Thanks for the detailed explanation.

I think the better change would be this then:

diff --git a/include/trace/events/fib6.h b/include/trace/events/fib6.h
index 8d22b2e98d48..3f95df1fd155 100644
--- a/include/trace/events/fib6.h
+++ b/include/trace/events/fib6.h

@@ -32,8 +32,9 @@ TRACE_EVENT(fib6_table_lookup,

		__field(        u16,	dport		)
		__field(        u8,	proto		)
		__field(        u8,	rt_type		)
-		__array(		char,	name,	IFNAMSIZ )
-		__array(		__u8,	gw,	16	 )
+		__string(	name,	res->nh && res->nh->fib_nh_dev ?
+					res->nh->fib_nh_dev->name : "-"	)
+		__array(	__u8,	gw,	16	)
	),

	TP_fast_assign(

@@ -64,11 +65,8 @@ TRACE_EVENT(fib6_table_lookup,

			__entry->dport = 0;
		}

-		if (res->nh && res->nh->fib_nh_dev) {
-			strscpy(__entry->name, res->nh->fib_nh_dev->name, IFNAMSIZ);
-		} else {
-			strcpy(__entry->name, "-");
-		}
+		__assign_str(name);
+
		if (res->f6i == net->ipv6.fib6_null_entry) {
			in6 = (struct in6_addr *)__entry->gw;
			*in6 = in6addr_any;

@@ -82,7 +80,7 @@ TRACE_EVENT(fib6_table_lookup,

		  __entry->tb_id, __entry->oif, __entry->iif, __entry->proto,
		  __entry->src, __entry->sport, __entry->dst, __entry->dport,
		  __entry->flowlabel, __entry->tos, __entry->scope,
-		  __entry->flags, __entry->name, __entry->gw, __entry->err)
+		  __entry->flags, __get_str(name), __entry->gw, __entry->err)
);

#endif /* _TRACE_FIB6_H */


I'll submit a v2 if you agree that this is correct.