__pneigh_lookup() is the lockless version of pneigh_lookup(), but its only caller pndisc_is_router() holds the table lock and reads pneigh_netry.flags. This is because accessing pneigh_entry after pneigh_lookup() was illegal unless the caller holds RTNL or the table lock. Now, pneigh_entry is guaranteed to be alive during the RCU critical section. Let's call pneigh_lookup() and use READ_ONCE() for n->flags in pndisc_is_router() and remove __pneigh_lookup(). Signed-off-by: Kuniyuki Iwashima --- include/net/neighbour.h | 2 -- net/core/neighbour.c | 11 ----------- net/ipv6/ndisc.c | 6 ++---- 3 files changed, 2 insertions(+), 17 deletions(-) diff --git a/include/net/neighbour.h b/include/net/neighbour.h index a877e56210b22..1670e2a388556 100644 --- a/include/net/neighbour.h +++ b/include/net/neighbour.h @@ -381,8 +381,6 @@ void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p, struct sk_buff *skb); struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); -struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, struct net *net, - const void *key, struct net_device *dev); struct pneigh_entry *pneigh_create(struct neigh_table *tbl, struct net *net, const void *key, struct net_device *dev); int pneigh_delete(struct neigh_table *tbl, struct net *net, const void *key, diff --git a/net/core/neighbour.c b/net/core/neighbour.c index e762e88328255..c1e5fda2cf628 100644 --- a/net/core/neighbour.c +++ b/net/core/neighbour.c @@ -736,17 +736,6 @@ static struct pneigh_entry *__pneigh_lookup_1(struct pneigh_entry *n, return NULL; } -struct pneigh_entry *__pneigh_lookup(struct neigh_table *tbl, - struct net *net, const void *pkey, struct net_device *dev) -{ - unsigned int key_len = tbl->key_len; - u32 hash_val = pneigh_hash(pkey, key_len); - - return __pneigh_lookup_1(tbl->phash_buckets[hash_val], - net, pkey, key_len, dev); -} -EXPORT_SYMBOL_GPL(__pneigh_lookup); - struct pneigh_entry *pneigh_lookup(struct neigh_table *tbl, struct net *net, const void *pkey, struct net_device *dev) diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index a3ac26c1df6d8..7d5abb3158ec9 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -768,11 +768,9 @@ static int pndisc_is_router(const void *pkey, struct pneigh_entry *n; int ret = -1; - read_lock_bh(&nd_tbl.lock); - n = __pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); + n = pneigh_lookup(&nd_tbl, dev_net(dev), pkey, dev); if (n) - ret = !!(n->flags & NTF_ROUTER); - read_unlock_bh(&nd_tbl.lock); + ret = !!(READ_ONCE(n->flags) & NTF_ROUTER); return ret; } -- 2.50.0.727.gbf7dc18ff4-goog