* [PATCH net-next] fix rtnl notification in atomic context
@ 2013-10-23 18:32 Alexei Starovoitov
2013-10-23 21:03 ` Stephen Hemminger
0 siblings, 1 reply; 4+ messages in thread
From: Alexei Starovoitov @ 2013-10-23 18:32 UTC (permalink / raw)
To: David S. Miller; +Cc: Nicolas Dichtel, Cong Wang, netdev
commit 991fb3f74c "dev: always advertise rx_flags changes via netlink"
introduced rtnl notification from __dev_set_promiscuity(),
which can be called in atomic context.
Steps to reproduce:
ip tuntap add dev tap1 mode tap
ifconfig tap1 up
tcpdump -nei tap1 &
ip tuntap del dev tap1 mode tap
[ 271.627994] device tap1 left promiscuous mode
[ 271.639897] BUG: sleeping function called from invalid context at mm/slub.c:940
[ 271.664491] in_atomic(): 1, irqs_disabled(): 0, pid: 3394, name: ip
[ 271.677525] INFO: lockdep is turned off.
[ 271.690503] CPU: 0 PID: 3394 Comm: ip Tainted: G W 3.12.0-rc3+ #73
[ 271.703996] Hardware name: System manufacturer System Product Name/P8Z77 WS, BIOS 3007 07/26/2012
[ 271.731254] ffffffff81a58506 ffff8807f0d57a58 ffffffff817544e5 ffff88082fa0f428
[ 271.760261] ffff8808071f5f40 ffff8807f0d57a88 ffffffff8108bad1 ffffffff81110ff8
[ 271.790683] 0000000000000010 00000000000000d0 00000000000000d0 ffff8807f0d57af8
[ 271.822332] Call Trace:
[ 271.838234] [<ffffffff817544e5>] dump_stack+0x55/0x76
[ 271.854446] [<ffffffff8108bad1>] __might_sleep+0x181/0x240
[ 271.870836] [<ffffffff81110ff8>] ? rcu_irq_exit+0x68/0xb0
[ 271.887076] [<ffffffff811a80be>] kmem_cache_alloc_node+0x4e/0x2a0
[ 271.903368] [<ffffffff810b4ddc>] ? vprintk_emit+0x1dc/0x5a0
[ 271.919716] [<ffffffff81614d67>] ? __alloc_skb+0x57/0x2a0
[ 271.936088] [<ffffffff810b4de0>] ? vprintk_emit+0x1e0/0x5a0
[ 271.952504] [<ffffffff81614d67>] __alloc_skb+0x57/0x2a0
[ 271.968902] [<ffffffff8163a0b2>] rtmsg_ifinfo+0x52/0x100
[ 271.985302] [<ffffffff8162ac6d>] __dev_notify_flags+0xad/0xc0
[ 272.001642] [<ffffffff8162ad0c>] __dev_set_promiscuity+0x8c/0x1c0
[ 272.017917] [<ffffffff81731ea5>] ? packet_notifier+0x5/0x380
[ 272.033961] [<ffffffff8162b109>] dev_set_promiscuity+0x29/0x50
[ 272.049855] [<ffffffff8172e937>] packet_dev_mc+0x87/0xc0
[ 272.065494] [<ffffffff81732052>] packet_notifier+0x1b2/0x380
[ 272.080915] [<ffffffff81731ea5>] ? packet_notifier+0x5/0x380
[ 272.096009] [<ffffffff81761c66>] notifier_call_chain+0x66/0x150
[ 272.110803] [<ffffffff8108503e>] __raw_notifier_call_chain+0xe/0x10
[ 272.125468] [<ffffffff81085056>] raw_notifier_call_chain+0x16/0x20
[ 272.139984] [<ffffffff81620190>] call_netdevice_notifiers_info+0x40/0x70
[ 272.154523] [<ffffffff816201d6>] call_netdevice_notifiers+0x16/0x20
[ 272.168552] [<ffffffff816224c5>] rollback_registered_many+0x145/0x240
[ 272.182263] [<ffffffff81622641>] rollback_registered+0x31/0x40
[ 272.195369] [<ffffffff816229c8>] unregister_netdevice_queue+0x58/0x90
[ 272.208230] [<ffffffff81547ca0>] __tun_detach+0x140/0x340
[ 272.220686] [<ffffffff81547ed6>] tun_chr_close+0x36/0x60
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
---
include/linux/rtnetlink.h | 4 +++-
net/core/dev.c | 2 +-
net/core/rtnetlink.c | 12 +++++++++---
3 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/include/linux/rtnetlink.h b/include/linux/rtnetlink.h
index f28544b..26f5edc 100644
--- a/include/linux/rtnetlink.h
+++ b/include/linux/rtnetlink.h
@@ -15,7 +15,9 @@ extern int rtnetlink_put_metrics(struct sk_buff *skb, u32 *metrics);
extern int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst,
u32 id, long expires, u32 error);
-extern void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change);
+void __rtmsg_ifinfo(int type, struct net_device *dev, unsigned change,
+ gfp_t flags);
+void rtmsg_ifinfo(int type, struct net_device *dev, unsigned change);
/* RTNL is used as a global lock for all changes to network configuration */
extern void rtnl_lock(void);
diff --git a/net/core/dev.c b/net/core/dev.c
index 0918aad..59b90fe 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -5257,7 +5257,7 @@ void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
unsigned int changes = dev->flags ^ old_flags;
if (gchanges)
- rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges);
+ __rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
if (changes & IFF_UP) {
if (dev->flags & IFF_UP)
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 4aedf03..5931af9 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1984,14 +1984,15 @@ static int rtnl_dump_all(struct sk_buff *skb, struct netlink_callback *cb)
return skb->len;
}
