traps: x86: finalize unification of traps.c

traps_32.c and traps_64.c are now equal. Move one to traps.c,
delete the other one and change the Makefile

Signed-off-by: Alexander van Heukelum <heukelum@fastmail.fm>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

3 files changed, 1 insertions, 1071 deletions

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index de63fed9fae8..0d41f0343dc0 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -23,7 +23,7 @@ CFLAGS_hpet.o		:= $(nostackp)
 CFLAGS_tsc.o		:= $(nostackp)
 
 obj-y			:= process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
-obj-y			+= traps_$(BITS).o irq_$(BITS).o dumpstack_$(BITS).o
+obj-y			+= traps.o irq_$(BITS).o dumpstack_$(BITS).o
 obj-y			+= time_$(BITS).o ioport.o ldt.o
 obj-y			+= setup.o i8259.o irqinit_$(BITS).o setup_percpu.o
 obj-$(CONFIG_X86_VISWS)	+= visws_quirks.o
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps.c
index ffb131f74f78..ffb131f74f78 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps.c
diff --git a/arch/x86/kernel/traps_64.c b/arch/x86/kernel/traps_64.c
deleted file mode 100644
index 60ecc855ab81..000000000000
--- a/arch/x86/kernel/traps_64.c
+++ /dev/null
@@ -1,1070 +0,0 @@
-/*
- *  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
- */
-
-/*
- * Handle hardware traps and faults.
- */
-#include <linux/interrupt.h>
-#include <linux/kallsyms.h>
-#include <linux/spinlock.h>
-#include <linux/kprobes.h>
-#include <linux/uaccess.h>
-#include <linux/utsname.h>
-#include <linux/kdebug.h>
-#include <linux/kernel.h>
-#include <linux/module.h>
-#include <linux/ptrace.h>
-#include <linux/string.h>
-#include <linux/unwind.h>
-#include <linux/delay.h>
-#include <linux/errno.h>
-#include <linux/kexec.h>
-#include <linux/sched.h>
-#include <linux/timer.h>
-#include <linux/init.h>
-#include <linux/bug.h>
-#include <linux/nmi.h>
-#include <linux/mm.h>
-#include <linux/smp.h>
-#include <linux/io.h>
-
-#ifdef CONFIG_EISA
-#include <linux/ioport.h>
-#include <linux/eisa.h>
-#endif
-
-#ifdef CONFIG_MCA
-#include <linux/mca.h>
-#endif
-
-#if defined(CONFIG_EDAC)
-#include <linux/edac.h>
-#endif
-
-#include <asm/stacktrace.h>
-#include <asm/processor.h>
-#include <asm/debugreg.h>
-#include <asm/atomic.h>
-#include <asm/system.h>
-#include <asm/unwind.h>
-#include <asm/traps.h>
-#include <asm/desc.h>
-#include <asm/i387.h>
-
-#include <mach_traps.h>
-
-#ifdef CONFIG_X86_64
-#include <asm/pgalloc.h>
-#include <asm/proto.h>
-#include <asm/pda.h>
-#else
-#include <asm/processor-flags.h>
-#include <asm/arch_hooks.h>
-#include <asm/nmi.h>
-#include <asm/smp.h>
-#include <asm/io.h>
-
-#include "cpu/mcheck/mce.h"
-
-DECLARE_BITMAP(used_vectors, NR_VECTORS);
-EXPORT_SYMBOL_GPL(used_vectors);
-
-asmlinkage int system_call(void);
-
-/* Do we ignore FPU interrupts ? */
-char ignore_fpu_irq;
-
-/*
- * The IDT has to be page-aligned to simplify the Pentium
- * F0 0F bug workaround.. We have a special link segment
- * for this.
- */
-gate_desc idt_table[256]
-	__attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
-#endif
-
-static int ignore_nmis;
-
-static inline void conditional_sti(struct pt_regs *regs)
-{
-	if (regs->flags & X86_EFLAGS_IF)
-		local_irq_enable();
-}
-
-static inline void preempt_conditional_sti(struct pt_regs *regs)
-{
-	inc_preempt_count();
-	if (regs->flags & X86_EFLAGS_IF)
-		local_irq_enable();
-}
-
-static inline void preempt_conditional_cli(struct pt_regs *regs)
-{
-	if (regs->flags & X86_EFLAGS_IF)
-		local_irq_disable();
-	dec_preempt_count();
-}
-
-#ifdef CONFIG_X86_32
-static inline void
-die_if_kernel(const char *str, struct pt_regs *regs, long err)
-{
-	if (!user_mode_vm(regs))
-		die(str, regs, err);
-}
-
-/*
- * Perform the lazy TSS's I/O bitmap copy. If the TSS has an
- * invalid offset set (the LAZY one) and the faulting thread has
- * a valid I/O bitmap pointer, we copy the I/O bitmap in the TSS,
- * we set the offset field correctly and return 1.
