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 #include "config.h"
  39 #include "wine/port.h"
  40
  41 #include <stdio.h>
  42 #include "windef.h"
  43 #include "winerror.h"
  44 #include "winternl.h"
  45 #include "wingdi.h"
  46 #include "winuser.h"
  47 #include "wine/exception.h"
  48 #include "wine/library.h"
  49 #include "thread.h"
  50 #include "stackframe.h"
  51 #include "msvcrt/excpt.h"
  52 #include "wine/server.h"
  53 #include "wine/unicode.h"
  54 #include "wine/debug.h"
  55
  56 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  57
  58 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
  59
  60 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
  61 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
  62
  63 /*******************************************************************
  64  *         RaiseException  (KERNEL32.@)
  65  */
  66 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
  67 {
  68     EXCEPTION_RECORD record;
  69
  70     /* Compose an exception record */
  71
  72     record.ExceptionCode    = code;
  73     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  74     record.ExceptionRecord  = NULL;
  75     record.ExceptionAddress = RaiseException;
  76     if (nbargs && args)
  77     {
  78         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  79         record.NumberParameters = nbargs;
  80         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  81     }
  82     else record.NumberParameters = 0;
  83
  84     RtlRaiseException( &record );
  85 }
  86
  87
  88 /*******************************************************************
  89  *         format_exception_msg
  90  */
  91 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
  92 {
  93     const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
  94     int len,len2;
  95
  96     switch(rec->ExceptionCode)
  97     {
  98     case EXCEPTION_INT_DIVIDE_BY_ZERO:
  99         len = snprintf( buffer, size, "Unhandled division by zero" );
 100         break;
 101     case EXCEPTION_INT_OVERFLOW:
 102         len = snprintf( buffer, size, "Unhandled overflow" );
 103         break;
 104     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 105         len = snprintf( buffer, size, "Unhandled array bounds" );
 106         break;
 107     case EXCEPTION_ILLEGAL_INSTRUCTION:
 108         len = snprintf( buffer, size, "Unhandled illegal instruction" );
 109         break;
 110     case EXCEPTION_STACK_OVERFLOW:
 111         len = snprintf( buffer, size, "Unhandled stack overflow" );
 112         break;
 113     case EXCEPTION_PRIV_INSTRUCTION:
 114         len = snprintf( buffer, size, "Unhandled privileged instruction" );
 115         break;
 116     case EXCEPTION_ACCESS_VIOLATION:
 117         if (rec->NumberParameters == 2)
 118             len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
 119                      rec->ExceptionInformation[0] ? "write" : "read",
 120                      rec->ExceptionInformation[1]);
 121         else
 122             len = snprintf( buffer, size, "Unhandled page fault");
 123         break;
 124     case EXCEPTION_DATATYPE_MISALIGNMENT:
 125         len = snprintf( buffer, size, "Unhandled alignment" );
 126         break;
 127     case CONTROL_C_EXIT:
 128         len = snprintf( buffer, size, "Unhandled ^C");
 129         break;
 130     case EXCEPTION_CRITICAL_SECTION_WAIT:
 131         len = snprintf( buffer, size, "Critical section %08lx wait failed",
 132                  rec->ExceptionInformation[0]);
 133         break;
 134     case EXCEPTION_WINE_STUB:
 135         len = snprintf( buffer, size, "Unimplemented function %s.%s called",
 136                  (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 137         break;
 138     case EXCEPTION_VM86_INTx:
 139         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 140                  rec->ExceptionInformation[0]);
 141         break;
 142     case EXCEPTION_VM86_STI:
 143         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 144         break;
 145     case EXCEPTION_VM86_PICRETURN:
 146         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 147         break;
 148     default:
 149         len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 150         break;
 151     }
 152     if ((len<0) || (len>=size))
 153         return -1;
 154 #ifdef __i386__
 155     if (ptr->ContextRecord->SegCs != wine_get_cs())
 156         len2 = snprintf(buffer+len, size-len,
 157                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 158                         ptr->ContextRecord->SegCs,
 159                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 160     else
 161 #endif
 162         len2 = snprintf(buffer+len, size-len,
