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 print_name_offset(struct seq_file *m, void *sym) 46 { 47 char symname[KSYM_NAME_LEN]; 48 49 if (lookup_symbol_name((unsigned long)sym, symname) < 0) 50 SEQ_printf(m, "<%pK>", sym); 51 else 52 SEQ_printf(m, "%s", symname); 53 } 54 55 static void 56 print_timer(struct seq_file *m, struct hrtimer *taddr, struct hrtimer *timer, 57 int idx, u64 now) 58 { 59 SEQ_printf(m, " #%d: ", idx); 60 print_name_offset(m, taddr); 61 SEQ_printf(m, ", "); 62 print_name_offset(m, timer->function); 63 SEQ_printf(m, ", S:%02x", timer->state); 64 SEQ_printf(m, "\n"); 65 SEQ_printf(m, " # expires at %Lu-%Lu nsecs [in %Ld to %Ld nsecs]\n", 66 (unsigned long long)ktime_to_ns(hrtimer_get_softexpires(timer)), 67 (unsigned long long)ktime_to_ns(hrtimer_get_expires(timer)), 68 (long long)(ktime_to_ns(hrtimer_get_softexpires(timer)) - now), 69 (long long)(ktime_to_ns(hrtimer_get_expires(timer)) - now)); 70 } 71 72 static void 73 print_active_timers(struct seq_file *m, struct hrtimer_clock_base *base, 74 u64 now) 75 { 76 struct hrtimer *timer, tmp; 77 unsigned long next = 0, i; 78 struct timerqueue_node *curr; 79 unsigned long flags; 80 81 next_one: 82 i = 0; 83 84 touch_nmi_watchdog(); 85 86 raw_spin_lock_irqsave(&base->cpu_base->lock, flags); 87 88 curr = timerqueue_getnext(&base->active); 89 /* 90 * Crude but we have to do this O(N*N) thing, because 91 * we have to unlock the base when printing: 92 */ 93 while (curr && i < next) { 94 curr = timerqueue_iterate_next(curr); 95 i++; 96 } 97 98 if (curr) { 99 100 timer = container_of(curr, struct hrtimer, node); 101 tmp = *timer; 102 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 103 104 print_timer(m, timer, &tmp, i, now); 105 next++; 106 goto next_one; 107 } 108 raw_spin_unlock_irqrestore(&base->cpu_base->lock, flags); 109 } 110 111 static void 112 print_base(struct seq_file *m, struct hrtimer_clock_base *base, u64 now) 113 { 114 SEQ_printf(m, " .base: %pK\n", base); 115 SEQ_printf(m, " .index: %d\n", base->index); 116 117 SEQ_printf(m, " .resolution: %u nsecs\n", hrtimer_resolution); 118 119 SEQ_printf(m, " .get_time: "); 120 print_name_offset(m, base->get_time); 121 SEQ_printf(m, "\n"); 122 #ifdef CONFIG_HIGH_RES_TIMERS 123 SEQ_printf(m, " .offset: %Lu nsecs\n", 124 (unsigned long long) ktime_to_ns(base->offset)); 125 #endif 126 SEQ_printf(m, "active timers:\n"); 127 print_active_timers(m, base, now + ktime_to_ns(base->offset)); 128 } 129 130 static void print_cpu(struct seq_file *m, int cpu, u64 now) 131 { 132 struct hrtimer_cpu_base *cpu_base = &per_cpu(hrtimer_bases, cpu); 133 int i; 134 135 SEQ_printf(m, "cpu: %d\n", cpu); 136 for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++) { 137 SEQ_printf(m, " clock %d:\n", i); 138 print_base(m, cpu_base->clock_base + i, now); 139 } 140 #define P(x) \ 141 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 142 (unsigned long long)(cpu_base->x)) 143 #define P_ns(x) \ 144 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 145 (unsigned long long)(ktime_to_ns(cpu_base->x))) 146 147 #ifdef CONFIG_HIGH_RES_TIMERS 148 P_ns(expires_next); 149 P(hres_active); 150 P(nr_events); 151 P(nr_retries); 152 P(nr_hangs); 153 P(max_hang_time); 154 #endif 155 #undef P 156 #undef P_ns 157 158 #ifdef CONFIG_TICK_ONESHOT 159 # define P(x) \ 160 SEQ_printf(m, " .%-15s: %Lu\n", #x, \ 161 (unsigned long long)(ts->x)) 162 # define P_ns(x) \ 163 SEQ_printf(m, " .%-15s: %Lu nsecs\n", #x, \ 164 (unsigned long long)(ktime_to_ns(ts->x))) 165 { 166 struct tick_sched *ts = tick_get_tick_sched(cpu); 167 P(nohz_mode); 168 P_ns(last_tick); 169 P(tick_stopped); 170 P(idle_jiffies); 171 P(idle_calls); 172 P(idle_sleeps); 173 P_ns(idle_entrytime); 174 P_ns(idle_waketime); 175 P_ns(idle_exittime); 176 P_ns(idle_sleeptime); 177 P_ns(iowait_sleeptime); 178 P(last_jiffies); 179 P(next_timer); 180 P_ns(idle_expires); 181 SEQ_printf(m, "jiffies: %Lu\n", 182 (unsigned long long)jiffies); 183 } 184 #endif 185 186 #undef P 187 #undef P_ns 188 SEQ_printf(m, "\n"); 189 } 190 191 #ifdef CONFIG_GENERIC_CLOCKEVENTS 192 static void 193 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 194 { 195 struct clock_event_device *dev = td->evtdev; 196 197 touch_nmi_watchdog(); 198 199 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 200 if (cpu < 0) 201 SEQ_printf(m, "Broadcast device\n"); 202 else 203 SEQ_printf(m, "Per CPU device: %d\n", cpu); 204 205 SEQ_printf(m, "Clock Event Device: "); 206 if (!dev) { 207 SEQ_printf(m, "<NULL>\n"); 208 return; 209 } 210 SEQ_printf(m, "%s\n", dev->name); 211 SEQ_printf(m, " max_delta_ns: %llu\n", 