75 lines
2.5 KiB
Diff
75 lines
2.5 KiB
Diff
From 5e6729ef1e7a1e3136965debb2f302c6b5570c45 Mon Sep 17 00:00:00 2001
|
|
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
Date: Mon, 21 Aug 2017 15:09:13 +0200
|
|
Subject: [PATCH 335/365] net: take the tcp_sk_lock lock with BH disabled
|
|
|
|
Lockdep may complain about an unsafe locking scenario:
|
|
| CPU0 CPU1
|
|
| ---- ----
|
|
| lock((tcp_sk_lock).lock);
|
|
| lock(&per_cpu(local_softirq_locks[i], __cpu).lock);
|
|
| lock((tcp_sk_lock).lock);
|
|
| lock(&per_cpu(local_softirq_locks[i], __cpu).lock);
|
|
|
|
in the call paths:
|
|
do_current_softirqs -> tcp_v4_send_ack()
|
|
vs
|
|
tcp_v4_send_reset -> do_current_softirqs().
|
|
|
|
This should not happen since local_softirq_locks is per CPU. Reversing
|
|
the order makes lockdep happy.
|
|
|
|
Change-Id: I4b773f3dd84f8bda96067e319cfd27469f3c5dfe
|
|
Reported-by: Jacek Konieczny <jajcus@jajcus.net>
|
|
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
|
|
---
|
|
net/ipv4/tcp_ipv4.c | 8 ++++----
|
|
1 file changed, 4 insertions(+), 4 deletions(-)
|
|
|
|
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
|
|
index 89d986d0d77d..736bd9f45c7f 100644
|
|
--- a/net/ipv4/tcp_ipv4.c
|
|
+++ b/net/ipv4/tcp_ipv4.c
|
|
@@ -705,8 +705,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
|
|
arg.tos = ip_hdr(skb)->tos;
|
|
arg.uid = sock_net_uid(net, sk && sk_fullsock(sk) ? sk : NULL);
|
|
|
|
- local_lock(tcp_sk_lock);
|
|
local_bh_disable();
|
|
+ local_lock(tcp_sk_lock);
|
|
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
|
|
skb, &TCP_SKB_CB(skb)->header.h4.opt,
|
|
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
|
|
@@ -714,8 +714,8 @@ static void tcp_v4_send_reset(const struct sock *sk, struct sk_buff *skb)
|
|
|
|
__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
|
|
__TCP_INC_STATS(net, TCP_MIB_OUTRSTS);
|
|
- local_bh_enable();
|
|
local_unlock(tcp_sk_lock);
|
|
+ local_bh_enable();
|
|
|
|
#ifdef CONFIG_TCP_MD5SIG
|
|
out:
|
|
@@ -793,16 +793,16 @@ static void tcp_v4_send_ack(const struct sock *sk,
|
|
arg.bound_dev_if = oif;
|
|
arg.tos = tos;
|
|
arg.uid = sock_net_uid(net, sk_fullsock(sk) ? sk : NULL);
|
|
- local_lock(tcp_sk_lock);
|
|
local_bh_disable();
|
|
+ local_lock(tcp_sk_lock);
|
|
ip_send_unicast_reply(*this_cpu_ptr(net->ipv4.tcp_sk),
|
|
skb, &TCP_SKB_CB(skb)->header.h4.opt,
|
|
ip_hdr(skb)->saddr, ip_hdr(skb)->daddr,
|
|
&arg, arg.iov[0].iov_len);
|
|
|
|
__TCP_INC_STATS(net, TCP_MIB_OUTSEGS);
|
|
- local_bh_enable();
|
|
local_unlock(tcp_sk_lock);
|
|
+ local_bh_enable();
|
|
}
|
|
|
|
static void tcp_v4_timewait_ack(struct sock *sk, struct sk_buff *skb)
|
|
--
|
|
2.28.0
|
|
|