 163                         " at address 0x%08lx.\nDo you wish to debug it ?",
 164                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 165     if ((len2<0) || (len>=size-len))
 166         return -1;
 167     return len+len2;
 168 }
 169
 170
 171 /**********************************************************************
 172  *           send_debug_event
 173  *
 174  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 175  */
 176 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 177 {
 178     int ret;
 179     HANDLE handle = 0;
 180
 181     SERVER_START_REQ( queue_exception_event )
 182     {
 183         req->first   = first_chance;
 184         wine_server_add_data( req, context, sizeof(*context) );
 185         wine_server_add_data( req, rec, sizeof(*rec) );
 186         if (!wine_server_call(req)) handle = reply->handle;
 187     }
 188     SERVER_END_REQ;
 189     if (!handle) return 0;  /* no debugger present or other error */
 190
 191     /* No need to wait on the handle since the process gets suspended
 192      * once the event is passed to the debugger, so when we get back
 193      * here the event has been continued already.
 194      */
 195     SERVER_START_REQ( get_exception_status )
 196     {
 197         req->handle = handle;
 198         wine_server_set_reply( req, context, sizeof(*context) );
 199         wine_server_call( req );
 200         ret = reply->status;
 201     }
 202     SERVER_END_REQ;
 203     NtClose( handle );
 204     return ret;
 205 }
 206
 207 /******************************************************************
 208  *              start_debugger
 209  *
 210  * Does the effective debugger startup according to 'format'
 211  */
 212 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 213 {
 214     OBJECT_ATTRIBUTES attr;
 215     UNICODE_STRING nameW;
 216     HKEY                hDbgConf;
 217     DWORD               bAuto = FALSE;
 218     PROCESS_INFORMATION info;
 219     STARTUPINFOA        startup;
 220     char*               cmdline;
 221     char*               format = NULL;
 222     BOOL                ret = FALSE;
 223
 224     static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
 225                                      'S','o','f','t','w','a','r','e','\\',
 226                                      'M','i','c','r','o','s','o','f','t','\\',
 227                                      'W','i','n','d','o','w','s',' ','N','T','\\',
 228                                      'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
 229                                      'A','e','D','e','b','u','g',0};
 230     static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
 231     static const WCHAR AutoW[] = {'A','u','t','o',0};
 232
 233     MESSAGE("wine: Unhandled exception, starting debugger...\n");
 234
 235     attr.Length = sizeof(attr);
 236     attr.RootDirectory = 0;
 237     attr.ObjectName = &nameW;
 238     attr.Attributes = 0;
 239     attr.SecurityDescriptor = NULL;
 240     attr.SecurityQualityOfService = NULL;
 241     RtlInitUnicodeString( &nameW, AeDebugW );
 242
 243     if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
 244     {
 245         char buffer[64];
 246         KEY_VALUE_PARTIAL_INFORMATION *info;
 247         DWORD format_size = 0;
 248
 249         RtlInitUnicodeString( &nameW, DebuggerW );
 250         if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 251                              NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
 252         {
 253             char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
 254             NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 255                              data, format_size, &format_size );
 256             info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
 257             RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
 258             format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
 259             RtlUnicodeToMultiByteN( format, format_size, NULL,
 260                                     (WCHAR *)info->Data, info->DataLength );
 261             format[format_size] = 0;
 262
 263             if (info->Type == REG_EXPAND_SZ)
 264             {
 265                 char* tmp;
 266
 267                 /* Expand environment variable references */
 268                 format_size=ExpandEnvironmentStringsA(format,NULL,0);
 269                 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 270                 ExpandEnvironmentStringsA(format,tmp,format_size);
 271                 HeapFree(GetProcessHeap(), 0, format);
 272                 format=tmp;
 273             }
 274             HeapFree( GetProcessHeap(), 0, data );
 275         }
 276
 277         RtlInitUnicodeString( &nameW, AutoW );
