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C4CrashHandlerWin32.cpp
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1 /*
2  * OpenClonk, http://www.openclonk.org
3  *
4  * Copyright (c) 1998-2000, Matthes Bender
5  * Copyright (c) 2001-2009, RedWolf Design GmbH, http://www.clonk.de/
6  * Copyright (c) 2009-2016, The OpenClonk Team and contributors
7  *
8  * Distributed under the terms of the ISC license; see accompanying file
9  * "COPYING" for details.
10  *
11  * "Clonk" is a registered trademark of Matthes Bender, used with permission.
12  * See accompanying file "TRADEMARK" for details.
13  *
14  * To redistribute this file separately, substitute the full license texts
15  * for the above references.
16  */
17 
18 // Crash handler, Win32 version
19 
20 #include "C4Include.h"
21 
22 #ifdef HAVE_DBGHELP
23 
24 // Dump generation on crash
25 #include "C4Version.h"
27 #include <dbghelp.h>
28 #include <tlhelp32.h>
29 #include <cinttypes>
30 #if defined(__CRT_WIDE) || (defined(_MSC_VER) && _MSC_VER >= 1900)
31 #define USE_WIDE_ASSERT
32 #endif
33 
34 static bool FirstCrash = true;
35 
36 namespace {
37 #define OC_MACHINE_UNKNOWN 0x0
38 #define OC_MACHINE_X86 0x1
39 #define OC_MACHINE_X64 0x2
40 #if defined(_M_X64) || defined(__amd64)
41 # define OC_MACHINE OC_MACHINE_X64
42 #elif defined(_M_IX86) || defined(__i386__)
43 # define OC_MACHINE OC_MACHINE_X86
44 #else
45 # define OC_MACHINE OC_MACHINE_UNKNOWN
46 #endif
47 
48  const size_t DumpBufferSize = 2048;
49  char DumpBuffer[DumpBufferSize];
50  char SymbolBuffer[DumpBufferSize];
51  // Dump crash info in a human readable format. Uses a static buffer to avoid heap allocations
52  // from an exception handler. For the same reason, this also doesn't use Log/LogF etc.
53  void SafeTextDump(LPEXCEPTION_POINTERS exc, int fd, const wchar_t *dump_filename)
54  {
55 #if defined(_MSC_VER)
56 # define LOG_SNPRINTF _snprintf
57 #else
58 # define LOG_SNPRINTF snprintf
59 #endif
60 #define LOG_STATIC_TEXT(text) write(fd, text, sizeof(text) - 1)
61 #define LOG_DYNAMIC_TEXT(...) write(fd, DumpBuffer, LOG_SNPRINTF(DumpBuffer, DumpBufferSize-1, __VA_ARGS__))
62 
63 // Figure out which kind of format string will output a pointer in hex
64 #if defined(PRIdPTR)
65 # define POINTER_FORMAT_SUFFIX PRIdPTR
66 #elif defined(_MSC_VER)
67 # define POINTER_FORMAT_SUFFIX "Ix"
68 #elif defined(__GNUC__)
69 # define POINTER_FORMAT_SUFFIX "zx"
70 #else
71 # define POINTER_FORMAT_SUFFIX "p"
72 #endif
73 #if OC_MACHINE == OC_MACHINE_X64
74 # define POINTER_FORMAT "0x%016" POINTER_FORMAT_SUFFIX
75 #elif OC_MACHINE == OC_MACHINE_X86
76 # define POINTER_FORMAT "0x%08" POINTER_FORMAT_SUFFIX
77 #else
78 # define POINTER_FORMAT "0x%" POINTER_FORMAT_SUFFIX
79 #endif
80 
81 #ifndef STATUS_ASSERTION_FAILURE
82 # define STATUS_ASSERTION_FAILURE ((DWORD)0xC0000420L)
83 #endif
84 
85  LOG_STATIC_TEXT("**********************************************************************\n");
86  LOG_STATIC_TEXT("* UNHANDLED EXCEPTION\n");
87  if (OC_BUILD_ID[0] != '\0')
88  LOG_STATIC_TEXT("* Build Identifier: " OC_BUILD_ID "\n");
89  if (exc->ExceptionRecord->ExceptionCode != STATUS_ASSERTION_FAILURE && dump_filename && dump_filename[0] != L'\0')
90  {
91  int cch = WideCharToMultiByte(CP_UTF8, 0, dump_filename, -1, SymbolBuffer, sizeof(SymbolBuffer), nullptr, nullptr);
92  if (cch > 0)
93  {
