libsanitizer/sanitizer_common/sanitizer_win.cpp

   1 //===-- sanitizer_win.cpp -------------------------------------------------===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file is shared between AddressSanitizer and ThreadSanitizer
  10 // run-time libraries and implements windows-specific functions from
  11 // sanitizer_libc.h.
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "sanitizer_platform.h"
  15 #if SANITIZER_WINDOWS
  16
  17 #define WIN32_LEAN_AND_MEAN
  18 #define NOGDI
  19 #include <windows.h>
  20 #include <io.h>
  21 #include <psapi.h>
  22 #include <stdlib.h>
  23
  24 #include "sanitizer_common.h"
  25 #include "sanitizer_file.h"
  26 #include "sanitizer_libc.h"
  27 #include "sanitizer_mutex.h"
  28 #include "sanitizer_placement_new.h"
  29 #include "sanitizer_win_defs.h"
  30
  31 #if defined(PSAPI_VERSION) && PSAPI_VERSION == 1
  32 #pragma comment(lib, "psapi")
  33 #endif
  34 #if SANITIZER_WIN_TRACE
  35 #include <traceloggingprovider.h>
  36 //  Windows trace logging provider init
  37 #pragma comment(lib, "advapi32.lib")
  38 TRACELOGGING_DECLARE_PROVIDER(g_asan_provider);
  39 // GUID must be the same in utils/AddressSanitizerLoggingProvider.wprp
  40 TRACELOGGING_DEFINE_PROVIDER(g_asan_provider, "AddressSanitizerLoggingProvider",
  41                              (0x6c6c766d, 0x3846, 0x4e6a, 0xa4, 0xfb, 0x5b,
  42                               0x53, 0x0b, 0xd0, 0xf3, 0xfa));
  43 #else
  44 #define TraceLoggingUnregister(x)
  45 #endif
  46
  47 // A macro to tell the compiler that this part of the code cannot be reached,
  48 // if the compiler supports this feature. Since we're using this in
  49 // code that is called when terminating the process, the expansion of the
  50 // macro should not terminate the process to avoid infinite recursion.
  51 #if defined(__clang__)
  52 # define BUILTIN_UNREACHABLE() __builtin_unreachable()
  53 #elif defined(__GNUC__) && \
  54     (__GNUC__ > 4 || (__GNUC__ == 4 && __GNUC_MINOR__ >= 5))
  55 # define BUILTIN_UNREACHABLE() __builtin_unreachable()
  56 #elif defined(_MSC_VER)
  57 # define BUILTIN_UNREACHABLE() __assume(0)
  58 #else
  59 # define BUILTIN_UNREACHABLE()
  60 #endif
  61
  62 namespace __sanitizer {
  63
  64 #include "sanitizer_syscall_generic.inc"
  65
  66 // --------------------- sanitizer_common.h
  67 uptr GetPageSize() {
  68   SYSTEM_INFO si;
  69   GetSystemInfo(&si);
  70   return si.dwPageSize;
  71 }
  72
  73 uptr GetMmapGranularity() {
  74   SYSTEM_INFO si;
  75   GetSystemInfo(&si);
  76   return si.dwAllocationGranularity;
  77 }
  78
  79 uptr GetMaxUserVirtualAddress() {
  80   SYSTEM_INFO si;
  81   GetSystemInfo(&si);
  82   return (uptr)si.lpMaximumApplicationAddress;
  83 }
  84
  85 uptr GetMaxVirtualAddress() {
  86   return GetMaxUserVirtualAddress();
  87 }
  88
  89 bool FileExists(const char *filename) {
  90   return ::GetFileAttributesA(filename) != INVALID_FILE_ATTRIBUTES;
  91 }
  92
  93 uptr internal_getpid() {
  94   return GetProcessId(GetCurrentProcess());
  95 }
  96
  97 int internal_dlinfo(void *handle, int request, void *p) {
  98   UNIMPLEMENTED();
  99 }
 100
 101 // In contrast to POSIX, on Windows GetCurrentThreadId()
 102 // returns a system-unique identifier.
 103 tid_t GetTid() {
 104   return GetCurrentThreadId();
 105 }
 106
 107 uptr GetThreadSelf() {
 108   return GetTid();
 109 }
 110
 111 #if !SANITIZER_GO
 112 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
 113                                 uptr *stack_bottom) {
 114   CHECK(stack_top);
 115   CHECK(stack_bottom);
 116   MEMORY_BASIC_INFORMATION mbi;
 117   CHECK_NE(VirtualQuery(&mbi /* on stack */, &mbi, sizeof(mbi)), 0);
 118   // FIXME: is it possible for the stack to not be a single allocation?
 119   // Are these values what ASan expects to get (reserved, not committed;
 120   // including stack guard page) ?
 121   *stack_top = (uptr)mbi.BaseAddress + mbi.RegionSize;
 122   *stack_bottom = (uptr)mbi.AllocationBase;
 123 }
 124 #endif  // #if !SANITIZER_GO
 125
 126 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
 127   void *rv = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
 128   if (rv == 0)
 129     ReportMmapFailureAndDie(size, mem_type, "allocate",
 130                             GetLastError(), raw_report);
 131   return rv;
 132 }
 133
 134 void UnmapOrDie(void *addr, uptr size) {
 135   if (!size || !addr)
 136     return;
 137
 138   MEMORY_BASIC_INFORMATION mbi;
 139   CHECK(VirtualQuery(addr, &mbi, sizeof(mbi)));
 140
 141   // MEM_RELEASE can only be used to unmap whole regions previously mapped with
 142   // VirtualAlloc. So we first try MEM_RELEASE since it is better, and if that
 143   // fails try MEM_DECOMMIT.
