android/server/SystemServer.java
index 46ec65d7567ca..1801e0effcb90 100644
--- a/services/java/com/android/server/SystemServer.java
+++ b/services/java/com/android/server/SystemServer.java
@@ -391,6 +391,11 @@ public final class SystemServer {
      */
     private static native void startSensorService();
 
+    /**
+     * Start the memtrack proxy service.
+     */
+    private static native void startMemtrackProxyService();
+
     /**
      * Start all HIDL services that are run inside the system server. This may take some time.
      */
@@ -829,6 +834,12 @@ public final class SystemServer {
         mSystemServiceManager.startService(UriGrantsManagerService.Lifecycle.class);
         t.traceEnd();
 
+        // Start MemtrackProxyService before ActivityManager, so that early calls
+        // to Memtrack::getMemory() don't fail.
+        t.traceBegin("MemtrackProxyService");
+        startMemtrackProxyService();
+        t.traceEnd();
+
         // Activity manager runs the show.
         t.traceBegin("StartActivityManager");
         // TODO: Might need to move after migration to WM.