trap.c revision 277379
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: stable/10/sys/amd64/amd64/trap.c 277379 2015-01-19 11:07:29Z kib $"); 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 54#include <sys/param.h> 55#include <sys/bus.h> 56#include <sys/systm.h> 57#include <sys/proc.h> 58#include <sys/pioctl.h> 59#include <sys/ptrace.h> 60#include <sys/kdb.h> 61#include <sys/kernel.h> 62#include <sys/ktr.h> 63#include <sys/lock.h> 64#include <sys/mutex.h> 65#include <sys/resourcevar.h> 66#include <sys/signalvar.h> 67#include <sys/syscall.h> 68#include <sys/sysctl.h> 69#include <sys/sysent.h> 70#include <sys/uio.h> 71#include <sys/vmmeter.h> 72#ifdef HWPMC_HOOKS 73#include <sys/pmckern.h> 74PMC_SOFT_DEFINE( , , page_fault, all); 75PMC_SOFT_DEFINE( , , page_fault, read); 76PMC_SOFT_DEFINE( , , page_fault, write); 77#endif 78 79#include <vm/vm.h> 80#include <vm/vm_param.h> 81#include <vm/pmap.h> 82#include <vm/vm_kern.h> 83#include <vm/vm_map.h> 84#include <vm/vm_page.h> 85#include <vm/vm_extern.h> 86 87#include <machine/cpu.h> 88#include <machine/intr_machdep.h> 89#include <x86/mca.h> 90#include <machine/md_var.h> 91#include <machine/pcb.h> 92#ifdef SMP 93#include <machine/smp.h> 94#endif 95#include <machine/tss.h> 96 97#ifdef KDTRACE_HOOKS 98#include <sys/dtrace_bsd.h> 99#endif 100 101extern void trap(struct trapframe *frame); 102extern void syscall(struct trapframe *frame); 103void dblfault_handler(struct trapframe *frame); 104 105static int trap_pfault(struct trapframe *, int); 106static void trap_fatal(struct trapframe *, vm_offset_t); 107 108#define MAX_TRAP_MSG 32 109static char *trap_msg[] = { 110 "", /* 0 unused */ 111 "privileged instruction fault", /* 1 T_PRIVINFLT */ 112 "", /* 2 unused */ 113 "breakpoint instruction fault", /* 3 T_BPTFLT */ 114 "", /* 4 unused */ 115 "", /* 5 unused */ 116 "arithmetic trap", /* 6 T_ARITHTRAP */ 117 "", /* 7 unused */ 118 "", /* 8 unused */ 119 "general protection fault", /* 9 T_PROTFLT */ 120 "trace trap", /* 10 T_TRCTRAP */ 121 "", /* 11 unused */ 122 "page fault", /* 12 T_PAGEFLT */ 123 "", /* 13 unused */ 124 "alignment fault", /* 14 T_ALIGNFLT */ 125 "", /* 15 unused */ 126 "", /* 16 unused */ 127 "", /* 17 unused */ 128 "integer divide fault", /* 18 T_DIVIDE */ 129 "non-maskable interrupt trap", /* 19 T_NMI */ 130 "overflow trap", /* 20 T_OFLOW */ 131 "FPU bounds check fault", /* 21 T_BOUND */ 132 "FPU device not available", /* 22 T_DNA */ 133 "double fault", /* 23 T_DOUBLEFLT */ 134 "FPU operand fetch fault", /* 24 T_FPOPFLT */ 135 "invalid TSS fault", /* 25 T_TSSFLT */ 136 "segment not present fault", /* 26 T_SEGNPFLT */ 137 "stack fault", /* 27 T_STKFLT */ 138 "machine check trap", /* 28 T_MCHK */ 139 "SIMD floating-point exception", /* 29 T_XMMFLT */ 140 "reserved (unknown) fault", /* 30 T_RESERVED */ 141 "", /* 31 unused (reserved) */ 142 "DTrace pid return trap", /* 32 T_DTRACE_RET */ 143}; 144 145#ifdef KDB 146static int kdb_on_nmi = 1; 147SYSCTL_INT(_machdep, OID_AUTO, kdb_on_nmi, CTLFLAG_RW, 148 &kdb_on_nmi, 0, "Go to KDB on NMI"); 149TUNABLE_INT("machdep.kdb_on_nmi", &kdb_on_nmi); 150#endif 151static int panic_on_nmi = 1; 152SYSCTL_INT(_machdep, OID_AUTO, panic_on_nmi, CTLFLAG_RW, 153 &panic_on_nmi, 0, "Panic on NMI"); 154TUNABLE_INT("machdep.panic_on_nmi", &panic_on_nmi); 155static int prot_fault_translation; 156SYSCTL_INT(_machdep, OID_AUTO, prot_fault_translation, CTLFLAG_RW, 157 &prot_fault_translation, 0, 158 "Select signal to deliver on protection fault"); 159static int uprintf_signal; 160SYSCTL_INT(_machdep, OID_AUTO, uprintf_signal, CTLFLAG_RW, 161 &uprintf_signal, 0, 162 "Print debugging information on trap signal to ctty"); 163 164/* 165 * Exception, fault, and trap interface to the FreeBSD kernel. 