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 cond_local_irq_enable(struct pt_regs *regs)
88 if (regs->flags & X86_EFLAGS_IF)
92 static inline void cond_local_irq_disable(struct pt_regs *regs)
94 if (regs->flags & X86_EFLAGS_IF)
98 void ist_enter(struct pt_regs *regs)
100 if (user_mode(regs)) {
101 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
104 * We might have interrupted pretty much anything. In
105 * fact, if we're a machine check, we can even interrupt
106 * NMI processing. We don't want in_nmi() to return true,
107 * but we need to notify RCU.
113 * We are atomic because we're on the IST stack; or we're on
114 * x86_32, in which case we still shouldn't schedule; or we're
115 * on x86_64 and entered from user mode, in which case we're
116 * still atomic unless ist_begin_non_atomic is called.
118 preempt_count_add(HARDIRQ_OFFSET);
120 /* This code is a bit fragile. Test it. */
121 RCU_LOCKDEP_WARN(!rcu_is_watching(), "ist_enter didn't work");
124 void ist_exit(struct pt_regs *regs)
126 preempt_count_sub(HARDIRQ_OFFSET);
128 if (!user_mode(regs))
133 * ist_begin_non_atomic() - begin a non-atomic section in an IST exception
134 * @regs: regs passed to the IST exception handler
136 * IST exception handlers normally cannot schedule. As a special
137 * exception, if the exception interrupted userspace code (i.e.
138 * user_mode(regs) would return true) and the exception was not
139 * a double fault, it can be safe to schedule. ist_begin_non_atomic()
140 * begins a non-atomic section within an ist_enter()/ist_exit() region.
141 * Callers are responsible for enabling interrupts themselves inside
142 * the non-atomic section, and callers must call ist_end_non_atomic()
145 void ist_begin_non_atomic(struct pt_regs *regs)
147 BUG_ON(!user_mode(regs));
150 * Sanity check: we need to be on the normal thread stack. This
151 * will catch asm bugs and any attempt to use ist_preempt_enable
154 BUG_ON((unsigned long)(current_top_of_stack() -
155 current_stack_pointer()) >= THREAD_SIZE);
157 preempt_count_sub(HARDIRQ_OFFSET);
161 * ist_end_non_atomic() - begin a non-atomic section in an IST exception
163 * Ends a non-atomic section started with ist_begin_non_atomic().
165 void ist_end_non_atomic(void)
167 preempt_count_add(HARDIRQ_OFFSET);
170 static nokprobe_inline int
171 do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str,
172 struct pt_regs *regs, long error_code)
174 if (v8086_mode(regs)) {
176 * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
177 * On nmi (interrupt 2), do_trap should not be called.
179 if (trapnr < X86_TRAP_UD) {
180 if (!handle_vm86_trap((struct kernel_vm86_regs *) regs,
187 if (!user_mode(regs)) {
188 if (!fixup_exception(regs)) {
189 tsk->thread.error_code = error_code;
190 tsk->thread.trap_nr = trapnr;
191 die(str, regs, error_code);
199 static siginfo_t *fill_trap_info(struct pt_regs *regs, int signr, int trapnr,
202 unsigned long siaddr;
207 return SEND_SIG_PRIV;
211 siaddr = uprobe_get_trap_addr(regs);
215 siaddr = uprobe_get_trap_addr(regs);
223 info->si_signo = signr;
225 info->si_code = sicode;
226 info->si_addr = (void __user *)siaddr;
231 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
232 long error_code, siginfo_t *info)
234 struct task_struct *tsk = current;
237 if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code))
240 * We want error_code and trap_nr set for userspace faults and
241 * kernelspace faults which result in die(), but not
242 * kernelspace faults which are fixed up. die() gives the
243 * process no chance to handle the signal and notice the
244 * kernel fault information, so that won't result in polluting
245 * the information about previously queued, but not yet
246 * delivered, faults. See also do_general_protection below.
