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/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> 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/stacktrace.h> 49 #include <asm/processor.h> 50 #include <asm/debugreg.h> 51 #include <asm/atomic.h> 52 #include <asm/system.h> 53 #include <asm/traps.h> 54 #include <asm/desc.h> 55 #include <asm/i387.h> 56 57 #include <asm/mach_traps.h> 58 59 #ifdef CONFIG_X86_64 60 #include <asm/pgalloc.h> 61 #include <asm/proto.h> 62 #else 63 #include <asm/processor-flags.h> 64 #include <asm/setup.h> 65 #include <asm/traps.h> 66 67 #include "cpu/mcheck/mce.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.. We have a special link segment 77 * for this. 78 */ 79 gate_desc idt_table[256] 80 __attribute__((__section__(".data.idt"))) = { { { { 0, 0 } } }, }; 81 #endif 82 83 DECLARE_BITMAP(used_vectors, NR_VECTORS); 84 EXPORT_SYMBOL_GPL(used_vectors); 85 86 static int ignore_nmis; 87 88 static inline void conditional_sti(struct pt_regs *regs) 89 { 90 if (regs->flags & X86_EFLAGS_IF) 91 local_irq_enable(); 92 } 93 94 static inline void preempt_conditional_sti(struct pt_regs *regs) 95 { 96 inc_preempt_count(); 97 if (regs->flags & X86_EFLAGS_IF) 98 local_irq_enable(); 99 } 100 101 static inline void conditional_cli(struct pt_regs *regs) 102 { 103 if (regs->flags & X86_EFLAGS_IF) 104 local_irq_disable(); 105 } 106 107 static inline void preempt_conditional_cli(struct pt_regs *regs) 108 { 109 if (regs->flags & X86_EFLAGS_IF) 110 local_irq_disable(); 111 dec_preempt_count(); 112 } 113 114 #ifdef CONFIG_X86_32 115 static inline void 116 die_if_kernel(const char *str, struct pt_regs *regs, long err) 117 { 118 if (!user_mode_vm(regs)) 119 die(str, regs, err); 120 } 121 #endif 122 123 static void __kprobes 124 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, 125 long error_code, siginfo_t *info) 126 { 127 struct task_struct *tsk = current; 128 129 #ifdef CONFIG_X86_32 130 if (regs->flags & X86_VM_MASK) { 131 /* 132 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86. 133 * On nmi (interrupt 2), do_trap should not be called. 134 */ 135 if (trapnr < 6) 136 goto vm86_trap; 137 goto trap_signal; 138 } 139 #endif 140 141 if (!user_mode(regs)) 142 goto kernel_trap; 143 144 #ifdef CONFIG_X86_32 145 trap_signal: 146 #endif 147 /* 148 * We want error_code and trap_no set for userspace faults and 149 * kernelspace faults which result in die(), but not 150 * kernelspace faults which are fixed up. die() gives the 151 * process no chance to handle the signal and notice the 152 * kernel fault information, so that won't result in polluting 153 * the information about previously queued, but not yet 154 * delivered, faults. See also do_general_protection below. 155 */ 156 tsk->thread.error_code = error_code; 157 tsk->thread.trap_no = trapnr; 158 159 #ifdef CONFIG_X86_64 160 if (show_unhandled_signals && unhandled_signal(tsk, signr) && 161 printk_ratelimit()) { 162 printk(KERN_INFO 163 "%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 printk("\n"); 168 } 169 #endif 170 171 if (info) 172 force_sig_info(signr, info, tsk); 173 else 174 force_sig(signr, tsk); 175 return; 176 177 kernel_trap: 178 if (!fixup_exception(regs)) { 179 tsk->thread.error_code = error_code; 180 tsk->thread.trap_no = trapnr; 181 die(str, regs, error_code); 182 } 183 return; 184 185 #ifdef CONFIG_X86_32 186 vm86_trap: 187 if (handle_vm86_trap((struct kernel_vm86_regs *) regs, 188 error_code, trapnr)) 189 goto trap_signal; 190 return; 191 #endif 192 } 193 194 #define DO_ERROR(trapnr, signr, str, name) \ 195 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 196 { \ 197 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ 198 == NOTIFY_STOP) \ 199 return; \ 200 conditional_sti(regs); \ 201 do_trap(trapnr, signr, str, regs, error_code, NULL); \ 202 } 203 204 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ 205 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 206 { \ 207 siginfo_t info; \ 208 info.si_signo = signr; \ 209 info.si_errno = 0; \ 210 info.si_code = sicode; \ 211 info.si_addr = (void __user *)siaddr; \ 212 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ 213 == NOTIFY_STOP) \ 214 return; \ 215 conditional_sti(regs); \ 216 do_trap(trapnr, signr, str, regs, error_code, &info); \ 217 } 218 219 DO_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip) 220 DO_ERROR(4, SIGSEGV, "overflow", overflow) 221 DO_ERROR(5, SIGSEGV, "bounds", bounds) 222 DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip) 223 DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun) 224 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) 225 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) 226 #ifdef CONFIG_X86_32 227 DO_ERROR(12, SIGBUS, "stack segment", stack_segment) 228 #endif 229 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) 230 231 #ifdef CONFIG_X86_64 232 /* Runs on IST stack */ 233 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) 234 { 235 if (notify_die(DIE_TRAP, "stack segment", regs, error_code, 236 12, SIGBUS) == NOTIFY_STOP) 237 return; 238 preempt_conditional_sti(regs); 239 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL); 240 preempt_conditional_cli(regs); 241 } 242 243 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) 244 { 245 static const char str[] = "double fault"; 246 struct task_struct *tsk = current; 247 248 /* Return not checked because double check cannot be ignored */ 249 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV); 250 251 tsk->thread.error_code = error_code; 252 tsk->thread.trap_no = 8; 253 254 /* 255 * This is always a kernel trap and never fixable (and thus must 256 * never return). 257 */ 258 for (;;) 259 die(str, regs, error_code); 260 } 261 #endif 262 263 dotraplinkage void __kprobes 264 do_general_protection(struct pt_regs *regs, long error_code) 265 { 266 struct task_struct *tsk; 267 268 conditional_sti(regs); 269 270 #ifdef CONFIG_X86_32 271 if (regs->flags & X86_VM_MASK) 272 goto gp_in_vm86; 273 #endif 274 275 tsk = current; 276 if (!user_mode(regs)) 277 goto gp_in_kernel; 278 279 tsk->thread.error_code = error_code; 280 tsk->thread.trap_no = 13; 281 282 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && 283 printk_ratelimit()) { 284 printk(KERN_INFO 285 "%s[%d] general protection ip:%lx sp:%lx error:%lx", 286 tsk->comm, task_pid_nr(tsk), 287 regs->ip, regs->sp, error_code); 288 print_vma_addr(" in ", regs->ip); 289 printk("\n"); 290 } 291 292 force_sig(SIGSEGV, tsk); 293 return; 294 295 #ifdef CONFIG_X86_32 296 gp_in_vm86: 297 local_irq_enable(); 298 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); 299 return; 300 #endif 301 302 gp_in_kernel: 303 if (fixup_exception(regs)) 304 return; 305 306 tsk->thread.error_code = error_code; 307 tsk->thread.trap_no = 13; 308 if (notify_die(DIE_GPF, "general protection fault", regs, 309 error_code, 13, SIGSEGV) == NOTIFY_STOP) 310 return; 311 die("general protection fault", regs, error_code); 312 } 313 314 static notrace __kprobes void 315 mem_parity_error(unsigned char reason, struct pt_regs *regs) 316 { 317 printk(KERN_EMERG 318 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", 319 reason, smp_processor_id()); 320 321 printk(KERN_EMERG 322 "You have some hardware problem, likely on the PCI bus.