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893 lines
22 KiB
893 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* linux/kernel/reboot.c |
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* |
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* Copyright (C) 2013 Linus Torvalds |
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*/ |
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#define pr_fmt(fmt) "reboot: " fmt |
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#include <linux/atomic.h> |
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#include <linux/ctype.h> |
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#include <linux/export.h> |
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#include <linux/kexec.h> |
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#include <linux/kmod.h> |
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#include <linux/kmsg_dump.h> |
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#include <linux/reboot.h> |
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#include <linux/suspend.h> |
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#include <linux/syscalls.h> |
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#include <linux/syscore_ops.h> |
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#include <linux/uaccess.h> |
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/* |
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* this indicates whether you can reboot with ctrl-alt-del: the default is yes |
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*/ |
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int C_A_D = 1; |
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struct pid *cad_pid; |
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EXPORT_SYMBOL(cad_pid); |
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#if defined(CONFIG_ARM) |
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#define DEFAULT_REBOOT_MODE = REBOOT_HARD |
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#else |
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#define DEFAULT_REBOOT_MODE |
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#endif |
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enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE; |
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enum reboot_mode panic_reboot_mode = REBOOT_UNDEFINED; |
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/* |
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* This variable is used privately to keep track of whether or not |
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* reboot_type is still set to its default value (i.e., reboot= hasn't |
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* been set on the command line). This is needed so that we can |
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* suppress DMI scanning for reboot quirks. Without it, it's |
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* impossible to override a faulty reboot quirk without recompiling. |
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*/ |
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int reboot_default = 1; |
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int reboot_cpu; |
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enum reboot_type reboot_type = BOOT_ACPI; |
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int reboot_force; |
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/* |
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* If set, this is used for preparing the system to power off. |
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*/ |
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void (*pm_power_off_prepare)(void); |
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EXPORT_SYMBOL_GPL(pm_power_off_prepare); |
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/** |
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* emergency_restart - reboot the system |
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* |
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* Without shutting down any hardware or taking any locks |
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* reboot the system. This is called when we know we are in |
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* trouble so this is our best effort to reboot. This is |
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* safe to call in interrupt context. |
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*/ |
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void emergency_restart(void) |
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{ |
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kmsg_dump(KMSG_DUMP_EMERG); |
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machine_emergency_restart(); |
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} |
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EXPORT_SYMBOL_GPL(emergency_restart); |
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void kernel_restart_prepare(char *cmd) |
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{ |
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blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); |
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system_state = SYSTEM_RESTART; |
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usermodehelper_disable(); |
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device_shutdown(); |
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} |
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/** |
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* register_reboot_notifier - Register function to be called at reboot time |
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* @nb: Info about notifier function to be called |
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* |
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* Registers a function with the list of functions |
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* to be called at reboot time. |
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* |
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* Currently always returns zero, as blocking_notifier_chain_register() |
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* always returns zero. |
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*/ |
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int register_reboot_notifier(struct notifier_block *nb) |
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{ |
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return blocking_notifier_chain_register(&reboot_notifier_list, nb); |
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} |
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EXPORT_SYMBOL(register_reboot_notifier); |
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/** |
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* unregister_reboot_notifier - Unregister previously registered reboot notifier |
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* @nb: Hook to be unregistered |
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* |
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* Unregisters a previously registered reboot |
