dlls/kernel32/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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, 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 <stdarg.h>
  42 #include <stdio.h>
  43 #include "ntstatus.h"
  44 #define WIN32_NO_STATUS
  45 #include "windef.h"
  46 #include "winbase.h"
  47 #include "winternl.h"
  48 #include "wingdi.h"
  49 #include "winuser.h"
  50 #include "wine/exception.h"
  51 #include "wine/library.h"
  52 #include "excpt.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 ULONG_PTR *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] == EXCEPTION_WRITE_FAULT ? "write" :
 120                             rec->ExceptionInformation[0] == EXCEPTION_EXECUTE_FAULT ? "execute" : "read",
 121                             rec->ExceptionInformation[1]);
 122         else
 123             len = snprintf( buffer, size, "Unhandled page fault");
 124         break;
 125     case EXCEPTION_DATATYPE_MISALIGNMENT:
 126         len = snprintf( buffer, size, "Unhandled alignment" );
 127         break;
 128     case CONTROL_C_EXIT:
 129         len = snprintf( buffer, size, "Unhandled ^C");
 130         break;
 131     case STATUS_POSSIBLE_DEADLOCK:
 132         len = snprintf( buffer, size, "Critical section %08lx wait failed",
 133                  rec->ExceptionInformation[0]);
 134         break;
 135     case EXCEPTION_WINE_STUB:
 136         if (HIWORD(rec->ExceptionInformation[1]))
 137             len = snprintf( buffer, size, "Unimplemented function %s.%s called",
 138                             (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 139         else
 140             len = snprintf( buffer, size, "Unimplemented function %s.%ld called",
 141                             (char *)rec->ExceptionInformation[0], rec->ExceptionInformation[1] );
 142         break;
 143     case EXCEPTION_WINE_ASSERTION:
 144         len = snprintf( buffer, size, "Assertion failed" );
 145         break;
 146     case EXCEPTION_VM86_INTx:
 147         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 148                  rec->ExceptionInformation[0]);
 149         break;
 150     case EXCEPTION_VM86_STI:
 151         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 152         break;
 153     case EXCEPTION_VM86_PICRETURN:
 154         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 155         break;
 156     default:
 157         len = snprintf( buffer, size, "Unhandled exception 0x%08x", rec->ExceptionCode);
 158         break;
 159     }
 160     if ((len<0) || (len>=size))
 161         return -1;
 162 #ifdef __i386__
 163     if (ptr->ContextRecord->SegCs != wine_get_cs())
 164         len2 = snprintf(buffer+len, size-len, " at address 0x%04x:0x%08x",
 165                         ptr->ContextRecord->SegCs,
 166                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 167     else
 168 #endif
 169         len2 = snprintf(buffer+len, size-len, " at address %p",
 170                         ptr->ExceptionRecord->ExceptionAddress);
 171     if ((len2<0) || (len>=size-len))
 172         return -1;
 173     return len+len2;
 174 }
 175
 176
 177 /******************************************************************
 178  *              start_debugger
 179  *
 180  * Does the effective debugger startup according to 'format'
 181  */
 182 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 183 {
 184     OBJECT_ATTRIBUTES attr;
 185     UNICODE_STRING nameW;
 186     char *cmdline, *env, *p;
 187     HANDLE              hDbgConf;
 188     DWORD               bAuto = TRUE;
 189     PROCESS_INFORMATION info;
 190     STARTUPINFOA        startup;
 191     char*               format = NULL;
 192     BOOL                ret = FALSE;
 193     char buffer[256];
 194
 195     static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
 196                                      'S','o','f','t','w','a','r','e','\\',
 197                                      'M','i','c','r','o','s','o','f','t','\\',
 198                                      'W','i','n','d','o','w','s',' ','N','T','\\',
 199                                      'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
 200                                      'A','e','D','e','b','u','g',0};
 201     static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
 202     static const WCHAR AutoW[] = {'A','u','t','o',0};
 203
 204     format_exception_msg( epointers, buffer, sizeof(buffer) );
 205     MESSAGE("wine: %s (thread %04x), starting debugger...\n", buffer, GetCurrentThreadId());
 206
 207     attr.Length = sizeof(attr);
 208     attr.RootDirectory = 0;
 209     attr.ObjectName = &nameW;
 210     attr.Attributes = 0;
 211     attr.SecurityDescriptor = NULL;
 212     attr.SecurityQualityOfService = NULL;
 213     RtlInitUnicodeString( &nameW, AeDebugW );
 214
 215     if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
 216     {
 217         char buffer[64];
 218         KEY_VALUE_PARTIAL_INFORMATION *info;
 219         DWORD format_size = 0;
 220
 221         RtlInitUnicodeString( &nameW, DebuggerW );
 222         if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 223                              NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
 224         {
 225             char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
 226             NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 227                              data, format_size, &format_size );
 228             info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
 229             RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
 230             format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
 231             RtlUnicodeToMultiByteN( format, format_size, NULL,
 232                                     (WCHAR *)info->Data, info->DataLength );
 233             format[format_size] = 0;
 234
 235             if (info->Type == REG_EXPAND_SZ)
 236             {
 237                 char* tmp;
 238
 239                 /* Expand environment variable references */
 240                 format_size=ExpandEnvironmentStringsA(format,NULL,0);
