1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2019 Facebook
3
4#include <linux/ptrace.h>
5#include <linux/bpf.h>
6#include <bpf/bpf_helpers.h>
7#include <bpf/bpf_tracing.h>
8
9struct {
10	__uint(type, BPF_MAP_TYPE_ARRAY);
11	__type(key, int);
12	__type(value, int);
13	__uint(max_entries, 1);
14} my_pid_map SEC(".maps");
15
16struct {
17	__uint(type, BPF_MAP_TYPE_PERF_EVENT_ARRAY);
18	__type(key, int);
19	__type(value, int);
20} perf_buf_map SEC(".maps");
21
22SEC("tp/raw_syscalls/sys_enter")
23int handle_sys_enter(void *ctx)
24{
25	int zero = 0, *my_pid, cur_pid;
26	int cpu = bpf_get_smp_processor_id();
27
28	my_pid = bpf_map_lookup_elem(&my_pid_map, &zero);
29	if (!my_pid)
30		return 1;
31
32	cur_pid = bpf_get_current_pid_tgid() >> 32;
33	if (cur_pid != *my_pid)
34		return 1;
35
36	bpf_perf_event_output(ctx, &perf_buf_map, BPF_F_CURRENT_CPU,
37			      &cpu, sizeof(cpu));
38	return 1;
39}
40
41char _license[] SEC("license") = "GPL";
42