This only takes effect if Hidden API access restrictions are enabled as well. */ public static final int DISABLE_TEST_API_ENFORCEMENT_POLICY = 1 << 18; public static final int MEMORY_TAG_LEVEL_MASK = (1 << 19) | (1 << 20); public static final int MEMORY_TAG_LEVEL_NONE = 0; /** * Enable pointer tagging in this process. * Tags are checked during memory deallocation, but not on access. * TBI stands for Top-Byte-Ignore, an ARM CPU feature. * {@link https://developer.arm.com/docs/den0024/latest/the-memory-management-unit/translation-table-configuration/virtual-address-tagging} */ public static final int MEMORY_TAG_LEVEL_TBI = 1 << 19; /** * Enable asynchronous memory tag checks in this process. */ public static final int MEMORY_TAG_LEVEL_ASYNC = 2 << 19; /** * Enable synchronous memory tag checks in this process. */ public static final int MEMORY_TAG_LEVEL_SYNC = 3 << 19; /** * A two-bit field for GWP-ASan level of this process. See the possible values below. */ public static final int GWP_ASAN_LEVEL_MASK = (1 << 21) | (1 << 22); /** * Disable GWP-ASan in this process. * GWP-ASan is a low-overhead memory bug detector using guard pages on a small * subset of heap allocations. */ public static final int GWP_ASAN_LEVEL_NEVER = 0 << 21; /** * Enable GWP-ASan in this process with a small sampling rate. * With approx. 1% chance GWP-ASan will be activated and apply its protection * to a small subset of heap allocations. * Otherwise (~99% chance) this process is unaffected. */ public static final int GWP_ASAN_LEVEL_LOTTERY = 1 << 21; /** * Always enable GWP-ASan in this process. * GWP-ASan is activated unconditionally (but still, only a small subset of * allocations is protected). */ public static final int GWP_ASAN_LEVEL_ALWAYS = 2 << 21; /** * GWP-ASan's `gwpAsanMode` manifest flag was unspecified. Currently, this * means GWP_ASAN_LEVEL_LOTTERY for system apps, and GWP_ASAN_LEVEL_NONE for * non-system apps. */ public static final int GWP_ASAN_LEVEL_DEFAULT = 3 << 21; /** Enable automatic zero-initialization of native heap memory allocations. */ public static final int NATIVE_HEAP_ZERO_INIT_ENABLED = 1 << 23; /** * Enable profiling from system services. This loads profiling related plugins in ART. */ public static final int PROFILEABLE = 1 << 24; /** * Enable ptrace. This is enabled on eng, if the app is debuggable, or if * the persist.debug.ptrace.enabled property is set. */ public static final int DEBUG_ENABLE_PTRACE = 1 << 25; /** Load 4KB ELF files on 16KB device using appcompat mode */ public static final int ENABLE_PAGE_SIZE_APP_COMPAT = 1 << 26; /** No external storage should be mounted. */ public static final int MOUNT_EXTERNAL_NONE = IVold.REMOUNT_MODE_NONE; /** Default external storage should be mounted. */ public static final int MOUNT_EXTERNAL_DEFAULT = IVold.REMOUNT_MODE_DEFAULT; /** * Mount mode for package installers which should give them access to * all obb dirs in addition to their package sandboxes */ public static final int MOUNT_EXTERNAL_INSTALLER = IVold.REMOUNT_MODE_INSTALLER; /** The lower file system should be bind mounted directly on external storage */ public static final int MOUNT_EXTERNAL_PASS_THROUGH = IVold.REMOUNT_MODE_PASS_THROUGH; /** Use the regular scoped storage filesystem, but Android/ should be writable. * Used to support the applications hosting DownloadManager and the MTP server. */ public static final int MOUNT_EXTERNAL_ANDROID_WRITABLE = IVold.REMOUNT_MODE_ANDROID_WRITABLE; /** Number of bytes sent to the Zygote over USAP pipes or the pool event FD */ static final int USAP_MANAGEMENT_MESSAGE_BYTES = 8; /** Make the new process have top application priority. */ public static final String START_AS_TOP_APP_ARG = "--is-top-app"; /** List of packages with the same uid, and its app data info: volume uuid and inode. */ public static final String PKG_DATA_INFO_MAP = "--pkg-data-info-map"; /** List of allowlisted packages and its app data info: volume uuid and inode. */ public static final String ALLOWLISTED_DATA_INFO_MAP = "--allowlisted-data-info-map"; /** Bind mount app storage dirs to lower fs not via fuse */ public static final String BIND_MOUNT_APP_STORAGE_DIRS = "--bind-mount-storage-dirs"; /** Bind mount app storage dirs to lower fs not via fuse */ public static final String BIND_MOUNT_APP_DATA_DIRS = "--bind-mount-data-dirs"; /** Bind the system properties to an alternate set, for appcompat reasons */ public static final