1 /*
2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen, SuSE Labs
4 *
5 * Pentium III FXSR, SSE support
6 * Gareth Hughes <gareth@valinux.com>, May 2000
7 */
8
9 /*
10 * Handle hardware traps and faults.
11 */
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/kdebug.h>
18 #include <linux/kgdb.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>
31 #include <linux/mm.h>
32 #include <linux/smp.h>
33 #include <linux/io.h>
34
35 #ifdef CONFIG_EISA
36 #include <linux/ioport.h>
37 #include <linux/eisa.h>
38 #endif
39
40 #ifdef CONFIG_MCA
41 #include <linux/mca.h>
42 #endif
43
44 #if defined(CONFIG_EDAC)
45 #include <linux/edac.h>
46 #endif
47
48 #include <asm/kmemcheck.h>
49 #include <asm/stacktrace.h>
50 #include <asm/processor.h>
51 #include <asm/debugreg.h>
52 #include <linux/atomic.h>
53 #include <asm/traps.h>
54 #include <asm/desc.h>
55 #include <asm/i387.h>
56 #include <asm/fpu-internal.h>
57 #include <asm/mce.h>
58
59 #include <asm/mach_traps.h>
60
61 #ifdef CONFIG_X86_64
62 #include <asm/x86_init.h>
63 #include <asm/pgalloc.h>
64 #include <asm/proto.h>
65 #else
66 #include <asm/processor-flags.h>
67 #include <asm/setup.h>
68
69 asmlinkage int system_call(void);
70
71 /* Do we ignore FPU interrupts ? */
72 char ignore_fpu_irq;
73
74 /*
75 * The IDT has to be page-aligned to simplify the Pentium
76 * F0 0F bug workaround.
77 */
78 gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, };
79 #endif
80
81 DECLARE_BITMAP(used_vectors, NR_VECTORS);
82 EXPORT_SYMBOL_GPL(used_vectors);
83
conditional_sti(struct pt_regs * regs)84 static inline void conditional_sti(struct pt_regs *regs)
85 {
86 if (regs->flags & X86_EFLAGS_IF)
87 local_irq_enable();
88 }
89
preempt_conditional_sti(struct pt_regs * regs)90 static inline void preempt_conditional_sti(struct pt_regs *regs)
91 {
92 inc_preempt_count();
93 if (regs->flags & X86_EFLAGS_IF)
94 local_irq_enable();
95 }
96
conditional_cli(struct pt_regs * regs)97 static inline void conditional_cli(struct pt_regs *regs)
98 {
99 if (regs->flags & X86_EFLAGS_IF)
100 local_irq_disable();
101 }
102
preempt_conditional_cli(struct pt_regs * regs)103 static inline void preempt_conditional_cli(struct pt_regs *regs)
104 {
105 if (regs->flags & X86_EFLAGS_IF)
106 local_irq_disable();
107 dec_preempt_count();
108 }
109
110 static void __kprobes
do_trap(int trapnr,int signr,char * str,struct pt_regs * regs,long error_code,siginfo_t * info)111 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs,
112 long error_code, siginfo_t *info)
113 {
114 struct task_struct *tsk = current;
115
116 #ifdef CONFIG_X86_32
117 if (regs->flags & X86_VM_MASK) {
118 /*
119 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86.
120 * On nmi (interrupt 2), do_trap should not be called.
121 */
122 if (trapnr < X86_TRAP_UD)
123 goto vm86_trap;
124 goto trap_signal;
125 }
126 #endif
127
128 if (!user_mode(regs))
129 goto kernel_trap;
130
131 #ifdef CONFIG_X86_32
132 trap_signal:
133 #endif
134 /*
135 * We want error_code and trap_nr set for userspace faults and
136 * kernelspace faults which result in die(), but not
137 * kernelspace faults which are fixed up. die() gives the
138 * process no chance to handle the signal and notice the
139 * kernel fault information, so that won't result in polluting
140 * the information about previously queued, but not yet
141 * delivered, faults. See also do_general_protection below.
