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1295 lines
32 KiB
C
1295 lines
32 KiB
C
// 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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static 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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EXPORT_SYMBOL_GPL(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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struct sys_off_handler {
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struct notifier_block nb;
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int (*sys_off_cb)(struct sys_off_data *data);
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void *cb_data;
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enum sys_off_mode mode;
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bool blocking;
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void *list;
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};
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/*
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* Temporary stub that prevents linkage failure while we're in process
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* of removing all uses of legacy pm_power_off() around the kernel.
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*/
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void __weak (*pm_power_off)(void);
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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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* Notifier list for kernel code which wants to be called
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* to prepare system for power off.
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*/
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static BLOCKING_NOTIFIER_HEAD(power_off_prep_handler_list);
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/*
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* Notifier list for kernel code which wants to be called
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* to power off system.
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*/
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static ATOMIC_NOTIFIER_HEAD(power_off_handler_list);
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static int sys_off_notify(struct notifier_block *nb,
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unsigned long mode, void *cmd)
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{
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struct sys_off_handler *handler;
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struct sys_off_data data = {};
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handler = container_of(nb, struct sys_off_handler, nb);
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data.cb_data = handler->cb_data;
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data.mode = mode;
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data.cmd = cmd;
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return handler->sys_off_cb(&data);
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}
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static struct sys_off_handler platform_sys_off_handler;
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static struct sys_off_handler *alloc_sys_off_handler(int priority)
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{
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struct sys_off_handler *handler;
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gfp_t flags;
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/*
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* Platforms like m68k can't allocate sys_off handler dynamically
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* at the early boot time because memory allocator isn't available yet.
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*/
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if (priority == SYS_OFF_PRIO_PLATFORM) {
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handler = &platform_sys_off_handler;
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if (handler->cb_data)
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return ERR_PTR(-EBUSY);
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} else {
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if (system_state > SYSTEM_RUNNING)
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flags = GFP_ATOMIC;
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else
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flags = GFP_KERNEL;
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handler = kzalloc(sizeof(*handler), flags);
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if (!handler)
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return ERR_PTR(-ENOMEM);
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}
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return handler;
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}
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static void free_sys_off_handler(struct sys_off_handler *handler)
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{
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if (handler == &platform_sys_off_handler)
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memset(handler, 0, sizeof(*handler));
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else
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kfree(handler);
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}
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/**
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* register_sys_off_handler - Register sys-off handler
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* @mode: Sys-off mode
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* @priority: Handler priority
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* @callback: Callback function
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* @cb_data: Callback argument
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*
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* Registers system power-off or restart handler that will be invoked
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* at the step corresponding to the given sys-off mode. Handler's callback
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* should return NOTIFY_DONE to permit execution of the next handler in
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* the call chain or NOTIFY_STOP to break the chain (in error case for
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* example).
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*
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* Multiple handlers can be registered at the default priority level.
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*
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* Only one handler can be registered at the non-default priority level,
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* otherwise ERR_PTR(-EBUSY) is returned.
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*
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* Returns a new instance of struct sys_off_handler on success, or
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* an ERR_PTR()-encoded error code otherwise.
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*/
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struct sys_off_handler *
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register_sys_off_handler(enum sys_off_mode mode,
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int priority,
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int (*callback)(struct sys_off_data *data),
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void *cb_data)
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{
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struct sys_off_handler *handler;
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int err;
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handler = alloc_sys_off_handler(priority);
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if (IS_ERR(handler))
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return handler;
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switch (mode) {
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case SYS_OFF_MODE_POWER_OFF_PREPARE:
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handler->list = &power_off_prep_handler_list;
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handler->blocking = true;
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break;
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case SYS_OFF_MODE_POWER_OFF:
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handler->list = &power_off_handler_list;
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break;
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case SYS_OFF_MODE_RESTART:
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handler->list = &restart_handler_list;
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break;
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default:
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free_sys_off_handler(handler);
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return ERR_PTR(-EINVAL);
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}
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handler->nb.notifier_call = sys_off_notify;
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handler->nb.priority = priority;
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handler->sys_off_cb = callback;
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handler->cb_data = cb_data;
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handler->mode = mode;
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if (handler->blocking) {
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if (priority == SYS_OFF_PRIO_DEFAULT)
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err = blocking_notifier_chain_register(handler->list,
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&handler->nb);
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else
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err = blocking_notifier_chain_register_unique_prio(handler->list,
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&handler->nb);
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} else {
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if (priority == SYS_OFF_PRIO_DEFAULT)
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err = atomic_notifier_chain_register(handler->list,
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&handler->nb);
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else
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err = atomic_notifier_chain_register_unique_prio(handler->list,
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&handler->nb);
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}
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if (err) {
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free_sys_off_handler(handler);
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return ERR_PTR(err);
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}
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return handler;
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}
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EXPORT_SYMBOL_GPL(register_sys_off_handler);
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/**
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* unregister_sys_off_handler - Unregister sys-off handler
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* @handler: Sys-off handler
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*
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* Unregisters given sys-off handler.
