From 356e2adb3f3b9fe4427224eec2f8819a3078665f Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Tue, 28 Mar 2023 18:44:15 +0200 Subject: [PATCH] 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: Florian Westphal --- net/netfilter/nfnetlink_log.c | 36 +++++++++++++++++++++++------------- 1 file changed, 23 insertions(+), 13 deletions(-) diff --git a/net/netfilter/nfnetlink_log.c b/net/netfilter/nfnetlink_log.c index d97eb28..e57eb16 100644 --- a/net/netfilter/nfnetlink_log.c +++ b/net/netfilter/nfnetlink_log.c @@ -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) -- 2.7.4