-void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change)
+void __rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change,
+ gfp_t flags)
{
struct net *net = dev_net(dev);
struct sk_buff *skb;
int err = -ENOBUFS;
size_t if_info_size;
- skb = nlmsg_new((if_info_size = if_nlmsg_size(dev, 0)), GFP_KERNEL);
+ skb = nlmsg_new((if_info_size = if_nlmsg_size(dev, 0)), flags);
if (skb == NULL)
goto errout;
@@ -2002,12 +2003,17 @@ void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change)
kfree_skb(skb);
goto errout;
}
- rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_KERNEL);
+ rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, flags);
return;
errout:
if (err < 0)
rtnl_set_sk_err(net, RTNLGRP_LINK, err);
}
+
+void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change)
+{
+ __rtmsg_ifinfo(type, dev, change, GFP_KERNEL);
+}
EXPORT_SYMBOL(rtmsg_ifinfo);
static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
--
1.7.9.5
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] fix rtnl notification in atomic context
2013-10-23 18:32 [PATCH net-next] fix rtnl notification in atomic context Alexei Starovoitov
@ 2013-10-23 21:03 ` Stephen Hemminger
2013-10-23 21:09 ` David Miller
0 siblings, 1 reply; 4+ messages in thread
From: Stephen Hemminger @ 2013-10-23 21:03 UTC (permalink / raw)
To: Alexei Starovoitov; +Cc: David S. Miller, Nicolas Dichtel, Cong Wang, netdev
On Wed, 23 Oct 2013 11:32:41 -0700
Alexei Starovoitov <ast@plumgrid.com> wrote:
> +
> +void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change)
> +{
> + __rtmsg_ifinfo(type, dev, change, GFP_KERNEL);
> +}
> EXPORT_SYMBOL(rtmsg_ifinfo);
>
> static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
> --
Why add another wrapper function? I think it cleaner to just change all the
callers to use the correct gfp flags.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] fix rtnl notification in atomic context
2013-10-23 21:03 ` Stephen Hemminger
@ 2013-10-23 21:09 ` David Miller
2013-10-23 21:25 ` Alexei Starovoitov
0 siblings, 1 reply; 4+ messages in thread
From: David Miller @ 2013-10-23 21:09 UTC (permalink / raw)
To: stephen; +Cc: ast, nicolas.dichtel, amwang, netdev
From: Stephen Hemminger <stephen@networkplumber.org>
Date: Wed, 23 Oct 2013 14:03:43 -0700
> On Wed, 23 Oct 2013 11:32:41 -0700
> Alexei Starovoitov <ast@plumgrid.com> wrote:
>
>> +
>> +void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change)
>> +{
>> + __rtmsg_ifinfo(type, dev, change, GFP_KERNEL);
>> +}
>> EXPORT_SYMBOL(rtmsg_ifinfo);
>>
>> static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
>> --
>
> Why add another wrapper function? I think it cleaner to just change all the
> callers to use the correct gfp flags.
Indeed, if this were targetted to "net" we'd have the argument of trying
to simplify the patch for -stable inclusion.
But since this is going into net-next, let's just put explicit GFP_* args
at the call site.
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH net-next] fix rtnl notification in atomic context
2013-10-23 21:09 ` David Miller
@ 2013-10-23 21:25 ` Alexei Starovoitov
0 siblings, 0 replies; 4+ messages in thread
From: Alexei Starovoitov @ 2013-10-23 21:25 UTC (permalink / raw)
To: David Miller; +Cc: stephen, nicolas.dichtel, amwang, netdev
On Wed, Oct 23, 2013 at 2:09 PM, David Miller <davem@davemloft.net> wrote:
> From: Stephen Hemminger <stephen@networkplumber.org>
> Date: Wed, 23 Oct 2013 14:03:43 -0700
>
>> On Wed, 23 Oct 2013 11:32:41 -0700
>> Alexei Starovoitov <ast@plumgrid.com> wrote:
>>
>>> +
>>> +void rtmsg_ifinfo(int type, struct net_device *dev, unsigned int change)
>>> +{
>>> + __rtmsg_ifinfo(type, dev, change, GFP_KERNEL);
>>> +}
>>> EXPORT_SYMBOL(rtmsg_ifinfo);
>>>
>>> static int nlmsg_populate_fdb_fill(struct sk_buff *skb,
>>> --
>>
>> Why add another wrapper function? I think it cleaner to just change all the
>> callers to use the correct gfp flags.
>
> Indeed, if this were targetted to "net" we'd have the argument of trying
> to simplify the patch for -stable inclusion.
>
> But since this is going into net-next, let's just put explicit GFP_* args
> at the call site.
sure. Will respin.
^ permalink raw reply [flat|nested] 4+ messages in thread
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2013-10-23 18:32 [PATCH net-next] fix rtnl notification in atomic context Alexei Starovoitov
2013-10-23 21:03 ` Stephen Hemminger
2013-10-23 21:09 ` David Miller
2013-10-23 21:25 ` Alexei Starovoitov
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