diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index c306684..7e61c39 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -166,6 +166,11 @@ static inline bool bpf_verifier_log_full(const struct bpf_verifier_log *log)
 	return log->len_used >= log->len_total - 1;
 }
 
+static inline bool bpf_verifier_log_needed(const struct bpf_verifier_log *log)
+{
+	return log->level && log->ubuf && !bpf_verifier_log_full(log);
+}
+
 #define BPF_MAX_SUBPROGS 256
 
 /* single container for all structs
@@ -192,6 +197,8 @@ struct bpf_verifier_env {
 	u32 subprog_cnt;
 };
 
+void bpf_verifier_vlog(struct bpf_verifier_log *log, const char *fmt,
+		       va_list args);
 __printf(2, 3) void bpf_verifier_log_write(struct bpf_verifier_env *env,
 					   const char *fmt, ...);