2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
5 * Pentium III FXSR, SSE support
6 * Gareth Hughes <gareth@valinux.com>, May 2000
10 * Handle hardware traps and faults.
12 #include <linux/interrupt.h>
13 #include <linux/kallsyms.h>
14 #include <linux/spinlock.h>
15 #include <linux/kprobes.h>
16 #include <linux/uaccess.h>
17 #include <linux/utsname.h>
18 #include <linux/kdebug.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/ptrace.h>
22 #include <linux/string.h>
23 #include <linux/delay.h>
24 #include <linux/errno.h>
25 #include <linux/kexec.h>
26 #include <linux/sched.h>
27 #include <linux/timer.h>
28 #include <linux/init.h>
29 #include <linux/bug.h>
30 #include <linux/nmi.h>
32 #include <linux/smp.h>
36 #include <linux/ioport.h>
37 #include <linux/eisa.h>
41 #include <linux/mca.h>
44 #if defined(CONFIG_EDAC)
45 #include <linux/edac.h>
48 #include <asm/kmemcheck.h>
49 #include <asm/stacktrace.h>
50 #include <asm/processor.h>
51 #include <asm/debugreg.h>
52 #include <asm/atomic.h>
53 #include <asm/system.h>
54 #include <asm/traps.h>
59 #include <asm/mach_traps.h>
62 #include <asm/x86_init.h>
63 #include <asm/pgalloc.h>
64 #include <asm/proto.h>
66 #include <asm/processor-flags.h>
67 #include <asm/setup.h>
68 #include <asm/traps.h>
70 asmlinkage int system_call(void);
72 /* Do we ignore FPU interrupts ? */
76 * The IDT has to be page-aligned to simplify the Pentium
77 * F0 0F bug workaround.. We have a special link segment
80 gate_desc idt_table[NR_VECTORS]
81 __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, };
84 DECLARE_BITMAP(used_vectors, NR_VECTORS);
85 EXPORT_SYMBOL_GPL(used_vectors);
87 static int ignore_nmis;
89 static inline void conditional_sti(struct pt_regs *regs)
91 if (regs->flags & X86_EFLAGS_IF)
95 static inline void preempt_conditional_sti(struct pt_regs *regs)
98 if (regs->flags & X86_EFLAGS_IF)
102 static inline void conditional_cli(struct pt_regs *regs)
104 if (regs->flags & X86_EFLAGS_IF)
108 static inline void preempt_conditional_cli(struct pt_regs *regs)
110 if (regs->flags & X86_EFLAGS_IF)
117 die_if_kernel(const char *str, struct pt_regs *regs, long err)
119 if (!user_mode_vm(regs))
124 static void __kprobes
125 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
126 long error_code, siginfo_t *info)
128 struct task_struct *tsk = current;
131 if (regs->flags & X86_VM_MASK) {
133 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
134 * On nmi (interrupt 2), do_trap should not be called.
142 if (!user_mode(regs))
149 * We want error_code and trap_no set for userspace faults and
150 * kernelspace faults which result in die(), but not
151 * kernelspace faults which are fixed up. die() gives the
152 * process no chance to handle the signal and notice the
153 * kernel fault information, so that won't result in polluting
154 * the information about previously queued, but not yet
155 * delivered, faults. See also do_general_protection below.
