All of lore.kernel.org
 help / color / mirror / Atom feed
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Jonathan Kowalski <bl0pbl33p@gmail.com>
Cc: Daniel Colascione <dancol@google.com>,
	Aleksa Sarai <cyphar@cyphar.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Christian Brauner <christian@brauner.io>,
	Jann Horn <jannh@google.com>, Andrew Lutomirski <luto@kernel.org>,
	David Howells <dhowells@redhat.com>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	Linux API <linux-api@vger.kernel.org>,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
	Kees Cook <keescook@chromium.org>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Michael Kerrisk-manpages <mtk.manpages@gmail.com>,
	"Dmitry V. Levin" <ldv@altlinux.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Oleg Nesterov <oleg@redhat.com>,
	Nagarathnam Muthusamy <nagarathnam.muthusamy@oracle.com>,
	Al Viro <viro@zeniv.linux.org.uk>,
	Joel Fernandes <joel@joelfernandes.org>
Subject: Re: [PATCH v2 0/5] pid: add pidfd_open()
Date: Mon, 1 Apr 2019 09:15:00 -0700	[thread overview]
Message-ID: <CAHk-=wi1UEsMv5wmBZB5S+5YiCbxd-AtVsoz1TfuD-KrdcLQew@mail.gmail.com> (raw)
In-Reply-To: <CAGLj2rF85hZLAR79oEA1dQARadw1OHr8bxqCLbvO6g9B6ou2Qw@mail.gmail.com>

On Mon, Apr 1, 2019 at 9:07 AM Jonathan Kowalski <bl0pbl33p@gmail.com> wrote:
>
> With the POLLHUP model on a simple pidfd, you'd know when the process
> you were referring to is dead (and one can map POLLPRI to dead and
> POLLHUP to zombie, etc).

Adding ->poll() to the pidfd should be easy. Again, it would be
trivially be made to work for the directory fd you get from
/proc/<pid> too.

Yeah, yeah, pollable directories are odd, but the vfs layer doesn't
care about things like "is this a directory or not". It will just call
the f_op->poll() method.

              Linus

WARNING: multiple messages have this Message-ID (diff)
From: Linus Torvalds <torvalds@linux-foundation.org>
To: Jonathan Kowalski <bl0pbl33p@gmail.com>
Cc: Daniel Colascione <dancol@google.com>,
	Aleksa Sarai <cyphar@cyphar.com>,
	Andy Lutomirski <luto@amacapital.net>,
	Christian Brauner <christian@brauner.io>,
	Jann Horn <jannh@google.com>, Andrew Lutomirski <luto@kernel.org>,
	David Howells <dhowells@redhat.com>,
	"Serge E. Hallyn" <serge@hallyn.com>,
	Linux API <linux-api@vger.kernel.org>,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	Arnd Bergmann <arnd@arndb.de>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
	Kees Cook <keescook@chromium.org>,
	Alexey Dobriyan <adobriyan@gmail.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Michael Kerrisk-manpages <mtk.manpages@gmail.com>,
	"Dmitry V. Levin" <ldv@altlinux.org>,
	Andrew Morton <akpm@linux-found>
Subject: Re: [PATCH v2 0/5] pid: add pidfd_open()
Date: Mon, 1 Apr 2019 09:15:00 -0700	[thread overview]
Message-ID: <CAHk-=wi1UEsMv5wmBZB5S+5YiCbxd-AtVsoz1TfuD-KrdcLQew@mail.gmail.com> (raw)
In-Reply-To: <CAGLj2rF85hZLAR79oEA1dQARadw1OHr8bxqCLbvO6g9B6ou2Qw@mail.gmail.com>

On Mon, Apr 1, 2019 at 9:07 AM Jonathan Kowalski <bl0pbl33p@gmail.com> wrote:
>
> With the POLLHUP model on a simple pidfd, you'd know when the process
> you were referring to is dead (and one can map POLLPRI to dead and
> POLLHUP to zombie, etc).

Adding ->poll() to the pidfd should be easy. Again, it would be
trivially be made to work for the directory fd you get from
/proc/<pid> too.

Yeah, yeah, pollable directories are odd, but the vfs layer doesn't
care about things like "is this a directory or not". It will just call
the f_op->poll() method.

              Linus

  reply	other threads:[~2019-04-01 16:21 UTC|newest]