142 */
143 tsk->thread.error_code = error_code;
144 tsk->thread.trap_nr = trapnr;
145
146 #ifdef CONFIG_X86_64
147 if (show_unhandled_signals && unhandled_signal(tsk, signr) &&
148 printk_ratelimit()) {
149 printk(KERN_INFO
150 "%s[%d] trap %s ip:%lx sp:%lx error:%lx",
151 tsk->comm, tsk->pid, str,
152 regs->ip, regs->sp, error_code);
153 print_vma_addr(" in ", regs->ip);
154 printk("\n");
155 }
156 #endif
157
158 if (info)
159 force_sig_info(signr, info, tsk);
160 else
161 force_sig(signr, tsk);
162 return;
163
164 kernel_trap:
165 if (!fixup_exception(regs)) {
166 tsk->thread.error_code = error_code;
167 tsk->thread.trap_nr = trapnr;
168 die(str, regs, error_code);
169 }
170 return;
171
172 #ifdef CONFIG_X86_32
173 vm86_trap:
174 if (handle_vm86_trap((struct kernel_vm86_regs *) regs,
175 error_code, trapnr))
176 goto trap_signal;
177 return;
178 #endif
179 }
180
181 #define DO_ERROR(trapnr, signr, str, name) \
182 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
183 { \
184 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
185 == NOTIFY_STOP) \
186 return; \
187 conditional_sti(regs); \
188 do_trap(trapnr, signr, str, regs, error_code, NULL); \
189 }
190
191 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \
192 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \
193 { \
194 siginfo_t info; \
195 info.si_signo = signr; \
196 info.si_errno = 0; \
197 info.si_code = sicode; \
198 info.si_addr = (void __user *)siaddr; \
199 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \
200 == NOTIFY_STOP) \
201 return; \
202 conditional_sti(regs); \
203 do_trap(trapnr, signr, str, regs, error_code, &info); \
204 }
205
206 DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV,
207 regs->ip)
208 DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow)
209 DO_ERROR(X86_TRAP_BR, SIGSEGV, "bounds", bounds)
210 DO_ERROR_INFO(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN,
211 regs->ip)
212 DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun",
213 coprocessor_segment_overrun)
214 DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS)
215 DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present)
216 #ifdef CONFIG_X86_32
217 DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment)
218 #endif
219 DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check,
220 BUS_ADRALN, 0)
221
222 #ifdef CONFIG_X86_64
223 /* Runs on IST stack */
do_stack_segment(struct pt_regs * regs,long error_code)224 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code)
225 {
226 if (notify_die(DIE_TRAP, "stack segment", regs, error_code,
227 X86_TRAP_SS, SIGBUS) == NOTIFY_STOP)
228 return;
229 preempt_conditional_sti(regs);
230 do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL);
231 preempt_conditional_cli(regs);
232 }
233
do_double_fault(struct pt_regs * regs,long error_code)234 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code)
235 {
236 static const char str[] = "double fault";
237 struct task_struct *tsk = current;
238
239 /* Return not checked because double check cannot be ignored */
240 notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV);
241
242 tsk->thread.error_code = error_code;
243 tsk->thread.trap_nr = X86_TRAP_DF;
244
245 /*
246 * This is always a kernel trap and never fixable (and thus must
247 * never return).
