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Date: Tue, 09 Apr 2013 11:26:55 -0700
From: "H. Peter Anvin" <hpa@zytor.com>
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To: Kees Cook <keescook@chromium.org>
CC: "kernel-hardening@lists.openwall.com" 
	<kernel-hardening@lists.openwall.com>,
        Ingo Molnar <mingo@redhat.com>, LKML <linux-kernel@vger.kernel.org>,
        "x86@kernel.org" <x86@kernel.org>,
        Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
        Jeremy Fitzhardinge <jeremy@goop.org>,
        Marcelo Tosatti <mtosatti@redhat.com>, Alex Shi <alex.shi@intel.com>,
        Borislav Petkov <borislav.petkov@amd.com>,
        Alexander Duyck <alexander.h.duyck@intel.com>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
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	<virtualization@lists.linux-foundation.org>,
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        Julien Tinnes <jln@google.com>, Will Drewry <wad@chromium.org>,
        Eric Northup <digitaleric@google.com>
Subject: Re: [kernel-hardening] Re: [PATCH] x86: make IDT read-only
References: <20130408224328.GA17641@www.outflux.net> <51634935.9010905@zytor.com> <alpine.LFD.2.02.1304091122490.21884@ionos> <CAGXu5jKo=11RrsvctcZjP6dusAj659O_GsaA2J2qFq-6mOeRwQ@mail.gmail.com>
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On 04/09/2013 11:22 AM, Kees Cook wrote:
> 
> $ ./sgdt
> ffff88001fc04000
> # cat /sys/kernel/debug/kernel_page_tables
> ...
> ---[ Low Kernel Mapping ]---
> ...
> 0xffff880001e00000-0xffff88001fe00000         480M     RW         PSE GLB NX pmd
> 

That is the 1:1 memory map area...

	-hpa
-- 
H. Peter Anvin, Intel Open Source Technology Center
I work for Intel.  I don't speak on their behalf.

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