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