 144   if (VirtualFree(addr, 0, MEM_RELEASE) == 0) {
 145     if (VirtualFree(addr, size, MEM_DECOMMIT) == 0) {
 146       Report("ERROR: %s failed to "
 147              "deallocate 0x%zx (%zd) bytes at address %p (error code: %d)\n",
 148              SanitizerToolName, size, size, addr, GetLastError());
 149       CHECK("unable to unmap" && 0);
 150     }
 151   }
 152 }
 153
 154 static void *ReturnNullptrOnOOMOrDie(uptr size, const char *mem_type,
 155                                      const char *mmap_type) {
 156   error_t last_error = GetLastError();
 157   if (last_error == ERROR_NOT_ENOUGH_MEMORY)
 158     return nullptr;
 159   ReportMmapFailureAndDie(size, mem_type, mmap_type, last_error);
 160 }
 161
 162 void *MmapOrDieOnFatalError(uptr size, const char *mem_type) {
 163   void *rv = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
 164   if (rv == 0)
 165     return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate");
 166   return rv;
 167 }
 168
 169 // We want to map a chunk of address space aligned to 'alignment'.
 170 void *MmapAlignedOrDieOnFatalError(uptr size, uptr alignment,
 171                                    const char *mem_type) {
 172   CHECK(IsPowerOfTwo(size));
 173   CHECK(IsPowerOfTwo(alignment));
 174
 175   // Windows will align our allocations to at least 64K.
 176   alignment = Max(alignment, GetMmapGranularity());
 177
 178   uptr mapped_addr =
 179       (uptr)VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
 180   if (!mapped_addr)
 181     return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate aligned");
 182
 183   // If we got it right on the first try, return. Otherwise, unmap it and go to
 184   // the slow path.
 185   if (IsAligned(mapped_addr, alignment))
 186     return (void*)mapped_addr;
 187   if (VirtualFree((void *)mapped_addr, 0, MEM_RELEASE) == 0)
 188     ReportMmapFailureAndDie(size, mem_type, "deallocate", GetLastError());
 189
 190   // If we didn't get an aligned address, overallocate, find an aligned address,
 191   // unmap, and try to allocate at that aligned address.
 192   int retries = 0;
 193   const int kMaxRetries = 10;
 194   for (; retries < kMaxRetries &&
 195          (mapped_addr == 0 || !IsAligned(mapped_addr, alignment));
 196        retries++) {
 197     // Overallocate size + alignment bytes.
 198     mapped_addr =
 199         (uptr)VirtualAlloc(0, size + alignment, MEM_RESERVE, PAGE_NOACCESS);
 200     if (!mapped_addr)
 201       return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate aligned");
 202
 203     // Find the aligned address.
 204     uptr aligned_addr = RoundUpTo(mapped_addr, alignment);
 205
 206     // Free the overallocation.
 207     if (VirtualFree((void *)mapped_addr, 0, MEM_RELEASE) == 0)
 208       ReportMmapFailureAndDie(size, mem_type, "deallocate", GetLastError());
 209
 210     // Attempt to allocate exactly the number of bytes we need at the aligned
 211     // address. This may fail for a number of reasons, in which case we continue
 212     // the loop.
 213     mapped_addr = (uptr)VirtualAlloc((void *)aligned_addr, size,
 214                                      MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
 215   }
 216
 217   // Fail if we can't make this work quickly.
 218   if (retries == kMaxRetries && mapped_addr == 0)
 219     return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate aligned");
 220
 221   return (void *)mapped_addr;
 222 }
 223
 224 bool MmapFixedNoReserve(uptr fixed_addr, uptr size, const char *name) {
 225   // FIXME: is this really "NoReserve"? On Win32 this does not matter much,
 226   // but on Win64 it does.
 227   (void)name;  // unsupported
 228 #if !SANITIZER_GO && SANITIZER_WINDOWS64
 229   // On asan/Windows64, use MEM_COMMIT would result in error
 230   // 1455:ERROR_COMMITMENT_LIMIT.
 231   // Asan uses exception handler to commit page on demand.
 232   void *p = VirtualAlloc((LPVOID)fixed_addr, size, MEM_RESERVE, PAGE_READWRITE);
 233 #else
 234   void *p = VirtualAlloc((LPVOID)fixed_addr, size, MEM_RESERVE | MEM_COMMIT,
 235                          PAGE_READWRITE);
 236 #endif
 237   if (p == 0) {
 238     Report("ERROR: %s failed to "
 239            "allocate %p (%zd) bytes at %p (error code: %d)\n",
 240            SanitizerToolName, size, size, fixed_addr, GetLastError());
 241     return false;
 242   }
 243   return true;
 244 }
 245
 246 bool MmapFixedSuperNoReserve(uptr fixed_addr, uptr size, const char *name) {
 247   // FIXME: Windows support large pages too. Might be worth checking
 248   return MmapFixedNoReserve(fixed_addr, size, name);
 249 }
 250
 251 // Memory space mapped by 'MmapFixedOrDie' must have been reserved by
 252 // 'MmapFixedNoAccess'.
 253 void *MmapFixedOrDie(uptr fixed_addr, uptr size, const char *name) {
 254   void *p = VirtualAlloc((LPVOID)fixed_addr, size,
 255       MEM_COMMIT, PAGE_READWRITE);
 256   if (p == 0) {
 257     char mem_type[30];
 258     internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
 259                       fixed_addr);
 260     ReportMmapFailureAndDie(size, mem_type, "allocate", GetLastError());
 261   }
 262   return p;
 263 }
 264
 265 // Uses fixed_addr for now.
 266 // Will use offset instead once we've implemented this function for real.
