x86_64: move kernel

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1138 insertions, 0 deletions

diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
new file mode 100644
index 000000000000..03888420775d
--- /dev/null
+++ b/arch/x86/kernel/traps_64.c
@@ -0,0 +1,1138 @@
+/*
+ *  linux/arch/x86-64/traps.c
+ *
+ *  Copyright (C) 1991, 1992  Linus Torvalds
+ *  Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
+ *
+ *  Pentium III FXSR, SSE support
+ *	Gareth Hughes <gareth@valinux.com>, May 2000
+ */
+
+/*
+ * 'Traps.c' handles hardware traps and faults after we have saved some
+ * state in 'entry.S'.
+ */
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/ptrace.h>
+#include <linux/timer.h>
+#include <linux/mm.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/kallsyms.h>
+#include <linux/module.h>
+#include <linux/moduleparam.h>
+#include <linux/nmi.h>
+#include <linux/kprobes.h>
+#include <linux/kexec.h>
+#include <linux/unwind.h>
+#include <linux/uaccess.h>
+#include <linux/bug.h>
+#include <linux/kdebug.h>
+
+#if defined(CONFIG_EDAC)
+#include <linux/edac.h>
+#endif
+
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/debugreg.h>
+#include <asm/desc.h>
+#include <asm/i387.h>
+#include <asm/processor.h>
+#include <asm/unwind.h>
+#include <asm/smp.h>
+#include <asm/pgalloc.h>
+#include <asm/pda.h>
+#include <asm/proto.h>
+#include <asm/nmi.h>
+#include <asm/stacktrace.h>
+
+asmlinkage void divide_error(void);
+asmlinkage void debug(void);
+asmlinkage void nmi(void);
+asmlinkage void int3(void);
+asmlinkage void overflow(void);
+asmlinkage void bounds(void);
+asmlinkage void invalid_op(void);
+asmlinkage void device_not_available(void);
+asmlinkage void double_fault(void);
+asmlinkage void coprocessor_segment_overrun(void);
+asmlinkage void invalid_TSS(void);
+asmlinkage void segment_not_present(void);
+asmlinkage void stack_segment(void);
+asmlinkage void general_protection(void);
+asmlinkage void page_fault(void);
+asmlinkage void coprocessor_error(void);
+asmlinkage void simd_coprocessor_error(void);
+asmlinkage void reserved(void);
+asmlinkage void alignment_check(void);
+asmlinkage void machine_check(void);
+asmlinkage void spurious_interrupt_bug(void);
+
+static inline void conditional_sti(struct pt_regs *regs)
+{
+	if (regs->eflags & X86_EFLAGS_IF)
+		local_irq_enable();
+}
+
+static inline void preempt_conditional_sti(struct pt_regs *regs)
+{
+	preempt_disable();
+	if (regs->eflags & X86_EFLAGS_IF)
+		local_irq_enable();
+}
+
+static inline void preempt_conditional_cli(struct pt_regs *regs)
+{
+	if (regs->eflags & X86_EFLAGS_IF)
+		local_irq_disable();
+	/* Make sure to not schedule here because we could be running
+	   on an exception stack. */
+	preempt_enable_no_resched();
+}
+
+int kstack_depth_to_print = 12;
+
+#ifdef CONFIG_KALLSYMS
+void printk_address(unsigned long address)
+{
+	unsigned long offset = 0, symsize;
+	const char *symname;
+	char *modname;
+	char *delim = ":";
+	char namebuf[128];
+
+	symname = kallsyms_lookup(address, &symsize, &offset,
+					&modname, namebuf);
+	if (!symname) {
+		printk(" [<%016lx>]\n", address);
+		return;
+	}
+	if (!modname)
+		modname = delim = ""; 		
+	printk(" [<%016lx>] %s%s%s%s+0x%lx/0x%lx\n",
+		address, delim, modname, delim, symname, offset, symsize);
+}
+#else
+void printk_address(unsigned long address)
+{
+	printk(" [<%016lx>]\n", address);
+}
+#endif
+
+static unsigned long *in_exception_stack(unsigned cpu, unsigned long stack,
+					unsigned *usedp, char **idp)
+{
+	static char ids[][8] = {
+		[DEBUG_STACK - 1] = "#DB",
+		[NMI_STACK - 1] = "NMI",
+		[DOUBLEFAULT_STACK - 1] = "#DF",
+		[STACKFAULT_STACK - 1] = "#SS",
+		[MCE_STACK - 1] = "#MC",
+#if DEBUG_STKSZ > EXCEPTION_STKSZ
+		[N_EXCEPTION_STACKS ... N_EXCEPTION_STACKS + DEBUG_STKSZ / EXCEPTION_STKSZ - 2] = "#DB[?]"