248 */
249 for (;;)
250 die(str, regs, error_code);
251 }
252 #endif
253
254 dotraplinkage void __kprobes
do_general_protection(struct pt_regs * regs,long error_code)255 do_general_protection(struct pt_regs *regs, long error_code)
256 {
257 struct task_struct *tsk;
258
259 conditional_sti(regs);
260
261 #ifdef CONFIG_X86_32
262 if (regs->flags & X86_VM_MASK)
263 goto gp_in_vm86;
264 #endif
265
266 tsk = current;
267 if (!user_mode(regs))
268 goto gp_in_kernel;
269
270 tsk->thread.error_code = error_code;
271 tsk->thread.trap_nr = X86_TRAP_GP;
272
273 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) &&
274 printk_ratelimit()) {
275 printk(KERN_INFO
276 "%s[%d] general protection ip:%lx sp:%lx error:%lx",
277 tsk->comm, task_pid_nr(tsk),
278 regs->ip, regs->sp, error_code);
279 print_vma_addr(" in ", regs->ip);
280 printk("\n");
281 }
282
283 force_sig(SIGSEGV, tsk);
284 return;
285
286 #ifdef CONFIG_X86_32
287 gp_in_vm86:
288 local_irq_enable();
289 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code);
290 return;
291 #endif
292
293 gp_in_kernel:
294 if (fixup_exception(regs))
295 return;
296
297 tsk->thread.error_code = error_code;
298 tsk->thread.trap_nr = X86_TRAP_GP;
299 if (notify_die(DIE_GPF, "general protection fault", regs, error_code,
300 X86_TRAP_GP, SIGSEGV) == NOTIFY_STOP)
301 return;
302 die("general protection fault", regs, error_code);
303 }
304
305 /* May run on IST stack. */
do_int3(struct pt_regs * regs,long error_code)306 dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code)
307 {
308 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP
309 if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
310 SIGTRAP) == NOTIFY_STOP)
311 return;
312 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */
313
314 if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP,
315 SIGTRAP) == NOTIFY_STOP)
316 return;
317
318 /*
319 * Let others (NMI) know that the debug stack is in use
320 * as we may switch to the interrupt stack.
321 */
322 debug_stack_usage_inc();
323 preempt_conditional_sti(regs);
324 do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL);
325 preempt_conditional_cli(regs);
326 debug_stack_usage_dec();
327 }
328
329 #ifdef CONFIG_X86_64
330 /*
331 * Help handler running on IST stack to switch back to user stack
332 * for scheduling or signal handling. The actual stack switch is done in
333 * entry.S
334 */
sync_regs(struct pt_regs * eregs)335 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs)
336 {
337 struct pt_regs *regs = eregs;
338 /* Did already sync */
339 if (eregs == (struct pt_regs *)eregs->sp)
340 ;
341 /* Exception from user space */
342 else if (user_mode(eregs))
343 regs = task_pt_regs(current);
344 /*
345 * Exception from kernel and interrupts are enabled. Move to
346 * kernel process stack.
347 */
348 else if (eregs->flags & X86_EFLAGS_IF)
349 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs));
350 if (eregs != regs)
351 *regs = *eregs;
352 return regs;
353 }
354 #endif
355
356 /*
357 * Our handling of the processor debug registers is non-trivial.
358 * We do not clear them on entry and exit from the kernel. Therefore
359 * it is possible to get a watchpoint trap here from inside the kernel.
360 * However, the code in ./ptrace.c has ensured that the user can
361 * only set watchpoints on userspace addresses. Therefore the in-kernel
362 * watchpoint trap can only occur in code which is reading/writing
363 * from user space. Such code must not hold kernel locks (since it
364 * can equally take a page fault), therefore it is safe to call
365 * force_sig_info even though that claims and releases locks.
366 *
367 * Code in ./signal.c ensures that the debug control register
368 * is restored before we deliver any signal, and therefore that
369 * user code runs with the correct debug control register even though
370 * we clear it here.
371 *
372 * Being careful here means that we don't have to be as careful in a
373 * lot of more complicated places (task switching can be a bit lazy
374 * about restoring all the debug state, and ptrace doesn't have to
375 * find every occurrence of the TF bit that could be saved away even
376 * by user code)
377 *
378 * May run on IST stack.
379 */
do_debug(struct pt_regs * regs,long error_code)380 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code)
381 {
382 struct task_struct *tsk = current;
383 int user_icebp = 0;
384 unsigned long dr6;
385 int si_code;
386
387 get_debugreg(dr6, 6);
388
389 /* Filter out all the reserved bits which are preset to 1 */
390 dr6 &= ~DR6_RESERVED;
391
392 /*
393 * If dr6 has no reason to give us about the origin of this trap,
394 * then it's very likely the result of an icebp/int01 trap.