94  LOG_STATIC_TEXT("* A crash dump may have been written to ");
95  write(fd, SymbolBuffer, cch - 1);
96  LOG_STATIC_TEXT("\n");
97  LOG_STATIC_TEXT("* If this file exists, please send it to a developer for investigation.\n");
98  }
99  }
100  LOG_STATIC_TEXT("**********************************************************************\n");
101  // Log exception type
102  switch (exc->ExceptionRecord->ExceptionCode)
103  {
104 #define LOG_EXCEPTION(code, text) case code: LOG_STATIC_TEXT(#code ": " text "\n"); break
105  LOG_EXCEPTION(EXCEPTION_ACCESS_VIOLATION, "The thread tried to read from or write to a virtual address for which it does not have the appropriate access.");
106  LOG_EXCEPTION(EXCEPTION_ILLEGAL_INSTRUCTION, "The thread tried to execute an invalid instruction.");
107  LOG_EXCEPTION(EXCEPTION_IN_PAGE_ERROR, "The thread tried to access a page that was not present, and the system was unable to load the page.");
108  LOG_EXCEPTION(EXCEPTION_NONCONTINUABLE_EXCEPTION, "The thread tried to continue execution after a noncontinuable exception occurred.");
109  LOG_EXCEPTION(EXCEPTION_PRIV_INSTRUCTION, "The thread tried to execute an instruction whose operation is not allowed in the current machine mode.");
110  LOG_EXCEPTION(EXCEPTION_STACK_OVERFLOW, "The thread used up its stack.");
111  LOG_EXCEPTION(EXCEPTION_GUARD_PAGE, "The thread accessed memory allocated with the PAGE_GUARD modifier.");
112  LOG_EXCEPTION(STATUS_ASSERTION_FAILURE, "The thread specified a pre- or postcondition that did not hold.");
113 #undef LOG_EXCEPTION
114  default:
115  LOG_DYNAMIC_TEXT("%#08x: The thread raised an unknown exception.\n", static_cast<unsigned int>(exc->ExceptionRecord->ExceptionCode));
116  break;
117  }
118  if (exc->ExceptionRecord->ExceptionFlags == EXCEPTION_NONCONTINUABLE)
119  LOG_STATIC_TEXT("This is a non-continuable exception.\n");
120  else
121  LOG_STATIC_TEXT("This is a continuable exception.\n");
122 
123  // For some exceptions, there is a defined meaning to the ExceptionInformation field
124  switch (exc->ExceptionRecord->ExceptionCode)
125  {
126  case EXCEPTION_ACCESS_VIOLATION:
127  case EXCEPTION_IN_PAGE_ERROR:
128  if (exc->ExceptionRecord->NumberParameters < 2)
129  {
130  LOG_STATIC_TEXT("Additional information for the exception was not provided.\n");
131  break;
132  }
133  LOG_STATIC_TEXT("Additional information for the exception: The thread ");
134  switch (exc->ExceptionRecord->ExceptionInformation[0])
135  {
136 #ifndef EXCEPTION_READ_FAULT
137 # define EXCEPTION_READ_FAULT 0
138 # define EXCEPTION_WRITE_FAULT 1
139 # define EXCEPTION_EXECUTE_FAULT 8
140 #endif
141  case EXCEPTION_READ_FAULT: LOG_STATIC_TEXT("tried to read from memory"); break;
142  case EXCEPTION_WRITE_FAULT: LOG_STATIC_TEXT("tried to write to memory"); break;
143  case EXCEPTION_EXECUTE_FAULT: LOG_STATIC_TEXT("caused an user-mode DEP violation"); break;
144  default: LOG_DYNAMIC_TEXT("tried to access (%#x) memory", static_cast<unsigned int>(exc->ExceptionRecord->ExceptionInformation[0])); break;
145  }
146  LOG_DYNAMIC_TEXT(" at address " POINTER_FORMAT ".\n", static_cast<size_t>(exc->ExceptionRecord->ExceptionInformation[1]));
147  if (exc->ExceptionRecord->ExceptionCode == EXCEPTION_IN_PAGE_ERROR)
148  {
149  if (exc->ExceptionRecord->NumberParameters >= 3)
