win32/except.c

   1 /*
   2  * Win32 exception functions
   3  *
   4  * Copyright (c) 1996 Onno Hovers, (onno@stack.urc.tue.nl)
   5  * Copyright (c) 1999 Alexandre Julliard
   6  *
   7  * Notes:
   8  *  What really happens behind the scenes of those new
   9  *  __try{...}__except(..){....}  and
  10  *  __try{...}__finally{...}
  11  *  statements is simply not documented by Microsoft. There could be different
  12  *  reasons for this:
  13  *  One reason could be that they try to hide the fact that exception
  14  *  handling in Win32 looks almost the same as in OS/2 2.x.
  15  *  Another reason could be that Microsoft does not want others to write
  16  *  binary compatible implementations of the Win32 API (like us).
  17  *
  18  *  Whatever the reason, THIS SUCKS!! Ensuring portability or future
  19  *  compatibility may be valid reasons to keep some things undocumented.
  20  *  But exception handling is so basic to Win32 that it should be
  21  *  documented!
  22  *
  23  */
  24
  25 #include <stdio.h>
  26 #include "windef.h"
  27 #include "winerror.h"
  28 #include "ntddk.h"
  29 #include "wingdi.h"
  30 #include "winuser.h"
  31 #include "wine/exception.h"
  32 #include "thread.h"
  33 #include "stackframe.h"
  34 #include "wine/server.h"
  35 #include "debugtools.h"
  36
  37 DEFAULT_DEBUG_CHANNEL(seh);
  38
  39 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
  40
  41 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
  42 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
  43
  44 /*******************************************************************
  45  *         RaiseException  (KERNEL32.@)
  46  */
  47 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
  48 {
  49     EXCEPTION_RECORD record;
  50
  51     /* Compose an exception record */
  52
  53     record.ExceptionCode    = code;
  54     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  55     record.ExceptionRecord  = NULL;
  56     record.ExceptionAddress = RaiseException;
  57     if (nbargs && args)
  58     {
  59         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  60         record.NumberParameters = nbargs;
  61         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  62     }
  63     else record.NumberParameters = 0;
  64
  65     RtlRaiseException( &record );
  66 }
  67
  68
  69 /*******************************************************************
  70  *         format_exception_msg
  71  */
  72 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
  73 {
  74     const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
  75     int len,len2;
  76
  77     switch(rec->ExceptionCode)
  78     {
  79     case EXCEPTION_INT_DIVIDE_BY_ZERO:
  80         len = snprintf( buffer, size, "Unhandled division by zero" );
  81         break;
  82     case EXCEPTION_INT_OVERFLOW:
  83         len = snprintf( buffer, size, "Unhandled overflow" );
  84         break;
  85     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
  86         len = snprintf( buffer, size, "Unhandled array bounds" );
  87         break;
  88     case EXCEPTION_ILLEGAL_INSTRUCTION:
  89         len = snprintf( buffer, size, "Unhandled illegal instruction" );
  90         break;
  91     case EXCEPTION_STACK_OVERFLOW:
  92         len = snprintf( buffer, size, "Unhandled stack overflow" );
  93         break;
  94     case EXCEPTION_PRIV_INSTRUCTION:
  95         len = snprintf( buffer, size, "Unhandled privileged instruction" );
  96         break;
  97     case EXCEPTION_ACCESS_VIOLATION:
  98         if (rec->NumberParameters == 2)
  99             len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
 100                      rec->ExceptionInformation[0] ? "write" : "read",
 101                      rec->ExceptionInformation[1]);
 102         else
 103             len = snprintf( buffer, size, "Unhandled page fault");
 104         break;
 105     case EXCEPTION_DATATYPE_MISALIGNMENT:
 106         len = snprintf( buffer, size, "Unhandled alignment" );
 107         break;
 108     case CONTROL_C_EXIT:
 109         len = snprintf( buffer, size, "Unhandled ^C");
 110         break;
 111     case EXCEPTION_CRITICAL_SECTION_WAIT:
 112         len = snprintf( buffer, size, "Critical section %08lx wait failed",
 113                  rec->ExceptionInformation[0]);
 114         break;
 115     case EXCEPTION_WINE_STUB:
 116         len = snprintf( buffer, size, "Unimplemented function %s.%s called",
 117                  (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 118         break;
 119     case EXCEPTION_VM86_INTx:
 120         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 121                  rec->ExceptionInformation[0]);
 122         break;
 123     case EXCEPTION_VM86_STI:
 124         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 125         break;
 126     case EXCEPTION_VM86_PICRETURN:
 127         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 128         break;
 129     default:
 130         len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 131         break;
 132     }
 133     if ((len<0) || (len>=size))
 134         return -1;
 135 #ifdef __i386__
 136     if (ptr->ContextRecord->SegCs != __get_cs())
 137         len2 = snprintf(buffer+len, size-len,
 138                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 139                         ptr->ContextRecord->SegCs,
 140                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 141     else
 142 #endif
 143         len2 = snprintf(buffer+len, size-len,
 144                         " at address 0x%08lx.\nDo you wish to debug it ?",
 145                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 146     if ((len2<0) || (len>=size-len))
 147         return -1;
 148     return len+len2;
 149 }
 150
 151
 152 /**********************************************************************
 153  *           send_debug_event
 154  *
 155  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 156  */
 157 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 158 {
 159     int ret;
 160     HANDLE handle = 0;
 161
 162     SERVER_START_REQ( queue_exception_event )
 163     {
 164         req->first   = first_chance;
 165         wine_server_add_data( req, context, sizeof(*context) );
 166         wine_server_add_data( req, rec, sizeof(*rec) );
 167         if (!wine_server_call(req)) handle = reply->handle;
 168     }
 169     SERVER_END_REQ;
 170     if (!handle) return 0;  /* no debugger present or other error */
 171
 172     /* No need to wait on the handle since the process gets suspended
 173      * once the event is passed to the debugger, so when we get back
 174      * here the event has been continued already.
