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 
20 extern const int bpf_testmod_ksym_percpu __ksym;
21 extern void bpf_testmod_test_mod_kfunc(int i) __ksym;
22 extern void bpf_testmod_invalid_mod_kfunc(void) __ksym __weak;
23 
24 int out_bpf_testmod_ksym = 0;
25 const volatile int x = 0;
26 
27 SEC("tc")
load(struct __sk_buff * skb)28 int 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 
41 SEC("tc")
load_256(struct __sk_buff * skb)42 int 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 
50 char LICENSE[] SEC("license") = "GPL";
51