From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ingo Molnar Subject: Re: [PATCH] Prefer kASLR over Hibernation Date: Thu, 7 Apr 2016 02:05:43 +0200 Message-ID: <20160407000543.GA26824@gmail.com> References: <20160406194404.GA11150@www.outflux.net> <20160406215638.GA25539@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-doc-owner@vger.kernel.org To: Kees Cook Cc: "Rafael J. Wysocki" , Linus Torvalds , Ard Biesheuvel , Matt Redfearn , Yves-Alexis Perez , Emrah Demir , Jonathan Corbet , "x86@kernel.org" , "Rafael J. Wysocki" , Len Brown , Pavel Machek , Borislav Petkov , Andy Lutomirski , "open list:DOCUMENTATION" , "linux-pm@vger.kernel.org" , Linux Kernel Mailing List , "kernel-hardening@lists.openwall.com" List-Id: linux-pm@vger.kernel.org * Kees Cook wrote: > >> I don't think this is a good idea, as it turns off emergency hibernation of > >> laptops - many desktop distros support it by default. > > > > Right, I forgot about this one. > > When I last checked Ubuntu doesn't enable hibernation by default any more: > https://help.ubuntu.com/16.04/ubuntu-help/power-hibernate.html > > And it seems like Fedora either doesn't either, or has a lot of people > for whom it doesn't work: > https://bugzilla.redhat.com/show_bug.cgi?id=1206936 > https://bugzilla.redhat.com/show_bug.cgi?id=1224151 > http://blog.kriptonium.com/2015/12/fedora-23-hibernate.html Ok, that's a relatively recent development, I distinctly remember my laptop being hibernated in such a fashion fairly recently. That makes it easier to hack around the kASLR incompatibility by making hibernation less useful. Personally I think that conceptually user space persistency (CRIU et al) is superior to kernel level hibernation - but user-space save/restore is nowhere near as complete as kernel hibernation, so it's still somewhat sad that it doesn't work ... Thanks, Ingo