linux-kernel - Re: [S+Q2 07/19] slub: Allow removal of slab caches during boot

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]

Message-ID: <1279498030.10390.1760.camel@pasglop>
Date:	Mon, 19 Jul 2010 10:07:10 +1000
From:	Benjamin Herrenschmidt <benh@...nel.crashing.org>
To:	David Rientjes <rientjes@...gle.com>
Cc:	Christoph Lameter <cl@...ux-foundation.org>,
	Pekka Enberg <penberg@...helsinki.fi>, linux-mm@...ck.org,
	Roland Dreier <rdreier@...co.com>,
	linux-kernel@...r.kernel.org, Nick Piggin <npiggin@...e.de>
Subject: Re: [S+Q2 07/19] slub: Allow removal of slab caches during boot

On Wed, 2010-07-14 at 16:48 -0700, David Rientjes wrote:
> On Fri, 9 Jul 2010, Christoph Lameter wrote:
> 
> > If a slab cache is removed before we have setup sysfs then simply skip over
> > the sysfs handling.
> > 
> > Cc: Benjamin Herrenschmidt <benh@...nel.crashing.org>
> > Cc: Roland Dreier <rdreier@...co.com>
> > Signed-off-by: Christoph Lameter <cl@...ux-foundation.org>
> 
> Acked-by: David Rientjes <rientjes@...gle.com>
> 
> I missed this case earlier because I didn't consider slab caches being 
> created and destroyed prior to slab_state == SYSFS, sorry!

Ok so I may be a bit sleepy or something but I still fail to see how
this whole thing isn't totally racy...

AFAIK. By the time we switch the slab state, we -do- have all CPUs up
and can race happily between creating slab caches and creating the sysfs
files...

Ben.
 

--
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/