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*/
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void unregister_sys_off_handler(struct sys_off_handler *handler)
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{
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int err;
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if (IS_ERR_OR_NULL(handler))
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return;
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if (handler->blocking)
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err = blocking_notifier_chain_unregister(handler->list,
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&handler->nb);
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else
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err = atomic_notifier_chain_unregister(handler->list,
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&handler->nb);
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/* sanity check, shall never happen */
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WARN_ON(err);
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free_sys_off_handler(handler);
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}
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EXPORT_SYMBOL_GPL(unregister_sys_off_handler);
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static void devm_unregister_sys_off_handler(void *data)
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{
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struct sys_off_handler *handler = data;
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unregister_sys_off_handler(handler);
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}
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/**
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* devm_register_sys_off_handler - Register sys-off handler
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* @dev: Device that registers handler
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* @mode: Sys-off mode
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* @priority: Handler priority
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* @callback: Callback function
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* @cb_data: Callback argument
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*
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* Registers resource-managed sys-off handler.
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*
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* Returns zero on success, or error code on failure.
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*/
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int devm_register_sys_off_handler(struct device *dev,
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enum sys_off_mode mode,
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int priority,
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int (*callback)(struct sys_off_data *data),
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void *cb_data)
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{
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struct sys_off_handler *handler;
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handler = register_sys_off_handler(mode, priority, callback, cb_data);
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if (IS_ERR(handler))
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return PTR_ERR(handler);
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return devm_add_action_or_reset(dev, devm_unregister_sys_off_handler,
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handler);
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}
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EXPORT_SYMBOL_GPL(devm_register_sys_off_handler);
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/**
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* devm_register_power_off_handler - Register power-off handler
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* @dev: Device that registers callback
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* @callback: Callback function
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* @cb_data: Callback's argument
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*
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* Registers resource-managed sys-off handler with a default priority
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* and using power-off mode.
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*
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* Returns zero on success, or error code on failure.
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*/
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int devm_register_power_off_handler(struct device *dev,
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int (*callback)(struct sys_off_data *data),
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void *cb_data)
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{
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return devm_register_sys_off_handler(dev,
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SYS_OFF_MODE_POWER_OFF,
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SYS_OFF_PRIO_DEFAULT,
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callback, cb_data);
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}
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EXPORT_SYMBOL_GPL(devm_register_power_off_handler);
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/**
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* devm_register_restart_handler - Register restart handler
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* @dev: Device that registers callback
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* @callback: Callback function
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* @cb_data: Callback's argument
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*
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* Registers resource-managed sys-off handler with a default priority
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* and using restart mode.
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*
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* Returns zero on success, or error code on failure.
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*/
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int devm_register_restart_handler(struct device *dev,
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int (*callback)(struct sys_off_data *data),
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void *cb_data)
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{
|
|
return devm_register_sys_off_handler(dev,
|
|
SYS_OFF_MODE_RESTART,
|
|
SYS_OFF_PRIO_DEFAULT,
|
|
callback, cb_data);
|
|
}
|
|
EXPORT_SYMBOL_GPL(devm_register_restart_handler);
|
|
|
|
static struct sys_off_handler *platform_power_off_handler;
|
|
|
|
static int platform_power_off_notify(struct sys_off_data *data)
|
|
{
|
|
void (*platform_power_power_off_cb)(void) = data->cb_data;
|
|
|
|
platform_power_power_off_cb();
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
/**
|
|
* register_platform_power_off - Register platform-level power-off callback
|
|
* @power_off: Power-off callback
|
|
*
|
|
* Registers power-off callback that will be called as last step
|
|
* of the power-off sequence. This callback is expected to be invoked
|
|
* for the last resort. Only one platform power-off callback is allowed
|
|
* to be registered at a time.