+#endif
+	};
+	unsigned k;
+
+	/*
+	 * Iterate over all exception stacks, and figure out whether
+	 * 'stack' is in one of them:
+	 */
+	for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+		unsigned long end = per_cpu(orig_ist, cpu).ist[k];
+		/*
+		 * Is 'stack' above this exception frame's end?
+		 * If yes then skip to the next frame.
+		 */
+		if (stack >= end)
+			continue;
+		/*
+		 * Is 'stack' above this exception frame's start address?
+		 * If yes then we found the right frame.
+		 */
+		if (stack >= end - EXCEPTION_STKSZ) {
+			/*
+			 * Make sure we only iterate through an exception
+			 * stack once. If it comes up for the second time
+			 * then there's something wrong going on - just
+			 * break out and return NULL:
+			 */
+			if (*usedp & (1U << k))
+				break;
+			*usedp |= 1U << k;
+			*idp = ids[k];
+			return (unsigned long *)end;
+		}
+		/*
+		 * If this is a debug stack, and if it has a larger size than
+		 * the usual exception stacks, then 'stack' might still
+		 * be within the lower portion of the debug stack:
+		 */
+#if DEBUG_STKSZ > EXCEPTION_STKSZ
+		if (k == DEBUG_STACK - 1 && stack >= end - DEBUG_STKSZ) {
+			unsigned j = N_EXCEPTION_STACKS - 1;
+
+			/*
+			 * Black magic. A large debug stack is composed of
+			 * multiple exception stack entries, which we
+			 * iterate through now. Dont look:
+			 */
+			do {
+				++j;
+				end -= EXCEPTION_STKSZ;
+				ids[j][4] = '1' + (j - N_EXCEPTION_STACKS);
+			} while (stack < end - EXCEPTION_STKSZ);
+			if (*usedp & (1U << j))
+				break;
+			*usedp |= 1U << j;
+			*idp = ids[j];
+			return (unsigned long *)end;
+		}
+#endif
+	}
+	return NULL;
+}
+
+#define MSG(txt) ops->warning(data, txt)
+
+/*
+ * x86-64 can have upto three kernel stacks: 
+ * process stack
+ * interrupt stack
+ * severe exception (double fault, nmi, stack fault, debug, mce) hardware stack
+ */
+
+static inline int valid_stack_ptr(struct thread_info *tinfo, void *p)
+{
+	void *t = (void *)tinfo;
+        return p > t && p < t + THREAD_SIZE - 3;
+}
+
+void dump_trace(struct task_struct *tsk, struct pt_regs *regs,
+		unsigned long *stack,
+		struct stacktrace_ops *ops, void *data)
+{
+	const unsigned cpu = get_cpu();
+	unsigned long *irqstack_end = (unsigned long*)cpu_pda(cpu)->irqstackptr;
+	unsigned used = 0;
+	struct thread_info *tinfo;
+
+	if (!tsk)
+		tsk = current;
+
+	if (!stack) {
+		unsigned long dummy;
+		stack = &dummy;
+		if (tsk && tsk != current)
+			stack = (unsigned long *)tsk->thread.rsp;
+	}
+
+	/*
+	 * Print function call entries within a stack. 'cond' is the
+	 * "end of stackframe" condition, that the 'stack++'
+	 * iteration will eventually trigger.
