> ZFS had a problem, where they were using something that should not be used (fp in kernel), which got removed and they had to find a replacement, which was GPL-only.
All that symbol did was tell the kernel to save the fpu registers.
It's dishonorable of the relevant kernel developers to pretend that's something relevant to the GPL.
It was more complicated than that. Some architectures do not support that.
And what's more pressing is, that it is an internal implementation details. Preserving it for ZFS would mean that they have to keep internal implementation detail for an external project, that does not care to cooperate!
These two symbols were obsolete for almost two decades. Should they keep them just for ZFS? Or should ZFS switch? If it were GPL project, or better, part of the kernel, it would be already fixed and everyone would go on with their lives.
There were two sets of exports. __kernel_fpu_begin/end and kernel_fpu_begin/end.
The only meaningful difference was that one was marked GPL and the other wasn't.
Removing the one with __ can be justified pretty easily.
Insisting that the ones they kept should still be marked 'GPL' is where it gets ridiculous. Going in and out of FPU mode is not something that makes your code derivative of the kernel code.
All that symbol did was tell the kernel to save the fpu registers.
It's dishonorable of the relevant kernel developers to pretend that's something relevant to the GPL.