Disallow starting new system services after apex services are started. (3350e9f7) · Commits · e / os / android_frameworks_base

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

+21 −9

Original line number	Diff line number	Diff line
		@@ -45,6 +45,8 @@ import java.io.File;
		import java.lang.reflect.Constructor;
		import java.lang.reflect.InvocationTargetException;
		import java.util.ArrayList;
		import java.util.Collections;
		import java.util.List;
		import java.util.concurrent.ExecutorService;
		import java.util.concurrent.Executors;
		import java.util.concurrent.TimeUnit;
		@@ -91,7 +93,7 @@ public final class SystemServiceManager implements Dumpable {
		private long mRuntimeStartUptime;

		// Services that should receive lifecycle events.
		private final ArrayList<SystemService> mServices = new ArrayList<SystemService>();
		private List<SystemService> mServices;

		private int mCurrentPhase = -1;

		@@ -113,6 +115,7 @@ public final class SystemServiceManager implements Dumpable {

		SystemServiceManager(Context context) {
		mContext = context;
		mServices = new ArrayList<>();
		// Disable using the thread pool for low ram devices
		sUseLifecycleThreadPool = sUseLifecycleThreadPool
		&& !ActivityManager.isLowRamDeviceStatic();
		@@ -220,6 +223,11 @@ public final class SystemServiceManager implements Dumpable {
		warnIfTooLong(SystemClock.elapsedRealtime() - time, service, "onStart");
		}

		/** Disallow starting new services after this call. */
		void sealStartedServices() {
		mServices = Collections.unmodifiableList(mServices);
		}

		/**
		* Starts the specified boot phase for all system services that have been started up to
		* this point.
		@@ -516,6 +524,7 @@ public final class SystemServiceManager implements Dumpable {

		/**
		* Returns whether we are booting into safe mode.
		*
		* @return safe mode flag
		*/
		public boolean isSafeMode() {
		@@ -559,9 +568,10 @@ public final class SystemServiceManager implements Dumpable {

		/**
		* Ensures that the system directory exist creating one if needed.
		*
		* @return The system directory.
		* @deprecated Use {@link Environment#getDataSystemCeDirectory()}
		* or {@link Environment#getDataSystemDeDirectory()} instead.
		* @return The system directory.
		*/
		@Deprecated
		public static File ensureSystemDir() {
		@@ -578,7 +588,9 @@ public final class SystemServiceManager implements Dumpable {
		pw.printf("Current phase: %d\n", mCurrentPhase);
		synchronized (mTargetUsers) {
		if (mCurrentUser != null) {
		pw.print("Current user: "); mCurrentUser.dump(pw); pw.println();
		pw.print("Current user: ");
		mCurrentUser.dump(pw);
		pw.println();
		} else {
		pw.println("Current user not set!");
		}

services/java/com/android/server/SystemServer.java

+8 −6

Original line number	Diff line number	Diff line
		@@ -920,12 +920,6 @@ public final class SystemServer implements Dumpable {
		startBootstrapServices(t);
		startCoreServices(t);
		startOtherServices(t);
		// Apex services must be the last category of services to start. No other service must
		// be starting after this point. This is to prevent unnessary stability issues when
		// these apexes are updated outside of OTA; and to avoid breaking dependencies from
		// system into apexes.
		// TODO(satayev): lock mSystemServiceManager.startService to stop accepting new services
		// after this step
		startApexServices(t);
		} catch (Throwable ex) {
		Slog.e("System", "******************************************");
		@@ -3051,6 +3045,10 @@ public final class SystemServer implements Dumpable {

		/**
		* Starts system services defined in apexes.
		*
		* <p>Apex services must be the last category of services to start. No other service must be
		* starting after this point. This is to prevent unnecessary stability issues when these apexes
		* are updated outside of OTA; and to avoid breaking dependencies from system into apexes.
		*/
		private void startApexServices(@NonNull TimingsTraceAndSlog t) {
		t.traceBegin("startApexServices");
		@@ -3067,6 +3065,10 @@ public final class SystemServer implements Dumpable {
		}
		t.traceEnd();
		}

		// make sure no other services are started after this point
		mSystemServiceManager.sealStartedServices();

		t.traceEnd(); // startApexServices
		}

services/tests/servicestests/src/com/android/server/SystemServiceManagerTest.java

0 → 100644

+55 −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.server;

		import static org.junit.Assert.assertThrows;

		import android.test.AndroidTestCase;

		import org.junit.Test;

		import java.util.concurrent.atomic.AtomicBoolean;


		/**
		* Tests for {@link SystemServiceManager}.
		*/
		public class SystemServiceManagerTest extends AndroidTestCase {

		private static final String TAG = "SystemServiceManagerTest";

		@Test
		public void testSealStartedServices() throws Exception {
		SystemServiceManager manager = new SystemServiceManager(getContext());
		// must be effectively final, since it's changed from inner class below
		AtomicBoolean serviceStarted = new AtomicBoolean(false);
		SystemService service = new SystemService(getContext()) {
		@Override
		public void onStart() {
		serviceStarted.set(true);
		}
		};

		// started services have their #onStart methods called
		manager.startService(service);
		assertTrue(serviceStarted.get());

		// however, after locking started services, it is not possible to start a new service
		manager.sealStartedServices();
		assertThrows(UnsupportedOperationException.class, () -> manager.startService(service));
		}
		}