Re: [PATCH bpf] bpf: fix unused-var without NETDEVICES

[Ferenc Fejes]

Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx> ezt Ãrta (idÅpont:
2020. jÃn. 3., Sze, 10:11):
>
> A recent commit added new variables only used if CONFIG_NETDEVICES is
> set.

Thank you for noticing and fixed this!

> A simple fix is to only declare these variables if the same
> condition is valid.
>
> Other solutions could be to move the code related to SO_BINDTODEVICE
> option from _bpf_setsockopt() function to a dedicated one or only
> declare these variables in the related "case" section.

Yes thats indeed a cleaner way to approach this. I will prepare a fix for that.

>
> Fixes: 70c58997c1e8 ("bpf: Allow SO_BINDTODEVICE opt in bpf_setsockopt")
> Signed-off-by: Matthieu Baerts <matthieu.baerts@xxxxxxxxxxxx>
> ---
>
> Notes:
>     This fix currently applies on net-next and bpf-next only. Except that
>     net-next is now closed and -net will get commits from net-next after
>     Linus' pull.
>
>     I hope it is fine to have picked [PATCH bpf] and not bpf-next (or net).
>
>  net/core/filter.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/core/filter.c b/net/core/filter.c
> index d01a244b5087..ee08c6fcee1a 100644
> --- a/net/core/filter.c
> +++ b/net/core/filter.c
> @@ -4286,9 +4286,11 @@ static const struct bpf_func_proto bpf_get_socket_uid_proto = {
>  static int _bpf_setsockopt(struct sock *sk, int level, int optname,
>                            char *optval, int optlen, u32 flags)
>  {
> +#ifdef CONFIG_NETDEVICES
>         char devname[IFNAMSIZ];
>         struct net *net;
>         int ifindex;
> +#endif
>         int ret = 0;
>         int val;
>
> --
> 2.25.1
>