On Sat, Apr 23, 2022 at 7:01 AM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
>
> Currently there're helpers for allowing to open/load/attach BPF object
> through BPF object skeleton. Let's also add helpers for pinning through
> BPF object skeleton. It could simplify BPF userspace code which wants to
> pin the progs into bpffs.
>
> After this change, with command 'bpftool gen skeleton XXX.bpf.o', the
> helpers for pinning BPF prog will be generated in BPF object skeleton.
>
> The new helpers are named with __{pin, unpin}_prog, because it only pins
> bpf progs. If the user also wants to pin bpf maps, he can use
> LIBBPF_PIN_BY_NAME.
API says it's pinning programs, but really it's trying to pin links.
But those links might not even be created for non-auto-attachable
programs, and for others users might or might not set
<skel>.links.<prog_name> links.
There are lots of questions about this new functionality... But the
main one is why do we need it? What does it bring that's hard to do
otherwise?
>
> Yafang Shao (4):
> libbpf: Define DEFAULT_BPFFS
> libbpf: Add helpers for pinning bpf prog through bpf object skeleton
> bpftool: Fix incorrect return in generated detach helper
> bpftool: Generate helpers for pinning prog through bpf object skeleton
>
> tools/bpf/bpftool/gen.c | 18 ++++++++++-
> tools/lib/bpf/bpf_helpers.h | 2 +-
> tools/lib/bpf/libbpf.c | 61 ++++++++++++++++++++++++++++++++++++-
> tools/lib/bpf/libbpf.h | 10 ++++--
> tools/lib/bpf/libbpf.map | 2 ++
> 5 files changed, 88 insertions(+), 5 deletions(-)
>
> --
> 2.17.1
>
