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 "wine/exception.h"
  30 #include "callback.h"
  31 #include "thread.h"
  32 #include "stackframe.h"
  33 #include "server.h"
  34 #include "debugtools.h"
  35
  36 DEFAULT_DEBUG_CHANNEL(seh);
  37
  38 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
  39
  40
  41 /*******************************************************************
  42  *         RaiseException  (KERNEL32.418)
  43  */
  44 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
  45 {
  46     EXCEPTION_RECORD record;
  47
  48     /* Compose an exception record */
  49
  50     record.ExceptionCode    = code;
  51     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  52     record.ExceptionRecord  = NULL;
  53     record.ExceptionAddress = RaiseException;
  54     if (nbargs && args)
  55     {
  56         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  57         record.NumberParameters = nbargs;
  58         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  59     }
  60     else record.NumberParameters = 0;
  61
  62     RtlRaiseException( &record );
  63 }
  64
  65
  66 /*******************************************************************
  67  *         format_exception_msg
  68  */
  69 static void format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer )
  70 {
  71     const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
  72
  73     switch(rec->ExceptionCode)
  74     {
  75     case EXCEPTION_INT_DIVIDE_BY_ZERO:
  76         sprintf( buffer, "Unhandled division by zero" );
  77         break;
  78     case EXCEPTION_INT_OVERFLOW:
  79         sprintf( buffer, "Unhandled overflow" );
  80         break;
  81     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
  82         sprintf( buffer, "Unhandled array bounds" );
  83         break;
  84     case EXCEPTION_ILLEGAL_INSTRUCTION:
  85         sprintf( buffer, "Unhandled illegal instruction" );
  86         break;
  87     case EXCEPTION_STACK_OVERFLOW:
  88         sprintf( buffer, "Unhandled stack overflow" );
  89         break;
  90     case EXCEPTION_PRIV_INSTRUCTION:
  91         sprintf( buffer, "Unhandled priviledged instruction" );
  92         break;
  93     case EXCEPTION_ACCESS_VIOLATION:
  94         if (rec->NumberParameters == 2)
  95             sprintf( buffer, "Unhandled page fault on %s access to 0x%08lx",
  96                      rec->ExceptionInformation[0] ? "write" : "read",
  97                      rec->ExceptionInformation[1]);
  98         else
  99             sprintf( buffer, "Unhandled page fault");
 100         break;
 101     case EXCEPTION_DATATYPE_MISALIGNMENT:
 102         sprintf( buffer, "Unhandled alignment" );
 103         break;
 104     case CONTROL_C_EXIT:
 105         sprintf( buffer, "Unhandled ^C");
 106         break;
 107     case EXCEPTION_CRITICAL_SECTION_WAIT:
 108         sprintf( buffer, "Critical section %08lx wait failed",
 109                  rec->ExceptionInformation[0]);
 110         break;
 111     case EXCEPTION_WINE_STUB:
 112         sprintf( buffer, "Unimplemented function %s.%s called",
 113                  (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 114         break;
 115     case EXCEPTION_VM86_INTx:
 116         sprintf( buffer, "Unhandled interrupt %02lx in vm86 mode",
 117                  rec->ExceptionInformation[0]);
 118         break;
 119     case EXCEPTION_VM86_STI:
 120         sprintf( buffer, "Unhandled sti in vm86 mode");
 121         break;
 122     case EXCEPTION_VM86_PICRETURN:
 123         sprintf( buffer, "Unhandled PIC return in vm86 mode");
 124         break;
 125     default:
 126         sprintf( buffer, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 127         break;
 128     }
 129 #ifdef __i386__
 130     if (ptr->ContextRecord->SegCs != __get_cs())
 131         sprintf( buffer+strlen(buffer), " at address 0x%04lx:0x%08lx.\n",
 132                  ptr->ContextRecord->SegCs, (DWORD)ptr->ExceptionRecord->ExceptionAddress );
 133     else
 134 #endif
 135     sprintf( buffer+strlen(buffer), " at address 0x%08lx.\n",
 136              (DWORD)ptr->ExceptionRecord->ExceptionAddress );
 137     strcat( buffer, "Do you wish to debug it ?" );
 138 }
 139
 140
 141 /**********************************************************************
 142  *           send_debug_event
 143  *
 144  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 145  */
 146 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 147 {
 148     int ret;
 149     HANDLE handle = 0;
 150
 151     SERVER_START_REQ
 152     {
 153         struct queue_exception_event_request *req = server_alloc_req( sizeof(*req),
 154                                                                       sizeof(*rec)+sizeof(*context) );
 155         CONTEXT *context_ptr = server_data_ptr(req);
 156         EXCEPTION_RECORD *rec_ptr = (EXCEPTION_RECORD *)(context_ptr + 1);
 157         req->first   = first_chance;
 158         *rec_ptr     = *rec;
 159         *context_ptr = *context;
 160         if (!server_call_noerr( REQ_QUEUE_EXCEPTION_EVENT )) handle = req->handle;
 161     }
 162     SERVER_END_REQ;
 163     if (!handle) return 0;  /* no debugger present or other error */
 164
 165     /* No need to wait on the handle since the process gets suspended
 166      * once the event is passed to the debugger, so when we get back
 167      * here the event has been continued already.
