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 "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/server.h"
  54 #include "wine/unicode.h"
  55 #include "wine/debug.h"
  56
  57 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  58
  59 static PTOP_LEVEL_EXCEPTION_FILTER top_filter;
  60
  61 typedef INT (WINAPI *MessageBoxA_funcptr)(HWND,LPCSTR,LPCSTR,UINT);
  62 typedef INT (WINAPI *MessageBoxW_funcptr)(HWND,LPCWSTR,LPCWSTR,UINT);
  63
  64 /*******************************************************************
  65  *         RaiseException  (KERNEL32.@)
  66  */
  67 void WINAPI RaiseException( DWORD code, DWORD flags, DWORD nbargs, const ULONG_PTR *args )
  68 {
  69     EXCEPTION_RECORD record;
  70
  71     /* Compose an exception record */
  72
  73     record.ExceptionCode    = code;
  74     record.ExceptionFlags   = flags & EH_NONCONTINUABLE;
  75     record.ExceptionRecord  = NULL;
  76     record.ExceptionAddress = RaiseException;
  77     if (nbargs && args)
  78     {
  79         if (nbargs > EXCEPTION_MAXIMUM_PARAMETERS) nbargs = EXCEPTION_MAXIMUM_PARAMETERS;
  80         record.NumberParameters = nbargs;
  81         memcpy( record.ExceptionInformation, args, nbargs * sizeof(*args) );
  82     }
  83     else record.NumberParameters = 0;
  84
  85     RtlRaiseException( &record );
  86 }
  87
  88
  89 /*******************************************************************
  90  *         format_exception_msg
  91  */
  92 static int format_exception_msg( const EXCEPTION_POINTERS *ptr, char *buffer, int size )
  93 {
  94     const EXCEPTION_RECORD *rec = ptr->ExceptionRecord;
  95     int len,len2;
  96
  97     switch(rec->ExceptionCode)
  98     {
  99     case EXCEPTION_INT_DIVIDE_BY_ZERO:
 100         len = snprintf( buffer, size, "Unhandled division by zero" );
 101         break;
 102     case EXCEPTION_INT_OVERFLOW:
 103         len = snprintf( buffer, size, "Unhandled overflow" );
 104         break;
 105     case EXCEPTION_ARRAY_BOUNDS_EXCEEDED:
 106         len = snprintf( buffer, size, "Unhandled array bounds" );
 107         break;
 108     case EXCEPTION_ILLEGAL_INSTRUCTION:
 109         len = snprintf( buffer, size, "Unhandled illegal instruction" );
 110         break;
 111     case EXCEPTION_STACK_OVERFLOW:
 112         len = snprintf( buffer, size, "Unhandled stack overflow" );
 113         break;
 114     case EXCEPTION_PRIV_INSTRUCTION:
 115         len = snprintf( buffer, size, "Unhandled privileged instruction" );
 116         break;
 117     case EXCEPTION_ACCESS_VIOLATION:
 118         if (rec->NumberParameters == 2)
 119             len = snprintf( buffer, size, "Unhandled page fault on %s access to 0x%08lx",
 120                      rec->ExceptionInformation[0] ? "write" : "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%08lx", 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,
 165                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 166                         ptr->ContextRecord->SegCs,
 167                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 168     else
 169 #endif
 170         len2 = snprintf(buffer+len, size-len,
 171                         " at address %p.\nDo you wish to debug it ?",
 172                         ptr->ExceptionRecord->ExceptionAddress);
 173     if ((len2<0) || (len>=size-len))
 174         return -1;
 175     return len+len2;
 176 }
 177
 178
 179 /**********************************************************************
 180  *           send_debug_event
 181  *
 182  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 183  */
 184 static NTSTATUS send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 185 {
 186     NTSTATUS ret;
 187     HANDLE handle = 0;
 188
 189     SERVER_START_REQ( queue_exception_event )
 190     {
 191         req->first   = first_chance;
 192         wine_server_add_data( req, context, sizeof(*context) );
 193         wine_server_add_data( req, rec, sizeof(*rec) );
 194         if (!(ret = wine_server_call( req ))) handle = reply->handle;
 195     }
 196     SERVER_END_REQ;
 197     if (ret) return ret;
 198
 199     /* No need to wait on the handle since the process gets suspended
 200      * once the event is passed to the debugger, so when we get back
 201      * here the event has been continued already.
