diff -r 28375a1de254 -r 27df68106e57 src/hotspot/share/memory/filemap.cpp
--- a/src/hotspot/share/memory/filemap.cpp	Mon Oct 15 11:36:20 2018 -0700
+++ b/src/hotspot/share/memory/filemap.cpp	Mon Oct 15 15:21:54 2018 -0400
@@ -1088,8 +1088,8 @@
 }
 
 bool FileMapInfo::verify_mapped_heap_regions(int first, int num) {
-  for (int i = first;
-           i <= first + num; i++) {
+  assert(num > 0, "sanity");
+  for (int i = first; i < first + num; i++) {
     if (!verify_region_checksum(i)) {
       return false;
     }