Re: mmotm 2010-03-23 - IPv6 warnings...

Re: mmotm 2010-03-23 - IPv6 warnings...

[Andrew Morton]

On Wed, 24 Mar 2010 21:36:41 -0400 Valdis.Kletnieks@vt.edu wrote:

> On Tue, 23 Mar 2010 15:34:59 PDT, akpm@linux-foundation.org said:
> > The mm-of-the-moment snapshot 2010-03-23-15-34 has been uploaded to
> > 
> >    http://userweb.kernel.org/~akpm/mmotm/
> 
> Seen in my dmesg.  It may be relevant that I'm at home, and my IPv6
> prefix arrives via a PPP VPN connection. This happened about 20-25 seconds
> after I launched pppd.

Yes, thanks, I get the same - it doesn't seem to break anything.  It
also happens some time after boot has completed, presumably when I do
something, but I haven't looked into what "something" is.  It's
certainly not as complex as a PPP VPN connection.

The net guys are crunching on it.

mmotm 2010-03-23 - IPv6 warnings...

[Valdis.Kletnieks]

[-- Attachment #1: Type: text/plain, Size: 5066 bytes --]

On Tue, 23 Mar 2010 15:34:59 PDT, akpm@linux-foundation.org said:
> The mm-of-the-moment snapshot 2010-03-23-15-34 has been uploaded to
> 
>    http://userweb.kernel.org/~akpm/mmotm/

Seen in my dmesg.  It may be relevant that I'm at home, and my IPv6
prefix arrives via a PPP VPN connection. This happened about 20-25 seconds
after I launched pppd.