 202      */
 203     SERVER_START_REQ( get_exception_status )
 204     {
 205         req->handle = handle;
 206         wine_server_set_reply( req, context, sizeof(*context) );
 207         wine_server_call( req );
 208         ret = reply->status;
 209     }
 210     SERVER_END_REQ;
 211     NtClose( handle );
 212     return ret;
 213 }
 214
 215 /******************************************************************
 216  *              start_debugger
 217  *
 218  * Does the effective debugger startup according to 'format'
 219  */
 220 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 221 {
 222     OBJECT_ATTRIBUTES attr;
 223     UNICODE_STRING nameW;
 224     char *cmdline, *env, *p;
 225     HANDLE              hDbgConf;
 226     DWORD               bAuto = FALSE;
 227     PROCESS_INFORMATION info;
 228     STARTUPINFOA        startup;
 229     char*               format = NULL;
 230     BOOL                ret = FALSE;
 231
 232     static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
 233                                      'S','o','f','t','w','a','r','e','\\',
 234                                      'M','i','c','r','o','s','o','f','t','\\',
 235                                      'W','i','n','d','o','w','s',' ','N','T','\\',
 236                                      'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
 237                                      'A','e','D','e','b','u','g',0};
 238     static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
 239     static const WCHAR AutoW[] = {'A','u','t','o',0};
 240
 241     MESSAGE("wine: Unhandled exception (thread %04lx), starting debugger...\n", GetCurrentThreadId());
 242
 243     attr.Length = sizeof(attr);
 244     attr.RootDirectory = 0;
 245     attr.ObjectName = &nameW;
 246     attr.Attributes = 0;
 247     attr.SecurityDescriptor = NULL;
 248     attr.SecurityQualityOfService = NULL;
 249     RtlInitUnicodeString( &nameW, AeDebugW );
 250
 251     if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
 252     {
 253         char buffer[64];
 254         KEY_VALUE_PARTIAL_INFORMATION *info;
 255         DWORD format_size = 0;
 256
 257         RtlInitUnicodeString( &nameW, DebuggerW );
 258         if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 259                              NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
 260         {
 261             char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
 262             NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 263                              data, format_size, &format_size );
 264             info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
 265             RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
 266             format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
 267             RtlUnicodeToMultiByteN( format, format_size, NULL,
 268                                     (WCHAR *)info->Data, info->DataLength );
 269             format[format_size] = 0;
 270
 271             if (info->Type == REG_EXPAND_SZ)
 272             {
 273                 char* tmp;
 274
 275                 /* Expand environment variable references */
 276                 format_size=ExpandEnvironmentStringsA(format,NULL,0);
 277                 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 278                 ExpandEnvironmentStringsA(format,tmp,format_size);
 279                 HeapFree(GetProcessHeap(), 0, format);
 280                 format=tmp;
 281             }
 282             HeapFree( GetProcessHeap(), 0, data );
 283         }
 284
 285         RtlInitUnicodeString( &nameW, AutoW );
 286         if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 287                               buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
 288        {
 289            info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
 290            if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
 291            else if (info->Type == REG_SZ)
 292            {
 293                WCHAR *str = (WCHAR *)info->Data;
 294                str[info->DataLength/sizeof(WCHAR)] = 0;
 295                bAuto = atoiW( str );
 296            }
 297        }
 298        else bAuto = TRUE;
 299
 300        NtClose(hDbgConf);
 301     }
 302
 303     if (format)
 304     {
 305         cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
 306         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 307         HeapFree(GetProcessHeap(), 0, format);
