From: Thomas Gleixner <tglx@linutronix.de>
To: Florian Weimer <fweimer@redhat.com>
Cc: Shawn Landden <shawn@git.icu>,
libc-alpha@sourceware.org, linux-api@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Deepa Dinamani <deepa.kernel@gmail.com>,
Oleg Nesterov <oleg@redhat.com>,
Andrew Morton <akpm@linux-foundation.org>,
Catalin Marinas <catalin.marinas@arm.com>,
Keith Packard <keithp@keithp.com>,
Peter Zijlstra <peterz@infradead.org>
Subject: Re: [RFC v2 PATCH] futex: extend set_robust_list to allow 2 locking ABIs at the same time.
Date: Tue, 5 Nov 2019 10:59:24 +0100 (CET) [thread overview]
Message-ID: <alpine.DEB.2.21.1911051053470.17054@nanos.tec.linutronix.de> (raw)
In-Reply-To: <87woceslfs.fsf@oldenburg2.str.redhat.com>
On Tue, 5 Nov 2019, Florian Weimer wrote:
> * Shawn Landden:
> > If this new ABI is used, then bit 1 of the *next pointer of the
> > user-space robust_list indicates that the futex_offset2 value should
> > be used in place of the existing futex_offset.
>
> The futex interface currently has some races which can only be fixed by
> API changes. I'm concerned that we sacrifice the last bit for some
> rather obscure feature. What if we need that bit for fixing the
> correctness issues?
That current approach is going nowhere and if we change the ABI ever then
this needs to happen with all *libc folks involved and agreeing.
Out of curiosity, what's the race issue vs. robust list which you are
trying to solve?
Thanks,
tglx
next prev parent reply other threads:[~2019-11-05 9:59 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-04 0:29 [RFC v2 PATCH] futex: extend set_robust_list to allow 2 locking ABIs at the same time Shawn Landden
2019-11-04 0:51 ` Shawn Landden
2019-11-04 15:37 ` Thomas Gleixner
2019-11-05 0:10 ` Thomas Gleixner
2019-11-05 9:48 ` Florian Weimer
2019-11-05 9:59 ` Thomas Gleixner [this message]
2019-11-05 10:06 ` Florian Weimer
2019-11-05 11:56 ` Thomas Gleixner
2019-11-05 14:10 ` Carlos O'Donell
2019-11-05 14:27 ` Florian Weimer
2019-11-05 14:53 ` Thomas Gleixner
2019-11-05 14:27 ` Thomas Gleixner
2019-11-05 14:33 ` Florian Weimer
2019-11-05 14:48 ` Thomas Gleixner
2019-11-06 14:00 ` Zack Weinberg
2019-11-06 14:04 ` Florian Weimer
2019-11-05 15:27 ` handle_exit_race && PF_EXITING Oleg Nesterov
2019-11-05 17:28 ` Thomas Gleixner
2019-11-05 17:59 ` Thomas Gleixner
2019-11-05 18:56 ` Thomas Gleixner
2019-11-05 19:19 ` Thomas Gleixner
2019-11-06 8:55 ` Oleg Nesterov
2019-11-06 9:53 ` Thomas Gleixner
2019-11-06 10:35 ` Oleg Nesterov
2019-11-06 11:07 ` Thomas Gleixner
2019-11-06 12:11 ` Oleg Nesterov
2019-11-06 13:38 ` Thomas Gleixner
2019-11-06 17:42 ` Thomas Gleixner
2019-11-07 15:51 ` Oleg Nesterov
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=alpine.DEB.2.21.1911051053470.17054@nanos.tec.linutronix.de \
--to=tglx@linutronix.de \
--cc=akpm@linux-foundation.org \
--cc=arnd@arndb.de \
--cc=catalin.marinas@arm.com \
--cc=deepa.kernel@gmail.com \
--cc=fweimer@redhat.com \
--cc=keithp@keithp.com \
--cc=libc-alpha@sourceware.org \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=oleg@redhat.com \
--cc=peterz@infradead.org \
--cc=shawn@git.icu \
/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).