Send the HotwordDetectionService UID to AudioPolicy

This change follows the pattern of how the IME UID is set.

The UID is stored in AudioService and re-sent there if the audio server
dies.

Fix: 194368677
Test: manual - hotword works when another app is using the mic and in
 Auto projection mode; also after restarting the process or killing
 audio server
Test: atest HotwordDetectionServiceBasicTest
Change-Id: I325cb33d17387e62302967b261b6fe61086d8893

Author: aha-goog

core/jni/android_media_AudioSystem.cpp

@@ -2429,6 +2429,12 @@ android_media_AudioSystem_setAssistantUid(JNIEnv *env, jobject thiz, jint uid)
     return (jint)nativeToJavaStatus(status);
 }
 
+static jint android_media_AudioSystem_setHotwordDetectionServiceUid(JNIEnv *env, jobject thiz,
+                                                                    jint uid) {
+    status_t status = AudioSystem::setHotwordDetectionServiceUid(uid);
+    return (jint)nativeToJavaStatus(status);
+}
+
 static jint
 android_media_AudioSystem_setA11yServicesUids(JNIEnv *env, jobject thiz, jintArray uids) {
     std::vector<uid_t> nativeUidsVector;
@@ -2799,6 +2805,8 @@ static const JNINativeMethod gMethods[] =
          {"setSurroundFormatEnabled", "(IZ)I",
           (void *)android_media_AudioSystem_setSurroundFormatEnabled},
          {"setAssistantUid", "(I)I", (void *)android_media_AudioSystem_setAssistantUid},
+         {"setHotwordDetectionServiceUid", "(I)I",
+          (void *)android_media_AudioSystem_setHotwordDetectionServiceUid},
          {"setA11yServicesUids", "([I)I", (void *)android_media_AudioSystem_setA11yServicesUids},
          {"isHapticPlaybackSupported", "()Z",
           (void *)android_media_AudioSystem_isHapticPlaybackSupported},

media/java/android/media/AudioManagerInternal.java

@@ -38,6 +38,17 @@ public abstract class AudioManagerInternal {
 
     public abstract void updateRingerModeAffectedStreamsInternal();
 
+    /**
+     * Notify the UID of the currently active {@link android.service.voice.HotwordDetectionService}.
+     *
+     * <p>The caller is expected to take care of any performance implications, e.g. by using a
+     * background thread to call this method.</p>
+     *
+     * @param uid UID of the currently active service or {@link android.os.Process#INVALID_UID} if
+     *            none.
+     */
+    public abstract void setHotwordDetectionServiceUid(int uid);
+
     public abstract void setAccessibilityServiceUids(IntArray uids);
 
     /**

media/java/android/media/AudioSystem.java

@@ -1768,6 +1768,13 @@ public static native int getHwOffloadEncodingFormatsSupportedForA2DP(
      */
     public static native int setAssistantUid(int uid);
 
+    /**
+     * Communicate UID of the current {@link android.service.voice.HotwordDetectionService} to audio
+     * policy service.
+     * @hide
+     */
+    public static native int setHotwordDetectionServiceUid(int uid);
+
     /**
      * @hide
      * Communicate UIDs of active accessibility services to audio policy service.

services/core/java/com/android/server/audio/AudioService.java

@@ -736,6 +736,11 @@ protected boolean removeEldestEntry(Map.Entry eldest) {
     private VolumePolicy mVolumePolicy = VolumePolicy.DEFAULT;
     private long mLoweredFromNormalToVibrateTime;
 
+    // Uid of the active hotword detection service to check if caller is the one or not.
+    @GuardedBy("mHotwordDetectionServiceUidLock")
+    private int mHotwordDetectionServiceUid = android.os.Process.INVALID_UID;
+    private final Object mHotwordDetectionServiceUidLock = new Object();
+
     // Array of Uids of valid accessibility services to check if caller is one of them
     private final Object mAccessibilityServiceUidsLock = new Object();
     @GuardedBy("mAccessibilityServiceUidsLock")
@@ -1337,6 +1342,9 @@ public void onAudioServerDied() {
             updateAssistantUId(true);
             AudioSystem.setRttEnabled(mRttEnabled);
         }
+        synchronized (mHotwordDetectionServiceUidLock) {
+            AudioSystem.setHotwordDetectionServiceUid(mHotwordDetectionServiceUid);
+        }
         synchronized (mAccessibilityServiceUidsLock) {
             AudioSystem.setA11yServicesUids(mAccessibilityServiceUids);
         }
@@ -9107,6 +9115,16 @@ public void updateRingerModeAffectedStreamsInternal() {
             }
         }
 
