Re: [PATCHv8 bpf-next 18/29] libbpf: Add bpf_link_create support for tracing_multi link

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Compilation Failure / Missing UAPI Dependency
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commit a8f03a666e6225df801b64bd21fc01afe54bd463
Author: Jiri Olsa <jolsa@kernel.org>

libbpf: Add bpf_link_create support for tracing_multi link
    
Adding bpf_link_create support for tracing_multi link with
new tracing_multi record in struct bpf_link_create_opts.

> diff --git a/tools/lib/bpf/bpf.c b/tools/lib/bpf/bpf.c
> index bc513aa8f4041..f37e3416f61a5 100644
> --- a/tools/lib/bpf/bpf.c
> +++ b/tools/lib/bpf/bpf.c
> @@ -845,6 +845,15 @@ int bpf_link_create(int prog_fd, int target_fd,
>  		if (!OPTS_ZEROED(opts, uprobe_multi))
>  			return libbpf_err(-EINVAL);
>  		break;
> +	case BPF_TRACE_FENTRY_MULTI:
> +	case BPF_TRACE_FEXIT_MULTI:
> +	case BPF_TRACE_FSESSION_MULTI:
> +		attr.link_create.tracing_multi.ids = ptr_to_u64(OPTS_GET(opts, tracing_multi.ids, 0));

[Severity: Low]
Are the UAPI definitions for BPF_TRACE_FENTRY_MULTI, BPF_TRACE_FEXIT_MULTI,
and BPF_TRACE_FSESSION_MULTI missing from this patch?

It looks like this code references these constants, as well as the
tracing_multi member in union bpf_attr, but they are not defined in the
corresponding UAPI header (tools/include/uapi/linux/bpf.h). Will this cause
an immediate compilation failure due to undeclared identifiers and missing
struct members?

> +		attr.link_create.tracing_multi.cookies = ptr_to_u64(OPTS_GET(opts, tracing_multi.cookies, 0));
> +		attr.link_create.tracing_multi.cnt = OPTS_GET(opts, tracing_multi.cnt, 0);
> +		if (!OPTS_ZEROED(opts, tracing_multi))
> +			return libbpf_err(-EINVAL);
> +		break;

[ ... ]

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Sashiko AI review · https://sashiko.dev/#/patchset/20260606123955.345967-19-jolsa@kernel.org?part=1