Thread overview: 158+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-29 15:54 [PATCH v2 0/5] pid: add pidfd_open() Christian Brauner
2019-03-29 15:54 ` [PATCH v2 1/5] Make anon_inodes unconditional Christian Brauner
2019-03-29 15:54 ` [PATCH v2 2/5] pid: add pidfd_open() Christian Brauner
2019-03-29 23:45   ` Jann Horn
2019-03-29 23:45     ` Jann Horn
2019-03-29 23:55     ` Christian Brauner
2019-03-29 23:55       ` Christian Brauner
2019-03-30 11:53   ` Jürg Billeter
2019-03-30 14:37     ` Christian Brauner
2019-03-30 14:51       ` Jonathan Kowalski
2019-03-30 14:51         ` Jonathan Kowalski
2019-03-29 15:54 ` [PATCH v2 3/5] signal: support pidfd_open() with pidfd_send_signal() Christian Brauner
2019-03-29 15:54 ` [PATCH v2 4/5] signal: PIDFD_SIGNAL_TID threads via pidfds Christian Brauner
2019-03-30  1:06   ` Jann Horn
2019-03-30  1:06     ` Jann Horn
2019-03-30  1:22     ` Christian Brauner
2019-03-30  1:22       ` Christian Brauner
2019-03-30  1:34       ` Christian Brauner
2019-03-30  1:34         ` Christian Brauner
2019-03-30  1:42         ` Christian Brauner
2019-03-30  1:42           ` Christian Brauner
2019-03-29 15:54 ` [PATCH v2 5/5] tests: add pidfd_open() tests Christian Brauner
2019-03-30 16:09 ` [PATCH v2 0/5] pid: add pidfd_open() Linus Torvalds
2019-03-30 16:09   ` Linus Torvalds
2019-03-30 16:11   ` Daniel Colascione
2019-03-30 16:11     ` Daniel Colascione
2019-03-30 16:16     ` Linus Torvalds
2019-03-30 16:16       ` Linus Torvalds
2019-03-30 16:18       ` Linus Torvalds
2019-03-30 16:18         ` Linus Torvalds
2019-03-31  1:07         ` Joel Fernandes
2019-03-31  1:07           ` Joel Fernandes
2019-03-31  2:34           ` Jann Horn
2019-03-31  2:34             ` Jann Horn
2019-03-31  4:08             ` Joel Fernandes
2019-03-31  4:08               ` Joel Fernandes
2019-03-31  4:46               ` Jann Horn
2019-03-31  4:46                 ` Jann Horn
2019-03-31 14:52                 ` Linus Torvalds
2019-03-31 14:52                   ` Linus Torvalds
2019-03-31 15:05                   ` Christian Brauner
2019-03-31 15:05                     ` Christian Brauner
2019-03-31 15:21                     ` Daniel Colascione
2019-03-31 15:21                       ` Daniel Colascione
2019-03-31 15:33                   ` Jonathan Kowalski
2019-03-31 15:33                     ` Jonathan Kowalski
2019-03-30 16:19   ` Christian Brauner
2019-03-30 16:19     ` Christian Brauner
2019-03-30 16:24     ` Linus Torvalds
2019-03-30 16:24       ` Linus Torvalds
2019-03-30 16:34       ` Daniel Colascione
2019-03-30 16:34         ` Daniel Colascione
2019-03-30 16:38         ` Christian Brauner
2019-03-30 16:38           ` Christian Brauner
2019-03-30 17:04         ` Linus Torvalds
2019-03-30 17:04           ` Linus Torvalds
2019-03-30 17:12           ` Christian Brauner
2019-03-30 17:12             ` Christian Brauner
2019-03-30 17:24             ` Linus Torvalds
2019-03-30 17:24               ` Linus Torvalds
2019-03-30 17:37               ` Christian Brauner
2019-03-30 17:37                 ` Christian Brauner
2019-03-30 17:50               ` Jonathan Kowalski
2019-03-30 17:50                 ` Jonathan Kowalski
2019-03-30 17:52                 ` Christian Brauner
2019-03-30 17:52                   ` Christian Brauner
2019-03-30 17:59                   ` Jonathan Kowalski
2019-03-30 17:59                     ` Jonathan Kowalski
2019-03-30 18:02                     ` Christian Brauner
2019-03-30 18:02                       ` Christian Brauner
2019-03-30 18:00               ` Jann Horn
2019-03-30 18:00                 ` Jann Horn
2019-03-31 20:09               ` Andy Lutomirski
2019-03-31 20:09                 ` Andy Lutomirski
2019-03-31 21:03                 ` Linus Torvalds
2019-03-31 21:03                   ` Linus Torvalds
2019-03-31 21:10                   ` Christian Brauner
2019-03-31 21:10                     ` Christian Brauner
2019-03-31 21:17                     ` Linus Torvalds
2019-03-31 21:17                       ` Linus Torvalds
2019-03-31 22:03                       ` Christian Brauner
2019-03-31 22:03                         ` Christian Brauner
2019-03-31 22:16                         ` Linus Torvalds
2019-03-31 22:16                           ` Linus Torvalds
2019-03-31 22:33                           ` Christian Brauner
2019-03-31 22:33                             ` Christian Brauner
2019-04-01  0:52                             ` Jann Horn
2019-04-01  0:52                               ` Jann Horn
2019-04-01  8:47                               ` Yann Droneaud
2019-04-01  8:47                                 ` Yann Droneaud
2019-04-01 10:03                               ` Jonathan Kowalski
2019-04-01 10:03                                 ` Jonathan Kowalski
2019-03-31 23:40                           ` Linus Torvalds
2019-03-31 23:40                             ` Linus Torvalds
2019-04-01  0:09                             ` Al Viro
2019-04-01  0:09                               ` Al Viro
