Re: [PATCH v4 bpf-next 5/5] tools/bpftool: add support for in-kernel and named BTF in `btf show`

From: Andrii Nakryiko
Date: Tue Nov 10 2020 - 23:20:00 EST


On Tue, Nov 10, 2020 at 5:15 PM Song Liu <songliubraving@xxxxxx> wrote:
>
>
>
> > On Nov 9, 2020, at 5:19 PM, Andrii Nakryiko <andrii@xxxxxxxxxx> wrote:
>
> [...]
>
> > ...
> >
> > Tested-by: Alan Maguire <alan.maguire@xxxxxxxxxx>
> > Signed-off-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
>
> Acked-by: Song Liu <songliubraving@xxxxxx>
>
> With one nit:
>
> > ---
> > tools/bpf/bpftool/btf.c | 28 +++++++++++++++++++++++++++-
> > 1 file changed, 27 insertions(+), 1 deletion(-)
> >
> > diff --git a/tools/bpf/bpftool/btf.c b/tools/bpf/bpftool/btf.c
> > index c96b56e8e3a4..ed5e97157241 100644
> > --- a/tools/bpf/bpftool/btf.c
> > +++ b/tools/bpf/bpftool/btf.c
> > @@ -742,9 +742,14 @@ show_btf_plain(struct bpf_btf_info *info, int fd,
> > struct btf_attach_table *btf_map_table)
> > {
> > struct btf_attach_point *obj;
> > + const char *name = u64_to_ptr(info->name);
> > int n;
> >
> > printf("%u: ", info->id);
> > + if (info->kernel_btf)
> > + printf("name [%s] ", name);
> > + else if (name && name[0])
> > + printf("name %s ", name);
>
> Maybe explicitly say "name <anonymous>" for btf without a name? I think
> it will benefit plain output.

This patch set is already landed. But I can do a follow-up patch to add this.

>
> > printf("size %uB", info->btf_size);
> >
> > n = 0;
>
> [...]