|
|
*
|
|
* Returns zero on success, or error code on failure.
|
|
*/
|
|
int register_platform_power_off(void (*power_off)(void))
|
|
{
|
|
struct sys_off_handler *handler;
|
|
|
|
handler = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
|
|
SYS_OFF_PRIO_PLATFORM,
|
|
platform_power_off_notify,
|
|
power_off);
|
|
if (IS_ERR(handler))
|
|
return PTR_ERR(handler);
|
|
|
|
platform_power_off_handler = handler;
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(register_platform_power_off);
|
|
|
|
/**
|
|
* unregister_platform_power_off - Unregister platform-level power-off callback
|
|
* @power_off: Power-off callback
|
|
*
|
|
* Unregisters previously registered platform power-off callback.
|
|
*/
|
|
void unregister_platform_power_off(void (*power_off)(void))
|
|
{
|
|
if (platform_power_off_handler &&
|
|
platform_power_off_handler->cb_data == power_off) {
|
|
unregister_sys_off_handler(platform_power_off_handler);
|
|
platform_power_off_handler = NULL;
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(unregister_platform_power_off);
|
|
|
|
static int legacy_pm_power_off(struct sys_off_data *data)
|
|
{
|
|
if (pm_power_off)
|
|
pm_power_off();
|
|
|
|
return NOTIFY_DONE;
|
|
}
|
|
|
|
static void do_kernel_power_off_prepare(void)
|
|
{
|
|
blocking_notifier_call_chain(&power_off_prep_handler_list, 0, NULL);
|
|
}
|
|
|
|
/**
|
|
* do_kernel_power_off - Execute kernel power-off handler call chain
|
|
*
|
|
* Expected to be called as last step of the power-off sequence.
|
|
*
|
|
* Powers off the system immediately if a power-off handler function has
|
|
* been registered. Otherwise does nothing.
|
|
*/
|
|
void do_kernel_power_off(void)
|
|
{
|
|
struct sys_off_handler *sys_off = NULL;
|
|
|
|
/*
|
|
* Register sys-off handlers for legacy PM callback. This allows
|
|
* legacy PM callbacks temporary co-exist with the new sys-off API.
|
|
*
|
|
* TODO: Remove legacy handlers once all legacy PM users will be
|
|
* switched to the sys-off based APIs.
|
|
*/
|
|
if (pm_power_off)
|
|
sys_off = register_sys_off_handler(SYS_OFF_MODE_POWER_OFF,
|
|
SYS_OFF_PRIO_DEFAULT,
|
|
legacy_pm_power_off, NULL);
|
|
|
|
atomic_notifier_call_chain(&power_off_handler_list, 0, NULL);
|
|
|
|
unregister_sys_off_handler(sys_off);
|
|
}
|
|
|
|
/**
|
|
* kernel_can_power_off - check whether system can be powered off
|
|
*
|
|
* Returns true if power-off handler is registered and system can be
|
|
* powered off, false otherwise.
|
|
*/
|
|
bool kernel_can_power_off(void)
|
|
{
|
|
return !atomic_notifier_call_chain_is_empty(&power_off_handler_list) ||
|
|
pm_power_off;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kernel_can_power_off);
|
|
|
|
/**
|
|
* kernel_power_off - power_off the system
|
|
*
|
|
* Shutdown everything and perform a clean system power_off.
|
|
*/
|
|
void kernel_power_off(void)
|
|
{
|
|
kernel_shutdown_prepare(SYSTEM_POWER_OFF);
|
|
do_kernel_power_off_prepare();
|
|
migrate_to_reboot_cpu();
|
|
syscore_shutdown();
|
|
pr_emerg("Power down\n");
|
|
kmsg_dump(KMSG_DUMP_SHUTDOWN);
|
|
machine_power_off();
|
|
}
|
|
EXPORT_SYMBOL_GPL(kernel_power_off);
|
|
|
|
DEFINE_MUTEX(system_transition_mutex);
|
|
|
|
/*
|
|
* Reboot system call: for obvious reasons only root may call it,
|
|
* and even root needs to set up some magic numbers in the registers
|
|
* so that some mistake won't make this reboot the whole machine.
