Commit | Line | Data |
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1da177e4 LT |
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/interrupt.h> | |
20 | #include <linux/nmi.h> | |
dc009d92 | 21 | #include <linux/kexec.h> |
1da177e4 LT |
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 | static long no_blink(long time) | |
41 | { | |
42 | return 0; | |
43 | } | |
44 | ||
45 | /* Returns how long it waited in ms */ | |
46 | long (*panic_blink)(long time); | |
47 | EXPORT_SYMBOL(panic_blink); | |
48 | ||
49 | /** | |
50 | * panic - halt the system | |
51 | * @fmt: The text string to print | |
52 | * | |
53 | * Display a message, then perform cleanups. | |
54 | * | |
55 | * This function never returns. | |
56 | */ | |
57 | ||
58 | NORET_TYPE void panic(const char * fmt, ...) | |
59 | { | |
60 | long i; | |
61 | static char buf[1024]; | |
62 | va_list args; | |
63 | #if defined(CONFIG_ARCH_S390) | |
64 | unsigned long caller = (unsigned long) __builtin_return_address(0); | |
65 | #endif | |
66 | ||
dc009d92 EB |
67 | /* |
68 | * It's possible to come here directly from a panic-assertion and not | |
69 | * have preempt disabled. Some functions called from here want | |
70 | * preempt to be disabled. No point enabling it later though... | |
71 | */ | |
72 | preempt_disable(); | |
73 | ||
1da177e4 LT |
74 | bust_spinlocks(1); |
75 | va_start(args, fmt); | |
76 | vsnprintf(buf, sizeof(buf), fmt, args); | |
77 | va_end(args); | |
78 | printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf); | |
79 | bust_spinlocks(0); | |
80 | ||
dc009d92 EB |
81 | /* |
82 | * If we have crashed and we have a crash kernel loaded let it handle | |
83 | * everything else. | |
84 | * Do we want to call this before we try to display a message? | |
85 | */ | |
6e274d14 | 86 | crash_kexec(NULL); |
dc009d92 | 87 | |
1da177e4 | 88 | #ifdef CONFIG_SMP |
dc009d92 EB |
89 | /* |
90 | * Note smp_send_stop is the usual smp shutdown function, which | |
91 | * unfortunately means it may not be hardened to work in a panic | |
92 | * situation. | |
93 | */ | |
1da177e4 LT |
94 | smp_send_stop(); |
95 | #endif | |
96 | ||
97 | notifier_call_chain(&panic_notifier_list, 0, buf); | |
98 | ||
99 | if (!panic_blink) | |
100 | panic_blink = no_blink; | |
101 | ||
dc009d92 | 102 | if (panic_timeout > 0) { |
1da177e4 LT |
103 | /* |
104 | * Delay timeout seconds before rebooting the machine. | |
105 | * We can't use the "normal" timers since we just panicked.. | |
106 | */ | |
107 | printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout); | |
108 | for (i = 0; i < panic_timeout*1000; ) { | |
109 | touch_nmi_watchdog(); | |
110 | i += panic_blink(i); | |
111 | mdelay(1); | |
112 | i++; | |
113 | } | |
114 | /* | |
115 | * Should we run the reboot notifier. For the moment Im | |
116 | * choosing not too. It might crash, be corrupt or do | |
117 | * more harm than good for other reasons. | |
118 | */ | |
119 | machine_restart(NULL); | |
120 | } | |
121 | #ifdef __sparc__ | |
122 | { | |
123 | extern int stop_a_enabled; | |
a271c241 | 124 | /* Make sure the user can actually press Stop-A (L1-A) */ |
1da177e4 | 125 | stop_a_enabled = 1; |
a271c241 | 126 | printk(KERN_EMERG "Press Stop-A (L1-A) to return to the boot prom\n"); |
1da177e4 LT |
127 | } |
128 | #endif | |
129 | #if defined(CONFIG_ARCH_S390) | |
130 | disabled_wait(caller); | |
131 | #endif | |
132 | local_irq_enable(); | |
133 | for (i = 0;;) { | |
134 | i += panic_blink(i); | |
135 | mdelay(1); | |
136 | i++; | |
137 | } | |
138 | } | |
139 | ||
140 | EXPORT_SYMBOL(panic); | |
141 | ||
142 | /** | |
143 | * print_tainted - return a string to represent the kernel taint state. | |
144 | * | |
145 | * 'P' - Proprietary module has been loaded. | |
146 | * 'F' - Module has been forcibly loaded. | |
147 | * 'S' - SMP with CPUs not designed for SMP. | |
148 | * 'R' - User forced a module unload. | |
149 | * 'M' - Machine had a machine check experience. | |
150 | * 'B' - System has hit bad_page. | |
151 | * | |
152 | * The string is overwritten by the next call to print_taint(). | |
153 | */ | |
154 | ||
155 | const char *print_tainted(void) | |
156 | { | |
157 | static char buf[20]; | |
158 | if (tainted) { | |
159 | snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c", | |
160 | tainted & TAINT_PROPRIETARY_MODULE ? 'P' : 'G', | |
161 | tainted & TAINT_FORCED_MODULE ? 'F' : ' ', | |
162 | tainted & TAINT_UNSAFE_SMP ? 'S' : ' ', | |
163 | tainted & TAINT_FORCED_RMMOD ? 'R' : ' ', | |
164 | tainted & TAINT_MACHINE_CHECK ? 'M' : ' ', | |
165 | tainted & TAINT_BAD_PAGE ? 'B' : ' '); | |
166 | } | |
167 | else | |
168 | snprintf(buf, sizeof(buf), "Not tainted"); | |
169 | return(buf); | |
170 | } | |
171 | ||
172 | void add_taint(unsigned flag) | |
173 | { | |
174 | tainted |= flag; | |
175 | } | |
176 | EXPORT_SYMBOL(add_taint); |