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 { 151 struct tick_sched *ts = tick_get_tick_sched(cpu); 152 P(nohz_mode); 153 P_ns(last_tick); 154 P(tick_stopped); 155 P(idle_jiffies); 156 P(idle_calls); 157 P(idle_sleeps); 158 P_ns(idle_entrytime); 159 P_ns(idle_waketime); 160 P_ns(idle_exittime); 161 P_ns(idle_sleeptime); 162 P_ns(iowait_sleeptime); 163 P(last_jiffies); 164 P(next_timer); 165 P_ns(idle_expires); 166 SEQ_printf(m, "jiffies: %Lu\n", 167 (unsigned long long)jiffies); 168 } 169 #endif 170 171 #undef P 172 #undef P_ns 173 SEQ_printf(m, "\n"); 174 } 175 176 #ifdef CONFIG_GENERIC_CLOCKEVENTS 177 static void 178 print_tickdevice(struct seq_file *m, struct tick_device *td, int cpu) 179 { 180 struct clock_event_device *dev = td->evtdev; 181 182 touch_nmi_watchdog(); 183 184 SEQ_printf(m, "Tick Device: mode: %d\n", td->mode); 185 if (cpu < 0) 186 SEQ_printf(m, "Broadcast device\n"); 187 else 188 SEQ_printf(m, "Per CPU device: %d\n", cpu); 189 190 SEQ_printf(m, "Clock Event Device: "); 191 if (!dev) { 192 SEQ_printf(m, "<NULL>\n"); 193 return; 194 } 195 SEQ_printf(m, "%s\n", dev->name); 196 SEQ_printf(m, " max_delta_ns: %llu\n", 197 (unsigned long long) dev->max_delta_ns); 198 SEQ_printf(m, " min_delta_ns: %llu\n", 199 (unsigned long long) dev->min_delta_ns); 200 SEQ_printf(m, " mult: %u\n", dev->mult); 201 SEQ_printf(m, " shift: %u\n", dev->shift); 202 SEQ_printf(m, " mode: %d\n", clockevent_get_state(dev)); 203 SEQ_printf(m, " next_event: %Ld nsecs\n", 204 (unsigned long long) ktime_to_ns(dev->next_event)); 205 206 SEQ_printf(m, " set_next_event: %ps\n", dev->set_next_event); 207 208 if (dev->set_state_shutdown) 209 SEQ_printf(m, " shutdown: %ps\n", 210 dev->set_state_shutdown); 211 212 if (dev->set_state_periodic) 213 SEQ_printf(m, " periodic: %ps\n", 214 dev->set_state_periodic); 215 216 if (dev->set_state_oneshot) 217 SEQ_printf(m, " oneshot: %ps\n", 218 dev->set_state_oneshot); 219 220 if (dev->set_state_oneshot_stopped) 221 SEQ_printf(m, " oneshot stopped: %ps\n", 222 dev->set_state_oneshot_stopped); 223 224 if (dev->tick_resume) 225 SEQ_printf(m, " resume: %ps\n", 226 dev->tick_resume); 227 228 SEQ_printf(m, " event_handler: %ps\n", dev->event_handler); 229 SEQ_printf(m, "\n"); 230 SEQ_printf(m, " retries: %lu\n", dev->retries); 231 SEQ_printf(m, "\n"); 232 } 233 234 static void timer_list_show_tickdevices_header(struct seq_file *m) 235 { 236 #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST 237 print_tickdevice(m, tick_get_broadcast_device(), -1); 238 SEQ_printf(m, "tick_broadcast_mask: %*pb\n", 239 cpumask_pr_args(tick_get_broadcast_mask())); 240 #ifdef CONFIG_TICK_ONESHOT 241 SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", 242 cpumask_pr_args(tick_get_broadcast_oneshot_mask())); 243 #endif 244 SEQ_printf(m, "\n"); 245 #endif 246 } 247 #endif 248 249 static inline void timer_list_header(struct seq_file *m, u64 now) 250 { 251 SEQ_printf(m, "Timer List Version: v0.8\n"); 252 SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); 253 SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); 254 SEQ_printf(m, "\n"); 255 } 256 257 void sysrq_timer_list_show(void) 258 { 259 u64 now = ktime_to_ns(ktime_get()); 260 int cpu; 261 262 timer_list_header(NULL, now); 263 264 for_each_online_cpu(cpu) 265 print_cpu(NULL, cpu, now); 266 267 #ifdef CONFIG_GENERIC_CLOCKEVENTS 268 timer_list_show_tickdevices_header(NULL); 269 for_each_online_cpu(cpu) 270 print_tickdevice(NULL, tick_get_device(cpu), cpu); 271 #endif 272 return; 273 } 274 275 #ifdef CONFIG_PROC_FS 276 static int timer_list_show(struct seq_file *m, void *v) 277 { 278 struct timer_list_iter *iter = v; 279 280 if (iter->cpu == -1 && !iter->second_pass) 281 timer_list_header(m, iter->now); 282 else if (!iter->second_pass) 283 print_cpu(m, iter->cpu, iter->now); 284 #ifdef CONFIG_GENERIC_CLOCKEVENTS 285 else if (iter->cpu == -1 && iter->second_pass) 286 timer_list_show_tickdevices_header(m); 287 else 288 print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); 289 #endif 290 return 0; 291 } 292 293 static void *move_iter(struct timer_list_iter *iter, loff_t offset) 294 { 295 for (; offset; offset--) { 296 iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); 297 if (iter->cpu >= nr_cpu_ids) { 298 #ifdef CONFIG_GENERIC_CLOCKEVENTS 299 if (!iter->second_pass) { 300 iter->cpu = -1; 301 iter->second_pass = true; 302 } else 303 return NULL; 304 #else 305 return NULL; 306 #endif 307 } 308 } 309 return iter; 310 } 311 312 static void *timer_list_start(struct seq_file *file, loff_t *offset) 313 { 314 struct timer_list_iter *iter = file->private; 315 316 if (!*offset) 317 iter->now = ktime_to_ns(ktime_get()); 318 iter->cpu = -1; 319 iter->second_pass = false; 320 return move_iter(iter, *offset); 321 } 322 323 static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) 324 { 325 struct timer_list_iter *iter = file->private; 326 ++*offset; 327 return move_iter(iter, 1); 328 } 329 330 static void timer_list_stop(struct seq_file *seq, void *v) 331 { 332 } 333 334 static const struct seq_operations timer_list_sops = { 335 .start = timer_list_start, 336 .next = timer_list_next, 337 .stop = timer_list_stop, 338 .show = timer_list_show, 339 }; 340 341 static int __init init_timer_list_procfs(void) 342 { 343 struct proc_dir_entry *pe; 344 345 pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops, 346 sizeof(struct timer_list_iter), NULL); 347 if (!pe) 348 return -ENOMEM; 349 return 0; 350 } 351 __initcall(init_timer_list_procfs); 352 #endif 353