diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 537213db6d7..7e89c749e80 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2017-04-28  Yao Qi  <yao.qi@linaro.org>
+
+	* regcache.c (regcache_dup): Assert !src->m_readonly_p and
+	call method save instead of regcache_cpy.
+	* regcache.h (struct regcache): Make regcache_dup a friend.
+
 2017-04-28  Yao Qi  <yao.qi@linaro.org>
 
 	* regcache.c (struct regcache): Move to regcache.h
diff --git a/gdb/regcache.c b/gdb/regcache.c
index 11f6a874f31..c30d1c73b81 100644
--- a/gdb/regcache.c
+++ b/gdb/regcache.c
@@ -422,8 +422,9 @@ regcache_dup (struct regcache *src)
 {
   struct regcache *newbuf;
 
+  gdb_assert (!src->m_readonly_p);
   newbuf = regcache_xmalloc (src->arch (), get_regcache_aspace (src));
-  regcache_cpy (newbuf, src);
+  newbuf->save (do_cooked_read, src);
   return newbuf;
 }
 
diff --git a/gdb/regcache.h b/gdb/regcache.h
index e03a39fbcef..c5d21f7439a 100644
--- a/gdb/regcache.h
+++ b/gdb/regcache.h
@@ -373,6 +373,9 @@ private:
 
   friend void
   regcache_cpy (struct regcache *dst, struct regcache *src);
+
+  friend struct regcache *
+  regcache_dup (struct regcache *src);
 };
 
 /* Copy/duplicate the contents of a register cache.  By default, the