linux-kernel - Re: [PATCH] x86: Construct 32 bit boot time page tables in native format.

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Date:	Mon, 28 Jan 2008 13:28:56 -0800
From:	"H. Peter Anvin" <hpa@...or.com>
To:	"Rafael J. Wysocki" <rjw@...k.pl>
CC:	Jeremy Fitzhardinge <jeremy@...p.org>, Pavel Machek <pavel@....cz>,
	Ingo Molnar <mingo@...e.hu>, Ian Campbell <ijc@...lion.org.uk>,
	Mika Penttilä <mika.penttila@...umbus.fi>,
	linux-kernel@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>
Subject: Re: [PATCH] x86: Construct 32 bit boot time page tables in native
 format.

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
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