Now available: The Design and Implementation of the FreeBSD Operating System (Second Edition)
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FreeBSD/Linux Kernel Cross Reference
sys/amd64/amd64/trap.c
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1 /*- 2 * Copyright (C) 1994, David Greenman 3 * Copyright (c) 1990, 1993 4 * The Regents of the University of California. All rights reserved. 5 * 6 * This code is derived from software contributed to Berkeley by 7 * the University of Utah, and William Jolitz. 8 * 9 * Redistribution and use in source and binary forms, with or without 10 * modification, are permitted provided that the following conditions 11 * are met: 12 * 1. Redistributions of source code must retain the above copyright 13 * notice, this list of conditions and the following disclaimer. 14 * 2. Redistributions in binary form must reproduce the above copyright 15 * notice, this list of conditions and the following disclaimer in the 16 * documentation and/or other materials provided with the distribution. 17 * 3. All advertising materials mentioning features or use of this software 18 * must display the following acknowledgement: 19 * This product includes software developed by the University of 20 * California, Berkeley and its contributors. 21 * 4. Neither the name of the University nor the names of its contributors 22 * may be used to endorse or promote products derived from this software 23 * without specific prior written permission. 24 * 25 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 26 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 27 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 28 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 29 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 30 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 31 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 32 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 33 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 34 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 35 * SUCH DAMAGE. 36 * 37 * from: @(#)trap.c 7.4 (Berkeley) 5/13/91 38 */ 39 40 #include <sys/cdefs.h> 41 __FBSDID("$FreeBSD: releng/8.2/sys/amd64/amd64/trap.c 236953 2012-06-12 12:10:10Z bz $"); 42 43 /* 44 * AMD64 Trap and System call handling 45 */ 46 47 #include "opt_clock.h" 48 #include "opt_cpu.h" 49 #include "opt_hwpmc_hooks.h" 50 #include "opt_isa.h" 51 #include "opt_kdb.h" 52 #include "opt_kdtrace.h" 53 #include "opt_ktrace.h" 54 55 #include <sys/param.h> 56 #include <sys/bus.h> 57 #include <sys/systm.h> 58 #include <sys/proc.h> 59 #include <sys/pioctl.h> 60 #include <sys/ptrace.h> 61 #include <sys/kdb.h> 62 #include <sys/kernel.h> 63 #include <sys/ktr.h> 64 #include <sys/lock.h> 65 #include <sys/mutex.h> 66 #include <sys/resourcevar.h> 67 #include <sys/signalvar.h> 68 #include <sys/syscall.h> 69 #include <sys/sysctl.h> 70 #include <sys/sysent.h> 71 #include <sys/uio.h> 72 #include <sys/vmmeter.h> 73 #ifdef KTRACE 74 #include <sys/ktrace.h> 75 #endif 76 #ifdef HWPMC_HOOKS 77 #include <sys/pmckern.h> 78 #endif 79 80 #include <vm/vm.h> 81 #include <vm/vm_param.h> 82 #include <vm/pmap.h> 83 #include <vm/vm_kern.h> 84 #include <vm/vm_map.h> 85 #include <vm/vm_page.h> 86 #include <vm/vm_extern.h> 87 88 #include <machine/cpu.h> 89 #include <machine/intr_machdep.h> 90 #include <machine/mca.h> 91 #include <machine/md_var.h> 92 #include <machine/pcb.h> 93 #ifdef SMP 94 #include <machine/smp.h> 95 #endif 96 #include <machine/tss.h> 97 98 #ifdef KDTRACE_HOOKS 99 #include <sys/dtrace_bsd.h> 100 101 /* 102 * This is a hook which is initialised by the dtrace module 103 * to handle traps which might occur during DTrace probe 104 * execution. 