|
|
* You can also set the meaning of the ctrl-alt-del-key here.
|
|
*
|
|
* reboot doesn't sync: do that yourself before calling this.
|
|
*/
|
|
SYSCALL_DEFINE4(reboot, int, magic1, int, magic2, unsigned int, cmd,
|
|
void __user *, arg)
|
|
{
|
|
struct pid_namespace *pid_ns = task_active_pid_ns(current);
|
|
char buffer[256];
|
|
int ret = 0;
|
|
|
|
/* We only trust the superuser with rebooting the system. */
|
|
if (!ns_capable(pid_ns->user_ns, CAP_SYS_BOOT))
|
|
return -EPERM;
|
|
|
|
/* For safety, we require "magic" arguments. */
|
|
if (magic1 != LINUX_REBOOT_MAGIC1 ||
|
|
(magic2 != LINUX_REBOOT_MAGIC2 &&
|
|
magic2 != LINUX_REBOOT_MAGIC2A &&
|
|
magic2 != LINUX_REBOOT_MAGIC2B &&
|
|
magic2 != LINUX_REBOOT_MAGIC2C))
|
|
return -EINVAL;
|
|
|
|
/*
|
|
* If pid namespaces are enabled and the current task is in a child
|
|
* pid_namespace, the command is handled by reboot_pid_ns() which will
|
|
* call do_exit().
|
|
*/
|
|
ret = reboot_pid_ns(pid_ns, cmd);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/* Instead of trying to make the power_off code look like
|
|
* halt when pm_power_off is not set do it the easy way.
|
|
*/
|
|
if ((cmd == LINUX_REBOOT_CMD_POWER_OFF) && !kernel_can_power_off())
|
|
cmd = LINUX_REBOOT_CMD_HALT;
|
|
|
|
mutex_lock(&system_transition_mutex);
|
|
switch (cmd) {
|
|
case LINUX_REBOOT_CMD_RESTART:
|
|
kernel_restart(NULL);
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_CAD_ON:
|
|
C_A_D = 1;
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_CAD_OFF:
|
|
C_A_D = 0;
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_HALT:
|
|
kernel_halt();
|
|
do_exit(0);
|
|
|
|
case LINUX_REBOOT_CMD_POWER_OFF:
|
|
kernel_power_off();
|
|
do_exit(0);
|
|
break;
|
|
|
|
case LINUX_REBOOT_CMD_RESTART2:
|
|
ret = strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1);
|
|
if (ret < 0) {
|
|
ret = -EFAULT;
|
|
break;
|
|
}
|
|
buffer[sizeof(buffer) - 1] = '\0';
|
|
|
|
kernel_restart(buffer);
|
|
break;
|
|
|
|
#ifdef CONFIG_KEXEC_CORE
|
|
case LINUX_REBOOT_CMD_KEXEC:
|
|
ret = kernel_kexec();
|
|
break;
|
|
#endif
|
|
|
|
#ifdef CONFIG_HIBERNATION
|
|
case LINUX_REBOOT_CMD_SW_SUSPEND:
|
|
ret = hibernate();
|
|
break;
|
|
#endif
|
|
|
|
default:
|
|
ret = -EINVAL;
|
|
break;
|
|
}
|
|
mutex_unlock(&system_transition_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static void deferred_cad(struct work_struct *dummy)
|
|
{
|
|
kernel_restart(NULL);
|
|
}
|
|
|
|
/*
|
|
* This function gets called by ctrl-alt-del - ie the keyboard interrupt.
|
|
* As it's called within an interrupt, it may NOT sync: the only choice
|
|
* is whether to reboot at once, or just ignore the ctrl-alt-del.
