Commit | Line | Data |
---|---|---|
457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
15d94b82 RH |
2 | /* |
3 | * linux/kernel/reboot.c | |
4 | * | |
5 | * Copyright (C) 2013 Linus Torvalds | |
6 | */ | |
7 | ||
972ee83d RH |
8 | #define pr_fmt(fmt) "reboot: " fmt |
9 | ||
dfa19b11 | 10 | #include <linux/atomic.h> |
1b3a5d02 | 11 | #include <linux/ctype.h> |
15d94b82 RH |
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 | ||
06d17766 | 26 | static int C_A_D = 1; |
15d94b82 RH |
27 | struct pid *cad_pid; |
28 | EXPORT_SYMBOL(cad_pid); | |
29 | ||
fb37409a | 30 | #if defined(CONFIG_ARM) |
1b3a5d02 RH |
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; | |
d46b3f5b | 36 | EXPORT_SYMBOL_GPL(reboot_mode); |
b287a25a | 37 | enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED; |
1b3a5d02 | 38 | |
e2f0b88e CL |
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; | |
1b3a5d02 RH |
47 | int reboot_cpu; |
48 | enum reboot_type reboot_type = BOOT_ACPI; | |
49 | int reboot_force; | |
50 | ||
232edc2f DO |
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; | |
db2d6038 | 58 | struct device *dev; |
232edc2f DO |
59 | }; |
60 | ||
a9a1d6ad DL |
61 | /* |
62 | * This variable is used to indicate if a halt was initiated instead of a | |
63 | * reboot when the reboot call was invoked with LINUX_REBOOT_CMD_POWER_OFF, but | |
64 | * the system cannot be powered off. This allowes kernel_halt() to notify users | |
65 | * of that. | |
66 | */ | |
67 | static bool poweroff_fallback_to_halt; | |
68 | ||
15d94b82 | 69 | /* |
5d34b41a DO |
70 | * Temporary stub that prevents linkage failure while we're in process |
71 | * of removing all uses of legacy pm_power_off() around the kernel. | |
15d94b82 | 72 | */ |
5d34b41a | 73 | void __weak (*pm_power_off)(void); |
15d94b82 RH |
74 | |
75 | /** | |
76 | * emergency_restart - reboot the system | |
77 | * | |
78 | * Without shutting down any hardware or taking any locks | |
79 | * reboot the system. This is called when we know we are in | |
80 | * trouble so this is our best effort to reboot. This is | |
81 | * safe to call in interrupt context. | |
82 | */ | |
83 | void emergency_restart(void) | |
84 | { | |
85 | kmsg_dump(KMSG_DUMP_EMERG); | |
60466c06 | 86 | system_state = SYSTEM_RESTART; |
15d94b82 RH |
87 | machine_emergency_restart(); |
88 | } | |
89 | EXPORT_SYMBOL_GPL(emergency_restart); | |
90 | ||
91 | void kernel_restart_prepare(char *cmd) | |
92 | { | |
93 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); | |
94 | system_state = SYSTEM_RESTART; | |
95 | usermodehelper_disable(); | |
96 | device_shutdown(); | |
97 | } | |
98 | ||
99 | /** | |
100 | * register_reboot_notifier - Register function to be called at reboot time | |
101 | * @nb: Info about notifier function to be called | |
102 | * | |
103 | * Registers a function with the list of functions | |
104 | * to be called at reboot time. | |
105 | * | |
106 | * Currently always returns zero, as blocking_notifier_chain_register() | |
107 | * always returns zero. | |
108 | */ | |
109 | int register_reboot_notifier(struct notifier_block *nb) | |
110 | { | |
111 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); | |
112 | } | |
113 | EXPORT_SYMBOL(register_reboot_notifier); | |
114 | ||
115 | /** | |
116 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
117 | * @nb: Hook to be unregistered | |
118 | * | |
119 | * Unregisters a previously registered reboot | |
120 | * notifier function. | |
121 | * | |
122 | * Returns zero on success, or %-ENOENT on failure. | |
123 | */ | |
124 | int unregister_reboot_notifier(struct notifier_block *nb) | |
125 | { | |
126 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | |
127 | } | |
128 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
129 | ||
2d8364ba AS |
130 | static void devm_unregister_reboot_notifier(struct device *dev, void *res) |
131 | { | |
132 | WARN_ON(unregister_reboot_notifier(*(struct notifier_block **)res)); | |
133 | } | |
134 | ||
135 | int devm_register_reboot_notifier(struct device *dev, struct notifier_block *nb) | |
136 | { | |
137 | struct notifier_block **rcnb; | |
138 | int ret; | |
139 | ||
140 | rcnb = devres_alloc(devm_unregister_reboot_notifier, | |
141 | sizeof(*rcnb), GFP_KERNEL); | |
142 | if (!rcnb) | |
143 | return -ENOMEM; | |
144 | ||
145 | ret = register_reboot_notifier(nb); | |
146 | if (!ret) { | |
147 | *rcnb = nb; | |
148 | devres_add(dev, rcnb); | |
149 | } else { | |
150 | devres_free(rcnb); | |
151 | } | |
152 | ||
153 | return ret; | |
154 | } | |
155 | EXPORT_SYMBOL(devm_register_reboot_notifier); | |
156 | ||
b63adb97 GR |
157 | /* |
158 | * Notifier list for kernel code which wants to be called | |
159 | * to restart the system. | |
160 | */ | |
161 | static ATOMIC_NOTIFIER_HEAD(restart_handler_list); | |
162 | ||
163 | /** | |
164 | * register_restart_handler - Register function to be called to reset | |
165 | * the system | |
166 | * @nb: Info about handler function to be called | |
167 | * @nb->priority: Handler priority. Handlers should follow the | |
168 | * following guidelines for setting priorities. | |
169 | * 0: Restart handler of last resort, | |
170 | * with limited restart capabilities | |
171 | * 128: Default restart handler; use if no other | |
172 | * restart handler is expected to be available, | |
173 | * and/or if restart functionality is | |
174 | * sufficient to restart the entire system | |
175 | * 255: Highest priority restart handler, will | |
176 | * preempt all other restart handlers | |
177 | * | |
178 | * Registers a function with code to be called to restart the | |
179 | * system. | |
180 | * | |
181 | * Registered functions will be called from machine_restart as last | |
182 | * step of the restart sequence (if the architecture specific | |
