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From: Mike Galbraith <efault@gmx.de>
To: Kees Cook <keescook@chromium.org>
Cc: LKML <linux-kernel@vger.kernel.org>, Ingo Molnar <mingo@elte.hu>,
	"Reshetova, Elena" <elena.reshetova@intel.com>
Subject: Re: tip -ENOBOOT - bisected to locking/refcounts, x86/asm: Implement fast refcount overflow protection
Date: Wed, 30 Aug 2017 19:55:35 +0200	[thread overview]
Message-ID: <1504115735.5852.11.camel@gmx.de> (raw)
In-Reply-To: <CAGXu5jJd80-0PJvB51x9ZDETPSoAtRVQ7dQ6HWwd0DYpKBgPFA@mail.gmail.com>

On Wed, 2017-08-30 at 10:32 -0700, Kees Cook wrote:
> On Wed, Aug 30, 2017 at 10:13 AM, Mike Galbraith <efault@gmx.de> wrote:
> > On Wed, 2017-08-30 at 09:35 -0700, Kees Cook wrote:
> >> On Tue, Aug 29, 2017 at 10:02 PM, Mike Galbraith <efault@gmx.de> wrote:
> >> > On Tue, 2017-08-29 at 11:41 -0700, Kees Cook wrote:
> >> >> Can you also test with 14afee4b6092 ("net: convert sock.sk_wmem_alloc
> >> >> from atomic_t to refcount_t") reverted (instead of ARCH_HAS_REFCOUNT
> >> >> disabled)?
> >> >
> >> > Nogo.
> >>
> >> Thanks for checking!
> >>
> >> > [   44.901930] WARNING: CPU: 5 PID: 0 at net/netlink/af_netlink.c:374 netlink_sock_destruct+0x82/0xa0
> >>
> >> This is so odd if 14afee4b6092 is reverted. What is line 374 for you
> >> in net/netlink/af_netlink.c?
> >
> > 374         WARN_ON(atomic_read(&sk->sk_rmem_alloc));
> >
> > That line is unchanged by 14afee4b6092.
> 
> Uuuuhmm. Wow, now I'm really baffled. I thought you were getting the
> warn from the next line with the refcount usage... I will keep
> digging. Thanks!

I just double checked freshly pulled tip (rapidly moving target), and
it's definitely nogo with CONFIG_ARCH_HAS_REFCOUNT=y and 14afee4b6092
reverted.

	-Mike

  reply	other threads:[~2017-08-30 17:55 UTC|newest]

Thread overview: 36+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-08-29  8:50 tip -ENOBOOT - bisected to locking/refcounts, x86/asm: Implement fast refcount overflow protection Mike Galbraith
2017-08-29  8:58 ` Ingo Molnar
2017-08-29  9:21   ` Mike Galbraith
2017-08-29  9:27     ` Ingo Molnar
2017-08-29 10:03       ` Mike Galbraith
2017-08-29 15:39         ` Kees Cook
2017-08-29 16:34           ` Mike Galbraith
2017-08-29 15:58 ` Kees Cook
2017-08-29 16:55   ` Mike Galbraith
2017-08-29 18:10     ` Mike Galbraith
2017-08-29 18:41       ` Kees Cook
2017-08-30  5:02         ` Mike Galbraith
2017-08-30 16:35           ` Kees Cook
2017-08-30 17:13             ` Mike Galbraith
2017-08-30 17:32               ` Kees Cook
2017-08-30 17:55                 ` Mike Galbraith [this message]
2017-08-30 19:19                   ` Kees Cook
2017-08-30 19:46                     ` Kees Cook
2017-08-31  2:09                       ` Mike Galbraith
2017-08-31  2:27                         ` Kees Cook
2017-08-31  3:12                           ` Mike Galbraith
2017-08-31  4:01                             ` Kees Cook
2017-08-31  4:10                               ` Kees Cook
2017-08-31  4:38                                 ` Mike Galbraith
2017-08-31 13:58                                 ` Mike Galbraith
2017-08-31 17:00                                   ` Kees Cook
2017-08-31 17:19                                     ` Mike Galbraith
2017-08-31 18:45                                       ` Kees Cook
2017-09-01  6:57                                         ` Mike Galbraith
2017-09-01 13:09                                           ` Mike Galbraith
2017-09-01 17:12                                             ` Kees Cook
2017-09-01 17:52                                               ` Mike Galbraith
2017-09-01 18:58                                                 ` Kees Cook
2017-09-01 19:24                                                   ` Mike Galbraith
2017-09-01 19:40                                                   ` Kees Cook
2017-08-31 19:28                                   ` Kees Cook

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