 267 uptr ReservedAddressRange::Map(uptr fixed_addr, uptr size, const char *name) {
 268   return reinterpret_cast<uptr>(MmapFixedOrDieOnFatalError(fixed_addr, size));
 269 }
 270
 271 uptr ReservedAddressRange::MapOrDie(uptr fixed_addr, uptr size,
 272                                     const char *name) {
 273   return reinterpret_cast<uptr>(MmapFixedOrDie(fixed_addr, size));
 274 }
 275
 276 void ReservedAddressRange::Unmap(uptr addr, uptr size) {
 277   // Only unmap if it covers the entire range.
 278   CHECK((addr == reinterpret_cast<uptr>(base_)) && (size == size_));
 279   // We unmap the whole range, just null out the base.
 280   base_ = nullptr;
 281   size_ = 0;
 282   UnmapOrDie(reinterpret_cast<void*>(addr), size);
 283 }
 284
 285 void *MmapFixedOrDieOnFatalError(uptr fixed_addr, uptr size, const char *name) {
 286   void *p = VirtualAlloc((LPVOID)fixed_addr, size,
 287       MEM_COMMIT, PAGE_READWRITE);
 288   if (p == 0) {
 289     char mem_type[30];
 290     internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
 291                       fixed_addr);
 292     return ReturnNullptrOnOOMOrDie(size, mem_type, "allocate");
 293   }
 294   return p;
 295 }
 296
 297 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
 298   // FIXME: make this really NoReserve?
 299   return MmapOrDie(size, mem_type);
 300 }
 301
 302 uptr ReservedAddressRange::Init(uptr size, const char *name, uptr fixed_addr) {
 303   base_ = fixed_addr ? MmapFixedNoAccess(fixed_addr, size) : MmapNoAccess(size);
 304   size_ = size;
 305   name_ = name;
 306   (void)os_handle_;  // unsupported
 307   return reinterpret_cast<uptr>(base_);
 308 }
 309
 310
 311 void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name) {
 312   (void)name; // unsupported
 313   void *res = VirtualAlloc((LPVOID)fixed_addr, size,
 314                            MEM_RESERVE, PAGE_NOACCESS);
 315   if (res == 0)
 316     Report("WARNING: %s failed to "
 317            "mprotect %p (%zd) bytes at %p (error code: %d)\n",
 318            SanitizerToolName, size, size, fixed_addr, GetLastError());
 319   return res;
 320 }
 321
 322 void *MmapNoAccess(uptr size) {
 323   void *res = VirtualAlloc(nullptr, size, MEM_RESERVE, PAGE_NOACCESS);
 324   if (res == 0)
 325     Report("WARNING: %s failed to "
 326            "mprotect %p (%zd) bytes (error code: %d)\n",
 327            SanitizerToolName, size, size, GetLastError());
 328   return res;
 329 }
 330
 331 bool MprotectNoAccess(uptr addr, uptr size) {
 332   DWORD old_protection;
 333   return VirtualProtect((LPVOID)addr, size, PAGE_NOACCESS, &old_protection);
 334 }
 335
 336 void ReleaseMemoryPagesToOS(uptr beg, uptr end) {
 337   // This is almost useless on 32-bits.
 338   // FIXME: add madvise-analog when we move to 64-bits.
 339 }
 340
 341 void SetShadowRegionHugePageMode(uptr addr, uptr size) {
 342   // FIXME: probably similar to ReleaseMemoryToOS.
 343 }
 344
 345 bool DontDumpShadowMemory(uptr addr, uptr length) {
 346   // This is almost useless on 32-bits.
 347   // FIXME: add madvise-analog when we move to 64-bits.
 348   return true;
 349 }
 350
 351 uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding,
 352                               uptr *largest_gap_found,
 353                               uptr *max_occupied_addr) {
 354   uptr address = 0;
 355   while (true) {
 356     MEMORY_BASIC_INFORMATION info;
 357     if (!::VirtualQuery((void*)address, &info, sizeof(info)))
 358       return 0;
 359
 360     if (info.State == MEM_FREE) {
 361       uptr shadow_address = RoundUpTo((uptr)info.BaseAddress + left_padding,
 362                                       alignment);
 363       if (shadow_address + size < (uptr)info.BaseAddress + info.RegionSize)
 364         return shadow_address;
 365     }
 366
 367     // Move to the next region.
 368     address = (uptr)info.BaseAddress + info.RegionSize;
 369   }
 370   return 0;
 371 }
 372
 373 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 374   MEMORY_BASIC_INFORMATION mbi;
 375   CHECK(VirtualQuery((void *)range_start, &mbi, sizeof(mbi)));
 376   return mbi.Protect == PAGE_NOACCESS &&
 377          (uptr)mbi.BaseAddress + mbi.RegionSize >= range_end;
 378 }
 379
 380 void *MapFileToMemory(const char *file_name, uptr *buff_size) {
 381   UNIMPLEMENTED();
 382 }
 383
 384 void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset) {
 385   UNIMPLEMENTED();
 386 }
 387
 388 static const int kMaxEnvNameLength = 128;
 389 static const DWORD kMaxEnvValueLength = 32767;
 390
 391 namespace {
 392
 393 struct EnvVariable {
 394   char name[kMaxEnvNameLength];
 395   char value[kMaxEnvValueLength];
 396 };
 397
 398 }  // namespace
 399
 400 static const int kEnvVariables = 5;
 401 static EnvVariable env_vars[kEnvVariables];
 402 static int num_env_vars;
 403
 404 const char *GetEnv(const char *name) {
 405   // Note: this implementation caches the values of the environment variables
 406   // and limits their quantity.
