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

[Quentin Monnet <quentin@isovalent.com>]

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