--- a/progs/README	Thu Oct 08 17:06:48 2015 +0100
+++ b/progs/README	Thu Oct 08 18:46:15 2015 +0100
@@ -64,6 +64,10 @@
   ./C4 "%s"
   ./C4 `./args4`
 
+This vulnerability does not need the defences, but prints out
+the string only correctly with `./args4`. The %s option needs
+
+  -mpreferred-stack-boundary=2
 
 
 ------------------------------------