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More DTrace envy

More DTrace envy

Posted Jul 3, 2008 14:57 UTC (Thu) by mjg59 (subscriber, #23239)
In reply to: More DTrace envy by tzafrir
Parent article: More DTrace envy

You've missed the point. If Microsoft (say) end up holding the copyright on part of the
kernel, they get to enforce that copyright. If they interpret the GPL as preventing the
incorporation of the CDDLed dtrace then they get to sue everyone distributing the Linux/dtrace
combination. With that as a possibility, I just don't see any major Linux vendor taking the

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More DTrace envy

Posted Jul 3, 2008 15:29 UTC (Thu) by tzafrir (subscriber, #11501) [Link]

If it was already published as GPL, then they cannot change that. (Otherwise they would have
done so already). That's the nice thing about free software.

BTW: look at the Tentacles of Evil test in
. We try to assume the worst. We try to assume that the copyright owners
will suddenly become a second Caldera/SCO. The software must remain usage,
distributable, modifiable etc. even in that case. 

If a software fails that test it won't make it into Debian.

In fact, there are those who claim that the CDDL does not qualify because it fails exactly
that test (due to the choice of venue clause).

More DTrace envy

Posted Jul 3, 2008 15:48 UTC (Thu) by mjg59 (subscriber, #23239) [Link]

No, you're still missing the point. For the sake of argument, we'll assume that using the
CDDLed dtrace code in Linux is a violation of the GPL[1]. Let's also assume that none of the
Linux copyright holders are going to sue anyone who distributes this infringing combined work.
Now let's imagine that Microsoft buy a small Linux contracting company that holds the
copyright for part of the Linux kernel. Microsoft now get to enforce the GPL against anyone
shipping Linux in a way that violates it, and so file takedown notices against Red Hat and
Novell. The only defence these companies would have is "It's not a derivative work of the
kernel", which runs counter to arguments that they've made in the past. Do you really think
anyone wants to be open to that situation?

[1] As Bryan points out, this is a grey area. But I don't see any of the major Linux vendors
being keen on being the first to have that tested in court.

More DTrace envy

Posted Jul 3, 2008 16:04 UTC (Thu) by paulj (subscriber, #341) [Link]

You have completely ignored the "if the Linux copyright holders agree" condition repeated
several times across, at least, my comments.

It is entirely within the power of the copyright holders to define the licence used, including
adding their exceptions to the GPL, such as "incorporating CDDL code is ok". My understanding
is that the Linux licence has even been modified in the past, and unilaterally at that!

We could imagine otherwise, sure. We could also imagine Jonathan Schwartz as He-Man battling
it out with Linus as Skeletor over who is master of Greyskull*... (feel free to mentally
reverse the roles according to preference).

* NB: humour..

More DTrace envy

Posted Jul 3, 2008 16:13 UTC (Thu) by mjg59 (subscriber, #23239) [Link]

Some of the Linux copyright holders are dead. Some have merely vanished. One of them's a
company that tried to kill Linux a few years ago. In some cases we probably don't even have a
solid idea who the copyright holder is. Changing the license isn't a real possibility.

(The last time the license changed was in 1992, when it probably was possible to identify
everyone who'd contributed any code to Linux using a single person's fingers. Since then Linus
has clarified what his interpretation of the license is at various points, but these
clarifications aren't binding)

More DTrace envy

Posted Jul 3, 2008 18:02 UTC (Thu) by paulj (subscriber, #341) [Link]

ISTR some kind of brouha, discussed on LWN I think, not so long ago about Linus changing the
Linux copyright to exclude the possibility of upgrading its GPLv2 to GPLv3 (it was claimed he
hadn't actually changed the licence, but that wasn't accepted all? I dont quite remember).

More DTrace envy

Posted Jul 3, 2008 18:11 UTC (Thu) by paulj (subscriber, #341) [Link]

Huh, nm. You covered the GPLv2 clarification. My bad for not reading.

More DTrace envy

Posted Jul 3, 2008 18:04 UTC (Thu) by paulj (subscriber, #341) [Link]

Oh.. dead copyright holders either have successors in interest, or else they don't matter, is
what I suspect a lawyer would tell me.

