linux-kernel - Re: [PATCH for v3.18] mm/slab: fix unalignment problem on Malta with EVA due to slab merge

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <alpine.DEB.2.11.1410311015490.14859@gentwo.org>
Date:	Fri, 31 Oct 2014 10:17:16 -0500 (CDT)
From:	Christoph Lameter <cl@...ux.com>
To:	Joonsoo Kim <iamjoonsoo.kim@....com>
cc:	Andrew Morton <akpm@...ux-foundation.org>,
	Pekka Enberg <penberg@...nel.org>,
	David Rientjes <rientjes@...gle.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	Markos Chandras <Markos.Chandras@...tec.com>,
	linux-mips@...ux-mips.org
Subject: Re: [PATCH for v3.18] mm/slab: fix unalignment problem on Malta with
 EVA due to slab merge

On Fri, 31 Oct 2014, Joonsoo Kim wrote:

> alloc_unbound_pwq() allocates slab object from pool_workqueue. This
> kmem_cache requires 256 bytes alignment, but, current merging code
> doesn't honor that, and merge it with kmalloc-256. kmalloc-256 requires
> only cacheline size alignment so that above failure occurs. However,
> in x86, kmalloc-256 is luckily aligned in 256 bytes, so the problem
> didn't happen on it.

That luck will run out when you enable debugging. But then that also
usually means disablign merging.

> To fix this problem, this patch introduces alignment mismatch check
> in find_mergeable(). This will fix the problem.

Acked-by: Christoph Lameter <cl@...ux.com>
--
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/