Merge "Fix deadlock in KeyguardDisableHandler" into qt-dev

core/java/android/app/admin/DevicePolicyCache.java

@@ -43,6 +43,12 @@ public abstract class DevicePolicyCache {
      */
     public abstract boolean getScreenCaptureDisabled(@UserIdInt int userHandle);
 
+    /**
+     * Caches {@link DevicePolicyManager#getPasswordQuality(android.content.ComponentName)} of the
+     * given user with {@code null} passed in as argument.
+     */
+    public abstract int getPasswordQuality(@UserIdInt int userHandle);
+
     /**
      * Empty implementation.
      */
@@ -53,5 +59,10 @@ public abstract class DevicePolicyCache {
         public boolean getScreenCaptureDisabled(int userHandle) {
             return false;
         }
+
+        @Override
+        public int getPasswordQuality(int userHandle) {
+            return DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED;
+        }
     }
 }

services/core/java/com/android/server/wm/KeyguardDisableHandler.java

@@ -19,6 +19,7 @@ package com.android.server.wm;
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WITH_CLASS_NAME;
 import static com.android.server.wm.WindowManagerDebugConfig.TAG_WM;
 
+import android.app.admin.DevicePolicyCache;
 import android.app.admin.DevicePolicyManager;
 import android.content.Context;
 import android.os.Handler;
@@ -125,9 +126,7 @@ class KeyguardDisableHandler {
         return new KeyguardDisableHandler(new Injector() {
             @Override
             public boolean dpmRequiresPassword(int userId) {
-                DevicePolicyManager dpm = (DevicePolicyManager) context.getSystemService(
+                return DevicePolicyCache.getInstance().getPasswordQuality(userId)
-                        Context.DEVICE_POLICY_SERVICE);
-                return dpm == null || dpm.getPasswordQuality(null, userId)
                         != DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED;
             }
 

services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyCacheImpl.java

@@ -15,11 +15,16 @@
  */
 package com.android.server.devicepolicy;
 
+import android.annotation.UserIdInt;
 import android.app.admin.DevicePolicyCache;
+import android.app.admin.DevicePolicyManager;
 import android.util.SparseBooleanArray;
+import android.util.SparseIntArray;
 
 import com.android.internal.annotations.GuardedBy;
 
+import java.io.PrintWriter;
+
 /**
  * Implementation of {@link DevicePolicyCache}, to which {@link DevicePolicyManagerService} pushes
  * policies.
@@ -36,9 +41,13 @@ public class DevicePolicyCacheImpl extends DevicePolicyCache {
     @GuardedBy("mLock")
     private final SparseBooleanArray mScreenCaptureDisabled = new SparseBooleanArray();
 
+    @GuardedBy("mLock")
+    private final SparseIntArray mPasswordQuality = new SparseIntArray();
+
     public void onUserRemoved(int userHandle) {
         synchronized (mLock) {
             mScreenCaptureDisabled.delete(userHandle);
+            mPasswordQuality.delete(userHandle);
         }
     }
 
@@ -54,4 +63,26 @@ public class DevicePolicyCacheImpl extends DevicePolicyCache {
             mScreenCaptureDisabled.put(userHandle, disabled);
         }
     }
+
+    @Override
+    public int getPasswordQuality(@UserIdInt int userHandle) {
+        synchronized (mLock) {
+            return mPasswordQuality.get(userHandle,
+                    DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED);
+        }
+    }
+
+    /** Updat the password quality cache for the given user */
+    public void setPasswordQuality(int userHandle, int quality) {
+        synchronized (mLock) {
+            mPasswordQuality.put(userHandle, quality);
+        }
+    }
+
+    /** Dump content */
+    public void dump(String prefix, PrintWriter pw) {
+        pw.println("Device policy cache");
+        pw.println(prefix + "Screen capture disabled: " + mScreenCaptureDisabled.toString());
+        pw.println(prefix + "Password quality: " + mPasswordQuality.toString());
+    }
 }

services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java

@@ -2333,8 +2333,8 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
                 Slog.w(LOG_TAG, "Tried to remove device policy file for user 0! Ignoring.");
                 return;
             }
+            updatePasswordQualityCacheForUserGroup(userHandle);
             mPolicyCache.onUserRemoved(userHandle);
-
             mOwners.removeProfileOwner(userHandle);
             mOwners.writeProfileOwner(userHandle);
 
