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(nohz_mode); 156 P_ns(last_tick); 157 P_flag(tick_stopped, TS_FLAG_STOPPED); 158 P(idle_jiffies); 159 P(idle_calls); 160 P(idle_sleeps); 161 P_ns(idle_entrytime); 162 P_ns(idle_waketime); 163 P_ns(idle_exittime); 164 P_ns(idle_sleeptime); 165 P_ns(iowait_sleeptime); 166 P(last_jiffies); 167 P(next_timer); 168 P_ns(idle_expires); 169 SEQ_printf(m, "jiffies: %Lu\n", 170 (unsigned long long)jiffies); 171 } 172 #endif 173 174 #undef P 175 #undef P_ns 176 SEQ_printf(m, "\n"); 177 } 178 179 #ifdef CONFIG_GENERIC_CLOCKEVENTS 180 static void 181 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 182 { 183 struct clock_event_device *dev = td->evtdev; 184 185 touch_nmi_watchdog(); 186 187 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 188 if (cpu < 0) 189 SEQ_printf(m, "Broadcast device\n"); 190 else 191 SEQ_printf(m, "Per CPU device: %d\n", cpu); 192 193 SEQ_printf(m, "Clock Event Device: "); 194 if (!dev) { 195 SEQ_printf(m, "<NULL>\n"); 196 return; 197 } 198 SEQ_printf(m, "%s\n", dev->name); 199 SEQ_printf(m, " max_delta_ns: %llu\n", 200 (unsigned long long) dev->max_delta_ns); 201 SEQ_printf(m, " min_delta_ns: %llu\n", 202 (unsigned long long) dev->min_delta_ns); 203 SEQ_printf(m, " mult: %u\n", dev->mult); 204 SEQ_printf(m, " shift: %u\n", dev->shift); 205 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 206 SEQ_printf(m, " next_event: %Ld nsecs\n", 207 (unsigned long long) ktime_to_ns(dev->next_event)); 208 209 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event); 210 211 if (dev->set_state_shutdown) 212 SEQ_printf(m, " shutdown: %ps\n", 213 dev->set_state_shutdown); 214 215 if (dev->set_state_periodic) 216 SEQ_printf(m, " periodic: %ps\n", 217 dev->set_state_periodic); 218 219 if (dev->set_state_oneshot) 220 SEQ_printf(m, " oneshot: %ps\n", 221 dev->set_state_oneshot); 222 223 if (dev->set_state_oneshot_stopped) 224 SEQ_printf(m, " oneshot stopped: %ps\n", 225 dev->set_state_oneshot_stopped); 226 227 if (dev->tick_resume) 228 SEQ_printf(m, " resume: %ps\n", 229 dev->tick_resume); 230 231 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler); 232 SEQ_printf(m, "\n"); 233 SEQ_printf(m, " retries: %lu\n", dev->retries); 234 235 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 236 if (cpu >= 0) { 237 const struct clock_event_device *wd = tick_get_wakeup_device(cpu); 238 239 SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>"); 240 } 241 #endif 242 SEQ_printf(m, "\n"); 243 } 244 245 static void timer_list_show_tickdevices_header(struct seq_file *m) 246 { 247 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 248 print_tickdevice(m, tick_get_broadcast_device(), -1); 249 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 250 cpumask_pr_args(tick_get_broadcast_mask())); 251 #ifdef CONFIG_TICK_ONESHOT 252 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 253 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 254 #endif 255 SEQ_printf(m, "\n"); 256 #endif 257 } 258 #endif 259 260 static inline void timer_list_header(struct seq_file *m, u64 now) 261 { 262 SEQ_printf(m, "Timer List Version: v0.9\n"); 263 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 264 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 265 SEQ_printf(m, "\n"); 266 } 267 268 void sysrq_timer_list_show(void) 269 { 270 u64 now = ktime_to_ns(ktime_get()); 271 int cpu; 272 273 timer_list_header(NULL, now); 274 275 for_each_online_cpu(cpu) 276 print_cpu(NULL, cpu, now); 277 278 #ifdef CONFIG_GENERIC_CLOCKEVENTS 279 timer_list_show_tickdevices_header(NULL); 280 for_each_online_cpu(cpu) 281 print_tickdevice(NULL, tick_get_device(cpu), cpu); 282 #endif 283 return; 284 } 285 286 #ifdef CONFIG_PROC_FS 287 static int timer_list_show(struct seq_file *m, void *v) 288 { 289 struct timer_list_iter *iter = v; 290 291 if (iter->cpu == -1 && !iter->second_pass) 292 timer_list_header(m, iter->now); 293 else if (!iter->second_pass) 294 print_cpu(m, iter->cpu, iter->now); 295 #ifdef CONFIG_GENERIC_CLOCKEVENTS 296 else if (iter->cpu == -1 && iter->second_pass) 297 timer_list_show_tickdevices_header(m); 298 else 299 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 300 #endif 301 return 0; 302 } 303 304 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 305 { 306 for (; offset; offset--) { 307 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 308 if (iter->cpu >= nr_cpu_ids) { 309 #ifdef CONFIG_GENERIC_CLOCKEVENTS 310 if (!iter->second_pass) { 311 iter->cpu = -1; 312 iter->second_pass = true; 313 } else 314 return NULL; 315 #else 316 return NULL; 317 #endif 318 } 319 } 320 return iter; 321 } 322 323 static void *timer_list_start(struct seq_file *file, loff_t *offset) 324 { 325 struct timer_list_iter *iter = file->private; 326 327 if (!*offset) 328 iter->now = ktime_to_ns(ktime_get()); 329 iter->cpu = -1; 330 iter->second_pass = false; 331 return move_iter(iter, *offset); 332 } 333 334 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 335 { 336 struct timer_list_iter *iter = file->private; 337 ++*offset; 338 return move_iter(iter, 1); 339 } 340 341 static void timer_list_stop(struct seq_file *seq, void *v) 342 { 343 } 344 345 static const struct seq_operations timer_list_sops = { 346 .start = timer_list_start, 347 .next = timer_list_next, 348 .stop = timer_list_stop, 349 .show = timer_list_show, 350 }; 351 352 static int __init init_timer_list_procfs(void) 353 { 354 struct proc_dir_entry *pe; 355 356 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops, 357 sizeof(struct timer_list_iter), NULL); 358 if (!pe) 359 return -ENOMEM; 360 return 0; 361 } 362 __initcall(init_timer_list_procfs); 363 #endif 364