1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * linux/kernel/reboot.c |
4 | * |
5 | * Copyright (C) 2013 Linus Torvalds |
6 | */ |
7 | |
8 | #define pr_fmt(fmt) "reboot: " fmt |
9 | |
10 | #include <linux/atomic.h> |
11 | #include <linux/ctype.h> |
12 | #include <linux/export.h> |
13 | #include <linux/kexec.h> |
14 | #include <linux/kmod.h> |
15 | #include <linux/kmsg_dump.h> |
16 | #include <linux/reboot.h> |
17 | #include <linux/suspend.h> |
18 | #include <linux/syscalls.h> |
19 | #include <linux/syscore_ops.h> |
20 | #include <linux/uaccess.h> |
21 | |
22 | /* |
23 | * this indicates whether you can reboot with ctrl-alt-del: the default is yes |
24 | */ |
25 | |
26 | static int C_A_D = 1; |
27 | struct pid *cad_pid; |
28 | EXPORT_SYMBOL(cad_pid); |
29 | |
30 | #if defined(CONFIG_ARM) |
31 | #define DEFAULT_REBOOT_MODE = REBOOT_HARD |
32 | #else |
33 | #define DEFAULT_REBOOT_MODE |
34 | #endif |
35 | enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE; |
36 | EXPORT_SYMBOL_GPL(reboot_mode); |
37 | enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED; |
38 | |
39 | /* |
40 | * This variable is used privately to keep track of whether or not |
41 | * reboot_type is still set to its default value (i.e., reboot= hasn't |
42 | * been set on the command line). This is needed so that we can |
43 | * suppress DMI scanning for reboot quirks. Without it, it's |
44 | * impossible to override a faulty reboot quirk without recompiling. |
45 | */ |
46 | int reboot_default = 1; |
47 | int reboot_cpu; |
48 | enum reboot_type reboot_type = BOOT_ACPI; |
49 | int reboot_force; |
50 | |
51 | struct sys_off_handler { |
52 | struct notifier_block nb; |
53 | int (*sys_off_cb)(struct sys_off_data *data); |
54 | void *cb_data; |
55 | enum sys_off_mode mode; |
56 | bool blocking; |
57 | void *list; |
58 | struct device *dev; |
59 | }; |
60 | |
61 | /* |
62 | * Temporary stub that prevents linkage failure while we're in process |
63 | * of removing all uses of legacy pm_power_off() around the kernel. |
64 | */ |
65 | void __weak (*pm_power_off)(void); |
66 | |
67 | /** |
68 | * emergency_restart - reboot the system |
69 | * |
70 | * Without shutting down any hardware or taking any locks |
71 | * reboot the system. This is called when we know we are in |
72 | * trouble so this is our best effort to reboot. This is |
73 | * safe to call in interrupt context. |
74 | */ |
75 | void emergency_restart(void) |
76 | { |
77 | kmsg_dump(reason: KMSG_DUMP_EMERG); |
78 | system_state = SYSTEM_RESTART; |
79 | machine_emergency_restart(); |
80 | } |
81 | EXPORT_SYMBOL_GPL(emergency_restart); |
82 | |
83 | void kernel_restart_prepare(char *cmd) |
84 | { |
85 | blocking_notifier_call_chain(nh: &reboot_notifier_list, SYS_RESTART, v: cmd); |
86 | system_state = SYSTEM_RESTART; |
87 | usermodehelper_disable(); |
88 | device_shutdown(); |
89 | } |
90 | |
91 | /** |
92 | * register_reboot_notifier - Register function to be called at reboot time |
93 | * @nb: Info about notifier function to be called |
94 | * |
95 | * Registers a function with the list of functions |
96 | * to be called at reboot time. |
97 | * |
98 | * Currently always returns zero, as blocking_notifier_chain_register() |
99 | * always returns zero. |
100 | */ |
101 | int register_reboot_notifier(struct notifier_block *nb) |
102 | { |
103 | return blocking_notifier_chain_register(nh: &reboot_notifier_list, nb); |
104 | } |
105 | EXPORT_SYMBOL(register_reboot_notifier); |
106 | |
107 | /** |
108 | * unregister_reboot_notifier - Unregister previously registered reboot notifier |
109 | * @nb: Hook to be unregistered |
110 | * |
111 | * Unregisters a previously registered reboot |
112 | * notifier function. |
113 | * |
114 | * Returns zero on success, or %-ENOENT on failure. |
115 | */ |
116 | int unregister_reboot_notifier(struct notifier_block *nb) |
117 | { |
118 | return blocking_notifier_chain_unregister(nh: &reboot_notifier_list, nb); |
119 | } |
120 | EXPORT_SYMBOL(unregister_reboot_notifier); |
121 | |
122 | static void devm_unregister_reboot_notifier(struct device *dev, void *res) |
123 | { |
124 | WARN_ON(unregister_reboot_notifier(*(struct notifier_block **)res)); |
125 | } |
126 | |
127 | int devm_register_reboot_notifier(struct device *dev, struct notifier_block *nb) |
128 | { |
129 | struct notifier_block **rcnb; |
130 | int ret; |
131 | |
132 | rcnb = devres_alloc(devm_unregister_reboot_notifier, |
133 | sizeof(*rcnb), GFP_KERNEL); |
134 | if (!rcnb) |
135 | return -ENOMEM; |
136 | |
137 | ret = register_reboot_notifier(nb); |
138 | if (!ret) { |
139 | *rcnb = nb; |
140 | devres_add(dev, res: rcnb); |
141 | } else { |
142 | devres_free(res: rcnb); |
143 | } |
144 | |
145 | return ret; |
146 | } |
147 | EXPORT_SYMBOL(devm_register_reboot_notifier); |
148 | |
149 | /* |
150 | * Notifier list for kernel code which wants to be called |
151 | * to restart the system. |
152 | */ |
153 | static ATOMIC_NOTIFIER_HEAD(restart_handler_list); |
154 | |
155 | /** |
156 | * register_restart_handler - Register function to be called to reset |
157 | * the system |
158 | * @nb: Info about handler function to be called |
159 | * @nb->priority: Handler priority. Handlers should follow the |
160 | * following guidelines for setting priorities. |
161 | * 0: Restart handler of last resort, |
162 | * with limited restart capabilities |
163 | * 128: Default restart handler; use if no other |
164 | * restart handler is expected to be available, |
165 | * and/or if restart functionality is |
166 | * sufficient to restart the entire system |
167 | * 255: Highest priority restart handler, will |
168 | * preempt all other restart handlers |
169 | * |
170 | * Registers a function with code to be called to restart the |
171 | * system. |
172 | * |
173 | * Registered functions will be called from machine_restart as last |
174 | * step of the restart sequence (if the architecture specific |
175 | * machine_restart function calls do_kernel_restart - see below |
176 | * for details). |
177 | * Registered functions are expected to restart the system immediately. |
178 | * If more than one function is registered, the restart handler priority |
179 | * selects which function will be called first. |
180 | * |
181 | * Restart handlers are expected to be registered from non-architecture |
182 | * code, typically from drivers. A typical use case would be a system |
183 | * where restart functionality is provided through a watchdog. Multiple |
184 | * restart handlers may exist; for example, one restart handler might |
185 | * restart the entire system, while another only restarts the CPU. |
186 | * In such cases, the restart handler which only restarts part of the |
187 | * hardware is expected to register with low priority to ensure that |
188 | * it only runs if no other means to restart the system is available. |
189 | * |
190 | * Currently always returns zero, as atomic_notifier_chain_register() |
191 | * always returns zero. |
192 | */ |
193 | int register_restart_handler(struct notifier_block *nb) |
194 | { |
195 | return atomic_notifier_chain_register(nh: &restart_handler_list, nb); |
196 | } |
197 | EXPORT_SYMBOL(register_restart_handler); |
198 | |
199 | /** |
200 | * unregister_restart_handler - Unregister previously registered |
201 | * restart handler |
202 | * @nb: Hook to be unregistered |
203 | * |
204 | * Unregisters a previously registered restart handler function. |
205 | * |
206 | * Returns zero on success, or %-ENOENT on failure. |
207 | */ |
208 | int unregister_restart_handler(struct notifier_block *nb) |
209 | { |
210 | return atomic_notifier_chain_unregister(nh: &restart_handler_list, nb); |
211 | } |
212 | EXPORT_SYMBOL(unregister_restart_handler); |
213 | |
214 | /** |
215 | * do_kernel_restart - Execute kernel restart handler call chain |
216 | * |
217 | * Calls functions registered with register_restart_handler. |
218 | * |
219 | * Expected to be called from machine_restart as last step of the restart |
220 | * sequence. |
221 | * |
222 | * Restarts the system immediately if a restart handler function has been |
223 | * registered. Otherwise does nothing. |
224 | */ |
225 | void do_kernel_restart(char *cmd) |
226 | { |
227 | atomic_notifier_call_chain(nh: &restart_handler_list, val: reboot_mode, v: cmd); |
228 | } |
229 | |
230 | void migrate_to_reboot_cpu(void) |
231 | { |
232 | /* The boot cpu is always logical cpu 0 */ |
233 | int cpu = reboot_cpu; |
234 | |
235 | cpu_hotplug_disable(); |
236 | |
237 | /* Make certain the cpu I'm about to reboot on is online */ |
238 | if (!cpu_online(cpu)) |
239 | cpu = cpumask_first(cpu_online_mask); |
240 | |
241 | /* Prevent races with other tasks migrating this task */ |
242 | current->flags |= PF_NO_SETAFFINITY; |
243 | |
244 | /* Make certain I only run on the appropriate processor */ |
245 | set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
246 | } |
247 | |
248 | /* |
249 | * Notifier list for kernel code which wants to be called |
250 | * to prepare system for restart. |
251 | */ |
252 | static BLOCKING_NOTIFIER_HEAD(restart_prep_handler_list); |
253 | |
254 | static void do_kernel_restart_prepare(void) |
255 | { |
256 | blocking_notifier_call_chain(nh: &restart_prep_handler_list, val: 0, NULL); |
257 | } |
258 | |
259 | /** |
260 | * kernel_restart - reboot the system |
261 | * @cmd: pointer to buffer containing command to execute for restart |
262 | * or %NULL |
263 | * |
264 | * Shutdown everything and perform a clean reboot. |
265 | * This is not safe to call in interrupt context. |
266 | */ |
267 | void kernel_restart(char *cmd) |
268 | { |
269 | kernel_restart_prepare(cmd); |
270 | do_kernel_restart_prepare(); |
271 | migrate_to_reboot_cpu(); |
272 | syscore_shutdown(); |
273 | if (!cmd) |
274 | pr_emerg("Restarting system\n" ); |
275 | else |
276 | pr_emerg("Restarting system with command '%s'\n" , cmd); |
277 | kmsg_dump(reason: KMSG_DUMP_SHUTDOWN); |
278 | machine_restart(cmd); |
279 | } |
280 | EXPORT_SYMBOL_GPL(kernel_restart); |
281 | |
282 | static void kernel_shutdown_prepare(enum system_states state) |
283 | { |
284 | blocking_notifier_call_chain(nh: &reboot_notifier_list, |
285 | val: (state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL); |
286 | system_state = state; |
287 | usermodehelper_disable(); |
288 | device_shutdown(); |
289 | } |
290 | /** |
291 | * kernel_halt - halt the system |
292 | * |
293 | * Shutdown everything and perform a clean system halt. |
294 | */ |
295 | void kernel_halt(void) |
296 | { |
297 | kernel_shutdown_prepare(state: SYSTEM_HALT); |
