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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 | ||
26 | int C_A_D = 1; | |
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 | ||
15d94b82 RH |
51 | /* |
52 | * If set, this is used for preparing the system to power off. | |
53 | */ | |
54 | ||
55 | void (*pm_power_off_prepare)(void); | |
74f008f2 | 56 | EXPORT_SYMBOL_GPL(pm_power_off_prepare); |
15d94b82 RH |
57 | |
58 | /** | |
59 | * emergency_restart - reboot the system | |
60 | * | |
61 | * Without shutting down any hardware or taking any locks | |
62 | * reboot the system. This is called when we know we are in | |
63 | * trouble so this is our best effort to reboot. This is | |
64 | * safe to call in interrupt context. | |
65 | */ | |
66 | void emergency_restart(void) | |
67 | { | |
68 | kmsg_dump(KMSG_DUMP_EMERG); | |
69 | machine_emergency_restart(); | |
70 | } | |
71 | EXPORT_SYMBOL_GPL(emergency_restart); | |
72 | ||
73 | void kernel_restart_prepare(char *cmd) | |
74 | { | |
75 | blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); | |
76 | system_state = SYSTEM_RESTART; | |
77 | usermodehelper_disable(); | |
78 | device_shutdown(); | |
79 | } | |
80 | ||
81 | /** | |
82 | * register_reboot_notifier - Register function to be called at reboot time | |
83 | * @nb: Info about notifier function to be called | |
84 | * | |
85 | * Registers a function with the list of functions | |
86 | * to be called at reboot time. | |
87 | * | |
88 | * Currently always returns zero, as blocking_notifier_chain_register() | |
89 | * always returns zero. | |
90 | */ | |
91 | int register_reboot_notifier(struct notifier_block *nb) | |
92 | { | |
93 | return blocking_notifier_chain_register(&reboot_notifier_list, nb); | |
94 | } | |
95 | EXPORT_SYMBOL(register_reboot_notifier); | |
96 | ||
97 | /** | |
98 | * unregister_reboot_notifier - Unregister previously registered reboot notifier | |
99 | * @nb: Hook to be unregistered | |
100 | * | |
101 | * Unregisters a previously registered reboot | |
102 | * notifier function. | |
103 | * | |
104 | * Returns zero on success, or %-ENOENT on failure. | |
105 | */ | |
106 | int unregister_reboot_notifier(struct notifier_block *nb) | |
107 | { | |
108 | return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | |
109 | } | |
110 | EXPORT_SYMBOL(unregister_reboot_notifier); | |
111 | ||
2d8364ba AS |
112 | static void devm_unregister_reboot_notifier(struct device *dev, void *res) |
113 | { | |
114 | WARN_ON(unregister_reboot_notifier(*(struct notifier_block **)res)); | |
115 | } | |
116 | ||
117 | int devm_register_reboot_notifier(struct device *dev, struct notifier_block *nb) | |
118 | { | |
119 | struct notifier_block **rcnb; | |
120 | int ret; | |
121 | ||
122 | rcnb = devres_alloc(devm_unregister_reboot_notifier, | |
123 | sizeof(*rcnb), GFP_KERNEL); | |
124 | if (!rcnb) | |
125 | return -ENOMEM; | |
126 | ||
127 | ret = register_reboot_notifier(nb); | |
128 | if (!ret) { | |
129 | *rcnb = nb; | |
130 | devres_add(dev, rcnb); | |
131 | } else { | |
132 | devres_free(rcnb); | |
133 | } | |
134 | ||
135 | return ret; | |
136 | } | |
137 | EXPORT_SYMBOL(devm_register_reboot_notifier); | |
138 | ||
b63adb97 GR |
139 | /* |
140 | * Notifier list for kernel code which wants to be called | |
141 | * to restart the system. | |
142 | */ | |
143 | static ATOMIC_NOTIFIER_HEAD(restart_handler_list); | |
144 | ||
145 | /** | |
146 | * register_restart_handler - Register function to be called to reset | |
147 | * the system | |
148 | * @nb: Info about handler function to be called | |
149 | * @nb->priority: Handler priority. Handlers should follow the | |
150 | * following guidelines for setting priorities. | |
