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 "excpt.h"
  51 #include "wine/server.h"
  52 #include "wine/unicode.h"
  53 #include "wine/debug.h"
  54
  55 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  56
  57 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
  58
  59 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
  60 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
  61
  62 /*******************************************************************
  63  *         RaiseException  (KERNEL32.@)
  64  */
  65 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
  66 {
  67     EXCEPTION_RECORD record;
  68
  69     /* Compose an exception record */
  70
  71     record.ExceptionCode    = code;
  72     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  73     record.ExceptionRecord  = NULL;
  74     record.ExceptionAddress = RaiseException;
  75     if (nbargs && args)
  76     {
  77         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  78         record.NumberParameters = nbargs;
  79         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  80     }
  81     else record.NumberParameters = 0;
  82
  83     RtlRaiseException( &record );
  84 }
  85
  86
  87 /*******************************************************************
  88  *         format_exception_msg
  89  */
  90 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
  91 {
  92     const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
  93     int len,len2;
  94
  95     switch(rec->ExceptionCode)
  96     {
  97     case EXCEPTION_INT_DIVIDE_BY_ZERO:
  98         len = snprintf( buffer, size, "Unhandled division by zero" );
  99         break;
 100     case EXCEPTION_INT_OVERFLOW:
 101         len = snprintf( buffer, size, "Unhandled overflow" );
 102         break;
 103     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 104         len = snprintf( buffer, size, "Unhandled array bounds" );
 105         break;
 106     case EXCEPTION_ILLEGAL_INSTRUCTION:
 107         len = snprintf( buffer, size, "Unhandled illegal instruction" );
 108         break;
 109     case EXCEPTION_STACK_OVERFLOW:
 110         len = snprintf( buffer, size, "Unhandled stack overflow" );
 111         break;
 112     case EXCEPTION_PRIV_INSTRUCTION:
 113         len = snprintf( buffer, size, "Unhandled privileged instruction" );
 114         break;
 115     case EXCEPTION_ACCESS_VIOLATION:
 116         if (rec->NumberParameters == 2)
 117             len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
 118                      rec->ExceptionInformation[0] ? "write" : "read",
 119                      rec->ExceptionInformation[1]);
 120         else
 121             len = snprintf( buffer, size, "Unhandled page fault");
 122         break;
 123     case EXCEPTION_DATATYPE_MISALIGNMENT:
 124         len = snprintf( buffer, size, "Unhandled alignment" );
 125         break;
 126     case CONTROL_C_EXIT:
 127         len = snprintf( buffer, size, "Unhandled ^C");
 128         break;
 129     case STATUS_POSSIBLE_DEADLOCK:
 130         len = snprintf( buffer, size, "Critical section %08lx wait failed",
 131                  rec->ExceptionInformation[0]);
 132         break;
 133     case EXCEPTION_WINE_STUB:
 134         len = snprintf( buffer, size, "Unimplemented function %s.%s called",
 135                  (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 136         break;
 137     case EXCEPTION_WINE_ASSERTION:
 138         len = snprintf( buffer, size, "Assertion failed" );
 139         break;
 140     case EXCEPTION_VM86_INTx:
 141         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 142                  rec->ExceptionInformation[0]);
 143         break;
 144     case EXCEPTION_VM86_STI:
 145         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 146         break;
 147     case EXCEPTION_VM86_PICRETURN:
 148         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 149         break;
 150     default:
 151         len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 152         break;
 153     }
 154     if ((len<0) || (len>=size))
 155         return -1;
 156 #ifdef __i386__
 157     if (ptr->ContextRecord->SegCs != wine_get_cs())
 158         len2 = snprintf(buffer+len, size-len,
 159                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 160                         ptr->ContextRecord->SegCs,
 161                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 162     else
 163 #endif
 164         len2 = snprintf(buffer+len, size-len,
 165                         " at address 0x%08lx.\nDo you wish to debug it ?",
 166                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 167     if ((len2<0) || (len>=size-len))
 168         return -1;
 169     return len+len2;
 170 }
 171
 172
 173 /**********************************************************************
 174  *           send_debug_event
 175  *
 176  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 177  */
 178 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 179 {
 180     int ret;
 181     HANDLE handle = 0;
 182
 183     SERVER_START_REQ( queue_exception_event )
 184     {
 185         req->first   = first_chance;
 186         wine_server_add_data( req, context, sizeof(*context) );
 187         wine_server_add_data( req, rec, sizeof(*rec) );
 188         if (!wine_server_call(req)) handle = reply->handle;
 189     }
 190     SERVER_END_REQ;
 191     if (!handle) return 0;  /* no debugger present or other error */
 192
 193     /* No need to wait on the handle since the process gets suspended
 194      * once the event is passed to the debugger, so when we get back
 195      * here the event has been continued already.
