reboot: move shutdown/reboot related functions to kernel/reboot.c
This patch is preparatory. It moves reboot related syscall, etc functions from kernel/sys.c to kernel/reboot.c. Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
		
							parent
							
								
									0efbee7089
								
							
						
					
					
						commit
						15d94b8256
					
				| @ -9,7 +9,7 @@ obj-y     = fork.o exec_domain.o panic.o printk.o \ | ||||
| 	    rcupdate.o extable.o params.o posix-timers.o \
 | ||||
| 	    kthread.o wait.o sys_ni.o posix-cpu-timers.o mutex.o \
 | ||||
| 	    hrtimer.o rwsem.o nsproxy.o srcu.o semaphore.o \
 | ||||
| 	    notifier.o ksysfs.o cred.o \
 | ||||
| 	    notifier.o ksysfs.o cred.o reboot.o \
 | ||||
| 	    async.o range.o groups.o lglock.o smpboot.o | ||||
| 
 | ||||
| ifdef CONFIG_FUNCTION_TRACER | ||||
|  | ||||
							
								
								
									
										346
									
								
								kernel/reboot.c
									
									
									
									
									
										Normal file
									
								
							
							
						
						
									
										346
									
								
								kernel/reboot.c
									
									
									
									
									
										Normal file
									
								
							| @ -0,0 +1,346 @@ | ||||
| /*
 | ||||
|  *  linux/kernel/reboot.c | ||||
|  * | ||||
|  *  Copyright (C) 2013  Linus Torvalds | ||||
|  */ | ||||
| 
 | ||||
| #include <linux/export.h> | ||||
| #include <linux/kexec.h> | ||||
| #include <linux/kmod.h> | ||||
| #include <linux/kmsg_dump.h> | ||||
| #include <linux/reboot.h> | ||||
| #include <linux/suspend.h> | ||||
| #include <linux/syscalls.h> | ||||
| #include <linux/syscore_ops.h> | ||||
| #include <linux/uaccess.h> | ||||
| 
 | ||||
| /*
 | ||||
|  * this indicates whether you can reboot with ctrl-alt-del: the default is yes | ||||
|  */ | ||||
| 
 | ||||
| int C_A_D = 1; | ||||
| struct pid *cad_pid; | ||||
| EXPORT_SYMBOL(cad_pid); | ||||
| 
 | ||||
| /*
 | ||||
|  * If set, this is used for preparing the system to power off. | ||||
|  */ | ||||
| 
 | ||||
| void (*pm_power_off_prepare)(void); | ||||
| 
 | ||||
| /**
 | ||||
|  *	emergency_restart - reboot the system | ||||
|  * | ||||
|  *	Without shutting down any hardware or taking any locks | ||||
|  *	reboot the system.  This is called when we know we are in | ||||
|  *	trouble so this is our best effort to reboot.  This is | ||||
|  *	safe to call in interrupt context. | ||||
|  */ | ||||
| void emergency_restart(void) | ||||
| { | ||||
| 	kmsg_dump(KMSG_DUMP_EMERG); | ||||
| 	machine_emergency_restart(); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(emergency_restart); | ||||
| 
 | ||||
| void kernel_restart_prepare(char *cmd) | ||||
| { | ||||
| 	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); | ||||
| 	system_state = SYSTEM_RESTART; | ||||
| 	usermodehelper_disable(); | ||||
| 	device_shutdown(); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  *	register_reboot_notifier - Register function to be called at reboot time | ||||
|  *	@nb: Info about notifier function to be called | ||||
|  * | ||||
|  *	Registers a function with the list of functions | ||||
|  *	to be called at reboot time. | ||||
|  * | ||||
|  *	Currently always returns zero, as blocking_notifier_chain_register() | ||||
|  *	always returns zero. | ||||
|  */ | ||||
| int register_reboot_notifier(struct notifier_block *nb) | ||||
| { | ||||
| 	return blocking_notifier_chain_register(&reboot_notifier_list, nb); | ||||
| } | ||||
| EXPORT_SYMBOL(register_reboot_notifier); | ||||
| 
 | ||||
| /**
 | ||||
|  *	unregister_reboot_notifier - Unregister previously registered reboot notifier | ||||
|  *	@nb: Hook to be unregistered | ||||
|  * | ||||
|  *	Unregisters a previously registered reboot | ||||
|  *	notifier function. | ||||
|  * | ||||
|  *	Returns zero on success, or %-ENOENT on failure. | ||||
|  */ | ||||
| int unregister_reboot_notifier(struct notifier_block *nb) | ||||
| { | ||||
| 	return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | ||||
| } | ||||
| EXPORT_SYMBOL(unregister_reboot_notifier); | ||||
| 
 | ||||
| static void migrate_to_reboot_cpu(void) | ||||
| { | ||||
| 	/* The boot cpu is always logical cpu 0 */ | ||||
| 	int cpu = 0; | ||||
| 
 | ||||
| 	cpu_hotplug_disable(); | ||||
| 
 | ||||
| 	/* Make certain the cpu I'm about to reboot on is online */ | ||||