\n"); 323 324 #if defined(CONFIG_EDAC) 325 if (edac_handler_set()) { 326 edac_atomic_assert_error(); 327 return; 328 } 329 #endif 330 331 if (panic_on_unrecovered_nmi) 332 panic("NMI: Not continuing"); 333 334 printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); 335 336 /* Clear and disable the memory parity error line. */ 337 reason = (reason & 0xf) | 4; 338 outb(reason, 0x61); 339 } 340 341 static notrace __kprobes void 342 io_check_error(unsigned char reason, struct pt_regs *regs) 343 { 344 unsigned long i; 345 346 printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n"); 347 show_registers(regs); 348 349 /* Re-enable the IOCK line, wait for a few seconds */ 350 reason = (reason & 0xf) | 8; 351 outb(reason, 0x61); 352 353 i = 2000; 354 while (--i) 355 udelay(1000); 356 357 reason &= ~8; 358 outb(reason, 0x61); 359 } 360 361 static notrace __kprobes void 362 unknown_nmi_error(unsigned char reason, struct pt_regs *regs) 363 { 364 if (notify_die(DIE_NMIUNKNOWN, "nmi", regs, reason, 2, SIGINT) == 365 NOTIFY_STOP) 366 return; 367 #ifdef CONFIG_MCA 368 /* 369 * Might actually be able to figure out what the guilty party 370 * is: 371 */ 372 if (MCA_bus) { 373 mca_handle_nmi(); 374 return; 375 } 376 #endif 377 printk(KERN_EMERG 378 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", 379 reason, smp_processor_id()); 380 381 printk(KERN_EMERG "Do you have a strange power saving mode enabled?\n"); 382 if (panic_on_unrecovered_nmi) 383 panic("NMI: Not continuing"); 384 385 printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); 386 } 387 388 static notrace __kprobes void default_do_nmi(struct pt_regs *regs) 389 { 390 unsigned char reason = 0; 391 int cpu; 392 393 cpu = smp_processor_id(); 394 395 /* Only the BSP gets external NMIs from the system. */ 396 if (!cpu) 397 reason = get_nmi_reason(); 398 399 if (!(reason & 0xc0)) { 400 if (notify_die(DIE_NMI_IPI, "nmi_ipi", regs, reason, 2, SIGINT) 401 == NOTIFY_STOP) 402 return; 403 #ifdef CONFIG_X86_LOCAL_APIC 404 /* 405 * Ok, so this is none of the documented NMI sources, 406 * so it must be the NMI watchdog. 407 */ 408 if (nmi_watchdog_tick(regs, reason)) 409 return; 410 if (!do_nmi_callback(regs, cpu)) 411 unknown_nmi_error(reason, regs); 412 #else 413 unknown_nmi_error(reason, regs); 414 #endif 415 416 return; 417 } 418 if (notify_die(DIE_NMI, "nmi", regs, reason, 2, SIGINT) == NOTIFY_STOP) 419 return; 420 421 /* AK: following checks seem to be broken on modern chipsets. FIXME */ 422 if (reason & 0x80) 423 mem_parity_error(reason, regs); 424 if (reason & 0x40) 425 io_check_error(reason, regs); 426 #ifdef CONFIG_X86_32 427 /* 428 * Reassert NMI in case it became active meanwhile 429 * as it's edge-triggered: 430 */ 431 reassert_nmi(); 432 #endif 433 } 434 435 dotraplinkage notrace __kprobes void 436 do_nmi(struct pt_regs *regs, long error_code) 437 { 438 nmi_enter(); 439 440 inc_irq_stat(__nmi_count); 441 442 if (!ignore_nmis) 443 default_do_nmi(regs); 444 445 nmi_exit(); 446 } 447 448 void stop_nmi(void) 449 { 450 acpi_nmi_disable(); 451 ignore_nmis++; 452 } 453 454 void restart_nmi(void) 455 { 456 ignore_nmis--; 457 acpi_nmi_enable(); 458 } 459 460 /* May run on IST stack. */ 461 dotraplinkage void __kprobes do_int3(struct pt_regs *regs, long error_code) 462 { 463 #ifdef CONFIG_KPROBES 464 if (notify_die(DIE_INT3, "int3", regs, error_code, 3, SIGTRAP) 465 == NOTIFY_STOP) 466 return; 467 #else 468 if (notify_die(DIE_TRAP, "int3", regs, error_code, 3, SIGTRAP) 469 == NOTIFY_STOP) 470 return; 471 #endif 472 473 preempt_conditional_sti(regs); 474 do_trap(3, SIGTRAP, "int3", regs, error_code, NULL); 475 preempt_conditional_cli(regs); 476 } 477 478 #ifdef CONFIG_X86_64 479 /* 480 * Help handler running on IST stack to switch back to user stack 481 * for scheduling or signal handling. The actual stack switch is done in 482 * entry.S 483 */ 484 asmlinkage __kprobes struct pt_regs *sync_regs(struct pt_regs *eregs) 485 { 486 struct pt_regs *regs = eregs; 487 /* Did already sync */ 488 if (eregs == (struct pt_regs *)eregs->sp) 489 ; 490 /* Exception from user space */ 491 else if (user_mode(eregs)) 492 regs = task_pt_regs(current); 493 /* 494 * Exception from kernel and interrupts are enabled. Move to 495 * kernel process stack. 