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https://github.com/torvalds/linux.git
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fb37409a01
The unicore32 port do not seem maintained for a long time now, there is no upstream toolchain that can create unicore32 binaries and all the links to prebuilt toolchains for unicore32 are dead. Even compilers that were available are not supported by the kernel anymore. Guenter Roeck says: I have stopped building unicore32 images since v4.19 since there is no available compiler that is still supported by the kernel. I am surprised that support for it has not been removed from the kernel. Remove unicore32 port. Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Guenter Roeck <linux@roeck-us.net>
597 lines
14 KiB
C
597 lines
14 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/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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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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* 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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if (!strncmp(str, "panic_", 6)) {
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mode = &panic_reboot_mode;
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str += 6;
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} else {
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|
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':
|
|
{
|
|
int rc;
|
|
|
|
if (isdigit(*(str+1))) {
|
|
rc = kstrtoint(str+1, 0, &reboot_cpu);
|
|
if (rc)
|
|
return rc;
|
|
} else if (str[1] == 'm' && str[2] == 'p' &&
|
|
isdigit(*(str+3))) {
|
|
rc = kstrtoint(str+3, 0, &reboot_cpu);
|
|
if (rc)
|
|
return rc;
|
|
} 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);
|