Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 948 insertions, 0 deletions

diff --git a/arch/x86_64/kernel/traps.c b/arch/x86_64/kernel/traps.c
new file mode 100644
index 00000000000..d87ac6496cc
--- /dev/null
+++ b/arch/x86_64/kernel/traps.c
@@ -0,0 +1,948 @@
+/*
+ *  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
+ *
+ *  $Id: traps.c,v 1.36 2002/03/24 11:09:10 ak Exp $
+ */
+
+/*
+ * 'Traps.c' handles hardware traps and faults after we have saved some
+ * state in 'entry.S'.
+ */
+#include <linux/config.h>
+#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/module.h>
+#include <linux/moduleparam.h>
+
+#include <asm/system.h>
+#include <asm/uaccess.h>
+#include <asm/io.h>
+#include <asm/atomic.h>
+#include <asm/debugreg.h>
+#include <asm/desc.h>
+#include <asm/i387.h>
+#include <asm/kdebug.h>
+#include <asm/processor.h>
+
+#include <asm/smp.h>
+#include <asm/pgalloc.h>
+#include <asm/pda.h>
+#include <asm/proto.h>
+#include <asm/nmi.h>
+
+#include <linux/irq.h>
+
+
+extern struct gate_struct idt_table[256]; 
+
+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);
+asmlinkage void call_debug(void);
+
+struct notifier_block *die_chain;
+static DEFINE_SPINLOCK(die_notifier_lock);
+
+int register_die_notifier(struct notifier_block *nb)
+{
+	int err = 0;
+	unsigned long flags;
+	spin_lock_irqsave(&die_notifier_lock, flags);
+	err = notifier_chain_register(&die_chain, nb);
+	spin_unlock_irqrestore(&die_notifier_lock, flags);
+	return err;
+}
+
+static inline void conditional_sti(struct pt_regs *regs)
+{
+	if (regs->eflags & X86_EFLAGS_IF)
+		local_irq_enable();
+}
+
+static int kstack_depth_to_print = 10;
+
+#ifdef CONFIG_KALLSYMS
+#include <linux/kallsyms.h> 
+int 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) 
+		return printk("[<%016lx>]", address);
+	if (!modname) 
+		modname = delim = ""; 		
+        return printk("<%016lx>{%s%s%s%s%+ld}",
+		      address,delim,modname,delim,symname,offset); 
+} 
+#else
+int printk_address(unsigned long address)
+{ 
+	return printk("[<%016lx>]", address);
+} 
+#endif
+
+unsigned long *in_exception_stack(int cpu, unsigned long stack) 
+{ 
+	int k;
+	for (k = 0; k < N_EXCEPTION_STACKS; k++) {
+		struct tss_struct *tss = &per_cpu(init_tss, cpu);
+		unsigned long start = tss->ist[k] - EXCEPTION_STKSZ;
+
+		if (stack >= start && stack < tss->ist[k])
+			return (unsigned long *)tss->ist[k];
+	}
+	return NULL;
+} 
+
+/*
+ * x86-64 can have upto three kernel stacks: 
+ * process stack
+ * interrupt stack
+ * severe exception (double fault, nmi, stack fault) hardware stack
+ * Check and process them in order.
+ */
+
+void show_trace(unsigned long *stack)
+{
+	unsigned long addr;
+	unsigned long *irqstack, *irqstack_end, *estack_end;
+	const int cpu = safe_smp_processor_id();
+	int i;
+
+	printk("\nCall Trace:");
+	i = 0; 
+	
+	estack_end = in_exception_stack(cpu, (unsigned long)stack); 
+	if (estack_end) { 
+		while (stack < estack_end) { 
+			addr = *stack++; 
+			if (__kernel_text_address(addr)) {
+				i += printk_address(addr);
+				i += printk(" "); 
+				if (i > 50) {
+					printk("\n"); 
+					i = 0;
+				}
+			}
+		}
+		i += printk(" <EOE> "); 
+		i += 7;
+		stack = (unsigned long *) estack_end[-2]; 
+	}  
+
+	irqstack_end = (unsigned long *) (cpu_pda[cpu].irqstackptr);
+	irqstack = (unsigned long *) (cpu_pda[cpu].irqstackptr - IRQSTACKSIZE + 64);
+
+	if (stack >= irqstack && stack < irqstack_end) {
+		printk("<IRQ> ");  
+		while (stack < irqstack_end) {
+			addr = *stack++;
+			/*
+			 * 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.
