src/compiler-rt/lib/sanitizer_common/sanitizer_win.cc

   1 //===-- sanitizer_win.cc --------------------------------------------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is shared between AddressSanitizer and ThreadSanitizer
  11 // run-time libraries and implements windows-specific functions from
  12 // sanitizer_libc.h.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "sanitizer_platform.h"
  16 #if SANITIZER_WINDOWS
  17
  18 #define WIN32_LEAN_AND_MEAN
  19 #define NOGDI
  20 #include <windows.h>
  21 #include <dbghelp.h>
  22 #include <io.h>
  23 #include <psapi.h>
  24 #include <stdlib.h>
  25
  26 #include "sanitizer_common.h"
  27 #include "sanitizer_libc.h"
  28 #include "sanitizer_mutex.h"
  29 #include "sanitizer_placement_new.h"
  30 #include "sanitizer_stacktrace.h"
  31 #include "sanitizer_symbolizer.h"
  32
  33 namespace __sanitizer {
  34
  35 #include "sanitizer_syscall_generic.inc"
  36
  37 // --------------------- sanitizer_common.h
  38 uptr GetPageSize() {
  39   SYSTEM_INFO si;
  40   GetSystemInfo(&si);
  41   return si.dwPageSize;
  42 }
  43
  44 uptr GetMmapGranularity() {
  45   SYSTEM_INFO si;
  46   GetSystemInfo(&si);
  47   return si.dwAllocationGranularity;
  48 }
  49
  50 uptr GetMaxVirtualAddress() {
  51   SYSTEM_INFO si;
  52   GetSystemInfo(&si);
  53   return (uptr)si.lpMaximumApplicationAddress;
  54 }
  55
  56 bool FileExists(const char *filename) {
  57   return ::GetFileAttributesA(filename) != INVALID_FILE_ATTRIBUTES;
  58 }
  59
  60 uptr internal_getpid() {
  61   return GetProcessId(GetCurrentProcess());
  62 }
  63
  64 // In contrast to POSIX, on Windows GetCurrentThreadId()
  65 // returns a system-unique identifier.
  66 uptr GetTid() {
  67   return GetCurrentThreadId();
  68 }
  69
  70 uptr GetThreadSelf() {
  71   return GetTid();
  72 }
  73
  74 #if !SANITIZER_GO
  75 void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
  76                                 uptr *stack_bottom) {
  77   CHECK(stack_top);
  78   CHECK(stack_bottom);
  79   MEMORY_BASIC_INFORMATION mbi;
  80   CHECK_NE(VirtualQuery(&mbi /* on stack */, &mbi, sizeof(mbi)), 0);
  81   // FIXME: is it possible for the stack to not be a single allocation?
  82   // Are these values what ASan expects to get (reserved, not committed;
  83   // including stack guard page) ?
  84   *stack_top = (uptr)mbi.BaseAddress + mbi.RegionSize;
  85   *stack_bottom = (uptr)mbi.AllocationBase;
  86 }
  87 #endif  // #if !SANITIZER_GO
  88
  89 void *MmapOrDie(uptr size, const char *mem_type, bool raw_report) {
  90   void *rv = VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
  91   if (rv == 0)
  92     ReportMmapFailureAndDie(size, mem_type, "allocate",
  93                             GetLastError(), raw_report);
  94   return rv;
  95 }
  96
  97 void UnmapOrDie(void *addr, uptr size) {
  98   if (!size || !addr)
  99     return;
 100
 101   MEMORY_BASIC_INFORMATION mbi;
 102   CHECK(VirtualQuery(addr, &mbi, sizeof(mbi)));
 103
 104   // MEM_RELEASE can only be used to unmap whole regions previously mapped with
 105   // VirtualAlloc. So we first try MEM_RELEASE since it is better, and if that
 106   // fails try MEM_DECOMMIT.
 107   if (VirtualFree(addr, 0, MEM_RELEASE) == 0) {
 108     if (VirtualFree(addr, size, MEM_DECOMMIT) == 0) {
 109       Report("ERROR: %s failed to "
 110              "deallocate 0x%zx (%zd) bytes at address %p (error code: %d)\n",
 111              SanitizerToolName, size, size, addr, GetLastError());
 112       CHECK("unable to unmap" && 0);
 113     }
 114   }
 115 }
 116
 117 // We want to map a chunk of address space aligned to 'alignment'.
 118 void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type) {
 119   CHECK(IsPowerOfTwo(size));
 120   CHECK(IsPowerOfTwo(alignment));
 121
 122   // Windows will align our allocations to at least 64K.
