Re: [PATCH bpf-next v7 05/11] bpf: implement BPF_PROG_QUERY for BPF_LSM_CGROUP

[Stanislav Fomichev <sdf@google.com>]

On Mon, May 23, 2022 at 4:24 PM Andrii Nakryiko
<andrii.nakryiko@gmail.com> wrote:
>
> On Wed, May 18, 2022 at 3:55 PM Stanislav Fomichev <sdf@google.com> wrote:
> >
> > We have two options:
> > 1. Treat all BPF_LSM_CGROUP the same, regardless of attach_btf_id
> > 2. Treat BPF_LSM_CGROUP+attach_btf_id as a separate hook point
> >
> > I was doing (2) in the original patch, but switching to (1) here:
> >
> > * bpf_prog_query returns all attached BPF_LSM_CGROUP programs
> > regardless of attach_btf_id
> > * attach_btf_id is exported via bpf_prog_info
> >
> > Signed-off-by: Stanislav Fomichev <sdf@google.com>
> > ---
> >  include/uapi/linux/bpf.h |   5 ++
> >  kernel/bpf/cgroup.c      | 103 +++++++++++++++++++++++++++------------
> >  kernel/bpf/syscall.c     |   4 +-
> >  3 files changed, 81 insertions(+), 31 deletions(-)
> >
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index b9d2d6de63a7..432fc5f49567 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -1432,6 +1432,7 @@ union bpf_attr {
> >                 __u32           attach_flags;
> >                 __aligned_u64   prog_ids;
> >                 __u32           prog_cnt;
> > +               __aligned_u64   prog_attach_flags; /* output: per-program attach_flags */
> >         } query;
> >
> >         struct { /* anonymous struct used by BPF_RAW_TRACEPOINT_OPEN command */
> > @@ -5911,6 +5912,10 @@ struct bpf_prog_info {
> >         __u64 run_cnt;
> >         __u64 recursion_misses;
> >         __u32 verified_insns;
> > +       /* BTF ID of the function to attach to within BTF object identified
> > +        * by btf_id.
> > +        */
> > +       __u32 attach_btf_func_id;
>
> it's called attach_btf_id for PROG_LOAD command, keep it consistently
> named (and a bit more generic)?
>
> >  } __attribute__((aligned(8)));
> >
> >  struct bpf_map_info {
>
> [...]

SG. Making it generic makes sense.