| 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 | |
| 232 | #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
| 233 | if (cpu >= 0) { |
| 234 | const struct clock_event_device *wd = tick_get_wakeup_device(cpu); |
| 235 | |
| 236 | SEQ_printf(m, "Wakeup Device: %s\n", wd ? wd->name : "<NULL>"); |
| 237 | } |
| 238 | #endif |
| 239 | SEQ_printf(m, "\n"); |
| 240 | } |
| 241 | |
| 242 | static void timer_list_show_tickdevices_header(struct seq_file *m) |
| 243 | { |
| 244 | #ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
| 245 | print_tickdevice(m, tick_get_broadcast_device(), -1); |
| 246 | SEQ_printf(m, "tick_broadcast_mask: %*pb\n", |
| 247 | cpumask_pr_args(tick_get_broadcast_mask())); |
| 248 | #ifdef CONFIG_TICK_ONESHOT |
| 249 | SEQ_printf(m, "tick_broadcast_oneshot_mask: %*pb\n", |
| 250 | cpumask_pr_args(tick_get_broadcast_oneshot_mask())); |
| 251 | #endif |
| 252 | SEQ_printf(m, "\n"); |
| 253 | #endif |
| 254 | } |
| 255 | #endif |
| 256 | |
| 257 | static inline void timer_list_header(struct seq_file *m, u64 now) |
| 258 | { |
| 259 | SEQ_printf(m, "Timer List Version: v0.9\n"); |
| 260 | SEQ_printf(m, "HRTIMER_MAX_CLOCK_BASES: %d\n", HRTIMER_MAX_CLOCK_BASES); |
| 261 | SEQ_printf(m, "now at %Ld nsecs\n", (unsigned long long)now); |
| 262 | SEQ_printf(m, "\n"); |
| 263 | } |
| 264 | |
| 265 | void sysrq_timer_list_show(void) |
| 266 | { |
| 267 | u64 now = ktime_to_ns(ktime_get()); |
| 268 | int cpu; |
| 269 | |
| 270 | timer_list_header(NULL, now); |
| 271 | |
| 272 | for_each_online_cpu(cpu) |
| 273 | print_cpu(NULL, cpu, now); |
| 274 | |
| 275 | #ifdef CONFIG_GENERIC_CLOCKEVENTS |
| 276 | timer_list_show_tickdevices_header(NULL); |
| 277 | for_each_online_cpu(cpu) |
| 278 | print_tickdevice(NULL, tick_get_device(cpu), cpu); |
| 279 | #endif |
| 280 | return; |
| 281 | } |
| 282 | |
| 283 | #ifdef CONFIG_PROC_FS |
| 284 | static int timer_list_show(struct seq_file *m, void *v) |
| 285 | { |
| 286 | struct timer_list_iter *iter = v; |
| 287 | |
| 288 | if (iter->cpu == -1 && !iter->second_pass) |
| 289 | timer_list_header(m, iter->now); |
| 290 | else if (!iter->second_pass) |
| 291 | print_cpu(m, iter->cpu, iter->now); |
| 292 | #ifdef CONFIG_GENERIC_CLOCKEVENTS |
| 293 | else if (iter->cpu == -1 && iter->second_pass) |
| 294 | timer_list_show_tickdevices_header(m); |
| 295 | else |
| 296 | print_tickdevice(m, tick_get_device(iter->cpu), iter->cpu); |
| 297 | #endif |
| 298 | return 0; |
| 299 | } |
| 300 | |
| 301 | static void *move_iter(struct timer_list_iter *iter, loff_t offset) |
| 302 | { |
| 303 | for (; offset; offset--) { |
| 304 | iter->cpu = cpumask_next(iter->cpu, cpu_online_mask); |
| 305 | if (iter->cpu >= nr_cpu_ids) { |
| 306 | #ifdef CONFIG_GENERIC_CLOCKEVENTS |
| 307 | if (!iter->second_pass) { |
| 308 | iter->cpu = -1; |
| 309 | iter->second_pass = true; |
| 310 | } else |
| 311 | return NULL; |
| 312 | #else |
| 313 | return NULL; |
| 314 | #endif |
| 315 | } |
| 316 | } |
| 317 | return iter; |
| 318 | } |
| 319 | |
| 320 | static void *timer_list_start(struct seq_file *file, loff_t *offset) |
| 321 | { |
| 322 | struct timer_list_iter *iter = file->private; |
| 323 | |
| 324 | if (!*offset) |
| 325 | iter->now = ktime_to_ns(ktime_get()); |
| 326 | iter->cpu = -1; |
| 327 | iter->second_pass = false; |
| 328 | return move_iter(iter, *offset); |
| 329 | } |
| 330 | |
| 331 | static void *timer_list_next(struct seq_file *file, void *v, loff_t *offset) |
| 332 | { |
| 333 | struct timer_list_iter *iter = file->private; |
| 334 | ++*offset; |
| 335 | return move_iter(iter, 1); |
| 336 | } |
| 337 | |
| 338 | static void timer_list_stop(struct seq_file *seq, void *v) |
| 339 | { |
| 340 | } |
| 341 | |
| 342 | static const struct seq_operations timer_list_sops = { |
| 343 | .start = timer_list_start, |
| 344 | .next = timer_list_next, |
| 345 | .stop = timer_list_stop, |
| 346 | .show = timer_list_show, |
| 347 | }; |
| 348 | |
| 349 | static int __init init_timer_list_procfs(void) |
| 350 | { |
| 351 | struct proc_dir_entry *pe; |
| 352 | |
| 353 | pe = proc_create_seq_private("timer_list", 0400, NULL, &timer_list_sops, |
| 354 | sizeof(struct timer_list_iter), NULL); |
| 355 | if (!pe) |
| 356 | return -ENOMEM; |
| 357 | return 0; |
| 358 | } |
| 359 | __initcall(init_timer_list_procfs); |
| 360 | #endif |