Handle the race condition when calling uncrypt services. (9bd481b3) · Commits · e / os / android_frameworks_base

core/java/android/os/IRecoverySystem.aidl

+1 −0

Original line number	Diff line number	Diff line
		@@ -25,4 +25,5 @@ interface IRecoverySystem {
		boolean uncrypt(in String packageFile, IRecoverySystemProgressListener listener);
		boolean setupBcb(in String command);
		boolean clearBcb();
		void rebootRecoveryWithCommand(in String command);
		}

core/java/android/os/RecoverySystem.java

+23 −18

Original line number	Diff line number	Diff line
		@@ -700,7 +700,6 @@ public class RecoverySystem {
		* @throws IOException if something goes wrong.
		*/
		private static void bootCommand(Context context, String... args) throws IOException {
		synchronized (sRequestLock) {
		LOG_FILE.delete();

		StringBuilder command = new StringBuilder();
		@@ -711,18 +710,13 @@ public class RecoverySystem {
		}
		}

		// Write the command into BCB (bootloader control block).
		RecoverySystem rs = (RecoverySystem) context.getSystemService(
		Context.RECOVERY_SERVICE);
		rs.setupBcb(command.toString());

		// Having set up the BCB, go ahead and reboot.
		PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
		pm.reboot(PowerManager.REBOOT_RECOVERY);
		// Write the command into BCB (bootloader control block) and boot from
		// there. Will not return unless failed.
		RecoverySystem rs = (RecoverySystem) context.getSystemService(Context.RECOVERY_SERVICE);
		rs.rebootRecoveryWithCommand(command.toString());

		throw new IOException("Reboot failed (no permissions?)");
		}
		}

		// Read last_install; then report time (in seconds) and I/O (in MiB) for
		// this update to tron.
		@@ -915,6 +909,17 @@ public class RecoverySystem {
		return false;
		}

		/**
		* Talks to RecoverySystemService via Binder to set up the BCB command and
		* reboot into recovery accordingly.
		*/
		private void rebootRecoveryWithCommand(String command) {
		try {
		mService.rebootRecoveryWithCommand(command);
		} catch (RemoteException ignored) {
		}
		}

		/**
		* Internally, recovery treats each line of the command file as a separate
		* argv, so we only need to protect against newlines and nulls.

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

+144 −70

Original line number	Diff line number	Diff line
		@@ -21,6 +21,7 @@ import android.net.LocalSocket;
		import android.net.LocalSocketAddress;
		import android.os.IRecoverySystem;
		import android.os.IRecoverySystemProgressListener;
		import android.os.PowerManager;
		import android.os.RecoverySystem;
		import android.os.RemoteException;
		import android.os.SystemProperties;
		@@ -50,8 +51,15 @@ public final class RecoverySystemService extends SystemService {
		// The socket at /dev/socket/uncrypt to communicate with uncrypt.
		private static final String UNCRYPT_SOCKET = "uncrypt";

		// The init services that communicate with /system/bin/uncrypt.
		private static final String INIT_SERVICE_UNCRYPT = "init.svc.uncrypt";
		private static final String INIT_SERVICE_SETUP_BCB = "init.svc.setup-bcb";
		private static final String INIT_SERVICE_CLEAR_BCB = "init.svc.clear-bcb";

		private static final int SOCKET_CONNECTION_MAX_RETRY = 30;

		private static final Object sRequestLock = new Object();

		private Context mContext;

		public RecoverySystemService(Context context) {
		@@ -69,8 +77,15 @@ public final class RecoverySystemService extends SystemService {
		public boolean uncrypt(String filename, IRecoverySystemProgressListener listener) {
		if (DEBUG) Slog.d(TAG, "uncrypt: " + filename);

		synchronized (sRequestLock) {
		mContext.enforceCallingOrSelfPermission(android.Manifest.permission.RECOVERY, null);

		final boolean available = checkAndWaitForUncryptService();
		if (!available) {
		Slog.e(TAG, "uncrypt service is unavailable.");
		return false;
		}

