Re: [PATCH net] mpls: fix af_mpls dependencies

[Arnd Bergmann <arnd@arndb.de>]

On Fri, Jun 14, 2019 at 4:07 PM David Ahern <dsahern@gmail.com> wrote:
> On 6/14/19 8:01 AM, Arnd Bergmann wrote:
> > On Wed, Jun 12, 2019 at 9:41 AM Randy Dunlap <rdunlap@infradead.org> wrote:
> >> On 6/11/19 5:08 PM, Matteo Croce wrote:
> >
> > It clearly shouldn't select PROC_SYSCTL, but I think it should not
> > have a 'depends on' statement either. I think the correct fix for the
> > original problem would have been something like
> >
> > --- a/net/mpls/af_mpls.c
> > +++ b/net/mpls/af_mpls.c
> > @@ -2659,6 +2659,9 @@ static int mpls_net_init(struct net *net)
> >         net->mpls.ip_ttl_propagate = 1;
> >         net->mpls.default_ttl = 255;
> >
> > +       if (!IS_ENABLED(CONFIG_PROC_SYSCTL))
> > +               return 0;
> > +
> >         table = kmemdup(mpls_table, sizeof(mpls_table), GFP_KERNEL);
> >         if (table == NULL)
> >                 return -ENOMEM;
> >
>
> Without sysctl, the entire mpls_router code is disabled. So if sysctl is
> not enabled there is no point in building this file.

Ok, I see.

There are a couple of other drivers that use 'depends on SYSCTL',
which may be the right thing to do here. In theory, one can still
build a kernel with CONFIG_SYSCTRL_SYSCALL=y and no
procfs.

        Arnd