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#define WIN32_LEAN_AND_MEAN
18#include <windows.h>
19#include <dbghelp.h>
20#pragma comment(lib, "dbghelp.lib")
21
22#include "sanitizer_symbolizer_internal.h"
23
24namespace __sanitizer {
25
26namespace {
27
28class WinSymbolizerTool : public SymbolizerTool {
29 public:
30  bool SymbolizePC(uptr addr, SymbolizedStack *stack) override;
31  bool SymbolizeData(uptr addr, DataInfo *info) override {
32    return false;
33  }
34  const char *Demangle(const char *name) override;
35};
36
37bool is_dbghelp_initialized = false;
38
39bool TrySymInitialize() {
40  SymSetOptions(SYMOPT_DEFERRED_LOADS | SYMOPT_UNDNAME | SYMOPT_LOAD_LINES);
41  return SymInitialize(GetCurrentProcess(), 0, TRUE);
42  // FIXME: We don't call SymCleanup() on exit yet - should we?
43}
44
45// Initializes DbgHelp library, if it's not yet initialized. Calls to this
46// function should be synchronized with respect to other calls to DbgHelp API
47// (e.g. from WinSymbolizerTool).
48void InitializeDbgHelpIfNeeded() {
49  if (is_dbghelp_initialized)
50    return;
51  if (!TrySymInitialize()) {
52    // OK, maybe the client app has called SymInitialize already.
53    // That's a bit unfortunate for us as all the DbgHelp functions are
54    // single-threaded and we can't coordinate with the app.
55    // FIXME: Can we stop the other threads at this point?
56    // Anyways, we have to reconfigure stuff to make sure that SymInitialize
57    // has all the appropriate options set.
58    // Cross our fingers and reinitialize DbgHelp.
59    Report("*** WARNING: Failed to initialize DbgHelp!              ***\n");
60    Report("*** Most likely this means that the app is already      ***\n");
61    Report("*** using DbgHelp, possibly with incompatible flags.    ***\n");
62    Report("*** Due to technical reasons, symbolization might crash ***\n");
63    Report("*** or produce wrong results.                           ***\n");
64    SymCleanup(GetCurrentProcess());
65    TrySymInitialize();
66  }
67  is_dbghelp_initialized = true;
68
69  // When an executable is run from a location different from the one where it
70  // was originally built, we may not see the nearby PDB files.
71  // To work around this, let's append the directory of the main module
72  // to the symbol search path.  All the failures below are not fatal.
73  const size_t kSymPathSize = 2048;
74  static wchar_t path_buffer[kSymPathSize + 1 + MAX_PATH];
75  if (!SymGetSearchPathW(GetCurrentProcess(), path_buffer, kSymPathSize)) {
76    Report("*** WARNING: Failed to SymGetSearchPathW ***\n");
77    return;
78  }
79  size_t sz = wcslen(path_buffer);
80  if (sz) {
81    CHECK_EQ(0, wcscat_s(path_buffer, L";"));
82    sz++;
83  }
84  DWORD res = GetModuleFileNameW(NULL, path_buffer + sz, MAX_PATH);
85  if (res == 0 || res == MAX_PATH) {
86    Report("*** WARNING: Failed to getting the EXE directory ***\n");
87    return;
88  }
89  // Write the zero character in place of the last backslash to get the
90  // directory of the main module at the end of path_buffer.
