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From: David Laight <David.Laight@ACULAB.COM>
To: 'Christian Brauner' <christian@brauner.io>,
	"ebiederm@xmission.com" <ebiederm@xmission.com>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Cc: "serge@hallyn.com" <serge@hallyn.com>,
	"jannh@google.com" <jannh@google.com>,
	"luto@kernel.org" <luto@kernel.org>,
	"akpm@linux-foundation.org" <akpm@linux-foundation.org>,
	"oleg@redhat.com" <oleg@redhat.com>,
	"cyphar@cyphar.com" <cyphar@cyphar.com>,
	"viro@zeniv.linux.org.uk" <viro@zeniv.linux.org.uk>,
	"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"linux-api@vger.kernel.org" <linux-api@vger.kernel.org>,
	"dancol@google.com" <dancol@google.com>,
	"timmurray@google.com" <timmurray@google.com>,
	Kees Cook <keescook@chromium.org>
Subject: RE: [PATCH] proc: allow killing processes via file descriptors
Date: Mon, 19 Nov 2018 14:15:31 +0000	[thread overview]
Message-ID: <9a269517770e4881b92756d47f17a5fd@AcuMS.aculab.com> (raw)
In-Reply-To: <20181118111751.6142-1-christian@brauner.io>

From: > Christian Brauner
> Sent: 18 November 2018 11:18
> 
> With this patch an open() call on /proc/<pid> will give userspace a handle
> to struct pid of the process associated with /proc/<pid>. This allows to
> maintain a stable handle on a process.

My 3c...

You need to add a version of fork() that returns an open fd to
/proc/pid to the parent.

Is it possible to overload fcntl() rather than ioctl() ?

More interestingly what about a 'unique pid' (eg the pid extended to
(say) 128 bits with a use count) that can be safely put into a /var/run/pid
file for a daemon and used later in a 'kill' that will only ever
reference the correct process.

	David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)


  parent reply	other threads:[~2018-11-19 14:15 UTC|newest]

Thread overview: 53+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-18 11:17 Christian Brauner
2018-11-18 13:59 ` Daniel Colascione
2018-11-18 15:38   ` Andy Lutomirski
2018-11-18 15:53     ` Daniel Colascione
2018-11-18 16:17       ` Andy Lutomirski
2018-11-18 16:29         ` Daniel Colascione
2018-11-18 17:13           ` Andy Lutomirski
2018-11-18 17:17             ` Daniel Colascione
2018-11-18 17:43               ` Eric W. Biederman
2018-11-18 17:45                 ` Andy Lutomirski
2018-11-18 17:56                 ` Daniel Colascione
2018-11-18 16:33         ` Randy Dunlap
2018-11-18 16:48           ` Daniel Colascione
2018-11-18 17:09             ` Andy Lutomirski
2018-11-18 17:24               ` Daniel Colascione
2018-11-18 17:42                 ` Andy Lutomirski
2018-11-18 17:51                   ` Daniel Colascione
2018-11-18 18:28                     ` Andy Lutomirski
2018-11-18 18:43                       ` Daniel Colascione
2018-11-18 19:05                         ` Aleksa Sarai
2018-11-18 19:44                           ` Daniel Colascione
2018-11-18 20:15                             ` Christian Brauner
2018-11-18 20:21                               ` Daniel Colascione
2018-11-18 20:28                             ` Andy Lutomirski
2018-11-18 20:32                               ` Daniel Colascione
2018-11-19  1:43                                 ` Andy Lutomirski
2018-11-18 20:43                               ` Christian Brauner
2018-11-18 20:54                                 ` Daniel Colascione
2018-11-18 21:23                                   ` Christian Brauner
2018-11-18 21:30                                     ` Christian Brauner
2018-11-19  0:31                                       ` Daniel Colascione
2018-11-19  0:40                                         ` Christian Brauner
2018-11-19  0:09                             ` Aleksa Sarai
2018-11-19  0:53                               ` Daniel Colascione
2018-11-19  1:16                                 ` Daniel Colascione
2018-11-19 16:13                       ` Dmitry Safonov
2018-11-19 16:26                         ` [PATCH] proc: allow killing processes via file descriptors (Larger pids) Eric W. Biederman
2018-11-19 16:27                         ` [PATCH] proc: allow killing processes via file descriptors Daniel Colascione
2018-11-19 20:21                           ` Aleksa Sarai
2018-11-19  2:47                   ` Al Viro
2018-11-19  3:01                     ` Andy Lutomirski
2018-11-18 17:41     ` Christian Brauner
2018-11-18 17:44       ` Andy Lutomirski
2018-11-18 18:07       ` Daniel Colascione
2018-11-18 18:15         ` Andy Lutomirski
2018-11-18 18:31           ` Daniel Colascione
2018-11-18 19:24         ` Christian Brauner
2018-11-19  0:08         ` Aleksa Sarai
2018-11-19  1:14           ` Daniel Colascione
2018-11-18 16:03 ` Daniel Colascione
2018-11-19 10:56 ` kbuild test robot
2018-11-19 14:15 ` David Laight [this message]
2018-11-19 15:49 ` Dave Martin

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