From 11d5c39f1d779e3c62398677a67740c7a64d6fba Mon Sep 17 00:00:00 2001
From: Olivier Gaillard <gaillard@google.com>
Date: Tue, 11 Jul 2023 13:29:23 +0000
Subject: [PATCH] Create a new subreason to track when apps are killed because
 of excessive binder calls

Bug: 290756408
Change-Id: Iab5b0a185ab0918d59292ba898334f6f0216228b
---
 core/java/android/app/ApplicationExitInfo.java | 11 +++++++++++
 .../server/am/ActivityManagerService.java      | 18 +++++++++++++-----
 2 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/core/java/android/app/ApplicationExitInfo.java b/core/java/android/app/ApplicationExitInfo.java
index d859f3f9e1759..7b3d017128670 100644
--- a/core/java/android/app/ApplicationExitInfo.java
+++ b/core/java/android/app/ApplicationExitInfo.java
@@ -460,6 +460,14 @@ public final class ApplicationExitInfo implements Parcelable {
      */
     public static final int SUBREASON_SDK_SANDBOX_NOT_NEEDED = 28;
 
+    /**
+     * The process was killed because the binder proxy limit for system server was exceeded.
+     *
+     * For internal use only.
+     * @hide
+     */
+    public static final int SUBREASON_EXCESSIVE_BINDER_OBJECTS = 29;
+
     // If there is any OEM code which involves additional app kill reasons, it should
     // be categorized in {@link #REASON_OTHER}, with subreason code starting from 1000.
 
@@ -635,6 +643,7 @@ public final class ApplicationExitInfo implements Parcelable {
         SUBREASON_KILL_BACKGROUND,
         SUBREASON_PACKAGE_UPDATE,
         SUBREASON_UNDELIVERED_BROADCAST,
+        SUBREASON_EXCESSIVE_BINDER_OBJECTS,
     })
     @Retention(RetentionPolicy.SOURCE)
     public @interface SubReason {}
@@ -1360,6 +1369,8 @@ public final class ApplicationExitInfo implements Parcelable {
                 return "PACKAGE UPDATE";
             case SUBREASON_UNDELIVERED_BROADCAST:
                 return "UNDELIVERED BROADCAST";
+            case SUBREASON_EXCESSIVE_BINDER_OBJECTS:
+                return "EXCESSIVE BINDER OBJECTS";
             default:
                 return "UNKNOWN";
         }
diff --git a/services/core/java/com/android/server/am/ActivityManagerService.java b/services/core/java/com/android/server/am/ActivityManagerService.java
index eaa1b97113a89..e6151471628be 100644
--- a/services/core/java/com/android/server/am/ActivityManagerService.java
+++ b/services/core/java/com/android/server/am/ActivityManagerService.java
@@ -8108,8 +8108,8 @@ public class ActivityManagerService extends IActivityManager.Stub
         return killed;
     }
 
-    @Override
-    public void killUid(int appId, int userId, String reason) {
+    private void killUid(int appId, int userId, int reason, int subReason,
+            String reasonAsString) {
         enforceCallingPermission(Manifest.permission.KILL_UID, "killUid");
         synchronized (this) {
             final long identity = Binder.clearCallingIdentity();
@@ -8120,9 +8120,9 @@ public class ActivityManagerService extends IActivityManager.Stub
                             true /* callerWillRestart */, true /* doit */,
                             true /* evenPersistent */, false /* setRemoved */,
                             false /* uninstalling */,
-                            ApplicationExitInfo.REASON_OTHER,
-                            ApplicationExitInfo.SUBREASON_KILL_UID,
-                            reason != null ? reason : "kill uid");
+                            reason,
+                            subReason,
+                            reasonAsString != null ? reasonAsString : "kill uid");
                 }
             } finally {
                 Binder.restoreCallingIdentity(identity);
@@ -8130,6 +8130,12 @@ public class ActivityManagerService extends IActivityManager.Stub
         }
     }
 
+    @Override
+    public void killUid(int appId, int userId, String reason) {
+        killUid(appId, userId, ApplicationExitInfo.REASON_OTHER,
+                ApplicationExitInfo.SUBREASON_KILL_UID, reason);
+    }
+
     @Override
     public void killUidForPermissionChange(int appId, int userId, String reason) {
         enforceCallingPermission(Manifest.permission.KILL_UID, "killUid");
@@ -8645,6 +8651,8 @@ public class ActivityManagerService extends IActivityManager.Stub
                             Slog.i(TAG, "Skipping kill (uid is SYSTEM)");
                         } else {
                             killUid(UserHandle.getAppId(uid), UserHandle.getUserId(uid),
+                                    ApplicationExitInfo.REASON_EXCESSIVE_RESOURCE_USAGE,
+                                    ApplicationExitInfo.SUBREASON_EXCESSIVE_BINDER_OBJECTS,
                                     "Too many Binders sent to SYSTEM");
                             // We need to run a GC here, because killing the processes involved
                             // actually isn't guaranteed to free up the proxies; in fact, if the