+			 */
+			 if (__kernel_text_address(addr)) {
+				 i += printk_address(addr);
+				 i += printk(" "); 
+				 if (i > 50) { 
+					printk("\n       ");
+					 i = 0;
+				 } 
+			}
+		} 
+		stack = (unsigned long *) (irqstack_end[-1]);
+		printk(" <EOI> ");
+		i += 7;
+	} 
+
+	while (((long) stack & (THREAD_SIZE-1)) != 0) {
+		addr = *stack++;
+		if (__kernel_text_address(addr)) {
+			i += printk_address(addr);
+			i += printk(" "); 
+			if (i > 50) { 
+				printk("\n       ");
+					 i = 0;
+			} 
+		}
+	}
+	printk("\n");
+}
+
+void show_stack(struct task_struct *tsk, unsigned long * rsp)
+{
+	unsigned long *stack;
+	int i;
+	const int cpu = safe_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++);
+	}
+	show_trace((unsigned long *)rsp);
+}
+
+/*
+ * The architecture-independent dump_stack generator
+ */
+void dump_stack(void)
+{
+	unsigned long dummy;
+	show_trace(&dummy);
+}
+
+EXPORT_SYMBOL(dump_stack);
+
+void show_registers(struct pt_regs *regs)
+{
+	int i;
+	int in_kernel = (regs->cs & 3) == 0;
+	unsigned long rsp;
+	const int cpu = safe_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, cur->thread_info, 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, (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");
+}	
+
+void handle_BUG(struct pt_regs *regs)
+{ 
+	struct bug_frame f;
+	char tmp;
+
+	if (regs->cs & 3)
+		return; 
+	if (__copy_from_user(&f, (struct bug_frame *) regs->rip, 
+			     sizeof(struct bug_frame)))
+		return; 
+	if ((unsigned long)f.filename < __PAGE_OFFSET || 
+	    f.ud2[0] != 0x0f || f.ud2[1] != 0x0b) 
+		return;
+	if (__get_user(tmp, f.filename))
+		f.filename = "unmapped filename"; 
+	printk("----------- [cut here ] --------- [please bite here ] ---------\n");
+	printk(KERN_ALERT "Kernel BUG at %.50s:%d\n", f.filename, f.line);
+} 
+
+void out_of_line_bug(void)
+{ 
+	BUG(); 
+} 
+
+static DEFINE_SPINLOCK(die_lock);
+static int die_owner = -1;
+
+void oops_begin(void)
+{
+	int cpu = safe_smp_processor_id(); 
+	/* racy, but better than risking deadlock. */ 
+	local_irq_disable();
+	if (!spin_trylock(&die_lock)) { 
+		if (cpu == die_owner) 
+			/* nested oops. should stop eventually */;
+		else
+			spin_lock(&die_lock); 
+	}
+	die_owner = cpu; 
+	console_verbose();
+	bust_spinlocks(1); 
+}
+
+void oops_end(void)
+{ 
+	die_owner = -1;
+	bust_spinlocks(0); 
+	spin_unlock(&die_lock); 
+	if (panic_on_oops)
+		panic("Oops"); 
+} 
+
+void __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, (char *)str, regs, err, 255, SIGSEGV);
+	show_registers(regs);
+	/* Executive summary in case the oops scrolled away */
+	printk(KERN_ALERT "RIP ");
+	printk_address(regs->rip); 
+	printk(" RSP <%016lx>\n", regs->rsp); 
+}
+
+void die(const char * str, struct pt_regs * regs, long err)
+{
+	oops_begin();
+	handle_BUG(regs);
+	__die(str, regs, err);
+	oops_end();
+	do_exit(SIGSEGV); 
+}
+static inline void die_if_kernel(const char * str, struct pt_regs * regs, long err)
+{
+	if (!(regs->eflags & VM_MASK) && (regs->cs == __KERNEL_CS))
+		die(str, regs, err);
+}
+
+void die_nmi(char *str, struct pt_regs *regs)
+{
+	oops_begin();
+	/*
+	 * We are in trouble anyway, lets at least try
+	 * to get a message out.
