dlls/kernel/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 <stdarg.h>
  42 #include <stdio.h>
  43 #include "ntstatus.h"
  44 #include "windef.h"
  45 #include "winbase.h"
  46 #include "winerror.h"
  47 #include "winreg.h"
  48 #include "winternl.h"
  49 #include "wingdi.h"
  50 #include "winuser.h"
  51 #include "wine/exception.h"
  52 #include "wine/library.h"
  53 #include "thread.h"
  54 #include "excpt.h"
  55 #include "wine/server.h"
  56 #include "wine/unicode.h"
  57 #include "wine/debug.h"
  58
  59 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  60
  61 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
  62
  63 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
  64 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
  65
  66 /*******************************************************************
  67  *         RaiseException  (KERNEL32.@)
  68  */
  69 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const LPDWORD args )
  70 {
  71     EXCEPTION_RECORD record;
  72
  73     /* Compose an exception record */
  74
  75     record.ExceptionCode    = code;
  76     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  77     record.ExceptionRecord  = NULL;
  78     record.ExceptionAddress = RaiseException;
  79     if (nbargs && args)
  80     {
  81         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  82         record.NumberParameters = nbargs;
  83         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  84     }
  85     else record.NumberParameters = 0;
  86
  87     RtlRaiseException( &record );
  88 }
  89
  90
  91 /*******************************************************************
  92  *         format_exception_msg
  93  */
  94 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
  95 {
  96     const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
  97     int len,len2;
  98
  99     switch(rec->ExceptionCode)
 100     {
 101     case EXCEPTION_INT_DIVIDE_BY_ZERO:
 102         len = snprintf( buffer, size, "Unhandled division by zero" );
 103         break;
 104     case EXCEPTION_INT_OVERFLOW:
 105         len = snprintf( buffer, size, "Unhandled overflow" );
 106         break;
 107     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 108         len = snprintf( buffer, size, "Unhandled array bounds" );
 109         break;
 110     case EXCEPTION_ILLEGAL_INSTRUCTION:
 111         len = snprintf( buffer, size, "Unhandled illegal instruction" );
 112         break;
 113     case EXCEPTION_STACK_OVERFLOW:
 114         len = snprintf( buffer, size, "Unhandled stack overflow" );
 115         break;
 116     case EXCEPTION_PRIV_INSTRUCTION:
 117         len = snprintf( buffer, size, "Unhandled privileged instruction" );
 118         break;
 119     case EXCEPTION_ACCESS_VIOLATION:
 120         if (rec->NumberParameters == 2)
 121             len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
 122                      rec->ExceptionInformation[0] ? "write" : "read",
 123                      rec->ExceptionInformation[1]);
 124         else
 125             len = snprintf( buffer, size, "Unhandled page fault");
 126         break;
 127     case EXCEPTION_DATATYPE_MISALIGNMENT:
 128         len = snprintf( buffer, size, "Unhandled alignment" );
 129         break;
 130     case CONTROL_C_EXIT:
 131         len = snprintf( buffer, size, "Unhandled ^C");
 132         break;
 133     case STATUS_POSSIBLE_DEADLOCK:
 134         len = snprintf( buffer, size, "Critical section %08lx wait failed",
 135                  rec->ExceptionInformation[0]);
 136         break;
 137     case EXCEPTION_WINE_STUB:
 138         len = snprintf( buffer, size, "Unimplemented function %s.%s called",
 139                  (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 140         break;
 141     case EXCEPTION_WINE_ASSERTION:
 142         len = snprintf( buffer, size, "Assertion failed" );
 143         break;
 144     case EXCEPTION_VM86_INTx:
 145         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 146                  rec->ExceptionInformation[0]);
 147         break;
 148     case EXCEPTION_VM86_STI:
 149         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 150         break;
 151     case EXCEPTION_VM86_PICRETURN:
 152         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 153         break;
 154     default:
 155         len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 156         break;
 157     }
 158     if ((len<0) || (len>=size))
 159         return -1;
 160 #ifdef __i386__
 161     if (ptr->ContextRecord->SegCs != wine_get_cs())
 162         len2 = snprintf(buffer+len, size-len,
 163                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 164                         ptr->ContextRecord->SegCs,
 165                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 166     else
 167 #endif
 168         len2 = snprintf(buffer+len, size-len,
 169                         " at address 0x%08lx.\nDo you wish to debug it ?",
 170                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 171     if ((len2<0) || (len>=size-len))
 172         return -1;
 173     return len+len2;
 174 }
 175
 176
 177 /**********************************************************************
 178  *           send_debug_event
 179  *
 180  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 181  */
 182 static NTSTATUS send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 183 {
 184     NTSTATUS ret;
 185     HANDLE handle = 0;
 186
 187     SERVER_START_REQ( queue_exception_event )
 188     {
 189         req->first   = first_chance;
 190         wine_server_add_data( req, context, sizeof(*context) );
 191         wine_server_add_data( req, rec, sizeof(*rec) );
 192         if (!(ret = wine_server_call( req ))) handle = reply->handle;
 193     }
 194     SERVER_END_REQ;
 195     if (ret) return ret;
 196
 197     /* No need to wait on the handle since the process gets suspended
 198      * once the event is passed to the debugger, so when we get back
 199      * here the event has been continued already.
