1 //===- KillTheDoctor - Prevent Dr. Watson from stopping tests ---*- C++ -*-===//
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 program provides an extremely hacky way to stop Dr. Watson from starting
11 // due to unhandled exceptions in child processes.
12 //
13 // This simply starts the program named in the first positional argument with
14 // the arguments following it under a debugger. All this debugger does is catch
15 // any unhandled exceptions thrown in the child process and close the program
16 // (and hopefully tells someone about it).
17 //
18 // This also provides another really hacky method to prevent assert dialog boxes
19 // from popping up. When --no-user32 is passed, if any process loads user32.dll,
20 // we assume it is trying to call MessageBoxEx and terminate it. The proper way
21 // to do this would be to actually set a break point, but there's quite a bit
22 // of code involved to get the address of MessageBoxEx in the remote process's
23 // address space due to Address space layout randomization (ASLR). This can be
24 // added if it's ever actually needed.
25 //
26 // If the subprocess exits for any reason other than successful termination, -1
27 // is returned. If the process exits normally the value it returned is returned.
28 //
29 // I hate Windows.
30 //
31 //===----------------------------------------------------------------------===//
32
33 #include "llvm/ADT/STLExtras.h"
34 #include "llvm/ADT/SmallString.h"
35 #include "llvm/ADT/SmallVector.h"
36 #include "llvm/ADT/StringExtras.h"
37 #include "llvm/ADT/StringRef.h"
38 #include "llvm/ADT/Twine.h"
39 #include "llvm/Support/CommandLine.h"
40 #include "llvm/Support/ManagedStatic.h"
41 #include "llvm/Support/Path.h"
42 #include "llvm/Support/PrettyStackTrace.h"
43 #include "llvm/Support/Signals.h"
44 #include "llvm/Support/WindowsError.h"
45 #include "llvm/Support/raw_ostream.h"
46 #include "llvm/Support/type_traits.h"
47 #include <algorithm>
48 #include <cerrno>
49 #include <cstdlib>
50 #include <map>
51 #include <string>
52 #include <system_error>
53
54 // These includes must be last.
55 #include <Windows.h>
56 #include <WinError.h>
57 #include <Dbghelp.h>
58 #include <psapi.h>
59
60 using namespace llvm;
61
62 #undef max
63
64 namespace {
65 cl::opt<std::string> ProgramToRun(cl::Positional,
66 cl::desc("<program to run>"));
67 cl::list<std::string> Argv(cl::ConsumeAfter,
68 cl::desc("<program arguments>..."));
69 cl::opt<bool> TraceExecution("x",
70 cl::desc("Print detailed output about what is being run to stderr."));
71 cl::opt<unsigned> Timeout("t", cl::init(0),
72 cl::desc("Set maximum runtime in seconds. Defaults to infinite."));
73 cl::opt<bool> NoUser32("no-user32",
74 cl::desc("Terminate process if it loads user32.dll."));
75
76 StringRef ToolName;
77
78 template <typename HandleType>
79 class ScopedHandle {
80 typedef typename HandleType::handle_type handle_type;
81
82 handle_type Handle;
83
84 public:
ScopedHandle()85 ScopedHandle()
86 : Handle(HandleType::GetInvalidHandle()) {}
87
ScopedHandle(handle_type handle)88 explicit ScopedHandle(handle_type handle)
89 : Handle(handle) {}
90
~ScopedHandle()91 ~ScopedHandle() {
92 HandleType::Destruct(Handle);
93 }
94
operator =(handle_type handle)95 ScopedHandle& operator=(handle_type handle) {
96 // Cleanup current handle.
97 if (!HandleType::isValid(Handle))
98 HandleType::Destruct(Handle);
99 Handle = handle;
100 return *this;
101 }
102
operator bool() const103 operator bool() const {
104 return HandleType::isValid(Handle);
105 }
106
operator handle_type()107 operator handle_type() {
108 return Handle;
109 }
110 };
111
112 // This implements the most common handle in the Windows API.