150  LOG_DYNAMIC_TEXT("The NTSTATUS code that resulted in this exception was " POINTER_FORMAT ".\n", static_cast<size_t>(exc->ExceptionRecord->ExceptionInformation[2]));
151  else
152  LOG_STATIC_TEXT("The NTSTATUS code that resulted in this exception was not provided.\n");
153  }
154  break;
155 
156  case STATUS_ASSERTION_FAILURE:
157  if (exc->ExceptionRecord->NumberParameters < 3)
158  {
159  LOG_STATIC_TEXT("Additional information for the exception was not provided.\n");
160  break;
161  }
162 #ifdef USE_WIDE_ASSERT
163 # define ASSERTION_INFO_FORMAT "%ls"
164 # define ASSERTION_INFO_TYPE wchar_t *
165 #else
166 # define ASSERTION_INFO_FORMAT "%s"
167 # define ASSERTION_INFO_TYPE char *
168 #endif
169  LOG_DYNAMIC_TEXT("Additional information for the exception:\n Assertion that failed: " ASSERTION_INFO_FORMAT "\n File: " ASSERTION_INFO_FORMAT "\n Line: %d\n",
170  reinterpret_cast<ASSERTION_INFO_TYPE>(exc->ExceptionRecord->ExceptionInformation[0]),
171  reinterpret_cast<ASSERTION_INFO_TYPE>(exc->ExceptionRecord->ExceptionInformation[1]),
172  (int) exc->ExceptionRecord->ExceptionInformation[2]);
173  break;
174  }
175 
176  // Dump registers
177 #if OC_MACHINE == OC_MACHINE_X64
178  LOG_STATIC_TEXT("\nProcessor registers (x86_64):\n");
179  LOG_DYNAMIC_TEXT("RAX: " POINTER_FORMAT ", RBX: " POINTER_FORMAT ", RCX: " POINTER_FORMAT ", RDX: " POINTER_FORMAT "\n",
180  static_cast<size_t>(exc->ContextRecord->Rax), static_cast<size_t>(exc->ContextRecord->Rbx),
181  static_cast<size_t>(exc->ContextRecord->Rcx), static_cast<size_t>(exc->ContextRecord->Rdx));
182  LOG_DYNAMIC_TEXT("RBP: " POINTER_FORMAT ", RSI: " POINTER_FORMAT ", RDI: " POINTER_FORMAT ", R8: " POINTER_FORMAT "\n",
183  static_cast<size_t>(exc->ContextRecord->Rbp), static_cast<size_t>(exc->ContextRecord->Rsi),
184  static_cast<size_t>(exc->ContextRecord->Rdi), static_cast<size_t>(exc->ContextRecord->R8));
185  LOG_DYNAMIC_TEXT(" R9: " POINTER_FORMAT ", R10: " POINTER_FORMAT ", R11: " POINTER_FORMAT ", R12: " POINTER_FORMAT "\n",
186  static_cast<size_t>(exc->ContextRecord->R9), static_cast<size_t>(exc->ContextRecord->R10),
187  static_cast<size_t>(exc->ContextRecord->R11), static_cast<size_t>(exc->ContextRecord->R12));
188  LOG_DYNAMIC_TEXT("R13: " POINTER_FORMAT ", R14: " POINTER_FORMAT ", R15: " POINTER_FORMAT "\n",
189  static_cast<size_t>(exc->ContextRecord->R13), static_cast<size_t>(exc->ContextRecord->R14),
190  static_cast<size_t>(exc->ContextRecord->R15));
191  LOG_DYNAMIC_TEXT("RSP: " POINTER_FORMAT ", RIP: " POINTER_FORMAT "\n",
192  static_cast<size_t>(exc->ContextRecord->Rsp), static_cast<size_t>(exc->ContextRecord->Rip));
193 #elif OC_MACHINE == OC_MACHINE_X86
194  LOG_STATIC_TEXT("\nProcessor registers (x86):\n");
195  LOG_DYNAMIC_TEXT("EAX: " POINTER_FORMAT ", EBX: " POINTER_FORMAT ", ECX: " POINTER_FORMAT ", EDX: " POINTER_FORMAT "\n",
196  static_cast<size_t>(exc->ContextRecord->Eax), static_cast<size_t>(exc->ContextRecord->Ebx),
197  static_cast<size_t>(exc->ContextRecord->Ecx), static_cast<size_t>(exc->ContextRecord->Edx));
198  LOG_DYNAMIC_TEXT("ESI: " POINTER_FORMAT ", EDI: " POINTER_FORMAT "\n",
199  static_cast<size_t>(exc->ContextRecord->Esi), static_cast<size_t>(exc->ContextRecord->Edi));
200  LOG_DYNAMIC_TEXT("EBP: " POINTER_FORMAT ", ESP: " POINTER_FORMAT ", EIP: " POINTER_FORMAT "\n",
201  static_cast<size_t>(exc->ContextRecord->Ebp), static_cast<size_t>(exc->ContextRecord->Esp),
