mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-26 10:49:33 +00:00
![Robin Holt](/assets/img/avatar_default.png)
Merge together the unicore32, arm, and x86 reboot= command line parameter handling. Signed-off-by: Robin Holt <holt@sgi.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Russ Anderson <rja@sgi.com> Cc: Robin Holt <holt@sgi.com> Acked-by: Ingo Molnar <mingo@kernel.org> Acked-by: Guan Xuetao <gxt@mprc.pku.edu.cn> Acked-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
419 lines
9.2 KiB
C
419 lines
9.2 KiB
C
/*
|
|
* linux/kernel/reboot.c
|
|
*
|
|
* Copyright (C) 2013 Linus Torvalds
|
|
*/
|
|
|
|
#define pr_fmt(fmt) "reboot: " fmt
|
|
|
|
#include <linux/ctype.h>
|
|
#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 defined(CONFIG_ARM) || defined(CONFIG_UNICORE32)
|
|
#define DEFAULT_REBOOT_MODE = REBOOT_HARD
|
|
#else
|
|
#define DEFAULT_REBOOT_MODE
|
|
#endif
|
|
enum reboot_mode reboot_mode DEFAULT_REBOOT_MODE;
|
|
|
|
int reboot_default;
|
|
int reboot_cpu;
|
|
enum reboot_type reboot_type = BOOT_ACPI;
|
|
int reboot_force;
|
|
|
|
/*
|
|
* 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 = reboot_cpu;
|
|
|
|
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)
|
|
pr_emerg("Restarting system\n");
|
|
else
|
|
pr_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();
|
|
pr_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();
|
|
pr_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:
|
|
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
|
|
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 {
|
|
ret = -ENOMEM;
|
|
}
|
|
|
|
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.
|
|
*/
|
|
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);
|
|
|
|
static int __init reboot_setup(char *str)
|
|
{
|
|
for (;;) {
|
|
/*
|
|
* Having anything passed on the command line via
|
|
* reboot= will cause us to disable DMI checking
|
|
* below.
|
|
*/
|
|
reboot_default = 0;
|
|
|
|
switch (*str) {
|
|
case 'w':
|
|
reboot_mode = REBOOT_WARM;
|
|
break;
|
|
|
|
case 'c':
|
|
reboot_mode = REBOOT_COLD;
|
|
break;
|
|
|
|
case 'h':
|
|
reboot_mode = REBOOT_HARD;
|
|
break;
|
|
|
|
case 's':
|
|
if (isdigit(*(str+1)))
|
|
reboot_cpu = simple_strtoul(str+1, NULL, 0);
|
|
else if (str[1] == 'm' && str[2] == 'p' &&
|
|
isdigit(*(str+3)))
|
|
reboot_cpu = simple_strtoul(str+3, NULL, 0);
|
|
else
|
|
reboot_mode = REBOOT_SOFT;
|
|
break;
|
|
|
|
case 'g':
|
|
reboot_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);
|