--- old/src/hotspot/share/utilities/ostream.cpp	2020-03-11 01:12:55.032412924 -0400
+++ new/src/hotspot/share/utilities/ostream.cpp	2020-03-11 01:12:53.892400250 -0400
@@ -29,6 +29,7 @@
 #include "oops/oop.inline.hpp"
 #include "runtime/arguments.hpp"
 #include "runtime/os.inline.hpp"
+#include "runtime/orderAccess.hpp"
 #include "runtime/vm_version.hpp"
 #include "utilities/defaultStream.hpp"
 #include "utilities/macros.hpp"
@@ -373,6 +374,11 @@
     NEW_C_HEAP_ARRAY(char, buffer_pos + 1, mtInternal) : NEW_RESOURCE_ARRAY(char, buffer_pos + 1);
   strncpy(copy, buffer, buffer_pos);
   copy[buffer_pos] = 0;  // terminating null
+  if (c_heap) {
+    // Need to ensure our content is written to memory before we return
+    // the pointer to it.
+    OrderAccess::storestore();
+  }
   return copy;
 }