1 // SPDX-License-Identifier: GPL-2.0-only
23  * this indicates whether you can reboot with ctrl-alt-del: the default is yes
64  * the system cannot be powered off. This allowes kernel_halt() to notify users
76  *	emergency_restart - reboot the system
100  *	register_reboot_notifier - Register function to be called at reboot time
101  *	@nb: Info about notifier function to be called
103  *	Registers a function with the list of functions
116  *	unregister_reboot_notifier - Unregister previously registered reboot notifier
120  *	notifier function.
122  *	Returns zero on success, or %-ENOENT on failure.
143 		return -ENOMEM;  in devm_register_reboot_notifier()
164  *	register_restart_handler - Register function to be called to reset
166  *	@nb: Info about handler function to be called
167  *	@nb->priority:	Handler priority. Handlers should follow the
178  *	Registers a function with code to be called to restart the
183  *	machine_restart function calls do_kernel_restart - see below
186  *	If more than one function is registered, the restart handler priority
187  *	selects which function will be called first.
189  *	Restart handlers are expected to be registered from non-architecture
208  *	unregister_restart_handler - Unregister previously registered
212  *	Unregisters a previously registered restart handler function.
214  *	Returns zero on success, or %-ENOENT on failure.
223  *	do_kernel_restart - Execute kernel restart handler call chain
230  *	Restarts the system immediately if a restart handler function has been
250 	current->flags |= PF_NO_SETAFFINITY;  in migrate_to_reboot_cpu()
268  *	kernel_restart - reboot the system
299  *	kernel_halt - halt the system
309 		pr_emerg("Power off not available: System halted instead\n");  in kernel_halt()
319  *	to prepare system for power off.
325  *	to power off system.
336 	data.cb_data = handler->cb_data;  in sys_off_notify()
339 	data.dev = handler->dev;  in sys_off_notify()
341 	return handler->sys_off_cb(&data);  in sys_off_notify()
357 		if (handler->cb_data)  in alloc_sys_off_handler()
358 			return ERR_PTR(-EBUSY);  in alloc_sys_off_handler()
367 			return ERR_PTR(-ENOMEM);  in alloc_sys_off_handler()
382  *	register_sys_off_handler - Register sys-off handler
383  *	@mode: Sys-off mode
385  *	@callback: Callback function
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
396  *	Only one handler can be registered at the non-default priority level,
397  *	otherwise ERR_PTR(-EBUSY) is returned.
400  *	an ERR_PTR()-encoded error code otherwise.
417 		handler->list = &power_off_prep_handler_list;  in register_sys_off_handler()
418 		handler->blocking = true;  in register_sys_off_handler()
422 		handler->list = &power_off_handler_list;  in register_sys_off_handler()
426 		handler->list = &restart_prep_handler_list;  in register_sys_off_handler()
427 		handler->blocking = true;  in register_sys_off_handler()
431 		handler->list = &restart_handler_list;  in register_sys_off_handler()
436 		return ERR_PTR(-EINVAL);  in register_sys_off_handler()
439 	handler->nb.notifier_call = sys_off_notify;  in register_sys_off_handler()
440 	handler->nb.priority = priority;  in register_sys_off_handler()
441 	handler->sys_off_cb = callback;  in register_sys_off_handler()
442 	handler->cb_data = cb_data;  in register_sys_off_handler()
443 	handler->mode = mode;  in register_sys_off_handler()
445 	if (handler->blocking) {  in register_sys_off_handler()
447 			err = blocking_notifier_chain_register(handler->list,  in register_sys_off_handler()
448 							       &handler->nb);  in register_sys_off_handler()
450 			err = blocking_notifier_chain_register_unique_prio(handler->list,  in register_sys_off_handler()
451 									   &handler->nb);  in register_sys_off_handler()
454 			err = atomic_notifier_chain_register(handler->list,  in register_sys_off_handler()
455 							     &handler->nb);  in register_sys_off_handler()
457 			err = atomic_notifier_chain_register_unique_prio(handler->list,  in register_sys_off_handler()
458 									 &handler->nb);  in register_sys_off_handler()
471  *	unregister_sys_off_handler - Unregister sys-off handler
472  *	@handler: Sys-off handler
474  *	Unregisters given sys-off handler.
