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