166 * This common code is called from assembly language IDT gate entry 167 * routines that prepare a suitable stack frame, and restore this 168 * frame after the exception has been processed. 169 */ 170 171void 172trap(struct trapframe *frame) 173{ 174#ifdef KDTRACE_HOOKS 175 struct reg regs; 176#endif 177 struct thread *td = curthread; 178 struct proc *p = td->td_proc; 179 int i = 0, ucode = 0, code; 180 u_int type; 181 register_t addr = 0; 182 ksiginfo_t ksi; 183 184 PCPU_INC(cnt.v_trap); 185 type = frame->tf_trapno; 186 187#ifdef SMP 188 /* Handler for NMI IPIs used for stopping CPUs. */ 189 if (type == T_NMI) { 190 if (ipi_nmi_handler() == 0) 191 goto out; 192 } 193#endif /* SMP */ 194 195#ifdef KDB 196 if (kdb_active) { 197 kdb_reenter(); 198 goto out; 199 } 200#endif 201 202 if (type == T_RESERVED) { 203 trap_fatal(frame, 0); 204 goto out; 205 } 206 207#ifdef HWPMC_HOOKS 208 /* 209 * CPU PMCs interrupt using an NMI. If the PMC module is 210 * active, pass the 'rip' value to the PMC module's interrupt 211 * handler. A return value of '1' from the handler means that 212 * the NMI was handled by it and we can return immediately. 213 */ 214 if (type == T_NMI && pmc_intr && 215 (*pmc_intr)(PCPU_GET(cpuid), frame)) 216 goto out; 217#endif 218 219 if (type == T_MCHK) { 220 mca_intr(); 221 goto out; 222 } 223 224#ifdef KDTRACE_HOOKS 225 /* 226 * A trap can occur while DTrace executes a probe. Before 227 * executing the probe, DTrace blocks re-scheduling and sets 228 * a flag in its per-cpu flags to indicate that it doesn't 229 * want to fault. On returning from the probe, the no-fault 230 * flag is cleared and finally re-scheduling is enabled. 231 */ 232 if (dtrace_trap_func != NULL && (*dtrace_trap_func)(frame, type)) 233 goto out; 234#endif 235 236 if ((frame->tf_rflags & PSL_I) == 0) { 237 /* 238 * Buggy application or kernel code has disabled 239 * interrupts and then trapped. Enabling interrupts 240 * now is wrong, but it is better than running with 241 * interrupts disabled until they are accidentally 242 * enabled later. 243 */ 244 if (ISPL(frame->tf_cs) == SEL_UPL) 245 uprintf( 246 "pid %ld (%s): trap %d with interrupts disabled\n", 247 (long)curproc->p_pid, curthread->td_name, type); 248 else if (type != T_NMI && type != T_BPTFLT && 249 type != T_TRCTRAP) { 250 /* 251 * XXX not quite right, since this may be for a 252 * multiple fault in user mode. 253 */ 254 printf("kernel trap %d with interrupts disabled\n", 255 type); 256 257 /* 258 * We shouldn't enable interrupts while holding a 259 * spin lock. 260 */ 261 if (td->td_md.md_spinlock_count == 0) 262 enable_intr(); 263 } 264 } 265 266 code = frame->tf_err; 267 268 if (ISPL(frame->tf_cs) == SEL_UPL) { 269 /* user trap */ 270 271 td->td_pticks = 0; 272 td->td_frame = frame; 273 addr = frame->tf_rip; 274 if (td->td_ucred != p->p_ucred) 275 cred_update_thread(td); 276 277 switch (type) { 278 case T_PRIVINFLT: /* privileged instruction fault */ 279 i = SIGILL; 280 ucode = ILL_PRVOPC; 281 break; 282 283 case T_BPTFLT: /* bpt instruction fault */ 284 case T_TRCTRAP: /* trace trap */ 285 enable_intr(); 286#ifdef KDTRACE_HOOKS 287 if (type == T_BPTFLT) { 288 fill_frame_regs(frame, ®s); 289 if (dtrace_pid_probe_ptr != NULL && 290 dtrace_pid_probe_ptr(®s) == 0) 291 goto out; 292 } 293#endif 294 frame->tf_rflags &= ~PSL_T; 295 i = SIGTRAP; 296 ucode = (type == T_TRCTRAP ? TRAP_TRACE : TRAP_BRKPT); 297 break; 298 299 case T_ARITHTRAP: /* arithmetic trap */ 300 ucode = fputrap_x87(); 301 if (ucode == -1) 302 goto userout; 303 i = SIGFPE; 304 break; 305 306 case T_PROTFLT: /* general protection fault */ 307 i = SIGBUS; 308 ucode = BUS_OBJERR; 309 break; 310 case T_STKFLT: /* stack fault */ 311 case T_SEGNPFLT: /* segment not present fault */ 312 i = SIGBUS; 313 ucode = BUS_ADRERR; 314 break; 315 case T_TSSFLT: /* invalid TSS fault */ 316 i = SIGBUS; 317 ucode = BUS_OBJERR; 318 break; 319 case T_ALIGNFLT: 320 i = SIGBUS; 321 ucode = BUS_ADRALN; 322 break; 323 case T_DOUBLEFLT: /* double fault */ 324 default: 325 i = SIGBUS; 326 ucode = BUS_OBJERR; 327 break; 328 329 case T_PAGEFLT: /* page fault */ 330 addr = frame->tf_addr; 331 i = trap_pfault(frame, TRUE); 332 if (i == -1) 333 goto userout; 334 if (i == 0) 335 goto user; 336 337 if (i == SIGSEGV) 338 ucode = SEGV_MAPERR; 339 else { 340 if (prot_fault_translation == 0) { 341 /* 342 * Autodetect. 343 * This check also covers the images 344 * without the ABI-tag ELF note. 345 */ 346 if (SV_CURPROC_ABI() == SV_ABI_FREEBSD 347 && p->p_osrel >= P_OSREL_SIGSEGV) { 348 i = SIGSEGV; 349 ucode = SEGV_ACCERR; 350 } else { 351 i = SIGBUS; 352 ucode = BUS_PAGE_FAULT; 353 } 354 } else if (prot_fault_translation == 1) { 355 /* 356 * Always compat mode. 357 */ 358 i = SIGBUS; 359 ucode = BUS_PAGE_FAULT; 360 } else { 361 /* 362 * Always SIGSEGV mode. 363 */ 364 i = SIGSEGV; 365 ucode = SEGV_ACCERR; 366 } 367 } 368 break; 369 370 case T_DIVIDE: /* integer divide fault */ 371 ucode = FPE_INTDIV; 372 i = SIGFPE; 373 break; 374 375#ifdef DEV_ISA 376 case T_NMI: 377 /* machine/parity/power fail/"kitchen sink" faults */ 378 if (isa_nmi(code) == 0) { 379#ifdef KDB 380 /* 381 * NMI can be hooked up to a pushbutton 382 * for debugging. 383 */ 384 if (kdb_on_nmi) { 385 printf ("NMI ... going to debugger\n"); 386 kdb_trap(type, 0, frame); 387 } 388#endif /* KDB */ 389 goto userout; 390 } else if (panic_on_nmi) 391 panic("NMI indicates hardware failure"); 392 break; 393#endif /* DEV_ISA */ 394 395 case T_OFLOW: /* integer overflow fault */ 396 ucode = FPE_INTOVF; 397 i = SIGFPE; 398 break; 399 400 case T_BOUND: /* bounds check fault */ 401 ucode = FPE_FLTSUB; 402 i = SIGFPE; 403 break; 404 405 case T_DNA: 406 /* transparent fault (due to context switch "late") */ 407 KASSERT(PCB_USER_FPU(td->td_pcb), 408 ("kernel FPU ctx has leaked")); 409 fpudna(); 410 goto userout; 411 412 case T_FPOPFLT: /* FPU operand fetch fault */ 413 ucode = ILL_COPROC; 414 i = SIGILL; 415 break; 416 417 case T_XMMFLT: /* SIMD floating-point exception */ 418 ucode = fputrap_sse(); 