Add corresponding unimplemented stub for when CONFIG_BPF_SYSCALL=n

Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
---
 include/linux/bpf.h | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/include/linux/bpf.h b/include/linux/bpf.h
index 39bd36359c1e..fcde14ae6e60 100644
--- a/include/linux/bpf.h
+++ b/include/linux/bpf.h
@@ -2157,6 +2157,15 @@ static inline struct bpf_prog *bpf_prog_by_id(u32 id)
 	return ERR_PTR(-ENOTSUPP);
 }
 
+static inline int btf_struct_access(struct bpf_verifier_log *log,
+				    const struct btf *btf,
+				    const struct btf_type *t, int off, int size,
+				    enum bpf_access_type atype,
+				    u32 *next_btf_id, enum bpf_type_flag *flag)
+{
+	return -EACCES;
+}
+
 static inline const struct bpf_func_proto *
 bpf_base_func_proto(enum bpf_func_id func_id)
 {
-- 
2.37.1