From 484e6dbb879cb59d0d3feab53884c64e2bf3b820 Mon Sep 17 00:00:00 2001
From: Hongyi Zhang <hongyiz@google.com>
Date: Thu, 7 May 2020 10:03:46 -0700
Subject: [PATCH] Start rebootPromptAndWipeUserData from a separate thread in
 RescueParty

Call rebootPromptAndWipeUserData from currently thread in RescueParty
will cause a deadlock in PackageWatchdog when shutting down device, if the reset is triggerred by PackageWatchdog.
Forking a separate thread to execute it to release the lock.

Test: Trigger final level of rescue on a local device, and now can
successfully shutdown and boot into recovery mode.
Bug: 155780451

Change-Id: I3a901a469e172252deac9f6e4f1f2ab7a455fa58
---
 .../java/com/android/server/RescueParty.java  | 27 +++++++++++++++----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/services/core/java/com/android/server/RescueParty.java b/services/core/java/com/android/server/RescueParty.java
index bfcde97d6c916..829fca66ec0da 100644
--- a/services/core/java/com/android/server/RescueParty.java
+++ b/services/core/java/com/android/server/RescueParty.java
@@ -253,10 +253,7 @@ public class RescueParty {
             logCriticalInfo(Log.DEBUG,
                     "Finished rescue level " + levelToString(level));
         } catch (Throwable t) {
-            final String msg = ExceptionUtils.getCompleteMessage(t);
-            EventLogTags.writeRescueFailure(level, msg);
-            logCriticalInfo(Log.ERROR,
-                    "Failed rescue level " + levelToString(level) + ": " + msg);
+            logRescueException(level, t);
         }
     }
 
@@ -274,11 +271,31 @@ public class RescueParty {
                 resetAllSettings(context, Settings.RESET_MODE_TRUSTED_DEFAULTS, failedPackage);
                 break;
             case LEVEL_FACTORY_RESET:
-                RecoverySystem.rebootPromptAndWipeUserData(context, TAG);
+                // Request the reboot from a separate thread to avoid deadlock on PackageWatchdog
+                // when device shutting down.
+                Runnable runnable = new Runnable() {
+                    @Override
+                    public void run() {
+                        try {
+                            RecoverySystem.rebootPromptAndWipeUserData(context, TAG);
+                        } catch (Throwable t) {
+                            logRescueException(level, t);
+                        }
+                    }
+                };
+                Thread thread = new Thread(runnable);
+                thread.start();
                 break;
         }
     }
 
+    private static void logRescueException(int level, Throwable t) {
+        final String msg = ExceptionUtils.getCompleteMessage(t);
+        EventLogTags.writeRescueFailure(level, msg);
+        logCriticalInfo(Log.ERROR,
+                "Failed rescue level " + levelToString(level) + ": " + msg);
+    }
+
     private static int mapRescueLevelToUserImpact(int rescueLevel) {
         switch(rescueLevel) {
             case LEVEL_RESET_SETTINGS_UNTRUSTED_DEFAULTS: