1 //===-- sanitizer_symbolizer_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. 11 // Windows-specific implementation of symbolizer parts. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_platform.h" 15 #if SANITIZER_WINDOWS 16 17 # include "sanitizer_dbghelp.h" 18 # include "sanitizer_symbolizer_internal.h" 19 20 namespace __sanitizer { 21 22 decltype(::StackWalk64) *StackWalk64; 23 decltype(::SymCleanup) *SymCleanup; 24 decltype(::SymFromAddr) *SymFromAddr; 25 decltype(::SymFunctionTableAccess64) *SymFunctionTableAccess64; 26 decltype(::SymGetLineFromAddr64) *SymGetLineFromAddr64; 27 decltype(::SymGetModuleBase64) *SymGetModuleBase64; 28 decltype(::SymGetSearchPathW) *SymGetSearchPathW; 29 decltype(::SymInitialize) *SymInitialize; 30 decltype(::SymSetOptions) *SymSetOptions; 31 decltype(::SymSetSearchPathW) *SymSetSearchPathW; 32 decltype(::UnDecorateSymbolName) *UnDecorateSymbolName; 33 34 namespace { 35 36 class WinSymbolizerTool final : public SymbolizerTool { 37 public: 38 // The constructor is provided to avoid synthesized memsets. 39 WinSymbolizerTool() {} 40 41 bool SymbolizePC(uptr addr, SymbolizedStack *stack) override; 42 bool SymbolizeData(uptr addr, DataInfo *info) override { 43 return false; 44 } 45 const char *Demangle(const char *name) override; 46 }; 47 48 bool is_dbghelp_initialized = false; 49 50 bool TrySymInitialize() { 51 SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME | SYMOPT_LOAD_LINES); 52 return SymInitialize(GetCurrentProcess(), 0, TRUE); 53 // FIXME: We don't call SymCleanup() on exit yet - should we? 54 } 55 56 } // namespace 57 58 // Initializes DbgHelp library, if it's not yet initialized. Calls to this 59 // function should be synchronized with respect to other calls to DbgHelp API 60 // (e.g. from WinSymbolizerTool). 61 void InitializeDbgHelpIfNeeded() { 62 if (is_dbghelp_initialized) 63 return; 64 65 HMODULE dbghelp = LoadLibraryA("dbghelp.dll"); 66 CHECK(dbghelp && "failed to load dbghelp.dll"); 67 68 # define DBGHELP_IMPORT(name) \ 69 do { \ 70 name = reinterpret_cast<decltype(::name) *>( \ 71 (void *)GetProcAddress(dbghelp, #name)); \ 72 CHECK(name != nullptr); \ 73 } while (0) 74 75 DBGHELP_IMPORT(StackWalk64); 76 DBGHELP_IMPORT(SymCleanup); 77 DBGHELP_IMPORT(SymFromAddr); 78 DBGHELP_IMPORT(SymFunctionTableAccess64); 79 DBGHELP_IMPORT(SymGetLineFromAddr64); 80 DBGHELP_IMPORT(SymGetModuleBase64); 81 DBGHELP_IMPORT(SymGetSearchPathW); 82 DBGHELP_IMPORT(SymInitialize); 83 DBGHELP_IMPORT(SymSetOptions); 84 DBGHELP_IMPORT(SymSetSearchPathW); 85 DBGHELP_IMPORT(UnDecorateSymbolName); 86 #undef DBGHELP_IMPORT 87 88 if (!TrySymInitialize()) { 89 // OK, maybe the client app has called SymInitialize already. 90 // That's a bit unfortunate for us as all the DbgHelp functions are 91 // single-threaded and we can't coordinate with the app. 92 // FIXME: Can we stop the other threads at this point? 93 // Anyways, we have to reconfigure stuff to make sure that SymInitialize 94 // has all the appropriate options set. 95 // Cross our fingers and reinitialize DbgHelp. 96 Report("*** WARNING: Failed to initialize DbgHelp! ***\n"); 97 Report("*** Most likely this means that the app is already ***\n"); 98 Report("*** using DbgHelp, possibly with incompatible flags. ***\n"); 99 Report("*** Due to technical reasons, symbolization might crash ***\n"); 100 Report("*** or produce wrong results. ***\n"); 101 SymCleanup(GetCurrentProcess()); 102 TrySymInitialize(); 103 } 104 is_dbghelp_initialized = true; 105 106 // When an executable is run from a location different from the one where it 107 // was originally built, we may not see the nearby PDB files. 108 // To work around this, let's append the directory of the main module 109 // to the symbol search path. All the failures below are not fatal. 