On Sat, Jun 28, 2014 at 8:35 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: > On Sat, Jun 28, 2014 at 8:21 AM, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> 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 <luto@xxxxxxxxxxxxxx> wrote: >>> > On Fri, Jun 27, 2014 at 11:12 PM, Alexei Starovoitov <ast@xxxxxxxxxxxx> 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. ok. sounds like module-like approach will be more acceptable to potential user base. Will change it. Last thing I want to do is to scary users away. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
