Re: [PATCH bpf-next v2 8/9] libbpf: add support for the multi-link of tracing

Quentin Monnet
2024-03-11T15:29:12Z

2024-03-11 09:35 UTC+0000 ~ Menglong Dong <dongmenglong.8@bytedance.com>
> Add support for the attach types of:
>
> BPF_TRACE_FENTRY_MULTI
> BPF_TRACE_FEXIT_MULTI
> BPF_MODIFY_RETURN_MULTI
>
> Signed-off-by: Menglong Dong <dongmenglong.8@bytedance.com>
> ---
> tools/bpf/bpftool/common.c | 3 +
> tools/lib/bpf/bpf.c | 10 +++
> tools/lib/bpf/bpf.h | 6 ++
> tools/lib/bpf/libbpf.c | 168 ++++++++++++++++++++++++++++++++++++-
> tools/lib/bpf/libbpf.h | 14 ++++
> tools/lib/bpf/libbpf.map | 1 +
> 6 files changed, 199 insertions(+), 3 deletions(-)
>
> diff --git a/tools/bpf/bpftool/common.c b/tools/bpf/bpftool/common.c
> index cc6e6aae2447..ffc85256671d 100644
> --- a/tools/bpf/bpftool/common.c
> +++ b/tools/bpf/bpftool/common.c
> @@ -1089,6 +1089,9 @@ const char *bpf_attach_type_input_str(enum bpf_attach_type t)
> case BPF_TRACE_FENTRY: return "fentry";
> case BPF_TRACE_FEXIT: return "fexit";
> case BPF_MODIFY_RETURN: return "mod_ret";
> + case BPF_TRACE_FENTRY_MULTI: return "fentry_multi";
> + case BPF_TRACE_FEXIT_MULTI: return "fexit_multi";
> + case BPF_MODIFY_RETURN_MULTI: return "mod_ret_multi";
> case BPF_SK_REUSEPORT_SELECT: return "sk_skb_reuseport_select";
> case BPF_SK_REUSEPORT_SELECT_OR_MIGRATE: return "sk_skb_reuseport_select_or_migrate";
> default: return libbpf_bpf_attach_type_str(t);

Hi, please drop this part in bpftool.

bpf_attach_type_input_str() is used for legacy attach type names that
were used before bpftool switched to libbpf_bpf_attach_type_str(), and
that are still supported today. The names for new attach types should
just be retrieved with libbpf_bpf_attach_type_str(). And function
bpf_attach_type_input_str() is also only used for attaching
cgroup-related programs with "bpftool cgroup (at|de)tach".

Thanks,
Quentin