[  175.269411] ------------[ cut here ]------------
[  175.269433] WARNING: at net/ipv6/addrconf.c:544 inet6_ifa_finish_destroy+0x40/0xbb()
[  175.269441] Hardware name: Latitude E6500                  
[  175.269447] Modules linked in: ppp_async sunrpc usb_storage [last unloaded: scsi_wait_scan]
[  175.269473] Pid: 7, comm: ksoftirqd/1 Tainted: G        W   2.6.34-rc2-mmotm0323 #1
[  175.269480] Call Trace:
[  175.269488]  <IRQ>  [<ffffffff8103728a>] warn_slowpath_common+0x80/0x98
[  175.269517]  [<ffffffff810372b7>] warn_slowpath_null+0x15/0x17
[  175.269530]  [<ffffffff814f2093>] inet6_ifa_finish_destroy+0x40/0xbb
[  175.269542]  [<ffffffff814f2122>] in6_ifa_put+0x14/0x16
[  175.269555]  [<ffffffff814f4893>] addrconf_prefix_rcv+0x583/0x786
[  175.269568]  [<ffffffff814f70b3>] ? rt6_get_dflt_router+0xab/0xbb
[  175.269581]  [<ffffffff814fd98c>] ndisc_rcv+0x90f/0xdb4
[  175.269595]  [<ffffffff810852a7>] ? __rcu_read_unlock+0x30c/0x341
[  175.269609]  [<ffffffff81502f6d>] ? debug_lockdep_rcu_enabled+0x33/0x39
[  175.269622]  [<ffffffff815040ae>] icmpv6_rcv+0x59b/0x659
[  175.269634]  [<ffffffff81504c9e>] ? ipv6_chk_mcast_addr+0xaf/0x13d
[  175.269648]  [<ffffffff81063e21>] ? trace_hardirqs_on_caller+0x16/0x13c
[  175.269661]  [<ffffffff8103d5b3>] ? _local_bh_enable_ip+0x15c/0x16e
[  175.269674]  [<ffffffff8103d5ce>] ? local_bh_enable_ip+0x9/0xb
[  175.269689]  [<ffffffff81598c44>] ? _raw_read_unlock_bh+0x39/0x3e
[  175.269702]  [<ffffffff81504d13>] ? ipv6_chk_mcast_addr+0x124/0x13d
[  175.269714]  [<ffffffff814eee7d>] ? ip6_input_finish+0x0/0x343
[  175.269726]  [<ffffffff814ef066>] ip6_input_finish+0x1e9/0x343
[  175.269737]  [<ffffffff814eee7d>] ? ip6_input_finish+0x0/0x343
[  175.269748]  [<ffffffff814ef20c>] NF_HOOK.clone.1+0x4c/0x53
[  175.269759]  [<ffffffff814ef6d6>] ip6_input+0x1c/0x1e
[  175.269769]  [<ffffffff814ef7df>] ip6_mc_input+0x107/0x11c
[  175.269780]  [<ffffffff814eee17>] ? ip6_rcv_finish+0x0/0x26
[  175.269791]  [<ffffffff814eee39>] ip6_rcv_finish+0x22/0x26
[  175.269802]  [<ffffffff814ef20c>] NF_HOOK.clone.1+0x4c/0x53
[  175.269812]  [<ffffffff814ef666>] ipv6_rcv+0x453/0x4a7
[  175.269827]  [<ffffffff8146527e>] __netif_receive_skb+0x2da/0x307
[  175.269839]  [<ffffffff81465348>] process_backlog+0x9d/0xd6
[  175.269851]  [<ffffffff81465631>] net_rx_action+0xf2/0x356
[  175.269863]  [<ffffffff8103dc41>] __do_softirq+0x14a/0x282
[  175.269876]  [<ffffffff8100360c>] call_softirq+0x1c/0x34
[  175.269882]  <EOI>  [<ffffffff81004b58>] ? do_softirq+0x44/0xf0
[  175.269901]  [<ffffffff8103d7dd>] run_ksoftirqd+0xbc/0x1fb
[  175.269912]  [<ffffffff8103d721>] ? run_ksoftirqd+0x0/0x1fb
[  175.269925]  [<ffffffff81052c6b>] kthread+0x7a/0x82
[  175.269937]  [<ffffffff81003514>] kernel_thread_helper+0x4/0x10
[  175.269949]  [<ffffffff81599900>] ? restore_args+0x0/0x30
[  175.269961]  [<ffffffff81052bf1>] ? kthread+0x0/0x82
[  175.269971]  [<ffffffff81003510>] ? kernel_thread_helper+0x0/0x10
[  175.269979] ---[ end trace a7919e7f17c0a727 ]---
[  175.269986] Freeing alive inet6 address ffff880107e1a400
[  176.472172] ------------[ cut here ]------------
[  176.472192] WARNING: at net/ipv6/addrconf.c:544 inet6_ifa_finish_destroy+0x40/0xbb()
[  176.472200] Hardware name: Latitude E6500                  
[  176.472206] Modules linked in: ppp_async sunrpc usb_storage [last unloaded: scsi_wait_scan]
[  176.472232] Pid: 4008, comm: fetchmail Tainted: G        W   2.6.34-rc2-mmotm0323 #1
[  176.472239] Call Trace:
[  176.472256]  [<ffffffff8103728a>] warn_slowpath_common+0x80/0x98
[  176.472269]  [<ffffffff810372b7>] warn_slowpath_null+0x15/0x17
[  176.472280]  [<ffffffff814f2093>] inet6_ifa_finish_destroy+0x40/0xbb
[  176.472291]  [<ffffffff814f2122>] in6_ifa_put+0x14/0x16
[  176.472303]  [<ffffffff814f2a7b>] ipv6_dev_get_saddr+0x2b3/0x2c7
[  176.472316]  [<ffffffff814f8f32>] ? fib6_rule_lookup+0x18/0x1a
[  176.472328]  [<ffffffff814ebb04>] ip6_dst_lookup_tail+0x90/0xc5
[  176.472339]  [<ffffffff814ebc37>] ip6_dst_lookup+0x10/0x12
[  176.472352]  [<ffffffff8150f712>] ip6_datagram_connect+0x334/0x4f6
[  176.472365]  [<ffffffff8103d5b3>] ? _local_bh_enable_ip+0x15c/0x16e
[  176.472378]  [<ffffffff81457d82>] ? release_sock+0xff/0x108
[  176.472390]  [<ffffffff814c0042>] inet_dgram_connect+0x56/0x5d
[  176.472402]  [<ffffffff81455907>] sys_connect+0x75/0x98
[  176.472415]  [<ffffffff810e24b4>] ? path_put+0x1d/0x22
[  176.472429]  [<ffffffff81063e21>] ? trace_hardirqs_on_caller+0x16/0x13c
[  176.472442]  [<ffffffff8107d442>] ? audit_syscall_entry+0xcb/0x19c
[  176.472455]  [<ffffffff810026eb>] system_call_fastpath+0x16/0x1b
[  176.472464] ---[ end trace a7919e7f17c0a728 ]---
[  176.472472] Freeing alive inet6 address ffff880107e1a400


[-- Attachment #2: Type: application/pgp-signature, Size: 227 bytes --]

Re: mmotm 2010-03-23 - IPv6 warnings...