 123   alignment = Max(alignment, GetMmapGranularity());
 124
 125   uptr mapped_addr =
 126       (uptr)VirtualAlloc(0, size, MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
 127   if (!mapped_addr)
 128     ReportMmapFailureAndDie(size, mem_type, "allocate aligned", GetLastError());
 129
 130   // If we got it right on the first try, return. Otherwise, unmap it and go to
 131   // the slow path.
 132   if (IsAligned(mapped_addr, alignment))
 133     return (void*)mapped_addr;
 134   if (VirtualFree((void *)mapped_addr, 0, MEM_RELEASE) == 0)
 135     ReportMmapFailureAndDie(size, mem_type, "deallocate", GetLastError());
 136
 137   // If we didn't get an aligned address, overallocate, find an aligned address,
 138   // unmap, and try to allocate at that aligned address.
 139   int retries = 0;
 140   const int kMaxRetries = 10;
 141   for (; retries < kMaxRetries &&
 142          (mapped_addr == 0 || !IsAligned(mapped_addr, alignment));
 143        retries++) {
 144     // Overallocate size + alignment bytes.
 145     mapped_addr =
 146         (uptr)VirtualAlloc(0, size + alignment, MEM_RESERVE, PAGE_NOACCESS);
 147     if (!mapped_addr)
 148       ReportMmapFailureAndDie(size, mem_type, "allocate aligned",
 149                               GetLastError());
 150
 151     // Find the aligned address.
 152     uptr aligned_addr = RoundUpTo(mapped_addr, alignment);
 153
 154     // Free the overallocation.
 155     if (VirtualFree((void *)mapped_addr, 0, MEM_RELEASE) == 0)
 156       ReportMmapFailureAndDie(size, mem_type, "deallocate", GetLastError());
 157
 158     // Attempt to allocate exactly the number of bytes we need at the aligned
 159     // address. This may fail for a number of reasons, in which case we continue
 160     // the loop.
 161     mapped_addr = (uptr)VirtualAlloc((void *)aligned_addr, size,
 162                                      MEM_RESERVE | MEM_COMMIT, PAGE_READWRITE);
 163   }
 164
 165   // Fail if we can't make this work quickly.
 166   if (retries == kMaxRetries && mapped_addr == 0)
 167     ReportMmapFailureAndDie(size, mem_type, "allocate aligned", GetLastError());
 168
 169   return (void *)mapped_addr;
 170 }
 171
 172 void *MmapFixedNoReserve(uptr fixed_addr, uptr size, const char *name) {
 173   // FIXME: is this really "NoReserve"? On Win32 this does not matter much,
 174   // but on Win64 it does.
 175   (void)name;  // unsupported
 176 #if SANITIZER_WINDOWS64
 177   // On Windows64, use MEM_COMMIT would result in error
 178   // 1455:ERROR_COMMITMENT_LIMIT.
 179   // We use exception handler to commit page on demand.
 180   void *p = VirtualAlloc((LPVOID)fixed_addr, size, MEM_RESERVE, PAGE_READWRITE);
 181 #else
 182   void *p = VirtualAlloc((LPVOID)fixed_addr, size, MEM_RESERVE | MEM_COMMIT,
 183                          PAGE_READWRITE);
 184 #endif
 185   if (p == 0)
 186     Report("ERROR: %s failed to "
 187            "allocate %p (%zd) bytes at %p (error code: %d)\n",
 188            SanitizerToolName, size, size, fixed_addr, GetLastError());
 189   return p;
 190 }
 191
 192 // Memory space mapped by 'MmapFixedOrDie' must have been reserved by
 193 // 'MmapFixedNoAccess'.
 194 void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
 195   void *p = VirtualAlloc((LPVOID)fixed_addr, size,
 196       MEM_COMMIT, PAGE_READWRITE);
 197   if (p == 0) {
 198     char mem_type[30];
 199     internal_snprintf(mem_type, sizeof(mem_type), "memory at address 0x%zx",
 200                       fixed_addr);
 201     ReportMmapFailureAndDie(size, mem_type, "allocate", GetLastError());
 202   }
 203   return p;
 204 }
 205
 206 void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
 207   // FIXME: make this really NoReserve?
 208   return MmapOrDie(size, mem_type);
 209 }
 210
 211 void *MmapFixedNoAccess(uptr fixed_addr, uptr size, const char *name) {
 212   (void)name; // unsupported
 213   void *res = VirtualAlloc((LPVOID)fixed_addr, size,
 214                            MEM_RESERVE, PAGE_NOACCESS);
 215   if (res == 0)
 216     Report("WARNING: %s failed to "
 217            "mprotect %p (%zd) bytes at %p (error code: %d)\n",
 218            SanitizerToolName, size, size, fixed_addr, GetLastError());
 219   return res;
 220 }
 221
 222 void *MmapNoAccess(uptr size) {
 223   // FIXME: unsupported.
