linux-kernel - Re: [PATCH 2/3 v2] futex: avoid double wake up in futex

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:	Thu, 16 Apr 2015 12:49:59 +0200 (CEST)
From:	Thomas Gleixner <tglx@...utronix.de>
To:	Peter Zijlstra <peterz@...radead.org>
cc:	Davidlohr Bueso <dave@...olabs.net>,
	Sebastian Andrzej Siewior <bigeasy@...utronix.de>,
	linux-kernel@...r.kernel.org, Ingo Molnar <mingo@...hat.com>,
	Darren Hart <darren@...art.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	fredrik.markstrom@...driver.com,
	Manfred Spraul <manfred@...orfullife.com>,
	Arnaldo Carvalho de Melo <acme@...nel.org>
Subject: Re: [PATCH 2/3 v2] futex: avoid double wake up in futex_wake() on
 -RT

On Thu, 16 Apr 2015, Peter Zijlstra wrote:

> On Thu, Apr 16, 2015 at 11:19:41AM +0200, Thomas Gleixner wrote:
> > So any code which does not handle a spurious wakeup is broken
> > independent of the futex changes. So really nothing to worry about.
> 
> Back when we did this:
> 
>  http://lkml.iu.edu/hypermail/linux/kernel/1109.1/01941.html
>  http://lkml.iu.edu/hypermail/linux/kernel/1109.1/01943.html
> 
> Things came apart -- notably sysvsems.
> 
> And yes its true that anything not dealing with spuriuos wakups is
> borken, but there's still quite a lot of borken out there, although I
> think we fixed all the really common ones.
> 
> But if we decide we want to go do this, I'd propose we reintroduce this
> delayed wake list thing again.

Indeed. Forgot about that completely.

Thanks,

	tglx
 
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/