[PATCH] net: TCP early demux cleanup
flat view
STALE5208d
From: Eric Dumazet <hidden>
Date: 2012-07-30 07:06:18
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
From: Eric Dumazet <redacted> early_demux() handlers should be called in RCU context, and as we use skb_dst_set_noref(skb, dst), caller must not exit from RCU context before dst use (skb_dst(skb)) or release (skb_drop(dst)) Therefore, rcu_read_lock()/rcu_read_unlock() pairs around ->early_demux() are confusing and not needed : Protocol handlers are already in an RCU read lock section. (__netif_receive_skb() does the rcu_read_lock() ) Signed-off-by: Eric Dumazet <redacted> --- net/ipv4/ip_input.c | 2 -- net/ipv6/ip6_input.c | 2 -- 2 files changed, 4 deletions(-)
diff --git a/net/ipv4/ip_input.c b/net/ipv4/ip_input.c
index 981ff1e..f1395a6 100644
--- a/net/ipv4/ip_input.c
+++ b/net/ipv4/ip_input.c@@ -325,14 +325,12 @@ static int ip_rcv_finish(struct sk_buff *skb) const struct net_protocol *ipprot; int protocol = iph->protocol; - rcu_read_lock(); ipprot = rcu_dereference(inet_protos[protocol]); if (ipprot && ipprot->early_demux) { ipprot->early_demux(skb); /* must reload iph, skb->head might have changed */ iph = ip_hdr(skb); } - rcu_read_unlock(); } /*
diff --git a/net/ipv6/ip6_input.c b/net/ipv6/ip6_input.c
index 47975e3..a52d864 100644
--- a/net/ipv6/ip6_input.c
+++ b/net/ipv6/ip6_input.c@@ -52,11 +52,9 @@ int ip6_rcv_finish(struct sk_buff *skb) if (sysctl_ip_early_demux && !skb_dst(skb)) { const struct inet6_protocol *ipprot; - rcu_read_lock(); ipprot = rcu_dereference(inet6_protos[ipv6_hdr(skb)->nexthdr]); if (ipprot && ipprot->early_demux) ipprot->early_demux(skb); - rcu_read_unlock(); } if (!skb_dst(skb)) ip6_route_input(skb);