Re: [PATCH 05/18] arm64: kbuild: reserve reg x18 from general allocation by the compiler

Sami Tolvanen
2019-10-18T19:01:02Z

On Fri, Oct 18, 2019 at 10:32 AM 'Nick Desaulniers' via Clang Built
Linux <clang-built-linux@googlegroups.com> wrote:
> > and remove the mention from
> > the LL/SC compiler flag override.
>
> was that cut/dropped from this patch?
>
> >
> > Link: https://patchwork.kernel.org/patch/9836881/
>
> ^ Looks like it. Maybe it doesn't matter, but if sending a V2, maybe
> the commit message to be updated?

True. The original patch is from 2017 and the relevant part of
arm64/lib/Makefile no longer exists. I'll update this accordingly.

> I like how this does not conditionally reserve it based on the CONFIG
> for SCS. Hopefully later patches don't wrap it, but I haven't looked
> through all of them yet.

In a later patch x18 is only reserved with SCS. I'm fine with dropping
that patch and reserving it always, but wouldn't mind hearing thoughts
from the maintainers about this first.

Sami