diff --git a/net/mac80211/trace_msg.h b/net/mac80211/trace_msg.h
index 40141df09f25..c9dbe9aab7bd 100644
--- a/net/mac80211/trace_msg.h
+++ b/net/mac80211/trace_msg.h
@@ -24,13 +24,11 @@ DECLARE_EVENT_CLASS(mac80211_msg_event,
 	TP_ARGS(vaf),
 
 	TP_STRUCT__entry(
-		__dynamic_array(char, msg, MAX_MSG_LEN)
+		__vstring(msg, vaf->fmt, vaf->va)
 	),
 
 	TP_fast_assign(
-		WARN_ON_ONCE(vsnprintf(__get_dynamic_array(msg),
-				       MAX_MSG_LEN, vaf->fmt,
-				       *vaf->va) >= MAX_MSG_LEN);
+		__assign_vstr(msg, vaf->fmt, vaf->va);
 	),
 
 	TP_printk("%s", __get_str(msg))