From: Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org>
To: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
Cc: Zefan Li <lizefan-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>,
Tetsuo Handa
<penguin-kernel-1yMVhJb1mP/7nzcFbJAaVXf5DAMn2ifp@public.gmane.org>,
Ingo Molnar <mingo-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>,
Tejun Heo <tj-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
Andrew Morton
<akpm-de/tnXTf+JLsfHDXvbKv3WD2FQJk+8+b@public.gmane.org>,
cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
LKML <linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
fernando_b1-Zyj7fXuS5i5L9jVzuh4AOg@public.gmane.org
Subject: Re: Racy manipulation of task_struct->flags in cgroups code causes hard to reproduce kernel panics
Date: Sat, 20 Sep 2014 20:04:18 +0200 [thread overview]
Message-ID: <20140920180418.GR2832@worktop.localdomain> (raw)
In-Reply-To: <CAGXu5j+P_kcgZuqYsemgL0KU_zRhz5HGJ6seh2oLyyst=cZP6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
On Sat, Sep 20, 2014 at 10:15:50AM -0700, Kees Cook wrote:
> On Sat, Sep 20, 2014 at 7:30 AM, Peter Zijlstra <peterz-wEGCiKHe2LqWVfeAwA7xHQ@public.gmane.org> wrote:
> > On Sat, Sep 20, 2014 at 01:55:54PM +0800, Zefan Li wrote:
> >> We should make the updating of this flag atomic.
> >
> >> /* Per-process atomic flags. */
> >> #define PFA_NO_NEW_PRIVS 0x00000001 /* May not gain new privileges. */
> >> +#define PFA_SPREAD_PAGE 0x00000002 /* Spread page cache over cpuset */
> >> +#define PFA_SPREAD_SLAB 0x00000004 /* Spread some slab caches over cpuset */
> >
> > Ooh, I was not ware we had those.. /me checks where that came from. Hmm
> > weird, while I did get that patch it had a seccomp prefix when landing
> > in my inbox so I ignored it. However the commit has a sched prefix
> > (which I would not have ignored). Dubious things happened here.
>
> The series went through a lot of revisions, so it probably gained the
> sched prefix later in its life. Is there anything that needs changing
> about how this has been implemented?
No, don't think so, just got surprised.
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Kees Cook <keescook@chromium.org>
Cc: Zefan Li <lizefan@huawei.com>,
Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
Ingo Molnar <mingo@redhat.com>, Tejun Heo <tj@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
cgroups@vger.kernel.org, LKML <linux-kernel@vger.kernel.org>,
fernando_b1@lab.ntt.co.jp
Subject: Re: Racy manipulation of task_struct->flags in cgroups code causes hard to reproduce kernel panics
Date: Sat, 20 Sep 2014 20:04:18 +0200 [thread overview]
Message-ID: <20140920180418.GR2832@worktop.localdomain> (raw)
In-Reply-To: <CAGXu5j+P_kcgZuqYsemgL0KU_zRhz5HGJ6seh2oLyyst=cZP6g@mail.gmail.com>
On Sat, Sep 20, 2014 at 10:15:50AM -0700, Kees Cook wrote:
> On Sat, Sep 20, 2014 at 7:30 AM, Peter Zijlstra <peterz@infradead.org> wrote:
> > On Sat, Sep 20, 2014 at 01:55:54PM +0800, Zefan Li wrote:
> >> We should make the updating of this flag atomic.
> >
> >> /* Per-process atomic flags. */
> >> #define PFA_NO_NEW_PRIVS 0x00000001 /* May not gain new privileges. */
> >> +#define PFA_SPREAD_PAGE 0x00000002 /* Spread page cache over cpuset */
> >> +#define PFA_SPREAD_SLAB 0x00000004 /* Spread some slab caches over cpuset */
> >
> > Ooh, I was not ware we had those.. /me checks where that came from. Hmm
> > weird, while I did get that patch it had a seccomp prefix when landing
> > in my inbox so I ignored it. However the commit has a sched prefix
> > (which I would not have ignored). Dubious things happened here.
>
> The series went through a lot of revisions, so it probably gained the
> sched prefix later in its life. Is there anything that needs changing
> about how this has been implemented?
No, don't think so, just got surprised.
next prev parent reply other threads:[~2014-09-20 18:04 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-19 11:53 Racy manipulation of task_struct->flags in cgroups code causes hard to reproduce kernel panics Tetsuo Handa
2014-09-19 11:53 ` Tetsuo Handa
[not found] ` <201409192053.IHJ35462.JLOMOSOFFVtQFH-JPay3/Yim36HaxMnTkn67Xf5DAMn2ifp@public.gmane.org>
2014-09-19 22:21 ` Peter Zijlstra
2014-09-19 22:21 ` Peter Zijlstra
2014-09-20 5:55 ` Zefan Li
2014-09-20 5:55 ` Zefan Li
2014-09-20 10:40 ` [PATCH 3.17-rc5] Fix confusing PFA_NO_NEW_PRIVS constant Tetsuo Handa
2014-09-20 10:40 ` Tetsuo Handa
2014-09-20 10:40 ` Tetsuo Handa
[not found] ` <201409201940.AHG21834.LJOFFHSFQOtVMO-JPay3/Yim36HaxMnTkn67Xf5DAMn2ifp@public.gmane.org>
2014-09-20 17:19 ` Kees Cook
2014-09-20 17:19 ` Kees Cook
2014-09-20 17:19 ` Kees Cook
[not found] ` <541D16EA.70407-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2014-09-20 14:30 ` Racy manipulation of task_struct->flags in cgroups code causes hard to reproduce kernel panics Peter Zijlstra
2014-09-20 14:30 ` Peter Zijlstra
[not found] ` <20140920143012.GL2832-IIpfhp3q70wB9AHHLWeGtNQXobZC6xk2@public.gmane.org>
2014-09-20 17:15 ` Kees Cook
2014-09-20 17:15 ` Kees Cook
[not found] ` <CAGXu5j+P_kcgZuqYsemgL0KU_zRhz5HGJ6seh2oLyyst=cZP6g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2014-09-20 18:04 ` Peter Zijlstra [this message]
2014-09-20 18:04 ` Peter Zijlstra
2014-09-20 17:28 ` Tejun Heo
2014-09-20 17:28 ` Tejun Heo
[not found] ` <20140920172819.GD3681-Gd/HAXX7CRxy/B6EtB590w@public.gmane.org>
2014-09-21 5:15 ` Tetsuo Handa
2014-09-21 5:15 ` Tetsuo Handa
[not found] ` <201409211415.GJG26578.MFQOHtSFVJLOOF-JPay3/Yim36HaxMnTkn67Xf5DAMn2ifp@public.gmane.org>
2014-09-22 2:15 ` Zefan Li
2014-09-22 2:15 ` Zefan Li
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