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GPL Issues Surrounding Commercial Device Drivers?

Posted by Cliff on from the a-large-hurdle-for-linux-support dept.

Demiurg asks: "My company has recently decided to support Linux for it's embedded networking products which means that I'm starting to write Linux device drivers for our hardware. The company was very concerned about GPL issues and consulted a lawyer - who advised us to go for a user-space driver, saying that this is the only safe way to avoid GPL issues. I tried to give them a few examples of companies distributing binary only drivers (NVIDIA and Rational) but was told that these companies do not distribute binary only drivers - they only allow you to download them from a web site (which is not an option for an embedded product). What does Slashdot have to say about the issue? Is writing a user-mode (and hence not very efficient) driver the only way for a company to protect it's intellectual property? Please refrain from giving answers like 'all code should be GPL' - although I personally may agree, such answers will not help me convince management to make the change." Are there any lawyers (or readers with the right legal knowledge) out there that can confirm or contradict this recommendation?

32 of 461 comments (clear)

  1. lawyers by Dionysus · · Score: 5, Insightful

    So, you got your advice from a legal consul, and you're thinking about ignoring it in favor of advice from the /. crowd? Is that smart?

    --
    Je ne parle pas francais.
    1. Re:lawyers by nicodaemos · · Score: 5, Insightful

      Many times the corporate lawyer is a liberal arts person who doesn't understand the finer points of technology and licensing. As such they don't have the background to come up with creative ways for you to achieve your goals while still remaining in compliance with licensing.

      I personally had to convince a VP of Development to consider my alternatives over the simple no answer that came from the corporate lawyer. It wasn't easy, but I was able to pursuade 2 other directors who backed up my ideas. No, this wasn't a dot-com startup, but a nasdaq listed company with a strong 25 year history. The conservatism and resistance to change was mind boggling.

      My advice is to do exactly what you're doing. Brainstorm the heck out of this and see if you can make it work. Good luck!

    2. Re:lawyers by Anonymous Coward · · Score: 5, Insightful
      So, you got your advice from a legal consul, and you're thinking about ignoring it in favor of advice from the /. crowd? Is that smart?

      FLAME ON--
      Actually yes and no. It is incredibly wise to ask the ./ crowd because there are a few of us out here who a) aren't school/college age geeks and b) have ACTUALLY DONE THIS IN A COMMERICAL PRODUCT and worried over the issue ourselves. It's dumb to take the ./ crowd advise in place of your lawyer's advice. Instead the rational thing to do is to ask here and if something looks interesting point it out to the lawyer.
      FLAME OFF--

      It is relatively well known the Linus has essentially modified the terms of the GPL under which the kernel is distributed w.r.t. loadable modules to allow exactly this functionality. You write a closed source driver for your odd exceeding proprietary hardware, make it a loadable module (not compiled in) and your driver does not have to be released under GPL. As soon as you distribute a version with the module compiled in "all your IP are ours", but as long as you dynamically load it your ok.
      Tell you lawyer to contact Linus to confirm this in writing; he's the freakin' copyright holder.
    3. Re:lawyers by kableh · · Score: 5, Informative

      My company uses Linux in some of our embedded products. Before doing so, and before we had fulltime counsel, we hired a lawyer to go over the GPL and tell us if it was going to present a problem. This lawyer seemed to think that anything compiled with GCC would fall under the GPL, which is incorrect. There are specific exceptions that allow it to be used to produce non-free software.

      I'm not saying he should ignore the lawyer, but that his lawyer could quite possibly be wrong. The GPL is 'viral' in a sense, but not in as devious a way as Microsoft FUD would indicate, and at least they are up front about being a bunch of commies =)

      See http://www.gnu.org/licenses/gpl-faq.html for more info.

    4. Re:lawyers by Anonymous Coward · · Score: 5, Insightful

      "No, this wasn't a dot-com startup, but a nasdaq listed company with a strong 25 year history. The conservatism and resistance to change was mind boggling."

      There may be a connection between `resistance to change` and `strong 25 year history`.

    5. Re:lawyers by ajs · · Score: 4, Insightful

      I'm getting very tired of this mistake. It's being pushed by MS, but it was started by the likes of Slashdotters who don't understand the terminology.

      The GPL is not viral, copyright law is. The GPL is an optional license which you can opt out of by simply never accepting its terms. In which case, it has no sway over you at all, and you can walk away unscathed.

      However, like all copyrighted works, GPLed software cannot be modified and "made your own". A modified (or "derived") work is just that.