298 | migrate_to_reboot_cpu(); |
299 | syscore_shutdown(); |
300 | pr_emerg("System halted\n" ); |
301 | kmsg_dump(reason: KMSG_DUMP_SHUTDOWN); |
302 | machine_halt(); |
303 | } |
304 | EXPORT_SYMBOL_GPL(kernel_halt); |
305 | |
306 | /* |
307 | * Notifier list for kernel code which wants to be called |
308 | * to prepare system for power off. |
309 | */ |
310 | static BLOCKING_NOTIFIER_HEAD(power_off_prep_handler_list); |
311 | |
312 | /* |
313 | * Notifier list for kernel code which wants to be called |
314 | * to power off system. |
315 | */ |
316 | static ATOMIC_NOTIFIER_HEAD(power_off_handler_list); |
317 | |
318 | static int sys_off_notify(struct notifier_block *nb, |
319 | unsigned long mode, void *cmd) |
320 | { |
321 | struct sys_off_handler *handler; |
322 | struct sys_off_data data = {}; |
323 | |
324 | handler = container_of(nb, struct sys_off_handler, nb); |
325 | data.cb_data = handler->cb_data; |
326 | data.mode = mode; |
327 | data.cmd = cmd; |
328 | data.dev = handler->dev; |
329 | |
330 | return handler->sys_off_cb(&data); |
331 | } |
332 | |
333 | static struct sys_off_handler platform_sys_off_handler; |
334 | |
335 | static struct sys_off_handler *alloc_sys_off_handler(int priority) |
336 | { |
337 | struct sys_off_handler *handler; |
338 | gfp_t flags; |
339 | |
340 | /* |
341 | * Platforms like m68k can't allocate sys_off handler dynamically |
342 | * at the early boot time because memory allocator isn't available yet. |
343 | */ |
344 | if (priority == SYS_OFF_PRIO_PLATFORM) { |
345 | handler = &platform_sys_off_handler; |
346 | if (handler->cb_data) |
347 | return ERR_PTR(error: -EBUSY); |
348 | } else { |
349 | if (system_state > SYSTEM_RUNNING) |
350 | flags = GFP_ATOMIC; |
351 | else |
352 | flags = GFP_KERNEL; |
353 | |
354 | handler = kzalloc(size: sizeof(*handler), flags); |
355 | if (!handler) |
356 | return ERR_PTR(error: -ENOMEM); |
357 | } |
358 | |
359 | return handler; |
360 | } |
361 | |
362 | static void free_sys_off_handler(struct sys_off_handler *handler) |
363 | { |
364 | if (handler == &platform_sys_off_handler) |
365 | memset(handler, 0, sizeof(*handler)); |
366 | else |
367 | kfree(objp: handler); |
368 | } |
369 | |
370 | /** |
371 | * register_sys_off_handler - Register sys-off handler |
372 | * @mode: Sys-off mode |
373 | * @priority: Handler priority |
374 | * @callback: Callback function |
375 | * @cb_data: Callback argument |
376 | * |
377 | * Registers system power-off or restart handler that will be invoked |
378 | * at the step corresponding to the given sys-off mode. Handler's callback |
379 | * should return NOTIFY_DONE to permit execution of the next handler in |
380 | * the call chain or NOTIFY_STOP to break the chain (in error case for |
381 | * example). |
382 | * |
383 | * Multiple handlers can be registered at the default priority level. |
384 | * |
385 | * Only one handler can be registered at the non-default priority level, |
386 | * otherwise ERR_PTR(-EBUSY) is returned. |
387 | * |
388 | * Returns a new instance of struct sys_off_handler on success, or |
389 | * an ERR_PTR()-encoded error code otherwise. |
390 | */ |
391 | struct sys_off_handler * |
392 | register_sys_off_handler(enum sys_off_mode mode, |
393 | int priority, |
394 | int (*callback)(struct sys_off_data *data), |
395 | void *cb_data) |
396 | { |
397 | struct sys_off_handler *handler; |
398 | int err; |
399 | |
400 | handler = alloc_sys_off_handler(priority); |
401 | if (IS_ERR(ptr: handler)) |
402 | return handler; |
403 | |
404 | switch (mode) { |
405 | case SYS_OFF_MODE_POWER_OFF_PREPARE: |
406 | handler->list = &power_off_prep_handler_list; |
407 | handler->blocking = true; |
408 | break; |
409 | |
410 | case SYS_OFF_MODE_POWER_OFF: |
411 | handler->list = &power_off_handler_list; |
412 | break; |
413 | |
414 | case SYS_OFF_MODE_RESTART_PREPARE: |
415 | handler->list = &restart_prep_handler_list; |
416 | handler->blocking = true; |
417 | break; |
418 | |
419 | case SYS_OFF_MODE_RESTART: |
420 | handler->list = &restart_handler_list; |
421 | break; |
422 | |
423 | default: |
424 | free_sys_off_handler(handler); |
425 | return ERR_PTR(error: -EINVAL); |
426 | } |
427 | |
428 | handler->nb.notifier_call = sys_off_notify; |
429 | handler->nb.priority = priority; |
430 | handler->sys_off_cb = callback; |
431 | handler->cb_data = cb_data; |
432 | handler->mode = mode; |
433 | |
434 | if (handler->blocking) { |
435 | if (priority == SYS_OFF_PRIO_DEFAULT) |
436 | err = blocking_notifier_chain_register(nh: handler->list, |
437 | nb: &handler->nb); |
438 | else |
439 | err = blocking_notifier_chain_register_unique_prio(nh: handler->list, |
440 | nb: &handler->nb); |
441 | } else { |
442 | if (priority == SYS_OFF_PRIO_DEFAULT) |
443 | err = atomic_notifier_chain_register(nh: handler->list, |
444 | nb: &handler->nb); |
445 | else |
446 | err = atomic_notifier_chain_register_unique_prio(nh: handler->list, |
447 | nb: &handler->nb); |
448 | } |
449 | |
450 | if (err) { |
451 | free_sys_off_handler(handler); |
452 | return ERR_PTR(error: err); |
453 | } |
454 | |
455 | return handler; |
456 | } |
457 | EXPORT_SYMBOL_GPL(register_sys_off_handler); |
458 | |
459 | /** |
460 | * unregister_sys_off_handler - Unregister sys-off handler |
461 | * @handler: Sys-off handler |
462 | * |