 278         if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 279                               buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
 280        {
 281            info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
 282            if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
 283            else if (info->Type == REG_SZ)
 284            {
 285                WCHAR *str = (WCHAR *)info->Data;
 286                str[info->DataLength/sizeof(WCHAR)] = 0;
 287                bAuto = atoiW( str );
 288            }
 289        }
 290        else bAuto = TRUE;
 291
 292        NtClose(hDbgConf);
 293     }
 294
 295     if (format)
 296     {
 297         cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
 298         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 299         HeapFree(GetProcessHeap(), 0, format);
 300     }
 301     else
 302     {
 303         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
 304         sprintf(cmdline, "winedbg --debugmsg -all --auto %ld %d", GetCurrentProcessId(), hEvent);
 305     }
 306
 307     if (!bAuto)
 308     {
 309         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 310         MessageBoxA_funcptr     pMessageBoxA = NULL;
 311
 312         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 313         if (pMessageBoxA)
 314         {
 315             char buffer[256];
 316             format_exception_msg( epointers, buffer, sizeof(buffer) );
 317             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 318             {
 319                 TRACE("Killing process\n");
 320                 goto EXIT;
 321             }
 322         }
 323     }
 324
 325     TRACE("Starting debugger %s\n", debugstr_a(cmdline));
 326     memset(&startup, 0, sizeof(startup));
 327     startup.cb = sizeof(startup);
 328     startup.dwFlags = STARTF_USESHOWWINDOW;
 329     startup.wShowWindow = SW_SHOWNORMAL;
 330     ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, NULL, NULL, &startup, &info);
 331
 332     if (ret) WaitForSingleObject(hEvent, INFINITE);  /* wait for debugger to come up... */
 333     else ERR("Couldn't start debugger (%s) (%ld)\n"
 334              "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 335              debugstr_a(cmdline), GetLastError());
 336 EXIT:
 337     HeapFree(GetProcessHeap(), 0, cmdline);
 338     return ret;
 339 }
 340
 341 /******************************************************************
 342  *              start_debugger_atomic
 343  *
 344  * starts the debugger in an atomic way:
 345  *      - either the debugger is not started and it is started
 346  *      - or the debugger has already been started by another thread
 347  *      - or the debugger couldn't be started
 348  *
 349  * returns TRUE for the two first conditions, FALSE for the last
 350  */
 351 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 352 {
 353     static HANDLE       hRunOnce /* = 0 */;
 354
 355     if (hRunOnce == 0)
 356     {
 357         OBJECT_ATTRIBUTES       attr;
 358         HANDLE                  hEvent;
 359
 360         attr.Length                   = sizeof(attr);
 361         attr.RootDirectory            = 0;
 362         attr.Attributes               = OBJ_INHERIT;
 363         attr.ObjectName               = NULL;
 364         attr.SecurityDescriptor       = NULL;
 365         attr.SecurityQualityOfService = NULL;
 366
 367         /* ask for manual reset, so that once the debugger is started,
 368          * every thread will know it */
 369         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 370         if (InterlockedCompareExchange( (LPLONG)&hRunOnce, hEvent, 0 ) == 0)
 371         {
 372             /* ok, our event has been set... we're the winning thread */
 373             BOOL        ret = start_debugger( epointers, hRunOnce );
 374             DWORD       tmp;
 375
 376             if (!ret)
 377             {
 378                 /* so that the other threads won't be stuck */
 379                 NtSetEvent( hRunOnce, &tmp );
 380             }
 381             return ret;
 382         }
 383
 384         /* someone beat us here... */
 385         CloseHandle( hEvent );
 386     }
 387
 388     /* and wait for the winner to have actually created the debugger */
 389     WaitForSingleObject( hRunOnce, INFINITE );
 390     /* in fact, here, we only know that someone has tried to start the debugger,
 391      * we'll know by reposting the exception if it has actually attached
 392      * to the current process */
 393     return TRUE;
 394 }
 395
 396
 397 /*******************************************************************
 398  *         check_resource_write
 399  *
 400  * Check if the exception is a write attempt to the resource data.
