Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Feedback-ID: i21f147d5:Fastmail
Date:   Wed, 27 Jul 2022 12:18:06 -0600
From:   Tycho Andersen <tycho@tycho.pizza>
To:     Oleg Nesterov <oleg@redhat.com>
Cc:     "Serge E. Hallyn" <serge@hallyn.com>,
        "Eric W . Biederman" <ebiederm@xmission.com>,
        Miklos Szeredi <miklos@szeredi.hu>,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH] sched: __fatal_signal_pending() should also check
 PF_EXITING
Message-ID: <YuGBXnqb5rPwAlYk@tycho.pizza>
References: <Ys2PwTS0qFmGNFqy@netflix>
 <20220713175305.1327649-1-tycho@tycho.pizza>
 <20220720150328.GA30749@mail.hallyn.com>
 <YthsgqAZYnwHZLn+@tycho.pizza>
 <20220721015459.GA4297@mail.hallyn.com>
 <YuFdUj5X4qckC/6g@tycho.pizza>
 <20220727175538.GC18822@redhat.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220727175538.GC18822@redhat.com>
Precedence: bulk

On Wed, Jul 27, 2022 at 07:55:39PM +0200, Oleg Nesterov wrote:
> On 07/27, Tycho Andersen wrote:
> >
> > Hi all,
> >
> > On Wed, Jul 20, 2022 at 08:54:59PM -0500, Serge E. Hallyn wrote:
> > > Oh - I didn't either - checking the sigkill in shared signals *seems*
> > > legit if they can be put there - but since you posted the new patch I
> > > assumed his reasoning was clear to you.  I know Eric's busy, cc:ing Oleg
> > > for his interpretation too.
> >
> > Any thoughts on this?
> 
> Cough... I don't know what can I say except I personally dislike this
> patch no matter what ;)
> 
> And I do not understand how can this patch help. OK, a single-threaded
> PF_EXITING task sleeps in TASK_KILLABLE. send_signal_locked() won't
> wake it up anyway?
> 
> I must have missed something.

What do you think of the patch in
https://lore.kernel.org/all/YsyHMVLuT5U6mm+I@netflix/ ? Hopefully that
has an explanation that makes more sense.

Tycho