1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1989, 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software developed by the Computer Systems 8 * Engineering group at Lawrence Berkeley Laboratory under DARPA contract 9 * BG 91-66 and contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 37 /* 38 * AMD64 machine dependent routines for kvm. Hopefully, the forthcoming 39 * vm code will one day obsolete this module. 40 */ 41 42 #include <sys/param.h> 43 #include <sys/endian.h> 44 #include <stdint.h> 45 #include <stdlib.h> 46 #include <string.h> 47 #include <unistd.h> 48 #include <vm/vm.h> 49 #include <kvm.h> 50 51 #include <limits.h> 52 53 #include "kvm_private.h" 54 #include "kvm_amd64.h" 55 56 struct vmstate { 57 size_t phnum; 58 GElf_Phdr *phdr; 59 amd64_pml4e_t *PML4; 60 }; 61 62 /* 63 * Translate a physical memory address to a file-offset in the crash-dump. 64 */ 65 static size_t 66 _kvm_pa2off(kvm_t *kd, uint64_t pa, off_t *ofs) 67 { 68 struct vmstate *vm = kd->vmst; 69 GElf_Phdr *p; 70 size_t n; 71 72 if (kd->rawdump) { 73 *ofs = pa; 74 return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK)); 75 } 76 77 p = vm->phdr; 78 n = vm->phnum; 79 while (n && (pa < p->p_paddr || pa >= p->p_paddr + p->p_memsz)) 80 p++, n--; 81 if (n == 0) 82 return (0); 83 *ofs = (pa - p->p_paddr) + p->p_offset; 84 return (AMD64_PAGE_SIZE - (pa & AMD64_PAGE_MASK)); 85 } 86 87 static void 88 _amd64_freevtop(kvm_t *kd) 89 { 90 struct vmstate *vm = kd->vmst; 91 92 if (vm->PML4) 93 free(vm->PML4); 94 free(vm->phdr); 95 free(vm); 96 kd->vmst = NULL; 97 } 98 99 static int 100 _amd64_probe(kvm_t *kd) 101 { 102 103 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) && 104 !_kvm_is_minidump(kd)); 105 } 106 107 static int 108 _amd64_initvtop(kvm_t *kd) 109 { 110 struct kvm_nlist nl[2]; 111 amd64_physaddr_t pa; 112 kvaddr_t kernbase; 113 amd64_pml4e_t *PML4; 114 115 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst)); 116 if (kd->vmst == NULL) { 117 _kvm_err(kd, kd->program, "cannot allocate vm"); 118 return (-1); 119 } 120 kd->vmst->PML4 = 0; 121 122 if (kd->rawdump == 0) { 123 if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum, 124 &kd->vmst->phdr) == -1) 125 return (-1); 126 } 127 128 nl[0].n_name = "kernbase"; 129 nl[1].n_name = 0; 130 131 if (kvm_nlist2(kd, nl) != 0) { 132 _kvm_err(kd, kd->program, "bad namelist - no kernbase"); 133 return (-1); 134 } 135 kernbase = nl[0].n_value; 136 137 nl[0].n_name = "KPML4phys"; 138 nl[1].n_name = 0; 139 140 if (kvm_nlist2(kd, nl) != 0) { 141 _kvm_err(kd, kd->program, "bad namelist - no KPML4phys"); 142 return (-1); 143 } 144 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa, sizeof(pa)) != 145 sizeof(pa)) { 146 _kvm_err(kd, kd->program, "cannot read KPML4phys"); 147 return (-1); 148 } 149 pa = le64toh(pa); 150 PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE); 151 if (PML4 == NULL) { 152 _kvm_err(kd, kd->program, "cannot allocate PML4"); 153 return (-1); 154 } 155 if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) { 156 _kvm_err(kd, kd->program, "cannot read KPML4phys"); 157 free(PML4); 158 return (-1); 159 } 160 kd->vmst->PML4 = PML4; 161 return (0); 162 } 163 164 static int 165 _amd64_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) 166 { 167 struct vmstate *vm; 168 amd64_physaddr_t offset; 169 amd64_physaddr_t pdpe_pa; 170 amd64_physaddr_t pde_pa; 171 amd64_physaddr_t pte_pa; 172 amd64_pml4e_t pml4e; 173 amd64_pdpe_t pdpe; 174 amd64_pde_t pde; 175 amd64_pte_t pte; 176 kvaddr_t pml4eindex; 177 kvaddr_t pdpeindex; 178 kvaddr_t pdeindex; 179 kvaddr_t pteindex; 180 amd64_physaddr_t a; 181 off_t ofs; 182 size_t s; 183 184 vm = kd->vmst; 185 offset = va & AMD64_PAGE_MASK; 186 187 /* 188 * If we are initializing (kernel page table descriptor pointer 189 * not yet set) then return pa == va to avoid infinite recursion. 