[PATCH 3.4 12/27] ipv6: some ipv6 statistic counters failed to disable bh

Greg Kroah-Hartman
2014-04-24T21:58:36Z

From: Hannes Frederic Sowa <hannes@stressinduktion.org>

[ 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@gmail.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
net/ipv6/icmp.c | 2 +-
net/ipv6/ip6_output.c | 4 ++--
net/ipv6/mcast.c | 11 ++++++-----
3 files changed, 9 insertions(+), 8 deletions(-)

--- a/net/ipv6/icmp.c
+++ b/net/ipv6/icmp.c
@@ -501,7 +501,7 @@ void icmpv6_send(struct sk_buff *skb, u8
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,
--- a/net/ipv6/ip6_output.c
+++ b/net/ipv6/ip6_output.c
@@ -1661,8 +1661,8 @@ int ip6_push_pending_frames(struct sock
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);
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -1430,11 +1430,12 @@ static void mld_sendpack(struct sk_buff
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;