183 | * machine_restart function calls do_kernel_restart - see below | |
184 | * for details). | |
185 | * Registered functions are expected to restart the system immediately. | |
186 | * If more than one function is registered, the restart handler priority | |
187 | * selects which function will be called first. | |
188 | * | |
189 | * Restart handlers are expected to be registered from non-architecture | |
190 | * code, typically from drivers. A typical use case would be a system | |
191 | * where restart functionality is provided through a watchdog. Multiple | |
192 | * restart handlers may exist; for example, one restart handler might | |
193 | * restart the entire system, while another only restarts the CPU. | |
194 | * In such cases, the restart handler which only restarts part of the | |
195 | * hardware is expected to register with low priority to ensure that | |
196 | * it only runs if no other means to restart the system is available. | |
197 | * | |
198 | * Currently always returns zero, as atomic_notifier_chain_register() | |
199 | * always returns zero. | |
200 | */ | |
201 | int register_restart_handler(struct notifier_block *nb) | |
202 | { | |
203 | return atomic_notifier_chain_register(&restart_handler_list, nb); | |
204 | } | |
205 | EXPORT_SYMBOL(register_restart_handler); | |
206 | ||
207 | /** | |
208 | * unregister_restart_handler - Unregister previously registered | |
209 | * restart handler | |
210 | * @nb: Hook to be unregistered | |
211 | * | |
212 | * Unregisters a previously registered restart handler function. | |
213 | * | |
214 | * Returns zero on success, or %-ENOENT on failure. | |
215 | */ | |
216 | int unregister_restart_handler(struct notifier_block *nb) | |
217 | { | |
218 | return atomic_notifier_chain_unregister(&restart_handler_list, nb); | |
219 | } | |
220 | EXPORT_SYMBOL(unregister_restart_handler); | |
221 | ||
222 | /** | |
223 | * do_kernel_restart - Execute kernel restart handler call chain | |
224 | * | |
225 | * Calls functions registered with register_restart_handler. | |
226 | * | |
227 | * Expected to be called from machine_restart as last step of the restart | |
228 | * sequence. | |
229 | * | |
230 | * Restarts the system immediately if a restart handler function has been | |
231 | * registered. Otherwise does nothing. | |
232 | */ | |
233 | void do_kernel_restart(char *cmd) | |
234 | { | |
235 | atomic_notifier_call_chain(&restart_handler_list, reboot_mode, cmd); | |
236 | } | |
237 | ||
c97102ba | 238 | void migrate_to_reboot_cpu(void) |
15d94b82 RH |
239 | { |
240 | /* The boot cpu is always logical cpu 0 */ | |
1b3a5d02 | 241 | int cpu = reboot_cpu; |
15d94b82 RH |
242 | |
243 | cpu_hotplug_disable(); | |
244 | ||
245 | /* Make certain the cpu I'm about to reboot on is online */ | |
246 | if (!cpu_online(cpu)) | |
247 | cpu = cpumask_first(cpu_online_mask); | |
248 | ||
249 | /* Prevent races with other tasks migrating this task */ | |
250 | current->flags |= PF_NO_SETAFFINITY; | |
251 | ||
252 | /* Make certain I only run on the appropriate processor */ | |
253 | set_cpus_allowed_ptr(current, cpumask_of(cpu)); | |
254 | } | |
255 | ||
e7fd8b68 KHF |
256 | /* |
257 | * Notifier list for kernel code which wants to be called | |
258 | * to prepare system for restart. | |
259 | */ | |
260 | static BLOCKING_NOTIFIER_HEAD(restart_prep_handler_list); | |
261 | ||
262 | static void do_kernel_restart_prepare(void) | |
263 | { | |
264 | blocking_notifier_call_chain(&restart_prep_handler_list, 0, NULL); | |
265 | } | |
266 | ||
15d94b82 RH |
267 | /** |
268 | * kernel_restart - reboot the system | |
269 | * @cmd: pointer to buffer containing command to execute for restart | |
270 | * or %NULL | |
271 | * | |
272 | * Shutdown everything and perform a clean reboot. | |
273 | * This is not safe to call in interrupt context. | |
274 | */ | |
275 | void kernel_restart(char *cmd) | |
276 | { | |
277 | kernel_restart_prepare(cmd); | |
e7fd8b68 | 278 | do_kernel_restart_prepare(); |
15d94b82 RH |
279 | migrate_to_reboot_cpu(); |
280 | syscore_shutdown(); | |
281 | if (!cmd) | |
972ee83d | 282 | pr_emerg("Restarting system\n"); |
15d94b82 | 283 | else |
972ee83d | 284 | pr_emerg("Restarting system with command '%s'\n", cmd); |
6d3cf962 | 285 | kmsg_dump(KMSG_DUMP_SHUTDOWN); |
15d94b82 RH |
286 | machine_restart(cmd); |
287 | } | |
288 | EXPORT_SYMBOL_GPL(kernel_restart); | |
289 | ||
290 | static void kernel_shutdown_prepare(enum system_states state) | |
291 | { | |
292 | blocking_notifier_call_chain(&reboot_notifier_list, | |
972ee83d | 293 | (state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL); |
15d94b82 RH |
294 | system_state = state; |
295 | usermodehelper_disable(); | |
296 | device_shutdown(); | |
297 | } | |
298 | /** | |
299 | * kernel_halt - halt the system | |
300 | * | |
301 | * Shutdown everything and perform a clean system halt. | |
302 | */ | |
303 | void kernel_halt(void) | |
304 | { | |
305 | kernel_shutdown_prepare(SYSTEM_HALT); | |
306 | migrate_to_reboot_cpu(); | |
307 | syscore_shutdown(); | |
a9a1d6ad DL |
308 | if (poweroff_fallback_to_halt) |
309 | pr_emerg("Power off not available: System halted instead\n"); | |
310 | else | |
311 | pr_emerg("System halted\n"); | |
6d3cf962 | 312 | kmsg_dump(KMSG_DUMP_SHUTDOWN); |
15d94b82 RH |
313 | machine_halt(); |
314 | } | |
15d94b82 RH |
315 | EXPORT_SYMBOL_GPL(kernel_halt); |
316 | ||
232edc2f DO |
317 | /* |
318 | * Notifier list for kernel code which wants to be called | |
319 | * to prepare system for power off. | |
320 | */ | |
321 | static BLOCKING_NOTIFIER_HEAD(power_off_prep_handler_list); | |
322 | ||
323 | /* | |
324 | * Notifier list for kernel code which wants to be called | |
325 | * to power off system. | |
