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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * List pending timers
4 *
5 * Copyright(C) 2006, Red Hat, Inc., Ingo Molnar
6 */
7
8#include <linux/proc_fs.h>
9#include <linux/module.h>
10#include <linux/spinlock.h>
11#include <linux/sched.h>
12#include <linux/seq_file.h>
13#include <linux/kallsyms.h>
14#include <linux/nmi.h>
15
16#include <linux/uaccess.h>
17
18#include "tick-internal.h"
19
20struct timer_list_iter {
21 int cpu;
22 bool second_pass;
23 ktime_t now;
24};
25
26/*
27 * This allows printing both to /proc/timer_list and
28 * to the console (on SysRq-Q):
29 */
30__printf(2, 3)
31static void SEQ_printf(struct seq_file *m, const char *fmt, ...)
32{
33 va_list args;
34
35 va_start(args, fmt);
36
37 if (m)
38 seq_vprintf(m, fmt, args);
39 else
40 vprintk(fmt, args);
41
42 va_end(args);
43}
44
45static void
46print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer,
47 int idx, ktime_t now)
48{
49 SEQ_printf(m, " #%d: <%p>, %ps", idx, taddr, ACCESS_PRIVATE(timer, function));
50 SEQ_printf(m, ", S:%02x", timer->is_queued);
51 SEQ_printf(m, "\n");
52 SEQ_printf(m, " # expires at %lld-%lld nsecs [in %lld to %lld nsecs]\n",
53 (long long)hrtimer_get_softexpires(timer),
54 (long long)hrtimer_get_expires(timer),
55 (long long)ktime_sub(hrtimer_get_softexpires(timer), now),
56 (long long)ktime_sub(hrtimer_get_expires(timer), now));
57}
58
59static void print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base, ktime_t now)
60{
61 struct timerqueue_linked_node *curr;
62 struct hrtimer *timer, tmp;
63 unsigned long next = 0, i;
64 unsigned long flags;
65
66next_one:
67 i = 0;
68
69 touch_nmi_watchdog();
70
71 raw_spin_lock_irqsave(&base->cpu_base->lock, flags);
72
73 curr = timerqueue_linked_first(&base->active);
74 /*
75 * Crude but we have to do this O(N*N) thing, because
76 * we have to unlock the base when printing:
77 */
78 while (curr && i < next) {
79 curr = timerqueue_linked_next(curr);
80 i++;
81 }
82
83 if (curr) {
84
85 timer = container_of(curr, struct hrtimer, node);
86 tmp = *timer;
87 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
88
89 print_timer(m, timer, &tmp, i, now);
90 next++;
91 goto next_one;
92 }
93 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags);
94}
95
96static void
97print_base(struct seq_file *m, struct hrtimer_clock_base *base, ktime_t now)
98{
99 SEQ_printf(m, " .base: %p\n", base);
100 SEQ_printf(m, " .index: %d\n", base->index);
101
102 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution);
103#ifdef CONFIG_HIGH_RES_TIMERS
104 SEQ_printf(m, " .offset: %lld nsecs\n",
105 (long long) base->offset);
106#endif
107 SEQ_printf(m, "active timers:\n");
108 print_active_timers(m, base, ktime_add(now, base->offset));
109}
110
111static void print_cpu(struct seq_file *m, int cpu, ktime_t now)
112{
113 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu);
114 int i;
115
116 SEQ_printf(m, "cpu: %d\n", cpu);
117 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) {
118 SEQ_printf(m, " clock %d:\n", i);
119 print_base(m, cpu_base->clock_base + i, now);
120 }
121
122#define DIAG_READ(x) data_race(READ_ONCE(x))
123
124#define P(x) \
125 SEQ_printf(m, " .%-15s: %llu\n", #x, \
126 (unsigned long long)DIAG_READ(cpu_base->x))
127#define P_ktime(x) \
128 SEQ_printf(m, " .%-15s: %lld nsecs\n", #x, (long long)DIAG_READ(cpu_base->x))
129
130#ifdef CONFIG_HIGH_RES_TIMERS
131 P_ktime(expires_next);
132 P(hres_active);
133 P(nr_events);
134 P(nr_retries);
135 P(nr_hangs);
136 P(max_hang_time);
137#endif
138#undef P
139#undef P_ktime
140
141#ifdef CONFIG_TICK_ONESHOT
142# define P(x) \
143 SEQ_printf(m, " .%-15s: %llu\n", #x, \
144 (unsigned long long)DIAG_READ(ts->x))
145# define P_ktime(x) \
146 SEQ_printf(m, " .%-15s: %lld nsecs\n", #x, (long long)DIAG_READ(ts->x))
147# define P_flag(x, f) \
148 SEQ_printf(m, " .%-15s: %d\n", #x, !!(DIAG_READ(ts->flags) & (f)))
149
150 {
151 struct tick_sched *ts = tick_get_tick_sched(cpu);
152 P_flag(nohz, TS_FLAG_NOHZ);
153 P_flag(highres, TS_FLAG_HIGHRES);
154 P_ktime(last_tick);
155 P_flag(tick_stopped, TS_FLAG_STOPPED);
156 P(idle_calls);
157 P(idle_sleeps);
158 P_ktime(idle_entrytime);
159 P_ktime(idle_waketime);
160 P(last_jiffies);
161 P(next_timer);
162 P_ktime(idle_expires);
163 SEQ_printf(m, "jiffies: %llu\n",
164 (unsigned long long)jiffies);
165 }
166#endif
167
168#undef P
169#undef P_ktime
170#undef P_flag
171#undef DIAG_READ
172 SEQ_printf(m, "\n");
173}
174
175#ifdef CONFIG_GENERIC_CLOCKEVENTS
176static void
177print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu)
178{
179 struct clock_event_device *dev = td->evtdev;
180
181 touch_nmi_watchdog();
182
183 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode);
184 if (cpu < 0)