+	 */
+	printk(str, safe_smp_processor_id());
+	show_registers(regs);
+	if (panic_on_timeout || panic_on_oops)
+		panic("nmi watchdog");
+	printk("console shuts up ...\n");
+	oops_end();
+	do_exit(SIGSEGV);
+}
+
+static void do_trap(int trapnr, int signr, char *str, 
+			   struct pt_regs * regs, long error_code, siginfo_t *info)
+{
+	conditional_sti(regs);
+
+#ifdef CONFIG_CHECKING
+       { 
+               unsigned long gs; 
+               struct x8664_pda *pda = cpu_pda + safe_smp_processor_id(); 
+               rdmsrl(MSR_GS_BASE, gs); 
+               if (gs != (unsigned long)pda) { 
+                       wrmsrl(MSR_GS_BASE, pda); 
+                       printk("%s: wrong gs %lx expected %p rip %lx\n", str, gs, pda,
+			      regs->rip);
+               }
+       }
+#endif
+
+	if ((regs->cs & 3)  != 0) { 
+		struct task_struct *tsk = current;
+
+		if (exception_trace && unhandled_signal(tsk, signr))
+			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); 
+
+		tsk->thread.error_code = error_code;
+		tsk->thread.trap_no = trapnr;
+		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	
+			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; \
+	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; \
+	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 operand", 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)
+
+#define DO_ERROR_STACK(trapnr, signr, str, name) \
+asmlinkage void *do_##name(struct pt_regs * regs, long error_code) \
+{ \
+	struct pt_regs *pr = ((struct pt_regs *)(current->thread.rsp0))-1; \
+	if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
+							== NOTIFY_STOP) \
+		return regs; \
+	if (regs->cs & 3) { \
+		memcpy(pr, regs, sizeof(struct pt_regs)); \
+		regs = pr; \
+	} \
+	do_trap(trapnr, signr, str, regs, error_code, NULL); \
+	return regs;		\
+}
+
+DO_ERROR_STACK(12, SIGBUS,  "stack segment", stack_segment)
+DO_ERROR_STACK( 8, SIGSEGV, "double fault", double_fault)
+
+asmlinkage void do_general_protection(struct pt_regs * regs, long error_code)
+{
+	conditional_sti(regs);
+
+#ifdef CONFIG_CHECKING
+       { 
+               unsigned long gs; 
+               struct x8664_pda *pda = cpu_pda + safe_smp_processor_id(); 
+               rdmsrl(MSR_GS_BASE, gs); 
+               if (gs != (unsigned long)pda) { 
+                       wrmsrl(MSR_GS_BASE, pda); 
+		       oops_in_progress++;
+                       printk("general protection handler: wrong gs %lx expected %p\n", gs, pda);
+		       oops_in_progress--;
+               }
+       }
+#endif
+
+	if ((regs->cs & 3)!=0) { 
+		struct task_struct *tsk = current;
+
+		if (exception_trace && unhandled_signal(tsk, SIGSEGV))
+			printk(KERN_INFO
+		       "%s[%d] general protection rip:%lx rsp:%lx error:%lx\n",
+			       tsk->comm, tsk->pid,
+			       regs->rip,regs->rsp,error_code); 
+
+		tsk->thread.error_code = error_code;
+		tsk->thread.trap_no = 13;
+		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;
+		}
+		if (notify_die(DIE_GPF, "general protection fault", regs,
+					error_code, 13, SIGSEGV) == NOTIFY_STOP)
+			return;
+		die("general protection fault", regs, error_code);
+	}
+}
+
+static void mem_parity_error(unsigned char reason, struct pt_regs * regs)
+{
+	printk("Uhhuh. NMI received. Dazed and confused, but trying to continue\n");
+	printk("You probably have a hardware problem with your RAM chips\n");
+
+	/* Clear and disable the memory parity error line. */
+	reason = (reason & 0xf) | 4;
+	outb(reason, 0x61);
+}
+
+static 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 void unknown_nmi_error(unsigned char reason, struct pt_regs * regs)
+{	printk("Uhhuh. NMI received for unknown reason %02x.\n", reason);
+	printk("Dazed and confused, but trying to continue\n");
+	printk("Do you have a strange power saving mode enabled?\n");
+}
+
+asmlinkage void default_do_nmi(struct pt_regs *regs)
+{
+	unsigned char reason = 0;
+
+	/* Only the BSP gets external NMIs from the system.  */
+	if (!smp_processor_id())
+		reason = get_nmi_reason();
+
+	if (!(reason & 0xc0)) {
+		if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 0, SIGINT)
+								== NOTIFY_STOP)
+			return;
+#ifdef CONFIG_X86_LOCAL_APIC
+		/*
+		 * Ok, so this is none of the documented NMI sources,
+		 * so it must be the NMI watchdog.