 401  * If yes, we unprotect the resources to let broken apps continue
 402  * (Windows does this too).
 403  */
 404 inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
 405 {
 406     void *addr, *rsrc;
 407     DWORD size;
 408     MEMORY_BASIC_INFORMATION info;
 409
 410     if (rec->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) return FALSE;
 411     if (!rec->ExceptionInformation[0]) return FALSE;  /* not a write access */
 412     addr = (void *)rec->ExceptionInformation[1];
 413     if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
 414     if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
 415                                               IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
 416         return FALSE;
 417     if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
 418     FIXME( "Broken app is writing to the resource data, enabling work-around\n" );
 419     VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
 420     return TRUE;
 421 }
 422
 423
 424 /*******************************************************************
 425  *         UnhandledExceptionFilter   (KERNEL32.@)
 426  */
 427 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 428 {
 429     int                 status;
 430     int                 loop = 0;
 431
 432     if (check_resource_write( epointers->ExceptionRecord )) return EXCEPTION_CONTINUE_EXECUTION;
 433
 434     for (loop = 0; loop <= 1; loop++)
 435     {
 436         /* send a last chance event to the debugger */
 437         status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 438         switch (status)
 439         {
 440         case DBG_CONTINUE:
 441             return EXCEPTION_CONTINUE_EXECUTION;
 442         case DBG_EXCEPTION_NOT_HANDLED:
 443             TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 444             break; /* not reached */
 445         case 0: /* no debugger is present */
 446             if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 447             {
 448                 /* do not launch the debugger on ^C, simply terminate the process */
 449                 TerminateProcess( GetCurrentProcess(), 1 );
 450             }
 451             /* second try, the debugger isn't present... */
 452             if (loop == 1) return EXCEPTION_EXECUTE_HANDLER;
 453             break;
 454         default:
 455             FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 456             return EXCEPTION_EXECUTE_HANDLER;
 457         }
 458
 459         /* should only be there when loop == 0 */
 460
 461         if (top_filter)
 462         {
 463             DWORD ret = top_filter( epointers );
 464             if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 465         }
 466
 467         /* FIXME: Should check the current error mode */
 468
 469         if (!start_debugger_atomic( epointers ))
 470             return EXCEPTION_EXECUTE_HANDLER;
 471         /* now that we should have a debugger attached, try to resend event */
 472     }
 473
 474     return EXCEPTION_EXECUTE_HANDLER;
 475 }
 476
 477
 478 /***********************************************************************
 479  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 480  */
 481 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 482                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 483 {
 484     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 485     top_filter = filter;
 486     return old;
 487 }
 488
 489
 490 /**************************************************************************
 491  *           FatalAppExitA   (KERNEL32.@)
 492  */
 493 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 494 {
 495     HMODULE mod = GetModuleHandleA( "user32.dll" );
 496     MessageBoxA_funcptr pMessageBoxA = NULL;
 497
 498     WARN("AppExit\n");
 499
 500     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 501     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 502     else ERR( "%s\n", debugstr_a(str) );
 503     ExitProcess(0);
 504 }
 505
 506
 507 /**************************************************************************
 508  *           FatalAppExitW   (KERNEL32.@)
 509  */
 510 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 511 {
 512     HMODULE mod = GetModuleHandleA( "user32.dll" );
 513     MessageBoxW_funcptr pMessageBoxW = NULL;
 514
 515     WARN("AppExit\n");
 516
 517     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 518     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 519     else ERR( "%s\n", debugstr_w(str) );
 520     ExitProcess(0);
 521 }