151 | * 0: Restart handler of last resort, | |
152 | * with limited restart capabilities | |
153 | * 128: Default restart handler; use if no other | |
154 | * restart handler is expected to be available, | |
155 | * and/or if restart functionality is | |
156 | * sufficient to restart the entire system | |
157 | * 255: Highest priority restart handler, will | |
158 | * preempt all other restart handlers | |
159 | * | |
160 | * Registers a function with code to be called to restart the | |
161 | * system. | |
162 | * | |
163 | * Registered functions will be called from machine_restart as last | |
164 | * step of the restart sequence (if the architecture specific | |
165 | * machine_restart function calls do_kernel_restart - see below | |
166 | * for details). | |
167 | * Registered functions are expected to restart the system immediately. | |
168 | * If more than one function is registered, the restart handler priority | |
169 | * selects which function will be called first. | |
170 | * | |
171 | * Restart handlers are expected to be registered from non-architecture | |
172 | * code, typically from drivers. A typical use case would be a system | |
173 | * where restart functionality is provided through a watchdog. Multiple | |
174 | * restart handlers may exist; for example, one restart handler might | |
175 | * restart the entire system, while another only restarts the CPU. | |
176 | * In such cases, the restart handler which only restarts part of the | |
177 | * hardware is expected to register with low priority to ensure that | |
178 | * it only runs if no other means to restart the system is available. | |
179 | * | |
180 | * Currently always returns zero, as atomic_notifier_chain_register() | |
181 | * always returns zero. | |
182 | */ | |
183 | int register_restart_handler(struct notifier_block *nb) | |
184 | { | |
185 | return atomic_notifier_chain_register(&restart_handler_list, nb); | |
186 | } | |
187 | EXPORT_SYMBOL(register_restart_handler); | |
188 | ||
189 | /** | |
190 | * unregister_restart_handler - Unregister previously registered | |
191 | * restart handler | |
192 | * @nb: Hook to be unregistered | |
193 | * | |
194 | * Unregisters a previously registered restart handler function. | |
195 | * | |
196 | * Returns zero on success, or %-ENOENT on failure. | |
197 | */ | |
198 | int unregister_restart_handler(struct notifier_block *nb) | |
199 | { | |
200 | return atomic_notifier_chain_unregister(&restart_handler_list, nb); | |
201 | } | |
202 | EXPORT_SYMBOL(unregister_restart_handler); | |
203 | ||
204 | /** | |
205 | * do_kernel_restart - Execute kernel restart handler call chain | |
206 | * | |
207 | * Calls functions registered with register_restart_handler. | |
208 | * | |
209 | * Expected to be called from machine_restart as last step of the restart | |
210 | * sequence. | |
211 | * | |
212 | * Restarts the system immediately if a restart handler function has been | |
213 | * registered. Otherwise does nothing. | |
214 | */ | |
215 | void do_kernel_restart(char *cmd) | |
216 | { | |
217 | atomic_notifier_call_chain(&restart_handler_list, reboot_mode, cmd); | |
218 | } | |
219 | ||
c97102ba | 220 | void migrate_to_reboot_cpu(void) |
15d94b82 RH |
221 | { |
222 | /* The boot cpu is always logical cpu 0 */ | |
1b3a5d02 | 223 | int cpu = reboot_cpu; |
15d94b82 RH |
224 | |
225 | cpu_hotplug_disable(); | |
226 | ||
227 | /* Make certain the cpu I'm about to reboot on is online */ | |
228 | if (!cpu_online(cpu)) | |
229 | cpu = cpumask_first(cpu_online_mask); | |
230 | ||
231 | /* Prevent races with other tasks migrating this task */ | |
232 | current->flags |= PF_NO_SETAFFINITY; | |
233 | ||