+		 */
+		if (nmi_watchdog > 0) {
+			nmi_watchdog_tick(regs,reason);
+			return;
+		}
+#endif
+		unknown_nmi_error(reason, regs);
+		return;
+	}
+	if (notify_die(DIE_NMI, "nmi", regs, reason, 0, 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);
+}
+
+asmlinkage void do_int3(struct pt_regs * regs, long error_code)
+{
+	if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) == NOTIFY_STOP) {
+		return;
+	}
+	do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
+	return;
+}
+
+/* runs on IST stack. */
+asmlinkage void *do_debug(struct pt_regs * regs, unsigned long error_code)
+{
+	struct pt_regs *pr;
+	unsigned long condition;
+	struct task_struct *tsk = current;
+	siginfo_t info;
+
+	pr = (struct pt_regs *)(current->thread.rsp0)-1;
+	if (regs->cs & 3) {
+		memcpy(pr, regs, sizeof(struct pt_regs));
+		regs = pr;
+	}	
+
+#ifdef CONFIG_CHECKING
+       { 
+	       /* RED-PEN interaction with debugger - could destroy gs */
+               unsigned long gs; 
+               struct x8664_pda *pda = cpu_pda + safe_smp_processor_id(); 
+               rdmsrl(MSR_GS_BASE, gs); 
+               if (gs != (unsigned long)pda) { 
+                       wrmsrl(MSR_GS_BASE, pda); 
+                       printk("debug handler: wrong gs %lx expected %p\n", gs, pda);
+               }
+       }
+#endif
+
+	asm("movq %%db6,%0" : "=r" (condition));
+
+	if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
+						SIGTRAP) == NOTIFY_STOP) {
+		return regs;
+	}
+	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) &&
+	    (notify_die(DIE_DEBUGSTEP, "debugstep", regs, condition,
+			1, SIGTRAP) != NOTIFY_STOP)) {
+		/*
+		 * 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 ((regs->cs & 3) == 0)
+                       goto clear_TF_reenable;
+		if ((tsk->ptrace & (PT_DTRACE|PT_PTRACED)) == PT_DTRACE)
+			goto clear_TF;
+	}
+
+	/* 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;
+	if ((regs->cs & 3) == 0) 
+		goto clear_dr7; 
+
+	info.si_addr = (void __user *)regs->rip;
+	force_sig_info(SIGTRAP, &info, tsk);	
+clear_dr7:
+	asm volatile("movq %0,%%db7"::"r"(0UL));
+	notify_die(DIE_DEBUG, "debug", regs, condition, 1, SIGTRAP);
+	return regs;
+
+clear_TF_reenable:
+	set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
+
+clear_TF:
+	/* RED-PEN could cause spurious errors */
+	if (notify_die(DIE_DEBUG, "debug2", regs, condition, 1, SIGTRAP) 
+								!= NOTIFY_STOP)
+	regs->eflags &= ~TF_MASK;
+	return regs;	
+}
+
+static int kernel_math_error(struct pt_regs *regs, char *str)
+{
+	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, 16, SIGFPE);
+#if 0
+	/* This should be a die, but warn only for now */
+	die(str, regs, 0);
+#else
+	printk(KERN_DEBUG "%s: %s at ", current->comm, str);
+	printk_address(regs->rip);
+	printk("\n");
+#endif
+	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 ((regs->cs & 3) == 0 &&
+	    kernel_math_error(regs, "kernel x87 math error"))
+		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 (((~cwd) & swd & 0x3f) | (swd & 0x240)) {
+		case 0x000:
+		default:
+			break;
+		case 0x001: /* Invalid Op */
+		case 0x041: /* Stack Fault */
+		case 0x241: /* Stack Fault | Direction */
+			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 ((regs->cs & 3) == 0 &&
+        	kernel_math_error(regs, "simd math error"))
+		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)
+{
+}
+
+/*
+ *  '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);
+	me->thread_info->status |= TS_USEDFPU;
+}
+
+void do_call_debug(struct pt_regs *regs) 
+{ 
+	notify_die(DIE_CALL, "debug call", regs, 0, 255, SIGINT); 
+}
+
+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(3,&int3);
+	set_system_gate(4,&overflow);	/* int4-5 can be called from all */
+	set_system_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
+       
+	set_intr_gate(KDB_VECTOR, call_debug);
+       
+	/*
+	 * Should be a barrier for any external CPU state.
+	 */
+	cpu_init();
+}
+
+
+/* Actual parsing is done early in setup.c. */
+static int __init oops_dummy(char *s)
+{ 
+	panic_on_oops = 1;
+	return -1; 
+} 
+__setup("oops=", oops_dummy); 
+
+static int __init kstack_setup(char *s)
+{
+	kstack_depth_to_print = simple_strtoul(s,NULL,0);
+	return 0;
+}
+__setup("kstack=", kstack_setup);
+