On Wed, Sep 23, 2015 at 10:46 PM, Sedat Dilek <[email protected]> wrote:
> On Wed, Sep 23, 2015 at 12:38 PM, Guillaume Nault <[email protected]>
> wrote:
>> On Wed, Sep 23, 2015 at 08:06:16AM +0200, Sedat Dilek wrote:
>>> Without reverting the below culprit ppp patch...
>>>
>>> commit/?id=8cb775bc0a34dc596837e7da03fd22c747be618b
>>> ("ppp: fix device unregistration upon netns deletion")
>>>
>>> ...I have an unstable Internet connection via Network-Manager/ModemManager.
>>>
>>> First I saw this with Linux v4.2.
>>>
>>
>> Thanks for reporting the issue. Can you test this patch ?
>>
>> ---
>> diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
>> index 0481daf..ed00446 100644
>> --- a/drivers/net/ppp/ppp_generic.c
>> +++ b/drivers/net/ppp/ppp_generic.c
>> @@ -2755,6 +2755,7 @@ static struct ppp *ppp_create_interface(struct net
>> *net, int unit,
>> */
>> dev_net_set(dev, net);
>>
>> + rtnl_lock();
>> mutex_lock(&pn->all_ppp_mutex);
>>
>> if (unit < 0) {
>> @@ -2785,7 +2786,7 @@ static struct ppp *ppp_create_interface(struct net
>> *net, int unit,
>> ppp->file.index = unit;
>> sprintf(dev->name, "ppp%d", unit);
>>
>> - ret = register_netdev(dev);
>> + ret = register_netdevice(dev);
>> if (ret != 0) {
>> unit_put(&pn->units_idr, unit);
>> netdev_err(ppp->dev, "PPP: couldn't register device %s
>> (%d)\n",
>> @@ -2797,6 +2798,7 @@ static struct ppp *ppp_create_interface(struct net
>> *net, int unit,
>>
>> atomic_inc(&ppp_unit_count);
>> mutex_unlock(&pn->all_ppp_mutex);
>> + rtnl_unlock();
>>
>> *retp = 0;
>> return ppp;
>
> I have adapted your patch against Linux v4.2.1 and it fixes the issue for me.
> Testcase:
> 1. Stop network-manager and unload "PPP Deflate Compression module".
> 2. Reload module and restart NM.
> ( No call-traces pointing to ppp. )
>
> Do you mind to send a proper patch with subject-line and commit-message?
> Can you embed the Fixes-tag and give credits like Reported-by/Tested-by?
>
> Thanks.
>
Do not forget CC-stable Tag, too.
Cc: [email protected]# v4.2+
See attached patch for-4.3.
- sed@ -
[1]
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/SubmittingPatches#n187
[2]
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/tree/Documentation/SubmittingPatches#n297
From 1109c55b54703416593be6275aeaad9aefcfe4b1 Mon Sep 17 00:00:00 2001
From: Sedat Dilek <[email protected]>
Date: Wed, 23 Sep 2015 22:54:48 +0200
Subject: [PATCH] ppp: Fix circular locking dependency in
ppp_create_interface()
From: Guillaume Nault <[email protected]>
For more details see [1].
[1] http://marc.info/?t=144298854300001&r=1&w=2
Reported-by: Sedat Dilek <[email protected]>
Tested-by: Sedat Dilek <[email protected]>
Cc: [email protected] # v4.2+
Fixes: 8cb775bc0a34 ("ppp: fix device unregistration upon netns deletion")
CC: Guillaume Nault <[email protected]>
CC: David S. Miller <[email protected]>
CC: [email protected]" <[email protected]>
---
drivers/net/ppp/ppp_generic.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 0481daf9201a..ed00446759b2 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -2755,6 +2755,7 @@ static struct ppp *ppp_create_interface(struct net *net, int unit,
*/
dev_net_set(dev, net);
+ rtnl_lock();
mutex_lock(&pn->all_ppp_mutex);
if (unit < 0) {
@@ -2785,7 +2786,7 @@ static struct ppp *ppp_create_interface(struct net *net, int unit,
ppp->file.index = unit;
sprintf(dev->name, "ppp%d", unit);
- ret = register_netdev(dev);
+ ret = register_netdevice(dev);
if (ret != 0) {
unit_put(&pn->units_idr, unit);
netdev_err(ppp->dev, "PPP: couldn't register device %s (%d)\n",
@@ -2797,6 +2798,7 @@ static struct ppp *ppp_create_interface(struct net *net, int unit,
atomic_inc(&ppp_unit_count);
mutex_unlock(&pn->all_ppp_mutex);
+ rtnl_unlock();
*retp = 0;
return ppp;
--
2.5.3
