-#define copy_to_user_ret(to,from,n,retval) ({ if (copy_to_user(to,from,n)) return retval; })
-#define copy_from_user_ret(to,from,n,retval) ({ if (copy_from_user(to,from,n)) return retval; })
-
-extern long strncpy_from_user(char *dst, const char *src, long count);
-extern long strnlen_user(const char *src, long count);
+extern long strncpy_from_user(char *dst, const char __user *src, long count);
+extern long strnlen_user(const char __user *src, long count);