- */
-static int lazy_iobitmap_copy(void)
-{
-	struct thread_struct *thread;
-	struct tss_struct *tss;
-	int cpu;
-
-	cpu = get_cpu();
-	tss = &per_cpu(init_tss, cpu);
-	thread = &current->thread;
-
-	if (tss->x86_tss.io_bitmap_base == INVALID_IO_BITMAP_OFFSET_LAZY &&
-	    thread->io_bitmap_ptr) {
-		memcpy(tss->io_bitmap, thread->io_bitmap_ptr,
-		       thread->io_bitmap_max);
-		/*
-		 * If the previously set map was extending to higher ports
-		 * than the current one, pad extra space with 0xff (no access).
-		 */
-		if (thread->io_bitmap_max < tss->io_bitmap_max) {
-			memset((char *) tss->io_bitmap +
-				thread->io_bitmap_max, 0xff,
-				tss->io_bitmap_max - thread->io_bitmap_max);
-		}
-		tss->io_bitmap_max = thread->io_bitmap_max;
-		tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
-		tss->io_bitmap_owner = thread;
-		put_cpu();
-
-		return 1;
-	}
-	put_cpu();
-
-	return 0;
-}
-#endif
-
-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;
-
-#ifdef CONFIG_X86_32
-	if (regs->flags & X86_VM_MASK) {
-		/*
-		 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
-		 * On nmi (interrupt 2), do_trap should not be called.
-		 */
-		if (trapnr < 6)
-			goto vm86_trap;
-		goto trap_signal;
-	}
-#endif
-
-	if (!user_mode(regs))
-		goto kernel_trap;
-
-#ifdef CONFIG_X86_32
-trap_signal:
-#endif
-	/*
-	 * 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;
-
-#ifdef CONFIG_X86_64
-	if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
-	    printk_ratelimit()) {
-		printk(KERN_INFO
-		       "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
-		       tsk->comm, tsk->pid, str,
-		       regs->ip, regs->sp, error_code);
-		print_vma_addr(" in ", regs->ip);
-		printk("\n");
-	}
-#endif
-
-	if (info)
-		force_sig_info(signr, info, tsk);
-	else
-		force_sig(signr, tsk);
-	return;
-
-kernel_trap:
-	if (!fixup_exception(regs)) {
-		tsk->thread.error_code = error_code;
-		tsk->thread.trap_no = trapnr;
-		die(str, regs, error_code);
-	}
-	return;
-
-#ifdef CONFIG_X86_32
-vm86_trap:
-	if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
-						error_code, trapnr))
-		goto trap_signal;
-	return;
-#endif
-}
-
-#define DO_ERROR(trapnr, signr, str, name)				\
-dotraplinkage 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)		\
-dotraplinkage 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->ip)
-DO_ERROR(4, SIGSEGV, "overflow", overflow)
-DO_ERROR(5, SIGSEGV, "bounds", bounds)
-DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
-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)
-#ifdef CONFIG_X86_32
-DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
-#endif
-DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
-
-#ifdef CONFIG_X86_64
-/* Runs on IST stack */
-dotraplinkage 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);
-}
-
-dotraplinkage 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);
-}
-#endif
-
-dotraplinkage void __kprobes
-do_general_protection(struct pt_regs *regs, long error_code)
-{
-	struct task_struct *tsk;
-
-	conditional_sti(regs);
-
-#ifdef CONFIG_X86_32
-	if (lazy_iobitmap_copy()) {
-		/* restart the faulting instruction */
-		return;
-	}
-
-	if (regs->flags & X86_VM_MASK)
-		goto gp_in_vm86;
-#endif
-
-	tsk = current;
-	if (!user_mode(regs))
-		goto gp_in_kernel;
-
-	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 ip:%lx sp:%lx error:%lx",
-			tsk->comm, task_pid_nr(tsk),
-			regs->ip, regs->sp, error_code);
-		print_vma_addr(" in ", regs->ip);
-		printk("\n");
-	}
-
-	force_sig(SIGSEGV, tsk);
-	return;
-
-#ifdef CONFIG_X86_32
-gp_in_vm86:
-	local_irq_enable();
-	handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
-	return;
-#endif
-
-gp_in_kernel:
-	if (fixup_exception(regs))
-		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 notrace __kprobes void
-mem_parity_error(unsigned char reason, struct pt_regs *regs)
-{
-	printk(KERN_EMERG
-		"Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
-			reason, smp_processor_id());
-
-	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 notrace __kprobes void