| 	if (!cpu_online(cpu)) | ||||
| 		cpu = cpumask_first(cpu_online_mask); | ||||
| 
 | ||||
| 	/* Prevent races with other tasks migrating this task */ | ||||
| 	current->flags |= PF_NO_SETAFFINITY; | ||||
| 
 | ||||
| 	/* Make certain I only run on the appropriate processor */ | ||||
| 	set_cpus_allowed_ptr(current, cpumask_of(cpu)); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  *	kernel_restart - reboot the system | ||||
|  *	@cmd: pointer to buffer containing command to execute for restart | ||||
|  *		or %NULL | ||||
|  * | ||||
|  *	Shutdown everything and perform a clean reboot. | ||||
|  *	This is not safe to call in interrupt context. | ||||
|  */ | ||||
| void kernel_restart(char *cmd) | ||||
| { | ||||
| 	kernel_restart_prepare(cmd); | ||||
| 	migrate_to_reboot_cpu(); | ||||
| 	syscore_shutdown(); | ||||
| 	if (!cmd) | ||||
| 		printk(KERN_EMERG "Restarting system.\n"); | ||||
| 	else | ||||
| 		printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); | ||||
| 	kmsg_dump(KMSG_DUMP_RESTART); | ||||
| 	machine_restart(cmd); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(kernel_restart); | ||||
| 
 | ||||
| static void kernel_shutdown_prepare(enum system_states state) | ||||
| { | ||||
| 	blocking_notifier_call_chain(&reboot_notifier_list, | ||||
| 		(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); | ||||
| 	system_state = state; | ||||
| 	usermodehelper_disable(); | ||||
| 	device_shutdown(); | ||||
| } | ||||
| /**
 | ||||
|  *	kernel_halt - halt the system | ||||
|  * | ||||
|  *	Shutdown everything and perform a clean system halt. | ||||
|  */ | ||||
| void kernel_halt(void) | ||||
| { | ||||
| 	kernel_shutdown_prepare(SYSTEM_HALT); | ||||
| 	migrate_to_reboot_cpu(); | ||||
| 	syscore_shutdown(); | ||||
| 	printk(KERN_EMERG "System halted.\n"); | ||||
| 	kmsg_dump(KMSG_DUMP_HALT); | ||||
| 	machine_halt(); | ||||
| } | ||||
| 
 | ||||
| EXPORT_SYMBOL_GPL(kernel_halt); | ||||
| 
 | ||||
| /**
 | ||||
|  *	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); | ||||
| 	if (pm_power_off_prepare) | ||||
| 		pm_power_off_prepare(); | ||||
| 	migrate_to_reboot_cpu(); | ||||
| 	syscore_shutdown(); | ||||
| 	printk(KERN_EMERG "Power down.\n"); | ||||
| 	kmsg_dump(KMSG_DUMP_POWEROFF); | ||||
| 	machine_power_off(); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(kernel_power_off); | ||||
| 
 | ||||
| static DEFINE_MUTEX(reboot_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) && !pm_power_off) | ||||
| 		cmd = LINUX_REBOOT_CMD_HALT; | ||||
| 
 | ||||
| 	mutex_lock(&reboot_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); | ||||
| 		panic("cannot halt"); | ||||
| 
 | ||||
| 	case LINUX_REBOOT_CMD_POWER_OFF: | ||||
| 		kernel_power_off(); | ||||
| 		do_exit(0); | ||||
| 		break; | ||||
| 
 | ||||
| 	case LINUX_REBOOT_CMD_RESTART2: | ||||
| 		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | ||||
| 			ret = -EFAULT; | ||||
| 			break; | ||||
| 		} | ||||
| 		buffer[sizeof(buffer) - 1] = '\0'; | ||||
| 
 | ||||
| 		kernel_restart(buffer); | ||||
| 		break; | ||||
| 
 | ||||
| #ifdef CONFIG_KEXEC | ||||
| 	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(&reboot_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); | ||||
| } | ||||
| 
 | ||||
| char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | ||||
| 
 | ||||
| static int __orderly_poweroff(bool force) | ||||
| { | ||||
| 	char **argv; | ||||
| 	static char *envp[] = { | ||||
| 		"HOME=/", | ||||
| 		"PATH=/sbin:/bin:/usr/sbin:/usr/bin", | ||||
| 		NULL | ||||
| 	}; | ||||
| 	int ret; | ||||
| 
 | ||||
| 	argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL); | ||||
| 	if (argv) { | ||||
| 		ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); | ||||
| 		argv_free(argv); | ||||
| 	} else { | ||||
| 		printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", | ||||
| 					 __func__, poweroff_cmd); | ||||
| 		ret = -ENOMEM; | ||||
| 	} | ||||
| 
 | ||||
| 	if (ret && force) { | ||||
| 		printk(KERN_WARNING "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. | ||||
|  */ | ||||
| int orderly_poweroff(bool force) | ||||
| { | ||||
| 	if (force) /* do not override the pending "true" */ | ||||
| 		poweroff_force = true; | ||||
| 	schedule_work(&poweroff_work); | ||||
| 	return 0; | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(orderly_poweroff); | ||||
							
