Merge "Prefetch standalone system server jars before switching domain." am:... (5a862711) · Commits · e / os / android_frameworks_base

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

0 → 100644

+50 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright (C) 2021 The Android Open Source Project
		*
		* Licensed under the Apache License, Version 2.0 (the "License");
		* you may not use this file except in compliance with the License.
		* You may obtain a copy of the License at
		*
		* http://www.apache.org/licenses/LICENSE-2.0
		*
		* Unless required by applicable law or agreed to in writing, software
		* distributed under the License is distributed on an "AS IS" BASIS,
		* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
		* See the License for the specific language governing permissions and
		* limitations under the License.
		*/

		package com.android.internal.os;

		import android.os.Build;
		import android.util.ArrayMap;

		import dalvik.system.PathClassLoader;

		/** @hide */
		public final class SystemServerClassLoaderFactory {
		/**
		* Map of paths to PathClassLoader for standalone system server jars.
		*/
		private static final ArrayMap<String, PathClassLoader> sLoadedPaths = new ArrayMap<>();

		/**
		* Creates and caches a ClassLoader for the jar at the given path, or returns a cached
		* ClassLoader if it exists.
		*
		* The parent class loader should always be the system server class loader. Changing it has
		* implications that require discussion with the mainline team.
		*
		* @hide for internal use only
		*/
		public static PathClassLoader getOrCreateClassLoader(String path, ClassLoader parent) {
		PathClassLoader pathClassLoader = sLoadedPaths.get(path);
		if (pathClassLoader == null) {
		pathClassLoader = (PathClassLoader) ClassLoaderFactory.createClassLoader(
		path, /librarySearchPath=/null, /libraryPermittedPath=/null, parent,
		Build.VERSION.SDK_INT, /isNamespaceShared=/true , /classLoaderName=/null);
		sLoadedPaths.put(path, pathClassLoader);
		}
		return pathClassLoader;
		}
		}

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

+26 −3

Original line number	Diff line number	Diff line
		@@ -46,6 +46,7 @@ import android.system.OsConstants;
		import android.system.StructCapUserData;
		import android.system.StructCapUserHeader;
		import android.text.Hyphenator;
		import android.text.TextUtils;
		import android.util.EventLog;
		import android.util.Log;
		import android.util.Slog;
		@@ -560,9 +561,8 @@ public class ZygoteInit {

		/**
		* Create the classloader for the system server and store it in
		* {@link sCachedSystemServerClassLoader}. This function may be called through JNI in
		* system server startup, when the runtime is in a critically low state. Do not do
		* extended computation etc here.
		* {@link sCachedSystemServerClassLoader}. This function is called through JNI in the forked
		* system server process in the zygote SELinux domain.
		*/
		private static ClassLoader getOrCreateSystemServerClassLoader() {
		if (sCachedSystemServerClassLoader == null) {
		@@ -575,6 +575,29 @@ public class ZygoteInit {
		return sCachedSystemServerClassLoader;
		}

		/**
		* Creates class loaders for standalone system server jars. This function is called through JNI
		* in the forked system server process in the zygote SELinux domain.
		*/
		private static void prefetchStandaloneSystemServerJars() {
		String envStr = Os.getenv("STANDALONE_SYSTEMSERVER_JARS");
		if (TextUtils.isEmpty(envStr)) {
		return;
		}
		for (String jar : envStr.split(":")) {
		try {
		SystemServerClassLoaderFactory.getOrCreateClassLoader(
		jar, getOrCreateSystemServerClassLoader());
		} catch (Error e) {
		// We don't want the process to crash for this error because prefetching is just an
		// optimization.
		Log.e(TAG,
		String.format("Failed to prefetch standalone system server jar \"%s\": %s",
		jar, e.toString()));
		}
		}
		}