 224   return nullptr;
 225 }
 226
 227 bool MprotectNoAccess(uptr addr, uptr size) {
 228   DWORD old_protection;
 229   return VirtualProtect((LPVOID)addr, size, PAGE_NOACCESS, &old_protection);
 230 }
 231
 232
 233 void FlushUnneededShadowMemory(uptr addr, uptr size) {
 234   // This is almost useless on 32-bits.
 235   // FIXME: add madvise-analog when we move to 64-bits.
 236 }
 237
 238 void NoHugePagesInRegion(uptr addr, uptr size) {
 239   // FIXME: probably similar to FlushUnneededShadowMemory.
 240 }
 241
 242 void DontDumpShadowMemory(uptr addr, uptr length) {
 243   // This is almost useless on 32-bits.
 244   // FIXME: add madvise-analog when we move to 64-bits.
 245 }
 246
 247 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
 248   MEMORY_BASIC_INFORMATION mbi;
 249   CHECK(VirtualQuery((void *)range_start, &mbi, sizeof(mbi)));
 250   return mbi.Protect == PAGE_NOACCESS &&
 251          (uptr)mbi.BaseAddress + mbi.RegionSize >= range_end;
 252 }
 253
 254 void *MapFileToMemory(const char *file_name, uptr *buff_size) {
 255   UNIMPLEMENTED();
 256 }
 257
 258 void *MapWritableFileToMemory(void *addr, uptr size, fd_t fd, OFF_T offset) {
 259   UNIMPLEMENTED();
 260 }
 261
 262 static const int kMaxEnvNameLength = 128;
 263 static const DWORD kMaxEnvValueLength = 32767;
 264
 265 namespace {
 266
 267 struct EnvVariable {
 268   char name[kMaxEnvNameLength];
 269   char value[kMaxEnvValueLength];
 270 };
 271
 272 }  // namespace
 273
 274 static const int kEnvVariables = 5;
 275 static EnvVariable env_vars[kEnvVariables];
 276 static int num_env_vars;
 277
 278 const char *GetEnv(const char *name) {
 279   // Note: this implementation caches the values of the environment variables
 280   // and limits their quantity.
 281   for (int i = 0; i < num_env_vars; i++) {
 282     if (0 == internal_strcmp(name, env_vars[i].name))
 283       return env_vars[i].value;
 284   }
 285   CHECK_LT(num_env_vars, kEnvVariables);
 286   DWORD rv = GetEnvironmentVariableA(name, env_vars[num_env_vars].value,
 287                                      kMaxEnvValueLength);
 288   if (rv > 0 && rv < kMaxEnvValueLength) {
 289     CHECK_LT(internal_strlen(name), kMaxEnvNameLength);
 290     internal_strncpy(env_vars[num_env_vars].name, name, kMaxEnvNameLength);
 291     num_env_vars++;
 292     return env_vars[num_env_vars - 1].value;
 293   }
 294   return 0;
 295 }
 296
 297 const char *GetPwd() {
 298   UNIMPLEMENTED();
 299 }
 300
 301 u32 GetUid() {
 302   UNIMPLEMENTED();
 303 }
 304
 305 namespace {
 306 struct ModuleInfo {
 307   const char *filepath;
 308   uptr base_address;
 309   uptr end_address;
 310 };
 311
 312 #ifndef SANITIZER_GO
 313 int CompareModulesBase(const void *pl, const void *pr) {
 314   const ModuleInfo *l = (ModuleInfo *)pl, *r = (ModuleInfo *)pr;
 315   if (l->base_address < r->base_address)
 316     return -1;
 317   return l->base_address > r->base_address;
 318 }
 319 #endif
 320 }  // namespace
 321
 322 #ifndef SANITIZER_GO
 323 void DumpProcessMap() {
 324   Report("Dumping process modules:\n");
 325   ListOfModules modules;
 326   modules.init();
 327   uptr num_modules = modules.size();
 328
 329   InternalScopedBuffer<ModuleInfo> module_infos(num_modules);
 330   for (size_t i = 0; i < num_modules; ++i) {
 331     module_infos[i].filepath = modules[i].full_name();
 332     module_infos[i].base_address = modules[i].base_address();
 333     module_infos[i].end_address = modules[i].ranges().front()->end;
 334   }
 335   qsort(module_infos.data(), num_modules, sizeof(ModuleInfo),
 336         CompareModulesBase);
 337
 338   for (size_t i = 0; i < num_modules; ++i) {
 339     const ModuleInfo &mi = module_infos[i];
 340     if (mi.end_address != 0) {
 341       Printf("\t%p-%p %s\n", mi.base_address, mi.end_address,
 342              mi.filepath[0] ? mi.filepath : "[no name]");
 343     } else if (mi.filepath[0]) {
 344       Printf("\t??\?-??? %s\n", mi.filepath);
 345     } else {
 346       Printf("\t???\n");
 347     }
 348   }
 349 }
 350 #endif
 351
 352 void DisableCoreDumperIfNecessary() {
 353   // Do nothing.
