| /* |
| * Copyright (C) 2017 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 com.android.server.pm.PackageManagerServiceUtils.logCriticalInfo; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.content.ContentResolver; |
| import android.content.Context; |
| import android.content.pm.ApplicationInfo; |
| import android.content.pm.PackageManager; |
| import android.content.pm.VersionedPackage; |
| import android.os.Build; |
| import android.os.Bundle; |
| import android.os.Environment; |
| import android.os.FileUtils; |
| import android.os.Process; |
| import android.os.RecoverySystem; |
| import android.os.RemoteCallback; |
| import android.os.SystemClock; |
| import android.os.SystemProperties; |
| import android.os.UserHandle; |
| import android.provider.DeviceConfig; |
| import android.provider.Settings; |
| import android.util.ArraySet; |
| import android.util.ExceptionUtils; |
| import android.util.Log; |
| import android.util.MathUtils; |
| import android.util.Slog; |
| |
| import com.android.internal.annotations.GuardedBy; |
| import com.android.internal.annotations.VisibleForTesting; |
| import com.android.internal.util.ArrayUtils; |
| import com.android.internal.util.FrameworkStatsLog; |
| import com.android.server.PackageWatchdog.FailureReasons; |
| import com.android.server.PackageWatchdog.PackageHealthObserver; |
| import com.android.server.PackageWatchdog.PackageHealthObserverImpact; |
| import com.android.server.am.SettingsToPropertiesMapper; |
| |
| import java.io.File; |
| import java.util.ArrayList; |
| import java.util.Arrays; |
| import java.util.HashMap; |
| import java.util.Iterator; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.TimeUnit; |
| |
| /** |
| * Utilities to help rescue the system from crash loops. Callers are expected to |
| * report boot events and persistent app crashes, and if they happen frequently |
| * enough this class will slowly escalate through several rescue operations |
| * before finally rebooting and prompting the user if they want to wipe data as |
| * a last resort. |
| * |
| * @hide |
| */ |
| public class RescueParty { |
| @VisibleForTesting |
| static final String PROP_ENABLE_RESCUE = "persist.sys.enable_rescue"; |
| @VisibleForTesting |
| static final String PROP_RESCUE_LEVEL = "sys.rescue_level"; |
| @VisibleForTesting |
| static final int LEVEL_NONE = 0; |
| @VisibleForTesting |
| static final int LEVEL_RESET_SETTINGS_UNTRUSTED_DEFAULTS = 1; |
| @VisibleForTesting |
| static final int LEVEL_RESET_SETTINGS_UNTRUSTED_CHANGES = 2; |
| @VisibleForTesting |
| static final int LEVEL_RESET_SETTINGS_TRUSTED_DEFAULTS = 3; |
| @VisibleForTesting |
| static final int LEVEL_FACTORY_RESET = 4; |
| @VisibleForTesting |
| static final String PROP_RESCUE_BOOT_COUNT = "sys.rescue_boot_count"; |
| @VisibleForTesting |
| static final String TAG = "RescueParty"; |
| @VisibleForTesting |
| static final long DEFAULT_OBSERVING_DURATION_MS = TimeUnit.DAYS.toMillis(2); |
| |
| private static final String NAME = "rescue-party-observer"; |
| |
| |
| private static final String PROP_DISABLE_RESCUE = "persist.sys.disable_rescue"; |
| private static final String PROP_VIRTUAL_DEVICE = "ro.hardware.virtual_device"; |
| |
| private static final int PERSISTENT_MASK = ApplicationInfo.FLAG_PERSISTENT |
| | ApplicationInfo.FLAG_SYSTEM; |
| |
| /** Register the Rescue Party observer as a Package Watchdog health observer */ |
| public static void registerHealthObserver(Context context) { |
| PackageWatchdog.getInstance(context).registerHealthObserver( |
| RescuePartyObserver.getInstance(context)); |
| } |
| |
| private static boolean isDisabled() { |
| // Check if we're explicitly enabled for testing |
| if (SystemProperties.getBoolean(PROP_ENABLE_RESCUE, false)) { |
| return false; |
| } |
| |
