1/* Copyright (c) 2016, Facebook
2 *
3 * This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
6 */
7#include "vmlinux.h"
8#include <linux/version.h>
9#include <bpf/bpf_helpers.h>
10#include <bpf/bpf_tracing.h>
11
12#ifndef PERF_MAX_STACK_DEPTH
13#define PERF_MAX_STACK_DEPTH         127
14#endif
15
16struct {
17	__uint(type, BPF_MAP_TYPE_HASH);
18	__type(key, long);
19	__type(value, long);
20	__uint(max_entries, 1024);
21} my_map SEC(".maps");
22struct {
23	__uint(type, BPF_MAP_TYPE_PERCPU_HASH);
24	__uint(key_size, sizeof(long));
25	__uint(value_size, sizeof(long));
26	__uint(max_entries, 1024);
27} my_map2 SEC(".maps");
28
29struct {
30	__uint(type, BPF_MAP_TYPE_STACK_TRACE);
31	__uint(key_size, sizeof(u32));
32	__uint(value_size, PERF_MAX_STACK_DEPTH * sizeof(u64));
33	__uint(max_entries, 10000);
34} stackmap SEC(".maps");
35
36#define PROG(foo) \
37int foo(struct pt_regs *ctx) \
38{ \
39	long v = PT_REGS_IP(ctx), *val; \
40\
41	val = bpf_map_lookup_elem(&my_map, &v); \
42	bpf_map_update_elem(&my_map, &v, &v, BPF_ANY); \
43	bpf_map_update_elem(&my_map2, &v, &v, BPF_ANY); \
44	bpf_map_delete_elem(&my_map2, &v); \
45	bpf_get_stackid(ctx, &stackmap, BPF_F_REUSE_STACKID); \
46	return 0; \
47}
48
49/* add kprobes to all possible *spin* functions */
50SEC("kprobe.multi/spin_*lock*")PROG(spin_lock)
51SEC("kprobe.multi/*_spin_on_owner")PROG(spin_on_owner)
52SEC("kprobe.multi/_raw_spin_*lock*")PROG(raw_spin_lock)
53
54/* and to inner bpf helpers */
55SEC("kprobe/htab_map_update_elem")PROG(p15)
56SEC("kprobe/__htab_percpu_map_update_elem")PROG(p16)
57SEC("kprobe/htab_map_alloc")PROG(p17)
58
59char _license[] SEC("license") = "GPL";
60u32 _version SEC("version") = LINUX_VERSION_CODE;
61