String BIND_MOUNT_SYSPROP_OVERRIDES = "--bind-mount-sysprop-overrides"; /** * An extraArg passed when a zygote process is forking a child-zygote, specifying a name * in the abstract socket namespace. This socket name is what the new child zygote * should listen for connections on. */ public static final String CHILD_ZYGOTE_SOCKET_NAME_ARG = "--zygote-socket="; /** * An extraArg passed when a zygote process is forking a child-zygote, specifying the * requested ABI for the child Zygote. */ public static final String CHILD_ZYGOTE_ABI_LIST_ARG = "--abi-list="; /** * An extraArg passed when a zygote process is forking a child-zygote, specifying the * start of the UID range the children of the Zygote may setuid()/setgid() to. This * will be enforced with a seccomp filter. */ public static final String CHILD_ZYGOTE_UID_RANGE_START = "--uid-range-start="; /** * An extraArg passed when a zygote process is forking a child-zygote, specifying the * end of the UID range the children of the Zygote may setuid()/setgid() to. This * will be enforced with a seccomp filter. */ public static final String CHILD_ZYGOTE_UID_RANGE_END = "--uid-range-end="; private static final String TAG = "Zygote"; /** Prefix prepended to socket names created by init */ private static final String ANDROID_SOCKET_PREFIX = "ANDROID_SOCKET_"; /** * The duration to wait before re-checking Zygote related system properties. * * One minute in milliseconds. */ public static final long PROPERTY_CHECK_INTERVAL = 60000; /** * @hide for internal use only */ public static final int SOCKET_BUFFER_SIZE = 256; /** * @hide for internal use only */ private static final int PRIORITY_MAX = -20; /** a prototype instance for a future List.toArray() */ static final int[][] INT_ARRAY_2D = new int[0][0]; /** * @hide for internal use only. */ public static final String PRIMARY_SOCKET_NAME = "zygote"; /** * @hide for internal use only. */ public static final String SECONDARY_SOCKET_NAME = "zygote_secondary"; /** * @hide for internal use only */ public static final String USAP_POOL_PRIMARY_SOCKET_NAME = "usap_pool_primary"; /** * @hide for internal use only */ public static final String USAP_POOL_SECONDARY_SOCKET_NAME = "usap_pool_secondary"; private Zygote() {} private static boolean containsInetGid(int[] gids) { for (int i = 0; i < gids.length; i++) { if (gids[i] == android.os.Process.INET_GID) return true; } return false; } /** * Forks a new VM instance. The current VM must have been started * with the -Xzygote flag. NOTE: new instance keeps all * root capabilities. The new process is expected to call capset(). * * @param uid the UNIX uid that the new process should setuid() to after * fork()ing and and before spawning any threads. * @param gid the UNIX gid that the new process should setgid() to after * fork()ing and and before spawning any threads. * @param gids null-ok; a list of UNIX gids that the new process should * setgroups() to after fork and before spawning any threads. * @param runtimeFlags bit flags that enable ART features. * @param rlimits null-ok an array of rlimit tuples, with the second * dimension having a length of 3 and representing * (resource, rlim_cur, rlim_max). These are set via the posix * setrlimit(2) call. * @param seInfo null-ok a string specifying SELinux information for * the new process. * @param niceName null-ok a string specifying the process name. * @param fdsToClose an array of ints, holding one or more POSIX * file descriptor numbers that are to be closed by the child * (and replaced by /dev/null) after forking. An integer value * of -1 in any entry in the array means "ignore this one". * @param fdsToIgnore null-ok an array of ints, either null or holding * one or more POSIX file descriptor numbers that are to be ignored * in the file descriptor table check. * @param startChildZygote if true, the new child process will itself be a * new zygote process. * @param instructionSet null-ok the instruction set to use. * @param appDataDir null-ok the data directory of the app. * @param isTopApp true if the process is for top (high priority) application. * @param pkgDataInfoList A list that stores related packages and its app data * info: volume uuid and inode. * @param allowlistedDataInfoList Like pkgDataInfoList, but it's for allowlisted apps. * @param bindMountAppDataDirs True if the zygote needs to mount data dirs. * @param bindMountAppStorageDirs True if the zygote needs to mount