I don't think they care about it having legal weight, that ship sailed long ago when they started advocating for just slapping SYMBOL_GPL on things out of spite; I think they care about excluding people from using their software.

IMO Linus should stop being half-and-half about it and either mark everything SYMBOL_GPL and see how well that goes or stop this nonsense.

I just don't understand why they're so anti-ZFS. I want my data to survive, please...

My impression is that some of the Linux kernel devs are anti-anything that's not GPL-compatible, of any sort, regardless of the particulars.

Linus himself also made remarks about ZFS at one point that were pretty...hostile. [1] [2]

> The fact is, the whole point of the GPL is that you're being "paid" in terms of tit-for-tat: we give source code to you for free, but we want source code improvements back. If you don't do that but instead say "I think this is _legal_, but I'm not going to help you" you certainly don't get any help from us.

> So things that are outside the kernel tree simply do not matter to us. They get absolutely zero attention. We simply don't care. It's that simple.

> And things that don't do that "give back" have no business talking about us being assholes when we don't care about them.

> See?

Note that there's at least one unfixed Linux kernel bug that was found by OpenZFS users, reproducible without using OpenZFS in any way, reported with a patch, and ignored. [3]

So "not giving back" is a dubious claim.

[1] - https://arstechnica.com/gadgets/2020/01/linus-torvalds-zfs-s...

[2] - https://www.realworldtech.com/forum/?threadid=189711&curpost...

[3] - https://bugzilla.kernel.org/show_bug.cgi?id=212295

Was ifconfig made to be hostile too? :D

(/s)

That's frankly speaking untrue - we have one off-hand comment by one person from Sun for this, and multiple claims opposite.

Also, ZFS goes with the same licensing interpretation as Linus used with AFS.

We see how well "including people into using your software" works out for pushover licenses almost every week now, FreeBSD itself being the prime example, having lost three major companies one after another from its list of users, sponsors, and developers a couple of years ago. Not that there were many to begin with. What Linus and the gang are doing have been working out great over the long term (much better than any competition, at least).

>having lost three major companies one after another from its list of users, sponsors, and developers a couple of years ago.

Which three?

Why don't you think it has legal weight? Or did you mean something else?

As far as know the point of EXPORT_SYMBOL_GPL was to push back on companies like Nvidia who wanted to exploit loopholes in the GPL. That seems to me like a reasonable objective.

Relevant Torvalds quote: https://yarchive.net/comp/linux/export_symbol_gpl.html

Sure, and that alone isn't an unreasonable premise - as he says, intent matters.

But if you're marking interfaces as GPL-only, or implementing taint detection that means if you use a non-SYMBOL_GPL kernel symbol which calls a GPL-only function it treats the non-SYMBOL_GPL symbol as GPL-only and blocks your linking, it gets a bit out of hand.

Building the kernel with certain kernel options makes modules like OpenZFS or OpenAFS not link because of that taint propagation - because things like the lockdep checker turn uninfringing calls into infringing ones.

Or a little while ago, there was a change which broke building on PPC because a change made a non-SYMBOL_GPL call on POWER into a SYMBOL_GPL one indirectly, and when the original author was contacted, he sent a patch reverting the changed symbol, and GregKH refused to pull it into stable, suggesting distros could carry it if they wanted to. (Of course, he had happily merged a change into -stable earlier that just implemented more aggressive GPL tainting and thereby broke things like the aforementioned...)

The Linux kernel has never supported out of tree modules like how ZFS works out of tree.

All ZFS needs to do is just have one of Oracles many lawyers say "CDDL is compatible with GPL". Yet, they Oracle don't.

"All."

It's explicitly not compatible with GPL, though. It has clauses that are more restrictive than GPL, and IIRC some people who contributed to the OpenZFS project did so explicitly without allowing later CDDL license revisions, which removes Oracle's ability to say CDDL-2 or whatever is GPL-compatible.

So even if someone rolled up dumptrucks of cash and convinced Oracle that everything was great, they don't have all the control needed to do that.

To have legal weight, it has to be a signal that you're implementing something that is derivative of kernel code. That's the directly stated intent of EXPORT_SYMBOL_GPL.

But "call an opaque function that saves SIMD state" is obviously not derivative of the kernel code in any way. The more exports that get badly marked this way, the more EXPORT_SYMBOL_GPL becomes indistinguishable from EXPORT_SYMBOL.

I see it as just a kind of "warranty void if seal broken". Don't do this or you may be in violation of the GPL. Maybe a legal court in $country would find in your favour (I'm not convinced it's as clear cut as you imply). Maybe they would find that you willfully infringed, despite the kernel devs clearly warning you not to do it.

The main "legal effect" I see is that you are not willing to take that risk, just like Oracle isn't.

If the goal was to prove someone saw the GPL, then the entire license enforcement mechanism wouldn't be in the kernel.

If enough symbols get restricted without valid copyright-based reasons, modules that legitimately have non-GPL licenses will have to lie to the kernel to get loaded. And that's a stupid situation all around.