From cf2ef0c0f9c1686d10f3c72c2818db24f2f09720 Mon Sep 17 00:00:00 2001
From: Riddle Hsu <riddlehsu@google.com>
Date: Fri, 13 Dec 2019 14:33:40 +0800
Subject: [PATCH] Add wtf log when starting activities with different uids

To know more about the use cases of startActivities.

Bug: 145669109
Test: Use startActivities to launch multiple activities
      in different apps (uids) and check event log.

Change-Id: Ica905b2c81b7b587ca55f29f82ed7685f15ca001
---
 .../server/wm/ActivityStartController.java    | 23 ++++++++++++++++---
 1 file changed, 20 insertions(+), 3 deletions(-)

diff --git a/services/core/java/com/android/server/wm/ActivityStartController.java b/services/core/java/com/android/server/wm/ActivityStartController.java
index 695f58c22e7d1..3f4f6751e236d 100644
--- a/services/core/java/com/android/server/wm/ActivityStartController.java
+++ b/services/core/java/com/android/server/wm/ActivityStartController.java
@@ -43,6 +43,7 @@ import android.os.Message;
 import android.os.UserHandle;
 import android.provider.Settings;
 import android.util.Slog;
+import android.util.SparseArray;
 import android.util.proto.ProtoOutputStream;
 import android.view.RemoteAnimationAdapter;
 
@@ -385,6 +386,7 @@ public class ActivityStartController {
         } else {
             callingPid = callingUid = -1;
         }
+        final SparseArray<String> startingUidPkgs = new SparseArray<>();
         final long origId = Binder.clearCallingIdentity();
         try {
             intents = ArrayUtils.filterNotNull(intents, Intent[]::new);
@@ -411,9 +413,14 @@ public class ActivityStartController {
                                 callingUid, realCallingUid, UserHandle.USER_NULL));
                 aInfo = mService.mAmInternal.getActivityInfoForUser(aInfo, userId);
 
-                if (aInfo != null && (aInfo.applicationInfo.privateFlags
-                        & ApplicationInfo.PRIVATE_FLAG_CANT_SAVE_STATE) != 0) {
-                    throw new IllegalArgumentException("FLAG_CANT_SAVE_STATE not supported here");
+                if (aInfo != null) {
+                    if ((aInfo.applicationInfo.privateFlags
+                            & ApplicationInfo.PRIVATE_FLAG_CANT_SAVE_STATE) != 0) {
+                        throw new IllegalArgumentException(
+                                "FLAG_CANT_SAVE_STATE not supported here");
+                    }
+                    startingUidPkgs.put(aInfo.applicationInfo.uid,
+                            aInfo.applicationInfo.packageName);
                 }
 
                 final boolean top = i == intents.length - 1;
@@ -439,6 +446,16 @@ public class ActivityStartController {
                         .setOriginatingPendingIntent(originatingPendingIntent)
                         .setAllowBackgroundActivityStart(allowBackgroundActivityStart);
             }
+            // Log if the activities to be started have different uids.
+            if (startingUidPkgs.size() > 1) {
+                final StringBuilder sb = new StringBuilder("startActivities: different apps [");
+                final int size = startingUidPkgs.size();
+                for (int i = 0; i < size; i++) {
+                    sb.append(startingUidPkgs.valueAt(i)).append(i == size - 1 ? "]" : ", ");
+                }
+                sb.append(" from ").append(callingPackage);
+                Slog.wtf(TAG, sb.toString());
+            }
 
             final ActivityRecord[] outActivity = new ActivityRecord[1];
             // Lock the loop to ensure the activities launched in a sequence.