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 13 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 14 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/string.h> 27 #include <linux/delay.h> 28 #include <linux/errno.h> 29 #include <linux/kexec.h> 30 #include <linux/sched.h> 31 #include <linux/timer.h> 32 #include <linux/init.h> 33 #include <linux/bug.h> 34 #include <linux/nmi.h> 35 #include <linux/mm.h> 36 #include <linux/smp.h> 37 #include <linux/io.h> 38 39 #ifdef CONFIG_EISA 40 #include <linux/ioport.h> 41 #include <linux/eisa.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/ftrace.h> 54 #include <asm/traps.h> 55 #include <asm/desc.h> 56 #include <asm/i387.h> 57 #include <asm/fpu-internal.h> 58 #include <asm/mce.h> 59 #include <asm/fixmap.h> 60 #include <asm/mach_traps.h> 61 #include <asm/alternative.h> 62 63 #ifdef CONFIG_X86_64 64 #include <asm/x86_init.h> 65 #include <asm/pgalloc.h> 66 #include <asm/proto.h> 67 68 /* No need to be aligned, but done to keep all IDTs defined the same way. */ 69 gate_desc debug_idt_table[NR_VECTORS] __page_aligned_bss; 70 #else 71 #include <asm/processor-flags.h> 72 #include <asm/setup.h> 73 74 asmlinkage int system_call(void); 75 #endif 76 77 /* Must be page-aligned because the real IDT is used in a fixmap. */ 78 gate_desc idt_table[NR_VECTORS] __page_aligned_bss; 79 80 DECLARE_BITMAP(used_vectors, NR_VECTORS); 81 EXPORT_SYMBOL_GPL(used_vectors); 82 83 static inline void conditional_sti(struct pt_regs *regs) 84 { 85 if (regs->flags & X86_EFLAGS_IF) 86 local_irq_enable(); 87 } 88 89 static inline void preempt_conditional_sti(struct pt_regs *regs) 90 { 91 preempt_count_inc(); 92 if (regs->flags & X86_EFLAGS_IF) 93 local_irq_enable(); 94 } 95 96 static inline void conditional_cli(struct pt_regs *regs) 97 { 98 if (regs->flags & X86_EFLAGS_IF) 99 local_irq_disable(); 100 } 101 102 static inline void preempt_conditional_cli(struct pt_regs *regs) 103 { 104 if (regs->flags & X86_EFLAGS_IF) 105 local_irq_disable(); 106 preempt_count_dec(); 107 } 108 109 static int __kprobes 110 do_trap_no_signal(struct task_struct *tsk, int trapnr, char *str, 111 struct pt_regs *regs, long error_code) 112 { 113 #ifdef CONFIG_X86_32 114 if (regs->flags & X86_VM_MASK) { 115 /* 116 * Traps 0, 1, 3, 4, and 5 should be forwarded to vm86. 117 * On nmi (interrupt 2), do_trap should not be called. 118 */ 119 if (trapnr < X86_TRAP_UD) { 120 if (!handle_vm86_trap((struct kernel_vm86_regs *) regs, 121 error_code, trapnr)) 122 return 0; 123 } 124 return -1; 125 } 126 #endif 127 if (!user_mode(regs)) { 128 if (!fixup_exception(regs)) { 129 tsk->thread.error_code = error_code; 130 tsk->thread.trap_nr = trapnr; 131 die(str, regs, error_code); 132 } 133 return 0; 134 } 135 136 return -1; 137 } 138 139 static void __kprobes 140 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, 141 long error_code, siginfo_t *info) 142 { 143 struct task_struct *tsk = current; 144 145 146 if (!do_trap_no_signal(tsk, trapnr, str, regs, error_code)) 147 return; 148 /* 149 * We want error_code and trap_nr 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. 