110 const size_t kSymPathSize = 2048; 111 static wchar_t path_buffer[kSymPathSize + 1 + MAX_PATH]; 112 if (!SymGetSearchPathW(GetCurrentProcess(), path_buffer, kSymPathSize)) { 113 Report("*** WARNING: Failed to SymGetSearchPathW ***\n"); 114 return; 115 } 116 size_t sz = wcslen(path_buffer); 117 if (sz) { 118 CHECK_EQ(0, wcscat_s(path_buffer, L";")); 119 sz++; 120 } 121 DWORD res = GetModuleFileNameW(NULL, path_buffer + sz, MAX_PATH); 122 if (res == 0 || res == MAX_PATH) { 123 Report("*** WARNING: Failed to getting the EXE directory ***\n"); 124 return; 125 } 126 // Write the zero character in place of the last backslash to get the 127 // directory of the main module at the end of path_buffer. 128 wchar_t *last_bslash = wcsrchr(path_buffer + sz, L'\\'); 129 CHECK_NE(last_bslash, 0); 130 *last_bslash = L'\0'; 131 if (!SymSetSearchPathW(GetCurrentProcess(), path_buffer)) { 132 Report("*** WARNING: Failed to SymSetSearchPathW\n"); 133 return; 134 } 135 } 136 137 bool WinSymbolizerTool::SymbolizePC(uptr addr, SymbolizedStack *frame) { 138 InitializeDbgHelpIfNeeded(); 139 140 // See https://docs.microsoft.com/en-us/windows/win32/debug/retrieving-symbol-information-by-address 141 InternalMmapVector<char> buffer(sizeof(SYMBOL_INFO) + 142 MAX_SYM_NAME * sizeof(CHAR)); 143 PSYMBOL_INFO symbol = (PSYMBOL_INFO)&buffer[0]; 144 symbol->SizeOfStruct = sizeof(SYMBOL_INFO); 145 symbol->MaxNameLen = MAX_SYM_NAME; 146 DWORD64 offset = 0; 147 BOOL got_objname = SymFromAddr(GetCurrentProcess(), 148 (DWORD64)addr, &offset, symbol); 149 if (!got_objname) 150 return false; 151 152 DWORD unused; 153 IMAGEHLP_LINE64 line_info; 154 line_info.SizeOfStruct = sizeof(IMAGEHLP_LINE64); 155 BOOL got_fileline = SymGetLineFromAddr64(GetCurrentProcess(), (DWORD64)addr, 156 &unused, &line_info); 157 frame->info.function = internal_strdup(symbol->Name); 158 frame->info.function_offset = (uptr)offset; 159 if (got_fileline) { 160 frame->info.file = internal_strdup(line_info.FileName); 161 frame->info.line = line_info.LineNumber; 162 } 163 // Only consider this a successful symbolization attempt if we got file info. 164 // Otherwise, try llvm-symbolizer. 165 return got_fileline; 166 } 167 168 const char *WinSymbolizerTool::Demangle(const char *name) { 169 CHECK(is_dbghelp_initialized); 170 static char demangle_buffer[1000]; 171 if (name[0] == '\01' && 172 UnDecorateSymbolName(name + 1, demangle_buffer, sizeof(demangle_buffer), 173 UNDNAME_NAME_ONLY)) 174 return demangle_buffer; 175 else 176 return name; 177 } 178 179 const char *Symbolizer::PlatformDemangle(const char *name) { return nullptr; } 180 181 namespace { 182 struct ScopedHandle { 183 ScopedHandle() : h_(nullptr) {} 184 explicit ScopedHandle(HANDLE h) : h_(h) {} 185 ~ScopedHandle() { 186 if (h_) 187 ::CloseHandle(h_); 188 } 189 HANDLE get() { return h_; } 190 HANDLE *receive() { return &h_; } 191 HANDLE release() { 192 HANDLE h = h_; 193 h_ = nullptr; 194 return h; 195 } 196 HANDLE h_; 197 }; 198 } // namespace 199 200 bool SymbolizerProcess::StartSymbolizerSubprocess() { 201 // Create inherited pipes for stdin and stdout. 202 ScopedHandle stdin_read, stdin_write; 203 ScopedHandle stdout_read, stdout_write; 204 SECURITY_ATTRIBUTES attrs; 205 attrs.nLength = sizeof(SECURITY_ATTRIBUTES); 206 attrs.bInheritHandle = TRUE; 207 attrs.lpSecurityDescriptor = nullptr; 208 if (!::CreatePipe(stdin_read.receive(), stdin_write.receive(), &attrs, 0) || 209 !::CreatePipe(stdout_read.receive(), stdout_write.receive(), &attrs, 0)) { 210 VReport(2, "WARNING: %s CreatePipe failed (error code: %d)\n", 211 SanitizerToolName, path_, GetLastError()); 212 return false; 213 } 214 215 // Don't inherit the writing end of stdin or the reading end of stdout. 