157 tsk->thread.error_code = error_code;
158 tsk->thread.trap_no = trapnr;
161 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
162 printk_ratelimit()) {
164 "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
165 tsk->comm, tsk->pid, str,
166 regs->ip, regs->sp, error_code);
167 print_vma_addr(" in ", regs->ip);
173 force_sig_info(signr, info, tsk);
175 force_sig(signr, tsk);
179 if (!fixup_exception(regs)) {
180 tsk->thread.error_code = error_code;
181 tsk->thread.trap_no = trapnr;
182 die(str, regs, error_code);
188 if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
195 #define DO_ERROR(trapnr, signr, str, name) \
196 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
198 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
201 conditional_sti(regs); \
202 do_trap(trapnr, signr, str, regs, error_code, NULL); \
205 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
206 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
209 info.si_signo = signr; \
211 info.si_code = sicode; \
212 info.si_addr = (void __user *)siaddr; \
213 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
216 conditional_sti(regs); \
217 do_trap(trapnr, signr, str, regs, error_code, &info); \
220 DO_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip)
221 DO_ERROR(4, SIGSEGV, "overflow", overflow)
222 DO_ERROR(5, SIGSEGV, "bounds", bounds)
223 DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip)
224 DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun)
225 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS)
226 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present)
228 DO_ERROR(12, SIGBUS, "stack segment", stack_segment)
230 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0)
233 /* Runs on IST stack */
234 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
236 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
237 12, SIGBUS) == NOTIFY_STOP)
239 preempt_conditional_sti(regs);
240 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL);
241 preempt_conditional_cli(regs);
244 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
246 static const char str[] = "double fault";
247 struct task_struct *tsk = current;
249 /* Return not checked because double check cannot be ignored */
250 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV);
252 tsk->thread.error_code = error_code;
253 tsk->thread.trap_no = 8;
256 * This is always a kernel trap and never fixable (and thus must
260 die(str, regs, error_code);
264 dotraplinkage void __kprobes
265 do_general_protection(struct pt_regs *regs, long error_code)
267 struct task_struct *tsk;
269 conditional_sti(regs);
272 if (regs->flags & X86_VM_MASK)
277 if (!user_mode(regs))
280 tsk->thread.error_code = error_code;
281 tsk->thread.trap_no = 13;
283 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
284 printk_ratelimit()) {
286 "%s[%d] general protection ip:%lx sp:%lx error:%lx",
287 tsk->comm, task_pid_nr(tsk),
288 regs->ip, regs->sp, error_code);
289 print_vma_addr(" in ", regs->ip);
293 force_sig(SIGSEGV, tsk);
299 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
304 if (fixup_exception(regs))
307 tsk->thread.error_code = error_code;
308 tsk->thread.trap_no = 13;
309 if (notify_die(DIE_GPF, "general protection fault", regs,
310 error_code, 13, SIGSEGV) == NOTIFY_STOP)
312 die("general protection fault", regs, error_code);
315 static notrace __kprobes void
316 mem_parity_error(unsigned char reason, struct pt_regs *regs)
319 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
320 reason, smp_processor_id());
323 "You have some hardware problem, likely on the PCI bus.\n");
325 #if defined(CONFIG_EDAC)
326 if (edac_handler_set()) {
327 edac_atomic_assert_error();
332 if (panic_on_unrecovered_nmi)
333 panic("NMI: Not continuing");
335 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
337 /* Clear and disable the memory parity error line. */
338 reason = (reason & 0xf) | 4;
342 static notrace __kprobes void
343 io_check_error(unsigned char reason, struct pt_regs *regs)
347 printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n");
348 show_registers(regs);
351 panic("NMI IOCK error: Not continuing");
353 /* Re-enable the IOCK line, wait for a few seconds */
354 reason = (reason & 0xf) | 8;
365 static notrace __kprobes void
366 unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
368 if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
373 * Might actually be able to figure out what the guilty party
382 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
383 reason, smp_processor_id());
385 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
386 if (panic_on_unrecovered_nmi)
387 panic("NMI: Not continuing");
389 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
392 static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
394 unsigned char reason = 0;
397 cpu = smp_processor_id();
399 /* Only the BSP gets external NMIs from the system. */
401 reason = get_nmi_reason();
403 if (!(reason & 0xc0)) {
404 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
407 #ifdef CONFIG_X86_LOCAL_APIC
409 * Ok, so this is none of the documented NMI sources,
410 * so it must be the NMI watchdog.
