net: Fix ipv6 neighbour unregister_sysctl_table warning

Submitted by Eric W. Biederman on Jan. 30, 2011, 8:15 p.m.

Details

Message ID m11v3utagp.fsf@fess.ebiederm.org
State Accepted
Delegated to: David Miller
Headers show

Commit Message

Eric W. Biederman Jan. 30, 2011, 8:15 p.m.
In my testing of 2.6.37 I was occassionally getting a warning about
sysctl table entries being unregistered in the wrong order.  Digging
in it turns out this dates back to the last great sysctl reorg done
where Al Viro introduced the requirement that sysctl directories
needed to be created before and destroyed after the files in them.

It turns out that in that great reorg /proc/sys/net/ipv6/neigh was
overlooked.  So this patch fixes that oversight and makes an annoying
warning message go away.

>------------[ cut here ]------------
>WARNING: at kernel/sysctl.c:1992 unregister_sysctl_table+0x134/0x164()
>Pid: 23951, comm: kworker/u:3 Not tainted 2.6.37-350888.2010AroraKernelBeta.fc14.x86_64 #1
>Call Trace:
> [<ffffffff8103e034>] warn_slowpath_common+0x80/0x98
> [<ffffffff8103e061>] warn_slowpath_null+0x15/0x17
> [<ffffffff810452f8>] unregister_sysctl_table+0x134/0x164
> [<ffffffff810e7834>] ? kfree+0xc4/0xd1
> [<ffffffff813439b2>] neigh_sysctl_unregister+0x22/0x3a
> [<ffffffffa02cd14e>] addrconf_ifdown+0x33f/0x37b [ipv6]
> [<ffffffff81331ec2>] ? skb_dequeue+0x5f/0x6b
> [<ffffffffa02ce4a5>] addrconf_notify+0x69b/0x75c [ipv6]
> [<ffffffffa02eb953>] ? ip6mr_device_event+0x98/0xa9 [ipv6]
> [<ffffffff813d2413>] notifier_call_chain+0x32/0x5e
> [<ffffffff8105bdea>] raw_notifier_call_chain+0xf/0x11
> [<ffffffff8133cdac>] call_netdevice_notifiers+0x45/0x4a
> [<ffffffff8133d2b0>] rollback_registered_many+0x118/0x201
> [<ffffffff8133d3af>] unregister_netdevice_many+0x16/0x6d
> [<ffffffff8133d571>] default_device_exit_batch+0xa4/0xb8
> [<ffffffff81337c42>] ? cleanup_net+0x0/0x194
> [<ffffffff81337a2a>] ops_exit_list+0x4e/0x56
> [<ffffffff81337d36>] cleanup_net+0xf4/0x194
> [<ffffffff81053318>] process_one_work+0x187/0x280
> [<ffffffff8105441b>] worker_thread+0xff/0x19f
> [<ffffffff8105431c>] ? worker_thread+0x0/0x19f
> [<ffffffff8105776d>] kthread+0x7d/0x85
> [<ffffffff81003824>] kernel_thread_helper+0x4/0x10
> [<ffffffff810576f0>] ? kthread+0x0/0x85
> [<ffffffff81003820>] ? kernel_thread_helper+0x0/0x10
>---[ end trace 8a7e9310b35e9486 ]---

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
---
 net/ipv6/sysctl_net_ipv6.c |    9 ++++++++-
 1 files changed, 8 insertions(+), 1 deletions(-)

Comments

David Miller Feb. 1, 2011, 4:55 a.m.
From: ebiederm@xmission.com (Eric W. Biederman)
Date: Sun, 30 Jan 2011 12:15:02 -0800

> 
> In my testing of 2.6.37 I was occassionally getting a warning about
> sysctl table entries being unregistered in the wrong order.  Digging
> in it turns out this dates back to the last great sysctl reorg done
> where Al Viro introduced the requirement that sysctl directories
> needed to be created before and destroyed after the files in them.
> 
> It turns out that in that great reorg /proc/sys/net/ipv6/neigh was
> overlooked.  So this patch fixes that oversight and makes an annoying
> warning message go away.
> 
>>------------[ cut here ]------------
>>WARNING: at kernel/sysctl.c:1992 unregister_sysctl_table+0x134/0x164()
>>Pid: 23951, comm: kworker/u:3 Not tainted 2.6.37-350888.2010AroraKernelBeta.fc14.x86_64 #1
>>Call Trace:
 ...
> 
> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>

Applied and queued for -stable, thanks a lot Eric.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Patch hide | download patch | download mbox

diff --git a/net/ipv6/sysctl_net_ipv6.c b/net/ipv6/sysctl_net_ipv6.c
index fa1d8f4..7cb65ef 100644
--- a/net/ipv6/sysctl_net_ipv6.c
+++ b/net/ipv6/sysctl_net_ipv6.c
@@ -15,6 +15,8 @@ 
 #include <net/addrconf.h>
 #include <net/inet_frag.h>
 
+static struct ctl_table empty[1];
+
 static ctl_table ipv6_table_template[] = {
 	{
 		.procname	= "route",
@@ -35,6 +37,12 @@  static ctl_table ipv6_table_template[] = {
 		.mode		= 0644,
 		.proc_handler	= proc_dointvec
 	},
+	{
+		.procname	= "neigh",
+		.maxlen		= 0,
+		.mode		= 0555,
+		.child		= empty,
+	},
 	{ }
 };
 
@@ -152,7 +160,6 @@  static struct ctl_table_header *ip6_base;
 
 int ipv6_static_sysctl_register(void)
 {
-	static struct ctl_table empty[1];
 	ip6_base = register_sysctl_paths(net_ipv6_ctl_path, empty);
 	if (ip6_base == NULL)
 		return -ENOMEM;