Re: [GIT PULL] x86/kaslr for v3.14

From: Pavel Machek
Date: Thu Jan 23 2014 - 04:39:30 EST


On Mon 2014-01-20 14:54:12, Linus Torvalds wrote:
> So I pulled this, but one question:
>
> On Mon, Jan 20, 2014 at 8:47 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
> > +config RANDOMIZE_BASE
> > + bool "Randomize the address of the kernel image"
> > + depends on RELOCATABLE
> > + depends on !HIBERNATION
>
> How fundamental is that "!HIBERNATION" issue? Right now that
> anti-dependency on hibernation support will mean that no distro kernel
> will actually use the kernel address space randomization. Which
> long-term is a problem.

Hibernation does some interesting tricks, and it did depend on image
layout staying same.

Rafael did some great work on x86-64 to enable resuming different
kernel version, so this should no longer be a problem (on
x86-64). Just test it, failure will not be subtle.
Pavel
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