113 struct CommonHandle {
114 typedef HANDLE handle_type;
115
GetInvalidHandle__anon96fe42700111::CommonHandle116 static handle_type GetInvalidHandle() {
117 return INVALID_HANDLE_VALUE;
118 }
119
Destruct__anon96fe42700111::CommonHandle120 static void Destruct(handle_type Handle) {
121 ::CloseHandle(Handle);
122 }
123
isValid__anon96fe42700111::CommonHandle124 static bool isValid(handle_type Handle) {
125 return Handle != GetInvalidHandle();
126 }
127 };
128
129 struct FileMappingHandle {
130 typedef HANDLE handle_type;
131
GetInvalidHandle__anon96fe42700111::FileMappingHandle132 static handle_type GetInvalidHandle() {
133 return NULL;
134 }
135
Destruct__anon96fe42700111::FileMappingHandle136 static void Destruct(handle_type Handle) {
137 ::CloseHandle(Handle);
138 }
139
isValid__anon96fe42700111::FileMappingHandle140 static bool isValid(handle_type Handle) {
141 return Handle != GetInvalidHandle();
142 }
143 };
144
145 struct MappedViewOfFileHandle {
146 typedef LPVOID handle_type;
147
GetInvalidHandle__anon96fe42700111::MappedViewOfFileHandle148 static handle_type GetInvalidHandle() {
149 return NULL;
150 }
151
Destruct__anon96fe42700111::MappedViewOfFileHandle152 static void Destruct(handle_type Handle) {
153 ::UnmapViewOfFile(Handle);
154 }
155
isValid__anon96fe42700111::MappedViewOfFileHandle156 static bool isValid(handle_type Handle) {
157 return Handle != GetInvalidHandle();
158 }
159 };
160
161 struct ProcessHandle : CommonHandle {};
162 struct ThreadHandle : CommonHandle {};
163 struct TokenHandle : CommonHandle {};
164 struct FileHandle : CommonHandle {};
165
166 typedef ScopedHandle<FileMappingHandle> FileMappingScopedHandle;
167 typedef ScopedHandle<MappedViewOfFileHandle> MappedViewOfFileScopedHandle;
168 typedef ScopedHandle<ProcessHandle> ProcessScopedHandle;
169 typedef ScopedHandle<ThreadHandle> ThreadScopedHandle;
170 typedef ScopedHandle<TokenHandle> TokenScopedHandle;
171 typedef ScopedHandle<FileHandle> FileScopedHandle;
172 }
173
windows_error(DWORD E)174 static std::error_code windows_error(DWORD E) { return mapWindowsError(E); }
175
GetFileNameFromHandle(HANDLE FileHandle,std::string & Name)176 static std::error_code GetFileNameFromHandle(HANDLE FileHandle,
177 std::string &Name) {
178 char Filename[MAX_PATH+1];
179 bool Success = false;
180 Name.clear();
181
182 // Get the file size.
183 LARGE_INTEGER FileSize;
184 Success = ::GetFileSizeEx(FileHandle, &FileSize);
185
186 if (!Success)
187 return windows_error(::GetLastError());
188
189 // Create a file mapping object.
190 FileMappingScopedHandle FileMapping(
191 ::CreateFileMappingA(FileHandle,
192 NULL,
193 PAGE_READONLY,
194 0,
195 1,
196 NULL));
197
198 if (!FileMapping)
199 return windows_error(::GetLastError());
200
201 // Create a file mapping to get the file name.
202 MappedViewOfFileScopedHandle MappedFile(
203 ::MapViewOfFile(FileMapping, FILE_MAP_READ, 0, 0, 1));
204
205 if (!MappedFile)
206 return windows_error(::GetLastError());
207
208 Success = ::GetMappedFileNameA(::GetCurrentProcess(),
209 MappedFile,
210 Filename,
211 array_lengthof(Filename) - 1);
212
213 if (!Success)
214 return windows_error(::GetLastError());
215 else {
216 Name = Filename;
217 return std::error_code();
218 }
219 }
220
221 /// @brief Find program using shell lookup rules.
