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Date: Thu, 7 Apr 2016 02:05:43 +0200
From: Ingo Molnar <mingo@kernel.org>
To: Kees Cook <keescook@chromium.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>,
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Subject: Re: [PATCH] Prefer kASLR over Hibernation
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* Kees Cook <keescook@chromium.org> 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