From 6de944c27a64a0a8db4d663873a3d099ad9be576 Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Wed, 30 Mar 2022 16:02:12 +0800
Subject: [PATCH] Skip reporting ANR on zero pid process

Though currently the only case is from broadcast timeout
on a process forking by unresponsive webview_zygote, skip
the case to avoid noise reports.

Bug: 227349843
Test: AnrHelperTest
Change-Id: I433c4d33e14619bec764b99a1334ebe7c6137bb0
---
 services/core/java/com/android/server/am/AnrHelper.java      | 5 +++++
 .../src/com/android/server/am/AnrHelperTest.java             | 2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/services/core/java/com/android/server/am/AnrHelper.java b/services/core/java/com/android/server/am/AnrHelper.java
index 1e1024e863142..e3544953e63d6 100644
--- a/services/core/java/com/android/server/am/AnrHelper.java
+++ b/services/core/java/com/android/server/am/AnrHelper.java
@@ -79,6 +79,11 @@ class AnrHelper {
             WindowProcessController parentProcess, boolean aboveSystem, String annotation) {
         final int incomingPid = anrProcess.mPid;
         synchronized (mAnrRecords) {
+            if (incomingPid == 0) {
+                // Extreme corner case such as zygote is no response to return pid for the process.
+                Slog.i(TAG, "Skip zero pid ANR, process=" + anrProcess.processName);
+                return;
+            }
             if (mProcessingPid == incomingPid) {
                 Slog.i(TAG, "Skip duplicated ANR, pid=" + incomingPid + " " + annotation);
                 return;
diff --git a/services/tests/servicestests/src/com/android/server/am/AnrHelperTest.java b/services/tests/servicestests/src/com/android/server/am/AnrHelperTest.java
index 782d519418092..c940ef5c290d5 100644
--- a/services/tests/servicestests/src/com/android/server/am/AnrHelperTest.java
+++ b/services/tests/servicestests/src/com/android/server/am/AnrHelperTest.java
@@ -70,6 +70,7 @@ public class AnrHelperTest {
         final Context context = getInstrumentation().getTargetContext();
         runWithDexmakerShareClassLoader(() -> {
             mAnrApp = mock(ProcessRecord.class);
+            mAnrApp.mPid = 12345;
             final ProcessErrorStateRecord errorState = mock(ProcessErrorStateRecord.class);
             setFieldValue(ProcessErrorStateRecord.class, errorState, "mProcLock",
                     new ActivityManagerProcLock());
@@ -130,7 +131,6 @@ public class AnrHelperTest {
         }).when(mAnrApp.mErrorState).appNotResponding(anyString(), any(), any(), any(),
                 anyBoolean(), anyString(), anyBoolean());
         final ApplicationInfo appInfo = new ApplicationInfo();
-        mAnrApp.mPid = 12345;
         final Runnable reportAnr = () -> mAnrHelper.appNotResponding(mAnrApp,
                 "activityShortComponentName", appInfo, "parentShortComponentName",
                 null /* parentProcess */, false /* aboveSystem */, "annotation");