arch/x86/kernel/dumpstack_32.c - maze/linux - Git at Google

 /*
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
  */
 #include <linux/kallsyms.h>
 #include <linux/kprobes.h>
 #include <linux/uaccess.h>
 #include <linux/utsname.h>
 #include <linux/hardirq.h>
 #include <linux/kdebug.h>
 #include <linux/module.h>
 #include <linux/ptrace.h>
 #include <linux/kexec.h>
 #include <linux/bug.h>
 #include <linux/nmi.h>
 #include <linux/sysfs.h>

 #include <asm/stacktrace.h>

 #define STACKSLOTS_PER_LINE 8
 #define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :)

 int panic_on_unrecovered_nmi;
 int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
 static unsigned int code_bytes = 64;
 static int die_counter;

 void printk_address(unsigned long address, int reliable)
 {
 	printk(" [<%p>] %s%pS\n", (void *) address,
 			reliable ? "" : "? ", (void *) address);
 }

 static inline int valid_stack_ptr(struct thread_info *tinfo,
 			void *p, unsigned int size, void *end)
 {
 	void *t = tinfo;
 	if (end) {
 		if (p < end && p >= (end-THREAD_SIZE))
 			return 1;
 		else
 			return 0;
 	}
 	return p > t && p < t + THREAD_SIZE - size;
 }

 /* The form of the top of the frame on the stack */
 struct stack_frame {
 	struct stack_frame *next_frame;
 	unsigned long return_address;
 };

 static inline unsigned long
 print_context_stack(struct thread_info *tinfo,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data,
 		unsigned long *end)
 {
 	struct stack_frame *frame = (struct stack_frame *)bp;

 	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
 		unsigned long addr;

 		addr = *stack;
 		if (__kernel_text_address(addr)) {
 			if ((unsigned long) stack == bp + sizeof(long)) {
 				ops->address(data, addr, 1);
 				frame = frame->next_frame;
 				bp = (unsigned long) frame;
 			} else {
 				ops->address(data, addr, bp == 0);
 			}
 		}
 		stack++;
 	}
 	return bp;
 }

 void dump_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data)
 {
 	if (!task)
 		task = current;

 	if (!stack) {
 		unsigned long dummy;
 		stack = &dummy;
 		if (task && task != current)
 			stack = (unsigned long *)task->thread.sp;
 	}

 #ifdef CONFIG_FRAME_POINTER
 	if (!bp) {
 		if (task == current) {
 			/* Grab bp right from our regs */
 			get_bp(bp);
 		} else {
 			/* bp is the last reg pushed by switch_to */
 			bp = *(unsigned long *) task->thread.sp;
 		}
 	}
 #endif

 	for (;;) {
 		struct thread_info *context;

 		context = (struct thread_info *)
 			((unsigned long)stack & (~(THREAD_SIZE - 1)));
 		bp = print_context_stack(context, stack, bp, ops, data, NULL);

 		stack = (unsigned long *)context->previous_esp;
 		if (!stack)
 			break;
 		if (ops->stack(data, "IRQ") < 0)
 			break;
 		touch_nmi_watchdog();
 	}
 }
 EXPORT_SYMBOL(dump_trace);

 static void
 print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
 {
 	printk(data);
 	print_symbol(msg, symbol);
 	printk("\n");
 }

 static void print_trace_warning(void *data, char *msg)
 {
 	printk("%s%s\n", (char *)data, msg);
 }

 static int print_trace_stack(void *data, char *name)
 {
 	printk("%s <%s> ", (char *)data, name);
 	return 0;
 }