222 /// @param Program This is either an absolute path, relative path, or simple a
223 /// program name. Look in PATH for any programs that match. If no
224 /// extension is present, try all extensions in PATHEXT.
225 /// @return If ec == errc::success, The absolute path to the program. Otherwise
226 /// the return value is undefined.
FindProgram(const std::string & Program,std::error_code & ec)227 static std::string FindProgram(const std::string &Program,
228 std::error_code &ec) {
229 char PathName[MAX_PATH + 1];
230 typedef SmallVector<StringRef, 12> pathext_t;
231 pathext_t pathext;
232 // Check for the program without an extension (in case it already has one).
233 pathext.push_back("");
234 SplitString(std::getenv("PATHEXT"), pathext, ";");
235
236 for (pathext_t::iterator i = pathext.begin(), e = pathext.end(); i != e; ++i){
237 SmallString<5> ext;
238 for (std::size_t ii = 0, e = i->size(); ii != e; ++ii)
239 ext.push_back(::tolower((*i)[ii]));
240 LPCSTR Extension = NULL;
241 if (ext.size() && ext[0] == '.')
242 Extension = ext.c_str();
243 DWORD length = ::SearchPathA(NULL,
244 Program.c_str(),
245 Extension,
246 array_lengthof(PathName),
247 PathName,
248 NULL);
249 if (length == 0)
250 ec = windows_error(::GetLastError());
251 else if (length > array_lengthof(PathName)) {
252 // This may have been the file, return with error.
253 ec = windows_error(ERROR_BUFFER_OVERFLOW);
254 break;
255 } else {
256 // We found the path! Return it.
257 ec = std::error_code();
258 break;
259 }
260 }
261
262 // Make sure PathName is valid.
263 PathName[MAX_PATH] = 0;
264 return PathName;
265 }
266
ExceptionCodeToString(DWORD ExceptionCode)267 static StringRef ExceptionCodeToString(DWORD ExceptionCode) {
268 switch(ExceptionCode) {
269 case EXCEPTION_ACCESS_VIOLATION: return "EXCEPTION_ACCESS_VIOLATION";
270 case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
271 return "EXCEPTION_ARRAY_BOUNDS_EXCEEDED";
272 case EXCEPTION_BREAKPOINT: return "EXCEPTION_BREAKPOINT";
273 case EXCEPTION_DATATYPE_MISALIGNMENT:
274 return "EXCEPTION_DATATYPE_MISALIGNMENT";
275 case EXCEPTION_FLT_DENORMAL_OPERAND: return "EXCEPTION_FLT_DENORMAL_OPERAND";
276 case EXCEPTION_FLT_DIVIDE_BY_ZERO: return "EXCEPTION_FLT_DIVIDE_BY_ZERO";
277 case EXCEPTION_FLT_INEXACT_RESULT: return "EXCEPTION_FLT_INEXACT_RESULT";
278 case EXCEPTION_FLT_INVALID_OPERATION:
279 return "EXCEPTION_FLT_INVALID_OPERATION";
280 case EXCEPTION_FLT_OVERFLOW: return "EXCEPTION_FLT_OVERFLOW";
281 case EXCEPTION_FLT_STACK_CHECK: return "EXCEPTION_FLT_STACK_CHECK";
282 case EXCEPTION_FLT_UNDERFLOW: return "EXCEPTION_FLT_UNDERFLOW";
283 case EXCEPTION_ILLEGAL_INSTRUCTION: return "EXCEPTION_ILLEGAL_INSTRUCTION";
284 case EXCEPTION_IN_PAGE_ERROR: return "EXCEPTION_IN_PAGE_ERROR";
285 case EXCEPTION_INT_DIVIDE_BY_ZERO: return "EXCEPTION_INT_DIVIDE_BY_ZERO";
286 case EXCEPTION_INT_OVERFLOW: return "EXCEPTION_INT_OVERFLOW";
287 case EXCEPTION_INVALID_DISPOSITION: return "EXCEPTION_INVALID_DISPOSITION";
288 case EXCEPTION_NONCONTINUABLE_EXCEPTION:
289 return "EXCEPTION_NONCONTINUABLE_EXCEPTION";
290 case EXCEPTION_PRIV_INSTRUCTION: return "EXCEPTION_PRIV_INSTRUCTION";
291 case EXCEPTION_SINGLE_STEP: return "EXCEPTION_SINGLE_STEP";
292 case EXCEPTION_STACK_OVERFLOW: return "EXCEPTION_STACK_OVERFLOW";
293 default: return "<unknown>";
294 }
295 }
296
main(int argc,char ** argv)297 int main(int argc, char **argv) {
298 // Print a stack trace if we signal out.