212 (unsigned long long) dev->max_delta_ns); 213 SEQ_printf(m, " min_delta_ns: %llu\n", 214 (unsigned long long) dev->min_delta_ns); 215 SEQ_printf(m, " mult: %u\n", dev->mult); 216 SEQ_printf(m, " shift: %u\n", dev->shift); 217 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 218 SEQ_printf(m, " next_event: %Ld nsecs\n", 219 (unsigned long long) ktime_to_ns(dev->next_event)); 220 221 SEQ_printf(m, " set_next_event: "); 222 print_name_offset(m, dev->set_next_event); 223 SEQ_printf(m, "\n"); 224 225 if (dev->set_state_shutdown) { 226 SEQ_printf(m, " shutdown: "); 227 print_name_offset(m, dev->set_state_shutdown); 228 SEQ_printf(m, "\n"); 229 } 230 231 if (dev->set_state_periodic) { 232 SEQ_printf(m, " periodic: "); 233 print_name_offset(m, dev->set_state_periodic); 234 SEQ_printf(m, "\n"); 235 } 236 237 if (dev->set_state_oneshot) { 238 SEQ_printf(m, " oneshot: "); 239 print_name_offset(m, dev->set_state_oneshot); 240 SEQ_printf(m, "\n"); 241 } 242 243 if (dev->set_state_oneshot_stopped) { 244 SEQ_printf(m, " oneshot stopped: "); 245 print_name_offset(m, dev->set_state_oneshot_stopped); 246 SEQ_printf(m, "\n"); 247 } 248 249 if (dev->tick_resume) { 250 SEQ_printf(m, " resume: "); 251 print_name_offset(m, dev->tick_resume); 252 SEQ_printf(m, "\n"); 253 } 254 255 SEQ_printf(m, " event_handler: "); 256 print_name_offset(m, dev->event_handler); 257 SEQ_printf(m, "\n"); 258 SEQ_printf(m, " retries: %lu\n", dev->retries); 259 SEQ_printf(m, "\n"); 260 } 261 262 static void timer_list_show_tickdevices_header(struct seq_file *m) 263 { 264 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 265 print_tickdevice(m, tick_get_broadcast_device(), -1); 266 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 267 cpumask_pr_args(tick_get_broadcast_mask())); 268 #ifdef CONFIG_TICK_ONESHOT 269 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 270 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 271 #endif 272 SEQ_printf(m, "\n"); 273 #endif 274 } 275 #endif 276 277 static inline void timer_list_header(struct seq_file *m, u64 now) 278 { 279 SEQ_printf(m, "Timer List Version: v0.8\n"); 280 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 281 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 282 SEQ_printf(m, "\n"); 283 } 284 285 static int timer_list_show(struct seq_file *m, void *v) 286 { 287 struct timer_list_iter *iter = v; 288 289 if (iter->cpu == -1 && !iter->second_pass) 290 timer_list_header(m, iter->now); 291 else if (!iter->second_pass) 292 print_cpu(m, iter->cpu, iter->now); 293 #ifdef CONFIG_GENERIC_CLOCKEVENTS 294 else if (iter->cpu == -1 && iter->second_pass) 295 timer_list_show_tickdevices_header(m); 296 else 297 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 298 #endif 299 return 0; 300 } 301 302 void sysrq_timer_list_show(void) 303 { 304 u64 now = ktime_to_ns(ktime_get()); 305 int cpu; 306 307 timer_list_header(NULL, now); 308 309 for_each_online_cpu(cpu) 310 print_cpu(NULL, cpu, now); 311 312 #ifdef CONFIG_GENERIC_CLOCKEVENTS 313 timer_list_show_tickdevices_header(NULL); 314 for_each_online_cpu(cpu) 315 print_tickdevice(NULL, tick_get_device(cpu), cpu); 316 #endif 317 return; 318 } 319 320 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 321 { 322 for (; offset; offset--) { 323 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 324 if (iter->cpu >= nr_cpu_ids) { 325 #ifdef CONFIG_GENERIC_CLOCKEVENTS 326 if (!iter->second_pass) { 327 iter->cpu = -1; 328 iter->second_pass = true; 329 } else 330 return NULL; 331 #else 332 return NULL; 333 #endif 334 } 335 } 336 return iter; 337 } 338 339 static void *timer_list_start(struct seq_file *file, loff_t *offset) 340 { 341 struct timer_list_iter *iter = file->private; 342 343 if (!*offset) 344 iter->now = ktime_to_ns(ktime_get()); 345 iter->cpu = -1; 346 iter->second_pass = false; 347 return move_iter(iter, *offset); 348 } 349 350 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 351 { 352 struct timer_list_iter *iter = file->private; 353 ++*offset; 354 return move_iter(iter, 1); 355 } 356 357 static void timer_list_stop(struct seq_file *seq, void *v) 358 { 359 } 360 361 static const struct seq_operations timer_list_sops = { 362 .start = timer_list_start, 363 .next = timer_list_next, 364 .stop = timer_list_stop, 365 .show = timer_list_show, 366 }; 367 368 static int __init init_timer_list_procfs(void) 369 { 370 struct proc_dir_entry *pe; 371 372 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops, 373 sizeof(struct timer_list_iter), NULL); 374 if (!pe) 375 return -ENOMEM; 376 return 0; 377 } 378 __initcall(init_timer_list_procfs); 379