1 /* 2 * Copyright (c) 2018 Virtuozzo International GmbH 3 * 4 * This work is licensed under the terms of the GNU GPL, version 2 or later. 5 * 6 */ 7 8 #include <inttypes.h> 9 10 #include "qemu/osdep.h" 11 #include "err.h" 12 #include "addrspace.h" 13 #include "pe.h" 14 #include "pdb.h" 15 #include "kdbg.h" 16 #include "download.h" 17 #include "qemu/win_dump_defs.h" 18 19 #define SYM_URL_BASE "https://msdl.microsoft.com/download/symbols/" 20 #define PDB_NAME "ntkrnlmp.pdb" 21 22 #define INITIAL_MXCSR 0x1f80 23 24 typedef struct idt_desc { 25 uint16_t offset1; /* offset bits 0..15 */ 26 uint16_t selector; 27 uint8_t ist; 28 uint8_t type_attr; 29 uint16_t offset2; /* offset bits 16..31 */ 30 uint32_t offset3; /* offset bits 32..63 */ 31 uint32_t rsrvd; 32 } __attribute__ ((packed)) idt_desc_t; 33 34 static uint64_t idt_desc_addr(idt_desc_t desc) 35 { 36 return (uint64_t)desc.offset1 | ((uint64_t)desc.offset2 << 16) | 37 ((uint64_t)desc.offset3 << 32); 38 } 39 40 static const uint64_t SharedUserData = 0xfffff78000000000; 41 42 #define KUSD_OFFSET_SUITE_MASK 0x2d0 43 #define KUSD_OFFSET_PRODUCT_TYPE 0x264 44 45 #define SYM_RESOLVE(base, r, s) ((s = pdb_resolve(base, r, #s)),\ 46 s ? printf(#s" = 0x%016"PRIx64"\n", s) :\ 47 eprintf("Failed to resolve "#s"\n"), s) 48 49 static uint64_t rol(uint64_t x, uint64_t y) 50 { 51 return (x << y) | (x >> (64 - y)); 52 } 53 54 /* 55 * Decoding algorithm can be found in Volatility project 56 */ 57 static void kdbg_decode(uint64_t *dst, uint64_t *src, size_t size, 58 uint64_t kwn, uint64_t kwa, uint64_t kdbe) 59 { 60 size_t i; 61 assert(size % sizeof(uint64_t) == 0); 62 for (i = 0; i < size / sizeof(uint64_t); i++) { 63 uint64_t block; 64 65 block = src[i]; 66 block = rol(block ^ kwn, (uint8_t)kwn); 67 block = __builtin_bswap64(block ^ kdbe) ^ kwa; 68 dst[i] = block; 69 } 70 } 71 72 static KDDEBUGGER_DATA64 *get_kdbg(uint64_t KernBase, struct pdb_reader *pdb, 73 struct va_space *vs, uint64_t KdDebuggerDataBlock) 74 { 75 const char OwnerTag[4] = "KDBG"; 76 KDDEBUGGER_DATA64 *kdbg = NULL; 77 DBGKD_DEBUG_DATA_HEADER64 kdbg_hdr; 78 bool decode = false; 79 uint64_t kwn, kwa, KdpDataBlockEncoded; 80 81 if (va_space_rw(vs, 82 KdDebuggerDataBlock + offsetof(KDDEBUGGER_DATA64, Header), 83 &kdbg_hdr, sizeof(kdbg_hdr), 0)) { 84 eprintf("Failed to extract KDBG header\n"); 85 return NULL; 86 } 87 88 if (memcmp(&kdbg_hdr.OwnerTag, OwnerTag, sizeof(OwnerTag))) { 89 uint64_t KiWaitNever, KiWaitAlways; 90 91 decode = true; 92 93 if (!SYM_RESOLVE(KernBase, pdb, KiWaitNever) || 94 !SYM_RESOLVE(KernBase, pdb, KiWaitAlways) || 95 !SYM_RESOLVE(KernBase, pdb, KdpDataBlockEncoded)) { 96 return NULL; 97 } 98 99 if (va_space_rw(vs, KiWaitNever, &kwn, sizeof(kwn), 0) || 100 va_space_rw(vs, KiWaitAlways, &kwa, sizeof(kwa), 0)) { 101 return NULL; 102 } 103 104 printf("[KiWaitNever] = 0x%016"PRIx64"\n", kwn); 105 printf("[KiWaitAlways] = 0x%016"PRIx64"\n", kwa); 106 107 /* 108 * If KDBG header can be decoded, KDBG size is available 109 * and entire KDBG can be decoded. 110 */ 111 printf("Decoding KDBG header...\n"); 112 kdbg_decode((uint64_t *)&kdbg_hdr, (uint64_t *)&kdbg_hdr, 113 sizeof(kdbg_hdr), kwn, kwa, KdpDataBlockEncoded); 114 115 printf("Owner tag is \'%.4s\'\n", (char *)&kdbg_hdr.OwnerTag); 116 if (memcmp(&kdbg_hdr.OwnerTag, OwnerTag, sizeof(OwnerTag))) { 117 eprintf("Failed to decode KDBG header\n"); 118 return NULL; 119 } 120 } 121 122 kdbg = malloc(kdbg_hdr.Size); 123 if (!kdbg) { 124 return NULL; 125 } 126 127 if (va_space_rw(vs, KdDebuggerDataBlock, kdbg, kdbg_hdr.Size, 0)) { 128 eprintf("Failed to extract entire KDBG\n"); 129 return NULL; 130 } 131 132 if (!decode) { 133 return kdbg; 134 } 135 136 printf("Decoding KdDebuggerDataBlock...\n"); 137 kdbg_decode((uint64_t *)kdbg, (uint64_t *)kdbg, kdbg_hdr.Size, 138 kwn, kwa, KdpDataBlockEncoded); 139 140 va_space_rw(vs, KdDebuggerDataBlock, kdbg, kdbg_hdr.Size, 1); 141 142 return kdbg; 143 } 144 145 static void win_context_init_from_qemu_cpu_state(WinContext *ctx, 146 QEMUCPUState *s) 147 { 148 WinContext win_ctx = (WinContext){ 149 .ContextFlags = WIN_CTX_X64 | WIN_CTX_INT | WIN_CTX_SEG | WIN_CTX_CTL, 150 .MxCsr = INITIAL_MXCSR, 151 152 .SegCs = s->cs.selector, 153 .SegSs = s->ss.selector, 154 .SegDs = s->ds.selector, 155 .SegEs = s->es.selector, 156 .SegFs = s->fs.selector, 157 .SegGs = s->gs.selector, 158 .EFlags = (uint32_t)s->rflags, 159 160 .Rax = s->rax, 161 .Rbx = s->rbx, 162 .Rcx = s->rcx, 163 .Rdx = s->rdx, 164 .Rsp = s->rsp, 165 .Rbp = s->rbp, 166 .Rsi = s->rsi, 167 .Rdi = s->rdi, 168 .R8 = s->r8, 169 .R9 = s->r9, 170 .R10 = s->r10, 171 .R11 = s->r11, 172 .R12 = s->r12, 173 .R13 = s->r13, 174 .R14 = s->r14, 175 .R15 = s->r15, 176 177 .Rip = s->rip, 178 .FltSave = { 179 .MxCsr = INITIAL_MXCSR, 180 }, 181 }; 182 183 *ctx = win_ctx; 184 } 185 186 /* 187 * Finds paging-structure hierarchy base, 188 * if previously set doesn't give access to kernel structures 189 */ 190 static int fix_dtb(struct va_space *vs, QEMU_Elf *qe) 191 { 192 /* 193 * Firstly, test previously set DTB. 194 */ 195 if (va_space_resolve(vs, SharedUserData)) { 196 return 0; 197 } 198 199 /* 200 * Secondly, find CPU which run system task. 201 */ 202 size_t i; 203 for (i = 0; i < qe->state_nr; i++) { 204 QEMUCPUState *s = qe->state[i]; 205 206 if (is_system(s)) { 207 va_space_set_dtb(vs, s->cr[3]); 208 printf("DTB 0x%016"PRIx64" has been found from CPU #%zu" 209 " as system task CR3\n", vs->dtb, i); 210 return !