Re: [RFC PATCH bpf-next 0/2] bpf, libbpf: share BTF data show functionality

From: Alexei Starovoitov
Date: Mon Jan 11 2021 - 21:49:13 EST


On Mon, Jan 11, 2021 at 05:32:51PM +0000, Alan Maguire wrote:
> The BPF Type Format (BTF) can be used in conjunction with the helper
> bpf_snprintf_btf() to display kernel data with type information.
>
> This series generalizes that support and shares it with libbpf so
> that libbpf can display typed data. BTF display functionality is
> factored out of kernel/bpf/btf.c into kernel/bpf/btf_show_common.c,
> and that file is duplicated in tools/lib/bpf. Similarly, common
> definitions and inline functions needed for this support are
> extracted into include/linux/btf_common.h and this header is again
> duplicated in tools/lib/bpf.

I think duplication will inevitable cause code to diverge.
Could you keep a single copy?
Take a look at kernel/bpf/disasm.[ch]
It compiled once for the kernel and once for bpftool.
So should be possible to do something similar for this case as well?