[PATCH v8 2/3] modpost: Produce extended MODVERSIONS information

[Luis Chamberlain]

On Thu, Oct 31, 2024 at 01:00:28PM -0700, Matthew Maurer wrote:
> > The question is, if only extended moversions are used, what new tooling
> > requirements are there? Can you test using only extended modversions?
> >
> >   Luis
> 
> I'm not sure precisely what you're asking for. Do you want:
> 1. A kconfig that suppresses the emission of today's MODVERSIONS
> format? 

Yes that's right, a brave new world, and with the warning of that.

> This would be fairly easy to do, but I was leaving it enabled
> for compatibility's sake, at least until extended modversions become
> more common. This way existing `kmod` tools and kernels would continue
> to be able to load new-style modules.

Sure, understood why we'd have both.

> 2. libkmod support for parsing the new format? I can do that fairly
> easily too, but wanted the format actually decided on and accepted
> before I started modifying things that read modversions.

This is implied, what I'd like is for an A vs B comparison to be able to
be done on even without rust modules, so that we can see if really
libkmod changes are all that's needed. Does boot fail without a new
libkmod for this? If so the Kconfig should specificy that for this new
brave new world.

If a distribution can leverage just one format, why would they not
consider it if they can ensure the proper tooling is in place. We
haven't itemized the differences in practice and this could help
with this. One clear difference so far is the kabi stuff, but that's
just evaluating one way of doing things so far, I suspect we'll get
more review on that from Petr soon.

  Luis