Re: [PATCHES] gnu: linux-libre: Full retpoline support on x86 [spectre mitigation]

[ludo@gnu.org (Ludovic Courtès)]

Hi Mark,

Mark H Weaver <mhw@netris.org> skribis:

> Here are two patches that:
>
> * Add gcc-7.3.0-RC-20180117, which includes support for retpoline.
> * Use gcc-7.3 to build linux-libre on x86 systems.

With GCC 7.3.0 now out, I think you can go ahead.

> From 387a02c3f9e157bdf40b2b5ad0e53e5b209f3aa5 Mon Sep 17 00:00:00 2001
> From: Mark H Weaver <mhw@netris.org>
> Date: Sat, 20 Jan 2018 15:15:19 -0500
> Subject: [PATCH 1/2] gnu: gcc: Add gcc 7.3.0-RC-20180117 [includes retpoline
>  support].
>
> * gnu/packages/gcc.scm (gcc-7.3): New variable.

I think we can upgrade ‘gcc-7’ directly instead of introducing a new
‘gcc-7.3’ variable.  Thoughts?

> --- a/gnu/packages/linux.scm
> +++ b/gnu/packages/linux.scm
> @@ -283,6 +283,12 @@ for ARCH and optionally VARIANT, or #f if there is no such configuration."
>         ("bc" ,bc)
>         ("openssl" ,openssl)
>         ("kmod" ,kmod)
> +       ,@(match (system->linux-architecture
> +                 (or (%current-target-system) (%current-system)))
> +           ((or "x86_64" "i386")
> +            `(("gcc" ,gcc-7.3)))

Perhaps add a comment that this is for the retpoline mitigation.

Otherwise LGTM, thank you!

Ludo’.