326 | */ | |
327 | static ATOMIC_NOTIFIER_HEAD(power_off_handler_list); | |
328 | ||
329 | static int sys_off_notify(struct notifier_block *nb, | |
330 | unsigned long mode, void *cmd) | |
331 | { | |
332 | struct sys_off_handler *handler; | |
333 | struct sys_off_data data = {}; | |
334 | ||
335 | handler = container_of(nb, struct sys_off_handler, nb); | |
336 | data.cb_data = handler->cb_data; | |
337 | data.mode = mode; | |
338 | data.cmd = cmd; | |
db2d6038 | 339 | data.dev = handler->dev; |
232edc2f DO |
340 | |
341 | return handler->sys_off_cb(&data); | |
342 | } | |
343 | ||
587b9bfe DO |
344 | static struct sys_off_handler platform_sys_off_handler; |
345 | ||
346 | static struct sys_off_handler *alloc_sys_off_handler(int priority) | |
347 | { | |
348 | struct sys_off_handler *handler; | |
2b8c612c | 349 | gfp_t flags; |
587b9bfe DO |
350 | |
351 | /* | |
352 | * Platforms like m68k can't allocate sys_off handler dynamically | |
353 | * at the early boot time because memory allocator isn't available yet. | |
354 | */ | |
355 | if (priority == SYS_OFF_PRIO_PLATFORM) { | |
356 | handler = &platform_sys_off_handler; | |
357 | if (handler->cb_data) | |
358 | return ERR_PTR(-EBUSY); | |
359 | } else { | |
2b8c612c DO |
360 | if (system_state > SYSTEM_RUNNING) |
361 | flags = GFP_ATOMIC; | |
362 | else | |
363 | flags = GFP_KERNEL; | |
364 | ||
365 | handler = kzalloc(sizeof(*handler), flags); | |
587b9bfe DO |
366 | if (!handler) |
367 | return ERR_PTR(-ENOMEM); | |
368 | } | |
369 | ||
370 | return handler; | |
371 | } | |
372 | ||
373 | static void free_sys_off_handler(struct sys_off_handler *handler) | |
374 | { | |
375 | if (handler == &platform_sys_off_handler) | |
376 | memset(handler, 0, sizeof(*handler)); | |
377 | else | |
378 | kfree(handler); | |
379 | } | |
380 | ||
232edc2f DO |
381 | /** |
382 | * register_sys_off_handler - Register sys-off handler | |
383 | * @mode: Sys-off mode | |
384 | * @priority: Handler priority | |
385 | * @callback: Callback function | |
386 | * @cb_data: Callback argument | |
387 | * | |
388 | * Registers system power-off or restart handler that will be invoked | |
389 | * at the step corresponding to the given sys-off mode. Handler's callback | |
390 | * should return NOTIFY_DONE to permit execution of the next handler in | |
391 | * the call chain or NOTIFY_STOP to break the chain (in error case for | |
392 | * example). | |
393 | * | |
394 | * Multiple handlers can be registered at the default priority level. | |
395 | * | |
396 | * Only one handler can be registered at the non-default priority level, | |
397 | * otherwise ERR_PTR(-EBUSY) is returned. | |
398 | * | |
399 | * Returns a new instance of struct sys_off_handler on success, or | |
400 | * an ERR_PTR()-encoded error code otherwise. | |
401 | */ | |
402 | struct sys_off_handler * | |
403 | register_sys_off_handler(enum sys_off_mode mode, | |
404 | int priority, | |
405 | int (*callback)(struct sys_off_data *data), | |
406 | void *cb_data) | |
407 | { | |
408 | struct sys_off_handler *handler; | |
409 | int err; | |
410 | ||
587b9bfe DO |
411 | handler = alloc_sys_off_handler(priority); |
412 | if (IS_ERR(handler)) | |
413 | return handler; | |
232edc2f DO |
414 | |
415 | switch (mode) { | |
416 | case SYS_OFF_MODE_POWER_OFF_PREPARE: | |
417 | handler->list = &power_off_prep_handler_list; | |
418 | handler->blocking = true; | |
419 | break; | |
420 | ||
421 | case SYS_OFF_MODE_POWER_OFF: | |
422 | handler->list = &power_off_handler_list; | |
423 | break; | |
424 | ||
e7fd8b68 KHF |
425 | case SYS_OFF_MODE_RESTART_PREPARE: |
426 | handler->list = &restart_prep_handler_list; | |
427 | handler->blocking = true; | |
428 | break; | |
429 | ||
232edc2f DO |
430 | case SYS_OFF_MODE_RESTART: |
431 | handler->list = &restart_handler_list; | |
432 | break; | |
433 | ||
434 | default: | |
587b9bfe | 435 | free_sys_off_handler(handler); |
232edc2f DO |
436 | return ERR_PTR(-EINVAL); |
437 | } | |
438 | ||
439 | handler->nb.notifier_call = sys_off_notify; | |
440 | handler->nb.priority = priority; | |
441 | handler->sys_off_cb = callback; | |
442 | handler->cb_data = cb_data; | |
443 | handler->mode = mode; | |
444 | ||
445 | if (handler->blocking) { | |
446 | if (priority == SYS_OFF_PRIO_DEFAULT) | |
447 | err = blocking_notifier_chain_register(handler->list, | |
448 | &handler->nb); | |
449 | else | |
450 | err = blocking_notifier_chain_register_unique_prio(handler->list, | |
451 | &handler->nb); | |
452 | } else { | |
453 | if (priority == SYS_OFF_PRIO_DEFAULT) | |
454 | err = atomic_notifier_chain_register(handler->list, | |
455 | &handler->nb); | |
456 | else | |
457 | err = atomic_notifier_chain_register_unique_prio(handler->list, | |
458 | &handler->nb); | |
459 | } | |
460 | ||
461 | if (err) { | |
587b9bfe | 462 | free_sys_off_handler(handler); |
232edc2f DO |
463 | return ERR_PTR(err); |
464 | } | |
465 | ||
466 | return handler; | |
467 | } | |
468 | EXPORT_SYMBOL_GPL(register_sys_off_handler); | |
469 | ||
470 | /** | |
471 | * unregister_sys_off_handler - Unregister sys-off handler | |
472 | * @handler: Sys-off handler | |
473 | * | |
474 | * Unregisters given sys-off handler. | |
475 | */ | |
476 | void unregister_sys_off_handler(struct sys_off_handler *handler) | |
477 | { | |
478 | int err; | |
479 | ||
2b8c612c | 480 | if (IS_ERR_OR_NULL(handler)) |
232edc2f DO |
481 | return; |
482 | ||
483 | if (handler->blocking) | |
484 | err = blocking_notifier_chain_unregister(handler->list, | |
485 | &handler->nb); | |
486 | else | |
487 | err = atomic_notifier_chain_unregister(handler->list, | |
488 | &handler->nb); | |
489 | ||
490 | /* sanity check, shall never happen */ | |
491 | WARN_ON(err); | |
492 | ||
587b9bfe | 493 | free_sys_off_handler(handler); |
232edc2f DO |