-io_check_error(unsigned char reason, struct pt_regs *regs)
-{
-	unsigned long i;
-
-	printk(KERN_EMERG "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);
-
-	i = 2000;
-	while (--i)
-		udelay(1000);
-
-	reason &= ~8;
-	outb(reason, 0x61);
-}
-
-static notrace __kprobes void
-unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
-{
-	if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
-			NOTIFY_STOP)
-		return;
-#ifdef CONFIG_MCA
-	/*
-	 * Might actually be able to figure out what the guilty party
-	 * is:
-	 */
-	if (MCA_bus) {
-		mca_handle_nmi();
-		return;
-	}
-#endif
-	printk(KERN_EMERG
-		"Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
-			reason, smp_processor_id());
-
-	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");
-}
-
-#ifdef CONFIG_X86_32
-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);
-	bust_spinlocks(0);
-
-	/*
-	 * 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);
-	}
-
-	do_exit(SIGSEGV);
-}
-#endif
-
-static notrace __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;
-#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_tick(regs, reason))
-			return;
-		if (!do_nmi_callback(regs, cpu))
-			unknown_nmi_error(reason, regs);
-#else
-		unknown_nmi_error(reason, regs);
-#endif
-
-		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);
-#ifdef CONFIG_X86_32
-	/*
-	 * Reassert NMI in case it became active meanwhile
-	 * as it's edge-triggered:
-	 */
-	reassert_nmi();
-#endif
-}
-
-dotraplinkage notrace __kprobes void
-do_nmi(struct pt_regs *regs, long error_code)
-{
-	nmi_enter();
-
-#ifdef CONFIG_X86_32
-	{ int cpu; cpu = smp_processor_id(); ++nmi_count(cpu); }
-#else
-	add_pda(__nmi_count, 1);
-#endif
-
-	if (!ignore_nmis)
-		default_do_nmi(regs);
-
-	nmi_exit();
-}
-
-void stop_nmi(void)
-{
-	acpi_nmi_disable();
-	ignore_nmis++;
-}
-
-void restart_nmi(void)
-{
-	ignore_nmis--;
-	acpi_nmi_enable();
-}
-
-/* May run on IST stack. */
-dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
-{
-#ifdef CONFIG_KPROBES
-	if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
-			== NOTIFY_STOP)
-		return;
-#else
-	if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
-			== NOTIFY_STOP)
-		return;
-#endif
-
-	preempt_conditional_sti(regs);
-	do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
-	preempt_conditional_cli(regs);
-}
-
-#ifdef CONFIG_X86_64
-/* 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->sp)
-		;
-	/* 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->flags & X86_EFLAGS_IF)
-		regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
-	if (eregs != regs)
-		*regs = *eregs;
-	return regs;
-}
-#endif
-
-/*
- * Our handling of the processor debug registers is non-trivial.
- * We do not clear them on entry and exit from the kernel. Therefore
- * it is possible to get a watchpoint trap here from inside the kernel.
- * However, the code in ./ptrace.c has ensured that the user can
- * only set watchpoints on userspace addresses. Therefore the in-kernel
- * watchpoint trap can only occur in code which is reading/writing
- * from user space. Such code must not hold kernel locks (since it
- * can equally take a page fault), therefore it is safe to call
- * force_sig_info even though that claims and releases locks.
- *
- * Code in ./signal.c ensures that the debug control register
- * is restored before we deliver any signal, and therefore that
- * user code runs with the correct debug control register even though
- * we clear it here.
- *
- * Being careful here means that we don't have to be as careful in a
- * lot of more complicated places (task switching can be a bit lazy
- * about restoring all the debug state, and ptrace doesn't have to
- * find every occurrence of the TF bit that could be saved away even
- * by user code)
- *
- * May run on IST stack.
- */
-dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
-{
-	struct task_struct *tsk = current;
-	unsigned long condition;
-	int si_code;
-
-	get_debugreg(condition, 6);
-
-	/*
-	 * The processor cleared BTF, so don't mark that we need it set.