 241                 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 242                 ExpandEnvironmentStringsA(format,tmp,format_size);
 243                 HeapFree(GetProcessHeap(), 0, format);
 244                 format=tmp;
 245             }
 246             HeapFree( GetProcessHeap(), 0, data );
 247         }
 248
 249         RtlInitUnicodeString( &nameW, AutoW );
 250         if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 251                               buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
 252        {
 253            info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
 254            if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
 255            else if (info->Type == REG_SZ)
 256            {
 257                WCHAR *str = (WCHAR *)info->Data;
 258                str[info->DataLength/sizeof(WCHAR)] = 0;
 259                bAuto = atoiW( str );
 260            }
 261        }
 262
 263        NtClose(hDbgConf);
 264     }
 265
 266     if (format)
 267     {
 268         cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
 269         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 270         HeapFree(GetProcessHeap(), 0, format);
 271     }
 272     else
 273     {
 274         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
 275         sprintf(cmdline, "winedbg --auto %d %ld",
 276                 GetCurrentProcessId(), (ULONG_PTR)hEvent);
 277     }
 278
 279     if (!bAuto)
 280     {
 281         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 282         MessageBoxA_funcptr     pMessageBoxA = NULL;
 283
 284         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 285         if (pMessageBoxA)
 286         {
 287             static const char msg[] = ".\nDo you wish to debug it?";
 288             char buffer[256];
 289
 290             format_exception_msg( epointers, buffer, sizeof(buffer)-sizeof(msg) );
 291             strcat( buffer, msg );
 292             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 293             {
 294                 TRACE("Killing process\n");
 295                 goto EXIT;
 296             }
 297         }
 298     }
 299
 300     /* make WINEDEBUG empty in the environment */
 301     env = GetEnvironmentStringsA();
 302     for (p = env; *p; p += strlen(p) + 1)
 303     {
 304         if (!memcmp( p, "WINEDEBUG=", sizeof("WINEDEBUG=")-1 ))
 305         {
 306             char *next = p + strlen(p);
 307             char *end = next + 1;
 308             while (*end) end += strlen(end) + 1;
 309             memmove( p + sizeof("WINEDEBUG=") - 1, next, end + 1 - next );
 310             break;
 311         }
 312     }
 313
 314     TRACE("Starting debugger %s\n", debugstr_a(cmdline));
 315     memset(&startup, 0, sizeof(startup));
 316     startup.cb = sizeof(startup);
 317     startup.dwFlags = STARTF_USESHOWWINDOW;
 318     startup.wShowWindow = SW_SHOWNORMAL;
 319     ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, env, NULL, &startup, &info);
 320     FreeEnvironmentStringsA( env );
 321
 322     if (ret)
 323     {
 324         /* wait for debugger to come up... */
 325         HANDLE handles[2];
 326         CloseHandle(info.hThread);
 327         handles[0]=hEvent;
 328         handles[1]=info.hProcess;
 329         WaitForMultipleObjects(2, handles, FALSE, INFINITE);
 330         CloseHandle(info.hProcess);
 331     }
 332     else ERR("Couldn't start debugger (%s) (%d)\n"
 333              "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 334              debugstr_a(cmdline), GetLastError());
 335 EXIT:
 336     HeapFree(GetProcessHeap(), 0, cmdline);
 337     return ret;
 338 }
 339
 340 /******************************************************************
 341  *              start_debugger_atomic
 342  *
 343  * starts the debugger in an atomic way:
 344  *      - either the debugger is not started and it is started
 345  *      - or the debugger has already been started by another thread
 346  *      - or the debugger couldn't be started
 347  *
 348  * returns TRUE for the two first conditions, FALSE for the last
 349  */
 350 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 351 {
 352     static HANDLE       hRunOnce /* = 0 */;
 353
 354     if (hRunOnce == 0)
 355     {
 356         OBJECT_ATTRIBUTES       attr;
 357         HANDLE                  hEvent;
 358
 359         attr.Length                   = sizeof(attr);
 360         attr.RootDirectory            = 0;
 361         attr.Attributes               = OBJ_INHERIT;
 362         attr.ObjectName               = NULL;
 363         attr.SecurityDescriptor       = NULL;
 364         attr.SecurityQualityOfService = NULL;
 365
 366         /* ask for manual reset, so that once the debugger is started,
 367          * every thread will know it */
 368         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 369         if (InterlockedCompareExchangePointer( &hRunOnce, hEvent, 0 ) == 0)
 370         {
 371             /* ok, our event has been set... we're the winning thread */
 372             BOOL        ret = start_debugger( epointers, hRunOnce );
 373             DWORD       tmp;
 374
 375             if (!ret)
 376             {
 377                 /* so that the other threads won't be stuck */
 378                 NtSetEvent( hRunOnce, &tmp );
 379             }
 380             return ret;
 381         }
 382
 383         /* someone beat us here... */
 384         CloseHandle( hEvent );
 385     }
 386
 387     /* and wait for the winner to have actually created the debugger */
 388     WaitForSingleObject( hRunOnce, INFINITE );
 389     /* in fact, here, we only know that someone has tried to start the debugger,
 390      * we'll know by reposting the exception if it has actually attached
 391      * to the current process */
 392     return TRUE;
 393 }
 394
 395
 396 /*******************************************************************
 397  *         check_resource_write
 398  *
 399  * Check if the exception is a write attempt to the resource data.
