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 
10 typedef __u64 stack_trace_t[PERF_MAX_STACK_DEPTH];
11 struct {
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 
18 struct {
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 
25 long stackid_kernel = 1;
26 long stackid_user = 1;
27 long stack_kernel = 1;
28 long stack_user = 1;
29 
30 SEC("perf_event")
31 int 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 
59 char LICENSE[] SEC("license") = "GPL";
60