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From: Jann Horn <jannh@google.com>
To: j@bitron.ch
Cc: Andrew Morton <akpm@linux-foundation.org>,
	Oleg Nesterov <oleg@redhat.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Linux API <linux-api@vger.kernel.org>,
	kernel list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] prctl: add PR_[GS]ET_KILLABLE
Date: Wed, 1 Aug 2018 09:56:41 +0200
Message-ID: <CAG48ez3uu9-QXOnAu0-3-3PcE=kn=uaWqv4A_uc666XqkisJrw@mail.gmail.com> (raw)
In-Reply-To: <625ede00c618783eb610b7109c35c514e8faa793.camel@bitron.ch>

On Wed, Aug 1, 2018 at 9:44 AM Jürg Billeter <j@bitron.ch> wrote:
>
> On Tue, 2018-07-31 at 18:26 +0200, Jann Horn wrote:
> > On Mon, Jul 30, 2018 at 10:01 AM Jürg Billeter <j@bitron.ch> wrote:
> >
> > [...]
> > > diff --git a/kernel/sys.c b/kernel/sys.c
> > > index 38509dc1f77b..264de630d548 100644
> > > --- a/kernel/sys.c
> > > +++ b/kernel/sys.c
> >
> > [...]
> > > +       case PR_SET_KILLABLE:
> > > +               if (arg2 != 1 || arg3 || arg4 || arg5)
> > > +                       return -EINVAL;
> > > +               me->signal->flags &= ~SIGNAL_UNKILLABLE;
> > > +               break;
> >
> > I don't have an opinion on this patchset otherwise, but should this
> > prctl maybe block PR_SET_KILLABLE if you're actually the real init
> > process? This seems like it could potentially lead to weird things.
>
> While I don't expect global init to use this, I can't think of a good
> reason to disallow it in the kernel. Do you have specific concerns or
> is the code in kernel/fork.c the only reason?

No, I don't have any other specific concerns.

> I prefer avoiding special cases unless really required.

  reply index

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-07-30  7:52 Jürg Billeter
2018-07-30 10:17 ` Oleg Nesterov
2018-07-30 19:32   ` Jürg Billeter
2018-07-30 19:39     ` Thomas Gleixner
2018-07-31  7:03 ` [PATCH v2] " Jürg Billeter
2018-07-31 14:39   ` Oleg Nesterov
2018-07-31 16:12     ` Jürg Billeter
2018-08-01 14:19       ` Oleg Nesterov
2018-08-03 10:15         ` Jürg Billeter
2018-08-03 12:14           ` Oleg Nesterov
2018-08-03 13:34           ` Eric W. Biederman
2018-08-03 14:39             ` Jürg Billeter
2018-07-31 16:26 ` [PATCH] " Jann Horn
2018-08-01  7:43   ` Jürg Billeter
2018-08-01  7:56     ` Jann Horn [this message]
2018-08-03 14:40 ` [PATCH v3 1/2] fork: do not rely on SIGNAL_UNKILLABLE for init check Jürg Billeter
2018-08-03 14:40   ` [PATCH v3 2/2] prctl: add PR_[GS]ET_KILLABLE Jürg Billeter
2018-09-06 22:42     ` Andrew Morton

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