463 | * Unregisters given sys-off handler. |
464 | */ |
465 | void unregister_sys_off_handler(struct sys_off_handler *handler) |
466 | { |
467 | int err; |
468 | |
469 | if (IS_ERR_OR_NULL(ptr: handler)) |
470 | return; |
471 | |
472 | if (handler->blocking) |
473 | err = blocking_notifier_chain_unregister(nh: handler->list, |
474 | nb: &handler->nb); |
475 | else |
476 | err = atomic_notifier_chain_unregister(nh: handler->list, |
477 | nb: &handler->nb); |
478 | |
479 | /* sanity check, shall never happen */ |
480 | WARN_ON(err); |
481 | |
482 | free_sys_off_handler(handler); |
483 | } |
484 | EXPORT_SYMBOL_GPL(unregister_sys_off_handler); |
485 | |
486 | static void devm_unregister_sys_off_handler(void *data) |
487 | { |
488 | struct sys_off_handler *handler = data; |
489 | |
490 | unregister_sys_off_handler(handler); |
491 | } |
492 | |
493 | /** |
494 | * devm_register_sys_off_handler - Register sys-off handler |
495 | * @dev: Device that registers handler |
496 | * @mode: Sys-off mode |
497 | * @priority: Handler priority |
498 | * @callback: Callback function |
499 | * @cb_data: Callback argument |
500 | * |
501 | * Registers resource-managed sys-off handler. |
502 | * |
503 | * Returns zero on success, or error code on failure. |
504 | */ |
505 | int devm_register_sys_off_handler(struct device *dev, |
506 | enum sys_off_mode mode, |
507 | int priority, |
508 | int (*callback)(struct sys_off_data *data), |
509 | void *cb_data) |
510 | { |
511 | struct sys_off_handler *handler; |
512 | |
513 | handler = register_sys_off_handler(mode, priority, callback, cb_data); |
514 | if (IS_ERR(ptr: handler)) |
515 | return PTR_ERR(ptr: handler); |
516 | handler->dev = dev; |
517 | |
518 | return devm_add_action_or_reset(dev, devm_unregister_sys_off_handler, |
519 | handler); |
520 | } |
521 | EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); |
522 | |
523 | /** |
524 | * devm_register_power_off_handler - Register power-off handler |
525 | * @dev: Device that registers callback |
526 | * @callback: Callback function |
527 | * @cb_data: Callback's argument |
528 | * |
529 | * Registers resource-managed sys-off handler with a default priority |
530 | * and using power-off mode. |
531 | * |
532 | * Returns zero on success, or error code on failure. |
533 | */ |
534 | int devm_register_power_off_handler(struct device *dev, |
535 | int (*callback)(struct sys_off_data *data), |
536 | void *cb_data) |
537 | { |
538 | return devm_register_sys_off_handler(dev, |
539 | SYS_OFF_MODE_POWER_OFF, |
540 | SYS_OFF_PRIO_DEFAULT, |
541 | callback, cb_data); |
542 | } |
543 | EXPORT_SYMBOL_GPL(devm_register_power_off_handler); |
544 | |
545 | /** |
546 | * devm_register_restart_handler - Register restart handler |
547 | * @dev: Device that registers callback |
548 | * @callback: Callback function |
549 | * @cb_data: Callback's argument |
550 | * |
551 | * Registers resource-managed sys-off handler with a default priority |
552 | * and using restart mode. |
553 | * |
554 | * Returns zero on success, or error code on failure. |
555 | */ |
556 | int devm_register_restart_handler(struct device *dev, |
557 | int (*callback)(struct sys_off_data *data), |
558 | void *cb_data) |
559 | { |
560 | return devm_register_sys_off_handler(dev, |
561 | SYS_OFF_MODE_RESTART, |
562 | SYS_OFF_PRIO_DEFAULT, |
563 | callback, cb_data); |
564 | } |
565 | EXPORT_SYMBOL_GPL(devm_register_restart_handler); |
566 | |
567 | static struct sys_off_handler *platform_power_off_handler; |
568 | |
569 | static int platform_power_off_notify(struct sys_off_data *data) |
570 | { |
571 | void (*platform_power_power_off_cb)(void) = data->cb_data; |
572 | |
573 | platform_power_power_off_cb(); |
574 | |
575 | return NOTIFY_DONE; |
576 | } |
577 | |
578 | /** |
579 | * register_platform_power_off - Register platform-level power-off callback |
580 | * @power_off: Power-off callback |
581 | * |
582 | * Registers power-off callback that will be called as last step |
583 | * of the power-off sequence. This callback is expected to be invoked |
584 | * for the last resort. Only one platform power-off callback is allowed |
585 | * to be registered at a time. |
586 | * |
587 | * Returns zero on success, or error code on failure. |
588 | */ |
589 | int register_platform_power_off(void (*power_off)(void)) |
590 | { |
591 | struct sys_off_handler *handler; |
592 | |
593 | handler = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, |
594 | SYS_OFF_PRIO_PLATFORM, |
595 | platform_power_off_notify, |
596 | power_off); |
597 | if (IS_ERR(ptr: handler)) |
598 | return PTR_ERR(ptr: handler); |
599 | |
600 | platform_power_off_handler = handler; |
601 | |
602 | return 0; |
603 | } |
604 | EXPORT_SYMBOL_GPL(register_platform_power_off); |
605 | |
606 | /** |
607 | * unregister_platform_power_off - Unregister platform-level power-off callback |
608 | * @power_off: Power-off callback |
609 | * |
610 | * Unregisters previously registered platform power-off callback. |
611 | */ |
612 | void unregister_platform_power_off(void (*power_off)(void)) |
613 | { |
614 | if (platform_power_off_handler && |
615 | platform_power_off_handler->cb_data == power_off) { |
616 | unregister_sys_off_handler(platform_power_off_handler); |
617 | platform_power_off_handler = NULL; |
618 | } |
619 | } |