| // We're disabled on all engineering devices |
| if (Build.IS_ENG) { |
| Slog.v(TAG, "Disabled because of eng build"); |
| return true; |
| } |
| |
| // We're disabled on userdebug devices connected over USB, since that's |
| // a decent signal that someone is actively trying to debug the device, |
| // or that it's in a lab environment. |
| if (Build.IS_USERDEBUG && isUsbActive()) { |
| Slog.v(TAG, "Disabled because of active USB connection"); |
| return true; |
| } |
| |
| // One last-ditch check |
| if (SystemProperties.getBoolean(PROP_DISABLE_RESCUE, false)) { |
| Slog.v(TAG, "Disabled because of manual property"); |
| return true; |
| } |
| |
| return false; |
| } |
| |
| /** |
| * Check if we're currently attempting to reboot for a factory reset. |
| */ |
| public static boolean isAttemptingFactoryReset() { |
| return SystemProperties.getInt(PROP_RESCUE_LEVEL, LEVEL_NONE) == LEVEL_FACTORY_RESET; |
| } |
| |
| /** |
| * Called when {@code SettingsProvider} has been published, which is a good |
| * opportunity to reset any settings depending on our rescue level. |
| */ |
| public static void onSettingsProviderPublished(Context context) { |
| handleNativeRescuePartyResets(); |
| executeRescueLevel(context, /*failedPackage=*/ null); |
| ContentResolver contentResolver = context.getContentResolver(); |
| Settings.Config.registerMonitorCallback(contentResolver, new RemoteCallback(result -> { |
| handleMonitorCallback(context, result); |
| })); |
| } |
| |
| @VisibleForTesting |
| static long getElapsedRealtime() { |
| return SystemClock.elapsedRealtime(); |
| } |
| |
| private static void handleMonitorCallback(Context context, Bundle result) { |
| String callbackType = result.getString(Settings.EXTRA_MONITOR_CALLBACK_TYPE, ""); |
| switch (callbackType) { |
| case Settings.EXTRA_NAMESPACE_UPDATED_CALLBACK: |
| String updatedNamespace = result.getString(Settings.EXTRA_NAMESPACE); |
| if (updatedNamespace != null) { |
| startObservingPackages(context, updatedNamespace); |
| } |
| break; |
| case Settings.EXTRA_ACCESS_CALLBACK: |
| String callingPackage = result.getString(Settings.EXTRA_CALLING_PACKAGE, null); |
| String namespace = result.getString(Settings.EXTRA_NAMESPACE, null); |
| if (namespace != null && callingPackage != null) { |
| RescuePartyObserver.getInstance(context).recordDeviceConfigAccess( |
| callingPackage, |
| namespace); |
| } |
| break; |
| default: |
| Slog.w(TAG, "Unrecognized DeviceConfig callback"); |
| break; |
| } |
| } |
| |
| private static void startObservingPackages(Context context, @NonNull String updatedNamespace) { |
| RescuePartyObserver rescuePartyObserver = RescuePartyObserver.getInstance(context); |
| Set<String> callingPackages = rescuePartyObserver.getCallingPackagesSet(updatedNamespace); |
| if (callingPackages == null) { |
| return; |
| } |
| List<String> callingPackageList = new ArrayList<>(); |
| callingPackageList.addAll(callingPackages); |
| Slog.i(TAG, "Starting to observe: " + callingPackageList + ", updated namespace: " |
| + updatedNamespace); |
| PackageWatchdog.getInstance(context).startObservingHealth( |
| rescuePartyObserver, |
| callingPackageList, |
| DEFAULT_OBSERVING_DURATION_MS); |
| } |
| |
| private static void handleNativeRescuePartyResets() { |
| if (SettingsToPropertiesMapper.isNativeFlagsResetPerformed()) { |
| String[] resetNativeCategories = SettingsToPropertiesMapper.getResetNativeCategories(); |
| for (int i = 0; i < resetNativeCategories.length; i++) { |
| DeviceConfig.resetToDefaults(Settings.RESET_MODE_TRUSTED_DEFAULTS, |
| resetNativeCategories[i]); |
| } |
| } |
| } |
| |
| /** |
| * Get the next rescue level. This indicates the next level of mitigation that may be taken. |
| */ |
| private static int getNextRescueLevel() { |
| return MathUtils.constrain(SystemProperties.getInt(PROP_RESCUE_LEVEL, LEVEL_NONE) + 1, |
