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