 354 }
 355
 356 void ReExec() {
 357   UNIMPLEMENTED();
 358 }
 359
 360 void PrepareForSandboxing(__sanitizer_sandbox_arguments *args) {
 361 #if !SANITIZER_GO
 362   CovPrepareForSandboxing(args);
 363 #endif
 364 }
 365
 366 bool StackSizeIsUnlimited() {
 367   UNIMPLEMENTED();
 368 }
 369
 370 void SetStackSizeLimitInBytes(uptr limit) {
 371   UNIMPLEMENTED();
 372 }
 373
 374 bool AddressSpaceIsUnlimited() {
 375   UNIMPLEMENTED();
 376 }
 377
 378 void SetAddressSpaceUnlimited() {
 379   UNIMPLEMENTED();
 380 }
 381
 382 bool IsPathSeparator(const char c) {
 383   return c == '\\' || c == '/';
 384 }
 385
 386 bool IsAbsolutePath(const char *path) {
 387   UNIMPLEMENTED();
 388 }
 389
 390 void SleepForSeconds(int seconds) {
 391   Sleep(seconds * 1000);
 392 }
 393
 394 void SleepForMillis(int millis) {
 395   Sleep(millis);
 396 }
 397
 398 u64 NanoTime() {
 399   return 0;
 400 }
 401
 402 void Abort() {
 403   if (::IsDebuggerPresent())
 404     __debugbreak();
 405   internal__exit(3);
 406 }
 407
 408 #ifndef SANITIZER_GO
 409 // Read the file to extract the ImageBase field from the PE header. If ASLR is
 410 // disabled and this virtual address is available, the loader will typically
 411 // load the image at this address. Therefore, we call it the preferred base. Any
 412 // addresses in the DWARF typically assume that the object has been loaded at
 413 // this address.
 414 static uptr GetPreferredBase(const char *modname) {
 415   fd_t fd = OpenFile(modname, RdOnly, nullptr);
 416   if (fd == kInvalidFd)
 417     return 0;
 418   FileCloser closer(fd);
 419
 420   // Read just the DOS header.
 421   IMAGE_DOS_HEADER dos_header;
 422   uptr bytes_read;
 423   if (!ReadFromFile(fd, &dos_header, sizeof(dos_header), &bytes_read) ||
 424       bytes_read != sizeof(dos_header))
 425     return 0;
 426
 427   // The file should start with the right signature.
 428   if (dos_header.e_magic != IMAGE_DOS_SIGNATURE)
 429     return 0;
 430
 431   // The layout at e_lfanew is:
 432   // "PE\0\0"
 433   // IMAGE_FILE_HEADER
 434   // IMAGE_OPTIONAL_HEADER
 435   // Seek to e_lfanew and read all that data.
 436   char buf[4 + sizeof(IMAGE_FILE_HEADER) + sizeof(IMAGE_OPTIONAL_HEADER)];
 437   if (::SetFilePointer(fd, dos_header.e_lfanew, nullptr, FILE_BEGIN) ==
 438       INVALID_SET_FILE_POINTER)
 439     return 0;
 440   if (!ReadFromFile(fd, &buf[0], sizeof(buf), &bytes_read) ||
 441       bytes_read != sizeof(buf))
 442     return 0;
 443
 444   // Check for "PE\0\0" before the PE header.
 445   char *pe_sig = &buf[0];
 446   if (internal_memcmp(pe_sig, "PE\0\0", 4) != 0)
 447     return 0;
 448
 449   // Skip over IMAGE_FILE_HEADER. We could do more validation here if we wanted.
 450   IMAGE_OPTIONAL_HEADER *pe_header =
 451       (IMAGE_OPTIONAL_HEADER *)(pe_sig + 4 + sizeof(IMAGE_FILE_HEADER));
 452
 453   // Check for more magic in the PE header.
 454   if (pe_header->Magic != IMAGE_NT_OPTIONAL_HDR_MAGIC)
 455     return 0;
 456
 457   // Finally, return the ImageBase.
