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) == -1) { 173 return (-1); 174 } 175 off += amd64_round_page(vmst->hdr.bitmapsize); 176 177 if (_kvm_pmap_init(kd, vmst->hdr.pmapsize, off) == -1) { 178 return (-1); 179 } 180 off += amd64_round_page(vmst->hdr.pmapsize); 181 182 return (0); 183 } 184 185 static int 186 _amd64_minidump_vatop_v1(kvm_t *kd, kvaddr_t va, off_t *pa) 187 { 188 struct vmstate *vm; 189 amd64_physaddr_t offset; 190 amd64_pte_t pte; 191 kvaddr_t pteindex; 192 amd64_physaddr_t a; 193 off_t ofs; 194 195 vm = kd->vmst; 196 offset = va & AMD64_PAGE_MASK; 197 198 if (va >= vm->hdr.kernbase) { 199 pteindex = (va - vm->hdr.kernbase) >> AMD64_PAGE_SHIFT; 200 if (pteindex >= vm->hdr.pmapsize / sizeof(pte)) 201 goto invalid; 202 pte = _amd64_pte_get(kd, pteindex); 203 if ((pte & AMD64_PG_V) == 0) { 204 _kvm_err(kd, kd->program, 205 "_amd64_minidump_vatop_v1: pte not valid"); 206 goto invalid; 207 } 208 a = pte & AMD64_PG_FRAME; 209 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 210 if (ofs == -1) { 211 _kvm_err(kd, kd->program, 212 "_amd64_minidump_vatop_v1: physical address 0x%jx not in minidump", 213 (uintmax_t)a); 214 goto invalid; 215 } 216 *pa = ofs + offset; 217 return (AMD64_PAGE_SIZE - offset); 218 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 219 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 220 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 221 if (ofs == -1) { 222 _kvm_err(kd, kd->program, 223 "_amd64_minidump_vatop_v1: direct map address 0x%jx not in minidump", 224 (uintmax_t)va); 225 goto invalid; 226 } 227 *pa = ofs + offset; 228 return (AMD64_PAGE_SIZE - offset); 229 } else { 230 _kvm_err(kd, kd->program, 231 "_amd64_minidump_vatop_v1: virtual address 0x%jx not minidumped", 232 (uintmax_t)va); 233 goto invalid; 234 } 235 236 invalid: 237 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 238 return (0); 239 } 240 241 static int 242 _amd64_minidump_vatop(kvm_t *kd, kvaddr_t va, off_t *pa) 243 { 244 amd64_pte_t pt[AMD64_NPTEPG]; 245 struct vmstate *vm; 246 amd64_physaddr_t offset; 247 amd64_pde_t pde; 248 amd64_pte_t pte; 249 kvaddr_t pteindex; 250 kvaddr_t pdeindex; 251 amd64_physaddr_t a; 252 off_t ofs; 253 254 vm = kd->vmst; 255 offset = va & AMD64_PAGE_MASK; 256 257 if (va >= vm->hdr.kernbase) { 258 pdeindex = (va - vm->hdr.kernbase) >> AMD64_PDRSHIFT; 259 if (pdeindex >= vm->hdr.pmapsize / sizeof(pde)) 260 goto invalid; 261 pde = _amd64_pde_get(kd, pdeindex); 262 if ((pde & AMD64_PG_V) == 0) { 263 _kvm_err(kd, kd->program, 264 "_amd64_minidump_vatop: pde not valid"); 265 goto invalid; 266 } 267 if ((pde & AMD64_PG_PS) == 0) { 268 a = pde & AMD64_PG_FRAME; 269 /* TODO: Just read the single PTE */ 270 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 271 if (ofs == -1) { 272 _kvm_err(kd, kd->program, 273 "cannot find page table entry for %ju", 274 (uintmax_t)a); 275 goto invalid; 276 } 277 if (pread(kd->pmfd, &pt, AMD64_PAGE_SIZE, ofs) != 278 AMD64_PAGE_SIZE) { 279 _kvm_err(kd, kd->program, 280 "cannot read page table entry for %ju", 281 (uintmax_t)a); 282 goto invalid; 283 } 284 pteindex = (va >> AMD64_PAGE_SHIFT) & 285 (AMD64_NPTEPG - 1); 286 pte = le64toh(pt[pteindex]); 287 if ((pte & AMD64_PG_V) == 0) { 288 _kvm_err(kd, kd->program, 289 "_amd64_minidump_vatop: pte not valid"); 290 goto invalid; 291 } 292 a = pte & AMD64_PG_FRAME; 293 } else { 294 a = pde & AMD64_PG_PS_FRAME; 295 a += (va & AMD64_PDRMASK) ^ offset; 296 } 297 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 298 if (ofs == -1) { 299 _kvm_err(kd, kd->program, 300 "_amd64_minidump_vatop: physical address 0x%jx not in minidump", 301 (uintmax_t)a); 302 goto invalid; 303 } 304 *pa = ofs + offset; 305 return (AMD64_PAGE_SIZE - offset); 306 } else if (va >= vm->hdr.dmapbase && va < vm->hdr.dmapend) { 