From: "Jürg Billeter" <j@bitron.ch>
To: Florian Weimer <fweimer@redhat.com>
Cc: Christian Brauner <christian@brauner.io>,
linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
luto@kernel.org, arnd@arndb.de, ebiederm@xmission.com,
serge@hallyn.com, jannh@google.com, akpm@linux-foundation.org,
oleg@redhat.com, cyphar@cyphar.com, viro@zeniv.linux.org.uk,
linux-fsdevel@vger.kernel.org, dancol@google.com,
timmurray@google.com, linux-man@vger.kernel.org,
keescook@chromium.org, tglx@linutronix.de, x86@kernel.org
Subject: Re: [PATCH v4] signal: add taskfd_send_signal() syscall
Date: Thu, 06 Dec 2018 14:18:36 +0100 [thread overview]
Message-ID: <89a6b3a24412d385a816d7d981c60cb1e1bbc0ca.camel@bitron.ch> (raw)
In-Reply-To: <87pnue6bp2.fsf@oldenburg2.str.redhat.com>
On Thu, 2018-12-06 at 14:12 +0100, Florian Weimer wrote:
> * Jürg Billeter:
>
> > On Thu, 2018-12-06 at 13:30 +0100, Florian Weimer wrote:
> > > * Christian Brauner:
> > >
> > > > /* zombies */
> > > > Zombies can be signaled just as any other process. No special error will be
> > > > reported since a zombie state is an unreliable state (cf. [3]).
> > >
> > > I still disagree with this analysis. If I know that the target process
> > > is still alive, and it is not, this is a persistent error condition
> > > which can be reliably reported. Given that someone might send SIGKILL
> > > to the process behind my back, detecting this error condition could be
> > > useful.
> >
> > As I understand it, kill() behaves the same way. I think it's good that
> > this new syscall keeps the behavior as close as possible to kill().
>
> No, kill does not behave in this way because the PID can be reused.
> The error condition is not stable there.
The PID can't be reused as long as it's a zombie. It can only be reused
when it has been wait()ed for. Or am I misunderstanding something?
Jürg
next prev parent reply other threads:[~2018-12-06 13:18 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-06 12:18 [PATCH v4] signal: add taskfd_send_signal() syscall Christian Brauner
2018-12-06 12:30 ` Florian Weimer
2018-12-06 12:45 ` Jürg Billeter
2018-12-06 13:12 ` Florian Weimer
2018-12-06 13:18 ` Jürg Billeter [this message]
2018-12-06 13:20 ` Florian Weimer
2018-12-06 13:40 ` Eric W. Biederman
2018-12-06 13:44 ` Florian Weimer
2018-12-06 14:27 ` Aleksa Sarai
2018-12-06 14:46 ` Eric W. Biederman
2018-12-06 12:53 ` Christian Brauner
2018-12-06 13:17 ` Florian Weimer
2018-12-06 15:01 ` Eric W. Biederman
2018-12-06 16:17 ` Daniel Colascione
2018-12-06 17:24 ` Eric W. Biederman
2018-12-06 17:41 ` Christian Brauner
2018-12-06 18:30 ` Kees Cook
2018-12-06 22:27 ` Serge E. Hallyn
2018-12-06 17:14 ` Christian Brauner
2018-12-06 19:17 ` Eric W. Biederman
2018-12-06 19:30 ` Christian Brauner
2018-12-06 20:29 ` Eric W. Biederman
2018-12-06 20:37 ` Daniel Colascione
2018-12-06 22:22 ` Eric W. Biederman
2018-12-06 22:43 ` Daniel Colascione
2018-12-06 21:31 ` Christian Brauner
2018-12-06 21:46 ` Eric W. Biederman
2018-12-06 22:01 ` Daniel Colascione
2018-12-06 22:39 ` Christian Brauner
2018-12-06 23:17 ` Christian Brauner
2018-12-07 0:31 ` Serge E. Hallyn
2018-12-07 0:34 ` Daniel Colascione
2018-12-07 0:59 ` Serge E. Hallyn
2018-12-07 1:39 ` Daniel Colascione
2018-12-07 1:54 ` Christian Brauner
2018-12-07 16:49 ` Serge E. Hallyn
2018-12-07 16:47 ` Serge E. Hallyn
2018-12-08 21:46 ` kbuild test robot
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=89a6b3a24412d385a816d7d981c60cb1e1bbc0ca.camel@bitron.ch \
--to=j@bitron.ch \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=christian@brauner.io \
--cc=cyphar@cyphar.com \
--cc=dancol@google.com \
--cc=ebiederm@xmission.com \
--cc=fweimer@redhat.com \
--cc=jannh@google.com \
--cc=keescook@chromium.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-man@vger.kernel.org \
--cc=luto@kernel.org \
--cc=oleg@redhat.com \
--cc=serge@hallyn.com \
--cc=tglx@linutronix.de \
--cc=timmurray@google.com \
--cc=viro@zeniv.linux.org.uk \
--cc=x86@kernel.org \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).