299 sys::PrintStackTraceOnErrorSignal(argv[0]);
300 PrettyStackTraceProgram X(argc, argv);
301 llvm_shutdown_obj Y; // Call llvm_shutdown() on exit.
302
303 ToolName = argv[0];
304
305 cl::ParseCommandLineOptions(argc, argv, "Dr. Watson Assassin.\n");
306 if (ProgramToRun.size() == 0) {
307 cl::PrintHelpMessage();
308 return -1;
309 }
310
311 if (Timeout > std::numeric_limits<uint32_t>::max() / 1000) {
312 errs() << ToolName << ": Timeout value too large, must be less than: "
313 << std::numeric_limits<uint32_t>::max() / 1000
314 << '\n';
315 return -1;
316 }
317
318 std::string CommandLine(ProgramToRun);
319
320 std::error_code ec;
321 ProgramToRun = FindProgram(ProgramToRun, ec);
322 if (ec) {
323 errs() << ToolName << ": Failed to find program: '" << CommandLine
324 << "': " << ec.message() << '\n';
325 return -1;
326 }
327
328 if (TraceExecution)
329 errs() << ToolName << ": Found Program: " << ProgramToRun << '\n';
330
331 for (const std::string &Arg : Argv) {
332 CommandLine.push_back(' ');
333 CommandLine.append(Arg);
334 }
335
336 if (TraceExecution)
337 errs() << ToolName << ": Program Image Path: " << ProgramToRun << '\n'
338 << ToolName << ": Command Line: " << CommandLine << '\n';
339
340 STARTUPINFOA StartupInfo;
341 PROCESS_INFORMATION ProcessInfo;
342 std::memset(&StartupInfo, 0, sizeof(StartupInfo));
343 StartupInfo.cb = sizeof(StartupInfo);
344 std::memset(&ProcessInfo, 0, sizeof(ProcessInfo));
345
346 // Set error mode to not display any message boxes. The child process inherits
347 // this.
348 ::SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOGPFAULTERRORBOX);
349 ::_set_error_mode(_OUT_TO_STDERR);
350
351 BOOL success = ::CreateProcessA(ProgramToRun.c_str(),
352 LPSTR(CommandLine.c_str()),
353 NULL,
354 NULL,
355 FALSE,
356 DEBUG_PROCESS,
357 NULL,
358 NULL,
359 &StartupInfo,
360 &ProcessInfo);
361 if (!success) {
362 errs() << ToolName << ": Failed to run program: '" << ProgramToRun << "': "
363 << std::error_code(windows_error(::GetLastError())).message()
364 << '\n';
365 return -1;
366 }
367
368 // Make sure ::CloseHandle is called on exit.
369 std::map<DWORD, HANDLE> ProcessIDToHandle;
370
371 DEBUG_EVENT DebugEvent;
372 std::memset(&DebugEvent, 0, sizeof(DebugEvent));
373 DWORD dwContinueStatus = DBG_CONTINUE;
374
375 // Run the program under the debugger until either it exits, or throws an
376 // exception.
