Re: [PATCH net-next] tracing: ipv6: Replace deprecated strcpy() with strscpy()

[Steven Rostedt <rostedt@goodmis.org>]

On Mon, 14 Jul 2025 09:54:33 +0200
Thorsten Blum <thorsten.blum@linux.dev> wrote:

> diff --git a/include/trace/events/fib6.h b/include/trace/events/fib6.h
> index 8d22b2e98d48..903a18836bc6 100644
> --- a/include/trace/events/fib6.h
> +++ b/include/trace/events/fib6.h
> @@ -64,11 +64,9 @@ 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, "-");
> -		}
> +		strscpy(__entry->name, res->nh && res->nh->fib_nh_dev ?
> +				       res->nh->fib_nh_dev->name : "-");
> +
>  		if (res->f6i == net->ipv6.fib6_null_entry) {
>  			in6 = (struct in6_addr *)__entry->gw;
>  			*in6 = in6addr_any;

Hmm, why is that string hard coded to 16 bytes and doesn't use the
dynamic string facility? Perhaps something like this?

[ I didn't even compile the below, so it may have a syntax error ]

-- Steve

diff --git a/include/trace/events/fib6.h b/include/trace/events/fib6.h
index 8d22b2e98d48..98d2edb02431 100644
--- a/include/trace/events/fib6.h
+++ b/include/trace/events/fib6.h
@@ -32,7 +32,8 @@ TRACE_EVENT(fib6_table_lookup,
 		__field(        u16,	dport		)
 		__field(        u8,	proto		)
 		__field(        u8,	rt_type		)
-		__array(		char,	name,	IFNAMSIZ )
+		__string(	name,	res->nh && res->nh->fib_nh_dev ?
+					res->nh->fib_nh_dev->name : "-")
 		__array(		__u8,	gw,	16	 )
 	),
 
@@ -64,11 +65,7 @@ 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 +79,7 @@ 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 */