+	 */
+#define HANDLE_STACK(cond) \
+	do while (cond) { \
+		unsigned long addr = *stack++; \
+		/* Use unlocked access here because except for NMIs	\
+		   we should be already protected against module unloads */ \
+		if (__kernel_text_address(addr)) { \
+			/* \
+			 * If the address is either in the text segment of the \
+			 * kernel, or in the region which contains vmalloc'ed \
+			 * memory, it *may* be the address of a calling \
+			 * routine; if so, print it so that someone tracing \
+			 * down the cause of the crash will be able to figure \
+			 * out the call path that was taken. \
+			 */ \
+			ops->address(data, addr);   \
+		} \
+	} while (0)
+
+	/*
+	 * Print function call entries in all stacks, starting at the
+	 * current stack address. If the stacks consist of nested
+	 * exceptions
+	 */
+	for (;;) {
+		char *id;
+		unsigned long *estack_end;
+		estack_end = in_exception_stack(cpu, (unsigned long)stack,
+						&used, &id);
+
+		if (estack_end) {
+			if (ops->stack(data, id) < 0)
+				break;
+			HANDLE_STACK (stack < estack_end);
+			ops->stack(data, "<EOE>");
+			/*
+			 * We link to the next stack via the
+			 * second-to-last pointer (index -2 to end) in the
+			 * exception stack:
+			 */
+			stack = (unsigned long *) estack_end[-2];
+			continue;
+		}
+		if (irqstack_end) {
+			unsigned long *irqstack;
+			irqstack = irqstack_end -
+				(IRQSTACKSIZE - 64) / sizeof(*irqstack);
+
+			if (stack >= irqstack && stack < irqstack_end) {
+				if (ops->stack(data, "IRQ") < 0)
+					break;
+				HANDLE_STACK (stack < irqstack_end);
+				/*
+				 * We link to the next stack (which would be
+				 * the process stack normally) the last
+				 * pointer (index -1 to end) in the IRQ stack:
+				 */
+				stack = (unsigned long *) (irqstack_end[-1]);
+				irqstack_end = NULL;
+				ops->stack(data, "EOI");
+				continue;
+			}
+		}
+		break;
+	}
+
+	/*
+	 * This handles the process stack:
+	 */
+	tinfo = task_thread_info(tsk);
+	HANDLE_STACK (valid_stack_ptr(tinfo, stack));
+#undef HANDLE_STACK
+	put_cpu();
+}
+EXPORT_SYMBOL(dump_trace);
+
+static void
+print_trace_warning_symbol(void *data, char *msg, unsigned long symbol)
+{
+	print_symbol(msg, symbol);
+	printk("\n");
+}
+
+static void print_trace_warning(void *data, char *msg)
+{
+	printk("%s\n", msg);
+}
+
+static int print_trace_stack(void *data, char *name)
+{
+	printk(" <%s> ", name);
+	return 0;
+}
+
+static void print_trace_address(void *data, unsigned long addr)
+{
+	touch_nmi_watchdog();
+	printk_address(addr);
+}
+
+static struct stacktrace_ops print_trace_ops = {
+	.warning = print_trace_warning,
+	.warning_symbol = print_trace_warning_symbol,
+	.stack = print_trace_stack,
+	.address = print_trace_address,
+};
+
+void
+show_trace(struct task_struct *tsk, struct pt_regs *regs, unsigned long *stack)
+{
+	printk("\nCall Trace:\n");
+	dump_trace(tsk, regs, stack, &print_trace_ops, NULL);
+	printk("\n");
+}
+
+static void
+_show_stack(struct task_struct *tsk, struct pt_regs *regs, unsigned long *rsp)
+{
+	unsigned long *stack;
+	int i;
+	const int cpu = smp_processor_id();
+	unsigned long *irqstack_end = (unsigned long *) (cpu_pda(cpu)->irqstackptr);
+	unsigned long *irqstack = (unsigned long *) (cpu_pda(cpu)->irqstackptr - IRQSTACKSIZE);
+
+	// debugging aid: "show_stack(NULL, NULL);" prints the
+	// back trace for this cpu.
+
+	if (rsp == NULL) {
+		if (tsk)
+			rsp = (unsigned long *)tsk->thread.rsp;
+		else
+			rsp = (unsigned long *)&rsp;
+	}
+
+	stack = rsp;
+	for(i=0; i < kstack_depth_to_print; i++) {
+		if (stack >= irqstack && stack <= irqstack_end) {
+			if (stack == irqstack_end) {
+				stack = (unsigned long *) (irqstack_end[-1]);
+				printk(" <EOI> ");
+			}
+		} else {
+		if (((long) stack & (THREAD_SIZE-1)) == 0)
+			break;
+		}
+		if (i && ((i % 4) == 0))
+			printk("\n");
+		printk(" %016lx", *stack++);
+		touch_nmi_watchdog();
+	}
+	show_trace(tsk, regs, rsp);
+}
+
+void show_stack(struct task_struct *tsk, unsigned long * rsp)
+{
+	_show_stack(tsk, NULL, rsp);
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+	unsigned long dummy;
+	show_trace(NULL, NULL, &dummy);
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+void show_registers(struct pt_regs *regs)
+{
+	int i;
+	int in_kernel = !user_mode(regs);
+	unsigned long rsp;
+	const int cpu = smp_processor_id();
+	struct task_struct *cur = cpu_pda(cpu)->pcurrent;
+
+	rsp = regs->rsp;
+	printk("CPU %d ", cpu);
+	__show_regs(regs);
+	printk("Process %s (pid: %d, threadinfo %p, task %p)\n",
+		cur->comm, cur->pid, task_thread_info(cur), cur);
+
+	/*
+	 * When in-kernel, we also print out the stack and code at the
+	 * time of the fault..
