1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (c) 2019 Facebook */
3 
4 #include <stdbool.h>
5 #include <linux/bpf.h>
6 #include <bpf/bpf_helpers.h>
7 
8 #define __read_mostly SEC(".data.read_mostly")
9 
10 struct s {
11 	int a;
12 	long long b;
13 } __attribute__((packed));
14 
15 /* .data section */
16 int in1 = -1;
17 long long in2 = -1;
18 
19 /* .bss section */
20 char in3 = '\0';
21 long long in4 __attribute__((aligned(64))) = 0;
22 struct s in5 = {};
23 
24 /* .rodata section */
25 const volatile struct {
26 	const int in6;
27 } in = {};
28 
29 /* .data section */
30 int out1 = -1;
31 long long out2 = -1;
32 
33 /* .bss section */
34 char out3 = 0;
35 long long out4 = 0;
36 int out6 = 0;
37 
38 extern bool CONFIG_BPF_SYSCALL __kconfig;
39 extern int LINUX_KERNEL_VERSION __kconfig;
40 bool bpf_syscall = 0;
41 int kern_ver = 0;
42 
43 struct s out5 = {};
44 
45 
46 const volatile int in_dynarr_sz SEC(".rodata.dyn");
47 const volatile int in_dynarr[4] SEC(".rodata.dyn") = { -1, -2, -3, -4 };
48 
49 int out_dynarr[4] SEC(".data.dyn") = { 1, 2, 3, 4 };
50 
51 int read_mostly_var __read_mostly;
52 int out_mostly_var;
53 
54 char huge_arr[16 * 1024 * 1024];
55 
56 /* non-mmapable custom .data section */
57 
58 struct my_value { int x, y, z; };
59 
60 __hidden int zero_key SEC(".data.non_mmapable");
61 static struct my_value zero_value SEC(".data.non_mmapable");
62 
63 struct {
64 	__uint(type, BPF_MAP_TYPE_ARRAY);
65 	__type(key, int);
66 	__type(value, struct my_value);
67 	__uint(max_entries, 1);
68 } my_map SEC(".maps");
69 
70 SEC("raw_tp/sys_enter")
71 int handler(const void *ctx)
72 {
73 	int i;
74 
75 	out1 = in1;
76 	out2 = in2;
77 	out3 = in3;
78 	out4 = in4;
79 	out5 = in5;
80 	out6 = in.in6;
81 
82 	bpf_syscall = CONFIG_BPF_SYSCALL;
83 	kern_ver = LINUX_KERNEL_VERSION;
84 
85 	for (i = 0; i < in_dynarr_sz; i++)
86 		out_dynarr[i] = in_dynarr[i];
87 
88 	out_mostly_var = read_mostly_var;
89 
90 	huge_arr[sizeof(huge_arr) - 1] = 123;
91 
92 	/* make sure zero_key and zero_value are not optimized out */
93 	bpf_map_update_elem(&my_map, &zero_key, &zero_value, BPF_ANY);
94 
95 	return 0;
96 }
97 
98 char _license[] SEC("license") = "GPL";
99