 200      */
 201     SERVER_START_REQ( get_exception_status )
 202     {
 203         req->handle = handle;
 204         wine_server_set_reply( req, context, sizeof(*context) );
 205         wine_server_call( req );
 206         ret = reply->status;
 207     }
 208     SERVER_END_REQ;
 209     NtClose( handle );
 210     return ret;
 211 }
 212
 213 /******************************************************************
 214  *              start_debugger
 215  *
 216  * Does the effective debugger startup according to 'format'
 217  */
 218 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 219 {
 220     OBJECT_ATTRIBUTES attr;
 221     UNICODE_STRING nameW;
 222     char *cmdline, *env, *p;
 223     HKEY                hDbgConf;
 224     DWORD               bAuto = FALSE;
 225     PROCESS_INFORMATION info;
 226     STARTUPINFOA        startup;
 227     char*               format = NULL;
 228     BOOL                ret = FALSE;
 229
 230     static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
 231                                      'S','o','f','t','w','a','r','e','\\',
 232                                      'M','i','c','r','o','s','o','f','t','\\',
 233                                      'W','i','n','d','o','w','s',' ','N','T','\\',
 234                                      'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
 235                                      'A','e','D','e','b','u','g',0};
 236     static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
 237     static const WCHAR AutoW[] = {'A','u','t','o',0};
 238
 239     MESSAGE("wine: Unhandled exception (thread %04lx), starting debugger...\n", GetCurrentThreadId());
 240
 241     attr.Length = sizeof(attr);
 242     attr.RootDirectory = 0;
 243     attr.ObjectName = &nameW;
 244     attr.Attributes = 0;
 245     attr.SecurityDescriptor = NULL;
 246     attr.SecurityQualityOfService = NULL;
 247     RtlInitUnicodeString( &nameW, AeDebugW );
 248
 249     if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
 250     {
 251         char buffer[64];
 252         KEY_VALUE_PARTIAL_INFORMATION *info;
 253         DWORD format_size = 0;
 254
 255         RtlInitUnicodeString( &nameW, DebuggerW );
 256         if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 257                              NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
 258         {
 259             char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
 260             NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 261                              data, format_size, &format_size );
 262             info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
 263             RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
 264             format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
 265             RtlUnicodeToMultiByteN( format, format_size, NULL,
 266                                     (WCHAR *)info->Data, info->DataLength );
 267             format[format_size] = 0;
 268
 269             if (info->Type == REG_EXPAND_SZ)
 270             {
 271                 char* tmp;
 272
 273                 /* Expand environment variable references */
 274                 format_size=ExpandEnvironmentStringsA(format,NULL,0);
 275                 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 276                 ExpandEnvironmentStringsA(format,tmp,format_size);
 277                 HeapFree(GetProcessHeap(), 0, format);
 278                 format=tmp;
 279             }
 280             HeapFree( GetProcessHeap(), 0, data );
 281         }
 282
 283         RtlInitUnicodeString( &nameW, AutoW );
 284         if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 285                               buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
 286        {
 287            info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
 288            if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
 289            else if (info->Type == REG_SZ)
 290            {
 291                WCHAR *str = (WCHAR *)info->Data;
 292                str[info->DataLength/sizeof(WCHAR)] = 0;
 293                bAuto = atoiW( str );
 294            }
 295        }
 296        else bAuto = TRUE;
 297
 298        NtClose(hDbgConf);
 299     }
 300
 301     if (format)
 302     {
 303         cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
 304         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 305         HeapFree(GetProcessHeap(), 0, format);
