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

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

[Jongman Heo]

------- Original Message -------
Sender : Jongman Heo <jongman.heo@samsung.com>
Date : 2013-11-29 11:08 (GMT+09:00)
Title : Re: [PATCH v2] inet: fix possible seqlock deadlocks
>
>
>------ Original Message -------
>Sender : Eric Dumazet
>Date : 2013-11-29 02:51 (GMT+09:00)
>Title : [PATCH v2] inet: fix possible seqlock deadlocks
>> 
>> 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.
>

Hi, Eric,

It has survived about 9 hours, looks fine. Thanks~.

Tested-by: Jongman Heo <jongman.heo@samsung.com>