190 */ 191 if (vm->PML4 == NULL) { 192 s = _kvm_pa2off(kd, va, pa); 193 if (s == 0) { 194 _kvm_err(kd, kd->program, 195 "_amd64_vatop: bootstrap data not in dump"); 196 goto invalid; 197 } else 198 return (AMD64_PAGE_SIZE - offset); 199 } 200 201 pml4eindex = (va >> AMD64_PML4SHIFT) & (AMD64_NPML4EPG - 1); 202 pml4e = le64toh(vm->PML4[pml4eindex]); 203 if ((pml4e & AMD64_PG_V) == 0) { 204 _kvm_err(kd, kd->program, "_amd64_vatop: pml4e not valid"); 205 goto invalid; 206 } 207 208 pdpeindex = (va >> AMD64_PDPSHIFT) & (AMD64_NPDPEPG - 1); 209 pdpe_pa = (pml4e & AMD64_PG_FRAME) + (pdpeindex * sizeof(amd64_pdpe_t)); 210 211 s = _kvm_pa2off(kd, pdpe_pa, &ofs); 212 if (s < sizeof(pdpe)) { 213 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe_pa not found"); 214 goto invalid; 215 } 216 if (pread(kd->pmfd, &pdpe, sizeof(pdpe), ofs) != sizeof(pdpe)) { 217 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pdpe"); 218 goto invalid; 219 } 220 pdpe = le64toh(pdpe); 221 if ((pdpe & AMD64_PG_V) == 0) { 222 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe not valid"); 223 goto invalid; 224 } 225 226 if (pdpe & AMD64_PG_PS) { 227 /* 228 * No next-level page table; pdpe describes one 1GB page. 229 */ 230 a = (pdpe & AMD64_PG_1GB_FRAME) + (va & AMD64_PDPMASK); 231 s = _kvm_pa2off(kd, a, pa); 232 if (s == 0) { 233 _kvm_err(kd, kd->program, 234 "_amd64_vatop: 1GB page address not in dump"); 235 goto invalid; 236 } else 237 return (AMD64_NBPDP - (va & AMD64_PDPMASK)); 238 } 239 240 pdeindex = (va >> AMD64_PDRSHIFT) & (AMD64_NPDEPG - 1); 241 pde_pa = (pdpe & AMD64_PG_FRAME) + (pdeindex * sizeof(amd64_pde_t)); 242 243 s = _kvm_pa2off(kd, pde_pa, &ofs); 244 if (s < sizeof(pde)) { 245 _kvm_syserr(kd, kd->program, "_amd64_vatop: pde_pa not found"); 246 goto invalid; 247 } 248 if (pread(kd->pmfd, &pde, sizeof(pde), ofs) != sizeof(pde)) { 249 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pde"); 250 goto invalid; 251 } 252 pde = le64toh(pde); 253 if ((pde & AMD64_PG_V) == 0) { 254 _kvm_err(kd, kd->program, "_amd64_vatop: pde not valid"); 255 goto invalid; 256 } 257 258 if (pde & AMD64_PG_PS) { 259 /* 260 * No final-level page table; pde describes one 2MB page. 261 */ 262 a = (pde & AMD64_PG_PS_FRAME) + (va & AMD64_PDRMASK); 263 s = _kvm_pa2off(kd, a, pa); 264 if (s == 0) { 265 _kvm_err(kd, kd->program, 266 "_amd64_vatop: 2MB page address not in dump"); 267 goto invalid; 268 } else 269 return (AMD64_NBPDR - (va & AMD64_PDRMASK)); 270 } 271 272 pteindex = (va >> AMD64_PAGE_SHIFT) & (AMD64_NPTEPG - 1); 273 pte_pa = (pde & AMD64_PG_FRAME) + (pteindex * sizeof(amd64_pte_t)); 274 275 s = _kvm_pa2off(kd, pte_pa, &ofs); 276 if (s < sizeof(pte)) { 277 _kvm_err(kd, kd->program, "_amd64_vatop: pte_pa not found"); 278 goto invalid; 279 } 280 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) { 281 _kvm_syserr(kd, kd->program, "_amd64_vatop: read"); 282 goto invalid; 283 } 284 if ((pte & AMD64_PG_V) == 0) { 285 _kvm_err(kd, kd->program, "_amd64_vatop: pte not valid"); 286 goto invalid; 287 } 288 289 a = (pte & AMD64_PG_FRAME) + offset; 290 s = _kvm_pa2off(kd, a, pa); 291 if (s == 0) { 292 _kvm_err(kd, kd->program, "_amd64_vatop: address not in dump"); 293 goto invalid; 294 } else 295 return (AMD64_PAGE_SIZE - offset); 296 297 invalid: 298 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 299 return (0); 300 } 301 302 static int 303 _amd64_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) 304 { 305 306 if (ISALIVE(kd)) { 307 _kvm_err(kd, 0, "kvm_kvatop called in live kernel!"); 308 return (0); 309 } 310 return (_amd64_vatop(kd, va, pa)); 311 } 312 313 int 314 _amd64_native(kvm_t *kd __unused) 315 { 316 317 #ifdef __amd64__ 318 return (1); 319 #else 320 return (0); 321 #endif 322 } 323 324 static struct kvm_arch kvm_amd64 = { 325 .ka_probe = _amd64_probe, 326 .ka_initvtop = _amd64_initvtop, 327 .ka_freevtop = _amd64_freevtop, 328 .ka_kvatop = _amd64_kvatop, 329 .ka_native = _amd64_native, 330 }; 331 332 KVM_ARCH(kvm_amd64); 333