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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 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"
47 #include "wine/exception.h"
48 #include "wine/library.h"
50 #include "stackframe.h"
51 #include "msvcrt/excpt.h"
52 #include "wine/server.h"
53 #include "wine/unicode.h"
54 #include "wine/debug.h"
56 WINE_DEFAULT_DEBUG_CHANNEL(seh);
58 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
60 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
61 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
63 /*******************************************************************
64 * RaiseException (KERNEL32.@)
66 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
68 EXCEPTION_RECORD record;
70 /* Compose an exception record */
72 record.ExceptionCode = code;
73 record.ExceptionFlags = flags & EH_NONCONTINUABLE;
74 record.ExceptionRecord = NULL;
75 record.ExceptionAddress = RaiseException;
78 if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
79 record.NumberParameters = nbargs;
80 memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
82 else record.NumberParameters = 0;
84 RtlRaiseException( &record );
88 /*******************************************************************
89 * format_exception_msg
91 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
93 const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
96 switch(rec->ExceptionCode)
98 case EXCEPTION_INT_DIVIDE_BY_ZERO:
99 len = snprintf( buffer, size, "Unhandled division by zero" );
101 case EXCEPTION_INT_OVERFLOW:
102 len = snprintf( buffer, size, "Unhandled overflow" );
104 case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
105 len = snprintf( buffer, size, "Unhandled array bounds" );
107 case EXCEPTION_ILLEGAL_INSTRUCTION:
108 len = snprintf( buffer, size, "Unhandled illegal instruction" );
110 case EXCEPTION_STACK_OVERFLOW:
111 len = snprintf( buffer, size, "Unhandled stack overflow" );
113 case EXCEPTION_PRIV_INSTRUCTION:
114 len = snprintf( buffer, size, "Unhandled privileged instruction" );
116 case EXCEPTION_ACCESS_VIOLATION:
117 if (rec->NumberParameters == 2)
118 len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
119 rec->ExceptionInformation[0] ? "write" : "read",
120 rec->ExceptionInformation[1]);
122 len = snprintf( buffer, size, "Unhandled page fault");
124 case EXCEPTION_DATATYPE_MISALIGNMENT:
125 len = snprintf( buffer, size, "Unhandled alignment" );
128 len = snprintf( buffer, size, "Unhandled ^C");
130 case EXCEPTION_CRITICAL_SECTION_WAIT:
131 len = snprintf( buffer, size, "Critical section %08lx wait failed",
132 rec->ExceptionInformation[0]);
134 case EXCEPTION_WINE_STUB:
135 len = snprintf( buffer, size, "Unimplemented function %s.%s called",
136 (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
138 case EXCEPTION_VM86_INTx:
139 len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
140 rec->ExceptionInformation[0]);
142 case EXCEPTION_VM86_STI:
143 len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
145 case EXCEPTION_VM86_PICRETURN:
146 len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
149 len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
152 if ((len<0) || (len>=size))
155 if (ptr->ContextRecord->SegCs != wine_get_cs())
156 len2 = snprintf(buffer+len, size-len,
157 " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
158 ptr->ContextRecord->SegCs,
159 (DWORD)ptr->ExceptionRecord->ExceptionAddress);
162 len2 = snprintf(buffer+len, size-len,
163 " at address 0x%08lx.\nDo you wish to debug it ?",
164 (DWORD)ptr->ExceptionRecord->ExceptionAddress);
165 if ((len2<0) || (len>=size-len))
171 /**********************************************************************
174 * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
176 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
181 SERVER_START_REQ( queue_exception_event )
183 req->first = first_chance;
184 wine_server_add_data( req, context, sizeof(*context) );
185 wine_server_add_data( req, rec, sizeof(*rec) );
186 if (!wine_server_call(req)) handle = reply->handle;
189 if (!handle) return 0; /* no debugger present or other error */
191 /* No need to wait on the handle since the process gets suspended
192 * once the event is passed to the debugger, so when we get back
193 * here the event has been continued already.