| LEVEL_NONE, LEVEL_FACTORY_RESET); |
| } |
| |
| /** |
| * Escalate to the next rescue level. After incrementing the level you'll |
| * probably want to call {@link #executeRescueLevel(Context, String)}. |
| */ |
| private static void incrementRescueLevel(int triggerUid) { |
| final int level = getNextRescueLevel(); |
| SystemProperties.set(PROP_RESCUE_LEVEL, Integer.toString(level)); |
| |
| EventLogTags.writeRescueLevel(level, triggerUid); |
| logCriticalInfo(Log.WARN, "Incremented rescue level to " |
| + levelToString(level) + " triggered by UID " + triggerUid); |
| } |
| |
| private static void executeRescueLevel(Context context, @Nullable String failedPackage) { |
| final int level = SystemProperties.getInt(PROP_RESCUE_LEVEL, LEVEL_NONE); |
| if (level == LEVEL_NONE) return; |
| |
| Slog.w(TAG, "Attempting rescue level " + levelToString(level)); |
| try { |
| executeRescueLevelInternal(context, level, failedPackage); |
| EventLogTags.writeRescueSuccess(level); |
| logCriticalInfo(Log.DEBUG, |
| "Finished rescue level " + levelToString(level)); |
| } catch (Throwable t) { |
| final String msg = ExceptionUtils.getCompleteMessage(t); |
| EventLogTags.writeRescueFailure(level, msg); |
| logCriticalInfo(Log.ERROR, |
| "Failed rescue level " + levelToString(level) + ": " + msg); |
| } |
| } |
| |
| private static void executeRescueLevelInternal(Context context, int level, @Nullable |
| String failedPackage) throws Exception { |
| FrameworkStatsLog.write(FrameworkStatsLog.RESCUE_PARTY_RESET_REPORTED, level); |
| switch (level) { |
| case LEVEL_RESET_SETTINGS_UNTRUSTED_DEFAULTS: |
| resetAllSettings(context, Settings.RESET_MODE_UNTRUSTED_DEFAULTS, failedPackage); |
| break; |
| case LEVEL_RESET_SETTINGS_UNTRUSTED_CHANGES: |
| resetAllSettings(context, Settings.RESET_MODE_UNTRUSTED_CHANGES, failedPackage); |
| break; |
| case LEVEL_RESET_SETTINGS_TRUSTED_DEFAULTS: |
| resetAllSettings(context, Settings.RESET_MODE_TRUSTED_DEFAULTS, failedPackage); |
| break; |
| case LEVEL_FACTORY_RESET: |
| RecoverySystem.rebootPromptAndWipeUserData(context, TAG); |
| break; |
| } |
| } |
| |
| private static int mapRescueLevelToUserImpact(int rescueLevel) { |
| switch(rescueLevel) { |
| case LEVEL_RESET_SETTINGS_UNTRUSTED_DEFAULTS: |
| case LEVEL_RESET_SETTINGS_UNTRUSTED_CHANGES: |
| return PackageHealthObserverImpact.USER_IMPACT_LOW; |
| case LEVEL_RESET_SETTINGS_TRUSTED_DEFAULTS: |
| case LEVEL_FACTORY_RESET: |
| return PackageHealthObserverImpact.USER_IMPACT_HIGH; |
| default: |
| return PackageHealthObserverImpact.USER_IMPACT_NONE; |
| } |
| } |
| |
| private static int getPackageUid(Context context, String packageName) { |
| try { |
| return context.getPackageManager().getPackageUid(packageName, 0); |
| } catch (PackageManager.NameNotFoundException e) { |
| // Since UIDs are always >= 0, this value means the UID could not be determined. |
| return -1; |
| } |
| } |
| |
| private static void resetAllSettings(Context context, int mode, @Nullable String failedPackage) |
| throws Exception { |
| // Try our best to reset all settings possible, and once finished |
| // rethrow any exception that we encountered |
| Exception res = null; |
| final ContentResolver resolver = context.getContentResolver(); |
| try { |
| resetDeviceConfig(context, mode, failedPackage); |
| } catch (Exception e) { |
| res = new RuntimeException("Failed to reset config settings", e); |
| } |
| try { |
| Settings.Global.resetToDefaultsAsUser(resolver, null, mode, UserHandle.USER_SYSTEM); |
| } catch (Exception e) { |
| res = new RuntimeException("Failed to reset global settings", e); |
| } |
| for (int userId : getAllUserIds()) { |
| try { |
| Settings.Secure.resetToDefaultsAsUser(resolver, null, mode, userId); |
| } catch (Exception e) { |
