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 "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_WINE_ASSERTION:
 139         len = snprintf( buffer, size, "Assertion failed" );
 140         break;
 141     case EXCEPTION_VM86_INTx:
 142         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 143                  rec->ExceptionInformation[0]);
 144         break;
 145     case EXCEPTION_VM86_STI:
 146         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 147         break;
 148     case EXCEPTION_VM86_PICRETURN:
 149         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 150         break;
 151     default:
 152         len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 153         break;
 154     }
 155     if ((len<0) || (len>=size))
 156         return -1;
 157 #ifdef __i386__
 158     if (ptr->ContextRecord->SegCs != wine_get_cs())
 159         len2 = snprintf(buffer+len, size-len,
 160                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 161                         ptr->ContextRecord->SegCs,
 162                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 163     else
 164 #endif
 165         len2 = snprintf(buffer+len, size-len,
 166                         " at address 0x%08lx.\nDo you wish to debug it ?",
 167                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 168     if ((len2<0) || (len>=size-len))
 169         return -1;
 170     return len+len2;
 171 }
 172
 173
 174 /**********************************************************************
 175  *           send_debug_event
 176  *
 177  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 178  */
 179 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 180 {
 181     int ret;
 182     HANDLE handle = 0;
 183
 184     SERVER_START_REQ( queue_exception_event )
 185     {
 186         req->first   = first_chance;
 187         wine_server_add_data( req, context, sizeof(*context) );
 188         wine_server_add_data( req, rec, sizeof(*rec) );
 189         if (!wine_server_call(req)) handle = reply->handle;
 190     }
 191     SERVER_END_REQ;
 192     if (!handle) return 0;  /* no debugger present or other error */
 193
 194     /* No need to wait on the handle since the process gets suspended
 195      * once the event is passed to the debugger, so when we get back
 196      * here the event has been continued already.
 197      */
 198     SERVER_START_REQ( get_exception_status )
 199     {
 200         req->handle = handle;
 201         wine_server_set_reply( req, context, sizeof(*context) );
 202         wine_server_call( req );
 203         ret = reply->status;
 204     }
 205     SERVER_END_REQ;
 206     NtClose( handle );
 207     return ret;
 208 }
 209
 210 /******************************************************************
 211  *              start_debugger
 212  *
 213  * Does the effective debugger startup according to 'format'
 214  */
 215 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 216 {
 217     OBJECT_ATTRIBUTES attr;
 218     UNICODE_STRING nameW;
 219     HKEY                hDbgConf;
 220     DWORD               bAuto = FALSE;
 221     PROCESS_INFORMATION info;
 222     STARTUPINFOA        startup;
 223     char*               cmdline;
 224     char*               format = NULL;
 225     BOOL                ret = FALSE;
 226
 227     static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
 228                                      'S','o','f','t','w','a','r','e','\\',
 229                                      'M','i','c','r','o','s','o','f','t','\\',
 230                                      'W','i','n','d','o','w','s',' ','N','T','\\',
 231                                      'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
 232                                      'A','e','D','e','b','u','g',0};
 233     static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
 234     static const WCHAR AutoW[] = {'A','u','t','o',0};
 235
 236     MESSAGE("wine: Unhandled exception, starting debugger...\n");
 237
 238     attr.Length = sizeof(attr);
 239     attr.RootDirectory = 0;
 240     attr.ObjectName = &nameW;
 241     attr.Attributes = 0;
 242     attr.SecurityDescriptor = NULL;
 243     attr.SecurityQualityOfService = NULL;
 244     RtlInitUnicodeString( &nameW, AeDebugW );
 245
 246     if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
 247     {
 248         char buffer[64];
 249         KEY_VALUE_PARTIAL_INFORMATION *info;
 250         DWORD format_size = 0;
 251
 252         RtlInitUnicodeString( &nameW, DebuggerW );
 253         if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 254                              NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
 255         {
 256             char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
 257             NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 258                              data, format_size, &format_size );
 259             info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
 260             RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
 261             format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
 262             RtlUnicodeToMultiByteN( format, format_size, NULL,
 263                                     (WCHAR *)info->Data, info->DataLength );
 264             format[format_size] = 0;
 265
 266             if (info->Type == REG_EXPAND_SZ)
 267             {
 268                 char* tmp;
 269
 270                 /* Expand environment variable references */
 271                 format_size=ExpandEnvironmentStringsA(format,NULL,0);
 272                 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 273                 ExpandEnvironmentStringsA(format,tmp,format_size);
 274                 HeapFree(GetProcessHeap(), 0, format);
 275                 format=tmp;
 276             }
 277             HeapFree( GetProcessHeap(), 0, data );
 278         }
 279
 280         RtlInitUnicodeString( &nameW, AutoW );
 281         if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 282                               buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
 283        {
 284            info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
 285            if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
 286            else if (info->Type == REG_SZ)
 287            {
 288                WCHAR *str = (WCHAR *)info->Data;
 289                str[info->DataLength/sizeof(WCHAR)] = 0;
 290                bAuto = atoiW( str );
 291            }
 292        }
 293        else bAuto = TRUE;
 294
 295        NtClose(hDbgConf);
 296     }
 297
 298     if (format)
 299     {
 300         cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
 301         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 302         HeapFree(GetProcessHeap(), 0, format);
 303     }
 304     else
 305     {
 306         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
 307         sprintf(cmdline, "winedbg --debugmsg -all --auto %ld %p", GetCurrentProcessId(), 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     HMODULE mod = GetModuleHandleA( "user32.dll" );
 516     MessageBoxW_funcptr pMessageBoxW = NULL;
 517
 518     WARN("AppExit\n");
 519
 520     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 521     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 522     else ERR( "%s\n", debugstr_w(str) );
 523     ExitProcess(0);
 524 }