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>
58 #include <asm/mach_traps.h>
61 #include <asm/pgalloc.h>
62 #include <asm/proto.h>
64 #include <asm/processor-flags.h>
65 #include <asm/setup.h>
66 #include <asm/traps.h>
68 #include "cpu/mcheck/mce.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[256]
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);
350 /* Re-enable the IOCK line, wait for a few seconds */
351 reason = (reason & 0xf) | 8;
362 static notrace __kprobes void
363 unknown_nmi_error(unsigned char reason, struct pt_regs *regs)
365 if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) ==
370 * Might actually be able to figure out what the guilty party
379 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n",
380 reason, smp_processor_id());
382 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n");
383 if (panic_on_unrecovered_nmi)
384 panic("NMI: Not continuing");
386 printk(KERN_EMERG "Dazed and confused, but trying to continue\n");
389 static notrace __kprobes void default_do_nmi(struct pt_regs *regs)
391 unsigned char reason = 0;
394 cpu = smp_processor_id();
396 /* Only the BSP gets external NMIs from the system. */
398 reason = get_nmi_reason();
400 if (!(reason & 0xc0)) {
401 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT)
404 #ifdef CONFIG_X86_LOCAL_APIC
406 * Ok, so this is none of the documented NMI sources,
407 * so it must be the NMI watchdog.
409 if (nmi_watchdog_tick(regs, reason))
411 if (!do_nmi_callback(regs, cpu))
412 unknown_nmi_error(reason, regs);
414 unknown_nmi_error(reason, regs);
419 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP)
422 /* AK: following checks seem to be broken on modern chipsets. FIXME */
424 mem_parity_error(reason, regs);
426 io_check_error(reason, regs);
429 * Reassert NMI in case it became active meanwhile
430 * as it's edge-triggered:
436 dotraplinkage notrace __kprobes void
437 do_nmi(struct pt_regs *regs, long error_code)
441 inc_irq_stat(__nmi_count);
444 default_do_nmi(regs);
455 void restart_nmi(void)
461 /* May run on IST stack. */
462 dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
464 #ifdef CONFIG_KPROBES
465 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP)
469 if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP)
474 preempt_conditional_sti(regs);
475 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL);
476 preempt_conditional_cli(regs);
481 * Help handler running on IST stack to switch back to user stack
482 * for scheduling or signal handling. The actual stack switch is done in
485 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
487 struct pt_regs *regs = eregs;
488 /* Did already sync */
489 if (eregs == (struct pt_regs *)eregs->sp)
491 /* Exception from user space */
492 else if (user_mode(eregs))
493 regs = task_pt_regs(current);
495 * Exception from kernel and interrupts are enabled. Move to
496 * kernel process stack.
498 else if (eregs->flags & X86_EFLAGS_IF)
499 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
507 * Our handling of the processor debug registers is non-trivial.
508 * We do not clear them on entry and exit from the kernel. Therefore
509 * it is possible to get a watchpoint trap here from inside the kernel.
510 * However, the code in ./ptrace.c has ensured that the user can
511 * only set watchpoints on userspace addresses. Therefore the in-kernel
512 * watchpoint trap can only occur in code which is reading/writing
513 * from user space. Such code must not hold kernel locks (since it
514 * can equally take a page fault), therefore it is safe to call
515 * force_sig_info even though that claims and releases locks.
517 * Code in ./signal.c ensures that the debug control register
518 * is restored before we deliver any signal, and therefore that
519 * user code runs with the correct debug control register even though
522 * Being careful here means that we don't have to be as careful in a
523 * lot of more complicated places (task switching can be a bit lazy
524 * about restoring all the debug state, and ptrace doesn't have to
525 * find every occurrence of the TF bit that could be saved away even
528 * May run on IST stack.
530 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
532 struct task_struct *tsk = current;
536 get_debugreg(dr6, 6);
538 /* Catch kmemcheck conditions first of all! */
539 if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
542 /* DR6 may or may not be cleared by the CPU */
545 * The processor cleared BTF, so don't mark that we need it set.
547 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR);
548 tsk->thread.debugctlmsr = 0;
550 /* Store the virtualized DR6 value */
551 tsk->thread.debugreg6 = dr6;
553 if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code,
554 SIGTRAP) == NOTIFY_STOP)
557 /* It's safe to allow irq's after DR6 has been saved */
558 preempt_conditional_sti(regs);
560 if (regs->flags & X86_VM_MASK) {
561 handle_vm86_trap((struct kernel_vm86_regs *) regs,
567 * Single-stepping through system calls: ignore any exceptions in
568 * kernel space, but re-enable TF when returning to user mode.