								
								
									
										331
									
								
								kernel/sys.c
									
									
									
									
									
								
							
							
						
						
									
										331
									
								
								kernel/sys.c
									
									
									
									
									
								
							| @ -115,20 +115,6 @@ int fs_overflowgid = DEFAULT_FS_OVERFLOWUID; | ||||
| EXPORT_SYMBOL(fs_overflowuid); | ||||
| EXPORT_SYMBOL(fs_overflowgid); | ||||
| 
 | ||||
| /*
 | ||||
|  * this indicates whether you can reboot with ctrl-alt-del: the default is yes | ||||
|  */ | ||||
| 
 | ||||
| int C_A_D = 1; | ||||
| struct pid *cad_pid; | ||||
| EXPORT_SYMBOL(cad_pid); | ||||
| 
 | ||||
| /*
 | ||||
|  * If set, this is used for preparing the system to power off. | ||||
|  */ | ||||
| 
 | ||||
| void (*pm_power_off_prepare)(void); | ||||
| 
 | ||||
| /*
 | ||||
|  * Returns true if current's euid is same as p's uid or euid, | ||||
|  * or has CAP_SYS_NICE to p's user_ns. | ||||
| @ -308,261 +294,6 @@ out_unlock: | ||||
| 	return retval; | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  *	emergency_restart - reboot the system | ||||
|  * | ||||
|  *	Without shutting down any hardware or taking any locks | ||||
|  *	reboot the system.  This is called when we know we are in | ||||
|  *	trouble so this is our best effort to reboot.  This is | ||||
|  *	safe to call in interrupt context. | ||||
|  */ | ||||
| void emergency_restart(void) | ||||
| { | ||||
| 	kmsg_dump(KMSG_DUMP_EMERG); | ||||
| 	machine_emergency_restart(); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(emergency_restart); | ||||
| 
 | ||||
| void kernel_restart_prepare(char *cmd) | ||||
| { | ||||
| 	blocking_notifier_call_chain(&reboot_notifier_list, SYS_RESTART, cmd); | ||||
| 	system_state = SYSTEM_RESTART; | ||||
| 	usermodehelper_disable(); | ||||
| 	device_shutdown(); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  *	register_reboot_notifier - Register function to be called at reboot time | ||||
|  *	@nb: Info about notifier function to be called | ||||
|  * | ||||
|  *	Registers a function with the list of functions | ||||
|  *	to be called at reboot time. | ||||
|  * | ||||
|  *	Currently always returns zero, as blocking_notifier_chain_register() | ||||
|  *	always returns zero. | ||||
|  */ | ||||
| int register_reboot_notifier(struct notifier_block *nb) | ||||
| { | ||||
| 	return blocking_notifier_chain_register(&reboot_notifier_list, nb); | ||||
| } | ||||
| EXPORT_SYMBOL(register_reboot_notifier); | ||||
| 
 | ||||
| /**
 | ||||
|  *	unregister_reboot_notifier - Unregister previously registered reboot notifier | ||||
|  *	@nb: Hook to be unregistered | ||||
|  * | ||||
|  *	Unregisters a previously registered reboot | ||||
