1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (C) 2022. Huawei Technologies Co., Ltd */
3#include <linux/bpf.h>
4#include <bpf/bpf_helpers.h>
5#include <bpf/bpf_tracing.h>
6
7char _license[] SEC("license") = "GPL";
8
9struct {
10	__uint(type, BPF_MAP_TYPE_HASH);
11	__uint(max_entries, 1);
12	__uint(key_size, sizeof(__u32));
13	__uint(value_size, sizeof(__u32));
14} htab SEC(".maps");
15
16int pid = 0;
17int update_err = 0;
18
19SEC("?fentry/lookup_elem_raw")
20int lookup_elem_raw(void *ctx)
21{
22	__u32 key = 0, value = 1;
23
24	if ((bpf_get_current_pid_tgid() >> 32) != pid)
25		return 0;
26
27	update_err = bpf_map_update_elem(&htab, &key, &value, 0);
28	return 0;
29}
30