3 ms·

Can someone ELI5 to me where the problem is because both perf and bfd seem to be GPL. Why would the former not be allowed to link to the latter?

loeg 5y ago
GPLv2 and GPLv3 are difference licences, despite sharing a name. The GNU people (FSF) intentionally made the GPL3 incompatible with GPL2, to enforce the virality of the GPL3 license (which they perceive to be superior to the older GPL2).
- Macha 5y ago
  The purpose of the GPLv3 was to address the "tivo" clause, where a vendor sells you a device with some modified GPL preloaded software included. You can request the software under GPL, but if you can't load it on the device then the FSF feels that's not very good. So GPLv3 bans that. That, by itself, is inherently an additional restriction not allowed by GPLv2. They don't need to go out of their way or have a conspiracy to deliberately make it incompatible. Especially since the GPL2, as distributed and suggested, includes the "or later" text which resolves this incompatibility to allow GPL3 software to use GPL2 code. If anything, this encourages GPL2+ as the default GPL license if maximum compatibility is your goal. Others (e.g. Linus), are more focused on getting the code changes so if they want to use them in the original project they can, and don't feel being able to install it on the device it was built for is as high up on the priority list.
  - pabs3 5y ago
    A couple of interesting posts from Software Freedom Conservancy make it clear that what Tivo did (breaking proprietary software when reinstalling Linux) is allowed, even by the GPLv3 and that allowing reinstall of libre software is a requirement of the GPLv2 license. https://sfconservancy.org/blog/2021/jul/23/tivoization-and-the-gpl-right-to-install/ https://sfconservancy.org/blog/2021/jul/23/tivoization-and-t... https://sfconservancy.org/blog/2021/mar/25/install-gplv2/ https://sfconservancy.org/blog/2021/mar/25/install-gplv2/ https://events19.linuxfoundation.org/wp-content/uploads/2017/11/Safely-Copylefted-Cars-Reexamining-GPLv3-Installation-Information-Requirements-ALS-Bradley-Kuhn-Behan-Webster-1.pdf https://events19.linuxfoundation.org/wp-content/uploads/2017...
  - pabs3 5y ago
    Its also interesting to note that none of the GPL licenses require giving code back, so what Linus wants from the license doesn't happen via the license, only via cultural standards. Indeed, there are many companies and persons violating those cultural standards by not sending patches back to Linus, as well as many companies violating the GPL licenses by not distributing source to their customers.
boomboomsubban 5y ago
Most GPL licenses permits their code to be redistributed as the same GPL version or any later version of the GPL, Linux releases as GPLv2 or later for example. Perf does not permit the license to be redistributed as anything except GPLv2, so it conflicts with GPLv3 code.
- Someone 5y ago
  “Linux releases as GPLv2 or later for example” Linux doesn’t use “or later”. https://github.com/torvalds/linux/blob/master/COPYING https://github.com/torvalds/linux/blob/master/COPYING: The Linux Kernel is provided under: SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note Being under the terms of the GNU General Public License version 2 only, according with: LICENSES/preferred/GPL-2.0 With an explicit syscall exception, as stated at: LICENSES/exceptions/Linux-syscall-note In addition, other licenses may also apply. Please see: Documentation/process/license-rules.rst for more details. All contributions to the Linux Kernel are subject to this COPYING file.
  - deleted 5y ago
    [deleted]

loeg 5y ago

GPLv2 and GPLv3 are difference licences, despite sharing a name. The GNU people (FSF) intentionally made the GPL3 incompatible with GPL2, to enforce the virality of the GPL3 license (which they perceive to be superior to the older GPL2).

Macha 5y ago
The purpose of the GPLv3 was to address the "tivo" clause, where a vendor sells you a device with some modified GPL preloaded software included. You can request the software under GPL, but if you can't load it on the device then the FSF feels that's not very good. So GPLv3 bans that. That, by itself, is inherently an additional restriction not allowed by GPLv2. They don't need to go out of their way or have a conspiracy to deliberately make it incompatible. Especially since the GPL2, as distributed and suggested, includes the "or later" text which resolves this incompatibility to allow GPL3 software to use GPL2 code. If anything, this encourages GPL2+ as the default GPL license if maximum compatibility is your goal. Others (e.g. Linus), are more focused on getting the code changes so if they want to use them in the original project they can, and don't feel being able to install it on the device it was built for is as high up on the priority list.
- pabs3 5y ago
  A couple of interesting posts from Software Freedom Conservancy make it clear that what Tivo did (breaking proprietary software when reinstalling Linux) is allowed, even by the GPLv3 and that allowing reinstall of libre software is a requirement of the GPLv2 license. https://sfconservancy.org/blog/2021/jul/23/tivoization-and-the-gpl-right-to-install/ https://sfconservancy.org/blog/2021/jul/23/tivoization-and-t... https://sfconservancy.org/blog/2021/mar/25/install-gplv2/ https://sfconservancy.org/blog/2021/mar/25/install-gplv2/ https://events19.linuxfoundation.org/wp-content/uploads/2017/11/Safely-Copylefted-Cars-Reexamining-GPLv3-Installation-Information-Requirements-ALS-Bradley-Kuhn-Behan-Webster-1.pdf https://events19.linuxfoundation.org/wp-content/uploads/2017...
- pabs3 5y ago
  Its also interesting to note that none of the GPL licenses require giving code back, so what Linus wants from the license doesn't happen via the license, only via cultural standards. Indeed, there are many companies and persons violating those cultural standards by not sending patches back to Linus, as well as many companies violating the GPL licenses by not distributing source to their customers.

boomboomsubban 5y ago

Most GPL licenses permits their code to be redistributed as the same GPL version or any later version of the GPL, Linux releases as GPLv2 or later for example. Perf does not permit the license to be redistributed as anything except GPLv2, so it conflicts with GPLv3 code.

Someone 5y ago
“Linux releases as GPLv2 or later for example” Linux doesn’t use “or later”. https://github.com/torvalds/linux/blob/master/COPYING https://github.com/torvalds/linux/blob/master/COPYING: The Linux Kernel is provided under: SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note Being under the terms of the GNU General Public License version 2 only, according with: LICENSES/preferred/GPL-2.0 With an explicit syscall exception, as stated at: LICENSES/exceptions/Linux-syscall-note In addition, other licenses may also apply. Please see: Documentation/process/license-rules.rst for more details. All contributions to the Linux Kernel are subject to this COPYING file.
- deleted 5y ago
  [deleted]