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* notifier function. |
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* |
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* Returns zero on success, or %-ENOENT on failure. |
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*/ |
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int unregister_reboot_notifier(struct notifier_block *nb) |
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{ |
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return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); |
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} |
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EXPORT_SYMBOL(unregister_reboot_notifier); |
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static void devm_unregister_reboot_notifier(struct device *dev, void *res) |
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{ |
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WARN_ON(unregister_reboot_notifier(*(struct notifier_block **)res)); |
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} |
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int devm_register_reboot_notifier(struct device *dev, struct notifier_block *nb) |
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{ |
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struct notifier_block **rcnb; |
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int ret; |
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rcnb = devres_alloc(devm_unregister_reboot_notifier, |
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sizeof(*rcnb), GFP_KERNEL); |
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if (!rcnb) |
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return -ENOMEM; |
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ret = register_reboot_notifier(nb); |
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if (!ret) { |
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*rcnb = nb; |
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devres_add(dev, rcnb); |
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} else { |
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devres_free(rcnb); |
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} |
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return ret; |
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} |
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EXPORT_SYMBOL(devm_register_reboot_notifier); |
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/* |
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* Notifier list for kernel code which wants to be called |
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* to restart the system. |
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*/ |
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static ATOMIC_NOTIFIER_HEAD(restart_handler_list); |
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/** |
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* register_restart_handler - Register function to be called to reset |
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* the system |
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* @nb: Info about handler function to be called |
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* @nb->priority: Handler priority. Handlers should follow the |
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* following guidelines for setting priorities. |
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* 0: Restart handler of last resort, |
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* with limited restart capabilities |
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* 128: Default restart handler; use if no other |
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* restart handler is expected to be available, |
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* and/or if restart functionality is |
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* sufficient to restart the entire system |
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* 255: Highest priority restart handler, will |
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* preempt all other restart handlers |
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* |
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* Registers a function with code to be called to restart the |
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* system. |
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* |
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* Registered functions will be called from machine_restart as last |
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* step of the restart sequence (if the architecture specific |
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* machine_restart function calls do_kernel_restart - see below |
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* for details). |
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* Registered functions are expected to restart the system immediately. |
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* If more than one function is registered, the restart handler priority |
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* selects which function will be called first. |
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* |
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* Restart handlers are expected to be registered from non-architecture |
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* code, typically from drivers. A typical use case would be a system |
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* where restart functionality is provided through a watchdog. Multiple |
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* restart handlers may exist; for example, one restart handler might |
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* restart the entire system, while another only restarts the CPU. |
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* In such cases, the restart handler which only restarts part of the |
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* hardware is expected to register with low priority to ensure that |
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* it only runs if no other means to restart the system is available. |
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* |
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* Currently always returns zero, as atomic_notifier_chain_register() |
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* always returns zero. |
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*/ |
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int register_restart_handler(struct notifier_block *nb) |
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{ |
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return atomic_notifier_chain_register(&restart_handler_list, nb); |
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} |
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EXPORT_SYMBOL(register_restart_handler); |
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/** |
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* unregister_restart_handler - Unregister previously registered |
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* restart handler |