 458   return (uptr)pe_header->ImageBase;
 459 }
 460
 461 void ListOfModules::init() {
 462   clear();
 463   HANDLE cur_process = GetCurrentProcess();
 464
 465   // Query the list of modules.  Start by assuming there are no more than 256
 466   // modules and retry if that's not sufficient.
 467   HMODULE *hmodules = 0;
 468   uptr modules_buffer_size = sizeof(HMODULE) * 256;
 469   DWORD bytes_required;
 470   while (!hmodules) {
 471     hmodules = (HMODULE *)MmapOrDie(modules_buffer_size, __FUNCTION__);
 472     CHECK(EnumProcessModules(cur_process, hmodules, modules_buffer_size,
 473                              &bytes_required));
 474     if (bytes_required > modules_buffer_size) {
 475       // Either there turned out to be more than 256 hmodules, or new hmodules
 476       // could have loaded since the last try.  Retry.
 477       UnmapOrDie(hmodules, modules_buffer_size);
 478       hmodules = 0;
 479       modules_buffer_size = bytes_required;
 480     }
 481   }
 482
 483   // |num_modules| is the number of modules actually present,
 484   size_t num_modules = bytes_required / sizeof(HMODULE);
 485   for (size_t i = 0; i < num_modules; ++i) {
 486     HMODULE handle = hmodules[i];
 487     MODULEINFO mi;
 488     if (!GetModuleInformation(cur_process, handle, &mi, sizeof(mi)))
 489       continue;
 490
 491     // Get the UTF-16 path and convert to UTF-8.
 492     wchar_t modname_utf16[kMaxPathLength];
 493     int modname_utf16_len =
 494         GetModuleFileNameW(handle, modname_utf16, kMaxPathLength);
 495     if (modname_utf16_len == 0)
 496       modname_utf16[0] = '\0';
 497     char module_name[kMaxPathLength];
 498     int module_name_len =
 499         ::WideCharToMultiByte(CP_UTF8, 0, modname_utf16, modname_utf16_len + 1,
 500                               &module_name[0], kMaxPathLength, NULL, NULL);
 501     module_name[module_name_len] = '\0';
 502
 503     uptr base_address = (uptr)mi.lpBaseOfDll;
 504     uptr end_address = (uptr)mi.lpBaseOfDll + mi.SizeOfImage;
 505
 506     // Adjust the base address of the module so that we get a VA instead of an
 507     // RVA when computing the module offset. This helps llvm-symbolizer find the
 508     // right DWARF CU. In the common case that the image is loaded at it's
 509     // preferred address, we will now print normal virtual addresses.
 510     uptr preferred_base = GetPreferredBase(&module_name[0]);
 511     uptr adjusted_base = base_address - preferred_base;
 512
 513     LoadedModule cur_module;
 514     cur_module.set(module_name, adjusted_base);
 515     // We add the whole module as one single address range.
 516     cur_module.addAddressRange(base_address, end_address, /*executable*/ true);
 517     modules_.push_back(cur_module);
 518   }
 519   UnmapOrDie(hmodules, modules_buffer_size);
 520 };
 521
 522 // We can't use atexit() directly at __asan_init time as the CRT is not fully
 523 // initialized at this point.  Place the functions into a vector and use
 524 // atexit() as soon as it is ready for use (i.e. after .CRT$XIC initializers).
 525 InternalMmapVectorNoCtor<void (*)(void)> atexit_functions;
 526
 527 int Atexit(void (*function)(void)) {
 528   atexit_functions.push_back(function);
 529   return 0;
 530 }
 531
 532 static int RunAtexit() {
 533   int ret = 0;
 534   for (uptr i = 0; i < atexit_functions.size(); ++i) {
 535     ret |= atexit(atexit_functions[i]);
 536   }
 537   return ret;
 538 }
 539
 540 #pragma section(".CRT$XID", long, read)  // NOLINT
 541 __declspec(allocate(".CRT$XID")) int (*__run_atexit)() = RunAtexit;
 542 #endif
 543
 544 // ------------------ sanitizer_libc.h
 545 fd_t OpenFile(const char *filename, FileAccessMode mode, error_t *last_error) {
 546   // FIXME: Use the wide variants to handle Unicode filenames.
