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  * 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.
  11  *
  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.
  16  *
  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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  *
  21  * Notes:
  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
  26  *  reasons for this:
  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).
  31  *
  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
  35  *  documented!
  36  *
  37  */
  38
  39 #include <stdio.h>
  40 #include "windef.h"
  41 #include "winerror.h"
  42 #include "ntddk.h"
  43 #include "wingdi.h"
  44 #include "winuser.h"
  45 #include "wine/exception.h"
  46 #include "wine/library.h"
  47 #include "thread.h"
  48 #include "stackframe.h"
  49 #include "wine/server.h"
  50 #include "wine/debug.h"
  51 #include "msvcrt/excpt.h"
  52
  53 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  54
  55 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
  56
  57 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
  58 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
  59
  60 /*******************************************************************
  61  *         RaiseException  (KERNEL32.@)
  62  */
  63 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
  64 {
  65     EXCEPTION_RECORD record;
  66
  67     /* Compose an exception record */
  68
  69     record.ExceptionCode    = code;
  70     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  71     record.ExceptionRecord  = NULL;
  72     record.ExceptionAddress = RaiseException;
  73     if (nbargs && args)
  74     {
  75         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  76         record.NumberParameters = nbargs;
  77         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  78     }
  79     else record.NumberParameters = 0;
  80
  81     RtlRaiseException( &record );
  82 }
  83
  84
  85 /*******************************************************************
  86  *         format_exception_msg
  87  */
  88 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
  89 {
  90     const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
  91     int len,len2;
  92
  93     switch(rec->ExceptionCode)
  94     {
  95     case EXCEPTION_INT_DIVIDE_BY_ZERO:
  96         len = snprintf( buffer, size, "Unhandled division by zero" );
  97         break;
  98     case EXCEPTION_INT_OVERFLOW:
  99         len = snprintf( buffer, size, "Unhandled overflow" );
 100         break;
 101     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 102         len = snprintf( buffer, size, "Unhandled array bounds" );
 103         break;
 104     case EXCEPTION_ILLEGAL_INSTRUCTION:
 105         len = snprintf( buffer, size, "Unhandled illegal instruction" );
 106         break;
 107     case EXCEPTION_STACK_OVERFLOW:
 108         len = snprintf( buffer, size, "Unhandled stack overflow" );
 109         break;
 110     case EXCEPTION_PRIV_INSTRUCTION:
 111         len = snprintf( buffer, size, "Unhandled privileged instruction" );
 112         break;
 113     case EXCEPTION_ACCESS_VIOLATION:
 114         if (rec->NumberParameters == 2)
 115             len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
 116                      rec->ExceptionInformation[0] ? "write" : "read",
 117                      rec->ExceptionInformation[1]);
 118         else
 119             len = snprintf( buffer, size, "Unhandled page fault");
 120         break;
 121     case EXCEPTION_DATATYPE_MISALIGNMENT:
 122         len = snprintf( buffer, size, "Unhandled alignment" );
 123         break;
 124     case CONTROL_C_EXIT:
 125         len = snprintf( buffer, size, "Unhandled ^C");
 126         break;
 127     case EXCEPTION_CRITICAL_SECTION_WAIT:
 128         len = snprintf( buffer, size, "Critical section %08lx wait failed",
 129                  rec->ExceptionInformation[0]);
 130         break;
 131     case EXCEPTION_WINE_STUB:
 132         len = snprintf( buffer, size, "Unimplemented function %s.%s called",
 133                  (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 134         break;
 135     case EXCEPTION_VM86_INTx:
 136         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 137                  rec->ExceptionInformation[0]);
 138         break;
 139     case EXCEPTION_VM86_STI:
 140         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 141         break;
 142     case EXCEPTION_VM86_PICRETURN:
 143         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 144         break;
 145     default:
 146         len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 147         break;
 148     }
 149     if ((len<0) || (len>=size))
 150         return -1;
 151 #ifdef __i386__
 152     if (ptr->ContextRecord->SegCs != wine_get_cs())
 153         len2 = snprintf(buffer+len, size-len,
 154                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 155                         ptr->ContextRecord->SegCs,
 156                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 157     else
 158 #endif
 159         len2 = snprintf(buffer+len, size-len,
 160                         " at address 0x%08lx.\nDo you wish to debug it ?",
 161                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 162     if ((len2<0) || (len>=size-len))
 163         return -1;
 164     return len+len2;
 165 }
 166
 167
 168 /**********************************************************************
 169  *           send_debug_event
 170  *
 171  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 172  */
 173 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 174 {
 175     int ret;
 176     HANDLE handle = 0;
 177
 178     SERVER_START_REQ( queue_exception_event )
 179     {
 180         req->first   = first_chance;
 181         wine_server_add_data( req, context, sizeof(*context) );
 182         wine_server_add_data( req, rec, sizeof(*rec) );
 183         if (!wine_server_call(req)) handle = reply->handle;
 184     }
 185     SERVER_END_REQ;
 186     if (!handle) return 0;  /* no debugger present or other error */
 187
 188     /* No need to wait on the handle since the process gets suspended
 189      * once the event is passed to the debugger, so when we get back
 190      * here the event has been continued already.