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* @nb: Hook to be unregistered |
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* |
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* Unregisters a previously registered restart handler function. |
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* |
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* Returns zero on success, or %-ENOENT on failure. |
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*/ |
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int unregister_restart_handler(struct notifier_block *nb) |
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{ |
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return atomic_notifier_chain_unregister(&restart_handler_list, nb); |
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} |
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EXPORT_SYMBOL(unregister_restart_handler); |
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/** |
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* do_kernel_restart - Execute kernel restart handler call chain |
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* |
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* Calls functions registered with register_restart_handler. |
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* |
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* Expected to be called from machine_restart as last step of the restart |
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* sequence. |
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* |
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* Restarts the system immediately if a restart handler function has been |
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* registered. Otherwise does nothing. |
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*/ |
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void do_kernel_restart(char *cmd) |
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{ |
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atomic_notifier_call_chain(&restart_handler_list, reboot_mode, cmd); |
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} |
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void migrate_to_reboot_cpu(void) |
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{ |
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/* The boot cpu is always logical cpu 0 */ |
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int cpu = reboot_cpu; |
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cpu_hotplug_disable(); |
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/* Make certain the cpu I'm about to reboot on is online */ |
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if (!cpu_online(cpu)) |
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cpu = cpumask_first(cpu_online_mask); |
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/* Prevent races with other tasks migrating this task */ |
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current->flags |= PF_NO_SETAFFINITY; |
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/* Make certain I only run on the appropriate processor */ |
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set_cpus_allowed_ptr(current, cpumask_of(cpu)); |
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} |
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/** |
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* kernel_restart - reboot the system |
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* @cmd: pointer to buffer containing command to execute for restart |
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* or %NULL |
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* |
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* Shutdown everything and perform a clean reboot. |
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* This is not safe to call in interrupt context. |
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*/ |
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void kernel_restart(char *cmd) |
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{ |
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kernel_restart_prepare(cmd); |
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migrate_to_reboot_cpu(); |
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syscore_shutdown(); |
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if (!cmd) |
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pr_emerg("Restarting system\n"); |
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else |
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pr_emerg("Restarting system with command '%s'\n", cmd); |
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kmsg_dump(KMSG_DUMP_SHUTDOWN); |
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machine_restart(cmd); |
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} |
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EXPORT_SYMBOL_GPL(kernel_restart); |
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static void kernel_shutdown_prepare(enum system_states state) |
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{ |
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blocking_notifier_call_chain(&reboot_notifier_list, |
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(state == SYSTEM_HALT) ? SYS_HALT : SYS_POWER_OFF, NULL); |
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system_state = state; |
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usermodehelper_disable(); |
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device_shutdown(); |
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} |
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/** |
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* kernel_halt - halt the system |
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* |
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* Shutdown everything and perform a clean system halt. |
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*/ |
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void kernel_halt(void) |
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{ |
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kernel_shutdown_prepare(SYSTEM_HALT); |
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migrate_to_reboot_cpu(); |
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syscore_shutdown(); |
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pr_emerg("System halted\n"); |
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kmsg_dump(KMSG_DUMP_SHUTDOWN); |
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machine_halt(); |
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} |
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EXPORT_SYMBOL_GPL(kernel_halt); |
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/** |
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* kernel_power_off - power_off the system |
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* |
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* Shutdown everything and perform a clean system power_off. |
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*/ |
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void kernel_power_off(void) |
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{ |