412 if (nmi_watchdog_tick(regs, reason))
414 if (!do_nmi_callback(regs, cpu))
415 unknown_nmi_error(reason, regs);
417 unknown_nmi_error(reason, regs);
422 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
425 /* AK: following checks seem to be broken on modern chipsets. FIXME */
427 mem_parity_error(reason, regs);
429 io_check_error(reason, regs);
432 * Reassert NMI in case it became active meanwhile
433 * as it's edge-triggered:
439 dotraplinkage notrace __kprobes void
440 do_nmi(struct pt_regs *regs, long error_code)
444 inc_irq_stat(__nmi_count);
447 default_do_nmi(regs);
458 void restart_nmi(void)
464 /* May run on IST stack. */
465 dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
467 #ifdef CONFIG_KPROBES
468 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
472 if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
477 preempt_conditional_sti(regs);
478 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
479 preempt_conditional_cli(regs);
484 * Help handler running on IST stack to switch back to user stack
485 * for scheduling or signal handling. The actual stack switch is done in
488 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
490 struct pt_regs *regs = eregs;
491 /* Did already sync */
492 if (eregs == (struct pt_regs *)eregs->sp)
494 /* Exception from user space */
495 else if (user_mode(eregs))
496 regs = task_pt_regs(current);
498 * Exception from kernel and interrupts are enabled. Move to
499 * kernel process stack.
501 else if (eregs->flags & X86_EFLAGS_IF)
502 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
510 * Our handling of the processor debug registers is non-trivial.
511 * We do not clear them on entry and exit from the kernel. Therefore
512 * it is possible to get a watchpoint trap here from inside the kernel.
513 * However, the code in ./ptrace.c has ensured that the user can
514 * only set watchpoints on userspace addresses. Therefore the in-kernel
515 * watchpoint trap can only occur in code which is reading/writing
516 * from user space. Such code must not hold kernel locks (since it
517 * can equally take a page fault), therefore it is safe to call
518 * force_sig_info even though that claims and releases locks.
520 * Code in ./signal.c ensures that the debug control register
521 * is restored before we deliver any signal, and therefore that
522 * user code runs with the correct debug control register even though
525 * Being careful here means that we don't have to be as careful in a
526 * lot of more complicated places (task switching can be a bit lazy
527 * about restoring all the debug state, and ptrace doesn't have to
528 * find every occurrence of the TF bit that could be saved away even
531 * May run on IST stack.
533 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
535 struct task_struct *tsk = current;
536 unsigned long condition;
539 get_debugreg(condition, 6);
541 /* Catch kmemcheck conditions first of all! */
542 if (condition & DR_STEP && kmemcheck_trap(regs))
546 * The processor cleared BTF, so don't mark that we need it set.
548 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
549 tsk->thread.debugctlmsr = 0;
551 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code,
552 SIGTRAP) == NOTIFY_STOP)
555 /* It's safe to allow irq's after DR6 has been saved */
556 preempt_conditional_sti(regs);
558 /* Mask out spurious debug traps due to lazy DR7 setting */
559 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
560 if (!tsk->thread.debugreg7)
565 if (regs->flags & X86_VM_MASK)
569 /* Save debug status register where ptrace can see it */
570 tsk->thread.debugreg6 = condition;
573 * Single-stepping through TF: make sure we ignore any events in
574 * kernel space (but re-enable TF when returning to user mode).
576 if (condition & DR_STEP) {
577 if (!user_mode(regs))
578 goto clear_TF_reenable;
581 si_code = get_si_code(condition);
582 /* Ok, finally something we can handle */
583 send_sigtrap(tsk, regs, error_code, si_code);
586 * Disable additional traps. They'll be re-enabled when
587 * the signal is delivered.
591 preempt_conditional_cli(regs);
596 /* reenable preemption: handle_vm86_trap() might sleep */
598 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1);
599 conditional_cli(regs);
604 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
605 regs->flags &= ~X86_EFLAGS_TF;
606 preempt_conditional_cli(regs);
611 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
613 if (fixup_exception(regs))
616 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
617 /* Illegal floating point operation in the kernel */
618 current->thread.trap_no = trapnr;
625 * Note that we play around with the 'TS' bit in an attempt to get
626 * the correct behaviour even in the presence of the asynchronous
629 void math_error(void __user *ip)
631 struct task_struct *task;
633 unsigned short cwd, swd, err;
636 * Save the info for the exception handler and clear the error.
