linux-kernel - Re: [PATCH 9/9] workqueue: remove PREPARE_[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] [day] [month] [year] [list]

Date:	Fri, 7 Mar 2014 10:27:44 -0500
From:	Tejun Heo <tj@...nel.org>
To:	laijs@...fujitsu.com
Cc:	linux-kernel@...r.kernel.org,
	Peter Hurley <peter@...leysoftware.com>
Subject: Re: [PATCH 9/9] workqueue: remove PREPARE_[DELAYED_]WORK()

On Thu, Feb 20, 2014 at 03:44:31PM -0500, Tejun Heo wrote:
> Peter Hurley noticed that since a2c1c57be8d9 ("workqueue: consider
> work function when searching for busy work items"), a work item which
> gets assigned a different work function would break out of the
> non-reentrancy guarantee as workqueue would consider it a different
> work item.
> 
> This is fragile and extremely subtle.  PREPARE_[DELAYED_]WORK() have
> never been used widely and its semantics has always been somewhat
> iffy.  If the work item is known not to be on queue when
> PREPARE_WORK() is called, there's no difference from using
> INIT_WORK().  If the work item may be queued at the time of
> PREPARE_WORK(), we can't really tell whether the old or new function
> will be executed the next time.
> 
> We really don't want this level of subtlety in workqueue interface for
> such marginal use cases.  The previous patches converted all existing
> users away from PREPARE_[DELAYED_]WORK().  Let's remove them.
> 
> Signed-off-by: Tejun Heo <tj@...nel.org>
> Cc: Peter Hurley <peter@...leysoftware.com>
> Link: http://lkml.kernel.org/g/1392493119-9277-1-git-send-email-peter@hurleysoftware.com

Applied to wq/for-3.15.

Thanks.

-- 
tejun
--
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/