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, dump_avail_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; version 3 adds the dumpavailsize field 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 vmst->hdr.dumpavailsize = vmst->hdr.version == MINIDUMP_VERSION ? 161 le32toh(vmst->hdr.dumpavailsize) : 0; 162 163 /* Skip header and msgbuf */ 164 dump_avail_off = AMD64_PAGE_SIZE + amd64_round_page(vmst->hdr.msgbufsize); 165 166 /* Skip dump_avail */ 167 off = dump_avail_off + amd64_round_page(vmst->hdr.dumpavailsize); 168 169 sparse_off = off + amd64_round_page(vmst->hdr.bitmapsize) + 170 amd64_round_page(vmst->hdr.pmapsize); 171 if (_kvm_pt_init(kd, vmst->hdr.dumpavailsize, dump_avail_off, 172 vmst->hdr.bitmapsize, off, sparse_off, AMD64_PAGE_SIZE, 173 sizeof(uint64_t)) == -1) { 174 return (-1); 175 } 176 off += amd64_round_page(vmst->hdr.bitmapsize); 177 178 if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) { 179 return (-1); 180 } 181 off += amd64_round_page(vmst->hdr.pmapsize); 182 183 return (0); 184 } 185 186 static int 187 _amd64_minidump_vatop_v1(kvm_t *kd, kvaddr_t va, off_t *pa) 188 { 189 struct vmstate *vm; 190 amd64_physaddr_t offset; 191 amd64_pte_t pte; 192 kvaddr_t pteindex; 193 amd64_physaddr_t a; 194 off_t ofs; 195 196 vm = kd->vmst; 197 offset = va & AMD64_PAGE_MASK; 198 199 if (va >= vm->hdr.kernbase) { 200 pteindex = (va - vm->hdr.kernbase) >> AMD64_PAGE_SHIFT; 201 if (pteindex >= vm->hdr.pmapsize / sizeof(pte)) 202 goto invalid; 203 pte = _amd64_pte_get(kd, pteindex); 204 if ((pte & AMD64_PG_V) == 0) { 205 _kvm_err(kd, kd->program, 206 "_amd64_minidump_vatop_v1: pte not valid"); 207 goto invalid; 208 } 209 a = pte & AMD64_PG_FRAME; 210 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 211 if (ofs == -1) { 212 _kvm_err(kd, kd->program, 213 "_amd64_minidump_vatop_v1: physical address 0x%jx not in minidump", 214 (uintmax_t)a); 215 goto invalid; 216 } 217 *pa = ofs + offset; 218 return (AMD64_PAGE_SIZE - offset); 219 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 220 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 221 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 222 if (ofs == -1) { 223 _kvm_err(kd, kd->program, 224 "_amd64_minidump_vatop_v1: direct map address 0x%jx not in minidump", 225 (uintmax_t)va); 226 goto invalid; 227 } 228 *pa = ofs + offset; 229 return (AMD64_PAGE_SIZE - offset); 230 } else { 231 _kvm_err(kd, kd->program, 232 "_amd64_minidump_vatop_v1: virtual address 0x%jx not minidumped", 233 (uintmax_t)va); 234 goto invalid; 235 } 236 237 invalid: 238 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 239 return (0); 240 } 241 242 static int 243 _amd64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) 244 { 245 amd64_pte_t pt[AMD64_NPTEPG]; 246 struct vmstate *vm; 247 amd64_physaddr_t offset; 248 amd64_pde_t pde; 249 amd64_pte_t pte; 250 kvaddr_t pteindex; 251 kvaddr_t pdeindex; 252 amd64_physaddr_t a; 253 off_t ofs; 254 255 vm = kd->vmst; 256 offset = va & AMD64_PAGE_MASK; 257 258 if (va >= vm->hdr.kernbase) { 259 pdeindex = (va - vm->hdr.kernbase) >> AMD64_PDRSHIFT; 260 if (pdeindex >= vm->hdr.pmapsize / sizeof(pde)) 261 goto invalid; 262 pde = _amd64_pde_get(kd, pdeindex); 263 if ((pde & AMD64_PG_V) == 0) { 264 _kvm_err(kd, kd->program, 265 "_amd64_minidump_vatop: pde not valid"); 266 goto invalid; 267 } 268 if ((pde & AMD64_PG_PS) == 0) { 269 a = pde & AMD64_PG_FRAME; 270 /* TODO: Just read the single PTE */ 271 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 272 if (ofs == -1) { 273 _kvm_err(kd, kd->program, 274 "cannot find page table entry for %ju", 275 (uintmax_t)a); 276 goto invalid; 277 } 278 if (pread(kd->pmfd, &pt, AMD64_PAGE_SIZE, ofs) != 279 AMD64_PAGE_SIZE) { 280 _kvm_err(kd, kd->program, 281 "cannot read page table entry for %ju", 282 (uintmax_t)a); 283 goto invalid; 284 } 285 pteindex = (va >> AMD64_PAGE_SHIFT) & 286 (AMD64_NPTEPG - 1); 287 pte = le64toh(pt[pteindex]); 288 if ((pte & AMD64_PG_V) == 0) { 289 _kvm_err(kd, kd->program, 290 "_amd64_minidump_vatop: pte not valid"); 291 goto invalid; 292 } 293 a = pte & AMD64_PG_FRAME; 294 } else { 295 a = pde & AMD64_PG_PS_FRAME; 296 a += (va & AMD64_PDRMASK) ^ offset; 297 } 298 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 299 if (ofs == -1) { 300 _kvm_err(kd, kd->program, 301 "_amd64_minidump_vatop: physical address 0x%jx not in minidump", 302 (uintmax_t)a); 303 goto invalid; 304 } 305 *pa = ofs + offset; 306 return (AMD64_PAGE_SIZE - offset); 307 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 308 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 309 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 310 if (ofs == -1) { 311 _kvm_err(kd, kd->program, 312 "_amd64_minidump_vatop: direct map address 0x%jx not in minidump", 313 (uintmax_t)va); 314 goto invalid; 315 } 316 *pa = ofs + offset; 317 return (AMD64_PAGE_SIZE - offset); 318 } else { 319 _kvm_err(kd, kd->program, 320 "_amd64_minidump_vatop: virtual address 0x%jx not minidumped", 321 (uintmax_t)va); 322 goto invalid; 323 } 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_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) 332 { 333 334 if (ISALIVE(kd)) { 335 _kvm_err(kd, 0, 336 "_amd64_minidump_kvatop called in live kernel!"); 337 return (0); 338 } 339 if (((struct vmstate *)kd->vmst)->hdr.version == 1) 340 return (_amd64_minidump_vatop_v1(kd, va, pa)); 341 else 342 return (_amd64_minidump_vatop(kd, va, pa)); 343 } 344 345 static int 346 _amd64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg) 347 { 348 struct vmstate *vm = kd->vmst; 349 u_long npdes = vm->hdr.pmapsize / sizeof(amd64_pde_t); 350 u_long bmindex, dva, pa, pdeindex, va; 351 struct kvm_bitmap bm; 352 int ret = 0; 353 vm_prot_t prot; 354 unsigned int pgsz = AMD64_PAGE_SIZE; 355 356 if (vm->hdr.version < 2) 357 return (0); 358 359 if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex)) 360 return (0); 361 362 for (pdeindex = 0; pdeindex < npdes; pdeindex++) { 363 amd64_pde_t pde = _amd64_pde_get(kd, pdeindex); 364 amd64_pte_t *ptes; 365 u_long i; 366 367 va = vm->hdr.kernbase + (pdeindex << AMD64_PDRSHIFT); 368 if ((pde & AMD64_PG_V) == 0) 369 continue; 370 371 if ((pde & AMD64_PG_PS) != 0) { 372 /* 373 * Large page. Iterate on each 4K page section 374 * within this page. This differs from 4K pages in 375 * that every page here uses the same PDE to 376 * generate permissions. 377 */ 378 pa = (pde & AMD64_PG_PS_FRAME) + 379 ((va & AMD64_PDRMASK) ^ VA_OFF(vm, va)); 380 dva = vm->hdr.dmapbase + pa; 381 _kvm_bitmap_set(&bm, _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE)); 382 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 383 _amd64_entry_to_prot(pde), AMD64_NBPDR, pgsz)) { 384 goto out; 385 } 386 continue; 387 } 388 389 /* 4K pages: pde references another page of entries. */ 390 ptes = _amd64_pde_first_pte(kd, pdeindex); 391 /* Ignore page directory pages that were not dumped. */ 392 if (ptes == NULL) 393 continue; 394 395 for (i = 0; i < AMD64_NPTEPG; i++) { 396 amd64_pte_t pte = (u_long)ptes[i]; 397 398 pa = pte & AMD64_PG_FRAME; 399 dva = vm->hdr.dmapbase + pa; 400 if ((pte & AMD64_PG_V) != 0) { 401 _kvm_bitmap_set(&bm, 402 _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE)); 403 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 404 _amd64_entry_to_prot(pte), pgsz, 0)) { 405 goto out; 406 } 407 } 408 va += AMD64_PAGE_SIZE; 409 } 410 } 411 412 while (_kvm_bitmap_next(&bm, &bmindex)) { 413 pa = _kvm_bit_id_pa(kd, bmindex, AMD64_PAGE_SIZE); 414 if (pa == _KVM_PA_INVALID) 415 break; 416 dva = vm->hdr.dmapbase + pa; 417 if (vm->hdr.dmapend < (dva + pgsz)) 418 break; 419 va = 0; 420 /* amd64/pmap.c: create_pagetables(): dmap always R|W. */ 421 prot = VM_PROT_READ | VM_PROT_WRITE; 422 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, prot, pgsz, 0)) { 423 goto out; 424 } 425 } 426 427 ret = 1; 428 429 out: 430 _kvm_bitmap_deinit(&bm); 431 return (ret); 432 } 433 434 static struct kvm_arch kvm_amd64_minidump = { 435 .ka_probe = _amd64_minidump_probe, 436 .ka_initvtop = _amd64_minidump_initvtop, 437 .ka_freevtop = _amd64_minidump_freevtop, 438 .ka_kvatop = _amd64_minidump_kvatop, 439 .ka_native = _amd64_native, 440 .ka_walk_pages = _amd64_minidump_walk_pages, 441 }; 442 443 KVM_ARCH(kvm_amd64_minidump); 444