Re: scsi target, likely GPL violation

[Dave Airlie <airlied@gmail.com>]

On Mon, Nov 12, 2012 at 8:41 AM, Julian Calaby <julian.calaby@gmail.com> wrote:
> Hi Lawrence,
>
> On Mon, Nov 12, 2012 at 9:13 AM, Lawrence Rosen <lrosen@rosenlaw.com> wrote:
>> Alan Cox wrote:
>>> So either your work is truely not derivative of the kernel (which I find
>>> wildly improbable) or you have a problem and since you are aware
>>> of the complaints publically I guess probably a triple damages sized
>>> problem. But that's one for your lawyers and whatever opinion they
>>> have on the subject.
>>
>> Hi Alan and others,
>>
>> I've been advising Rising Tide Systems (RTS) in this matter. Please let me
>> reassure you that RTS is acting on advice of counsel.
>
> It's nice to hear from legal counsel on this matter.
>
> I don't think that the *usage* of the kernel APIs is the biggest issue
> here. There are many examples where proprietary code uses these APIs
> and is not violating the GPL.
>
> As I see it, one of the main concerns is because the proprietary and
> in-kernel target systems are, from what I understand, quite similar,
> there is the possibility that GPL licensed contributions to the
> in-kernel target code may have "leaked" into to the proprietary code.
> That said, proving this is a very difficult problem, but the question
> must still be asked:
>
> Can Rising Tide Systems assure us that there is no GPL licensed code
> within their proprietary target code?

Its a bit of both actually.

The problem is if you design a kernel subsystem specifically for the
Linux kernel, even if you use the internal APIs, you are most likely
creating a derived work of the Linux kernel.

questions that would need to be asked:
Can the scsi target code work completely separate from a Linux kernel?
Does it work with another operating system? was it designed for that
operating system?

The whole in-kernel version under the GPL isn't the problem here and
has nothing to do with the violation. Its the one they distribute
separately with their RTS OS kernel, and if they distribute it in one
combined work, then a GPL violation is possibly indicated.

The reasons for non-derived work status that have been suggested (but
not accepted by all the community):
a) AFS, a file system clearly not developed for Linux, where it being
a derived work of something that came after it would be a bit crazy,
b) binary GPU drivers, built from the same source base on their
Windows platform, and the code existed on Windows before Linux,
arguing this driver is a derived work is difficult as well. Also
nvidia specifically don't distribute this driver linked against the
kernel, and distros who have done this in the past have been on the
end of cease-and-desist letters.

So really this is purely a derived work issue, whether they release a
trailing edge version of their code afterwards under the GPL isn't
significant, other than a this might keep the community off our back.

(Yes the secondary issue of people who contributed code and cleanups
back to that code base and if they integrated it back into their
internal code base, is a problem, but I don't believe its the primary
issue).

Dave.