+	 */
+	if (in_kernel) {
+		printk("Stack: ");
+		_show_stack(NULL, regs, (unsigned long*)rsp);
+
+		printk("\nCode: ");
+		if (regs->rip < PAGE_OFFSET)
+			goto bad;
+
+		for (i=0; i<20; i++) {
+			unsigned char c;
+			if (__get_user(c, &((unsigned char*)regs->rip)[i])) {
+bad:
+				printk(" Bad RIP value.");
+				break;
+			}
+			printk("%02x ", c);
+		}
+	}
+	printk("\n");
+}	
+
+int is_valid_bugaddr(unsigned long rip)
+{
+	unsigned short ud2;
+
+	if (__copy_from_user(&ud2, (const void __user *) rip, sizeof(ud2)))
+		return 0;
+
+	return ud2 == 0x0b0f;
+}
+
+#ifdef CONFIG_BUG
+void out_of_line_bug(void)
+{ 
+	BUG(); 
+} 
+EXPORT_SYMBOL(out_of_line_bug);
+#endif
+
+static DEFINE_SPINLOCK(die_lock);
+static int die_owner = -1;
+static unsigned int die_nest_count;
+
+unsigned __kprobes long oops_begin(void)
+{
+	int cpu;
+	unsigned long flags;
+
+	oops_enter();
+
+	/* racy, but better than risking deadlock. */
+	local_irq_save(flags);
+	cpu = smp_processor_id();
+	if (!spin_trylock(&die_lock)) { 
+		if (cpu == die_owner) 
+			/* nested oops. should stop eventually */;
+		else
+			spin_lock(&die_lock);
+	}
+	die_nest_count++;
+	die_owner = cpu;
+	console_verbose();
+	bust_spinlocks(1);
+	return flags;
+}
+
+void __kprobes oops_end(unsigned long flags)
+{ 
+	die_owner = -1;
+	bust_spinlocks(0);
+	die_nest_count--;
+	if (die_nest_count)
+		/* We still own the lock */
+		local_irq_restore(flags);
+	else
+		/* Nest count reaches zero, release the lock. */
+		spin_unlock_irqrestore(&die_lock, flags);
+	if (panic_on_oops)
+		panic("Fatal exception");
+	oops_exit();
+}
+
+void __kprobes __die(const char * str, struct pt_regs * regs, long err)
+{
+	static int die_counter;
+	printk(KERN_EMERG "%s: %04lx [%u] ", 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");
+	notify_die(DIE_OOPS, str, regs, err, current->thread.trap_no, SIGSEGV);
+	show_registers(regs);
+	add_taint(TAINT_DIE);
+	/* Executive summary in case the oops scrolled away */
+	printk(KERN_ALERT "RIP ");
+	printk_address(regs->rip); 
+	printk(" RSP <%016lx>\n", regs->rsp); 
+	if (kexec_should_crash(current))
+		crash_kexec(regs);
+}
+
+void die(const char * str, struct pt_regs * regs, long err)
+{
+	unsigned long flags = oops_begin();
+
+	if (!user_mode(regs))
+		report_bug(regs->rip, regs);
+
+	__die(str, regs, err);
+	oops_end(flags);
+	do_exit(SIGSEGV); 
+}
+
+void __kprobes die_nmi(char *str, struct pt_regs *regs, int do_panic)
+{
+	unsigned long flags = oops_begin();
+
+	/*
+	 * We are in trouble anyway, lets at least try
+	 * to get a message out.
+	 */
+	printk(str, smp_processor_id());
+	show_registers(regs);
+	if (kexec_should_crash(current))
+		crash_kexec(regs);
+	if (do_panic || panic_on_oops)
+		panic("Non maskable interrupt");
+	oops_end(flags);
+	nmi_exit();
+	local_irq_enable();
+	do_exit(SIGSEGV);
+}
+
+static void __kprobes do_trap(int trapnr, int signr, char *str,
+			      struct pt_regs * regs, long error_code,
+			      siginfo_t *info)
+{
+	struct task_struct *tsk = current;
+
+	if (user_mode(regs)) {
+		/*
+		 * We want error_code and trap_no set for userspace
+		 * faults and kernelspace faults which result in
+		 * die(), but not kernelspace faults which are fixed
+		 * up.  die() gives the process no chance to handle
+		 * the signal and notice the kernel fault information,
+		 * so that won't result in polluting the information
+		 * about previously queued, but not yet delivered,
+		 * faults.  See also do_general_protection below.
