From ead5142af0da2ff525935ec6daa115c9a9e80334 Mon Sep 17 00:00:00 2001
From: Eric Laurent <elaurent@google.com>
Date: Mon, 1 Feb 2021 13:28:03 +0100
Subject: AudioService: make setAccessibilityServiceUids async

Call AudioSystem.setA11yServicesUids() in the AudioService message
handler thread to avoid potential cross deadlock with AccessibilityService.

Bug: 156421041
Test: atest AudioManagerTest
Change-Id: I1608bd613d97661083d3a72f61dbc0fc2e9d4414
---
 .../com/android/server/audio/AudioService.java     | 35 ++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/services/core/java/com/android/server/audio/AudioService.java b/services/core/java/com/android/server/audio/AudioService.java
index d5759633bf2d..c88b49dac813 100644
--- a/services/core/java/com/android/server/audio/AudioService.java
+++ b/services/core/java/com/android/server/audio/AudioService.java
@@ -300,6 +300,7 @@ public class AudioService extends IAudioService.Stub
     private static final int MSG_STREAM_DEVICES_CHANGED = 32;
     private static final int MSG_UPDATE_VOLUME_STATES_FOR_DEVICE = 33;
     private static final int MSG_REINIT_VOLUMES = 34;
+    private static final int MSG_UPDATE_A11Y_SERVICE_UIDS = 35;
     // start of messages handled under wakelock
     //   these messages can only be queued, i.e. sent with queueMsgUnderWakeLock(),
     //   and not with sendMsg(..., ..., SENDMSG_QUEUE, ...)
@@ -699,8 +700,9 @@ public class AudioService extends IAudioService.Stub
     private long mLoweredFromNormalToVibrateTime;
 
     // Array of Uids of valid accessibility services to check if caller is one of them
-    private int[] mAccessibilityServiceUids;
     private final Object mAccessibilityServiceUidsLock = new Object();
+    @GuardedBy("mAccessibilityServiceUidsLock")
+    private int[] mAccessibilityServiceUids;
 
     // Uid of the active input method service to check if caller is the one or not.
     private int mInputMethodServiceUid = android.os.Process.INVALID_UID;
@@ -7082,6 +7084,10 @@ public class AudioService extends IAudioService.Stub
                 case MSG_REINIT_VOLUMES:
                     onReinitVolumes((String) msg.obj);
                     break;
+                case MSG_UPDATE_A11Y_SERVICE_UIDS:
+                    onUpdateAccessibilityServiceUids();
+                    break;
+
             }
         }
     }
@@ -8153,6 +8159,9 @@ public class AudioService extends IAudioService.Stub
                         + " FromRestrictions=" + mMicMuteFromRestrictions
                         + " FromApi=" + mMicMuteFromApi
                         + " from system=" + mMicMuteFromSystemCached);
+        pw.print("\n  mAssistantUid="); pw.println(mAssistantUid);
+        pw.print("  mCurrentImeUid="); pw.println(mCurrentImeUid);
+        dumpAccessibilityServiceUids(pw);
 
         dumpAudioPolicies(pw);
         mDynPolicyLogger.dump(pw);
@@ -8186,6 +8195,19 @@ public class AudioService extends IAudioService.Stub
         }
     }
 
+    private void dumpAccessibilityServiceUids(PrintWriter pw) {
+        synchronized (mSupportedSystemUsagesLock) {
+            if (mAccessibilityServiceUids != null && mAccessibilityServiceUids.length > 0) {
+                pw.println("  Accessibility service Uids:");
+                for (int uid : mAccessibilityServiceUids) {
+                    pw.println("  - " + uid);
+                }
+            } else {
+                pw.println("  No accessibility service Uids.");
+            }
+        }
+    }
+
     /**
      * Audio Analytics ids.
      */
@@ -8489,7 +8511,8 @@ public class AudioService extends IAudioService.Stub
                         mAccessibilityServiceUids = uids.toArray();
                     }
                 }
-                AudioSystem.setA11yServicesUids(mAccessibilityServiceUids);
+                sendMsg(mAudioHandler, MSG_UPDATE_A11Y_SERVICE_UIDS, SENDMSG_REPLACE,
+                        0, 0, null, 0);
             }
         }
 
@@ -8507,6 +8530,14 @@ public class AudioService extends IAudioService.Stub
         }
     }
 
+    private void onUpdateAccessibilityServiceUids() {
+        int[] accessibilityServiceUids;
+        synchronized (mAccessibilityServiceUidsLock) {
+            accessibilityServiceUids = mAccessibilityServiceUids;
+        }
+        AudioSystem.setA11yServicesUids(accessibilityServiceUids);
+    }
+
     //==========================================================================================
     // Audio policy management
     //==========================================================================================
-- 
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