linux-kernel - Re: [PATCH] make cancel_rearming_delayed

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:	Mon, 14 May 2007 01:25:48 +0400
From:	Oleg Nesterov <oleg@...sign.ru>
To:	Tejun Heo <htejun@...il.com>
Cc:	Andrew Morton <akpm@...ux-foundation.org>,
	David Chinner <dgc@....com>,
	David Howells <dhowells@...hat.com>,
	Gautham Shenoy <ego@...ibm.com>,
	Jarek Poplawski <jarkao2@...pl>, Ingo Molnar <mingo@...e.hu>,
	Srivatsa Vaddagiri <vatsa@...ibm.com>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] make cancel_rearming_delayed_work() reliable

Hi Tejun,

Sorry, I can't give a "complete" reply today (will do tomorrow),
just one note right now...

On 05/13, Tejun Heo wrote:
> 
> Oleg Nesterov wrote:
> >> * try_to_grab_pending() checks VALID && pointers equal after grabbing
> >> cwq->lock.
> > 
> > We don't even need to check the pointers. VALID bit is always changed
> > under cwq->lock. So, if we see VALID under cwq->lock, we have a right
> > pointer.
> 
> But there are multiple cwq->lock's.  VALID can be set with one of other
> cwq->lock's locked.

Oops. Thanks for correcting me. _This_ was a reson for a stupid barrier!

Oleg.

-
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/