|
|
*/
|
|
void ctrl_alt_del(void)
|
|
{
|
|
static DECLARE_WORK(cad_work, deferred_cad);
|
|
|
|
if (C_A_D)
|
|
schedule_work(&cad_work);
|
|
else
|
|
kill_cad_pid(SIGINT, 1);
|
|
}
|
|
|
|
#define POWEROFF_CMD_PATH_LEN 256
|
|
static char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff";
|
|
static const char reboot_cmd[] = "/sbin/reboot";
|
|
|
|
static int run_cmd(const char *cmd)
|
|
{
|
|
char **argv;
|
|
static char *envp[] = {
|
|
"HOME=/",
|
|
"PATH=/sbin:/bin:/usr/sbin:/usr/bin",
|
|
NULL
|
|
};
|
|
int ret;
|
|
argv = argv_split(GFP_KERNEL, cmd, NULL);
|
|
if (argv) {
|
|
ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC);
|
|
argv_free(argv);
|
|
} else {
|
|
ret = -ENOMEM;
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __orderly_reboot(void)
|
|
{
|
|
int ret;
|
|
|
|
ret = run_cmd(reboot_cmd);
|
|
|
|
if (ret) {
|
|
pr_warn("Failed to start orderly reboot: forcing the issue\n");
|
|
emergency_sync();
|
|
kernel_restart(NULL);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static int __orderly_poweroff(bool force)
|
|
{
|
|
int ret;
|
|
|
|
ret = run_cmd(poweroff_cmd);
|
|
|
|
if (ret && force) {
|
|
pr_warn("Failed to start orderly shutdown: forcing the issue\n");
|
|
|
|
/*
|
|
* I guess this should try to kick off some daemon to sync and
|
|
* poweroff asap. Or not even bother syncing if we're doing an
|
|
* emergency shutdown?
|
|
*/
|
|
emergency_sync();
|
|
kernel_power_off();
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
static bool poweroff_force;
|
|
|
|
static void poweroff_work_func(struct work_struct *work)
|
|
{
|
|
__orderly_poweroff(poweroff_force);
|
|
}
|
|
|
|
static DECLARE_WORK(poweroff_work, poweroff_work_func);
|
|
|
|
/**
|
|
* orderly_poweroff - Trigger an orderly system poweroff
|
|
* @force: force poweroff if command execution fails
|
|
*
|
|
* This may be called from any context to trigger a system shutdown.
|
|
* If the orderly shutdown fails, it will force an immediate shutdown.
|
|
*/
|
|
void orderly_poweroff(bool force)
|
|
{
|
|
if (force) /* do not override the pending "true" */
|
|
poweroff_force = true;
|
|
schedule_work(&poweroff_work);
|
|
}
|
|
EXPORT_SYMBOL_GPL(orderly_poweroff);
|
|
|
|
static void reboot_work_func(struct work_struct *work)
|
|
{
|
|
__orderly_reboot();
|
|
}
|
|
|
|
static DECLARE_WORK(reboot_work, reboot_work_func);
|
|
|
|
/**
|
|
* orderly_reboot - Trigger an orderly system reboot
|
|
*
|
|
* This may be called from any context to trigger a system reboot.
|
|
* If the orderly reboot fails, it will force an immediate reboot.
|
|
*/
|
|
void orderly_reboot(void)
|
|
{
|
|
schedule_work(&reboot_work);
|
|
}
|
|
EXPORT_SYMBOL_GPL(orderly_reboot);
|
|
|
|
/**
|
|
* hw_failure_emergency_poweroff_func - emergency poweroff work after a known delay
|
|
* @work: work_struct associated with the emergency poweroff function
|
|
*
|
|
* This function is called in very critical situations to force
|
|
* a kernel poweroff after a configurable timeout value.
|
|
*/
|
|
static void hw_failure_emergency_poweroff_func(struct work_struct *work)
|
|
{
|
|
/*
|
|
* We have reached here after the emergency shutdown waiting period has
|
|
* expired. This means orderly_poweroff has not been able to shut off
|
|
* the system for some reason.
