From e02d4e358bded3ee13ebe28d31cdd1df2026986c Mon Sep 17 00:00:00 2001
From: Eran Messeri <eranm@google.com>
Date: Mon, 1 Feb 2021 16:50:05 +0000
Subject: [PATCH] Cache permission policy

Since the Permission Controller calls into DPM, to avoid a potential
circular dependency (where the DPMS holds a lock while the Permission
Controller calls it), cache the permission policy.

Bug: 158735247
Test: atest com.android.cts.devicepolicy.MixedProfileOwnerTest#testDelegation com.android.cts.devicepolicy.MixedDeviceOwnerTest#testDelegation com.android.cts.devicepolicy.MixedManagedProfileOwnerTest#testDelegation
Test: atest com.android.cts.devicepolicy.MixedProfileOwnerTest#testPermissionAppUpdate com.android.cts.devicepolicy.MixedProfileOwnerTest#testPermissionPolicy com.android.cts.devicepolicy.MixedDeviceOwnerTest#testPermissionAppUpdate com.android.cts.devicepolicy.MixedDeviceOwnerTest#testPermissionPolicy com.android.cts.devicepolicy.MixedManagedProfileOwnerTest#testPermissionAppUpdate com.android.cts.devicepolicy.MixedManagedProfileOwnerTest#testPermissionPolicy
Change-Id: I6cfc027b063f43053d1ff4cc42d37935491064ff
---
 .../android/app/admin/DevicePolicyCache.java  | 11 ++++++++++
 .../devicepolicy/DevicePolicyCacheImpl.java   | 20 +++++++++++++++++++
 .../DevicePolicyManagerService.java           | 19 ++++++++++++------
 3 files changed, 44 insertions(+), 6 deletions(-)

diff --git a/core/java/android/app/admin/DevicePolicyCache.java b/core/java/android/app/admin/DevicePolicyCache.java
index 15ff531b445d9..8b0c7061925f0 100644
--- a/core/java/android/app/admin/DevicePolicyCache.java
+++ b/core/java/android/app/admin/DevicePolicyCache.java
@@ -50,6 +50,12 @@ public abstract class DevicePolicyCache {
      */
     public abstract int getPasswordQuality(@UserIdInt int userHandle);
 
+    /**
+     * Caches {@link DevicePolicyManager#getPermissionPolicy(android.content.ComponentName)} of
+     * the given user.
+     */
+    public abstract int getPermissionPolicy(@UserIdInt int userHandle);
+
     /**
      * Empty implementation.
      */
@@ -66,5 +72,10 @@ public abstract class DevicePolicyCache {
         public int getPasswordQuality(int userHandle) {
             return DevicePolicyManager.PASSWORD_QUALITY_UNSPECIFIED;
         }
+
+        @Override
+        public int getPermissionPolicy(int userHandle) {
+            return DevicePolicyManager.PERMISSION_POLICY_PROMPT;
+        }
     }
 }
diff --git a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyCacheImpl.java b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyCacheImpl.java
index 15bc93e0419a1..8b2beb22bead6 100644
--- a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyCacheImpl.java
+++ b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyCacheImpl.java
@@ -43,10 +43,14 @@ public class DevicePolicyCacheImpl extends DevicePolicyCache {
     @GuardedBy("mLock")
     private final SparseIntArray mPasswordQuality = new SparseIntArray();
 
+    @GuardedBy("mLock")
+    private final SparseIntArray mPermissionPolicy = new SparseIntArray();
+
     public void onUserRemoved(int userHandle) {
         synchronized (mLock) {
             mScreenCaptureDisabled.delete(userHandle);
             mPasswordQuality.delete(userHandle);
+            mPermissionPolicy.delete(userHandle);
         }
     }
 
@@ -78,12 +82,28 @@ public class DevicePolicyCacheImpl extends DevicePolicyCache {
         }
     }
 
+    @Override
+    public int getPermissionPolicy(@UserIdInt int userHandle) {
+        synchronized (mLock) {
+            return mPermissionPolicy.get(userHandle,
+                    DevicePolicyManager.PERMISSION_POLICY_PROMPT);
+        }
+    }
+
+    /** Update the permission policy for the given user. */
+    public void setPermissionPolicy(@UserIdInt int userHandle, int policy) {
+        synchronized (mLock) {
+            mPermissionPolicy.put(userHandle, policy);
+        }
+    }
+
     /** Dump content */
     public void dump(IndentingPrintWriter pw) {
         pw.println("Device policy cache:");
         pw.increaseIndent();
         pw.println("Screen capture disabled: " + mScreenCaptureDisabled.toString());
         pw.println("Password quality: " + mPasswordQuality.toString());
+        pw.println("Permission policy: " + mPermissionPolicy.toString());
         pw.decreaseIndent();
     }
 }
diff --git a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
index c3bb757634c28..74b88f1c59d7e 100644
--- a/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
+++ b/services/devicepolicy/java/com/android/server/devicepolicy/DevicePolicyManagerService.java
@@ -2942,6 +2942,7 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
         // reading the value during user switch, due to onStartUser() being asynchronous.
         updatePasswordQualityCacheForUserGroup(
                 userId == UserHandle.USER_SYSTEM ? UserHandle.USER_ALL : userId);
+        updatePermissionPolicyCache(userId);
 
         startOwnerService(userId, "start-user");
     }
@@ -12498,11 +12499,13 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
                 || (caller.hasPackage() && isCallerDelegate(caller, DELEGATION_PERMISSION_GRANT)));
         checkCanExecuteOrThrowUnsafe(DevicePolicyManager.OPERATION_SET_PERMISSION_POLICY);
 
+        final int forUser = caller.getUserId();
         synchronized (getLockObject()) {
-            DevicePolicyData userPolicy = getUserData(caller.getUserId());
+            DevicePolicyData userPolicy = getUserData(forUser);
             if (userPolicy.mPermissionPolicy != policy) {
                 userPolicy.mPermissionPolicy = policy;
-                saveSettingsLocked(caller.getUserId());
+                mPolicyCache.setPermissionPolicy(forUser, policy);
+                saveSettingsLocked(forUser);
             }
         }
         DevicePolicyEventLogger
@@ -12513,13 +12516,17 @@ public class DevicePolicyManagerService extends BaseIDevicePolicyManager {
                 .write();
     }
 
+    private void updatePermissionPolicyCache(int userId) {
+        synchronized (getLockObject()) {
+            DevicePolicyData userPolicy = getUserData(userId);
+            mPolicyCache.setPermissionPolicy(userId, userPolicy.mPermissionPolicy);
+        }
+    }
+
     @Override
     public int getPermissionPolicy(ComponentName admin) throws RemoteException {
         int userId = UserHandle.getCallingUserId();
-        synchronized (getLockObject()) {
-            DevicePolicyData userPolicy = getUserData(userId);
-            return userPolicy.mPermissionPolicy;
-        }
+        return mPolicyCache.getPermissionPolicy(userId);
     }
 
     @Override