395 * User wants a sigtrap for that.
396 */
397 if (!dr6 && user_mode(regs))
398 user_icebp = 1;
399
400 /* Catch kmemcheck conditions first of all! */
401 if ((dr6 & DR_STEP) && kmemcheck_trap(regs))
402 return;
403
404 /* DR6 may or may not be cleared by the CPU */
405 set_debugreg(0, 6);
406
407 /*
408 * The processor cleared BTF, so don't mark that we need it set.
409 */
410 clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP);
411
412 /* Store the virtualized DR6 value */
413 tsk->thread.debugreg6 = dr6;
414
415 if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code,
416 SIGTRAP) == NOTIFY_STOP)
417 return;
418
419 /*
420 * Let others (NMI) know that the debug stack is in use
421 * as we may switch to the interrupt stack.
422 */
423 debug_stack_usage_inc();
424
425 /* It's safe to allow irq's after DR6 has been saved */
426 preempt_conditional_sti(regs);
427
428 if (regs->flags & X86_VM_MASK) {
429 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code,
430 X86_TRAP_DB);
431 preempt_conditional_cli(regs);
432 debug_stack_usage_dec();
433 return;
434 }
435
436 /*
437 * Single-stepping through system calls: ignore any exceptions in
438 * kernel space, but re-enable TF when returning to user mode.
439 *
440 * We already checked v86 mode above, so we can check for kernel mode
441 * by just checking the CPL of CS.
442 */
443 if ((dr6 & DR_STEP) && !user_mode(regs)) {
444 tsk->thread.debugreg6 &= ~DR_STEP;
445 set_tsk_thread_flag(tsk, TIF_SINGLESTEP);
446 regs->flags &= ~X86_EFLAGS_TF;
447 }
448 si_code = get_si_code(tsk->thread.debugreg6);
449 if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp)
450 send_sigtrap(tsk, regs, error_code, si_code);
451 preempt_conditional_cli(regs);
452 debug_stack_usage_dec();
453
454 return;
455 }
456
457 /*
458 * Note that we play around with the 'TS' bit in an attempt to get
459 * the correct behaviour even in the presence of the asynchronous
460 * IRQ13 behaviour
461 */
math_error(struct pt_regs * regs,int error_code,int trapnr)462 void math_error(struct pt_regs *regs, int error_code, int trapnr)
463 {
464 struct task_struct *task = current;
465 siginfo_t info;
466 unsigned short err;
467 char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" :
468 "simd exception";
469
470 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP)
471 return;
472 conditional_sti(regs);
473
474 if (!user_mode_vm(regs))
475 {
476 if (!fixup_exception(regs)) {
477 task->thread.error_code = error_code;
478 task->thread.trap_nr = trapnr;
479 die(str, regs, error_code);
480 }
481 return;
482 }
483
484 /*
485 * Save the info for the exception handler and clear the error.
486 */
487 save_init_fpu(task);
488 task->thread.trap_nr = trapnr;
489 task->thread.error_code = error_code;
490 info.si_signo = SIGFPE;
491 info.si_errno = 0;
492 info.si_addr = (void __user *)regs->ip;
493 if (trapnr == X86_TRAP_MF) {
494 unsigned short cwd, swd;
495 /*
496 * (~cwd & swd) will mask out exceptions that are not set to unmasked
497 * status. 0x3f is the exception bits in these regs, 0x200 is the
498 * C1 reg you need in case of a stack fault, 0x040 is the stack
499 * fault bit. We should only be taking one exception at a time,
500 * so if this combination doesn't produce any single exception,
501 * then we have a bad program that isn't synchronizing its FPU usage
502 * and it will suffer the consequences since we won't be able to
503 * fully reproduce the context of the exception
504 */
505 cwd = get_fpu_cwd(task);
506 swd = get_fpu_swd(task);
507
508 err = swd & ~cwd;
509 } else {
510 /*
511 * The SIMD FPU exceptions are handled a little differently, as there
512 * is only a single status/control register. Thus, to determine which
513 * unmasked exception was caught we must mask the exception mask bits
514 * at 0x1f80, and then use these to mask the exception bits at 0x3f.