 407   for (int i = 0; i < num_env_vars; i++) {
 408     if (0 == internal_strcmp(name, env_vars[i].name))
 409       return env_vars[i].value;
 410   }
 411   CHECK_LT(num_env_vars, kEnvVariables);
 412   DWORD rv = GetEnvironmentVariableA(name, env_vars[num_env_vars].value,
 413                                      kMaxEnvValueLength);
 414   if (rv > 0 && rv < kMaxEnvValueLength) {
 415     CHECK_LT(internal_strlen(name), kMaxEnvNameLength);
 416     internal_strncpy(env_vars[num_env_vars].name, name, kMaxEnvNameLength);
 417     num_env_vars++;
 418     return env_vars[num_env_vars - 1].value;
 419   }
 420   return 0;
 421 }
 422
 423 const char *GetPwd() {
 424   UNIMPLEMENTED();
 425 }
 426
 427 u32 GetUid() {
 428   UNIMPLEMENTED();
 429 }
 430
 431 namespace {
 432 struct ModuleInfo {
 433   const char *filepath;
 434   uptr base_address;
 435   uptr end_address;
 436 };
 437
 438 #if !SANITIZER_GO
 439 int CompareModulesBase(const void *pl, const void *pr) {
 440   const ModuleInfo *l = (const ModuleInfo *)pl, *r = (const ModuleInfo *)pr;
 441   if (l->base_address < r->base_address)
 442     return -1;
 443   return l->base_address > r->base_address;
 444 }
 445 #endif
 446 }  // namespace
 447
 448 #if !SANITIZER_GO
 449 void DumpProcessMap() {
 450   Report("Dumping process modules:\n");
 451   ListOfModules modules;
 452   modules.init();
 453   uptr num_modules = modules.size();
 454
 455   InternalMmapVector<ModuleInfo> module_infos(num_modules);
 456   for (size_t i = 0; i < num_modules; ++i) {
 457     module_infos[i].filepath = modules[i].full_name();
 458     module_infos[i].base_address = modules[i].ranges().front()->beg;
 459     module_infos[i].end_address = modules[i].ranges().back()->end;
 460   }
 461   qsort(module_infos.data(), num_modules, sizeof(ModuleInfo),
 462         CompareModulesBase);
 463
 464   for (size_t i = 0; i < num_modules; ++i) {
 465     const ModuleInfo &mi = module_infos[i];
 466     if (mi.end_address != 0) {
 467       Printf("\t%p-%p %s\n", mi.base_address, mi.end_address,
 468              mi.filepath[0] ? mi.filepath : "[no name]");
 469     } else if (mi.filepath[0]) {
 470       Printf("\t??\?-??? %s\n", mi.filepath);
 471     } else {
 472       Printf("\t???\n");
 473     }
 474   }
 475 }
 476 #endif
 477
 478 void PrintModuleMap() { }
 479
 480 void DisableCoreDumperIfNecessary() {
 481   // Do nothing.
 482 }
 483
 484 void ReExec() {
 485   UNIMPLEMENTED();
 486 }
 487
 488 void PlatformPrepareForSandboxing(__sanitizer_sandbox_arguments *args) {}
 489
 490 bool StackSizeIsUnlimited() {
 491   UNIMPLEMENTED();
 492 }
 493
 494 void SetStackSizeLimitInBytes(uptr limit) {
 495   UNIMPLEMENTED();
 496 }
 497
 498 bool AddressSpaceIsUnlimited() {
 499   UNIMPLEMENTED();
 500 }
 501
 502 void SetAddressSpaceUnlimited() {
 503   UNIMPLEMENTED();
 504 }
 505
 506 bool IsPathSeparator(const char c) {
 507   return c == '\\' || c == '/';
 508 }
 509
 510 static bool IsAlpha(char c) {
 511   c = ToLower(c);
 512   return c >= 'a' && c <= 'z';
 513 }
 514
 515 bool IsAbsolutePath(const char *path) {
 516   return path != nullptr && IsAlpha(path[0]) && path[1] == ':' &&
 517          IsPathSeparator(path[2]);
 518 }
 519
 520 void SleepForSeconds(int seconds) {
 521   Sleep(seconds * 1000);
 522 }
 523
 524 void SleepForMillis(int millis) {
 525   Sleep(millis);
 526 }
 527
 528 u64 NanoTime() {
 529   static LARGE_INTEGER frequency = {};
 530   LARGE_INTEGER counter;
 531   if (UNLIKELY(frequency.QuadPart == 0)) {
 532     QueryPerformanceFrequency(&frequency);
 533     CHECK_NE(frequency.QuadPart, 0);
 534   }
 535   QueryPerformanceCounter(&counter);
 536   counter.QuadPart *= 1000ULL * 1000000ULL;
 537   counter.QuadPart /= frequency.QuadPart;
 538   return counter.QuadPart;
 539 }
 540
 541 u64 MonotonicNanoTime() { return NanoTime(); }
 542
 543 void Abort() {
 544   internal__exit(3);
 545 }
 546
 547 #if !SANITIZER_GO
 548 // Read the file to extract the ImageBase field from the PE header. If ASLR is
 549 // disabled and this virtual address is available, the loader will typically
 550 // load the image at this address. Therefore, we call it the preferred base. Any
 551 // addresses in the DWARF typically assume that the object has been loaded at
 552 // this address.
 553 static uptr GetPreferredBase(const char *modname) {
 554   fd_t fd = OpenFile(modname, RdOnly, nullptr);
 555   if (fd == kInvalidFd)
 556     return 0;
 557   FileCloser closer(fd);
 558
 559   // Read just the DOS header.
 560   IMAGE_DOS_HEADER dos_header;
 561   uptr bytes_read;
 562   if (!ReadFromFile(fd, &dos_header, sizeof(dos_header), &bytes_read) ||
 563       bytes_read != sizeof(dos_header))
 564     return 0;
 565
 566   // The file should start with the right signature.