| res = new RuntimeException("Failed to reset secure settings for " + userId, e); |
| } |
| } |
| if (res != null) { |
| throw res; |
| } |
| } |
| |
| private static void resetDeviceConfig(Context context, int resetMode, |
| @Nullable String failedPackage) { |
| if (!shouldPerformScopedResets() || failedPackage == null) { |
| DeviceConfig.resetToDefaults(resetMode, /*namespace=*/ null); |
| } else { |
| performScopedReset(context, resetMode, failedPackage); |
| } |
| } |
| |
| private static boolean shouldPerformScopedResets() { |
| int rescueLevel = MathUtils.constrain( |
| SystemProperties.getInt(PROP_RESCUE_LEVEL, LEVEL_NONE), |
| LEVEL_NONE, LEVEL_FACTORY_RESET); |
| return rescueLevel <= LEVEL_RESET_SETTINGS_UNTRUSTED_CHANGES; |
| } |
| |
| private static void performScopedReset(Context context, int resetMode, |
| @NonNull String failedPackage) { |
| RescuePartyObserver rescuePartyObserver = RescuePartyObserver.getInstance(context); |
| Set<String> affectedNamespaces = rescuePartyObserver.getAffectedNamespaceSet( |
| failedPackage); |
| if (affectedNamespaces == null) { |
| DeviceConfig.resetToDefaults(resetMode, /*namespace=*/ null); |
| } else { |
| Slog.w(TAG, |
| "Performing scoped reset for package: " + failedPackage |
| + ", affected namespaces: " |
| + Arrays.toString(affectedNamespaces.toArray())); |
| Iterator<String> it = affectedNamespaces.iterator(); |
| while (it.hasNext()) { |
| DeviceConfig.resetToDefaults(resetMode, it.next()); |
| } |
| } |
| } |
| |
| /** |
| * Handle mitigation action for package failures. This observer will be register to Package |
| * Watchdog and will receive calls about package failures. This observer is persistent so it |
| * may choose to mitigate failures for packages it has not explicitly asked to observe. |
| */ |
| public static class RescuePartyObserver implements PackageHealthObserver { |
| |
| private final Context mContext; |
| private final Map<String, Set<String>> mCallingPackageNamespaceSetMap = new HashMap<>(); |
| private final Map<String, Set<String>> mNamespaceCallingPackageSetMap = new HashMap<>(); |
| |
| @GuardedBy("RescuePartyObserver.class") |
| static RescuePartyObserver sRescuePartyObserver; |
| |
| private RescuePartyObserver(Context context) { |
| mContext = context; |
| } |
| |
| /** Creates or gets singleton instance of RescueParty. */ |
| public static RescuePartyObserver getInstance(Context context) { |
| synchronized (RescuePartyObserver.class) { |
| if (sRescuePartyObserver == null) { |
| sRescuePartyObserver = new RescuePartyObserver(context); |
| } |
| return sRescuePartyObserver; |
| } |
| } |
| |
| @VisibleForTesting |
| static void reset() { |
| synchronized (RescuePartyObserver.class) { |
| sRescuePartyObserver = null; |
| } |
| } |
| |
| @Override |
| public int onHealthCheckFailed(@Nullable VersionedPackage failedPackage, |
| @FailureReasons int failureReason) { |
| if (!isDisabled() && (failureReason == PackageWatchdog.FAILURE_REASON_APP_CRASH |
| || failureReason == PackageWatchdog.FAILURE_REASON_APP_NOT_RESPONDING)) { |
| return mapRescueLevelToUserImpact(getNextRescueLevel()); |
| } else { |
| return PackageHealthObserverImpact.USER_IMPACT_NONE; |
| } |
| } |
| |
| @Override |
| public boolean execute(@Nullable VersionedPackage failedPackage, |
| @FailureReasons int failureReason) { |
| if (isDisabled()) { |
| return false; |
| } |
| if (failureReason == PackageWatchdog.FAILURE_REASON_APP_CRASH |
| || failureReason == PackageWatchdog.FAILURE_REASON_APP_NOT_RESPONDING) { |
| int triggerUid = getPackageUid(mContext, failedPackage.getPackageName()); |
| incrementRescueLevel(triggerUid); |
| executeRescueLevel(mContext, |
| failedPackage == null ? null : failedPackage.getPackageName()); |
| return true; |
| } else { |
| return false; |
| } |
| } |
| |
| @Override |
| public boolean isPersistent() { |