+		 */
+		tsk->thread.error_code = error_code;
+		tsk->thread.trap_no = trapnr;
+
+		if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
+		    printk_ratelimit())
+			printk(KERN_INFO
+			       "%s[%d] trap %s rip:%lx rsp:%lx error:%lx\n",
+			       tsk->comm, tsk->pid, str,
+			       regs->rip, regs->rsp, error_code); 
+
+		if (info)
+			force_sig_info(signr, info, tsk);
+		else
+			force_sig(signr, tsk);
+		return;
+	}
+
+
+	/* kernel trap */ 
+	{	     
+		const struct exception_table_entry *fixup;
+		fixup = search_exception_tables(regs->rip);
+		if (fixup)
+			regs->rip = fixup->fixup;
+		else {
+			tsk->thread.error_code = error_code;
+			tsk->thread.trap_no = trapnr;
+			die(str, regs, error_code);
+		}
+		return;
+	}
+}
+
+#define DO_ERROR(trapnr, signr, str, name) \
+asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
+{ \
+	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+							== NOTIFY_STOP) \
+		return; \
+	conditional_sti(regs);						\
+	do_trap(trapnr, signr, str, regs, error_code, NULL); \
+}
+
+#define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
+asmlinkage void do_##name(struct pt_regs * regs, long error_code) \
+{ \
+	siginfo_t info; \
+	info.si_signo = signr; \
+	info.si_errno = 0; \
+	info.si_code = sicode; \
+	info.si_addr = (void __user *)siaddr; \
+	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+							== NOTIFY_STOP) \
+		return; \
+	conditional_sti(regs);						\
+	do_trap(trapnr, signr, str, regs, error_code, &info); \
+}
+
+DO_ERROR_INFO( 0, SIGFPE,  "divide error", divide_error, FPE_INTDIV, regs->rip)
+DO_ERROR( 4, SIGSEGV, "overflow", overflow)
+DO_ERROR( 5, SIGSEGV, "bounds", bounds)
+DO_ERROR_INFO( 6, SIGILL,  "invalid opcode", invalid_op, ILL_ILLOPN, regs->rip)
+DO_ERROR( 7, SIGSEGV, "device not available", device_not_available)
+DO_ERROR( 9, SIGFPE,  "coprocessor segment overrun", coprocessor_segment_overrun)
+DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
+DO_ERROR(11, SIGBUS,  "segment not present", segment_not_present)
+DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
+DO_ERROR(18, SIGSEGV, "reserved", reserved)
+
+/* Runs on IST stack */
+asmlinkage void do_stack_segment(struct pt_regs *regs, long error_code)
+{
+	if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
+			12, SIGBUS) == NOTIFY_STOP)
+		return;
+	preempt_conditional_sti(regs);
+	do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
+	preempt_conditional_cli(regs);
+}
+
+asmlinkage void do_double_fault(struct pt_regs * regs, long error_code)
+{
+	static const char str[] = "double fault";
+	struct task_struct *tsk = current;
+
+	/* Return not checked because double check cannot be ignored */
+	notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
+
+	tsk->thread.error_code = error_code;
+	tsk->thread.trap_no = 8;
+
+	/* This is always a kernel trap and never fixable (and thus must
+	   never return). */
+	for (;;)
+		die(str, regs, error_code);
+}
+
+asmlinkage void __kprobes do_general_protection(struct pt_regs * regs,
+						long error_code)
+{
+	struct task_struct *tsk = current;
+
+	conditional_sti(regs);
+
+	if (user_mode(regs)) {
+		tsk->thread.error_code = error_code;
+		tsk->thread.trap_no = 13;
+
+		if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
+		    printk_ratelimit())
+			printk(KERN_INFO
+		       "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
+			       tsk->comm, tsk->pid,
+			       regs->rip, regs->rsp, error_code); 
+
+		force_sig(SIGSEGV, tsk);
+		return;
+	} 
+
+	/* kernel gp */
+	{
+		const struct exception_table_entry *fixup;
+		fixup = search_exception_tables(regs->rip);
+		if (fixup) {
+			regs->rip = fixup->fixup;
+			return;
+		}
+
+		tsk->thread.error_code = error_code;
+		tsk->thread.trap_no = 13;
+		if (notify_die(DIE_GPF, "general protection fault", regs,
+					error_code, 13, SIGSEGV) == NOTIFY_STOP)
+			return;
+		die("general protection fault", regs, error_code);
+	}
+}
+
+static __kprobes void
+mem_parity_error(unsigned char reason, struct pt_regs * regs)
+{
+	printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
+		reason);
