Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759809AbZGIKOs (ORCPT ); Thu, 9 Jul 2009 06:14:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755833AbZGIKOk (ORCPT ); Thu, 9 Jul 2009 06:14:40 -0400 Received: from atrey.karlin.mff.cuni.cz ([195.113.26.193]:58411 "EHLO atrey.karlin.mff.cuni.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751609AbZGIKOk (ORCPT ); Thu, 9 Jul 2009 06:14:40 -0400 Date: Thu, 9 Jul 2009 12:14:33 +0200 From: Pavel Machek To: Jeremy Maitin-Shepard Cc: Nigel Cunningham , tuxonice-devel@lists.tuxonice.net, linux-kernel@vger.kernel.org, Rafael Wysocki Subject: Re: [TuxOnIce-devel] RFC: Suspend-to-ram cold boot protection by encrypting page cache Message-ID: <20090709101433.GG10937@elf.ucw.cz> References: <87hbxx0wcp.fsf@jeremyms.com> <4A4B0125.2090502@crca.org.au> <87d48k2992.fsf@jeremyms.com> <4A4B27D0.8020906@crca.org.au> <20090704024432.GB1345@ucw.cz> <87hbxn78o6.fsf@jeremyms.com> <20090704025755.GA1500@ucw.cz> <87d48b77nu.fsf@jeremyms.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87d48b77nu.fsf@jeremyms.com> X-Warning: Reading this can be dangerous to your mental health. User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1422 Lines: 34 On Wed 2009-07-08 04:09:41, Jeremy Maitin-Shepard wrote: > Pavel Machek writes: > > > On Wed 2009-07-08 03:47:53, Jeremy Maitin-Shepard wrote: > >> Pavel Machek writes: > >> > >> [snip] > >> > >> > I believe uswsusp could be used rather easily. Just modify s2disk to > >> > encrypt image in ram without writing it out, then decrypt it from ram > >> > and resume... it should be interesting hack. > >> > >> As far as I understand, that would be completely useless since the image > >> that would be encrypted would just be a copy of what would still remain > >> in memory. > > > Yes... so next step would be kernel call that would erase all the > > pagecache and anonymous pages. You would still leave some data in > > kernel structures, but that would be quite hard to fix. > > Okay. (This does still require the same assumption as TuxOnIce > regarding the page cache, though.) (Not sure; clearing the page cache could be done atomically, from interrupts disabled. But I'm no mm expert.) Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/