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