Initial support for application Zygote. (7e6fa672) · Commits · e / os / android_frameworks_base

core/java/android/os/AppZygote.java

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			/*
			* Copyright (C) 2018 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 android.os;

			import android.content.pm.ApplicationInfo;
			import android.util.Log;

			import com.android.internal.annotations.GuardedBy;

			/**
			* AppZygote is responsible for interfacing with an application-specific zygote.
			*
			* Application zygotes can pre-load app-specific code and data, and this interface can
			* be used to spawn isolated services from such an application zygote.
			*
			* Note that we'll have only one instance of this per application / uid combination.
			*
			* @hide
			*/
			public class AppZygote {
			private static final String LOG_TAG = "AppZygote";

			private final Object mLock = new Object();

			/**
			* Instance that maintains the socket connection to the zygote. This is {@code null} if the
			* zygote is not running or is not connected.
			*/
			@GuardedBy("mLock")
			private ChildZygoteProcess mZygote;

			private final ApplicationInfo mAppInfo;

			public AppZygote(ApplicationInfo appInfo) {
			mAppInfo = appInfo;
			}

			/**
			* Returns the zygote process associated with this app zygote.
			* Creates the process if it's not already running.
			*/
			public ChildZygoteProcess getProcess() {
			synchronized (mLock) {
			if (mZygote != null) return mZygote;

			connectToZygoteIfNeededLocked();
			return mZygote;
			}
			}

			/**
			* Stops the Zygote and kills the zygote process.
			*/
			public void stopZygote() {
			synchronized (mLock) {
			stopZygoteLocked();
			}
			}

			public ApplicationInfo getAppInfo() {
			return mAppInfo;
			}

			@GuardedBy("mLock")
			private void stopZygoteLocked() {
			if (mZygote != null) {
			// Close the connection and kill the zygote process. This will not cause
			// child processes to be killed by itself.
			mZygote.close();
			Process.killProcess(mZygote.getPid());
			mZygote = null;
			}
			}

			@GuardedBy("mLock")
			private void connectToZygoteIfNeededLocked() {
			String abi = mAppInfo.primaryCpuAbi != null ? mAppInfo.primaryCpuAbi :
			Build.SUPPORTED_ABIS[0];
			try {
			mZygote = Process.zygoteProcess.startChildZygote(
			"com.android.internal.os.AppZygoteInit",
			mAppInfo.processName + "_zygote",
			mAppInfo.uid,
			mAppInfo.uid,
			null, // gids
			0, // runtimeFlags
			"app_zygote", // seInfo
			abi, // abi
			abi, // acceptedAbiList
			null); // instructionSet

			ZygoteProcess.waitForConnectionToZygote(mZygote.getPrimarySocketAddress());
			// preload application code in the zygote
			Log.i(LOG_TAG, "Starting application preload.");
			mZygote.preloadApp(mAppInfo, abi);
			Log.i(LOG_TAG, "Application preload done.");
			} catch (Exception e) {
			Log.e(LOG_TAG, "Error connecting to app zygote", e);
			stopZygoteLocked();
			}
			}
			}

core/java/android/os/ZygoteProcess.java

+49 −1

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	@@ -18,6 +18,7 @@ package android.os;

	import android.annotation.NonNull;		import android.annotation.NonNull;
	import android.annotation.Nullable;		import android.annotation.Nullable;
			import android.content.pm.ApplicationInfo;
	import android.net.LocalSocket;		import android.net.LocalSocket;
	import android.net.LocalSocketAddress;		import android.net.LocalSocketAddress;
	import android.util.Log;		import android.util.Log;
	@@ -34,6 +35,7 @@ import java.io.OutputStreamWriter;
	import java.nio.charset.StandardCharsets;		import java.nio.charset.StandardCharsets;
	import java.util.ArrayList;		import java.util.ArrayList;
	import java.util.Arrays;		import java.util.Arrays;
			import java.util.Base64;
	import java.util.Collections;		import java.util.Collections;
	import java.util.List;		import java.util.List;
	import java.util.UUID;		import java.util.UUID;
	@@ -672,6 +674,36 @@ public class ZygoteProcess {
	throw new ZygoteStartFailedEx("Unsupported zygote ABI: " + abi);		throw new ZygoteStartFailedEx("Unsupported zygote ABI: " + abi);
	}		}