156 */ 157 tsk->thread.error_code = error_code; 158 tsk->thread.trap_nr = trapnr; 159 160 #ifdef CONFIG_X86_64 161 if (show_unhandled_signals && unhandled_signal(tsk, signr) && 162 printk_ratelimit()) { 163 pr_info("%s[%d] trap %s ip:%lx sp:%lx error:%lx", 164 tsk->comm, tsk->pid, str, 165 regs->ip, regs->sp, error_code); 166 print_vma_addr(" in ", regs->ip); 167 pr_cont("\n"); 168 } 169 #endif 170 171 if (info) 172 force_sig_info(signr, info, tsk); 173 else 174 force_sig(signr, tsk); 175 } 176 177 #define DO_ERROR(trapnr, signr, str, name) \ 178 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 179 { \ 180 enum ctx_state prev_state; \ 181 \ 182 prev_state = exception_enter(); \ 183 if (notify_die(DIE_TRAP, str, regs, error_code, \ 184 trapnr, signr) == NOTIFY_STOP) { \ 185 exception_exit(prev_state); \ 186 return; \ 187 } \ 188 conditional_sti(regs); \ 189 do_trap(trapnr, signr, str, regs, error_code, NULL); \ 190 exception_exit(prev_state); \ 191 } 192 193 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ 194 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 195 { \ 196 siginfo_t info; \ 197 enum ctx_state prev_state; \ 198 \ 199 info.si_signo = signr; \ 200 info.si_errno = 0; \ 201 info.si_code = sicode; \ 202 info.si_addr = (void __user *)siaddr; \ 203 prev_state = exception_enter(); \ 204 if (notify_die(DIE_TRAP, str, regs, error_code, \ 205 trapnr, signr) == NOTIFY_STOP) { \ 206 exception_exit(prev_state); \ 207 return; \ 208 } \ 209 conditional_sti(regs); \ 210 do_trap(trapnr, signr, str, regs, error_code, &info); \ 211 exception_exit(prev_state); \ 212 } 213 214 DO_ERROR_INFO(X86_TRAP_DE, SIGFPE, "divide error", divide_error, FPE_INTDIV, 215 regs->ip) 216 DO_ERROR(X86_TRAP_OF, SIGSEGV, "overflow", overflow) 217 DO_ERROR(X86_TRAP_BR, SIGSEGV, "bounds", bounds) 218 DO_ERROR_INFO(X86_TRAP_UD, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, 219 regs->ip) 220 DO_ERROR(X86_TRAP_OLD_MF, SIGFPE, "coprocessor segment overrun", 221 coprocessor_segment_overrun) 222 DO_ERROR(X86_TRAP_TS, SIGSEGV, "invalid TSS", invalid_TSS) 223 DO_ERROR(X86_TRAP_NP, SIGBUS, "segment not present", segment_not_present) 224 #ifdef CONFIG_X86_32 225 DO_ERROR(X86_TRAP_SS, SIGBUS, "stack segment", stack_segment) 226 #endif 227 DO_ERROR_INFO(X86_TRAP_AC, SIGBUS, "alignment check", alignment_check, 228 BUS_ADRALN, 0) 229 230 #ifdef CONFIG_X86_64 231 /* Runs on IST stack */ 232 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) 233 { 234 enum ctx_state prev_state; 235 236 prev_state = exception_enter(); 237 if (notify_die(DIE_TRAP, "stack segment", regs, error_code, 238 X86_TRAP_SS, SIGBUS) != NOTIFY_STOP) { 239 preempt_conditional_sti(regs); 240 do_trap(X86_TRAP_SS, SIGBUS, "stack segment", regs, error_code, NULL); 241 preempt_conditional_cli(regs); 242 } 243 exception_exit(prev_state); 244 } 245 246 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) 247 { 248 static const char str[] = "double fault"; 249 struct task_struct *tsk = current; 250 251 exception_enter(); 252 /* Return not checked because double check cannot be ignored */ 253 notify_die(DIE_TRAP, str, regs, error_code, X86_TRAP_DF, SIGSEGV); 254 255 tsk->thread.error_code = error_code; 256 tsk->thread.trap_nr = X86_TRAP_DF; 257 258 #ifdef CONFIG_DOUBLEFAULT 259 df_debug(regs, error_code); 260 #endif 261 /* 262 * This is always a kernel trap and never fixable (and thus must 263 * never return). 