1 /*- 2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD 3 * 4 * Copyright (c) 2006 Peter Wemm 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 16 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 18 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 19 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 20 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 21 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 23 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 24 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 25 * SUCH DAMAGE. 26 */ 27 28 #include <sys/cdefs.h> 29 __FBSDID("$FreeBSD$"); 30 31 /* 32 * AMD64 machine dependent routines for kvm and minidumps. 33 */ 34 35 #include <sys/param.h> 36 #include <sys/endian.h> 37 #include <stdint.h> 38 #include <stdlib.h> 39 #include <string.h> 40 #include <unistd.h> 41 #include <vm/vm.h> 42 #include <kvm.h> 43 44 #include "../../sys/amd64/include/minidump.h" 45 46 #include <limits.h> 47 48 #include "kvm_private.h" 49 #include "kvm_amd64.h" 50 51 #define amd64_round_page(x) roundup2((kvaddr_t)(x), AMD64_PAGE_SIZE) 52 #define VM_IS_V1(vm) (vm->hdr.version == 1) 53 #define VA_OFF(vm, va) \ 54 (VM_IS_V1(vm) ? ((va) & (AMD64_PAGE_SIZE - 1)) : ((va) & AMD64_PAGE_MASK)) 55 56 struct vmstate { 57 struct minidumphdr hdr; 58 }; 59 60 static vm_prot_t 61 _amd64_entry_to_prot(uint64_t entry) 62 { 63 vm_prot_t prot = VM_PROT_READ; 64 65 if ((entry & AMD64_PG_RW) != 0) 66 prot |= VM_PROT_WRITE; 67 if ((entry & AMD64_PG_NX) == 0) 68 prot |= VM_PROT_EXECUTE; 69 return prot; 70 } 71 72 /* 73 * Version 2 minidumps use page directory entries, while version 1 use page 74 * table entries. 75 */ 76 77 static amd64_pde_t 78 _amd64_pde_get(kvm_t *kd, u_long pdeindex) 79 { 80 amd64_pde_t *pde = _kvm_pmap_get(kd, pdeindex, sizeof(*pde)); 81 82 return le64toh(*pde); 83 } 84 85 static amd64_pte_t 86 _amd64_pte_get(kvm_t *kd, u_long pteindex) 87 { 88 amd64_pte_t *pte = _kvm_pmap_get(kd, pteindex, sizeof(*pte)); 89 90 return le64toh(*pte); 91 } 92 93 /* Get the first page table entry for a given page directory index. */ 94 static amd64_pte_t * 95 _amd64_pde_first_pte(kvm_t *kd, u_long pdeindex) 96 { 97 u_long *pa; 98 99 pa = _kvm_pmap_get(kd, pdeindex, sizeof(amd64_pde_t)); 100 if (pa == NULL) 101 return NULL; 102 return _kvm_map_get(kd, *pa & AMD64_PG_FRAME, AMD64_PAGE_SIZE); 103 } 104 105 static int 106 _amd64_minidump_probe(kvm_t *kd) 107 { 108 109 return (_kvm_probe_elf_kernel(kd, ELFCLASS64, EM_X86_64) && 110 _kvm_is_minidump(kd)); 111 } 112 113 static void 114 _amd64_minidump_freevtop(kvm_t *kd) 115 { 116 struct vmstate *vm = kd->vmst; 117 118 free(vm); 119 kd->vmst = NULL; 120 } 121 122 static int 123 _amd64_minidump_initvtop(kvm_t *kd) 124 { 125 struct vmstate *vmst; 126 off_t off, sparse_off; 127 128 vmst = _kvm_malloc(kd, sizeof(*vmst)); 129 if (vmst == NULL) { 130 _kvm_err(kd, kd->program, "cannot allocate vm"); 131 return (-1); 132 } 133 kd->vmst = vmst; 134 if (pread(kd->pmfd, &vmst->hdr, sizeof(vmst->hdr), 0) != 135 sizeof(vmst->hdr)) { 136 _kvm_err(kd, kd->program, "cannot read dump header"); 137 return (-1); 138 } 139 if (strncmp(MINIDUMP_MAGIC, vmst->hdr.magic, sizeof(vmst->hdr.magic)) != 0) { 140 _kvm_err(kd, kd->program, "not a minidump for this platform"); 141 return (-1); 142 } 143 144 /* 145 * NB: amd64 minidump header is binary compatible between version 1 146 * and version 2; this may not be the case for the future versions. 