105 */ 106 dtrace_trap_func_t dtrace_trap_func; 107 108 dtrace_doubletrap_func_t dtrace_doubletrap_func; 109 110 /* 111 * This is a hook which is initialised by the systrace module 112 * when it is loaded. This keeps the DTrace syscall provider 113 * implementation opaque. 114 */ 115 systrace_probe_func_t systrace_probe_func; 116 #endif 117 118 extern void trap(struct trapframe *frame); 119 extern void syscall(struct trapframe *frame); 120 void dblfault_handler(struct trapframe *frame); 121 122 static int trap_pfault(struct trapframe *, int); 123 static void trap_fatal(struct trapframe *, vm_offset_t); 124 125 #define MAX_TRAP_MSG 30 126 static char *trap_msg[] = { 127 "", /* 0 unused */ 128 "privileged instruction fault", /* 1 T_PRIVINFLT */ 129 "", /* 2 unused */ 130 "breakpoint instruction fault", /* 3 T_BPTFLT */ 131 "", /* 4 unused */ 132 "", /* 5 unused */ 133 "arithmetic trap", /* 6 T_ARITHTRAP */ 134 "", /* 7 unused */ 135 "", /* 8 unused */ 136 "general protection fault", /* 9 T_PROTFLT */ 137 "trace trap", /* 10 T_TRCTRAP */ 138 "", /* 11 unused */ 139 "page fault", /* 12 T_PAGEFLT */ 140 "", /* 13 unused */ 141 "alignment fault", /* 14 T_ALIGNFLT */ 142 "", /* 15 unused */ 143 "", /* 16 unused */ 144 "", /* 17 unused */ 145 "integer divide fault", /* 18 T_DIVIDE */ 146 "non-maskable interrupt trap", /* 19 T_NMI */ 147 "overflow trap", /* 20 T_OFLOW */ 148 "FPU bounds check fault", /* 21 T_BOUND */ 149 "FPU device not available", /* 22 T_DNA */ 150 "double fault", /* 23 T_DOUBLEFLT */ 151 "FPU operand fetch fault", /* 24 T_FPOPFLT */ 152 "invalid TSS fault", /* 25 T_TSSFLT */ 153 "segment not present fault", /* 26 T_SEGNPFLT */ 154 "stack fault", /* 27 T_STKFLT */ 155 "machine check trap", /* 28 T_MCHK */ 156 "SIMD floating-point exception", /* 29 T_XMMFLT */ 157 "reserved (unknown) fault", /* 30 T_RESERVED */ 158 }; 159 160 #ifdef KDB 161 static int kdb_on_nmi = 1; 162 SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RW, 163 &kdb_on_nmi, 0, "Go to KDB on NMI"); 164 #endif 165 static int panic_on_nmi = 1; 166 SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW, 167 &panic_on_nmi, 0, "Panic on NMI"); 168 static int prot_fault_translation = 0; 169 SYSCTL_INT(_machdep, OID_AUTO, prot_fault_translation, CTLFLAG_RW, 170 &prot_fault_translation, 0, "Select signal to deliver on protection fault"); 171 172 /* 173 * Exception, fault, and trap interface to the FreeBSD kernel. 174 * This common code is called from assembly language IDT gate entry 175 * routines that prepare a suitable stack frame, and restore this 176 * frame after the exception has been processed. 