 /*
  * Print one address/symbol entries per line.
  */
 static void print_trace_address(void *data, unsigned long addr, int reliable)
 {
 	touch_nmi_watchdog();
 	printk(data);
 	printk_address(addr, reliable);
 }

 static const struct stacktrace_ops print_trace_ops = {
 	.warning = print_trace_warning,
 	.warning_symbol = print_trace_warning_symbol,
 	.stack = print_trace_stack,
 	.address = print_trace_address,
 };

 static void
 show_trace_log_lvl(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp, char *log_lvl)
 {
 	printk("%sCall Trace:\n", log_lvl);
 	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
 }

 void show_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp)
 {
 	show_trace_log_lvl(task, regs, stack, bp, "");
 }

 static void
 show_stack_log_lvl(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *sp, unsigned long bp, char *log_lvl)
 {
 	unsigned long *stack;
 	int i;

 	if (sp == NULL) {
 		if (task)
 			sp = (unsigned long *)task->thread.sp;
 		else
 			sp = (unsigned long *)&sp;
 	}

 	stack = sp;
 	for (i = 0; i < kstack_depth_to_print; i++) {
 		if (kstack_end(stack))
 			break;
 		if (i && ((i % STACKSLOTS_PER_LINE) == 0))
 			printk("\n%s", log_lvl);
 		printk(" %08lx", *stack++);
 		touch_nmi_watchdog();
 	}
 	printk("\n");
 	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
 }

 void show_stack(struct task_struct *task, unsigned long *sp)
 {
 	show_stack_log_lvl(task, NULL, sp, 0, "");
 }

 /*
  * The architecture-independent dump_stack generator
  */
 void dump_stack(void)
 {
 	unsigned long bp = 0;
 	unsigned long stack;

 #ifdef CONFIG_FRAME_POINTER
 	if (!bp)
 		get_bp(bp);
 #endif

 	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
 		current->pid, current->comm, print_tainted(),
 		init_utsname()->release,
 		(int)strcspn(init_utsname()->version, " "),
 		init_utsname()->version);
 	show_trace(NULL, NULL, &stack, bp);
 }

 EXPORT_SYMBOL(dump_stack);

 void show_registers(struct pt_regs *regs)
 {
 	int i;

 	print_modules();
 	__show_regs(regs, 0);

 	printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
 		TASK_COMM_LEN, current->comm, task_pid_nr(current),
 		current_thread_info(), current, task_thread_info(current));
 	/*
 	 * When in-kernel, we also print out the stack and code at the
 	 * time of the fault..
 	 */
 	if (!user_mode_vm(regs)) {
 		unsigned int code_prologue = code_bytes * 43 / 64;
 		unsigned int code_len = code_bytes;
 		unsigned char c;
 		u8 *ip;

 		printk(KERN_EMERG "Stack:\n");
 		show_stack_log_lvl(NULL, regs, &regs->sp,
 				0, KERN_EMERG);

 		printk(KERN_EMERG "Code: ");

 		ip = (u8 *)regs->ip - code_prologue;
 		if (ip < (u8 *)PAGE_OFFSET || probe_kernel_address(ip, c)) {
 			/* try starting at IP */
 			ip = (u8 *)regs->ip;
 			code_len = code_len - code_prologue + 1;
 		}
 		for (i = 0; i < code_len; i++, ip++) {
 			if (ip < (u8 *)PAGE_OFFSET ||
 					probe_kernel_address(ip, c)) {
 				printk(" Bad EIP value.");
 				break;
 			}
 			if (ip == (u8 *)regs->ip)
 				printk("<%02x> ", c);
 			else
 				printk("%02x ", c);
 		}
 	}
 	printk("\n");
 }

 int is_valid_bugaddr(unsigned long ip)
 {
 	unsigned short ud2;

 	if (ip < PAGE_OFFSET)
 		return 0;
 	if (probe_kernel_address((unsigned short *)ip, ud2))
 		return 0;

 	return ud2 == 0x0b0f;
 }

 static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
 static int die_owner = -1;
 static unsigned int die_nest_count;

 unsigned __kprobes long oops_begin(void)
 {
 	unsigned long flags;

 	oops_enter();

 	if (die_owner != raw_smp_processor_id()) {
 		console_verbose();
 		raw_local_irq_save(flags);
 		__raw_spin_lock(&die_lock);
 		die_owner = smp_processor_id();
 		die_nest_count = 0;
 		bust_spinlocks(1);
 	} else {
 		raw_local_irq_save(flags);
 	}
 	die_nest_count++;
 	return flags;
 }

