Re: [PATCHv5 bpf-next 18/28] libbpf: Add bpf_link_create support for tracing_multi link

On Sat, Apr 18, 2026 at 03:50:10AM +0000, [email protected] wrote:
> Sashiko AI review found 1 potential issue(s):
> - [Low] The patch relies on UAPI identifiers (`BPF_TRACE_FENTRY_MULTI`, `BPF_TRACE_FEXIT_MULTI`, `BPF_TRACE_FSESSION_MULTI` and `attr.link_create.tracing_multi`) that are missing from the kernel's UAPI headers.
> --
> 
> commit c0f93aeff516311471202b8e10f7e659acca62b7
> Author: Jiri Olsa <[email protected]>
> 
> libbpf: Add bpf_link_create support for tracing_multi link
> 
> This commit adds bpf_link_create support for the tracing_multi link,
> introducing a 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 5846de3642090..ad4c94b6758d3 100644
> > --- a/tools/lib/bpf/bpf.c
> > +++ b/tools/lib/bpf/bpf.c
> > @@ -790,6 +790,15 @@ 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));
> 
> Are BPF_TRACE_FENTRY_MULTI, BPF_TRACE_FEXIT_MULTI, BPF_TRACE_FSESSION_MULTI,
> and attr.link_create.tracing_multi defined in the kernel's UAPI headers?

it part of the related kernel patches:
  bpf: Add multi tracing attach types
  bpf: Add support for tracing multi link

jirka


> 
> It looks like these enum variants and the tracing_multi structure within the
> link_create union of union bpf_attr are missing from include/uapi/linux/bpf.h
> and tools/include/uapi/linux/bpf.h. Attempting to use these undeclared
> identifiers breaks compilation. Is there a missing patch in this series that
> updates the UAPI headers?
> 
> > +		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;
> >  	case BPF_TRACE_RAW_TP:
> 
> -- 
> Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1