Re: [PATCH bpf-next] bpftool: Add SPDX identifier to btf-dump-file output

[Alexei Starovoitov]

On Tue, Mar 15, 2022 at 4:10 PM Daniel Xu <dxu@xxxxxxxxx> wrote:
>
> Hi Alexei,
>
> On Tue, Mar 15, 2022, at 2:38 PM, Alexei Starovoitov wrote:
> > On Sun, Mar 13, 2022 at 4:01 PM Daniel Xu <dxu@xxxxxxxxx> wrote:
> >>
> >> A concern about potential GPL violations came up at the new $DAYJOB when
> >> I tried to vendor the vmlinux.h output. The central point was that the
> >> generated vmlinux.h does not embed a license string -- making the
> >> licensing of the file non-obvious.
> >>
> >> This commit adds a LGPL-2.1 OR BSD-2-Clause SPDX license identifier to
> >> the generated vmlinux.h output. This is line with what bpftool generates
> >> in object file skeletons.
> >>
> >> Signed-off-by: Daniel Xu <dxu@xxxxxxxxx>
> >> ---
> >>  tools/bpf/bpftool/btf.c | 1 +
> >>  1 file changed, 1 insertion(+)
> >>
> >> diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
> >> index a2c665beda87..fca810a27768 100644
> >> --- a/tools/bpf/bpftool/btf.c
> >> +++ b/tools/bpf/bpftool/btf.c
> >> @@ -425,6 +425,7 @@ static int dump_btf_c(const struct btf *btf,
> >>         if (err)
> >>                 return err;
> >>
> >> +       printf("/* SPDX-License-Identifier: (LGPL-2.1 OR BSD-2-Clause) */\n\n");
> >
> > I don't think we can add any kind of license identifier
> > to the auto generated output.
> > vmlinux.h is a pretty printed dwarfdump.
>
> Just so I understand better, when you say "I don't think we can",
> do you mean:
>
> 1) There may be legal issues w/ adding the license identifier
> 2) It doesn't make sense to add the license header
> 3) Something else?

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