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 "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 priviledged 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_VAR_REQ( queue_exception_event, sizeof(*rec) + sizeof(*context) )
 163     {
 164         CONTEXT *context_ptr = server_data_ptr(req);
 165         EXCEPTION_RECORD *rec_ptr = (EXCEPTION_RECORD *)(context_ptr + 1);
 166         req->first   = first_chance;
 167         *rec_ptr     = *rec;
 168         *context_ptr = *context;
 169         if (!SERVER_CALL()) handle = req->handle;
 170     }
 171     SERVER_END_VAR_REQ;
 172     if (!handle) return 0;  /* no debugger present or other error */
 173
 174     /* No need to wait on the handle since the process gets suspended
 175      * once the event is passed to the debugger, so when we get back
 176      * here the event has been continued already.
 177      */
 178     SERVER_START_VAR_REQ( get_exception_status, sizeof(*context) )
 179     {
 180         req->handle = handle;
 181         if (!SERVER_CALL()) *context = *(CONTEXT *)server_data_ptr(req);
 182         ret = req->status;
 183     }
 184     SERVER_END_VAR_REQ;
 185     NtClose( handle );
 186     return ret;
 187 }
 188
 189
 190 /*******************************************************************
 191  *         UnhandledExceptionFilter   (KERNEL32.@)
 192  */
 193 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 194 {
 195     char                format[256];
 196     char                buffer[256];
 197     HKEY                hDbgConf;
 198     DWORD               bAuto = FALSE;
 199     DWORD               ret = EXCEPTION_EXECUTE_HANDLER;
 200     int status;
 201
 202     /* send a last chance event to the debugger */
 203     status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 204     switch (status)
 205     {
 206     case DBG_CONTINUE:
 207         return EXCEPTION_CONTINUE_EXECUTION;
 208     case DBG_EXCEPTION_NOT_HANDLED:
 209         TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 210         break; /* not reached */
 211     case 0: /* no debugger is present */
 212         if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 213         {
 214             /* do not launch the debugger on ^C, simply terminate the process */
 215             TerminateProcess( GetCurrentProcess(), 1 );
 216         }
 217         break;
 218     default:
 219         FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 220     }
 221
 222     if (top_filter)
 223     {
 224         DWORD ret = top_filter( epointers );
 225         if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 226     }
 227
 228     /* FIXME: Should check the current error mode */
 229
 230     if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
 231                      "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug",
 232                      &hDbgConf)) {
 233        DWORD    type;
 234        DWORD    count;
 235
 236        count = sizeof(format);
 237        if (RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &count))
 238           format[0] = 0;
 239
 240        count = sizeof(bAuto);
 241        if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
 242           bAuto = TRUE;
 243        else if (type == REG_SZ)
 244        {
 245            char autostr[10];
 246            count = sizeof(autostr);
 247            if (!RegQueryValueExA(hDbgConf, "Auto", 0, &type, autostr, &count))
 248                bAuto = atoi(autostr);
 249        }
 250        RegCloseKey(hDbgConf);
 251     } else {
 252        /* format[0] = 0; */
 253        strcpy(format, "debugger/winedbg %ld %ld");
 254     }
 255
 256     if (!bAuto)
 257     {
 258         HMODULE mod = GetModuleHandleA( "user32.dll" );
 259         MessageBoxA_funcptr pMessageBoxA = NULL;
 260         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 261         if (pMessageBoxA)
 262         {
 263             format_exception_msg( epointers, buffer, sizeof(buffer) );
 264             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 265             {
 266                 TRACE("Killing process\n");
 267                 return EXCEPTION_EXECUTE_HANDLER;
 268             }
 269         }
 270     }
 271
 272     if (format[0]) {
 273        HANDLE                   hEvent;
 274        PROCESS_INFORMATION      info;
 275        STARTUPINFOA             startup;
 276        OBJECT_ATTRIBUTES        attr;
 277
 278        attr.Length                   = sizeof(attr);
 279        attr.RootDirectory            = 0;
 280        attr.Attributes               = OBJ_INHERIT;
 281        attr.ObjectName               = NULL;
 282        attr.SecurityDescriptor       = NULL;
 283        attr.SecurityQualityOfService = NULL;
 284
 285        TRACE("Starting debugger (fmt=%s)\n", format);
 286        NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, FALSE, FALSE );
 287        sprintf(buffer, format, GetCurrentProcessId(), hEvent);
 288        memset(&startup, 0, sizeof(startup));
 289        startup.cb = sizeof(startup);
 290        startup.dwFlags = STARTF_USESHOWWINDOW;
 291        startup.wShowWindow = SW_SHOWNORMAL;
 292        if (CreateProcessA(NULL, buffer, NULL, NULL,
 293                           TRUE, 0, NULL, NULL, &startup, &info)) {
 294           WaitForSingleObject(hEvent, INFINITE);
 295           ret = EXCEPTION_CONTINUE_SEARCH;
 296        } else {
 297            ERR("Couldn't start debugger (%s) (%ld)\n"
 298                "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 299                buffer, GetLastError());
 300        }
 301        CloseHandle(hEvent);
 302     } else {
 303        ERR("No standard debugger defined in the registry => no debugging session\n");
 304     }
 305
 306     return ret;
 307 }
 308
 309
 310 /***********************************************************************
 311  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 312  */
 313 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 314                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 315 {
 316     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 317     top_filter = filter;
 318     return old;
 319 }
 320
 321
 322 /**************************************************************************
 323  *           FatalAppExitA   (KERNEL32.@)
 324  */
 325 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 326 {
 327     HMODULE mod = GetModuleHandleA( "user32.dll" );
 328     MessageBoxA_funcptr pMessageBoxA = NULL;
 329
 330     WARN("AppExit\n");
 331
 332     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 333     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 334     else ERR( "%s\n", debugstr_a(str) );
 335     ExitProcess(0);
 336 }
 337
 338
 339 /**************************************************************************
 340  *           FatalAppExitW   (KERNEL32.@)
 341  */
 342 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 343 {
 344     HMODULE mod = GetModuleHandleA( "user32.dll" );
 345     MessageBoxW_funcptr pMessageBoxW = NULL;
 346
 347     WARN("AppExit\n");
 348
 349     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 350     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 351     else ERR( "%s\n", debugstr_w(str) );
 352     ExitProcess(0);
 353 }