--- a/src/hotspot/os/posix/gc/z/zVirtualMemory_posix.cpp	Fri Sep 27 09:01:39 2019 +0200
+++ b/src/hotspot/os/posix/gc/z/zVirtualMemory_posix.cpp	Thu Oct 03 10:54:18 2019 +0200
@@ -43,7 +43,7 @@
 
   if ((uintptr_t)res != start) {
     // Failed to reserve memory at the requested address
-    unmap(start, size);
+    unmap((uintptr_t)res, size);
     return false;
   }