234 | /* Make certain I only run on the appropriate processor */ | |
235 | set_cpus_allowed_ptr(current, cpumask_of(cpu)); | |
236 | } | |
237 | ||
238 | /** | |
239 | * kernel_restart - reboot the system | |
240 | * @cmd: pointer to buffer containing command to execute for restart | |
241 | * or %NULL | |
242 | * | |
243 | * Shutdown everything and perform a clean reboot. | |
244 | * This is not safe to call in interrupt context. | |
245 | */ | |
246 | void kernel_restart(char *cmd) | |
247 | { | |
248 | kernel_restart_prepare(cmd); | |
249 | migrate_to_reboot_cpu(); | |
250 | syscore_shutdown(); | |
251 | if (!cmd) | |
972ee83d | 252 | pr_emerg("Restarting system\n"); |
15d94b82 | 253 | else |
972ee83d | 254 | pr_emerg("Restarting system with command '%s'\n", cmd); |
6d3cf962 | 255 | kmsg_dump(KMSG_DUMP_SHUTDOWN); |
15d94b82 RH |
256 | machine_restart(cmd); |
257 | } | |
258 | EXPORT_SYMBOL_GPL(kernel_restart); | |
259 | ||
260 | static void kernel_shutdown_prepare(enum system_states state) | |
261 | { | |
262 | blocking_notifier_call_chain(&reboot_notifier_list, | |
972ee83d | 263 | (state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL); |
15d94b82 RH |
264 | system_state = state; |
265 | usermodehelper_disable(); | |
266 | device_shutdown(); | |
267 | } | |
268 | /** | |
269 | * kernel_halt - halt the system | |
270 | * | |
271 | * Shutdown everything and perform a clean system halt. | |
272 | */ | |
273 | void kernel_halt(void) | |
274 | { | |
275 | kernel_shutdown_prepare(SYSTEM_HALT); | |
276 | migrate_to_reboot_cpu(); | |
277 | syscore_shutdown(); | |
972ee83d | 278 | pr_emerg("System halted\n"); |
6d3cf962 | 279 | kmsg_dump(KMSG_DUMP_SHUTDOWN); |
15d94b82 RH |
280 | machine_halt(); |
281 | } | |
15d94b82 RH |
282 | EXPORT_SYMBOL_GPL(kernel_halt); |
283 | ||
284 | /** | |
285 | * kernel_power_off - power_off the system | |
286 | * | |
287 | * Shutdown everything and perform a clean system power_off. | |
288 | */ | |
289 | void kernel_power_off(void) | |
290 | { | |
291 | kernel_shutdown_prepare(SYSTEM_POWER_OFF); | |
292 | if (pm_power_off_prepare) | |
293 | pm_power_off_prepare(); | |
294 | migrate_to_reboot_cpu(); | |
295 | syscore_shutdown(); | |
972ee83d | 296 | pr_emerg("Power down\n"); |
6d3cf962 | 297 | kmsg_dump(KMSG_DUMP_SHUTDOWN); |
15d94b82 RH |
298 | machine_power_off(); |
299 | } | |
300 | EXPORT_SYMBOL_GPL(kernel_power_off); | |
301 | ||
55f2503c | 302 | DEFINE_MUTEX(system_transition_mutex); |
15d94b82 RH |
303 | |
304 | /* | |
305 | * Reboot system call: for obvious reasons only root may call it, | |
306 | * and even root needs to set up some magic numbers in the registers | |
307 | * so that some mistake won't make this reboot the whole machine. | |
308 | * You can also set the meaning of the ctrl-alt-del-key here. | |
309 | * | |
310 | * reboot doesn't sync: do that yourself before calling this. | |
311 | */ | |
312 | SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, | |
313 | void __user *, arg) | |
314 | { | |
315 | struct pid_namespace *pid_ns = task_active_pid_ns(current); | |
316 | char buffer[256]; | |
317 | int ret = 0; | |
318 | ||
319 | /* We only trust the superuser with rebooting the system. */ | |
320 | if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT)) | |
321 | return -EPERM; | |
322 | ||
323 | /* For safety, we require "magic" arguments. */ | |
324 | if (magic1 != LINUX_REBOOT_MAGIC1 || | |
972ee83d RH |
325 | (magic2 != LINUX_REBOOT_MAGIC2 && |
326 | magic2 != LINUX_REBOOT_MAGIC2A && | |
15d94b82 | 327 | magic2 != LINUX_REBOOT_MAGIC2B && |
972ee83d | 328 | magic2 != LINUX_REBOOT_MAGIC2C)) |
15d94b82 RH |
329 | return -EINVAL; |
330 | ||
331 | /* | |
332 | * If pid namespaces are enabled and the current task is in a child | |
