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
20namespace __sanitizer {
21
22decltype(::StackWalk64) *StackWalk64;
23decltype(::SymCleanup) *SymCleanup;
24decltype(::SymFromAddr) *SymFromAddr;
25decltype(::SymFunctionTableAccess64) *SymFunctionTableAccess64;
26decltype(::SymGetLineFromAddr64) *SymGetLineFromAddr64;
27decltype(::SymGetModuleBase64) *SymGetModuleBase64;
28decltype(::SymGetSearchPathW) *SymGetSearchPathW;
29decltype(::SymInitialize) *SymInitialize;
30decltype(::SymSetOptions) *SymSetOptions;
31decltype(::SymSetSearchPathW) *SymSetSearchPathW;
32decltype(::UnDecorateSymbolName) *UnDecorateSymbolName;
33
34namespace {
35
36class 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
48bool is_dbghelp_initialized = false;
49
50bool 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).
61void 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
136bool 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
167const 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
178const char *Symbolizer::PlatformDemangle(const char *name) { return nullptr; }
179
180namespace {
181struct 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
199bool 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
274static 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
308Symbolizer *Symbolizer::PlatformInit() {
309 IntrusiveList<SymbolizerTool> list;
310 list.clear();
311 ChooseSymbolizerTools(&list, &symbolizer_allocator_);
312
313 return new(symbolizer_allocator_) Symbolizer(list);
314}
315
316void Symbolizer::LateInitialize() {
317 Symbolizer::GetOrInit();
318}
319
320} // namespace __sanitizer
321
322#endif // _WIN32
323

source code of compiler-rt/lib/sanitizer_common/sanitizer_symbolizer_win.cpp