Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Tue, 30 Apr 2019 14:39:01 +0200
From:   Oleg Nesterov <oleg@redhat.com>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Jann Horn <jannh@google.com>, Kevin Easton <kevin@guarana.org>,
        Andy Lutomirski <luto@kernel.org>,
        Christian Brauner <christian@brauner.io>,
        Aleksa Sarai <cyphar@cyphar.com>,
        "Enrico Weigelt, metux IT consult" <lkml@metux.net>,
        Al Viro <viro@zeniv.linux.org.uk>,
        David Howells <dhowells@redhat.com>,
        Linux API <linux-api@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        "Serge E. Hallyn" <serge@hallyn.com>,
        Arnd Bergmann <arnd@arndb.de>,
        "Eric W. Biederman" <ebiederm@xmission.com>,
        Kees Cook <keescook@chromium.org>,
        Thomas Gleixner <tglx@linutronix.de>,
        Michael Kerrisk <mtk.manpages@gmail.com>,
        Andrew Morton <akpm@linux-foundation.org>,
        Joel Fernandes <joel@joelfernandes.org>,
        Daniel Colascione <dancol@google.com>
Subject: Re: RFC: on adding new CLONE_* flags [WAS Re: [PATCH 0/4] clone: add
 CLONE_PIDFD]
Message-ID: <20190430123901.GD23020@redhat.com>
References: <20190414201436.19502-1-christian@brauner.io>
 <dc05ffe3-c2ff-8b3e-d181-e0cc620bf91d@metux.net>
 <20190415195911.z7b7miwsj67ha54y@yavin>
 <CALCETrWxMnaPvwicqkMLswMynWvJVteazD-bFv3ZnBKWp-1joQ@mail.gmail.com>
 <20190420071406.GA22257@ip-172-31-15-78>
 <CAG48ez0gG4bd-t1wdR2p6-N2FjWbCqm_+ZThKfF7yKnD=KLqAQ@mail.gmail.com>
 <CAG48ez15bf1EJB0XTJsGFpvf8r5pj9+rv1axKVr13H1NW7ARZw@mail.gmail.com>
 <CAHk-=wi_N81mKYFz33ycoWiL7_tGbZBMJOsAs16inYzSza+OEw@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <CAHk-=wi_N81mKYFz33ycoWiL7_tGbZBMJOsAs16inYzSza+OEw@mail.gmail.com>
User-Agent: Mutt/1.5.24 (2015-08-30)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 04/29, Linus Torvalds wrote:
>
> Linux vfork() is very much a real vfork(). What do you mean?

Yes, but I am wondering if man vfork should clarify what "child terminates"
actually means. I mean, the child can do clone(CLONE_THREAD) + sys_exit(),
this will wake the parent thread up before the child process exits or execs.

I see nothing wrong, but I was always curious whether it was designed this
way on purpose or not.

Oleg.