[PATCH 3.8 019/133] ipv6: some ipv6 statistic counters failed to disable bh

From: Kamal Mostafa
Date: Tue Apr 22 2014 - 17:41:13 EST


3.8.13.22 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>

[ Upstream commit 43a43b6040165f7b40b5b489fe61a4cb7f8c4980 ]

After commit c15b1ccadb323ea ("ipv6: move DAD and addrconf_verify
processing to workqueue") some counters are now updated in process context
and thus need to disable bh before doing so, otherwise deadlocks can
happen on 32-bit archs. Fabio Estevam noticed this while while mounting
a NFS volume on an ARM board.

As a compensation for missing this I looked after the other *_STATS_BH
and found three other calls which need updating:

1) icmp6_send: ip6_fragment -> icmpv6_send -> icmp6_send (error handling)
2) ip6_push_pending_frames: rawv6_sendmsg -> rawv6_push_pending_frames -> ...
(only in case of icmp protocol with raw sockets in error handling)
3) ping6_v6_sendmsg (error handling)

Fixes: c15b1ccadb323ea ("ipv6: move DAD and addrconf_verify processing to workqueue")
Reported-by: Fabio Estevam <festevam@xxxxxxxxx>
Tested-by: Fabio Estevam <fabio.estevam@xxxxxxxxxxxxx>
Cc: Eric Dumazet <eric.dumazet@xxxxxxxxx>
Signed-off-by: Hannes Frederic Sowa <hannes@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
net/ipv6/icmp.c | 2 +-
net/ipv6/ip6_output.c | 4 ++--
net/ipv6/mcast.c | 11 ++++++-----
3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c
index 7463f05..9b3e4cb 100644
--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -517,7 +517,7 @@ void icmpv6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info)
np->tclass, NULL, &fl6, (struct rt6_info *)dst,
MSG_DONTWAIT, np->dontfrag);
if (err) {
- ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTERRORS);
+ ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTERRORS);
ip6_flush_pending_frames(sk);
} else {
err = icmpv6_push_pending_frames(sk, &fl6, &tmp_hdr,
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c
index 84d7632..64809bd 100644
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1577,8 +1577,8 @@ 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);
}

err = ip6_local_out(skb);
diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index ac1b533..1f93b61 100644
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1436,11 +1436,12 @@ static void mld_sendpack(struct sk_buff *skb)
dst_output);
out:
if (!err) {
- ICMP6MSGOUT_INC_STATS_BH(net, idev, ICMPV6_MLD2_REPORT);
- ICMP6_INC_STATS_BH(net, idev, ICMP6_MIB_OUTMSGS);
- IP6_UPD_PO_STATS_BH(net, idev, IPSTATS_MIB_OUTMCAST, payload_len);
- } else
- IP6_INC_STATS_BH(net, idev, IPSTATS_MIB_OUTDISCARDS);
+ ICMP6MSGOUT_INC_STATS(net, idev, ICMPV6_MLD2_REPORT);
+ ICMP6_INC_STATS(net, idev, ICMP6_MIB_OUTMSGS);
+ IP6_UPD_PO_STATS(net, idev, IPSTATS_MIB_OUTMCAST, payload_len);
+ } else {
+ IP6_INC_STATS(net, idev, IPSTATS_MIB_OUTDISCARDS);
+ }

rcu_read_unlock();
return;
--
1.9.1

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