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 * i386 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 #ifdef __i386__ 52 #include <machine/vmparam.h> /* For KERNBASE. */ 53 #endif 54 55 #include <limits.h> 56 57 #include "kvm_private.h" 58 #include "kvm_i386.h" 59 60 struct vmstate { 61 void *PTD; 62 int pae; 63 size_t phnum; 64 GElf_Phdr *phdr; 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 (I386_PAGE_SIZE - (pa & I386_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 (I386_PAGE_SIZE - (pa & I386_PAGE_MASK)); 90 } 91 92 static void 93 _i386_freevtop(kvm_t *kd) 94 { 95 struct vmstate *vm = kd->vmst; 96 97 if (vm->PTD) 98 free(vm->PTD); 99 free(vm->phdr); 100 free(vm); 101 kd->vmst = NULL; 102 } 103 104 static int 105 _i386_probe(kvm_t *kd) 106 { 107 108 return (_kvm_probe_elf_kernel(kd, ELFCLASS32, EM_386) && 109 !_kvm_is_minidump(kd)); 110 } 111 112 static int 113 _i386_initvtop(kvm_t *kd) 114 { 115 struct kvm_nlist nl[2]; 116 i386_physaddr_t pa; 117 kvaddr_t kernbase; 118 char *PTD; 119 int i; 120 121 kd->vmst = (struct vmstate *)_kvm_malloc(kd, sizeof(struct vmstate)); 122 if (kd->vmst == NULL) { 123 _kvm_err(kd, kd->program, "cannot allocate vm"); 124 return (-1); 125 } 126 kd->vmst->PTD = 0; 127 128 if (kd->rawdump == 0) { 129 if (_kvm_read_core_phdrs(kd, &kd->vmst->phnum, 130 &kd->vmst->phdr) == -1) 131 return (-1); 132 } 133 134 nl[0].n_name = "kernbase"; 135 nl[1].n_name = 0; 136 137 if (kvm_nlist2(kd, nl) != 0) { 138 #ifdef __i386__ 139 kernbase = KERNBASE; /* for old kernels */ 140 #else 141 _kvm_err(kd, kd->program, "cannot resolve kernbase"); 142 return (-1); 143 #endif 144 } else 145 kernbase = nl[0].n_value; 146 147 nl[0].n_name = "IdlePDPT"; 148 nl[1].n_name = 0; 149 150 if (kvm_nlist2(kd, nl) == 0) { 151 i386_physaddr_pae_t pa64; 152 153 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa, 154 sizeof(pa)) != sizeof(pa)) { 155 _kvm_err(kd, kd->program, "cannot read IdlePDPT"); 156 return (-1); 157 } 158 pa = le32toh(pa); 159 PTD = _kvm_malloc(kd, 4 * I386_PAGE_SIZE); 160 if (PTD == NULL) { 161 _kvm_err(kd, kd->program, "cannot allocate PTD"); 162 return (-1); 163 } 164 for (i = 0; i < 4; i++) { 165 if (kvm_read2(kd, pa + (i * sizeof(pa64)), &pa64, 166 sizeof(pa64)) != sizeof(pa64)) { 167 _kvm_err(kd, kd->program, "Cannot read PDPT"); 168 free(PTD); 169 return (-1); 170 } 171 pa64 = le64toh(pa64); 172 if (kvm_read2(kd, pa64 & I386_PG_FRAME_PAE, 173 PTD + (i * I386_PAGE_SIZE), I386_PAGE_SIZE) != 174 I386_PAGE_SIZE) { 175 _kvm_err(kd, kd->program, "cannot read PDPT"); 176 free(PTD); 177 return (-1); 178 } 179 } 180 kd->vmst->PTD = PTD; 181 kd->vmst->pae = 1; 182 } else { 183 nl[0].n_name = "IdlePTD"; 184 nl[1].n_name = 0; 185 186 if (kvm_nlist2(kd, nl) != 0) { 187 _kvm_err(kd, kd->program, "bad namelist"); 188 return (-1); 189 } 190 if (kvm_read2(kd, (nl[0].n_value - kernbase), &pa, 191 sizeof(pa)) != sizeof(pa)) { 192 _kvm_err(kd, kd->program, "cannot read IdlePTD"); 193 return (-1); 194 } 195 pa = le32toh(pa); 