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 = 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
137bool 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
168const 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
179const char *Symbolizer::PlatformDemangle(const char *name) { return nullptr; }
180
181namespace {
182struct 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
200bool 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
275static 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
309Symbolizer *Symbolizer::PlatformInit() {
310 IntrusiveList<SymbolizerTool> list;
311 list.clear();
312 ChooseSymbolizerTools(&list, &symbolizer_allocator_);
313
314 return new(symbolizer_allocator_) Symbolizer(list);
315}
316
317void Symbolizer::LateInitialize() {
318 Symbolizer::GetOrInit();
319}
320
321} // namespace __sanitizer
322
323#endif // _WIN32
324