333 | * pid_namespace, the command is handled by reboot_pid_ns() which will | |
334 | * call do_exit(). | |
335 | */ | |
336 | ret = reboot_pid_ns(pid_ns, cmd); | |
337 | if (ret) | |
338 | return ret; | |
339 | ||
340 | /* Instead of trying to make the power_off code look like | |
341 | * halt when pm_power_off is not set do it the easy way. | |
342 | */ | |
343 | if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) | |
344 | cmd = LINUX_REBOOT_CMD_HALT; | |
345 | ||
55f2503c | 346 | mutex_lock(&system_transition_mutex); |
15d94b82 RH |
347 | switch (cmd) { |
348 | case LINUX_REBOOT_CMD_RESTART: | |
349 | kernel_restart(NULL); | |
350 | break; | |
351 | ||
352 | case LINUX_REBOOT_CMD_CAD_ON: | |
353 | C_A_D = 1; | |
354 | break; | |
355 | ||
356 | case LINUX_REBOOT_CMD_CAD_OFF: | |
357 | C_A_D = 0; | |
358 | break; | |
359 | ||
360 | case LINUX_REBOOT_CMD_HALT: | |
361 | kernel_halt(); | |
362 | do_exit(0); | |
15d94b82 RH |
363 | |
364 | case LINUX_REBOOT_CMD_POWER_OFF: | |
365 | kernel_power_off(); | |
366 | do_exit(0); | |
367 | break; | |
368 | ||
369 | case LINUX_REBOOT_CMD_RESTART2: | |
972ee83d RH |
370 | ret = strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1); |
371 | if (ret < 0) { | |
15d94b82 RH |
372 | ret = -EFAULT; |
373 | break; | |
374 | } | |
375 | buffer[sizeof(buffer) - 1] = '\0'; | |
376 | ||
377 | kernel_restart(buffer); | |
378 | break; | |
379 | ||
2965faa5 | 380 | #ifdef CONFIG_KEXEC_CORE |
15d94b82 RH |
381 | case LINUX_REBOOT_CMD_KEXEC: |
382 | ret = kernel_kexec(); | |
383 | break; | |
384 | #endif | |
385 | ||
386 | #ifdef CONFIG_HIBERNATION | |
387 | case LINUX_REBOOT_CMD_SW_SUSPEND: | |
388 | ret = hibernate(); | |
389 | break; | |
390 | #endif | |
391 | ||
392 | default: | |
393 | ret = -EINVAL; | |
394 | break; | |
395 | } | |
55f2503c | 396 | mutex_unlock(&system_transition_mutex); |
15d94b82 RH |
397 | return ret; |
398 | } | |
399 | ||
400 | static void deferred_cad(struct work_struct *dummy) | |
401 | { | |
402 | kernel_restart(NULL); | |
403 | } | |
404 | ||
405 | /* | |
406 | * This function gets called by ctrl-alt-del - ie the keyboard interrupt. | |
407 | * As it's called within an interrupt, it may NOT sync: the only choice | |
408 | * is whether to reboot at once, or just ignore the ctrl-alt-del. | |
409 | */ | |
410 | void ctrl_alt_del(void) | |
411 | { | |
412 | static DECLARE_WORK(cad_work, deferred_cad); | |
413 | ||
414 | if (C_A_D) | |
415 | schedule_work(&cad_work); | |
416 | else | |
417 | kill_cad_pid(SIGINT, 1); | |
418 | } | |
419 | ||
420 | char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | |
7a54f46b | 421 | static const char reboot_cmd[] = "/sbin/reboot"; |
15d94b82 | 422 | |
7a54f46b | 423 | static int run_cmd(const char *cmd) |
15d94b82 RH |
424 | { |
425 | char **argv; | |
426 | static char *envp[] = { | |
427 | "HOME=/", | |
428 | "PATH=/sbin:/bin:/usr/sbin:/usr/bin", | |
429 | NULL | |
430 | }; | |
431 | int ret; | |
7a54f46b | 432 | argv = argv_split(GFP_KERNEL, cmd, NULL); |
15d94b82 RH |
433 | if (argv) { |
434 | ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); | |
435 | argv_free(argv); | |
436 | } else { | |
15d94b82 RH |
437 | ret = -ENOMEM; |
438 | } | |
439 | ||
7a54f46b JS |
440 | return ret; |
441 | } | |
442 | ||
443 | static int __orderly_reboot(void) | |
444 | { | |
445 | int ret; | |
446 | ||
447 | ret = run_cmd(reboot_cmd); | |
448 | ||
449 | if (ret) { | |
2bb2b7b5 | 450 | printk_prefer_direct_enter(); |
7a54f46b JS |
451 | pr_warn("Failed to start orderly reboot: forcing the issue\n"); |
452 | emergency_sync(); | |
453 | kernel_restart(NULL); | |
2bb2b7b5 | 454 | printk_prefer_direct_exit(); |
7a54f46b JS |
455 | } |