+	printk(KERN_EMERG "You have some hardware problem, likely on the PCI bus.\n");
+
+#if defined(CONFIG_EDAC)
+	if(edac_handler_set()) {
+		edac_atomic_assert_error();
+		return;
+	}
+#endif
+
+	if (panic_on_unrecovered_nmi)
+		panic("NMI: Not continuing");
+
+	printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
+
+	/* Clear and disable the memory parity error line. */
+	reason = (reason & 0xf) | 4;
+	outb(reason, 0x61);
+}
+
+static __kprobes void
+io_check_error(unsigned char reason, struct pt_regs * regs)
+{
+	printk("NMI: IOCK error (debug interrupt?)\n");
+	show_registers(regs);
+
+	/* Re-enable the IOCK line, wait for a few seconds */
+	reason = (reason & 0xf) | 8;
+	outb(reason, 0x61);
+	mdelay(2000);
+	reason &= ~8;
+	outb(reason, 0x61);
+}
+
+static __kprobes void
+unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
+{
+	printk(KERN_EMERG "Uhhuh. NMI received for unknown reason %02x.\n",
+		reason);
+	printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
+
+	if (panic_on_unrecovered_nmi)
+		panic("NMI: Not continuing");
+
+	printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
+}
+
+/* Runs on IST stack. This code must keep interrupts off all the time.
+   Nested NMIs are prevented by the CPU. */
+asmlinkage __kprobes void default_do_nmi(struct pt_regs *regs)
+{
+	unsigned char reason = 0;
+	int cpu;
+
+	cpu = smp_processor_id();
+
+	/* Only the BSP gets external NMIs from the system.  */
+	if (!cpu)
+		reason = get_nmi_reason();
+
+	if (!(reason & 0xc0)) {
+		if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
+								== NOTIFY_STOP)
+			return;
+		/*
+		 * Ok, so this is none of the documented NMI sources,
+		 * so it must be the NMI watchdog.
+		 */
+		if (nmi_watchdog_tick(regs,reason))
+			return;
+		if (!do_nmi_callback(regs,cpu))
+			unknown_nmi_error(reason, regs);
+
+		return;
+	}
+	if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
+		return; 
+
+	/* AK: following checks seem to be broken on modern chipsets. FIXME */
+
+	if (reason & 0x80)
+		mem_parity_error(reason, regs);
+	if (reason & 0x40)
+		io_check_error(reason, regs);
+}
+
+/* runs on IST stack. */
+asmlinkage void __kprobes do_int3(struct pt_regs * regs, long error_code)
+{
+	if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
+		return;
+	}
+	preempt_conditional_sti(regs);
+	do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
+	preempt_conditional_cli(regs);
+}
+
+/* Help handler running on IST stack to switch back to user stack
+   for scheduling or signal handling. The actual stack switch is done in
+   entry.S */
+asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
+{
+	struct pt_regs *regs = eregs;
+	/* Did already sync */
+	if (eregs == (struct pt_regs *)eregs->rsp)
+		;
+	/* Exception from user space */
+	else if (user_mode(eregs))
+		regs = task_pt_regs(current);
+	/* Exception from kernel and interrupts are enabled. Move to
+ 	   kernel process stack. */
+	else if (eregs->eflags & X86_EFLAGS_IF)
+		regs = (struct pt_regs *)(eregs->rsp -= sizeof(struct pt_regs));
+	if (eregs != regs)
+		*regs = *eregs;
+	return regs;
+}
+
+/* runs on IST stack. */
+asmlinkage void __kprobes do_debug(struct pt_regs * regs,
+				   unsigned long error_code)
+{
+	unsigned long condition;
+	struct task_struct *tsk = current;
+	siginfo_t info;
+
+	get_debugreg(condition, 6);
+
+	if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
+						SIGTRAP) == NOTIFY_STOP)
+		return;
+
+	preempt_conditional_sti(regs);
+
+	/* Mask out spurious debug traps due to lazy DR7 setting */
+	if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
+		if (!tsk->thread.debugreg7) { 
+			goto clear_dr7;
+		}
+	}
+
+	tsk->thread.debugreg6 = condition;
+
+	/* Mask out spurious TF errors due to lazy TF clearing */
+	if (condition & DR_STEP) {
+		/*
+		 * The TF error should be masked out only if the current
+		 * process is not traced and if the TRAP flag has been set
+		 * previously by a tracing process (condition detected by
+		 * the PT_DTRACE flag); remember that the i386 TRAP flag
+		 * can be modified by the process itself in user mode,
+		 * allowing programs to debug themselves without the ptrace()
+		 * interface.