620 | EXPORT_SYMBOL_GPL(unregister_platform_power_off); |
621 | |
622 | static int legacy_pm_power_off(struct sys_off_data *data) |
623 | { |
624 | if (pm_power_off) |
625 | pm_power_off(); |
626 | |
627 | return NOTIFY_DONE; |
628 | } |
629 | |
630 | static void do_kernel_power_off_prepare(void) |
631 | { |
632 | blocking_notifier_call_chain(nh: &power_off_prep_handler_list, val: 0, NULL); |
633 | } |
634 | |
635 | /** |
636 | * do_kernel_power_off - Execute kernel power-off handler call chain |
637 | * |
638 | * Expected to be called as last step of the power-off sequence. |
639 | * |
640 | * Powers off the system immediately if a power-off handler function has |
641 | * been registered. Otherwise does nothing. |
642 | */ |
643 | void do_kernel_power_off(void) |
644 | { |
645 | struct sys_off_handler *sys_off = NULL; |
646 | |
647 | /* |
648 | * Register sys-off handlers for legacy PM callback. This allows |
649 | * legacy PM callbacks temporary co-exist with the new sys-off API. |
650 | * |
651 | * TODO: Remove legacy handlers once all legacy PM users will be |
652 | * switched to the sys-off based APIs. |
653 | */ |
654 | if (pm_power_off) |
655 | sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, |
656 | SYS_OFF_PRIO_DEFAULT, |
657 | legacy_pm_power_off, NULL); |
658 | |
659 | atomic_notifier_call_chain(nh: &power_off_handler_list, val: 0, NULL); |
660 | |
661 | unregister_sys_off_handler(sys_off); |
662 | } |
663 | |
664 | /** |
665 | * kernel_can_power_off - check whether system can be powered off |
666 | * |
667 | * Returns true if power-off handler is registered and system can be |
668 | * powered off, false otherwise. |
669 | */ |
670 | bool kernel_can_power_off(void) |
671 | { |
672 | return !atomic_notifier_call_chain_is_empty(nh: &power_off_handler_list) || |
673 | pm_power_off; |
674 | } |
675 | EXPORT_SYMBOL_GPL(kernel_can_power_off); |
676 | |
677 | /** |
678 | * kernel_power_off - power_off the system |
679 | * |
680 | * Shutdown everything and perform a clean system power_off. |
681 | */ |
682 | void kernel_power_off(void) |
683 | { |
684 | kernel_shutdown_prepare(state: SYSTEM_POWER_OFF); |
685 | do_kernel_power_off_prepare(); |
686 | migrate_to_reboot_cpu(); |
687 | syscore_shutdown(); |
688 | pr_emerg("Power down\n" ); |
689 | kmsg_dump(reason: KMSG_DUMP_SHUTDOWN); |
690 | machine_power_off(); |
691 | } |
692 | EXPORT_SYMBOL_GPL(kernel_power_off); |
693 | |
694 | DEFINE_MUTEX(system_transition_mutex); |
695 | |
696 | /* |
697 | * Reboot system call: for obvious reasons only root may call it, |
698 | * and even root needs to set up some magic numbers in the registers |
699 | * so that some mistake won't make this reboot the whole machine. |
700 | * You can also set the meaning of the ctrl-alt-del-key here. |
701 | * |
702 | * reboot doesn't sync: do that yourself before calling this. |
703 | */ |
704 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, |
705 | void __user *, arg) |
706 | { |
707 | struct pid_namespace *pid_ns = task_active_pid_ns(current); |
708 | char buffer[256]; |
709 | int ret = 0; |
710 | |
711 | /* We only trust the superuser with rebooting the system. */ |
712 | if (!ns_capable(ns: pid_ns->user_ns, CAP_SYS_BOOT)) |
713 | return -EPERM; |
714 | |
715 | /* For safety, we require "magic" arguments. */ |
716 | if (magic1 != LINUX_REBOOT_MAGIC1 || |
717 | (magic2 != LINUX_REBOOT_MAGIC2 && |
718 | magic2 != LINUX_REBOOT_MAGIC2A && |
719 | magic2 != LINUX_REBOOT_MAGIC2B && |
720 | magic2 != LINUX_REBOOT_MAGIC2C)) |
721 | return -EINVAL; |
722 | |
723 | /* |
724 | * If pid namespaces are enabled and the current task is in a child |
725 | * pid_namespace, the command is handled by reboot_pid_ns() which will |
726 | * call do_exit(). |
727 | */ |
728 | ret = reboot_pid_ns(pid_ns, cmd); |
729 | if (ret) |
730 | return ret; |
731 | |
732 | /* Instead of trying to make the power_off code look like |
733 | * halt when pm_power_off is not set do it the easy way. |
734 | */ |
735 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off()) |
736 | cmd = LINUX_REBOOT_CMD_HALT; |
737 | |
738 | mutex_lock(&system_transition_mutex); |
739 | switch (cmd) { |
740 | case LINUX_REBOOT_CMD_RESTART: |
741 | kernel_restart(NULL); |
742 | break; |
743 | |
744 | case LINUX_REBOOT_CMD_CAD_ON: |
745 | C_A_D = 1; |
746 | break; |
747 | |
748 | case LINUX_REBOOT_CMD_CAD_OFF: |
749 | C_A_D = 0; |
750 | break; |
751 | |
752 | case LINUX_REBOOT_CMD_HALT: |
753 | kernel_halt(); |
754 | do_exit(error_code: 0); |
755 | |
756 | case LINUX_REBOOT_CMD_POWER_OFF: |
757 | kernel_power_off(); |
758 | do_exit(error_code: 0); |
759 | break; |
760 | |
761 | case LINUX_REBOOT_CMD_RESTART2: |
762 | ret = strncpy_from_user(dst: &buffer[0], src: arg, count: sizeof(buffer) - 1); |
763 | if (ret < 0) { |
764 | ret = -EFAULT; |
765 | break; |
766 | } |
767 | buffer[sizeof(buffer) - 1] = '\0'; |
768 | |
769 | kernel_restart(buffer); |
770 | break; |
771 | |
772 | #ifdef CONFIG_KEXEC_CORE |
773 | case LINUX_REBOOT_CMD_KEXEC: |
774 | ret = kernel_kexec(); |
775 | break; |
776 | #endif |
777 | |
778 | #ifdef CONFIG_HIBERNATION |
779 | case LINUX_REBOOT_CMD_SW_SUSPEND: |
780 | ret = hibernate(); |
781 | break; |
782 | #endif |
783 | |
784 | default: |
785 | ret = -EINVAL; |
786 | break; |
787 | } |
