/* * linux/kernel/panic.c * * Copyright (C) 1991, 1992 Linus Torvalds */ /* * This function is used through-out the kernel (including mm and fs) * to indicate a major problem. */ #include <linux/config.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/delay.h> #include <linux/reboot.h> #include <linux/notifier.h> #include <linux/init.h> #include <linux/sysrq.h> #include <linux/interrupt.h> #include <linux/nmi.h> #include <linux/kexec.h> int panic_timeout; int panic_on_oops; int tainted; EXPORT_SYMBOL(panic_timeout); struct notifier_block *panic_notifier_list; EXPORT_SYMBOL(panic_notifier_list); static int __init panic_setup(char *str) { panic_timeout = simple_strtoul(str, NULL, 0); return 1; } __setup("panic=", panic_setup); static long no_blink(long time) { return 0; } /* Returns how long it waited in ms */ long (*panic_blink)(long time); EXPORT_SYMBOL(panic_blink); /** * panic - halt the system * @fmt: The text string to print * * Display a message, then perform cleanups. * * This function never returns. */ NORET_TYPE void panic(const char * fmt, ...) { long i; static char buf[1024]; va_list args; #if defined(CONFIG_ARCH_S390) unsigned long caller = (unsigned long) __builtin_return_address(0); #endif /* * It's possible to come here directly from a panic-assertion and not * have preempt disabled. Some functions called from here want * preempt to be disabled. No point enabling it later though... */ preempt_disable(); bust_spinlocks(1); va_start(args, fmt); vsnprintf(buf, sizeof(buf), fmt, args); va_end(args); printk(KERN_EMERG "Kernel panic - not syncing: %s\n",buf); bust_spinlocks(0); /* * If we have crashed and we have a crash kernel loaded let it handle * everything else. * Do we want to call this before we try to display a message? */ crash_kexec(NULL); #ifdef CONFIG_SMP /* * Note smp_send_stop is the usual smp shutdown function, which * unfortunately means it may not be hardened to work in a panic * situation. */ smp_send_stop(); #endif notifier_call_chain(&panic_notifier_list, 0, buf); if (!panic_blink) panic_blink = no_blink; if (panic_timeout > 0) { /* * Delay timeout seconds before rebooting the machine. * We can't use the "normal" timers since we just panicked.. */ printk(KERN_EMERG "Rebooting in %d seconds..",panic_timeout); for (i = 0; i < panic_timeout*1000; ) { touch_nmi_watchdog(); i += panic_blink(i); mdelay(1); i++; } /* This will not be a clean reboot, with everything * shutting down. But if there is a chance of * rebooting the system it will be rebooted. */ emergency_restart(); } #ifdef __sparc__ { extern int stop_a_enabled; /* Make sure the user can actually press Stop-A (L1-A) */ stop_a_enabled = 1; printk(KERN_EMERG "Press Stop-A (L1-A) to return to the boot prom\n"); } #endif #if defined(CONFIG_ARCH_S390) disabled_wait(caller); #endif local_irq_enable(); for (i = 0;;) { i += panic_blink(i); mdelay(1); i++; } } EXPORT_SYMBOL(panic); /** * print_tainted - return a string to represent the kernel taint state. * * 'P' - Proprietary module has been loaded. * 'F' - Module has been forcibly loaded. * 'S' - SMP with CPUs not designed for SMP. * 'R' - User forced a module unload. * 'M' - Machine had a machine check experience. * 'B' - System has hit bad_page. * * The string is overwritten by the next call to print_taint(). */ const char *print_tainted(void) { static char buf[20]; if (tainted) { snprintf(buf, sizeof(buf), "Tainted: %c%c%c%c%c%c", tainted & TAINT_PROPRIETARY_MODULE ? 'P' : 'G', tainted & TAINT_FORCED_MODULE ? 'F' : ' ', tainted & TAINT_UNSAFE_SMP ? 'S' : ' ', tainted & TAINT_FORCED_RMMOD ? 'R' : ' ', tainted & TAINT_MACHINE_CHECK ? 'M' : ' ', tainted & TAINT_BAD_PAGE ? 'B' : ' '); } else snprintf(buf, sizeof(buf), "Not tainted"); return(buf); } void add_taint(unsigned flag) { tainted |= flag; } EXPORT_SYMBOL(add_taint);