1// SPDX-License-Identifier: GPL-2.0
 2// Copyright (c) 2019 Facebook
 3
 4#include <linux/bpf.h>
 5#include <stdint.h>
 6#include <bpf/bpf_helpers.h>
 7
 8char _license[] SEC("license") = "GPL";
 9
10struct {
11	__uint(type, BPF_MAP_TYPE_ARRAY);
12	__uint(max_entries, 4096);
13	__uint(map_flags, BPF_F_MMAPABLE | BPF_F_RDONLY_PROG);
14	__type(key, __u32);
15	__type(value, char);
16} rdonly_map SEC(".maps");
17
18struct {
19	__uint(type, BPF_MAP_TYPE_ARRAY);
20	__uint(max_entries, 512 * 4); /* at least 4 pages of data */
21	__uint(map_flags, BPF_F_MMAPABLE);
22	__type(key, __u32);
23	__type(value, __u64);
24} data_map SEC(".maps");
25
26__u64 in_val = 0;
27__u64 out_val = 0;
28
29SEC("raw_tracepoint/sys_enter")
30int test_mmap(void *ctx)
31{
32	int zero = 0, one = 1, two = 2, far = 1500;
33	__u64 val, *p;
34
35	out_val = in_val;
36
37	/* data_map[2] = in_val; */
38	bpf_map_update_elem(&data_map, &two, (const void *)&in_val, 0);
39
40	/* data_map[1] = data_map[0] * 2; */
41	p = bpf_map_lookup_elem(&data_map, &zero);
42	if (p) {
43		val = (*p) * 2;
44		bpf_map_update_elem(&data_map, &one, &val, 0);
45	}
46
47	/* data_map[far] = in_val * 3; */
48	val = in_val * 3;
49	bpf_map_update_elem(&data_map, &far, &val, 0);
50
51	return 0;
52}
53

 1// SPDX-License-Identifier: GPL-2.0
 2// Copyright (c) 2019 Facebook
 3
 4#include <linux/bpf.h>
 5#include <stdint.h>
 6#include <bpf/bpf_helpers.h>
 7
 8char _license[] SEC("license") = "GPL";
 9
10struct {
11	__uint(type, BPF_MAP_TYPE_ARRAY);
 
12	__uint(map_flags, BPF_F_MMAPABLE | BPF_F_RDONLY_PROG);
13	__type(key, __u32);
14	__type(value, char);
15} rdonly_map SEC(".maps");
16
17struct {
18	__uint(type, BPF_MAP_TYPE_ARRAY);
 
19	__uint(map_flags, BPF_F_MMAPABLE);
20	__type(key, __u32);
21	__type(value, __u64);
22} data_map SEC(".maps");
23
24__u64 in_val = 0;
25__u64 out_val = 0;
26
27SEC("raw_tracepoint/sys_enter")
28int test_mmap(void *ctx)
29{
30	int zero = 0, one = 1, two = 2, far = 1500;
31	__u64 val, *p;
32
33	out_val = in_val;
34
35	/* data_map[2] = in_val; */
36	bpf_map_update_elem(&data_map, &two, (const void *)&in_val, 0);
37
38	/* data_map[1] = data_map[0] * 2; */
39	p = bpf_map_lookup_elem(&data_map, &zero);
40	if (p) {
41		val = (*p) * 2;
42		bpf_map_update_elem(&data_map, &one, &val, 0);
43	}
44
45	/* data_map[far] = in_val * 3; */
46	val = in_val * 3;
47	bpf_map_update_elem(&data_map, &far, &val, 0);
48
49	return 0;
50}
51