1 files changed, 464 insertions, 0 deletions
diff --git a/kernel/panic.c b/kernel/panic.c
new file mode 100644
index 00000000..564c7bc6
--- /dev/null
+++ b/kernel/panic.c
@@ -0,0 +1,464 @@
+/*
+ *  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/debug_locks.h>
+#include <linux/interrupt.h>
+#include <linux/kmsg_dump.h>
+#include <linux/kallsyms.h>
+#include <linux/notifier.h>
+#include <linux/module.h>
+#include <linux/random.h>
+#include <linux/reboot.h>
+#include <linux/delay.h>
+#include <linux/kexec.h>
+#include <linux/sched.h>
+#include <linux/sysrq.h>
+#include <linux/init.h>
+#include <linux/nmi.h>
+#include <linux/dmi.h>
+
+#define PANIC_TIMER_STEP 100
+#define PANIC_BLINK_SPD 18
+
+/* Machine specific panic information string */
+char *mach_panic_string;
+
+int panic_on_oops;
+static unsigned long tainted_mask;
+static int pause_on_oops;
+static int pause_on_oops_flag;
+static DEFINE_SPINLOCK(pause_on_oops_lock);
+
+#ifndef CONFIG_PANIC_TIMEOUT
+#define CONFIG_PANIC_TIMEOUT 0
+#endif
+int panic_timeout = CONFIG_PANIC_TIMEOUT;
+EXPORT_SYMBOL_GPL(panic_timeout);
+
+ATOMIC_NOTIFIER_HEAD(panic_notifier_list);
+
+EXPORT_SYMBOL(panic_notifier_list);
+
+static long no_blink(int state)
+{
+	return 0;
+}
+
+/* Returns how long it waited in ms */
+long (*panic_blink)(int state);
+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, ...)
+{
+	static char buf[1024];
+	va_list args;
+	long i, i_next = 0;
+	int state = 0;
+
+	/*
+	 * 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();
+
+	console_verbose();
+	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);
+#ifdef CONFIG_DEBUG_BUGVERBOSE
+	dump_stack();
+#endif
+
+	/*
+	 * 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);
+
+	kmsg_dump(KMSG_DUMP_PANIC);
+
+	/*
+	 * 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();
+
+	atomic_notifier_call_chain(&panic_notifier_list, 0, buf);
+
+	bust_spinlocks(0);
+
+	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; i += PANIC_TIMER_STEP) {
+			touch_nmi_watchdog();
+			if (i >= i_next) {
+				i += panic_blink(state ^= 1);
+				i_next = i + 3600 / PANIC_BLINK_SPD;
+			}
+			mdelay(PANIC_TIMER_STEP);
+		}
+		/*
+		 * 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_S390)
+	{
+		unsigned long caller;
+
+		caller = (unsigned long)__builtin_return_address(0);
+		disabled_wait(caller);
+	}
+#endif
+	local_irq_enable();
+	for (i = 0; ; i += PANIC_TIMER_STEP) {
+		touch_softlockup_watchdog();
+		if (i >= i_next) {
+			i += panic_blink(state ^= 1);
+			i_next = i + 3600 / PANIC_BLINK_SPD;
+		}
+		mdelay(PANIC_TIMER_STEP);
+	}
+}
+
+EXPORT_SYMBOL(panic);
+
+
+struct tnt {
+	u8	bit;
+	char	true;
+	char	false;
+};
+
+static const struct tnt tnts[] = {
+	{ TAINT_PROPRIETARY_MODULE,	'P', 'G' },
+	{ TAINT_FORCED_MODULE,		'F', ' ' },
+	{ TAINT_UNSAFE_SMP,		'S', ' ' },
+	{ TAINT_FORCED_RMMOD,		'R', ' ' },
+	{ TAINT_MACHINE_CHECK,		'M', ' ' },
+	{ TAINT_BAD_PAGE,		'B', ' ' },
+	{ TAINT_USER,			'U', ' ' },
+	{ TAINT_DIE,			'D', ' ' },
+	{ TAINT_OVERRIDDEN_ACPI_TABLE,	'A', ' ' },
+	{ TAINT_WARN,			'W', ' ' },
+	{ TAINT_CRAP,			'C', ' ' },
+	{ TAINT_FIRMWARE_WORKAROUND,	'I', ' ' },
+};
+
+/**
+ *	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' - System experienced a machine check exception.
