#undef __string_len
#define __string_len(item, src, len) __dynamic_array(char, item, (len) + 1)
+#undef __vstring
+#define __vstring(item, fmt, ap) __dynamic_array(char, item, \
+ __trace_event_vstr_len(fmt, ap))
+
#undef __rel_dynamic_array
#define __rel_dynamic_array(type, item, len) \
__item_length = (len) * sizeof(type); \