| return true; |
| } |
| |
| @Override |
| public boolean mayObservePackage(String packageName) { |
| PackageManager pm = mContext.getPackageManager(); |
| try { |
| // A package is a Mainline module if this is non-null |
| if (pm.getModuleInfo(packageName, 0) != null) { |
| return true; |
| } |
| ApplicationInfo info = pm.getApplicationInfo(packageName, 0); |
| return (info.flags & PERSISTENT_MASK) == PERSISTENT_MASK; |
| } catch (PackageManager.NameNotFoundException e) { |
| return false; |
| } |
| } |
| |
| @Override |
| public int onBootLoop() { |
| if (isDisabled()) { |
| return PackageHealthObserverImpact.USER_IMPACT_NONE; |
| } |
| return mapRescueLevelToUserImpact(getNextRescueLevel()); |
| } |
| |
| @Override |
| public boolean executeBootLoopMitigation() { |
| if (isDisabled()) { |
| return false; |
| } |
| incrementRescueLevel(Process.ROOT_UID); |
| executeRescueLevel(mContext, /*failedPackage=*/ null); |
| return true; |
| } |
| |
| @Override |
| public String getName() { |
| return NAME; |
| } |
| |
| private synchronized void recordDeviceConfigAccess(@NonNull String callingPackage, |
| @NonNull String namespace) { |
| // Record it in calling packages to namespace map |
| Set<String> namespaceSet = mCallingPackageNamespaceSetMap.get(callingPackage); |
| if (namespaceSet == null) { |
| namespaceSet = new ArraySet<>(); |
| mCallingPackageNamespaceSetMap.put(callingPackage, namespaceSet); |
| } |
| namespaceSet.add(namespace); |
| // Record it in namespace to calling packages map |
| Set<String> callingPackageSet = mNamespaceCallingPackageSetMap.get(namespace); |
| if (callingPackageSet == null) { |
| callingPackageSet = new ArraySet<>(); |
| } |
| callingPackageSet.add(callingPackage); |
| mNamespaceCallingPackageSetMap.put(namespace, callingPackageSet); |
| } |
| |
| private synchronized Set<String> getAffectedNamespaceSet(String failedPackage) { |
| return mCallingPackageNamespaceSetMap.get(failedPackage); |
| } |
| |
| private synchronized Set<String> getCallingPackagesSet(String namespace) { |
| return mNamespaceCallingPackageSetMap.get(namespace); |
| } |
| } |
| |
| private static int[] getAllUserIds() { |
| int[] userIds = { UserHandle.USER_SYSTEM }; |
| try { |
| for (File file : FileUtils.listFilesOrEmpty(Environment.getDataSystemDeDirectory())) { |
| try { |
| final int userId = Integer.parseInt(file.getName()); |
| if (userId != UserHandle.USER_SYSTEM) { |
| userIds = ArrayUtils.appendInt(userIds, userId); |
| } |
| } catch (NumberFormatException ignored) { |
| } |
| } |
| } catch (Throwable t) { |
| Slog.w(TAG, "Trouble discovering users", t); |
| } |
| return userIds; |
| } |
| |
| /** |
| * Hacky test to check if the device has an active USB connection, which is |
| * a good proxy for someone doing local development work. |
| */ |
| private static boolean isUsbActive() { |
| if (SystemProperties.getBoolean(PROP_VIRTUAL_DEVICE, false)) { |
| Slog.v(TAG, "Assuming virtual device is connected over USB"); |
| return true; |
| } |
| try { |
| final String state = FileUtils |
| .readTextFile(new File("/sys/class/android_usb/android0/state"), 128, ""); |
| return "CONFIGURED".equals(state.trim()); |
| } catch (Throwable t) { |
| Slog.w(TAG, "Failed to determine if device was on USB", t); |
| return false; |
| } |
| } |
| |
| private static String levelToString(int level) { |
| switch (level) { |
| case LEVEL_NONE: return "NONE"; |
| case LEVEL_RESET_SETTINGS_UNTRUSTED_DEFAULTS: return "RESET_SETTINGS_UNTRUSTED_DEFAULTS"; |
| case LEVEL_RESET_SETTINGS_UNTRUSTED_CHANGES: return "RESET_SETTINGS_UNTRUSTED_CHANGES"; |
| case LEVEL_RESET_SETTINGS_TRUSTED_DEFAULTS: return "RESET_SETTINGS_TRUSTED_DEFAULTS"; |
| case LEVEL_FACTORY_RESET: return "FACTORY_RESET"; |
| default: return Integer.toString(level); |
| } |
| } |
| } |