248 tsk->thread.error_code = error_code;
249 tsk->thread.trap_nr = trapnr;
252 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
253 printk_ratelimit()) {
254 pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx",
255 tsk->comm, tsk->pid, str,
256 regs->ip, regs->sp, error_code);
257 print_vma_addr(" in ", regs->ip);
262 force_sig_info(signr, info ?: SEND_SIG_PRIV, tsk);
264 NOKPROBE_SYMBOL(do_trap);
266 static void do_error_trap(struct pt_regs *regs, long error_code, char *str,
267 unsigned long trapnr, int signr)
271 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
273 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) !=
275 cond_local_irq_enable(regs);
276 do_trap(trapnr, signr, str, regs, error_code,
277 fill_trap_info(regs, signr, trapnr, &info));
281 #define DO_ERROR(trapnr, signr, str, name) \
282 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
284 do_error_trap(regs, error_code, str, trapnr, signr); \
287 DO_ERROR(X86_TRAP_DE, SIGFPE, "divide error", divide_error)
288 DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow)
289 DO_ERROR(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op)
290 DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun",coprocessor_segment_overrun)
291 DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS)
292 DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present)
293 DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment)
294 DO_ERROR(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check)
297 /* Runs on IST stack */
298 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
300 static const char str[] = "double fault";
301 struct task_struct *tsk = current;
303 #ifdef CONFIG_X86_ESPFIX64
304 extern unsigned char native_irq_return_iret[];
307 * If IRET takes a non-IST fault on the espfix64 stack, then we
308 * end up promoting it to a doublefault. In that case, modify
309 * the stack to make it look like we just entered the #GP
310 * handler from user space, similar to bad_iret.
312 * No need for ist_enter here because we don't use RCU.
314 if (((long)regs->sp >> PGDIR_SHIFT) == ESPFIX_PGD_ENTRY &&
315 regs->cs == __KERNEL_CS &&
316 regs->ip == (unsigned long)native_irq_return_iret)
318 struct pt_regs *normal_regs = task_pt_regs(current);
320 /* Fake a #GP(0) from userspace. */
321 memmove(&normal_regs->ip, (void *)regs->sp, 5*8);
322 normal_regs->orig_ax = 0; /* Missing (lost) #GP error code */
323 regs->ip = (unsigned long)general_protection;
324 regs->sp = (unsigned long)&normal_regs->orig_ax;
331 notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
333 tsk->thread.error_code = error_code;
334 tsk->thread.trap_nr = X86_TRAP_DF;
336 #ifdef CONFIG_DOUBLEFAULT
337 df_debug(regs, error_code);
340 * This is always a kernel trap and never fixable (and thus must
344 die(str, regs, error_code);
348 dotraplinkage void do_bounds(struct pt_regs *regs, long error_code)
350 const struct mpx_bndcsr *bndcsr;
353 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
354 if (notify_die(DIE_TRAP, "bounds", regs, error_code,
355 X86_TRAP_BR, SIGSEGV) == NOTIFY_STOP)
357 cond_local_irq_enable(regs);
359 if (!user_mode(regs))
360 die("bounds", regs, error_code);
362 if (!cpu_feature_enabled(X86_FEATURE_MPX)) {
363 /* The exception is not from Intel MPX */
368 * We need to look at BNDSTATUS to resolve this exception.
369 * A NULL here might mean that it is in its 'init state',
370 * which is all zeros which indicates MPX was not
371 * responsible for the exception.
373 bndcsr = get_xsave_field_ptr(XFEATURE_MASK_BNDCSR);
377 trace_bounds_exception_mpx(bndcsr);
379 * The error code field of the BNDSTATUS register communicates status
380 * information of a bound range exception #BR or operation involving
383 switch (bndcsr->bndstatus & MPX_BNDSTA_ERROR_CODE) {
384 case 2: /* Bound directory has invalid entry. */
385 if (mpx_handle_bd_fault())
387 break; /* Success, it was handled */
388 case 1: /* Bound violation. */
389 info = mpx_generate_siginfo(regs);
392 * We failed to decode the MPX instruction. Act as if
393 * the exception was not caused by MPX.
398 * Success, we decoded the instruction and retrieved
399 * an 'info' containing the address being accessed
400 * which caused the exception. This information
401 * allows and application to possibly handle the
402 * #BR exception itself.
