1//===-- sanitizer_symbolizer_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.
12// Windows-specific implementation of symbolizer parts.
13//===----------------------------------------------------------------------===//
14
15#include "sanitizer_platform.h"
16#if SANITIZER_WINDOWS
17
18#include "sanitizer_dbghelp.h"
19#include "sanitizer_symbolizer_internal.h"
20
21namespace __sanitizer {
22
23decltype(::StackWalk64) *StackWalk64;
24decltype(::SymCleanup) *SymCleanup;
25decltype(::SymFromAddr) *SymFromAddr;
26decltype(::SymFunctionTableAccess64) *SymFunctionTableAccess64;
27decltype(::SymGetLineFromAddr64) *SymGetLineFromAddr64;
28decltype(::SymGetModuleBase64) *SymGetModuleBase64;
29decltype(::SymGetSearchPathW) *SymGetSearchPathW;
30decltype(::SymInitialize) *SymInitialize;
31decltype(::SymSetOptions) *SymSetOptions;
32decltype(::SymSetSearchPathW) *SymSetSearchPathW;
33decltype(::UnDecorateSymbolName) *UnDecorateSymbolName;
34
35namespace {
36
37class WinSymbolizerTool : public SymbolizerTool {
38 public:
39  bool SymbolizePC(uptr addr, SymbolizedStack *stack) override;
40  bool SymbolizeData(uptr addr, DataInfo *info) override {
41    return false;
42  }
43  const char *Demangle(const char *name) override;
44};
45
46bool is_dbghelp_initialized = false;
47
48bool TrySymInitialize() {
49  SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME | SYMOPT_LOAD_LINES);
50  return SymInitialize(GetCurrentProcess(), 0, TRUE);
51  // FIXME: We don't call SymCleanup() on exit yet - should we?
52}
53
54}  // namespace
55
56// Initializes DbgHelp library, if it's not yet initialized. Calls to this
57// function should be synchronized with respect to other calls to DbgHelp API
58// (e.g. from WinSymbolizerTool).
59void InitializeDbgHelpIfNeeded() {
60  if (is_dbghelp_initialized)
61    return;
62
63  HMODULE dbghelp = LoadLibraryA("dbghelp.dll");
64  CHECK(dbghelp && "failed to load dbghelp.dll");
65
66#define DBGHELP_IMPORT(name)                                                  \
67  do {                                                                        \
68    name =                                                                    \
69        reinterpret_cast<decltype(::name) *>(GetProcAddress(dbghelp, #name)); \
70    CHECK(name != nullptr);                                                   \
71  } while (0)
72  DBGHELP_IMPORT(StackWalk64);
73  DBGHELP_IMPORT(SymCleanup);
74  DBGHELP_IMPORT(SymFromAddr);
75  DBGHELP_IMPORT(SymFunctionTableAccess64);
76  DBGHELP_IMPORT(SymGetLineFromAddr64);
77  DBGHELP_IMPORT(SymGetModuleBase64);
78  DBGHELP_IMPORT(SymGetSearchPathW);
79  DBGHELP_IMPORT(SymInitialize);
80  DBGHELP_IMPORT(SymSetOptions);
81  DBGHELP_IMPORT(SymSetSearchPathW);
82  DBGHELP_IMPORT(UnDecorateSymbolName);
83#undef DBGHELP_IMPORT
84
85  if (!TrySymInitialize()) {
86    // OK, maybe the client app has called SymInitialize already.
87    // That's a bit unfortunate for us as all the DbgHelp functions are
88    // single-threaded and we can't coordinate with the app.
89    // FIXME: Can we stop the other threads at this point?
90    // Anyways, we have to reconfigure stuff to make sure that SymInitialize
91    // has all the appropriate options set.
92    // Cross our fingers and reinitialize DbgHelp.
