From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andi Kleen <andi@firstfloor.org>
Subject: Re: [PATCH] Fix performance problems with mprotect()
Date: Mon, 07 Jan 2008 16:18:59 +0100
Message-ID: <p73d4sdsly4.fsf@bingen.suse.de>
References: <477EAC09.5C6B.0048.1@novell.com>
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In-Reply-To: <477EAC09.5C6B.0048.1@novell.com> (Bruce Rogers's message of
	"Fri\, 04 Jan 2008 21\:49\:41 -0700")
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"Bruce Rogers" <brogers@novell.com> writes:
> +
> +        /* Allowed to change in Accessed/Dirty flags only. */
> +        BUG_ON((t ^ old) & ~(intpte_t)(_PAGE_ACCESSED|_PAGE_DIRTY));


Are you sure that BUG_ON can't be triggered from the hypercall?
It should error out in this case I think.

-Andi