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Date: Mon, 28 Jan 2008 13:28:56 -0800
From: "H. Peter Anvin" <hpa@zytor.com>
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To: "Rafael J. Wysocki" <rjw@sisk.pl>
CC: Jeremy Fitzhardinge <jeremy@goop.org>, Pavel Machek <pavel@ucw.cz>,
       Ingo Molnar <mingo@elte.hu>, Ian Campbell <ijc@hellion.org.uk>,
       =?ISO-8859-1?Q?Mika_Penttil=E4?= <mika.penttila@kolumbus.fi>,
       linux-kernel@vger.kernel.org, Thomas Gleixner <tglx@linutronix.de>,
       Ingo Molnar <mingo@redhat.com>,
       "Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [PATCH] x86: Construct 32 bit boot time page tables in native
 format.
References: <1201167544.30671.64.camel@cthulhu.hellion.org.uk> <200801282126.45751.rjw@sisk.pl> <479E3EC6.5070800@goop.org> <200801282150.15411.rjw@sisk.pl>
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Rafael J. Wysocki wrote:
> On Monday, 28 of January 2008, Jeremy Fitzhardinge wrote:
>> Rafael J. Wysocki wrote:
>>> Actually, no.  We only do that with the kernel code mapping which should be
>>> safe as long as TLBs are not flushed (and they aren't).
>>>   
>> Er, what?  Assuming the TLB will retain some mappings while you 
>> overwrite the pagetable is a highly dubious prospect.  Are you copying 
>> the same values over, or something else?
> 
> As long as a relocatable kernel is not used to restore a non-relocatable one
> (or vice versa), we're copying the same values over.
> 

So that case is deliberately considered broken?

	-hpa