      When you use something like a compiler, there's some grey involved as to what the end product is. It has incorporated some headers and libraries that are part of the compiler suite (crt0.o, for example), so it's not just a "printing press for computers". This means that applications which incorporate parts of themselves into their ouput must make a special exception in their licensing terms in order to clarify the status of that output.

      Now, here's the kicker... this is true regardless of what license you use! Yep, you can use the MIT/X license, the BSD license, the GPL, Microsoft's EULA (which is legally on much shakier ground than the GPL, BTW because it relies on this idea that you do not own the software that you purchased, which has been defeated as a tactic for books).

      The only difference between using the GPL and a weaker license like the MIT/X or BSD licenses is that those licenses allow you to do nearly everything that Copyright law takes away. Not that I'm comparing those licenses to the GPL for any real reason. They're both very good licenses for what they are meant to do.

      However, to say that it's the GPL that's viral is silly. Try cutting up a magazine, reassembling the articles and then publishing the result. I think you'll find that copyright law has infected your creative work without the GPL (or any other license) coming anywhere near you.

    6. Re: lawyers by Black+Parrot · · Score: 5, Funny


      > The GPL is 'viral' in a sense

      The GPL isn't viral; it's hereditary.

      I have had both GPL and non-GPL software installed together on my system for years, and none of the non-GPL software has ever been infected.

      --
      Sheesh, evil *and* a jerk. -- Jade
    7. Re:lawyers by flossie · · Score: 5, Interesting
      The major difference is that if you include a copyrighted image/paragraph/etc in your original work (whether by permission or via fair use) the copyright on the cited work does not infect the remaining 90% of your original work.

      ditto for the GPL. If you copy with permission other than the GPL, no problem. If you copy under fair use, also no problem. The GPL only applies if permission and fair use do not apply.

      The GPL gives rights; it does not take any away. Where copyright doesn't restrict you, nor does the GPL.

      So maybe you ought to think about this issue a little more before you post this tripe again.

      Maybe you should read the GPL again.

      --
      flossie

      Write now. Defend liberty

    8. Re:lawyers by paulbd · · Score: 4, Insightful

      Dude, you are completely full of shit. Copyright law is a little bit viral, but the GPL is ebola viral. The major difference is that if you include a copyrighted image/paragraph/etc in your original work (whether by permission or via fair use) the copyright on the cited work does not infect the remaining 90% of your original work. How can you gloss over a detail like that. It makes ALL the difference.

      Who's full of shit here? You would be able to reprint/reissue your work without the copied work, but until you did that, continued duplication of your work would be a violation of copyright law (and you would remain in violation of it for the prior duplication).

      Get a sense of proportion. There is a huge difference between someone who wants to take a GPL'ed app, tweak it a bit, and sell it under a non-GPL license, and someone who wants to take a GPL'ed library and include it as a small part of a non-GPL'ed program. That would be stretching the definition of "derivative work" beyond the level of common sense.

      If someone's work is copyrighted then you have no rights whatsoever to duplicate or use it unless they give you such rights. The author of the GPL'ed library has decided to give such rights only to people who give her and others the same rights in return. The author could have chosen to give you no rights whatsoever, in which case, they need not bother with a license at all. When you use somebody else's code, whatever license it is under, it is only legal if they have given express permission to do so. If they have not, or if they have added conditions under which you may use it, the law does not permit you wriggle out of this with lines like "get a sense of proportion."

      Again, you're full of shit. Each of the excerpts is covered by its own copyright; they aren't infecting each other. If you take some excerpts from Tom Clancy and mix them in with some quotes from Charles Dickens, it doesn't mean that Tom Clancy gets copyright over the Dickens quotes, nor does the public domain status of the Dickens quotes cause the Clancy quotes to fall into the public domain. *THAT* would be viral licensing, and that's what the GPL does.

      You need to be careful with that "shit" term. You are right about the lack of "transfer of copyright" in the domain of the printed word. But the same thing applies to software too. The GPL cannot cause transfer of copyright between owners. If there is an existing body of GPL'ed source code and it is merged with or used to derive new source code, the exact same rules apply as they would with books: genuinely new work is copyright the new author, quoted work is copyright of the old author. The point is: without a license of some sort, you have NO permission to use the existing work in any way, not to copy, not to quote, not to use to derive new work from. If the work was GPL'ed, the author has given you permission to use it as you wish, as long as you use the same license for your own work. The author has no copyright claim on your own original work whatsoever. You are free to issue work that is entirely your own under any license you wish. Work that is derived from the original work (and "derived" here is a technical term that may include compile time linkage, but never includes run time execution) is controlled by the copyright holder of the original work. the copyright holder may choose to prohibit you from using HER work unless you choose a certain license. If you don't agree with that, then you have no permission to use her work; if you do so anyway, you are in violation not of the GPL, but of US and international copyright law.