storage dirs. * @param bindMountSyspropOverrides True if the zygote needs to mount the override system * properties * * @return 0 if this is the child, pid of the child * if this is the parent, or -1 on error. */ static int forkAndSpecialize(int uid, int gid, int[] gids, int runtimeFlags, int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose, int[] fdsToIgnore, boolean startChildZygote, String instructionSet, String appDataDir, boolean isTopApp, String[] pkgDataInfoList, String[] allowlistedDataInfoList, boolean bindMountAppDataDirs, boolean bindMountAppStorageDirs, boolean bindMountSyspropOverrides) { ZygoteHooks.preFork(); int pid = nativeForkAndSpecialize( uid, gid, gids, runtimeFlags, rlimits, mountExternal, seInfo, niceName, fdsToClose, fdsToIgnore, startChildZygote, instructionSet, appDataDir, isTopApp, pkgDataInfoList, allowlistedDataInfoList, bindMountAppDataDirs, bindMountAppStorageDirs, bindMountSyspropOverrides); if (pid == 0) { // Note that this event ends at the end of handleChildProc, Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "PostFork"); // If no GIDs were specified, don't make any permissions changes based on groups. if (gids != null && gids.length > 0) { NetworkUtilsInternal.setAllowNetworkingForProcess(containsInetGid(gids)); } } // Set the Java Language thread priority to the default value for new apps. Thread.currentThread().setPriority(Thread.NORM_PRIORITY); ZygoteHooks.postForkCommon(); return pid; } private static native int nativeForkAndSpecialize(int uid, int gid, int[] gids, int runtimeFlags, int[][] rlimits, int mountExternal, String seInfo, String niceName, int[] fdsToClose, int[] fdsToIgnore, boolean startChildZygote, String instructionSet, String appDataDir, boolean isTopApp, String[] pkgDataInfoList, String[] allowlistedDataInfoList, boolean bindMountAppDataDirs, boolean bindMountAppStorageDirs, boolean bindMountSyspropOverrides); /** * Specialize an unspecialized app process. The current VM must have been started * with the -Xzygote flag. * * @param uid The UNIX uid that the new process should setuid() to before spawning any threads * @param gid The UNIX gid that the new process should setgid() to before spawning any threads * @param gids null-ok; A list of UNIX gids that the new process should * setgroups() to before spawning any threads * @param runtimeFlags Bit flags that enable ART features * @param rlimits null-ok An array of rlimit tuples, with the second * dimension having a length of 3 and representing * (resource, rlim_cur, rlim_max). These are set via the posix * setrlimit(2) call. * @param seInfo null-ok A string specifying SELinux information for * the new process. * @param niceName null-ok A string specifying the process name. * @param startChildZygote If true, the new child process will itself be a * new zygote process. * @param instructionSet null-ok The instruction set to use. * @param appDataDir null-ok The data directory of the app. * @param isTopApp True if the process is for top (high priority) application. * @param pkgDataInfoList A list that stores related packages and its app data * volume uuid and CE dir inode. For example, pkgDataInfoList = [app_a_pkg_name, * app_a_data_volume_uuid, app_a_ce_inode, app_b_pkg_name, app_b_data_volume_uuid, * app_b_ce_inode, ...]; * @param allowlistedDataInfoList Like pkgDataInfoList, but it's for allowlisted apps. * @param bindMountAppDataDirs True if the zygote needs to mount data dirs. * @param bindMountAppStorageDirs True if the zygote needs to mount storage dirs. * @param bindMountSyspropOverrides True if the zygote needs to mount the override system * properties */ private static void specializeAppProcess(int uid, int gid, int[] gids, int runtimeFlags, int[][] rlimits, int mountExternal, String seInfo, String niceName, boolean startChildZygote, String instructionSet, String appDataDir, boolean isTopApp, String[] pkgDataInfoList, String[] allowlistedDataInfoList, boolean bindMountAppDataDirs, boolean bindMountAppStorageDirs, boolean bindMountSyspropOverrides) { nativeSpecializeAppProcess(uid, gid, gids, runtimeFlags, rlimits, mountExternal, seInfo, niceName, startChildZygote, instructionSet, appDataDir, isTopApp, pkgDataInfoList, allowlistedDataInfoList, bindMountAppDataDirs, bindMountAppStorageDirs, bindMountSyspropOverrides); // Note that this event ends at the end of handleChildProc. Trace.traceBegin(Trace.TRACE_TAG_ACTIVITY_MANAGER, "PostFork"); if (gids != null && gids.length > 0) { NetworkUtilsInternal.setAllowNetworkingForProcess(containsInetGid(gids)); } // Set the Java Language thread priority to the default value for new apps. Thread.currentThread().setPriority(Thread.NORM_PRIORITY); /* * This is called here (instead of after the fork but before the specialize) to maintain * consistancy with the code paths for forkAndSpecialize. * * TODO (chriswailes): Look into moving this to immediately after the fork. */ ZygoteHooks.postForkCommon(); } private static native void nativeSpecializeAppProcess(int uid, int gid, int[] gids, int runtimeFlags, int[][] rlimits, int mountExternal, String seInfo, String niceName, boolean startChildZygote, String instructionSet, String appDataDir, boolean isTopApp, String[] pkgDataInfoList, String[] allowlistedDataInfoList, boolean bindMountAppDataDirs, boolean bindMountAppStorageDirs, boolean bindMountSyspropOverrides); /** * Called to do any initialization before starting an application. */ static native void nativePreApplicationInit(); /** * Special method to start the system server process. In addition to the * common actions performed in forkAndSpecialize, the pid of the child * process is recorded such that the death of the child process will cause * zygote to exit. * * @param uid the UNIX uid that the new process should setuid() to after * fork()ing and and before spawning any threads. * @param gid the UNIX gid that the new process should setgid() to after * fork()ing and and before spawning any threads. * @param gids null-ok; a list of UNIX gids that the new process should * setgroups() to after fork and before spawning any threads. * @param runtimeFlags bit flags that enable ART features. * @param rlimits null-ok an array of rlimit tuples, with the second * dimension having a length of 3 and representing * (resource, rlim_cur, rlim_max). These are set via the posix * setrlimit(2) call. * @param permittedCapabilities argument for setcap() * @param effectiveCapabilities argument for setcap() * * @return 0 if this is the child, pid of the child * if this is the parent, or -1 on error. */ static int forkSystemServer(int uid, int gid, int[] gids, int runtimeFlags, int[][] rlimits, long permittedCapabilities, long effectiveCapabilities) { ZygoteHooks.preFork(); int pid = nativeForkSystemServer( uid, gid, gids, runtimeFlags, rlimits, permittedCapabilities, effectiveCapabilities); // Set the Java Language thread priority to the default value for new apps. Thread.currentThread().setPriority(Thread.NORM_PRIORITY); ZygoteHooks.postForkCommon(); return pid; } private static native int nativeForkSystemServer(int uid, int gid, int[] gids, int runtimeFlags, int[][] rlimits, long permittedCapabilities, long effectiveCapabilities); /** * Lets children of the zygote inherit open file descriptors to this path. */ protected static native void nativeAllowFileAcrossFork(String path); /** * Lets children of the zygote inherit open file descriptors that belong to the * ApplicationInfo that is passed in. * * @param appInfo ApplicationInfo of the application */ static void allowAppFilesAcrossFork(ApplicationInfo appInfo) { for (String path : appInfo.getAllApkPaths()) { Zygote.nativeAllowFileAcrossFork(path); } } /** * Scans file descriptors in /proc/self/fd/, stores their metadata from readlink(2)/stat(2) when * available. Saves this information in a global on native side, to be used by subsequent call * to allowFilesOpenedByPreload(). Fatally fails if the FDs are of unsupported type and are not * explicitly allowed. Ignores repeated invocations. * * Inspecting the FDs is more permissive than in forkAndSpecialize() because preload is invoked * earlier and hence needs to allow a few open sockets. The checks in forkAndSpecialize() * enforce that these sockets are closed when forking. */ static void markOpenedFilesBeforePreload() { nativeMarkOpenedFilesBeforePreload(); } private static native void nativeMarkOpenedFilesBeforePreload(); /** * By scanning /proc/self/fd/ determines file descriptor numbers in this process opened since * the first call to markOpenedFilesBeforePreload(). These FDs are treated as 'owned' by the * custom preload of the App Zygote - the app is responsible for not sharing data with its other * processes using these FDs, including by lseek(2). File descriptor types and file names are * not checked. Changes in FDs recorded by markOpenedFilesBeforePreload() are