+		 */
+                if (!user_mode(regs))
+                       goto clear_TF_reenable;
+		/*
+		 * Was the TF flag set by a debugger? If so, clear it now,
+		 * so that register information is correct.
+		 */
+		if (tsk->ptrace & PT_DTRACE) {
+			regs->eflags &= ~TF_MASK;
+			tsk->ptrace &= ~PT_DTRACE;
+		}
+	}
+
+	/* Ok, finally something we can handle */
+	tsk->thread.trap_no = 1;
+	tsk->thread.error_code = error_code;
+	info.si_signo = SIGTRAP;
+	info.si_errno = 0;
+	info.si_code = TRAP_BRKPT;
+	info.si_addr = user_mode(regs) ? (void __user *)regs->rip : NULL;
+	force_sig_info(SIGTRAP, &info, tsk);
+
+clear_dr7:
+	set_debugreg(0UL, 7);
+	preempt_conditional_cli(regs);
+	return;
+
+clear_TF_reenable:
+	set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
+	regs->eflags &= ~TF_MASK;
+	preempt_conditional_cli(regs);
+}
+
+static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
+{
+	const struct exception_table_entry *fixup;
+	fixup = search_exception_tables(regs->rip);
+	if (fixup) {
+		regs->rip = fixup->fixup;
+		return 1;
+	}
+	notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
+	/* Illegal floating point operation in the kernel */
+	current->thread.trap_no = trapnr;
+	die(str, regs, 0);
+	return 0;
+}
+
+/*
+ * Note that we play around with the 'TS' bit in an attempt to get
+ * the correct behaviour even in the presence of the asynchronous
+ * IRQ13 behaviour
+ */
+asmlinkage void do_coprocessor_error(struct pt_regs *regs)
+{
+	void __user *rip = (void __user *)(regs->rip);
+	struct task_struct * task;
+	siginfo_t info;
+	unsigned short cwd, swd;
+
+	conditional_sti(regs);
+	if (!user_mode(regs) &&
+	    kernel_math_error(regs, "kernel x87 math error", 16))
+		return;
+
+	/*
+	 * Save the info for the exception handler and clear the error.
+	 */
+	task = current;
+	save_init_fpu(task);
+	task->thread.trap_no = 16;
+	task->thread.error_code = 0;
+	info.si_signo = SIGFPE;
+	info.si_errno = 0;
+	info.si_code = __SI_FAULT;
+	info.si_addr = rip;
+	/*
+	 * (~cwd & swd) will mask out exceptions that are not set to unmasked
+	 * status.  0x3f is the exception bits in these regs, 0x200 is the
+	 * C1 reg you need in case of a stack fault, 0x040 is the stack
+	 * fault bit.  We should only be taking one exception at a time,
+	 * so if this combination doesn't produce any single exception,
+	 * then we have a bad program that isn't synchronizing its FPU usage
+	 * and it will suffer the consequences since we won't be able to
+	 * fully reproduce the context of the exception
+	 */
+	cwd = get_fpu_cwd(task);
+	swd = get_fpu_swd(task);
+	switch (swd & ~cwd & 0x3f) {
+		case 0x000:
+		default:
+			break;
+		case 0x001: /* Invalid Op */
+			/*
+			 * swd & 0x240 == 0x040: Stack Underflow
+			 * swd & 0x240 == 0x240: Stack Overflow
+			 * User must clear the SF bit (0x40) if set
+			 */
+			info.si_code = FPE_FLTINV;
+			break;
+		case 0x002: /* Denormalize */
+		case 0x010: /* Underflow */
+			info.si_code = FPE_FLTUND;
+			break;
+		case 0x004: /* Zero Divide */
+			info.si_code = FPE_FLTDIV;
+			break;
+		case 0x008: /* Overflow */
+			info.si_code = FPE_FLTOVF;
+			break;
+		case 0x020: /* Precision */
+			info.si_code = FPE_FLTRES;
+			break;
+	}
+	force_sig_info(SIGFPE, &info, task);
+}
+
+asmlinkage void bad_intr(void)
+{
+	printk("bad interrupt"); 
+}
+
+asmlinkage void do_simd_coprocessor_error(struct pt_regs *regs)
+{
+	void __user *rip = (void __user *)(regs->rip);
+	struct task_struct * task;
+	siginfo_t info;
+	unsigned short mxcsr;
+
+	conditional_sti(regs);
+	if (!user_mode(regs) &&
+        	kernel_math_error(regs, "kernel simd math error", 19))
+		return;
+
+	/*
+	 * Save the info for the exception handler and clear the error.
