On Sat, Jun 28, 2014 at 8:21 AM, Greg KH <gre...@linuxfoundation.org> wrote: > On Sat, Jun 28, 2014 at 12:26:14AM -0700, Alexei Starovoitov wrote: >> On Fri, Jun 27, 2014 at 11:28 PM, Andy Lutomirski <l...@amacapital.net> >> wrote: >> > On Fri, Jun 27, 2014 at 11:12 PM, Alexei Starovoitov <a...@plumgrid.com> >> > wrote: >> > If you want to add GPL-only functions in the future, that would be one >> > thing. But if someone writes a nice eBPF compiler, and someone else >> > writes a little program that filters on network packets, I see no >> > reason to claim that the little program is a derivative work of the >> > kernel and therefore must be GPL. >> >> I think we have to draw a line somewhere. Say, tomorrow I want >> to modify libpcap to emit eBPF based on existing tcpdump syntax. >> Would it mean that tcpdump filter strings are GPLed? Definitely not, >> since they existed before and can function without new libpcap. >> But if I write a new packet filtering program in C, compile it >> using LLVM->eBPF and call into in-kernel helper functions >> (like bpf_map_lookup_elem()), I think it's exactly the derivative work. >> It's analogous to kernel modules. If module wants to call >> export_symbol_gpl() functions, it needs to be GPLed. Here all helper >> functions are GPL. So we just have a blank check for eBPF program. > > I agree, these eBFP programs should be GPL-compatible licensed as well.
I think I'd be happy with an export_symbol_gpl analogue. I might argue that bpf_map_lookup_elem shouldn't be gpl-only, though. Something like "look up the uid that opened a port," on the other hand, maybe should be. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