More DTrace envy

Posted Jul 3, 2008 18:31 UTC (Thu) by mjg59 (subscriber, #23239) [Link]

Indeed, my understanding is that the copyright will generally end up with whoever holds the
estate. That doesn't make it easy to track them down.

More DTrace envy

Posted Jul 3, 2008 19:18 UTC (Thu) by paulj (subscriber, #341) [Link]

I bet there are ways to solve this problem, such as publicising a proposed change and asking
for objections. Perhaps the law has already dealt with cases where some minority of copyright
holders in a collective work can't be found and/or don't take an interest...

It's not Suns' problem though..

More DTrace envy

Posted Jul 3, 2008 19:33 UTC (Thu) by mjg59 (subscriber, #23239) [Link]

I agree - it's unfortunate for Linux that Sun chose a license that the GPL is incompatible
with, but they were entirely within their rights to do so. My only objection is to the
repeatedly raised "Linux people hate dtrace for irrational reasons" type claims. Linux vendors
feel they can't ship dtrace for justifiable legal reasons, which means that there's little
incentive to work on the technical details. Whatever NIH tendencies the Linux community may
have, they're not the reason for ignoring dtrace.

More DTrace envy

Posted Jul 3, 2008 21:32 UTC (Thu) by bronson (subscriber, #4806) [Link]

No, it's not Sun's problem.  Unfortunately, it's not Linux's problem either -- the GPLv2 was
written 15 years before the CDDL.

It's a mutual problem.

The Linux team is unable to modify the Linux Kernel's license, and the DTrace team sounds
quite unwilling to amend/modify/dual license DTrace, so I guess we're at an impasse.  Can
anything be done?

More DTrace envy

Posted Jul 3, 2008 21:51 UTC (Thu) by paulj (subscriber, #341) [Link]

I'm sure we could find licences which predate the GPL which also would *not* have served
OpenSolaris. E.g. Solaris engineering has a fairly strong BSD background and you can bet that
licence was at least mentioned..

So, sorry, that's just a daft argument.

More DTrace envy

Posted Jul 3, 2008 22:55 UTC (Thu) by bronson (subscriber, #4806) [Link]

Hm, I don't understand.  What is a daft argument?  That it's a mutual problem?  That combining
CDDL and GPL code appears to be at an impasse?

More DTrace envy

Posted Jul 3, 2008 18:35 UTC (Thu) by smoogen (subscriber, #97) [Link]

There are probably over 1000 Linux copyright holders. Getting 100% agreement out of 1000
people is rare if not impossible. One of the bonuses Sun can say as a business argument is
that OpenSolaris is 100% theirs and they can do whatever they want when they want without
having to get such agreement. 

More DTrace envy

Posted Jul 3, 2008 19:06 UTC (Thu) by paulj (subscriber, #341) [Link]

Getting 100% agreement out of 1000 people is rare if not impossible.

Asked a lawyer whether 100% of 1000+ is required? It's very tempting for programmers to try interpret law almost programmatically, yet incorrectly. There surely must be case law from the music industry..

This still isn't Suns' problem though. It's not reasonable to expect Sun to open-source Solaris under any licence but one that suits the needs of Solaris users and Suns' business (see Bryan's post, and ealier post of mine).

More DTrace envy

Posted Jul 3, 2008 17:50 UTC (Thu) by bcantrill (guest, #31087) [Link]

Now we've drifted into the absurd.  What are the supposed damages in this hypothetical case?
In the historical conflict between open and closed source, the case for damages is clear:  if
Hacker's GPL code is swiped by Meglocorp and ships as a (closed-source) component in a
Meglocorp product, the revenues from that product are (arguably) damaging Hacker.  But when
all of the components are open source, I don't really see the case for damages -- how could a
Linux copyright holder possibly be harmed by the presence of another open source component in
the same address space?  This is not a theoretical point, by the way:  if there are no
damages, there is no tort.

License incompatibility

Posted Jul 3, 2008 18:42 UTC (Thu) by corbet (editor, #1) [Link]

So you're saying that free software license incompatibility does not exist, at least as far as the US legal system goes?