570 * We already checked v86 mode above, so we can check for kernel mode
571 * by just checking the CPL of CS.
573 if ((dr6 & DR_STEP) && !user_mode(regs)) {
574 tsk->thread.debugreg6 &= ~DR_STEP;
575 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
576 regs->flags &= ~X86_EFLAGS_TF;
578 si_code = get_si_code(tsk->thread.debugreg6);
579 if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS))
580 send_sigtrap(tsk, regs, error_code, si_code);
581 preempt_conditional_cli(regs);
587 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr)
589 if (fixup_exception(regs))
592 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE);
593 /* Illegal floating point operation in the kernel */
594 current->thread.trap_no = trapnr;
601 * Note that we play around with the 'TS' bit in an attempt to get
602 * the correct behaviour even in the presence of the asynchronous
605 void math_error(void __user *ip)
607 struct task_struct *task;
609 unsigned short cwd, swd, err;
612 * Save the info for the exception handler and clear the error.
616 task->thread.trap_no = 16;
617 task->thread.error_code = 0;
618 info.si_signo = SIGFPE;
622 * (~cwd & swd) will mask out exceptions that are not set to unmasked
623 * status. 0x3f is the exception bits in these regs, 0x200 is the
624 * C1 reg you need in case of a stack fault, 0x040 is the stack
625 * fault bit. We should only be taking one exception at a time,
626 * so if this combination doesn't produce any single exception,
627 * then we have a bad program that isn't synchronizing its FPU usage
628 * and it will suffer the consequences since we won't be able to
629 * fully reproduce the context of the exception
631 cwd = get_fpu_cwd(task);
632 swd = get_fpu_swd(task);
636 if (err & 0x001) { /* Invalid op */
638 * swd & 0x240 == 0x040: Stack Underflow
639 * swd & 0x240 == 0x240: Stack Overflow
640 * User must clear the SF bit (0x40) if set
642 info.si_code = FPE_FLTINV;
643 } else if (err & 0x004) { /* Divide by Zero */
644 info.si_code = FPE_FLTDIV;
645 } else if (err & 0x008) { /* Overflow */
646 info.si_code = FPE_FLTOVF;
647 } else if (err & 0x012) { /* Denormal, Underflow */
648 info.si_code = FPE_FLTUND;
649 } else if (err & 0x020) { /* Precision */
650 info.si_code = FPE_FLTRES;
653 * If we're using IRQ 13, or supposedly even some trap 16
654 * implementations, it's possible we get a spurious trap...
656 return; /* Spurious trap, no error */
658 force_sig_info(SIGFPE, &info, task);
661 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
663 conditional_sti(regs);
668 if (!user_mode(regs) &&
669 kernel_math_error(regs, "kernel x87 math error", 16))
673 math_error((void __user *)regs->ip);
676 static void simd_math_error(void __user *ip)
678 struct task_struct *task;
680 unsigned short mxcsr;
683 * Save the info for the exception handler and clear the error.
687 task->thread.trap_no = 19;
688 task->thread.error_code = 0;
689 info.si_signo = SIGFPE;
691 info.si_code = __SI_FAULT;
694 * The SIMD FPU exceptions are handled a little differently, as there
695 * is only a single status/control register. Thus, to determine which
696 * unmasked exception was caught we must mask the exception mask bits
697 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
699 mxcsr = get_fpu_mxcsr(task);
700 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) {
704 case 0x001: /* Invalid Op */
705 info.si_code = FPE_FLTINV;
707 case 0x002: /* Denormalize */
708 case 0x010: /* Underflow */
709 info.si_code = FPE_FLTUND;
711 case 0x004: /* Zero Divide */
712 info.si_code = FPE_FLTDIV;
714 case 0x008: /* Overflow */
715 info.si_code = FPE_FLTOVF;
717 case 0x020: /* Precision */
718 info.si_code = FPE_FLTRES;
721 force_sig_info(SIGFPE, &info, task);
725 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
727 conditional_sti(regs);
731 /* Handle SIMD FPU exceptions on PIII+ processors. */
733 simd_math_error((void __user *)regs->ip);
737 * Handle strange cache flush from user space exception
738 * in all other cases. This is undocumented behaviour.