264 */ 265 for (;;) 266 die(str, regs, error_code); 267 } 268 #endif 269 270 dotraplinkage void __kprobes 271 do_general_protection(struct pt_regs *regs, long error_code) 272 { 273 struct task_struct *tsk; 274 enum ctx_state prev_state; 275 276 prev_state = exception_enter(); 277 conditional_sti(regs); 278 279 #ifdef CONFIG_X86_32 280 if (regs->flags & X86_VM_MASK) { 281 local_irq_enable(); 282 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); 283 goto exit; 284 } 285 #endif 286 287 tsk = current; 288 if (!user_mode(regs)) { 289 if (fixup_exception(regs)) 290 goto exit; 291 292 tsk->thread.error_code = error_code; 293 tsk->thread.trap_nr = X86_TRAP_GP; 294 if (notify_die(DIE_GPF, "general protection fault", regs, error_code, 295 X86_TRAP_GP, SIGSEGV) != NOTIFY_STOP) 296 die("general protection fault", regs, error_code); 297 goto exit; 298 } 299 300 tsk->thread.error_code = error_code; 301 tsk->thread.trap_nr = X86_TRAP_GP; 302 303 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && 304 printk_ratelimit()) { 305 pr_info("%s[%d] general protection ip:%lx sp:%lx error:%lx", 306 tsk->comm, task_pid_nr(tsk), 307 regs->ip, regs->sp, error_code); 308 print_vma_addr(" in ", regs->ip); 309 pr_cont("\n"); 310 } 311 312 force_sig(SIGSEGV, tsk); 313 exit: 314 exception_exit(prev_state); 315 } 316 317 /* May run on IST stack. */ 318 dotraplinkage void __kprobes notrace do_int3(struct pt_regs *regs, long error_code) 319 { 320 enum ctx_state prev_state; 321 322 #ifdef CONFIG_DYNAMIC_FTRACE 323 /* 324 * ftrace must be first, everything else may cause a recursive crash. 325 * See note by declaration of modifying_ftrace_code in ftrace.c 326 */ 327 if (unlikely(atomic_read(&modifying_ftrace_code)) && 328 ftrace_int3_handler(regs)) 329 return; 330 #endif 331 if (poke_int3_handler(regs)) 332 return; 333 334 prev_state = exception_enter(); 335 #ifdef CONFIG_KGDB_LOW_LEVEL_TRAP 336 if (kgdb_ll_trap(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, 337 SIGTRAP) == NOTIFY_STOP) 338 goto exit; 339 #endif /* CONFIG_KGDB_LOW_LEVEL_TRAP */ 340 341 if (notify_die(DIE_INT3, "int3", regs, error_code, X86_TRAP_BP, 342 SIGTRAP) == NOTIFY_STOP) 343 goto exit; 344 345 /* 346 * Let others (NMI) know that the debug stack is in use 347 * as we may switch to the interrupt stack. 348 */ 349 debug_stack_usage_inc(); 350 preempt_conditional_sti(regs); 351 do_trap(X86_TRAP_BP, SIGTRAP, "int3", regs, error_code, NULL); 352 preempt_conditional_cli(regs); 353 debug_stack_usage_dec(); 354 exit: 355 exception_exit(prev_state); 356 } 357 358 #ifdef CONFIG_X86_64 359 /* 360 * Help handler running on IST stack to switch back to user stack 361 * for scheduling or signal handling. The actual stack switch is done in 362 * entry.S 363 */ 364 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) 365 { 366 struct pt_regs *regs = eregs; 367 /* Did already sync */ 368 if (eregs == (struct pt_regs *)eregs->sp) 369 ; 370 /* Exception from user space */ 371 else if (user_mode(eregs)) 372 regs = task_pt_regs(current); 373 /* 374 * Exception from kernel and interrupts are enabled. Move to 375 * kernel process stack. 