177 */ 178 179 void 180 trap(struct trapframe *frame) 181 { 182 struct thread *td = curthread; 183 struct proc *p = td->td_proc; 184 int i = 0, ucode = 0, code; 185 u_int type; 186 register_t addr = 0; 187 ksiginfo_t ksi; 188 189 PCPU_INC(cnt.v_trap); 190 type = frame->tf_trapno; 191 192 #ifdef SMP 193 /* Handler for NMI IPIs used for stopping CPUs. */ 194 if (type == T_NMI) { 195 if (ipi_nmi_handler() == 0) 196 goto out; 197 } 198 #endif /* SMP */ 199 200 #ifdef KDB 201 if (kdb_active) { 202 kdb_reenter(); 203 goto out; 204 } 205 #endif 206 207 if (type == T_RESERVED) { 208 trap_fatal(frame, 0); 209 goto out; 210 } 211 212 #ifdef HWPMC_HOOKS 213 /* 214 * CPU PMCs interrupt using an NMI. If the PMC module is 215 * active, pass the 'rip' value to the PMC module's interrupt 216 * handler. A return value of '1' from the handler means that 217 * the NMI was handled by it and we can return immediately. 218 */ 219 if (type == T_NMI && pmc_intr && 220 (*pmc_intr)(PCPU_GET(cpuid), frame)) 221 goto out; 222 #endif 223 224 if (type == T_MCHK) { 225 if (!mca_intr()) 226 trap_fatal(frame, 0); 227 goto out; 228 } 229 230 #ifdef KDTRACE_HOOKS 231 /* 232 * A trap can occur while DTrace executes a probe. Before 233 * executing the probe, DTrace blocks re-scheduling and sets 234 * a flag in it's per-cpu flags to indicate that it doesn't 235 * want to fault. On returning from the the probe, the no-fault 236 * flag is cleared and finally re-scheduling is enabled. 237 * 238 * If the DTrace kernel module has registered a trap handler, 239 * call it and if it returns non-zero, assume that it has 240 * handled the trap and modified the trap frame so that this 241 * function can return normally. 242 */ 243 if (dtrace_trap_func != NULL) 244 if ((*dtrace_trap_func)(frame, type)) 245 goto out; 246 #endif 247 248 if ((frame->tf_rflags & PSL_I) == 0) { 249 /* 250 * Buggy application or kernel code has disabled 251 * interrupts and then trapped. Enabling interrupts 252 * now is wrong, but it is better than running with 253 * interrupts disabled until they are accidentally 254 * enabled later. 255 */ 256 if (ISPL(frame->tf_cs) == SEL_UPL) 257 uprintf( 258 "pid %ld (%s): trap %d with interrupts disabled\n", 259 (long)curproc->p_pid, curthread->td_name, type); 260 else if (type != T_NMI && type != T_BPTFLT && 261 type != T_TRCTRAP) { 262 /* 263 * XXX not quite right, since this may be for a 264 * multiple fault in user mode. 265 */ 266 printf("kernel trap %d with interrupts disabled\n", 267 type); 268 269 /* 270 * We shouldn't enable interrupts while holding a 271 * spin lock. 272 */ 273 if (td->td_md.md_spinlock_count == 0) 274 enable_intr(); 275 } 276 } 277 278 code = frame->tf_err; 279 if (type == T_PAGEFLT) { 280 /* 281 * If we get a page fault while in a critical section, then 282 * it is most likely a fatal kernel page fault. The kernel 283 * is already going to panic trying to get a sleep lock to 284 * do the VM lookup, so just consider it a fatal trap so the 285 * kernel can print out a useful trap message and even get 286 * to the debugger. 287 * 288 * If we get a page fault while holding a non-sleepable 289 * lock, then it is most likely a fatal kernel page fault. 290 * If WITNESS is enabled, then it's going to whine about 291 * bogus LORs with various VM locks, so just skip to the 292 * fatal trap handling directly. 