404 do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, info);
407 case 0: /* No exception caused by Intel MPX operations. */
410 die("bounds", regs, error_code);
417 * This path out is for all the cases where we could not
418 * handle the exception in some way (like allocating a
419 * table or telling userspace about it. We will also end
420 * up here if the kernel has MPX turned off at compile
423 do_trap(X86_TRAP_BR, SIGSEGV, "bounds", regs, error_code, NULL);
427 do_general_protection(struct pt_regs *regs, long error_code)
429 struct task_struct *tsk;
431 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
432 cond_local_irq_enable(regs);
434 if (v8086_mode(regs)) {
436 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
441 if (!user_mode(regs)) {
442 if (fixup_exception(regs))
445 tsk->thread.error_code = error_code;
446 tsk->thread.trap_nr = X86_TRAP_GP;
447 if (notify_die(DIE_GPF, "general protection fault", regs, error_code,
448 X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP)
449 die("general protection fault", regs, error_code);
453 tsk->thread.error_code = error_code;
454 tsk->thread.trap_nr = X86_TRAP_GP;
456 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
457 printk_ratelimit()) {
458 pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx",
459 tsk->comm, task_pid_nr(tsk),
460 regs->ip, regs->sp, error_code);
461 print_vma_addr(" in ", regs->ip);
465 force_sig_info(SIGSEGV, SEND_SIG_PRIV, tsk);
467 NOKPROBE_SYMBOL(do_general_protection);
469 /* May run on IST stack. */
470 dotraplinkage void notrace do_int3(struct pt_regs *regs, long error_code)
472 #ifdef CONFIG_DYNAMIC_FTRACE
474 * ftrace must be first, everything else may cause a recursive crash.
475 * See note by declaration of modifying_ftrace_code in ftrace.c
477 if (unlikely(atomic_read(&modifying_ftrace_code)) &&
478 ftrace_int3_handler(regs))
481 if (poke_int3_handler(regs))
485 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
486 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
487 if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
488 SIGTRAP) == NOTIFY_STOP)
490 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
492 #ifdef CONFIG_KPROBES
493 if (kprobe_int3_handler(regs))
497 if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
498 SIGTRAP) == NOTIFY_STOP)
502 * Let others (NMI) know that the debug stack is in use
503 * as we may switch to the interrupt stack.
505 debug_stack_usage_inc();
507 cond_local_irq_enable(regs);
508 do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
509 cond_local_irq_disable(regs);
510 preempt_enable_no_resched();
511 debug_stack_usage_dec();
515 NOKPROBE_SYMBOL(do_int3);
519 * Help handler running on IST stack to switch off the IST stack if the
520 * interrupted code was in user mode. The actual stack switch is done in
523 asmlinkage __visible notrace struct pt_regs *sync_regs(struct pt_regs *eregs)
525 struct pt_regs *regs = task_pt_regs(current);
529 NOKPROBE_SYMBOL(sync_regs);
531 struct bad_iret_stack {
532 void *error_entry_ret;
536 asmlinkage __visible notrace
537 struct bad_iret_stack *fixup_bad_iret(struct bad_iret_stack *s)
540 * This is called from entry_64.S early in handling a fault
541 * caused by a bad iret to user mode. To handle the fault
542 * correctly, we want move our stack frame to task_pt_regs
543 * and we want to pretend that the exception came from the
546 struct bad_iret_stack *new_stack =
547 container_of(task_pt_regs(current),
548 struct bad_iret_stack, regs);
550 /* Copy the IRET target to the new stack. */
551 memmove(&new_stack->regs.ip, (void *)s->regs.sp, 5*8);
553 /* Copy the remainder of the stack from the current stack. */
554 memmove(new_stack, s, offsetof(struct bad_iret_stack, regs.ip));
556 BUG_ON(!user_mode(&new_stack->regs));
559 NOKPROBE_SYMBOL(fixup_bad_iret);
563 * Our handling of the processor debug registers is non-trivial.
564 * We do not clear them on entry and exit from the kernel. Therefore
565 * it is possible to get a watchpoint trap here from inside the kernel.
566 * However, the code in ./ptrace.c has ensured that the user can
567 * only set watchpoints on userspace addresses. Therefore the in-kernel
568 * watchpoint trap can only occur in code which is reading/writing
569 * from user space. Such code must not hold kernel locks (since it
570 * can equally take a page fault), therefore it is safe to call
571 * force_sig_info even though that claims and releases locks.
