reboot: move shutdown/reboot related functions to kernel/reboot.c
authorRobin Holt <holt@sgi.com>
Mon, 8 Jul 2013 23:01:32 +0000 (16:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 9 Jul 2013 17:33:29 +0000 (10:33 -0700)
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>
kernel/Makefile
kernel/reboot.c [new file with mode: 0644]
kernel/sys.c

index 271fd3119af9bac708773e30267077b3a5a5d276..470839d1a30ed72f68789df711bfa78bdc60e5f4 100644 (file)
@@ -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
diff --git a/kernel/reboot.c b/kernel/reboot.c
new file mode 100644 (file)
index 0000000..37d2636
--- /dev/null
@@ -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);
index b882440bd0c0cbec27f240d5c9842197f862d48e..771129b299f8865d176f233e1f14c290da8c89c8 100644 (file)
@@ -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