Re: [PATCH 00/46] gcc-LTO support for the kernel

Ard Biesheuvel
2022-11-14T11:59:52Z

On Mon, 14 Nov 2022 at 12:44, Jiri Slaby (SUSE) <jirislaby@kernel.org> wrote:
>
> Hi,
>
> this is the first call for comments (and kbuild complaints) for this
> support of gcc (full) LTO in the kernel. Most of the patches come from
> Andi. Me and Martin rebased them to new kernels and fixed the to-use
> known issues. Also I updated most of the commit logs and reordered the
> patches to groups of patches with similar intent.
>
> The very first patch comes from Alexander and is pending on some x86
> queue already (I believe). I am attaching it only for completeness.
> Without that, the kernel does not boot (LTO reorders a lot).
>

You didn't cc me on that patch so I will reply here: I don't think
this is the right solution.
On x86, there is a lot of stuff injected into .head.text that simply
does not belong there, and getting rid of the __head annotation and
dropping __HEAD from the Xen pvh head.S file would be a much better
solution.