93    Report("*** WARNING: Failed to initialize DbgHelp!              ***\n");
94    Report("*** Most likely this means that the app is already      ***\n");
95    Report("*** using DbgHelp, possibly with incompatible flags.    ***\n");
96    Report("*** Due to technical reasons, symbolization might crash ***\n");
97    Report("*** or produce wrong results.                           ***\n");
98    SymCleanup(GetCurrentProcess());
99    TrySymInitialize();
100  }
101  is_dbghelp_initialized = true;
102
103  // When an executable is run from a location different from the one where it
104  // was originally built, we may not see the nearby PDB files.
105  // To work around this, let's append the directory of the main module
106  // to the symbol search path.  All the failures below are not fatal.
107  const size_t kSymPathSize = 2048;
108  static wchar_t path_buffer[kSymPathSize + 1 + MAX_PATH];
109  if (!SymGetSearchPathW(GetCurrentProcess(), path_buffer, kSymPathSize)) {
110    Report("*** WARNING: Failed to SymGetSearchPathW ***\n");
111    return;
112  }
113  size_t sz = wcslen(path_buffer);
114  if (sz) {
115    CHECK_EQ(0, wcscat_s(path_buffer, L";"));
116    sz++;
117  }
118  DWORD res = GetModuleFileNameW(NULL, path_buffer + sz, MAX_PATH);
119  if (res == 0 || res == MAX_PATH) {
120    Report("*** WARNING: Failed to getting the EXE directory ***\n");
121    return;
122  }
123  // Write the zero character in place of the last backslash to get the
124  // directory of the main module at the end of path_buffer.
125  wchar_t *last_bslash = wcsrchr(path_buffer + sz, L'\\');
126  CHECK_NE(last_bslash, 0);
127  *last_bslash = L'\0';
128  if (!SymSetSearchPathW(GetCurrentProcess(), path_buffer)) {
129    Report("*** WARNING: Failed to SymSetSearchPathW\n");
130    return;
131  }
132}
133
134bool WinSymbolizerTool::SymbolizePC(uptr addr, SymbolizedStack *frame) {
135  InitializeDbgHelpIfNeeded();
136
137  // See http://msdn.microsoft.com/en-us/library/ms680578(VS.85).aspx
138  char buffer[sizeof(SYMBOL_INFO) + MAX_SYM_NAME * sizeof(CHAR)];
139  PSYMBOL_INFO symbol = (PSYMBOL_INFO)buffer;
140  symbol->SizeOfStruct = sizeof(SYMBOL_INFO);
141  symbol->MaxNameLen = MAX_SYM_NAME;
142  DWORD64 offset = 0;
143  BOOL got_objname = SymFromAddr(GetCurrentProcess(),
144                                 (DWORD64)addr, &offset, symbol);
145  if (!got_objname)
146    return false;
147
148  DWORD unused;
149  IMAGEHLP_LINE64 line_info;
150  line_info.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
151  BOOL got_fileline = SymGetLineFromAddr64(GetCurrentProcess(), (DWORD64)addr,
152                                           &unused, &line_info);
153  frame->info.function = internal_strdup(symbol->Name);
154  frame->info.function_offset = (uptr)offset;
155  if (got_fileline) {
156    frame->info.file = internal_strdup(line_info.FileName);
157    frame->info.line = line_info.LineNumber;
158  }
159  // Only consider this a successful symbolization attempt if we got file info.
160  // Otherwise, try llvm-symbolizer.
