Patent issues are not new for the linux kernel. Redhat patented Ingo Molnar's work, and the SELinux project faced patent claims from the company hired to do most of the coding. Now patent concerns are plauging the VM. Linux Weekly News has posted a few stories, and Slashdot picked them up. However, none of these summaries reflect the breath of debate found on the lkml. The debate centers around this question: What should OSS projects do about software patents?

I have included some of the more relevant posts (at last count google indicates that there are 109 posts in the thread, though not all of them discuss the patent issues) so that all arguments can be examined. Included emails are from Rob Landley, Daniel Phillips, Alexander Viro, Rik van Riel [earlier interview], Larry McVoy [earlier interview], Alan Cox [earlier interview] and Linus Torvalds.

From: Alan Cox
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 12:20:05 PST

On Fri, 2002-08-09 at 16:20, Daniel Phillips wrote:
> On Sunday 04 August 2002 19:19, Hubertus Franke wrote:
> > "General Purpose Operating System Support for Multiple Page Sizes"
> > link
> 
> This reference describes roughly what I had in mind for active 
> defragmentation, which depends on reverse mapping.  The main additional
> wrinkle I'd contemplated is introducing a new ZONE_LARGE, and GPF_LARGE,
> which means the caller promises not to pin the allocation unit for long
> periods and does not mind if the underlying physical page changes
> spontaneously.  Defragmenting in this zone is straightforward.

Slight problem. This paper is about a patented SGI method for handling
defragmentation into large pages (6,182,089). They patented it before
the presentation.

They also hold patents on the other stuff that you've recently been
discussing about not keeping seperate rmap structures until there are
more than some value 'n' when they switch from direct to indirect lists
of reverse mappings (6,112,286)

If you are going read and propose things you find on Usenix at least
check what the authors policies on patents are.

Perhaps someone should first of all ask SGI to give the Linux community
permission to use it in a GPL'd operating system ?


From: Daniel Phillips
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 15:40:07 PST 

See 'straightforward' above, i.e., obvious to a practitioner of the art.
This is another one-click patent.

Look at claim 16, it covers our buddy allocator quite nicely:

   link
 
Claim 1 covers the idea of per-size freelist thresholds, below which no
coalescing is done.

Claim 13 covers the idea of having a buddy system on each node of a numa
system.  Bill is going to be somewhat disappointed to find out he can't do
that any more.

It goes on in this vein.  I suggest all vm hackers have a close look at
this.  Yes, it's stupid, but we can't just ignore it.

> They also hold patents on the other stuff that you've recently been
> discussing about not keeping seperate rmap structures until there are
> more than some value 'n' when they switch from direct to indirect lists
> of reverse mappings (6,112,286)

This is interesting.  By setting their 'm' to 1, you get essentially the
scheme implemented by Dave a few weeks ago, and by setting 'm' to 0, the
patent covers pretty much every imaginable reverse mapping scheme.  Gee,
so SGI thought of reverse mapping in 1997 or thereabouts, and nobody ever
did before?

   link

Claim 2 covers use of their reverse mapping scheme, which as we have seen,
includes all reverse mapping schemes, for migrating the data content of
pages, and updating the page table pointers.

Claim 4 goes on to cover migration of data pages between nodes of a numa
system.  (Got that wli?)

This patent goes on to claim just about everything you can do with a
reverse map.  It's sure lucky for SGI that they were the first to think
of the idea of reverse mapping.

> If you are going read and propose things you find on Usenix at least
> check what the authors policies on patents are.

As always, I developed my ideas from first principles.  I never saw or
heard of the paper until a few days ago.  I don't need their self-serving
paper to figure this stuff out, and if they are going to do blatantly
commercial stuff like that, I'd rather the paper were not published at
all.  Perhaps Usenix needs to establish a policy about that.

> Perhaps someone should first of all ask SGI to give the Linux community
> permission to use it in a GPL'd operating system ?

Yes, we should ask nicely, if we run into something that matters.  Asking
nicely isn't the only option though.

And yes, I'm trying to be polite.  It's just so stupid.

--
Daniel

From: Linus Torvalds
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 16:11:12 PST

On Mon, 12 Aug 2002, Daniel Phillips wrote:
> 
> It goes on in this vein.  I suggest all vm hackers have a close look at
> this.  Yes, it's stupid, but we can't just ignore it.

Actually, we can, and I will.

I do not look up any patents on _principle_, because (a) it's a horrible 
waste of time and (b) I don't want to know. 

The fact is, technical people are better off not looking at patents. If
you don't know what they cover and where they are, you won't be knowingly
infringing on them. If somebody sues you, you change the algorithm or you 
just hire a hit-man to whack the stupid git.

