lib/libkvm/kvm_amd64.c

   1 /*-
   2  * Copyright (c) 1989, 1992, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software developed by the Computer Systems
   6  * Engineering group at Lawrence Berkeley Laboratory under DARPA contract
   7  * BG 91-66 and contributed to Berkeley.
   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  * 4. Neither the name of the University nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #if defined(LIBC_SCCS) && !defined(lint)
  38 #if 0
  39 static char sccsid[] = "@(#)kvm_hp300.c 8.1 (Berkeley) 6/4/93";
  40 #endif
  41 #endif /* LIBC_SCCS and not lint */
  42
  43 /*
  44  * AMD64 machine dependent routines for kvm.  Hopefully, the forthcoming
  45  * vm code will one day obsolete this module.
  46  */
  47
  48 #include <sys/param.h>
  49 #include <sys/endian.h>
  50 #include <stdint.h>
  51 #include <stdlib.h>
  52 #include <string.h>
  53 #include <unistd.h>
  54 #include <kvm.h>
  55
  56 #include <limits.h>
  57
  58 #include "kvm_private.h"
  59 #include "kvm_amd64.h"
  60
  61 struct vmstate {
  62         size_t          phnum;
  63         GElf_Phdr       *phdr;
  64         amd64_pml4e_t   *PML4;
  65 };
  66
  67 /*
  68  * Translate a physical memory address to a file-offset in the crash-dump.
  69  */
  70 static size_t
  71 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs)
  72 {
  73         struct vmstate *vm = kd->vmst;
  74         GElf_Phdr *p;
  75         size_t n;
  76
  77         if (kd->rawdump) {
  78                 *ofs = pa;
  79                 return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
  80         }
  81
  82         p = vm->phdr;
  83         n = vm->phnum;
  84         while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz))
  85                 p++, n--;
  86         if (n == 0)
  87                 return (0);
  88         *ofs = (pa - p->p_paddr) + p->p_offset;
  89         return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK));
  90 }
  91
  92 static void
  93 _amd64_freevtop(kvm_t *kd)
  94 {
  95         struct vmstate *vm = kd->vmst;
  96
  97         if (vm->PML4)
  98                 free(vm->PML4);
  99         free(vm->phdr);
 100         free(vm);
 101         kd->vmst = NULL;
 102 }
 103
 104 static int
 105 _amd64_probe(kvm_t *kd)
 106 {
 107
 108         return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) &&
 109             !_kvm_is_minidump(kd));
 110 }
 111
 112 static int
 113 _amd64_initvtop(kvm_t *kd)
 114 {
 115         struct kvm_nlist nl[2];
 116         amd64_physaddr_t pa;
 117         kvaddr_t kernbase;
 118         amd64_pml4e_t *PML4;
 119
 120         kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst));
 121         if (kd->vmst == NULL) {
 122                 _kvm_err(kd, kd->program, "cannot allocate vm");
 123                 return (-1);
 124         }
 125         kd->vmst->PML4 = 0;
 126
 127         if (kd->rawdump == 0) {
 128                 if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum,
 129                     &kd->vmst->phdr) == -1)
 130                         return (-1);
 131         }
 132
 133         nl[0].n_name = "kernbase";
 134         nl[1].n_name = 0;
 135
 136         if (kvm_nlist2(kd, nl) != 0) {
 137                 _kvm_err(kd, kd->program, "bad namelist - no kernbase");
 138                 return (-1);
 139         }
 140         kernbase = nl[0].n_value;
 141
 142         nl[0].n_name = "KPML4phys";
 143         nl[1].n_name = 0;
 144
 145         if (kvm_nlist2(kd, nl) != 0) {
 146                 _kvm_err(kd, kd->program, "bad namelist - no KPML4phys");
 147                 return (-1);
 148         }
 149         if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa, sizeof(pa)) !=
 150             sizeof(pa)) {
 151                 _kvm_err(kd, kd->program, "cannot read KPML4phys");
 152                 return (-1);
 153         }
 154         pa = le64toh(pa);
 155         PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE);
 156         if (PML4 == NULL) {
 157                 _kvm_err(kd, kd->program, "cannot allocate PML4");
 158                 return (-1);
 159         }
 160         if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) {
 161                 _kvm_err(kd, kd->program, "cannot read KPML4phys");
 162                 free(PML4);
 163                 return (-1);
 164         }
 165         kd->vmst->PML4 = PML4;
 166         return (0);
 167 }
 168
 169 static int
 170 _amd64_vatop(kvm_t *kd, kvaddr_t va, off_t *pa)
 171 {
 172         struct vmstate *vm;
 173         amd64_physaddr_t offset;
 174         amd64_physaddr_t pdpe_pa;
 175         amd64_physaddr_t pde_pa;
 176         amd64_physaddr_t pte_pa;
 177         amd64_pml4e_t pml4e;
 178         amd64_pdpe_t pdpe;
 179         amd64_pde_t pde;
 180         amd64_pte_t pte;
 181         kvaddr_t pml4eindex;
 182         kvaddr_t pdpeindex;
 183         kvaddr_t pdeindex;
 184         kvaddr_t pteindex;
 185         amd64_physaddr_t a;
 186         off_t ofs;
 187         size_t s;
 188
 189         vm = kd->vmst;
 190         offset = va & AMD64_PAGE_MASK;
 191
 192         /*
 193          * If we are initializing (kernel page table descriptor pointer
 194          * not yet set) then return pa == va to avoid infinite recursion.