@@ -3650,6 +3650,11 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         updateScreenCaptureDisabled(userId,
                 getScreenCaptureDisabled(null, userId));
         pushUserRestrictions(userId);
+        // When system user is started (device boot), load cache for all users.
+        // This is to mitigate the potential race between loading the cache and keyguard
+        // reading the value during user switch, due to onStartUser() being asynchronous.
+        updatePasswordQualityCacheForUserGroup(
+                userId == UserHandle.USER_SYSTEM ? UserHandle.USER_ALL : userId);
 
         startOwnerService(userId, "start-user");
     }
@@ -4135,13 +4140,19 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         synchronized (getLockObject()) {
             ActiveAdmin ap = getActiveAdminForCallerLocked(
                     who, DeviceAdminInfo.USES_POLICY_LIMIT_PASSWORD, parent);
+            final long ident = mInjector.binderClearCallingIdentity();
+            try {
                 final PasswordMetrics metrics = ap.minimumPasswordMetrics;
                 if (metrics.quality != quality) {
                     metrics.quality = quality;
                     updatePasswordValidityCheckpointLocked(userId, parent);
+                    updatePasswordQualityCacheForUserGroup(userId);
                     saveSettingsLocked(userId);
                 }
                 maybeLogPasswordComplexitySet(who, userId, parent, metrics);
+            } finally {
+                mInjector.binderRestoreCallingIdentity(ident);
+            }
         }
         DevicePolicyEventLogger
                 .createEvent(DevicePolicyEnums.SET_PASSWORD_QUALITY)
@@ -4173,6 +4184,32 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         saveSettingsLocked(credentialOwner);
     }
 
+    /**
+     * Update password quality values in policy cache for all users in the same user group as
+     * the given user. The cached password quality for user X is the aggregated quality among all
+     * admins who have influence of user X's screenlock, i.e. it's equivalent to the return value of
+     * getPasswordQuality(null, user X, false).
+     *
+     * Caches for all users in the same user group often need to be updated alltogether because a
+     * user's admin policy can affect another's aggregated password quality in some situation.
+     * For example a managed profile's policy will affect the parent user if the profile has unified
+     * challenge. A profile can also explicitly set a parent password quality which will affect the
+     * aggregated password quality of the parent user.
+     */
+    private void updatePasswordQualityCacheForUserGroup(@UserIdInt int userId) {
+        final List<UserInfo> users;
+        if (userId == UserHandle.USER_ALL) {
+            users = mUserManager.getUsers();
+        } else {
+            users = mUserManager.getProfiles(userId);
+        }
+        for (UserInfo userInfo : users) {
+            final int currentUserId = userInfo.id;
+            mPolicyCache.setPasswordQuality(currentUserId,
+                    getPasswordQuality(null, currentUserId, false));
+        }
+    }
+
     @Override
     public int getPasswordQuality(ComponentName who, int userHandle, boolean parent) {
         if (!mHasFeature) {
@@ -8849,6 +8886,8 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
             mStatLogger.dump(pw, "  ");
             pw.println();
             pw.println("  Encryption Status: " + getEncryptionStatusName(getEncryptionStatus()));
+            pw.println();
+            mPolicyCache.dump("  ", pw);
         }
     }
 
@@ -11319,8 +11358,14 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
 
         @Override
         public void reportSeparateProfileChallengeChanged(@UserIdInt int userId) {
+            final long ident = mInjector.binderClearCallingIdentity();
+            try {
                 synchronized (getLockObject()) {
                     updateMaximumTimeToLockLocked(userId);
+                    updatePasswordQualityCacheForUserGroup(userId);
+                }
+            } finally {
+                mInjector.binderRestoreCallingIdentity(ident);
             }
             DevicePolicyEventLogger
                     .createEvent(DevicePolicyEnums.SEPARATE_PROFILE_CHALLENGE_CHANGED)
@@ -11336,7 +11381,6 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         @Override
         public CharSequence getPrintingDisabledReasonForUser(@UserIdInt int userId) {
             synchronized (getLockObject()) {
-                DevicePolicyData policy = getUserData(userId);
                 if (!mUserManager.hasUserRestriction(UserManager.DISALLOW_PRINTING,
                         UserHandle.of(userId))) {
                     Log.e(LOG_TAG, "printing is enabled");