Commit 356e2adb authored by Florian Westphal's avatar Florian Westphal
Browse files

netfilter: nfnetlink_log: remove rcu_bh usage 



structure is free'd via call_rcu, so its safe to use rcu_read_lock only.

While at it, skip rcu_read_lock for lookup from packet path, its always
called with rcu held.

Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
parent da617cd8

net/netfilter/nfnetlink_log.c

+23 −13
Original line number Diff line number Diff line
@@ -103,9 +103,9 @@ static inline u_int8_t instance_hashfn(u_int16_t group_num) 
}



static struct nfulnl_instance *

__instance_lookup(struct nfnl_log_net *log, u_int16_t group_num)

__instance_lookup(const struct nfnl_log_net *log, u16 group_num)

{

	struct hlist_head *head;

	const struct hlist_head *head;

	struct nfulnl_instance *inst;



	head = &log->instance_table[instance_hashfn(group_num)];
@@ -123,15 +123,25 @@ instance_get(struct nfulnl_instance *inst) 
}



static struct nfulnl_instance *

instance_lookup_get(struct nfnl_log_net *log, u_int16_t group_num)

instance_lookup_get_rcu(const struct nfnl_log_net *log, u16 group_num)

{

	struct nfulnl_instance *inst;



	rcu_read_lock_bh();

	inst = __instance_lookup(log, group_num);

	if (inst && !refcount_inc_not_zero(&inst->use))

		inst = NULL;

	rcu_read_unlock_bh();



	return inst;

}



static struct nfulnl_instance *

instance_lookup_get(const struct nfnl_log_net *log, u16 group_num)

{

	struct nfulnl_instance *inst;



	rcu_read_lock();

	inst = instance_lookup_get_rcu(log, group_num);

	rcu_read_unlock();



	return inst;

}
@@ -698,7 +708,7 @@ nfulnl_log_packet(struct net *net, 
	else

		li = &default_loginfo;



	inst = instance_lookup_get(log, li->u.ulog.group);

	inst = instance_lookup_get_rcu(log, li->u.ulog.group);

	if (!inst)

		return;
@@ -1030,7 +1040,7 @@ static struct hlist_node *get_first(struct net *net, struct iter_state *st) 
		struct hlist_head *head = &log->instance_table[st->bucket];



		if (!hlist_empty(head))

			return rcu_dereference_bh(hlist_first_rcu(head));

			return rcu_dereference(hlist_first_rcu(head));

	}

	return NULL;

}
@@ -1038,7 +1048,7 @@ static struct hlist_node *get_first(struct net *net, struct iter_state *st) 
static struct hlist_node *get_next(struct net *net, struct iter_state *st,

				   struct hlist_node *h)

{

	h = rcu_dereference_bh(hlist_next_rcu(h));

	h = rcu_dereference(hlist_next_rcu(h));

	while (!h) {

		struct nfnl_log_net *log;

		struct hlist_head *head;
@@ -1048,7 +1058,7 @@ static struct hlist_node *get_next(struct net *net, struct iter_state *st, 


		log = nfnl_log_pernet(net);

		head = &log->instance_table[st->bucket];

		h = rcu_dereference_bh(hlist_first_rcu(head));

		h = rcu_dereference(hlist_first_rcu(head));

	}

	return h;

}
@@ -1066,9 +1076,9 @@ static struct hlist_node *get_idx(struct net *net, struct iter_state *st, 
}



static void *seq_start(struct seq_file *s, loff_t *pos)

	__acquires(rcu_bh)

	__acquires(rcu)

{

	rcu_read_lock_bh();

	rcu_read_lock();

	return get_idx(seq_file_net(s), s->private, *pos);

}
@@ -1079,9 +1089,9 @@ static void *seq_next(struct seq_file *s, void *v, loff_t *pos) 
}



static void seq_stop(struct seq_file *s, void *v)

	__releases(rcu_bh)

	__releases(rcu)

{

	rcu_read_unlock_bh();

	rcu_read_unlock();

}



static int seq_show(struct seq_file *s, void *v)