161  return got_fileline;
162}
163
164const char *WinSymbolizerTool::Demangle(const char *name) {
165  CHECK(is_dbghelp_initialized);
166  static char demangle_buffer[1000];
167  if (name[0] == '\01' &&
168      UnDecorateSymbolName(name + 1, demangle_buffer, sizeof(demangle_buffer),
169                           UNDNAME_NAME_ONLY))
170    return demangle_buffer;
171  else
172    return name;
173}
174
175const char *Symbolizer::PlatformDemangle(const char *name) {
176  return name;
177}
178
179namespace {
180struct ScopedHandle {
181  ScopedHandle() : h_(nullptr) {}
182  explicit ScopedHandle(HANDLE h) : h_(h) {}
183  ~ScopedHandle() {
184    if (h_)
185      ::CloseHandle(h_);
186  }
187  HANDLE get() { return h_; }
188  HANDLE *receive() { return &h_; }
189  HANDLE release() {
190    HANDLE h = h_;
191    h_ = nullptr;
192    return h;
193  }
194  HANDLE h_;
195};
196} // namespace
197
198bool SymbolizerProcess::StartSymbolizerSubprocess() {
199  // Create inherited pipes for stdin and stdout.
200  ScopedHandle stdin_read, stdin_write;
201  ScopedHandle stdout_read, stdout_write;
202  SECURITY_ATTRIBUTES attrs;
203  attrs.nLength = sizeof(SECURITY_ATTRIBUTES);
204  attrs.bInheritHandle = TRUE;
205  attrs.lpSecurityDescriptor = nullptr;
206  if (!::CreatePipe(stdin_read.receive(), stdin_write.receive(), &attrs, 0) ||
207      !::CreatePipe(stdout_read.receive(), stdout_write.receive(), &attrs, 0)) {
208    VReport(2, "WARNING: %s CreatePipe failed (error code: %d)\n",
209            SanitizerToolName, path_, GetLastError());
210    return false;
211  }
212
213  // Don't inherit the writing end of stdin or the reading end of stdout.
214  if (!SetHandleInformation(stdin_write.get(), HANDLE_FLAG_INHERIT, 0) ||
215      !SetHandleInformation(stdout_read.get(), HANDLE_FLAG_INHERIT, 0)) {
216    VReport(2, "WARNING: %s SetHandleInformation failed (error code: %d)\n",
217            SanitizerToolName, path_, GetLastError());
218    return false;
219  }
220
221  // Compute the command line. Wrap double quotes around everything.
222  const char *argv[kArgVMax];
223  GetArgV(path_, argv);
224  InternalScopedString command_line(kMaxPathLength * 3);
225  for (int i = 0; argv[i]; i++) {
226    const char *arg = argv[i];
227    int arglen = internal_strlen(arg);
228    // Check that tool command lines are simple and that complete escaping is
229    // unnecessary.
230    CHECK(!internal_strchr(arg, '"') && "quotes in args unsupported");
231    CHECK(!internal_strstr(arg, "\\\\") &&
232          "double backslashes in args unsupported");
233    CHECK(arglen > 0 && arg[arglen - 1] != '\\' &&
234          "args ending in backslash and empty args unsupported");
235    command_line.append("\"%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 in case the binary has dwarf.
283  const char *user_path = common_flags()->external_symbolizer_path;
284  const char *path =
285      user_path ? user_path : FindPathToBinary("llvm-symbolizer.exe");
286  if (path) {
287    VReport(2, "Using llvm-symbolizer at %spath: %s\n",
288            user_path ? "user-specified " : "", path);
289    list->push_back(new(*allocator) LLVMSymbolizer(path, allocator));
290  } else {
291    if (user_path && user_path[0] == '\0') {
292      VReport(2, "External symbolizer is explicitly disabled.\n");
293    } else {
294      VReport(2, "External symbolizer is not present.\n");
295    }
296  }
297
298  // Add the dbghelp based symbolizer.
299  list->push_back(new(*allocator) WinSymbolizerTool());
300}
301
302Symbolizer *Symbolizer::PlatformInit() {
303  IntrusiveList<SymbolizerTool> list;
304  list.clear();
305  ChooseSymbolizerTools(&list, &symbolizer_allocator_);
306
307  return new(symbolizer_allocator_) Symbolizer(list);
308}
309
310void Symbolizer::LateInitialize() {
311  Symbolizer::GetOrInit();
312}
313
314}  // namespace __sanitizer
315
316#endif  // _WIN32
317