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 #include <linux/console.h>
20
21 asmlinkage void sys_sync(void); /* it's really int */
22
23 int panic_timeout;
24
25 struct notifier_block *panic_notifier_list;
26
panic_setup(char * str)27 static int __init panic_setup(char *str)
28 {
29 panic_timeout = simple_strtoul(str, NULL, 0);
30 return 1;
31 }
32
33 __setup("panic=", panic_setup);
34
35 int machine_paniced;
36
37 /**
38 * panic - halt the system
39 * @fmt: The text string to print
40 *
41 * Display a message, then perform cleanups. Functions in the panic
42 * notifier list are called after the filesystem cache is flushed (when possible).
43 *
44 * This function never returns.
45 */
46
panic(const char * fmt,...)47 NORET_TYPE void panic(const char * fmt, ...)
48 {
49 static char buf[1024];
50 va_list args;
51 #if defined(CONFIG_ARCH_S390)
52 unsigned long caller = (unsigned long) __builtin_return_address(0);
53 #endif
54
55 #ifdef CONFIG_VT
56 disable_console_blank();
57 #endif
58 machine_paniced = 1;
59
60 bust_spinlocks(1);
61 va_start(args, fmt);
62 vsnprintf(buf, sizeof(buf), fmt, args);
63 va_end(args);
64 printk(KERN_EMERG "Kernel panic: %s\n",buf);
65 if (in_interrupt())
66 printk(KERN_EMERG "In interrupt handler - not syncing\n");
67 else if (!current->pid)
68 printk(KERN_EMERG "In idle task - not syncing\n");
69 else
70 sys_sync();
71 bust_spinlocks(0);
72
73 #ifdef CONFIG_SMP
74 smp_send_stop();
75 #endif
76
77 notifier_call_chain(&panic_notifier_list, 0, NULL);
78
79 if (panic_timeout > 0)
80 {
81 /*
82 * Delay timeout seconds before rebooting the machine.
83 * We can't use the "normal" timers since we just panicked..
84 */
85 printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout);
86 mdelay(panic_timeout*1000);
87 /*
88 * Should we run the reboot notifier. For the moment Im
89 * choosing not too. It might crash, be corrupt or do
90 * more harm than good for other reasons.
91 */
92 machine_restart(NULL);
93 }
94 #ifdef __sparc__
95 {
96 extern int stop_a_enabled;
97 /* Make sure the user can actually press L1-A */
98 stop_a_enabled = 1;
99 printk("Press L1-A to return to the boot prom\n");
100 }
101 #endif
102 #if defined(CONFIG_ARCH_S390)
103 disabled_wait(caller);
104 #endif
105 sti();
106 for(;;) {
107 #if defined(CONFIG_X86) && defined(CONFIG_VT) && !defined(CONFIG_DUMMY_KEYB)
108 extern void panic_blink(void);
109 panic_blink();
110 #endif
111 CHECK_EMERGENCY_SYNC
112 }
113 }
114
115 /**
116 * print_tainted - return a string to represent the kernel taint state.
117 *
118 * The string is overwritten by the next call to print_taint().
119 */
120
print_tainted()121 const char *print_tainted()
122 {
123 static char buf[20];
124 if (tainted) {
125 snprintf(buf, sizeof(buf), "Tainted: %c%c",
126 tainted & 1 ? 'P' : 'G',
127 tainted & 2 ? 'F' : ' ');
128 }
129 else
130 snprintf(buf, sizeof(buf), "Not tainted");
131 return(buf);
132 }
133
134 int tainted = 0;
135
136 /*
137 * A BUG() call in an inline function in a header should be avoided,
138 * because it can seriously bloat the kernel. So here we have
139 * helper functions.
140 * We lose the BUG()-time file-and-line info this way, but it's
141 * usually not very useful from an inline anyway. The backtrace
142 * tells us what we want to know.
143 */
144
__out_of_line_bug(int line)145 void __out_of_line_bug(int line)
146 {
147 printk("kernel BUG in header file at line %d\n", line);
148
149 BUG();
150
151 /* Satisfy __attribute__((noreturn)) */
152 for ( ; ; )
153 ;
154 }
155