494 | } |
495 | EXPORT_SYMBOL_GPL(unregister_sys_off_handler); | |
496 | ||
497 | static void devm_unregister_sys_off_handler(void *data) | |
498 | { | |
499 | struct sys_off_handler *handler = data; | |
500 | ||
501 | unregister_sys_off_handler(handler); | |
502 | } | |
503 | ||
504 | /** | |
505 | * devm_register_sys_off_handler - Register sys-off handler | |
506 | * @dev: Device that registers handler | |
507 | * @mode: Sys-off mode | |
508 | * @priority: Handler priority | |
509 | * @callback: Callback function | |
510 | * @cb_data: Callback argument | |
511 | * | |
512 | * Registers resource-managed sys-off handler. | |
513 | * | |
514 | * Returns zero on success, or error code on failure. | |
515 | */ | |
516 | int devm_register_sys_off_handler(struct device *dev, | |
517 | enum sys_off_mode mode, | |
518 | int priority, | |
519 | int (*callback)(struct sys_off_data *data), | |
520 | void *cb_data) | |
521 | { | |
522 | struct sys_off_handler *handler; | |
523 | ||
524 | handler = register_sys_off_handler(mode, priority, callback, cb_data); | |
525 | if (IS_ERR(handler)) | |
526 | return PTR_ERR(handler); | |
db2d6038 | 527 | handler->dev = dev; |
232edc2f DO |
528 | |
529 | return devm_add_action_or_reset(dev, devm_unregister_sys_off_handler, | |
530 | handler); | |
531 | } | |
532 | EXPORT_SYMBOL_GPL(devm_register_sys_off_handler); | |
533 | ||
d2c54153 DO |
534 | /** |
535 | * devm_register_power_off_handler - Register power-off handler | |
536 | * @dev: Device that registers callback | |
537 | * @callback: Callback function | |
538 | * @cb_data: Callback's argument | |
539 | * | |
540 | * Registers resource-managed sys-off handler with a default priority | |
541 | * and using power-off mode. | |
542 | * | |
543 | * Returns zero on success, or error code on failure. | |
544 | */ | |
545 | int devm_register_power_off_handler(struct device *dev, | |
546 | int (*callback)(struct sys_off_data *data), | |
547 | void *cb_data) | |
548 | { | |
549 | return devm_register_sys_off_handler(dev, | |
550 | SYS_OFF_MODE_POWER_OFF, | |
551 | SYS_OFF_PRIO_DEFAULT, | |
552 | callback, cb_data); | |
553 | } | |
554 | EXPORT_SYMBOL_GPL(devm_register_power_off_handler); | |
555 | ||
6779db97 DO |
556 | /** |
557 | * devm_register_restart_handler - Register restart handler | |
558 | * @dev: Device that registers callback | |
559 | * @callback: Callback function | |
560 | * @cb_data: Callback's argument | |
561 | * | |
562 | * Registers resource-managed sys-off handler with a default priority | |
563 | * and using restart mode. | |
564 | * | |
565 | * Returns zero on success, or error code on failure. | |
566 | */ | |
567 | int devm_register_restart_handler(struct device *dev, | |
568 | int (*callback)(struct sys_off_data *data), | |
569 | void *cb_data) | |
570 | { | |
571 | return devm_register_sys_off_handler(dev, | |
572 | SYS_OFF_MODE_RESTART, | |
573 | SYS_OFF_PRIO_DEFAULT, | |
574 | callback, cb_data); | |
575 | } | |
576 | EXPORT_SYMBOL_GPL(devm_register_restart_handler); | |
577 | ||
fb61375e DO |
578 | static struct sys_off_handler *platform_power_off_handler; |
579 | ||
580 | static int platform_power_off_notify(struct sys_off_data *data) | |
581 | { | |
582 | void (*platform_power_power_off_cb)(void) = data->cb_data; | |
583 | ||
584 | platform_power_power_off_cb(); | |
585 | ||
586 | return NOTIFY_DONE; | |
587 | } | |
588 | ||
589 | /** | |
590 | * register_platform_power_off - Register platform-level power-off callback | |
591 | * @power_off: Power-off callback | |
592 | * | |
593 | * Registers power-off callback that will be called as last step | |
594 | * of the power-off sequence. This callback is expected to be invoked | |
595 | * for the last resort. Only one platform power-off callback is allowed | |
596 | * to be registered at a time. | |
597 | * | |
598 | * Returns zero on success, or error code on failure. | |
599 | */ | |
600 | int register_platform_power_off(void (*power_off)(void)) | |
601 | { | |
602 | struct sys_off_handler *handler; | |
603 | ||
604 | handler = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, | |
605 | SYS_OFF_PRIO_PLATFORM, | |
606 | platform_power_off_notify, | |
607 | power_off); | |
608 | if (IS_ERR(handler)) | |
609 | return PTR_ERR(handler); | |
610 | ||
611 | platform_power_off_handler = handler; | |
612 | ||
613 | return 0; | |
614 | } | |
615 | EXPORT_SYMBOL_GPL(register_platform_power_off); | |
616 | ||
617 | /** | |
618 | * unregister_platform_power_off - Unregister platform-level power-off callback | |
619 | * @power_off: Power-off callback | |
620 | * | |
621 | * Unregisters previously registered platform power-off callback. | |
622 | */ | |
623 | void unregister_platform_power_off(void (*power_off)(void)) | |
624 | { | |
625 | if (platform_power_off_handler && | |
626 | platform_power_off_handler->cb_data == power_off) { | |
627 | unregister_sys_off_handler(platform_power_off_handler); | |
628 | platform_power_off_handler = NULL; | |
629 | } | |
630 | } | |
631 | EXPORT_SYMBOL_GPL(unregister_platform_power_off); | |
632 | ||
7b9a3de9 DO |
633 | static int legacy_pm_power_off(struct sys_off_data *data) |
634 | { | |
635 | if (pm_power_off) | |
636 | pm_power_off(); | |
637 | ||
638 | return NOTIFY_DONE; | |
639 | } | |
640 | ||
7b9a3de9 DO |
641 | static void do_kernel_power_off_prepare(void) |
642 | { | |
643 | blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL); | |
644 | } | |
645 | ||
2b6aa733 DO |
646 | /** |
647 | * do_kernel_power_off - Execute kernel power-off handler call chain | |
648 | * | |
649 | * Expected to be called as last step of the power-off sequence. | |
650 | * | |
651 | * Powers off the system immediately if a power-off handler function has | |
652 | * been registered. Otherwise does nothing. | |
