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] == EXCEPTION_WRITE_FAULT ? "write" :
121 rec->ExceptionInformation[0] == EXCEPTION_EXECUTE_FAULT ? "execute" : "read",
122 rec->ExceptionInformation[1]);
124 len = snprintf( buffer, size, "Unhandled page fault");
126 case EXCEPTION_DATATYPE_MISALIGNMENT:
127 len = snprintf( buffer, size, "Unhandled alignment" );
130 len = snprintf( buffer, size, "Unhandled ^C");
132 case STATUS_POSSIBLE_DEADLOCK:
133 len = snprintf( buffer, size, "Critical section %08lx wait failed",
134 rec->ExceptionInformation[0]);
136 case EXCEPTION_WINE_STUB:
137 if (HIWORD(rec->ExceptionInformation[1]))
138 len = snprintf( buffer, size, "Unimplemented function %s.%s called",
139 (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
141 len = snprintf( buffer, size, "Unimplemented function %s.%ld called",
142 (char *)rec->ExceptionInformation[0], rec->ExceptionInformation[1] );
144 case EXCEPTION_WINE_ASSERTION:
145 len = snprintf( buffer, size, "Assertion failed" );
147 case EXCEPTION_VM86_INTx:
148 len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
149 rec->ExceptionInformation[0]);
151 case EXCEPTION_VM86_STI:
152 len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
154 case EXCEPTION_VM86_PICRETURN:
155 len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
158 len = snprintf( buffer, size, "Unhandled exception 0x%08x", rec->ExceptionCode);
161 if ((len<0) || (len>=size))
164 if (ptr->ContextRecord->SegCs != wine_get_cs())
165 len2 = snprintf(buffer+len, size-len, " at address 0x%04x:0x%08x",
166 ptr->ContextRecord->SegCs,
167 (DWORD)ptr->ExceptionRecord->ExceptionAddress);
170 len2 = snprintf(buffer+len, size-len, " at address %p",
171 ptr->ExceptionRecord->ExceptionAddress);
172 if ((len2<0) || (len>=size-len))
178 /******************************************************************
181 * Does the effective debugger startup according to 'format'
183 static BOOL start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
185 OBJECT_ATTRIBUTES attr;
186 UNICODE_STRING nameW;
187 char *cmdline, *env, *p;
190 PROCESS_INFORMATION info;
191 STARTUPINFOA startup;
196 static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
197 'S','o','f','t','w','a','r','e','\\',
198 'M','i','c','r','o','s','o','f','t','\\',
199 'W','i','n','d','o','w','s',' ','N','T','\\',
200 'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
201 'A','e','D','e','b','u','g',0};
202 static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
203 static const WCHAR AutoW[] = {'A','u','t','o',0};
205 format_exception_msg( epointers, buffer, sizeof(buffer) );
206 MESSAGE("wine: %s (thread %04x), starting debugger...\n", buffer, GetCurrentThreadId());
208 attr.Length = sizeof(attr);
209 attr.RootDirectory = 0;
210 attr.ObjectName = &nameW;
212 attr.SecurityDescriptor = NULL;
213 attr.SecurityQualityOfService = NULL;
214 RtlInitUnicodeString( &nameW, AeDebugW );
216 if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
219 KEY_VALUE_PARTIAL_INFORMATION *info;
220 DWORD format_size = 0;
222 RtlInitUnicodeString( &nameW, DebuggerW );
223 if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
224 NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
226 char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
227 NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
228 data, format_size, &format_size );
229 info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
230 RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
231 format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
232 RtlUnicodeToMultiByteN( format, format_size, NULL,
233 (WCHAR *)info->Data, info->DataLength );
234 format[format_size] = 0;
236 if (info->Type == REG_EXPAND_SZ)
240 /* Expand environment variable references */
241 format_size=ExpandEnvironmentStringsA(format,NULL,0);
242 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
243 ExpandEnvironmentStringsA(format,tmp,format_size);