419 if (ucode == -1) 420 goto userout; 421 i = SIGFPE; 422 break; 423#ifdef KDTRACE_HOOKS 424 case T_DTRACE_RET: 425 enable_intr(); 426 fill_frame_regs(frame, ®s); 427 if (dtrace_return_probe_ptr != NULL && 428 dtrace_return_probe_ptr(®s) == 0) 429 goto out; 430 break; 431#endif 432 } 433 } else { 434 /* kernel trap */ 435 436 KASSERT(cold || td->td_ucred != NULL, 437 ("kernel trap doesn't have ucred")); 438 switch (type) { 439 case T_PAGEFLT: /* page fault */ 440 (void) trap_pfault(frame, FALSE); 441 goto out; 442 443 case T_DNA: 444 KASSERT(!PCB_USER_FPU(td->td_pcb), 445 ("Unregistered use of FPU in kernel")); 446 fpudna(); 447 goto out; 448 449 case T_ARITHTRAP: /* arithmetic trap */ 450 case T_XMMFLT: /* SIMD floating-point exception */ 451 case T_FPOPFLT: /* FPU operand fetch fault */ 452 /* 453 * For now, supporting kernel handler 454 * registration for FPU traps is overkill. 455 */ 456 trap_fatal(frame, 0); 457 goto out; 458 459 case T_STKFLT: /* stack fault */ 460 break; 461 462 case T_PROTFLT: /* general protection fault */ 463 case T_SEGNPFLT: /* segment not present fault */ 464 if (td->td_intr_nesting_level != 0) 465 break; 466 467 /* 468 * Invalid segment selectors and out of bounds 469 * %rip's and %rsp's can be set up in user mode. 470 * This causes a fault in kernel mode when the 471 * kernel tries to return to user mode. We want 472 * to get this fault so that we can fix the 473 * problem here and not have to check all the 474 * selectors and pointers when the user changes 475 * them. 476 */ 477 if (frame->tf_rip == (long)doreti_iret) { 478 frame->tf_rip = (long)doreti_iret_fault; 479 goto out; 480 } 481 if (frame->tf_rip == (long)ld_ds) { 482 frame->tf_rip = (long)ds_load_fault; 483 goto out; 484 } 485 if (frame->tf_rip == (long)ld_es) { 486 frame->tf_rip = (long)es_load_fault; 487 goto out; 488 } 489 if (frame->tf_rip == (long)ld_fs) { 490 frame->tf_rip = (long)fs_load_fault; 491 goto out; 492 } 493 if (frame->tf_rip == (long)ld_gs) { 494 frame->tf_rip = (long)gs_load_fault; 495 goto out; 496 } 497 if (frame->tf_rip == (long)ld_gsbase) { 498 frame->tf_rip = (long)gsbase_load_fault; 499 goto out; 500 } 501 if (frame->tf_rip == (long)ld_fsbase) { 502 frame->tf_rip = (long)fsbase_load_fault; 503 goto out; 504 } 505 if (curpcb->pcb_onfault != NULL) { 506 frame->tf_rip = (long)curpcb->pcb_onfault; 507 goto out; 508 } 509 break; 510 511 case T_TSSFLT: 512 /* 513 * PSL_NT can be set in user mode and isn't cleared 514 * automatically when the kernel is entered. This 515 * causes a TSS fault when the kernel attempts to 516 * `iret' because the TSS link is uninitialized. We 517 * want to get this fault so that we can fix the 518 * problem here and not every time the kernel is 519 * entered. 520 */ 521 if (frame->tf_rflags & PSL_NT) { 522 frame->tf_rflags &= ~PSL_NT; 523 goto out; 524 } 525 break; 526 527 case T_TRCTRAP: /* trace trap */ 528 /* 529 * Ignore debug register trace traps due to 530 * accesses in the user's address space, which 531 * can happen under several conditions such as 532 * if a user sets a watchpoint on a buffer and 533 * then passes that buffer to a system call. 534 * We still want to get TRCTRAPS for addresses 535 * in kernel space because that is useful when 536 * debugging the kernel. 