-	 */
-	clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
-	tsk->thread.debugctlmsr = 0;
-
-	if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
-						SIGTRAP) == NOTIFY_STOP)
-		return;
-
-	/* It's safe to allow irq's after DR6 has been saved */
-	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;
-	}
-
-#ifdef CONFIG_X86_32
-	if (regs->flags & X86_VM_MASK)
-		goto debug_vm86;
-#endif
-
-	/* Save debug status register where ptrace can see it */
-	tsk->thread.debugreg6 = condition;
-
-	/*
-	 * Single-stepping through TF: make sure we ignore any events in
-	 * kernel space (but re-enable TF when returning to user mode).
-	 */
-	if (condition & DR_STEP) {
-		if (!user_mode(regs))
-			goto clear_TF_reenable;
-	}
-
-	si_code = get_si_code(condition);
-	/* Ok, finally something we can handle */
-	send_sigtrap(tsk, regs, error_code, si_code);
-
-	/*
-	 * Disable additional traps. They'll be re-enabled when
-	 * the signal is delivered.
-	 */
-clear_dr7:
-	set_debugreg(0, 7);
-	preempt_conditional_cli(regs);
-	return;
-
-#ifdef CONFIG_X86_32
-debug_vm86:
-	handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
-	preempt_conditional_cli(regs);
-	return;
-#endif
-
-clear_TF_reenable:
-	set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
-	regs->flags &= ~X86_EFLAGS_TF;
-	preempt_conditional_cli(regs);
-	return;
-}
-
-#ifdef CONFIG_X86_64
-static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
-{
-	if (fixup_exception(regs))
-		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;
-}
-#endif
-
-/*
- * 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
- */
-void math_error(void __user *ip)
-{
-	struct task_struct *task;
-	siginfo_t info;
-	unsigned short cwd, swd;
-
-	/*
-	 * 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 = ip;
-	/*
-	 * (~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: /* No unmasked exception */
-#ifdef CONFIG_X86_32
-		return;
-#endif
-	default: /* Multiple exceptions */
-		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);
-}
-
-dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
-{
-	conditional_sti(regs);
-
-#ifdef CONFIG_X86_32
-	ignore_fpu_irq = 1;
-#else
-	if (!user_mode(regs) &&
-	    kernel_math_error(regs, "kernel x87 math error", 16))
-		return;
-#endif
-
-	math_error((void __user *)regs->ip);
-}
-
-static void simd_math_error(void __user *ip)
-{
-	struct task_struct *task;
-	siginfo_t info;
-	unsigned short mxcsr;
-
-	/*
-	 * 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 = ip;
-	/*
-	 * 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);
-}
-
-dotraplinkage void
-do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
-{
-	conditional_sti(regs);
-
-#ifdef CONFIG_X86_32
-	if (cpu_has_xmm) {
-		/* Handle SIMD FPU exceptions on PIII+ processors. */
-		ignore_fpu_irq = 1;
-		simd_math_error((void __user *)regs->ip);
-		return;
-	}
-	/*
-	 * Handle strange cache flush from user space exception
-	 * in all other cases.  This is undocumented behaviour.
-	 */
-	if (regs->flags & X86_VM_MASK) {
-		handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
-		return;
-	}
-	current->thread.trap_no = 19;
-	current->thread.error_code = error_code;
-	die_if_kernel("cache flush denied", regs, error_code);
-	force_sig(SIGSEGV, current);
-#else
-	if (!user_mode(regs) &&
-			kernel_math_error(regs, "kernel simd math error", 19))
-		return;
-	simd_math_error((void __user *)regs->ip);
-#endif
-}
-
-dotraplinkage void
-do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
-{
-	conditional_sti(regs);
-#if 0
-	/* No need to warn about this any longer. */
-	printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
-#endif
-}
-
-#ifdef CONFIG_X86_32
-unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
-{
-	struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id());
-	unsigned long base = (kesp - uesp) & -THREAD_SIZE;
-	unsigned long new_kesp = kesp - base;
-	unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
-	__u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
-
-	/* Set up base for espfix segment */
-	desc &= 0x00f0ff0000000000ULL;
-	desc |=	((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
-		((((__u64)base) << 32) & 0xff00000000000000ULL) |
-		((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
-		(lim_pages & 0xffff);
-	*(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
-
-	return new_kesp;
-}
-#else
-asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
-{
-}
-
-asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void)
-{
-}
-#endif
-
-/*
- * '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.
- *
- * Must be called with kernel preemption disabled (in this case,
- * local interrupts are disabled at the call-site in entry.S).