244 HeapFree(GetProcessHeap(), 0, format);
247 HeapFree( GetProcessHeap(), 0, data );
250 RtlInitUnicodeString( &nameW, AutoW );
251 if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
252 buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
254 info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
255 if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
256 else if (info->Type == REG_SZ)
258 WCHAR *str = (WCHAR *)info->Data;
259 str[info->DataLength/sizeof(WCHAR)] = 0;
260 bAuto = atoiW( str );
270 cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
271 sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
272 HeapFree(GetProcessHeap(), 0, format);
276 cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
277 sprintf(cmdline, "winedbg --auto %d %ld",
278 GetCurrentProcessId(), (ULONG_PTR)hEvent);
283 HMODULE mod = GetModuleHandleA( "user32.dll" );
284 MessageBoxA_funcptr pMessageBoxA = NULL;
286 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
289 static const char msg[] = ".\nDo you wish to debug it?";
292 format_exception_msg( epointers, buffer, sizeof(buffer)-sizeof(msg) );
293 strcat( buffer, msg );
294 if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
296 TRACE("Killing process\n");
302 /* make WINEDEBUG empty in the environment */
303 env = GetEnvironmentStringsA();
304 for (p = env; *p; p += strlen(p) + 1)
306 if (!memcmp( p, "WINEDEBUG=", sizeof("WINEDEBUG=")-1 ))
308 char *next = p + strlen(p);
309 char *end = next + 1;
310 while (*end) end += strlen(end) + 1;
311 memmove( p + sizeof("WINEDEBUG=") - 1, next, end + 1 - next );
316 TRACE("Starting debugger %s\n", debugstr_a(cmdline));
317 memset(&startup, 0, sizeof(startup));
318 startup.cb = sizeof(startup);
319 startup.dwFlags = STARTF_USESHOWWINDOW;
320 startup.wShowWindow = SW_SHOWNORMAL;
321 ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, env, NULL, &startup, &info);
322 FreeEnvironmentStringsA( env );
324 if (ret) WaitForSingleObject(hEvent, INFINITE); /* wait for debugger to come up... */
325 else ERR("Couldn't start debugger (%s) (%d)\n"
326 "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
327 debugstr_a(cmdline), GetLastError());
329 HeapFree(GetProcessHeap(), 0, cmdline);
333 /******************************************************************
334 * start_debugger_atomic
336 * starts the debugger in an atomic way:
337 * - either the debugger is not started and it is started
338 * - or the debugger has already been started by another thread
339 * - or the debugger couldn't be started
341 * returns TRUE for the two first conditions, FALSE for the last
343 static int start_debugger_atomic(PEXCEPTION_POINTERS epointers)
345 static HANDLE hRunOnce /* = 0 */;
349 OBJECT_ATTRIBUTES attr;
352 attr.Length = sizeof(attr);
353 attr.RootDirectory = 0;
354 attr.Attributes = OBJ_INHERIT;
355 attr.ObjectName = NULL;
356 attr.SecurityDescriptor = NULL;
357 attr.SecurityQualityOfService = NULL;
359 /* ask for manual reset, so that once the debugger is started,
360 * every thread will know it */
361 NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
362 if (InterlockedCompareExchangePointer( (PVOID)&hRunOnce, hEvent, 0 ) == 0)
364 /* ok, our event has been set... we're the winning thread */
365 BOOL ret = start_debugger( epointers, hRunOnce );
370 /* so that the other threads won't be stuck */
371 NtSetEvent( hRunOnce, &tmp );
376 /* someone beat us here... */
377 CloseHandle( hEvent );
380 /* and wait for the winner to have actually created the debugger */
381 WaitForSingleObject( hRunOnce, INFINITE );
382 /* in fact, here, we only know that someone has tried to start the debugger,
383 * we'll know by reposting the exception if it has actually attached
384 * to the current process */
389 /*******************************************************************
390 * check_resource_write
392 * Check if the exception is a write attempt to the resource data.