573 * Code in ./signal.c ensures that the debug control register
574 * is restored before we deliver any signal, and therefore that
575 * user code runs with the correct debug control register even though
578 * Being careful here means that we don't have to be as careful in a
579 * lot of more complicated places (task switching can be a bit lazy
580 * about restoring all the debug state, and ptrace doesn't have to
581 * find every occurrence of the TF bit that could be saved away even
584 * May run on IST stack.
586 dotraplinkage void do_debug(struct pt_regs *regs, long error_code)
588 struct task_struct *tsk = current;
595 get_debugreg(dr6, 6);
597 /* Filter out all the reserved bits which are preset to 1 */
598 dr6 &= ~DR6_RESERVED;
601 * If dr6 has no reason to give us about the origin of this trap,
602 * then it's very likely the result of an icebp/int01 trap.
603 * User wants a sigtrap for that.
605 if (!dr6 && user_mode(regs))
608 /* Catch kmemcheck conditions first of all! */
609 if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
612 /* DR6 may or may not be cleared by the CPU */
616 * The processor cleared BTF, so don't mark that we need it set.
618 clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP);
620 /* Store the virtualized DR6 value */
621 tsk->thread.debugreg6 = dr6;
623 #ifdef CONFIG_KPROBES
624 if (kprobe_debug_handler(regs))
628 if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code,
629 SIGTRAP) == NOTIFY_STOP)
633 * Let others (NMI) know that the debug stack is in use
634 * as we may switch to the interrupt stack.
636 debug_stack_usage_inc();
638 /* It's safe to allow irq's after DR6 has been saved */
640 cond_local_irq_enable(regs);
642 if (v8086_mode(regs)) {
643 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
645 cond_local_irq_disable(regs);
646 preempt_enable_no_resched();
647 debug_stack_usage_dec();
652 * Single-stepping through system calls: ignore any exceptions in
653 * kernel space, but re-enable TF when returning to user mode.
655 * We already checked v86 mode above, so we can check for kernel mode
656 * by just checking the CPL of CS.
658 if ((dr6 & DR_STEP) && !user_mode(regs)) {
659 tsk->thread.debugreg6 &= ~DR_STEP;
660 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
661 regs->flags &= ~X86_EFLAGS_TF;
663 si_code = get_si_code(tsk->thread.debugreg6);
664 if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
665 send_sigtrap(tsk, regs, error_code, si_code);
666 cond_local_irq_disable(regs);
667 preempt_enable_no_resched();
668 debug_stack_usage_dec();
673 NOKPROBE_SYMBOL(do_debug);
676 * Note that we play around with the 'TS' bit in an attempt to get
677 * the correct behaviour even in the presence of the asynchronous
680 static void math_error(struct pt_regs *regs, int error_code, int trapnr)
682 struct task_struct *task = current;
683 struct fpu *fpu = &task->thread.fpu;
685 char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" :
688 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)
690 cond_local_irq_enable(regs);
692 if (!user_mode(regs)) {
693 if (!fixup_exception(regs)) {
694 task->thread.error_code = error_code;
695 task->thread.trap_nr = trapnr;
696 die(str, regs, error_code);
702 * Save the info for the exception handler and clear the error.