788 | mutex_unlock(lock: &system_transition_mutex); |
789 | return ret; |
790 | } |
791 | |
792 | static void deferred_cad(struct work_struct *dummy) |
793 | { |
794 | kernel_restart(NULL); |
795 | } |
796 | |
797 | /* |
798 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. |
799 | * As it's called within an interrupt, it may NOT sync: the only choice |
800 | * is whether to reboot at once, or just ignore the ctrl-alt-del. |
801 | */ |
802 | void ctrl_alt_del(void) |
803 | { |
804 | static DECLARE_WORK(cad_work, deferred_cad); |
805 | |
806 | if (C_A_D) |
807 | schedule_work(work: &cad_work); |
808 | else |
809 | kill_cad_pid(SIGINT, priv: 1); |
810 | } |
811 | |
812 | #define POWEROFF_CMD_PATH_LEN 256 |
813 | static char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff" ; |
814 | static const char reboot_cmd[] = "/sbin/reboot" ; |
815 | |
816 | static int run_cmd(const char *cmd) |
817 | { |
818 | char **argv; |
819 | static char *envp[] = { |
820 | "HOME=/" , |
821 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin" , |
822 | NULL |
823 | }; |
824 | int ret; |
825 | argv = argv_split(GFP_KERNEL, str: cmd, NULL); |
826 | if (argv) { |
827 | ret = call_usermodehelper(path: argv[0], argv, envp, UMH_WAIT_EXEC); |
828 | argv_free(argv); |
829 | } else { |
830 | ret = -ENOMEM; |
831 | } |
832 | |
833 | return ret; |
834 | } |
835 | |
836 | static int __orderly_reboot(void) |
837 | { |
838 | int ret; |
839 | |
840 | ret = run_cmd(cmd: reboot_cmd); |
841 | |
842 | if (ret) { |
843 | pr_warn("Failed to start orderly reboot: forcing the issue\n" ); |
844 | emergency_sync(); |
845 | kernel_restart(NULL); |
846 | } |
847 | |
848 | return ret; |
849 | } |
850 | |
851 | static int __orderly_poweroff(bool force) |
852 | { |
853 | int ret; |
854 | |
855 | ret = run_cmd(cmd: poweroff_cmd); |
856 | |
857 | if (ret && force) { |
858 | pr_warn("Failed to start orderly shutdown: forcing the issue\n" ); |
859 | |
860 | /* |
861 | * I guess this should try to kick off some daemon to sync and |
862 | * poweroff asap. Or not even bother syncing if we're doing an |
863 | * emergency shutdown? |
864 | */ |
865 | emergency_sync(); |
866 | kernel_power_off(); |
867 | } |
868 | |
869 | return ret; |
870 | } |
871 | |
872 | static bool poweroff_force; |
873 | |
874 | static void poweroff_work_func(struct work_struct *work) |
875 | { |
876 | __orderly_poweroff(force: poweroff_force); |
877 | } |
878 | |
879 | static DECLARE_WORK(poweroff_work, poweroff_work_func); |
880 | |
881 | /** |
882 | * orderly_poweroff - Trigger an orderly system poweroff |
883 | * @force: force poweroff if command execution fails |
884 | * |
885 | * This may be called from any context to trigger a system shutdown. |
886 | * If the orderly shutdown fails, it will force an immediate shutdown. |
887 | */ |
888 | void orderly_poweroff(bool force) |
889 | { |
890 | if (force) /* do not override the pending "true" */ |
891 | poweroff_force = true; |
892 | schedule_work(work: &poweroff_work); |
893 | } |
894 | EXPORT_SYMBOL_GPL(orderly_poweroff); |
895 | |
896 | static void reboot_work_func(struct work_struct *work) |
897 | { |
898 | __orderly_reboot(); |
899 | } |
900 | |
901 | static DECLARE_WORK(reboot_work, reboot_work_func); |
902 | |
903 | /** |
904 | * orderly_reboot - Trigger an orderly system reboot |
905 | * |
906 | * This may be called from any context to trigger a system reboot. |
907 | * If the orderly reboot fails, it will force an immediate reboot. |
908 | */ |
909 | void orderly_reboot(void) |
910 | { |
911 | schedule_work(work: &reboot_work); |
912 | } |
913 | EXPORT_SYMBOL_GPL(orderly_reboot); |
914 | |
915 | /** |
916 | * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay |
917 | * @work: work_struct associated with the emergency poweroff function |
918 | * |
919 | * This function is called in very critical situations to force |
920 | * a kernel poweroff after a configurable timeout value. |
921 | */ |
922 | static void hw_failure_emergency_poweroff_func(struct work_struct *work) |
923 | { |
924 | /* |
925 | * We have reached here after the emergency shutdown waiting period has |
926 | * expired. This means orderly_poweroff has not been able to shut off |
927 | * the system for some reason. |
928 | * |
929 | * Try to shut down the system immediately using kernel_power_off |
930 | * if populated |
931 | */ |
932 | pr_emerg("Hardware protection timed-out. Trying forced poweroff\n" ); |
933 | kernel_power_off(); |
934 | |
935 | /* |
936 | * Worst of the worst case trigger emergency restart |
937 | */ |
938 | pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n" ); |
939 | emergency_restart(); |
940 | } |
941 | |
942 | static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, |
943 | hw_failure_emergency_poweroff_func); |
944 | |
945 | /** |
946 | * hw_failure_emergency_poweroff - Trigger an emergency system poweroff |
947 | * |
948 | * This may be called from any critical situation to trigger a system shutdown |
949 | * after a given period of time. If time is negative this is not scheduled. |
950 | */ |
951 | static void hw_failure_emergency_poweroff(int poweroff_delay_ms) |
952 | { |
953 | if (poweroff_delay_ms <= 0) |
954 | return; |
955 | schedule_delayed_work(dwork: &hw_failure_emergency_poweroff_work, |