293 */ 294 if (td->td_critnest != 0 || 295 WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL, 296 "Kernel page fault") != 0) 297 trap_fatal(frame, frame->tf_addr); 298 } 299 300 if (ISPL(frame->tf_cs) == SEL_UPL) { 301 /* user trap */ 302 303 td->td_pticks = 0; 304 td->td_frame = frame; 305 addr = frame->tf_rip; 306 if (td->td_ucred != p->p_ucred) 307 cred_update_thread(td); 308 309 switch (type) { 310 case T_PRIVINFLT: /* privileged instruction fault */ 311 i = SIGILL; 312 ucode = ILL_PRVOPC; 313 break; 314 315 case T_BPTFLT: /* bpt instruction fault */ 316 case T_TRCTRAP: /* trace trap */ 317 enable_intr(); 318 frame->tf_rflags &= ~PSL_T; 319 i = SIGTRAP; 320 ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT); 321 break; 322 323 case T_ARITHTRAP: /* arithmetic trap */ 324 ucode = fputrap(); 325 if (ucode == -1) 326 goto userout; 327 i = SIGFPE; 328 break; 329 330 case T_PROTFLT: /* general protection fault */ 331 i = SIGBUS; 332 ucode = BUS_OBJERR; 333 break; 334 case T_STKFLT: /* stack fault */ 335 case T_SEGNPFLT: /* segment not present fault */ 336 i = SIGBUS; 337 ucode = BUS_ADRERR; 338 break; 339 case T_TSSFLT: /* invalid TSS fault */ 340 i = SIGBUS; 341 ucode = BUS_OBJERR; 342 break; 343 case T_DOUBLEFLT: /* double fault */ 344 default: 345 i = SIGBUS; 346 ucode = BUS_OBJERR; 347 break; 348 349 case T_PAGEFLT: /* page fault */ 350 addr = frame->tf_addr; 351 i = trap_pfault(frame, TRUE); 352 if (i == -1) 353 goto userout; 354 if (i == 0) 355 goto user; 356 357 if (i == SIGSEGV) 358 ucode = SEGV_MAPERR; 359 else { 360 if (prot_fault_translation == 0) { 361 /* 362 * Autodetect. 363 * This check also covers the images 364 * without the ABI-tag ELF note. 365 */ 366 if (SV_CURPROC_ABI() == SV_ABI_FREEBSD 367 && p->p_osrel >= P_OSREL_SIGSEGV) { 368 i = SIGSEGV; 369 ucode = SEGV_ACCERR; 370 } else { 371 i = SIGBUS; 372 ucode = BUS_PAGE_FAULT; 373 } 374 } else if (prot_fault_translation == 1) { 375 /* 376 * Always compat mode. 377 */ 378 i = SIGBUS; 379 ucode = BUS_PAGE_FAULT; 380 } else { 381 /* 382 * Always SIGSEGV mode. 383 */ 384 i = SIGSEGV; 385 ucode = SEGV_ACCERR; 386 } 387 } 388 break; 389 390 case T_DIVIDE: /* integer divide fault */ 391 ucode = FPE_INTDIV; 392 i = SIGFPE; 393 break; 394 395 #ifdef DEV_ISA 396 case T_NMI: 397 /* machine/parity/power fail/"kitchen sink" faults */ 398 if (isa_nmi(code) == 0) { 399 #ifdef KDB 400 /* 401 * NMI can be hooked up to a pushbutton 402 * for debugging. 403 */ 404 if (kdb_on_nmi) { 405 printf ("NMI ... going to debugger\n"); 406 kdb_trap(type, 0, frame); 407 } 408 #endif /* KDB */ 409 goto userout; 410 } else if (panic_on_nmi) 411 panic("NMI indicates hardware failure"); 412 break; 413 #endif /* DEV_ISA */ 414 415 case T_OFLOW: /* integer overflow fault */ 416 ucode = FPE_INTOVF; 417 i = SIGFPE; 418 break; 419 420 case T_BOUND: /* bounds check fault */ 421 ucode = FPE_FLTSUB; 422 i = SIGFPE; 423 break; 424 425 case T_DNA: 426 /* transparent fault (due to context switch "late") */ 427 KASSERT(PCB_USER_FPU(td->td_pcb), 428 ("kernel FPU ctx has leaked")); 429 fpudna(); 430 goto userout; 431 432 case T_FPOPFLT: /* FPU operand fetch fault */ 433 ucode = ILL_COPROC; 434 i = SIGILL; 435 break; 436 437 case T_XMMFLT: /* SIMD floating-point exception */ 438 ucode = 0; /* XXX */ 439 i = SIGFPE; 440 break; 441 } 442 } else { 443 /* kernel trap */ 444 445 KASSERT(cold || td->td_ucred != NULL, 446 ("kernel trap doesn't have ucred")); 447 switch (type) { 448 case T_PAGEFLT: /* page fault */ 449 (void) trap_pfault(frame, FALSE); 450 goto out; 451 452 case T_DNA: 453 KASSERT(!PCB_USER_FPU(td->td_pcb), 454 ("Unregistered use of FPU in kernel")); 455 fpudna(); 456 goto out; 457 458 case T_ARITHTRAP: /* arithmetic trap */ 459 case T_XMMFLT: /* SIMD floating-point exception */ 460 case T_FPOPFLT: /* FPU operand fetch fault */ 461 /* 462 * XXXKIB for now disable any FPU traps in kernel 463 * handler registration seems to be overkill 464 */ 465 trap_fatal(frame, 0); 466 goto out; 467 468 case T_STKFLT: /* stack fault */ 469 break; 470 471 case T_PROTFLT: /* general protection fault */ 472 case T_SEGNPFLT: /* segment not present fault */ 473 if (td->td_intr_nesting_level != 0) 474 break; 475 476 /* 477 * Invalid segment selectors and out of bounds 478 * %rip's and %rsp's can be set up in user mode. 479 * This causes a fault in kernel mode when the 480 * kernel tries to return to user mode. We want 481 * to get this fault so that we can fix the 482 * problem here and not have to check all the 483 * selectors and pointers when the user changes 484 * them. 485 */ 486 if (frame->tf_rip == (long)doreti_iret) { 487 frame->tf_rip = (long)doreti_iret_fault; 488 goto out; 489 } 490 if (frame->tf_rip == (long)ld_ds) { 491 frame->tf_rip = (long)ds_load_fault; 492 goto out; 493 } 494 if (frame->tf_rip == (long)ld_es) { 495 frame->tf_rip = (long)es_load_fault; 496 goto out; 497 } 498 if (frame->tf_rip == (long)ld_fs) { 499 frame->tf_rip = (long)fs_load_fault; 500 goto out; 501 } 502 if (frame->tf_rip == (long)ld_gs) { 503 frame->tf_rip = (long)gs_load_fault; 504 goto out; 505 } 506 if (frame->tf_rip == (long)ld_gsbase) { 507 frame->tf_rip = (long)gsbase_load_fault; 508 goto out; 509 } 510 if (frame->tf_rip == (long)ld_fsbase) { 511 frame->tf_rip = (long)fsbase_load_fault; 512 goto out; 513 } 514 if (PCPU_GET(curpcb)->pcb_onfault != NULL) { 515 frame->tf_rip = 516 (long)PCPU_GET(curpcb)->pcb_onfault; 517 goto out; 518 } 519 break; 520 521 case T_TSSFLT: 522 /* 523 * PSL_NT can be set in user mode and isn't cleared 524 * automatically when the kernel is entered. This 525 * causes a TSS fault when the kernel attempts to 526 * `iret' because the TSS link is uninitialized. We 527 * want to get this fault so that we can fix the 528 * problem here and not every time the kernel is 529 * entered. 530 */ 531 if (frame->tf_rflags & PSL_NT) { 532 frame->tf_rflags &= ~PSL_NT; 533 goto out; 534 } 535 break; 536 537 case T_TRCTRAP: /* trace trap */ 538 /* 539 * Ignore debug register trace traps due to 540 * accesses in the user's address space, which 541 * can happen under several conditions such as 542 * if a user sets a watchpoint on a buffer and 543 * then passes that buffer to a system call. 544 * We still want to get TRCTRAPS for addresses 545 * in kernel space because that is useful when 546 * debugging the kernel. 547 */ 548 if (user_dbreg_trap()) { 549 /* 550 * Reset breakpoint bits because the 551 * processor doesn't 552 */ 553 /* XXX check upper bits here */ 554 load_dr6(rdr6() & 0xfffffff0); 555 goto out; 556 } 557 /* 558 * FALLTHROUGH (TRCTRAP kernel mode, kernel address) 559 */ 560 case T_BPTFLT: 561 /* 562 * If KDB is enabled, let it handle the debugger trap. 563 * Otherwise, debugger traps "can't happen". 