376 */ 377 else if (eregs->flags & X86_EFLAGS_IF) 378 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs)); 379 if (eregs != regs) 380 *regs = *eregs; 381 return regs; 382 } 383 #endif 384 385 /* 386 * Our handling of the processor debug registers is non-trivial. 387 * We do not clear them on entry and exit from the kernel. Therefore 388 * it is possible to get a watchpoint trap here from inside the kernel. 389 * However, the code in ./ptrace.c has ensured that the user can 390 * only set watchpoints on userspace addresses. Therefore the in-kernel 391 * watchpoint trap can only occur in code which is reading/writing 392 * from user space. Such code must not hold kernel locks (since it 393 * can equally take a page fault), therefore it is safe to call 394 * force_sig_info even though that claims and releases locks. 395 * 396 * Code in ./signal.c ensures that the debug control register 397 * is restored before we deliver any signal, and therefore that 398 * user code runs with the correct debug control register even though 399 * we clear it here. 400 * 401 * Being careful here means that we don't have to be as careful in a 402 * lot of more complicated places (task switching can be a bit lazy 403 * about restoring all the debug state, and ptrace doesn't have to 404 * find every occurrence of the TF bit that could be saved away even 405 * by user code) 406 * 407 * May run on IST stack. 408 */ 409 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) 410 { 411 struct task_struct *tsk = current; 412 enum ctx_state prev_state; 413 int user_icebp = 0; 414 unsigned long dr6; 415 int si_code; 416 417 prev_state = exception_enter(); 418 419 get_debugreg(dr6, 6); 420 421 /* Filter out all the reserved bits which are preset to 1 */ 422 dr6 &= ~DR6_RESERVED; 423 424 /* 425 * If dr6 has no reason to give us about the origin of this trap, 426 * then it's very likely the result of an icebp/int01 trap. 427 * User wants a sigtrap for that. 428 */ 429 if (!dr6 && user_mode(regs)) 430 user_icebp = 1; 431 432 /* Catch kmemcheck conditions first of all! */ 433 if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) 434 goto exit; 435 436 /* DR6 may or may not be cleared by the CPU */ 437 set_debugreg(0, 6); 438 439 /* 440 * The processor cleared BTF, so don't mark that we need it set. 441 */ 442 clear_tsk_thread_flag(tsk, TIF_BLOCKSTEP); 443 444 /* Store the virtualized DR6 value */ 445 tsk->thread.debugreg6 = dr6; 446 447 if (notify_die(DIE_DEBUG, "debug", regs, (long)&dr6, error_code, 448 SIGTRAP) == NOTIFY_STOP) 449 goto exit; 450 451 /* 452 * Let others (NMI) know that the debug stack is in use 453 * as we may switch to the interrupt stack. 454 */ 455 debug_stack_usage_inc(); 456 457 /* It's safe to allow irq's after DR6 has been saved */ 458 preempt_conditional_sti(regs); 459 460 if (regs->flags & X86_VM_MASK) { 461 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 462 X86_TRAP_DB); 463 preempt_conditional_cli(regs); 464 debug_stack_usage_dec(); 465 goto exit; 466 } 467 468 /* 469 * Single-stepping through system calls: ignore any exceptions in 470 * kernel space, but re-enable TF when returning to user mode. 471 * 472 * We already checked v86 mode above, so we