483 	if (handler->blocking)  in unregister_sys_off_handler()
484 		err = blocking_notifier_chain_unregister(handler->list,  in unregister_sys_off_handler()
485 							 &handler->nb);  in unregister_sys_off_handler()
487 		err = atomic_notifier_chain_unregister(handler->list,  in unregister_sys_off_handler()
488 						       &handler->nb);  in unregister_sys_off_handler()
505  *	devm_register_sys_off_handler - Register sys-off handler
507  *	@mode: Sys-off mode
509  *	@callback: Callback function
512  *	Registers resource-managed sys-off handler.
527 	handler->dev = dev;  in devm_register_sys_off_handler()
535  *	devm_register_power_off_handler - Register power-off handler
537  *	@callback: Callback function
540  *	Registers resource-managed sys-off handler with a default priority
541  *	and using power-off mode.
557  *	devm_register_restart_handler - Register restart handler
559  *	@callback: Callback function
562  *	Registers resource-managed sys-off handler with a default priority
582 	void (*platform_power_power_off_cb)(void) = data->cb_data;  in platform_power_off_notify()
590  *	register_platform_power_off - Register platform-level power-off callback
591  *	@power_off: Power-off callback
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
618  *	unregister_platform_power_off - Unregister platform-level power-off callback
619  *	@power_off: Power-off callback
621  *	Unregisters previously registered platform power-off callback.
626 	    platform_power_off_handler->cb_data == power_off) {  in unregister_platform_power_off()
647  *	do_kernel_power_off - Execute kernel power-off handler call chain
649  *	Expected to be called as last step of the power-off sequence.
651  *	Powers off the system immediately if a power-off handler function has
659 	 * Register sys-off handlers for legacy PM callback. This allows  in do_kernel_power_off()
660 	 * legacy PM callbacks temporary co-exist with the new sys-off API.  in do_kernel_power_off()
663 	 *       switched to the sys-off based APIs.  in do_kernel_power_off()
676  *	kernel_can_power_off - check whether system can be powered off
678  *	Returns true if power-off handler is registered and system can be
679  *	powered off, false otherwise.
689  *	kernel_power_off - power_off the system
711  * You can also set the meaning of the ctrl-alt-del-key here.
723 	if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))  in SYSCALL_DEFINE4()
724 		return -EPERM;  in SYSCALL_DEFINE4()
732 		return -EINVAL;  in SYSCALL_DEFINE4()
775 		ret = strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1);  in SYSCALL_DEFINE4()
777 			ret = -EFAULT;  in SYSCALL_DEFINE4()
780 		buffer[sizeof(buffer) - 1] = '\0';  in SYSCALL_DEFINE4()
798 		ret = -EINVAL;  in SYSCALL_DEFINE4()
811  * This function gets called by ctrl-alt-del - ie the keyboard interrupt.
813  * is whether to reboot at once, or just ignore the ctrl-alt-del.
843 		ret = -ENOMEM;  in run_cmd()
874 		 * I guess this should try to kick off some daemon to sync and  in __orderly_poweroff()
895  * orderly_poweroff - Trigger an orderly system poweroff
917  * orderly_reboot - Trigger an orderly system reboot
929  * hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay
930  * @work: work_struct associated with the emergency poweroff function
932  * This function is called in very critical situations to force
939 	 * expired. This means orderly_poweroff has not been able to shut off  in hw_failure_emergency_poweroff_func()
945 	pr_emerg("Hardware protection timed-out. Trying forced poweroff\n");  in hw_failure_emergency_poweroff_func()
959  * hw_failure_emergency_poweroff - Trigger an emergency system poweroff
973  * __hw_protection_shutdown - Trigger an emergency system shutdown or reboot
1139 		return -EPERM;  in mode_store()
1152 		return -EINVAL;  in mode_store()
1171 		return -EPERM;  in force_store()
1174 		return -EINVAL;  in force_store()
1216 		return -EPERM;  in type_store()
1231 		return -EINVAL;  in type_store()
1252 		return -EPERM;  in cpu_store()
1260 		return -ERANGE;  in cpu_store()
1292 		.procname       = "ctrl-alt-del",
1319 		return -ENOMEM;  in reboot_ksysfs_init()