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 20 struct timer_list_iter { 21 int cpu; 22 bool second_pass; 23 u64 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) 31 static 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 45 static void 46 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer, 47 int idx, u64 now) 48 { 49 SEQ_printf(m, " #%d: <%pK>, %ps", idx, taddr, timer->function); 50 SEQ_printf(m, ", S:%02x", timer->state); 51 SEQ_printf(m, "\n"); 52 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n", 53 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)), 54 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)), 55 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now), 56 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now)); 57 } 58 59 static void 60 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base, 61 u64 now) 62 { 63 struct hrtimer *timer, tmp; 64 unsigned long next = 0, i; 65 struct timerqueue_node *curr; 66 unsigned long flags; 67 68 next_one: 69 i = 0; 70 71 touch_nmi_watchdog(); 72 73 raw_spin_lock_irqsave(&base->cpu_base->lock, flags); 74 75 curr = timerqueue_getnext(&base->active); 76 /* 77 * Crude but we have to do this O(N*N) thing, because 78 * we have to unlock the base when printing: 79 */ 80 while (curr && i < next) { 81 curr = timerqueue_iterate_next(curr); 82 i++; 83 } 84 85 if (curr) { 86 87 timer = container_of(curr, struct hrtimer, node); 88 tmp = *timer; 89 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 90 91 print_timer(m, timer, &tmp, i, now); 92 next++; 93 goto next_one; 94 } 95 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 96 } 97 98 static void 99 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) 100 { 101 SEQ_printf(m, " .base: %pK\n", base); 102 SEQ_printf(m, " .index: %d\n", base->index); 103 104 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution); 105 106 SEQ_printf(m, " .get_time: %ps\n", base->get_time); 107 #ifdef CONFIG_HIGH_RES_TIMERS 108 SEQ_printf(m, " .offset: %Lu nsecs\n", 109 (unsigned long long) ktime_to_ns(base->offset)); 110 #endif 111 SEQ_printf(m, "active timers:\n"); 112 print_active_timers(m, base, now + ktime_to_ns(base->offset)); 113 } 114 115 static void print_cpu(struct seq_file *m, int cpu, u64 now) 116 { 117 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); 118 int i; 119 120 SEQ_printf(m, "cpu: %d\n", cpu); 121 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { 122 SEQ_printf(m, " clock %d:\n", i); 123 print_base(m, cpu_base->clock_base + i, now); 124 } 125 #define P(x) \ 126 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 127 (unsigned long long)(cpu_base->x)) 128 #define P_ns(x) \ 129 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 130 (unsigned long long)(ktime_to_ns(cpu_base->x))) 131 132 #ifdef CONFIG_HIGH_RES_TIMERS 133 P_ns(expires_next); 134 P(hres_active); 135 P(nr_events); 136 P(nr_retries); 137 P(nr_hangs); 138 P(max_hang_time); 139 #endif 140 #undef P 141 #undef P_ns 142 143 #ifdef CONFIG_TICK_ONESHOT 144 # define P(x) \ 145 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 146 (unsigned long long)(ts->x)) 147 # define P_ns(x) \ 148 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 149 (unsigned long long)(ktime_to_ns(ts->x))) 150 # define P_flag(x, f) \ 151 SEQ_printf(m, " .%-15s: %d\n", #x, !!(ts->flags & (f))) 152 153 { 154 struct tick_sched *ts = tick_get_tick_sched(cpu); 155 P_flag(nohz, TS_FLAG_NOHZ); 156 P_flag(highres, TS_FLAG_HIGHRES); 157 P_ns(last_tick); 158 P_flag(tick_stopped, TS_FLAG_STOPPED); 159 P(idle_jiffies); 160 P(idle_calls); 161 P(idle_sleeps); 162 P_ns(idle_entrytime); 163 P_ns(idle_waketime); 164 P_ns(idle_exittime); 165 P_ns(idle_sleeptime); 166 P_ns(iowait_sleeptime); 167 P(last_jiffies); 168 P(next_timer); 169 P_ns(idle_expires); 170 SEQ_printf(m, "jiffies: %Lu\n", 171 (unsigned long long)jiffies); 172 } 173 #endif 174 175 #undef P 176 #undef P_ns 177 SEQ_printf(m, "\n"); 178 } 179 180 #ifdef CONFIG_GENERIC_CLOCKEVENTS 181 static void 182 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 183 { 184 struct clock_event_device *dev = td->evtdev; 185 186 touch_nmi_watchdog(); 187 188 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 189 if (cpu < 0) 190 SEQ_printf(m, "Broadcast device\n"); 191 else 192 SEQ_printf(m, "Per CPU device: %d\n", cpu); 193 194 SEQ_printf(m, "Clock Event Device: "); 195 if (!dev) { 196 SEQ_printf(m, "<NULL>\n"); 197 return; 198 } 199 SEQ_printf(m, "%s\n", dev->name); 200 SEQ_printf(m, " max_delta_ns: %llu\n", 201 (unsigned long