 308     }
 309     else
 310     {
 311         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
 312         sprintf(cmdline, "winedbg --auto %ld %ld",
 313                 GetCurrentProcessId(), (ULONG_PTR)hEvent);
 314     }
 315
 316     if (!bAuto)
 317     {
 318         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 319         MessageBoxA_funcptr     pMessageBoxA = NULL;
 320
 321         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 322         if (pMessageBoxA)
 323         {
 324             char buffer[256];
 325             format_exception_msg( epointers, buffer, sizeof(buffer) );
 326             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 327             {
 328                 TRACE("Killing process\n");
 329                 goto EXIT;
 330             }
 331         }
 332     }
 333
 334     /* remove WINEDEBUG from the environment */
 335     env = GetEnvironmentStringsA();
 336     for (p = env; *p; p += strlen(p) + 1)
 337     {
 338         if (!memcmp( p, "WINEDEBUG=", sizeof("WINEDEBUG=")-1 ))
 339         {
 340             char *next = p + strlen(p) + 1;
 341             char *end = next;
 342             while (*end) end += strlen(end) + 1;
 343             memmove( p, next, end + 1 - next );
 344             break;
 345         }
 346     }
 347
 348     TRACE("Starting debugger %s\n", debugstr_a(cmdline));
 349     memset(&startup, 0, sizeof(startup));
 350     startup.cb = sizeof(startup);
 351     startup.dwFlags = STARTF_USESHOWWINDOW;
 352     startup.wShowWindow = SW_SHOWNORMAL;
 353     ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, env, NULL, &startup, &info);
 354     FreeEnvironmentStringsA( env );
 355
 356     if (ret) WaitForSingleObject(hEvent, INFINITE);  /* wait for debugger to come up... */
 357     else ERR("Couldn't start debugger (%s) (%ld)\n"
 358              "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 359              debugstr_a(cmdline), GetLastError());
 360 EXIT:
 361     HeapFree(GetProcessHeap(), 0, cmdline);
 362     return ret;
 363 }
 364
 365 /******************************************************************
 366  *              start_debugger_atomic
 367  *
 368  * starts the debugger in an atomic way:
 369  *      - either the debugger is not started and it is started
 370  *      - or the debugger has already been started by another thread
 371  *      - or the debugger couldn't be started
 372  *
 373  * returns TRUE for the two first conditions, FALSE for the last
 374  */
 375 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 376 {
 377     static HANDLE       hRunOnce /* = 0 */;
 378
 379     if (hRunOnce == 0)
 380     {
 381         OBJECT_ATTRIBUTES       attr;
 382         HANDLE                  hEvent;
 383
 384         attr.Length                   = sizeof(attr);
 385         attr.RootDirectory            = 0;
 386         attr.Attributes               = OBJ_INHERIT;
 387         attr.ObjectName               = NULL;
 388         attr.SecurityDescriptor       = NULL;
 389         attr.SecurityQualityOfService = NULL;
 390
 391         /* ask for manual reset, so that once the debugger is started,
 392          * every thread will know it */
 393         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 394         if (InterlockedCompareExchangePointer( (PVOID)&hRunOnce, hEvent, 0 ) == 0)
 395         {
 396             /* ok, our event has been set... we're the winning thread */
 397             BOOL        ret = start_debugger( epointers, hRunOnce );
 398             DWORD       tmp;
 399
 400             if (!ret)
 401             {
 402                 /* so that the other threads won't be stuck */
 403                 NtSetEvent( hRunOnce, &tmp );
 404             }
 405             return ret;
 406         }
 407
 408         /* someone beat us here... */
 409         CloseHandle( hEvent );
 410     }
 411
 412     /* and wait for the winner to have actually created the debugger */
 413     WaitForSingleObject( hRunOnce, INFINITE );
 414     /* in fact, here, we only know that someone has tried to start the debugger,
 415      * we'll know by reposting the exception if it has actually attached
 416      * to the current process */
 417     return TRUE;
 418 }
 419
 420
 421 /*******************************************************************
 422  *         check_resource_write
 423  *
 424  * Check if the exception is a write attempt to the resource data.
