diff --git a/services/core/java/com/android/server/wm/ActivityStarter.java b/services/core/java/com/android/server/wm/ActivityStarter.java
index da1c045..d63dc19 100644
--- a/services/core/java/com/android/server/wm/ActivityStarter.java
+++ b/services/core/java/com/android/server/wm/ActivityStarter.java
@@ -341,7 +341,6 @@
         int filterCallingUid;
         PendingIntentRecord originatingPendingIntent;
         boolean allowBackgroundActivityStart;
-        boolean isDream;
 
         /**
          * If set to {@code true}, allows this activity start to look into
@@ -393,7 +392,6 @@
             filterCallingUid = UserHandle.USER_NULL;
             originatingPendingIntent = null;
             allowBackgroundActivityStart = false;
-            isDream = false;
         }
 
         /**
@@ -434,7 +432,6 @@
             filterCallingUid = request.filterCallingUid;
             originatingPendingIntent = request.originatingPendingIntent;
             allowBackgroundActivityStart = request.allowBackgroundActivityStart;
-            isDream = request.isDream;
         }
 
         /**
@@ -985,7 +982,7 @@
                 restrictedBgActivity = shouldAbortBackgroundActivityStart(callingUid,
                         callingPid, callingPackage, realCallingUid, realCallingPid, callerApp,
                         request.originatingPendingIntent, request.allowBackgroundActivityStart,
-                        request.isDream, intent);
+                        intent);
             } finally {
                 Trace.traceEnd(Trace.TRACE_TAG_WINDOW_MANAGER);
             }
@@ -1195,7 +1192,7 @@
     boolean shouldAbortBackgroundActivityStart(int callingUid, int callingPid,
             final String callingPackage, int realCallingUid, int realCallingPid,
             WindowProcessController callerApp, PendingIntentRecord originatingPendingIntent,
-            boolean allowBackgroundActivityStart, boolean isDream, Intent intent) {
+            boolean allowBackgroundActivityStart, Intent intent) {
         // don't abort for the most important UIDs
         final int callingAppId = UserHandle.getAppId(callingUid);
         if (callingUid == Process.ROOT_UID || callingAppId == Process.SYSTEM_UID
@@ -1203,10 +1200,6 @@
             return false;
         }
 
-        // don't abort if this is the dream activity
-        if (isDream) {
-            return false;
-        }
         // don't abort if the callingUid has a visible window or is a persistent system process
         final int callingUidProcState = mService.getUidState(callingUid);
         final boolean callingUidHasAnyVisibleWindow =
@@ -2717,11 +2710,6 @@
         return this;
     }
 
-    ActivityStarter setIsDream(boolean isDream) {
-        mRequest.isDream = isDream;
-        return this;
-    }
-
     void dump(PrintWriter pw, String prefix) {
         prefix = prefix + "  ";
         pw.print(prefix);
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;
             }
diff --git a/services/core/java/com/android/server/wm/AppTaskImpl.java b/services/core/java/com/android/server/wm/AppTaskImpl.java
index 4cce212..8fa8119 100644
--- a/services/core/java/com/android/server/wm/AppTaskImpl.java
+++ b/services/core/java/com/android/server/wm/AppTaskImpl.java
@@ -111,7 +111,7 @@
                 final ActivityStarter starter = mService.getActivityStartController().obtainStarter(
                         null /* intent */, "moveToFront");
                 if (starter.shouldAbortBackgroundActivityStart(callingUid, callingPid,
-                        callingPackage, -1, -1, callerApp, null, false, false, null)) {
+                        callingPackage, -1, -1, callerApp, null, false, null)) {
                     if (!mService.isBackgroundActivityStartsEnabled()) {
                         return;
                     }