1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2021 Facebook */
3
4#include "vmlinux.h"
5#include <bpf/bpf_helpers.h>
6
7#define X_0(x)
8#define X_1(x) x X_0(x)
9#define X_2(x) x X_1(x)
10#define X_3(x) x X_2(x)
11#define X_4(x) x X_3(x)
12#define X_5(x) x X_4(x)
13#define X_6(x) x X_5(x)
14#define X_7(x) x X_6(x)
15#define X_8(x) x X_7(x)
16#define X_9(x) x X_8(x)
17#define X_10(x) x X_9(x)
18#define REPEAT_256(Y) X_2(X_10(X_10(Y))) X_5(X_10(Y)) X_6(Y)
19
20extern const int bpf_testmod_ksym_percpu __ksym;
21extern void bpf_testmod_test_mod_kfunc(int i) __ksym;
22extern void bpf_testmod_invalid_mod_kfunc(void) __ksym __weak;
23
24int out_bpf_testmod_ksym = 0;
25const volatile int x = 0;
26
27SEC("tc")
28int load(struct __sk_buff *skb)
29{
30	/* This will be kept by clang, but removed by verifier. Since it is
31	 * marked as __weak, libbpf and gen_loader don't error out if BTF ID
32	 * is not found for it, instead imm and off is set to 0 for it.
33	 */
34	if (x)
35		bpf_testmod_invalid_mod_kfunc();
36	bpf_testmod_test_mod_kfunc(42);
37	out_bpf_testmod_ksym = *(int *)bpf_this_cpu_ptr(&bpf_testmod_ksym_percpu);
38	return 0;
39}
40
41SEC("tc")
42int load_256(struct __sk_buff *skb)
43{
44	/* this will fail if kfunc doesn't reuse its own btf fd index */
45	REPEAT_256(bpf_testmod_test_mod_kfunc(42););
46	bpf_testmod_test_mod_kfunc(42);
47	return 0;
48}
49
50char LICENSE[] SEC("license") = "GPL";
51