can check for kernel mode 473 * by just checking the CPL of CS. 474 */ 475 if ((dr6 & DR_STEP) && !user_mode(regs)) { 476 tsk->thread.debugreg6 &= ~DR_STEP; 477 set_tsk_thread_flag(tsk, TIF_SINGLESTEP); 478 regs->flags &= ~X86_EFLAGS_TF; 479 } 480 si_code = get_si_code(tsk->thread.debugreg6); 481 if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS) || user_icebp) 482 send_sigtrap(tsk, regs, error_code, si_code); 483 preempt_conditional_cli(regs); 484 debug_stack_usage_dec(); 485 486 exit: 487 exception_exit(prev_state); 488 } 489 490 /* 491 * Note that we play around with the 'TS' bit in an attempt to get 492 * the correct behaviour even in the presence of the asynchronous 493 * IRQ13 behaviour 494 */ 495 void math_error(struct pt_regs *regs, int error_code, int trapnr) 496 { 497 struct task_struct *task = current; 498 siginfo_t info; 499 unsigned short err; 500 char *str = (trapnr == X86_TRAP_MF) ? "fpu exception" : 501 "simd exception"; 502 503 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, SIGFPE) == NOTIFY_STOP) 504 return; 505 conditional_sti(regs); 506 507 if (!user_mode_vm(regs)) 508 { 509 if (!fixup_exception(regs)) { 510 task->thread.error_code = error_code; 511 task->thread.trap_nr = trapnr; 512 die(str, regs, error_code); 513 } 514 return; 515 } 516 517 /* 518 * Save the info for the exception handler and clear the error. 519 */ 520 save_init_fpu(task); 521 task->thread.trap_nr = trapnr; 522 task->thread.error_code = error_code; 523 info.si_signo = SIGFPE; 524 info.si_errno = 0; 525 info.si_addr = (void __user *)regs->ip; 526 if (trapnr == X86_TRAP_MF) { 527 unsigned short cwd, swd; 528 /* 529 * (~cwd & swd) will mask out exceptions that are not set to unmasked 530 * status. 0x3f is the exception bits in these regs, 0x200 is the 531 * C1 reg you need in case of a stack fault, 0x040 is the stack 532 * fault bit. We should only be taking one exception at a time, 533 * so if this combination doesn't produce any single exception, 534 * then we have a bad program that isn't synchronizing its FPU usage 535 * and it will suffer the consequences since we won't be able to 536 * fully reproduce the context of the exception 537 */ 538 cwd = get_fpu_cwd(task); 539 swd = get_fpu_swd(task); 540 541 err = swd & ~cwd; 542 } else { 543 /* 544 * The SIMD FPU exceptions are handled a little differently, as there 545 * is only a single status/control register. Thus, to determine which 546 * unmasked exception was caught we must mask the exception mask bits 547 * at 0x1f80, and then use these to mask the exception bits at 0x3f. 548 */ 549 unsigned short mxcsr = get_fpu_mxcsr(task); 550 err = ~(mxcsr >> 7) & mxcsr; 551 } 552 553 if (err & 0x001) { /* Invalid op */ 554 /* 555 * swd & 0x240 == 0x040: Stack Underflow 556 * swd & 0x240 == 0x240: Stack Overflow 557 * User must clear the SF bit (0x40) if set 558 */ 559 info.si_code = FPE_FLTINV; 560 } else if (err & 0x004) { /* Divide by Zero */ 561 info.si_code = FPE_FLTDIV; 562 } else if (err & 0x008) { /* Overflow */ 563 info.si_code = FPE_FLTOVF; 564 } else if (err & 0x012) { /* Denormal, Underflow */ 565 info.si_code = FPE_FLTUND; 566 } else if (err & 0x020) { /* Precision */ 567 info.si_code = FPE_FLTRES; 568 } else { 569 /* 570 * If we're using IRQ 13, or supposedly even some trap 571 * X86_TRAP_MF implementations, it's possible 572 * we get a spurious trap, which is not an error. 