377 if (TraceExecution)
378 errs() << ToolName << ": Debugging...\n";
379
380 while(true) {
381 DWORD TimeLeft = INFINITE;
382 if (Timeout > 0) {
383 FILETIME CreationTime, ExitTime, KernelTime, UserTime;
384 ULARGE_INTEGER a, b;
385 success = ::GetProcessTimes(ProcessInfo.hProcess,
386 &CreationTime,
387 &ExitTime,
388 &KernelTime,
389 &UserTime);
390 if (!success) {
391 ec = windows_error(::GetLastError());
392
393 errs() << ToolName << ": Failed to get process times: "
394 << ec.message() << '\n';
395 return -1;
396 }
397 a.LowPart = KernelTime.dwLowDateTime;
398 a.HighPart = KernelTime.dwHighDateTime;
399 b.LowPart = UserTime.dwLowDateTime;
400 b.HighPart = UserTime.dwHighDateTime;
401 // Convert 100-nanosecond units to milliseconds.
402 uint64_t TotalTimeMiliseconds = (a.QuadPart + b.QuadPart) / 10000;
403 // Handle the case where the process has been running for more than 49
404 // days.
405 if (TotalTimeMiliseconds > std::numeric_limits<uint32_t>::max()) {
406 errs() << ToolName << ": Timeout Failed: Process has been running for"
407 "more than 49 days.\n";
408 return -1;
409 }
410
411 // We check with > instead of using Timeleft because if
412 // TotalTimeMiliseconds is greater than Timeout * 1000, TimeLeft would
413 // underflow.
414 if (TotalTimeMiliseconds > (Timeout * 1000)) {
415 errs() << ToolName << ": Process timed out.\n";
416 ::TerminateProcess(ProcessInfo.hProcess, -1);
417 // Otherwise other stuff starts failing...
418 return -1;
419 }
420
421 TimeLeft = (Timeout * 1000) - static_cast<uint32_t>(TotalTimeMiliseconds);
422 }
423 success = WaitForDebugEvent(&DebugEvent, TimeLeft);
424
425 if (!success) {
426 DWORD LastError = ::GetLastError();
427 ec = windows_error(LastError);
428
429 if (LastError == ERROR_SEM_TIMEOUT || LastError == WSAETIMEDOUT) {
430 errs() << ToolName << ": Process timed out.\n";
431 ::TerminateProcess(ProcessInfo.hProcess, -1);
432 // Otherwise other stuff starts failing...
433 return -1;
434 }
435
436 errs() << ToolName << ": Failed to wait for debug event in program: '"
437 << ProgramToRun << "': " << ec.message() << '\n';
438 return -1;
439 }
440
441 switch(DebugEvent.dwDebugEventCode) {
442 case CREATE_PROCESS_DEBUG_EVENT:
443 // Make sure we remove the handle on exit.
444 if (TraceExecution)
445 errs() << ToolName << ": Debug Event: CREATE_PROCESS_DEBUG_EVENT\n";
446 ProcessIDToHandle[DebugEvent.dwProcessId] =
447 DebugEvent.u.CreateProcessInfo.hProcess;
448 ::CloseHandle(DebugEvent.u.CreateProcessInfo.hFile);
449 break;
450 case EXIT_PROCESS_DEBUG_EVENT: {
451 if (TraceExecution)
452 errs() << ToolName << ": Debug Event: EXIT_PROCESS_DEBUG_EVENT\n";
453
454 // If this is the process we originally created, exit with its exit
455 // code.
456 if (DebugEvent.dwProcessId == ProcessInfo.dwProcessId)
457 return DebugEvent.u.ExitProcess.dwExitCode;
458
459 // Otherwise cleanup any resources we have for it.
