Re: [PATCH 12/23] kbuild: avoid re-running compiler and linker probes

[Lorenzo Stoakes (ARM)]

On Fri, Sep 11, 2026 at 08:17:57PM +0200, Nicolas Schier wrote:
> On Fri, Sep 11, 2026 at 06:33:33PM +0100, David Laight wrote:
> > On Thu, 10 Sep 2026 17:42:35 +0200
> > Nicolas Schier <n.schier@xxxxxxxxx> wrote:
> >
> > ...
> > > Yes, skimming through the patch, I thought about that, too.  Moving more
> > > cc option checks to Kconfig will make building out-of-tree kmods with a
> > > different compiler more dangerous.  Maybe we will have to make the
> > > warning in Makefile's prepare (external kmods) target a bit louder.
> >
> > One problem is that distributions have a nasty habit of shipping kernels
> > that are compiled with a different compiler version to they actually
> > ship as a compiler.
> > In some cases the versions are clearly the same - but the version
> > strings differ.
>
> yeah, I guess you hit the mark.

I mean this is a problem that already exists for any flags already specified in
Kconfig.

Out-of-tree modules are historically something that we don't go to great lengths
to support and haven't historically worried about breaking, either.

I'm sure distros can find ways around this if a problem were to arise. But I
don't think it's something to worry about all that much.

I expect a _lot_ of these, in any case, would only require the compilers to be
within a fair few major versions of one another anyway.

>
> --
> Nicolas

--
Cheers, Lorenzo