195 SERVER_START_REQ( get_exception_status )
197 req->handle = handle;
198 wine_server_set_reply( req, context, sizeof(*context) );
199 wine_server_call( req );
207 /******************************************************************
210 * Does the effective debugger startup according to 'format'
212 static BOOL start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
214 OBJECT_ATTRIBUTES attr;
215 UNICODE_STRING nameW;
218 PROCESS_INFORMATION info;
219 STARTUPINFOA startup;
220 char* cmdline = NULL;
225 static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
226 'S','o','f','t','w','a','r','e','\\',
227 'M','i','c','r','o','s','o','f','t','\\',
228 'W','i','n','d','o','w','s',' ','N','T','\\',
229 'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
230 'A','e','D','e','b','u','g',0};
231 static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
232 static const WCHAR AutoW[] = {'A','u','t','o',0};
234 MESSAGE("wine: Unhandled exception, starting debugger...\n");
236 attr.Length = sizeof(attr);
237 attr.RootDirectory = 0;
238 attr.ObjectName = &nameW;
240 attr.SecurityDescriptor = NULL;
241 attr.SecurityQualityOfService = NULL;
242 RtlInitUnicodeString( &nameW, AeDebugW );
244 if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
247 KEY_VALUE_PARTIAL_INFORMATION *info;
250 RtlInitUnicodeString( &nameW, DebuggerW );
251 if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
252 NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
254 char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
255 NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
256 data, format_size, &format_size );
257 info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
258 RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
259 format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
260 RtlUnicodeToMultiByteN( format, format_size, NULL,
261 (WCHAR *)info->Data, info->DataLength );
262 format[format_size] = 0;
264 if (info->Type == REG_EXPAND_SZ)
268 /* Expand environment variable references */
269 format_size=ExpandEnvironmentStringsA(format,NULL,0);
270 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
271 ExpandEnvironmentStringsA(format,tmp,format_size);
272 HeapFree(GetProcessHeap(), 0, format);
275 HeapFree( GetProcessHeap(), 0, data );
278 RtlInitUnicodeString( &nameW, AutoW );
279 if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
280 buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
282 info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
283 if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
284 else if (info->Type == REG_SZ)
286 WCHAR *str = (WCHAR *)info->Data;
287 str[info->DataLength/sizeof(WCHAR)] = 0;
288 bAuto = atoiW( str );
295 /* try a default setup... */
296 strcpy( format, "winedbg --debugmsg -all --auto %ld %ld" );
301 HMODULE mod = GetModuleHandleA( "user32.dll" );
302 MessageBoxA_funcptr pMessageBoxA = NULL;
304 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
308 format_exception_msg( epointers, buffer, sizeof(buffer) );
309 if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
311 TRACE("Killing process\n");
318 TRACE("Starting debugger (fmt=%s)\n", format);
319 cmdline=HeapAlloc(GetProcessHeap(), 0, format_size+2*20);
320 sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
321 memset(&startup, 0, sizeof(startup));
322 startup.cb = sizeof(startup);
323 startup.dwFlags = STARTF_USESHOWWINDOW;
324 startup.wShowWindow = SW_SHOWNORMAL;
325 if (CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, NULL, NULL, &startup, &info)) {
326 /* wait for debugger to come up... */
327 WaitForSingleObject(hEvent, INFINITE);
334 ERR("Couldn't start debugger (%s) (%ld)\n"
335 "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
336 debugstr_a(cmdline), GetLastError());
340 HeapFree(GetProcessHeap(), 0, cmdline);
342 HeapFree(GetProcessHeap(), 0, format);
346 /******************************************************************
347 * start_debugger_atomic
349 * starts the debugger in an atomic way:
350 * - either the debugger is not started and it is started
351 * - or the debugger has already been started by another thread
352 * - or the debugger couldn't be started
354 * returns TRUE for the two first conditions, FALSE for the last
356 static int start_debugger_atomic(PEXCEPTION_POINTERS epointers)
358 static HANDLE hRunOnce /* = 0 */;
362 OBJECT_ATTRIBUTES attr;
365 attr.Length = sizeof(attr);
366 attr.RootDirectory = 0;