 567   if (dos_header.e_magic != IMAGE_DOS_SIGNATURE)
 568     return 0;
 569
 570   // The layout at e_lfanew is:
 571   // "PE\0\0"
 572   // IMAGE_FILE_HEADER
 573   // IMAGE_OPTIONAL_HEADER
 574   // Seek to e_lfanew and read all that data.
 575   char buf[4 + sizeof(IMAGE_FILE_HEADER) + sizeof(IMAGE_OPTIONAL_HEADER)];
 576   if (::SetFilePointer(fd, dos_header.e_lfanew, nullptr, FILE_BEGIN) ==
 577       INVALID_SET_FILE_POINTER)
 578     return 0;
 579   if (!ReadFromFile(fd, &buf[0], sizeof(buf), &bytes_read) ||
 580       bytes_read != sizeof(buf))
 581     return 0;
 582
 583   // Check for "PE\0\0" before the PE header.
 584   char *pe_sig = &buf[0];
 585   if (internal_memcmp(pe_sig, "PE\0\0", 4) != 0)
 586     return 0;
 587
 588   // Skip over IMAGE_FILE_HEADER. We could do more validation here if we wanted.
 589   IMAGE_OPTIONAL_HEADER *pe_header =
 590       (IMAGE_OPTIONAL_HEADER *)(pe_sig + 4 + sizeof(IMAGE_FILE_HEADER));
 591
 592   // Check for more magic in the PE header.
 593   if (pe_header->Magic != IMAGE_NT_OPTIONAL_HDR_MAGIC)
 594     return 0;
 595
 596   // Finally, return the ImageBase.
 597   return (uptr)pe_header->ImageBase;
 598 }
 599
 600 void ListOfModules::init() {
 601   clearOrInit();
 602   HANDLE cur_process = GetCurrentProcess();
 603
 604   // Query the list of modules.  Start by assuming there are no more than 256
 605   // modules and retry if that's not sufficient.
 606   HMODULE *hmodules = 0;
 607   uptr modules_buffer_size = sizeof(HMODULE) * 256;
 608   DWORD bytes_required;
 609   while (!hmodules) {
 610     hmodules = (HMODULE *)MmapOrDie(modules_buffer_size, __FUNCTION__);
 611     CHECK(EnumProcessModules(cur_process, hmodules, modules_buffer_size,
 612                              &bytes_required));
 613     if (bytes_required > modules_buffer_size) {
 614       // Either there turned out to be more than 256 hmodules, or new hmodules
 615       // could have loaded since the last try.  Retry.
 616       UnmapOrDie(hmodules, modules_buffer_size);
 617       hmodules = 0;
 618       modules_buffer_size = bytes_required;
 619     }
 620   }
 621
 622   // |num_modules| is the number of modules actually present,
 623   size_t num_modules = bytes_required / sizeof(HMODULE);
 624   for (size_t i = 0; i < num_modules; ++i) {
 625     HMODULE handle = hmodules[i];
 626     MODULEINFO mi;
 627     if (!GetModuleInformation(cur_process, handle, &mi, sizeof(mi)))
 628       continue;
 629
 630     // Get the UTF-16 path and convert to UTF-8.
 631     wchar_t modname_utf16[kMaxPathLength];
 632     int modname_utf16_len =
 633         GetModuleFileNameW(handle, modname_utf16, kMaxPathLength);
 634     if (modname_utf16_len == 0)
 635       modname_utf16[0] = '\0';
 636     char module_name[kMaxPathLength];
 637     int module_name_len =
 638         ::WideCharToMultiByte(CP_UTF8, 0, modname_utf16, modname_utf16_len + 1,
 639                               &module_name[0], kMaxPathLength, NULL, NULL);
 640     module_name[module_name_len] = '\0';
 641
 642     uptr base_address = (uptr)mi.lpBaseOfDll;
 643     uptr end_address = (uptr)mi.lpBaseOfDll + mi.SizeOfImage;
 644
 645     // Adjust the base address of the module so that we get a VA instead of an
 646     // RVA when computing the module offset. This helps llvm-symbolizer find the
 647     // right DWARF CU. In the common case that the image is loaded at it's
 648     // preferred address, we will now print normal virtual addresses.
 649     uptr preferred_base = GetPreferredBase(&module_name[0]);
 650     uptr adjusted_base = base_address - preferred_base;
 651
 652     LoadedModule cur_module;
 653     cur_module.set(module_name, adjusted_base);
 654     // We add the whole module as one single address range.
 655     cur_module.addAddressRange(base_address, end_address, /*executable*/ true,
 656                                /*writable*/ true);
 657     modules_.push_back(cur_module);
 658   }
 659   UnmapOrDie(hmodules, modules_buffer_size);
 660 }
 661
 662 void ListOfModules::fallbackInit() { clear(); }
 663
 664 // We can't use atexit() directly at __asan_init time as the CRT is not fully
 665 // initialized at this point.  Place the functions into a vector and use
 666 // atexit() as soon as it is ready for use (i.e. after .CRT$XIC initializers).
 667 InternalMmapVectorNoCtor<void (*)(void)> atexit_functions;
 668
 669 int Atexit(void (*function)(void)) {
 670   atexit_functions.push_back(function);
 671   return 0;
 672 }
 673
 674 static int RunAtexit() {
 675   TraceLoggingUnregister(g_asan_provider);
 676   int ret = 0;
 677   for (uptr i = 0; i < atexit_functions.size(); ++i) {
 678     ret |= atexit(atexit_functions[i]);
 679   }
 680   return ret;
 681 }
 682
 683 #pragma section(".CRT$XID", long, read)
 684 __declspec(allocate(".CRT$XID")) int (*__run_atexit)() = RunAtexit;
 685 #endif
 686
 687 // ------------------ sanitizer_libc.h
 688 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *last_error) {
 689   // FIXME: Use the wide variants to handle Unicode filenames.