 void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 {
 	bust_spinlocks(0);
 	die_owner = -1;
 	add_taint(TAINT_DIE);
 	__raw_spin_unlock(&die_lock);
 	raw_local_irq_restore(flags);

 	if (!regs)
 		return;

 	if (kexec_should_crash(current))
 		crash_kexec(regs);
 	if (in_interrupt())
 		panic("Fatal exception in interrupt");
 	if (panic_on_oops)
 		panic("Fatal exception");
 	oops_exit();
 	do_exit(signr);
 }

 int __kprobes __die(const char *str, struct pt_regs *regs, long err)
 {
 	unsigned short ss;
 	unsigned long sp;

 	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
 #ifdef CONFIG_PREEMPT
 	printk("PREEMPT ");
 #endif
 #ifdef CONFIG_SMP
 	printk("SMP ");
 #endif
 #ifdef CONFIG_DEBUG_PAGEALLOC
 	printk("DEBUG_PAGEALLOC");
 #endif
 	printk("\n");
 	sysfs_printk_last_file();
 	if (notify_die(DIE_OOPS, str, regs, err,
 			current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
 		return 1;

 	show_registers(regs);
 	/* Executive summary in case the oops scrolled away */
 	sp = (unsigned long) (&regs->sp);
 	savesegment(ss, ss);
 	if (user_mode(regs)) {
 		sp = regs->sp;
 		ss = regs->ss & 0xffff;
 	}
 	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
 	print_symbol("%s", regs->ip);
 	printk(" SS:ESP %04x:%08lx\n", ss, sp);
 	return 0;
 }

 /*
  * This is gone through when something in the kernel has done something bad
  * and is about to be terminated:
  */
 void die(const char *str, struct pt_regs *regs, long err)
 {
 	unsigned long flags = oops_begin();

 	if (die_nest_count < 3) {
 		report_bug(regs->ip, regs);

 		if (__die(str, regs, err))
 			regs = NULL;
 	} else {
 		printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
 	}

 	oops_end(flags, regs, SIGSEGV);
 }

 static DEFINE_SPINLOCK(nmi_print_lock);

 void notrace __kprobes
 die_nmi(char *str, struct pt_regs *regs, int do_panic)
 {
 	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
 		return;

 	spin_lock(&nmi_print_lock);
 	/*
 	* We are in trouble anyway, lets at least try
 	* to get a message out:
 	*/
 	bust_spinlocks(1);
 	printk(KERN_EMERG "%s", str);
 	printk(" on CPU%d, ip %08lx, registers:\n",
 		smp_processor_id(), regs->ip);
 	show_registers(regs);
 	if (do_panic)
 		panic("Non maskable interrupt");
 	console_silent();
 	spin_unlock(&nmi_print_lock);

 	/*
 	 * If we are in kernel we are probably nested up pretty bad
 	 * and might aswell get out now while we still can:
 	 */
 	if (!user_mode_vm(regs)) {
 		current->thread.trap_no = 2;
 		crash_kexec(regs);
 	}

 	bust_spinlocks(0);
 	do_exit(SIGSEGV);
 }

 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);

 static int __init kstack_setup(char *s)
 {
 	if (!s)
 		return -EINVAL;
 	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
 	return 0;
 }
 early_param("kstack", kstack_setup);

 static int __init code_bytes_setup(char *s)
 {
 	code_bytes = simple_strtoul(s, NULL, 0);
 	if (code_bytes > 8192)
 		code_bytes = 8192;

 	return 1;
 }
 __setup("code_bytes=", code_bytes_setup);
	/*
	* Copyright (C) 1991, 1992 Linus Torvalds
	* Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
	*/
	#include <linux/kallsyms.h>
	#include <linux/kprobes.h>
	#include <linux/uaccess.h>
	#include <linux/utsname.h>
	#include <linux/hardirq.h>
	#include <linux/kdebug.h>
	#include <linux/module.h>
	#include <linux/ptrace.h>
	#include <linux/kexec.h>
	#include <linux/bug.h>
	#include <linux/nmi.h>
	#include <linux/sysfs.h>

