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.
13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
15 #include <linux/context_tracking.h>
16 #include <linux/interrupt.h>
17 #include <linux/kallsyms.h>
18 #include <linux/spinlock.h>
19 #include <linux/kprobes.h>
20 #include <linux/uaccess.h>
21 #include <linux/kdebug.h>
22 #include <linux/kgdb.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/ptrace.h>
26 #include <linux/uprobes.h>
27 #include <linux/string.h>
28 #include <linux/delay.h>
29 #include <linux/errno.h>
30 #include <linux/kexec.h>
31 #include <linux/sched.h>
32 #include <linux/timer.h>
33 #include <linux/init.h>
34 #include <linux/bug.h>
35 #include <linux/nmi.h>
37 #include <linux/smp.h>
41 #include <linux/ioport.h>
42 #include <linux/eisa.h>
45 #if defined(CONFIG_EDAC)
46 #include <linux/edac.h>
49 #include <asm/kmemcheck.h>
50 #include <asm/stacktrace.h>
51 #include <asm/processor.h>
52 #include <asm/debugreg.h>
53 #include <linux/atomic.h>
54 #include <asm/ftrace.h>
55 #include <asm/traps.h>
57 #include <asm/fpu/internal.h>
59 #include <asm/fixmap.h>
60 #include <asm/mach_traps.h>
61 #include <asm/alternative.h>
62 #include <asm/fpu/xstate.h>
63 #include <asm/trace/mpx.h>
68 #include <asm/x86_init.h>
69 #include <asm/pgalloc.h>
70 #include <asm/proto.h>
72 /* No need to be aligned, but done to keep all IDTs defined the same way. */
73 gate_desc debug_idt_table[NR_VECTORS] __page_aligned_bss;
75 #include <asm/processor-flags.h>
76 #include <asm/setup.h>
77 #include <asm/proto.h>
80 /* Must be page-aligned because the real IDT is used in a fixmap. */
81 gate_desc idt_table[NR_VECTORS] __page_aligned_bss;
83 DECLARE_BITMAP(used_vectors, NR_VECTORS);
84 EXPORT_SYMBOL_GPL(used_vectors);
86 static inline void conditional_sti(struct pt_regs *regs)
88 if (regs->flags & X86_EFLAGS_IF)
92 static inline void preempt_conditional_sti(struct pt_regs *regs)
95 if (regs->flags & X86_EFLAGS_IF)
99 static inline void conditional_cli(struct pt_regs *regs)
101 if (regs->flags & X86_EFLAGS_IF)
105 static inline void preempt_conditional_cli(struct pt_regs *regs)
107 if (regs->flags & X86_EFLAGS_IF)
113 * In IST context, we explicitly disable preemption. This serves two
114 * purposes: it makes it much less likely that we would accidentally
115 * schedule in IST context and it will force a warning if we somehow
116 * manage to schedule by accident.
118 void ist_enter(struct pt_regs *regs)
120 if (user_mode(regs)) {
121 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
124 * We might have interrupted pretty much anything. In
125 * fact, if we're a machine check, we can even interrupt
126 * NMI processing. We don't want in_nmi() to return true,
127 * but we need to notify RCU.
134 /* This code is a bit fragile. Test it. */
135 RCU_LOCKDEP_WARN(!rcu_is_watching(), "ist_enter didn't work");
138 void ist_exit(struct pt_regs *regs)
140 preempt_enable_no_resched();
142 if (!user_mode(regs))
147 * ist_begin_non_atomic() - begin a non-atomic section in an IST exception
148 * @regs: regs passed to the IST exception handler
150 * IST exception handlers normally cannot schedule. As a special
151 * exception, if the exception interrupted userspace code (i.e.
152 * user_mode(regs) would return true) and the exception was not
153 * a double fault, it can be safe to schedule. ist_begin_non_atomic()
154 * begins a non-atomic section within an ist_enter()/ist_exit() region.
155 * Callers are responsible for enabling interrupts themselves inside
156 * the non-atomic section, and callers must call ist_end_non_atomic()
159 void ist_begin_non_atomic(struct pt_regs *regs)
161 BUG_ON(!user_mode(regs));
164 * Sanity check: we need to be on the normal thread stack. This
165 * will catch asm bugs and any attempt to use ist_preempt_enable
168 BUG_ON((unsigned long)(current_top_of_stack() -
169 current_stack_pointer()) >= THREAD_SIZE);
171 preempt_enable_no_resched();
175 * ist_end_non_atomic() - begin a non-atomic section in an IST exception
177 * Ends a non-atomic section started with ist_begin_non_atomic().
