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Date: Thu, 09 Aug 2007 19:35:39 -0400
From: Chuck Ebbert <cebbert@redhat.com>
Organization: Red Hat
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To: Andi Kleen <andi@firstfloor.org>
CC: linux-kernel <linux-kernel@vger.kernel.org>,
       Jeremy Fitzhardinge <jeremy@goop.org>
Subject: Re: i386 doublefault handler is broken with CONFIG_DEBUG_SPINLOCK
References: <46BB4599.2020900@redhat.com> <p73zm10egym.fsf@bingen.suse.de> <46BB5F9B.6050808@redhat.com> <20070809231618.GC1845@one.firstfloor.org>
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On 08/09/2007 07:16 PM, Andi Kleen wrote:
> 
> I tested it. Even on a box without spin lock debugging I get a hard
> hang after
> 
> double fault, gdt at c1404000 [255 bytes]
> 
> even though it should have printed the registers.
> So it looks like there is more broken in the DF handler than just
> this.

Looks like it just fails the ptr_ok() test:

#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + 0x1000000)

page_offset  c0000000
            + 1000000

           < c1404000

What should that be changed to, or is there some easier way to test that?