956 | delay: msecs_to_jiffies(m: poweroff_delay_ms)); |
957 | } |
958 | |
959 | /** |
960 | * hw_protection_shutdown - Trigger an emergency system poweroff |
961 | * |
962 | * @reason: Reason of emergency shutdown to be printed. |
963 | * @ms_until_forced: Time to wait for orderly shutdown before tiggering a |
964 | * forced shudown. Negative value disables the forced |
965 | * shutdown. |
966 | * |
967 | * Initiate an emergency system shutdown in order to protect hardware from |
968 | * further damage. Usage examples include a thermal protection or a voltage or |
969 | * current regulator failures. |
970 | * NOTE: The request is ignored if protection shutdown is already pending even |
971 | * if the previous request has given a large timeout for forced shutdown. |
972 | * Can be called from any context. |
973 | */ |
974 | void hw_protection_shutdown(const char *reason, int ms_until_forced) |
975 | { |
976 | static atomic_t allow_proceed = ATOMIC_INIT(1); |
977 | |
978 | pr_emerg("HARDWARE PROTECTION shutdown (%s)\n" , reason); |
979 | |
980 | /* Shutdown should be initiated only once. */ |
981 | if (!atomic_dec_and_test(v: &allow_proceed)) |
982 | return; |
983 | |
984 | /* |
985 | * Queue a backup emergency shutdown in the event of |
986 | * orderly_poweroff failure |
987 | */ |
988 | hw_failure_emergency_poweroff(poweroff_delay_ms: ms_until_forced); |
989 | orderly_poweroff(true); |
990 | } |
991 | EXPORT_SYMBOL_GPL(hw_protection_shutdown); |
992 | |
993 | static int __init reboot_setup(char *str) |
994 | { |
995 | for (;;) { |
996 | enum reboot_mode *mode; |
997 | |
998 | /* |
999 | * Having anything passed on the command line via |
1000 | * reboot= will cause us to disable DMI checking |
1001 | * below. |
1002 | */ |
1003 | reboot_default = 0; |
1004 | |
1005 | if (!strncmp(str, "panic_" , 6)) { |
1006 | mode = &panic_reboot_mode; |
1007 | str += 6; |
1008 | } else { |
1009 | mode = &reboot_mode; |
1010 | } |
1011 | |
1012 | switch (*str) { |
1013 | case 'w': |
1014 | *mode = REBOOT_WARM; |
1015 | break; |
1016 | |
1017 | case 'c': |
1018 | *mode = REBOOT_COLD; |
1019 | break; |
1020 | |
1021 | case 'h': |
1022 | *mode = REBOOT_HARD; |
1023 | break; |
1024 | |
1025 | case 's': |
1026 | /* |
1027 | * reboot_cpu is s[mp]#### with #### being the processor |
1028 | * to be used for rebooting. Skip 's' or 'smp' prefix. |
1029 | */ |
1030 | str += str[1] == 'm' && str[2] == 'p' ? 3 : 1; |
1031 | |
1032 | if (isdigit(c: str[0])) { |
1033 | int cpu = simple_strtoul(str, NULL, 0); |
1034 | |
1035 | if (cpu >= num_possible_cpus()) { |
1036 | pr_err("Ignoring the CPU number in reboot= option. " |
1037 | "CPU %d exceeds possible cpu number %d\n" , |
1038 | cpu, num_possible_cpus()); |
1039 | break; |
1040 | } |
1041 | reboot_cpu = cpu; |
1042 | } else |
1043 | *mode = REBOOT_SOFT; |
1044 | break; |
1045 | |
1046 | case 'g': |
1047 | *mode = REBOOT_GPIO; |
1048 | break; |
1049 | |
1050 | case 'b': |
1051 | case 'a': |
1052 | case 'k': |
1053 | case 't': |
1054 | case 'e': |
1055 | case 'p': |
1056 | reboot_type = *str; |
1057 | break; |
1058 | |
1059 | case 'f': |
1060 | reboot_force = 1; |
1061 | break; |
1062 | } |
1063 | |
1064 | str = strchr(str, ','); |
1065 | if (str) |
1066 | str++; |
1067 | else |
1068 | break; |
1069 | } |
1070 | return 1; |
1071 | } |
1072 | __setup("reboot=" , reboot_setup); |
1073 | |
1074 | #ifdef CONFIG_SYSFS |
1075 | |
1076 | #define REBOOT_COLD_STR "cold" |
1077 | #define REBOOT_WARM_STR "warm" |
1078 | #define REBOOT_HARD_STR "hard" |
1079 | #define REBOOT_SOFT_STR "soft" |
1080 | #define REBOOT_GPIO_STR "gpio" |
1081 | #define REBOOT_UNDEFINED_STR "undefined" |
1082 | |
1083 | #define BOOT_TRIPLE_STR "triple" |
1084 | #define BOOT_KBD_STR "kbd" |
1085 | #define BOOT_BIOS_STR "bios" |
1086 | #define BOOT_ACPI_STR "acpi" |
1087 | #define BOOT_EFI_STR "efi" |
1088 | #define BOOT_PCI_STR "pci" |
1089 | |
1090 | static ssize_t mode_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
1091 | { |
1092 | const char *val; |
1093 | |
1094 | switch (reboot_mode) { |
1095 | case REBOOT_COLD: |
1096 | val = REBOOT_COLD_STR; |
1097 | break; |
1098 | case REBOOT_WARM: |
1099 | val = REBOOT_WARM_STR; |
1100 | break; |
1101 | case REBOOT_HARD: |
1102 | val = REBOOT_HARD_STR; |
1103 | break; |
1104 | case REBOOT_SOFT: |
1105 | val = REBOOT_SOFT_STR; |
1106 | break; |
1107 | case REBOOT_GPIO: |
1108 | val = REBOOT_GPIO_STR; |
1109 | break; |
1110 | default: |
1111 | val = REBOOT_UNDEFINED_STR; |
1112 | } |
1113 | |
1114 | return sprintf(buf, fmt: "%s\n" , val); |
1115 | } |
1116 | static ssize_t mode_store(struct kobject *kobj, struct kobj_attribute *attr, |
1117 | const char *buf, size_t count) |
1118 | { |
1119 | if (!capable(CAP_SYS_BOOT)) |
1120 | return -EPERM; |
1121 | |
1122 | if (!strncmp(buf, REBOOT_COLD_STR, strlen(REBOOT_COLD_STR))) |
1123 | reboot_mode = REBOOT_COLD; |
1124 | else if (!strncmp(buf, REBOOT_WARM_STR, strlen(REBOOT_WARM_STR))) |
1125 | reboot_mode = REBOOT_WARM; |
1126 | else if (!strncmp(buf, REBOOT_HARD_STR, strlen(REBOOT_HARD_STR))) |
1127 | reboot_mode = REBOOT_HARD; |
1128 | else if (!strncmp(buf, REBOOT_SOFT_STR, strlen(REBOOT_SOFT_STR))) |
1129 | reboot_mode = REBOOT_SOFT; |
1130 | else if (!strncmp(buf, REBOOT_GPIO_STR, strlen(REBOOT_GPIO_STR))) |
1131 | reboot_mode = REBOOT_GPIO; |