573 */ 574 return; 575 } 576 force_sig_info(SIGFPE, &info, task); 577 } 578 579 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) 580 { 581 enum ctx_state prev_state; 582 583 prev_state = exception_enter(); 584 math_error(regs, error_code, X86_TRAP_MF); 585 exception_exit(prev_state); 586 } 587 588 dotraplinkage void 589 do_simd_coprocessor_error(struct pt_regs *regs, long error_code) 590 { 591 enum ctx_state prev_state; 592 593 prev_state = exception_enter(); 594 math_error(regs, error_code, X86_TRAP_XF); 595 exception_exit(prev_state); 596 } 597 598 dotraplinkage void 599 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) 600 { 601 conditional_sti(regs); 602 #if 0 603 /* No need to warn about this any longer. */ 604 pr_info("Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); 605 #endif 606 } 607 608 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) 609 { 610 } 611 612 asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void) 613 { 614 } 615 616 /* 617 * 'math_state_restore()' saves the current math information in the 618 * old math state array, and gets the new ones from the current task 619 * 620 * Careful.. There are problems with IBM-designed IRQ13 behaviour. 621 * Don't touch unless you *really* know how it works. 622 * 623 * Must be called with kernel preemption disabled (eg with local 624 * local interrupts as in the case of do_device_not_available). 625 */ 626 void math_state_restore(void) 627 { 628 struct task_struct *tsk = current; 629 630 if (!tsk_used_math(tsk)) { 631 local_irq_enable(); 632 /* 633 * does a slab alloc which can sleep 634 */ 635 if (init_fpu(tsk)) { 636 /* 637 * ran out of memory! 638 */ 639 do_group_exit(SIGKILL); 640 return; 641 } 642 local_irq_disable(); 643 } 644 645 __thread_fpu_begin(tsk); 646 647 /* 648 * Paranoid restore. send a SIGSEGV if we fail to restore the state. 649 */ 650 if (unlikely(restore_fpu_checking(tsk))) { 651 drop_init_fpu(tsk); 652 force_sig(SIGSEGV, tsk); 653 return; 654 } 655 656 tsk->thread.fpu_counter++; 657 } 658 EXPORT_SYMBOL_GPL(math_state_restore); 659 660 dotraplinkage void __kprobes 661 do_device_not_available(struct pt_regs *regs, long error_code) 662 { 663 enum ctx_state prev_state; 664 665 prev_state = exception_enter(); 666 BUG_ON(use_eager_fpu()); 667 668 #ifdef CONFIG_MATH_EMULATION 669 if (read_cr0() & X86_CR0_EM) { 670 struct math_emu_info info = { }; 671 672 conditional_sti(regs); 673 674 info.regs = regs; 675 math_emulate(&info); 676 exception_exit(prev_state); 677 return; 678 } 679 #endif 680 math_state_restore(); /* interrupts still off */ 681 #ifdef CONFIG_X86_32 682 conditional_sti(regs); 683 #endif 684 exception_exit(prev_state); 685 } 686 687 #ifdef CONFIG_X86_32 688 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) 689 { 690 siginfo_t info; 691 enum ctx_state prev_state; 692 693 prev_state = exception_enter(); 694 local_irq_enable(); 695 696 info.si_signo = SIGILL; 697 info.si_errno = 0; 698 info.si_code = ILL_BADSTK; 699 info.si_addr = NULL; 700 if (notify_die(DIE_TRAP, "iret