 690   fd_t res;
 691   if (mode == RdOnly) {
 692     res = CreateFileA(filename, GENERIC_READ,
 693                       FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
 694                       nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
 695   } else if (mode == WrOnly) {
 696     res = CreateFileA(filename, GENERIC_WRITE, 0, nullptr, CREATE_ALWAYS,
 697                       FILE_ATTRIBUTE_NORMAL, nullptr);
 698   } else {
 699     UNIMPLEMENTED();
 700   }
 701   CHECK(res != kStdoutFd || kStdoutFd == kInvalidFd);
 702   CHECK(res != kStderrFd || kStderrFd == kInvalidFd);
 703   if (res == kInvalidFd && last_error)
 704     *last_error = GetLastError();
 705   return res;
 706 }
 707
 708 void CloseFile(fd_t fd) {
 709   CloseHandle(fd);
 710 }
 711
 712 bool ReadFromFile(fd_t fd, void *buff, uptr buff_size, uptr *bytes_read,
 713                   error_t *error_p) {
 714   CHECK(fd != kInvalidFd);
 715
 716   // bytes_read can't be passed directly to ReadFile:
 717   // uptr is unsigned long long on 64-bit Windows.
 718   unsigned long num_read_long;
 719
 720   bool success = ::ReadFile(fd, buff, buff_size, &num_read_long, nullptr);
 721   if (!success && error_p)
 722     *error_p = GetLastError();
 723   if (bytes_read)
 724     *bytes_read = num_read_long;
 725   return success;
 726 }
 727
 728 bool SupportsColoredOutput(fd_t fd) {
 729   // FIXME: support colored output.
 730   return false;
 731 }
 732
 733 bool WriteToFile(fd_t fd, const void *buff, uptr buff_size, uptr *bytes_written,
 734                  error_t *error_p) {
 735   CHECK(fd != kInvalidFd);
 736
 737   // Handle null optional parameters.
 738   error_t dummy_error;
 739   error_p = error_p ? error_p : &dummy_error;
 740   uptr dummy_bytes_written;
 741   bytes_written = bytes_written ? bytes_written : &dummy_bytes_written;
 742
 743   // Initialize output parameters in case we fail.
 744   *error_p = 0;
 745   *bytes_written = 0;
 746
 747   // Map the conventional Unix fds 1 and 2 to Windows handles. They might be
 748   // closed, in which case this will fail.
 749   if (fd == kStdoutFd || fd == kStderrFd) {
 750     fd = GetStdHandle(fd == kStdoutFd ? STD_OUTPUT_HANDLE : STD_ERROR_HANDLE);
 751     if (fd == 0) {
 752       *error_p = ERROR_INVALID_HANDLE;
 753       return false;
 754     }
 755   }
 756
 757   DWORD bytes_written_32;
 758   if (!WriteFile(fd, buff, buff_size, &bytes_written_32, 0)) {
 759     *error_p = GetLastError();
 760     return false;
 761   } else {
 762     *bytes_written = bytes_written_32;
 763     return true;
 764   }
 765 }
 766
 767 uptr internal_sched_yield() {
 768   Sleep(0);
 769   return 0;
 770 }
 771
 772 void internal__exit(int exitcode) {
 773   TraceLoggingUnregister(g_asan_provider);
 774   // ExitProcess runs some finalizers, so use TerminateProcess to avoid that.
 775   // The debugger doesn't stop on TerminateProcess like it does on ExitProcess,
 776   // so add our own breakpoint here.
 777   if (::IsDebuggerPresent())
 778     __debugbreak();
 779   TerminateProcess(GetCurrentProcess(), exitcode);
 780   BUILTIN_UNREACHABLE();
 781 }
 782
 783 uptr internal_ftruncate(fd_t fd, uptr size) {
 784   UNIMPLEMENTED();
 785 }
 786
 787 uptr GetRSS() {
 788   PROCESS_MEMORY_COUNTERS counters;
 789   if (!GetProcessMemoryInfo(GetCurrentProcess(), &counters, sizeof(counters)))
 790     return 0;
 791   return counters.WorkingSetSize;
 792 }
 793
 794 void *internal_start_thread(void *(*func)(void *arg), void *arg) { return 0; }
 795 void internal_join_thread(void *th) { }
 796
 797 // ---------------------- BlockingMutex ---------------- {{{1
 798
 799 BlockingMutex::BlockingMutex() {
 800   CHECK(sizeof(SRWLOCK) <= sizeof(opaque_storage_));
 801   internal_memset(this, 0, sizeof(*this));
 802 }
 803
 804 void BlockingMutex::Lock() {
 805   AcquireSRWLockExclusive((PSRWLOCK)opaque_storage_);
 806   CHECK_EQ(owner_, 0);
 807   owner_ = GetThreadSelf();
 808 }
 809
 810 void BlockingMutex::Unlock() {
 811   CheckLocked();
 812   owner_ = 0;
 813   ReleaseSRWLockExclusive((PSRWLOCK)opaque_storage_);
 814 }
 815
 816 void BlockingMutex::CheckLocked() {
 817   CHECK_EQ(owner_, GetThreadSelf());
 818 }
 819
 820 uptr GetTlsSize() {
 821   return 0;
 822 }
 823
 824 void InitTlsSize() {
 825 }
 826
 827 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 828                           uptr *tls_addr, uptr *tls_size) {
 829 #if SANITIZER_GO
 830   *stk_addr = 0;
 831   *stk_size = 0;
 832   *tls_addr = 0;
 833   *tls_size = 0;
 834 #else
 835   uptr stack_top, stack_bottom;
 836   GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
 837   *stk_addr = stack_bottom;
 838   *stk_size = stack_top - stack_bottom;
 839   *tls_addr = 0;
 840   *tls_size = 0;
 841 #endif
 842 }
 843
 844 void ReportFile::Write(const char *buffer, uptr length) {
 845   SpinMutexLock l(mu);
 846   ReopenIfNecessary();
 847   if (!WriteToFile(fd, buffer, length)) {
 848     // stderr may be closed, but we may be able to print to the debugger
 849     // instead.  This is the case when launching a program from Visual Studio,
 850     // and the following routine should write to its console.