456 | ||
457 | return ret; | |
458 | } | |
459 | ||
460 | static int __orderly_poweroff(bool force) | |
461 | { | |
462 | int ret; | |
463 | ||
464 | ret = run_cmd(poweroff_cmd); | |
465 | ||
15d94b82 | 466 | if (ret && force) { |
2bb2b7b5 | 467 | printk_prefer_direct_enter(); |
972ee83d | 468 | pr_warn("Failed to start orderly shutdown: forcing the issue\n"); |
7a54f46b | 469 | |
15d94b82 RH |
470 | /* |
471 | * I guess this should try to kick off some daemon to sync and | |
472 | * poweroff asap. Or not even bother syncing if we're doing an | |
473 | * emergency shutdown? | |
474 | */ | |
475 | emergency_sync(); | |
476 | kernel_power_off(); | |
2bb2b7b5 | 477 | printk_prefer_direct_exit(); |
15d94b82 RH |
478 | } |
479 | ||
480 | return ret; | |
481 | } | |
482 | ||
483 | static bool poweroff_force; | |
484 | ||
485 | static void poweroff_work_func(struct work_struct *work) | |
486 | { | |
487 | __orderly_poweroff(poweroff_force); | |
488 | } | |
489 | ||
490 | static DECLARE_WORK(poweroff_work, poweroff_work_func); | |
491 | ||
492 | /** | |
493 | * orderly_poweroff - Trigger an orderly system poweroff | |
494 | * @force: force poweroff if command execution fails | |
495 | * | |
496 | * This may be called from any context to trigger a system shutdown. | |
497 | * If the orderly shutdown fails, it will force an immediate shutdown. | |
498 | */ | |
7a54f46b | 499 | void orderly_poweroff(bool force) |
15d94b82 RH |
500 | { |
501 | if (force) /* do not override the pending "true" */ | |
502 | poweroff_force = true; | |
503 | schedule_work(&poweroff_work); | |
15d94b82 RH |
504 | } |
505 | EXPORT_SYMBOL_GPL(orderly_poweroff); | |
1b3a5d02 | 506 | |
7a54f46b JS |
507 | static void reboot_work_func(struct work_struct *work) |
508 | { | |
509 | __orderly_reboot(); | |
510 | } | |
511 | ||
512 | static DECLARE_WORK(reboot_work, reboot_work_func); | |
513 | ||
514 | /** | |
515 | * orderly_reboot - Trigger an orderly system reboot | |
516 | * | |
517 | * This may be called from any context to trigger a system reboot. | |
518 | * If the orderly reboot fails, it will force an immediate reboot. | |
519 | */ | |
520 | void orderly_reboot(void) | |
521 | { | |
522 | schedule_work(&reboot_work); | |
523 | } | |
524 | EXPORT_SYMBOL_GPL(orderly_reboot); | |
525 | ||
dfa19b11 MV |
526 | /** |
527 | * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay | |
528 | * @work: work_struct associated with the emergency poweroff function | |
529 | * | |
530 | * This function is called in very critical situations to force | |
531 | * a kernel poweroff after a configurable timeout value. | |
532 | */ | |
533 | static void hw_failure_emergency_poweroff_func(struct work_struct *work) | |
534 | { | |
2bb2b7b5 JO |
535 | printk_prefer_direct_enter(); |
536 | ||
dfa19b11 MV |
537 | /* |
538 | * We have reached here after the emergency shutdown waiting period has | |
539 | * expired. This means orderly_poweroff has not been able to shut off | |
540 | * the system for some reason. | |
541 | * | |
542 | * Try to shut down the system immediately using kernel_power_off | |
543 | * if populated | |
544 | */ | |
545 | pr_emerg("Hardware protection timed-out. Trying forced poweroff\n"); | |
546 | kernel_power_off(); | |
547 | ||
548 | /* | |
549 | * Worst of the worst case trigger emergency restart | |
550 | */ | |
551 | pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n"); | |
552 | emergency_restart(); | |
2bb2b7b5 JO |
553 | |
554 | printk_prefer_direct_exit(); | |
dfa19b11 MV |
555 | } |
556 | ||
557 | static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, | |
558 | hw_failure_emergency_poweroff_func); | |
559 | ||
560 | /** | |
