Re: [v3 03/12] x86/fsgsbase/64: Add intrinsics/macros for FSGSBASE instructions

From: Linus Torvalds
Date: Thu Oct 25 2018 - 19:32:01 EST

On Thu, Oct 25, 2018 at 4:14 PM Andy Lutomirski <luto@xxxxxxxxxx> wrote:
> On Wed, Oct 24, 2018 at 12:21 PM Andi Kleen <ak@xxxxxxxxxxxxxxx> wrote:
> >
> > BTW the other option would be to update the min-binutils requirement
> > to 2.21 (currently it is 2.20) and then write it directly without .byte.
> > I believe 2.21 added support for these instructions.
> >
> > (It's only a binutils requirement, don't need gcc support)
> I'd personally be fine with this. Linus? Thomas? Ingo?

I always vote for "require modern tools" as long as it doesn't cause problems.

binutils-2.21 is something like seven years old by now, but the real
issue would be what versions distros are actually shipping. I don't
want people to have to build their own binutils just to build a

It's usually some ancient enterprise distro that is stuck on old
versions. Anybody have any idea?