185 SEQ_printf(m, "Broadcast device\n");
186 else
187 SEQ_printf(m, "Per CPU device: %d\n", cpu);
188
189 SEQ_printf(m, "Clock Event Device: ");
190 if (!dev) {
191 SEQ_printf(m, "<NULL>\n");
192 return;
193 }
194 SEQ_printf(m, "%s\n", dev->name);
195 SEQ_printf(m, " max_delta_ns: %llu\n",
196 (unsigned long long) dev->max_delta_ns);
197 SEQ_printf(m, " min_delta_ns: %llu\n",
198 (unsigned long long) dev->min_delta_ns);
199 SEQ_printf(m, " mult: %u\n", dev->mult);
200 SEQ_printf(m, " shift: %u\n", dev->shift);
201 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev));
202 SEQ_printf(m, " next_event: %lld nsecs\n", (long long)dev->next_event);
203
204 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event);
205
206 if (dev->set_state_shutdown)
207 SEQ_printf(m, " shutdown: %ps\n",
208 dev->set_state_shutdown);
209
210 if (dev->set_state_periodic)
211 SEQ_printf(m, " periodic: %ps\n",
212 dev->set_state_periodic);
213
214 if (dev->set_state_oneshot)
215 SEQ_printf(m, " oneshot: %ps\n",
216 dev->set_state_oneshot);
217
218 if (dev->set_state_oneshot_stopped)
219 SEQ_printf(m, " oneshot stopped: %ps\n",
220 dev->set_state_oneshot_stopped);
221
222 if (dev->tick_resume)
223 SEQ_printf(m, " resume: %ps\n",
224 dev->tick_resume);
225
226 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler);
227 SEQ_printf(m, "\n");
228 SEQ_printf(m, " retries: %lu\n", dev->retries);
229
230#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
231 if (cpu >= 0) {
232 const struct clock_event_device *wd = tick_get_wakeup_device(cpu);
233
234 SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>");
235 }
236#endif
237 SEQ_printf(m, "\n");
238}
239
240static void timer_list_show_tickdevices_header(struct seq_file *m)
241{
242#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
243 print_tickdevice(m, tick_get_broadcast_device(), -1);
244 SEQ_printf(m, "tick_broadcast_mask: %*pb\n",
245 cpumask_pr_args(tick_get_broadcast_mask()));
246#ifdef CONFIG_TICK_ONESHOT
247 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n",
248 cpumask_pr_args(tick_get_broadcast_oneshot_mask()));
249#endif
250 SEQ_printf(m, "\n");
251#endif
252}
253#endif
254
255static inline void timer_list_header(struct seq_file *m, ktime_t now)
256{
257 SEQ_printf(m, "Timer List Version: v0.11\n");
258 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES);
259 SEQ_printf(m, "now at %lld nsecs\n", (long long)now);
260 SEQ_printf(m, "\n");
261}
262
263void sysrq_timer_list_show(void)
264{
265 ktime_t now = ktime_get();
266 int cpu;
267
268 timer_list_header(NULL, now);
269
270 for_each_online_cpu(cpu)
271 print_cpu(NULL, cpu, now);
272
273#ifdef CONFIG_GENERIC_CLOCKEVENTS
274 timer_list_show_tickdevices_header(NULL);
275 for_each_online_cpu(cpu)
276 print_tickdevice(NULL, tick_get_device(cpu), cpu);
277#endif
278 return;
279}
280
281#ifdef CONFIG_PROC_FS
282static int timer_list_show(struct seq_file *m, void *v)
283{
284 struct timer_list_iter *iter = v;
285
286 if (iter->cpu == -1 && !iter->second_pass)
287 timer_list_header(m, iter->now);
288 else if (!iter->second_pass)
289 print_cpu(m, iter->cpu, iter->now);
290#ifdef CONFIG_GENERIC_CLOCKEVENTS
291 else if (iter->cpu == -1 && iter->second_pass)
292 timer_list_show_tickdevices_header(m);
293 else
294 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu);
295#endif
296 return 0;
297}
298
299static void *move_iter(struct timer_list_iter *iter, loff_t offset)
300{
301 for (; offset; offset--) {
302 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask);
303 if (iter->cpu >= nr_cpu_ids) {
304#ifdef CONFIG_GENERIC_CLOCKEVENTS
305 if (!iter->second_pass) {
306 iter->cpu = -1;
307 iter->second_pass = true;
308 } else
309 return NULL;
310#else
311 return NULL;
312#endif
313 }
314 }
315 return iter;
316}
317
318static void *timer_list_start(struct seq_file *file, loff_t *offset)
319{
320 struct timer_list_iter *iter = file->private;
321
322 if (!*offset)
323 iter->now = ktime_get();
324 iter->cpu = -1;
325 iter->second_pass = false;
326 return move_iter(iter, *offset);
327}
328
329static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset)
330{
331 struct timer_list_iter *iter = file->private;
332 ++*offset;
333 return move_iter(iter, 1);
334}
335
336static void timer_list_stop(struct seq_file *seq, void *v)
337{
338}
339
340static const struct seq_operations timer_list_sops = {
341 .start = timer_list_start,
342 .next = timer_list_next,
343 .stop = timer_list_stop,
344 .show = timer_list_show,
345};
346
347static int __init init_timer_list_procfs(void)
348{
349 struct proc_dir_entry *pe;
350
351 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops,
352 sizeof(struct timer_list_iter), NULL);
353 if (!pe)
354 return -ENOMEM;
355 return 0;
356}
357__initcall(init_timer_list_procfs);
358#endif