(va_space_resolve(vs, SharedUserData)); 211 } 212 } 213 214 /* 215 * Thirdly, use KERNEL_GS_BASE from CPU #0 as PRCB address and 216 * CR3 as [Prcb+0x7000] 217 */ 218 if (qe->has_kernel_gs_base) { 219 QEMUCPUState *s = qe->state[0]; 220 uint64_t Prcb = s->kernel_gs_base; 221 uint64_t *cr3 = va_space_resolve(vs, Prcb + 0x7000); 222 223 if (!cr3) { 224 return 1; 225 } 226 227 va_space_set_dtb(vs, *cr3); 228 printf("DirectoryTableBase = 0x%016"PRIx64" has been found from CPU #0" 229 " as interrupt handling CR3\n", vs->dtb); 230 return !(va_space_resolve(vs, SharedUserData)); 231 } 232 233 return 1; 234 } 235 236 static int fill_header(WinDumpHeader64 *hdr, struct pa_space *ps, 237 struct va_space *vs, uint64_t KdDebuggerDataBlock, 238 KDDEBUGGER_DATA64 *kdbg, uint64_t KdVersionBlock, int nr_cpus) 239 { 240 uint32_t *suite_mask = va_space_resolve(vs, SharedUserData + 241 KUSD_OFFSET_SUITE_MASK); 242 int32_t *product_type = va_space_resolve(vs, SharedUserData + 243 KUSD_OFFSET_PRODUCT_TYPE); 244 DBGKD_GET_VERSION64 kvb; 245 WinDumpHeader64 h; 246 size_t i; 247 248 QEMU_BUILD_BUG_ON(KUSD_OFFSET_SUITE_MASK >= PAGE_SIZE); 249 QEMU_BUILD_BUG_ON(KUSD_OFFSET_PRODUCT_TYPE >= PAGE_SIZE); 250 251 if (!suite_mask || !product_type) { 252 return 1; 253 } 254 255 if (va_space_rw(vs, KdVersionBlock, &kvb, sizeof(kvb), 0)) { 256 eprintf("Failed to extract KdVersionBlock\n"); 257 return 1; 258 } 259 260 h = (WinDumpHeader64) { 261 .Signature = "PAGE", 262 .ValidDump = "DU64", 263 .MajorVersion = kvb.MajorVersion, 264 .MinorVersion = kvb.MinorVersion, 265 .DirectoryTableBase = vs->dtb, 266 .PfnDatabase = kdbg->MmPfnDatabase, 267 .PsLoadedModuleList = kdbg->PsLoadedModuleList, 268 .PsActiveProcessHead = kdbg->PsActiveProcessHead, 269 .MachineImageType = kvb.MachineType, 270 .NumberProcessors = nr_cpus, 271 .BugcheckCode = LIVE_SYSTEM_DUMP, 272 .KdDebuggerDataBlock = KdDebuggerDataBlock, 273 .DumpType = 1, 274 .Comment = "Hello from elf2dmp!", 275 .SuiteMask = *suite_mask, 276 .ProductType = *product_type, 277 .SecondaryDataState = kvb.KdSecondaryVersion, 278 .PhysicalMemoryBlock = (WinDumpPhyMemDesc64) { 279 .NumberOfRuns = ps->block_nr, 280 }, 281 .RequiredDumpSpace = sizeof(h), 282 }; 283 284 for (i = 0; i < ps->block_nr; i++) { 285 h.PhysicalMemoryBlock.NumberOfPages += ps->block[i].size / PAGE_SIZE; 286 h.PhysicalMemoryBlock.Run[i] = (WinDumpPhyMemRun64) { 287 .BasePage = ps->block[i].paddr / PAGE_SIZE, 288 .PageCount = ps->block[i].size / PAGE_SIZE, 289 }; 290 } 291 292 h.RequiredDumpSpace += h.PhysicalMemoryBlock.NumberOfPages << PAGE_BITS; 293 294 *hdr = h; 295 296 return 0; 297 } 298 299 static int fill_context(KDDEBUGGER_DATA64 *kdbg, 300 struct va_space *vs, QEMU_Elf *qe) 301 { 302 int i; 303 for (i = 0; i < qe->state_nr; i++) { 304 uint64_t Prcb; 305 uint64_t Context; 306 WinContext ctx; 307 QEMUCPUState *s = qe->state[i]; 308 309 if (va_space_rw(vs, kdbg->KiProcessorBlock + sizeof(Prcb) * i, 310 &Prcb, sizeof(Prcb), 0)) { 311 eprintf("Failed to read CPU #%d PRCB location\n", i); 312 return 1; 313 } 314 315 if (va_space_rw(vs, Prcb + kdbg->OffsetPrcbContext, 316 &Context, sizeof(Context), 0)) { 317 eprintf("Failed to read CPU #%d ContextFrame location\n", i); 318 return 1; 319 } 320 321 printf("Filling context for CPU #%d...\n", i); 322 win_context_init_from_qemu_cpu_state(&ctx, s); 323 324 if (va_space_rw(vs, Context, &ctx, sizeof(ctx), 1)) { 325 eprintf("Failed to fill CPU #%d context\n", i); 326 return 1; 327 } 328 } 329 330 return 0; 331 } 332 333 static int write_dump(struct pa_space *ps, 334 WinDumpHeader64 *hdr, const char *name) 335 { 336 FILE *dmp_file = fopen(name, "wb"); 337 size_t i; 338 339 if (!dmp_file) { 340 eprintf("Failed to open output file \'%s\'\n", name); 341 return 1; 342 } 343 344 printf("Writing header to file...\n"); 345 346 if (fwrite(hdr, sizeof(*hdr), 1, dmp_file) != 1) { 347 eprintf("Failed to write dump header\n"); 348 fclose(dmp_file); 349 return 1; 350 } 351 352 for (i = 0; i < ps->block_nr; i++) { 353 struct pa_block *b = &ps->block[i]; 354 355 printf("Writing block #%zu/%zu to file...\n", i, ps->block_nr); 356 if (fwrite(b->addr, b->size, 1, dmp_file) != 1) { 357 eprintf("Failed to write dump header\n"); 358 fclose(dmp_file); 359 return 1; 360 } 361 } 362 363 return fclose(dmp_file); 364 } 365 366 static int pe_get_pdb_symstore_hash(uint64_t base, void *start_addr, 367 char *hash, struct va_space *vs) 368 { 369 const char e_magic[2] = "MZ"; 370 const char Signature[4] = "PE\0\0"; 371 const char sign_rsds[4] = "RSDS"; 372 IMAGE_DOS_HEADER *dos_hdr = start_addr; 373 IMAGE_NT_HEADERS64 nt_hdrs; 374 IMAGE_FILE_HEADER *file_hdr = &nt_hdrs.FileHeader; 375 IMAGE_OPTIONAL_HEADER64 *opt_hdr = &nt_hdrs.OptionalHeader; 376 IMAGE_DATA_DIRECTORY *data_dir = nt_hdrs.OptionalHeader.DataDirectory; 377 IMAGE_DEBUG_DIRECTORY debug_dir; 378 OMFSignatureRSDS rsds; 379 char *pdb_name; 380 size_t pdb_name_sz; 381 size_t i; 382 383 QEMU_BUILD_BUG_ON(sizeof(*dos_hdr) >= PAGE_SIZE); 384 385 if (memcmp(&dos_hdr->e_magic, e_magic, sizeof(e_magic))) { 386 return 1; 387 } 388 389 if (va_space_rw(vs, base + dos_hdr->e_lfanew, 390 &nt_hdrs, sizeof(nt_hdrs), 0)) { 391 return 1; 392 } 393 394 if (memcmp(&nt_hdrs.Signature, Signature, sizeof(Signature)) || 395 file_hdr->Machine != 0x8664 || opt_hdr->Magic != 0x020b) { 396 return 1; 397 } 398 399 printf("Debug Directory RVA = 0x%08"PRIx32"\n", 400 (uint32_t)data_dir[IMAGE_FILE_DEBUG_DIRECTORY].VirtualAddress); 401 402 if (va_space_rw(vs, 403 base + data_dir[IMAGE_FILE_DEBUG_DIRECTORY].VirtualAddress, 404 &debug_dir, sizeof(debug_dir), 0)) { 405 return 1; 406 } 407 408 if (debug_dir.Type != IMAGE_DEBUG_TYPE_CODEVIEW) { 409 return 1; 410 } 411 412 if (va_space_rw(vs, 413 base + debug_dir.AddressOfRawData, 414 &rsds, sizeof(rsds), 0)) { 415 return 1; 416 } 417 418 printf("CodeView signature is \'%.4s\'\n", rsds.Signature); 419 420 if (memcmp(&rsds.Signature, sign_rsds, sizeof(sign_rsds))) { 421 return 1; 422 } 423 424 pdb_name_sz = debug_dir.SizeOfData - sizeof(rsds); 425 pdb_name = malloc(pdb_name_sz); 426 if (!pdb_name) { 427 return 1; 428 } 429 430 if (va_space_rw(vs, base + debug_dir.AddressOfRawData + 431 offsetof(OMFSignatureRSDS, name), pdb_name, pdb_name_sz, 0)) { 432 free(pdb_name); 433 return 1; 434 } 435 436 printf("PDB name is \'%s\', \'%s\' expected\n", pdb_name, PDB_NAME); 437 438 if (strcmp(pdb_name, PDB_NAME)) { 439 eprintf("Unexpected PDB name, it seems the kernel isn't found\n"); 440 free(pdb_name); 441 return 1; 442 } 443 444 free(pdb_name); 445 446 sprintf(hash, "%.08x%.04x%.04x%.02x%.02x", rsds.guid.a, rsds.guid.b, 447 rsds.guid.c, rsds.guid.d[0], rsds.guid.d[1]); 448 hash += 20; 449 for (i = 0; i < 6; i++, hash += 2) { 450 sprintf(hash, "%.02x", rsds.guid.e[i]); 451 } 452 453 sprintf(hash, "%.01x", rsds.age); 454 455 return 0; 456 } 457 458 int main(int argc, char *argv[]) 459 { 460 int err = 0; 461 QEMU_Elf qemu_elf; 462 struct pa_space ps; 463 struct va_space vs; 464 QEMUCPUState *state; 465 idt_desc_t first_idt_desc; 466 uint64_t KernBase; 467 void *nt_start_addr = NULL; 468 WinDumpHeader64 header; 469 char pdb_hash[34]; 470 char pdb_url[] = SYM_URL_BASE PDB_NAME 471 "/0123456789ABCDEF0123456789ABCDEFx/" PDB_NAME; 472 struct pdb_reader pdb; 473 uint64_t KdDebuggerDataBlock; 474 KDDEBUGGER_DATA64 *kdbg; 475 uint64_t KdVersionBlock; 476 477 if (argc != 3) { 478 eprintf("usage:\n\t%s elf_file dmp_file\n", argv[0]); 479 return 1; 480 } 481 482 if (QEMU_Elf_init(&qemu_elf, argv[1])) { 483 eprintf("Failed to initialize QEMU ELF dump\n"); 484 return 1; 485 } 486 487 if (pa_space_create(&ps, &qemu_elf)) { 488 