740 if (regs->flags & X86_VM_MASK) {
741 handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code);
744 current->thread.trap_no = 19;
745 current->thread.error_code = error_code;
746 die_if_kernel("cache flush denied", regs, error_code);
747 force_sig(SIGSEGV, current);
749 if (!user_mode(regs) &&
750 kernel_math_error(regs, "kernel simd math error", 19))
752 simd_math_error((void __user *)regs->ip);
757 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
759 conditional_sti(regs);
761 /* No need to warn about this any longer. */
762 printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
767 unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp)
769 struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id());
770 unsigned long base = (kesp - uesp) & -THREAD_SIZE;
771 unsigned long new_kesp = kesp - base;
772 unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT;
773 __u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS];
775 /* Set up base for espfix segment */
776 desc &= 0x00f0ff0000000000ULL;
777 desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) |
778 ((((__u64)base) << 32) & 0xff00000000000000ULL) |
779 ((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) |
780 (lim_pages & 0xffff);
781 *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc;
787 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
791 asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
796 * 'math_state_restore()' saves the current math information in the
797 * old math state array, and gets the new ones from the current task
799 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
800 * Don't touch unless you *really* know how it works.
802 * Must be called with kernel preemption disabled (in this case,
803 * local interrupts are disabled at the call-site in entry.S).
805 asmlinkage void math_state_restore(void)
807 struct thread_info *thread = current_thread_info();
808 struct task_struct *tsk = thread->task;
810 if (!tsk_used_math(tsk)) {
813 * does a slab alloc which can sleep
819 do_group_exit(SIGKILL);
825 clts(); /* Allow maths ops (or we recurse) */
827 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
829 if (unlikely(restore_fpu_checking(tsk))) {
831 force_sig(SIGSEGV, tsk);
835 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */
838 EXPORT_SYMBOL_GPL(math_state_restore);
840 #ifndef CONFIG_MATH_EMULATION
841 void math_emulate(struct math_emu_info *info)
844 "math-emulation not enabled and no coprocessor found.\n");
845 printk(KERN_EMERG "killing %s.\n", current->comm);
846 force_sig(SIGFPE, current);
849 #endif /* CONFIG_MATH_EMULATION */
851 dotraplinkage void __kprobes
852 do_device_not_available(struct pt_regs *regs, long error_code)
855 if (read_cr0() & X86_CR0_EM) {
856 struct math_emu_info info = { };
858 conditional_sti(regs);
863 math_state_restore(); /* interrupts still off */
864 conditional_sti(regs);
867 math_state_restore();
872 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
877 info.si_signo = SIGILL;
879 info.si_code = ILL_BADSTK;
881 if (notify_die(DIE_TRAP, "iret exception",
882 regs, error_code, 32, SIGILL) == NOTIFY_STOP)
884 do_trap(32, SIGILL, "iret exception", regs, error_code, &info);
888 void __init trap_init(void)
893 void __iomem *p = early_ioremap(0x0FFFD9, 4);
895 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
900 set_intr_gate(0, ÷_error);
901 set_intr_gate_ist(1, &debug, DEBUG_STACK);
902 set_intr_gate_ist(2, &nmi, NMI_STACK);
903 /* int3 can be called from all */
904 set_system_intr_gate_ist(3, &int3, DEBUG_STACK);
905 /* int4 can be called from all */
906 set_system_intr_gate(4, &overflow);
907 set_intr_gate(5, &bounds);
908 set_intr_gate(6, &invalid_op);
909 set_intr_gate(7, &device_not_available);
911 set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS);
913 set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK);
915 set_intr_gate(9, &coprocessor_segment_overrun);
916 set_intr_gate(10, &invalid_TSS);
917 set_intr_gate(11, &segment_not_present);
918 set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK);
919 set_intr_gate(13, &general_protection);
920 set_intr_gate(14, &page_fault);
921 set_intr_gate(15, &spurious_interrupt_bug);
922 set_intr_gate(16, &coprocessor_error);
923 set_intr_gate(17, &alignment_check);
924 #ifdef CONFIG_X86_MCE
925 set_intr_gate_ist(18, &machine_check, MCE_STACK);
927 set_intr_gate(19, &simd_coprocessor_error);
929 /* Reserve all the builtin and the syscall vector: */
930 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
931 set_bit(i, used_vectors);
933 #ifdef CONFIG_IA32_EMULATION
934 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
935 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
940 printk(KERN_INFO "Enabling fast FPU save and restore... ");
941 set_in_cr4(X86_CR4_OSFXSR);
946 "Enabling unmasked SIMD FPU exception support... ");
947 set_in_cr4(X86_CR4_OSXMMEXCPT);
951 set_system_trap_gate(SYSCALL_VECTOR, &system_call);
952 set_bit(SYSCALL_VECTOR, used_vectors);
956 * Should be a barrier for any external CPU state:
961 x86_quirk_trap_init();