564 */ 565 #ifdef KDB 566 if (kdb_trap(type, 0, frame)) 567 goto out; 568 #endif 569 break; 570 571 #ifdef DEV_ISA 572 case T_NMI: 573 /* machine/parity/power fail/"kitchen sink" faults */ 574 if (isa_nmi(code) == 0) { 575 #ifdef KDB 576 /* 577 * NMI can be hooked up to a pushbutton 578 * for debugging. 579 */ 580 if (kdb_on_nmi) { 581 printf ("NMI ... going to debugger\n"); 582 kdb_trap(type, 0, frame); 583 } 584 #endif /* KDB */ 585 goto out; 586 } else if (panic_on_nmi == 0) 587 goto out; 588 /* FALLTHROUGH */ 589 #endif /* DEV_ISA */ 590 } 591 592 trap_fatal(frame, 0); 593 goto out; 594 } 595 596 /* Translate fault for emulators (e.g. Linux) */ 597 if (*p->p_sysent->sv_transtrap) 598 i = (*p->p_sysent->sv_transtrap)(i, type); 599 600 ksiginfo_init_trap(&ksi); 601 ksi.ksi_signo = i; 602 ksi.ksi_code = ucode; 603 ksi.ksi_trapno = type; 604 ksi.ksi_addr = (void *)addr; 605 trapsignal(td, &ksi); 606 607 user: 608 userret(td, frame); 609 mtx_assert(&Giant, MA_NOTOWNED); 610 KASSERT(PCB_USER_FPU(td->td_pcb), 611 ("Return from trap with kernel FPU ctx leaked")); 612 userout: 613 out: 614 return; 615 } 616 617 static int 618 trap_pfault(frame, usermode) 619 struct trapframe *frame; 620 int usermode; 621 { 622 vm_offset_t va; 623 struct vmspace *vm = NULL; 624 vm_map_t map; 625 int rv = 0; 626 vm_prot_t ftype; 627 struct thread *td = curthread; 628 struct proc *p = td->td_proc; 629 vm_offset_t eva = frame->tf_addr; 630 631 va = trunc_page(eva); 632 if (va >= VM_MIN_KERNEL_ADDRESS) { 633 /* 634 * Don't allow user-mode faults in kernel address space. 635 */ 636 if (usermode) 637 goto nogo; 638 639 map = kernel_map; 640 } else { 641 /* 642 * This is a fault on non-kernel virtual memory. 643 * vm is initialized above to NULL. If curproc is NULL 644 * or curproc->p_vmspace is NULL the fault is fatal. 645 */ 646 if (p != NULL) 647 vm = p->p_vmspace; 648 649 if (vm == NULL) 650 goto nogo; 651 652 map = &vm->vm_map; 653 } 654 655 /* 656 * PGEX_I is defined only if the execute disable bit capability is 657 * supported and enabled. 658 */ 659 if (frame->tf_err & PGEX_W) 660 ftype = VM_PROT_WRITE; 661 else if ((frame->tf_err & PGEX_I) && pg_nx != 0) 662 ftype = VM_PROT_EXECUTE; 663 else 664 ftype = VM_PROT_READ; 665 666 if (map != kernel_map) { 667 /* 668 * Keep swapout from messing with us during this 669 * critical time. 670 */ 671 PROC_LOCK(p); 672 ++p->p_lock; 673 PROC_UNLOCK(p); 674 675 /* Fault in the user page: */ 676 rv = vm_fault(map, va, ftype, 677 (ftype & VM_PROT_WRITE) ? VM_FAULT_DIRTY 678 : VM_FAULT_NORMAL); 679 680 PROC_LOCK(p); 681 --p->p_lock; 682 PROC_UNLOCK(p); 683 } else { 684 /* 685 * Don't have to worry about process locking or stacks in the 686 * kernel. 