License incompatibility

Posted Jul 3, 2008 20:23 UTC (Thu) by bcantrill (guest, #31087) [Link]

In terms of the law, I think that the GPL is in a dimly lit area to begin with -- and the
issue of free software license incompatibility extinguishes whatever light remains.  So
strictly in terms of case law, no, it doesn't exist. Not that this is desirable, of course; I
think software desperately needs legal precedent on the linking issue in particular.  If (as I
personally believe) dynamic linking does not create a derived work, there is no real
"incompatibility" issue to speak of, and we can stop wasting our collective time huffing and
puffing about it.  Unfortunately, it is in nearly everyone's best interests (FSF, companies,
lawyers) for this issue to stay murky -- and I expect it to remain so for the foreseeable

More DTrace envy

Posted Jul 3, 2008 18:42 UTC (Thu) by mjg59 (subscriber, #23239) [Link]

The DMCA allows for damages to be set at the profit realised as a result of the infringement
(504(b)). An injunction against Red Hat or Novell would almost certainly be rather more
crippling for them than the actual monetary damages.

More DTrace envy

Posted Jul 3, 2008 20:27 UTC (Thu) by bronson (subscriber, #4806) [Link]

> if there are no damages, there is no tort.

Erm, it's fairly easy to get injunctive relief and attorney's fees even without damages.

On top of this, there are plenty of reasons to sue other than tort.  Unfair competition,
deceptive business practices, breach of contract, etc.  Any of these might apply.

More generally, while article 3 of the constitution leaves this open for interpretation, a few
of the recent Supreme Court decisions have allowed large suits with some awfully vague damages
(Mass v. EPA).  And many states have their own laws, like CA's recent prop 64, that
essentially do allow tort without damages in certain circumstances.

So, depending the state where the lawsuit is brought and the current makeup of the Supreme
Court, your statement ranges from somewhat incorrect to completely false.

So, just because two entites are making no profits, that doesn't mean they can wantonly
violate their mutual licenses and contracts.  Now *that* would be absurd!

More DTrace envy

Posted Jul 3, 2008 20:45 UTC (Thu) by paulj (subscriber, #341) [Link]

So who is going to sue whom on what grounds? Say Novell ships a Linux-DTrace and SCO file for
injunction relief based on their copyright interest in Linux (see mjg's comments). What are
the grounds exactly?

If you really want to find reasons why you can't port DTrace, knock yourself out. Seems a
productive use of energy..

More DTrace envy

Posted Jul 3, 2008 20:55 UTC (Thu) by mjg59 (subscriber, #23239) [Link]

The argument would be that any Linux implementation of dtrace is going to end up being a
derived work of the Linux kernel, and therefore would have to be available under the terms of
the GPL. The CDDL includes restrictions not present in the GPL, making it impossible to
satisfy both licenses simultaneously. Shipping the combined work would therefore be a
violation of the GPL. In the absence of the GPL there's no further permission to distribute
the Linux (and Linux derived) code, and therefore doing so constitutes a copyright

Various people have various opinions on the validity of that argument. I'm aware of various
legal opinions that have been professionally offered. To the best of my knowledge, though,
there's no especially useful case law and so it's difficult to know which way the courts would
go. People tend to err on the side of caution when the potential cost (injunctions against
distributing their primary product) outweigh the potential benefit (a single, even if useful,

More DTrace envy

Posted Jul 4, 2008 0:52 UTC (Fri) by giraffedata (subscriber, #1954) [Link]

You missed his point. He's saying even stipulating that a Linux copyright holder would have a legal right to stop someone from distributing a Dtrace-enhanced Linux kernel, why would he do it?

The answer lies in the basis of the free software movement: Any free software activist who happens to be a copyright holder and able to stop Red Hat from distributing a Dtrace-enhanced Linux kernel would want to do so. The movement is about encouraging the proliferation of free software by restricting the proliferation of less free software, using copyright. So yes, he would deprive the world of Linux Dtrace so that 1) he wouldn't be personally contributing to the expansion of less free software, and 2) to put pressure on Red Hat to create some GPL alternative.