367 attr.Attributes = OBJ_INHERIT;
368 attr.ObjectName = NULL;
369 attr.SecurityDescriptor = NULL;
370 attr.SecurityQualityOfService = NULL;
372 /* ask for manual reset, so that once the debugger is started,
373 * every thread will know it */
374 NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
375 if (InterlockedCompareExchange( (LPLONG)&hRunOnce, hEvent, 0 ) == 0)
377 /* ok, our event has been set... we're the winning thread */
378 BOOL ret = start_debugger( epointers, hRunOnce );
383 /* so that the other threads won't be stuck */
384 NtSetEvent( hRunOnce, &tmp );
389 /* someone beat us here... */
390 CloseHandle( hEvent );
393 /* and wait for the winner to have actually created the debugger */
394 WaitForSingleObject( hRunOnce, INFINITE );
395 /* in fact, here, we only know that someone has tried to start the debugger,
396 * we'll know by reposting the exception if it has actually attached
397 * to the current process */
402 /*******************************************************************
403 * check_resource_write
405 * Check if the exception is a write attempt to the resource data.
406 * If yes, we unprotect the resources to let broken apps continue
407 * (Windows does this too).
409 inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
413 MEMORY_BASIC_INFORMATION info;
415 if (rec->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) return FALSE;
416 if (!rec->ExceptionInformation[0]) return FALSE; /* not a write access */
417 addr = (void *)rec->ExceptionInformation[1];
418 if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
419 if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
420 IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
422 if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
423 FIXME( "Broken app is writing to the resource data, enabling work-around\n" );
424 VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
429 /*******************************************************************
430 * UnhandledExceptionFilter (KERNEL32.@)
432 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
437 if (check_resource_write( epointers->ExceptionRecord )) return EXCEPTION_CONTINUE_EXECUTION;
439 for (loop = 0; loop <= 1; loop++)
441 /* send a last chance event to the debugger */
442 status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
446 return EXCEPTION_CONTINUE_EXECUTION;
447 case DBG_EXCEPTION_NOT_HANDLED:
448 TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
449 break; /* not reached */
450 case 0: /* no debugger is present */
451 if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
453 /* do not launch the debugger on ^C, simply terminate the process */
454 TerminateProcess( GetCurrentProcess(), 1 );
456 /* second try, the debugger isn't present... */
457 if (loop == 1) return EXCEPTION_EXECUTE_HANDLER;
460 FIXME("Unsupported yet debug continue value %d (please report)\n", status);
461 return EXCEPTION_EXECUTE_HANDLER;
464 /* should only be there when loop == 0 */
468 DWORD ret = top_filter( epointers );
469 if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
472 /* FIXME: Should check the current error mode */
474 if (!start_debugger_atomic( epointers ))
475 return EXCEPTION_EXECUTE_HANDLER;
476 /* now that we should have a debugger attached, try to resend event */
479 return EXCEPTION_EXECUTE_HANDLER;
483 /***********************************************************************
484 * SetUnhandledExceptionFilter (KERNEL32.@)
486 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
487 LPTOP_LEVEL_EXCEPTION_FILTER filter )
489 LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
495 /**************************************************************************
496 * FatalAppExitA (KERNEL32.@)
498 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
500 HMODULE mod = GetModuleHandleA( "user32.dll" );
501 MessageBoxA_funcptr pMessageBoxA = NULL;
505 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
506 if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
507 else ERR( "%s\n", debugstr_a(str) );
512 /**************************************************************************
513 * FatalAppExitW (KERNEL32.@)
515 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
517 HMODULE mod = GetModuleHandleA( "user32.dll" );
518 MessageBoxW_funcptr pMessageBoxW = NULL;
522 if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
523 if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
524 else ERR( "%s\n", debugstr_w(str) );