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