	#include <asm/stacktrace.h>

	#define STACKSLOTS_PER_LINE 8
	#define get_bp(bp) asm("movl %%ebp, %0" : "=r" (bp) :)

	int panic_on_unrecovered_nmi;
	int kstack_depth_to_print = 3 * STACKSLOTS_PER_LINE;
	static unsigned int code_bytes = 64;
	static int die_counter;

	void printk_address(unsigned long address, int reliable)
	{
	printk(" [<%p>] %s%pS\n", (void *) address,
	reliable ? "" : "? ", (void *) address);
	}

	static inline int valid_stack_ptr(struct thread_info *tinfo,
	void p, unsigned int size, void end)
	{
	void *t = tinfo;
	if (end) {
	if (p < end && p >= (end-THREAD_SIZE))
	return 1;
	else
	return 0;
	}
	return p > t && p < t + THREAD_SIZE - size;
	}

	/* The form of the top of the frame on the stack */
	struct stack_frame {
	struct stack_frame *next_frame;
	unsigned long return_address;
	};

	static inline unsigned long
	print_context_stack(struct thread_info *tinfo,
	unsigned long *stack, unsigned long bp,
	const struct stacktrace_ops ops, void data,
	unsigned long *end)
	{
	struct stack_frame frame = (struct stack_frame )bp;

	while (valid_stack_ptr(tinfo, stack, sizeof(*stack), end)) {
	unsigned long addr;

	addr = *stack;
	if (__kernel_text_address(addr)) {
	if ((unsigned long) stack == bp + sizeof(long)) {
	ops->address(data, addr, 1);
	frame = frame->next_frame;
	bp = (unsigned long) frame;
	} else {
	ops->address(data, addr, bp == 0);
	}
	}
	stack++;
	}
	return bp;
	}

	void dump_trace(struct task_struct task, struct pt_regs regs,
	unsigned long *stack, unsigned long bp,
	const struct stacktrace_ops ops, void data)
	{
	if (!task)
	task = current;

	if (!stack) {
	unsigned long dummy;
	stack = &dummy;
	if (task && task != current)
	stack = (unsigned long *)task->thread.sp;
	}

	#ifdef CONFIG_FRAME_POINTER
	if (!bp) {
	if (task == current) {
	/* Grab bp right from our regs */
	get_bp(bp);
	} else {
	/* bp is the last reg pushed by switch_to */
	bp = (unsigned long ) task->thread.sp;
	}
	}
	#endif

	for (;;) {
	struct thread_info *context;

	context = (struct thread_info *)
	((unsigned long)stack & (~(THREAD_SIZE - 1)));
	bp = print_context_stack(context, stack, bp, ops, data, NULL);

	stack = (unsigned long *)context->previous_esp;
	if (!stack)
	break;
	if (ops->stack(data, "IRQ") < 0)
	break;
	touch_nmi_watchdog();
	}
	}
	EXPORT_SYMBOL(dump_trace);

	static void
	print_trace_warning_symbol(void data, char msg, unsigned long symbol)
	{
	printk(data);
	print_symbol(msg, symbol);
	printk("\n");
	}

	static void print_trace_warning(void data, char msg)
	{
	printk("%s%s\n", (char *)data, msg);
	}

	static int print_trace_stack(void data, char name)
	{
	printk("%s <%s> ", (char *)data, name);
	return 0;
	}

	/*
	* Print one address/symbol entries per line.
	*/
	static void print_trace_address(void *data, unsigned long addr, int reliable)
	{
	touch_nmi_watchdog();
	printk(data);
	printk_address(addr, reliable);
	}

	static const struct stacktrace_ops print_trace_ops = {
	.warning = print_trace_warning,
	.warning_symbol = print_trace_warning_symbol,
	.stack = print_trace_stack,
	.address = print_trace_address,
	};

	static void
	show_trace_log_lvl(struct task_struct task, struct pt_regs regs,
	unsigned long stack, unsigned long bp, char log_lvl)
	{
	printk("%sCall Trace:\n", log_lvl);
	dump_trace(task, regs, stack, bp, &print_trace_ops, log_lvl);
	}