 196      */
 197     SERVER_START_REQ( get_exception_status )
 198     {
 199         req->handle = handle;
 200         wine_server_set_reply( req, context, sizeof(*context) );
 201         wine_server_call( req );
 202         ret = reply->status;
 203     }
 204     SERVER_END_REQ;
 205     NtClose( handle );
 206     return ret;
 207 }
 208
 209 /******************************************************************
 210  *              start_debugger
 211  *
 212  * Does the effective debugger startup according to 'format'
 213  */
 214 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 215 {
 216     OBJECT_ATTRIBUTES attr;
 217     UNICODE_STRING nameW;
 218     HKEY                hDbgConf;
 219     DWORD               bAuto = FALSE;
 220     PROCESS_INFORMATION info;
 221     STARTUPINFOA        startup;
 222     char*               cmdline;
 223     char*               format = NULL;
 224     BOOL                ret = FALSE;
 225
 226     static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
 227                                      'S','o','f','t','w','a','r','e','\\',
 228                                      'M','i','c','r','o','s','o','f','t','\\',
 229                                      'W','i','n','d','o','w','s',' ','N','T','\\',
 230                                      'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
 231                                      'A','e','D','e','b','u','g',0};
 232     static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
 233     static const WCHAR AutoW[] = {'A','u','t','o',0};
 234
 235     MESSAGE("wine: Unhandled exception (thread %04lx), starting debugger...\n", GetCurrentThreadId());
 236
 237     attr.Length = sizeof(attr);
 238     attr.RootDirectory = 0;
 239     attr.ObjectName = &nameW;
 240     attr.Attributes = 0;
 241     attr.SecurityDescriptor = NULL;
 242     attr.SecurityQualityOfService = NULL;
 243     RtlInitUnicodeString( &nameW, AeDebugW );
 244
 245     if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
 246     {
 247         char buffer[64];
 248         KEY_VALUE_PARTIAL_INFORMATION *info;
 249         DWORD format_size = 0;
 250
 251         RtlInitUnicodeString( &nameW, DebuggerW );
 252         if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 253                              NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
 254         {
 255             char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
 256             NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 257                              data, format_size, &format_size );
 258             info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
 259             RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
 260             format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
 261             RtlUnicodeToMultiByteN( format, format_size, NULL,
 262                                     (WCHAR *)info->Data, info->DataLength );
 263             format[format_size] = 0;
 264
 265             if (info->Type == REG_EXPAND_SZ)
 266             {
 267                 char* tmp;
 268
 269                 /* Expand environment variable references */
 270                 format_size=ExpandEnvironmentStringsA(format,NULL,0);
 271                 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 272                 ExpandEnvironmentStringsA(format,tmp,format_size);
 273                 HeapFree(GetProcessHeap(), 0, format);
 274                 format=tmp;
 275             }
 276             HeapFree( GetProcessHeap(), 0, data );
 277         }
 278
 279         RtlInitUnicodeString( &nameW, AutoW );
 280         if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 281                               buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
 282        {
 283            info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
 284            if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
 285            else if (info->Type == REG_SZ)
 286            {
 287                WCHAR *str = (WCHAR *)info->Data;
 288                str[info->DataLength/sizeof(WCHAR)] = 0;
 289                bAuto = atoiW( str );
 290            }
 291        }
 292        else bAuto = TRUE;
