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 
7 char _license[] SEC("license") = "GPL";
8 
9 struct {
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 
16 int pid = 0;
17 int update_err = 0;
18 
19 SEC("?fentry/lookup_elem_raw")
20 int 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