653 | */ | |
654 | void do_kernel_power_off(void) | |
655 | { | |
2b8c612c DO |
656 | struct sys_off_handler *sys_off = NULL; |
657 | ||
658 | /* | |
659 | * Register sys-off handlers for legacy PM callback. This allows | |
660 | * legacy PM callbacks temporary co-exist with the new sys-off API. | |
661 | * | |
662 | * TODO: Remove legacy handlers once all legacy PM users will be | |
663 | * switched to the sys-off based APIs. | |
664 | */ | |
665 | if (pm_power_off) | |
666 | sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, | |
667 | SYS_OFF_PRIO_DEFAULT, | |
668 | legacy_pm_power_off, NULL); | |
669 | ||
2b6aa733 | 670 | atomic_notifier_call_chain(&power_off_handler_list, 0, NULL); |
2b8c612c DO |
671 | |
672 | unregister_sys_off_handler(sys_off); | |
2b6aa733 DO |
673 | } |
674 | ||
0e2110d2 DO |
675 | /** |
676 | * kernel_can_power_off - check whether system can be powered off | |
677 | * | |
678 | * Returns true if power-off handler is registered and system can be | |
679 | * powered off, false otherwise. | |
680 | */ | |
681 | bool kernel_can_power_off(void) | |
682 | { | |
2b8c612c DO |
683 | return !atomic_notifier_call_chain_is_empty(&power_off_handler_list) || |
684 | pm_power_off; | |
0e2110d2 DO |
685 | } |
686 | EXPORT_SYMBOL_GPL(kernel_can_power_off); | |
687 | ||
15d94b82 RH |
688 | /** |
689 | * kernel_power_off - power_off the system | |
690 | * | |
691 | * Shutdown everything and perform a clean system power_off. | |
692 | */ | |
693 | void kernel_power_off(void) | |
694 | { | |
695 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); | |
7b9a3de9 | 696 | do_kernel_power_off_prepare(); |
15d94b82 RH |
697 | migrate_to_reboot_cpu(); |
698 | syscore_shutdown(); | |
972ee83d | 699 | pr_emerg("Power down\n"); |
6d3cf962 | 700 | kmsg_dump(KMSG_DUMP_SHUTDOWN); |
15d94b82 RH |
701 | machine_power_off(); |
702 | } | |
703 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
704 | ||
55f2503c | 705 | DEFINE_MUTEX(system_transition_mutex); |
15d94b82 RH |
706 | |
707 | /* | |
708 | * Reboot system call: for obvious reasons only root may call it, | |
709 | * and even root needs to set up some magic numbers in the registers | |
710 | * so that some mistake won't make this reboot the whole machine. | |
711 | * You can also set the meaning of the ctrl-alt-del-key here. | |
712 | * | |
713 | * reboot doesn't sync: do that yourself before calling this. | |
714 | */ | |
715 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, | |
716 | void __user *, arg) | |
717 | { | |
718 | struct pid_namespace *pid_ns = task_active_pid_ns(current); | |
719 | char buffer[256]; | |
720 | int ret = 0; | |
721 | ||
722 | /* We only trust the superuser with rebooting the system. */ | |
723 | if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT)) | |
724 | return -EPERM; | |
725 | ||
726 | /* For safety, we require "magic" arguments. */ | |
727 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
972ee83d RH |
728 | (magic2 != LINUX_REBOOT_MAGIC2 && |
729 | magic2 != LINUX_REBOOT_MAGIC2A && | |
15d94b82 | 730 | magic2 != LINUX_REBOOT_MAGIC2B && |
972ee83d | 731 | magic2 != LINUX_REBOOT_MAGIC2C)) |
15d94b82 RH |
732 | return -EINVAL; |
733 | ||
734 | /* | |
735 | * If pid namespaces are enabled and the current task is in a child | |
736 | * pid_namespace, the command is handled by reboot_pid_ns() which will | |
737 | * call do_exit(). | |
738 | */ | |
739 | ret = reboot_pid_ns(pid_ns, cmd); | |
740 | if (ret) | |
741 | return ret; | |
742 | ||
743 | /* Instead of trying to make the power_off code look like | |
744 | * halt when pm_power_off is not set do it the easy way. | |
745 | */ | |
a9a1d6ad DL |
746 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off()) { |
747 | poweroff_fallback_to_halt = true; | |
15d94b82 | 748 | cmd = LINUX_REBOOT_CMD_HALT; |
a9a1d6ad | 749 | } |
15d94b82 | 750 | |
55f2503c | 751 | mutex_lock(&system_transition_mutex); |
15d94b82 RH |
752 | switch (cmd) { |
753 | case LINUX_REBOOT_CMD_RESTART: | |
754 | kernel_restart(NULL); | |
755 | break; | |
756 | ||
757 | case LINUX_REBOOT_CMD_CAD_ON: | |
758 | C_A_D = 1; | |
759 | break; | |
760 | ||
761 | case LINUX_REBOOT_CMD_CAD_OFF: | |
762 | C_A_D = 0; | |
763 | break; | |
764 | ||
765 | case LINUX_REBOOT_CMD_HALT: | |
766 | kernel_halt(); | |
767 | do_exit(0); | |
15d94b82 RH |
768 | |
769 | case LINUX_REBOOT_CMD_POWER_OFF: | |
770 | kernel_power_off(); | |
771 | do_exit(0); | |
772 | break; | |
773 | ||
774 | case LINUX_REBOOT_CMD_RESTART2: | |
972ee83d RH |
775 | ret = strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1); |
776 | if (ret < 0) { | |
15d94b82 RH |
777 | ret = -EFAULT; |
778 | break; | |
779 | } | |
780 | buffer[sizeof(buffer) - 1] = '\0'; | |
781 | ||
782 | kernel_restart(buffer); | |
783 | break; | |
784 | ||
2965faa5 | 785 | #ifdef CONFIG_KEXEC_CORE |
15d94b82 RH |
786 | case LINUX_REBOOT_CMD_KEXEC: |
787 | ret = kernel_kexec(); | |
788 | break; | |
789 | #endif | |
790 | ||
791 | #ifdef CONFIG_HIBERNATION | |
792 | case LINUX_REBOOT_CMD_SW_SUSPEND: | |
793 | ret = hibernate(); | |
794 | break; | |
795 | #endif | |
796 | ||
797 | default: | |
798 | ret = -EINVAL; | |
799 | break; | |
800 | } | |
55f2503c | 801 | mutex_unlock(&system_transition_mutex); |
15d94b82 RH |
802 | return ret; |
803 | } | |
804 | ||
805 | static void deferred_cad(struct work_struct *dummy) | |
806 | { | |
807 | kernel_restart(NULL); | |
808 | } | |
809 | ||
810 | /* | |
811 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
812 | * As it's called within an interrupt, it may NOT sync: the only choice | |
813 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
814 | */ | |
815 | void ctrl_alt_del(void) | |
816 | { | |
817 | static DECLARE_WORK(cad_work, deferred_cad); | |
