Merge "DO NOT MERGE -- Merge PPRL.190405.003 into master"

services/core/java/com/android/server/AlarmManagerService.java

@@ -48,6 +48,7 @@ import android.content.pm.PermissionInfo;
 import android.database.ContentObserver;
 import android.net.Uri;
 import android.os.Binder;
+import android.os.Build;
 import android.os.Bundle;
 import android.os.Environment;
 import android.os.Handler;
@@ -1288,9 +1289,13 @@ class AlarmManagerService extends SystemService {
         // because kernel doesn't keep this after reboot
         setTimeZoneImpl(SystemProperties.get(TIMEZONE_PROPERTY));
 
-        // Also sure that we're booting with a halfway sensible current time
         if (mNativeData != 0) {
-            final long systemBuildTime = Environment.getRootDirectory().lastModified();
+            // Ensure that we're booting with a halfway sensible current time.  Use the
+            // most recent of Build.TIME, the root file system's timestamp, and the
+            // value of the ro.build.date.utc system property (which is in seconds).
+            final long systemBuildTime =  Long.max(
+                    1000L * SystemProperties.getLong("ro.build.date.utc", -1L),
+                    Long.max(Environment.getRootDirectory().lastModified(), Build.TIME));
             if (System.currentTimeMillis() < systemBuildTime) {
                 Slog.i(TAG, "Current time only " + System.currentTimeMillis()
                         + ", advancing to build time " + systemBuildTime);