202  static_cast<size_t>(exc->ContextRecord->Eip));
203 #endif
204 #if OC_MACHINE == OC_MACHINE_X64 || OC_MACHINE == OC_MACHINE_X86
205  LOG_DYNAMIC_TEXT("EFLAGS: 0x%08x (%c%c%c%c%c%c%c)\n", static_cast<unsigned int>(exc->ContextRecord->EFlags),
206  exc->ContextRecord->EFlags & 0x800 ? 'O' : '.', // overflow
207  exc->ContextRecord->EFlags & 0x400 ? 'D' : '.', // direction
208  exc->ContextRecord->EFlags & 0x80 ? 'S' : '.', // sign
209  exc->ContextRecord->EFlags & 0x40 ? 'Z' : '.', // zero
210  exc->ContextRecord->EFlags & 0x10 ? 'A' : '.', // auxiliary carry
211  exc->ContextRecord->EFlags & 0x4 ? 'P' : '.', // parity
212  exc->ContextRecord->EFlags & 0x1 ? 'C' : '.'); // carry
213 #endif
214 
215  // Dump stack
216  LOG_STATIC_TEXT("\nStack contents:\n");
217  MEMORY_BASIC_INFORMATION stack_info;
218  intptr_t stack_pointer =
219 #if OC_MACHINE == OC_MACHINE_X64
220  exc->ContextRecord->Rsp
221 #elif OC_MACHINE == OC_MACHINE_X86
222  exc->ContextRecord->Esp
223 #endif
224  ;
225  if (VirtualQuery(reinterpret_cast<LPCVOID>(stack_pointer), &stack_info, sizeof(stack_info)))
226  {
227  intptr_t stack_base = reinterpret_cast<intptr_t>(stack_info.BaseAddress);
228  intptr_t dump_min = std::max<intptr_t>(stack_base, (stack_pointer - 256) & ~0xF);
229  intptr_t dump_max = std::min<intptr_t>(stack_base + stack_info.RegionSize, (stack_pointer + 256) | 0xF);
230 
231  for (intptr_t dump_row_base = dump_min & ~0xF; dump_row_base < dump_max; dump_row_base += 0x10)
232  {
233  LOG_DYNAMIC_TEXT(POINTER_FORMAT ": ", dump_row_base);
234  // Hex dump
235  for (intptr_t dump_row_cursor = dump_row_base; dump_row_cursor < dump_row_base + 16; ++dump_row_cursor)
236  {
237  if (dump_row_cursor < dump_min || dump_row_cursor > dump_max)
238  LOG_STATIC_TEXT(" ");
239  else
240  LOG_DYNAMIC_TEXT("%02x ", (unsigned int)*reinterpret_cast<unsigned char*>(dump_row_cursor)); // Safe, since it's inside the VM of our process
241  }
242  LOG_STATIC_TEXT(" ");
243  // Text dump
244  for (intptr_t dump_row_cursor = dump_row_base; dump_row_cursor < dump_row_base + 16; ++dump_row_cursor)
245  {
246  if (dump_row_cursor < dump_min || dump_row_cursor > dump_max)
247  LOG_STATIC_TEXT(" ");
248  else
249  {
250  unsigned char c = *reinterpret_cast<unsigned char*>(dump_row_cursor); // Safe, since it's inside the VM of our process
251  if (c < 0x20 || (c > 0x7e && c < 0xa1))
252  LOG_STATIC_TEXT(".");
253  else
254  LOG_DYNAMIC_TEXT("%c", static_cast<char>(c));
255  }
256  }
257  LOG_STATIC_TEXT("\n");
258  }
259  }
260  else
261  {
262  LOG_STATIC_TEXT("[Failed to access stack memory]\n");
263  }
264 
265  // Initialize DbgHelp.dll symbol functions
266  SymSetOptions(SYMOPT_UNDNAME | SYMOPT_DEFERRED_LOADS | SYMOPT_LOAD_LINES);
267  HANDLE process = GetCurrentProcess();
268  if (SymInitialize(process, nullptr, true))
269  {
270  LOG_STATIC_TEXT("\nStack trace:\n");
271  auto frame = STACKFRAME64();
272  DWORD image_type;
273  CONTEXT context = *exc->ContextRecord;
274  // Setup frame info
275  frame.AddrPC.Mode = AddrModeFlat;
276  frame.AddrStack.Mode = AddrModeFlat;
277  frame.AddrFrame.Mode = AddrModeFlat;
278 #if OC_MACHINE == OC_MACHINE_X64
279  image_type = IMAGE_FILE_MACHINE_AMD64;
280  frame.AddrPC.Offset = context.Rip;
281  frame.AddrStack.Offset = context.Rsp;
282  // Some compilers use rdi for their frame pointer instead. Let's hope they're in the minority.