exception", regs, error_code, 701 X86_TRAP_IRET, SIGILL) != NOTIFY_STOP) { 702 do_trap(X86_TRAP_IRET, SIGILL, "iret exception", regs, error_code, 703 &info); 704 } 705 exception_exit(prev_state); 706 } 707 #endif 708 709 /* Set of traps needed for early debugging. */ 710 void __init early_trap_init(void) 711 { 712 set_intr_gate_ist(X86_TRAP_DB, &debug, DEBUG_STACK); 713 /* int3 can be called from all */ 714 set_system_intr_gate_ist(X86_TRAP_BP, &int3, DEBUG_STACK); 715 #ifdef CONFIG_X86_32 716 set_intr_gate(X86_TRAP_PF, page_fault); 717 #endif 718 load_idt(&idt_descr); 719 } 720 721 void __init early_trap_pf_init(void) 722 { 723 #ifdef CONFIG_X86_64 724 set_intr_gate(X86_TRAP_PF, page_fault); 725 #endif 726 } 727 728 void __init trap_init(void) 729 { 730 int i; 731 732 #ifdef CONFIG_EISA 733 void __iomem *p = early_ioremap(0x0FFFD9, 4); 734 735 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) 736 EISA_bus = 1; 737 early_iounmap(p, 4); 738 #endif 739 740 set_intr_gate(X86_TRAP_DE, divide_error); 741 set_intr_gate_ist(X86_TRAP_NMI, &nmi, NMI_STACK); 742 /* int4 can be called from all */ 743 set_system_intr_gate(X86_TRAP_OF, &overflow); 744 set_intr_gate(X86_TRAP_BR, bounds); 745 set_intr_gate(X86_TRAP_UD, invalid_op); 746 set_intr_gate(X86_TRAP_NM, device_not_available); 747 #ifdef CONFIG_X86_32 748 set_task_gate(X86_TRAP_DF, GDT_ENTRY_DOUBLEFAULT_TSS); 749 #else 750 set_intr_gate_ist(X86_TRAP_DF, &double_fault, DOUBLEFAULT_STACK); 751 #endif 752 set_intr_gate(X86_TRAP_OLD_MF, coprocessor_segment_overrun); 753 set_intr_gate(X86_TRAP_TS, invalid_TSS); 754 set_intr_gate(X86_TRAP_NP, segment_not_present); 755 set_intr_gate_ist(X86_TRAP_SS, &stack_segment, STACKFAULT_STACK); 756 set_intr_gate(X86_TRAP_GP, general_protection); 757 set_intr_gate(X86_TRAP_SPURIOUS, spurious_interrupt_bug); 758 set_intr_gate(X86_TRAP_MF, coprocessor_error); 759 set_intr_gate(X86_TRAP_AC, alignment_check); 760 #ifdef CONFIG_X86_MCE 761 set_intr_gate_ist(X86_TRAP_MC, &machine_check, MCE_STACK); 762 #endif 763 set_intr_gate(X86_TRAP_XF, simd_coprocessor_error); 764 765 /* Reserve all the builtin and the syscall vector: */ 766 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) 767 set_bit(i, used_vectors); 768 769 #ifdef CONFIG_IA32_EMULATION 770 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); 771 set_bit(IA32_SYSCALL_VECTOR, used_vectors); 772 #endif 773 774 #ifdef CONFIG_X86_32 775 set_system_trap_gate(SYSCALL_VECTOR, &system_call); 776 set_bit(SYSCALL_VECTOR, used_vectors); 777 #endif 778 779 /* 780 * Set the IDT descriptor to a fixed read-only location, so that the 781 * "sidt" instruction will not leak the location of the kernel, and 782 * to defend the IDT against arbitrary memory write vulnerabilities. 783 * It will be reloaded in cpu_init() */ 784 __set_fixmap(FIX_RO_IDT, __pa_symbol(idt_table), PAGE_KERNEL_RO); 785 idt_descr.address = fix_to_virt(FIX_RO_IDT); 786 787 /* 788 * Should be a barrier for any external CPU state: 789 */ 790 cpu_init(); 791 792 x86_init.irqs.trap_init(); 793 794 #ifdef CONFIG_X86_64 795 memcpy(&debug_idt_table, &idt_table, IDT_ENTRIES * 16); 796 set_nmi_gate(X86_TRAP_DB, &debug); 797 set_nmi_gate(X86_TRAP_BP, &int3); 798 #endif 799 } 800