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-next>] [day] [month] [year] [list]
Message-Id: <1222708257.4723.23.camel@localhost.localdomain>
Date:	Mon, 29 Sep 2008 19:10:57 +0200
From:	Gerald Schaefer <gerald.schaefer@...ibm.com>
To:	linux-kernel@...r.kernel.org
Cc:	linux-mm@...ck.org, schwidefsky@...ibm.com,
	heiko.carstens@...ibm.com,
	KAMEZAWA Hiroyuki <kamezawa.hiroyu@...fujitsu.com>,
	Yasunori Goto <y-goto@...fujitsu.com>,
	Mel Gorman <mel@....ul.ie>, Andy Whitcroft <apw@...dowen.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: setup_per_zone_pages_min(): zone->lock vs. zone->lru_lock

Hi,

is zone->lru_lock really the right lock to take in setup_per_zone_pages_min()?
All other functions in mm/page_alloc.c take zone->lock instead, for working
with page->lru free-list or PageBuddy().

setup_per_zone_pages_min() eventually calls move_freepages(), which is also
manipulating the page->lru free-list and checking for PageBuddy(). Both
should be protected by zone->lock instead of zone->lru_lock, if I understood
that right, or else there could be a race with the other functions in
mm/page_alloc.c.

We ran into a list corruption bug in free_pages_bulk() once, during memory
hotplug stress test, but cannot reproduce it easily. So I cannot verify if
using zone->lock instead of zone->lru_lock would fix it, but to me it looks
like this may be the problem.

Any thoughts?

BTW, I also wonder if a spin_lock_irq() would be enough, instead of
spin_lock_irqsave(), because this function should never be called from
interrupt context, right?

Thanks,
Gerald


--
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/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