Re: [PATCH v2] inet: fix possible seqlock deadlocks

From: Jongman Heo <hidden>
Date: 2013-11-29 02:08:34
Also in: lkml

 
------ Original Message -------
Sender : Eric Dumazet[off-list ref]
Date : 2013-11-29 02:51 (GMT+09:00)
Title : [PATCH v2] inet: fix possible seqlock deadlocks
quoted hunk
From: Eric Dumazet 

In commit c9e9042994d3 ("ipv4: fix possible seqlock deadlock") I left
another places where IP_INC_STATS_BH() were improperly used.

udp_sendmsg(), ping_v4_sendmsg() and tcp_v4_connect() are called from
process context, not from softirq context.

This was detected by lockdep seqlock support.

Reported-by: jongman heo 
Fixes: 584bdf8cbdf6 ("[IPV4]: Fix "ipOutNoRoutes" counter error for TCP and UDP")
Fixes: c319b4d76b9e ("net: ipv4: add IPPROTO_ICMP socket kind")
Signed-off-by: Eric Dumazet 
Cc: Hannes Frederic Sowa 
---
net/ipv4/ping.c     |    2 +-
net/ipv4/tcp_ipv4.c |    2 +-
net/ipv4/udp.c      |    2 +-
3 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 840cf1b9e6ee..242e7f4ed6f4 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -772,7 +772,7 @@ int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
err = PTR_ERR(rt);
rt = NULL;
if (err == -ENETUNREACH)
- IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
+ IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
goto out;
}
diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c
index 59a6f8b90cd9..067213924751 100644
--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -177,7 +177,7 @@ int tcp_v4_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
if (IS_ERR(rt)) {
err = PTR_ERR(rt);
if (err == -ENETUNREACH)
- IP_INC_STATS_BH(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
+ IP_INC_STATS(sock_net(sk), IPSTATS_MIB_OUTNOROUTES);
return err;
}
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 44dfaa09b584..44e3884f9e4c 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -999,7 +999,7 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
err = PTR_ERR(rt);
rt = NULL;
if (err == -ENETUNREACH)
- IP_INC_STATS_BH(net, IPSTATS_MIB_OUTNOROUTES);
+ IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES);
goto out;
}
Hi, Eric,

I've applied your patch, and will let you know the result, after a full day or half day test.
Usually the issue happens within 10 minutes after boot, but to be sure...

Regards,
Jongman Heo.
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