			/**
			* Instructs the zygote to pre-load the application code for the given Application.
			* Only the app zygote supports this function.
			* TODO preloadPackageForAbi() can probably be removed and the callers an use this instead.
			*/
			public boolean preloadApp(ApplicationInfo appInfo, String abi) throws ZygoteStartFailedEx,
			IOException {
			synchronized (mLock) {
			ZygoteState state = openZygoteSocketIfNeeded(abi);
			state.writer.write("2");
			state.writer.newLine();

			state.writer.write("--preload-app");
			state.writer.newLine();

			// Zygote args needs to be strings, so in order to pass ApplicationInfo,
			// write it to a Parcel, and base64 the raw Parcel bytes to the other side.
			Parcel parcel = Parcel.obtain();
			appInfo.writeToParcel(parcel, 0 /* flags */);
			String encodedParcelData = Base64.getEncoder().encodeToString(parcel.marshall());
			parcel.recycle();
			state.writer.write(encodedParcelData);
			state.writer.newLine();

			state.writer.flush();

			return (state.inputStream.readInt() == 0);
			}
			}

	/**		/**
	* Instructs the zygote to pre-load the classes and native libraries at the given paths		* Instructs the zygote to pre-load the classes and native libraries at the given paths
	* for the specified abi. Not all zygotes support this function.		* for the specified abi. Not all zygotes support this function.
	@@ -763,6 +795,20 @@ public class ZygoteProcess {
	* secondary zygotes that inherit data from the zygote that this object		* secondary zygotes that inherit data from the zygote that this object
	* communicates with. This returns a new ZygoteProcess representing a connection		* communicates with. This returns a new ZygoteProcess representing a connection
	* to the newly created zygote. Throws an exception if the zygote cannot be started.		* to the newly created zygote. Throws an exception if the zygote cannot be started.
			*
			* @param processClass The class to use as the child zygote's main entry
			* point.
			* @param niceName A more readable name to use for the process.
			* @param uid The user-id under which the child zygote will run.
			* @param gid The group-id under which the child zygote will run.
			* @param gids Additional group-ids associated with the child zygote process.
			* @param runtimeFlags Additional flags.
			* @param seInfo null-ok SELinux information for the child zygote process.
			* @param abi non-null the ABI of the child zygote
			* @param acceptedAbiList ABIs this child zygote will accept connections for; this
			* may be different from <code>abi</code> in case the children
			* spawned from this Zygote only communicate using ABI-safe methods.
			* @param instructionSet null-ok the instruction set to use.
	*/		*/
	public ChildZygoteProcess startChildZygote(final String processClass,		public ChildZygoteProcess startChildZygote(final String processClass,
	final String niceName,		final String niceName,
	@@ -770,12 +816,14 @@ public class ZygoteProcess {
	int runtimeFlags,		int runtimeFlags,
	String seInfo,		String seInfo,
	String abi,		String abi,
			String acceptedAbiList,
	String instructionSet) {		String instructionSet) {
	// Create an unguessable address in the global abstract namespace.		// Create an unguessable address in the global abstract namespace.
	final LocalSocketAddress serverAddress = new LocalSocketAddress(		final LocalSocketAddress serverAddress = new LocalSocketAddress(
	processClass + "/" + UUID.randomUUID().toString());		processClass + "/" + UUID.randomUUID().toString());

	final String[] extraArgs = {Zygote.CHILD_ZYGOTE_SOCKET_NAME_ARG + serverAddress.getName()};		final String[] extraArgs = {Zygote.CHILD_ZYGOTE_SOCKET_NAME_ARG + serverAddress.getName(),
			Zygote.CHILD_ZYGOTE_ABI_LIST_ARG + acceptedAbiList};

	Process.ProcessStartResult result;		Process.ProcessStartResult result;
	try {		try {

core/java/android/webkit/WebViewZygote.java

+1 −0

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	@@ -159,6 +159,7 @@ public class WebViewZygote {
	0, // runtimeFlags		0, // runtimeFlags
	"webview_zygote", // seInfo		"webview_zygote", // seInfo
	sPackage.applicationInfo.primaryCpuAbi, // abi		sPackage.applicationInfo.primaryCpuAbi, // abi
			TextUtils.join(",", Build.SUPPORTED_ABIS),
	null); // instructionSet		null); // instructionSet

	// All the work below is usually done by LoadedApk, but the zygote can't talk to		// All the work below is usually done by LoadedApk, but the zygote can't talk to

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

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			/*
			* Copyright (C) 2018 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.app.LoadedApk;
			import android.content.pm.ApplicationInfo;
			import android.net.LocalSocket;
			import android.util.Log;

			import java.io.DataOutputStream;
			import java.io.IOException;