2019-04-01  0:18                               ` Linus Torvalds
2019-04-01  0:18                                 ` Linus Torvalds
2019-04-01  0:21                                 ` Christian Brauner
2019-04-01  0:21                                   ` Christian Brauner
2019-04-01  6:37                                 ` Al Viro
2019-04-01  6:37                                   ` Al Viro
2019-04-01  6:41                                   ` Al Viro
2019-04-01  6:41                                     ` Al Viro
2019-03-31 22:03                       ` Jonathan Kowalski
2019-03-31 22:03                         ` Jonathan Kowalski
2019-04-01  2:13                       ` Andy Lutomirski
2019-04-01  2:13                         ` Andy Lutomirski
2019-04-01 11:40                         ` Aleksa Sarai
2019-04-01 11:40                           ` Aleksa Sarai
2019-04-01 15:36                           ` Linus Torvalds
2019-04-01 15:36                             ` Linus Torvalds
2019-04-01 15:47                             ` Christian Brauner
2019-04-01 15:47                               ` Christian Brauner
2019-04-01 15:55                             ` Daniel Colascione
2019-04-01 15:55                               ` Daniel Colascione
2019-04-01 16:01                               ` Linus Torvalds
2019-04-01 16:01                                 ` Linus Torvalds
2019-04-01 16:13                                 ` Daniel Colascione
2019-04-01 16:13                                   ` Daniel Colascione
2019-04-01 19:42                                 ` Christian Brauner
2019-04-01 19:42                                   ` Christian Brauner
2019-04-01 21:30                                   ` Linus Torvalds
2019-04-01 21:30                                     ` Linus Torvalds
2019-04-01 21:58                                     ` Jonathan Kowalski
2019-04-01 21:58                                       ` Jonathan Kowalski
2019-04-01 22:13                                       ` Linus Torvalds
2019-04-01 22:13                                         ` Linus Torvalds
2019-04-01 22:34                                         ` Daniel Colascione
2019-04-01 22:34                                           ` Daniel Colascione
2019-04-01 16:07                               ` Jonathan Kowalski
2019-04-01 16:07                                 ` Jonathan Kowalski
2019-04-01 16:15                                 ` Linus Torvalds [this message]
2019-04-01 16:15                                   ` Linus Torvalds
2019-04-01 16:27                                   ` Jonathan Kowalski
2019-04-01 16:27                                     ` Jonathan Kowalski
2019-04-01 16:21                                 ` Daniel Colascione
2019-04-01 16:21                                   ` Daniel Colascione
2019-04-01 16:29                                   ` Linus Torvalds
2019-04-01 16:29                                     ` Linus Torvalds
2019-04-01 16:45                                     ` Daniel Colascione
2019-04-01 16:45                                       ` Daniel Colascione
2019-04-01 17:00                                       ` David Laight
2019-04-01 17:00                                         ` David Laight
2019-04-01 17:32                                       ` Linus Torvalds
2019-04-01 17:32                                         ` Linus Torvalds
2019-04-02 11:03                                       ` Florian Weimer
2019-04-02 11:03                                         ` Florian Weimer
2019-04-01 16:10                             ` Andy Lutomirski
2019-04-01 16:10                               ` Andy Lutomirski
2019-04-01 12:04                         ` Christian Brauner
2019-04-01 12:04                           ` Christian Brauner
2019-04-01 13:43                           ` Jann Horn
2019-04-01 13:43                             ` Jann Horn
2019-03-31 21:19                 ` Christian Brauner
2019-03-31 21:19                   ` Christian Brauner
2019-03-30 16:37       ` Christian Brauner
2019-03-30 16:37         ` Christian Brauner

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='CAHk-=wi1UEsMv5wmBZB5S+5YiCbxd-AtVsoz1TfuD-KrdcLQew@mail.gmail.com' \
    --to=torvalds@linux-foundation.org \
    --cc=adobriyan@gmail.com \
    --cc=akpm@linux-foundation.org \
    --cc=arnd@arndb.de \
    --cc=bl0pbl33p@gmail.com \
    --cc=christian@brauner.io \
    --cc=cyphar@cyphar.com \
    --cc=dancol@google.com \
    --cc=dhowells@redhat.com \
    --cc=ebiederm@xmission.com \
    --cc=jannh@google.com \
    --cc=joel@joelfernandes.org \
    --cc=keescook@chromium.org \
    --cc=khlebnikov@yandex-team.ru \
    --cc=ldv@altlinux.org \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=luto@amacapital.net \
    --cc=luto@kernel.org \
    --cc=mtk.manpages@gmail.com \
    --cc=nagarathnam.muthusamy@oracle.com \
    --cc=oleg@redhat.com \
    --cc=serge@hallyn.com \
    --cc=tglx@linutronix.de \
    --cc=viro@zeniv.linux.org.uk \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.