561 | * hw_failure_emergency_poweroff - Trigger an emergency system poweroff | |
562 | * | |
563 | * This may be called from any critical situation to trigger a system shutdown | |
564 | * after a given period of time. If time is negative this is not scheduled. | |
565 | */ | |
566 | static void hw_failure_emergency_poweroff(int poweroff_delay_ms) | |
567 | { | |
568 | if (poweroff_delay_ms <= 0) | |
569 | return; | |
570 | schedule_delayed_work(&hw_failure_emergency_poweroff_work, | |
571 | msecs_to_jiffies(poweroff_delay_ms)); | |
572 | } | |
573 | ||
574 | /** | |
575 | * hw_protection_shutdown - Trigger an emergency system poweroff | |
576 | * | |
577 | * @reason: Reason of emergency shutdown to be printed. | |
578 | * @ms_until_forced: Time to wait for orderly shutdown before tiggering a | |
579 | * forced shudown. Negative value disables the forced | |
580 | * shutdown. | |
581 | * | |
582 | * Initiate an emergency system shutdown in order to protect hardware from | |
583 | * further damage. Usage examples include a thermal protection or a voltage or | |
584 | * current regulator failures. | |
585 | * NOTE: The request is ignored if protection shutdown is already pending even | |
586 | * if the previous request has given a large timeout for forced shutdown. | |
587 | * Can be called from any context. | |
588 | */ | |
589 | void hw_protection_shutdown(const char *reason, int ms_until_forced) | |
590 | { | |
591 | static atomic_t allow_proceed = ATOMIC_INIT(1); | |
592 | ||
2bb2b7b5 JO |
593 | printk_prefer_direct_enter(); |
594 | ||
dfa19b11 MV |
595 | pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason); |
596 | ||
597 | /* Shutdown should be initiated only once. */ | |
598 | if (!atomic_dec_and_test(&allow_proceed)) | |
2bb2b7b5 | 599 | goto out; |
dfa19b11 MV |
600 | |
601 | /* | |
602 | * Queue a backup emergency shutdown in the event of | |
603 | * orderly_poweroff failure | |
604 | */ | |
605 | hw_failure_emergency_poweroff(ms_until_forced); | |
606 | orderly_poweroff(true); | |
2bb2b7b5 JO |
607 | out: |
608 | printk_prefer_direct_exit(); | |
dfa19b11 MV |
609 | } |
610 | EXPORT_SYMBOL_GPL(hw_protection_shutdown); | |
611 | ||
1b3a5d02 RH |
612 | static int __init reboot_setup(char *str) |
613 | { | |
614 | for (;;) { | |
b287a25a AK |
615 | enum reboot_mode *mode; |
616 | ||
1b3a5d02 RH |
617 | /* |
618 | * Having anything passed on the command line via | |
619 | * reboot= will cause us to disable DMI checking | |
620 | * below. | |
621 | */ | |
622 | reboot_default = 0; | |
623 | ||
b287a25a AK |
624 | if (!strncmp(str, "panic_", 6)) { |
625 | mode = &panic_reboot_mode; | |
626 | str += 6; | |
627 | } else { | |
628 | mode = &reboot_mode; | |
629 | } | |
630 | ||
1b3a5d02 RH |
631 | switch (*str) { |
632 | case 'w': | |
b287a25a | 633 | *mode = REBOOT_WARM; |
1b3a5d02 RH |
634 | break; |
635 | ||
636 | case 'c': | |
b287a25a | 637 | *mode = REBOOT_COLD; |
1b3a5d02 RH |
638 | break; |
639 | ||
640 | case 'h': | |
b287a25a | 641 | *mode = REBOOT_HARD; |
1b3a5d02 RH |
642 | break; |
643 | ||
644 | case 's': | |
f9a90501 MC |
645 | /* |
646 | * reboot_cpu is s[mp]#### with #### being the processor | |
647 | * to be used for rebooting. Skip 's' or 'smp' prefix. | |
648 | */ | |
649 | str += str[1] == 'm' && str[2] == 'p' ? 3 : 1; | |
650 | ||
651 | if (isdigit(str[0])) { | |
652 | int cpu = simple_strtoul(str, NULL, 0); | |
653 | ||
654 | if (cpu >= num_possible_cpus()) { | |
655 | pr_err("Ignoring the CPU number in reboot= option. " | |
656 | "CPU %d exceeds possible cpu number %d\n", | |
657 | cpu, num_possible_cpus()); | |
658 | break; | |
659 | } | |
660 | reboot_cpu = cpu; | |
661 | } else | |
b287a25a | 662 | *mode = REBOOT_SOFT; |
1b3a5d02 | 663 | break; |