			/**
			* Startup class for an Application zygote process.
			*
			* See {@link ZygoteInit} for generic zygote startup documentation.
			*
			* @hide
			*/
			class AppZygoteInit {
			public static final String TAG = "AppZygoteInit";

			private static ZygoteServer sServer;

			private static class AppZygoteServer extends ZygoteServer {
			@Override
			protected ZygoteConnection createNewConnection(LocalSocket socket, String abiList)
			throws IOException {
			return new AppZygoteConnection(socket, abiList);
			}
			}

			private static class AppZygoteConnection extends ZygoteConnection {
			AppZygoteConnection(LocalSocket socket, String abiList) throws IOException {
			super(socket, abiList);
			}

			@Override
			protected void preload() {
			// Nothing to preload by default.
			}

			@Override
			protected boolean isPreloadComplete() {
			// App zygotes don't preload any classes or resources or defaults, all of their
			// preloading is package specific.
			return true;
			}

			@Override
			protected boolean canPreloadApp() {
			return true;
			}

			@Override
			protected void handlePreloadApp(ApplicationInfo appInfo) {
			Log.i(TAG, "Beginning application preload for " + appInfo.packageName);
			LoadedApk loadedApk = new LoadedApk(null, appInfo, null, null, false, true, false);
			// Initialize the classLoader
			ClassLoader loader = loadedApk.getClassLoader();

			try {
			DataOutputStream socketOut = getSocketOutputStream();
			socketOut.writeInt(loader != null ? 1 : 0);
			} catch (IOException e) {
			throw new IllegalStateException("Error writing to command socket", e);
			}

			Log.i(TAG, "Application preload done");
			}
			}

			public static void main(String[] argv) {
			AppZygoteServer server = new AppZygoteServer();
			ChildZygoteInit.runZygoteServer(server, argv);
			}
			}

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

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+99 −0

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			/*
			* Copyright (C) 2018 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.system.ErrnoException;
			import android.system.Os;
			import android.system.OsConstants;
			import android.util.Log;

			/**
			* ChildZygoteInit is shared by both the Application and WebView zygote to initialize
			* and run a (child) Zygote server.
			*
			* @hide
			*/
			public class ChildZygoteInit {
			private static final String TAG = "ChildZygoteInit";

			static String parseSocketNameFromArgs(String[] argv) {
			for (String arg : argv) {
			if (arg.startsWith(Zygote.CHILD_ZYGOTE_SOCKET_NAME_ARG)) {
			return arg.substring(Zygote.CHILD_ZYGOTE_SOCKET_NAME_ARG.length());
			}
			}

			return null;
			}

			static String parseAbiListFromArgs(String[] argv) {
			for (String arg : argv) {
			if (arg.startsWith(Zygote.CHILD_ZYGOTE_ABI_LIST_ARG)) {
			return arg.substring(Zygote.CHILD_ZYGOTE_ABI_LIST_ARG.length());
			}
			}

			return null;
			}

			/**
			* Starts a ZygoteServer and listens for requests
			*
			* @param server An instance of a ZygoteServer to listen on
			* @param args Passed in arguments for this ZygoteServer
			*/
			static void runZygoteServer(ZygoteServer server, String[] args) {
			String socketName = parseSocketNameFromArgs(args);
			if (socketName == null) {
			throw new NullPointerException("No socketName specified");
			}

			String abiList = parseAbiListFromArgs(args);
			if (abiList == null) {
			throw new NullPointerException("No abiList specified");
			}

			try {
			Os.prctl(OsConstants.PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0);
			} catch (ErrnoException ex) {
			throw new RuntimeException("Failed to set PR_SET_NO_NEW_PRIVS", ex);
			}

			final Runnable caller;
			try {
			server.registerServerSocketAtAbstractName(socketName);

			// Add the abstract socket to the FD whitelist so that the native zygote code
			// can properly detach it after forking.
			Zygote.nativeAllowFileAcrossFork("ABSTRACT/" + socketName);

			// The select loop returns early in the child process after a fork and
			// loops forever in the zygote.
			caller = server.runSelectLoop(abiList);
			} catch (RuntimeException e) {
			Log.e(TAG, "Fatal exception:", e);
			throw e;
			} finally {
			server.closeServerSocket();
			}

			// We're in the child process and have exited the select loop. Proceed to execute the
			// command.
			if (caller != null) {
			caller.run();
			}
			}
			}