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/kernel.h> 19 #include <linux/module.h> 20 #include <linux/ptrace.h> 21 #include <linux/string.h> 22 #include <linux/delay.h> 23 #include <linux/errno.h> 24 #include <linux/kexec.h> 25 #include <linux/sched.h> 26 #include <linux/timer.h> 27 #include <linux/init.h> 28 #include <linux/bug.h> 29 #include <linux/nmi.h> 30 #include <linux/mm.h> 31 #include <linux/smp.h> 32 #include <linux/io.h> 33 34 #ifdef CONFIG_EISA 35 #include <linux/ioport.h> 36 #include <linux/eisa.h> 37 #endif 38 39 #ifdef CONFIG_MCA 40 #include <linux/mca.h> 41 #endif 42 43 #if defined(CONFIG_EDAC) 44 #include <linux/edac.h> 45 #endif 46 47 #include <asm/kmemcheck.h> 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 #include <asm/mce.h> 57 58 #include <asm/mach_traps.h> 59 60 #ifdef CONFIG_X86_64 61 #include <asm/x86_init.h> 62 #include <asm/pgalloc.h> 63 #include <asm/proto.h> 64 #else 65 #include <asm/processor-flags.h> 66 #include <asm/setup.h> 67 68 asmlinkage int system_call(void); 69 70 /* Do we ignore FPU interrupts ? */ 71 char ignore_fpu_irq; 72 73 /* 74 * The IDT has to be page-aligned to simplify the Pentium 75 * F0 0F bug workaround. 76 */ 77 gate_desc idt_table[NR_VECTORS] __page_aligned_data = { { { { 0, 0 } } }, }; 78 #endif 79 80 DECLARE_BITMAP(used_vectors, NR_VECTORS); 81 EXPORT_SYMBOL_GPL(used_vectors); 82 83 static int ignore_nmis; 84 85 static inline void conditional_sti(struct pt_regs *regs) 86 { 87 if (regs->flags & X86_EFLAGS_IF) 88 local_irq_enable(); 89 } 90 91 static inline void preempt_conditional_sti(struct pt_regs *regs) 92 { 93 inc_preempt_count(); 94 if (regs->flags & X86_EFLAGS_IF) 95 local_irq_enable(); 96 } 97 98 static inline void conditional_cli(struct pt_regs *regs) 99 { 100 if (regs->flags & X86_EFLAGS_IF) 101 local_irq_disable(); 102 } 103 104 static inline void preempt_conditional_cli(struct pt_regs *regs) 105 { 106 if (regs->flags & X86_EFLAGS_IF) 107 local_irq_disable(); 108 dec_preempt_count(); 109 } 110 111 #ifdef CONFIG_X86_32 112 static inline void 113 die_if_kernel(const char *str, struct pt_regs *regs, long err) 114 { 115 if (!user_mode_vm(regs)) 116 die(str, regs, err); 117 } 118 #endif 119 120 static void __kprobes 121 do_trap(int trapnr, int signr, char *str, struct pt_regs *regs, 122 long error_code, siginfo_t *info) 123 { 124 struct task_struct *tsk = current; 125 126 #ifdef CONFIG_X86_32 127 if (regs->flags & X86_VM_MASK) { 128 /* 129 * traps 0, 1, 3, 4, and 5 should be forwarded to vm86. 130 * On nmi (interrupt 2), do_trap should not be called. 131 */ 132 if (trapnr < 6) 133 goto vm86_trap; 134 goto trap_signal; 135 } 136 #endif 137 138 if (!user_mode(regs)) 139 goto kernel_trap; 140 141 #ifdef CONFIG_X86_32 142 trap_signal: 143 #endif 144 /* 145 * We want error_code and trap_no set for userspace faults and 146 * kernelspace faults which result in die(), but not 147 * kernelspace faults which are fixed up. die() gives the 148 * process no chance to handle the signal and notice the 149 * kernel fault information, so that won't result in polluting 150 * the information about previously queued, but not yet 151 * delivered, faults. See also do_general_protection below. 