196 PTD = _kvm_malloc(kd, I386_PAGE_SIZE); 197 if (PTD == NULL) { 198 _kvm_err(kd, kd->program, "cannot allocate PTD"); 199 return (-1); 200 } 201 if (kvm_read2(kd, pa, PTD, I386_PAGE_SIZE) != I386_PAGE_SIZE) { 202 _kvm_err(kd, kd->program, "cannot read PTD"); 203 return (-1); 204 } 205 kd->vmst->PTD = PTD; 206 kd->vmst->pae = 0; 207 } 208 return (0); 209 } 210 211 static int 212 _i386_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) 213 { 214 struct vmstate *vm; 215 i386_physaddr_t offset; 216 i386_physaddr_t pte_pa; 217 i386_pde_t pde; 218 i386_pte_t pte; 219 kvaddr_t pdeindex; 220 kvaddr_t pteindex; 221 size_t s; 222 i386_physaddr_t a; 223 off_t ofs; 224 i386_pde_t *PTD; 225 226 vm = kd->vmst; 227 PTD = (i386_pde_t *)vm->PTD; 228 offset = va & I386_PAGE_MASK; 229 230 /* 231 * If we are initializing (kernel page table descriptor pointer 232 * not yet set) then return pa == va to avoid infinite recursion. 233 */ 234 if (PTD == NULL) { 235 s = _kvm_pa2off(kd, va, pa); 236 if (s == 0) { 237 _kvm_err(kd, kd->program, 238 "_i386_vatop: bootstrap data not in dump"); 239 goto invalid; 240 } else 241 return (I386_PAGE_SIZE - offset); 242 } 243 244 pdeindex = va >> I386_PDRSHIFT; 245 pde = le32toh(PTD[pdeindex]); 246 if ((pde & I386_PG_V) == 0) { 247 _kvm_err(kd, kd->program, "_i386_vatop: pde not valid"); 248 goto invalid; 249 } 250 251 if (pde & I386_PG_PS) { 252 /* 253 * No second-level page table; ptd describes one 4MB 254 * page. (We assume that the kernel wouldn't set 255 * PG_PS without enabling it cr0). 256 */ 257 offset = va & I386_PAGE_PS_MASK; 258 a = (pde & I386_PG_PS_FRAME) + offset; 259 s = _kvm_pa2off(kd, a, pa); 260 if (s == 0) { 261 _kvm_err(kd, kd->program, 262 "_i386_vatop: 4MB page address not in dump"); 263 goto invalid; 264 } 265 return (I386_NBPDR - offset); 266 } 267 268 pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG - 1); 269 pte_pa = (pde & I386_PG_FRAME) + (pteindex * sizeof(pte)); 270 271 s = _kvm_pa2off(kd, pte_pa, &ofs); 272 if (s < sizeof(pte)) { 273 _kvm_err(kd, kd->program, "_i386_vatop: pte_pa not found"); 274 goto invalid; 275 } 276 277 /* XXX This has to be a physical address read, kvm_read is virtual */ 278 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) { 279 _kvm_syserr(kd, kd->program, "_i386_vatop: pread"); 280 goto invalid; 281 } 282 pte = le32toh(pte); 283 if ((pte & I386_PG_V) == 0) { 284 _kvm_err(kd, kd->program, "_kvm_kvatop: pte not valid"); 285 goto invalid; 286 } 287 288 a = (pte & I386_PG_FRAME) + offset; 289 s = _kvm_pa2off(kd, a, pa); 290 if (s == 0) { 291 _kvm_err(kd, kd->program, "_i386_vatop: address not in dump"); 292 goto invalid; 293 } else 294 return (I386_PAGE_SIZE - offset); 295 296 invalid: 297 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 298 return (0); 299 } 300 301 static int 302 _i386_vatop_pae(kvm_t *kd, kvaddr_t va, off_t *pa) 303 { 304 struct vmstate *vm; 305 i386_physaddr_pae_t offset; 306 i386_physaddr_pae_t pte_pa; 307 i386_pde_pae_t pde; 308 i386_pte_pae_t pte; 309 kvaddr_t pdeindex; 310 kvaddr_t pteindex; 311 size_t s; 312 i386_physaddr_pae_t a; 313 off_t ofs; 314 i386_pde_pae_t *PTD; 315 316 vm = kd->vmst; 317 PTD = (i386_pde_pae_t *)vm->PTD; 318 offset = va & I386_PAGE_MASK; 319 320 /* 321 * If we are initializing (kernel page table descriptor pointer 322 * not yet set) then return pa == va to avoid infinite recursion. 