Re: [PATCH RFC] gcc-plugins: Handle GCC version mismatch for OOT modules

Peter Zijlstra
2021-01-26T15:21:11Z

On Tue, Jan 26, 2021 at 08:51:55AM -0600, Josh Poimboeuf wrote:
> User space mixes compiler versions all the time. The C ABI is stable.
>
> What specifically is the harder issue you're referring to?

I don't think the C ABI captures nearly enough. Imagine trying to mix a
compiler with and without asm-goto support (ok, we fail to build without
by now, but just imagine).

No C ABI violated, but having that GCC extention vs not having it
radically changes the kernel ABI.

I think I'm with Greg here, just don't do it.