152 */ 153 tsk->thread.error_code = error_code; 154 tsk->thread.trap_no = trapnr; 155 156 #ifdef CONFIG_X86_64 157 if (show_unhandled_signals && unhandled_signal(tsk, signr) && 158 printk_ratelimit()) { 159 printk(KERN_INFO 160 "%s[%d] trap %s ip:%lx sp:%lx error:%lx", 161 tsk->comm, tsk->pid, str, 162 regs->ip, regs->sp, error_code); 163 print_vma_addr(" in ", regs->ip); 164 printk("\n"); 165 } 166 #endif 167 168 if (info) 169 force_sig_info(signr, info, tsk); 170 else 171 force_sig(signr, tsk); 172 return; 173 174 kernel_trap: 175 if (!fixup_exception(regs)) { 176 tsk->thread.error_code = error_code; 177 tsk->thread.trap_no = trapnr; 178 die(str, regs, error_code); 179 } 180 return; 181 182 #ifdef CONFIG_X86_32 183 vm86_trap: 184 if (handle_vm86_trap((struct kernel_vm86_regs *) regs, 185 error_code, trapnr)) 186 goto trap_signal; 187 return; 188 #endif 189 } 190 191 #define DO_ERROR(trapnr, signr, str, name) \ 192 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 193 { \ 194 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ 195 == NOTIFY_STOP) \ 196 return; \ 197 conditional_sti(regs); \ 198 do_trap(trapnr, signr, str, regs, error_code, NULL); \ 199 } 200 201 #define DO_ERROR_INFO(trapnr, signr, str, name, sicode, siaddr) \ 202 dotraplinkage void do_##name(struct pt_regs *regs, long error_code) \ 203 { \ 204 siginfo_t info; \ 205 info.si_signo = signr; \ 206 info.si_errno = 0; \ 207 info.si_code = sicode; \ 208 info.si_addr = (void __user *)siaddr; \ 209 if (notify_die(DIE_TRAP, str, regs, error_code, trapnr, signr) \ 210 == NOTIFY_STOP) \ 211 return; \ 212 conditional_sti(regs); \ 213 do_trap(trapnr, signr, str, regs, error_code, &info); \ 214 } 215 216 DO_ERROR_INFO(0, SIGFPE, "divide error", divide_error, FPE_INTDIV, regs->ip) 217 DO_ERROR(4, SIGSEGV, "overflow", overflow) 218 DO_ERROR(5, SIGSEGV, "bounds", bounds) 219 DO_ERROR_INFO(6, SIGILL, "invalid opcode", invalid_op, ILL_ILLOPN, regs->ip) 220 DO_ERROR(9, SIGFPE, "coprocessor segment overrun", coprocessor_segment_overrun) 221 DO_ERROR(10, SIGSEGV, "invalid TSS", invalid_TSS) 222 DO_ERROR(11, SIGBUS, "segment not present", segment_not_present) 223 #ifdef CONFIG_X86_32 224 DO_ERROR(12, SIGBUS, "stack segment", stack_segment) 225 #endif 226 DO_ERROR_INFO(17, SIGBUS, "alignment check", alignment_check, BUS_ADRALN, 0) 227 228 #ifdef CONFIG_X86_64 229 /* Runs on IST stack */ 230 dotraplinkage void do_stack_segment(struct pt_regs *regs, long error_code) 231 { 232 if (notify_die(DIE_TRAP, "stack segment", regs, error_code, 233 12, SIGBUS) == NOTIFY_STOP) 234 return; 235 preempt_conditional_sti(regs); 236 do_trap(12, SIGBUS, "stack segment", regs, error_code, NULL); 237 preempt_conditional_cli(regs); 238 } 239 240 dotraplinkage void do_double_fault(struct pt_regs *regs, long error_code) 241 { 242 static const char str[] = "double fault"; 243 struct task_struct *tsk = current; 244 245 /* Return not checked because double check cannot be ignored */ 246 notify_die(DIE_TRAP, str, regs, error_code, 8, SIGSEGV); 247 248 tsk->thread.error_code = error_code; 249 tsk->thread.trap_no = 8; 250 251 /* 252 * This is always a kernel trap and never fixable (and thus must 253 * never return). 254 */ 255 for (;;) 256 die(str, regs, error_code); 257 } 258 #endif 259 260 dotraplinkage void __kprobes 261 do_general_protection(struct pt_regs *regs, long error_code) 262 { 263 struct task_struct *tsk; 264 265 conditional_sti(regs); 266 267 #ifdef CONFIG_X86_32 268 if (regs->flags & X86_VM_MASK) 269 goto gp_in_vm86; 270 #endif 271 272 tsk = current; 273 if (!user_mode(regs)) 274 goto gp_in_kernel; 275 276 tsk->thread.error_code = error_code; 277 tsk->thread.trap_no = 13; 278 279 if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && 280 printk_ratelimit()) { 281 printk(KERN_INFO 282 "%s[%d] general protection ip:%lx sp:%lx error:%lx", 283 tsk->comm, task_pid_nr(tsk), 284 regs->ip, regs->sp, error_code); 285 print_vma_addr(" in ", regs->ip); 286 printk("\n"); 287 } 288 289 force_sig(SIGSEGV, tsk); 290 return; 291 292 #ifdef CONFIG_X86_32 293 gp_in_vm86: 294 local_irq_enable(); 295 handle_vm86_fault((struct kernel_vm86_regs *) regs, error_code); 296 return; 297 #endif 298 299 gp_in_kernel: 300 if (fixup_exception(regs)) 301 return; 302 303 tsk->thread.error_code = error_code; 304 tsk->thread.trap_no = 13; 305 if (notify_die(DIE_GPF, "general protection fault", regs, 306 error_code, 13, SIGSEGV) == NOTIFY_STOP) 307 return; 308 die("general protection fault", regs, error_code); 309 } 310 311 static notrace __kprobes void 312 mem_parity_error(unsigned char reason, struct pt_regs *regs) 313 { 314 printk(KERN_EMERG 315 "Uhhuh. NMI received for unknown reason %02x on CPU %d.\n", 316 reason, smp_processor_id()); 317 318 printk(KERN_EMERG 319 "You have some hardware problem, likely on the PCI bus.\n"); 320 321 #if defined(CONFIG_EDAC) 322 if (edac_handler_set()) { 323 edac_atomic_assert_error(); 324 return; 325 } 326 #endif 327 328 if (panic_on_unrecovered_nmi) 329 panic("NMI: Not continuing"); 330 331 printk(KERN_EMERG "Dazed and confused, but trying to continue\n"); 332 333 /* Clear and disable the memory parity error line. */ 334 reason = (reason & 0xf) | 4; 335 outb(reason, 0x61); 336 } 337 338 static notrace __kprobes void 339 io_check_error(unsigned char reason, struct pt_regs *regs) 340 { 341 unsigned long i; 342 343 printk(KERN_EMERG "NMI: IOCK error (debug interrupt?)\n"); 344 show_registers(regs); 345 346 if (panic_on_io_nmi) 347 panic("NMI IOCK error: Not continuing"); 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 dr6; 533 int si_code; 534 535 get_debugreg(dr6, 6); 536 537 /* Filter out all the reserved bits which are preset to 1 */ 538 dr6 &= ~DR6_RESERVED; 539 540 /* Catch kmemcheck conditions first of all! */ 541 if ((dr6 & DR_STEP) && kmemcheck_trap(regs)) 542 return; 543 544 /* DR6 may or may not be cleared by the CPU */ 545 set_debugreg(0, 6); 546 /* 547 * The processor cleared BTF, so don't mark that we need it set. 548 */ 549 clear_tsk_thread_flag(tsk, TIF_DEBUGCTLMSR); 550 tsk->thread.debugctlmsr = 0; 551 552 /* Store the virtualized DR6 value */ 553 tsk->thread.debugreg6 = dr6; 554 555 if (notify_die(DIE_DEBUG, "debug", regs, PTR_ERR(&dr6), error_code, 556 SIGTRAP) == NOTIFY_STOP) 557 return; 558 559 /* It's safe to allow irq's after DR6 has been saved */ 560 preempt_conditional_sti(regs); 561 562 if (regs->flags & X86_VM_MASK) { 563 handle_vm86_trap((struct kernel_vm86_regs *) regs, 564 error_code, 1); 565 return; 566 } 567 568 /* 569 * Single-stepping through system calls: ignore any exceptions in 570 * kernel space, but re-enable TF when returning to user mode. 571 * 572 * We already checked v86 mode above, so we can check for kernel mode 573 * by just checking the CPL of CS. 574 */ 575 if ((dr6 & DR_STEP) && !user_mode(regs)) { 576 tsk->thread.debugreg6 &= ~DR_STEP; 577 set_tsk_thread_flag(tsk, TIF_SINGLESTEP); 578 regs->flags &= ~X86_EFLAGS_TF; 579 } 580 si_code = get_si_code(tsk->thread.debugreg6); 581 if (tsk->thread.debugreg6 & (DR_STEP | DR_TRAP_BITS)) 582 send_sigtrap(tsk, regs, error_code, si_code); 583 preempt_conditional_cli(regs); 584 585 return; 586 } 587 588 #ifdef CONFIG_X86_64 589 static int