91  wchar_t *last_bslash = wcsrchr(path_buffer + sz, L'\\');
92  CHECK_NE(last_bslash, 0);
93  *last_bslash = L'\0';
94  if (!SymSetSearchPathW(GetCurrentProcess(), path_buffer)) {
95    Report("*** WARNING: Failed to SymSetSearchPathW\n");
96    return;
97  }
98}
99
100}  // namespace
101
102bool WinSymbolizerTool::SymbolizePC(uptr addr, SymbolizedStack *frame) {
103  InitializeDbgHelpIfNeeded();
104
105  // See http://msdn.microsoft.com/en-us/library/ms680578(VS.85).aspx
106  char buffer[sizeof(SYMBOL_INFO) + MAX_SYM_NAME * sizeof(CHAR)];
107  PSYMBOL_INFO symbol = (PSYMBOL_INFO)buffer;
108  symbol->SizeOfStruct = sizeof(SYMBOL_INFO);
109  symbol->MaxNameLen = MAX_SYM_NAME;
110  DWORD64 offset = 0;
111  BOOL got_objname = SymFromAddr(GetCurrentProcess(),
112                                 (DWORD64)addr, &offset, symbol);
113  if (!got_objname)
114    return false;
115
116  DWORD unused;
117  IMAGEHLP_LINE64 line_info;
118  line_info.SizeOfStruct = sizeof(IMAGEHLP_LINE64);
119  BOOL got_fileline = SymGetLineFromAddr64(GetCurrentProcess(), (DWORD64)addr,
120                                           &unused, &line_info);
121  frame->info.function = internal_strdup(symbol->Name);
122  frame->info.function_offset = (uptr)offset;
123  if (got_fileline) {
124    frame->info.file = internal_strdup(line_info.FileName);
125    frame->info.line = line_info.LineNumber;
126  }
127  // Only consider this a successful symbolization attempt if we got file info.
128  // Otherwise, try llvm-symbolizer.
129  return got_fileline;
130}
131
132const char *WinSymbolizerTool::Demangle(const char *name) {
133  CHECK(is_dbghelp_initialized);
134  static char demangle_buffer[1000];
135  if (name[0] == '\01' &&
136      UnDecorateSymbolName(name + 1, demangle_buffer, sizeof(demangle_buffer),
137                           UNDNAME_NAME_ONLY))
138    return demangle_buffer;
139  else
140    return name;
141}
142
143const char *Symbolizer::PlatformDemangle(const char *name) {
144  return name;
145}
146
147void Symbolizer::PlatformPrepareForSandboxing() {
148  // Do nothing.
149}
150
151namespace {
152struct ScopedHandle {
153  ScopedHandle() : h_(nullptr) {}
154  explicit ScopedHandle(HANDLE h) : h_(h) {}
155  ~ScopedHandle() {
156    if (h_)
157      ::CloseHandle(h_);
158  }
159  HANDLE get() { return h_; }
160  HANDLE *receive() { return &h_; }
161  HANDLE release() {
162    HANDLE h = h_;
163    h_ = nullptr;
164    return h;
165  }
166  HANDLE h_;
167};
168} // namespace
169
170bool SymbolizerProcess::StartSymbolizerSubprocess() {
171  // Create inherited pipes for stdin and stdout.
172  ScopedHandle stdin_read, stdin_write;
173  ScopedHandle stdout_read, stdout_write;
174  SECURITY_ATTRIBUTES attrs;
175  attrs.nLength = sizeof(SECURITY_ATTRIBUTES);
176  attrs.bInheritHandle = TRUE;
177  attrs.lpSecurityDescriptor = nullptr;
178  if (!::CreatePipe(stdin_read.receive(), stdin_write.receive(), &attrs, 0) ||
179      !::CreatePipe(stdout_read.receive(), stdout_write.receive(), &attrs, 0)) {
180    VReport(2, "WARNING: %s CreatePipe failed (error code: %d)\n",
181            SanitizerToolName, path_, GetLastError());
182    return false;
183  }
184
185  // Don't inherit the writing end of stdin or the reading end of stdout.
186  if (!SetHandleInformation(stdin_write.get(), HANDLE_FLAG_INHERIT, 0) ||
187      !SetHandleInformation(stdout_read.get(), HANDLE_FLAG_INHERIT, 0)) {
188    VReport(2, "WARNING: %s SetHandleInformation failed (error code: %d)\n",
189            SanitizerToolName, path_, GetLastError());
190    return false;
191  }
192
193  // Compute the command line. Wrap double quotes around everything.