818 | ||
819 | if (C_A_D) | |
820 | schedule_work(&cad_work); | |
821 | else | |
822 | kill_cad_pid(SIGINT, 1); | |
823 | } | |
824 | ||
06d17766 | 825 | #define POWEROFF_CMD_PATH_LEN 256 |
826 | static char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | |
7a54f46b | 827 | static const char reboot_cmd[] = "/sbin/reboot"; |
15d94b82 | 828 | |
7a54f46b | 829 | static int run_cmd(const char *cmd) |
15d94b82 RH |
830 | { |
831 | char **argv; | |
832 | static char *envp[] = { | |
833 | "HOME=/", | |
834 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", | |
835 | NULL | |
836 | }; | |
837 | int ret; | |
7a54f46b | 838 | argv = argv_split(GFP_KERNEL, cmd, NULL); |
15d94b82 RH |
839 | if (argv) { |
840 | ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); | |
841 | argv_free(argv); | |
842 | } else { | |
15d94b82 RH |
843 | ret = -ENOMEM; |
844 | } | |
845 | ||
7a54f46b JS |
846 | return ret; |
847 | } | |
848 | ||
849 | static int __orderly_reboot(void) | |
850 | { | |
851 | int ret; | |
852 | ||
853 | ret = run_cmd(reboot_cmd); | |
854 | ||
855 | if (ret) { | |
856 | pr_warn("Failed to start orderly reboot: forcing the issue\n"); | |
857 | emergency_sync(); | |
858 | kernel_restart(NULL); | |
859 | } | |
860 | ||
861 | return ret; | |
862 | } | |
863 | ||
864 | static int __orderly_poweroff(bool force) | |
865 | { | |
866 | int ret; | |
867 | ||
868 | ret = run_cmd(poweroff_cmd); | |
869 | ||
15d94b82 | 870 | if (ret && force) { |
972ee83d | 871 | pr_warn("Failed to start orderly shutdown: forcing the issue\n"); |
7a54f46b | 872 | |
15d94b82 RH |
873 | /* |
874 | * I guess this should try to kick off some daemon to sync and | |
875 | * poweroff asap. Or not even bother syncing if we're doing an | |
876 | * emergency shutdown? | |
877 | */ | |
878 | emergency_sync(); | |
879 | kernel_power_off(); | |
880 | } | |
881 | ||
882 | return ret; | |
883 | } | |
884 | ||
885 | static bool poweroff_force; | |
886 | ||
887 | static void poweroff_work_func(struct work_struct *work) | |
888 | { | |
889 | __orderly_poweroff(poweroff_force); | |
890 | } | |
891 | ||
892 | static DECLARE_WORK(poweroff_work, poweroff_work_func); | |
893 | ||
894 | /** | |
895 | * orderly_poweroff - Trigger an orderly system poweroff | |
896 | * @force: force poweroff if command execution fails | |
897 | * | |
898 | * This may be called from any context to trigger a system shutdown. | |
899 | * If the orderly shutdown fails, it will force an immediate shutdown. | |
900 | */ | |
7a54f46b | 901 | void orderly_poweroff(bool force) |
15d94b82 RH |
902 | { |
903 | if (force) /* do not override the pending "true" */ | |
904 | poweroff_force = true; | |
905 | schedule_work(&poweroff_work); | |
15d94b82 RH |
906 | } |
907 | EXPORT_SYMBOL_GPL(orderly_poweroff); | |
1b3a5d02 | 908 | |
7a54f46b JS |
909 | static void reboot_work_func(struct work_struct *work) |
910 | { | |
911 | __orderly_reboot(); | |
912 | } | |
913 | ||
914 | static DECLARE_WORK(reboot_work, reboot_work_func); | |
915 | ||
916 | /** | |
917 | * orderly_reboot - Trigger an orderly system reboot | |
918 | * | |
919 | * This may be called from any context to trigger a system reboot. | |
920 | * If the orderly reboot fails, it will force an immediate reboot. | |
921 | */ | |
922 | void orderly_reboot(void) | |
923 | { | |
924 | schedule_work(&reboot_work); | |
925 | } | |
926 | EXPORT_SYMBOL_GPL(orderly_reboot); | |
927 | ||
dfa19b11 MV |
928 | /** |
929 | * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay | |
930 | * @work: work_struct associated with the emergency poweroff function | |
931 | * | |
932 | * This function is called in very critical situations to force | |
933 | * a kernel poweroff after a configurable timeout value. | |
934 | */ | |
935 | static void hw_failure_emergency_poweroff_func(struct work_struct *work) | |
936 | { | |
937 | /* | |
938 | * We have reached here after the emergency shutdown waiting period has | |
939 | * expired. This means orderly_poweroff has not been able to shut off | |
940 | * the system for some reason. | |
941 | * | |
942 | * Try to shut down the system immediately using kernel_power_off | |
943 | * if populated | |
944 | */ | |
945 | pr_emerg("Hardware protection timed-out. Trying forced poweroff\n"); | |
946 | kernel_power_off(); | |
947 | ||
948 | /* | |
949 | * Worst of the worst case trigger emergency restart | |
950 | */ | |
951 | pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n"); | |
952 | emergency_restart(); | |
953 | } | |
954 | ||
955 | static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, | |
956 | hw_failure_emergency_poweroff_func); | |
957 | ||
958 | /** | |
959 | * hw_failure_emergency_poweroff - Trigger an emergency system poweroff | |
960 | * | |
961 | * This may be called from any critical situation to trigger a system shutdown | |
962 | * after a given period of time. If time is negative this is not scheduled. | |
963 | */ | |
964 | static void hw_failure_emergency_poweroff(int poweroff_delay_ms) | |
965 | { | |
966 | if (poweroff_delay_ms <= 0) | |
967 | return; | |
968 | schedule_delayed_work(&hw_failure_emergency_poweroff_work, | |
969 | msecs_to_jiffies(poweroff_delay_ms)); | |
970 | } | |
971 | ||
972 | /** | |
79fa723b | 973 | * __hw_protection_shutdown - Trigger an emergency system shutdown or reboot |
dfa19b11 | 974 | * |
79fa723b FE |
975 | * @reason: Reason of emergency shutdown or reboot to be printed. |
976 | * @ms_until_forced: Time to wait for orderly shutdown or reboot before | |
977 | * triggering it. Negative value disables the forced | |
978 | * shutdown or reboot. | |
979 | * @shutdown: If true, indicates that a shutdown will happen | |
980 | * after the critical tempeature is reached. | |
981 | * If false, indicates that a reboot will happen | |
