| 1 | |
| 2 | * linux/kernel/panic.c
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| 3 | *
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| 4 | * Copyright (C) 1991, 1992 Linus Torvalds
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| 5 |
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| 6 |
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| 7 | |
| 8 | * This function is used through-out the kernel (including mm and fs)
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| 9 | * to indicate a major problem.
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| 10 |
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| 11 | #include <linux/config.h>
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| 12 | #include <linux/module.h>
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| 13 | #include <linux/sched.h>
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| 14 | #include <linux/delay.h>
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| 15 | #include <linux/reboot.h>
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| 16 | #include <linux/notifier.h>
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| 17 | #include <linux/init.h>
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| 18 | #include <linux/sysrq.h>
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| 19 | #include <linux/interrupt.h>
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| 20 | #include <linux/nmi.h>
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| 21 | #include <linux/kexec.h>
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| 22 |
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| 23 | int panic_timeout;
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| 24 | int panic_on_oops;
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| 25 | int tainted;
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| 26 |
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| 27 | EXPORT_SYMBOL(panic_timeout);
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| 28 |
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| 29 | struct notifier_block *panic_notifier_list;
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| 30 |
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| 31 | EXPORT_SYMBOL(panic_notifier_list);
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| 32 |
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| 33 | static int __init panic_setup(char *str)
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| 34 | {
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| 35 | panic_timeout = simple_strtoul(str, NULL, 0);
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| 36 | return 1;
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| 37 | }
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| 38 | __setup("panic=", panic_setup);
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| 39 |
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| 40 | static long no_blink(long time)
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| 41 | {
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| 42 | return 0;
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| 43 | }
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| 44 |
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| 45 |
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| 46 | long (*panic_blink)(long time);
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| 47 | EXPORT_SYMBOL(panic_blink);
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| 48 |
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| 49 | |
| 50 | * panic - halt the system
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| 51 | * @fmt: The text string to print
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| 52 | *
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| 53 | * Display a message, then perform cleanups.
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| 54 | *
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| 55 | * This function never returns.
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| 56 |
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| 57 |
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| 58 | NORET_TYPE void panic(const char * fmt, ...)
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| 59 | {
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| 60 | long i;
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| 61 | static char buf[1024];
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| 62 | va_list args;
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| 63 | #if defined(CONFIG_S390)
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| 64 | unsigned long caller = (unsigned long) __builtin_return_address(0);
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| 65 | #endif
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| 66 |
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| 67 | |
| 68 | * It's possible to come here directly from a panic-assertion and not
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| 69 | * have preempt disabled. Some functions called from here want
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| 70 | * preempt to be disabled. No point enabling it later though...
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| 71 |
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| 72 | preempt_disable();
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| 73 |
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| 74 | bust_spinlocks(1);
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| 75 | va_start(args, fmt);
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| 76 | vsnprintf(buf, sizeof(buf), fmt, args);
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| 77 | va_end(args);
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| 78 | printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf);
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| 79 | bust_spinlocks(0);
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| 80 |
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| 81 | |
| 82 | * If we have crashed and we have a crash kernel loaded let it handle
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| 83 | * everything else.
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| 84 | * Do we want to call this before we try to display a message?
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| 85 |
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| 86 | crash_kexec(NULL);
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| 87 |
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| 88 | #ifdef CONFIG_SMP
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| 89 | |
| 90 | * Note smp_send_stop is the usual smp shutdown function, which
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| 91 | * unfortunately means it may not be hardened to work in a panic
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| 92 | * situation.
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| 93 |
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| 94 | smp_send_stop();
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| 95 | #endif
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| 96 |
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| 97 | notifier_call_chain(&panic_notifier_list, 0, buf);
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| 98 |
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| 99 | if (!panic_blink)
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| 100 | panic_blink = no_blink;
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| 101 |
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| 102 | if (panic_timeout > 0) {
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| 103 | |
| 104 | * Delay timeout seconds before rebooting the machine.
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| 105 | * We can't use the "normal" timers since we just panicked..
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| 106 |
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| 107 | printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
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| 108 | for (i = 0; i < panic_timeout*1000; ) {
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| 109 | touch_nmi_watchdog();
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| 110 | i += panic_blink(i);
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| 111 | mdelay(1);
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| 112 | i++;
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| 113 | }
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| 114 | |
| 115 | * shutting down. But if there is a chance of
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| 116 | * rebooting the system it will be rebooted.
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| 117 |
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| 118 | emergency_restart();
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| 119 | }
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| 120 | #ifdef __sparc__
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| 121 | {
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| 122 | extern int stop_a_enabled;
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| 123 |
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| 124 | stop_a_enabled = 1;
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| 125 | printk(KERN_EMERG "Press Stop-A (L1-A) to return to the boot prom\n");
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| 126 | }
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| 127 | #endif
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| 128 | #if defined(CONFIG_S390)
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| 129 | disabled_wait(caller);
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| 130 | #endif
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| 131 | local_irq_enable();
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| 132 | for (i = 0;;) {
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| 133 | touch_softlockup_watchdog();
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| 134 | i += panic_blink(i);
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| 135 | mdelay(1);
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| 136 | i++;
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| 137 | }
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| 138 | }
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| 139 |
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| 140 | EXPORT_SYMBOL(panic);
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| 141 |
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| 142 | |
| 143 | * print_tainted - return a string to represent the kernel taint state.
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| 144 | *
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| 145 | * 'P' - Proprietary module has been loaded.
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| 146 | * 'F' - Module has been forcibly loaded.
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| 147 | * 'S' - SMP with CPUs not designed for SMP.
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| 148 | * 'R' - User forced a module unload.
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| 149 | * 'M' - Machine had a machine check experience.
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| 150 | * 'B' - System has hit bad_page.
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| 151 | *
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| 152 | * The string is overwritten by the next call to print_taint().
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| 153 |
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| 154 |
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| 155 | const char *print_tainted(void)
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| 156 | {
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| 157 | static char buf[20];
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| 158 | if (tainted) {
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| 159 | snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c",
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| 160 | tainted & TAINT_PROPRIETARY_MODULE ? 'P' : 'G',
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| 161 | tainted & TAINT_FORCED_MODULE ? 'F' : ' ',
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| 162 | tainted & TAINT_UNSAFE_SMP ? 'S' : ' ',
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| 163 | tainted & TAINT_FORCED_RMMOD ? 'R' : ' ',
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| 164 | tainted & TAINT_MACHINE_CHECK ? 'M' : ' ',
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| 165 | tainted & TAINT_BAD_PAGE ? 'B' : ' ');
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| 166 | }
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| 167 | else
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| 168 | snprintf(buf, sizeof(buf), "Not tainted");
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| 169 | return(buf);
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| 170 | }
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| 171 |
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| 172 | void add_taint(unsigned flag)
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| 173 | {
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| 174 | tainted |= flag;
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| 175 | }
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| 176 | EXPORT_SYMBOL(add_taint);
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