		// Write the filename into UNCRYPT_PACKAGE_FILE to be read by
		// uncrypt.
		RecoverySystem.UNCRYPT_PACKAGE_FILE.delete();
		@@ -78,8 +93,8 @@ public final class RecoverySystemService extends SystemService {
		try (FileWriter uncryptFile = new FileWriter(RecoverySystem.UNCRYPT_PACKAGE_FILE)) {
		uncryptFile.write(filename + "\n");
		} catch (IOException e) {
		Slog.e(TAG, "IOException when writing \"" + RecoverySystem.UNCRYPT_PACKAGE_FILE +
		"\": ", e);
		Slog.e(TAG, "IOException when writing \"" +
		RecoverySystem.UNCRYPT_PACKAGE_FILE + "\":", e);
		return false;
		}

		@@ -147,18 +162,71 @@ public final class RecoverySystemService extends SystemService {

		return true;
		}
		}

		@Override // Binder call
		public boolean clearBcb() {
		if (DEBUG) Slog.d(TAG, "clearBcb");
		synchronized (sRequestLock) {
		return setupOrClearBcb(false, null);
		}
		}

		@Override // Binder call
		public boolean setupBcb(String command) {
		if (DEBUG) Slog.d(TAG, "setupBcb: [" + command + "]");
		synchronized (sRequestLock) {
		return setupOrClearBcb(true, command);
		}
		}

		@Override // Binder call
		public void rebootRecoveryWithCommand(String command) {
		if (DEBUG) Slog.d(TAG, "rebootRecoveryWithCommand: [" + command + "]");
		synchronized (sRequestLock) {
		if (!setupOrClearBcb(true, command)) {
		return;
		}

		// Having set up the BCB, go ahead and reboot.
		PowerManager pm = (PowerManager) mContext.getSystemService(Context.POWER_SERVICE);
		pm.reboot(PowerManager.REBOOT_RECOVERY);
		}
		}

		/**
		* Check if any of the init services is still running. If so, we cannot
		* start a new uncrypt/setup-bcb/clear-bcb service right away; otherwise
		* it may break the socket communication since init creates / deletes
		* the socket (/dev/socket/uncrypt) on service start / exit.
		*/
		private boolean checkAndWaitForUncryptService() {
		for (int retry = 0; retry < SOCKET_CONNECTION_MAX_RETRY; retry++) {
		final String uncryptService = SystemProperties.get(INIT_SERVICE_UNCRYPT);
		final String setupBcbService = SystemProperties.get(INIT_SERVICE_SETUP_BCB);
		final String clearBcbService = SystemProperties.get(INIT_SERVICE_CLEAR_BCB);
		final boolean busy = "running".equals(uncryptService) \|\|
		"running".equals(setupBcbService) \|\| "running".equals(clearBcbService);
		if (DEBUG) {
		Slog.i(TAG, "retry: " + retry + " busy: " + busy +
		" uncrypt: [" + uncryptService + "]" +
		" setupBcb: [" + setupBcbService + "]" +
		" clearBcb: [" + clearBcbService + "]");
		}

		if (!busy) {
		return true;
		}

		try {
		Thread.sleep(1000);
		} catch (InterruptedException e) {
		Slog.w(TAG, "Interrupted:", e);
		}
		}

		return false;
		}

		private LocalSocket connectService() {
		LocalSocket socket = new LocalSocket();
		@@ -190,6 +258,12 @@ public final class RecoverySystemService extends SystemService {
		private boolean setupOrClearBcb(boolean isSetup, String command) {
		mContext.enforceCallingOrSelfPermission(android.Manifest.permission.RECOVERY, null);

		final boolean available = checkAndWaitForUncryptService();
		if (!available) {
		Slog.e(TAG, "uncrypt service is unavailable.");
		return false;
		}

		if (isSetup) {
		SystemProperties.set("ctl.start", "setup-bcb");
		} else {