From 9fac2c86ce2a441463cb523e20746a92e6f735f8 Mon Sep 17 00:00:00 2001
From: Ytai Ben-Tsvi <ytai@google.com>
Date: Thu, 9 Apr 2020 15:21:07 -0700
Subject: [PATCH] Reboot the soundtrigger HAL on failure

... and avoid rebooting system_server.
There is no benefit in rebooting the system_server.

Fixes: 153461865
Test: Tested via a shell command that the sound trigger middleware
      service can indeed reboot the HAL and correctly recover from it
      dying.
Change-Id: Ie476968b6acf97bf701d0e2929e7bd099e19cd56
---
 .../SoundTriggerMiddlewareService.java        | 41 ++++++++++++++++++-
 .../SoundTriggerMiddlewareValidation.java     |  8 +---
 2 files changed, 41 insertions(+), 8 deletions(-)

diff --git a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareService.java b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareService.java
index 929d92f56c443..635cb613b934d 100644
--- a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareService.java
+++ b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareService.java
@@ -27,7 +27,9 @@ import android.media.soundtrigger_middleware.PhraseSoundModel;
 import android.media.soundtrigger_middleware.RecognitionConfig;
 import android.media.soundtrigger_middleware.SoundModel;
 import android.media.soundtrigger_middleware.SoundTriggerModuleDescriptor;
+import android.os.Parcel;
 import android.os.RemoteException;
+import android.os.SystemProperties;
 import android.util.Log;
 
 import com.android.server.SystemService;
@@ -99,6 +101,28 @@ public class SoundTriggerMiddlewareService extends ISoundTriggerMiddlewareServic
         }
     }
 
+    @Override
+    public boolean onTransact(int code, Parcel data, Parcel reply, int flags)
+            throws RemoteException {
+        try {
+            return super.onTransact(code, data, reply, flags);
+        } catch (InternalServerError e) {
+            if (e.getCause() instanceof HalException) {
+                // We recover from any sort of HAL failure by rebooting the HAL process.
+                // This will likely reboot more than just the sound trigger HAL.
+                // The rest of the system should be able to tolerate that.
+                rebootHal();
+            }
+            throw e;
+        }
+    }
+
+    private static void rebootHal() {
+        Log.i(TAG, "Rebooting the sound trigger HAL");
+        // This property needs to be defined in an init.rc script and trigger a HAL reboot.
+        SystemProperties.set("sys.audio.restart.hal", "1");
+    }
+
     private final static class ModuleService extends ISoundTriggerModule.Stub {
         private final ISoundTriggerModule mDelegate;
 
@@ -119,7 +143,6 @@ public class SoundTriggerMiddlewareService extends ISoundTriggerMiddlewareServic
         @Override
         public void unloadModel(int modelHandle) throws RemoteException {
             mDelegate.unloadModel(modelHandle);
-            ;
         }
 
         @Override
@@ -159,6 +182,22 @@ public class SoundTriggerMiddlewareService extends ISoundTriggerMiddlewareServic
         public void detach() throws RemoteException {
             mDelegate.detach();
         }
+
+        @Override
+        public boolean onTransact(int code, Parcel data, Parcel reply, int flags)
+                throws RemoteException {
+            try {
+                return super.onTransact(code, data, reply, flags);
+            } catch (InternalServerError e) {
+                if (e.getCause() instanceof HalException) {
+                    // We recover from any sort of HAL failure by rebooting the HAL process.
+                    // This will likely reboot more than just the sound trigger HAL.
+                    // The rest of the system should be able to tolerate that.
+                    rebootHal();
+                }
+                throw e;
+            }
+        }
     }
 
     /**
diff --git a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareValidation.java b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareValidation.java
index da1b7f3113c41..23259558eeb79 100644
--- a/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareValidation.java
+++ b/services/core/java/com/android/server/soundtrigger_middleware/SoundTriggerMiddlewareValidation.java
@@ -149,13 +149,7 @@ public class SoundTriggerMiddlewareValidation implements ISoundTriggerMiddleware
                     e.getMessage());
         }
 
-        /* Throwing an exception is not enough in this case. When the HAL behaves unexpectedly, the
-           system service and the HAL must be reset and the client must be notified. Without a full
-           reset in this catastrophic case, the state of the HAL and the system service cannot be
-           guaranteed to the client.
-         */
-        Log.wtf(TAG, "Crashing system server due to unrecoverable exception", e);
-        Process.killProcess(Process.myPid());
+        Log.wtf(TAG, "Unexpected exception", e);
         throw new InternalServerError(e);
     }