 175      */
 176     SERVER_START_REQ( get_exception_status )
 177     {
 178         req->handle = handle;
 179         wine_server_set_reply( req, context, sizeof(*context) );
 180         wine_server_call( req );
 181         ret = reply->status;
 182     }
 183     SERVER_END_REQ;
 184     NtClose( handle );
 185     return ret;
 186 }
 187
 188 /******************************************************************
 189  *              start_debugger
 190  *
 191  * Does the effective debugger startup according to 'format'
 192  */
 193 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 194 {
 195     HKEY                hDbgConf;
 196     DWORD               bAuto = FALSE;
 197     PROCESS_INFORMATION info;
 198     STARTUPINFOA        startup;
 199     char*               cmdline = NULL;
 200     char*               format = NULL;
 201     DWORD               format_size;
 202     BOOL                ret = FALSE;
 203
 204     MESSAGE("wine: Unhandled exception, starting debugger...\n");
 205
 206     if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
 207                      "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug", &hDbgConf)) {
 208        DWORD    type;
 209        DWORD    count;
 210
 211        format_size = 0;
 212        if (!RegQueryValueExA(hDbgConf, "Debugger", 0, &type, NULL, &format_size)) {
 213            format = HeapAlloc(GetProcessHeap(), 0, format_size);
 214            RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &format_size);
 215            if (type==REG_EXPAND_SZ) {
 216                char* tmp;
 217
 218                /* Expand environment variable references */
 219                format_size=ExpandEnvironmentStringsA(format,NULL,0);
 220                tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 221                ExpandEnvironmentStringsA(format,tmp,format_size);
 222                HeapFree(GetProcessHeap(), 0, format);
 223                format=tmp;
 224            }
 225        }
 226
 227        count = sizeof(bAuto);
 228        if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
 229           bAuto = TRUE;
 230        else if (type == REG_SZ)
 231        {
 232            char autostr[10];
 233            count = sizeof(autostr);
 234            if (!RegQueryValueExA(hDbgConf, "Auto", 0, &type, autostr, &count))
 235                bAuto = atoi(autostr);
 236        }
 237        RegCloseKey(hDbgConf);
 238     } else {
 239         /* try a default setup... */
 240         strcpy( format, "winedbg --debugmsg -all -- --auto %ld %ld" );
 241     }
 242
 243     if (!bAuto)
 244     {
 245         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 246         MessageBoxA_funcptr     pMessageBoxA = NULL;
 247
 248         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 249         if (pMessageBoxA)
 250         {
 251             char buffer[256];
 252             format_exception_msg( epointers, buffer, sizeof(buffer) );
 253             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 254             {
 255                 TRACE("Killing process\n");
 256                 goto EXIT;
 257             }
 258         }
 259     }
 260
 261     if (format) {
 262         TRACE("Starting debugger (fmt=%s)\n", format);
 263         cmdline=HeapAlloc(GetProcessHeap(), 0, format_size+2*20);
 264         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 265         memset(&startup, 0, sizeof(startup));
 266         startup.cb = sizeof(startup);
 267         startup.dwFlags = STARTF_USESHOWWINDOW;
 268         startup.wShowWindow = SW_SHOWNORMAL;
 269         if (CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, NULL, NULL, &startup, &info)) {
 270             /* wait for debugger to come up... */
 271             WaitForSingleObject(hEvent, INFINITE);
 272             ret = TRUE;
 273             goto EXIT;
 274         }
 275     } else {
 276         cmdline = NULL;
 277     }
 278     ERR("Couldn't start debugger (%s) (%ld)\n"
 279         "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 280         debugstr_a(cmdline), GetLastError());
 281
 282 EXIT:
 283     if (cmdline)
 284         HeapFree(GetProcessHeap(), 0, cmdline);
 285     if (format)
 286         HeapFree(GetProcessHeap(), 0, format);
 287     return ret;
 288 }
 289
 290 /******************************************************************
 291  *              start_debugger_atomic
 292  *
 293  * starts the debugger in an atomic way:
 294  *      - either the debugger is not started and it is started
 295  *      - or the debugger has already been started by another thread
 296  *      - or the debugger couldn't be started
 297  *
 298  * returns TRUE for the two first conditions, FALSE for the last
 299  */
 300 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 301 {
 302     static HANDLE       hRunOnce /* = 0 */;
 303
 304     if (hRunOnce == 0)
 305     {
 306         OBJECT_ATTRIBUTES       attr;
 307         HANDLE                  hEvent;
