1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2020 Facebook
3#include <linux/bpf.h>
4#include <bpf/bpf_helpers.h>
5#include <bpf/bpf_tracing.h>
6
7struct {
8 __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
9 __uint(max_entries, 1);
10 __type(key, int);
11 __type(value, int);
12} array_1 SEC(".maps");
13
14struct {
15 __uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
16 __uint(max_entries, 1);
17 __type(key, int);
18 __type(value, int);
19 __uint(map_flags, BPF_F_PRESERVE_ELEMS);
20} array_2 SEC(".maps");
21
22SEC("raw_tp/sched_switch")
23int BPF_PROG(read_array_1)
24{
25 struct bpf_perf_event_value val;
26
27 return bpf_perf_event_read_value(&array_1, 0, &val, sizeof(val));
28}
29
30SEC("raw_tp/task_rename")
31int BPF_PROG(read_array_2)
32{
33 struct bpf_perf_event_value val;
34
35 return bpf_perf_event_read_value(&array_2, 0, &val, sizeof(val));
36}
37
38char LICENSE[] SEC("license") = "GPL";
39

source code of linux/tools/testing/selftests/bpf/progs/test_pe_preserve_elems.c