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kernel_shutdown_prepare(SYSTEM_POWER_OFF); |
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if (pm_power_off_prepare) |
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pm_power_off_prepare(); |
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migrate_to_reboot_cpu(); |
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syscore_shutdown(); |
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pr_emerg("Power down\n"); |
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kmsg_dump(KMSG_DUMP_SHUTDOWN); |
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machine_power_off(); |
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} |
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EXPORT_SYMBOL_GPL(kernel_power_off); |
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DEFINE_MUTEX(system_transition_mutex); |
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/* |
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* Reboot system call: for obvious reasons only root may call it, |
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* and even root needs to set up some magic numbers in the registers |
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* so that some mistake won't make this reboot the whole machine. |
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* You can also set the meaning of the ctrl-alt-del-key here. |
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* |
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* reboot doesn't sync: do that yourself before calling this. |
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*/ |
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SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd, |
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void __user *, arg) |
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{ |
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struct pid_namespace *pid_ns = task_active_pid_ns(current); |
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char buffer[256]; |
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int ret = 0; |
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/* We only trust the superuser with rebooting the system. */ |
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if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT)) |
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return -EPERM; |
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/* For safety, we require "magic" arguments. */ |
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if (magic1 != LINUX_REBOOT_MAGIC1 || |
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(magic2 != LINUX_REBOOT_MAGIC2 && |
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magic2 != LINUX_REBOOT_MAGIC2A && |
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magic2 != LINUX_REBOOT_MAGIC2B && |
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magic2 != LINUX_REBOOT_MAGIC2C)) |
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return -EINVAL; |
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/* |
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* If pid namespaces are enabled and the current task is in a child |
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* pid_namespace, the command is handled by reboot_pid_ns() which will |
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* call do_exit(). |
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*/ |
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ret = reboot_pid_ns(pid_ns, cmd); |
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if (ret) |
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return ret; |
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/* Instead of trying to make the power_off code look like |
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* halt when pm_power_off is not set do it the easy way. |
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*/ |
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if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !pm_power_off) |
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cmd = LINUX_REBOOT_CMD_HALT; |
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mutex_lock(&system_transition_mutex); |
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switch (cmd) { |
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case LINUX_REBOOT_CMD_RESTART: |
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kernel_restart(NULL); |
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break; |
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case LINUX_REBOOT_CMD_CAD_ON: |
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C_A_D = 1; |
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break; |
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case LINUX_REBOOT_CMD_CAD_OFF: |
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C_A_D = 0; |
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break; |
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case LINUX_REBOOT_CMD_HALT: |
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kernel_halt(); |
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do_exit(0); |
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panic("cannot halt"); |
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case LINUX_REBOOT_CMD_POWER_OFF: |
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kernel_power_off(); |
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do_exit(0); |
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break; |
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case LINUX_REBOOT_CMD_RESTART2: |
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ret = strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1); |
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if (ret < 0) { |
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ret = -EFAULT; |
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break; |
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} |
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buffer[sizeof(buffer) - 1] = '\0'; |
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kernel_restart(buffer); |
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break; |
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#ifdef CONFIG_KEXEC_CORE |
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case LINUX_REBOOT_CMD_KEXEC: |
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ret = kernel_kexec(); |
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break; |
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#endif |
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#ifdef CONFIG_HIBERNATION |
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case LINUX_REBOOT_CMD_SW_SUSPEND: |
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ret = hibernate(); |
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break; |
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#endif |
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default: |
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ret = -EINVAL; |
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break; |
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} |
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mutex_unlock(&system_transition_mutex); |
