From 2c344c0fec0f6fc247a1432cd599ce71876218a0 Mon Sep 17 00:00:00 2001
From: Ytai Ben-Tsvi <ytai@google.com>
Date: Thu, 13 Aug 2020 16:25:45 -0700
Subject: [PATCH] Correctly handle HAL death

In the presence of multiple sessions, we would modify the
mActiveSessions list while iterating it, causing a runtime exception.
This has not been observed before, since we never had more than one
session.

In addition, unified the exception used to convey a dead module.

Test: Killed STHAL process and observed recovery.
Bug: 163865561
Change-Id: Ib5c5f81463d51e0f1bacae3a689fd9c8515cecc9
---
 .../soundtrigger_middleware/SoundTriggerHw2Enforcer.java   | 7 ++++---
 .../server/soundtrigger_middleware/SoundTriggerModule.java | 5 +++--
 2 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerHw2Enforcer.java b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerHw2Enforcer.java
index 761858ccd2385..eced8940947ac 100644
--- a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerHw2Enforcer.java
+++ b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerHw2Enforcer.java
@@ -21,6 +21,7 @@ import android.hardware.soundtrigger.V2_1.ISoundTriggerHwCallback;
 import android.hardware.soundtrigger.V2_3.ModelParameterRange;
 import android.hardware.soundtrigger.V2_3.Properties;
 import android.hardware.soundtrigger.V2_3.RecognitionConfig;
+import android.media.soundtrigger_middleware.Status;
 import android.os.DeadObjectException;
 import android.os.IHwBinder;
 import android.os.RemoteException;
@@ -195,10 +196,10 @@ public class SoundTriggerHw2Enforcer implements ISoundTriggerHw2 {
         if (e.getCause() instanceof DeadObjectException) {
             // Server is dead, no need to reboot.
             Log.e(TAG, "HAL died");
-        } else {
-            Log.e(TAG, "Exception caught from HAL, rebooting HAL");
-            rebootHal();
+            throw new RecoverableException(Status.DEAD_OBJECT);
         }
+        Log.e(TAG, "Exception caught from HAL, rebooting HAL");
+        rebootHal();
         throw e;
     }
 
diff --git a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerModule.java b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerModule.java
index 5a587cc9764c8..02d978dfdf994 100644
--- a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerModule.java
+++ b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerModule.java
@@ -184,11 +184,13 @@ class SoundTriggerModule implements IHwBinder.DeathRecipient {
     @Override
     public void serviceDied(long cookie) {
         Log.w(TAG, String.format("Underlying HAL driver died."));
-        List<ISoundTriggerCallback> callbacks = new ArrayList<>(mActiveSessions.size());
+        List<ISoundTriggerCallback> callbacks;
         synchronized (this) {
+            callbacks = new ArrayList<>(mActiveSessions.size());
             for (Session session : mActiveSessions) {
                 callbacks.add(session.moduleDied());
             }
+            mActiveSessions.clear();
             reset();
         }
         // Trigger the callbacks outside of the lock to avoid deadlocks.
@@ -431,7 +433,6 @@ class SoundTriggerModule implements IHwBinder.DeathRecipient {
          */
         private ISoundTriggerCallback moduleDied() {
             ISoundTriggerCallback callback = mCallback;
-            removeSession(this);
             mCallback = null;
             return callback;
         }