537 */ 538 if (user_dbreg_trap()) { 539 /* 540 * Reset breakpoint bits because the 541 * processor doesn't 542 */ 543 /* XXX check upper bits here */ 544 load_dr6(rdr6() & 0xfffffff0); 545 goto out; 546 } 547 /* 548 * FALLTHROUGH (TRCTRAP kernel mode, kernel address) 549 */ 550 case T_BPTFLT: 551 /* 552 * If KDB is enabled, let it handle the debugger trap. 553 * Otherwise, debugger traps "can't happen". 554 */ 555#ifdef KDB 556 if (kdb_trap(type, 0, frame)) 557 goto out; 558#endif 559 break; 560 561#ifdef DEV_ISA 562 case T_NMI: 563 /* machine/parity/power fail/"kitchen sink" faults */ 564 if (isa_nmi(code) == 0) { 565#ifdef KDB 566 /* 567 * NMI can be hooked up to a pushbutton 568 * for debugging. 569 */ 570 if (kdb_on_nmi) { 571 printf ("NMI ... going to debugger\n"); 572 kdb_trap(type, 0, frame); 573 } 574#endif /* KDB */ 575 goto out; 576 } else if (panic_on_nmi == 0) 577 goto out; 578 /* FALLTHROUGH */ 579#endif /* DEV_ISA */ 580 } 581 582 trap_fatal(frame, 0); 583 goto out; 584 } 585 586 /* Translate fault for emulators (e.g. Linux) */ 587 if (*p->p_sysent->sv_transtrap) 588 i = (*p->p_sysent->sv_transtrap)(i, type); 589 590 ksiginfo_init_trap(&ksi); 591 ksi.ksi_signo = i; 592 ksi.ksi_code = ucode; 593 ksi.ksi_trapno = type; 594 ksi.ksi_addr = (void *)addr; 595 if (uprintf_signal) { 596 uprintf("pid %d comm %s: signal %d err %lx code %d type %d " 597 "addr 0x%lx rsp 0x%lx rip 0x%lx " 598 "<%02x %02x %02x %02x %02x %02x %02x %02x>\n", 599 p->p_pid, p->p_comm, i, frame->tf_err, ucode, type, addr, 600 frame->tf_rsp, frame->tf_rip, 601 fubyte((void *)(frame->tf_rip + 0)), 602 fubyte((void *)(frame->tf_rip + 1)), 603 fubyte((void *)(frame->tf_rip + 2)), 604 fubyte((void *)(frame->tf_rip + 3)), 605 fubyte((void *)(frame->tf_rip + 4)), 606 fubyte((void *)(frame->tf_rip + 5)), 607 fubyte((void *)(frame->tf_rip + 6)), 608 fubyte((void *)(frame->tf_rip + 7))); 609 } 610 KASSERT((read_rflags() & PSL_I) != 0, ("interrupts disabled")); 611 trapsignal(td, &ksi); 612 613user: 614 userret(td, frame); 615 KASSERT(PCB_USER_FPU(td->td_pcb), 616 ("Return from trap with kernel FPU ctx leaked")); 617userout: 618out: 619 return; 620} 621 622static int 623trap_pfault(frame, usermode) 624 struct trapframe *frame; 625 int usermode; 626{ 627 vm_offset_t va; 628 struct vmspace *vm; 629 vm_map_t map; 630 int rv = 0; 631 vm_prot_t ftype; 632 struct thread *td = curthread; 633 struct proc *p = td->td_proc; 634 vm_offset_t eva = frame->tf_addr; 635 636 if (__predict_false((td->td_pflags & TDP_NOFAULTING) != 0)) { 637 /* 638 * Due to both processor errata and lazy TLB invalidation when 639 * access restrictions are removed from virtual pages, memory 640 * accesses that are allowed by the physical mapping layer may 641 * nonetheless cause one spurious page fault per virtual page. 642 * When the thread is executing a "no faulting" section that 643 * is bracketed by vm_fault_{disable,enable}_pagefaults(), 644 * every page fault is treated as a spurious page fault, 645 * unless it accesses the same virtual address as the most 646 * recent page fault within the same "no faulting" section. 647 */ 648 if (td->td_md.md_spurflt_addr != eva || 649 (td->td_pflags & TDP_RESETSPUR) != 0) { 650 /* 651 * Do nothing to the TLB. A stale TLB entry is 652 * flushed automatically by a page fault. 