179 void ist_end_non_atomic(void)
184 static nokprobe_inline int
185 do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
186 struct pt_regs *regs, long error_code)
188 if (v8086_mode(regs)) {
190 * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
191 * On nmi (interrupt 2), do_trap should not be called.
193 if (trapnr < X86_TRAP_UD) {
194 if (!handle_vm86_trap((struct kernel_vm86_regs *) regs,
201 if (!user_mode(regs)) {
202 if (!fixup_exception(regs)) {
203 tsk->thread.error_code = error_code;
204 tsk->thread.trap_nr = trapnr;
205 die(str, regs, error_code);
213 static siginfo_t *fill_trap_info(struct pt_regs *regs, int signr, int trapnr,
216 unsigned long siaddr;
221 return SEND_SIG_PRIV;
225 siaddr = uprobe_get_trap_addr(regs);
229 siaddr = uprobe_get_trap_addr(regs);
237 info->si_signo = signr;
239 info->si_code = sicode;
240 info->si_addr = (void __user *)siaddr;
245 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
246 long error_code, siginfo_t *info)
248 struct task_struct *tsk = current;
251 if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code))
254 * We want error_code and trap_nr set for userspace faults and
255 * kernelspace faults which result in die(), but not
256 * kernelspace faults which are fixed up. die() gives the
257 * process no chance to handle the signal and notice the
258 * kernel fault information, so that won't result in polluting
259 * the information about previously queued, but not yet
260 * delivered, faults. See also do_general_protection below.
262 tsk->thread.error_code = error_code;
263 tsk->thread.trap_nr = trapnr;
266 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
267 printk_ratelimit()) {
268 pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx",
269 tsk->comm, tsk->pid, str,
270 regs->ip, regs->sp, error_code);
271 print_vma_addr(" in ", regs->ip);
276 force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk);
278 NOKPROBE_SYMBOL(do_trap);
280 static void do_error_trap(struct pt_regs *regs, long error_code, char *str,
281 unsigned long trapnr, int signr)
285 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
287 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) !=
289 conditional_sti(regs);
290 do_trap(trapnr, signr, str, regs, error_code,
291 fill_trap_info(regs, signr, trapnr, &info));
295 #define DO_ERROR(trapnr, signr, str, name) \
296 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
298 do_error_trap(regs, error_code, str, trapnr, signr); \
301 DO_ERROR(X86_TRAP_DE, SIGFPE, "divide error", divide_error)
302 DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow)
303 DO_ERROR(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op)
304 DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun",coprocessor_segment_overrun)
305 DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS)
306 DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present)
307 DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment)
308 DO_ERROR(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check)
311 /* Runs on IST stack */
312 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
314 static const char str[] = "double fault";
315 struct task_struct *tsk = current;
317 #ifdef CONFIG_X86_ESPFIX64
318 extern unsigned char native_irq_return_iret[];
321 * If IRET takes a non-IST fault on the espfix64 stack, then we
322 * end up promoting it to a doublefault. In that case, modify
323 * the stack to make it look like we just entered the #GP
324 * handler from user space, similar to bad_iret.
326 * No need for ist_enter here because we don't use RCU.
328 if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY &&
329 regs->cs == __KERNEL_CS &&
330 regs->ip == (unsigned long)native_irq_return_iret)
332 struct pt_regs *normal_regs = task_pt_regs(current);
334 /* Fake a #GP(0) from userspace. */
335 memmove(&normal_regs->ip, (void *)regs->sp, 5*8);
336 normal_regs->orig_ax = 0; /* Missing (lost) #GP error code */
337 regs->ip = (unsigned long)general_protection;
338 regs->sp = (unsigned long)&normal_regs->orig_ax;
345 notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
347 tsk->thread.error_code = error_code;
348 tsk->thread.trap_nr = X86_TRAP_DF;
350 #ifdef CONFIG_DOUBLEFAULT
351 df_debug(regs, error_code);
354 * This is always a kernel trap and never fixable (and thus must
358 die(str, regs, error_code);
362 dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
364 const struct mpx_bndcsr *bndcsr;
367 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
368 if (notify_die(DIE_TRAP, "bounds", regs, error_code,
369 X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP)
371 conditional_sti(regs);
373 if (!user_mode(regs))
374 die("bounds", regs, error_code);
376 if (!cpu_feature_enabled(X86_FEATURE_MPX)) {
377 /* The exception is not from Intel MPX */
382 * We need to look at BNDSTATUS to resolve this exception.