 851     OutputDebugStringA(buffer);
 852   }
 853 }
 854
 855 void SetAlternateSignalStack() {
 856   // FIXME: Decide what to do on Windows.
 857 }
 858
 859 void UnsetAlternateSignalStack() {
 860   // FIXME: Decide what to do on Windows.
 861 }
 862
 863 void InstallDeadlySignalHandlers(SignalHandlerType handler) {
 864   (void)handler;
 865   // FIXME: Decide what to do on Windows.
 866 }
 867
 868 HandleSignalMode GetHandleSignalMode(int signum) {
 869   // FIXME: Decide what to do on Windows.
 870   return kHandleSignalNo;
 871 }
 872
 873 // Check based on flags if we should handle this exception.
 874 bool IsHandledDeadlyException(DWORD exceptionCode) {
 875   switch (exceptionCode) {
 876     case EXCEPTION_ACCESS_VIOLATION:
 877     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 878     case EXCEPTION_STACK_OVERFLOW:
 879     case EXCEPTION_DATATYPE_MISALIGNMENT:
 880     case EXCEPTION_IN_PAGE_ERROR:
 881       return common_flags()->handle_segv;
 882     case EXCEPTION_ILLEGAL_INSTRUCTION:
 883     case EXCEPTION_PRIV_INSTRUCTION:
 884     case EXCEPTION_BREAKPOINT:
 885       return common_flags()->handle_sigill;
 886     case EXCEPTION_FLT_DENORMAL_OPERAND:
 887     case EXCEPTION_FLT_DIVIDE_BY_ZERO:
 888     case EXCEPTION_FLT_INEXACT_RESULT:
 889     case EXCEPTION_FLT_INVALID_OPERATION:
 890     case EXCEPTION_FLT_OVERFLOW:
 891     case EXCEPTION_FLT_STACK_CHECK:
 892     case EXCEPTION_FLT_UNDERFLOW:
 893     case EXCEPTION_INT_DIVIDE_BY_ZERO:
 894     case EXCEPTION_INT_OVERFLOW:
 895       return common_flags()->handle_sigfpe;
 896   }
 897   return false;
 898 }
 899
 900 bool IsAccessibleMemoryRange(uptr beg, uptr size) {
 901   SYSTEM_INFO si;
 902   GetNativeSystemInfo(&si);
 903   uptr page_size = si.dwPageSize;
 904   uptr page_mask = ~(page_size - 1);
 905
 906   for (uptr page = beg & page_mask, end = (beg + size - 1) & page_mask;
 907        page <= end;) {
 908     MEMORY_BASIC_INFORMATION info;
 909     if (VirtualQuery((LPCVOID)page, &info, sizeof(info)) != sizeof(info))
 910       return false;
 911
 912     if (info.Protect == 0 || info.Protect == PAGE_NOACCESS ||
 913         info.Protect == PAGE_EXECUTE)
 914       return false;
 915
 916     if (info.RegionSize == 0)
 917       return false;
 918
 919     page += info.RegionSize;
 920   }
 921
 922   return true;
 923 }
 924
 925 bool SignalContext::IsStackOverflow() const {
 926   return (DWORD)GetType() == EXCEPTION_STACK_OVERFLOW;
 927 }
 928
 929 void SignalContext::InitPcSpBp() {
 930   EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
 931   CONTEXT *context_record = (CONTEXT *)context;
 932
 933   pc = (uptr)exception_record->ExceptionAddress;
 934 #ifdef _WIN64
 935   bp = (uptr)context_record->Rbp;
 936   sp = (uptr)context_record->Rsp;
 937 #else
 938   bp = (uptr)context_record->Ebp;
 939   sp = (uptr)context_record->Esp;
 940 #endif
 941 }
 942
 943 uptr SignalContext::GetAddress() const {
 944   EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
 945   return exception_record->ExceptionInformation[1];
 946 }
 947
 948 bool SignalContext::IsMemoryAccess() const {
 949   return GetWriteFlag() != SignalContext::UNKNOWN;
 950 }
 951
 952 bool SignalContext::IsTrueFaultingAddress() const {
 953   // FIXME: Provide real implementation for this. See Linux and Mac variants.
 954   return IsMemoryAccess();
 955 }
 956
 957 SignalContext::WriteFlag SignalContext::GetWriteFlag() const {
 958   EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
 959   // The contents of this array are documented at
 960   // https://msdn.microsoft.com/en-us/library/windows/desktop/aa363082(v=vs.85).aspx
 961   // The first element indicates read as 0, write as 1, or execute as 8.  The
 962   // second element is the faulting address.
 963   switch (exception_record->ExceptionInformation[0]) {
 964     case 0:
 965       return SignalContext::READ;
 966     case 1:
 967       return SignalContext::WRITE;
 968     case 8:
 969       return SignalContext::UNKNOWN;
 970   }
 971   return SignalContext::UNKNOWN;
 972 }
 973
 974 void SignalContext::DumpAllRegisters(void *context) {
 975   // FIXME: Implement this.