+        @Override
+        public void setHotwordDetectionServiceUid(int uid) {
+            synchronized (mHotwordDetectionServiceUidLock) {
+                if (mHotwordDetectionServiceUid != uid) {
+                    mHotwordDetectionServiceUid = uid;
+                    AudioSystem.setHotwordDetectionServiceUid(mHotwordDetectionServiceUid);
+                }
+            }
+        }
+
         @Override
         public void setAccessibilityServiceUids(IntArray uids) {
             synchronized (mAccessibilityServiceUidsLock) {

services/core/java/com/android/server/audio/AudioSystemAdapter.java

@@ -366,6 +366,14 @@ public int muteMicrophone(boolean on) {
         return AudioSystem.muteMicrophone(on);
     }
 
+    /**
+     * Same as {@link AudioSystem#setHotwordDetectionServiceUid(int)}
+     * Communicate UID of current HotwordDetectionService to audio policy service.
+     */
+    public int setHotwordDetectionServiceUid(int uid) {
+        return AudioSystem.setHotwordDetectionServiceUid(uid);
+    }
+
     /**
      * Same as {@link AudioSystem#setCurrentImeUid(int)}
      * Communicate UID of current InputMethodService to audio policy service.

services/voiceinteraction/java/com/android/server/voiceinteraction/HotwordDetectionConnection.java

@@ -36,6 +36,7 @@
 import android.hardware.soundtrigger.IRecognitionStatusCallback;
 import android.hardware.soundtrigger.SoundTrigger;
 import android.media.AudioFormat;
+import android.media.AudioManagerInternal;
 import android.media.permission.Identity;
 import android.media.permission.PermissionUtil;
 import android.os.Binder;
@@ -44,6 +45,7 @@
 import android.os.IRemoteCallback;
 import android.os.ParcelFileDescriptor;
 import android.os.PersistableBundle;
+import android.os.Process;
 import android.os.RemoteException;
 import android.os.ServiceManager;
 import android.os.SharedMemory;
@@ -275,6 +277,7 @@ void cancelLocked() {
             LocalServices.getService(PermissionManagerServiceInternal.class)
                     .setHotwordDetectionServiceProvider(null);
             mIdentity = null;
+            updateServiceUidForAudioPolicy(Process.INVALID_UID);
         }
         mCancellationTaskFuture.cancel(/* may interrupt */ true);
         if (mAudioFlinger != null) {
@@ -893,6 +896,8 @@ private void updateServiceIdentity(ServiceConnection connection) {
         connection.run(service -> service.ping(new IRemoteCallback.Stub() {
             @Override
             public void sendResult(Bundle bundle) throws RemoteException {
+                // TODO: Exit if the service has been unbound already (though there's a very low
+                // chance this happens).
                 if (DEBUG) {
                     Slog.d(TAG, "updating hotword UID " + Binder.getCallingUid());
                 }
@@ -902,10 +907,21 @@ public void sendResult(Bundle bundle) throws RemoteException {
                 LocalServices.getService(PermissionManagerServiceInternal.class)
                         .setHotwordDetectionServiceProvider(() -> uid);
                 mIdentity = new HotwordDetectionServiceIdentity(uid, mVoiceInteractionServiceUid);
+                updateServiceUidForAudioPolicy(uid);
             }
         }));
     }
 
+    private void updateServiceUidForAudioPolicy(int uid) {
+        mScheduledExecutorService.execute(() -> {
+            final AudioManagerInternal audioManager =
+                    LocalServices.getService(AudioManagerInternal.class);
+            if (audioManager != null) {
+                audioManager.setHotwordDetectionServiceUid(uid);
+            }
+        });
+    }
+
     private static void bestEffortClose(Closeable closeable) {
         try {
             closeable.close();