 168      */
 169     SERVER_START_REQ
 170     {
 171         struct get_exception_status_request *req = server_alloc_req( sizeof(*req), sizeof(*context) );
 172         req->handle = handle;
 173         if (!server_call_noerr( REQ_GET_EXCEPTION_STATUS ))
 174             *context = *(CONTEXT *)server_data_ptr(req);
 175         ret = req->status;
 176     }
 177     SERVER_END_REQ;
 178     NtClose( handle );
 179     return ret;
 180 }
 181
 182
 183 /*******************************************************************
 184  *         UnhandledExceptionFilter   (KERNEL32.537)
 185  */
 186 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 187 {
 188     char                format[256];
 189     char                buffer[256];
 190     HKEY                hDbgConf;
 191     DWORD               bAuto = FALSE;
 192     DWORD               ret = EXCEPTION_EXECUTE_HANDLER;
 193     int status;
 194
 195     /* send a last chance event to the debugger */
 196     status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 197     switch (status)
 198     {
 199     case DBG_CONTINUE:
 200         return EXCEPTION_CONTINUE_EXECUTION;
 201     case DBG_EXCEPTION_NOT_HANDLED:
 202         TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 203         break; /* not reached */
 204     case 0: /* no debugger is present */
 205         break;
 206     default:
 207         FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 208     }
 209
 210     if (top_filter)
 211     {
 212         DWORD ret = top_filter( epointers );
 213         if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 214     }
 215
 216     /* FIXME: Should check the current error mode */
 217
 218     if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
 219                      "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug",
 220                      &hDbgConf)) {
 221        DWORD    type;
 222        DWORD    count;
 223
 224        count = sizeof(format);
 225        if (RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &count))
 226           format[0] = 0;
 227
 228        count = sizeof(bAuto);
 229        if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
 230           bAuto = TRUE;
 231        else if (type == REG_SZ)
 232        {
 233            char autostr[10];
 234            count = sizeof(autostr);
 235            if (!RegQueryValueExA(hDbgConf, "Auto", 0, &type, autostr, &count))
 236                bAuto = atoi(autostr);
 237        }
 238        RegCloseKey(hDbgConf);
 239     } else {
 240        /* format[0] = 0; */
 241        strcpy(format, "debugger/winedbg %ld %ld");
 242     }
 243
 244     if (!bAuto && Callout.MessageBoxA) {
 245         format_exception_msg( epointers, buffer );
 246        if (Callout.MessageBoxA( 0, buffer, "Error", MB_YESNO | MB_ICONHAND ) == IDNO) {
 247           TRACE("Killing process\n");
 248           return EXCEPTION_EXECUTE_HANDLER;
 249        }
 250     }
 251
 252     if (format[0]) {
 253        HANDLE                   hEvent;
 254        PROCESS_INFORMATION      info;
 255        STARTUPINFOA             startup;
 256        OBJECT_ATTRIBUTES        attr;
 257
 258        attr.Length                   = sizeof(attr);
 259        attr.RootDirectory            = 0;
 260        attr.Attributes               = OBJ_INHERIT;
 261        attr.ObjectName               = NULL;
 262        attr.SecurityDescriptor       = NULL;
 263        attr.SecurityQualityOfService = NULL;
 264
 265        TRACE("Starting debugger (fmt=%s)\n", format);
 266        NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, FALSE, FALSE );
 267        sprintf(buffer, format, GetCurrentProcessId(), hEvent);
 268        memset(&startup, 0, sizeof(startup));
 269        startup.cb = sizeof(startup);
 270        startup.dwFlags = STARTF_USESHOWWINDOW;
 271        startup.wShowWindow = SW_SHOWNORMAL;
 272        if (CreateProcessA(NULL, buffer, NULL, NULL,
 273                           TRUE, 0, NULL, NULL, &startup, &info)) {
 274           WaitForSingleObject(hEvent, INFINITE);
 275           ret = EXCEPTION_CONTINUE_SEARCH;
 276        } else {
 277            ERR("Couldn't start debugger (%s) (%ld)\n"
 278                "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 279                buffer, GetLastError());
 280        }
 281        CloseHandle(hEvent);
 282     } else {
 283        ERR("No standard debugger defined in the registry => no debugging session\n");
 284     }
 285
 286     return ret;
 287 }
 288
 289
 290 /***********************************************************************
 291  *            SetUnhandledExceptionFilter   (KERNEL32.516)
 292  */
 293 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 294                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 295 {
 296     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 297     top_filter = filter;
 298     return old;
 299 }
 300
 301
 302 /**************************************************************************
 303  *           FatalAppExitA   (KERNEL32.108)
 304  */
 305 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 306 {
 307     WARN("AppExit\n");
 308     if (Callout.MessageBoxA)
 309         Callout.MessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 310     else
 311         ERR( "%s\n", debugstr_a(str) );
 312     ExitProcess(0);
 313 }
 314
 315
 316 /**************************************************************************
 317  *           FatalAppExitW   (KERNEL32.109)
 318  */
 319 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 320 {
 321     WARN("AppExit\n");
 322     if (Callout.MessageBoxW)
 323         Callout.MessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 324     else
 325         ERR( "%s\n", debugstr_w(str) );
 326     ExitProcess(0);
 327 }