323 */ 324 if (PTD == NULL) { 325 s = _kvm_pa2off(kd, va, pa); 326 if (s == 0) { 327 _kvm_err(kd, kd->program, 328 "_i386_vatop_pae: bootstrap data not in dump"); 329 goto invalid; 330 } else 331 return (I386_PAGE_SIZE - offset); 332 } 333 334 pdeindex = va >> I386_PDRSHIFT_PAE; 335 pde = le64toh(PTD[pdeindex]); 336 if ((pde & I386_PG_V) == 0) { 337 _kvm_err(kd, kd->program, "_kvm_kvatop_pae: pde not valid"); 338 goto invalid; 339 } 340 341 if (pde & I386_PG_PS) { 342 /* 343 * No second-level page table; ptd describes one 2MB 344 * page. (We assume that the kernel wouldn't set 345 * PG_PS without enabling it cr0). 346 */ 347 offset = va & I386_PAGE_PS_MASK_PAE; 348 a = (pde & I386_PG_PS_FRAME_PAE) + offset; 349 s = _kvm_pa2off(kd, a, pa); 350 if (s == 0) { 351 _kvm_err(kd, kd->program, 352 "_i386_vatop: 2MB page address not in dump"); 353 goto invalid; 354 } 355 return (I386_NBPDR_PAE - offset); 356 } 357 358 pteindex = (va >> I386_PAGE_SHIFT) & (I386_NPTEPG_PAE - 1); 359 pte_pa = (pde & I386_PG_FRAME_PAE) + (pteindex * sizeof(pde)); 360 361 s = _kvm_pa2off(kd, pte_pa, &ofs); 362 if (s < sizeof(pte)) { 363 _kvm_err(kd, kd->program, "_i386_vatop_pae: pdpe_pa not found"); 364 goto invalid; 365 } 366 367 /* XXX This has to be a physical address read, kvm_read is virtual */ 368 if (pread(kd->pmfd, &pte, sizeof(pte), ofs) != sizeof(pte)) { 369 _kvm_syserr(kd, kd->program, "_i386_vatop_pae: read"); 370 goto invalid; 371 } 372 pte = le64toh(pte); 373 if ((pte & I386_PG_V) == 0) { 374 _kvm_err(kd, kd->program, "_i386_vatop_pae: pte not valid"); 375 goto invalid; 376 } 377 378 a = (pte & I386_PG_FRAME_PAE) + offset; 379 s = _kvm_pa2off(kd, a, pa); 380 if (s == 0) { 381 _kvm_err(kd, kd->program, 382 "_i386_vatop_pae: address not in dump"); 383 goto invalid; 384 } else 385 return (I386_PAGE_SIZE - offset); 386 387 invalid: 388 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 389 return (0); 390 } 391 392 static int 393 _i386_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) 394 { 395 396 if (ISALIVE(kd)) { 397 _kvm_err(kd, 0, "vatop called in live kernel!"); 398 return (0); 399 } 400 if (kd->vmst->pae) 401 return (_i386_vatop_pae(kd, va, pa)); 402 else 403 return (_i386_vatop(kd, va, pa)); 404 } 405 406 int 407 _i386_native(kvm_t *kd __unused) 408 { 409 410 #ifdef __i386__ 411 return (1); 412 #else 413 return (0); 414 #endif 415 } 416 417 static struct kvm_arch kvm_i386 = { 418 .ka_probe = _i386_probe, 419 .ka_initvtop = _i386_initvtop, 420 .ka_freevtop = _i386_freevtop, 421 .ka_kvatop = _i386_kvatop, 422 .ka_native = _i386_native, 423 }; 424 425 KVM_ARCH(kvm_i386); 426