+ *  'B' - System has hit bad_page.
+ *  'U' - Userspace-defined naughtiness.
+ *  'D' - Kernel has oopsed before
+ *  'A' - ACPI table overridden.
+ *  'W' - Taint on warning.
+ *  'C' - modules from drivers/staging are loaded.
+ *  'I' - Working around severe firmware bug.
+ *
+ *	The string is overwritten by the next call to print_tainted().
+ */
+const char *print_tainted(void)
+{
+	static char buf[ARRAY_SIZE(tnts) + sizeof("Tainted: ") + 1];
+
+	if (tainted_mask) {
+		char *s;
+		int i;
+
+		s = buf + sprintf(buf, "Tainted: ");
+		for (i = 0; i < ARRAY_SIZE(tnts); i++) {
+			const struct tnt *t = &tnts[i];
+			*s++ = test_bit(t->bit, &tainted_mask) ?
+					t->true : t->false;
+		}
+		*s = 0;
+	} else
+		snprintf(buf, sizeof(buf), "Not tainted");
+
+	return buf;
+}
+
+int test_taint(unsigned flag)
+{
+	return test_bit(flag, &tainted_mask);
+}
+EXPORT_SYMBOL(test_taint);
+
+unsigned long get_taint(void)
+{
+	return tainted_mask;
+}
+
+void add_taint(unsigned flag)
+{
+	/*
+	 * Can't trust the integrity of the kernel anymore.
+	 * We don't call directly debug_locks_off() because the issue
+	 * is not necessarily serious enough to set oops_in_progress to 1
+	 * Also we want to keep up lockdep for staging development and
+	 * post-warning case.
+	 */
+	switch (flag) {
+	case TAINT_CRAP:
+	case TAINT_WARN:
+	case TAINT_FIRMWARE_WORKAROUND:
+		break;
+
+	default:
+		if (__debug_locks_off())
+			printk(KERN_WARNING "Disabling lock debugging due to kernel taint\n");
+	}
+
+	set_bit(flag, &tainted_mask);
+}
+EXPORT_SYMBOL(add_taint);
+
+static void spin_msec(int msecs)
+{
+	int i;
+
+	for (i = 0; i < msecs; i++) {
+		touch_nmi_watchdog();
+		mdelay(1);
+	}
+}
+
+/*
+ * It just happens that oops_enter() and oops_exit() are identically
+ * implemented...
+ */
+static void do_oops_enter_exit(void)
+{
+	unsigned long flags;
+	static int spin_counter;
+
+	if (!pause_on_oops)
+		return;
+
+	spin_lock_irqsave(&pause_on_oops_lock, flags);
+	if (pause_on_oops_flag == 0) {
+		/* This CPU may now print the oops message */
+		pause_on_oops_flag = 1;
+	} else {
+		/* We need to stall this CPU */
+		if (!spin_counter) {
+			/* This CPU gets to do the counting */
+			spin_counter = pause_on_oops;
+			do {
+				spin_unlock(&pause_on_oops_lock);
+				spin_msec(MSEC_PER_SEC);
+				spin_lock(&pause_on_oops_lock);
+			} while (--spin_counter);
+			pause_on_oops_flag = 0;
+		} else {
+			/* This CPU waits for a different one */
+			while (spin_counter) {
+				spin_unlock(&pause_on_oops_lock);
+				spin_msec(1);
+				spin_lock(&pause_on_oops_lock);
+			}
+		}
+	}
+	spin_unlock_irqrestore(&pause_on_oops_lock, flags);
+}
+
+/*
+ * Return true if the calling CPU is allowed to print oops-related info.
+ * This is a bit racy..
+ */
+int oops_may_print(void)
+{
+	return pause_on_oops_flag == 0;
+}
+
+/*
+ * Called when the architecture enters its oops handler, before it prints
+ * anything.  If this is the first CPU to oops, and it's oopsing the first
+ * time then let it proceed.