|
|
*
|
|
* Try to shut down the system immediately using kernel_power_off
|
|
* if populated
|
|
*/
|
|
pr_emerg("Hardware protection timed-out. Trying forced poweroff\n");
|
|
kernel_power_off();
|
|
|
|
/*
|
|
* Worst of the worst case trigger emergency restart
|
|
*/
|
|
pr_emerg("Hardware protection shutdown failed. Trying emergency restart\n");
|
|
emergency_restart();
|
|
}
|
|
|
|
static DECLARE_DELAYED_WORK(hw_failure_emergency_poweroff_work,
|
|
hw_failure_emergency_poweroff_func);
|
|
|
|
/**
|
|
* hw_failure_emergency_poweroff - Trigger an emergency system poweroff
|
|
*
|
|
* This may be called from any critical situation to trigger a system shutdown
|
|
* after a given period of time. If time is negative this is not scheduled.
|
|
*/
|
|
static void hw_failure_emergency_poweroff(int poweroff_delay_ms)
|
|
{
|
|
if (poweroff_delay_ms <= 0)
|
|
return;
|
|
schedule_delayed_work(&hw_failure_emergency_poweroff_work,
|
|
msecs_to_jiffies(poweroff_delay_ms));
|
|
}
|
|
|
|
/**
|
|
* hw_protection_shutdown - Trigger an emergency system poweroff
|
|
*
|
|
* @reason: Reason of emergency shutdown to be printed.
|
|
* @ms_until_forced: Time to wait for orderly shutdown before tiggering a
|
|
* forced shudown. Negative value disables the forced
|
|
* shutdown.
|
|
*
|
|
* Initiate an emergency system shutdown in order to protect hardware from
|
|
* further damage. Usage examples include a thermal protection or a voltage or
|
|
* current regulator failures.
|
|
* NOTE: The request is ignored if protection shutdown is already pending even
|
|
* if the previous request has given a large timeout for forced shutdown.
|
|
* Can be called from any context.
|
|
*/
|
|
void hw_protection_shutdown(const char *reason, int ms_until_forced)
|
|
{
|
|
static atomic_t allow_proceed = ATOMIC_INIT(1);
|
|
|
|
pr_emerg("HARDWARE PROTECTION shutdown (%s)\n", reason);
|
|
|
|
/* Shutdown should be initiated only once. */
|
|
if (!atomic_dec_and_test(&allow_proceed))
|
|
return;
|
|
|
|
/*
|
|
* Queue a backup emergency shutdown in the event of
|
|
* orderly_poweroff failure
|
|
*/
|
|
hw_failure_emergency_poweroff(ms_until_forced);
|
|
orderly_poweroff(true);
|
|
}
|
|
EXPORT_SYMBOL_GPL(hw_protection_shutdown);
|
|
|
|
static int __init reboot_setup(char *str)
|
|
{
|
|
for (;;) {
|
|
enum reboot_mode *mode;
|
|
|
|
/*
|
|
* Having anything passed on the command line via
|
|
* reboot= will cause us to disable DMI checking
|
|
* below.
|
|
*/
|
|
reboot_default = 0;
|
|
|
|
if (!strncmp(str, "panic_", 6)) {
|
|
mode = &panic_reboot_mode;
|
|
str += 6;
|
|
} 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,
|
|
};
|
|
|
|
#ifdef CONFIG_SYSCTL
|
|
static struct ctl_table kern_reboot_table[] = {
|
|
{
|
|
.procname = "poweroff_cmd",
|
|
.data = &poweroff_cmd,
|
|
.maxlen = POWEROFF_CMD_PATH_LEN,
|
|
.mode = 0644,
|
|
.proc_handler = proc_dostring,
|
|
},
|
|
{
|
|
.procname = "ctrl-alt-del",
|
|
.data = &C_A_D,
|
|
.maxlen = sizeof(int),
|
|
.mode = 0644,
|
|
.proc_handler = proc_dointvec,
|
|
},
|
|
{ }
|
|
};
|
|
|
|
static void __init kernel_reboot_sysctls_init(void)
|
|
{
|
|
register_sysctl_init("kernel", kern_reboot_table);
|
|
}
|
|
#else
|
|
#define kernel_reboot_sysctls_init() do { } while (0)
|
|
#endif /* CONFIG_SYSCTL */
|
|
|
|
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;
|
|
}
|
|
|
|
kernel_reboot_sysctls_init();
|
|
|
|
return 0;
|
|
}
|
|
late_initcall(reboot_ksysfs_init);
|
|
|
|
#endif
|