393 * If yes, we unprotect the resources to let broken apps continue
394 * (Windows does this too).
396 inline static BOOL check_resource_write( void *addr )
400 MEMORY_BASIC_INFORMATION info;
402 if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
403 if (info.State == MEM_FREE || !(info.Type & MEM_IMAGE)) return FALSE;
404 if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
405 IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
407 if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
408 TRACE( "Broken app is writing to the resource data, enabling work-around\n" );
409 VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
414 /*******************************************************************
417 * Check for executing a protected area.
419 inline static BOOL check_no_exec( void *addr )
421 MEMORY_BASIC_INFORMATION info;
423 if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
424 if (info.State == MEM_FREE) return FALSE;
426 /* prot |= PAGE_EXECUTE would be a lot easier, but MS developers
427 * apparently don't grasp the notion of protection bits */
430 case PAGE_READONLY: info.Protect = PAGE_EXECUTE_READ; break;
431 case PAGE_READWRITE: info.Protect = PAGE_EXECUTE_READWRITE; break;
432 case PAGE_WRITECOPY: info.Protect = PAGE_EXECUTE_WRITECOPY; break;
433 default: return FALSE;
435 /* FIXME: we should probably have a per-app option, and maybe a message box */
436 FIXME( "No-exec fault triggered at %p, enabling work-around\n", addr );
437 return VirtualProtect( addr, 1, info.Protect, NULL );
441 /*******************************************************************
442 * UnhandledExceptionFilter (KERNEL32.@)
444 LONG WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
446 const EXCEPTION_RECORD *rec = epointers->ExceptionRecord;
448 if (rec->ExceptionCode == EXCEPTION_ACCESS_VIOLATION && rec->NumberParameters >= 2)
450 switch(rec->ExceptionInformation[0])
452 case EXCEPTION_WRITE_FAULT:
453 if (check_resource_write( (void *)rec->ExceptionInformation[1] ))
454 return EXCEPTION_CONTINUE_EXECUTION;
456 case EXCEPTION_EXECUTE_FAULT:
457 if (check_no_exec( (void *)rec->ExceptionInformation[1] ))
458 return EXCEPTION_CONTINUE_EXECUTION;
463 if (!NtCurrentTeb()->Peb->BeingDebugged)
465 if (rec->ExceptionCode == CONTROL_C_EXIT)
467 /* do not launch the debugger on ^C, simply terminate the process */
468 TerminateProcess( GetCurrentProcess(), 1 );
473 LONG ret = top_filter( epointers );
474 if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
477 /* FIXME: Should check the current error mode */
479 if (!start_debugger_atomic( epointers ) || !NtCurrentTeb()->Peb->BeingDebugged)
480 return EXCEPTION_EXECUTE_HANDLER;
482 return EXCEPTION_CONTINUE_SEARCH;
486 /***********************************************************************
487 * SetUnhandledExceptionFilter (KERNEL32.@)
489 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
490 LPTOP_LEVEL_EXCEPTION_FILTER filter )
492 LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
498 /**************************************************************************
499 * FatalAppExitA (KERNEL32.@)
501 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
503 HMODULE mod = GetModuleHandleA( "user32.dll" );
504 MessageBoxA_funcptr pMessageBoxA = NULL;
508 if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
509 if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
510 else ERR( "%s\n", debugstr_a(str) );
515 /**************************************************************************
516 * FatalAppExitW (KERNEL32.@)
518 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
520 static const WCHAR User32DllW[] = {'u','s','e','r','3','2','.','d','l','l',0};
522 HMODULE mod = GetModuleHandleW( User32DllW );
523 MessageBoxW_funcptr pMessageBoxW = NULL;
527 if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
528 if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
529 else ERR( "%s\n", debugstr_w(str) );
534 /**************************************************************************
535 * FatalExit (KERNEL32.@)
537 void WINAPI FatalExit(int ExitCode)
540 ExitProcess(ExitCode);