283  frame.AddrFrame.Offset = context.Rbp;
284 #elif OC_MACHINE == OC_MACHINE_X86
285  image_type = IMAGE_FILE_MACHINE_I386;
286  frame.AddrPC.Offset = context.Eip;
287  frame.AddrStack.Offset = context.Esp;
288  frame.AddrFrame.Offset = context.Ebp;
289 #endif
290  // Dump stack trace
291  SYMBOL_INFO *symbol = reinterpret_cast<SYMBOL_INFO*>(SymbolBuffer);
292  static_assert(DumpBufferSize >= sizeof(*symbol), "SYMBOL_INFO too large to fit into buffer");
293  IMAGEHLP_MODULE64 *module = reinterpret_cast<IMAGEHLP_MODULE64*>(SymbolBuffer);
294  static_assert(DumpBufferSize >= sizeof(*module), "IMAGEHLP_MODULE64 too large to fit into buffer");
295  IMAGEHLP_LINE64 *line = reinterpret_cast<IMAGEHLP_LINE64*>(SymbolBuffer);
296  static_assert(DumpBufferSize >= sizeof(*line), "IMAGEHLP_LINE64 too large to fit into buffer");
297  int frame_number = 0;
298  while (StackWalk64(image_type, process, GetCurrentThread(), &frame, &context, nullptr, SymFunctionTableAccess64, SymGetModuleBase64, nullptr))
299  {
300  LOG_DYNAMIC_TEXT("#%3d ", frame_number);
301  module->SizeOfStruct = sizeof(*module);
302  DWORD64 image_base = 0;
303  if (SymGetModuleInfo64(process, frame.AddrPC.Offset, module))
304  {
305  LOG_DYNAMIC_TEXT("%s", module->ModuleName);
306  image_base = module->BaseOfImage;
307  }
308  DWORD64 disp64;
309  symbol->MaxNameLen = DumpBufferSize - sizeof(*symbol);
310  symbol->SizeOfStruct = sizeof(*symbol);
311  if (SymFromAddr(process, frame.AddrPC.Offset, &disp64, symbol))
312  {
313  LOG_DYNAMIC_TEXT("!%s+%#lx", symbol->Name, static_cast<long>(disp64));
314  }
315  else if (image_base > 0)
316  {
317  LOG_DYNAMIC_TEXT("+%#lx", static_cast<long>(frame.AddrPC.Offset - image_base));
318  }
319  else
320  {
321  LOG_DYNAMIC_TEXT("%#lx", static_cast<long>(frame.AddrPC.Offset));
322  }
323  DWORD disp;
324  line->SizeOfStruct = sizeof(*line);
325  if (SymGetLineFromAddr64(process, frame.AddrPC.Offset, &disp, line))
326  {
327  LOG_DYNAMIC_TEXT(" [%s @ %u]", line->FileName, static_cast<unsigned int>(line->LineNumber));
328  }
329  LOG_STATIC_TEXT("\n");
330  ++frame_number;
331  }
332  SymCleanup(process);
333  }
334  else
335  {
336  LOG_STATIC_TEXT("[Stack trace not available: failed to initialize Debugging Help Library]\n");
337  }
338 
339  // Dump loaded modules
340  HANDLE snapshot;
341  while((snapshot = CreateToolhelp32Snapshot(TH32CS_SNAPMODULE, 0)) == INVALID_HANDLE_VALUE)
342  if (GetLastError() != ERROR_BAD_LENGTH) break;
343  if (snapshot != INVALID_HANDLE_VALUE)
344  {
345  LOG_STATIC_TEXT("\nLoaded modules:\n");
346  MODULEENTRY32 *module = reinterpret_cast<MODULEENTRY32*>(SymbolBuffer);
347  static_assert(DumpBufferSize >= sizeof(*module), "MODULEENTRY32 too large to fit into buffer");
348  module->dwSize = sizeof(*module);
349  for (BOOL success = Module32First(snapshot, module); success; success = Module32Next(snapshot, module))
350  {
351  LOG_DYNAMIC_TEXT("%32ls loaded at " POINTER_FORMAT " - " POINTER_FORMAT " (%ls)\n", module->szModule,
352  reinterpret_cast<size_t>(module->modBaseAddr), reinterpret_cast<size_t>(module->modBaseAddr + module->modBaseSize),
353  module->szExePath);
354  }
355  CloseHandle(snapshot);
356  }
357 #undef POINTER_FORMAT_SUFFIX
358 #undef POINTER_FORMAT
359 #undef LOG_SNPRINTF
360 #undef LOG_DYNAMIC_TEXT
361 #undef LOG_STATIC_TEXT
362  }
363 }
364 LONG WINAPI GenerateDump(EXCEPTION_POINTERS* pExceptionPointers)
365 {
366  enum
367  {
368  MDST_BuildId = LastReservedStream + 1
369  };
370 
371  if (!FirstCrash) return EXCEPTION_EXECUTE_HANDLER;
372  FirstCrash = false;
373 
374  // Open dump file
375  // Work on the assumption that the config isn't corrupted
376  wchar_t *filename = reinterpret_cast<wchar_t*>(DumpBuffer);
377  const size_t filename_buffer_size = DumpBufferSize / sizeof(wchar_t);
378  if (!MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, ::Config.General.UserDataPath, strnlen(::Config.General.UserDataPath, sizeof(::Config.General.UserDataPath)), filename, filename_buffer_size))
379  {
380  // Conversion failed; the likely reason for this is a corrupted config.
