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

David Laight
2021-03-08T09:40:42Z

> - "External modules must be built with the same GCC version"
>
> As has been stated repeatedly, by Linus and others, there's no
> technical reason behind this claim. It ignores the realities of how
> distros release the kernel and compiler independently, with separate
> cadences. Minor variances in compiler version are ABI compatible.

Aren't major versions ABI compatible?
Otherwise it is a different architecture.

> Also, for features which are dependent on compiler version, many of
> those are now enabled by kbuild. As I suggested to you previously,
> kbuild should warn when such features get disabled (which can happen
> due to a compiler/toolchain change or due to a .config copied from
> another system).

Anything that is just an optimisation (or pessimisation) really
doesn't matter.
AFAICT most of these options are in the latter category.

One think people might do is download a kernel from kernel.org
and then build an extra module for it.
The compiler they have will be completely different.

David

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