not expected and * kill the current process. */ static void allowFilesOpenedByPreload() { nativeAllowFilesOpenedByPreload(); } private static native void nativeAllowFilesOpenedByPreload(); /** * Installs a seccomp filter that limits setresuid()/setresgid() to the passed-in range * @param uidGidMin The smallest allowed uid/gid * @param uidGidMax The largest allowed uid/gid */ native protected static void nativeInstallSeccompUidGidFilter(int uidGidMin, int uidGidMax); /** * Initialize the native state of the Zygote. This inclues * - Fetching socket FDs from the environment * - Initializing security properties * - Unmounting storage as appropriate * - Loading necessary performance profile information * * @param isPrimary True if this is the zygote process, false if it is zygote_secondary */ static void initNativeState(boolean isPrimary) { nativeInitNativeState(isPrimary); } protected static native void nativeInitNativeState(boolean isPrimary); /** * Returns the raw string value of a system property. * * Note that Device Config is not available without an application so SystemProperties is used * instead. * * TODO (chriswailes): Cache the system property location in native code and then write a JNI * function to fetch it. */ public static String getConfigurationProperty(String propertyName, String defaultValue) { return SystemProperties.get( String.join(".", "persist.device_config", DeviceConfig.NAMESPACE_RUNTIME_NATIVE, propertyName), defaultValue); } static void emptyUsapPool() { nativeEmptyUsapPool(); } private static native void nativeEmptyUsapPool(); /** * Returns the value of a system property converted to a boolean using specific logic. * * Note that Device Config is not available without an application so SystemProperties is used * instead. * * @see SystemProperties#getBoolean * * TODO (chriswailes): Cache the system property location in native code and then write a JNI * function to fetch it. * TODO (chriswailes): Move into ZygoteConfig.java once the necessary CL lands (go/ag/6580627) */ public static boolean getConfigurationPropertyBoolean( String propertyName, Boolean defaultValue) { return SystemProperties.getBoolean( String.join(".", "persist.device_config", DeviceConfig.NAMESPACE_RUNTIME_NATIVE, propertyName), defaultValue); } /** * @return Number of unspecialized app processes currently in the pool */ static int getUsapPoolCount() { return nativeGetUsapPoolCount(); } private static native int nativeGetUsapPoolCount(); /** * @return The event FD used for communication between the signal handler and the ZygoteServer * poll loop */ static FileDescriptor getUsapPoolEventFD() { FileDescriptor fd = new FileDescriptor(); fd.setInt$(nativeGetUsapPoolEventFD()); return fd; } private static native int nativeGetUsapPoolEventFD(); /** * Fork a new unspecialized app process from the zygote. Adds the Usap to the native * Usap table. * * @param usapPoolSocket The server socket the USAP will call accept on * @param sessionSocketRawFDs Anonymous session sockets that are currently open. * These are closed in the child. * @param isPriorityFork Raise the initial process priority level because this is on the * critical path for application startup. * @return In the child process, this returns a Runnable that waits for specialization * info to start an app process. In the sygote/parent process this returns null. */ static @Nullable Runnable forkUsap(LocalServerSocket usapPoolSocket, int[] sessionSocketRawFDs, boolean isPriorityFork) { FileDescriptor readFD; FileDescriptor writeFD; try { FileDescriptor[] pipeFDs = Os.pipe2(O_CLOEXEC); readFD = pipeFDs[0]; writeFD = pipeFDs[1]; } catch (ErrnoException errnoEx) { throw new IllegalStateException("Unable to create USAP pipe.", errnoEx); } int pid = nativeForkApp(readFD.getInt$(), writeFD.getInt$(), sessionSocketRawFDs, /*argsKnown=*/ false, isPriorityFork); if (pid == 0) { IoUtils.closeQuietly(readFD); return childMain(null, usapPoolSocket, writeFD); } else if (pid == -1) { // Fork failed. return null; } else { // readFD will be closed by the native code. See removeUsapTableEntry(); IoUtils.closeQuietly(writeFD); nativeAddUsapTableEntry(pid, readFD.getInt$()); return null; } } private static native int nativeForkApp(int readPipeFD, int writePipeFD, int[] sessionSocketRawFDs, boolean argsKnown, boolean isPriorityFork); /** * Add an entry for a new Usap to the table maintained in native code. */ @CriticalNative