From: Maxim Kammerer <mk@dee.su>
To: linux-mm@kvack.org
Subject: Re: PROBLEM: memtest tests only LOWMEM
Date: Thu, 12 Jan 2012 22:27:48 +0200 [thread overview]
Message-ID: <CAHsXYDCSCLCBwwDyzfAtW9sHLOkHQAaBxaBWaZ-ws0u7kknWkQ@mail.gmail.com> (raw)
In-Reply-To: <CAHsXYDCWJSCOe3DkK2kkR4Yvie6WW2DYCi=h_CAwjotwNZWihg@mail.gmail.com>
Hi,
There have been no reply in two weeks. Does it mean that this is the
wrong mailing list for this bug? Or that there is no interest in
fixing it?
Thanks,
Maxim
On Mon, Dec 26, 2011 at 04:18, Maxim Kammerer <mk@dee.su> wrote:
> 1. On 32-bit x86, memtest=n tests only LOWMEM memory (~ 895 MiB),
> HIGHMEM is ignored
>
> 2. On 3.0.4-hardened-r5, HIGHMEM memory (HIGHMEM64G in my tests) is
> apparently ignored during memtest. Looking at arch/x86/mm/memtest.c,
> no special mapping is performed (kmap/kunmap?), so it seems that at
> most ~895 MiB can be tested in 32-bit x86 kernels. This might not
> appear like an important issue (as there are other memory testing
> tools available), but memtest is extremely useful for anti-forensic
> memory wiping on shutdown/reboot in security-oriented distributions
> like Liberté Linux and Tails, and there is no other good substitute.
> See, for instance, some background in Debian bug
> http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=646361.
>
> 3. Keywords: memtest, highmem, mm, security
>
> 4. Kernel version: 3.0.4-hardened-r5 (Gentoo) x86 32-bit with PAE
--
Maxim Kammerer
Liberté Linux (discussion / support: http://dee.su/liberte-contribute)
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prev parent reply other threads:[~2012-01-12 20:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-12-26 2:18 Maxim Kammerer
2012-01-12 20:27 ` Maxim Kammerer [this message]
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