653 */ 654 td->td_md.md_spurflt_addr = eva; 655 td->td_pflags &= ~TDP_RESETSPUR; 656 return (0); 657 } 658 } else { 659 /* 660 * If we get a page fault while in a critical section, then 661 * it is most likely a fatal kernel page fault. The kernel 662 * is already going to panic trying to get a sleep lock to 663 * do the VM lookup, so just consider it a fatal trap so the 664 * kernel can print out a useful trap message and even get 665 * to the debugger. 666 * 667 * If we get a page fault while holding a non-sleepable 668 * lock, then it is most likely a fatal kernel page fault. 669 * If WITNESS is enabled, then it's going to whine about 670 * bogus LORs with various VM locks, so just skip to the 671 * fatal trap handling directly. 672 */ 673 if (td->td_critnest != 0 || 674 WITNESS_CHECK(WARN_SLEEPOK | WARN_GIANTOK, NULL, 675 "Kernel page fault") != 0) { 676 trap_fatal(frame, eva); 677 return (-1); 678 } 679 } 680 va = trunc_page(eva); 681 if (va >= VM_MIN_KERNEL_ADDRESS) { 682 /* 683 * Don't allow user-mode faults in kernel address space. 684 */ 685 if (usermode) 686 goto nogo; 687 688 map = kernel_map; 689 } else { 690 /* 691 * This is a fault on non-kernel virtual memory. If either 692 * p or p->p_vmspace is NULL, then the fault is fatal. 693 */ 694 if (p == NULL || (vm = p->p_vmspace) == NULL) 695 goto nogo; 696 697 map = &vm->vm_map; 698 699 /* 700 * When accessing a usermode address, kernel must be 701 * ready to accept the page fault, and provide a 702 * handling routine. Since accessing the address 703 * without the handler is a bug, do not try to handle 704 * it normally, and panic immediately. 705 */ 706 if (!usermode && (td->td_intr_nesting_level != 0 || 707 curpcb->pcb_onfault == NULL)) { 708 trap_fatal(frame, eva); 709 return (-1); 710 } 711 } 712 713 /* 714 * If the trap was caused by errant bits in the PTE then panic. 715 */ 716 if (frame->tf_err & PGEX_RSV) { 717 trap_fatal(frame, eva); 718 return (-1); 719 } 720 721 /* 722 * PGEX_I is defined only if the execute disable bit capability is 723 * supported and enabled. 724 */ 725 if (frame->tf_err & PGEX_W) 726 ftype = VM_PROT_WRITE; 727 else if ((frame->tf_err & PGEX_I) && pg_nx != 0) 728 ftype = VM_PROT_EXECUTE; 729 else 730 ftype = VM_PROT_READ; 731 732 if (map != kernel_map) { 733 /* 734 * Keep swapout from messing with us during this 735 * critical time. 736 */ 737 PROC_LOCK(p); 738 ++p->p_lock; 739 PROC_UNLOCK(p); 740 741 /* Fault in the user page: */ 742 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 743 744 PROC_LOCK(p); 745 --p->p_lock; 746 PROC_UNLOCK(p); 747 } else { 748 /* 749 * Don't have to worry about process locking or stacks in the 750 * kernel. 751 */ 752 rv = vm_fault(map, va, ftype, VM_FAULT_NORMAL); 753 } 754 if (rv == KERN_SUCCESS) { 755#ifdef HWPMC_HOOKS 756 if (ftype == VM_PROT_READ || ftype == VM_PROT_WRITE) { 757 PMC_SOFT_CALL_TF( , , page_fault, all, frame); 758 if (ftype == VM_PROT_READ) 759 PMC_SOFT_CALL_TF( , , page_fault, read, 760 frame); 761 else 762 PMC_SOFT_CALL_TF( , , page_fault, write, 763 frame); 764 } 765#endif 766 return (0); 767 } 768nogo: 769 if (!usermode) { 770 if (td->td_intr_nesting_level == 0 && 771 curpcb->pcb_onfault != NULL) { 772 frame->tf_rip = (long)curpcb->pcb_onfault; 773 return (0); 774 } 775 trap_fatal(frame, eva); 776 return (-1); 777 } 778 return ((rv == KERN_PROTECTION_FAILURE) ? SIGBUS : SIGSEGV); 779} 780 781static void 782trap_fatal(frame, eva) 783 struct trapframe *frame; 784 vm_offset_t eva; 785{ 786 int code, ss; 787 u_int type; 788 long esp; 789 struct soft_segment_descriptor softseg; 790 char *msg; 791 792 code = frame->tf_err; 793 type = frame->tf_trapno; 794 sdtossd(&gdt[NGDT * PCPU_GET(cpuid) + IDXSEL(frame->tf_cs & 0xffff)], 795 &softseg); 796 797 if (type <= MAX_TRAP_MSG) 798 msg = trap_msg[type]; 799 else 800 msg = "UNKNOWN"; 801 printf("\n\nFatal trap %d: %s while in %s mode\n", type, msg, 802 ISPL(frame->tf_cs) == SEL_UPL ? "user" : "kernel"); 803#ifdef SMP 804 /* two separate prints in case of a trap on an unmapped page */ 805 printf("cpuid = %d; ", PCPU_GET(cpuid)); 806 printf("apic id = %02x\n", PCPU_GET(apic_id)); 807#endif 808 if (type == T_PAGEFLT) { 809 printf("fault virtual address = 0x%lx\n", eva); 810 printf("fault code = %s %s %s%s, %s\n", 811 code & PGEX_U ? "user" : "supervisor", 812 code & PGEX_W ? "write" : "read", 813 code & PGEX_I ? "instruction" : "data", 814 code & PGEX_RSV ? " rsv" : "", 815 code & PGEX_P ? "protection violation" : "page not present"); 816 } 817 printf("instruction pointer = 0x%lx:0x%lx\n", 818 frame->tf_cs & 0xffff, frame->tf_rip); 819 if (ISPL(frame->tf_cs) == SEL_UPL) { 820 ss = frame->tf_ss & 0xffff; 821 esp = frame->tf_rsp; 822 } else { 823 ss = GSEL(GDATA_SEL, SEL_KPL); 824 esp = (long)&frame->tf_rsp; 825 } 826 printf("stack pointer = 0x%x:0x%lx\n", ss, esp); 827 printf("frame pointer = 0x%x:0x%lx\n", ss, frame->tf_rbp); 828 printf("code segment = base 0x%lx, limit 0x%lx, type 0x%x\n", 829 softseg.ssd_base, softseg.ssd_limit, softseg.ssd_type); 830 printf(" = DPL %d, pres %d, long %d, def32 %d, gran %d\n", 831 softseg.ssd_dpl, softseg.ssd_p, softseg.ssd_long, softseg.ssd_def32, 832 softseg.ssd_gran); 833 printf("processor eflags = "); 834 if (frame->tf_rflags & PSL_T) 835 printf("trace trap, "); 836 if (frame->tf_rflags & PSL_I) 837 printf("interrupt enabled, "); 838 if (frame->tf_rflags & PSL_NT) 839 printf("nested task, "); 840 if (frame->tf_rflags & PSL_RF) 841 printf("resume, "); 842 printf("IOPL = %ld\n", (frame->tf_rflags & PSL_IOPL) >> 12); 843 printf("current process = "); 844 if (curproc) { 845 printf("%lu (%s)\n", 846 (u_long)curproc->p_pid, curthread->td_name ? 847 curthread->td_name : ""); 848 } else { 849 printf("Idle\n"); 850 } 851 852#ifdef KDB 853 if (debugger_on_panic || kdb_active) 854 if (kdb_trap(type, 0, frame)) 855 return; 856#endif 857 printf("trap number = %d\n", type); 858 if (type <= MAX_TRAP_MSG) 859 panic("%s", trap_msg[type]); 860 else 861 panic("unknown/reserved trap"); 862} 863 864/* 865 * Double fault handler. Called when a fault occurs while writing 866 * a frame for a trap/exception onto the stack. This usually occurs 867 * when the stack overflows (such is the case with infinite recursion, 868 * for example). 