netdev - [PATCH bpf-next v3 1/4] bpf: Allow verifier to fixup kernel module kfuncs

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Message-ID: <20251017215627.722338-2-ameryhung@gmail.com>
Date: Fri, 17 Oct 2025 14:56:24 -0700
From: Amery Hung <ameryhung@...il.com>
To: bpf@...r.kernel.org
Cc: netdev@...r.kernel.org,
	alexei.starovoitov@...il.com,
	andrii@...nel.org,
	daniel@...earbox.net,
	tj@...nel.org,
	martin.lau@...nel.org,
	ameryhung@...il.com,
	kernel-team@...a.com
Subject: [PATCH bpf-next v3 1/4] bpf: Allow verifier to fixup kernel module kfuncs

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(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index e892df386eed..d5f1046d08b7 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -21889,8 +21889,7 @@ 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