147 */ 148 vmst->hdr.version = le32toh(vmst->hdr.version); 149 if (vmst->hdr.version != MINIDUMP_VERSION && vmst->hdr.version != 1) { 150 _kvm_err(kd, kd->program, "wrong minidump version. expected %d got %d", 151 MINIDUMP_VERSION, vmst->hdr.version); 152 return (-1); 153 } 154 vmst->hdr.msgbufsize = le32toh(vmst->hdr.msgbufsize); 155 vmst->hdr.bitmapsize = le32toh(vmst->hdr.bitmapsize); 156 vmst->hdr.pmapsize = le32toh(vmst->hdr.pmapsize); 157 vmst->hdr.kernbase = le64toh(vmst->hdr.kernbase); 158 vmst->hdr.dmapbase = le64toh(vmst->hdr.dmapbase); 159 vmst->hdr.dmapend = le64toh(vmst->hdr.dmapend); 160 161 /* Skip header and msgbuf */ 162 off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize); 163 164 sparse_off = off + amd64_round_page(vmst->hdr.bitmapsize) + 165 amd64_round_page(vmst->hdr.pmapsize); 166 if (_kvm_pt_init(kd, vmst->hdr.bitmapsize, off, sparse_off, 167 AMD64_PAGE_SIZE, sizeof(uint64_t)) == -1) { 168 return (-1); 169 } 170 off += amd64_round_page(vmst->hdr.bitmapsize); 171 172 if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) { 173 return (-1); 174 } 175 off += amd64_round_page(vmst->hdr.pmapsize); 176 177 return (0); 178 } 179 180 static int 181 _amd64_minidump_vatop_v1(kvm_t *kd, kvaddr_t va, off_t *pa) 182 { 183 struct vmstate *vm; 184 amd64_physaddr_t offset; 185 amd64_pte_t pte; 186 kvaddr_t pteindex; 187 amd64_physaddr_t a; 188 off_t ofs; 189 190 vm = kd->vmst; 191 offset = va & AMD64_PAGE_MASK; 192 193 if (va >= vm->hdr.kernbase) { 194 pteindex = (va - vm->hdr.kernbase) >> AMD64_PAGE_SHIFT; 195 if (pteindex >= vm->hdr.pmapsize / sizeof(pte)) 196 goto invalid; 197 pte = _amd64_pte_get(kd, pteindex); 198 if ((pte & AMD64_PG_V) == 0) { 199 _kvm_err(kd, kd->program, 200 "_amd64_minidump_vatop_v1: pte not valid"); 201 goto invalid; 202 } 203 a = pte & AMD64_PG_FRAME; 204 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 205 if (ofs == -1) { 206 _kvm_err(kd, kd->program, 207 "_amd64_minidump_vatop_v1: physical address 0x%jx not in minidump", 208 (uintmax_t)a); 209 goto invalid; 210 } 211 *pa = ofs + offset; 212 return (AMD64_PAGE_SIZE - offset); 213 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 214 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 215 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 216 if (ofs == -1) { 217 _kvm_err(kd, kd->program, 218 "_amd64_minidump_vatop_v1: direct map address 0x%jx not in minidump", 219 (uintmax_t)va); 220 goto invalid; 221 } 222 *pa = ofs + offset; 223 return (AMD64_PAGE_SIZE - offset); 224 } else { 225 _kvm_err(kd, kd->program, 226 "_amd64_minidump_vatop_v1: virtual address 0x%jx not minidumped", 227 (uintmax_t)va); 228 goto invalid; 229 } 230 231 invalid: 232 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 233 return (0); 234 } 235 236 static int 237 _amd64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) 238 { 239 amd64_pte_t pt[AMD64_NPTEPG]; 240 struct vmstate *vm; 241 amd64_physaddr_t offset; 242 amd64_pde_t pde; 243 amd64_pte_t pte; 244 kvaddr_t pteindex; 245 kvaddr_t pdeindex; 246 amd64_physaddr_t a; 247 off_t ofs; 248 249 vm = kd->vmst; 250 offset = va & AMD64_PAGE_MASK; 251 252 if (va >= vm->hdr.kernbase) { 253 pdeindex = (va - vm->hdr.kernbase) >> AMD64_PDRSHIFT; 254 if (pdeindex >= vm->hdr.pmapsize / sizeof(pde)) 255 goto invalid; 256 pde = _amd64_pde_get(kd, pdeindex); 257 if ((pde & AMD64_PG_V) == 0) { 258 _kvm_err(kd, kd->program, 259 "_amd64_minidump_vatop: pde not valid"); 260 goto invalid; 261 } 262 if ((pde & AMD64_PG_PS) == 0) { 263 a = pde & AMD64_PG_FRAME; 264 /* TODO: Just read the single PTE */ 265 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 266 if (ofs == -1) { 267 _kvm_err(kd, kd->program, 268 "cannot find page table entry for %ju", 269 (uintmax_t)a); 270 goto invalid; 271 } 272 if (pread(kd->pmfd, &pt, AMD64_PAGE_SIZE, ofs) != 273 AMD64_PAGE_SIZE) { 274 _kvm_err(kd, kd->program, 275 "cannot read page table entry for %ju", 276 (uintmax_t)a); 277 goto invalid; 278 } 279 pteindex = (va >> AMD64_PAGE_SHIFT) & 280 (AMD64_NPTEPG - 1); 281 pte = le64toh(pt[pteindex]); 282 if ((pte & AMD64_PG_V) == 0) { 283 _kvm_err(kd, kd->program, 284 "_amd64_minidump_vatop: pte not valid"); 285 goto invalid; 286 } 287 a = pte & AMD64_PG_FRAME; 288 } else { 289 a = pde & AMD64_PG_PS_FRAME; 290 a += (va & AMD64_PDRMASK) ^ offset; 291 } 292 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 293 if (ofs == -1) { 294 _kvm_err(kd, kd->program, 295 "_amd64_minidump_vatop: physical address 0x%jx not in minidump", 296 (uintmax_t)a); 297 goto invalid; 298 } 299 *pa = ofs + offset; 300 return (AMD64_PAGE_SIZE - offset); 301 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 302 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 303 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 304 if (ofs == -1) { 305 _kvm_err(kd, kd->program, 306 "_amd64_minidump_vatop: direct map address 0x%jx not in minidump", 307 (uintmax_t)va); 308 goto invalid; 309 } 310 *pa = ofs + offset; 311 return (AMD64_PAGE_SIZE - offset); 312 } else { 313 _kvm_err(kd, kd->program, 314 "_amd64_minidump_vatop: virtual address 0x%jx not minidumped", 315 (uintmax_t)va); 316 goto invalid; 317 } 318 319 invalid: 320 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 321 return (0); 322 } 323 324 static int 325 _amd64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) 326 { 327 328 if (ISALIVE(kd)) { 329 _kvm_err(kd, 0, 330 "_amd64_minidump_kvatop called in live kernel!"); 331 return (0); 332 } 333 if (((struct vmstate *)kd->vmst)->hdr.version == 1) 334 return (_amd64_minidump_vatop_v1(kd, va, pa)); 335 else 336 return (_amd64_minidump_vatop(kd, va, pa)); 337 } 338 339 static int 340 _amd64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg) 341 { 342 struct vmstate *vm = kd->vmst; 343 u_long npdes = vm->hdr.pmapsize / sizeof(amd64_pde_t); 344 u_long bmindex, dva, pa, pdeindex, va; 345 struct kvm_bitmap bm; 346 int ret = 0; 347 vm_prot_t prot; 348 unsigned int pgsz = AMD64_PAGE_SIZE; 349 350 if (vm->hdr.version < 2) 351 return (0); 352 353 if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex)) 354 return (0); 355 356 for (pdeindex = 0; pdeindex < npdes; pdeindex++) { 357 amd64_pde_t pde = _amd64_pde_get(kd, pdeindex); 358 amd64_pte_t *ptes; 359 u_long i; 360 361 va = vm->hdr.kernbase + (pdeindex << AMD64_PDRSHIFT); 362 if ((pde & AMD64_PG_V) == 0) 363 continue; 364 365 if ((pde & AMD64_PG_PS) != 0) { 366 /* 367 * Large page. Iterate on each 4K page section 368 * within this page. This differs from 4K pages in 369 * that every page here uses the same PDE to 370 * generate permissions. 371 */ 372 pa = (pde & AMD64_PG_PS_FRAME) + 373 ((va & AMD64_PDRMASK) ^ VA_OFF(vm, va)); 374 dva = vm->hdr.dmapbase + pa; 375 _kvm_bitmap_set(&bm, pa, AMD64_PAGE_SIZE); 376 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 377 _amd64_entry_to_prot(pde), AMD64_NBPDR, pgsz)) { 378 goto out; 379 } 380 continue; 381 } 382 383 /* 4K pages: pde references another page of entries. */ 384 ptes = _amd64_pde_first_pte(kd, pdeindex); 385 /* Ignore page directory pages that were not dumped. */ 386 if (ptes == NULL) 387 continue; 388 389 for (i = 0; i < AMD64_NPTEPG; i++) { 390 amd64_pte_t pte = (u_long)ptes[i]; 391 392 pa = pte & AMD64_PG_FRAME; 393 dva = vm->hdr.dmapbase + pa; 394 if ((pte & AMD64_PG_V) != 0) { 395 _kvm_bitmap_set(&bm, pa, AMD64_PAGE_SIZE); 396 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 397 _amd64_entry_to_prot(pte), pgsz, 0)) { 398 goto out; 399 } 400 } 401 va += AMD64_PAGE_SIZE; 402 } 403 } 404 405 while (_kvm_bitmap_next(&bm, &bmindex)) { 406 pa = bmindex * AMD64_PAGE_SIZE; 407 dva = vm->hdr.dmapbase + pa; 408 if (vm->hdr.dmapend < (dva + pgsz)) 409 break; 410 va = 0; 411 /* amd64/pmap.c: create_pagetables(): dmap always R|W. */ 412 prot = VM_PROT_READ | VM_PROT_WRITE; 413 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, prot, pgsz, 0)) { 414 goto out; 415 } 416 } 417 418 ret = 1; 419 420 out: 421 _kvm_bitmap_deinit(&bm); 422 return (ret); 423 } 424 425 static struct kvm_arch kvm_amd64_minidump = { 426 .ka_probe = _amd64_minidump_probe, 427 .ka_initvtop = _amd64_minidump_initvtop, 428 .ka_freevtop = _amd64_minidump_freevtop, 429 .ka_kvatop = _amd64_minidump_kvatop, 430 .ka_native = _amd64_native, 431 .ka_walk_pages = _amd64_minidump_walk_pages, 432 }; 433 434 KVM_ARCH(kvm_amd64_minidump); 435