From: Jann Horn <jannh@google.com>
To: Christian Brauner <christian@brauner.io>
Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>,
Andy Lutomirski <luto@kernel.org>,
David Howells <dhowells@redhat.com>,
"Serge E. Hallyn" <serge@hallyn.com>,
"Eric W. Biederman" <ebiederm@xmission.com>,
Linux API <linux-api@vger.kernel.org>,
kernel list <linux-kernel@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
Alexey Dobriyan <adobriyan@gmail.com>,
Thomas Gleixner <tglx@linutronix.de>,
Michael Kerrisk-manpages <mtk.manpages@gmail.com>,
bl0pbl33p@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>,
cyphar@cyphar.com, Al Viro <viro@zeniv.linux.org.uk>,
"Joel Fernandes (Google)" <joel@joelfernandes.org>,
Daniel Colascione <dancol@google.com>
Subject: Re: [PATCH 3/4] signal: support pidctl() with pidfd_send_signal()
Date: Mon, 25 Mar 2019 19:39:25 +0100 [thread overview]
Message-ID: <CAG48ez1QSJTOb-DAQuVpa5feUe9K-pr8aYuyd=yXg0n9eSg-LQ@mail.gmail.com> (raw)
In-Reply-To: <20190325162052.28987-4-christian@brauner.io>
On Mon, Mar 25, 2019 at 5:21 PM Christian Brauner <christian@brauner.io> wrote:
> Let pidfd_send_signal() use pidfds retrieved via pidctl(). With this patch
> pidfd_send_signal() becomes independent of procfs. This fullfils the
> request made when we merged the pidfd_send_signal() patchset. The
> pidfd_send_signal() syscall is now always available allowing for it to be
> used by users without procfs mounted or even users without procfs support
> compiled into the kernel.
[...]
> static bool access_pidfd_pidns(struct pid *pid)
> {
> + int ret;
> struct pid_namespace *active = task_active_pid_ns(current);
> struct pid_namespace *p = ns_of_pid(pid);
>
> - for (;;) {
> - if (!p)
> - return false;
> - if (p == active)
> - break;
> - p = p->parent;
> - }
> + ret = pidnscmp(active, p);
> + if (ret < 0)
> + return false;
>
> return true;
> }
Nit, if we keep this function: "if (...) return false; return true;"
seems like an antipattern to me. How about "return ret >= 0", or even
"return pidnscmp(active, p) >= 0"?
next prev parent reply other threads:[~2019-03-25 18:39 UTC|newest]
Thread overview: 42+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-25 16:20 [PATCH 0/4] pid: add pidctl() Christian Brauner
2019-03-25 16:20 ` [PATCH 1/4] Make anon_inodes unconditional Christian Brauner
2019-03-25 16:20 ` [PATCH 2/4] pid: add pidctl() Christian Brauner
2019-03-25 17:20 ` Mika Penttilä
2019-03-25 19:59 ` Christian Brauner
2019-03-25 18:18 ` Jann Horn
2019-03-25 19:58 ` Christian Brauner
2019-03-26 16:07 ` Joel Fernandes
2019-03-26 16:15 ` Christian Brauner
2019-03-25 16:20 ` [PATCH 3/4] signal: support pidctl() with pidfd_send_signal() Christian Brauner
2019-03-25 18:28 ` Jonathan Kowalski
2019-03-25 20:05 ` Christian Brauner
2019-03-25 18:39 ` Jann Horn [this message]
2019-03-25 19:41 ` Christian Brauner
2019-03-25 16:20 ` [PATCH 4/4] tests: add pidctl() tests Christian Brauner
2019-03-25 16:48 ` [PATCH 0/4] pid: add pidctl() Daniel Colascione
2019-03-25 17:05 ` Konstantin Khlebnikov
2019-03-25 17:07 ` Daniel Colascione
2019-03-25 17:36 ` Joel Fernandes
2019-03-25 17:53 ` Daniel Colascione
2019-03-25 18:19 ` Jonathan Kowalski
2019-03-25 18:57 ` Daniel Colascione
2019-03-25 19:42 ` Jonathan Kowalski
2019-03-25 20:14 ` Daniel Colascione
2019-03-25 20:34 ` Jann Horn
2019-03-25 20:40 ` Jonathan Kowalski
2019-03-25 21:14 ` Jonathan Kowalski
2019-03-25 21:15 ` Jann Horn
2019-03-25 20:40 ` Christian Brauner
2019-03-25 20:15 ` Christian Brauner
2019-03-25 21:11 ` Joel Fernandes
2019-03-25 21:17 ` Daniel Colascione
2019-03-25 21:19 ` Jann Horn
2019-03-25 21:43 ` Joel Fernandes
2019-03-25 21:54 ` Jonathan Kowalski
2019-03-25 22:07 ` Daniel Colascione
2019-03-25 22:37 ` Jonathan Kowalski
2019-03-25 23:14 ` Daniel Colascione
2019-03-26 3:03 ` Joel Fernandes
2019-03-25 16:56 ` David Howells
2019-03-25 16:58 ` Daniel Colascione
2019-03-25 23:39 ` Andy Lutomirski
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='CAG48ez1QSJTOb-DAQuVpa5feUe9K-pr8aYuyd=yXg0n9eSg-LQ@mail.gmail.com' \
--to=jannh@google.com \
--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=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@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 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).