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author | Taehee Yoo <ap420073@gmail.com> | 2017-07-19 14:27:33 +0900 |
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committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-07-24 13:24:46 +0200 |
commit | 0b35f6031a00329800bacc04085188c300c3a4d8 (patch) | |
tree | b4e34d6ab10b8b065583f1ce7c75ec05dea5a107 /net/netfilter/xt_hashlimit.c | |
parent | 9f08ea848117ab521efcfd3e004d8e1a0edc640c (diff) | |
download | op-kernel-dev-0b35f6031a00329800bacc04085188c300c3a4d8.zip op-kernel-dev-0b35f6031a00329800bacc04085188c300c3a4d8.tar.gz |
netfilter: Remove duplicated rcu_read_lock.
This patch removes duplicate rcu_read_lock().
1. IPVS part:
According to Julian Anastasov's mention, contexts of ipvs are described
at: http://marc.info/?l=netfilter-devel&m=149562884514072&w=2, in summary:
- packet RX/TX: does not need locks because packets come from hooks.
- sync msg RX: backup server uses RCU locks while registering new
connections.
- ip_vs_ctl.c: configuration get/set, RCU locks needed.
- xt_ipvs.c: It is a netfilter match, running from hook context.
As result, rcu_read_lock and rcu_read_unlock can be removed from:
- ip_vs_core.c: all
- ip_vs_ctl.c:
- only from ip_vs_has_real_service
- ip_vs_ftp.c: all
- ip_vs_proto_sctp.c: all
- ip_vs_proto_tcp.c: all
- ip_vs_proto_udp.c: all
- ip_vs_xmit.c: all (contains only packet processing)
2. Netfilter part:
There are three types of functions that are guaranteed the rcu_read_lock().
First, as result, functions are only called by nf_hook():
- nf_conntrack_broadcast_help(), pptp_expectfn(), set_expected_rtp_rtcp().
- tcpmss_reverse_mtu(), tproxy_laddr4(), tproxy_laddr6().
- match_lookup_rt6(), check_hlist(), hashlimit_mt_common().
- xt_osf_match_packet().
Second, functions that caller already held the rcu_read_lock().
- destroy_conntrack(), ctnetlink_conntrack_event().
- ctnl_timeout_find_get(), nfqnl_nf_hook_drop().
Third, functions that are mixed with type1 and type2.
These functions are called by nf_hook() also these are called by
ordinary functions that already held the rcu_read_lock():
- __ctnetlink_glue_build(), ctnetlink_expect_event().
- ctnetlink_proto_size().
Applied files are below:
- nf_conntrack_broadcast.c, nf_conntrack_core.c, nf_conntrack_netlink.c.
- nf_conntrack_pptp.c, nf_conntrack_sip.c, nfnetlink_cttimeout.c.
- nfnetlink_queue.c, xt_TCPMSS.c, xt_TPROXY.c, xt_addrtype.c.
- xt_connlimit.c, xt_hashlimit.c, xt_osf.c
Detailed calltrace can be found at:
http://marc.info/?l=netfilter-devel&m=149667610710350&w=2
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/xt_hashlimit.c')
-rw-r--r-- | net/netfilter/xt_hashlimit.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c index 762e187..ffdb611 100644 --- a/net/netfilter/xt_hashlimit.c +++ b/net/netfilter/xt_hashlimit.c @@ -659,12 +659,12 @@ hashlimit_mt_common(const struct sk_buff *skb, struct xt_action_param *par, if (hashlimit_init_dst(hinfo, &dst, skb, par->thoff) < 0) goto hotdrop; - rcu_read_lock_bh(); + local_bh_disable(); dh = dsthash_find(hinfo, &dst); if (dh == NULL) { dh = dsthash_alloc_init(hinfo, &dst, &race); if (dh == NULL) { - rcu_read_unlock_bh(); + local_bh_enable(); goto hotdrop; } else if (race) { /* Already got an entry, update expiration timeout */ @@ -689,12 +689,12 @@ hashlimit_mt_common(const struct sk_buff *skb, struct xt_action_param *par, /* below the limit */ dh->rateinfo.credit -= cost; spin_unlock(&dh->lock); - rcu_read_unlock_bh(); + local_bh_enable(); return !(cfg->mode & XT_HASHLIMIT_INVERT); } spin_unlock(&dh->lock); - rcu_read_unlock_bh(); + local_bh_enable(); /* default match is underlimit - so over the limit, we need to invert */ return cfg->mode & XT_HASHLIMIT_INVERT; |