kernel_math_error(struct pt_regs *regs, const char *str, int trapnr) 590 { 591 if (fixup_exception(regs)) 592 return 1; 593 594 notify_die(DIE_GPF, str, regs, 0, trapnr, SIGFPE); 595 /* Illegal floating point operation in the kernel */ 596 current->thread.trap_no = trapnr; 597 die(str, regs, 0); 598 return 0; 599 } 600 #endif 601 602 /* 603 * Note that we play around with the 'TS' bit in an attempt to get 604 * the correct behaviour even in the presence of the asynchronous 605 * IRQ13 behaviour 606 */ 607 void math_error(void __user *ip) 608 { 609 struct task_struct *task; 610 siginfo_t info; 611 unsigned short cwd, swd, err; 612 613 /* 614 * Save the info for the exception handler and clear the error. 615 */ 616 task = current; 617 save_init_fpu(task); 618 task->thread.trap_no = 16; 619 task->thread.error_code = 0; 620 info.si_signo = SIGFPE; 621 info.si_errno = 0; 622 info.si_addr = ip; 623 /* 624 * (~cwd & swd) will mask out exceptions that are not set to unmasked 625 * status. 0x3f is the exception bits in these regs, 0x200 is the 626 * C1 reg you need in case of a stack fault, 0x040 is the stack 627 * fault bit. We should only be taking one exception at a time, 628 * so if this combination doesn't produce any single exception, 629 * then we have a bad program that isn't synchronizing its FPU usage 630 * and it will suffer the consequences since we won't be able to 631 * fully reproduce the context of the exception 632 */ 633 cwd = get_fpu_cwd(task); 634 swd = get_fpu_swd(task); 635 636 err = swd & ~cwd; 637 638 if (err & 0x001) { /* Invalid op */ 639 /* 640 * swd & 0x240 == 0x040: Stack Underflow 641 * swd & 0x240 == 0x240: Stack Overflow 642 * User must clear the SF bit (0x40) if set 643 */ 644 info.si_code = FPE_FLTINV; 645 } else if (err & 0x004) { /* Divide by Zero */ 646 info.si_code = FPE_FLTDIV; 647 } else if (err & 0x008) { /* Overflow */ 648 info.si_code = FPE_FLTOVF; 649 } else if (err & 0x012) { /* Denormal, Underflow */ 650 info.si_code = FPE_FLTUND; 651 } else if (err & 0x020) { /* Precision */ 652 info.si_code = FPE_FLTRES; 653 } else { 654 /* 655 * If we're using IRQ 13, or supposedly even some trap 16 656 * implementations, it's possible we get a spurious trap... 657 */ 658 return; /* Spurious trap, no error */ 659 } 660 force_sig_info(SIGFPE, &info, task); 661 } 662 663 dotraplinkage void do_coprocessor_error(struct pt_regs *regs, long error_code) 664 { 665 conditional_sti(regs); 666 667 #ifdef CONFIG_X86_32 668 ignore_fpu_irq = 1; 669 #else 670 if (!user_mode(regs) && 671 kernel_math_error(regs, "kernel x87 math error", 16)) 672 return; 673 #endif 674 675 math_error((void __user *)regs->ip); 676 } 677 678 static void simd_math_error(void __user *ip) 679 { 680 struct task_struct *task; 681 siginfo_t info; 682 unsigned short mxcsr; 683 684 /* 685 * Save the info for the exception handler and clear the error. 686 */ 687 task = current; 688 save_init_fpu(task); 689 task->thread.trap_no = 19; 690 task->thread.error_code = 0; 691 info.si_signo = SIGFPE; 692 info.si_errno = 0; 693 info.si_code = __SI_FAULT; 694 info.si_addr = ip; 695 /* 696 * The SIMD FPU exceptions are handled a little differently, as there 697 * is only a single status/control register. Thus, to determine which 698 * unmasked exception was caught we must mask the exception mask bits 699 * at 0x1f80, and then use these to mask the exception bits at 0x3f. 700 */ 701 mxcsr = get_fpu_mxcsr(task); 702 switch (~((mxcsr & 0x1f80) >> 7) & (mxcsr & 0x3f)) { 703 case 0x000: 704 default: 705 break; 706 case 0x001: /* Invalid Op */ 707 info.si_code = FPE_FLTINV; 708 break; 709 case 0x002: /* Denormalize */ 710 case 0x010: /* Underflow */ 711 info.si_code = FPE_FLTUND; 712 break; 713 case 0x004: /* Zero Divide */ 714 info.si_code = FPE_FLTDIV; 715 break; 716 case 0x008: /* Overflow */ 717 info.si_code = FPE_FLTOVF; 718 break; 719 case 0x020: /* Precision */ 720 info.si_code = FPE_FLTRES; 721 break; 722 } 723 force_sig_info(SIGFPE, &info, task); 724 } 725 726 dotraplinkage void 727 do_simd_coprocessor_error(struct pt_regs *regs, long error_code) 728 { 729 conditional_sti(regs); 730 731 #ifdef CONFIG_X86_32 732 if (cpu_has_xmm) { 733 /* Handle SIMD FPU exceptions on PIII+ processors. */ 734 ignore_fpu_irq = 1; 735 simd_math_error((void __user *)regs->ip); 736 return; 737 } 738 /* 739 * Handle strange cache flush from user space exception 740 * in all other cases. This is undocumented behaviour. 741 */ 742 if (regs->flags & X86_VM_MASK) { 743 handle_vm86_fault((struct kernel_vm86_regs *)regs, error_code); 744 return; 745 } 746 current->thread.trap_no = 19; 747 current->thread.error_code = error_code; 748 die_if_kernel("cache flush denied", regs, error_code); 749 force_sig(SIGSEGV, current); 750 #else 751 if (!user_mode(regs) && 752 kernel_math_error(regs, "kernel simd math error", 19)) 753 return; 754 simd_math_error((void __user *)regs->ip); 755 #endif 756 } 757 758 dotraplinkage void 759 do_spurious_interrupt_bug(struct pt_regs *regs, long error_code) 760 { 761 conditional_sti(regs); 762 #if 0 763 /* No need to warn about this any longer. */ 764 printk(KERN_INFO "Ignoring P6 Local APIC Spurious Interrupt Bug...\n"); 765 #endif 766 } 767 768 asmlinkage void __attribute__((weak)) smp_thermal_interrupt(void) 769 { 770 } 771 772 asmlinkage void __attribute__((weak)) smp_threshold_interrupt(void) 773 { 774 } 775 776 /* 777 * __math_state_restore assumes that cr0.TS is already clear and the 778 * fpu state is all ready for use. Used during context switch. 779 */ 780 void __math_state_restore(void) 781 { 782 struct thread_info *thread = current_thread_info(); 783 struct task_struct *tsk = thread->task; 784 785 /* 786 * Paranoid restore. send a SIGSEGV if we fail to restore the state. 787 */ 788 if (unlikely(restore_fpu_checking(tsk))) { 789 stts(); 790 force_sig(SIGSEGV, tsk); 791 return; 792 } 793 794 thread->status |= TS_USEDFPU; /* So we fnsave on switch_to() */ 795 tsk->fpu_counter++; 796 } 797 798 /* 799 * 'math_state_restore()' saves the current math information in the 800 * old math state array, and gets the new ones from the current task 801 * 802 * Careful.. There are problems with IBM-designed IRQ13 behaviour. 803 * Don't touch unless you *really* know how it works. 804 * 805 * Must be called with kernel preemption disabled (in this case, 806 * local interrupts are disabled at the call-site in entry.S). 807 */ 808 asmlinkage void math_state_restore(void) 809 { 810 struct thread_info *thread = current_thread_info(); 811 struct task_struct *tsk = thread->task; 812 813 if (!tsk_used_math(tsk)) { 814 local_irq_enable(); 815 /* 816 * does a slab alloc which can sleep 817 */ 818 if (init_fpu(tsk)) { 819 /* 820 * ran out of memory! 821 */ 822 do_group_exit(SIGKILL); 823 return; 824 } 825 local_irq_disable(); 826 } 827 828 clts(); /* Allow maths ops (or we recurse) */ 829 830 __math_state_restore(); 831 } 832 EXPORT_SYMBOL_GPL(math_state_restore); 833 834 #ifndef CONFIG_MATH_EMULATION 835 void math_emulate(struct math_emu_info *info) 836 { 837 printk(KERN_EMERG 838 "math-emulation not enabled and no coprocessor found.