netdev - Re: [PATCH bpf-next v7 1/6] bpf: Allow verifier to fixup kernel module kfuncs

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Message-ID: <CAEf4BzaOM2GL+ieYyvTr9Gp6YC7e1GDfjHb42X7zb5Gs3ChtiQ@mail.gmail.com>
Date: Tue, 25 Nov 2025 15:54:12 -0800
From: Andrii Nakryiko <andrii.nakryiko@...il.com>
To: Amery Hung <ameryhung@...il.com>
Cc: bpf@...r.kernel.org, netdev@...r.kernel.org, alexei.starovoitov@...il.com, 
	andrii@...nel.org, daniel@...earbox.net, tj@...nel.org, martin.lau@...nel.org, 
	kernel-team@...a.com
Subject: Re: [PATCH bpf-next v7 1/6] bpf: Allow verifier to fixup kernel
 module kfuncs

On Fri, Nov 21, 2025 at 3:13 PM Amery Hung <ameryhung@...il.com> wrote:
>
> Allow verifier to fixup kfuncs in kernel module to support kfuncs with
> __prog arguments. Currently, special kfuncs and kfuncs with __prog
> arguments are kernel kfuncs. Allowing kernel module kfuncs should not
> affect existing kfunc fixup as kernel module kfuncs have BTF IDs greater
> than kernel kfuncs' BTF IDs.
>
> Signed-off-by: Amery Hung <ameryhung@...il.com>
> ---
>  kernel/bpf/verifier.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>

Acked-by: Andrii Nakryiko <andrii@...nel.org>


> diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
> index 098dd7f21c89..182d63b075af 100644
> --- a/kernel/bpf/verifier.c
> +++ b/kernel/bpf/verifier.c
> @@ -22432,8 +22432,7 @@ static int fixup_kfunc_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
>
>         if (!bpf_jit_supports_far_kfunc_call())
>                 insn->imm = BPF_CALL_IMM(desc->addr);
> -       if (insn->off)
> -               return 0;
> +
>         if (desc->func_id == special_kfunc_list[KF_bpf_obj_new_impl] ||
>             desc->func_id == special_kfunc_list[KF_bpf_percpu_obj_new_impl]) {
>                 struct btf_struct_meta *kptr_struct_meta = env->insn_aux_data[insn_idx].kptr_struct_meta;
> --
> 2.47.3
>