 547   fd_t res;
 548   if (mode == RdOnly) {
 549     res = CreateFileA(filename, GENERIC_READ,
 550                       FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,
 551                       nullptr, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, nullptr);
 552   } else if (mode == WrOnly) {
 553     res = CreateFileA(filename, GENERIC_WRITE, 0, nullptr, CREATE_ALWAYS,
 554                       FILE_ATTRIBUTE_NORMAL, nullptr);
 555   } else {
 556     UNIMPLEMENTED();
 557   }
 558   CHECK(res != kStdoutFd || kStdoutFd == kInvalidFd);
 559   CHECK(res != kStderrFd || kStderrFd == kInvalidFd);
 560   if (res == kInvalidFd && last_error)
 561     *last_error = GetLastError();
 562   return res;
 563 }
 564
 565 void CloseFile(fd_t fd) {
 566   CloseHandle(fd);
 567 }
 568
 569 bool ReadFromFile(fd_t fd, void *buff, uptr buff_size, uptr *bytes_read,
 570                   error_t *error_p) {
 571   CHECK(fd != kInvalidFd);
 572
 573   // bytes_read can't be passed directly to ReadFile:
 574   // uptr is unsigned long long on 64-bit Windows.
 575   unsigned long num_read_long;
 576
 577   bool success = ::ReadFile(fd, buff, buff_size, &num_read_long, nullptr);
 578   if (!success && error_p)
 579     *error_p = GetLastError();
 580   if (bytes_read)
 581     *bytes_read = num_read_long;
 582   return success;
 583 }
 584
 585 bool SupportsColoredOutput(fd_t fd) {
 586   // FIXME: support colored output.
 587   return false;
 588 }
 589
 590 bool WriteToFile(fd_t fd, const void *buff, uptr buff_size, uptr *bytes_written,
 591                  error_t *error_p) {
 592   CHECK(fd != kInvalidFd);
 593
 594   // Handle null optional parameters.
 595   error_t dummy_error;
 596   error_p = error_p ? error_p : &dummy_error;
 597   uptr dummy_bytes_written;
 598   bytes_written = bytes_written ? bytes_written : &dummy_bytes_written;
 599
 600   // Initialize output parameters in case we fail.
 601   *error_p = 0;
 602   *bytes_written = 0;
 603
 604   // Map the conventional Unix fds 1 and 2 to Windows handles. They might be
 605   // closed, in which case this will fail.
 606   if (fd == kStdoutFd || fd == kStderrFd) {
 607     fd = GetStdHandle(fd == kStdoutFd ? STD_OUTPUT_HANDLE : STD_ERROR_HANDLE);
 608     if (fd == 0) {
 609       *error_p = ERROR_INVALID_HANDLE;
 610       return false;
 611     }
 612   }
 613
 614   DWORD bytes_written_32;
 615   if (!WriteFile(fd, buff, buff_size, &bytes_written_32, 0)) {
 616     *error_p = GetLastError();
 617     return false;
 618   } else {
 619     *bytes_written = bytes_written_32;
 620     return true;
 621   }
 622 }
 623
 624 bool RenameFile(const char *oldpath, const char *newpath, error_t *error_p) {
 625   UNIMPLEMENTED();
 626 }
 627
 628 uptr internal_sched_yield() {
 629   Sleep(0);
 630   return 0;
 631 }
 632
 633 void internal__exit(int exitcode) {
 634   ExitProcess(exitcode);
 635 }
 636
 637 uptr internal_ftruncate(fd_t fd, uptr size) {
 638   UNIMPLEMENTED();
 639 }
 640
 641 uptr GetRSS() {
 642   return 0;
 643 }
 644
 645 void *internal_start_thread(void (*func)(void *arg), void *arg) { return 0; }
 646 void internal_join_thread(void *th) { }
 647
 648 // ---------------------- BlockingMutex ---------------- {{{1
 649 const uptr LOCK_UNINITIALIZED = 0;
 650 const uptr LOCK_READY = (uptr)-1;
 651
 652 BlockingMutex::BlockingMutex(LinkerInitialized li) {
 653   // FIXME: see comments in BlockingMutex::Lock() for the details.
 654   CHECK(li == LINKER_INITIALIZED || owner_ == LOCK_UNINITIALIZED);
 655
 656   CHECK(sizeof(CRITICAL_SECTION) <= sizeof(opaque_storage_));
 657   InitializeCriticalSection((LPCRITICAL_SECTION)opaque_storage_);
 658   owner_ = LOCK_READY;
 659 }
 660
 661 BlockingMutex::BlockingMutex() {
 662   CHECK(sizeof(CRITICAL_SECTION) <= sizeof(opaque_storage_));
 663   InitializeCriticalSection((LPCRITICAL_SECTION)opaque_storage_);
 664   owner_ = LOCK_READY;
 665 }
 666
 667 void BlockingMutex::Lock() {
 668   if (owner_ == LOCK_UNINITIALIZED) {
 669     // FIXME: hm, global BlockingMutex objects are not initialized?!?
