linux-kernel - Re: Major slab mem leak with 2.6.17 / GCC 4.1.1

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, 16 Oct 2006 09:07:30 +0100
From:	"Catalin Marinas" <catalin.marinas@...il.com>
To:	"Mike Galbraith" <efault@....de>
Cc:	"Pekka Enberg" <penberg@...helsinki.fi>,
	"nmeyers@...tmark.com" <nmeyers@...tmark.com>,
	linux-kernel@...r.kernel.org
Subject: Re: Major slab mem leak with 2.6.17 / GCC 4.1.1

On 16/10/06, Mike Galbraith <efault@....de> wrote:
> On Sun, 2006-10-15 at 07:59 +0000, Mike Galbraith wrote:
>
> > 2.6.19-rc1 + patch-2.6.19-rc1-kmemleak-0.11 compiles fine now (unless
> > CONFIG_DEBUG_KEEP_INIT is set), boots and runs too.. but axle grease
> > runs a lot faster ;-)  I'll try a stripped down config sometime.
>
> My roughly three orders of magnitude (amusing to watch:) boot slowdown
> turned out to be stack unwinding.  With CONFIG_UNWIND_INFO disabled,
> 2.6.19-rc2 + patch-2.6.19-rc1-kmemleak-0.11 runs just fine.

Kmemleak introduces some overhead but shouldn't be that bad.
DEBUG_SLAB also introduces an overhead by erasing the data in the
allocated blocks.

Note that if the allocated blocks are added to a list and never
removed, kmemleak won't be able to detect the leak as the objects are
stilled referred. In this case, you can only use DEBUG_SLAB_LEAK.

-- 
Catalin
-
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/