706 task->thread.trap_nr = trapnr;
707 task->thread.error_code = error_code;
708 info.si_signo = SIGFPE;
710 info.si_addr = (void __user *)uprobe_get_trap_addr(regs);
712 info.si_code = fpu__exception_code(fpu, trapnr);
714 /* Retry when we get spurious exceptions: */
718 force_sig_info(SIGFPE, &info, task);
721 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
723 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
724 math_error(regs, error_code, X86_TRAP_MF);
728 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
730 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
731 math_error(regs, error_code, X86_TRAP_XF);
735 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
737 cond_local_irq_enable(regs);
741 do_device_not_available(struct pt_regs *regs, long error_code)
743 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
744 BUG_ON(use_eager_fpu());
746 #ifdef CONFIG_MATH_EMULATION
747 if (read_cr0() & X86_CR0_EM) {
748 struct math_emu_info info = { };
750 cond_local_irq_enable(regs);
757 fpu__restore(¤t->thread.fpu); /* interrupts still off */
759 cond_local_irq_enable(regs);
762 NOKPROBE_SYMBOL(do_device_not_available);
765 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
769 RCU_LOCKDEP_WARN(!rcu_is_watching(), "entry code didn't wake RCU");
772 info.si_signo = SIGILL;
774 info.si_code = ILL_BADSTK;
776 if (notify_die(DIE_TRAP, "iret exception", regs, error_code,
777 X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) {
778 do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
784 /* Set of traps needed for early debugging. */
785 void __init early_trap_init(void)
788 * Don't use IST to set DEBUG_STACK as it doesn't work until TSS
789 * is ready in cpu_init() <-- trap_init(). Before trap_init(),
790 * CPU runs at ring 0 so it is impossible to hit an invalid
791 * stack. Using the original stack works well enough at this
792 * early stage. DEBUG_STACK will be equipped after cpu_init() in
795 * We don't need to set trace_idt_table like set_intr_gate(),
796 * since we don't have trace_debug and it will be reset to
797 * 'debug' in trap_init() by set_intr_gate_ist().
799 set_intr_gate_notrace(X86_TRAP_DB, debug);
800 /* int3 can be called from all */
801 set_system_intr_gate(X86_TRAP_BP, &int3);
803 set_intr_gate(X86_TRAP_PF, page_fault);
805 load_idt(&idt_descr);
808 void __init early_trap_pf_init(void)
811 set_intr_gate(X86_TRAP_PF, page_fault);
815 void __init trap_init(void)
820 void __iomem *p = early_ioremap(0x0FFFD9, 4);
822 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
827 set_intr_gate(X86_TRAP_DE, divide_error);
828 set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK);
829 /* int4 can be called from all */
830 set_system_intr_gate(X86_TRAP_OF, &overflow);
831 set_intr_gate(X86_TRAP_BR, bounds);
832 set_intr_gate(X86_TRAP_UD, invalid_op);
833 set_intr_gate(X86_TRAP_NM, device_not_available);
835 set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS);
837 set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK);
839 set_intr_gate(X86_TRAP_OLD_MF, coprocessor_segment_overrun);
840 set_intr_gate(X86_TRAP_TS, invalid_TSS);
841 set_intr_gate(X86_TRAP_NP, segment_not_present);
842 set_intr_gate(X86_TRAP_SS, stack_segment);
843 set_intr_gate(X86_TRAP_GP, general_protection);
844 set_intr_gate(X86_TRAP_SPURIOUS, spurious_interrupt_bug);
845 set_intr_gate(X86_TRAP_MF, coprocessor_error);
846 set_intr_gate(X86_TRAP_AC, alignment_check);
847 #ifdef CONFIG_X86_MCE
848 set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK);
850 set_intr_gate(X86_TRAP_XF, simd_coprocessor_error);
852 /* Reserve all the builtin and the syscall vector: */
853 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
854 set_bit(i, used_vectors);
856 #ifdef CONFIG_IA32_EMULATION
857 set_system_intr_gate(IA32_SYSCALL_VECTOR, entry_INT80_compat);
858 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
862 set_system_trap_gate(IA32_SYSCALL_VECTOR, entry_INT80_32);
863 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
867 * Set the IDT descriptor to a fixed read-only location, so that the
868 * "sidt" instruction will not leak the location of the kernel, and
869 * to defend the IDT against arbitrary memory write vulnerabilities.
870 * It will be reloaded in cpu_init() */
871 __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO);
872 idt_descr.address = fix_to_virt(FIX_RO_IDT);
875 * Should be a barrier for any external CPU state:
880 * X86_TRAP_DB and X86_TRAP_BP have been set
881 * in early_trap_init(). However, ITS works only after
882 * cpu_init() loads TSS. See comments in early_trap_init().
884 set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK);
885 /* int3 can be called from all */
886 set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK);
888 x86_init.irqs.trap_init();
891 memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16);
892 set_nmi_gate(X86_TRAP_DB, &debug);
893 set_nmi_gate(X86_TRAP_BP, &int3);