private static native void nativeAddUsapTableEntry(int pid, int readPipeFD); /** * Fork a new app process from the zygote. argBuffer contains a fork command that * request neither a child zygote, nor a wrapped process. Continue to accept connections * on the specified socket, use those to refill argBuffer, and continue to process * sufficiently simple fork requests. We presume that the only open file descriptors * requiring special treatment are the session socket embedded in argBuffer, and * zygoteSocket. * @param argBuffer containing initial command and the connected socket from which to * read more * @param zygoteSocket socket from which to obtain new connections when current argBuffer * one is disconnected * @param expectedUId Uid of peer for initial requests. Subsequent requests from a different * peer will cause us to return rather than perform the requested fork. * @param minUid Minimum Uid enforced for all but first fork request. The caller checks * the Uid policy for the initial request. * @param firstNiceName name of first created process. Used for error reporting only. * @return A Runnable in each child process, null in the parent. * If this returns in then argBuffer still contains a command needing to be executed. */ static @Nullable Runnable forkSimpleApps(@NonNull ZygoteCommandBuffer argBuffer, @NonNull FileDescriptor zygoteSocket, int expectedUid, int minUid, @Nullable String firstNiceName) { boolean in_child = argBuffer.forkRepeatedly(zygoteSocket, expectedUid, minUid, firstNiceName); if (in_child) { return childMain(argBuffer, /*usapPoolSocket=*/null, /*writePipe=*/null); } else { return null; } } /** * Specialize the current process into one described by argBuffer or the command read from * usapPoolSocket. Exactly one of those must be null. If we are given an argBuffer, we close * it. Used both for a specializing a USAP process, and for process creation without USAPs. * In both cases, we specialize the process after first returning to Java code. * * @param writePipe The write end of the reporting pipe used to communicate with the poll loop * of the ZygoteServer. * @return A runnable oject representing the new application. */ private static Runnable childMain(@Nullable ZygoteCommandBuffer argBuffer, @Nullable LocalServerSocket usapPoolSocket, FileDescriptor writePipe) { final int pid = Process.myPid(); DataOutputStream usapOutputStream = null; ZygoteArguments args = null; LocalSocket sessionSocket = null; if (argBuffer == null) { // Read arguments from usapPoolSocket instead. Process.setArgV0(Process.is64Bit() ? "usap64" : "usap32"); // Change the priority to max before calling accept so we can respond to new // specialization requests as quickly as possible. This will be reverted to the // default priority in the native specialization code. boostUsapPriority(); while (true) { ZygoteCommandBuffer tmpArgBuffer = null; try { sessionSocket = usapPoolSocket.accept(); // Block SIGTERM so we won't be killed if the Zygote flushes the USAP pool. // This is safe from a race condition because the pool is only flushed after // the SystemServer changes its internal state to stop using the USAP pool. blockSigTerm(); usapOutputStream = new DataOutputStream(sessionSocket.getOutputStream()); Credentials peerCredentials = sessionSocket.getPeerCredentials(); tmpArgBuffer = new ZygoteCommandBuffer(sessionSocket); args = ZygoteArguments.getInstance(tmpArgBuffer); applyUidSecurityPolicy(args, peerCredentials); // TODO (chriswailes): Should this only be run for debug builds? validateUsapCommand(args); break; } catch (Exception ex) { Log.e("USAP", ex.getMessage()); } // Re-enable SIGTERM so the USAP can be flushed from the pool if necessary. unblockSigTerm(); IoUtils.closeQuietly(sessionSocket); IoUtils.closeQuietly(tmpArgBuffer); } } else { // Block SIGTERM so we won't be killed if the Zygote flushes the USAP pool. blockSigTerm(); try { args = ZygoteArguments.getInstance(argBuffer); } catch (Exception ex) { Log.e("AppStartup", ex.getMessage()); throw new AssertionError("Failed to parse application start command", ex); } // peerCredentials were checked in parent. } if (args == null) { throw new AssertionError("Empty command line"); } try { // SIGTERM is blocked here. This prevents a USAP that is specializing from being // killed during a pool flush. applyDebuggerSystemProperty(args); int[][] rlimits = null; if (args.mRLimits != null) { rlimits = args.mRLimits.toArray(INT_ARRAY_2D); } if (argBuffer == null) { // This must happen before the SELinux policy for this process is // changed when specializing. try { // Used by ZygoteProcess.zygoteSendArgsAndGetResult to fill in a // Process.ProcessStartResult object. usapOutputStream.writeInt(pid); } catch (IOException ioEx) { Log.e("USAP", "Failed to write response to session socket: " + ioEx.getMessage()); throw new RuntimeException(ioEx); } finally { try { // Since the raw FD is created by init and then loaded from an environment // variable (as opposed to being created by the LocalSocketImpl itself), // the LocalSocket/LocalSocketImpl does not own the Os-level socket. See // the spec for LocalSocket.createConnectedLocalSocket(FileDescriptor fd). // Thus closing the LocalSocket does not suffice. See b/130309968 for more // discussion. FileDescriptor fd = usapPoolSocket.getFileDescriptor(); usapPoolSocket.close(); Os.close(fd); } catch (ErrnoException | IOException ex) { Log.e("USAP", "Failed to close USAP pool socket"); throw new RuntimeException(ex); } } } if (writePipe != null) { try { ByteArrayOutputStream buffer = new ByteArrayOutputStream(Zygote.USAP_MANAGEMENT_MESSAGE_BYTES); DataOutputStream outputStream = new DataOutputStream(buffer); // This is written as a long so that the USAP reporting pipe and USAP pool // event FD handlers in ZygoteServer.runSelectLoop can be unified. These two // cases should both send/receive 8 bytes. // TODO: Needs tweaking to handle the non-Usap invoke-with case, which expects // a different format. outputStream.writeLong(pid); outputStream.flush(); Os.write(writePipe, buffer.toByteArray(), 0, buffer.size()); } catch (Exception ex) { Log.e("USAP", String.format("Failed to write PID (%d) to pipe (%d): %s", pid, writePipe.getInt$(), ex.getMessage())); throw new RuntimeException(ex); } finally { IoUtils.closeQuietly(writePipe); } } specializeAppProcess(args.mUid, args.mGid, args.mGids, args.mRuntimeFlags, rlimits, args.mMountExternal, args.mSeInfo, args.mNiceName, args.mStartChildZygote, args.mInstructionSet, args.mAppDataDir, args.mIsTopApp, args.mPkgDataInfoList, args.mAllowlistedDataInfoList, args.mBindMountAppDataDirs, args.mBindMountAppStorageDirs, args.mBindMountSyspropOverrides); // While `specializeAppProcess` sets the thread name on the process's main thread, this // is distinct from the app process name which appears in stack traces, as the latter is // sourced from the argument buffer of the Process class. Set the app process name here. Zygote.setAppProcessName(args, TAG); Trace.traceEnd(Trace.TRACE_TAG_ACTIVITY_MANAGER); return ZygoteInit.zygoteInit(args.mTargetSdkVersion, args.mDisabledCompatChanges, args.mRemainingArgs, null /* classLoader */); } finally { // Unblock SIGTERM to restore the process to default behavior. unblockSigTerm(); } } private static void blockSigTerm() { nativeBlockSigTerm(); } private static native void nativeBlockSigTerm(); private static void unblockSigTerm() { nativeUnblockSigTerm(); } private static native void nativeUnblockSigTerm(); private static void boostUsapPriority() { nativeBoostUsapPriority(); } private static native void nativeBoostUsapPriority(); static void setAppProcessName(ZygoteArguments args, String loggingTag) { if (args.mNiceName != null) { Process.setArgV0(args.mNiceName); } else if (args.mPackageName != null) { Process.setArgV0(args.mPackageName); } else { Log.w(loggingTag, "Unable to set package name."); } } private static final String USAP_ERROR_PREFIX = "Invalid command to USAP: "; /** * Checks a set of zygote arguments to see if they can be handled by a USAP. Throws an * exception if an invalid arugment is encountered. * @param args The arguments to test */ private static void validateUsapCommand(ZygoteArguments args) { if (args.mAbiListQuery) { throw new IllegalArgumentException(USAP_ERROR_PREFIX + "--query-abi-list"); } else if (args.mPidQuery) { throw new IllegalArgumentException(USAP_ERROR_PREFIX + "--get-pid"); } else if (args.mPreloadDefault) { throw new IllegalArgumentException(USAP_ERROR_PREFIX + "--preload-default"); } else if (args.mPreloadPackage != null) { throw new IllegalArgumentException(USAP_ERROR_PREFIX + "--preload-package"); } else if (args.mPreloadApp != null) { throw new IllegalArgumentException(USAP_ERROR_PREFIX + "--preload-app"); } else if (args.mStartChildZygote) { throw new IllegalArgumentException(USAP_ERROR_PREFIX + "--start-child-zygote"); } else if (args.mApiDenylistExemptions != null) { throw new IllegalArgumentException( USAP_ERROR_PREFIX + "--set-api-denylist-exemptions"); } else if (args.mHiddenApiAccessLogSampleRate != -1) { throw new IllegalArgumentException( USAP_ERROR_PREFIX + "--hidden-api-log-sampling-rate="); } else if (args.mHiddenApiAccessStatslogSampleRate != -1) { throw new IllegalArgumentException( USAP_ERROR_PREFIX + "--hidden-api-statslog-sampling-rate="); } else if (args.mInvokeWith != null) { throw new IllegalArgumentException(USAP_ERROR_PREFIX + "--invoke-with"); } else if (args.mPermittedCapabilities != 0 || args.mEffectiveCapabilities != 0) { throw new ZygoteSecurityException("Client may not specify capabilities: " + "permitted=0x" + Long.toHexString(args.mPermittedCapabilities) + ", effective=0x" + Long.toHexString(args.mEffectiveCapabilities)); } } /** * @return Raw file descriptors for the read-end of USAP reporting pipes. */ static int[] getUsapPipeFDs() { return nativeGetUsapPipeFDs(); } private static native int[] nativeGetUsapPipeFDs(); /** * Remove the USAP table entry for the provided process ID. * * @param usapPID Process ID of the entry to remove * @return True if the entry was removed; false if it doesn't exist */ static boolean removeUsapTableEntry(int usapPID) { return nativeRemoveUsapTableEntry(usapPID); } @CriticalNative private static native boolean nativeRemoveUsapTableEntry(int usapPID); /** * Return the minimum child uid that the given peer is allowed to create. * uid 1000 (Process.SYSTEM_UID) may specify any uid ≥ 1000 in normal * operation. It may also specify any gid and setgroups() list it chooses. * In factory test mode, it may specify any UID. */ static int minChildUid(Credentials peer) { if (peer.getUid() == Process.SYSTEM_UID && FactoryTest.getMode() == FactoryTest.FACTORY_TEST_OFF) { /* In normal operation, SYSTEM_UID can only specify a restricted * set of UIDs. In factory test mode, SYSTEM_UID may specify any uid. */ return Process.SYSTEM_UID; } else { return 0; } } /* * Adjust uid and gid arguments, ensuring that the security policy is satisfied. * @param args non-null; zygote spawner arguments * @param peer non-null; peer credentials * @throws ZygoteSecurityException Indicates a security issue when applying the UID based * security policies */ static void applyUidSecurityPolicy(ZygoteArguments args, Credentials peer) throws ZygoteSecurityException { if (args.mUidSpecified && (args.mUid < minChildUid(peer))) { throw new ZygoteSecurityException( "System UID may not launch process with UID < " + Process.SYSTEM_UID); } // If not otherwise specified, uid and gid are inherited from peer if (!args.mUidSpecified) { args.mUid = peer.getUid(); args.mUidSpecified = true; } if (!args.mGidSpecified) { args.mGid = peer.getGid(); args.mGidSpecified = true; } } /** * This will enable jdwp by default for all apps. It is OK to cache this property * because we expect to reboot the system whenever this property changes */ private static final boolean ENABLE_JDWP = SystemProperties.get( "persist.debug.dalvik.vm.jdwp.enabled").equals("1"); /** * This will enable ptrace by default for all apps. It is OK to cache this property * because we expect to reboot the system whenever this property changes */ private static final boolean ENABLE_PTRACE = SystemProperties.get( "persist.debug.ptrace.enabled").equals("1"); /** * Applies debugger system properties to the zygote arguments. * * For eng builds all apps are debuggable with JDWP and ptrace. * * On userdebug builds if persist.debug.dalvik.vm.jdwp.enabled * is 1 all apps are debuggable with JDWP and ptrace. Otherwise, the * debugger state is specified via the "--enable-jdwp" flag in the * spawn request. * * On userdebug builds if persist.debug.ptrace.enabled is 1 all * apps are debuggable with ptrace. * * @param args non-null; zygote spawner args */ static void applyDebuggerSystemProperty(ZygoteArguments args) { if (Build.IS_ENG || (Build.IS_USERDEBUG && ENABLE_JDWP)) { args.mRuntimeFlags |= Zygote.DEBUG_ENABLE_JDWP; // Also enable ptrace when JDWP is enabled for consistency with // before persist.debug.ptrace.enabled existed. args.mRuntimeFlags |= Zygote.DEBUG_ENABLE_PTRACE; } if (Build.IS_ENG || (Build.IS_USERDEBUG && ENABLE_PTRACE)) { args.mRuntimeFlags |= Zygote.DEBUG_ENABLE_PTRACE; } } /** * Applies zygote security policy. * Based on the credentials of the process issuing a zygote command: *