640 task->thread.trap_no = 16;
641 task->thread.error_code = 0;
642 info.si_signo = SIGFPE;
646 * (~cwd & swd) will mask out exceptions that are not set to unmasked
647 * status. 0x3f is the exception bits in these regs, 0x200 is the
648 * C1 reg you need in case of a stack fault, 0x040 is the stack
649 * fault bit. We should only be taking one exception at a time,
650 * so if this combination doesn't produce any single exception,
651 * then we have a bad program that isn't synchronizing its FPU usage
652 * and it will suffer the consequences since we won't be able to
653 * fully reproduce the context of the exception
655 cwd = get_fpu_cwd(task);
656 swd = get_fpu_swd(task);
660 if (err & 0x001) { /* Invalid op */
662 * swd & 0x240 == 0x040: Stack Underflow
663 * swd & 0x240 == 0x240: Stack Overflow
664 * User must clear the SF bit (0x40) if set
666 info.si_code = FPE_FLTINV;
667 } else if (err & 0x004) { /* Divide by Zero */
668 info.si_code = FPE_FLTDIV;
669 } else if (err & 0x008) { /* Overflow */
670 info.si_code = FPE_FLTOVF;
671 } else if (err & 0x012) { /* Denormal, Underflow */
672 info.si_code = FPE_FLTUND;
673 } else if (err & 0x020) { /* Precision */
674 info.si_code = FPE_FLTRES;
677 * If we're using IRQ 13, or supposedly even some trap 16
678 * implementations, it's possible we get a spurious trap...
680 return; /* Spurious trap, no error */
682 force_sig_info(SIGFPE, &info, task);
685 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
687 conditional_sti(regs);
692 if (!user_mode(regs) &&
693 kernel_math_error(regs, "kernel x87 math error", 16))
697 math_error((void __user *)regs->ip);
700 static void simd_math_error(void __user *ip)
702 struct task_struct *task;
704 unsigned short mxcsr;
707 * Save the info for the exception handler and clear the error.
711 task->thread.trap_no = 19;
712 task->thread.error_code = 0;
713 info.si_signo = SIGFPE;
715 info.si_code = __SI_FAULT;
718 * The SIMD FPU exceptions are handled a little differently, as there
719 * is only a single status/control register. Thus, to determine which
720 * unmasked exception was caught we must mask the exception mask bits
721 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
723 mxcsr = get_fpu_mxcsr(task);
724 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
728 case 0x001: /* Invalid Op */
729 info.si_code = FPE_FLTINV;
731 case 0x002: /* Denormalize */
732 case 0x010: /* Underflow */
733 info.si_code = FPE_FLTUND;
735 case 0x004: /* Zero Divide */
736 info.si_code = FPE_FLTDIV;
738 case 0x008: /* Overflow */
739 info.si_code = FPE_FLTOVF;
741 case 0x020: /* Precision */
742 info.si_code = FPE_FLTRES;
745 force_sig_info(SIGFPE, &info, task);
749 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
751 conditional_sti(regs);
755 /* Handle SIMD FPU exceptions on PIII+ processors. */
757 simd_math_error((void __user *)regs->ip);
761 * Handle strange cache flush from user space exception
762 * in all other cases. This is undocumented behaviour.
764 if (regs->flags & X86_VM_MASK) {
765 handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
768 current->thread.trap_no = 19;
769 current->thread.error_code = error_code;
770 die_if_kernel("cache flush denied", regs, error_code);
771 force_sig(SIGSEGV, current);
773 if (!user_mode(regs) &&
774 kernel_math_error(regs, "kernel simd math error", 19))
776 simd_math_error((void __user *)regs->ip);
781 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
783 conditional_sti(regs);
785 /* No need to warn about this any longer. */
786 printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
791 unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
793 struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id());
794 unsigned long base = (kesp - uesp) & -THREAD_SIZE;
795 unsigned long new_kesp = kesp - base;
796 unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
797 __u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
799 /* Set up base for espfix segment */
800 desc &= 0x00f0ff0000000000ULL;
801 desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
802 ((((__u64)base) << 32) & 0xff00000000000000ULL) |
803 ((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
804 (lim_pages & 0xffff);
805 *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
811 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
815 asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
820 * 'math_state_restore()' saves the current math information in the
821 * old math state array, and gets the new ones from the current task
823 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
824 * Don't touch unless you *really* know how it works.