982 | * after the critical tempeature is reached. | |
dfa19b11 | 983 | * |
79fa723b FE |
984 | * Initiate an emergency system shutdown or reboot in order to protect |
985 | * hardware from further damage. Usage examples include a thermal protection. | |
986 | * NOTE: The request is ignored if protection shutdown or reboot is already | |
987 | * pending even if the previous request has given a large timeout for forced | |
988 | * shutdown/reboot. | |
dfa19b11 | 989 | */ |
5a0e2410 | 990 | void __hw_protection_shutdown(const char *reason, int ms_until_forced, bool shutdown) |
dfa19b11 MV |
991 | { |
992 | static atomic_t allow_proceed = ATOMIC_INIT(1); | |
993 | ||
994 | pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason); | |
995 | ||
996 | /* Shutdown should be initiated only once. */ | |
997 | if (!atomic_dec_and_test(&allow_proceed)) | |
07a22b61 | 998 | return; |
dfa19b11 MV |
999 | |
1000 | /* | |
1001 | * Queue a backup emergency shutdown in the event of | |
1002 | * orderly_poweroff failure | |
1003 | */ | |
1004 | hw_failure_emergency_poweroff(ms_until_forced); | |
5a0e2410 FE |
1005 | if (shutdown) |
1006 | orderly_poweroff(true); | |
79fa723b FE |
1007 | else |
1008 | orderly_reboot(); | |
dfa19b11 | 1009 | } |
79fa723b | 1010 | EXPORT_SYMBOL_GPL(__hw_protection_shutdown); |
dfa19b11 | 1011 | |
1b3a5d02 RH |
1012 | static int __init reboot_setup(char *str) |
1013 | { | |
1014 | for (;;) { | |
b287a25a AK |
1015 | enum reboot_mode *mode; |
1016 | ||
1b3a5d02 RH |
1017 | /* |
1018 | * Having anything passed on the command line via | |
1019 | * reboot= will cause us to disable DMI checking | |
1020 | * below. | |
1021 | */ | |
1022 | reboot_default = 0; | |
1023 | ||
b287a25a AK |
1024 | if (!strncmp(str, "panic_", 6)) { |
1025 | mode = &panic_reboot_mode; | |
1026 | str += 6; | |
1027 | } else { | |
1028 | mode = &reboot_mode; | |
1029 | } | |
1030 | ||
1b3a5d02 RH |
1031 | switch (*str) { |
1032 | case 'w': | |
b287a25a | 1033 | *mode = REBOOT_WARM; |
1b3a5d02 RH |
1034 | break; |
1035 | ||
1036 | case 'c': | |
b287a25a | 1037 | *mode = REBOOT_COLD; |
1b3a5d02 RH |
1038 | break; |
1039 | ||
1040 | case 'h': | |
b287a25a | 1041 | *mode = REBOOT_HARD; |
1b3a5d02 RH |
1042 | break; |
1043 | ||
1044 | case 's': | |
f9a90501 MC |
1045 | /* |
1046 | * reboot_cpu is s[mp]#### with #### being the processor | |
1047 | * to be used for rebooting. Skip 's' or 'smp' prefix. | |
1048 | */ | |
1049 | str += str[1] == 'm' && str[2] == 'p' ? 3 : 1; | |
1050 | ||
1051 | if (isdigit(str[0])) { | |
1052 | int cpu = simple_strtoul(str, NULL, 0); | |
1053 | ||
1054 | if (cpu >= num_possible_cpus()) { | |
1055 | pr_err("Ignoring the CPU number in reboot= option. " | |
1056 | "CPU %d exceeds possible cpu number %d\n", | |
1057 | cpu, num_possible_cpus()); | |
1058 | break; | |
1059 | } | |
1060 | reboot_cpu = cpu; | |
1061 | } else | |
b287a25a | 1062 | *mode = REBOOT_SOFT; |
1b3a5d02 | 1063 | break; |
8b92c4ff | 1064 | |
1b3a5d02 | 1065 | case 'g': |
b287a25a | 1066 | *mode = REBOOT_GPIO; |
1b3a5d02 RH |
1067 | break; |
1068 | ||
1069 | case 'b': | |
1070 | case 'a': | |
1071 | case 'k': | |
1072 | case 't': | |
1073 | case 'e': | |
1074 | case 'p': | |
1075 | reboot_type = *str; | |
1076 | break; | |
1077 | ||
1078 | case 'f': | |
1079 | reboot_force = 1; | |
1080 | break; | |
1081 | } | |
1082 | ||
1083 | str = strchr(str, ','); | |
1084 | if (str) | |
1085 | str++; | |
1086 | else | |
1087 | break; | |
1088 | } | |
1089 | return 1; | |
1090 | } | |
1091 | __setup("reboot=", reboot_setup); | |
2c622ed0 MC |
1092 | |
1093 | #ifdef CONFIG_SYSFS | |
1094 | ||
1095 | #define REBOOT_COLD_STR "cold" | |
1096 | #define REBOOT_WARM_STR "warm" | |
1097 | #define REBOOT_HARD_STR "hard" | |
1098 | #define REBOOT_SOFT_STR "soft" | |
1099 | #define REBOOT_GPIO_STR "gpio" | |
1100 | #define REBOOT_UNDEFINED_STR "undefined" | |
1101 | ||
1102 | #define BOOT_TRIPLE_STR "triple" | |
1103 | #define BOOT_KBD_STR "kbd" | |
1104 | #define BOOT_BIOS_STR "bios" | |
1105 | #define BOOT_ACPI_STR "acpi" | |
1106 | #define BOOT_EFI_STR "efi" | |
0c5c0179 | 1107 | #define BOOT_PCI_STR "pci" |
2c622ed0 MC |
1108 | |
1109 | static ssize_t mode_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) | |
1110 | { | |
1111 | const char *val; | |
1112 | ||
1113 | switch (reboot_mode) { | |
1114 | case REBOOT_COLD: | |
1115 | val = REBOOT_COLD_STR; | |
1116 | break; | |
1117 | case REBOOT_WARM: | |
1118 | val = REBOOT_WARM_STR; | |
1119 | break; | |
1120 | case REBOOT_HARD: | |
1121 | val = REBOOT_HARD_STR; | |
1122 | break; | |
1123 | case REBOOT_SOFT: | |
1124 | val = REBOOT_SOFT_STR; | |
1125 | break; | |
1126 | case REBOOT_GPIO: | |
1127 | val = REBOOT_GPIO_STR; | |
1128 | break; | |
1129 | default: | |
1130 | val = REBOOT_UNDEFINED_STR; | |
1131 | } | |
1132 | ||
1133 | return sprintf(buf, "%s\n", val); | |
1134 | } | |
1135 | static ssize_t mode_store(struct kobject *kobj, struct kobj_attribute *attr, | |
1136 | const char *buf, size_t count) | |
1137 | { | |
1138 | if (!capable(CAP_SYS_BOOT)) | |
1139 | return -EPERM; | |
1140 | ||
1141 | if (!strncmp(buf, REBOOT_COLD_STR, strlen(REBOOT_COLD_STR))) | |
1142 | reboot_mode = REBOOT_COLD; | |
1143 | else if (!strncmp(buf, REBOOT_WARM_STR, strlen(REBOOT_WARM_STR))) | |
1144 | reboot_mode = REBOOT_WARM; | |
1145 | else if (!strncmp(buf, REBOOT_HARD_STR, strlen(REBOOT_HARD_STR))) | |
1146 | reboot_mode = REBOOT_HARD; | |
1147 | else if (!strncmp(buf, REBOOT_SOFT_STR, strlen(REBOOT_SOFT_STR))) | |
1148 | reboot_mode = REBOOT_SOFT; | |
1149 | else if (!strncmp(buf, REBOOT_GPIO_STR, strlen(REBOOT_GPIO_STR))) | |
1150 | reboot_mode = REBOOT_GPIO; | |
1151 | else | |
1152 | return -EINVAL; | |
1153 | ||
1a9d079f MC |