 293
 294        NtClose(hDbgConf);
 295     }
 296
 297     if (format)
 298     {
 299         cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
 300         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 301         HeapFree(GetProcessHeap(), 0, format);
 302     }
 303     else
 304     {
 305         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
 306         sprintf(cmdline, "winedbg --debugmsg -all --auto %ld %ld",
 307                 GetCurrentProcessId(), (ULONG_PTR)hEvent);
 308     }
 309
 310     if (!bAuto)
 311     {
 312         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 313         MessageBoxA_funcptr     pMessageBoxA = NULL;
 314
 315         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 316         if (pMessageBoxA)
 317         {
 318             char buffer[256];
 319             format_exception_msg( epointers, buffer, sizeof(buffer) );
 320             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 321             {
 322                 TRACE("Killing process\n");
 323                 goto EXIT;
 324             }
 325         }
 326     }
 327
 328     TRACE("Starting debugger %s\n", debugstr_a(cmdline));
 329     memset(&startup, 0, sizeof(startup));
 330     startup.cb = sizeof(startup);
 331     startup.dwFlags = STARTF_USESHOWWINDOW;
 332     startup.wShowWindow = SW_SHOWNORMAL;
 333     ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, NULL, NULL, &startup, &info);
 334
 335     if (ret) WaitForSingleObject(hEvent, INFINITE);  /* wait for debugger to come up... */
 336     else ERR("Couldn't start debugger (%s) (%ld)\n"
 337              "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 338              debugstr_a(cmdline), GetLastError());
 339 EXIT:
 340     HeapFree(GetProcessHeap(), 0, cmdline);
 341     return ret;
 342 }
 343
 344 /******************************************************************
 345  *              start_debugger_atomic
 346  *
 347  * starts the debugger in an atomic way:
 348  *      - either the debugger is not started and it is started
 349  *      - or the debugger has already been started by another thread
 350  *      - or the debugger couldn't be started
 351  *
 352  * returns TRUE for the two first conditions, FALSE for the last
 353  */
 354 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 355 {
 356     static HANDLE       hRunOnce /* = 0 */;
 357
 358     if (hRunOnce == 0)
 359     {
 360         OBJECT_ATTRIBUTES       attr;
 361         HANDLE                  hEvent;
 362
 363         attr.Length                   = sizeof(attr);
 364         attr.RootDirectory            = 0;
 365         attr.Attributes               = OBJ_INHERIT;
 366         attr.ObjectName               = NULL;
 367         attr.SecurityDescriptor       = NULL;
 368         attr.SecurityQualityOfService = NULL;
 369
 370         /* ask for manual reset, so that once the debugger is started,
 371          * every thread will know it */
 372         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 373         if (InterlockedCompareExchangePointer( (PVOID)&hRunOnce, hEvent, 0 ) == 0)
 374         {
 375             /* ok, our event has been set... we're the winning thread */
 376             BOOL        ret = start_debugger( epointers, hRunOnce );
 377             DWORD       tmp;
 378
 379             if (!ret)
 380             {
 381                 /* so that the other threads won't be stuck */
 382                 NtSetEvent( hRunOnce, &tmp );
 383             }
 384             return ret;
 385         }
 386
 387         /* someone beat us here... */
 388         CloseHandle( hEvent );
 389     }
 390
 391     /* and wait for the winner to have actually created the debugger */
 392     WaitForSingleObject( hRunOnce, INFINITE );
 393     /* in fact, here, we only know that someone has tried to start the debugger,
 394      * we'll know by reposting the exception if it has actually attached
 395      * to the current process */
 396     return TRUE;
 397 }
 398
 399
 400 /*******************************************************************
 401  *         check_resource_write
 402  *
 403  * Check if the exception is a write attempt to the resource data.