460 std::map<DWORD, HANDLE>::iterator ExitingProcess =
461 ProcessIDToHandle.find(DebugEvent.dwProcessId);
462 if (ExitingProcess == ProcessIDToHandle.end()) {
463 errs() << ToolName << ": Got unknown process id!\n";
464 return -1;
465 }
466 ::CloseHandle(ExitingProcess->second);
467 ProcessIDToHandle.erase(ExitingProcess);
468 }
469 break;
470 case CREATE_THREAD_DEBUG_EVENT:
471 ::CloseHandle(DebugEvent.u.CreateThread.hThread);
472 break;
473 case LOAD_DLL_DEBUG_EVENT: {
474 // Cleanup the file handle.
475 FileScopedHandle DLLFile(DebugEvent.u.LoadDll.hFile);
476 std::string DLLName;
477 ec = GetFileNameFromHandle(DLLFile, DLLName);
478 if (ec) {
479 DLLName = "<failed to get file name from file handle> : ";
480 DLLName += ec.message();
481 }
482 if (TraceExecution) {
483 errs() << ToolName << ": Debug Event: LOAD_DLL_DEBUG_EVENT\n";
484 errs().indent(ToolName.size()) << ": DLL Name : " << DLLName << '\n';
485 }
486
487 if (NoUser32 && sys::path::stem(DLLName) == "user32") {
488 // Program is loading user32.dll, in the applications we are testing,
489 // this only happens if an assert has fired. By now the message has
490 // already been printed, so simply close the program.
491 errs() << ToolName << ": user32.dll loaded!\n";
492 errs().indent(ToolName.size())
493 << ": This probably means that assert was called. Closing "
494 "program to prevent message box from popping up.\n";
495 dwContinueStatus = DBG_CONTINUE;
496 ::TerminateProcess(ProcessIDToHandle[DebugEvent.dwProcessId], -1);
497 return -1;
498 }
499 }
500 break;
501 case EXCEPTION_DEBUG_EVENT: {
502 // Close the application if this exception will not be handled by the
503 // child application.
504 if (TraceExecution)
505 errs() << ToolName << ": Debug Event: EXCEPTION_DEBUG_EVENT\n";
506
507 EXCEPTION_DEBUG_INFO &Exception = DebugEvent.u.Exception;
508 if (Exception.dwFirstChance > 0) {
509 if (TraceExecution) {
510 errs().indent(ToolName.size()) << ": Debug Info : ";
511 errs() << "First chance exception at "
512 << Exception.ExceptionRecord.ExceptionAddress
513 << ", exception code: "
514 << ExceptionCodeToString(
515 Exception.ExceptionRecord.ExceptionCode)
516 << " (" << Exception.ExceptionRecord.ExceptionCode << ")\n";
517 }
518 dwContinueStatus = DBG_EXCEPTION_NOT_HANDLED;
519 } else {
520 errs() << ToolName << ": Unhandled exception in: " << ProgramToRun
521 << "!\n";
522 errs().indent(ToolName.size()) << ": location: ";
523 errs() << Exception.ExceptionRecord.ExceptionAddress
524 << ", exception code: "
525 << ExceptionCodeToString(
526 Exception.ExceptionRecord.ExceptionCode)
527 << " (" << Exception.ExceptionRecord.ExceptionCode
528 << ")\n";
529 dwContinueStatus = DBG_CONTINUE;
530 ::TerminateProcess(ProcessIDToHandle[DebugEvent.dwProcessId], -1);
531 return -1;
532 }
533 }
534 break;
535 default:
536 // Do nothing.
537 if (TraceExecution)
538 errs() << ToolName << ": Debug Event: <unknown>\n";
539 break;
540 }
541
542 success = ContinueDebugEvent(DebugEvent.dwProcessId,
543 DebugEvent.dwThreadId,
544 dwContinueStatus);
545 if (!success) {
546 ec = windows_error(::GetLastError());
547 errs() << ToolName << ": Failed to continue debugging program: '"
548 << ProgramToRun << "': " << ec.message() << '\n';
549 return -1;
550 }
551
552 dwContinueStatus = DBG_CONTINUE;
553 }
554
555 assert(0 && "Fell out of debug loop. This shouldn't be possible!");
556 return -1;
557 }
558