Messages in this thread |  | | Date | Thu, 28 Nov 2013 22:27:00 +0100 | From | Hannes Frederic Sowa <> | Subject | Re: [PATCH] inet: further fixes of possible seqlock deadlocks |
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On Thu, Nov 28, 2013 at 01:01:42PM -0800, Eric Dumazet wrote: > On Thu, 2013-11-28 at 20:22 +0100, Hannes Frederic Sowa wrote: > > This fixes more incorrect uses of *_STATS_BH in process context. > > > > Cc: Eric Dumazet <edumazet@google.com> > > Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> > > --- > > net/ipv4/udp.c | 8 ++++---- > > net/ipv6/ip6_output.c | 8 ++++---- > > net/ipv6/ping.c | 4 ++-- > > 3 files changed, 10 insertions(+), 10 deletions(-) > > > > diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c > > index 44e3884..f5cc018 100644 > > --- a/net/ipv4/udp.c > > +++ b/net/ipv4/udp.c > > @@ -1160,10 +1160,10 @@ static unsigned int first_packet_length(struct sock *sk) > > spin_lock_bh(&rcvq->lock); > > Here we block BH, because of spin_lock_bh() > > > while ((skb = skb_peek(rcvq)) != NULL && > > udp_lib_checksum_complete(skb)) { > > - UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_CSUMERRORS, > > - IS_UDPLITE(sk)); > > - UDP_INC_STATS_BH(sock_net(sk), UDP_MIB_INERRORS, > > - IS_UDPLITE(sk)); > > So this is the right thing, this change is not needed.
Oh yes, I was mechanically going through the a grep of _BH\( in ipv4 and ipv6 and missed that.
> > + UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_CSUMERRORS, > > + IS_UDPLITE(sk)); > > + UDP_INC_STATS_USER(sock_net(sk), UDP_MIB_INERRORS, > > + IS_UDPLITE(sk)); > > atomic_inc(&sk->sk_drops); > > __skb_unlink(skb, rcvq); > > __skb_queue_tail(&list_kill, skb); > > diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c > > index 59df872..e05cf0a 100644 > > --- a/net/ipv6/ip6_output.c > > +++ b/j > > @@ -116,8 +116,8 @@ static int ip6_finish_output2(struct sk_buff *skb) > > } > > rcu_read_unlock_bh(); > > > > - IP6_INC_STATS_BH(dev_net(dst->dev), > > - ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); > > + IP6_INC_STATS(dev_net(dst->dev), > > + ip6_dst_idev(dst), IPSTATS_MIB_OUTNOROUTES); > > This is ipv6, not inet changes ;)
I always considered inet both for ipv4+ipv6, otherwise I would use ipv4 or ipv6 as patch prefix.
> > > kfree_skb(skb); > > return -EINVAL; > > } > > @@ -1524,8 +1524,8 @@ int ip6_push_pending_frames(struct sock *sk) > > if (proto == IPPROTO_ICMPV6) { > > struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb)); > > > > - ICMP6MSGOUT_INC_STATS_BH(net, idev, icmp6_hdr(skb)->icmp6_type); > > - ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS); > > + ICMP6MSGOUT_INC_STATS(net, idev, icmp6_hdr(skb)->icmp6_type); > > + ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS); > > I am not sure we use a seqlock for ICMP stats. > > seqlocks were used for 64bit IP stats
True, atomic longs get used here in both cases.
Will update the patch. Thanks, Eric!
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