+	 */
+	task = current;
+	save_init_fpu(task);
+	task->thread.trap_no = 19;
+	task->thread.error_code = 0;
+	info.si_signo = SIGFPE;
+	info.si_errno = 0;
+	info.si_code = __SI_FAULT;
+	info.si_addr = rip;
+	/*
+	 * The SIMD FPU exceptions are handled a little differently, as there
+	 * is only a single status/control register.  Thus, to determine which
+	 * unmasked exception was caught we must mask the exception mask bits
+	 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
+	 */
+	mxcsr = get_fpu_mxcsr(task);
+	switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
+		case 0x000:
+		default:
+			break;
+		case 0x001: /* Invalid Op */
+			info.si_code = FPE_FLTINV;
+			break;
+		case 0x002: /* Denormalize */
+		case 0x010: /* Underflow */
+			info.si_code = FPE_FLTUND;
+			break;
+		case 0x004: /* Zero Divide */
+			info.si_code = FPE_FLTDIV;
+			break;
+		case 0x008: /* Overflow */
+			info.si_code = FPE_FLTOVF;
+			break;
+		case 0x020: /* Precision */
+			info.si_code = FPE_FLTRES;
+			break;
+	}
+	force_sig_info(SIGFPE, &info, task);
+}
+
+asmlinkage void do_spurious_interrupt_bug(struct pt_regs * regs)
+{
+}
+
+asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
+{
+}
+
+asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
+{
+}
+
+/*
+ *  'math_state_restore()' saves the current math information in the
+ * old math state array, and gets the new ones from the current task
+ *
+ * Careful.. There are problems with IBM-designed IRQ13 behaviour.
+ * Don't touch unless you *really* know how it works.
+ */
+asmlinkage void math_state_restore(void)
+{
+	struct task_struct *me = current;
+	clts();			/* Allow maths ops (or we recurse) */
+
+	if (!used_math())
+		init_fpu(me);
+	restore_fpu_checking(&me->thread.i387.fxsave);
+	task_thread_info(me)->status |= TS_USEDFPU;
+	me->fpu_counter++;
+}
+
+void __init trap_init(void)
+{
+	set_intr_gate(0,&divide_error);
+	set_intr_gate_ist(1,&debug,DEBUG_STACK);
+	set_intr_gate_ist(2,&nmi,NMI_STACK);
+ 	set_system_gate_ist(3,&int3,DEBUG_STACK); /* int3 can be called from all */
+	set_system_gate(4,&overflow);	/* int4 can be called from all */
+	set_intr_gate(5,&bounds);
+	set_intr_gate(6,&invalid_op);
+	set_intr_gate(7,&device_not_available);
+	set_intr_gate_ist(8,&double_fault, DOUBLEFAULT_STACK);
+	set_intr_gate(9,&coprocessor_segment_overrun);
+	set_intr_gate(10,&invalid_TSS);
+	set_intr_gate(11,&segment_not_present);
+	set_intr_gate_ist(12,&stack_segment,STACKFAULT_STACK);
+	set_intr_gate(13,&general_protection);
+	set_intr_gate(14,&page_fault);
+	set_intr_gate(15,&spurious_interrupt_bug);
+	set_intr_gate(16,&coprocessor_error);
+	set_intr_gate(17,&alignment_check);
+#ifdef CONFIG_X86_MCE
+	set_intr_gate_ist(18,&machine_check, MCE_STACK); 
+#endif
+	set_intr_gate(19,&simd_coprocessor_error);
+
+#ifdef CONFIG_IA32_EMULATION
+	set_system_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
+#endif
+       
+	/*
+	 * Should be a barrier for any external CPU state.
+	 */
+	cpu_init();
+}
+
+
+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);