			Linus

From: Linus Torvalds
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 16:11:12 PST

On Sun, 11 Aug 2002, Linus Torvalds wrote:
> 
> If somebody sues you, you change the algorithm or you just hire a
> hit-man to whack the stupid git.

Btw, I'm not a lawyer, and I suspect this may not be legally tenable 
advice. Whatever. I refuse to bother with the crap.

		Linus


From: Alan Cox
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 16:30:10 PST

On Sun, 2002-08-11 at 23:56, Linus Torvalds wrote:
> 
> On Sun, 11 Aug 2002, Linus Torvalds wrote:
> > 
> > If somebody sues you, you change the algorithm or you just hire a
> > hit-man to whack the stupid git.
> 
> Btw, I'm not a lawyer, and I suspect this may not be legally tenable 
> advice. Whatever. I refuse to bother with the crap.

In which case you might as well do the rest of the world a favour and
restrict US usage of Linux in the license file while you are at it.
Unfortunately the USA forces people to deal with this crap. I'd hope SGI
would be decent enough to explicitly state they will license this stuff
freely for GPL use (although having shipping Linux themselves the
question is partly moot as the GPL says they can't impose additional
restrictions)

Alan


From: Daniel Phillips
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 16:50:05 PST

On Monday 12 August 2002 02:46, Alan Cox wrote:
> On Sun, 2002-08-11 at 23:56, Linus Torvalds wrote:
> > 
> > On Sun, 11 Aug 2002, Linus Torvalds wrote:
> > > 
> > > If somebody sues you, you change the algorithm or you just hire a
> > > hit-man to whack the stupid git.
> > 
> > Btw, I'm not a lawyer, and I suspect this may not be legally tenable 
> > advice. Whatever. I refuse to bother with the crap.
> 
> In which case you might as well do the rest of the world a favour and
> restrict US usage of Linux in the license file while you are at it.
> Unfortunately the USA forces people to deal with this crap. I'd hope SGI
> would be decent enough to explicitly state they will license this stuff
> freely for GPL use (although having shipping Linux themselves the
> question is partly moot as the GPL says they can't impose additional
> restrictions)

I do not agree that it is enough to license it for 'GPL' use.  If there is
a license, it should impose no restrictions that the GPL does not.  There
is a big distinction.  Anything else, and the licensor is sending the message 
that they reserve the right to enforce against Linux users.

In other words, a license grant has to cover *all* uses of Linux and not just 
GPL uses.

In my opinion, RedHat has set a bad example by stopping short of promising 
free use of Ingo's patents for all Linux users.  We are entering a difficult 
time, and such a wrong-footed move simply makes it more difficult.

-- 
Daniel

From: Rob Landley
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-13 07:00:09 PST

On Sunday 11 August 2002 07:44 pm, Daniel Phillips wrote:

> In other words, a license grant has to cover *all* uses of Linux and not
> just GPL uses.

Including a BSD license where source code is never released?  Or dot-net 
application servers hosted on a Linux system under lock and key in a vault 
somewhere?  And no termination clause, so this jerk can still sue you over 
other frivolous patents?

So you would object to microsoft granting rights to its patents saying "you 
can use this patent in software that runs on windows, but use it on any other 
platform and we'll sue you", but you don't mind going the other way?

Either way BSD gets the shaft, of course.  But then BSDI was doing that them 
a decade ago, and Sun hired away Bill Joy and forked off SunOS years before 
that, so they should be used to it by now... :)  (And BSD runs plenty of GPL 
application code...)

> In my opinion, RedHat has set a bad example by stopping short of promising
> free use of Ingo's patents for all Linux users.  We are entering a
> difficult time, and such a wrong-footed move simply makes it more
> difficult.

Imagine a slimeball company that puts out proprietary software, gets a patent 
on turning a computer on, and sues everybody in the northern hemisphere ala 
rambus.  They run a Linux system in the corner in their office, therefore 
they are "a linux user".  How do you stop somebody with that mindset from 
finding a similarly trivial loophole in your language?  (Think Spamford 
Wallace.  Think the CEO of Rambus.  Think Unisys and the gif patent.  Think 
the people who recently got a patent on JPEG.  Think the british telecom 
idiots trying to patent hyperlinking a decade after Tim Berners-Lee's first 
code drop to usenet...)

Today, all these people do NOT sue IBM, unless they're really stupid.  (And 
if they do, they will have cross-licensed their patent portfolio with IBM in 
a year or two.  Pretty much guaranteed.)

Rob

From: Larry McVoy
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 17:00:07 PST

On Sun, Aug 11, 2002 at 08:42:16PM -0300, Rik van Riel wrote:
> On 12 Aug 2002, Alan Cox wrote:
> 
> > Unfortunately the USA forces people to deal with this crap. I'd hope SGI
> > would be decent enough to explicitly state they will license this stuff
> > freely for GPL use
> 
> I seem to remember Apple having a clause for this in
> their Darwin sources, forbidding people who contribute
> code from suing them about patent violations due to
> the code they themselves contributed.

