LXR RHEL4/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
  23int panic_timeout;
  24int panic_on_oops = 1;
  25int panic_on_unrecovered_nmi;
  26int tainted;
  27int halt_on_dump_err = 0;
  28
  29EXPORT_SYMBOL(panic_timeout);
  30EXPORT_SYMBOL_GPL(halt_on_dump_err);
  31
  32struct notifier_block *panic_notifier_list;
  33
  34EXPORT_SYMBOL(panic_notifier_list);
  35
  36static int __init panic_setup(char *str)
  37{
  38        panic_timeout = simple_strtoul(str, NULL, 0);
  39        return 1;
  40}
  41__setup("panic=", panic_setup);
  42
  43static long no_blink(long time)
  44{
  45        return 0;
  46}
  47
  48/* Returns how long it waited in ms */
  49long (*panic_blink)(long time) = no_blink;
  50EXPORT_SYMBOL(panic_blink);
  51
  52/**
  53 *      panic - halt the system
  54 *      @fmt: The text string to print
  55 *
  56 *      Display a message, then perform cleanups. Functions in the panic
  57 *      notifier list are called after the filesystem cache is flushed (when possible).
  58 *
  59 *      This function never returns.
  60 */
  61 
  62NORET_TYPE void panic(const char * fmt, ...)
  63{
  64        long i;
  65        static char buf[1024];
  66        va_list args;
  67#if defined(CONFIG_ARCH_S390)
  68        unsigned long caller = (unsigned long) __builtin_return_address(0);
  69#endif
  70
  71        bust_spinlocks(1);
  72        va_start(args, fmt);
  73        vsnprintf(buf, sizeof(buf), fmt, args);
  74        va_end(args);
  75        printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
  76        if (crashdump_func())
  77                BUG();
  78        bust_spinlocks(0);
  79
  80#ifdef CONFIG_SMP
  81        if (!crashdump_mode())
  82                smp_send_stop();
  83#endif
  84
  85       notifier_call_chain(&panic_notifier_list, 0, buf);
  86
  87        if (panic_timeout > 0 && !halt_on_dump_err)
  88        {
  89                /*
  90                 * Delay timeout seconds before rebooting the machine. 
  91                 * We can't use the "normal" timers since we just panicked..
  92                 */
  93                printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
  94                for (i = 0; i < panic_timeout*1000; ) {
  95                        touch_nmi_watchdog();
  96                        i += panic_blink(i);
  97                        mdelay(1);
  98                        i++;
  99                }
 100                /*
 101                 *      Should we run the reboot notifier. For the moment Im
 102                 *      choosing not too. It might crash, be corrupt or do
 103                 *      more harm than good for other reasons.
 104                 */
 105                machine_restart(NULL);
 106        }
 107#ifdef __sparc__
 108        {
 109                extern int stop_a_enabled;
 110                /* Make sure the user can actually press L1-A */
 111                stop_a_enabled = 1;
 112                printk(KERN_EMERG "Press L1-A to return to the boot prom\n");
 113        }
 114#endif
 115#if defined(CONFIG_ARCH_S390)
 116        disabled_wait(caller);
 117#endif
 118        local_irq_enable();
 119        for (i = 0;;) { 
 120                i += panic_blink(i);
 121                mdelay(1); 
 122                i++; 
 123        }
 124}
 125
 126EXPORT_SYMBOL(panic);
 127
 128/**
 129 *      print_tainted - return a string to represent the kernel taint state.
 130 *
 131 *  'P' - Proprietary module has been loaded.
 132 *  'F' - Module has been forcibly loaded.
 133 *  'S' - SMP with CPUs not designed for SMP.
 134 *  'R' - User forced a module unload.
 135 *  'M' - Machine had a machine check experience.
 136 *  'B' - System has hit bad_page.
 137 *
 138 *      The string is overwritten by the next call to print_taint().
 139 */
 140 
 141const char *print_tainted(void)
 142{
 143        static char buf[20];
 144        if (tainted) {
 145                snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c",
 146                        tainted & TAINT_PROPRIETARY_MODULE ? 'P' : 'G',
 147                        tainted & TAINT_FORCED_MODULE ? 'F' : ' ',
 148                        tainted & TAINT_UNSAFE_SMP ? 'S' : ' ',
 149                        tainted & TAINT_FORCED_RMMOD ? 'R' : ' ',
 150                        tainted & TAINT_MACHINE_CHECK ? 'M' : ' ',
 151                        tainted & TAINT_BAD_PAGE ? 'B' : ' ');
 152        }
 153        else
 154                snprintf(buf, sizeof(buf), "Not tainted");
 155        return(buf);
 156}
 157
 158void add_taint(unsigned flag)
 159{
 160        tainted |= flag;
 161}
 162EXPORT_SYMBOL(add_taint);
 163