On the value of EXPORT_SYMBOL_GPL
Posted Oct 8, 2005 12:27 UTC (Sat) by dwmw2
In reply to: On the value of EXPORT_SYMBOL_GPL
Parent article: On the value of EXPORT_SYMBOL_GPL
So it boils back to the "is the binary-only module derived from Linux" argument.
No. It boils back to a question of whether the resulting whole (including the kernel and the module in question) is a combined work, or whether it's mere aggregation on a volume of a storage or distribution medium.
There can be a lot of ambiguity there -- but there are some cases where it's fairly obvious too. For example:
In the case where a computer magazine happens to include a bunch of gratis software and/or shareware on a cover CD, and some of it happens to be GPL'd while other parts are not, that would clearly be 'mere aggregation on a volume of a distribution medium'
- On the other hand, in the case where the firmware for an embedded router device contains both a Linux kernel and some binary-only network driver modules, and the device cannot perform its intended function if either of those integral parts of its software is removed, that's equally clearly a combined work and not 'mere aggregation on a volume of a storage medium'
- When a Linux driver is shipped in the form of GPL'd wrapper code and a binary-only object, those two parts are fundamentally interdependent. It isn't merely coincidence that they're both present in the tarball you download. It would be very hard to argue that it's "mere aggregation on a volume of a distribution medium" rather than being a complete work made up of those two parts.
The case of a Linux distribution is an interesting one. Not so much because of the kernel, which makes an explicit exception for userspace, but because of GPL'd userspace software. If it's 'mere aggregation on a distribution medium' then that's fine -- it can include both GPL'd and non-GPL'd software (like Apache). However, if the distributors are explicitly claiming a copyright on the distribution itself as a combined work, that would seem to be problematic.
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