496 */ 497 else if (eregs->flags & X86_EFLAGS_IF) 498 regs = (struct pt_regs *)(eregs->sp -= sizeof(struct pt_regs)); 499 if (eregs != regs) 500 *regs = *eregs; 501 return regs; 502 } 503 #endif 504 505 /* 506 * Our handling of the processor debug registers is non-trivial. 507 * We do not clear them on entry and exit from the kernel. Therefore 508 * it is possible to get a watchpoint trap here from inside the kernel. 509 * However, the code in ./ptrace.c has ensured that the user can 510 * only set watchpoints on userspace addresses. Therefore the in-kernel 511 * watchpoint trap can only occur in code which is reading/writing 512 * from user space. Such code must not hold kernel locks (since it 513 * can equally take a page fault), therefore it is safe to call 514 * force_sig_info even though that claims and releases locks. 515 * 516 * Code in ./signal.c ensures that the debug control register 517 * is restored before we deliver any signal, and therefore that 518 * user code runs with the correct debug control register even though 519 * we clear it here. 520 * 521 * Being careful here means that we don't have to be as careful in a 522 * lot of more complicated places (task switching can be a bit lazy 523 * about restoring all the debug state, and ptrace doesn't have to 524 * find every occurrence of the TF bit that could be saved away even 525 * by user code) 526 * 527 * May run on IST stack. 528 */ 529 dotraplinkage void __kprobes do_debug(struct pt_regs *regs, long error_code) 530 { 531 struct task_struct *tsk = current; 532 unsigned long condition; 533 int si_code; 534 535 get_debugreg(condition, 6); 536 537 /* 538 * The processor cleared BTF, so don't mark that we need it set. 539 */ 540 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR); 541 tsk->thread.debugctlmsr = 0; 542 543 if (notify_die(DIE_DEBUG, "debug", regs, condition, error_code, 544 SIGTRAP) == NOTIFY_STOP) 545 return; 546 547 /* It's safe to allow irq's after DR6 has been saved */ 548 preempt_conditional_sti(regs); 549 550 /* Mask out spurious debug traps due to lazy DR7 setting */ 551 if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) { 552 if (!tsk->thread.debugreg7) 553 goto clear_dr7; 554 } 555 556 #ifdef CONFIG_X86_32 557 if (regs->flags & X86_VM_MASK) 558 goto debug_vm86; 559 #endif 560 561 /* Save debug status register where ptrace can see it */ 562 tsk->thread.debugreg6 = condition; 563 564 /* 565 * Single-stepping through TF: make sure we ignore any events in 566 * kernel space (but re-enable TF when returning to user mode). 567 */ 568 if (condition & DR_STEP) { 569 if (!user_mode(regs)) 570 goto clear_TF_reenable; 571 } 572 573 si_code = get_si_code(condition); 574 /* Ok, finally something we can handle */ 575 send_sigtrap(tsk, regs, error_code, si_code); 576 577 /* 578 * Disable additional traps. They'll be re-enabled when 579 * the signal is delivered. 