826 * Must be called with kernel preemption disabled (in this case,
827 * local interrupts are disabled at the call-site in entry.S).
829 asmlinkage void math_state_restore(void)
831 struct thread_info *thread = current_thread_info();
832 struct task_struct *tsk = thread->task;
834 if (!tsk_used_math(tsk)) {
837 * does a slab alloc which can sleep
843 do_group_exit(SIGKILL);
849 clts(); /* Allow maths ops (or we recurse) */
851 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
853 if (unlikely(restore_fpu_checking(tsk))) {
855 force_sig(SIGSEGV, tsk);
859 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
862 EXPORT_SYMBOL_GPL(math_state_restore);
864 #ifndef CONFIG_MATH_EMULATION
865 void math_emulate(struct math_emu_info *info)
868 "math-emulation not enabled and no coprocessor found.\n");
869 printk(KERN_EMERG "killing %s.\n", current->comm);
870 force_sig(SIGFPE, current);
873 #endif /* CONFIG_MATH_EMULATION */
875 dotraplinkage void __kprobes
876 do_device_not_available(struct pt_regs *regs, long error_code)
879 if (read_cr0() & X86_CR0_EM) {
880 struct math_emu_info info = { };
882 conditional_sti(regs);
887 math_state_restore(); /* interrupts still off */
888 conditional_sti(regs);
891 math_state_restore();
896 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
901 info.si_signo = SIGILL;
903 info.si_code = ILL_BADSTK;
905 if (notify_die(DIE_TRAP, "iret exception",
906 regs, error_code, 32, SIGILL) == NOTIFY_STOP)
908 do_trap(32, SIGILL, "iret exception", regs, error_code, &info);
912 void __init trap_init(void)
917 void __iomem *p = early_ioremap(0x0FFFD9, 4);
919 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
924 set_intr_gate(0, ÷_error);
925 set_intr_gate_ist(1, &debug, DEBUG_STACK);
926 set_intr_gate_ist(2, &nmi, NMI_STACK);
927 /* int3 can be called from all */
928 set_system_intr_gate_ist(3, &int3, DEBUG_STACK);
929 /* int4 can be called from all */
930 set_system_intr_gate(4, &overflow);
931 set_intr_gate(5, &bounds);
932 set_intr_gate(6, &invalid_op);
933 set_intr_gate(7, &device_not_available);
935 set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS);
937 set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK);
939 set_intr_gate(9, &coprocessor_segment_overrun);
940 set_intr_gate(10, &invalid_TSS);
941 set_intr_gate(11, &segment_not_present);
942 set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK);
943 set_intr_gate(13, &general_protection);
944 set_intr_gate(14, &page_fault);
945 set_intr_gate(15, &spurious_interrupt_bug);
946 set_intr_gate(16, &coprocessor_error);
947 set_intr_gate(17, &alignment_check);
948 #ifdef CONFIG_X86_MCE
949 set_intr_gate_ist(18, &machine_check, MCE_STACK);
951 set_intr_gate(19, &simd_coprocessor_error);
953 /* Reserve all the builtin and the syscall vector: */
954 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
955 set_bit(i, used_vectors);
957 #ifdef CONFIG_IA32_EMULATION
958 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
959 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
964 printk(KERN_INFO "Enabling fast FPU save and restore... ");
965 set_in_cr4(X86_CR4_OSFXSR);
970 "Enabling unmasked SIMD FPU exception support... ");
971 set_in_cr4(X86_CR4_OSXMMEXCPT);
975 set_system_trap_gate(SYSCALL_VECTOR, &system_call);
976 set_bit(SYSCALL_VECTOR, used_vectors);
980 * Should be a barrier for any external CPU state:
984 x86_init.irqs.trap_init();