8b92c4ff | 664 | |
1b3a5d02 | 665 | case 'g': |
b287a25a | 666 | *mode = REBOOT_GPIO; |
1b3a5d02 RH |
667 | break; |
668 | ||
669 | case 'b': | |
670 | case 'a': | |
671 | case 'k': | |
672 | case 't': | |
673 | case 'e': | |
674 | case 'p': | |
675 | reboot_type = *str; | |
676 | break; | |
677 | ||
678 | case 'f': | |
679 | reboot_force = 1; | |
680 | break; | |
681 | } | |
682 | ||
683 | str = strchr(str, ','); | |
684 | if (str) | |
685 | str++; | |
686 | else | |
687 | break; | |
688 | } | |
689 | return 1; | |
690 | } | |
691 | __setup("reboot=", reboot_setup); | |
2c622ed0 MC |
692 | |
693 | #ifdef CONFIG_SYSFS | |
694 | ||
695 | #define REBOOT_COLD_STR "cold" | |
696 | #define REBOOT_WARM_STR "warm" | |
697 | #define REBOOT_HARD_STR "hard" | |
698 | #define REBOOT_SOFT_STR "soft" | |
699 | #define REBOOT_GPIO_STR "gpio" | |
700 | #define REBOOT_UNDEFINED_STR "undefined" | |
701 | ||
702 | #define BOOT_TRIPLE_STR "triple" | |
703 | #define BOOT_KBD_STR "kbd" | |
704 | #define BOOT_BIOS_STR "bios" | |
705 | #define BOOT_ACPI_STR "acpi" | |
706 | #define BOOT_EFI_STR "efi" | |
0c5c0179 | 707 | #define BOOT_PCI_STR "pci" |
2c622ed0 MC |
708 | |
709 | static ssize_t mode_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) | |
710 | { | |
711 | const char *val; | |
712 | ||
713 | switch (reboot_mode) { | |
714 | case REBOOT_COLD: | |
715 | val = REBOOT_COLD_STR; | |
716 | break; | |
717 | case REBOOT_WARM: | |
718 | val = REBOOT_WARM_STR; | |
719 | break; | |
720 | case REBOOT_HARD: | |
721 | val = REBOOT_HARD_STR; | |
722 | break; | |
723 | case REBOOT_SOFT: | |
724 | val = REBOOT_SOFT_STR; | |
725 | break; | |
726 | case REBOOT_GPIO: | |
727 | val = REBOOT_GPIO_STR; | |
728 | break; | |
729 | default: | |
730 | val = REBOOT_UNDEFINED_STR; | |
731 | } | |
732 | ||
733 | return sprintf(buf, "%s\n", val); | |
734 | } | |
735 | static ssize_t mode_store(struct kobject *kobj, struct kobj_attribute *attr, | |
736 | const char *buf, size_t count) | |
737 | { | |
738 | if (!capable(CAP_SYS_BOOT)) | |
739 | return -EPERM; | |
740 | ||
741 | if (!strncmp(buf, REBOOT_COLD_STR, strlen(REBOOT_COLD_STR))) | |
742 | reboot_mode = REBOOT_COLD; | |
743 | else if (!strncmp(buf, REBOOT_WARM_STR, strlen(REBOOT_WARM_STR))) | |
744 | reboot_mode = REBOOT_WARM; | |
745 | else if (!strncmp(buf, REBOOT_HARD_STR, strlen(REBOOT_HARD_STR))) | |
746 | reboot_mode = REBOOT_HARD; | |
747 | else if (!strncmp(buf, REBOOT_SOFT_STR, strlen(REBOOT_SOFT_STR))) | |
748 | reboot_mode = REBOOT_SOFT; | |
749 | else if (!strncmp(buf, REBOOT_GPIO_STR, strlen(REBOOT_GPIO_STR))) | |
750 | reboot_mode = REBOOT_GPIO; | |
751 | else | |
752 | return -EINVAL; | |
753 | ||
1a9d079f MC |
754 | reboot_default = 0; |
755 | ||
2c622ed0 MC |
756 | return count; |
757 | } | |
758 | static struct kobj_attribute reboot_mode_attr = __ATTR_RW(mode); | |
759 | ||
40247e55 MC |
760 | #ifdef CONFIG_X86 |
761 | static ssize_t force_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) | |
762 | { | |
763 | return sprintf(buf, "%d\n", reboot_force); | |
764 | } | |
765 | static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr, | |
766 | const char *buf, size_t count) | |
767 | { | |
768 | bool res; | |
769 | ||
770 | if (!capable(CAP_SYS_BOOT)) | |
771 | return -EPERM; | |
772 | ||
773 | if (kstrtobool(buf, &res)) | |
774 | return -EINVAL; | |
775 | ||
776 | reboot_default = 0; | |
777 | reboot_force = res; | |
778 | ||
779 | return count; | |
780 | } | |
781 | static struct kobj_attribute reboot_force_attr = __ATTR_RW(force); | |
782 | ||
2c622ed0 MC |
783 | static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
784 | { | |
785 | const char *val; | |
786 | ||
787 | switch (reboot_type) { | |