383 * A NULL here might mean that it is in its 'init state',
384 * which is all zeros which indicates MPX was not
385 * responsible for the exception.
387 bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR);
391 trace_bounds_exception_mpx(bndcsr);
393 * The error code field of the BNDSTATUS register communicates status
394 * information of a bound range exception #BR or operation involving
397 switch (bndcsr->bndstatus & MPX_BNDSTA_ERROR_CODE) {
398 case 2: /* Bound directory has invalid entry. */
399 if (mpx_handle_bd_fault())
401 break; /* Success, it was handled */
402 case 1: /* Bound violation. */
403 info = mpx_generate_siginfo(regs);
406 * We failed to decode the MPX instruction. Act as if
407 * the exception was not caused by MPX.
412 * Success, we decoded the instruction and retrieved
413 * an 'info' containing the address being accessed
414 * which caused the exception. This information
415 * allows and application to possibly handle the
416 * #BR exception itself.
418 do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, info);
421 case 0: /* No exception caused by Intel MPX operations. */
424 die("bounds", regs, error_code);
431 * This path out is for all the cases where we could not
432 * handle the exception in some way (like allocating a
433 * table or telling userspace about it. We will also end
434 * up here if the kernel has MPX turned off at compile
437 do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, NULL);
441 do_general_protection(struct pt_regs *regs, long error_code)
443 struct task_struct *tsk;
445 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
446 conditional_sti(regs);
448 if (v8086_mode(regs)) {
450 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
455 if (!user_mode(regs)) {
456 if (fixup_exception(regs))
459 tsk->thread.error_code = error_code;
460 tsk->thread.trap_nr = X86_TRAP_GP;
461 if (notify_die(DIE_GPF, "general protection fault", regs, error_code,
462 X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP)
463 die("general protection fault", regs, error_code);
467 tsk->thread.error_code = error_code;
468 tsk->thread.trap_nr = X86_TRAP_GP;
470 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
471 printk_ratelimit()) {
472 pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx",
473 tsk->comm, task_pid_nr(tsk),
474 regs->ip, regs->sp, error_code);
475 print_vma_addr(" in ", regs->ip);
479 force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk);
481 NOKPROBE_SYMBOL(do_general_protection);
483 /* May run on IST stack. */
484 dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
486 #ifdef CONFIG_DYNAMIC_FTRACE
488 * ftrace must be first, everything else may cause a recursive crash.
489 * See note by declaration of modifying_ftrace_code in ftrace.c
491 if (unlikely(atomic_read(&modifying_ftrace_code)) &&
492 ftrace_int3_handler(regs))
495 if (poke_int3_handler(regs))
499 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
500 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
501 if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
502 SIGTRAP) == NOTIFY_STOP)
504 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
506 #ifdef CONFIG_KPROBES
507 if (kprobe_int3_handler(regs))
511 if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
512 SIGTRAP) == NOTIFY_STOP)
516 * Let others (NMI) know that the debug stack is in use
517 * as we may switch to the interrupt stack.
519 debug_stack_usage_inc();
520 preempt_conditional_sti(regs);
521 do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
522 preempt_conditional_cli(regs);
523 debug_stack_usage_dec();
527 NOKPROBE_SYMBOL(do_int3);
531 * Help handler running on IST stack to switch off the IST stack if the
532 * interrupted code was in user mode. The actual stack switch is done in
535 asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs)
537 struct pt_regs *regs = task_pt_regs(current);
541 NOKPROBE_SYMBOL(sync_regs);
543 struct bad_iret_stack {
544 void *error_entry_ret;
548 asmlinkage __visible notrace
549 struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s)
552 * This is called from entry_64.S early in handling a fault
553 * caused by a bad iret to user mode. To handle the fault
554 * correctly, we want move our stack frame to task_pt_regs
555 * and we want to pretend that the exception came from the
558 struct bad_iret_stack *new_stack =
559 container_of(task_pt_regs(current),
560 struct bad_iret_stack, regs);
562 /* Copy the IRET target to the new stack. */
563 memmove(&new_stack->regs.ip, (void *)s->regs.sp, 5*8);
565 /* Copy the remainder of the stack from the current stack. */
566 memmove(new_stack, s, offsetof(struct bad_iret_stack, regs.ip));
568 BUG_ON(!user_mode(&new_stack->regs));
571 NOKPROBE_SYMBOL(fixup_bad_iret);
575 * Our handling of the processor debug registers is non-trivial.