It's the same reason Linux people have sued router manufacturers for distributing enhanced Linux kernels that contain code for which you can't get the source.

More DTrace envy

Posted Jul 4, 2008 12:14 UTC (Fri) by mjg59 (subscriber, #23239) [Link]

You missed his point

No, I didn't.

More DTrace envy

Posted Aug 31, 2008 20:10 UTC (Sun) by rlhamil (guest, #6472) [Link]

> The movement is about encouraging the proliferation of free software by restricting the
> proliferation of less free software, using copyright.

_That's_ what makes me crazy about the GPL: to advance the Cause and preserve one's
own freedom, it restricts other freedoms that might have more immediate practical benefit.

I never saw how some could argue that BSD is _less_ free than GPL, especially the GPL
adherents, from whom there's usually the sucking sound of one-way transfers of code
from BSD to GPL. Someone creating a proprietary fork of a BSD licensed program takes
away _nothing_ from the freedom of those who continue to retain access to the pre-fork

GPL strikes me as equivalent to the mandatory volunteerism one sees in high schools today
(community service as a requirement of passing). A great idea to _offer_ such a thing, but
apalling to require it. There _is_no_virtue_ when virtue is enforced rather than chosen

Nevertheless, I don't deny it serves a purpose, just that its purpose is not and should not
be the only one worth serving.

Sure would be nice if someone worked out a way to dual-license that required that
derivatives of the dual-licensed code remain subject to the choice of license, but
was otherwise clearly non-viral, so that neither side could lay claim to more than what
they brought to the table, allowing DTrace, and zfs (native, not FUSE) on Linux, for example.
The source file scope of CDDL seems to me useful in that regard, avoiding issues about
static vs dynamic linking and binaries altogether. Despite that having more practical benefit
to Linux (which could then receive dual-licensed code) than OpenSolaris (for which I doubt
GPL ideologues and Linux zealots would choose to return the favor by dual-licensing
anything), simply getting more input might well at least improve the software shared as
a result faster than the originators alone could do so.

IMO, the _real_ problem isn't license incompatibility so much as it is what causes a lot of
it: hardware with closed specifications and thus closed drivers. But given the often blurry
line between hardware and software, enouraging open hardware specs might require
tolerating at last _narrowly scoped_ software patents, which are landmines in their own

There may not be any good answers given a range of perfectly legitimate if widely varying
interests. But I'd sure like to see an attempt to strike a different balance between
ideology (which carried to its logical conclusion is often self-contradictory) and pragmatic
concerns (which arguably are often short-sighted). And though they're not the same thing,
both cooperation _and_ competition serve a purpose; on the far side of Eternity, there may
be One True Answer, but until then, a selection of approaches remains useful, especially
given the power-tripping that those who think they have the One True Answer prematurely
tend to eventually descend to.

More DTrace envy

Posted Jul 3, 2008 22:46 UTC (Thu) by bronson (subscriber, #4806) [Link]

> So who is going to sue whom

Doesn't matter.

> on what grounds?

From my previous post: unfair competition, deceptive business practices, breach of contract,
etc.  Depends on the circumstances and parties.

> If you really want to find reasons why you can't port DTrace, knock yourself out.

Nobody's trying to create reasons not to port DTrace if that's what you're implying.  But
here's the thing: if it isn't clearly legal and moral to snake someone else's code, then it's
only considerate and safe to assume that you can't!

I've been searching for reasons to believe that they're compatible but I haven't found any
clear legal statement from Sun or anyone else, nor even any tiny nugget of estoppel.  Did Sun
ever produce the Devleoper's Bill of Rights?

More DTrace envy

Posted Jul 3, 2008 22:10 UTC (Thu) by bronson (subscriber, #4806) [Link]

I showed my engineer-attemptls-law post to a friend and she said:

> Sometimes when you sue for breach of contract, you can be awarded restitutionary damages
which means that even if you can't prove that you have been damaged, you can be awarded money
equivalent to the other party's "ill gotten gain".  So if the other party unfairly got some
advantage that was, for lack of a better term "unfair", you could recover their gain just
because it is unfair for them to keep it.

