ambiguity [LWN.net]

ambiguity

Posted Dec 26, 2025 3:15 UTC (Fri) by anselm (subscriber, #2796)
In reply to: ambiguity by sashal
Parent article: A partial ruling in the Vizio GPL suit

The problem is SFC's original language was ambiguous: "All features of the original program are retained" could reasonably be read either way.

The GPL talks about “the Program” when it means “the work licensed under the GPL”. This is clearly the Linux kernel (and/or possibly some other separately-licensed GPL code on the TV) but not the non-GPL software added by the manufacturer and included on the device by “mere aggregation” (GPLv2 section 2). The GPL requires that you should be able to change the Program, i.e., in this case the Linux kernel, and get your modified version to run on the device, but it makes no claim about the non-GPL software – the non-GPL software could check that, e.g., the Linux kernel has a certain cryptographic hash and refuse to run if that wasn't the case, which would be perfectly acceptable as far as the GPL is concerned. In that case you would still have a functional Linux kernel running on the TV on which you could install your own application (possibly but not limited to one that received some sort of TV signal and rendered that on the TV screen).

I don't think that when the SFC said “the program” they meant “everything on the TV, regardless of the license”, because (Linus Torvalds' comments notwithstanding) I do believe that the SFC can actually read, as well as differentiate between the GPLed and proprietary components of the TV's software package.

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ambiguity

Posted Dec 26, 2025 12:09 UTC (Fri) by sashal (✭ supporter ✭, #81842) [Link] (2 responses)

> The GPL talks about “the Program” when it means “the work licensed under the GPL”

SFC didn't say "the Program" (capitalized, as the GPL uses it), they said "the original program" (lowercase) and specifically "all features of the original program are retained." If they meant the narrow GPL definition, why not use the GPL's actual terminology?

And why "all features"? The word "feature" isn't defined in the GPL nor does it appear in the GPL at all.

If SFC was trying to articulate what the GPL requires, they introduced a word ("features") that has no GPL meaning. So now we're interpreting SFC's gloss on the GPL, not the GPL itself. On the other hand, it also means SFC can't fall back on "we were just using GPL terminology", they chose to say "all features of the original program are retained" which is their own formulation and "all features retained" in plain English does suggest a fairly high bar: not just "it compiles" but "it works like it did before."

All I'm saying is that the SFC's response that triggered Vizio's motion could be reasonably understood in multiple ways.

ambiguity

Posted Dec 26, 2025 13:38 UTC (Fri) by anselm (subscriber, #2796) [Link] (1 responses)

I agree that if the SFC had meant “the Program” in the GPL sense, they would have done better to capitalise the P. OTOH, I haven't seen the SFC's original submission, and whether there was a “p” or a “P” in the original submission that was then (mis?)quoted by Vizio in their motion or the court in its summary judgement should be checked.

As far as the word “features” go, a Program obviously has features even if the GPL doesn't say so explicitly. The GPL is – implicitly – all about adding new features to the Program or changing the ones that are already there. The expectation on the part of the GPL is that if you take the TV set's Linux kernel source code as provided by Vizio under the GPL, recompile it, and deploy it to the TV set (which according to the GPL you should be able to do), it should have the features of a Linux kernel. The features of the TV set as a whole are another concern - in particular, whether the proprietary TV application on the TV likes your self-compiled Linux kernel enough to make the TV set as a whole work just as it would with the kernel binary provided by Vizio is a different question entirely that the GPL does not address.

Finally, the question remains why the SFC didn't clarify its position vis-à-vis the scope of the word “program” to the court before the summary judgment. The SFC has been around long enough to be aware that the GPL can't regulate the behaviour of non-GPL code that happens to be on the same TV set (after all they argue exactly that in their after-the-fact blog post), so the sensible thing would have been to make it unambiguously clear earlier in the process that this is indeed not what they are after.

ambiguity

Posted Dec 26, 2025 13:50 UTC (Fri) by sashal (✭ supporter ✭, #81842) [Link]

Ack. The SFC should really have been clearer on this from the beginning.

The judge has also mentioned it in his ruling:

> Plaintiff’s interrogatory response can be reasonably construed to include the issue raised in the motion.
> Moreover, Plaintiff has chosen to oppose the motion on the merits rather than concede the issue of duty
> raised in the motion, indicating Plaintiff alleges the disputed duty applies to Defendant. Moreover,
> Defendant cites paragraphs 116 and 118 of Plaintiff’s FAC and the testimony of Plaintiff’s witnesses
> which have asserted the existence of such a duty.

Which doesn't stop SFC from writing "Unfortunately, Vizio's motion is likely to confuse the public" in their blog post, even though the ones causing this confusion are the SFC themselves.