381  assert (GetLastError() == ERROR_NO_UNICODE_TRANSLATION);
382  // Fall back to the temporary files directory to write dump.
383  DWORD temp_size = GetTempPath(filename_buffer_size, filename);
384  if (temp_size == 0 || temp_size > filename_buffer_size)
385  {
386  // Getting the temp path failed as well; dump to current working directory as a last resort.
387  temp_size = GetCurrentDirectory(filename_buffer_size, filename);
388  if (temp_size == 0 || temp_size > filename_buffer_size)
389  {
390  // We don't really have any directory where we can store the dump, so just
391  // write the text log (we already have a FD for that)
392  filename[0] = L'\0';
393  }
394  }
395  }
396  HANDLE file = INVALID_HANDLE_VALUE;
397 
398  if (filename[0] != L'\0')
399  {
400  // There is some path where we want to store our data
401  const wchar_t tmpl[] = TEXT(C4ENGINENICK) L"-crash-YYYY-MM-DD-HH-MM-SS.dmp";
402  size_t path_len = wcslen(filename);
403  if (path_len + sizeof(tmpl) / sizeof(*tmpl) > filename_buffer_size)
404  {
405  // Somehow the length of the required path is too long to fit in
406  // our buffer. Don't dump anything then.
407  filename[0] = L'\0';
408  }
409  else
410  {
411  // Make sure the path ends in a backslash.
412  if (filename[path_len - 1] != L'\\')
413  {
414  filename[path_len] = L'\\';
415  filename[++path_len] = L'\0';
416  }
417  SYSTEMTIME st;
418  GetSystemTime(&st);
419  wsprintf(&filename[path_len], L"%s-crash-%04d-%02d-%02d-%02d-%02d-%02d.dmp",
420  TEXT(C4ENGINENICK), st.wYear, st.wMonth, st.wDay, st.wHour, st.wMinute, st.wSecond);
421  }
422  }
423 
424  if (filename[0] != L'\0')
425  {
426  file = CreateFile(filename, GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_DELETE, nullptr, CREATE_NEW, FILE_ATTRIBUTE_NORMAL, nullptr);
427  // If we can't create a *new* file to dump into, don't dump at all.
428  if (file == INVALID_HANDLE_VALUE)
429  filename[0] = L'\0';
430  }
431 
432  // Write dump (human readable format)
433  if (GetLogFD() != -1)
434  SafeTextDump(pExceptionPointers, GetLogFD(), filename);
435 
436  if (file != INVALID_HANDLE_VALUE)
437  {
438  auto user_stream_info = MINIDUMP_USER_STREAM_INFORMATION();
439  auto user_stream = MINIDUMP_USER_STREAM();
440  char build_id[] = OC_BUILD_ID;
441  if (OC_BUILD_ID[0] != '\0')
442  {
443  user_stream.Type = MDST_BuildId;
444  user_stream.Buffer = build_id;
445  user_stream.BufferSize = sizeof(build_id) - 1; // don't need the terminating NUL
446  user_stream_info.UserStreamCount = 1;
447  user_stream_info.UserStreamArray = &user_stream;
448  }
449 
450  MINIDUMP_EXCEPTION_INFORMATION ExpParam;
451  ExpParam.ThreadId = GetCurrentThreadId();
452  ExpParam.ExceptionPointers = pExceptionPointers;
453  ExpParam.ClientPointers = true;
454  MiniDumpWriteDump(GetCurrentProcess(), GetCurrentProcessId(),
455  file, MiniDumpNormal, &ExpParam, &user_stream_info, nullptr);
456  CloseHandle(file);
457  }
458 
459  // Pass exception
460  return EXCEPTION_EXECUTE_HANDLER;
461 }
462 
463 #ifndef NDEBUG
464 namespace {
465  // Assertion logging hook. This will replace the prologue of the standard assertion
466  // handler with a trampoline to assertion_handler(), which logs the assertion, then
467  // replaces the trampoline with the original prologue, and calls the handler.