 191      */
 192     SERVER_START_REQ( get_exception_status )
 193     {
 194         req->handle = handle;
 195         wine_server_set_reply( req, context, sizeof(*context) );
 196         wine_server_call( req );
 197         ret = reply->status;
 198     }
 199     SERVER_END_REQ;
 200     NtClose( handle );
 201     return ret;
 202 }
 203
 204 /******************************************************************
 205  *              start_debugger
 206  *
 207  * Does the effective debugger startup according to 'format'
 208  */
 209 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 210 {
 211     HKEY                hDbgConf;
 212     DWORD               bAuto = FALSE;
 213     PROCESS_INFORMATION info;
 214     STARTUPINFOA        startup;
 215     char*               cmdline = NULL;
 216     char*               format = NULL;
 217     DWORD               format_size;
 218     BOOL                ret = FALSE;
 219
 220     MESSAGE("wine: Unhandled exception, starting debugger...\n");
 221
 222     if (!RegOpenKeyA(HKEY_LOCAL_MACHINE,
 223                      "Software\\Microsoft\\Windows NT\\CurrentVersion\\AeDebug", &hDbgConf)) {
 224        DWORD    type;
 225        DWORD    count;
 226
 227        format_size = 0;
 228        if (!RegQueryValueExA(hDbgConf, "Debugger", 0, &type, NULL, &format_size)) {
 229            format = HeapAlloc(GetProcessHeap(), 0, format_size);
 230            RegQueryValueExA(hDbgConf, "Debugger", 0, &type, format, &format_size);
 231            if (type==REG_EXPAND_SZ) {
 232                char* tmp;
 233
 234                /* Expand environment variable references */
 235                format_size=ExpandEnvironmentStringsA(format,NULL,0);
 236                tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 237                ExpandEnvironmentStringsA(format,tmp,format_size);
 238                HeapFree(GetProcessHeap(), 0, format);
 239                format=tmp;
 240            }
 241        }
 242
 243        count = sizeof(bAuto);
 244        if (RegQueryValueExA(hDbgConf, "Auto", 0, &type, (char*)&bAuto, &count))
 245           bAuto = TRUE;
 246        else if (type == REG_SZ)
 247        {
 248            char autostr[10];
 249            count = sizeof(autostr);
 250            if (!RegQueryValueExA(hDbgConf, "Auto", 0, &type, autostr, &count))
 251                bAuto = atoi(autostr);
 252        }
 253        RegCloseKey(hDbgConf);
 254     } else {
 255         /* try a default setup... */
 256         strcpy( format, "winedbg --debugmsg -all -- --auto %ld %ld" );
 257     }
 258
 259     if (!bAuto)
 260     {
 261         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 262         MessageBoxA_funcptr     pMessageBoxA = NULL;
 263
 264         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 265         if (pMessageBoxA)
 266         {
 267             char buffer[256];
 268             format_exception_msg( epointers, buffer, sizeof(buffer) );
 269             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 270             {
 271                 TRACE("Killing process\n");
 272                 goto EXIT;
 273             }
 274         }
 275     }
 276
 277     if (format) {
 278         TRACE("Starting debugger (fmt=%s)\n", format);
 279         cmdline=HeapAlloc(GetProcessHeap(), 0, format_size+2*20);
 280         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 281         memset(&startup, 0, sizeof(startup));
 282         startup.cb = sizeof(startup);
 283         startup.dwFlags = STARTF_USESHOWWINDOW;
 284         startup.wShowWindow = SW_SHOWNORMAL;
 285         if (CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, NULL, NULL, &startup, &info)) {
 286             /* wait for debugger to come up... */
 287             WaitForSingleObject(hEvent, INFINITE);
 288             ret = TRUE;
 289             goto EXIT;
 290         }
 291     } else {
 292         cmdline = NULL;
 293     }
 294     ERR("Couldn't start debugger (%s) (%ld)\n"
 295         "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 296         debugstr_a(cmdline), GetLastError());
 297
 298 EXIT:
 299     if (cmdline)
 300         HeapFree(GetProcessHeap(), 0, cmdline);
 301     if (format)
 302         HeapFree(GetProcessHeap(), 0, format);
 303     return ret;
 304 }
 305
 306 /******************************************************************
 307  *              start_debugger_atomic
 308  *
 309  * starts the debugger in an atomic way:
 310  *      - either the debugger is not started and it is started
 311  *      - or the debugger has already been started by another thread
 312  *      - or the debugger couldn't be started
 313  *
 314  * returns TRUE for the two first conditions, FALSE for the last
 315  */
 316 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 317 {
 318     static HANDLE       hRunOnce /* = 0 */;
 319
 320     if (hRunOnce == 0)
 321     {
 322         OBJECT_ATTRIBUTES       attr;
 323         HANDLE                  hEvent;
