Re: [PATCH v11 00/11] x86: PIE support to extend KASLR randomization

From: Peter Zijlstra
Date: Tue Mar 03 2020 - 04:56:21 EST


On Mon, Mar 02, 2020 at 09:02:15PM -0800, Kees Cook wrote:
> On Thu, Feb 27, 2020 at 04:00:45PM -0800, Thomas Garnier wrote:
> > Minor changes based on feedback and rebase from v10.
> >
> > Splitting the previous serie in two. This part contains assembly code
> > changes required for PIE but without any direct dependencies with the
> > rest of the patchset.
> >
> > Note: Using objtool to detect non-compliant PIE relocations is not yet
> > possible as this patchset only includes the simplest PIE changes.
> > Additional changes are needed in kvm, xen and percpu code.
> >
> > Changes:
> > - patch v11 (assembly);
> > - Fix comments on x86/entry/64.
> > - Remove KASLR PIE explanation on all commits.
> > - Add note on objtool not being possible at this stage of the patchset.
>
> This moves us closer to PIE in a clean first step. I think these patches
> look good to go, and unblock the work in kvm, xen, and percpu code. Can
> one of the x86 maintainers pick this series up?

But,... do we still need this in the light of that fine-grained kaslr
stuff?

What is the actual value of this PIE crud in the face of that?