diff --git a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
index e83ac7b..a75420e 100644
--- a/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
+++ b/services/core/java/com/android/server/wm/ActivityTaskManagerService.java
@@ -212,7 +212,6 @@
 import android.os.storage.StorageManager;
 import android.provider.Settings;
 import android.service.dreams.DreamActivity;
-import android.service.dreams.DreamManagerInternal;
 import android.service.voice.IVoiceInteractionSession;
 import android.service.voice.VoiceInteractionManagerInternal;
 import android.sysprop.DisplayProperties;
@@ -1245,36 +1244,29 @@
         }
     }
 
-    @Override
-    public boolean startDreamActivity(Intent intent) {
-        final WindowProcessController process = mProcessMap.getProcess(Binder.getCallingPid());
+    private void enforceCallerIsDream(String callerPackageName) {
         final long origId = Binder.clearCallingIdentity();
-
-        // The dream activity is only called for non-doze dreams.
-        final ComponentName currentDream = LocalServices.getService(DreamManagerInternal.class)
-                .getActiveDreamComponent(/* doze= */ false);
-
-        if (currentDream == null || currentDream.getPackageName() == null
-                || !currentDream.getPackageName().equals(process.mInfo.packageName)) {
-            Slog.e(TAG, "Calling package is not the current dream package. "
-                    + "Aborting startDreamActivity...");
-            return false;
+        try {
+            if (!ActivityRecord.canLaunchDreamActivity(callerPackageName)) {
+                throw new SecurityException("The dream activity can be started only when the device"
+                        + " is dreaming and only by the active dream package.");
+            }
+        } finally {
+            Binder.restoreCallingIdentity(origId);
         }
+    }
+
+    @Override
+    public boolean startDreamActivity(@NonNull Intent intent) {
+        assertPackageMatchesCallingUid(intent.getPackage());
+        enforceCallerIsDream(intent.getPackage());
 
         final ActivityInfo a = new ActivityInfo();
         a.theme = com.android.internal.R.style.Theme_Dream;
         a.exported = true;
         a.name = DreamActivity.class.getName();
-
-
-        a.packageName = process.mInfo.packageName;
-        a.applicationInfo = process.mInfo;
-        a.processName = process.mInfo.processName;
-        a.uiOptions = process.mInfo.uiOptions;
-        a.taskAffinity = "android:" + a.packageName + "/dream";
         a.enabled = true;
         a.launchMode = ActivityInfo.LAUNCH_SINGLE_INSTANCE;
-
         a.persistableMode = ActivityInfo.PERSIST_NEVER;
         a.screenOrientation = ActivityInfo.SCREEN_ORIENTATION_UNSPECIFIED;
         a.colorMode = ActivityInfo.COLOR_MODE_DEFAULT;
@@ -1283,15 +1275,34 @@
         final ActivityOptions options = ActivityOptions.makeBasic();
         options.setLaunchActivityType(ACTIVITY_TYPE_DREAM);
 
-        try {
-            getActivityStartController().obtainStarter(intent, "dream")
-                    .setActivityInfo(a)
-                    .setActivityOptions(options.toBundle())
-                    .setIsDream(true)
-                    .execute();
-            return true;
-        } finally {
-            Binder.restoreCallingIdentity(origId);
+        synchronized (mGlobalLock) {
+            final WindowProcessController process = mProcessMap.getProcess(Binder.getCallingPid());
+
+            a.packageName = process.mInfo.packageName;
+            a.applicationInfo = process.mInfo;
+            a.processName = process.mInfo.processName;
+            a.uiOptions = process.mInfo.uiOptions;
+            a.taskAffinity = "android:" + a.packageName + "/dream";
+
+            final int callingUid = Binder.getCallingUid();
+            final int callingPid = Binder.getCallingPid();
+
+            final long origId = Binder.clearCallingIdentity();
+            try {
+                getActivityStartController().obtainStarter(intent, "dream")
+                        .setCallingUid(callingUid)
+                        .setCallingPid(callingPid)
+                        .setActivityInfo(a)
+                        .setActivityOptions(options.toBundle())
+                        // To start the dream from background, we need to start it from a persistent
+                        // system process. Here we set the real calling uid to the system server uid
+                        .setRealCallingUid(Binder.getCallingUid())
+                        .setAllowBackgroundActivityStart(true)
+                        .execute();
+                return true;
+            } finally {
+                Binder.restoreCallingIdentity(origId);
+            }
         }
     }
 
@@ -2478,7 +2489,7 @@
         final ActivityStarter starter = getActivityStartController().obtainStarter(
                 null /* intent */, "moveTaskToFront");
         if (starter.shouldAbortBackgroundActivityStart(callingUid, callingPid, callingPackage, -1,
-                -1, callerApp, null, false, false, null)) {
+                -1, callerApp, null, false, null)) {
             if (!isBackgroundActivityStartsEnabled()) {
                 return;
             }