194  const char *argv[kArgVMax];
195  GetArgV(path_, argv);
196  InternalScopedString command_line(kMaxPathLength * 3);
197  for (int i = 0; argv[i]; i++) {
198    const char *arg = argv[i];
199    int arglen = internal_strlen(arg);
200    // Check that tool command lines are simple and that complete escaping is
201    // unnecessary.
202    CHECK(!internal_strchr(arg, '"') && "quotes in args unsupported");
203    CHECK(!internal_strstr(arg, "\\\\") &&
204          "double backslashes in args unsupported");
205    CHECK(arglen > 0 && arg[arglen - 1] != '\\' &&
206          "args ending in backslash and empty args unsupported");
207    command_line.append("\"%s\" ", arg);
208  }
209  VReport(3, "Launching symbolizer command: %s\n", command_line.data());
210
211  // Launch llvm-symbolizer with stdin and stdout redirected.
212  STARTUPINFOA si;
213  memset(&si, 0, sizeof(si));
214  si.cb = sizeof(si);
215  si.dwFlags |= STARTF_USESTDHANDLES;
216  si.hStdInput = stdin_read.get();
217  si.hStdOutput = stdout_write.get();
218  PROCESS_INFORMATION pi;
219  memset(&pi, 0, sizeof(pi));
220  if (!CreateProcessA(path_,               // Executable
221                      command_line.data(), // Command line
222                      nullptr,             // Process handle not inheritable
223                      nullptr,             // Thread handle not inheritable
224                      TRUE,                // Set handle inheritance to TRUE
225                      0,                   // Creation flags
226                      nullptr,             // Use parent's environment block
227                      nullptr,             // Use parent's starting directory
228                      &si, &pi)) {
229    VReport(2, "WARNING: %s failed to create process for %s (error code: %d)\n",
230            SanitizerToolName, path_, GetLastError());
231    return false;
232  }
233
234  // Process creation succeeded, so transfer handle ownership into the fields.
235  input_fd_ = stdout_read.release();
236  output_fd_ = stdin_write.release();
237
238  // The llvm-symbolizer process is responsible for quitting itself when the
239  // stdin pipe is closed, so we don't need these handles. Close them to prevent
240  // leaks. If we ever want to try to kill the symbolizer process from the
241  // parent, we'll want to hang on to these handles.
242  CloseHandle(pi.hProcess);
243  CloseHandle(pi.hThread);
244  return true;
245}
246
247static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,
248                                  LowLevelAllocator *allocator) {
249  if (!common_flags()->symbolize) {
250    VReport(2, "Symbolizer is disabled.\n");
251    return;
252  }
253
254  // Add llvm-symbolizer in case the binary has dwarf.
255  const char *user_path = common_flags()->external_symbolizer_path;
256  const char *path =
257      user_path ? user_path : FindPathToBinary("llvm-symbolizer.exe");
258  if (path) {
259    VReport(2, "Using llvm-symbolizer at %spath: %s\n",
260            user_path ? "user-specified " : "", path);
261    list->push_back(new(*allocator) LLVMSymbolizer(path, allocator));
262  } else {
263    if (user_path && user_path[0] == '\0') {
264      VReport(2, "External symbolizer is explicitly disabled.\n");
265    } else {
266      VReport(2, "External symbolizer is not present.\n");
267    }
268  }
269
270  // Add the dbghelp based symbolizer.
271  list->push_back(new(*allocator) WinSymbolizerTool());
272}
273
274Symbolizer *Symbolizer::PlatformInit() {
275  IntrusiveList<SymbolizerTool> list;
276  list.clear();
277  ChooseSymbolizerTools(&list, &symbolizer_allocator_);
278
279  return new(symbolizer_allocator_) Symbolizer(list);
280}
281
282void Symbolizer::LateInitialize() {
283  Symbolizer::GetOrInit();
284}
285
286}  // namespace __sanitizer
287
288#endif  // _WIN32
289