 976 }
 977
 978 int SignalContext::GetType() const {
 979   return static_cast<const EXCEPTION_RECORD *>(siginfo)->ExceptionCode;
 980 }
 981
 982 const char *SignalContext::Describe() const {
 983   unsigned code = GetType();
 984   // Get the string description of the exception if this is a known deadly
 985   // exception.
 986   switch (code) {
 987     case EXCEPTION_ACCESS_VIOLATION:
 988       return "access-violation";
 989     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 990       return "array-bounds-exceeded";
 991     case EXCEPTION_STACK_OVERFLOW:
 992       return "stack-overflow";
 993     case EXCEPTION_DATATYPE_MISALIGNMENT:
 994       return "datatype-misalignment";
 995     case EXCEPTION_IN_PAGE_ERROR:
 996       return "in-page-error";
 997     case EXCEPTION_ILLEGAL_INSTRUCTION:
 998       return "illegal-instruction";
 999     case EXCEPTION_PRIV_INSTRUCTION:
1000       return "priv-instruction";
1001     case EXCEPTION_BREAKPOINT:
1002       return "breakpoint";
1003     case EXCEPTION_FLT_DENORMAL_OPERAND:
1004       return "flt-denormal-operand";
1005     case EXCEPTION_FLT_DIVIDE_BY_ZERO:
1006       return "flt-divide-by-zero";
1007     case EXCEPTION_FLT_INEXACT_RESULT:
1008       return "flt-inexact-result";
1009     case EXCEPTION_FLT_INVALID_OPERATION:
1010       return "flt-invalid-operation";
1011     case EXCEPTION_FLT_OVERFLOW:
1012       return "flt-overflow";
1013     case EXCEPTION_FLT_STACK_CHECK:
1014       return "flt-stack-check";
1015     case EXCEPTION_FLT_UNDERFLOW:
1016       return "flt-underflow";
1017     case EXCEPTION_INT_DIVIDE_BY_ZERO:
1018       return "int-divide-by-zero";
1019     case EXCEPTION_INT_OVERFLOW:
1020       return "int-overflow";
1021   }
1022   return "unknown exception";
1023 }
1024
1025 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
1026   // FIXME: Actually implement this function.
1027   CHECK_GT(buf_len, 0);
1028   buf[0] = 0;
1029   return 0;
1030 }
1031
1032 uptr ReadLongProcessName(/*out*/char *buf, uptr buf_len) {
1033   return ReadBinaryName(buf, buf_len);
1034 }
1035
1036 void CheckVMASize() {
1037   // Do nothing.
1038 }
1039
1040 void InitializePlatformEarly() {
1041   // Do nothing.
1042 }
1043
1044 void MaybeReexec() {
1045   // No need to re-exec on Windows.
1046 }
1047
1048 void CheckASLR() {
1049   // Do nothing
1050 }
1051
1052 void CheckMPROTECT() {
1053   // Do nothing
1054 }
1055
1056 char **GetArgv() {
1057   // FIXME: Actually implement this function.
1058   return 0;
1059 }
1060
1061 char **GetEnviron() {
1062   // FIXME: Actually implement this function.
1063   return 0;
1064 }
1065
1066 pid_t StartSubprocess(const char *program, const char *const argv[],
1067                       const char *const envp[], fd_t stdin_fd, fd_t stdout_fd,
1068                       fd_t stderr_fd) {
1069   // FIXME: implement on this platform
1070   // Should be implemented based on
1071   // SymbolizerProcess::StarAtSymbolizerSubprocess
1072   // from lib/sanitizer_common/sanitizer_symbolizer_win.cpp.
1073   return -1;
1074 }
1075
1076 bool IsProcessRunning(pid_t pid) {
1077   // FIXME: implement on this platform.
1078   return false;
1079 }
1080
1081 int WaitForProcess(pid_t pid) { return -1; }
1082
1083 // FIXME implement on this platform.
1084 void GetMemoryProfile(fill_profile_f cb, uptr *stats, uptr stats_size) { }
1085
1086 void CheckNoDeepBind(const char *filename, int flag) {
1087   // Do nothing.
1088 }
1089
1090 // FIXME: implement on this platform.
1091 bool GetRandom(void *buffer, uptr length, bool blocking) {
1092   UNIMPLEMENTED();
1093 }
1094
1095 u32 GetNumberOfCPUs() {
1096   SYSTEM_INFO sysinfo = {};
1097   GetNativeSystemInfo(&sysinfo);
1098   return sysinfo.dwNumberOfProcessors;
1099 }
1100
1101 #if SANITIZER_WIN_TRACE
1102 // TODO(mcgov): Rename this project-wide to PlatformLogInit
1103 void AndroidLogInit(void) {
1104   HRESULT hr = TraceLoggingRegister(g_asan_provider);
1105   if (!SUCCEEDED(hr))
1106     return;
1107 }
1108
1109 void SetAbortMessage(const char *) {}
1110
1111 void LogFullErrorReport(const char *buffer) {
1112   if (common_flags()->log_to_syslog) {
1113     InternalMmapVector<wchar_t> filename;
1114     DWORD filename_length = 0;
1115     do {
1116       filename.resize(filename.size() + 0x100);
1117       filename_length =
1118           GetModuleFileNameW(NULL, filename.begin(), filename.size());
1119     } while (filename_length >= filename.size());
1120     TraceLoggingWrite(g_asan_provider, "AsanReportEvent",
1121                       TraceLoggingValue(filename.begin(), "ExecutableName"),
1122                       TraceLoggingValue(buffer, "AsanReportContents"));
1123   }
1124 }
1125 #endif // SANITIZER_WIN_TRACE
1126
1127 }  // namespace __sanitizer
1128
1129 #endif  // _WIN32