2 * Win32 exception functions
4 * Copyright (c) 1996 Onno Hovers, (onno@stack.urc.tue.nl)
5 * Copyright (c) 1999 Alexandre Julliard
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
22 * What really happens behind the scenes of those new
23 * __try{...}__except(..){....} and
24 * __try{...}__finally{...}
25 * statements is simply not documented by Microsoft. There could be different
27 * One reason could be that they try to hide the fact that exception
28 * handling in Win32 looks almost the same as in OS/2 2.x.
29 * Another reason could be that Microsoft does not want others to write
30 * binary compatible implementations of the Win32 API (like us).
32 * Whatever the reason, THIS SUCKS!! Ensuring portability or future
33 * compatibility may be valid reasons to keep some things undocumented.
34 * But exception handling is so basic to Win32 that it should be
39 #include "wine/port.h"
44 #define WIN32_NO_STATUS
51 #include "wine/exception.h"
52 #include "wine/library.h"
54 #include "wine/unicode.h"
55 #include "wine/debug.h"
57 WINE_DEFAULT_DEBUG_CHANNEL(seh);
59 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
61 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
62 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
64 /*******************************************************************
65 * RaiseException (KERNEL32.@)
67 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const ULONG_PTR *args )
69 EXCEPTION_RECORD record;
71 /* Compose an exception record */
73 record.ExceptionCode = code;
74 record.ExceptionFlags = flags & EH_NONCONTINUABLE;
75 record.ExceptionRecord = NULL;
76 record.ExceptionAddress = RaiseException;
79 if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
80 record.NumberParameters = nbargs;
81 memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
83 else record.NumberParameters = 0;
85 RtlRaiseException( &record );
89 /*******************************************************************
90 * format_exception_msg
92 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
94 const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
97 switch(rec->ExceptionCode)
99 case EXCEPTION_INT_DIVIDE_BY_ZERO:
100 len = snprintf( buffer, size, "Unhandled division by zero" );
102 case EXCEPTION_INT_OVERFLOW:
103 len = snprintf( buffer, size, "Unhandled overflow" );
105 case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
106 len = snprintf( buffer, size, "Unhandled array bounds" );
108 case EXCEPTION_ILLEGAL_INSTRUCTION:
109 len = snprintf( buffer, size, "Unhandled illegal instruction" );
111 case EXCEPTION_STACK_OVERFLOW:
112 len = snprintf( buffer, size, "Unhandled stack overflow" );
114 case EXCEPTION_PRIV_INSTRUCTION:
115 len = snprintf( buffer, size, "Unhandled privileged instruction" );
117 case EXCEPTION_ACCESS_VIOLATION:
118 if (rec->NumberParameters == 2)
119 len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
120 rec->ExceptionInformation[0] ? "write" : "read",
121 rec->ExceptionInformation[1]);
123 len = snprintf( buffer, size, "Unhandled page fault");
125 case EXCEPTION_DATATYPE_MISALIGNMENT:
126 len = snprintf( buffer, size, "Unhandled alignment" );
129 len = snprintf( buffer, size, "Unhandled ^C");
131 case STATUS_POSSIBLE_DEADLOCK:
132 len = snprintf( buffer, size, "Critical section %08lx wait failed",
133 rec->ExceptionInformation[0]);
135 case EXCEPTION_WINE_STUB:
136 if (HIWORD(rec->ExceptionInformation[1]))
137 len = snprintf( buffer, size, "Unimplemented function %s.%s called",
138 (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
140 len = snprintf( buffer, size, "Unimplemented function %s.%ld called",
141 (char *)rec->ExceptionInformation[0], rec->ExceptionInformation[1] );
143 case EXCEPTION_WINE_ASSERTION:
144 len = snprintf( buffer, size, "Assertion failed" );
146 case EXCEPTION_VM86_INTx:
147 len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
148 rec->ExceptionInformation[0]);
150 case EXCEPTION_VM86_STI:
151 len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
153 case EXCEPTION_VM86_PICRETURN:
154 len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
157 len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
160 if ((len<0) || (len>=size))
163 if (ptr->ContextRecord->SegCs != wine_get_cs())
164 len2 = snprintf(buffer+len, size-len, " at address 0x%04lx:0x%08lx",
165 ptr->ContextRecord->SegCs,
166 (DWORD)ptr->ExceptionRecord->ExceptionAddress);
169 len2 = snprintf(buffer+len, size-len, " at address %p",
170 ptr->ExceptionRecord->ExceptionAddress);
171 if ((len2<0) || (len>=size-len))
177 /******************************************************************
180 * Does the effective debugger startup according to 'format'
182 static BOOL start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
184 OBJECT_ATTRIBUTES attr;
185 UNICODE_STRING nameW;
186 char *cmdline, *env, *p;
189 PROCESS_INFORMATION info;
190 STARTUPINFOA startup;
195 static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
196 'S','o','f','t','w','a','r','e','\\',
197 'M','i','c','r','o','s','o','f','t','\\',
198 'W','i','n','d','o','w','s',' ','N','T','\\',
199 'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
200 'A','e','D','e','b','u','g',0};
201 static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
202 static const WCHAR AutoW[] = {'A','u','t','o',0};
