Index: sys/kern/kern_crashme.c
===================================================================
RCS file: /cvsroot/src/sys/kern/kern_crashme.c,v
retrieving revision 1.1
diff -p -u -r1.1 kern_crashme.c
--- sys/kern/kern_crashme.c	9 Jan 2019 04:01:20 -0000	1.1
+++ sys/kern/kern_crashme.c	11 Jan 2019 10:46:37 -0000
@@ -227,10 +227,13 @@ crashme_panic(int flags)
 	return -1;
 }
 
+/* non-static to avoid optimisation */
+char *null_pointer;
+
 static int
 crashme_null_deref(int flags)
 {
 
-	*(char *)0 = 0;
+	*null_pointer = 0;
 	return -1;
 }