307 a = (va - vm->hdr.dmapbase) & ~AMD64_PAGE_MASK; 308 ofs = _kvm_pt_find(kd, a, AMD64_PAGE_SIZE); 309 if (ofs == -1) { 310 _kvm_err(kd, kd->program, 311 "_amd64_minidump_vatop: direct map address 0x%jx not in minidump", 312 (uintmax_t)va); 313 goto invalid; 314 } 315 *pa = ofs + offset; 316 return (AMD64_PAGE_SIZE - offset); 317 } else { 318 _kvm_err(kd, kd->program, 319 "_amd64_minidump_vatop: virtual address 0x%jx not minidumped", 320 (uintmax_t)va); 321 goto invalid; 322 } 323 324 invalid: 325 _kvm_err(kd, 0, "invalid address (0x%jx)", (uintmax_t)va); 326 return (0); 327 } 328 329 static int 330 _amd64_minidump_kvatop(kvm_t *kd, kvaddr_t va, off_t *pa) 331 { 332 333 if (ISALIVE(kd)) { 334 _kvm_err(kd, 0, 335 "_amd64_minidump_kvatop called in live kernel!"); 336 return (0); 337 } 338 if (((struct vmstate *)kd->vmst)->hdr.version == 1) 339 return (_amd64_minidump_vatop_v1(kd, va, pa)); 340 else 341 return (_amd64_minidump_vatop(kd, va, pa)); 342 } 343 344 static int 345 _amd64_minidump_walk_pages(kvm_t *kd, kvm_walk_pages_cb_t *cb, void *arg) 346 { 347 struct vmstate *vm = kd->vmst; 348 u_long npdes = vm->hdr.pmapsize / sizeof(amd64_pde_t); 349 u_long bmindex, dva, pa, pdeindex, va; 350 struct kvm_bitmap bm; 351 int ret = 0; 352 vm_prot_t prot; 353 unsigned int pgsz = AMD64_PAGE_SIZE; 354 355 if (vm->hdr.version < 2) 356 return (0); 357 358 if (!_kvm_bitmap_init(&bm, vm->hdr.bitmapsize, &bmindex)) 359 return (0); 360 361 for (pdeindex = 0; pdeindex < npdes; pdeindex++) { 362 amd64_pde_t pde = _amd64_pde_get(kd, pdeindex); 363 amd64_pte_t *ptes; 364 u_long i; 365 366 va = vm->hdr.kernbase + (pdeindex << AMD64_PDRSHIFT); 367 if ((pde & AMD64_PG_V) == 0) 368 continue; 369 370 if ((pde & AMD64_PG_PS) != 0) { 371 /* 372 * Large page. Iterate on each 4K page section 373 * within this page. This differs from 4K pages in 374 * that every page here uses the same PDE to 375 * generate permissions. 376 */ 377 pa = (pde & AMD64_PG_PS_FRAME) + 378 ((va & AMD64_PDRMASK) ^ VA_OFF(vm, va)); 379 dva = vm->hdr.dmapbase + pa; 380 _kvm_bitmap_set(&bm, _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE)); 381 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 382 _amd64_entry_to_prot(pde), AMD64_NBPDR, pgsz)) { 383 goto out; 384 } 385 continue; 386 } 387 388 /* 4K pages: pde references another page of entries. */ 389 ptes = _amd64_pde_first_pte(kd, pdeindex); 390 /* Ignore page directory pages that were not dumped. */ 391 if (ptes == NULL) 392 continue; 393 394 for (i = 0; i < AMD64_NPTEPG; i++) { 395 amd64_pte_t pte = (u_long)ptes[i]; 396 397 pa = pte & AMD64_PG_FRAME; 398 dva = vm->hdr.dmapbase + pa; 399 if ((pte & AMD64_PG_V) != 0) { 400 _kvm_bitmap_set(&bm, 401 _kvm_pa_bit_id(kd, pa, AMD64_PAGE_SIZE)); 402 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, 403 _amd64_entry_to_prot(pte), pgsz, 0)) { 404 goto out; 405 } 406 } 407 va += AMD64_PAGE_SIZE; 408 } 409 } 410 411 while (_kvm_bitmap_next(&bm, &bmindex)) { 412 pa = _kvm_bit_id_pa(kd, bmindex, AMD64_PAGE_SIZE); 413 if (pa == _KVM_PA_INVALID) 414 break; 415 dva = vm->hdr.dmapbase + pa; 416 if (vm->hdr.dmapend < (dva + pgsz)) 417 break; 418 va = 0; 419 /* amd64/pmap.c: create_pagetables(): dmap always R|W. */ 420 prot = VM_PROT_READ | VM_PROT_WRITE; 421 if (!_kvm_visit_cb(kd, cb, arg, pa, va, dva, prot, pgsz, 0)) { 422 goto out; 423 } 424 } 425 426 ret = 1; 427 428 out: 429 _kvm_bitmap_deinit(&bm); 430 return (ret); 431 } 432 433 static struct kvm_arch kvm_amd64_minidump = { 434 .ka_probe = _amd64_minidump_probe, 435 .ka_initvtop = _amd64_minidump_initvtop, 436 .ka_freevtop = _amd64_minidump_freevtop, 437 .ka_kvatop = _amd64_minidump_kvatop, 438 .ka_native = _amd64_native, 439 .ka_walk_pages = _amd64_minidump_walk_pages, 440 }; 441 442 KVM_ARCH(kvm_amd64_minidump); 443