204 format_exception_msg( epointers, buffer, sizeof(buffer) );
205 MESSAGE("wine: %s (thread %04lx), starting debugger...\n", buffer, GetCurrentThreadId());
207 attr.Length = sizeof(attr);
208 attr.RootDirectory = 0;
209 attr.ObjectName = &nameW;
211 attr.SecurityDescriptor = NULL;
212 attr.SecurityQualityOfService = NULL;
213 RtlInitUnicodeString( &nameW, AeDebugW );
215 if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
218 KEY_VALUE_PARTIAL_INFORMATION *info;
219 DWORD format_size = 0;
221 RtlInitUnicodeString( &nameW, DebuggerW );
222 if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
223 NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
225 char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
226 NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
227 data, format_size, &format_size );
228 info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
229 RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
230 format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
231 RtlUnicodeToMultiByteN( format, format_size, NULL,
232 (WCHAR *)info->Data, info->DataLength );
233 format[format_size] = 0;
235 if (info->Type == REG_EXPAND_SZ)
239 /* Expand environment variable references */
240 format_size=ExpandEnvironmentStringsA(format,NULL,0);
241 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
242 ExpandEnvironmentStringsA(format,tmp,format_size);
243 HeapFree(GetProcessHeap(), 0, format);
246 HeapFree( GetProcessHeap(), 0, data );
249 RtlInitUnicodeString( &nameW, AutoW );
250 if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
251 buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
253 info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
254 if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
255 else if (info->Type == REG_SZ)
257 WCHAR *str = (WCHAR *)info->Data;
258 str[info->DataLength/sizeof(WCHAR)] = 0;
259 bAuto = atoiW( str );
269 cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
270 sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
271 HeapFree(GetProcessHeap(), 0, format);
275 cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
276 sprintf(cmdline, "winedbg --auto %ld %ld",
277 GetCurrentProcessId(), (ULONG_PTR)hEvent);
282 HMODULE mod = GetModuleHandleA( "user32.dll" );
283 MessageBoxA_funcptr pMessageBoxA = NULL;
285 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
288 static const char msg[] = ".\nDo you wish to debug it?";
291 format_exception_msg( epointers, buffer, sizeof(buffer)-sizeof(msg) );
292 strcat( buffer, msg );
293 if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
295 TRACE("Killing process\n");
301 /* make WINEDEBUG empty in the environment */
302 env = GetEnvironmentStringsA();
303 for (p = env; *p; p += strlen(p) + 1)
305 if (!memcmp( p, "WINEDEBUG=", sizeof("WINEDEBUG=")-1 ))
307 char *next = p + strlen(p);
308 char *end = next + 1;
309 while (*end) end += strlen(end) + 1;
310 memmove( p + sizeof("WINEDEBUG=") - 1, next, end + 1 - next );
315 TRACE("Starting debugger %s\n", debugstr_a(cmdline));
316 memset(&startup, 0, sizeof(startup));
317 startup.cb = sizeof(startup);
318 startup.dwFlags = STARTF_USESHOWWINDOW;
319 startup.wShowWindow = SW_SHOWNORMAL;
320 ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, env, NULL, &startup, &info);
321 FreeEnvironmentStringsA( env );
323 if (ret) WaitForSingleObject(hEvent, INFINITE); /* wait for debugger to come up... */
324 else ERR("Couldn't start debugger (%s) (%ld)\n"
325 "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
326 debugstr_a(cmdline), GetLastError());
328 HeapFree(GetProcessHeap(), 0, cmdline);
332 /******************************************************************
333 * start_debugger_atomic
335 * starts the debugger in an atomic way:
336 * - either the debugger is not started and it is started
337 * - or the debugger has already been started by another thread
338 * - or the debugger couldn't be started
340 * returns TRUE for the two first conditions, FALSE for the last
342 static int start_debugger_atomic(PEXCEPTION_POINTERS epointers)
344 static HANDLE hRunOnce /* = 0 */;
348 OBJECT_ATTRIBUTES attr;
351 attr.Length = sizeof(attr);
352 attr.RootDirectory = 0;
353 attr.Attributes = OBJ_INHERIT;
354 attr.ObjectName = NULL;
355 attr.SecurityDescriptor = NULL;
356 attr.SecurityQualityOfService = NULL;
358 /* ask for manual reset, so that once the debugger is started,
359 * every thread will know it */
360 NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
361 if (InterlockedCompareExchangePointer( (PVOID)&hRunOnce, hEvent, 0 ) == 0)
363 /* ok, our event has been set... we're the winning thread */
364 BOOL ret = start_debugger( epointers, hRunOnce );
369 /* so that the other threads won't be stuck */
370 NtSetEvent( hRunOnce, &tmp );
375 /* someone beat us here... */
376 CloseHandle( hEvent );
379 /* and wait for the winner to have actually created the debugger */
380 WaitForSingleObject( hRunOnce, INFINITE );
381 /* in fact, here, we only know that someone has tried to start the debugger,
382 * we'll know by reposting the exception if it has actually attached
383 * to the current process */
388 /*******************************************************************
389 * check_resource_write
391 * Check if the exception is a write attempt to the resource data.