IBM has a fantastic clause in their open source license.  The license grants
you various rights to use, etc., and then goes on to say something in 
the termination section (I think) along the lines of 

	In the event that You or your affiliates instigate patent, trademark,
	and/or any other intellectual property suits, this license terminates
	as of the filing date of said suit[s].

You get the idea.  It's basically "screw me, OK, then screw you too" language.
-- 

---
Larry McVoy            	 lm at bitmover.com           http://www.bitmover.com/lm 


From: Daniel Phillips
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-12 01:30:09 PST

On Monday 12 August 2002 01:50, Larry McVoy wrote:
> On Sun, Aug 11, 2002 at 08:42:16PM -0300, Rik van Riel wrote:
> > On 12 Aug 2002, Alan Cox wrote:
> > 
> > > Unfortunately the USA forces people to deal with this crap. I'd hope SGI
> > > would be decent enough to explicitly state they will license this stuff
> > > freely for GPL use
> > 
> > I seem to remember Apple having a clause for this in
> > their Darwin sources, forbidding people who contribute
> > code from suing them about patent violations due to
> > the code they themselves contributed.
> 
> IBM has a fantastic clause in their open source license.  The license grants
> you various rights to use, etc., and then goes on to say something in 
> the termination section (I think) along the lines of 
> 
> 	In the event that You or your affiliates instigate patent, trademark,
> 	and/or any other intellectual property suits, this license terminates
> 	as of the filing date of said suit[s].
> 
> You get the idea.  It's basically "screw me, OK, then screw you too" language.

Yes.  I would like to add my current rmap optimization work, if it is worthy
for the usual reasons, to the kernel under a DPL license which is in every
respect the GPL, except that it adds one additional restriction along the
lines:

  "If you enforce a patent against a user of this code, or you have a
   beneficial relationship with someone who does, then your licence to
   use or distribute this code is automatically terminated"

with more language to extend the protection to the aggregate work, and to
specify that we are talking about enforcement of patents concerned with any
part of the aggregate work.  Would something like that fly?

In other words, use copyright law as a lever against patent law.

This would tend to provide protection against 'our friends', who on the one
hand, depend on Linux in their businesses, and on the other hand, do seem to
be holding large portfolios of equivalently stupid patents.

As far as protection against those who would have no intention or need to use
the aggregate work anyway, that's an entirely separate question.  Frankly, I
enjoy the sport of undermining a patent much more when it is held by someone
who is not a friend.

-- 
Daniel


From: Alan Cox
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-13 08:20:08 PST

On Tue, 2002-08-13 at 09:40, Rob Landley wrote:
> Unfortunately, the maintainer of the GPL is Stallman, so he's the logical guy 
> to spearhead a "GPL patent pool" project, but any time anybody mentions the 
> phrase "intellectual property" to him he goes off on a tangent about how you 
> shouldn't call anything "intellectual property", so how can you have a 
> discussion about it, and nothing ever gets done.  It's FRUSTRATING to see 
> somebody with such brilliant ideas hamstrung not just by idealism, but 
> PEDANTIC idealism.
> 

Richard isnt daft on this one. The FSF does not have the 30 million
dollars needed to fight a *single* US patent lawsuit. The problem also
reflects back on things like Debian, because Debian certainly cannot
afford to play the patent game either.

From: Rik van Riel
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-13 10:40:07 PST

On Tue, 13 Aug 2002, Linus Torvalds wrote:

> Also, a license is a two-way street. I do not think it is morally right
> to change an _existing_ license for any other reason than the fact that
> it has some technical legal problem.

Agreed, but we might be running into one of these.

> I don't like patents. But I absolutely _hate_ people who play politics
> with other peoples code. Be up-front, not sneaky after-the-fact.

Suppose somebody sends you a patch which implements a nice
algorithm that just happens to be patented by that same
somebody.  You don't know about the patent.

You integrate the patch into the kernel and distribute it,
one year later you get sued by the original contributor of
that patch because you distribute code that is patented by
that person.

Not having some protection in the license could open you
up to sneaky after-the-fact problems.

Having a license that explicitly states that people who
contribute and use Linux shouldn't sue you over it might
prevent some problems.

regards,

Rik

From: Alexander Viro
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-13 10:50:20 PST

On Tue, 13 Aug 2002, Rik van Riel wrote:

> Suppose somebody sends you a patch which implements a nice
> algorithm that just happens to be patented by that same
> somebody.  You don't know about the patent.
> 
> You integrate the patch into the kernel and distribute it,
> one year later you get sued by the original contributor of
> that patch because you distribute code that is patented by
> that person.
> 
> Not having some protection in the license could open you
> up to sneaky after-the-fact problems.