	void show_trace(struct task_struct task, struct pt_regs regs,
	unsigned long *stack, unsigned long bp)
	{
	show_trace_log_lvl(task, regs, stack, bp, "");
	}

	static void
	show_stack_log_lvl(struct task_struct task, struct pt_regs regs,
	unsigned long sp, unsigned long bp, char log_lvl)
	{
	unsigned long *stack;
	int i;

	if (sp == NULL) {
	if (task)
	sp = (unsigned long *)task->thread.sp;
	else
	sp = (unsigned long *)&sp;
	}

	stack = sp;
	for (i = 0; i < kstack_depth_to_print; i++) {
	if (kstack_end(stack))
	break;
	if (i && ((i % STACKSLOTS_PER_LINE) == 0))
	printk("\n%s", log_lvl);
	printk(" %08lx", *stack++);
	touch_nmi_watchdog();
	}
	printk("\n");
	show_trace_log_lvl(task, regs, sp, bp, log_lvl);
	}

	void show_stack(struct task_struct task, unsigned long sp)
	{
	show_stack_log_lvl(task, NULL, sp, 0, "");
	}

	/*
	* The architecture-independent dump_stack generator
	*/
	void dump_stack(void)
	{
	unsigned long bp = 0;
	unsigned long stack;

	#ifdef CONFIG_FRAME_POINTER
	if (!bp)
	get_bp(bp);
	#endif

	printk("Pid: %d, comm: %.20s %s %s %.*s\n",
	current->pid, current->comm, print_tainted(),
	init_utsname()->release,
	(int)strcspn(init_utsname()->version, " "),
	init_utsname()->version);
	show_trace(NULL, NULL, &stack, bp);
	}

	EXPORT_SYMBOL(dump_stack);

	void show_registers(struct pt_regs *regs)
	{
	int i;

	print_modules();
	__show_regs(regs, 0);

	printk(KERN_EMERG "Process %.*s (pid: %d, ti=%p task=%p task.ti=%p)\n",
	TASK_COMM_LEN, current->comm, task_pid_nr(current),
	current_thread_info(), current, task_thread_info(current));
	/*
	* When in-kernel, we also print out the stack and code at the
	* time of the fault..
	*/
	if (!user_mode_vm(regs)) {
	unsigned int code_prologue = code_bytes * 43 / 64;
	unsigned int code_len = code_bytes;
	unsigned char c;
	u8 *ip;

	printk(KERN_EMERG "Stack:\n");
	show_stack_log_lvl(NULL, regs, &regs->sp,
	0, KERN_EMERG);

	printk(KERN_EMERG "Code: ");

	ip = (u8 *)regs->ip - code_prologue;
	if (ip < (u8 *)PAGE_OFFSET \|\| probe_kernel_address(ip, c)) {
	/* try starting at IP */
	ip = (u8 *)regs->ip;
	code_len = code_len - code_prologue + 1;
	}
	for (i = 0; i < code_len; i++, ip++) {
	if (ip < (u8 *)PAGE_OFFSET \|\|
	probe_kernel_address(ip, c)) {
	printk(" Bad EIP value.");
	break;
	}
	if (ip == (u8 *)regs->ip)
	printk("<%02x> ", c);
	else
	printk("%02x ", c);
	}
	}
	printk("\n");
	}

	int is_valid_bugaddr(unsigned long ip)
	{
	unsigned short ud2;

	if (ip < PAGE_OFFSET)
	return 0;
	if (probe_kernel_address((unsigned short *)ip, ud2))
	return 0;

	return ud2 == 0x0b0f;
	}

	static raw_spinlock_t die_lock = __RAW_SPIN_LOCK_UNLOCKED;
	static int die_owner = -1;
	static unsigned int die_nest_count;

	unsigned __kprobes long oops_begin(void)
	{
	unsigned long flags;

	oops_enter();

	if (die_owner != raw_smp_processor_id()) {
	console_verbose();
	raw_local_irq_save(flags);
	__raw_spin_lock(&die_lock);
	die_owner = smp_processor_id();
	die_nest_count = 0;
	bust_spinlocks(1);
	} else {
	raw_local_irq_save(flags);
	}
	die_nest_count++;
	return flags;
	}