392 * If yes, we unprotect the resources to let broken apps continue
393 * (Windows does this too).
395 inline static BOOL check_resource_write( void *addr )
399 MEMORY_BASIC_INFORMATION info;
401 if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
402 if (info.State == MEM_FREE || !(info.Type & MEM_IMAGE)) return FALSE;
403 if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
404 IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
406 if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
407 TRACE( "Broken app is writing to the resource data, enabling work-around\n" );
408 VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
413 /*******************************************************************
416 * Check for executing a protected area.
418 inline static BOOL check_no_exec( void *addr )
420 MEMORY_BASIC_INFORMATION info;
422 if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
423 if (info.State == MEM_FREE) return FALSE;
425 /* prot |= PAGE_EXECUTE would be a lot easier, but MS developers
426 * apparently don't grasp the notion of protection bits */
429 case PAGE_READONLY: info.Protect = PAGE_EXECUTE_READ; break;
430 case PAGE_READWRITE: info.Protect = PAGE_EXECUTE_READWRITE; break;
431 case PAGE_WRITECOPY: info.Protect = PAGE_EXECUTE_WRITECOPY; break;
432 default: return FALSE;
434 /* FIXME: we should probably have a per-app option, and maybe a message box */
435 FIXME( "No-exec fault triggered at %p, enabling work-around\n", addr );
436 return VirtualProtect( addr, 1, info.Protect, NULL );
440 /*******************************************************************
441 * UnhandledExceptionFilter (KERNEL32.@)
443 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
445 const EXCEPTION_RECORD *rec = epointers->ExceptionRecord;
447 if (rec->ExceptionCode == EXCEPTION_ACCESS_VIOLATION && rec->NumberParameters >= 2)
449 switch(rec->ExceptionInformation[0])
451 case 1: /* write access */
452 if (check_resource_write( (void *)rec->ExceptionInformation[1] ))
453 return EXCEPTION_CONTINUE_EXECUTION;
455 case 8: /* execute access */
456 if (check_no_exec( (void *)rec->ExceptionInformation[1] ))
457 return EXCEPTION_CONTINUE_EXECUTION;
462 if (!NtCurrentTeb()->Peb->BeingDebugged)
464 if (rec->ExceptionCode == CONTROL_C_EXIT)
466 /* do not launch the debugger on ^C, simply terminate the process */
467 TerminateProcess( GetCurrentProcess(), 1 );
472 DWORD ret = top_filter( epointers );
473 if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
476 /* FIXME: Should check the current error mode */
478 if (!start_debugger_atomic( epointers ) || !NtCurrentTeb()->Peb->BeingDebugged)
479 return EXCEPTION_EXECUTE_HANDLER;
481 return EXCEPTION_CONTINUE_SEARCH;
485 /***********************************************************************
486 * SetUnhandledExceptionFilter (KERNEL32.@)
488 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
489 LPTOP_LEVEL_EXCEPTION_FILTER filter )
491 LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
497 /**************************************************************************
498 * FatalAppExitA (KERNEL32.@)
500 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
502 HMODULE mod = GetModuleHandleA( "user32.dll" );
503 MessageBoxA_funcptr pMessageBoxA = NULL;
507 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
508 if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
509 else ERR( "%s\n", debugstr_a(str) );
514 /**************************************************************************
515 * FatalAppExitW (KERNEL32.@)
517 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
519 static const WCHAR User32DllW[] = {'u','s','e','r','3','2','.','d','l','l',0};
521 HMODULE mod = GetModuleHandleW( User32DllW );
522 MessageBoxW_funcptr pMessageBoxW = NULL;
526 if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
527 if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
528 else ERR( "%s\n", debugstr_w(str) );
533 /**************************************************************************
534 * FatalExit (KERNEL32.@)
536 void WINAPI FatalExit(int ExitCode)
539 ExitProcess(ExitCode);