 400  * If yes, we unprotect the resources to let broken apps continue
 401  * (Windows does this too).
 402  */
 403 static inline BOOL check_resource_write( void *addr )
 404 {
 405     void *rsrc;
 406     DWORD size;
 407     MEMORY_BASIC_INFORMATION info;
 408
 409     if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
 410     if (info.State == MEM_FREE || !(info.Type & MEM_IMAGE)) return FALSE;
 411     if (!(rsrc = RtlImageDirectoryEntryToData( info.AllocationBase, TRUE,
 412                                               IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
 413         return FALSE;
 414     if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
 415     TRACE( "Broken app is writing to the resource data, enabling work-around\n" );
 416     VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
 417     return TRUE;
 418 }
 419
 420
 421 /*******************************************************************
 422  *         UnhandledExceptionFilter   (KERNEL32.@)
 423  */
 424 LONG WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 425 {
 426     const EXCEPTION_RECORD *rec = epointers->ExceptionRecord;
 427
 428     if (rec->ExceptionCode == EXCEPTION_ACCESS_VIOLATION && rec->NumberParameters >= 2)
 429     {
 430         switch(rec->ExceptionInformation[0])
 431         {
 432         case EXCEPTION_WRITE_FAULT:
 433             if (check_resource_write( (void *)rec->ExceptionInformation[1] ))
 434                 return EXCEPTION_CONTINUE_EXECUTION;
 435             break;
 436         }
 437     }
 438
 439     if (!NtCurrentTeb()->Peb->BeingDebugged)
 440     {
 441         if (rec->ExceptionCode == CONTROL_C_EXIT)
 442         {
 443             /* do not launch the debugger on ^C, simply terminate the process */
 444             TerminateProcess( GetCurrentProcess(), 1 );
 445         }
 446
 447         if (top_filter)
 448         {
 449             LONG ret = top_filter( epointers );
 450             if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 451         }
 452
 453         /* FIXME: Should check the current error mode */
 454
 455         if (!start_debugger_atomic( epointers ) || !NtCurrentTeb()->Peb->BeingDebugged)
 456             return EXCEPTION_EXECUTE_HANDLER;
 457     }
 458     return EXCEPTION_CONTINUE_SEARCH;
 459 }
 460
 461
 462 /***********************************************************************
 463  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 464  */
 465 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 466                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 467 {
 468     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 469     top_filter = filter;
 470     return old;
 471 }
 472
 473
 474 /**************************************************************************
 475  *           FatalAppExitA   (KERNEL32.@)
 476  */
 477 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 478 {
 479     HMODULE mod = GetModuleHandleA( "user32.dll" );
 480     MessageBoxA_funcptr pMessageBoxA = NULL;
 481
 482     WARN("AppExit\n");
 483
 484     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 485     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 486     else ERR( "%s\n", debugstr_a(str) );
 487     ExitProcess(0);
 488 }
 489
 490
 491 /**************************************************************************
 492  *           FatalAppExitW   (KERNEL32.@)
 493  */
 494 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 495 {
 496     static const WCHAR User32DllW[] = {'u','s','e','r','3','2','.','d','l','l',0};
 497
 498     HMODULE mod = GetModuleHandleW( User32DllW );
 499     MessageBoxW_funcptr pMessageBoxW = NULL;
 500
 501     WARN("AppExit\n");
 502
 503     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 504     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 505     else ERR( "%s\n", debugstr_w(str) );
 506     ExitProcess(0);
 507 }
 508
 509
 510 /**************************************************************************
 511  *           FatalExit   (KERNEL32.@)
 512  */
 513 void WINAPI FatalExit(int ExitCode)
 514 {
 515     WARN("FatalExit\n");
 516     ExitProcess(ExitCode);
 517 }