From: Christian Brauner <christian@brauner.io>
To: Florian Weimer <fweimer@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Jann Horn <jannh@google.com>, Kevin Easton <kevin@guarana.org>,
Andy Lutomirski <luto@kernel.org>,
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>,
Oleg Nesterov <oleg@redhat.com>,
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]
Date: Mon, 29 Apr 2019 22:51:39 +0200 [thread overview]
Message-ID: <CAHrFyr5HxpGXA2YrKza-oB-GGwJCqwPfyhD-Y5wbktWZdt0sGQ@mail.gmail.com> (raw)
In-Reply-To: <87zho8bl8x.fsf@oldenburg2.str.redhat.com>
On Mon, Apr 29, 2019 at 10:38 PM Florian Weimer <fweimer@redhat.com> wrote:
>
> * Linus Torvalds:
>
> > On Mon, Apr 29, 2019 at 12:55 PM Jann Horn <jannh@google.com> wrote:
> >>
> >> ... I guess that already has a name, and it's called vfork(). (Well,
> >> except that the Linux vfork() isn't a real vfork().)
> >
> > What?
> >
> > Linux vfork() is very much a real vfork(). What do you mean?
>
> In Linux-as-the-ABI (as opposed to Linux-as-the-implementation), vfork
> is sometimes implemented as fork, so applications cannot rely on the
> vfork behavior regarding the stopped parent and the shared address
> space.
>
> In fact, it would be nice to have a flag we can check in the posix_spawn
> implementation, so that we can support vfork-as-fork without any run
> time cost to native Linux.
After the next merge window we'll be out of flags if things go as planned.
To address this problem, Jann and I are currently in the middle of working
on a clone version that we intend to send out for discussion afterwards.
If the proposal is acceptable it would bump the number of available flags
significantly, putting things like this within reach.
Christian
next prev parent reply other threads:[~2019-04-29 20:51 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
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 [this message]
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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