Accepting non-trivial patches from malicious source means running code
from malicious source on your boxen.  In kernel mode.  And in that case
patents are the least of your troubles...

From: Linus Torvalds
Subject: Re: large page patch (fwd) (fwd)
View this article only
Date: 2002-08-13 11:20:05 PST

On Tue, 13 Aug 2002, Rik van Riel wrote:
> 
> Having a license that explicitly states that people who
> contribute and use Linux shouldn't sue you over it might
> prevent some problems.

The thing is, if you own the patent, and you sneaked the code into the
kernel, you will almost certainly be laughed out of court for trying to
enforce it.

And if somebody else owns the patent, no amount of copyright license makes 
any difference.

		Linus

From: Rob Landley
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-13 11:40:07 PST

On Tuesday 13 August 2002 01:59 pm, Rik van Riel wrote:
> On Tue, 13 Aug 2002, Linus Torvalds wrote:
> > On Tue, 13 Aug 2002, Rik van Riel wrote:
> > > Having a license that explicitly states that people who
> > > contribute and use Linux shouldn't sue you over it might
> > > prevent some problems.
> >
> > The thing is, if you own the patent, and you sneaked the code into the
> > kernel, you will almost certainly be laughed out of court for trying to
> > enforce it.
>
> Apparently not everybody agrees on this:
>
> http://zdnet.com.com/2100-1106-884681.html

This is just a case of IBM's left hand not knowing what the right hand is 
doing.  An official representative of IBM gave statements to the committee 
that their contributions were unencumbered.  If he honestly was acting in his 
capacity as a representative of IBM, and had the authority to make that 
statement, then that statement IS permission equivalent to a royalty-free 
license to use the patent.

Going through court to prove this could, of course, take years and millions 
of dollars, and nobody's going to use the standard until it's resolved, which 
is why everybody's groaning that big blue is being either evil or really 
really stupid by not just giving in on this one.

It's a PR black eye for IBM ("We're big, we're blue, we're dumb") but doesn't 
change the nature of the legal arguments...

Any time ANYBODY sues you, no matter how frivolous, it could easily be long 
and exensive.  That's why you countersue for damages and get them to pay your 
costs for the trial if you win, plus punitive damages, plus pain and 
suffering, plus a stupidity tax, plus...)

This topic's wandering a bit far afield.  CC: list trimmed...

Rob

From: Linus Torvalds
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-13 11:50:07 PST

On Tue, 13 Aug 2002, Rob Landley wrote:
> 
> > Having a license that explicitly states that people who
> > contribute and use Linux shouldn't sue you over it might
> > prevent some problems.
> 
> Such a clause is what IBM insisted on having in ITS open source license.  You 
> sue, your rights under this license terminate, which is basically automatic 
> grounds for a countersuit for infringement.

Note that I personally think the "you screw with me, I screw with you"  
approach is a fine one. After all, the GPL is based on "you help me, I'll
help you", so it fits fine.

However, it doesn't work due to the distributed nature of the GPL. The FSF
tried to do something like it in the GPL 3.0 discussions, and the end
result was a total disaster. The GPL 3.0 suggestion was something along
the lines of "you sue any GPL project, you lose all GPL rights". Which to 
me makes no sense at all - I could imagine that there might be some GPL 
project out there that _deserves_ getting sued(*) and it has nothing to do 
with Linux.

		Linus

From: Linus Torvalds
To: linux-kernel
Subject: Re: large page patch (fwd) (fwd)
Date: 2002-08-11 18:50:04 PST

On Sun, 11 Aug 2002, Larry McVoy wrote:
> 
> This issue is more complicated than you might think.

No, it's not. You miss the point.

>					  Big companies with 
> big pockets are very nervous about being too closely associated with 
> Linux because of this problem. 

The point being that that is _their_ problem, and at a level that has 
nothing to do with technology.

I'm saying that technical people shouldn't care. I certainly don't. The 
people who _should_ care are patent attourneys etc, since they actually 
get paid for it, and can better judge the matter anyway.

Everybody in the whole software industry knows that any non-trivial
program (and probably most trivial programs too, for that matter) will
infringe on _some_ patent. Ask anybody. It's apparently an accepted fact,
or at least a saying that I've heard too many times. 

I just don't care. Clearly, if all significant programs infringe on 
something, the issue is no longer "do we infringe", but "is it an issue"?

And that's _exactly_ why technical people shouldn't care. The "is it an 
issue" is not something a technical guy can answer, since the answer 
depends on totally non-technical things.

Ask your legal counsel, and I strongly suspect that if he is any good, he
will tell you the same thing. Namely that it's _his_ problem, and that
your engineers should not waste their time trying to find existing
patents.

			Linus