long) dev->max_delta_ns); 202 SEQ_printf(m, " min_delta_ns: %llu\n", 203 (unsigned long long) dev->min_delta_ns); 204 SEQ_printf(m, " mult: %u\n", dev->mult); 205 SEQ_printf(m, " shift: %u\n", dev->shift); 206 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 207 SEQ_printf(m, " next_event: %Ld nsecs\n", 208 (unsigned long long) ktime_to_ns(dev->next_event)); 209 210 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event); 211 212 if (dev->set_state_shutdown) 213 SEQ_printf(m, " shutdown: %ps\n", 214 dev->set_state_shutdown); 215 216 if (dev->set_state_periodic) 217 SEQ_printf(m, " periodic: %ps\n", 218 dev->set_state_periodic); 219 220 if (dev->set_state_oneshot) 221 SEQ_printf(m, " oneshot: %ps\n", 222 dev->set_state_oneshot); 223 224 if (dev->set_state_oneshot_stopped) 225 SEQ_printf(m, " oneshot stopped: %ps\n", 226 dev->set_state_oneshot_stopped); 227 228 if (dev->tick_resume) 229 SEQ_printf(m, " resume: %ps\n", 230 dev->tick_resume); 231 232 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler); 233 SEQ_printf(m, "\n"); 234 SEQ_printf(m, " retries: %lu\n", dev->retries); 235 236 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 237 if (cpu >= 0) { 238 const struct clock_event_device *wd = tick_get_wakeup_device(cpu); 239 240 SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>"); 241 } 242 #endif 243 SEQ_printf(m, "\n"); 244 } 245 246 static void timer_list_show_tickdevices_header(struct seq_file *m) 247 { 248 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 249 print_tickdevice(m, tick_get_broadcast_device(), -1); 250 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 251 cpumask_pr_args(tick_get_broadcast_mask())); 252 #ifdef CONFIG_TICK_ONESHOT 253 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 254 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 255 #endif 256 SEQ_printf(m, "\n"); 257 #endif 258 } 259 #endif 260 261 static inline void timer_list_header(struct seq_file *m, u64 now) 262 { 263 SEQ_printf(m, "Timer List Version: v0.10\n"); 264 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 265 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 266 SEQ_printf(m, "\n"); 267 } 268 269 void sysrq_timer_list_show(void) 270 { 271 u64 now = ktime_to_ns(ktime_get()); 272 int cpu; 273 274 timer_list_header(NULL, now); 275 276 for_each_online_cpu(cpu) 277 print_cpu(NULL, cpu, now); 278 279 #ifdef CONFIG_GENERIC_CLOCKEVENTS 280 timer_list_show_tickdevices_header(NULL); 281 for_each_online_cpu(cpu) 282 print_tickdevice(NULL, tick_get_device(cpu), cpu); 283 #endif 284 return; 285 } 286 287 #ifdef CONFIG_PROC_FS 288 static int timer_list_show(struct seq_file *m, void *v) 289 { 290 struct timer_list_iter *iter = v; 291 292 if (iter->cpu == -1 && !iter->second_pass) 293 timer_list_header(m, iter->now); 294 else if (!iter->second_pass) 295 print_cpu(m, iter->cpu, iter->now); 296 #ifdef CONFIG_GENERIC_CLOCKEVENTS 297 else if (iter->cpu == -1 && iter->second_pass) 298 timer_list_show_tickdevices_header(m); 299 else 300 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 301 #endif 302 return 0; 303 } 304 305 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 306 { 307 for (; offset; offset--) { 308 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 309 if (iter->cpu >= nr_cpu_ids) { 310 #ifdef CONFIG_GENERIC_CLOCKEVENTS 311 if (!iter->second_pass) { 312 iter->cpu = -1; 313 iter->second_pass = true; 314 } else 315 return NULL; 316 #else 317 return NULL; 318 #endif 319 } 320 } 321 return iter; 322 } 323 324 static void *timer_list_start(struct seq_file *file, loff_t *offset) 325 { 326 struct timer_list_iter *iter = file->private; 327 328 if (!*offset) 329 iter->now = ktime_to_ns(ktime_get()); 330 iter->cpu = -1; 331 iter->second_pass = false; 332 return move_iter(iter, *offset); 333 } 334 335 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 336 { 337 struct timer_list_iter *iter = file->private; 338 ++*offset; 339 return move_iter(iter, 1); 340 } 341 342 static void timer_list_stop(struct seq_file *seq, void *v) 343 { 344 } 345 346 static const struct seq_operations timer_list_sops = { 347 .start = timer_list_start, 348 .next = timer_list_next, 349 .stop = timer_list_stop, 350 .show = timer_list_show, 351 }; 352 353 static int __init init_timer_list_procfs(void) 354 { 355 struct proc_dir_entry *pe; 356 357 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops, 358 sizeof(struct timer_list_iter), NULL); 359 if (!pe) 360 return -ENOMEM; 361 return 0; 362 } 363 __initcall(init_timer_list_procfs); 364 #endif 365