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 "selectors.h"
  31 #include "callback.h"
  32 #include "process.h"
  33 #include "thread.h"
  34 #include "stackframe.h"
  35 #include "server.h"
  36 #include "debugtools.h"
  37
  38 DEFAULT_DEBUG_CHANNEL(seh);
  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  *         UnhandledExceptionFilter   (KERNEL32.537)
 143  */
 144 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 145 {
 146     PDB*                pdb = PROCESS_Current();
 147     char                format[256];
 148     char                buffer[256];
 149     HKEY                hDbgConf;
 150     DWORD               bAuto = FALSE;
 151     DWORD               ret = EXCEPTION_EXECUTE_HANDLER;
 152     int status;
 153
 154     /* send a last chance event to the debugger */
 155     SERVER_START_REQ
 156     {
 157         struct exception_event_request *req = server_alloc_req( sizeof(*req),
 158                                                   sizeof(EXCEPTION_RECORD)+sizeof(CONTEXT) );
 159         CONTEXT *context_ptr = server_data_ptr(req);
 160         EXCEPTION_RECORD *rec_ptr = (EXCEPTION_RECORD *)(context_ptr + 1);
 161         req->first   = 0;
 162         *rec_ptr     = *epointers->ExceptionRecord;
 163         *context_ptr = *epointers->ContextRecord;
 164         if (!server_call_noerr( REQ_EXCEPTION_EVENT )) *epointers->ContextRecord = *context_ptr;
 165         status = req->status;
 166     }
 167     SERVER_END_REQ;
 168
 169     switch (status)
 170     {
 171     case DBG_CONTINUE:
 172         return EXCEPTION_CONTINUE_EXECUTION;
 173     case DBG_EXCEPTION_NOT_HANDLED:
 174         TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 175         break; /* not reached */
 176     case 0: /* no debugger is present */
 177         break;
 178     default:
 179         FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 180     }
 181
 182     if (pdb->top_filter)
 183     {
 184         DWORD ret = pdb->top_filter( epointers );
 185         if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 186     }
 187
 188     /* FIXME: Should check the current error mode */
 189
 190     if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
 191                      "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug",
 192                      &hDbgConf)) {
 193        DWORD    type;
 194        DWORD    count;
 195
 196        count = sizeof(format);
 197        if (RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &count))
 198           format[0] = 0;
 199
 200        count = sizeof(bAuto);
 201        if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
 202           bAuto = TRUE;
 203        else if (type == REG_SZ)
 204        {
 205            char autostr[10];
 206            count = sizeof(autostr);
 207            if (!RegQueryValueExA(hDbgConf, "Auto", 0, &type, autostr, &count))
 208                bAuto = atoi(autostr);
 209        }
 210        RegCloseKey(hDbgConf);
 211     } else {
 212        /* format[0] = 0; */
 213        strcpy(format, "debugger/winedbg %ld %ld");
 214     }
 215
 216     if (!bAuto && Callout.MessageBoxA) {
 217         format_exception_msg( epointers, buffer );
 218        if (Callout.MessageBoxA( 0, buffer, "Error", MB_YESNO | MB_ICONHAND ) == IDNO) {
 219           TRACE("Killing process\n");
 220           return EXCEPTION_EXECUTE_HANDLER;
 221        }
 222     }
 223
 224     if (format[0]) {
 225        HANDLE                   hEvent;
 226        PROCESS_INFORMATION      info;
 227        STARTUPINFOA             startup;
 228        OBJECT_ATTRIBUTES        attr;
 229
 230        attr.Length                   = sizeof(attr);
 231        attr.RootDirectory            = 0;
 232        attr.Attributes               = OBJ_INHERIT;
 233        attr.ObjectName               = NULL;
 234        attr.SecurityDescriptor       = NULL;
 235        attr.SecurityQualityOfService = NULL;
 236
 237        TRACE("Starting debugger (fmt=%s)\n", format);
 238        NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, FALSE, FALSE );
 239        sprintf(buffer, format, GetCurrentProcessId(), hEvent);
 240        memset(&startup, 0, sizeof(startup));
 241        startup.cb = sizeof(startup);
 242        startup.dwFlags = STARTF_USESHOWWINDOW;
 243        startup.wShowWindow = SW_SHOWNORMAL;
 244        if (CreateProcessA(NULL, buffer, NULL, NULL,
 245                           TRUE, 0, NULL, NULL, &startup, &info)) {
 246           WaitForSingleObject(hEvent, INFINITE);
 247           ret = EXCEPTION_CONTINUE_SEARCH;
 248        } else {
 249            ERR("Couldn't start debugger (%s) (%ld)\n"
 250                "Read the documentation on how to set up winedbg or another debugger\n",
 251                buffer, GetLastError());
 252        }
 253        CloseHandle(hEvent);
 254     } else {
 255        ERR("No standard debugger defined in the registry => no debugging session\n");
 256     }
 257
 258     return ret;
 259 }
 260
 261
 262 /***********************************************************************
 263  *            SetUnhandledExceptionFilter   (KERNEL32.516)
 264  */
 265 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 266                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 267 {
 268     PDB *pdb = PROCESS_Current();
 269     LPTOP_LEVEL_EXCEPTION_FILTER old = pdb->top_filter;
 270     pdb->top_filter = filter;
 271     return old;
 272 }
 273
 274
 275 /**************************************************************************
 276  *           FatalAppExitA   (KERNEL32.108)
 277  */
 278 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 279 {
 280     WARN("AppExit\n");
 281     if (Callout.MessageBoxA)
 282         Callout.MessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 283     else
 284         ERR( "%s\n", debugstr_a(str) );
 285     ExitProcess(0);
 286 }
 287
 288
 289 /**************************************************************************
 290  *           FatalAppExitW   (KERNEL32.109)
 291  */
 292 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 293 {
 294     WARN("AppExit\n");
 295     if (Callout.MessageBoxW)
 296         Callout.MessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 297     else
 298         ERR( "%s\n", debugstr_w(str) );
 299     ExitProcess(0);
 300 }