- */
-asmlinkage void math_state_restore(void)
-{
-	struct thread_info *thread = current_thread_info();
-	struct task_struct *tsk = thread->task;
-
-	if (!tsk_used_math(tsk)) {
-		local_irq_enable();
-		/*
-		 * does a slab alloc which can sleep
-		 */
-		if (init_fpu(tsk)) {
-			/*
-			 * ran out of memory!
-			 */
-			do_group_exit(SIGKILL);
-			return;
-		}
-		local_irq_disable();
-	}
-
-	clts();				/* Allow maths ops (or we recurse) */
-#ifdef CONFIG_X86_32
-	restore_fpu(tsk);
-#else
-	/*
-	 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
-	 */
-	if (unlikely(restore_fpu_checking(tsk))) {
-		stts();
-		force_sig(SIGSEGV, tsk);
-		return;
-	}
-#endif
-	thread->status |= TS_USEDFPU;	/* So we fnsave on switch_to() */
-	tsk->fpu_counter++;
-}
-EXPORT_SYMBOL_GPL(math_state_restore);
-
-#ifndef CONFIG_MATH_EMULATION
-asmlinkage void math_emulate(long arg)
-{
-	printk(KERN_EMERG
-		"math-emulation not enabled and no coprocessor found.\n");
-	printk(KERN_EMERG "killing %s.\n", current->comm);
-	force_sig(SIGFPE, current);
-	schedule();
-}
-#endif /* CONFIG_MATH_EMULATION */
-
-dotraplinkage void __kprobes
-do_device_not_available(struct pt_regs *regs, long error)
-{
-#ifdef CONFIG_X86_32
-	if (read_cr0() & X86_CR0_EM) {
-		conditional_sti(regs);
-		math_emulate(0);
-	} else {
-		math_state_restore(); /* interrupts still off */
-		conditional_sti(regs);
-	}
-#else
-	math_state_restore();
-#endif
-}
-
-#ifdef CONFIG_X86_32
-#ifdef CONFIG_X86_MCE
-dotraplinkage void __kprobes do_machine_check(struct pt_regs *regs, long error)
-{
-	conditional_sti(regs);
-	machine_check_vector(regs, error);
-}
-#endif
-
-dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
-{
-	siginfo_t info;
-	local_irq_enable();
-
-	info.si_signo = SIGILL;
-	info.si_errno = 0;
-	info.si_code = ILL_BADSTK;
-	info.si_addr = 0;
-	if (notify_die(DIE_TRAP, "iret exception",
-			regs, error_code, 32, SIGILL) == NOTIFY_STOP)
-		return;
-	do_trap(32, SIGILL, "iret exception", regs, error_code, &info);
-}
-#endif
-
-void __init trap_init(void)
-{
-#ifdef CONFIG_X86_32
-	int i;
-#endif
-
-#ifdef CONFIG_EISA
-	void __iomem *p = early_ioremap(0x0FFFD9, 4);
-
-	if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
-		EISA_bus = 1;
-	early_iounmap(p, 4);
-#endif
-
-	set_intr_gate(0, &divide_error);
-	set_intr_gate_ist(1, &debug, DEBUG_STACK);
-	set_intr_gate_ist(2, &nmi, NMI_STACK);
-	/* int3 can be called from all */
-	set_system_intr_gate_ist(3, &int3, DEBUG_STACK);
-	/* int4 can be called from all */
-	set_system_intr_gate(4, &overflow);
-	set_intr_gate(5, &bounds);
-	set_intr_gate(6, &invalid_op);
-	set_intr_gate(7, &device_not_available);
-#ifdef CONFIG_X86_32
-	set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS);
-#else
-	set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK);
-#endif
-	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_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
-#endif
-
-#ifdef CONFIG_X86_32
-	if (cpu_has_fxsr) {
-		printk(KERN_INFO "Enabling fast FPU save and restore... ");
-		set_in_cr4(X86_CR4_OSFXSR);
-		printk("done.\n");
-	}
-	if (cpu_has_xmm) {
-		printk(KERN_INFO
-			"Enabling unmasked SIMD FPU exception support... ");
-		set_in_cr4(X86_CR4_OSXMMEXCPT);
-		printk("done.\n");
-	}
-
-	set_system_trap_gate(SYSCALL_VECTOR, &system_call);
-
-	/* Reserve all the builtin and the syscall vector: */
-	for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
-		set_bit(i, used_vectors);
-
-	set_bit(SYSCALL_VECTOR, used_vectors);
-#endif
-	/*
-	 * Should be a barrier for any external CPU state:
-	 */
-	cpu_init();
-
-#ifdef CONFIG_X86_32
-	trap_init_hook();
-#endif
-}