1// SPDX-License-Identifier: GPL-2.0-only
  2#include <time.h>
  3#include <linux/bpf.h>
  4#include <bpf/bpf_helpers.h>
  5
  6struct timer {
  7	struct bpf_timer t;
  8};
  9
 10struct lock {
 11	struct bpf_spin_lock l;
 12};
 13
 14struct {
 15	__uint(type, BPF_MAP_TYPE_ARRAY);
 16	__uint(max_entries, 1);
 17	__type(key, __u32);
 18	__type(value, struct timer);
 19} timers SEC(".maps");
 20
 21struct {
 22	__uint(type, BPF_MAP_TYPE_ARRAY);
 23	__uint(max_entries, 1);
 24	__type(key, __u32);
 25	__type(value, struct lock);
 26} locks SEC(".maps");
 27
 28static int timer_cb(void *map, int *key, struct timer *timer)
 29{
 30	return 0;
 31}
 32
 33static void timer_work(void)
 34{
 35	struct timer *timer;
 36	const int key = 0;
 37
 38	timer  = bpf_map_lookup_elem(&timers, &key);
 39	if (timer) {
 40		bpf_timer_init(&timer->t, &timers, CLOCK_MONOTONIC);
 41		bpf_timer_set_callback(&timer->t, timer_cb);
 42		bpf_timer_start(&timer->t, 10E9, 0);
 43		bpf_timer_cancel(&timer->t);
 44	}
 45}
 46
 47static void spin_lock_work(void)
 48{
 49	const int key = 0;
 50	struct lock *lock;
 51
 52	lock = bpf_map_lookup_elem(&locks, &key);
 53	if (lock) {
 54		bpf_spin_lock(&lock->l);
 55		bpf_spin_unlock(&lock->l);
 56	}
 57}
 58
 59SEC("?raw_tp/sys_enter")
 60int raw_tp_timer(void *ctx)
 61{
 62	timer_work();
 63
 64	return 0;
 65}
 66
 67SEC("?tp/syscalls/sys_enter_nanosleep")
 68int tp_timer(void *ctx)
 69{
 70	timer_work();
 71
 72	return 0;
 73}
 74
 75SEC("?kprobe")
 76int kprobe_timer(void *ctx)
 77{
 78	timer_work();
 79
 80	return 0;
 81}
 82
 83SEC("?perf_event")
 84int perf_event_timer(void *ctx)
 85{
 86	timer_work();
 87
 88	return 0;
 89}
 90
 91SEC("?raw_tp/sys_enter")
 92int raw_tp_spin_lock(void *ctx)
 93{
 94	spin_lock_work();
 95
 96	return 0;
 97}
 98
 99SEC("?tp/syscalls/sys_enter_nanosleep")
100int tp_spin_lock(void *ctx)
101{
102	spin_lock_work();
103
104	return 0;
105}
106
107SEC("?kprobe")
108int kprobe_spin_lock(void *ctx)
109{
110	spin_lock_work();
111
112	return 0;
113}
114
115SEC("?perf_event")
116int perf_event_spin_lock(void *ctx)
117{
118	spin_lock_work();
119
120	return 0;
121}
122
123const char LICENSE[] SEC("license") = "GPL";