eprintf("Failed to initialize physical address space\n"); 489 err = 1; 490 goto out_elf; 491 } 492 493 state = qemu_elf.state[0]; 494 printf("CPU #0 CR3 is 0x%016"PRIx64"\n", state->cr[3]); 495 496 va_space_create(&vs, &ps, state->cr[3]); 497 if (fix_dtb(&vs, &qemu_elf)) { 498 eprintf("Failed to find paging base\n"); 499 err = 1; 500 goto out_elf; 501 } 502 503 printf("CPU #0 IDT is at 0x%016"PRIx64"\n", state->idt.base); 504 505 if (va_space_rw(&vs, state->idt.base, 506 &first_idt_desc, sizeof(first_idt_desc), 0)) { 507 eprintf("Failed to get CPU #0 IDT[0]\n"); 508 err = 1; 509 goto out_ps; 510 } 511 printf("CPU #0 IDT[0] -> 0x%016"PRIx64"\n", idt_desc_addr(first_idt_desc)); 512 513 KernBase = idt_desc_addr(first_idt_desc) & ~(PAGE_SIZE - 1); 514 printf("Searching kernel downwards from 0x%016"PRIx64"...\n", KernBase); 515 516 for (; KernBase >= 0xfffff78000000000; KernBase -= PAGE_SIZE) { 517 nt_start_addr = va_space_resolve(&vs, KernBase); 518 if (!nt_start_addr) { 519 continue; 520 } 521 522 if (*(uint16_t *)nt_start_addr == 0x5a4d) { /* MZ */ 523 break; 524 } 525 } 526 527 printf("KernBase = 0x%016"PRIx64", signature is \'%.2s\'\n", KernBase, 528 (char *)nt_start_addr); 529 530 if (pe_get_pdb_symstore_hash(KernBase, nt_start_addr, pdb_hash, &vs)) { 531 eprintf("Failed to get PDB symbol store hash\n"); 532 err = 1; 533 goto out_ps; 534 } 535 536 sprintf(pdb_url, "%s%s/%s/%s", SYM_URL_BASE, PDB_NAME, pdb_hash, PDB_NAME); 537 printf("PDB URL is %s\n", pdb_url); 538 539 if (download_url(PDB_NAME, pdb_url)) { 540 eprintf("Failed to download PDB file\n"); 541 err = 1; 542 goto out_ps; 543 } 544 545 if (pdb_init_from_file(PDB_NAME, &pdb)) { 546 eprintf("Failed to initialize PDB reader\n"); 547 err = 1; 548 goto out_pdb_file; 549 } 550 551 if (!SYM_RESOLVE(KernBase, &pdb, KdDebuggerDataBlock) || 552 !SYM_RESOLVE(KernBase, &pdb, KdVersionBlock)) { 553 err = 1; 554 goto out_pdb; 555 } 556 557 kdbg = get_kdbg(KernBase, &pdb, &vs, KdDebuggerDataBlock); 558 if (!kdbg) { 559 err = 1; 560 goto out_pdb; 561 } 562 563 if (fill_header(&header, &ps, &vs, KdDebuggerDataBlock, kdbg, 564 KdVersionBlock, qemu_elf.state_nr)) { 565 err = 1; 566 goto out_pdb; 567 } 568 569 if (fill_context(kdbg, &vs, &qemu_elf)) { 570 err = 1; 571 goto out_pdb; 572 } 573 574 if (write_dump(&ps, &header, argv[2])) { 575 eprintf("Failed to save dump\n"); 576 err = 1; 577 goto out_kdbg; 578 } 579 580 out_kdbg: 581 free(kdbg); 582 out_pdb: 583 pdb_exit(&pdb); 584 out_pdb_file: 585 unlink(PDB_NAME); 586 out_ps: 587 pa_space_destroy(&ps); 588 out_elf: 589 QEMU_Elf_exit(&qemu_elf); 590 591 return err; 592 } 593