 324
 325         attr.Length                   = sizeof(attr);
 326         attr.RootDirectory            = 0;
 327         attr.Attributes               = OBJ_INHERIT;
 328         attr.ObjectName               = NULL;
 329         attr.SecurityDescriptor       = NULL;
 330         attr.SecurityQualityOfService = NULL;
 331
 332         /* ask for manual reset, so that once the debugger is started,
 333          * every thread will know it */
 334         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 335         if (InterlockedCompareExchange( (LPLONG)&hRunOnce, hEvent, 0 ) == 0)
 336         {
 337             /* ok, our event has been set... we're the winning thread */
 338             BOOL        ret = start_debugger( epointers, hRunOnce );
 339             DWORD       tmp;
 340
 341             if (!ret)
 342             {
 343                 /* so that the other threads won't be stuck */
 344                 NtSetEvent( hRunOnce, &tmp );
 345             }
 346             return ret;
 347         }
 348
 349         /* someone beat us here... */
 350         CloseHandle( hEvent );
 351     }
 352
 353     /* and wait for the winner to have actually created the debugger */
 354     WaitForSingleObject( hRunOnce, INFINITE );
 355     /* in fact, here, we only know that someone has tried to start the debugger,
 356      * we'll know by reposting the exception if it has actually attached
 357      * to the current process */
 358     return TRUE;
 359 }
 360
 361
 362 /*******************************************************************
 363  *         UnhandledExceptionFilter   (KERNEL32.@)
 364  */
 365 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 366 {
 367     int                 status;
 368     int                 loop = 0;
 369
 370     for (loop = 0; loop <= 1; loop++)
 371     {
 372         /* send a last chance event to the debugger */
 373         status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 374         switch (status)
 375         {
 376         case DBG_CONTINUE:
 377             return EXCEPTION_CONTINUE_EXECUTION;
 378         case DBG_EXCEPTION_NOT_HANDLED:
 379             TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 380             break; /* not reached */
 381         case 0: /* no debugger is present */
 382             if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 383             {
 384                 /* do not launch the debugger on ^C, simply terminate the process */
 385                 TerminateProcess( GetCurrentProcess(), 1 );
 386             }
 387             /* second try, the debugger isn't present... */
 388             if (loop == 1) return EXCEPTION_EXECUTE_HANDLER;
 389             break;
 390         default:
 391             FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 392             return EXCEPTION_EXECUTE_HANDLER;
 393         }
 394
 395         /* should only be there when loop == 0 */
 396
 397         if (top_filter)
 398         {
 399             DWORD ret = top_filter( epointers );
 400             if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 401         }
 402
 403         /* FIXME: Should check the current error mode */
 404
 405         if (!start_debugger_atomic( epointers ))
 406             return EXCEPTION_EXECUTE_HANDLER;
 407         /* now that we should have a debugger attached, try to resend event */
 408     }
 409
 410     return EXCEPTION_EXECUTE_HANDLER;
 411 }
 412
 413
 414 /***********************************************************************
 415  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 416  */
 417 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 418                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 419 {
 420     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 421     top_filter = filter;
 422     return old;
 423 }
 424
 425
 426 /**************************************************************************
 427  *           FatalAppExitA   (KERNEL32.@)
 428  */
 429 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 430 {
 431     HMODULE mod = GetModuleHandleA( "user32.dll" );
 432     MessageBoxA_funcptr pMessageBoxA = NULL;
 433
 434     WARN("AppExit\n");
 435
 436     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 437     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 438     else ERR( "%s\n", debugstr_a(str) );
 439     ExitProcess(0);
 440 }
 441
 442
 443 /**************************************************************************
 444  *           FatalAppExitW   (KERNEL32.@)
 445  */
 446 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 447 {
 448     HMODULE mod = GetModuleHandleA( "user32.dll" );
 449     MessageBoxW_funcptr pMessageBoxW = NULL;
 450
 451     WARN("AppExit\n");
 452
 453     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 454     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 455     else ERR( "%s\n", debugstr_w(str) );
 456     ExitProcess(0);
 457 }