|  *	notifier function. | ||||
|  * | ||||
|  *	Returns zero on success, or %-ENOENT on failure. | ||||
|  */ | ||||
| int unregister_reboot_notifier(struct notifier_block *nb) | ||||
| { | ||||
| 	return blocking_notifier_chain_unregister(&reboot_notifier_list, nb); | ||||
| } | ||||
| EXPORT_SYMBOL(unregister_reboot_notifier); | ||||
| 
 | ||||
| static void migrate_to_reboot_cpu(void) | ||||
| { | ||||
| 	/* The boot cpu is always logical cpu 0 */ | ||||
| 	int cpu = 0; | ||||
| 
 | ||||
| 	cpu_hotplug_disable(); | ||||
| 
 | ||||
| 	/* Make certain the cpu I'm about to reboot on is online */ | ||||
| 	if (!cpu_online(cpu)) | ||||
| 		cpu = cpumask_first(cpu_online_mask); | ||||
| 
 | ||||
| 	/* Prevent races with other tasks migrating this task */ | ||||
| 	current->flags |= PF_NO_SETAFFINITY; | ||||
| 
 | ||||
| 	/* Make certain I only run on the appropriate processor */ | ||||
| 	set_cpus_allowed_ptr(current, cpumask_of(cpu)); | ||||
| } | ||||
| 
 | ||||
| /**
 | ||||
|  *	kernel_restart - reboot the system | ||||
|  *	@cmd: pointer to buffer containing command to execute for restart | ||||
|  *		or %NULL | ||||
|  * | ||||
|  *	Shutdown everything and perform a clean reboot. | ||||
|  *	This is not safe to call in interrupt context. | ||||
|  */ | ||||
| void kernel_restart(char *cmd) | ||||
| { | ||||
| 	kernel_restart_prepare(cmd); | ||||
| 	migrate_to_reboot_cpu(); | ||||
| 	syscore_shutdown(); | ||||
| 	if (!cmd) | ||||
| 		printk(KERN_EMERG "Restarting system.\n"); | ||||
| 	else | ||||
| 		printk(KERN_EMERG "Restarting system with command '%s'.\n", cmd); | ||||
| 	kmsg_dump(KMSG_DUMP_RESTART); | ||||
| 	machine_restart(cmd); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(kernel_restart); | ||||
| 
 | ||||
| static void kernel_shutdown_prepare(enum system_states state) | ||||
| { | ||||
| 	blocking_notifier_call_chain(&reboot_notifier_list, | ||||
| 		(state == SYSTEM_HALT)?SYS_HALT:SYS_POWER_OFF, NULL); | ||||
| 	system_state = state; | ||||
| 	usermodehelper_disable(); | ||||
| 	device_shutdown(); | ||||
| } | ||||
| /**
 | ||||
|  *	kernel_halt - halt the system | ||||
|  * | ||||
|  *	Shutdown everything and perform a clean system halt. | ||||
|  */ | ||||
| void kernel_halt(void) | ||||
| { | ||||
| 	kernel_shutdown_prepare(SYSTEM_HALT); | ||||
| 	migrate_to_reboot_cpu(); | ||||
| 	syscore_shutdown(); | ||||
| 	printk(KERN_EMERG "System halted.\n"); | ||||
| 	kmsg_dump(KMSG_DUMP_HALT); | ||||
| 	machine_halt(); | ||||
| } | ||||
| 
 | ||||
| EXPORT_SYMBOL_GPL(kernel_halt); | ||||
| 
 | ||||
| /**
 | ||||
|  *	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); | ||||
| 	if (pm_power_off_prepare) | ||||
| 		pm_power_off_prepare(); | ||||
