linux-kernel - Re: [Xen-devel] [PATCH 2/2] x86: add pte_set_flags/clear

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <497E14E3.2080509@goop.org>
Date:	Mon, 26 Jan 2009 11:54:11 -0800
From:	Jeremy Fitzhardinge <jeremy@...p.org>
To:	Jan Beulich <jbeulich@...ell.com>
CC:	Ingo Molnar <mingo@...e.hu>,
	Xen-devel <xen-devel@...ts.xensource.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Nick Piggin <nickpiggin@...oo.com.au>
Subject: Re: [Xen-devel] [PATCH 2/2] x86: add	 pte_set_flags/clear_flags	
 forpteflag manipulation

Jan Beulich wrote:
> Whether a pte is live doesn't matter here: If you change P on Xen, the
> frame number representation *must* change from/to PFN to/from MFN.
> In no case (other than iomem pages) is it allowed to flip just this bit.

Yes, true. Same with _PAGE_SPECIAL, which is actually flipped by code 
here.  I guess a warning here might be useful, but really the calling 
code needs to be properly disciplined; after all setting P on a swap 
entry is no fun either.

    J
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/