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return ret; |
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} |
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static void deferred_cad(struct work_struct *dummy) |
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{ |
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kernel_restart(NULL); |
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} |
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/* |
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* This function gets called by ctrl-alt-del - ie the keyboard interrupt. |
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* As it's called within an interrupt, it may NOT sync: the only choice |
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* is whether to reboot at once, or just ignore the ctrl-alt-del. |
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*/ |
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void ctrl_alt_del(void) |
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{ |
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static DECLARE_WORK(cad_work, deferred_cad); |
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if (C_A_D) |
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schedule_work(&cad_work); |
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else |
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kill_cad_pid(SIGINT, 1); |
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} |
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char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; |
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static const char reboot_cmd[] = "/sbin/reboot"; |
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static int run_cmd(const char *cmd) |
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{ |
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char **argv; |
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static char *envp[] = { |
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"HOME=/", |
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"PATH=/sbin:/bin:/usr/sbin:/usr/bin", |
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NULL |
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}; |
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int ret; |
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argv = argv_split(GFP_KERNEL, cmd, NULL); |
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if (argv) { |
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ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); |
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argv_free(argv); |
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} else { |
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ret = -ENOMEM; |
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} |
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return ret; |
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} |
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static int __orderly_reboot(void) |
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{ |
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int ret; |
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ret = run_cmd(reboot_cmd); |
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if (ret) { |
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pr_warn("Failed to start orderly reboot: forcing the issue\n"); |
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emergency_sync(); |
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kernel_restart(NULL); |
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} |
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return ret; |
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} |
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static int __orderly_poweroff(bool force) |
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{ |
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int ret; |
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ret = run_cmd(poweroff_cmd); |
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if (ret && force) { |
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pr_warn("Failed to start orderly shutdown: forcing the issue\n"); |
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/* |
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* I guess this should try to kick off some daemon to sync and |
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* poweroff asap. Or not even bother syncing if we're doing an |
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* emergency shutdown? |
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*/ |
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emergency_sync(); |
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kernel_power_off(); |
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} |
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return ret; |
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} |
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static bool poweroff_force; |
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static void poweroff_work_func(struct work_struct *work) |
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{ |
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__orderly_poweroff(poweroff_force); |
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} |
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static DECLARE_WORK(poweroff_work, poweroff_work_func); |
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/** |
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* orderly_poweroff - Trigger an orderly system poweroff |
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* @force: force poweroff if command execution fails |
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* |
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* This may be called from any context to trigger a system shutdown. |
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* If the orderly shutdown fails, it will force an immediate shutdown. |
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*/ |
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void orderly_poweroff(bool force) |
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{ |
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if (force) /* do not override the pending "true" */ |
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poweroff_force = true; |
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schedule_work(&poweroff_work); |
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} |
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EXPORT_SYMBOL_GPL(orderly_poweroff); |
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static void reboot_work_func(struct work_struct *work) |
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{ |
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__orderly_reboot(); |
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} |
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static DECLARE_WORK(reboot_work, reboot_work_func); |
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/** |
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* orderly_reboot - Trigger an orderly system reboot |