216 if (!SetHandleInformation(stdin_write.get(), HANDLE_FLAG_INHERIT, 0) || 217 !SetHandleInformation(stdout_read.get(), HANDLE_FLAG_INHERIT, 0)) { 218 VReport(2, "WARNING: %s SetHandleInformation failed (error code: %d)\n", 219 SanitizerToolName, path_, GetLastError()); 220 return false; 221 } 222 223 // Compute the command line. Wrap double quotes around everything. 224 const char *argv[kArgVMax]; 225 GetArgV(path_, argv); 226 InternalScopedString command_line; 227 for (int i = 0; argv[i]; i++) { 228 const char *arg = argv[i]; 229 int arglen = internal_strlen(arg); 230 // Check that tool command lines are simple and that complete escaping is 231 // unnecessary. 232 CHECK(!internal_strchr(arg, '"') && "quotes in args unsupported"); 233 CHECK(arglen > 0 && arg[arglen - 1] != '\\' && 234 "args ending in backslash and empty args unsupported"); 235 command_line.AppendF("\"%s\" ", arg); 236 } 237 VReport(3, "Launching symbolizer command: %s\n", command_line.data()); 238 239 // Launch llvm-symbolizer with stdin and stdout redirected. 240 STARTUPINFOA si; 241 memset(&si, 0, sizeof(si)); 242 si.cb = sizeof(si); 243 si.dwFlags |= STARTF_USESTDHANDLES; 244 si.hStdInput = stdin_read.get(); 245 si.hStdOutput = stdout_write.get(); 246 PROCESS_INFORMATION pi; 247 memset(&pi, 0, sizeof(pi)); 248 if (!CreateProcessA(path_, // Executable 249 command_line.data(), // Command line 250 nullptr, // Process handle not inheritable 251 nullptr, // Thread handle not inheritable 252 TRUE, // Set handle inheritance to TRUE 253 0, // Creation flags 254 nullptr, // Use parent's environment block 255 nullptr, // Use parent's starting directory 256 &si, &pi)) { 257 VReport(2, "WARNING: %s failed to create process for %s (error code: %d)\n", 258 SanitizerToolName, path_, GetLastError()); 259 return false; 260 } 261 262 // Process creation succeeded, so transfer handle ownership into the fields. 263 input_fd_ = stdout_read.release(); 264 output_fd_ = stdin_write.release(); 265 266 // The llvm-symbolizer process is responsible for quitting itself when the 267 // stdin pipe is closed, so we don't need these handles. Close them to prevent 268 // leaks. If we ever want to try to kill the symbolizer process from the 269 // parent, we'll want to hang on to these handles. 270 CloseHandle(pi.hProcess); 271 CloseHandle(pi.hThread); 272 return true; 273 } 274 275 static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list, 276 LowLevelAllocator *allocator) { 277 if (!common_flags()->symbolize) { 278 VReport(2, "Symbolizer is disabled.\n"); 279 return; 280 } 281 282 // Add llvm-symbolizer. 283 const char *user_path = common_flags()->external_symbolizer_path; 284 285 if (user_path && internal_strchr(user_path, '%')) { 286 char *new_path = (char *)InternalAlloc(kMaxPathLength); 287 SubstituteForFlagValue(user_path, new_path, kMaxPathLength); 288 user_path = new_path; 289 } 290 291 const char *path = 292 user_path ? user_path : FindPathToBinary("llvm-symbolizer.exe"); 293 if (path) { 294 if (user_path && user_path[0] == '\0') { 295 VReport(2, "External symbolizer is explicitly disabled.\n"); 296 } else { 297 VReport(2, "Using llvm-symbolizer at %spath: %s\n", 298 user_path ? "user-specified " : "", path); 299 list->push_back(new (*allocator) LLVMSymbolizer(path, allocator)); 300 } 301 } else { 302 VReport(2, "External symbolizer is not present.\n"); 303 } 304 305 // Add the dbghelp based symbolizer. 306 list->push_back(new(*allocator) WinSymbolizerTool()); 307 } 308 309 Symbolizer *Symbolizer::PlatformInit() { 310 IntrusiveList<SymbolizerTool> list; 311 list.clear(); 312 ChooseSymbolizerTools(&list, &symbolizer_allocator_); 313 314 return new(symbolizer_allocator_) Symbolizer(list); 315 } 316 317 void Symbolizer::LateInitialize() { 318 Symbolizer::GetOrInit(); 319 } 320 321 } // namespace __sanitizer 322 323 #endif // _WIN32 324