1132 | else |
1133 | return -EINVAL; |
1134 | |
1135 | reboot_default = 0; |
1136 | |
1137 | return count; |
1138 | } |
1139 | static struct kobj_attribute reboot_mode_attr = __ATTR_RW(mode); |
1140 | |
1141 | #ifdef CONFIG_X86 |
1142 | static ssize_t force_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
1143 | { |
1144 | return sprintf(buf, fmt: "%d\n" , reboot_force); |
1145 | } |
1146 | static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr, |
1147 | const char *buf, size_t count) |
1148 | { |
1149 | bool res; |
1150 | |
1151 | if (!capable(CAP_SYS_BOOT)) |
1152 | return -EPERM; |
1153 | |
1154 | if (kstrtobool(s: buf, res: &res)) |
1155 | return -EINVAL; |
1156 | |
1157 | reboot_default = 0; |
1158 | reboot_force = res; |
1159 | |
1160 | return count; |
1161 | } |
1162 | static struct kobj_attribute reboot_force_attr = __ATTR_RW(force); |
1163 | |
1164 | static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
1165 | { |
1166 | const char *val; |
1167 | |
1168 | switch (reboot_type) { |
1169 | case BOOT_TRIPLE: |
1170 | val = BOOT_TRIPLE_STR; |
1171 | break; |
1172 | case BOOT_KBD: |
1173 | val = BOOT_KBD_STR; |
1174 | break; |
1175 | case BOOT_BIOS: |
1176 | val = BOOT_BIOS_STR; |
1177 | break; |
1178 | case BOOT_ACPI: |
1179 | val = BOOT_ACPI_STR; |
1180 | break; |
1181 | case BOOT_EFI: |
1182 | val = BOOT_EFI_STR; |
1183 | break; |
1184 | case BOOT_CF9_FORCE: |
1185 | val = BOOT_PCI_STR; |
1186 | break; |
1187 | default: |
1188 | val = REBOOT_UNDEFINED_STR; |
1189 | } |
1190 | |
1191 | return sprintf(buf, fmt: "%s\n" , val); |
1192 | } |
1193 | static ssize_t type_store(struct kobject *kobj, struct kobj_attribute *attr, |
1194 | const char *buf, size_t count) |
1195 | { |
1196 | if (!capable(CAP_SYS_BOOT)) |
1197 | return -EPERM; |
1198 | |
1199 | if (!strncmp(buf, BOOT_TRIPLE_STR, strlen(BOOT_TRIPLE_STR))) |
1200 | reboot_type = BOOT_TRIPLE; |
1201 | else if (!strncmp(buf, BOOT_KBD_STR, strlen(BOOT_KBD_STR))) |
1202 | reboot_type = BOOT_KBD; |
1203 | else if (!strncmp(buf, BOOT_BIOS_STR, strlen(BOOT_BIOS_STR))) |
1204 | reboot_type = BOOT_BIOS; |
1205 | else if (!strncmp(buf, BOOT_ACPI_STR, strlen(BOOT_ACPI_STR))) |
1206 | reboot_type = BOOT_ACPI; |
1207 | else if (!strncmp(buf, BOOT_EFI_STR, strlen(BOOT_EFI_STR))) |
1208 | reboot_type = BOOT_EFI; |
1209 | else if (!strncmp(buf, BOOT_PCI_STR, strlen(BOOT_PCI_STR))) |
1210 | reboot_type = BOOT_CF9_FORCE; |
1211 | else |
1212 | return -EINVAL; |
1213 | |
1214 | reboot_default = 0; |
1215 | |
1216 | return count; |
1217 | } |
1218 | static struct kobj_attribute reboot_type_attr = __ATTR_RW(type); |
1219 | #endif |
1220 | |
1221 | #ifdef CONFIG_SMP |
1222 | static ssize_t cpu_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
1223 | { |
1224 | return sprintf(buf, fmt: "%d\n" , reboot_cpu); |
1225 | } |
1226 | static ssize_t cpu_store(struct kobject *kobj, struct kobj_attribute *attr, |
1227 | const char *buf, size_t count) |
1228 | { |
1229 | unsigned int cpunum; |
1230 | int rc; |
1231 | |
1232 | if (!capable(CAP_SYS_BOOT)) |
1233 | return -EPERM; |
1234 | |
1235 | rc = kstrtouint(s: buf, base: 0, res: &cpunum); |
1236 | |
1237 | if (rc) |
1238 | return rc; |
1239 | |
1240 | if (cpunum >= num_possible_cpus()) |
1241 | return -ERANGE; |
1242 | |
1243 | reboot_default = 0; |
1244 | reboot_cpu = cpunum; |
1245 | |
1246 | return count; |
1247 | } |
1248 | static struct kobj_attribute reboot_cpu_attr = __ATTR_RW(cpu); |
1249 | #endif |
1250 | |
1251 | static struct attribute *reboot_attrs[] = { |
1252 | &reboot_mode_attr.attr, |
1253 | #ifdef CONFIG_X86 |
1254 | &reboot_force_attr.attr, |
1255 | &reboot_type_attr.attr, |
1256 | #endif |
1257 | #ifdef CONFIG_SMP |
1258 | &reboot_cpu_attr.attr, |
1259 | #endif |
1260 | NULL, |
1261 | }; |
1262 | |
1263 | #ifdef CONFIG_SYSCTL |
1264 | static struct ctl_table kern_reboot_table[] = { |
1265 | { |
1266 | .procname = "poweroff_cmd" , |
1267 | .data = &poweroff_cmd, |
1268 | .maxlen = POWEROFF_CMD_PATH_LEN, |
1269 | .mode = 0644, |
1270 | .proc_handler = proc_dostring, |
1271 | }, |
1272 | { |
1273 | .procname = "ctrl-alt-del" , |
1274 | .data = &C_A_D, |
1275 | .maxlen = sizeof(int), |
1276 | .mode = 0644, |
1277 | .proc_handler = proc_dointvec, |
1278 | }, |
1279 | { } |
1280 | }; |
1281 | |
1282 | static void __init kernel_reboot_sysctls_init(void) |
1283 | { |
1284 | register_sysctl_init("kernel" , kern_reboot_table); |
1285 | } |
1286 | #else |
1287 | #define kernel_reboot_sysctls_init() do { } while (0) |
1288 | #endif /* CONFIG_SYSCTL */ |
1289 | |
1290 | static const struct attribute_group reboot_attr_group = { |
1291 | .attrs = reboot_attrs, |
1292 | }; |
1293 | |
1294 | static int __init reboot_ksysfs_init(void) |
1295 | { |
1296 | struct kobject *reboot_kobj; |
1297 | int ret; |
1298 | |
1299 | reboot_kobj = kobject_create_and_add(name: "reboot" , parent: kernel_kobj); |
1300 | if (!reboot_kobj) |
1301 | return -ENOMEM; |
1302 | |
1303 | ret = sysfs_create_group(kobj: reboot_kobj, grp: &reboot_attr_group); |
1304 | if (ret) { |
1305 | kobject_put(kobj: reboot_kobj); |
1306 | return ret; |
1307 | } |
1308 | |
1309 | kernel_reboot_sysctls_init(); |
1310 | |
1311 | return 0; |
1312 | } |
1313 | late_initcall(reboot_ksysfs_init); |
1314 | |
1315 | #endif |
1316 | |