  2. Linus allows an exception for device drivers by LordNimon · · Score: 5, Informative
    You may need to dig up the reference from some mailing list archive, but Linus Torvalds himself has said that he will allow binary-only drivers, as long as they're loadable modules, to be distributed.

    It all boils down to the concept of "derivative work". Is a device driver a derivative work of the kernel? My opinion is no, but only the courts can truly answer that question, and no one has asked them yet.

    --
    And the men who hold high places must be the ones who start
    To mold a new reality... closer to the heart
    1. Re:Linus allows an exception for device drivers by ch-chuck · · Score: 5, Informative

      One example of this was the Proxim RangeLAN wireless drivers - the author Dave Komacke works at Proxim, and was able to distribute a binary-only module for Linux. Worked fine for me. Web Page here.

      --
      try { do() || do_not(); } catch (JediException err) { yoda(err); }
    2. Re:Linus allows an exception for device drivers by strredwolf · · Score: 5, Informative

      The Linux Kernel Mailing List has a FAQ on such drivers (including NVIDIA). I think it's question #19 where you can access the actual posts.

      --

      --
      # Canmephians for a better Linux Kernel
      $Stalag99{"URL"}="http://stalag99.net";
    3. Re:Linus allows an exception for device drivers by wfrp01 · · Score: 5, Informative

      Linus Torvalds himself has said that he will allow binary-only drivers, as long as they're loadable modules, to be distributed.

      That's been a long standing supposition. However, lwn recently ran an article in which Linus' view on this matter doesn't seem to support this point of view:

      There is NOTHING in the kernel license that allows modules to be non-GPL'd. The _only_ thing that allows for non-GPL modules is copyright law, and in particular the "derived work" issue. A vendor who distributes non-GPL modules is _not_ protected by the module interface per se, and should feel very confident that they can show in a court of law that the code is not derived.

      and also

      The original binary-only modules were for things that were pre-existing works of code, ie drivers and filesystems ported from other operating systems, which thus could clearly be argued to not be derived works, and the original limited export table also acted somewhat as a barrier to show a level of distance.

      --

      --Lawrence Lessig for Congress!
  3. Why necessarily slower in userland? by drinkypoo · · Score: 5, Informative

    Why is a userland driver on linux necessarily slower? Shouldn't a well-written user space driver at an appropriate priority level be just as fast as a kernel driver? And if not, why is this slow on linux but fast on some other operating systems, and what can be done to fix it?

    --
    "You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
  4. Tried asking the FSF or lkml directly? by StandardDeviant · · Score: 5, Insightful

    Seems like you might get good info by directly talking to the FSF or linux kernel mailing list... I'm sure some people would piss and moan about binary this and proprietary that, but in the end I think you'd find more people eager to help expand linux's reach in an optimally efficient manner. IIRC the FSF's head legal eagle is a guy named Eben Moglen (there was something posted on /. just yesterday that involved his name, again IIRC.) Personally, although IANAL, making something available for public download from a website sounds pretty much like "distributing" something. True, the user has to decide to download it, but then again your users would have to decide to buy your particular widget (thus potentially getting the linux driver) also...

    --

    News for Geeks in Austin, TX
  5. Distribution Method by ShadowFlyP · · Score: 5, Insightful

    Nvidia and others do "distribute" binary-only drivers. Just because they don't actively send out CD's with their drivers does not mean they do not distribute them. Under the GPL both methods are concidered a distribution. As far as writing drivers, as long you use the driver module method and do not need to directly change any preexisting kernel code, I do not believe there is any problem at all. That is how Nvidia and others can get away with that.

  6. What exactly are you trying to keep secret? by Brian+the+Bold · · Score: 5, Interesting

    You need to look at exactly what parts of your hardware a GPL'd driver source would reveal, and whether there is really any need to avoid a GPL'd driver for this reason.

    Only the people who know what the hardware does and why the features in question need to be kept secret can make this decision.

