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From: Pavel Machek <pavel@ucw.cz>
To: Dmitry Vyukov <dvyukov@google.com>
Cc: syzkaller <syzkaller@googlegroups.com>,
	Oleg Nesterov <oleg@redhat.com>,
	Denys Vlasenko <dvlasenk@redhat.com>,
	jan.kratochvil@redhat.com, palves@redhat.com,
	Roland McGrath <roland@hack.frob.com>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: Unkillable processes due to PTRACE_TRACEME again
Date: Sat, 3 Dec 2016 20:11:13 +0100	[thread overview]
Message-ID: <20161203191113.GA13417@amd> (raw)
In-Reply-To: <CACT4Y+YUnM1kAZo6orq2oqjAvuYF6z47yZ5gjrKzT4gmQ7fktg@mail.gmail.com>

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Hi!

You cc-ed me on initial mail, I replied, and you removed me from cc. Ouch.

On Sat 2016-12-03 16:55:49, Dmitry Vyukov wrote:
> On Fri, Dec 2, 2016 at 10:02 PM, Pavel Machek <pavel@ucw.cz> wrote:
> > On Fri 2016-12-02 19:48:40, Dmitry Vyukov wrote:
> >> Hello,
> >>
> >> There was an issue discussed a year ago which leads to
> >> unkillalble/unwaitable zombie processes due to PTRACE_TRACEME:
> >> https://groups.google.com/d/msg/syzkaller/uGzwvhlCXAw/E-cfY2ejAgAJ
> >> and I though it has been fixed by "wait/ptrace: assume __WALL if the
> >> child is traced":
> >> https://groups.google.com/d/msg/syzkaller/caeB1ebZWAs/gcbvcM2HDAAJ
> >>
> >> I am not on 2caceb3294a78c389b462e7e236a4e744a53a474 (Dec 1). And see
> >
> > "Now on"?
> 
> Yes.
> 
> >> the same unwaitable zombie processes.
> >
> > Well.. I guess git bisect is one option...?
> 
> I've checked on:
> 
> commit 91c4e8ea8f05916df0c8a6f383508ac7c9e10dba
> Author: Oleg Nesterov <oleg@redhat.com>
> Date:   Mon May 23 16:23:53 2016 -0700
>     wait: allow sys_waitid() to accept __WNOTHREAD/__WCLONE/__WALL
> 
> and the program hangs the same way. So it seems that it was just never fixed.

Ouch #2. Oleg, any ideas?

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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  reply	other threads:[~2016-12-03 19:11 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-12-02 18:48 Unkillable processes due to PTRACE_TRACEME again Dmitry Vyukov
2016-12-02 21:02 ` Pavel Machek
2016-12-03 15:55   ` Dmitry Vyukov
2016-12-03 19:11     ` Pavel Machek [this message]
2016-12-05 10:46 ` Oleg Nesterov
2016-12-05 11:00   ` Oleg Nesterov
2016-12-05 14:07     ` Dmitry Vyukov
2016-12-05 16:59       ` Oleg Nesterov

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