 404  * If yes, we unprotect the resources to let broken apps continue
 405  * (Windows does this too).
 406  */
 407 inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
 408 {
 409     void *addr, *rsrc;
 410     DWORD size;
 411     MEMORY_BASIC_INFORMATION info;
 412
 413     if (rec->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) return FALSE;
 414     if (!rec->ExceptionInformation[0]) return FALSE;  /* not a write access */
 415     addr = (void *)rec->ExceptionInformation[1];
 416     if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
 417     if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
 418                                               IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
 419         return FALSE;
 420     if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
 421     FIXME( "Broken app is writing to the resource data, enabling work-around\n" );
 422     VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
 423     return TRUE;
 424 }
 425
 426
 427 /*******************************************************************
 428  *         UnhandledExceptionFilter   (KERNEL32.@)
 429  */
 430 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 431 {
 432     int                 status;
 433     int                 loop = 0;
 434
 435     if (check_resource_write( epointers->ExceptionRecord )) return EXCEPTION_CONTINUE_EXECUTION;
 436
 437     for (loop = 0; loop <= 1; loop++)
 438     {
 439         /* send a last chance event to the debugger */
 440         status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 441         switch (status)
 442         {
 443         case DBG_CONTINUE:
 444             return EXCEPTION_CONTINUE_EXECUTION;
 445         case DBG_EXCEPTION_NOT_HANDLED:
 446             TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 447             break; /* not reached */
 448         case 0: /* no debugger is present */
 449             if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 450             {
 451                 /* do not launch the debugger on ^C, simply terminate the process */
 452                 TerminateProcess( GetCurrentProcess(), 1 );
 453             }
 454             /* second try, the debugger isn't present... */
 455             if (loop == 1) return EXCEPTION_EXECUTE_HANDLER;
 456             break;
 457         default:
 458             FIXME("Unsupported yet debug continue value %d (please report)\n", status);
 459             return EXCEPTION_EXECUTE_HANDLER;
 460         }
 461
 462         /* should only be there when loop == 0 */
 463
 464         if (top_filter)
 465         {
 466             DWORD ret = top_filter( epointers );
 467             if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 468         }
 469
 470         /* FIXME: Should check the current error mode */
 471
 472         if (!start_debugger_atomic( epointers ))
 473             return EXCEPTION_EXECUTE_HANDLER;
 474         /* now that we should have a debugger attached, try to resend event */
 475     }
 476
 477     return EXCEPTION_EXECUTE_HANDLER;
 478 }
 479
 480
 481 /***********************************************************************
 482  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 483  */
 484 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 485                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 486 {
 487     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 488     top_filter = filter;
 489     return old;
 490 }
 491
 492
 493 /**************************************************************************
 494  *           FatalAppExitA   (KERNEL32.@)
 495  */
 496 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 497 {
 498     HMODULE mod = GetModuleHandleA( "user32.dll" );
 499     MessageBoxA_funcptr pMessageBoxA = NULL;
 500
 501     WARN("AppExit\n");
 502
 503     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 504     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 505     else ERR( "%s\n", debugstr_a(str) );
 506     ExitProcess(0);
 507 }
 508
 509
 510 /**************************************************************************
 511  *           FatalAppExitW   (KERNEL32.@)
 512  */
 513 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 514 {
 515     static const WCHAR User32DllW[] = {'u','s','e','r','3','2','.','d','l','l',0};
 516
 517     HMODULE mod = GetModuleHandleW( User32DllW );
 518     MessageBoxW_funcptr pMessageBoxW = NULL;
 519
 520     WARN("AppExit\n");
 521
 522     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 523     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 524     else ERR( "%s\n", debugstr_w(str) );
 525     ExitProcess(0);
 526 }
 527
 528
 529 /**************************************************************************
 530  *           FatalExit   (KERNEL32.@)
 531  */
 532 void WINAPI FatalExit(int ExitCode)
 533 {
 534     WARN("FatalExit\n");
 535     ExitProcess(ExitCode);
 536 }