1// SPDX-License-Identifier: GPL-2.0
2// Copyright (c) 2020 Facebook
3#include "vmlinux.h"
4#include <bpf/bpf_helpers.h>
5
6#ifndef PERF_MAX_STACK_DEPTH
7#define PERF_MAX_STACK_DEPTH         127
8#endif
9
10typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH];
11struct {
12	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
13	__uint(max_entries, 16384);
14	__type(key, __u32);
15	__type(value, stack_trace_t);
16} stackmap SEC(".maps");
17
18struct {
19	__uint(type, BPF_MAP_TYPE_PERCPU_ARRAY);
20	__uint(max_entries, 1);
21	__type(key, __u32);
22	__type(value, stack_trace_t);
23} stackdata_map SEC(".maps");
24
25long stackid_kernel = 1;
26long stackid_user = 1;
27long stack_kernel = 1;
28long stack_user = 1;
29
30SEC("perf_event")
31int oncpu(void *ctx)
32{
33	stack_trace_t *trace;
34	__u32 key = 0;
35	long val;
36
37	val = bpf_get_stackid(ctx, &stackmap, 0);
38	if (val >= 0)
39		stackid_kernel = 2;
40	val = bpf_get_stackid(ctx, &stackmap, BPF_F_USER_STACK);
41	if (val >= 0)
42		stackid_user = 2;
43
44	trace = bpf_map_lookup_elem(&stackdata_map, &key);
45	if (!trace)
46		return 0;
47
48	val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), 0);
49	if (val > 0)
50		stack_kernel = 2;
51
52	val = bpf_get_stack(ctx, trace, sizeof(stack_trace_t), BPF_F_USER_STACK);
53	if (val > 0)
54		stack_user = 2;
55
56	return 0;
57}
58
59char LICENSE[] SEC("license") = "GPL";
60