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* |
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* This may be called from any context to trigger a system reboot. |
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* If the orderly reboot fails, it will force an immediate reboot. |
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*/ |
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void orderly_reboot(void) |
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{ |
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schedule_work(&reboot_work); |
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} |
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EXPORT_SYMBOL_GPL(orderly_reboot); |
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/** |
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* hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay |
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* @work: work_struct associated with the emergency poweroff function |
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* |
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* This function is called in very critical situations to force |
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* a kernel poweroff after a configurable timeout value. |
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*/ |
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static void hw_failure_emergency_poweroff_func(struct work_struct *work) |
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{ |
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/* |
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* We have reached here after the emergency shutdown waiting period has |
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* expired. This means orderly_poweroff has not been able to shut off |
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* the system for some reason. |
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* |
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* Try to shut down the system immediately using kernel_power_off |
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* if populated |
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*/ |
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pr_emerg("Hardware protection timed-out. Trying forced poweroff\n"); |
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kernel_power_off(); |
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/* |
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* Worst of the worst case trigger emergency restart |
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*/ |
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pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n"); |
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emergency_restart(); |
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} |
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static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work, |
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hw_failure_emergency_poweroff_func); |
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/** |
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* hw_failure_emergency_poweroff - Trigger an emergency system poweroff |
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* |
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* This may be called from any critical situation to trigger a system shutdown |
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* after a given period of time. If time is negative this is not scheduled. |
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*/ |
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static void hw_failure_emergency_poweroff(int poweroff_delay_ms) |
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{ |
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if (poweroff_delay_ms <= 0) |
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return; |
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schedule_delayed_work(&hw_failure_emergency_poweroff_work, |
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msecs_to_jiffies(poweroff_delay_ms)); |
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} |
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|
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/** |
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* hw_protection_shutdown - Trigger an emergency system poweroff |
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* |
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* @reason: Reason of emergency shutdown to be printed. |
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* @ms_until_forced: Time to wait for orderly shutdown before tiggering a |
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* forced shudown. Negative value disables the forced |
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* shutdown. |
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* |
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* Initiate an emergency system shutdown in order to protect hardware from |
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* further damage. Usage examples include a thermal protection or a voltage or |
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* current regulator failures. |
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* NOTE: The request is ignored if protection shutdown is already pending even |
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* if the previous request has given a large timeout for forced shutdown. |
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* Can be called from any context. |
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*/ |
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void hw_protection_shutdown(const char *reason, int ms_until_forced) |
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{ |
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static atomic_t allow_proceed = ATOMIC_INIT(1); |
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pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason); |
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|
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/* Shutdown should be initiated only once. */ |
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if (!atomic_dec_and_test(&allow_proceed)) |
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return; |
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/* |
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* Queue a backup emergency shutdown in the event of |
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* orderly_poweroff failure |
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*/ |
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hw_failure_emergency_poweroff(ms_until_forced); |
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orderly_poweroff(true); |
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} |
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EXPORT_SYMBOL_GPL(hw_protection_shutdown); |
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static int __init reboot_setup(char *str) |
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{ |
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for (;;) { |
