commit 46724e73705e02e7b25e29d0fc38533b9a2506f7
author Orion Hodson <oth@google.com> Fri Oct 19 13:05:33 2018 +0100
committer Orion Hodson <oth@google.com> Wed Oct 31 06:32:13 2018 +0000
tree 9e1bfc3e60c549ab14679ae9d7a2e7c4e96e19f3
parent 0d63da86e2e4093e9785cfc1df2f8ec4308a9ead

Add post fork hook for System Server

Adds a post fork hook for System Server that is used to enable JIT.

Bug: 62356545
Bug: 66095511
Test: device boots, no permission errors
Change-Id: I963e8c4903fb20fd0b5a207fdc6746035b69c569

core/java/com/android/internal/os/Zygote.java

diff --git a/core/java/com/android/internal/os/Zygote.java b/core/java/com/android/internal/os/Zygote.java
index 4ee950a..8b3829b3 100644
--- a/core/java/com/android/internal/os/Zygote.java
+++ b/core/java/com/android/internal/os/Zygote.java
@@ -211,6 +211,11 @@
      */
     native protected static void nativeUnmountStorageOnInit();
 
+    private static void callPostForkSystemServerHooks() {
+        // SystemServer specific post fork hooks run before child post fork hooks.
+        VM_HOOKS.postForkSystemServer();
+    }
+
     private static void callPostForkChildHooks(int runtimeFlags, boolean isSystemServer,
             boolean isZygote, String instructionSet) {
         VM_HOOKS.postForkChild(runtimeFlags, isSystemServer, isZygote, instructionSet);

core/jni/com_android_internal_os_Zygote.cpp

diff --git a/core/jni/com_android_internal_os_Zygote.cpp b/core/jni/com_android_internal_os_Zygote.cpp
index 0022cf88..da25801 100644
--- a/core/jni/com_android_internal_os_Zygote.cpp
+++ b/core/jni/com_android_internal_os_Zygote.cpp
@@ -81,6 +81,7 @@
 
 static const char kZygoteClassName[] = "com/android/internal/os/Zygote";
 static jclass gZygoteClass;
+static jmethodID gCallPostForkSystemServerHooks;
 static jmethodID gCallPostForkChildHooks;
 
 static bool g_is_security_enforced = true;
@@ -728,6 +729,18 @@
   // Unset the SIGCHLD handler, but keep ignoring SIGHUP (rationale in SetSignalHandlers).
   UnsetChldSignalHandler();
 
+  if (is_system_server) {
+    env->CallStaticVoidMethod(gZygoteClass, gCallPostForkSystemServerHooks);
+    if (env->ExceptionCheck()) {
+      fail_fn("Error calling post fork system server hooks.");
+    }
+    // TODO(oth): Remove hardcoded label here (b/117874058).
+    static const char* kSystemServerLabel = "u:r:system_server:s0";
+    if (selinux_android_setcon(kSystemServerLabel) != 0) {
+      fail_fn(CREATE_ERROR("selinux_android_setcon(%s)", kSystemServerLabel));
+    }
+  }
+
   env->CallStaticVoidMethod(gZygoteClass, gCallPostForkChildHooks, runtime_flags,
                             is_system_server, is_child_zygote, instructionSet);
   if (env->ExceptionCheck()) {
@@ -1020,6 +1033,9 @@
 
 int register_com_android_internal_os_Zygote(JNIEnv* env) {
   gZygoteClass = MakeGlobalRefOrDie(env, FindClassOrDie(env, kZygoteClassName));
+  gCallPostForkSystemServerHooks = GetStaticMethodIDOrDie(env, gZygoteClass,
+                                                          "callPostForkSystemServerHooks",
+                                                          "()V");
   gCallPostForkChildHooks = GetStaticMethodIDOrDie(env, gZygoteClass, "callPostForkChildHooks",
                                                    "(IZZLjava/lang/String;)V");