diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 5b3b5fb1a8ef..6a30fa74f74b 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2012-01-19  Jakub Jelinek  <jakub@redhat.com>
 
+	PR libmudflap/40778
+	* tree-mudflap.c (mf_artificial): New function.
+	(execute_mudflap_function_ops, execute_mudflap_function_decls,
+	mx_register_decls, mudflap_enqueue_decl): Use it.
+
 	PR target/51876
 	* config/arm/neon.md (*neon_vswp<mode>): Fix up operand
 	numbers in the insn pattern.
diff --git a/gcc/tree-mudflap.c b/gcc/tree-mudflap.c
index 67fea759459f..e4f6ec0b3319 100644
--- a/gcc/tree-mudflap.c
+++ b/gcc/tree-mudflap.c
@@ -1,5 +1,5 @@
 /* Mudflap: narrow-pointer bounds-checking by tree rewriting.
-   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010
+   Copyright (C) 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2012
    Free Software Foundation, Inc.
    Contributed by Frank Ch. Eigler <fche@redhat.com>
    and Graydon Hoare <graydon@redhat.com>
@@ -69,6 +69,13 @@ static tree mx_xfn_xform_decls (gimple_stmt_iterator *, bool *,
 static gimple_seq mx_register_decls (tree, gimple_seq, location_t);
 static unsigned int execute_mudflap_function_decls (void);
 
+/* Return true if DECL is artificial stub that shouldn't be instrumented by
+   mf.  We should instrument clones of non-artificial functions.  */
+static inline bool
+mf_artificial (const_tree decl)
+{
+  return DECL_ARTIFICIAL (DECL_ORIGIN (decl));
+}
 
 /* ------------------------------------------------------------------------ */
 /* Some generally helpful functions for mudflap instrumentation.  */
@@ -412,8 +419,8 @@ execute_mudflap_function_ops (void)
 
   /* Don't instrument functions such as the synthetic constructor
      built during mudflap_finish_file.  */
-  if (mf_marked_p (current_function_decl) ||
-      DECL_ARTIFICIAL (current_function_decl))
+  if (mf_marked_p (current_function_decl)
+      || mf_artificial (current_function_decl))
     return 0;
 
   push_gimplify_context (&gctx);
@@ -994,8 +1001,8 @@ execute_mudflap_function_decls (void)
 
   /* Don't instrument functions such as the synthetic constructor
      built during mudflap_finish_file.  */
-  if (mf_marked_p (current_function_decl) ||
-      DECL_ARTIFICIAL (current_function_decl))
+  if (mf_marked_p (current_function_decl)
+      || mf_artificial (current_function_decl))
     return 0;
 
   push_gimplify_context (&gctx);
@@ -1078,7 +1085,7 @@ mx_register_decls (tree decl, gimple_seq seq, location_t location)
           /* Add the __mf_register call at the current appending point.  */
           if (gsi_end_p (initially_stmts))
 	    {
-	      if (!DECL_ARTIFICIAL (decl))
+	      if (!mf_artificial (decl))
 		warning (OPT_Wmudflap,
 			 "mudflap cannot track %qE in stub function",
 			 DECL_NAME (decl));
@@ -1249,7 +1256,7 @@ mudflap_enqueue_decl (tree obj)
      during mudflap_finish_file ().  That would confuse the user,
      since the text would refer to variables that don't show up in the
      user's source code.  */
-  if (DECL_P (obj) && DECL_EXTERNAL (obj) && DECL_ARTIFICIAL (obj))
+  if (DECL_P (obj) && DECL_EXTERNAL (obj) && mf_artificial (obj))
     return;
 
   VEC_safe_push (tree, gc, deferred_static_decls, obj);
diff --git a/libmudflap/ChangeLog b/libmudflap/ChangeLog
index edcfb1995994..3d3e5af21a93 100644
--- a/libmudflap/ChangeLog
+++ b/libmudflap/ChangeLog
@@ -1,3 +1,8 @@
+2012-01-19  Jakub Jelinek  <jakub@redhat.com>
+
+	PR libmudflap/40778
+	* testsuite/libmudflap.c/fail68-frag.c: New test.
+
 2012-01-01  Jakub Jelinek  <jakub@redhat.com>
 
 	* mf-runtime.c (__mf_usage): Update copyright notice dates.
diff --git a/libmudflap/testsuite/libmudflap.c/fail68-frag.c b/libmudflap/testsuite/libmudflap.c/fail68-frag.c
new file mode 100644
index 000000000000..7b2f8cf2cb04
--- /dev/null
+++ b/libmudflap/testsuite/libmudflap.c/fail68-frag.c
@@ -0,0 +1,27 @@
+/* PR libmudflap/40778 */
+
+char p[32];
+static int j;
+
+__attribute__((noinline))
+static void foo (int i)
+{
+  if (j++ == 0)
+    p[i + 4] = 12;
+  else
+    p[i - 4] = 13;
+}
+
+int
+main ()
+{
+  foo (30);
+  foo (30);
+  foo (30);
+  return 0;
+}
+
+/* { dg-output "mudflap violation 1.*" } */
+/* { dg-output "Nearby object 1.*" } */
+/* { dg-output "mudflap object.*name.*p" } */
+/* { dg-do run { xfail *-*-* } } */