 195          */
 196         if (vm->PML4 == NULL) {
 197                 s = _kvm_pa2off(kd, va, pa);
 198                 if (s == 0) {
 199                         _kvm_err(kd, kd->program,
 200                             "_amd64_vatop: bootstrap data not in dump");
 201                         goto invalid;
 202                 } else
 203                         return (AMD64_PAGE_SIZE - offset);
 204         }
 205
 206         pml4eindex = (va >> AMD64_PML4SHIFT) & (AMD64_NPML4EPG - 1);
 207         pml4e = le64toh(vm->PML4[pml4eindex]);
 208         if ((pml4e & AMD64_PG_V) == 0) {
 209                 _kvm_err(kd, kd->program, "_amd64_vatop: pml4e not valid");
 210                 goto invalid;
 211         }
 212
 213         pdpeindex = (va >> AMD64_PDPSHIFT) & (AMD64_NPDPEPG - 1);
 214         pdpe_pa = (pml4e & AMD64_PG_FRAME) + (pdpeindex * sizeof(amd64_pdpe_t));
 215
 216         s = _kvm_pa2off(kd, pdpe_pa, &ofs);
 217         if (s < sizeof(pdpe)) {
 218                 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe_pa not found");
 219                 goto invalid;
 220         }
 221         if (pread(kd->pmfd, &pdpe, sizeof(pdpe), ofs) != sizeof(pdpe)) {
 222                 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pdpe");
 223                 goto invalid;
 224         }
 225         pdpe = le64toh(pdpe);
 226         if ((pdpe & AMD64_PG_V) == 0) {
 227                 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe not valid");
 228                 goto invalid;
 229         }
 230
 231         if (pdpe & AMD64_PG_PS) {
 232                 /*
 233                  * No next-level page table; pdpe describes one 1GB page.
 234                  */
 235                 a = (pdpe & AMD64_PG_1GB_FRAME) + (va & AMD64_PDPMASK);
 236                 s = _kvm_pa2off(kd, a, pa);
 237                 if (s == 0) {
 238                         _kvm_err(kd, kd->program,
 239                             "_amd64_vatop: 1GB page address not in dump");
 240                         goto invalid;
 241                 } else
 242                         return (AMD64_NBPDP - (va & AMD64_PDPMASK));
 243         }
 244
 245         pdeindex = (va >> AMD64_PDRSHIFT) & (AMD64_NPDEPG - 1);
 246         pde_pa = (pdpe & AMD64_PG_FRAME) + (pdeindex * sizeof(amd64_pde_t));
 247
 248         s = _kvm_pa2off(kd, pde_pa, &ofs);
 249         if (s < sizeof(pde)) {
 250                 _kvm_syserr(kd, kd->program, "_amd64_vatop: pde_pa not found");
 251                 goto invalid;
 252         }
 253         if (pread(kd->pmfd, &pde, sizeof(pde), ofs) != sizeof(pde)) {
 254                 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pde");
 255                 goto invalid;
 256         }
 257         pde = le64toh(pde);
 258         if ((pde & AMD64_PG_V) == 0) {
 259                 _kvm_err(kd, kd->program, "_amd64_vatop: pde not valid");
 260                 goto invalid;
 261         }
 262
 263         if (pde & AMD64_PG_PS) {
 264                 /*
 265                  * No final-level page table; pde describes one 2MB page.
 266                  */
 267                 a = (pde & AMD64_PG_PS_FRAME) + (va & AMD64_PDRMASK);
 268                 s = _kvm_pa2off(kd, a, pa);
 269                 if (s == 0) {
 270                         _kvm_err(kd, kd->program,
 271                             "_amd64_vatop: 2MB page address not in dump");
 272                         goto invalid;
 273                 } else
 274                         return (AMD64_NBPDR - (va & AMD64_PDRMASK));
 275         }
 276
 277         pteindex = (va >> AMD64_PAGE_SHIFT) & (AMD64_NPTEPG - 1);
 278         pte_pa = (pde & AMD64_PG_FRAME) + (pteindex * sizeof(amd64_pte_t));
 279
 280         s = _kvm_pa2off(kd, pte_pa, &ofs);
 281         if (s < sizeof(pte)) {
 282                 _kvm_err(kd, kd->program, "_amd64_vatop: pte_pa not found");
 283                 goto invalid;
 284         }
 285         if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) {
 286                 _kvm_syserr(kd, kd->program, "_amd64_vatop: read");
 287                 goto invalid;
 288         }
 289         if ((pte & AMD64_PG_V) == 0) {
 290                 _kvm_err(kd, kd->program, "_amd64_vatop: pte not valid");
 291                 goto invalid;
 292         }
 293
 294         a = (pte & AMD64_PG_FRAME) + offset;
 295         s = _kvm_pa2off(kd, a, pa);
 296         if (s == 0) {
 297                 _kvm_err(kd, kd->program, "_amd64_vatop: address not in dump");
 298                 goto invalid;
 299         } else
 300                 return (AMD64_PAGE_SIZE - offset);
 301
 302 invalid:
 303         _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va);
 304         return (0);
 305 }
 306
 307 static int
 308 _amd64_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa)
 309 {
 310
 311         if (ISALIVE(kd)) {
 312                 _kvm_err(kd, 0, "kvm_kvatop called in live kernel!");
 313                 return (0);
 314         }
 315         return (_amd64_vatop(kd, va, pa));
 316 }
 317
 318 int
 319 _amd64_native(kvm_t *kd)
 320 {
 321
 322 #ifdef __amd64__
 323         return (1);
 324 #else
 325         return (0);
 326 #endif
 327 }
 328
 329 struct kvm_arch kvm_amd64 = {
 330         .ka_probe = _amd64_probe,
 331         .ka_initvtop = _amd64_initvtop,
 332         .ka_freevtop = _amd64_freevtop,
 333         .ka_kvatop = _amd64_kvatop,
 334         .ka_native = _amd64_native,
 335 };
 336
 337 KVM_ARCH(kvm_amd64);