 670     // This might be a side effect of the clang+cl+link Frankenbuild...
 671     new(this) BlockingMutex((LinkerInitialized)(LINKER_INITIALIZED + 1));
 672
 673     // FIXME: If it turns out the linker doesn't invoke our
 674     // constructors, we should probably manually Lock/Unlock all the global
 675     // locks while we're starting in one thread to avoid double-init races.
 676   }
 677   EnterCriticalSection((LPCRITICAL_SECTION)opaque_storage_);
 678   CHECK_EQ(owner_, LOCK_READY);
 679   owner_ = GetThreadSelf();
 680 }
 681
 682 void BlockingMutex::Unlock() {
 683   CHECK_EQ(owner_, GetThreadSelf());
 684   owner_ = LOCK_READY;
 685   LeaveCriticalSection((LPCRITICAL_SECTION)opaque_storage_);
 686 }
 687
 688 void BlockingMutex::CheckLocked() {
 689   CHECK_EQ(owner_, GetThreadSelf());
 690 }
 691
 692 uptr GetTlsSize() {
 693   return 0;
 694 }
 695
 696 void InitTlsSize() {
 697 }
 698
 699 void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
 700                           uptr *tls_addr, uptr *tls_size) {
 701 #ifdef SANITIZER_GO
 702   *stk_addr = 0;
 703   *stk_size = 0;
 704   *tls_addr = 0;
 705   *tls_size = 0;
 706 #else
 707   uptr stack_top, stack_bottom;
 708   GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
 709   *stk_addr = stack_bottom;
 710   *stk_size = stack_top - stack_bottom;
 711   *tls_addr = 0;
 712   *tls_size = 0;
 713 #endif
 714 }
 715
 716 #if !SANITIZER_GO
 717 void BufferedStackTrace::SlowUnwindStack(uptr pc, u32 max_depth) {
 718   CHECK_GE(max_depth, 2);
 719   // FIXME: CaptureStackBackTrace might be too slow for us.
 720   // FIXME: Compare with StackWalk64.
 721   // FIXME: Look at LLVMUnhandledExceptionFilter in Signals.inc
 722   size = CaptureStackBackTrace(1, Min(max_depth, kStackTraceMax),
 723                                (void**)trace, 0);
 724   if (size == 0)
 725     return;
 726
 727   // Skip the RTL frames by searching for the PC in the stacktrace.
 728   uptr pc_location = LocatePcInTrace(pc);
 729   PopStackFrames(pc_location);
 730 }
 731
 732 void BufferedStackTrace::SlowUnwindStackWithContext(uptr pc, void *context,
 733                                                     u32 max_depth) {
 734   CONTEXT ctx = *(CONTEXT *)context;
 735   STACKFRAME64 stack_frame;
 736   memset(&stack_frame, 0, sizeof(stack_frame));
 737
 738   size = 0;
 739 #if defined(_WIN64)
 740   int machine_type = IMAGE_FILE_MACHINE_AMD64;
 741   stack_frame.AddrPC.Offset = ctx.Rip;
 742   stack_frame.AddrFrame.Offset = ctx.Rbp;
 743   stack_frame.AddrStack.Offset = ctx.Rsp;
 744 #else
 745   int machine_type = IMAGE_FILE_MACHINE_I386;
 746   stack_frame.AddrPC.Offset = ctx.Eip;
 747   stack_frame.AddrFrame.Offset = ctx.Ebp;
 748   stack_frame.AddrStack.Offset = ctx.Esp;
 749 #endif
 750   stack_frame.AddrPC.Mode = AddrModeFlat;
 751   stack_frame.AddrFrame.Mode = AddrModeFlat;
 752   stack_frame.AddrStack.Mode = AddrModeFlat;
 753   while (StackWalk64(machine_type, GetCurrentProcess(), GetCurrentThread(),
 754                      &stack_frame, &ctx, NULL, &SymFunctionTableAccess64,
 755                      &SymGetModuleBase64, NULL) &&
 756          size < Min(max_depth, kStackTraceMax)) {
 757     trace_buffer[size++] = (uptr)stack_frame.AddrPC.Offset;
 758   }
 759 }
 760 #endif  // #if !SANITIZER_GO
 761
 762 void ReportFile::Write(const char *buffer, uptr length) {
 763   SpinMutexLock l(mu);
 764   ReopenIfNecessary();
 765   if (!WriteToFile(fd, buffer, length)) {
 766     // stderr may be closed, but we may be able to print to the debugger
 767     // instead.  This is the case when launching a program from Visual Studio,
 768     // and the following routine should write to its console.
