Re: [RFC PATCH bpf-next v2 2/3] libbpf: Add FEAT_KPROBE_MULTI_LINK feature probe.

[Varun R Mallya]

On Mon, Mar 30, 2026 at 10:42:57PM +0800, Leon Hwang wrote:
> On 2026/3/30 19:00, Varun R Mallya wrote:
> > diff --git a/tools/lib/bpf/libbpf_internal.h b/tools/lib/bpf/libbpf_internal.h
> > index 4bcb6ca69bb1..633106a687c7 100644
> > --- a/tools/lib/bpf/libbpf_internal.h
> > +++ b/tools/lib/bpf/libbpf_internal.h
> > @@ -388,6 +388,8 @@ enum kern_feature_id {
> >  	FEAT_SYSCALL_WRAPPER,
> >  	/* BPF multi-uprobe link support */
> >  	FEAT_UPROBE_MULTI_LINK,
> > +	/* BPF multi-kprobe link support */
> > +	FEAT_KPROBE_MULTI_LINK,
> 
> Even though it seems good to put FEAT_KPROBE_MULTI_LINK here, better to
> put it at last to keep backwards compatibility?
> 
> When users compile application using old libbpf and run it against such
> new libbpf.so, will they get incorrect feature support?
> 
> Thanks,
> Leon
Changing in v3. Thanks!
> >  	/* Kernel supports arg:ctx tag (__arg_ctx) for global subprogs natively */
> >  	FEAT_ARG_CTX_TAG,
> >  	/* Kernel supports '?' at the front of datasec names */
>