cvs.zerfleddert.de Git - ms2-kexec/blob - sys.c

   1 /*
   2  *  linux/kernel/sys.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 #include <linux/module.h>
   8 #include <linux/mm.h>
   9 #include <linux/utsname.h>
  10 #include <linux/mman.h>
  11 #include <linux/smp_lock.h>
  12 #include <linux/notifier.h>
  13 #include <linux/reboot.h>
  14 #include <linux/prctl.h>
  15 #include <linux/highuid.h>
  16 #include <linux/fs.h>
  17 #include <linux/resource.h>
  18 #include <linux/kernel.h>
  19 #include <linux/kexec.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/capability.h>
  22 #include <linux/device.h>
  23 #include <linux/key.h>
  24 #include <linux/times.h>
  25 #include <linux/posix-timers.h>
  26 #include <linux/security.h>
  27 #include <linux/dcookies.h>
  28 #include <linux/suspend.h>
  29 #include <linux/tty.h>
  30 #include <linux/signal.h>
  31 #include <linux/cn_proc.h>
  32 #include <linux/getcpu.h>
  33 #include <linux/task_io_accounting_ops.h>
  34 #include <linux/seccomp.h>
  35 #include <linux/cpu.h>
  36 #include <linux/ptrace.h>
  37
  38 #include <linux/compat.h>
  39 #include <linux/syscalls.h>
  40 #include <linux/kprobes.h>
  41 #include <linux/user_namespace.h>
  42
  43 #include <asm/uaccess.h>
  44 #include <asm/io.h>
  45 #include <asm/unistd.h>
  46
  47 extern asmlinkage long (*original_reboot)(int magic1, int magic2, unsigned int cmd, void __user *arg);
  48
  49 static struct notifier_block dummy_notifier_reboot = {
  50          .notifier_call  = NULL,
  51          .next           = NULL,
  52          .priority       = INT_MAX
  53 };
  54
  55 BLOCKING_NOTIFIER_HEAD(notifier_head);
  56
  57
  58 void kernel_restart_prepare(char *cmd)
  59 {
  60         register_reboot_notifier(&dummy_notifier_reboot);
  61         notifier_head.head=dummy_notifier_reboot.next;
  62         unregister_reboot_notifier(&dummy_notifier_reboot);
  63
  64         blocking_notifier_call_chain(&notifier_head, SYS_RESTART, cmd);
  65         system_state = SYSTEM_RESTART;
  66 //      device_shutdown();
  67 //      sysdev_shutdown();
  68 }
  69
  70 /*
  71  * Reboot system call: for obvious reasons only root may call it,
  72  * and even root needs to set up some magic numbers in the registers
  73  * so that some mistake won't make this reboot the whole machine.
  74  * You can also set the meaning of the ctrl-alt-del-key here.
  75  *
  76  * reboot doesn't sync: do that yourself before calling this.
  77  */
  78 asmlinkage long reboot(int magic1, int magic2, unsigned int cmd, void __user *arg)
  79 {
  80         int ret;
  81         if(cmd==LINUX_REBOOT_CMD_KEXEC) {
  82                 /* We only trust the superuser with rebooting the system. */
  83                 if (!capable(CAP_SYS_BOOT))
  84                         return -EPERM;
  85
  86                 /* For safety, we require "magic" arguments. */
  87                 if (magic1 != LINUX_REBOOT_MAGIC1 ||
  88                     (magic2 != LINUX_REBOOT_MAGIC2 &&
  89                                 magic2 != LINUX_REBOOT_MAGIC2A &&
  90                                 magic2 != LINUX_REBOOT_MAGIC2B &&
  91                                 magic2 != LINUX_REBOOT_MAGIC2C))
  92                         return -EINVAL;
  93
  94                 lock_kernel();
  95                 ret = kernel_kexec();
  96                 unlock_kernel();
  97                 return ret;
  98         } else {
  99                 return original_reboot(magic1, magic2, cmd, arg);
 100         }
 101 }