From: Guillaume Nault <g.nault@alphalink•fr>
To: Denys Fedoryshchenko <nuclearcat@nuclearcat•com>
Cc: Linux Kernel Network Developers <netdev@vger•kernel.org>
Subject: Re: ppp/pppoe, still panic 4.15.3 in ppp_push
Date: Thu, 15 Feb 2018 20:20:08 +0100 [thread overview]
Message-ID: <20180215192008.GJ1422@alphalink.fr> (raw)
In-Reply-To: <802ba894fee75e34576d39aed5022dc8@nuclearcat.com>
On Wed, Feb 14, 2018 at 06:49:19PM +0200, Denys Fedoryshchenko wrote:
> On 2018-02-14 18:47, Guillaume Nault wrote:
> > On Wed, Feb 14, 2018 at 06:29:34PM +0200, Denys Fedoryshchenko wrote:
> > > On 2018-02-14 18:07, Guillaume Nault wrote:
> > > > On Wed, Feb 14, 2018 at 03:17:23PM +0200, Denys Fedoryshchenko wrote:
> > > > > Hi,
> > > > >
> > > > > Upgraded kernel to 4.15.3, still it crashes after while (several
> > > > > hours,
> > > > > cannot do bisect, as it is production server).
> > > > >
> > > > > dev ppp # gdb ppp_generic.o
> > > > > GNU gdb (Gentoo 7.12.1 vanilla) 7.12.1
> > > > > <<skipped>>
> > > > > Reading symbols from ppp_generic.o...done.
> > > > > (gdb) list *ppp_push+0x73
> > > > > 0x681 is in ppp_push (drivers/net/ppp/ppp_generic.c:1663).
> > > > > 1658 list = list->next;
> > > > > 1659 pch = list_entry(list, struct channel, clist);
> > > > > 1660
> > > > > 1661 spin_lock(&pch->downl);
> > > > > 1662 if (pch->chan) {
> > > > > 1663 if (pch->chan->ops->start_xmit(pch->chan, skb))
> > > > > 1664 ppp->xmit_pending = NULL;
> > > > > 1665 } else {
> > > > > 1666 /* channel got unregistered */
> > > > > 1667 kfree_skb(skb);
> > > > >
> > > > >
> > > > I expect a memory corruption. Do you have the possibility to run with
> > > > KASAN by any chance?
> > > I will try to enable it tonight. For now i reverted "drivers, net,
> > > ppp:
> > > convert ppp_file.refcnt from atomic_t to refcount_t" for test.
> > >
> > This commit looks good to me. Do you have doubts about it because it's
> > new in 4.15? Does it mean that your last known-good kernel is 4.14?
>
> I am just doing "manual" bisect, checking all possibilities, and picking
> patch to revert randomly.
> Yes, correct, my known-good is 4.14.2.
>
Then maybe try reverting commit 0171c4183559 ("ppp: unlock all_ppp_mutex before registering device").
I can't see how it could lead to the bug you observed, but the other
ppp_generic patches introduced since 4.14 were rather trivial.
prev parent reply other threads:[~2018-02-15 19:20 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-02-14 13:17 ppp/pppoe, still panic 4.15.3 in ppp_push Denys Fedoryshchenko
2018-02-14 16:07 ` Guillaume Nault
2018-02-14 16:29 ` Denys Fedoryshchenko
2018-02-14 16:47 ` Guillaume Nault
2018-02-14 16:49 ` Denys Fedoryshchenko
2018-02-14 17:25 ` Guillaume Nault
2018-02-15 10:19 ` Denys Fedoryshchenko
2018-02-15 15:55 ` Guillaume Nault
2018-02-15 16:01 ` Denys Fedoryshchenko
2018-02-15 19:31 ` Guillaume Nault
2018-02-15 19:34 ` Denys Fedoryshchenko
2018-02-15 19:42 ` Guillaume Nault
2018-02-16 11:13 ` Denys Fedoryshchenko
2018-02-16 18:48 ` Guillaume Nault
2018-02-18 10:01 ` Denys Fedoryshchenko
2018-02-21 18:38 ` Guillaume Nault
2018-02-20 9:05 ` Denys Fedoryshchenko
2018-02-21 10:26 ` Denys Fedoryshchenko
2018-02-21 18:55 ` Guillaume Nault
2018-02-21 19:30 ` Denys Fedoryshchenko
2018-02-21 20:04 ` Cong Wang
2018-02-22 18:30 ` Guillaume Nault
2018-02-22 18:51 ` Denys Fedoryshchenko
2018-02-23 9:38 ` Guillaume Nault
2018-02-23 9:41 ` Denys Fedoryshchenko
2018-02-23 10:07 ` Guillaume Nault
2018-02-23 10:54 ` Denys Fedoryshchenko
2018-02-24 21:22 ` Denys Fedoryshchenko
2018-02-27 10:58 ` Denys Fedoryshchenko
2018-02-27 18:56 ` Guillaume Nault
2018-03-01 20:01 ` Guillaume Nault
2018-03-01 20:07 ` Denys Fedoryshchenko
2018-03-02 17:43 ` Guillaume Nault
2018-03-03 9:33 ` Denys Fedoryshchenko
2018-03-05 17:22 ` Guillaume Nault
2018-02-27 18:54 ` Guillaume Nault
2018-02-15 19:20 ` Guillaume Nault [this message]
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