	void __kprobes oops_end(unsigned long flags, struct pt_regs *regs, int signr)
	{
	bust_spinlocks(0);
	die_owner = -1;
	add_taint(TAINT_DIE);
	__raw_spin_unlock(&die_lock);
	raw_local_irq_restore(flags);

	if (!regs)
	return;

	if (kexec_should_crash(current))
	crash_kexec(regs);
	if (in_interrupt())
	panic("Fatal exception in interrupt");
	if (panic_on_oops)
	panic("Fatal exception");
	oops_exit();
	do_exit(signr);
	}

	int __kprobes __die(const char str, struct pt_regs regs, long err)
	{
	unsigned short ss;
	unsigned long sp;

	printk(KERN_EMERG "%s: %04lx [#%d] ", str, err & 0xffff, ++die_counter);
	#ifdef CONFIG_PREEMPT
	printk("PREEMPT ");
	#endif
	#ifdef CONFIG_SMP
	printk("SMP ");
	#endif
	#ifdef CONFIG_DEBUG_PAGEALLOC
	printk("DEBUG_PAGEALLOC");
	#endif
	printk("\n");
	sysfs_printk_last_file();
	if (notify_die(DIE_OOPS, str, regs, err,
	current->thread.trap_no, SIGSEGV) == NOTIFY_STOP)
	return 1;

	show_registers(regs);
	/* Executive summary in case the oops scrolled away */
	sp = (unsigned long) (&regs->sp);
	savesegment(ss, ss);
	if (user_mode(regs)) {
	sp = regs->sp;
	ss = regs->ss & 0xffff;
	}
	printk(KERN_EMERG "EIP: [<%08lx>] ", regs->ip);
	print_symbol("%s", regs->ip);
	printk(" SS:ESP %04x:%08lx\n", ss, sp);
	return 0;
	}

	/*
	* This is gone through when something in the kernel has done something bad
	* and is about to be terminated:
	*/
	void die(const char str, struct pt_regs regs, long err)
	{
	unsigned long flags = oops_begin();

	if (die_nest_count < 3) {
	report_bug(regs->ip, regs);

	if (__die(str, regs, err))
	regs = NULL;
	} else {
	printk(KERN_EMERG "Recursive die() failure, output suppressed\n");
	}

	oops_end(flags, regs, SIGSEGV);
	}

	static DEFINE_SPINLOCK(nmi_print_lock);

	void notrace __kprobes
	die_nmi(char str, struct pt_regs regs, int do_panic)
	{
	if (notify_die(DIE_NMIWATCHDOG, str, regs, 0, 2, SIGINT) == NOTIFY_STOP)
	return;

	spin_lock(&nmi_print_lock);
	/*
	* We are in trouble anyway, lets at least try
	* to get a message out:
	*/
	bust_spinlocks(1);
	printk(KERN_EMERG "%s", str);
	printk(" on CPU%d, ip %08lx, registers:\n",
	smp_processor_id(), regs->ip);
	show_registers(regs);
	if (do_panic)
	panic("Non maskable interrupt");
	console_silent();
	spin_unlock(&nmi_print_lock);

	/*
	* If we are in kernel we are probably nested up pretty bad
	* and might aswell get out now while we still can:
	*/
	if (!user_mode_vm(regs)) {
	current->thread.trap_no = 2;
	crash_kexec(regs);
	}

	bust_spinlocks(0);
	do_exit(SIGSEGV);
	}

	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);

	static int __init kstack_setup(char *s)
	{
	if (!s)
	return -EINVAL;
	kstack_depth_to_print = simple_strtoul(s, NULL, 0);
	return 0;
	}
	early_param("kstack", kstack_setup);

	static int __init code_bytes_setup(char *s)
	{
	code_bytes = simple_strtoul(s, NULL, 0);
	if (code_bytes > 8192)
	code_bytes = 8192;

	return 1;
	}
	__setup("code_bytes=", code_bytes_setup);