Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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>
21#include <linux/kexec.h>
22
23int panic_timeout;
24int panic_on_oops;
25int tainted;
26
27EXPORT_SYMBOL(panic_timeout);
28
29struct notifier_block *panic_notifier_list;
30
31EXPORT_SYMBOL(panic_notifier_list);
32
33static 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
40static long no_blink(long time)
41{
42 return 0;
43}
44
45/* Returns how long it waited in ms */
46long (*panic_blink)(long time);
47EXPORT_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
58NORET_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
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
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
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 */
86 crash_kexec(NULL);
87
88#ifdef CONFIG_SMP
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 */
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
102 if (panic_timeout > 0) {
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;
124 /* Make sure the user can actually press Stop-A (L1-A) */
125 stop_a_enabled = 1;
126 printk(KERN_EMERG "Press Stop-A (L1-A) to return to the boot prom\n");
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
140EXPORT_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
155const 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
172void add_taint(unsigned flag)
173{
174 tainted |= flag;
175}
176EXPORT_SYMBOL(add_taint);