diff options
| author | Taehee Yoo <ap420073@gmail.com> | 2017-07-19 14:27:33 +0900 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2017-07-24 13:24:46 +0200 |
| commit | 0b35f6031a00329800bacc04085188c300c3a4d8 (patch) | |
| tree | b4e34d6ab10b8b065583f1ce7c75ec05dea5a107 /net/netfilter/xt_osf.c | |
| parent | 9f08ea848117ab521efcfd3e004d8e1a0edc640c (diff) | |
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_osf.c')
| -rw-r--r-- | net/netfilter/xt_osf.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/net/netfilter/xt_osf.c b/net/netfilter/xt_osf.c index 71cfa9551d08..36e14b1f061d 100644 --- a/net/netfilter/xt_osf.c +++ b/net/netfilter/xt_osf.c @@ -226,7 +226,6 @@ xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p) sizeof(struct tcphdr), optsize, opts); } - rcu_read_lock(); list_for_each_entry_rcu(kf, &xt_osf_fingers[df], finger_entry) { int foptsize, optnum; @@ -340,7 +339,6 @@ xt_osf_match_packet(const struct sk_buff *skb, struct xt_action_param *p) info->loglevel == XT_OSF_LOGLEVEL_FIRST) break; } - rcu_read_unlock(); if (!fcount && (info->flags & XT_OSF_LOG)) nf_log_packet(net, xt_family(p), xt_hooknum(p), skb, xt_in(p), |