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enum reboot_mode *mode; |
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|
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/* |
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* Having anything passed on the command line via |
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* reboot= will cause us to disable DMI checking |
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* below. |
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*/ |
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reboot_default = 0; |
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|
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if (!strncmp(str, "panic_", 6)) { |
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mode = &panic_reboot_mode; |
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str += 6; |
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} else { |
|
mode = &reboot_mode; |
|
} |
|
|
|
switch (*str) { |
|
case 'w': |
|
*mode = REBOOT_WARM; |
|
break; |
|
|
|
case 'c': |
|
*mode = REBOOT_COLD; |
|
break; |
|
|
|
case 'h': |
|
*mode = REBOOT_HARD; |
|
break; |
|
|
|
case 's': |
|
/* |
|
* reboot_cpu is s[mp]#### with #### being the processor |
|
* to be used for rebooting. Skip 's' or 'smp' prefix. |
|
*/ |
|
str += str[1] == 'm' && str[2] == 'p' ? 3 : 1; |
|
|
|
if (isdigit(str[0])) { |
|
int cpu = simple_strtoul(str, NULL, 0); |
|
|
|
if (cpu >= num_possible_cpus()) { |
|
pr_err("Ignoring the CPU number in reboot= option. " |
|
"CPU %d exceeds possible cpu number %d\n", |
|
cpu, num_possible_cpus()); |
|
break; |
|
} |
|
reboot_cpu = cpu; |
|
} else |
|
*mode = REBOOT_SOFT; |
|
break; |
|
|
|
case 'g': |
|
*mode = REBOOT_GPIO; |
|
break; |
|
|
|
case 'b': |
|
case 'a': |
|
case 'k': |
|
case 't': |
|
case 'e': |
|
case 'p': |
|
reboot_type = *str; |
|
break; |
|
|
|
case 'f': |
|
reboot_force = 1; |
|
break; |
|
} |
|
|
|
str = strchr(str, ','); |
|
if (str) |
|
str++; |
|
else |
|
break; |
|
} |
|
return 1; |
|
} |
|
__setup("reboot=", reboot_setup); |
|
|
|
#ifdef CONFIG_SYSFS |
|
|
|
#define REBOOT_COLD_STR "cold" |
|
#define REBOOT_WARM_STR "warm" |
|
#define REBOOT_HARD_STR "hard" |
|
#define REBOOT_SOFT_STR "soft" |
|
#define REBOOT_GPIO_STR "gpio" |
|
#define REBOOT_UNDEFINED_STR "undefined" |
|
|
|
#define BOOT_TRIPLE_STR "triple" |
|
#define BOOT_KBD_STR "kbd" |
|
#define BOOT_BIOS_STR "bios" |
|
#define BOOT_ACPI_STR "acpi" |
|
#define BOOT_EFI_STR "efi" |
|
#define BOOT_PCI_STR "pci" |
|
|
|
static ssize_t mode_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
|
{ |
|
const char *val; |
|
|
|
switch (reboot_mode) { |
|
case REBOOT_COLD: |
|
val = REBOOT_COLD_STR; |
|
break; |
|
case REBOOT_WARM: |
|
val = REBOOT_WARM_STR; |
|
break; |
|
case REBOOT_HARD: |
|
val = REBOOT_HARD_STR; |
|
break; |
|
case REBOOT_SOFT: |
|
val = REBOOT_SOFT_STR; |
|
break; |
|
case REBOOT_GPIO: |
|
val = REBOOT_GPIO_STR; |
|
break; |
|
default: |
|
val = REBOOT_UNDEFINED_STR; |
|
} |
|
|
|
return sprintf(buf, "%s\n", val); |
|
} |
|
static ssize_t mode_store(struct kobject *kobj, struct kobj_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
if (!capable(CAP_SYS_BOOT)) |
|
return -EPERM; |
|
|
|
if (!strncmp(buf, REBOOT_COLD_STR, strlen(REBOOT_COLD_STR))) |
|
reboot_mode = REBOOT_COLD; |
|
else if (!strncmp(buf, REBOOT_WARM_STR, strlen(REBOOT_WARM_STR))) |
|
reboot_mode = REBOOT_WARM; |
|
else if (!strncmp(buf, REBOOT_HARD_STR, strlen(REBOOT_HARD_STR))) |
|
reboot_mode = REBOOT_HARD; |
|
else if (!strncmp(buf, REBOOT_SOFT_STR, strlen(REBOOT_SOFT_STR))) |
|
reboot_mode = REBOOT_SOFT; |
|
else if (!strncmp(buf, REBOOT_GPIO_STR, strlen(REBOOT_GPIO_STR))) |
|
reboot_mode = REBOOT_GPIO; |
|
else |
|
return -EINVAL; |
|
|
|
reboot_default = 0; |
|
|
|
return count; |
|
} |
|
static struct kobj_attribute reboot_mode_attr = __ATTR_RW(mode); |
|
|
|
#ifdef CONFIG_X86 |
|
static ssize_t force_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
|
{ |
|
return sprintf(buf, "%d\n", reboot_force); |
|
} |
|
static ssize_t force_store(struct kobject *kobj, struct kobj_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
bool res; |
|
|
|
if (!capable(CAP_SYS_BOOT)) |
|
return -EPERM; |
|
|
|
if (kstrtobool(buf, &res)) |
|
return -EINVAL; |
|
|
|
reboot_default = 0; |
|
reboot_force = res; |
|
|
|
return count; |
|
} |
|
static struct kobj_attribute reboot_force_attr = __ATTR_RW(force); |
|
|
|
static ssize_t type_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
|
{ |
|
const char *val; |
|
|
|
switch (reboot_type) { |
|
case BOOT_TRIPLE: |
|
val = BOOT_TRIPLE_STR; |
|
break; |
|
case BOOT_KBD: |
|
val = BOOT_KBD_STR; |
|
break; |
|
case BOOT_BIOS: |
|
val = BOOT_BIOS_STR; |
|
break; |
|
case BOOT_ACPI: |
|
val = BOOT_ACPI_STR; |
|
break; |
|
case BOOT_EFI: |
|
val = BOOT_EFI_STR; |
|
break; |
|
case BOOT_CF9_FORCE: |
|
val = BOOT_PCI_STR; |
|
break; |
|
default: |
|
val = REBOOT_UNDEFINED_STR; |
|
} |
|
|
|
return sprintf(buf, "%s\n", val); |
|
} |
|
static ssize_t type_store(struct kobject *kobj, struct kobj_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
if (!capable(CAP_SYS_BOOT)) |
|
return -EPERM; |
|
|
|
if (!strncmp(buf, BOOT_TRIPLE_STR, strlen(BOOT_TRIPLE_STR))) |
|
reboot_type = BOOT_TRIPLE; |
|
else if (!strncmp(buf, BOOT_KBD_STR, strlen(BOOT_KBD_STR))) |
|
reboot_type = BOOT_KBD; |
|
else if (!strncmp(buf, BOOT_BIOS_STR, strlen(BOOT_BIOS_STR))) |
|
reboot_type = BOOT_BIOS; |
|
else if (!strncmp(buf, BOOT_ACPI_STR, strlen(BOOT_ACPI_STR))) |
|
reboot_type = BOOT_ACPI; |
|
else if (!strncmp(buf, BOOT_EFI_STR, strlen(BOOT_EFI_STR))) |
|
reboot_type = BOOT_EFI; |
|
else if (!strncmp(buf, BOOT_PCI_STR, strlen(BOOT_PCI_STR))) |
|
reboot_type = BOOT_CF9_FORCE; |
|
else |
|
return -EINVAL; |
|
|
|
reboot_default = 0; |
|
|
|
return count; |
|
} |
|
static struct kobj_attribute reboot_type_attr = __ATTR_RW(type); |
|
#endif |
|
|
|
#ifdef CONFIG_SMP |
|
static ssize_t cpu_show(struct kobject *kobj, struct kobj_attribute *attr, char *buf) |
|
{ |
|
return sprintf(buf, "%d\n", reboot_cpu); |
|
} |
|
static ssize_t cpu_store(struct kobject *kobj, struct kobj_attribute *attr, |
|
const char *buf, size_t count) |
|
{ |
|
unsigned int cpunum; |
|
int rc; |
|
|
|
if (!capable(CAP_SYS_BOOT)) |
|
return -EPERM; |
|
|
|
rc = kstrtouint(buf, 0, &cpunum); |
|
|
|
if (rc) |
|
return rc; |
|
|
|
if (cpunum >= num_possible_cpus()) |
|
return -ERANGE; |
|
|
|
reboot_default = 0; |
|
reboot_cpu = cpunum; |
|
|
|
return count; |
|
} |
|
static struct kobj_attribute reboot_cpu_attr = __ATTR_RW(cpu); |
|
#endif |
|
|
|
static struct attribute *reboot_attrs[] = { |
|
&reboot_mode_attr.attr, |
|
#ifdef CONFIG_X86 |
|
&reboot_force_attr.attr, |
|
&reboot_type_attr.attr, |
|
#endif |
|
#ifdef CONFIG_SMP |
|
&reboot_cpu_attr.attr, |
|
#endif |
|
NULL, |
|
}; |
|
|
|
static const struct attribute_group reboot_attr_group = { |
|
.attrs = reboot_attrs, |
|
}; |
|
|
|
static int __init reboot_ksysfs_init(void) |
|
{ |
|
struct kobject *reboot_kobj; |
|
int ret; |
|
|
|
reboot_kobj = kobject_create_and_add("reboot", kernel_kobj); |
|
if (!reboot_kobj) |
|
return -ENOMEM; |
|
|
|
ret = sysfs_create_group(reboot_kobj, &reboot_attr_group); |
|
if (ret) { |
|
kobject_put(reboot_kobj); |
|
return ret; |
|
} |
|
|
|
return 0; |
|
} |
|
late_initcall(reboot_ksysfs_init); |
|
|
|
#endif
|
|
|