--- sim/arm/armsupp.c.orig	2005-05-12 00:36:58.000000000 -0700
+++ sim/arm/armsupp.c	2015-11-22 20:07:49.000000000 -0800
@@ -636,7 +636,7 @@
   if (! CP_ACCESS_ALLOWED (state, CPNum))
     {
       ARMul_UndefInstr (state, instr);
-      return;
+      return result;
     }
 
   cpab = (state->MRC[CPNum]) (state, ARMul_FIRST, instr, &result);