+ *
+ * This is all enabled by the pause_on_oops kernel boot option.  We do all
+ * this to ensure that oopses don't scroll off the screen.  It has the
+ * side-effect of preventing later-oopsing CPUs from mucking up the display,
+ * too.
+ *
+ * It turns out that the CPU which is allowed to print ends up pausing for
+ * the right duration, whereas all the other CPUs pause for twice as long:
+ * once in oops_enter(), once in oops_exit().
+ */
+void oops_enter(void)
+{
+	tracing_off();
+	/* can't trust the integrity of the kernel anymore: */
+	debug_locks_off();
+	do_oops_enter_exit();
+}
+
+/*
+ * 64-bit random ID for oopses:
+ */
+static u64 oops_id;
+
+static int init_oops_id(void)
+{
+	if (!oops_id)
+		get_random_bytes(&oops_id, sizeof(oops_id));
+	else
+		oops_id++;
+
+	return 0;
+}
+late_initcall(init_oops_id);
+
+void print_oops_end_marker(void)
+{
+	init_oops_id();
+
+	if (mach_panic_string)
+		printk(KERN_WARNING "Board Information: %s\n",
+		       mach_panic_string);
+
+	printk(KERN_WARNING "---[ end trace %016llx ]---\n",
+		(unsigned long long)oops_id);
+}
+
+/*
+ * Called when the architecture exits its oops handler, after printing
+ * everything.
+ */
+void oops_exit(void)
+{
+	do_oops_enter_exit();
+	print_oops_end_marker();
+	kmsg_dump(KMSG_DUMP_OOPS);
+}
+
+#ifdef WANT_WARN_ON_SLOWPATH
+struct slowpath_args {
+	const char *fmt;
+	va_list args;
+};
+
+static void warn_slowpath_common(const char *file, int line, void *caller,
+				 unsigned taint, struct slowpath_args *args)
+{
+	const char *board;
+
+	printk(KERN_WARNING "------------[ cut here ]------------\n");
+	printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
+	board = dmi_get_system_info(DMI_PRODUCT_NAME);
+	if (board)
+		printk(KERN_WARNING "Hardware name: %s\n", board);
+
+	if (args)
+		vprintk(args->fmt, args->args);
+
+	print_modules();
+	dump_stack();
+	print_oops_end_marker();
+	add_taint(taint);
+}
+
+void warn_slowpath_fmt(const char *file, int line, const char *fmt, ...)
+{
+	struct slowpath_args args;
+
+	args.fmt = fmt;
+	va_start(args.args, fmt);
+	warn_slowpath_common(file, line, __builtin_return_address(0),
+			     TAINT_WARN, &args);
+	va_end(args.args);
+}
+EXPORT_SYMBOL(warn_slowpath_fmt);
+
+void warn_slowpath_fmt_taint(const char *file, int line,
+			     unsigned taint, const char *fmt, ...)
+{
+	struct slowpath_args args;
+
+	args.fmt = fmt;
+	va_start(args.args, fmt);
+	warn_slowpath_common(file, line, __builtin_return_address(0),
+			     taint, &args);
+	va_end(args.args);
+}
+EXPORT_SYMBOL(warn_slowpath_fmt_taint);
+
+void warn_slowpath_null(const char *file, int line)
+{
+	warn_slowpath_common(file, line, __builtin_return_address(0),
+			     TAINT_WARN, NULL);
+}
+EXPORT_SYMBOL(warn_slowpath_null);
+#endif
+
+#ifdef CONFIG_CC_STACKPROTECTOR
+
+/*
+ * Called when gcc's -fstack-protector feature is used, and
+ * gcc detects corruption of the on-stack canary value
+ */
+void __stack_chk_fail(void)
+{
+	panic("stack-protector: Kernel stack is corrupted in: %p\n",
+		__builtin_return_address(0));
+}
+EXPORT_SYMBOL(__stack_chk_fail);
+
+#endif
+
+core_param(panic, panic_timeout, int, 0644);
+core_param(pause_on_oops, pause_on_oops, int, 0644);
+
+static int __init oops_setup(char *s)
+{
+	if (!s)
+		return -EINVAL;
+	if (!strcmp(s, "panic"))
+		panic_on_oops = 1;
+	return 0;
+}
+early_param("oops", oops_setup);