576 * We do not clear them on entry and exit from the kernel. Therefore
577 * it is possible to get a watchpoint trap here from inside the kernel.
578 * However, the code in ./ptrace.c has ensured that the user can
579 * only set watchpoints on userspace addresses. Therefore the in-kernel
580 * watchpoint trap can only occur in code which is reading/writing
581 * from user space. Such code must not hold kernel locks (since it
582 * can equally take a page fault), therefore it is safe to call
583 * force_sig_info even though that claims and releases locks.
585 * Code in ./signal.c ensures that the debug control register
586 * is restored before we deliver any signal, and therefore that
587 * user code runs with the correct debug control register even though
590 * Being careful here means that we don't have to be as careful in a
591 * lot of more complicated places (task switching can be a bit lazy
592 * about restoring all the debug state, and ptrace doesn't have to
593 * find every occurrence of the TF bit that could be saved away even
596 * May run on IST stack.
598 dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
600 struct task_struct *tsk = current;
607 get_debugreg(dr6, 6);
609 /* Filter out all the reserved bits which are preset to 1 */
610 dr6 &= ~DR6_RESERVED;
613 * If dr6 has no reason to give us about the origin of this trap,
614 * then it's very likely the result of an icebp/int01 trap.
615 * User wants a sigtrap for that.
617 if (!dr6 && user_mode(regs))
620 /* Catch kmemcheck conditions first of all! */
621 if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
624 /* DR6 may or may not be cleared by the CPU */
628 * The processor cleared BTF, so don't mark that we need it set.
630 clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP);
632 /* Store the virtualized DR6 value */
633 tsk->thread.debugreg6 = dr6;
635 #ifdef CONFIG_KPROBES
636 if (kprobe_debug_handler(regs))
640 if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code,
641 SIGTRAP) == NOTIFY_STOP)
645 * Let others (NMI) know that the debug stack is in use
646 * as we may switch to the interrupt stack.
648 debug_stack_usage_inc();
650 /* It's safe to allow irq's after DR6 has been saved */
651 preempt_conditional_sti(regs);
653 if (v8086_mode(regs)) {
654 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
656 preempt_conditional_cli(regs);
657 debug_stack_usage_dec();
662 * Single-stepping through system calls: ignore any exceptions in
663 * kernel space, but re-enable TF when returning to user mode.
665 * We already checked v86 mode above, so we can check for kernel mode
666 * by just checking the CPL of CS.
668 if ((dr6 & DR_STEP) && !user_mode(regs)) {
669 tsk->thread.debugreg6 &= ~DR_STEP;
670 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
671 regs->flags &= ~X86_EFLAGS_TF;
673 si_code = get_si_code(tsk->thread.debugreg6);
674 if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
675 send_sigtrap(tsk, regs, error_code, si_code);
676 preempt_conditional_cli(regs);
677 debug_stack_usage_dec();
682 NOKPROBE_SYMBOL(do_debug);
685 * Note that we play around with the 'TS' bit in an attempt to get
686 * the correct behaviour even in the presence of the asynchronous
689 static void math_error(struct pt_regs *regs, int error_code, int trapnr)
691 struct task_struct *task = current;
692 struct fpu *fpu = &task->thread.fpu;
694 char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" :
697 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)
699 conditional_sti(regs);
701 if (!user_mode(regs)) {
702 if (!fixup_exception(regs)) {
703 task->thread.error_code = error_code;
704 task->thread.trap_nr = trapnr;
705 die(str, regs, error_code);
711 * Save the info for the exception handler and clear the error.