468  // If the standard handler returns control to assertion_handler(), it will then
469  // restore the hook.
470 #ifdef USE_WIDE_ASSERT
471  typedef void (__cdecl *ASSERT_FUNC)(const wchar_t *, const wchar_t *, unsigned);
472  const ASSERT_FUNC assert_func =
473  &_wassert;
474 #else
475  typedef void (__cdecl *ASSERT_FUNC)(const char *, const char *, int);
476  const ASSERT_FUNC assert_func =
477  &_assert;
478 #endif
479  unsigned char trampoline[] = {
480 #if OC_MACHINE == OC_MACHINE_X64
481  // MOV rax, 0xCCCCCCCCCCCCCCCC
482  0x48 /* REX.W */, 0xB8, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC, 0xCC,
483  // JMP rax
484  0xFF, 0xE0
485 #elif OC_MACHINE == OC_MACHINE_X86
486  // NOP ; to align jump target
487  0x90,
488  // MOV eax, 0xCCCCCCCC
489  0xB8, 0xCC, 0xCC, 0xCC, 0xCC,
490  // JMP eax
491  0xFF, 0xE0
492 #endif
493  };
494  unsigned char trampoline_backup[sizeof(trampoline)];
495  void HookAssert(ASSERT_FUNC hook)
496  {
497  // Write hook function address to trampoline
498  memcpy(trampoline + 2, (void*)&hook, sizeof(void*));
499  // Make target location writable
500  DWORD old_protect = 0;
501  if (!VirtualProtect((LPVOID)assert_func, sizeof(trampoline), PAGE_EXECUTE_READWRITE, &old_protect))
502  return;
503  // Take backup of old target function and replace it with trampoline
504  memcpy(trampoline_backup, (void*)assert_func, sizeof(trampoline_backup));
505  memcpy((void*)assert_func, trampoline, sizeof(trampoline));
506  // Restore memory protection
507  VirtualProtect((LPVOID)assert_func, sizeof(trampoline), old_protect, &old_protect);
508  // Flush processor caches. Not strictly necessary on x86 and x64.
509  FlushInstructionCache(GetCurrentProcess(), (LPCVOID)assert_func, sizeof(trampoline));
510  }
511  void UnhookAssert()
512  {
513  DWORD old_protect = 0;
514  if (!VirtualProtect((LPVOID)assert_func, sizeof(trampoline_backup), PAGE_EXECUTE_READWRITE, &old_protect))
515  // Couldn't make assert function writable. Abort program (it's what assert() is supposed to do anyway).
516  abort();
517  // Replace function with backup
518  memcpy((void*)assert_func, trampoline_backup, sizeof(trampoline_backup));
519  VirtualProtect((LPVOID)assert_func, sizeof(trampoline_backup), old_protect, &old_protect);
520  FlushInstructionCache(GetCurrentProcess(), (LPCVOID)assert_func, sizeof(trampoline_backup));
521  }
522 
523  struct dump_thread_t {
524  HANDLE thread;
525 #ifdef USE_WIDE_ASSERT
526  const wchar_t
527 #else
528  const char
529 #endif
530  *expression, *file;
531  size_t line;
532  };
533  // Helper function to get a valid thread context for the main thread
534  static DWORD WINAPI dump_thread(LPVOID t)
535  {
536  dump_thread_t *data = static_cast<dump_thread_t*>(t);
537 
538  // Stop calling thread so we can take a snapshot
539  if (SuspendThread(data->thread) == -1)
540  return FALSE;
541 
542  // Get thread info
543  auto ctx = CONTEXT();
544 #ifndef CONTEXT_ALL
545 #define CONTEXT_ALL (CONTEXT_CONTROL | CONTEXT_INTEGER | CONTEXT_SEGMENTS | \
546  CONTEXT_FLOATING_POINT | CONTEXT_DEBUG_REGISTERS | CONTEXT_EXTENDED_REGISTERS)
547 #endif
548  ctx.ContextFlags = CONTEXT_ALL;
549  BOOL result = GetThreadContext(data->thread, &ctx);
550 
551  // Setup a fake exception to log
552  auto erec = EXCEPTION_RECORD();
553  erec.ExceptionCode = STATUS_ASSERTION_FAILURE;
554  erec.ExceptionFlags = 0L;
555  erec.ExceptionInformation[0] = (ULONG_PTR)data->expression;
556  erec.ExceptionInformation[1] = (ULONG_PTR)data->file;
557  erec.ExceptionInformation[2] = (ULONG_PTR)data->line;
