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From: Jeremy Fitzhardinge <jeremy@goop.org>
To: Bill Irwin <bill.irwin@oracle.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Dan Kruchinin <dubalom@gmail.com>,
	linux-kernel@vger.kernel.org,
	Jeremy Fitzhardinge <jeremy@xensource.com>,
	Andi Kleen <ak@suse.de>, Ingo Molnar <mingo@elte.hu>,
	"Eric W. Biederman" <ebiederm@xmission.com>
Subject: Re: [RFC BUG?] dereference PAGE_OFFSET address (rc7-mm2)
Date: Wed, 02 May 2007 09:28:46 -0700	[thread overview]
Message-ID: <4638BC3E.9080708@goop.org> (raw)
In-Reply-To: <20070502100600.GZ26598@holomorphy.com>

Bill Irwin wrote:
> Brain dump before crashing for the night:
>
> The patch refuses to clobber already-present pagetable entries of
> whatever origin. There are pagetables prior to this setup covering the
> address range just above PAGE_OFFSET. If this theory is correct, you
> should only be able to go a few MB above PAGE_OFFSET before encountering
> unreadable kernel memory. IIRC those pagetables are a statically
> allocated array in assembly; altering that array to set supervisor bits
> may resolve it, though it may also be freed as initmem.
>   

I think this should be fixed now.  Eric made all those writes
unconditional (to fix a problem with PSE superpages not being created). 
The patch is in Andi's queue.

    J

  reply	other threads:[~2007-05-02 16:29 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2007-05-02  3:26 [RFC BUG?] dereference PAGE_OFFSET address (rc7-mm2) Dan Kruchinin
2007-05-02  7:51 ` Andrew Morton
2007-05-02  8:46   ` Bill Irwin
2007-05-02 10:06     ` Bill Irwin
2007-05-02 16:28       ` Jeremy Fitzhardinge [this message]
2007-05-02 16:32         ` Bill Irwin
2007-05-02 16:51           ` Andi Kleen
2007-05-02 17:16           ` Eric W. Biederman
2007-05-02 17:52             ` Bill Irwin
2007-05-02 19:13               ` Eric W. Biederman

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