[Valdis.Kletnieks]

[-- Attachment #1: Type: text/plain, Size: 1484 bytes --]

On Wed, 24 Mar 2010 18:42:26 EDT, Andrew Morton said:
> On Wed, 24 Mar 2010 21:36:41 -0400 Valdis.Kletnieks@vt.edu wrote:
> 
> > On Tue, 23 Mar 2010 15:34:59 PDT, akpm@linux-foundation.org said:
> > > The mm-of-the-moment snapshot 2010-03-23-15-34 has been uploaded to
> > > 
> > >    http://userweb.kernel.org/~akpm/mmotm/
> > 
> > Seen in my dmesg.  It may be relevant that I'm at home, and my IPv6
> > prefix arrives via a PPP VPN connection. This happened about 20-25 seconds
> > after I launched pppd.
> 
> Yes, thanks, I get the same - it doesn't seem to break anything.  It
> also happens some time after boot has completed.

Just doing an 'ifup eth0' on a network with IPv6 on it is sufficient.

And it does break stuff:

% ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:24:E8:C6:AD:17  
          inet addr:128.173.14.107  Bcast:128.173.15.255  Mask:255.255.252.0
          inet6 addr: fe80::224:e8ff:fec6:ad17/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

With 2.6.34-rc1-mmotm0309, I see:

% ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:24:E8:C6:AD:17  
          inet addr:128.173.14.107  Bcast:128.173.15.255  Mask:255.255.252.0
          inet6 addr: 2001:468:c80:2103:224:e8ff:fec6:ad17/64 Scope:Global
          inet6 addr: fe80::224:e8ff:fec6:ad17/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1

Something ate my IPv6 address.  We run a lot of IPv6 in production, so stuff
is acting wonky.



[-- Attachment #2: Type: application/pgp-signature, Size: 227 bytes --]

Re: mmotm 2010-03-23 - IPv6 warnings...

[David Miller]

From: Valdis.Kletnieks@vt.edu
Date: Thu, 25 Mar 2010 12:45:30 -0400

> On Wed, 24 Mar 2010 18:42:26 EDT, Andrew Morton said:
>> On Wed, 24 Mar 2010 21:36:41 -0400 Valdis.Kletnieks@vt.edu wrote:
>> 
>> > On Tue, 23 Mar 2010 15:34:59 PDT, akpm@linux-foundation.org said:
>> > > The mm-of-the-moment snapshot 2010-03-23-15-34 has been uploaded to
>> > > 
>> > >    http://userweb.kernel.org/~akpm/mmotm/
>> > 
>> > Seen in my dmesg.  It may be relevant that I'm at home, and my IPv6
>> > prefix arrives via a PPP VPN connection. This happened about 20-25 seconds
>> > after I launched pppd.
>> 
>> Yes, thanks, I get the same - it doesn't seem to break anything.  It
>> also happens some time after boot has completed.
> 
> Just doing an 'ifup eth0' on a network with IPv6 on it is sufficient.

I'm going to look into this more deeply tonight.

Re: mmotm 2010-03-23 - IPv6 warnings...

[David Miller]

From: Valdis.Kletnieks@vt.edu
Date: Thu, 25 Mar 2010 12:45:30 -0400

> On Wed, 24 Mar 2010 18:42:26 EDT, Andrew Morton said:
>> On Wed, 24 Mar 2010 21:36:41 -0400 Valdis.Kletnieks@vt.edu wrote:
>> 
>> > On Tue, 23 Mar 2010 15:34:59 PDT, akpm@linux-foundation.org said:
>> > > The mm-of-the-moment snapshot 2010-03-23-15-34 has been uploaded to
>> > > 
>> > >    http://userweb.kernel.org/~akpm/mmotm/
>> > 
>> > Seen in my dmesg.  It may be relevant that I'm at home, and my IPv6
>> > prefix arrives via a PPP VPN connection. This happened about 20-25 seconds
>> > after I launched pppd.
>> 
>> Yes, thanks, I get the same - it doesn't seem to break anything.  It
>> also happens some time after boot has completed.
> 
> Just doing an 'ifup eth0' on a network with IPv6 on it is sufficient.

I just checked the following into net-next-2.6 which should at least
kill that dmesg log.

If you still are missing your ipv6 addresses, let me know how
they normally get added, maybe that's enough to let me figure
it out.

Thanks.

ipv6: Fix result generation in ipv6_get_ifaddr().

Finishing naturally from hlist_for_each_entry(x, ...) does not result
in 'x' being NULL.

Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv6/addrconf.c |    7 ++++---
 1 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 9995683..21b4c9e 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1341,9 +1341,9 @@ EXPORT_SYMBOL(ipv6_chk_prefix);
 struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *addr,
 				     struct net_device *dev, int strict)
 {
-	struct inet6_ifaddr *ifp = NULL;
-	struct hlist_node *node;
+	struct inet6_ifaddr *ifp, *result = NULL;
 	unsigned int hash = ipv6_addr_hash(addr);
+	struct hlist_node *node;
 
 	rcu_read_lock_bh();
 	hlist_for_each_entry_rcu(ifp, node, &inet6_addr_lst[hash], addr_lst) {
@@ -1352,6 +1352,7 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add
 		if (ipv6_addr_equal(&ifp->addr, addr)) {
 			if (dev == NULL || ifp->idev->dev == dev ||
 			    !(ifp->scope&(IFA_LINK|IFA_HOST) || strict)) {
+				result = ifp;
 				in6_ifa_hold(ifp);
 				break;
 			}
@@ -1359,7 +1360,7 @@ struct inet6_ifaddr *ipv6_get_ifaddr(struct net *net, const struct in6_addr *add
 	}
 	rcu_read_unlock_bh();
 
-	return ifp;
+	return result;
 }
 
 /* Gets referenced address, destroys ifaddr */
-- 
1.7.0.3

Re: mmotm 2010-03-23 - IPv6 warnings...

[Valdis.Kletnieks]

[-- Attachment #1: Type: text/plain, Size: 1777 bytes --]

On Thu, 25 Mar 2010 21:40:50 PDT, David Miller said:
> From: Valdis.Kletnieks@vt.edu
> Date: Thu, 25 Mar 2010 12:45:30 -0400
> 
> > On Wed, 24 Mar 2010 18:42:26 EDT, Andrew Morton said:
> >> On Wed, 24 Mar 2010 21:36:41 -0400 Valdis.Kletnieks@vt.edu wrote:
> >> 
> >> > On Tue, 23 Mar 2010 15:34:59 PDT, akpm@linux-foundation.org said:
> >> > > The mm-of-the-moment snapshot 2010-03-23-15-34 has been uploaded to
> >> > > 
> >> > >    http://userweb.kernel.org/~akpm/mmotm/
> >> > 
> >> > Seen in my dmesg.  It may be relevant that I'm at home, and my IPv6
> >> > prefix arrives via a PPP VPN connection. This happened about 20-25 secon
ds
> >> > after I launched pppd.
> >> 
> >> Yes, thanks, I get the same - it doesn't seem to break anything.  It
> >> also happens some time after boot has completed.
> > 
> > Just doing an 'ifup eth0' on a network with IPv6 on it is sufficient.
> 
> I just checked the following into net-next-2.6 which should at least
> kill that dmesg log.
> 
> If you still are missing your ipv6 addresses, let me know how
> they normally get added, maybe that's enough to let me figure
> it out.

Confirming looks like a good fix - no cruft in dmesg, and I have ipv6 addresses:

%  ifconfig ppp0
ppp0      Link encap:Point-to-Point Protocol  
          inet addr:128.173.34.103  P-t-P:128.173.32.21  Mask:255.255.255.255
          inet6 addr: 2001:468:c80:3b04:105d:a65c:28c4:75d1/64 Scope:Global
          inet6 addr: fe80::105d:a65c:28c4:75d1/10 Scope:Link
          UP POINTOPOINT RUNNING NOARP MULTICAST  MTU:1460  Metric:1
          RX packets:79 errors:0 dropped:0 overruns:0 frame:0
          TX packets:85 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:3 
          RX bytes:30943 (30.2 KiB)  TX bytes:6746 (6.5 KiB)

[-- Attachment #2: Type: application/pgp-signature, Size: 227 bytes --]

Re: mmotm 2010-03-23 - IPv6 warnings...

[David Miller]

From: Valdis.Kletnieks@vt.edu
Date: Fri, 26 Mar 2010 02:18:22 -0400

> Confirming looks like a good fix - no cruft in dmesg, and I have ipv6 addresses:

Great, thanks for testing.

Andrew your box should be good now too.

Re: mmotm 2010-03-23 - IPv6 warnings...

[Stephen Hemminger]

On Thu, 25 Mar 2010 23:23:49 -0700 (PDT)
David Miller <davem@davemloft.net> wrote:

> From: Valdis.Kletnieks@vt.edu
> Date: Fri, 26 Mar 2010 02:18:22 -0400
> 
> > Confirming looks like a good fix - no cruft in dmesg, and I have ipv6 addresses:
> 
> Great, thanks for testing.
> 
> Andrew your box should be good now too.

Thanks for fixing this.

--