687 */ 688 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 689 } 690 if (rv == KERN_SUCCESS) 691 return (0); 692 nogo: 693 if (!usermode) { 694 if (td->td_intr_nesting_level == 0 && 695 PCPU_GET(curpcb)->pcb_onfault != NULL) { 696 frame->tf_rip = (long)PCPU_GET(curpcb)->pcb_onfault; 697 return (0); 698 } 699 trap_fatal(frame, eva); 700 return (-1); 701 } 702 703 return((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); 704 } 705 706 static void 707 trap_fatal(frame, eva) 708 struct trapframe *frame; 709 vm_offset_t eva; 710 { 711 int code, ss; 712 u_int type; 713 long esp; 714 struct soft_segment_descriptor softseg; 715 char *msg; 716 717 code = frame->tf_err; 718 type = frame->tf_trapno; 719 sdtossd(&gdt[NGDT * PCPU_GET(cpuid) + IDXSEL(frame->tf_cs & 0xffff)], 720 &softseg); 721 722 if (type <= MAX_TRAP_MSG) 723 msg = trap_msg[type]; 724 else 725 msg = "UNKNOWN"; 726 printf("\n\nFatal trap %d: %s while in %s mode\n", type, msg, 727 ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel"); 728 #ifdef SMP 729 /* two separate prints in case of a trap on an unmapped page */ 730 printf("cpuid = %d; ", PCPU_GET(cpuid)); 731 printf("apic id = %02x\n", PCPU_GET(apic_id)); 732 #endif 733 if (type == T_PAGEFLT) { 734 printf("fault virtual address = 0x%lx\n", eva); 735 printf("fault code = %s %s %s, %s\n", 736 code & PGEX_U ? "user" : "supervisor", 737 code & PGEX_W ? "write" : "read", 738 code & PGEX_I ? "instruction" : "data", 739 code & PGEX_P ? "protection violation" : "page not present"); 740 } 741 printf("instruction pointer = 0x%lx:0x%lx\n", 742 frame->tf_cs & 0xffff, frame->tf_rip); 743 if (ISPL(frame->tf_cs) == SEL_UPL) { 744 ss = frame->tf_ss & 0xffff; 745 esp = frame->tf_rsp; 746 } else { 747 ss = GSEL(GDATA_SEL, SEL_KPL); 748 esp = (long)&frame->tf_rsp; 749 } 750 printf("stack pointer = 0x%x:0x%lx\n", ss, esp); 751 printf("frame pointer = 0x%x:0x%lx\n", ss, frame->tf_rbp); 752 printf("code segment = base 0x%lx, limit 0x%lx, type 0x%x\n", 753 softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type); 754 printf(" = DPL %d, pres %d, long %d, def32 %d, gran %d\n", 755 softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_long, softseg.ssd_def32, 756 softseg.ssd_gran); 757 printf("processor eflags = "); 758 if (frame->tf_rflags & PSL_T) 759 printf("trace trap, "); 760 if (frame->tf_rflags & PSL_I) 761 printf("interrupt enabled, "); 762 if (frame->tf_rflags & PSL_NT) 763 printf("nested task, "); 764 if (frame->tf_rflags & PSL_RF) 765 printf("resume, "); 766 printf("IOPL = %ld\n", (frame->tf_rflags & PSL_IOPL) >> 12); 767 printf("current process = "); 768 if (curproc) { 769 printf("%lu (%s)\n", 770 (u_long)curproc->p_pid, curthread->td_name ? 771 curthread->td_name : ""); 772 } else { 773 printf("Idle\n"); 774 } 775 776 #ifdef KDB 777 if (debugger_on_panic || kdb_active) 778 if (kdb_trap(type, 0, frame)) 779 return; 780 #endif 781 printf("trap number = %d\n", type); 782 if (type <= MAX_TRAP_MSG) 783 panic("%s", trap_msg[type]); 784 else 785 panic("unknown/reserved trap"); 786 } 787 788 /* 789 * Double fault handler. Called when a fault occurs while writing 790 * a frame for a trap/exception onto the stack. This usually occurs 791 * when the stack overflows (such is the case with infinite recursion, 792 * for example). 