| 	migrate_to_reboot_cpu(); | ||||
| 	syscore_shutdown(); | ||||
| 	printk(KERN_EMERG "Power down.\n"); | ||||
| 	kmsg_dump(KMSG_DUMP_POWEROFF); | ||||
| 	machine_power_off(); | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(kernel_power_off); | ||||
| 
 | ||||
| static DEFINE_MUTEX(reboot_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) && !pm_power_off) | ||||
| 		cmd = LINUX_REBOOT_CMD_HALT; | ||||
| 
 | ||||
| 	mutex_lock(&reboot_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); | ||||
| 		panic("cannot halt.\n"); | ||||
| 
 | ||||
| 	case LINUX_REBOOT_CMD_POWER_OFF: | ||||
| 		kernel_power_off(); | ||||
| 		do_exit(0); | ||||
| 		break; | ||||
| 
 | ||||
| 	case LINUX_REBOOT_CMD_RESTART2: | ||||
| 		if (strncpy_from_user(&buffer[0], arg, sizeof(buffer) - 1) < 0) { | ||||
| 			ret = -EFAULT; | ||||
| 			break; | ||||
| 		} | ||||
| 		buffer[sizeof(buffer) - 1] = '\0'; | ||||
| 
 | ||||
| 		kernel_restart(buffer); | ||||
| 		break; | ||||
| 
 | ||||
| #ifdef CONFIG_KEXEC | ||||
| 	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(&reboot_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); | ||||
| } | ||||
| 	 | ||||
| /*
 | ||||
|  * Unprivileged users may change the real gid to the effective gid | ||||
|  * or vice versa.  (BSD-style) | ||||
| @ -2287,68 +2018,6 @@ SYSCALL_DEFINE3(getcpu, unsigned __user *, cpup, unsigned __user *, nodep, | ||||
| 	return err ? -EFAULT : 0; | ||||
| } | ||||
| 
 | ||||
| char poweroff_cmd[POWEROFF_CMD_PATH_LEN] = "/sbin/poweroff"; | ||||
| 
 | ||||
| static int __orderly_poweroff(bool force) | ||||
| { | ||||
| 	char **argv; | ||||
| 	static char *envp[] = { | ||||
| 		"HOME=/", | ||||
| 		"PATH=/sbin:/bin:/usr/sbin:/usr/bin", | ||||
| 		NULL | ||||
| 	}; | ||||
| 	int ret; | ||||
| 
 | ||||
| 	argv = argv_split(GFP_KERNEL, poweroff_cmd, NULL); | ||||
| 	if (argv) { | ||||
| 		ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_EXEC); | ||||
| 		argv_free(argv); | ||||
| 	} else { | ||||
| 		printk(KERN_WARNING "%s failed to allocate memory for \"%s\"\n", | ||||
| 					 __func__, poweroff_cmd); | ||||
| 		ret = -ENOMEM; | ||||
| 	} | ||||
| 
 | ||||
| 	if (ret && force) { | ||||
| 		printk(KERN_WARNING "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. | ||||
|  */ | ||||
| int orderly_poweroff(bool force) | ||||
| { | ||||
| 	if (force) /* do not override the pending "true" */ | ||||
| 		poweroff_force = true; | ||||
| 	schedule_work(&poweroff_work); | ||||
| 	return 0; | ||||
| } | ||||
| EXPORT_SYMBOL_GPL(orderly_poweroff); | ||||
| 
 | ||||
| /**
 | ||||
|  * do_sysinfo - fill in sysinfo struct | ||||
|  * @info: pointer to buffer to fill | ||||
|  | ||||
		Loading…
	
		Reference in New Issue
	
	Block a user