kernel/panic.c

   1 /*
   2  *  linux/kernel/panic.c
   3  *
   4  *  Copyright (C) 1991, 1992  Linus Torvalds
   5  */
   6
   7 /*
   8  * This function is used through-out the kernel (including mm and fs)
   9  * to indicate a major problem.
  10  */
  11 #include <linux/sched.h>
  12 #include <linux/delay.h>
  13 #include <linux/reboot.h>
  14 #include <linux/notifier.h>
  15 #include <linux/init.h>
  16 #include <linux/sysrq.h>
  17 #include <linux/interrupt.h>
  18
  19 #ifdef __alpha__
  20 #include <asm/machvec.h>
  21 #endif
  22
  23 asmlinkage void sys_sync(void); /* it's really int */
  24 extern void unblank_console(void);
  25 extern int C_A_D;
  26
  27 int panic_timeout = 0;
  28
  29 struct notifier_block *panic_notifier_list = NULL;
  30
  31 static int __init panic_setup(char *str)
  32 {
  33         panic_timeout = simple_strtoul(str, NULL, 0);
  34         return 1;
  35 }
  36
  37 __setup("panic=", panic_setup);
  38
  39 NORET_TYPE void panic(const char * fmt, ...)
  40 {
  41         static char buf[1024];
  42         va_list args;
  43
  44         va_start(args, fmt);
  45         vsprintf(buf, fmt, args);
  46         va_end(args);
  47         printk(KERN_EMERG "Kernel panic: %s\n",buf);
  48         if (current == init_tasks[0])
  49                 printk(KERN_EMERG "In swapper task - not syncing\n");
  50         else if (in_interrupt())
  51                 printk(KERN_EMERG "In interrupt handler - not syncing\n");
  52         else
  53                 sys_sync();
  54
  55         unblank_console();
  56
  57 #ifdef __SMP__
  58         smp_send_stop();
  59 #endif
  60
  61         notifier_call_chain(&panic_notifier_list, 0, NULL);
  62
  63         if (panic_timeout > 0)
  64         {
  65                 /*
  66                  * Delay timeout seconds before rebooting the machine.
  67                  * We can't use the "normal" timers since we just panicked..
  68                  */
  69                 printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
  70                 mdelay(panic_timeout*1000);
  71                 /*
  72                  *      Should we run the reboot notifier. For the moment Im
  73                  *      choosing not too. It might crash, be corrupt or do
  74                  *      more harm than good for other reasons.
  75                  */
  76                 machine_restart(NULL);
  77         }
  78 #ifdef __sparc__
  79         printk("Press L1-A to return to the boot prom\n");
  80 #endif
  81 #ifdef __alpha__
  82         if (alpha_using_srm)
  83                 halt();
  84 #endif
  85         sti();
  86         for(;;) {
  87                 CHECK_EMERGENCY_SYNC
  88         }
  89 }