    --
    -- BtB
    1. Re:What exactly are you trying to keep secret? by Jaeger · · Score: 4, Insightful
      if you're selling hardware, sell the hardware. give away the software--it's no good without the hardware anyway.
      I personally agree with you, but I can see two reasons why companies might think this is a bad idea:
      • Suppose most of the interesting work takes place in the driver (as in the case of a software printer or modem -- although I imagine this could be the case in other devices as well). The driver then provides an emulation layer between the rest of the operating system and the hardware. Some enterprising clone maker could easily throw a DSP, a transformer, and an RJ-11 jack on a PCI card, copy the driver, and sell a software modem for far less than the original manufacturer.
      • There are plenty of companies in the world who still think that it is possible to ship a device that cannot be reverse-engineered, and that any additional information released to the general public is additional information that the Asian clone manufacturerers will use to screw them in the marketplace. They ignore the fact that said Asian clone manufacturerers have enough manpower to disassemble their drivers line-by-line and pour over wall-sized X-ray blowups of their chips to reverse-engineer the silicon at a transistor level. The only people they're hurting in this situation are those who use free operating systems -- and, by extention, their own market share, because those who use free operating systems won't buy their products.
  7. not revealing intellectual property versus GPL by John_Sauter · · Score: 5, Interesting
    I suggest you divide your code into two parts. Write a device driver which does not reveal any of your secrets but provides support for your application, which uses the device driver to interface to your device but need not be licensed under the GPL. Put all code that would reveal any important secrets into the application.


    John Sauter (J_Sauter@Empire.Net)

  8. Protect? by OttoM · · Score: 5, Insightful
    Why should a hardware company protect the driver? If you make a quality, high performance driver, more people would want to buy the hardware. If you make a lousy, slow driver, not many people would buy the hardware to use on Linux.

    So you your company should go for the best possible driver, to increase hardware sales. If that means GPL'ing the driver, you can also benefit from the expertise of a lot of developers.

  9. The counterexample is NVidia by Isle · · Score: 5, Insightful

    Ask your lawyer how distributing something over the internet is not distributing?

    NVidia are distributing binary-only drivers. They do a trick however, where the code that needs to be loaded into the kernel is (L)GPL, and then this cpde interfaces their binary driver. This both allows a buffer to the GPL code but also to support various different versions of the kernel with the same driver.
    Moreover it allows for a lot of naive trolls claiming that Nvidia is distribting the source-code because they have seen this little module.

  10. Context switches. by cduffy · · Score: 5, Informative

    Why is a userland driver on linux necessarily slower?

    See subject.

    And if not, why is this slow on linux but fast on some other operating systems, and what can be done to fix it?

    No operating system can have userspace drivers without context switches. Some OSes have very low context switch times and *do* put all their drivers in userspace (which has a number of very big advantages I'm not going into right now) -- but they still, unavoidably, pay some performance penalty for doing so.

  11. Not sued != legal by amorsen · · Score: 5, Interesting

    The fact that NVIDIA and Rational have not been sued does not imply that they are legally in the clear. There are certainly several kernel developers who have said clearly that the "module exception" invented by Linus Torvalds does not extend to linking to their code. So far they have not sued anyone. Maybe they never will.

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  12. He is not a kernel hacker by Daniel+Phillips · · Score: 4, Funny

    In general, do not take advice on how to write a device driver from a laywer. Or, if he/she insists, invite them to write the driver for you. Pay only if it works.

    --
    Have you got your LWN subscription yet?
    1. Re:He is not a kernel hacker by jpvlsmv · · Score: 5, Funny

      He's not looking for advice on writing the driver. He's looking for advice on LICENSING the driver.

      In general, do not take advice on how to license a device driver from a programmer. Or, if he/she insists, invite them to be sued. Pay only if they win.

  13. What are they trying to protect? by CaptainAlbert · · Score: 5, Insightful

    I don't quite see what is lost by releasing a device driver under GPL.

    You get:

    1) an army of geeks who will instantly worship your company and buy your products;

    2) a slightly smaller army of geeks who can actually help you fix bugs in your own product FOR FREE.

    You lose... erm, nothing?

    The only drawback is that the interface to your hardware (register maps etc.) are no longer as secret as they were. Perhaps you're concerned about competitors stealing your ideas based on that knowledge? Well, think about it this way - if they badly want that information, they will already be reverse engineering your products and your binary-only drivers with a debugger and some elbow-grease.

    IMO - you have nothing to lose. Embrace the future... :)

    --
    These sigs are more interesting tha
    1. Re:What are they trying to protect? by Art+Popp · · Score: 5, Insightful

      Though I agree that those should be important considerations in this company's decision, the dangers involved are neither imagined nor trivial.

      1) In a technology sector where "time to market" is a crucial feature, distributing source for your drivers gives your competition a considerable edge. Everyone reading this who codes will know exactly what I mean when I say that having a known-good chunk of software to modify is vastly easier than starting from #include <linux/kernel.h>. Drivers are, in fact, a bitch to get right. On a device of median complexity you probably save your competitors a month of dev. time by presenting them with all your clever ideas and a working model on which to base their clone. On a truly clever device you may save them several months.

