Re: [PATCH net 1/4] ipv6: silence compilation warning for non-IPV6 builds

[Jakub Kicinski]

On Tue,  2 Feb 2021 15:55:41 +0200 Leon Romanovsky wrote:
> From: Leon Romanovsky <leonro@xxxxxxxxxx>
> 
> The W=1 compilation of allmodconfig generates the following warning:
> 
> net/ipv6/icmp.c:448:6: warning: no previous prototype for 'icmp6_send' [-Wmissing-prototypes]
>   448 | void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
>       |      ^~~~~~~~~~
> 
> In such configuration, the icmp6_send() is not used outside of icmp.c, so close
> its EXPORT_SYMBOL and add "static" word to limit the scope.
> 
> Fixes: cc7a21b6fbd9 ("ipv6: icmp6: avoid indirect call for icmpv6_send()")
> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx>

That's a little much ifdefinery, why not move the declaration from
under the ifdef in the header instead?

If you repost please target net-next, admittedly these fixes are pretty
"obviously correct" but they are not urgent either.

> diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
> index f3d05866692e..5d4232b492dc 100644
> --- a/net/ipv6/icmp.c
> +++ b/net/ipv6/icmp.c
> @@ -445,6 +445,9 @@ static int icmp6_iif(const struct sk_buff *skb)
>  /*
>   *	Send an ICMP message in response to a packet in error
>   */
> +#if !IS_BUILTIN(CONFIG_IPV6)
> +static
> +#endif
>  void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
>  		const struct in6_addr *force_saddr)
>  {
> @@ -634,7 +637,10 @@ void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info,
>  out_bh_enable:
>  	local_bh_enable();
>  }
> +
> +#if IS_BUILTIN(CONFIG_IPV6)
>  EXPORT_SYMBOL(icmp6_send);
> +#endif
> 
>  /* Slightly more convenient version of icmp6_send.
>   */
> --
> 2.29.2
>