558  erec.NumberParameters = 3;
559 
560  erec.ExceptionAddress = (LPVOID)
561 #if OC_MACHINE == OC_MACHINE_X64
562  ctx.Rip
563 #elif OC_MACHINE == OC_MACHINE_X86
564  ctx.Eip
565 #else
566  0
567 #endif
568  ;
569  EXCEPTION_POINTERS eptr;
570  eptr.ContextRecord = &ctx;
571  eptr.ExceptionRecord = &erec;
572 
573  // Log
574  if (GetLogFD() != -1)
575  SafeTextDump(&eptr, GetLogFD(), nullptr);
576 
577  // Continue caller
578  if (ResumeThread(data->thread) == -1)
579  abort();
580  return result;
581  }
582 
583  // Replacement assertion handler
584 #ifdef USE_WIDE_ASSERT
585  void __cdecl assertion_handler(const wchar_t *expression, const wchar_t *file, unsigned line)
586 #else
587  void __cdecl assertion_handler(const char *expression, const char *file, int line)
588 #endif
589  {
590  // Dump thread status on a different thread because we can't get a valid thread context otherwise
591  HANDLE this_thread;
592  DuplicateHandle(GetCurrentProcess(), GetCurrentThread(), GetCurrentProcess(), &this_thread, 0, FALSE, DUPLICATE_SAME_ACCESS);
593  dump_thread_t dump_thread_data = {
594  this_thread,
595  expression, file, line
596  };
597  HANDLE ctx_thread = CreateThread(nullptr, 0L, &dump_thread, &dump_thread_data, 0L, nullptr);
598  WaitForSingleObject(ctx_thread, INFINITE);
599  CloseHandle(this_thread);
600  CloseHandle(ctx_thread);
601  // Unhook _wassert/_assert
602  UnhookAssert();
603  // Call old _wassert/_assert
604  assert_func(expression, file, line);
605  // If we get here: rehook
606  HookAssert(&assertion_handler);
607  }
608 }
609 #endif
610 
611 void InstallCrashHandler()
612 {
613  // Disable process-wide callback filter for exceptions on Windows Vista.
614  // Newer versions of Windows already get this disabled by the application
615  // manifest. Without turning this off, we won't be able to handle crashes
616  // inside window procedures on 64-bit Windows, regardless of whether we
617  // are 32 or 64 bit ourselves.
618  typedef BOOL (WINAPI *SetProcessUserModeExceptionPolicyProc)(DWORD);
619  typedef BOOL (WINAPI *GetProcessUserModeExceptionPolicyProc)(LPDWORD);
620  HMODULE kernel32 = LoadLibrary(TEXT("kernel32"));
621  const SetProcessUserModeExceptionPolicyProc SetProcessUserModeExceptionPolicy =
622  (SetProcessUserModeExceptionPolicyProc)GetProcAddress(kernel32, "SetProcessUserModeExceptionPolicy");
623  const GetProcessUserModeExceptionPolicyProc GetProcessUserModeExceptionPolicy =
624  (GetProcessUserModeExceptionPolicyProc)GetProcAddress(kernel32, "GetProcessUserModeExceptionPolicy");
625 #ifndef PROCESS_CALLBACK_FILTER_ENABLED
626 # define PROCESS_CALLBACK_FILTER_ENABLED 0x1
627 #endif
628  if (SetProcessUserModeExceptionPolicy && GetProcessUserModeExceptionPolicy)
629  {
630  DWORD flags;
631  if (GetProcessUserModeExceptionPolicy(&flags))
632  {
633  SetProcessUserModeExceptionPolicy(flags & ~PROCESS_CALLBACK_FILTER_ENABLED);
634  }
635  }
636  FreeLibrary(kernel32);
637 
638  SetUnhandledExceptionFilter(GenerateDump);
639 
640 #ifndef NDEBUG
641  // Hook _wassert/_assert, unless we're running under a debugger
642  if (!IsDebuggerPresent())
643  HookAssert(&assertion_handler);
644 #endif
645 }
646 
647 #else
648 
650 {
651  // no-op
652 }
653 
654 #endif // HAVE_DBGHELP
C4Config Config
Definition: C4Config.cpp:833
C4ConfigGeneral General
Definition: C4Config.h:251
int GetLogFD()
Definition: C4Log.cpp:116
char UserDataPath[CFG_MaxString+1]
Definition: C4Config.h:54
#define INFINITE
Definition: StdSync.h:58
uint32_t DWORD
void InstallCrashHandler()