      2) More importantly for some applications, if there are over-broad patents that concern your device, supplying source code can easily make the difference between your opponents having grounds for suit and not having them. Your source code reveals your intent behind your arrays, and the purpose of your function calls. When a lawyer is trying to prove your product is infringing, this is significantly better ammunition than hundreds of lines of debugger output that has to be "interpreted" by their experts.

      An earlier poster had what I'd consider the best suggestion. Embed the secret stuff in your app. If your device supports it, make the kernel driver little more than a tool for getting data quickly in and out of user space. This approach has several advantages, among the better is that I (or any user who mucks about with these things) can then upgrade the kernel and recompile your trivial kernel space driver (say past an unrelated, but nasty bug) without begging for your help. I can do this to fix bugs you haven't encountered and present you with fixes for bugs you can't easily recreate, but others may be suffering from.

      Best of luck.

  14. Addition/Correction by cduffy · · Score: 5, Informative

    No operating system can have userspace drivers without context switches.

    By that I mean no operating system with memory protection for userspace apps. It's possible to give up this benefit (even selectively) for improved userspace performance; see Kernel Mode Linux for a kernel patch that does just that (and which might be applicable to this fellow's situation).

  15. Re:Another Winner by dasmegabyte · · Score: 5, Insightful

    Easy. People ask slashdot because slashdot readers have actually had to deal with these matters on a day to day basis. Your average lawyer may see a handful of case studies.

    Now, he may have gone to the sort of lawyer that specializes in software licenses (what sort of lawyer is this? a very very rich sort), in which case you're right that it is kind of stupid to approach the trolls and IANALs. But if he went to Joe Q. Publicstein of Publicstein, Stern and Lowe, chances are he'll get a much more specific answer and leads on a case he may be able to point his legal eagle towards. Which could result in a much more informed decision.

    By the by, I've got a feeling that the people who MIGHT press a case on the GPL have bigger fish to fry than a company writing a device driver. If they can't catch Microsoft biting GPL code, why are they going to hunt down developers expanding the OSS market?

    --
    Hey freaks: now you're ju
  16. Module API by be-fan · · Score: 5, Informative

    The kernel exports certain symbols that are available for driver modules to link to. These symbols are classified by license. Many symbols a driver can link to without having to be a GPL'ed driver. These symbols, presumably, are written by people who grant permission to link against non-GPLed code. Other symbols (for example the new work-queues stuff) are exported as so-called GPL_ONLY symbols, and linking against those in a non-GPL module is illegal. Thus, if you avoid using the GPL_ONLY symbols you can probably get away with a binary only module. The fact that this mechanism exists implies permission, so this aspect would be important to bring up to the lawyer.

    --
    A deep unwavering belief is a sure sign you're missing something...
  17. Living With The GPL by Compulawyer · · Score: 5, Insightful
    I am a patent guy, so my licensing experience with the GPL is rather limited (except for using GPL'ed software). However, upon a cursory review, it seems as if this section of the GPL is the cause of most of the concern:

    If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it.

    I think the keys here are what count as distribution and separate works. Obviously, the GPL was drafted with traditional software in mind and is not tailored toward embedded systems. You have to answer the questions "Is this a work based on the Program [a piece of software covered by the GPL]?" and "Is this an independent and separate work?" Unfortunately, I don't have enough facts about your system, and we don't have an attorney-client relationship, so I can't give you an answer. What I can tell you is that you should make sure your lawyer is familiar with your code development processes and distributions systems and knows enough about software development so that he can draw principled distinctions between different ways of doing things.

    --

    Laws affecting technology will always be bad until enough techies become lawyers.

  18. GPL questions are very fact-intensive by n8ur · · Score: 5, Insightful
    IAAL, so unlike most of the posters here, I'm not going to give you a black-and-white answer :-)


    My gut feeling is that a loadable module that does not itself incorporate any GPL'd code does not fall under the GPL just because it's run in conjunction with a GPL'd kernel. After all, even if the kernel + driver are considered together to create a derivative work, it's the user, and not you, who creates that derivative work at runtime.


    And, the fact that you're using GCC to compile the module doesn't mean anything in and of itself. The real question is the license status of any libs that are linked into the resulting object code file. Whether they are under GPL, LGPL, or something else makes a big difference.


    Now for the shades of gray part... any time you're dealing with GPL questions, you have to look at the genealogy of the running executable, working backwards to see what licenses govern the component pieces. It's a very fact-intensive process, and without understanding where all the code came from, you can't come close to giving a reasonable answer.