1154 | reboot_default = 0; |
1155 | ||
2c622ed0 MC |
1156 | return count; |
1157 | } | |
1158 | static struct kobj_attribute reboot_mode_attr = __ATTR_RW(mode); | |
1159 | ||
40247e55 MC |
1160 | #ifdef CONFIG_X86 |
1161 | static ssize_t force_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) | |
1162 | { | |
1163 | return sprintf(buf, "%d\n", reboot_force); | |
1164 | } | |
1165 | static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr, | |
1166 | const char *buf, size_t count) | |
1167 | { | |
1168 | bool res; | |
1169 | ||
1170 | if (!capable(CAP_SYS_BOOT)) | |
1171 | return -EPERM; | |
1172 | ||
1173 | if (kstrtobool(buf, &res)) | |
1174 | return -EINVAL; | |
1175 | ||
1176 | reboot_default = 0; | |
1177 | reboot_force = res; | |
1178 | ||
1179 | return count; | |
1180 | } | |
1181 | static struct kobj_attribute reboot_force_attr = __ATTR_RW(force); | |
1182 | ||
2c622ed0 MC |
1183 | static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
1184 | { | |
1185 | const char *val; | |
1186 | ||
1187 | switch (reboot_type) { | |
1188 | case BOOT_TRIPLE: | |
1189 | val = BOOT_TRIPLE_STR; | |
1190 | break; | |
1191 | case BOOT_KBD: | |
1192 | val = BOOT_KBD_STR; | |
1193 | break; | |
1194 | case BOOT_BIOS: | |
1195 | val = BOOT_BIOS_STR; | |
1196 | break; | |
1197 | case BOOT_ACPI: | |
1198 | val = BOOT_ACPI_STR; | |
1199 | break; | |
1200 | case BOOT_EFI: | |
1201 | val = BOOT_EFI_STR; | |
1202 | break; | |
1203 | case BOOT_CF9_FORCE: | |
0c5c0179 | 1204 | val = BOOT_PCI_STR; |
2c622ed0 MC |
1205 | break; |
1206 | default: | |
1207 | val = REBOOT_UNDEFINED_STR; | |
1208 | } | |
1209 | ||
1210 | return sprintf(buf, "%s\n", val); | |
1211 | } | |
1212 | static ssize_t type_store(struct kobject *kobj, struct kobj_attribute *attr, | |
1213 | const char *buf, size_t count) | |
1214 | { | |
1215 | if (!capable(CAP_SYS_BOOT)) | |
1216 | return -EPERM; | |
1217 | ||
1218 | if (!strncmp(buf, BOOT_TRIPLE_STR, strlen(BOOT_TRIPLE_STR))) | |
1219 | reboot_type = BOOT_TRIPLE; | |
1220 | else if (!strncmp(buf, BOOT_KBD_STR, strlen(BOOT_KBD_STR))) | |
1221 | reboot_type = BOOT_KBD; | |
1222 | else if (!strncmp(buf, BOOT_BIOS_STR, strlen(BOOT_BIOS_STR))) | |
1223 | reboot_type = BOOT_BIOS; | |
1224 | else if (!strncmp(buf, BOOT_ACPI_STR, strlen(BOOT_ACPI_STR))) | |
1225 | reboot_type = BOOT_ACPI; | |
1226 | else if (!strncmp(buf, BOOT_EFI_STR, strlen(BOOT_EFI_STR))) | |
1227 | reboot_type = BOOT_EFI; | |
0c5c0179 | 1228 | else if (!strncmp(buf, BOOT_PCI_STR, strlen(BOOT_PCI_STR))) |
2c622ed0 | 1229 | reboot_type = BOOT_CF9_FORCE; |
2c622ed0 MC |
1230 | else |
1231 | return -EINVAL; | |
1232 | ||
1a9d079f MC |
1233 | reboot_default = 0; |
1234 | ||
2c622ed0 MC |
1235 | return count; |
1236 | } | |
1237 | static struct kobj_attribute reboot_type_attr = __ATTR_RW(type); | |
40247e55 | 1238 | #endif |
2c622ed0 | 1239 | |
40247e55 | 1240 | #ifdef CONFIG_SMP |
2c622ed0 MC |
1241 | static ssize_t cpu_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
1242 | { | |
1243 | return sprintf(buf, "%d\n", reboot_cpu); | |
1244 | } | |
1245 | static ssize_t cpu_store(struct kobject *kobj, struct kobj_attribute *attr, | |
1246 | const char *buf, size_t count) | |
1247 | { | |
1248 | unsigned int cpunum; | |
1249 | int rc; | |
1250 | ||
1251 | if (!capable(CAP_SYS_BOOT)) | |
1252 | return -EPERM; | |
1253 | ||
1254 | rc = kstrtouint(buf, 0, &cpunum); | |
1255 | ||
1256 | if (rc) | |
1257 | return rc; | |
1258 | ||
1259 | if (cpunum >= num_possible_cpus()) | |
1260 | return -ERANGE; | |
1261 | ||
1a9d079f | 1262 | reboot_default = 0; |
2c622ed0 MC |
1263 | reboot_cpu = cpunum; |
1264 | ||
1265 | return count; | |
1266 | } | |
1267 | static struct kobj_attribute reboot_cpu_attr = __ATTR_RW(cpu); | |
40247e55 | 1268 | #endif |
2c622ed0 MC |
1269 | |
1270 | static struct attribute *reboot_attrs[] = { | |
1271 | &reboot_mode_attr.attr, | |
40247e55 MC |
1272 | #ifdef CONFIG_X86 |
1273 | &reboot_force_attr.attr, | |
2c622ed0 | 1274 | &reboot_type_attr.attr, |
40247e55 MC |
1275 | #endif |
1276 | #ifdef CONFIG_SMP | |
2c622ed0 | 1277 | &reboot_cpu_attr.attr, |
40247e55 | 1278 | #endif |
2c622ed0 MC |
1279 | NULL, |
1280 | }; | |
1281 | ||
764aaf44 Y |
1282 | #ifdef CONFIG_SYSCTL |
1283 | static struct ctl_table kern_reboot_table[] = { | |
1284 | { | |
1285 | .procname = "poweroff_cmd", | |
1286 | .data = &poweroff_cmd, | |
1287 | .maxlen = POWEROFF_CMD_PATH_LEN, | |
1288 | .mode = 0644, | |
1289 | .proc_handler = proc_dostring, | |
1290 | }, | |
1291 | { | |
1292 | .procname = "ctrl-alt-del", | |
1293 | .data = &C_A_D, | |
1294 | .maxlen = sizeof(int), | |
1295 | .mode = 0644, | |
1296 | .proc_handler = proc_dointvec, | |
1297 | }, | |
1298 | { } | |
1299 | }; | |
1300 | ||
1301 | static void __init kernel_reboot_sysctls_init(void) | |
1302 | { | |
1303 | register_sysctl_init("kernel", kern_reboot_table); | |
1304 | } | |
1305 | #else | |
1306 | #define kernel_reboot_sysctls_init() do { } while (0) | |
1307 | #endif /* CONFIG_SYSCTL */ | |
1308 | ||
2c622ed0 MC |
1309 | static const struct attribute_group reboot_attr_group = { |
1310 | .attrs = reboot_attrs, | |
1311 | }; | |
1312 | ||
1313 | static int __init reboot_ksysfs_init(void) | |
1314 | { | |
1315 | struct kobject *reboot_kobj; | |
1316 | int ret; | |
1317 | ||
1318 | reboot_kobj = kobject_create_and_add("reboot", kernel_kobj); | |
1319 | if (!reboot_kobj) | |
1320 | return -ENOMEM; | |
1321 | ||
1322 | ret = sysfs_create_group(reboot_kobj, &reboot_attr_group); | |
1323 | if (ret) { | |
1324 | kobject_put(reboot_kobj); | |
1325 | return ret; | |
1326 | } | |
1327 | ||
06d17766 | 1328 | kernel_reboot_sysctls_init(); |
1329 | ||
2c622ed0 MC |
1330 | return 0; |
1331 | } | |
1332 | late_initcall(reboot_ksysfs_init); | |
1333 | ||
1334 | #endif |