1 // SPDX-License-Identifier: GPL-2.0-only 2 #include <time.h> 3 #include <linux/bpf.h> 4 #include <bpf/bpf_helpers.h> 5 6 struct timer { 7 struct bpf_timer t; 8 }; 9 10 struct lock { 11 struct bpf_spin_lock l; 12 }; 13 14 struct { 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 21 struct { 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 28 static int timer_cb(void *map, int *key, struct timer *timer) 29 { 30 return 0; 31 } 32 33 static 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 47 static 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 59 SEC("?raw_tp/sys_enter") 60 int raw_tp_timer(void *ctx) 61 { 62 timer_work(); 63 64 return 0; 65 } 66 67 SEC("?tp/syscalls/sys_enter_nanosleep") 68 int tp_timer(void *ctx) 69 { 70 timer_work(); 71 72 return 0; 73 } 74 75 SEC("?kprobe") 76 int kprobe_timer(void *ctx) 77 { 78 timer_work(); 79 80 return 0; 81 } 82 83 SEC("?perf_event") 84 int perf_event_timer(void *ctx) 85 { 86 timer_work(); 87 88 return 0; 89 } 90 91 SEC("?raw_tp/sys_enter") 92 int raw_tp_spin_lock(void *ctx) 93 { 94 spin_lock_work(); 95 96 return 0; 97 } 98 99 SEC("?tp/syscalls/sys_enter_nanosleep") 100 int tp_spin_lock(void *ctx) 101 { 102 spin_lock_work(); 103 104 return 0; 105 } 106 107 SEC("?kprobe") 108 int kprobe_spin_lock(void *ctx) 109 { 110 spin_lock_work(); 111 112 return 0; 113 } 114 115 SEC("?perf_event") 116 int perf_event_spin_lock(void *ctx) 117 { 118 spin_lock_work(); 119 120 return 0; 121 } 122 123 const char LICENSE[] SEC("license") = "GPL"; 124