\n"); 839 printk(KERN_EMERG "killing %s.\n", current->comm); 840 force_sig(SIGFPE, current); 841 schedule(); 842 } 843 #endif /* CONFIG_MATH_EMULATION */ 844 845 dotraplinkage void __kprobes 846 do_device_not_available(struct pt_regs *regs, long error_code) 847 { 848 #ifdef CONFIG_X86_32 849 if (read_cr0() & X86_CR0_EM) { 850 struct math_emu_info info = { }; 851 852 conditional_sti(regs); 853 854 info.regs = regs; 855 math_emulate(&info); 856 } else { 857 math_state_restore(); /* interrupts still off */ 858 conditional_sti(regs); 859 } 860 #else 861 math_state_restore(); 862 #endif 863 } 864 865 #ifdef CONFIG_X86_32 866 dotraplinkage void do_iret_error(struct pt_regs *regs, long error_code) 867 { 868 siginfo_t info; 869 local_irq_enable(); 870 871 info.si_signo = SIGILL; 872 info.si_errno = 0; 873 info.si_code = ILL_BADSTK; 874 info.si_addr = NULL; 875 if (notify_die(DIE_TRAP, "iret exception", 876 regs, error_code, 32, SIGILL) == NOTIFY_STOP) 877 return; 878 do_trap(32, SIGILL, "iret exception", regs, error_code, &info); 879 } 880 #endif 881 882 void __init trap_init(void) 883 { 884 int i; 885 886 #ifdef CONFIG_EISA 887 void __iomem *p = early_ioremap(0x0FFFD9, 4); 888 889 if (readl(p) == 'E' + ('I'<<8) + ('S'<<16) + ('A'<<24)) 890 EISA_bus = 1; 891 early_iounmap(p, 4); 892 #endif 893 894 set_intr_gate(0, ÷_error); 895 set_intr_gate_ist(1, &debug, DEBUG_STACK); 896 set_intr_gate_ist(2, &nmi, NMI_STACK); 897 /* int3 can be called from all */ 898 set_system_intr_gate_ist(3, &int3, DEBUG_STACK); 899 /* int4 can be called from all */ 900 set_system_intr_gate(4, &overflow); 901 set_intr_gate(5, &bounds); 902 set_intr_gate(6, &invalid_op); 903 set_intr_gate(7, &device_not_available); 904 #ifdef CONFIG_X86_32 905 set_task_gate(8, GDT_ENTRY_DOUBLEFAULT_TSS); 906 #else 907 set_intr_gate_ist(8, &double_fault, DOUBLEFAULT_STACK); 908 #endif 909 set_intr_gate(9, &coprocessor_segment_overrun); 910 set_intr_gate(10, &invalid_TSS); 911 set_intr_gate(11, &segment_not_present); 912 set_intr_gate_ist(12, &stack_segment, STACKFAULT_STACK); 913 set_intr_gate(13, &general_protection); 914 set_intr_gate(14, &page_fault); 915 set_intr_gate(15, &spurious_interrupt_bug); 916 set_intr_gate(16, &coprocessor_error); 917 set_intr_gate(17, &alignment_check); 918 #ifdef CONFIG_X86_MCE 919 set_intr_gate_ist(18, &machine_check, MCE_STACK); 920 #endif 921 set_intr_gate(19, &simd_coprocessor_error); 922 923 /* Reserve all the builtin and the syscall vector: */ 924 for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++) 925 set_bit(i, used_vectors); 926 927 #ifdef CONFIG_IA32_EMULATION 928 set_system_intr_gate(IA32_SYSCALL_VECTOR, ia32_syscall); 929 set_bit(IA32_SYSCALL_VECTOR, used_vectors); 930 #endif 931 932 #ifdef CONFIG_X86_32 933 if (cpu_has_fxsr) { 934 printk(KERN_INFO "Enabling fast FPU save and restore... "); 935 set_in_cr4(X86_CR4_OSFXSR); 936 printk("done.\n"); 937 } 938 if (cpu_has_xmm) { 939 printk(KERN_INFO 940 "Enabling unmasked SIMD FPU exception support... "); 941 set_in_cr4(X86_CR4_OSXMMEXCPT); 942 printk("done.\n"); 943 } 944 945 set_system_trap_gate(SYSCALL_VECTOR, &system_call); 946 set_bit(SYSCALL_VECTOR, used_vectors); 947 #endif 948 949 /* 950 * Should be a barrier for any external CPU state: 951 */ 952 cpu_init(); 953 954 x86_init.irqs.trap_init(); 955 } 956