Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH RFC net-next 07/14] bpf: expand BPF syscall with program load/unload | Date | Mon, 30 Jun 2014 10:06:23 +0000 |
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From: Alexei Starovoitov > On Fri, Jun 27, 2014 at 5:19 PM, Andy Lutomirski <luto@amacapital.net> wrote: > > On Fri, Jun 27, 2014 at 5:05 PM, Alexei Starovoitov <ast@plumgrid.com> wrote: > >> eBPF programs are safe run-to-completion functions with load/unload > >> methods from userspace similar to kernel modules. > >> > >> User space API: > >> > >> - load eBPF program > >> prog_id = bpf_prog_load(int prog_id, bpf_prog_type, struct nlattr *prog, int len) > >> > >> where 'prog' is a sequence of sections (currently TEXT and LICENSE) > >> TEXT - array of eBPF instructions > >> LICENSE - GPL compatible > >> + > >> + err = -EINVAL; > >> + /* look for mandatory license string */ > >> + if (!tb[BPF_PROG_LICENSE]) > >> + goto free_attr; > >> + > >> + /* eBPF programs must be GPL compatible */ > >> + if (!license_is_gpl_compatible(nla_data(tb[BPF_PROG_LICENSE]))) > >> + goto free_attr; > > > > Seriously? My mind boggles. > > Yes. Quite a bit of logic can fit into one eBPF program. I don't think it's wise > to leave this door open for abuse. This check makes it clear that if you > write a program in C, the source code must be available.
That seems utterly extreme. Loadable kernel modules don't have to be GPL.
I can imagine that some people might not want to load code for which they don't have the source - but in that case they probably want to compile it themselves anyway.
I don't want to have to put a gpl licence on random pieces of test code I might happen to write for my own use.
David
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