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/config.h>
  12 #include <linux/module.h>
  13 #include <linux/sched.h>
  14 #include <linux/delay.h>
  15 #include <linux/reboot.h>
  16 #include <linux/notifier.h>
  17 #include <linux/init.h>
  18 #include <linux/sysrq.h>
  19 #include <linux/syscalls.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/nmi.h>
  22
  23 int panic_timeout;
  24 int panic_on_oops;
  25 int tainted;
  26
  27 EXPORT_SYMBOL(panic_timeout);
  28
  29 struct notifier_block *panic_notifier_list;
  30
  31 EXPORT_SYMBOL(panic_notifier_list);
  32
  33 static int __init panic_setup(char *str)
  34 {
  35         panic_timeout = simple_strtoul(str, NULL, 0);
  36         return 1;
  37 }
  38 __setup("panic=", panic_setup);
  39
  40 /**
  41  *      panic - halt the system
  42  *      @fmt: The text string to print
  43  *
  44  *      Display a message, then perform cleanups. Functions in the panic
  45  *      notifier list are called after the filesystem cache is flushed (when possible).
  46  *
  47  *      This function never returns.
  48  */
  49
  50 NORET_TYPE void panic(const char * fmt, ...)
  51 {
  52         static char buf[1024];
  53         va_list args;
  54 #if defined(CONFIG_ARCH_S390)
  55         unsigned long caller = (unsigned long) __builtin_return_address(0);
  56 #endif
  57
  58         bust_spinlocks(1);
  59         va_start(args, fmt);
  60         vsnprintf(buf, sizeof(buf), fmt, args);
  61         va_end(args);
  62         printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
  63         bust_spinlocks(0);
  64
  65 #ifdef CONFIG_SMP
  66         smp_send_stop();
  67 #endif
  68
  69        notifier_call_chain(&panic_notifier_list, 0, buf);
  70
  71         if (panic_timeout > 0)
  72         {
  73                 int i;
  74                 /*
  75                  * Delay timeout seconds before rebooting the machine.
  76                  * We can't use the "normal" timers since we just panicked..
  77                  */
  78                 printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
  79                 for (i = 0; i < panic_timeout; i++) {
  80                         touch_nmi_watchdog();
  81                         mdelay(1000);
  82                 }
  83                 /*
  84                  *      Should we run the reboot notifier. For the moment Im
  85                  *      choosing not too. It might crash, be corrupt or do
  86                  *      more harm than good for other reasons.
  87                  */
  88                 machine_restart(NULL);
  89         }
  90 #ifdef __sparc__
  91         {
  92                 extern int stop_a_enabled;
  93                 /* Make sure the user can actually press L1-A */
  94                 stop_a_enabled = 1;
  95                 printk(KERN_EMERG "Press L1-A to return to the boot prom\n");
  96         }
  97 #endif
  98 #if defined(CONFIG_ARCH_S390)
  99         disabled_wait(caller);
 100 #endif
 101         local_irq_enable();
 102         for (;;)
 103                 ;
 104 }
 105
 106 EXPORT_SYMBOL(panic);
 107
 108 /**
 109  *      print_tainted - return a string to represent the kernel taint state.
 110  *
 111  *  'P' - Proprietary module has been loaded.
 112  *  'F' - Module has been forcibly loaded.
 113  *  'S' - SMP with CPUs not designed for SMP.
 114  *
 115  *      The string is overwritten by the next call to print_taint().
 116  */
 117
 118 const char *print_tainted(void)
 119 {
 120         static char buf[20];
 121         if (tainted) {
 122                 snprintf(buf, sizeof(buf), "Tainted: %c%c%c",
 123                         tainted & TAINT_PROPRIETARY_MODULE ? 'P' : 'G',
 124                         tainted & TAINT_FORCED_MODULE ? 'F' : ' ',
 125                         tainted & TAINT_UNSAFE_SMP ? 'S' : ' ');
 126         }
 127         else
 128                 snprintf(buf, sizeof(buf), "Not tainted");
 129         return(buf);
 130 }