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From: Oleg Nesterov <oleg@redhat.com>
To: Christian Brauner <christian@brauner.io>
Cc: torvalds@linux-foundation.org, viro@zeniv.linux.org.uk,
	jannh@google.com, dhowells@redhat.com, linux-api@vger.kernel.org,
	linux-kernel@vger.kernel.org, serge@hallyn.com, luto@kernel.org,
	arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org,
	tglx@linutronix.de, mtk.manpages@gmail.com,
	akpm@linux-foundation.org, cyphar@cyphar.com,
	joel@joelfernandes.org, dancol@google.com
Subject: Re: [PATCH 2/4] clone: add CLONE_PIDFD
Date: Mon, 15 Apr 2019 12:52:09 +0200	[thread overview]
Message-ID: <20190415105209.GA22204@redhat.com> (raw)
In-Reply-To: <20190414201436.19502-3-christian@brauner.io>

On 04/14, Christian Brauner wrote:
>
> @@ -2260,6 +2363,10 @@ long _do_fork(unsigned long clone_flags,
>  	}
>
>  	put_pid(pid);
> +
> +	if (clone_flags & CLONE_PIDFD)
> +		nr = pidfd;
> +

Well, this doesn't look nice ...

CLONE_PARENT_SETTID doesn't look very usefule, so what if we add

	if ((clone_flags & (CLONE_PIDFD|CLONE_PARENT_SETTID)) ==
	                   (CLONE_PIDFD|CLONE_PARENT_SETTID))
		return ERR_PTR(-EINVAL);

at the start of copy_process() ?

Then it can do

	if (clone_flags & CLONE_PIDFD) {
		retval = pidfd_create(pid, &pidfdf);
		if (retval < 0)
			goto bad_fork_free_pid;
		retval = put_user(retval, parent_tidptr)
		if (retval < 0)
			goto bad_fork_free_pid;
	}

Oleg.


  reply	other threads:[~2019-04-15 10:52 UTC|newest]

Thread overview: 52+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-14 20:14 [PATCH 0/4] clone: add CLONE_PIDFD Christian Brauner
2019-04-14 20:14 ` [PATCH 1/4] Make anon_inodes unconditional Christian Brauner
2019-04-14 20:14 ` [PATCH 2/4] clone: add CLONE_PIDFD Christian Brauner
2019-04-15 10:52   ` Oleg Nesterov [this message]
2019-04-15 11:42     ` Christian Brauner
2019-04-15 13:24       ` Oleg Nesterov
2019-04-15 13:52         ` Christian Brauner
2019-04-15 16:25           ` Joel Fernandes
2019-04-15 17:15         ` Jonathan Kowalski
2019-04-15 19:39           ` Daniel Colascione
2019-04-14 20:14 ` [PATCH 3/4] signal: support CLONE_PIDFD with pidfd_send_signal Christian Brauner
2019-04-14 20:14 ` [PATCH 4/4] samples: show race-free pidfd metadata access Christian Brauner
2019-04-15 10:08 ` RFC: on adding new CLONE_* flags [WAS Re: [PATCH 0/4] clone: add CLONE_PIDFD] Enrico Weigelt, metux IT consult
2019-04-15 15:50   ` Serge E. Hallyn
2019-04-16 18:32     ` Enrico Weigelt, metux IT consult
2019-04-29 15:49       ` Serge E. Hallyn
2019-04-29 17:31         ` Enrico Weigelt, metux IT consult
2019-05-05  2:32           ` Serge E. Hallyn
2019-04-15 19:59   ` Aleksa Sarai
2019-04-15 20:29     ` Andy Lutomirski
2019-04-15 21:27       ` Jonathan Kowalski
2019-04-15 23:58         ` Andy Lutomirski
2019-04-16 18:45       ` Enrico Weigelt, metux IT consult
2019-04-16 21:31         ` Andy Lutomirski
2019-04-17 12:03           ` Enrico Weigelt, metux IT consult
2019-04-17 12:54             ` Christian Brauner
2019-04-18 15:46               ` Enrico Weigelt, metux IT consult
2019-04-17 12:19       ` Florian Weimer
2019-04-17 16:46         ` Andy Lutomirski
2019-04-20  7:14       ` Kevin Easton
2019-04-20 11:15         ` Christian Brauner
2019-04-20 15:06         ` Daniel Colascione
2019-04-29 19:30         ` Jann Horn
2019-04-29 19:55           ` Jann Horn
2019-04-29 20:21             ` Linus Torvalds
2019-04-29 20:38               ` Florian Weimer
2019-04-29 20:51                 ` Christian Brauner
2019-04-29 21:31                 ` Linus Torvalds
2019-04-30  7:01                   ` Florian Weimer
2019-04-30  0:38               ` Jann Horn
2019-04-30  2:16                 ` Linus Torvalds
2019-04-30  8:21                   ` Florian Weimer
2019-04-30 16:19                     ` Linus Torvalds
2019-04-30 16:26                       ` Linus Torvalds
2019-04-30 17:07                         ` Florian Weimer
2019-04-30 12:39               ` Oleg Nesterov
2019-04-30 16:24                 ` Linus Torvalds
2019-04-29 20:49             ` Florian Weimer
2019-04-29 20:52               ` Christian Brauner
2019-04-20 15:28       ` Al Viro
2019-04-16 18:37     ` Enrico Weigelt, metux IT consult
2019-04-15 10:16 ` [PATCH 0/4] clone: add CLONE_PIDFD Enrico Weigelt, metux IT consult

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