1// SPDX-License-Identifier: GPL-2.0
2/* Copyright (c) 2020 Tessares SA <http://www.tessares.net> */
3
4#include "vmlinux.h"
5#include <bpf/bpf_helpers.h>
6
7__u64 inKey = 0;
8__u64 inValue = 0;
9__u32 inPid = 0;
10
11struct {
12	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
13	__uint(max_entries, 2);
14	__type(key, __u64);
15	__type(value, __u64);
16} hashmap1 SEC(".maps");
17
18
19SEC("tp/syscalls/sys_enter_getpgid")
20int sysenter_getpgid(const void *ctx)
21{
22	/* Just do it for once, when called from our own test prog. This
23	 * ensures the map value is only updated for a single CPU.
24	 */
25	int cur_pid = bpf_get_current_pid_tgid() >> 32;
26
27	if (cur_pid == inPid)
28		bpf_map_update_elem(&hashmap1, &inKey, &inValue, BPF_NOEXIST);
29
30	return 0;
31}
32
33char _license[] SEC("license") = "GPL";
34