515 */
516 unsigned short mxcsr = get_fpu_mxcsr(task);
517 err = ~(mxcsr >> 7) & mxcsr;
518 }
519
520 if (err & 0x001) { /* Invalid op */
521 /*
522 * swd & 0x240 == 0x040: Stack Underflow
523 * swd & 0x240 == 0x240: Stack Overflow
524 * User must clear the SF bit (0x40) if set
525 */
526 info.si_code = FPE_FLTINV;
527 } else if (err & 0x004) { /* Divide by Zero */
528 info.si_code = FPE_FLTDIV;
529 } else if (err & 0x008) { /* Overflow */
530 info.si_code = FPE_FLTOVF;
531 } else if (err & 0x012) { /* Denormal, Underflow */
532 info.si_code = FPE_FLTUND;
533 } else if (err & 0x020) { /* Precision */
534 info.si_code = FPE_FLTRES;
535 } else {
536 /*
537 * If we're using IRQ 13, or supposedly even some trap
538 * X86_TRAP_MF implementations, it's possible
539 * we get a spurious trap, which is not an error.
540 */
541 return;
542 }
543 force_sig_info(SIGFPE, &info, task);
544 }
545
do_coprocessor_error(struct pt_regs * regs,long error_code)546 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code)
547 {
548 #ifdef CONFIG_X86_32
549 ignore_fpu_irq = 1;
550 #endif
551
552 math_error(regs, error_code, X86_TRAP_MF);
553 }
554
555 dotraplinkage void
do_simd_coprocessor_error(struct pt_regs * regs,long error_code)556 do_simd_coprocessor_error(struct pt_regs *regs, long error_code)
557 {
558 math_error(regs, error_code, X86_TRAP_XF);
559 }
560
561 dotraplinkage void
do_spurious_interrupt_bug(struct pt_regs * regs,long error_code)562 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code)
563 {
564 conditional_sti(regs);
565 #if 0
566 /* No need to warn about this any longer. */
567 printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n");
568 #endif
569 }
570
smp_thermal_interrupt(void)571 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void)
572 {
573 }
574
smp_threshold_interrupt(void)575 asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void)
576 {
577 }
578
579 /*
580 * 'math_state_restore()' saves the current math information in the
581 * old math state array, and gets the new ones from the current task
582 *
583 * Careful.. There are problems with IBM-designed IRQ13 behaviour.
584 * Don't touch unless you *really* know how it works.
585 *
586 * Must be called with kernel preemption disabled (eg with local
587 * local interrupts as in the case of do_device_not_available).
588 */
math_state_restore(void)589 void math_state_restore(void)
590 {
591 struct task_struct *tsk = current;
592
593 if (!tsk_used_math(tsk)) {
594 local_irq_enable();
595 /*
596 * does a slab alloc which can sleep
597 */
598 if (init_fpu(tsk)) {
599 /*
600 * ran out of memory!
601 */
602 do_group_exit(SIGKILL);
603 return;
604 }
605 local_irq_disable();
606 }
607
608 __thread_fpu_begin(tsk);
609 /*
610 * Paranoid restore. send a SIGSEGV if we fail to restore the state.