793 */ 794 void 795 dblfault_handler(struct trapframe *frame) 796 { 797 #ifdef KDTRACE_HOOKS 798 if (dtrace_doubletrap_func != NULL) 799 (*dtrace_doubletrap_func)(); 800 #endif 801 printf("\nFatal double fault\n"); 802 printf("rip = 0x%lx\n", frame->tf_rip); 803 printf("rsp = 0x%lx\n", frame->tf_rsp); 804 printf("rbp = 0x%lx\n", frame->tf_rbp); 805 #ifdef SMP 806 /* two separate prints in case of a trap on an unmapped page */ 807 printf("cpuid = %d; ", PCPU_GET(cpuid)); 808 printf("apic id = %02x\n", PCPU_GET(apic_id)); 809 #endif 810 panic("double fault"); 811 } 812 813 int 814 cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 815 { 816 struct proc *p; 817 struct trapframe *frame; 818 register_t *argp; 819 caddr_t params; 820 int reg, regcnt, error; 821 822 p = td->td_proc; 823 frame = td->td_frame; 824 reg = 0; 825 regcnt = 6; 826 827 params = (caddr_t)frame->tf_rsp + sizeof(register_t); 828 sa->code = frame->tf_rax; 829 830 if (sa->code == SYS_syscall || sa->code == SYS___syscall) { 831 sa->code = frame->tf_rdi; 832 reg++; 833 regcnt--; 834 } 835 if (p->p_sysent->sv_mask) 836 sa->code &= p->p_sysent->sv_mask; 837 838 if (sa->code >= p->p_sysent->sv_size) 839 sa->callp = &p->p_sysent->sv_table[0]; 840 else 841 sa->callp = &p->p_sysent->sv_table[sa->code]; 842 843 sa->narg = sa->callp->sy_narg; 844 KASSERT(sa->narg <= sizeof(sa->args) / sizeof(sa->args[0]), 845 ("Too many syscall arguments!")); 846 error = 0; 847 argp = &frame->tf_rdi; 848 argp += reg; 849 bcopy(argp, sa->args, sizeof(sa->args[0]) * regcnt); 850 if (sa->narg > regcnt) { 851 KASSERT(params != NULL, ("copyin args with no params!")); 852 error = copyin(params, &sa->args[regcnt], 853 (sa->narg - regcnt) * sizeof(sa->args[0])); 854 } 855 856 if (error == 0) { 857 td->td_retval[0] = 0; 858 td->td_retval[1] = frame->tf_rdx; 859 } 860 861 return (error); 862 } 863 864 /* 865 * syscall - system call request C handler 866 * 867 * A system call is essentially treated as a trap. 868 */ 869 void 870 syscall(struct trapframe *frame) 871 { 872 struct thread *td; 873 struct syscall_args sa; 874 register_t orig_tf_rflags; 875 int error; 876 ksiginfo_t ksi; 877 878 #ifdef DIAGNOSTIC 879 if (ISPL(frame->tf_cs) != SEL_UPL) { 880 panic("syscall"); 881 /* NOT REACHED */ 882 } 883 #endif 884 orig_tf_rflags = frame->tf_rflags; 885 td = curthread; 886 td->td_frame = frame; 887 888 error = syscallenter(td, &sa); 889 890 /* 891 * Traced syscall. 892 */ 893 if (orig_tf_rflags & PSL_T) { 894 frame->tf_rflags &= ~PSL_T; 895 ksiginfo_init_trap(&ksi); 896 ksi.ksi_signo = SIGTRAP; 897 ksi.ksi_code = TRAP_TRACE; 898 ksi.ksi_addr = (void *)frame->tf_rip; 899 trapsignal(td, &ksi); 900 } 901 902 KASSERT(PCB_USER_FPU(td->td_pcb), 903 ("System call %s returing with kernel FPU ctx leaked", 904 syscallname(td->td_proc, sa.code))); 905 KASSERT(td->td_pcb->pcb_save == &td->td_pcb->pcb_user_save, 906 ("System call %s returning with mangled pcb_save", 907 syscallname(td->td_proc, sa.code))); 908 909 syscallret(td, error, &sa); 910 911 /* 912 * If the user-supplied value of %rip is not a canonical 913 * address, then some CPUs will trigger a ring 0 #GP during 914 * the sysret instruction. However, the fault handler would 915 * execute with the user's %gs and %rsp in ring 0 which would 916 * not be safe. Instead, preemptively kill the thread with a 917 * SIGBUS. 918 */ 919 if (td->td_frame->tf_rip >= VM_MAXUSER_ADDRESS) { 920 ksiginfo_init_trap(&ksi); 921 ksi.ksi_signo = SIGBUS; 922 ksi.ksi_code = BUS_OBJERR; 923 ksi.ksi_trapno = T_PROTFLT; 924 ksi.ksi_addr = (void *)td->td_frame->tf_rip; 925 trapsignal(td, &ksi); 926 } 927 }
Cache object: 802728754f5f4dfc3816b8d1bac24755
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