 769     OutputDebugStringA(buffer);
 770   }
 771 }
 772
 773 void SetAlternateSignalStack() {
 774   // FIXME: Decide what to do on Windows.
 775 }
 776
 777 void UnsetAlternateSignalStack() {
 778   // FIXME: Decide what to do on Windows.
 779 }
 780
 781 void InstallDeadlySignalHandlers(SignalHandlerType handler) {
 782   (void)handler;
 783   // FIXME: Decide what to do on Windows.
 784 }
 785
 786 bool IsHandledDeadlySignal(int signum) {
 787   // FIXME: Decide what to do on Windows.
 788   return false;
 789 }
 790
 791 bool IsAccessibleMemoryRange(uptr beg, uptr size) {
 792   SYSTEM_INFO si;
 793   GetNativeSystemInfo(&si);
 794   uptr page_size = si.dwPageSize;
 795   uptr page_mask = ~(page_size - 1);
 796
 797   for (uptr page = beg & page_mask, end = (beg + size - 1) & page_mask;
 798        page <= end;) {
 799     MEMORY_BASIC_INFORMATION info;
 800     if (VirtualQuery((LPCVOID)page, &info, sizeof(info)) != sizeof(info))
 801       return false;
 802
 803     if (info.Protect == 0 || info.Protect == PAGE_NOACCESS ||
 804         info.Protect == PAGE_EXECUTE)
 805       return false;
 806
 807     if (info.RegionSize == 0)
 808       return false;
 809
 810     page += info.RegionSize;
 811   }
 812
 813   return true;
 814 }
 815
 816 SignalContext SignalContext::Create(void *siginfo, void *context) {
 817   EXCEPTION_RECORD *exception_record = (EXCEPTION_RECORD *)siginfo;
 818   CONTEXT *context_record = (CONTEXT *)context;
 819
 820   uptr pc = (uptr)exception_record->ExceptionAddress;
 821 #ifdef _WIN64
 822   uptr bp = (uptr)context_record->Rbp;
 823   uptr sp = (uptr)context_record->Rsp;
 824 #else
 825   uptr bp = (uptr)context_record->Ebp;
 826   uptr sp = (uptr)context_record->Esp;
 827 #endif
 828   uptr access_addr = exception_record->ExceptionInformation[1];
 829
 830   // The contents of this array are documented at
 831   // https://msdn.microsoft.com/en-us/library/windows/desktop/aa363082(v=vs.85).aspx
 832   // The first element indicates read as 0, write as 1, or execute as 8.  The
 833   // second element is the faulting address.
 834   WriteFlag write_flag = SignalContext::UNKNOWN;
 835   switch (exception_record->ExceptionInformation[0]) {
 836   case 0: write_flag = SignalContext::READ; break;
 837   case 1: write_flag = SignalContext::WRITE; break;
 838   case 8: write_flag = SignalContext::UNKNOWN; break;
 839   }
 840   bool is_memory_access = write_flag != SignalContext::UNKNOWN;
 841   return SignalContext(context, access_addr, pc, sp, bp, is_memory_access,
 842                        write_flag);
 843 }
 844
 845 uptr ReadBinaryName(/*out*/char *buf, uptr buf_len) {
 846   // FIXME: Actually implement this function.
 847   CHECK_GT(buf_len, 0);
 848   buf[0] = 0;
 849   return 0;
 850 }
 851
 852 uptr ReadLongProcessName(/*out*/char *buf, uptr buf_len) {
 853   return ReadBinaryName(buf, buf_len);
 854 }
 855
 856 void CheckVMASize() {
 857   // Do nothing.
 858 }
 859
 860 void MaybeReexec() {
 861   // No need to re-exec on Windows.
 862 }
 863
 864 char **GetArgv() {
 865   // FIXME: Actually implement this function.
 866   return 0;
 867 }
 868
 869 pid_t StartSubprocess(const char *program, const char *const argv[],
 870                       fd_t stdin_fd, fd_t stdout_fd, fd_t stderr_fd) {
 871   // FIXME: implement on this platform
 872   // Should be implemented based on
 873   // SymbolizerProcess::StarAtSymbolizerSubprocess
 874   // from lib/sanitizer_common/sanitizer_symbolizer_win.cc.
 875   return -1;
 876 }
 877
 878 bool IsProcessRunning(pid_t pid) {
 879   // FIXME: implement on this platform.
 880   return false;
 881 }
 882
 883 int WaitForProcess(pid_t pid) { return -1; }
 884
 885 }  // namespace __sanitizer
 886
 887 #endif  // _WIN32