--- a/src/hotspot/os/posix/os_posix.cpp	Sun Jan 13 17:33:26 2019 +0100
+++ b/src/hotspot/os/posix/os_posix.cpp	Sun Jan 13 16:54:01 2019 -0500
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1999, 2018, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1999, 2019, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -554,6 +554,10 @@
   return ::fdopen(fd, mode);
 }
 
+ssize_t os::read_at(int fd, void *buf, unsigned int nBytes, jlong offset) {
+  return ::pread(fd, buf, nBytes, offset);
+}
+
 void os::flockfile(FILE* fp) {
   ::flockfile(fp);
 }