580 */ 581 clear_dr7: 582 set_debugreg(0, 7); 583 preempt_conditional_cli(regs); 584 return; 585 586 #ifdef CONFIG_X86_32 587 debug_vm86: 588 /* reenable preemption: handle_vm86_trap() might sleep */ 589 dec_preempt_count(); 590 handle_vm86_trap((struct kernel_vm86_regs *) regs, error_code, 1); 591 conditional_cli(regs); 592 return; 593 #endif 594 595 clear_TF_reenable: 596 set_tsk_thread_flag(tsk, TIF_SINGLESTEP); 597 regs->flags &= ~X86_EFLAGS_TF; 598 preempt_conditional_cli(regs); 599 return; 600 } 601 602 #ifdef CONFIG_X86_64 603 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr) 604 { 605 if (fixup_exception(regs)) 606 return 1; 607 608 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE); 609 /* Illegal floating point operation in the kernel */ 610 current->thread.trap_no = trapnr; 611 die(str, regs, 0); 612 return 0; 613 } 614 #endif 615 616 /* 617 * Note that we play around with the 'TS' bit in an attempt to get 618 * the correct behaviour even in the presence of the asynchronous 619 * IRQ13 behaviour 620 */ 621 void math_error(void __user *ip) 622 { 623 struct task_struct *task; 624 siginfo_t info; 625 unsigned short cwd, swd, err; 626 627 /* 628 * Save the info for the exception handler and clear the error. 629 */ 630 task = current; 631 save_init_fpu(task); 632 task->thread.trap_no = 16; 633 task->thread.error_code = 0; 634 info.si_signo = SIGFPE; 635 info.si_errno = 0; 636 info.si_addr = ip; 637 /* 638 * (~cwd & swd) will mask out exceptions that are not set to unmasked 639 * status. 0x3f is the exception bits in these regs, 0x200 is the 640 * C1 reg you need in case of a stack fault, 0x040 is the stack 641 * fault bit. We should only be taking one exception at a time, 642 * so if this combination doesn't produce any single exception, 643 * then we have a bad program that isn't synchronizing its FPU usage 644 * and it will suffer the consequences since we won't be able to 645 * fully reproduce the context of the exception 646 */ 647 cwd = get_fpu_cwd(task); 648 swd = get_fpu_swd(task); 649 650 err = swd & ~cwd; 651 652 if (err & 0x001) { /* Invalid op */ 653 /* 654 * swd & 0x240 == 0x040: Stack Underflow 655 * swd & 0x240 == 0x240: Stack Overflow 656 * User must clear the SF bit (0x40) if set 657 */ 658 info.si_code = FPE_FLTINV; 659 } else if (err & 0x004) { /* Divide by Zero */ 660 info.si_code = FPE_FLTDIV; 661 } else if (err & 0x008) { /* Overflow */ 662 info.si_code = FPE_FLTOVF; 663 } else if (err & 0x012) { /* Denormal, Underflow */ 664 info.si_code = FPE_FLTUND; 665 } else if (err & 0x020) { /* Precision */ 666 info.si_code = FPE_FLTRES; 667 } else { 668 /* 669 * If we're using IRQ 13, or supposedly even some trap 16 670 * implementations, it's possible we get a spurious trap... 671 */ 672 return; /* Spurious trap, no error */ 673 } 674 force_sig_info(SIGFPE, &info, task); 675 } 676 677 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) 678 { 679 conditional_sti(regs); 680 681 #ifdef CONFIG_X86_32 682 ignore_fpu_irq = 1; 683 #else 684 if (!user_mode(regs) && 685 kernel_math_error(regs, "kernel x87 math error", 16)) 686 return; 687 #endif 688 689 math_error((void __user *)regs->ip); 690 } 691 692 static void simd_math_error(void __user *ip) 693 { 694 struct task_struct *task; 695 siginfo_t info; 696 unsigned short mxcsr; 697 698 /* 699 * Save the info for the exception handler and clear the error. 700 */ 701 task = current; 702 save_init_fpu(task); 703 task->thread.trap_no = 19; 704 task->thread.error_code = 0; 705 info.si_signo = SIGFPE; 706 info.si_errno = 0; 707 info.si_code = __SI_FAULT; 708 info.si_addr = ip; 709 /* 710 * The SIMD FPU exceptions are handled a little differently, as there 711 * is only a single status/control register. Thus, to determine which 712 * unmasked exception was caught we must mask the exception mask bits 713 * at 0x1f80, and then use these to mask the exception bits at 0x3f. 714 */ 715 mxcsr = get_fpu_mxcsr(task); 716 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) { 717 case 0x000: 718 default: 719 break; 720 case 0x001: /* Invalid Op */ 721 info.si_code = FPE_FLTINV; 722 break; 723 case 0x002: /* Denormalize */ 724 case 0x010: /* Underflow */ 725 info.si_code = FPE_FLTUND; 726 break; 727 case 0x004: /* Zero Divide */ 728 info.si_code = FPE_FLTDIV; 729 break; 730 case 0x008: /* Overflow */ 731 info.si_code = FPE_FLTOVF; 732 break; 733 case 0x020: /* Precision */ 734 info.si_code = FPE_FLTRES; 735 break; 736 } 737 force_sig_info(SIGFPE, &info, task); 738 } 739 740 dotraplinkage void 741 do_simd_coprocessor_error(struct pt_regs *regs, long error_code) 742 { 743 conditional_sti(regs); 744 745 #ifdef CONFIG_X86_32 746 if (cpu_has_xmm) { 747 /* Handle SIMD FPU exceptions on PIII+ processors. */ 748 ignore_fpu_irq = 1; 749 simd_math_error((void __user *)regs->ip); 750 return; 751 } 752 /* 753 * Handle strange cache flush from user space exception 754 * in all other cases. This is undocumented behaviour. 755 */ 756 if (regs->flags & X86_VM_MASK) { 757 handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code); 758 return; 759 } 760 current->thread.trap_no = 19; 761 current->thread.error_code = error_code; 762 die_if_kernel("cache flush denied", regs, error_code); 763 force_sig(SIGSEGV, current); 764 #else 765 if (!user_mode(regs) && 766 kernel_math_error(regs, "kernel simd math error", 19)) 767 return; 768 simd_math_error((void __user *)regs->ip); 769 #endif 770 } 771 772 dotraplinkage void 773 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) 774 { 775 conditional_sti(regs); 776 #if 0 777 /* No need to warn about this any longer. */ 778 printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); 779 #endif 780 } 781 782 #ifdef CONFIG_X86_32 783 unsigned long patch_espfix_desc(unsigned long uesp, unsigned long kesp) 784 { 785 struct desc_struct *gdt = get_cpu_gdt_table(smp_processor_id()); 786 unsigned long base = (kesp - uesp) & -THREAD_SIZE; 787 unsigned long new_kesp = kesp - base; 788 unsigned long lim_pages = (new_kesp | (THREAD_SIZE - 1)) >> PAGE_SHIFT; 789 __u64 desc = *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS]; 790 791 /* Set up base for espfix segment */ 792 desc &= 0x00f0ff0000000000ULL; 793 desc |= ((((__u64)base) << 16) & 0x000000ffffff0000ULL) | 794 ((((__u64)base) << 32) & 0xff00000000000000ULL) | 795 ((((__u64)lim_pages) << 32) & 0x000f000000000000ULL) | 796 (lim_pages & 0xffff); 797 *(__u64 *)&gdt[GDT_ENTRY_ESPFIX_SS] = desc; 798 799 return new_kesp; 800 } 801 #else 802 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) 803 { 804 } 805 806 asmlinkage void __attribute__((weak)) mce_threshold_interrupt(void) 807 { 808 } 809 #endif 810 811 /* 812 * 'math_state_restore()' saves the current math information in the 813 * old math state array, and gets the new ones from the current task 814 * 815 * Careful.. There are problems with IBM-designed IRQ13 behaviour. 816 * Don't touch unless you *really* know how it works. 817 * 818 * Must be called with kernel preemption disabled (in this case, 819 * local interrupts are disabled at the call-site in entry.S). 820 */ 821 asmlinkage void math_state_restore(void) 822 { 823 struct thread_info *thread = current_thread_info(); 824 struct task_struct *tsk = thread->task; 825 826 if (!tsk_used_math(tsk)) { 827 local_irq_enable(); 828 /* 829 * does a slab alloc which can sleep 830 */ 831 if (init_fpu(tsk)) { 832 /* 833 * ran out of memory! 834 */ 835 do_group_exit(SIGKILL); 836 return; 837 } 838 local_irq_disable(); 839 } 840 841 clts(); /* Allow maths ops (or we recurse) */ 842 #ifdef CONFIG_X86_32 843 restore_fpu(tsk); 844 #else 845 /* 846 * Paranoid restore. send a SIGSEGV if we fail to restore the state. 