> That's one reason why it is dangerous for profitable companies to use open source code.  You
use code in a way that breaks your contract with the programmer ... that programmer could
recover your "ill gotten gain".

Wow.  Now I'm curious if this has been used in any of the GPL violation cases.  I'll have to
watch them a little closer!

More DTrace envy

Posted Jul 3, 2008 22:47 UTC (Thu) by bcantrill (guest, #31087) [Link]

You (or rather your friend) is making my point:  the restitutionary damages that she mentions
are the case of Meglocorp shipping GPL'd goober in proprietary product, and Hacker suing for
damages.  That's not the case that was being floated; the assertion was that Meglocorp would
become a Linux copyright holder and then could sue when CDDL'd source was distributed with
the(ir) GPL'd source.  I don't see what the damages are in this case -- compensatory or
restitutionary.  I think if it's flipped around -- Meglocorp ships GPL'd+CDDL'd goober, Hacker
sues because GPL has been violated -- one at least has a case, but I happen to think it's an
extraordinarily weak case: it relies on both an expansive definition of a derived work, and a
creative approach to damages.

More DTrace envy

Posted Jul 3, 2008 22:58 UTC (Thu) by mjg59 (subscriber, #23239) [Link]

Nobody knows how far the derived work clause of the GPL would actually reach. Staking your
future business to a legal gamble isn't a move many people are willing to make without a large
resulting benefit, and dtrace simply isn't perceived as a sufficiently large benefit. It's
perfectly rational reasoning.

More DTrace envy

Posted Jul 4, 2008 0:03 UTC (Fri) by bronson (subscriber, #4806) [Link]

> Meglocorp ships GPL'd+CDDL'd goober, Hacker sues because GPL has been violated

Agreed.  This is the only one that seems plausible.  But proving damages seems to be rather
easy nowadays.  And just about anybody involved with Meglocorp could sue; it doesn't have to
be a Linux kernel hacker.

Here's the big-picture problem as I see it: after the SCO disaster, the Linux kernel devs will
not incorporate any code of questionable license status into the kernel.  They want to keep
the entire tree completely unencumbered by legal issues.  It was a good lesson at a good time.

So, until it can be demonstrated that CDDL and GPL code absolutely can be mixed, they won't
accept CDDL-licensed code into the kernel.  it's just too risky.

As far as derived work, while I agree that those parts of the GPL are horribly murky and
untested, I don't think it's very relevant here...  Even if someone *could* claim that DTrace
is a derived work (a stretch!), as long as the CDDL+GPL combination is "licensed as a whole at
no charge to all third parties under the terms of [the GPL]" everything is good.  If the CDDL
and the GPL are compatible, the terms of the GPL are met, and the whole derived work issue is
moot.  (Right?)

To make CDDL+GPL compatible, IIUC the patent issues just need to be resolved the way Mozilla
did with the MPL.  Everything else in the CDDL and the GPL is compatible today.  (I'm no
expert though so I'd sure value someone else's opinion.  That almost sounds too easy!)

It would be nice to see someone reject license prejudices and try to maintain an out-of-tree
DTrace-Linux but...  can you imagine?  The git-rebases would make the even the heartiest
programmer cower in fear!


Posted Jul 3, 2008 23:13 UTC (Thu) by corbet (editor, #1) [Link]

This scenario, of course, depends on the idea that the GPL is a contract; the people who wrote the GPL did not intend that, however; they wrote a license. Assuming that legal reasoning holds, there's no contract to be sued for breaching. And no, I do not believe any GPL-violation case has been a breach-of-contract case; they are copyright infringement cases.


Posted Jul 3, 2008 23:17 UTC (Thu) by bcantrill (guest, #31087) [Link]

Yes, the authors did intend it to be a license -- but the attorneys that I have spoken with on
this issue believe that the expansive views of the GPL require it to be interpreted as a
contract.  Again, some case law here would be quite helpful...


Posted Jul 4, 2008 0:22 UTC (Fri) by bronson (subscriber, #4806) [Link]

That's a relief, although it does diminish the chances of me finding my code in the Google
Toolbar and making a quick hundred million.  :)

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