869 */ 870void 871dblfault_handler(struct trapframe *frame) 872{ 873#ifdef KDTRACE_HOOKS 874 if (dtrace_doubletrap_func != NULL) 875 (*dtrace_doubletrap_func)(); 876#endif 877 printf("\nFatal double fault\n"); 878 printf("rip = 0x%lx\n", frame->tf_rip); 879 printf("rsp = 0x%lx\n", frame->tf_rsp); 880 printf("rbp = 0x%lx\n", frame->tf_rbp); 881#ifdef SMP 882 /* two separate prints in case of a trap on an unmapped page */ 883 printf("cpuid = %d; ", PCPU_GET(cpuid)); 884 printf("apic id = %02x\n", PCPU_GET(apic_id)); 885#endif 886 panic("double fault"); 887} 888 889int 890cpu_fetch_syscall_args(struct thread *td, struct syscall_args *sa) 891{ 892 struct proc *p; 893 struct trapframe *frame; 894 register_t *argp; 895 caddr_t params; 896 int reg, regcnt, error; 897 898 p = td->td_proc; 899 frame = td->td_frame; 900 reg = 0; 901 regcnt = 6; 902 903 params = (caddr_t)frame->tf_rsp + sizeof(register_t); 904 sa->code = frame->tf_rax; 905 906 if (sa->code == SYS_syscall || sa->code == SYS___syscall) { 907 sa->code = frame->tf_rdi; 908 reg++; 909 regcnt--; 910 } 911 if (p->p_sysent->sv_mask) 912 sa->code &= p->p_sysent->sv_mask; 913 914 if (sa->code >= p->p_sysent->sv_size) 915 sa->callp = &p->p_sysent->sv_table[0]; 916 else 917 sa->callp = &p->p_sysent->sv_table[sa->code]; 918 919 sa->narg = sa->callp->sy_narg; 920 KASSERT(sa->narg <= sizeof(sa->args) / sizeof(sa->args[0]), 921 ("Too many syscall arguments!")); 922 error = 0; 923 argp = &frame->tf_rdi; 924 argp += reg; 925 bcopy(argp, sa->args, sizeof(sa->args[0]) * regcnt); 926 if (sa->narg > regcnt) { 927 KASSERT(params != NULL, ("copyin args with no params!")); 928 error = copyin(params, &sa->args[regcnt], 929 (sa->narg - regcnt) * sizeof(sa->args[0])); 930 } 931 932 if (error == 0) { 933 td->td_retval[0] = 0; 934 td->td_retval[1] = frame->tf_rdx; 935 } 936 937 return (error); 938} 939 940#include "../../kern/subr_syscall.c" 941 942/* 943 * System call handler for native binaries. The trap frame is already 944 * set up by the assembler trampoline and a pointer to it is saved in 945 * td_frame. 946 */ 947void 948amd64_syscall(struct thread *td, int traced) 949{ 950 struct syscall_args sa; 951 int error; 952 ksiginfo_t ksi; 953 954#ifdef DIAGNOSTIC 955 if (ISPL(td->td_frame->tf_cs) != SEL_UPL) { 956 panic("syscall"); 957 /* NOT REACHED */ 958 } 959#endif 960 error = syscallenter(td, &sa); 961 962 /* 963 * Traced syscall. 964 */ 965 if (__predict_false(traced)) { 966 td->td_frame->tf_rflags &= ~PSL_T; 967 ksiginfo_init_trap(&ksi); 968 ksi.ksi_signo = SIGTRAP; 969 ksi.ksi_code = TRAP_TRACE; 970 ksi.ksi_addr = (void *)td->td_frame->tf_rip; 971 trapsignal(td, &ksi); 972 } 973 974 KASSERT(PCB_USER_FPU(td->td_pcb), 975 ("System call %s returing with kernel FPU ctx leaked", 976 syscallname(td->td_proc, sa.code))); 977 KASSERT(td->td_pcb->pcb_save == get_pcb_user_save_td(td), 978 ("System call %s returning with mangled pcb_save", 979 syscallname(td->td_proc, sa.code))); 980 981 syscallret(td, error, &sa); 982 983 /* 984 * If the user-supplied value of %rip is not a canonical 985 * address, then some CPUs will trigger a ring 0 #GP during 986 * the sysret instruction. However, the fault handler would 987 * execute in ring 0 with the user's %gs and %rsp which would 988 * not be safe. Instead, use the full return path which 989 * catches the problem safely. 990 */ 991 if (td->td_frame->tf_rip >= VM_MAXUSER_ADDRESS) 992 set_pcb_flags(td->td_pcb, PCB_FULL_IRET); 993} 994