611 */
612 if (unlikely(restore_fpu_checking(tsk))) {
613 __thread_fpu_end(tsk);
614 force_sig(SIGSEGV, tsk);
615 return;
616 }
617
618 tsk->fpu_counter++;
619 }
620 EXPORT_SYMBOL_GPL(math_state_restore);
621
622 dotraplinkage void __kprobes
do_device_not_available(struct pt_regs * regs,long error_code)623 do_device_not_available(struct pt_regs *regs, long error_code)
624 {
625 #ifdef CONFIG_MATH_EMULATION
626 if (read_cr0() & X86_CR0_EM) {
627 struct math_emu_info info = { };
628
629 conditional_sti(regs);
630
631 info.regs = regs;
632 math_emulate(&info);
633 return;
634 }
635 #endif
636 math_state_restore(); /* interrupts still off */
637 #ifdef CONFIG_X86_32
638 conditional_sti(regs);
639 #endif
640 }
641
642 #ifdef CONFIG_X86_32
do_iret_error(struct pt_regs * regs,long error_code)643 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code)
644 {
645 siginfo_t info;
646 local_irq_enable();
647
648 info.si_signo = SIGILL;
649 info.si_errno = 0;
650 info.si_code = ILL_BADSTK;
651 info.si_addr = NULL;
652 if (notify_die(DIE_TRAP, "iret exception", regs, error_code,
653 X86_TRAP_IRET, SIGILL) == NOTIFY_STOP)
654 return;
655 do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code,
656 &info);
657 }
658 #endif
659
660 /* Set of traps needed for early debugging. */
early_trap_init(void)661 void __init early_trap_init(void)
662 {
663 set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK);
664 /* int3 can be called from all */
665 set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK);
666 set_intr_gate(X86_TRAP_PF, &page_fault);
667 load_idt(&idt_descr);
668 }
669
trap_init(void)670 void __init trap_init(void)
671 {
672 int i;
673
674 #ifdef CONFIG_EISA
675 void __iomem *p = early_ioremap(0x0FFFD9, 4);
676
677 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24))
678 EISA_bus = 1;
679 early_iounmap(p, 4);
680 #endif
681
682 set_intr_gate(X86_TRAP_DE, ÷_error);
683 set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK);
684 /* int4 can be called from all */
685 set_system_intr_gate(X86_TRAP_OF, &overflow);
686 set_intr_gate(X86_TRAP_BR, &bounds);
687 set_intr_gate(X86_TRAP_UD, &invalid_op);
688 set_intr_gate(X86_TRAP_NM, &device_not_available);
689 #ifdef CONFIG_X86_32
690 set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS);
691 #else
692 set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK);
693 #endif
694 set_intr_gate(X86_TRAP_OLD_MF, &coprocessor_segment_overrun);
695 set_intr_gate(X86_TRAP_TS, &invalid_TSS);
696 set_intr_gate(X86_TRAP_NP, &segment_not_present);
697 set_intr_gate_ist(X86_TRAP_SS, &stack_segment, STACKFAULT_STACK);
698 set_intr_gate(X86_TRAP_GP, &general_protection);
699 set_intr_gate(X86_TRAP_SPURIOUS, &spurious_interrupt_bug);
700 set_intr_gate(X86_TRAP_MF, &coprocessor_error);
701 set_intr_gate(X86_TRAP_AC, &alignment_check);
702 #ifdef CONFIG_X86_MCE
703 set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK);
704 #endif
705 set_intr_gate(X86_TRAP_XF, &simd_coprocessor_error);
706
707 /* Reserve all the builtin and the syscall vector: */
708 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
709 set_bit(i, used_vectors);
710
711 #ifdef CONFIG_IA32_EMULATION
712 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall);
713 set_bit(IA32_SYSCALL_VECTOR, used_vectors);
714 #endif
715
716 #ifdef CONFIG_X86_32
717 set_system_trap_gate(SYSCALL_VECTOR, &system_call);
718 set_bit(SYSCALL_VECTOR, used_vectors);
719 #endif
720
721 /*
722 * Should be a barrier for any external CPU state:
723 */
724 cpu_init();
725
726 x86_init.irqs.trap_init();
727
728 #ifdef CONFIG_X86_64
729 memcpy(&nmi_idt_table, &idt_table, IDT_ENTRIES * 16);
730 set_nmi_gate(X86_TRAP_DB, &debug);
731 set_nmi_gate(X86_TRAP_BP, &int3);
732 #endif
733 }
734