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, kernphys; 113 amd64_pml4e_t *PML4; 114 int found = 0; 115 116 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(*kd->vmst)); 117 if (kd->vmst == NULL) { 118 _kvm_err(kd, kd->program, "cannot allocate vm"); 119 return (-1); 120 } 121 kd->vmst->PML4 = 0; 122 123 if (kd->rawdump == 0) { 124 if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum, 125 &kd->vmst->phdr) == -1) 126 return (-1); 127 128 for (size_t i = 0; i < kd->vmst->phnum; i++) { 129 if (kd->vmst->phdr[i].p_type == PT_DUMP_DELTA) { 130 /* Account for the 2M hole at KERNBASE. */ 131 kernphys = kd->vmst->phdr[i].p_paddr - 132 kd->vmst->phdr[i].p_align; 133 kernbase = kd->vmst->phdr[i].p_vaddr; 134 135 found = 1; 136 break; 137 } 138 } 139 } 140 141 if (found == 0) { 142 nl[0].n_name = "kernbase"; 143 nl[1].n_name = 0; 144 145 if (kvm_nlist2(kd, nl) != 0) { 146 _kvm_err(kd, kd->program, "bad namelist - no kernbase"); 147 return (-1); 148 } 149 150 nl[0].n_name = "kernphys"; 151 nl[1].n_name = 0; 152 153 /* XXX 154 * Relocatable kernels can still be loaded at 2M. 155 */ 156 if (kvm_nlist2(kd, nl) != 1) { 157 _kvm_err(kd, kd->program, "cannot determine kernphys"); 158 return (-1); 159 } 160 161 kernphys = 0; 162 kernbase = nl[0].n_value; 163 } 164 165 nl[0].n_name = "KPML4phys"; 166 nl[1].n_name = 0; 167 168 if (kvm_nlist2(kd, nl) != 0) { 169 _kvm_err(kd, kd->program, "bad namelist - no KPML4phys"); 170 return (-1); 171 } 172 if (kvm_read2(kd, (nl[0].n_value - kernbase + kernphys), &pa, 173 sizeof(pa)) != sizeof(pa)) { 174 _kvm_err(kd, kd->program, "cannot read KPML4phys"); 175 return (-1); 176 } 177 pa = le64toh(pa); 178 PML4 = _kvm_malloc(kd, AMD64_PAGE_SIZE); 179 if (PML4 == NULL) { 180 _kvm_err(kd, kd->program, "cannot allocate PML4"); 181 return (-1); 182 } 183 if (kvm_read2(kd, pa, PML4, AMD64_PAGE_SIZE) != AMD64_PAGE_SIZE) { 184 _kvm_err(kd, kd->program, "cannot read KPML4phys"); 185 free(PML4); 186 return (-1); 187 } 188 kd->vmst->PML4 = PML4; 189 return (0); 190 } 191 192 static int 193 _amd64_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) 194 { 195 struct vmstate *vm; 196 amd64_physaddr_t offset; 197 amd64_physaddr_t pdpe_pa; 198 amd64_physaddr_t pde_pa; 199 amd64_physaddr_t pte_pa; 200 amd64_pml4e_t pml4e; 201 amd64_pdpe_t pdpe; 202 amd64_pde_t pde; 203 amd64_pte_t pte; 204 kvaddr_t pml4eindex; 205 kvaddr_t pdpeindex; 206 kvaddr_t pdeindex; 207 kvaddr_t pteindex; 208 amd64_physaddr_t a; 209 off_t ofs; 210 size_t s; 211 212 vm = kd->vmst; 213 offset = va & AMD64_PAGE_MASK; 214 215 /* 216 * If we are initializing (kernel page table descriptor pointer 217 * not yet set) then return pa == va to avoid infinite recursion. 218 */ 219 if (vm->PML4 == NULL) { 220 s = _kvm_pa2off(kd, va, pa); 221 if (s == 0) { 222 _kvm_err(kd, kd->program, 223 "_amd64_vatop: bootstrap data not in dump"); 224 goto invalid; 225 } else 226 return (AMD64_PAGE_SIZE - offset); 227 } 228 229 pml4eindex = (va >> AMD64_PML4SHIFT) & (AMD64_NPML4EPG - 1); 230 pml4e = le64toh(vm->PML4[pml4eindex]); 231 if ((pml4e & AMD64_PG_V) == 0) { 232 _kvm_err(kd, kd->program, "_amd64_vatop: pml4e not valid"); 233 goto invalid; 234 } 235 236 pdpeindex = (va >> AMD64_PDPSHIFT) & (AMD64_NPDPEPG - 1); 237 pdpe_pa = (pml4e & AMD64_PG_FRAME) + (pdpeindex * sizeof(amd64_pdpe_t)); 238 239 s = _kvm_pa2off(kd, pdpe_pa, &ofs); 240 if (s < sizeof(pdpe)) { 241 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe_pa not found"); 242 goto invalid; 243 } 244 if (pread(kd->pmfd, &pdpe, sizeof(pdpe), ofs) != sizeof(pdpe)) { 245 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pdpe"); 246 goto invalid; 247 } 248 pdpe = le64toh(pdpe); 249 if ((pdpe & AMD64_PG_V) == 0) { 250 _kvm_err(kd, kd->program, "_amd64_vatop: pdpe not valid"); 251 goto invalid; 252 } 253 254 if (pdpe & AMD64_PG_PS) { 255 /* 256 * No next-level page table; pdpe describes one 1GB page. 257 */ 258 a = (pdpe & AMD64_PG_1GB_FRAME) + (va & AMD64_PDPMASK); 259 s = _kvm_pa2off(kd, a, pa); 260 if (s == 0) { 261 _kvm_err(kd, kd->program, 262 "_amd64_vatop: 1GB page address not in dump"); 263 goto invalid; 264 } else 265 return (AMD64_NBPDP - (va & AMD64_PDPMASK)); 266 } 267 268 pdeindex = (va >> AMD64_PDRSHIFT) & (AMD64_NPDEPG - 1); 269 pde_pa = (pdpe & AMD64_PG_FRAME) + (pdeindex * sizeof(amd64_pde_t)); 270 271 s = _kvm_pa2off(kd, pde_pa, &ofs); 272 if (s < sizeof(pde)) { 273 _kvm_syserr(kd, kd->program, "_amd64_vatop: pde_pa not found"); 274 goto invalid; 275 } 276 if (pread(kd->pmfd, &pde, sizeof(pde), ofs) != sizeof(pde)) { 277 _kvm_syserr(kd, kd->program, "_amd64_vatop: read pde"); 278 goto invalid; 279 } 280 pde = le64toh(pde); 281 if ((pde & AMD64_PG_V) == 0) { 282 _kvm_err(kd, kd->program, "_amd64_vatop: pde not valid"); 283 goto invalid; 284 } 285 286 if (pde & AMD64_PG_PS) { 287 /* 288 * No final-level page table; pde describes one 2MB page. 289 */ 290 a = (pde & AMD64_PG_PS_FRAME) + (va & AMD64_PDRMASK); 291 s = _kvm_pa2off(kd, a, pa); 292 if (s == 0) { 293 _kvm_err(kd, kd->program, 294 "_amd64_vatop: 2MB page address not in dump"); 295 goto invalid; 296 } else 297 return (AMD64_NBPDR - (va & AMD64_PDRMASK)); 298 } 299 300 pteindex = (va >> AMD64_PAGE_SHIFT) & (AMD64_NPTEPG - 1); 301 pte_pa = (pde & AMD64_PG_FRAME) + (pteindex * sizeof(amd64_pte_t)); 302 303 s = _kvm_pa2off(kd, pte_pa, &ofs); 304 if (s < sizeof(pte)) { 305 _kvm_err(kd, kd->program, "_amd64_vatop: pte_pa not found"); 306 goto invalid; 307 } 308 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) { 309 _kvm_syserr(kd, kd->program, "_amd64_vatop: read"); 310 goto invalid; 311 } 312 if ((pte & AMD64_PG_V) == 0) { 313 _kvm_err(kd, kd->program, "_amd64_vatop: pte not valid"); 314 goto invalid; 315 } 316 317 a = (pte & AMD64_PG_FRAME) + offset; 318 s = _kvm_pa2off(kd, a, pa); 319 if (s == 0) { 320 _kvm_err(kd, kd->program, "_amd64_vatop: address not in dump"); 321 goto invalid; 322 } else 323 return (AMD64_PAGE_SIZE - offset); 324 325 invalid: 326 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 327 return (0); 328 } 329 330 static int 331 _amd64_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) 332 { 333 334 if (ISALIVE(kd)) { 335 _kvm_err(kd, 0, "kvm_kvatop called in live kernel!"); 336 return (0); 337 } 338 return (_amd64_vatop(kd, va, pa)); 339 } 340 341 int 342 _amd64_native(kvm_t *kd __unused) 343 { 344 345 #ifdef __amd64__ 346 return (1); 347 #else 348 return (0); 349 #endif 350 } 351 352 static struct kvm_arch kvm_amd64 = { 353 .ka_probe = _amd64_probe, 354 .ka_initvtop = _amd64_initvtop, 355 .ka_freevtop = _amd64_freevtop, 356 .ka_kvatop = _amd64_kvatop, 357 .ka_native = _amd64_native, 358 }; 359 360 KVM_ARCH(kvm_amd64); 361