On Mon, Feb 18, 2019 at 3:06 AM Vlad Buslov <vla...@mellanox.com> wrote:
>
> On Fri 15 Feb 2019 at 22:35, Cong Wang <xiyou.wangc...@gmail.com> wrote:
> > On Mon, Feb 11, 2019 at 12:56 AM Vlad Buslov <vla...@mellanox.com> wrote:
> >> +#ifdef CONFIG_PROVE_LOCKING
> >> +static inline bool lockdep_tcf_chain_is_locked(struct tcf_chain *chain)
> >> +{
> >> + return lockdep_is_held(&chain->filter_chain_lock);
> >> +}
> >> +#else
> >> +static inline bool lockdep_tcf_chain_is_locked(struct tcf_block *chain)
> >> +{
> >> + return true;
> >> +}
> >> +#endif /* #ifdef CONFIG_PROVE_LOCKING */
> >> +
> >> +#define tcf_chain_dereference(p, chain)
> >> \
> >> + rcu_dereference_protected(p, lockdep_tcf_chain_is_locked(chain))
> >
> >
> > Are you sure you need this #ifdef CONFIG_PROVE_LOCKING?
> > rcu_dereference_protected() should already test CONFIG_PROVE_RCU.
> >
> > Ditto for tcf_proto_dereference().
>
> I implemented these macro same way as rtnl_dereference() is implemented,
> which they are intended to substitute.
>
> After removing them I get following compilation error with
> CONFIG_PROVE_LOCKING disabled:
This is pretty odd, because net/core/neighbour.c uses it without
any #ifdef CONFIG_PROVE_LOCKING, for instance:
192 neigh = rcu_dereference_protected(n->next,
193
lockdep_is_held(&tbl->lock));
194 rcu_assign_pointer(*np, neigh);
195 neigh_mark_dead(n);
196 retval = true;
So how does this compile when CONFIG_PROVE_LOCKING
is disabled? :-/