788 | case BOOT_TRIPLE: | |
789 | val = BOOT_TRIPLE_STR; | |
790 | break; | |
791 | case BOOT_KBD: | |
792 | val = BOOT_KBD_STR; | |
793 | break; | |
794 | case BOOT_BIOS: | |
795 | val = BOOT_BIOS_STR; | |
796 | break; | |
797 | case BOOT_ACPI: | |
798 | val = BOOT_ACPI_STR; | |
799 | break; | |
800 | case BOOT_EFI: | |
801 | val = BOOT_EFI_STR; | |
802 | break; | |
803 | case BOOT_CF9_FORCE: | |
0c5c0179 | 804 | val = BOOT_PCI_STR; |
2c622ed0 MC |
805 | break; |
806 | default: | |
807 | val = REBOOT_UNDEFINED_STR; | |
808 | } | |
809 | ||
810 | return sprintf(buf, "%s\n", val); | |
811 | } | |
812 | static ssize_t type_store(struct kobject *kobj, struct kobj_attribute *attr, | |
813 | const char *buf, size_t count) | |
814 | { | |
815 | if (!capable(CAP_SYS_BOOT)) | |
816 | return -EPERM; | |
817 | ||
818 | if (!strncmp(buf, BOOT_TRIPLE_STR, strlen(BOOT_TRIPLE_STR))) | |
819 | reboot_type = BOOT_TRIPLE; | |
820 | else if (!strncmp(buf, BOOT_KBD_STR, strlen(BOOT_KBD_STR))) | |
821 | reboot_type = BOOT_KBD; | |
822 | else if (!strncmp(buf, BOOT_BIOS_STR, strlen(BOOT_BIOS_STR))) | |
823 | reboot_type = BOOT_BIOS; | |
824 | else if (!strncmp(buf, BOOT_ACPI_STR, strlen(BOOT_ACPI_STR))) | |
825 | reboot_type = BOOT_ACPI; | |
826 | else if (!strncmp(buf, BOOT_EFI_STR, strlen(BOOT_EFI_STR))) | |
827 | reboot_type = BOOT_EFI; | |
0c5c0179 | 828 | else if (!strncmp(buf, BOOT_PCI_STR, strlen(BOOT_PCI_STR))) |
2c622ed0 | 829 | reboot_type = BOOT_CF9_FORCE; |
2c622ed0 MC |
830 | else |
831 | return -EINVAL; | |
832 | ||
1a9d079f MC |
833 | reboot_default = 0; |
834 | ||
2c622ed0 MC |
835 | return count; |
836 | } | |
837 | static struct kobj_attribute reboot_type_attr = __ATTR_RW(type); | |
40247e55 | 838 | #endif |
2c622ed0 | 839 | |
40247e55 | 840 | #ifdef CONFIG_SMP |
2c622ed0 MC |
841 | static ssize_t cpu_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
842 | { | |
843 | return sprintf(buf, "%d\n", reboot_cpu); | |
844 | } | |
845 | static ssize_t cpu_store(struct kobject *kobj, struct kobj_attribute *attr, | |
846 | const char *buf, size_t count) | |
847 | { | |
848 | unsigned int cpunum; | |
849 | int rc; | |
850 | ||
851 | if (!capable(CAP_SYS_BOOT)) | |
852 | return -EPERM; | |
853 | ||
854 | rc = kstrtouint(buf, 0, &cpunum); | |
855 | ||
856 | if (rc) | |
857 | return rc; | |
858 | ||
859 | if (cpunum >= num_possible_cpus()) | |
860 | return -ERANGE; | |
861 | ||
1a9d079f | 862 | reboot_default = 0; |
2c622ed0 MC |
863 | reboot_cpu = cpunum; |
864 | ||
865 | return count; | |
866 | } | |
867 | static struct kobj_attribute reboot_cpu_attr = __ATTR_RW(cpu); | |
40247e55 | 868 | #endif |
2c622ed0 MC |
869 | |
870 | static struct attribute *reboot_attrs[] = { | |
871 | &reboot_mode_attr.attr, | |
40247e55 MC |
872 | #ifdef CONFIG_X86 |
873 | &reboot_force_attr.attr, | |
2c622ed0 | 874 | &reboot_type_attr.attr, |
40247e55 MC |
875 | #endif |
876 | #ifdef CONFIG_SMP | |
2c622ed0 | 877 | &reboot_cpu_attr.attr, |
40247e55 | 878 | #endif |
2c622ed0 MC |
879 | NULL, |
880 | }; | |
881 | ||
882 | static const struct attribute_group reboot_attr_group = { | |
883 | .attrs = reboot_attrs, | |
884 | }; | |
885 | ||
886 | static int __init reboot_ksysfs_init(void) | |
887 | { | |
888 | struct kobject *reboot_kobj; | |
889 | int ret; | |
890 | ||
891 | reboot_kobj = kobject_create_and_add("reboot", kernel_kobj); | |
892 | if (!reboot_kobj) | |
893 | return -ENOMEM; | |
894 | ||
895 | ret = sysfs_create_group(reboot_kobj, &reboot_attr_group); | |
896 | if (ret) { | |
897 | kobject_put(reboot_kobj); | |
898 | return ret; | |
899 | } | |
900 | ||
901 | return 0; | |
902 | } | |
903 | late_initcall(reboot_ksysfs_init); | |
904 | ||
905 | #endif |