linux-kernel - Re: [PATCH 1/2] clone3: add CLONE3_CLEAR

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Sat, 12 Oct 2019 08:53:34 +0200
From:   "Michael Kerrisk (man-pages)" <mtk.manpages@...il.com>
To:     Aleksa Sarai <cyphar@...har.com>
Cc:     Christian Brauner <christian.brauner@...ntu.com>,
        Linux Kernel <linux-kernel@...r.kernel.org>,
        Oleg Nesterov <oleg@...hat.com>,
        Florian Weimer <fweimer@...hat.com>,
        "libc-alpha@...rceware.org" <libc-alpha@...rceware.org>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        Shuah Khan <shuah@...nel.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Michal Hocko <mhocko@...e.com>,
        Elena Reshetova <elena.reshetova@...el.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        Roman Gushchin <guro@...com>,
        Andrea Arcangeli <aarcange@...hat.com>,
        Al Viro <viro@...iv.linux.org.uk>,
        "Dmitry V. Levin" <ldv@...linux.org>,
        linux-kselftest@...r.kernel.org
Subject: Re: [PATCH 1/2] clone3: add CLONE3_CLEAR_SIGHAND

Hello Aleksa,

On Sat, 12 Oct 2019 at 00:12, Aleksa Sarai <cyphar@...har.com> wrote:
>
> On 2019-10-11, Michael Kerrisk <mtk.manpages@...il.com> wrote:
> > Why CLONE3_CLEAR_SIGHAND rather than just CLONE_CLEAR_SIGHAND?
>
> There are no more flag bits left for the classic clone()/clone2() (the
> last one was used up by CLONE_PIDFD) -- thus this flag is clone3()-only.

Yes, I understand that. But, I'm not sure that the "3" in the prefix
is necessary. "CLONE_" still seems better to me.

Consider this: sometime in the near future we will probably have time
namespaces. The new flag for those namespaces will only be usable with
clone3(). It should NOT be called CLONE3_NEWTIME, but rather
CLONE_NEWTIME (or similar), because that same flag will presumably
also be used in other APIs such as unshare() and setns(). (Hmm -- I
wonder if we are going to need a new unshare2() or some such...)

Thanks,

Michael


-- 
Michael Kerrisk
Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/
Linux/UNIX System Programming Training: http://man7.org/training/