 308
 309         attr.Length                   = sizeof(attr);
 310         attr.RootDirectory            = 0;
 311         attr.Attributes               = OBJ_INHERIT;
 312         attr.ObjectName               = NULL;
 313         attr.SecurityDescriptor       = NULL;
 314         attr.SecurityQualityOfService = NULL;
 315
 316         /* ask for manual reset, so that once the debugger is started,
 317          * every thread will know it */
 318         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 319         if (InterlockedCompareExchange( (LPLONG)&hRunOnce, hEvent, 0 ) == 0)
 320         {
 321             /* ok, our event has been set... we're the winning thread */
 322             BOOL        ret = start_debugger( epointers, hRunOnce );
 323             DWORD       tmp;
 324
 325             if (!ret)
 326             {
 327                 /* so that the other threads won't be stuck */
 328                 NtSetEvent( hRunOnce, &tmp );
 329             }
 330             return ret;
 331         }
 332
 333         /* someone beat us here... */
 334         CloseHandle( hEvent );
 335     }
 336
 337     /* and wait for the winner to have actually created the debugger */
 338     WaitForSingleObject( hRunOnce, INFINITE );
 339     /* in fact, here, we only know that someone has tried to start the debugger,
 340      * we'll know by reposting the exception if it has actually attached
 341      * to the current process */
 342     return TRUE;
 343 }
 344
 345
 346 /*******************************************************************
 347  *         UnhandledExceptionFilter   (KERNEL32.@)
 348  */
 349 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 350 {
 351     int                 status;
 352     int                 loop = 0;
 353
 354     for (loop = 0; loop <= 1; loop++)
 355     {
 356         /* send a last chance event to the debugger */
 357         status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 358         switch (status)
 359         {
 360         case DBG_CONTINUE:
 361             return EXCEPTION_CONTINUE_EXECUTION;
 362         case DBG_EXCEPTION_NOT_HANDLED:
 363             TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 364             break; /* not reached */
 365         case 0: /* no debugger is present */
 366             if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 367             {
 368                 /* do not launch the debugger on ^C, simply terminate the process */
 369                 TerminateProcess( GetCurrentProcess(), 1 );
 370             }
 371             /* second try, the debugger isn't present... */
 372             if (loop == 1) return EXCEPTION_EXECUTE_HANDLER;
 373             break;
 374         default:
 375             FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 376             return EXCEPTION_EXECUTE_HANDLER;
 377         }
 378
 379         /* should only be there when loop == 0 */
 380
 381         if (top_filter)
 382         {
 383             DWORD ret = top_filter( epointers );
 384             if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 385         }
 386
 387         /* FIXME: Should check the current error mode */
 388
 389         if (!start_debugger_atomic( epointers ))
 390             return EXCEPTION_EXECUTE_HANDLER;
 391         /* now that we should have a debugger attached, try to resend event */
 392     }
 393
 394     return EXCEPTION_EXECUTE_HANDLER;
 395 }
 396
 397
 398 /***********************************************************************
 399  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 400  */
 401 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 402                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 403 {
 404     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 405     top_filter = filter;
 406     return old;
 407 }
 408
 409
 410 /**************************************************************************
 411  *           FatalAppExitA   (KERNEL32.@)
 412  */
 413 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 414 {
 415     HMODULE mod = GetModuleHandleA( "user32.dll" );
 416     MessageBoxA_funcptr pMessageBoxA = NULL;
 417
 418     WARN("AppExit\n");
 419
 420     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 421     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 422     else ERR( "%s\n", debugstr_a(str) );
 423     ExitProcess(0);
 424 }
 425
 426
 427 /**************************************************************************
 428  *           FatalAppExitW   (KERNEL32.@)
 429  */
 430 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 431 {
 432     HMODULE mod = GetModuleHandleA( "user32.dll" );
 433     MessageBoxW_funcptr pMessageBoxW = NULL;
 434
 435     WARN("AppExit\n");
 436
 437     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 438     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 439     else ERR( "%s\n", debugstr_w(str) );
 440     ExitProcess(0);
 441 }