 425  * If yes, we unprotect the resources to let broken apps continue
 426  * (Windows does this too).
 427  */
 428 inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
 429 {
 430     void *addr, *rsrc;
 431     DWORD size;
 432     MEMORY_BASIC_INFORMATION info;
 433
 434     if (rec->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) return FALSE;
 435     if (rec->NumberParameters < 2) return FALSE;
 436     if (!rec->ExceptionInformation[0]) return FALSE;  /* not a write access */
 437     addr = (void *)rec->ExceptionInformation[1];
 438     if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
 439     if (info.State == MEM_FREE) return FALSE;
 440     if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
 441                                               IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
 442         return FALSE;
 443     if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
 444     TRACE( "Broken app is writing to the resource data, enabling work-around\n" );
 445     VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
 446     return TRUE;
 447 }
 448
 449
 450 /*******************************************************************
 451  *         UnhandledExceptionFilter   (KERNEL32.@)
 452  */
 453 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 454 {
 455     NTSTATUS status;
 456
 457     if (check_resource_write( epointers->ExceptionRecord )) return EXCEPTION_CONTINUE_EXECUTION;
 458
 459     if (!NtCurrentTeb()->Peb->BeingDebugged)
 460     {
 461         if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 462         {
 463             /* do not launch the debugger on ^C, simply terminate the process */
 464             TerminateProcess( GetCurrentProcess(), 1 );
 465         }
 466
 467         if (top_filter)
 468         {
 469             DWORD ret = top_filter( epointers );
 470             if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 471         }
 472
 473         /* FIXME: Should check the current error mode */
 474
 475         if (!start_debugger_atomic( epointers ) || !NtCurrentTeb()->Peb->BeingDebugged)
 476             return EXCEPTION_EXECUTE_HANDLER;
 477     }
 478
 479     /* send a last chance event to the debugger */
 480     status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 481     switch (status)
 482     {
 483     case DBG_CONTINUE:
 484         return EXCEPTION_CONTINUE_EXECUTION;
 485     case DBG_EXCEPTION_NOT_HANDLED:
 486         TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 487         break; /* not reached */
 488     default:
 489         FIXME("Unhandled error on debug event: %lx\n", status);
 490         break;
 491     }
 492     return EXCEPTION_EXECUTE_HANDLER;
 493 }
 494
 495
 496 /***********************************************************************
 497  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 498  */
 499 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 500                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 501 {
 502     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 503     top_filter = filter;
 504     return old;
 505 }
 506
 507
 508 /**************************************************************************
 509  *           FatalAppExitA   (KERNEL32.@)
 510  */
 511 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 512 {
 513     HMODULE mod = GetModuleHandleA( "user32.dll" );
 514     MessageBoxA_funcptr pMessageBoxA = NULL;
 515
 516     WARN("AppExit\n");
 517
 518     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 519     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 520     else ERR( "%s\n", debugstr_a(str) );
 521     ExitProcess(0);
 522 }
 523
 524
 525 /**************************************************************************
 526  *           FatalAppExitW   (KERNEL32.@)
 527  */
 528 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 529 {
 530     static const WCHAR User32DllW[] = {'u','s','e','r','3','2','.','d','l','l',0};
 531
 532     HMODULE mod = GetModuleHandleW( User32DllW );
 533     MessageBoxW_funcptr pMessageBoxW = NULL;
 534
 535     WARN("AppExit\n");
 536
 537     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 538     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 539     else ERR( "%s\n", debugstr_w(str) );
 540     ExitProcess(0);
 541 }
 542
 543
 544 /**************************************************************************
 545  *           FatalExit   (KERNEL32.@)
 546  */
 547 void WINAPI FatalExit(int ExitCode)
 548 {
 549     WARN("FatalExit\n");
 550     ExitProcess(ExitCode);
 551 }