 306     }
 307     else
 308     {
 309         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
 310         sprintf(cmdline, "winedbg --auto %ld %ld",
 311                 GetCurrentProcessId(), (ULONG_PTR)hEvent);
 312     }
 313
 314     if (!bAuto)
 315     {
 316         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 317         MessageBoxA_funcptr     pMessageBoxA = NULL;
 318
 319         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 320         if (pMessageBoxA)
 321         {
 322             char buffer[256];
 323             format_exception_msg( epointers, buffer, sizeof(buffer) );
 324             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 325             {
 326                 TRACE("Killing process\n");
 327                 goto EXIT;
 328             }
 329         }
 330     }
 331
 332     /* remove WINEDEBUG from the environment */
 333     env = GetEnvironmentStringsA();
 334     for (p = env; *p; p += strlen(p) + 1)
 335     {
 336         if (!memcmp( p, "WINEDEBUG=", sizeof("WINEDEBUG=")-1 ))
 337         {
 338             char *next = p + strlen(p) + 1;
 339             char *end = next;
 340             while (*end) end += strlen(end) + 1;
 341             memmove( p, next, end + 1 - next );
 342             break;
 343         }
 344     }
 345
 346     TRACE("Starting debugger %s\n", debugstr_a(cmdline));
 347     memset(&startup, 0, sizeof(startup));
 348     startup.cb = sizeof(startup);
 349     startup.dwFlags = STARTF_USESHOWWINDOW;
 350     startup.wShowWindow = SW_SHOWNORMAL;
 351     ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, env, NULL, &startup, &info);
 352     FreeEnvironmentStringsA( env );
 353
 354     if (ret) WaitForSingleObject(hEvent, INFINITE);  /* wait for debugger to come up... */
 355     else ERR("Couldn't start debugger (%s) (%ld)\n"
 356              "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 357              debugstr_a(cmdline), GetLastError());
 358 EXIT:
 359     HeapFree(GetProcessHeap(), 0, cmdline);
 360     return ret;
 361 }
 362
 363 /******************************************************************
 364  *              start_debugger_atomic
 365  *
 366  * starts the debugger in an atomic way:
 367  *      - either the debugger is not started and it is started
 368  *      - or the debugger has already been started by another thread
 369  *      - or the debugger couldn't be started
 370  *
 371  * returns TRUE for the two first conditions, FALSE for the last
 372  */
 373 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 374 {
 375     static HANDLE       hRunOnce /* = 0 */;
 376
 377     if (hRunOnce == 0)
 378     {
 379         OBJECT_ATTRIBUTES       attr;
 380         HANDLE                  hEvent;
 381
 382         attr.Length                   = sizeof(attr);
 383         attr.RootDirectory            = 0;
 384         attr.Attributes               = OBJ_INHERIT;
 385         attr.ObjectName               = NULL;
 386         attr.SecurityDescriptor       = NULL;
 387         attr.SecurityQualityOfService = NULL;
 388
 389         /* ask for manual reset, so that once the debugger is started,
 390          * every thread will know it */
 391         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 392         if (InterlockedCompareExchangePointer( (PVOID)&hRunOnce, hEvent, 0 ) == 0)
 393         {
 394             /* ok, our event has been set... we're the winning thread */
 395             BOOL        ret = start_debugger( epointers, hRunOnce );
 396             DWORD       tmp;
 397
 398             if (!ret)
 399             {
 400                 /* so that the other threads won't be stuck */
 401                 NtSetEvent( hRunOnce, &tmp );
 402             }
 403             return ret;
 404         }
 405
 406         /* someone beat us here... */
 407         CloseHandle( hEvent );
 408     }
 409
 410     /* and wait for the winner to have actually created the debugger */
 411     WaitForSingleObject( hRunOnce, INFINITE );
 412     /* in fact, here, we only know that someone has tried to start the debugger,
 413      * we'll know by reposting the exception if it has actually attached
 414      * to the current process */
 415     return TRUE;
 416 }
 417
 418
 419 /*******************************************************************
 420  *         check_resource_write
 421  *
 422  * Check if the exception is a write attempt to the resource data.