847 */ 848 if (unlikely(restore_fpu_checking(tsk))) { 849 stts(); 850 force_sig(SIGSEGV, tsk); 851 return; 852 } 853 #endif 854 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */ 855 tsk->fpu_counter++; 856 } 857 EXPORT_SYMBOL_GPL(math_state_restore); 858 859 #ifndef CONFIG_MATH_EMULATION 860 void math_emulate(struct math_emu_info *info) 861 { 862 printk(KERN_EMERG 863 "math-emulation not enabled and no coprocessor found.\n"); 864 printk(KERN_EMERG "killing %s.\n", current->comm); 865 force_sig(SIGFPE, current); 866 schedule(); 867 } 868 #endif /* CONFIG_MATH_EMULATION */ 869 870 dotraplinkage void __kprobes 871 do_device_not_available(struct pt_regs *regs, long error_code) 872 { 873 #ifdef CONFIG_X86_32 874 if (read_cr0() & X86_CR0_EM) { 875 struct math_emu_info info = { }; 876 877 conditional_sti(regs); 878 879 info.regs = regs; 880 math_emulate(&info); 881 } else { 882 math_state_restore(); /* interrupts still off */ 883 conditional_sti(regs); 884 } 885 #else 886 math_state_restore(); 887 #endif 888 } 889 890 #ifdef CONFIG_X86_32 891 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) 892 { 893 siginfo_t info; 894 local_irq_enable(); 895 896 info.si_signo = SIGILL; 897 info.si_errno = 0; 898 info.si_code = ILL_BADSTK; 899 info.si_addr = NULL; 900 if (notify_die(DIE_TRAP, "iret exception", 901 regs, error_code, 32, SIGILL) == NOTIFY_STOP) 902 return; 903 do_trap(32, SIGILL, "iret exception", regs, error_code, &info); 904 } 905 #endif 906 907 void __init trap_init(void) 908 { 909 int i; 910 911 #ifdef CONFIG_EISA 912 void __iomem *p = early_ioremap(0x0FFFD9, 4); 913 914 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) 915 EISA_bus = 1; 916 early_iounmap(p, 4); 917 #endif 918 919 set_intr_gate(0, ÷_error); 920 set_intr_gate_ist(1, &debug, DEBUG_STACK); 921 set_intr_gate_ist(2, &nmi, NMI_STACK); 922 /* int3 can be called from all */ 923 set_system_intr_gate_ist(3, &int3, DEBUG_STACK); 924 /* int4 can be called from all */ 925 set_system_intr_gate(4, &overflow); 926 set_intr_gate(5, &bounds); 927 set_intr_gate(6, &invalid_op); 928 set_intr_gate(7, &device_not_available); 929 #ifdef CONFIG_X86_32 930 set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS); 931 #else 932 set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK); 933 #endif 934 set_intr_gate(9, &coprocessor_segment_overrun); 935 set_intr_gate(10, &invalid_TSS); 936 set_intr_gate(11, &segment_not_present); 937 set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK); 938 set_intr_gate(13, &general_protection); 939 set_intr_gate(14, &page_fault); 940 set_intr_gate(15, &spurious_interrupt_bug); 941 set_intr_gate(16, &coprocessor_error); 942 set_intr_gate(17, &alignment_check); 943 #ifdef CONFIG_X86_MCE 944 set_intr_gate_ist(18, &machine_check, MCE_STACK); 945 #endif 946 set_intr_gate(19, &simd_coprocessor_error); 947 948 #ifdef CONFIG_IA32_EMULATION 949 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); 950 #endif 951 952 #ifdef CONFIG_X86_32 953 if (cpu_has_fxsr) { 954 printk(KERN_INFO "Enabling fast FPU save and restore... "); 955 set_in_cr4(X86_CR4_OSFXSR); 956 printk("done.\n"); 957 } 958 if (cpu_has_xmm) { 959 printk(KERN_INFO 960 "Enabling unmasked SIMD FPU exception support... "); 961 set_in_cr4(X86_CR4_OSXMMEXCPT); 962 printk("done.\n"); 963 } 964 965 set_system_trap_gate(SYSCALL_VECTOR, &system_call); 966 #endif 967 968 /* Reserve all the builtin and the syscall vector: */ 969 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) 970 set_bit(i, used_vectors); 971 972 #ifdef CONFIG_X86_64 973 set_bit(IA32_SYSCALL_VECTOR, used_vectors); 974 #else 975 set_bit(SYSCALL_VECTOR, used_vectors); 976 #endif 977 /* 978 * Should be a barrier for any external CPU state: 979 */ 980 cpu_init(); 981 982 #ifdef CONFIG_X86_32 983 x86_quirk_trap_init(); 984 #endif 985 } 986