715 task->thread.trap_nr = trapnr;
716 task->thread.error_code = error_code;
717 info.si_signo = SIGFPE;
719 info.si_addr = (void __user *)uprobe_get_trap_addr(regs);
721 info.si_code = fpu__exception_code(fpu, trapnr);
723 /* Retry when we get spurious exceptions: */
727 force_sig_info(SIGFPE, &info, task);
730 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
732 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
733 math_error(regs, error_code, X86_TRAP_MF);
737 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
739 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
740 math_error(regs, error_code, X86_TRAP_XF);
744 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
746 conditional_sti(regs);
750 do_device_not_available(struct pt_regs *regs, long error_code)
752 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
753 BUG_ON(use_eager_fpu());
755 #ifdef CONFIG_MATH_EMULATION
756 if (read_cr0() & X86_CR0_EM) {
757 struct math_emu_info info = { };
759 conditional_sti(regs);
766 fpu__restore(¤t->thread.fpu); /* interrupts still off */
768 conditional_sti(regs);
771 NOKPROBE_SYMBOL(do_device_not_available);
774 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
778 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
781 info.si_signo = SIGILL;
783 info.si_code = ILL_BADSTK;
785 if (notify_die(DIE_TRAP, "iret exception", regs, error_code,
786 X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) {
787 do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
793 /* Set of traps needed for early debugging. */
794 void __init early_trap_init(void)
797 * Don't use IST to set DEBUG_STACK as it doesn't work until TSS
798 * is ready in cpu_init() <-- trap_init(). Before trap_init(),
799 * CPU runs at ring 0 so it is impossible to hit an invalid
800 * stack. Using the original stack works well enough at this
801 * early stage. DEBUG_STACK will be equipped after cpu_init() in
804 * We don't need to set trace_idt_table like set_intr_gate(),
805 * since we don't have trace_debug and it will be reset to
806 * 'debug' in trap_init() by set_intr_gate_ist().
808 set_intr_gate_notrace(X86_TRAP_DB, debug);
809 /* int3 can be called from all */
810 set_system_intr_gate(X86_TRAP_BP, &int3);
812 set_intr_gate(X86_TRAP_PF, page_fault);
814 load_idt(&idt_descr);
817 void __init early_trap_pf_init(void)
820 set_intr_gate(X86_TRAP_PF, page_fault);
824 void __init trap_init(void)
829 void __iomem *p = early_ioremap(0x0FFFD9, 4);
831 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
836 set_intr_gate(X86_TRAP_DE, divide_error);
837 set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK);
838 /* int4 can be called from all */
839 set_system_intr_gate(X86_TRAP_OF, &overflow);
840 set_intr_gate(X86_TRAP_BR, bounds);
841 set_intr_gate(X86_TRAP_UD, invalid_op);
842 set_intr_gate(X86_TRAP_NM, device_not_available);
844 set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS);
846 set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK);
848 set_intr_gate(X86_TRAP_OLD_MF, coprocessor_segment_overrun);
849 set_intr_gate(X86_TRAP_TS, invalid_TSS);
850 set_intr_gate(X86_TRAP_NP, segment_not_present);
851 set_intr_gate(X86_TRAP_SS, stack_segment);
852 set_intr_gate(X86_TRAP_GP, general_protection);
853 set_intr_gate(X86_TRAP_SPURIOUS, spurious_interrupt_bug);
854 set_intr_gate(X86_TRAP_MF, coprocessor_error);
855 set_intr_gate(X86_TRAP_AC, alignment_check);
856 #ifdef CONFIG_X86_MCE
857 set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK);
859 set_intr_gate(X86_TRAP_XF, simd_coprocessor_error);
861 /* Reserve all the builtin and the syscall vector: */
862 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
863 set_bit(i, used_vectors);
865 #ifdef CONFIG_IA32_EMULATION
866 set_system_intr_gate(IA32_SYSCALL_VECTOR, entry_INT80_compat);
867 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
871 set_system_trap_gate(IA32_SYSCALL_VECTOR, entry_INT80_32);
872 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
876 * Set the IDT descriptor to a fixed read-only location, so that the
877 * "sidt" instruction will not leak the location of the kernel, and
878 * to defend the IDT against arbitrary memory write vulnerabilities.
879 * It will be reloaded in cpu_init() */
880 __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO);
881 idt_descr.address = fix_to_virt(FIX_RO_IDT);
884 * Should be a barrier for any external CPU state:
889 * X86_TRAP_DB and X86_TRAP_BP have been set
890 * in early_trap_init(). However, ITS works only after
891 * cpu_init() loads TSS. See comments in early_trap_init().
893 set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK);
894 /* int3 can be called from all */
895 set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK);
897 x86_init.irqs.trap_init();
900 memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
901 set_nmi_gate(X86_TRAP_DB, &debug);
902 set_nmi_gate(X86_TRAP_BP, &int3);