 423  * If yes, we unprotect the resources to let broken apps continue
 424  * (Windows does this too).
 425  */
 426 inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
 427 {
 428     void *addr, *rsrc;
 429     DWORD size;
 430     MEMORY_BASIC_INFORMATION info;
 431
 432     if (rec->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) return FALSE;
 433     if (rec->NumberParameters < 2) return FALSE;
 434     if (!rec->ExceptionInformation[0]) return FALSE;  /* not a write access */
 435     addr = (void *)rec->ExceptionInformation[1];
 436     if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
 437     if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
 438                                               IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
 439         return FALSE;
 440     if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
 441     TRACE( "Broken app is writing to the resource data, enabling work-around\n" );
 442     VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
 443     return TRUE;
 444 }
 445
 446
 447 /*******************************************************************
 448  *         UnhandledExceptionFilter   (KERNEL32.@)
 449  */
 450 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 451 {
 452     NTSTATUS status;
 453
 454     if (check_resource_write( epointers->ExceptionRecord )) return EXCEPTION_CONTINUE_EXECUTION;
 455
 456     if (!NtCurrentTeb()->Peb->BeingDebugged)
 457     {
 458         if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 459         {
 460             /* do not launch the debugger on ^C, simply terminate the process */
 461             TerminateProcess( GetCurrentProcess(), 1 );
 462         }
 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 ) || !NtCurrentTeb()->Peb->BeingDebugged)
 473             return EXCEPTION_EXECUTE_HANDLER;
 474     }
 475
 476     /* send a last chance event to the debugger */
 477     status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 478     switch (status)
 479     {
 480     case DBG_CONTINUE:
 481         return EXCEPTION_CONTINUE_EXECUTION;
 482     case DBG_EXCEPTION_NOT_HANDLED:
 483         TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 484         break; /* not reached */
 485     default:
 486         FIXME("Unhandled error on debug event: %lx\n", status);
 487         break;
 488     }
 489     return EXCEPTION_EXECUTE_HANDLER;
 490 }
 491
 492
 493 /***********************************************************************
 494  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 495  */
 496 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 497                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 498 {
 499     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 500     top_filter = filter;
 501     return old;
 502 }
 503
 504
 505 /**************************************************************************
 506  *           FatalAppExitA   (KERNEL32.@)
 507  */
 508 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 509 {
 510     HMODULE mod = GetModuleHandleA( "user32.dll" );
 511     MessageBoxA_funcptr pMessageBoxA = NULL;
 512
 513     WARN("AppExit\n");
 514
 515     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 516     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 517     else ERR( "%s\n", debugstr_a(str) );
 518     ExitProcess(0);
 519 }
 520
 521
 522 /**************************************************************************
 523  *           FatalAppExitW   (KERNEL32.@)
 524  */
 525 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 526 {
 527     static const WCHAR User32DllW[] = {'u','s','e','r','3','2','.','d','l','l',0};
 528
 529     HMODULE mod = GetModuleHandleW( User32DllW );
 530     MessageBoxW_funcptr pMessageBoxW = NULL;
 531
 532     WARN("AppExit\n");
 533
 534     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 535     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 536     else ERR( "%s\n", debugstr_w(str) );
 537     ExitProcess(0);
 538 }
 539
 540
 541 /**************************************************************************
 542  *           FatalExit   (KERNEL32.@)
 543  */
 544 void WINAPI FatalExit(int ExitCode)
 545 {
 546     WARN("FatalExit\n");
 547     ExitProcess(ExitCode);
 548 }