		/**
		* Note that preparing the profiles for system server does not require special selinux
		* permissions. From the installer perspective the system server is a regular package which can

core/jni/com_android_internal_os_Zygote.cpp

+10 −0

Original line number	Diff line number	Diff line
		@@ -124,6 +124,7 @@ static jmethodID gCallPostForkChildHooks;
		static constexpr const char* kZygoteInitClassName = "com/android/internal/os/ZygoteInit";
		static jclass gZygoteInitClass;
		static jmethodID gGetOrCreateSystemServerClassLoader;
		static jmethodID gPrefetchStandaloneSystemServerJars;

		static bool gIsSecurityEnforced = true;

		@@ -1617,6 +1618,12 @@ static void SpecializeCommon(JNIEnv* env, uid_t uid, gid_t gid, jintArray gids,
		// at a later point (but may not have rights to use AoT artifacts).
		env->ExceptionClear();
		}
		// Also prefetch standalone system server jars. The reason for doing this here is the same
		// as above.
		env->CallStaticObjectMethod(gZygoteInitClass, gPrefetchStandaloneSystemServerJars);
		if (env->ExceptionCheck()) {
		env->ExceptionClear();
		}
		}

		if (setresgid(gid, gid, gid) == -1) {
		@@ -2678,6 +2685,9 @@ int register_com_android_internal_os_Zygote(JNIEnv* env) {
		gGetOrCreateSystemServerClassLoader =
		GetStaticMethodIDOrDie(env, gZygoteInitClass, "getOrCreateSystemServerClassLoader",
		"()Ljava/lang/ClassLoader;");
		gPrefetchStandaloneSystemServerJars =
		GetStaticMethodIDOrDie(env, gZygoteInitClass, "prefetchStandaloneSystemServerJars",
		"()V");

		RegisterMethodsOrDie(env, "com/android/internal/os/Zygote", gMethods, NELEM(gMethods));

services/core/java/com/android/server/SystemServiceManager.java

+3 −16

Original line number	Diff line number	Diff line
		@@ -21,18 +21,16 @@ import android.annotation.Nullable;
		import android.annotation.UserIdInt;
		import android.content.Context;
		import android.content.pm.UserInfo;
		import android.os.Build;
		import android.os.Environment;
		import android.os.SystemClock;
		import android.os.Trace;
		import android.util.ArrayMap;
		import android.util.EventLog;
		import android.util.IndentingPrintWriter;
		import android.util.Slog;
		import android.util.SparseArray;

		import com.android.internal.annotations.GuardedBy;
		import com.android.internal.os.ClassLoaderFactory;
		import com.android.internal.os.SystemServerClassLoaderFactory;
		import com.android.internal.util.Preconditions;
		import com.android.server.SystemService.TargetUser;
		import com.android.server.am.EventLogTags;
		@@ -77,9 +75,6 @@ public final class SystemServiceManager implements Dumpable {
		// Services that should receive lifecycle events.
		private final ArrayList<SystemService> mServices = new ArrayList<SystemService>();

		// Map of paths to PathClassLoader, so we don't load the same path multiple times.
		private final ArrayMap<String, PathClassLoader> mLoadedPaths = new ArrayMap<>();

		private int mCurrentPhase = -1;

		private UserManagerInternal mUserManagerInternal;
		@@ -119,16 +114,8 @@ public final class SystemServiceManager implements Dumpable {
		* @return The service instance.
		*/
		public SystemService startServiceFromJar(String className, String path) {
		PathClassLoader pathClassLoader = mLoadedPaths.get(path);
		if (pathClassLoader == null) {
		// NB: the parent class loader should always be the system server class loader.
		// Changing it has implications that require discussion with the mainline team.
		pathClassLoader = (PathClassLoader) ClassLoaderFactory.createClassLoader(
		path, null /* librarySearchPath /, null / libraryPermittedPath */,
		this.getClass().getClassLoader(), Build.VERSION.SDK_INT,
		true /* isNamespaceShared /, null / classLoaderName */);
		mLoadedPaths.put(path, pathClassLoader);
		}
		PathClassLoader pathClassLoader = SystemServerClassLoaderFactory.getOrCreateClassLoader(
		path, this.getClass().getClassLoader());
		final Class<SystemService> serviceClass = loadClassFromLoader(className, pathClassLoader);
		return startService(serviceClass);
		}