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         if (HIWORD(rec->ExceptionInformation[1]))
 139             len = snprintf( buffer, size, "Unimplemented function %s.%s called",
 140                             (char *)rec->ExceptionInformation[0], (char *)rec->ExceptionInformation[1] );
 141         else
 142             len = snprintf( buffer, size, "Unimplemented function %s.%ld called",
 143                             (char *)rec->ExceptionInformation[0], rec->ExceptionInformation[1] );
 144         break;
 145     case EXCEPTION_WINE_ASSERTION:
 146         len = snprintf( buffer, size, "Assertion failed" );
 147         break;
 148     case EXCEPTION_VM86_INTx:
 149         len = snprintf( buffer, size, "Unhandled interrupt %02lx in vm86 mode",
 150                  rec->ExceptionInformation[0]);
 151         break;
 152     case EXCEPTION_VM86_STI:
 153         len = snprintf( buffer, size, "Unhandled sti in vm86 mode");
 154         break;
 155     case EXCEPTION_VM86_PICRETURN:
 156         len = snprintf( buffer, size, "Unhandled PIC return in vm86 mode");
 157         break;
 158     default:
 159         len = snprintf( buffer, size, "Unhandled exception 0x%08lx", rec->ExceptionCode);
 160         break;
 161     }
 162     if ((len<0) || (len>=size))
 163         return -1;
 164 #ifdef __i386__
 165     if (ptr->ContextRecord->SegCs != wine_get_cs())
 166         len2 = snprintf(buffer+len, size-len,
 167                         " at address 0x%04lx:0x%08lx.\nDo you wish to debug it ?",
 168                         ptr->ContextRecord->SegCs,
 169                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 170     else
 171 #endif
 172         len2 = snprintf(buffer+len, size-len,
 173                         " at address 0x%08lx.\nDo you wish to debug it ?",
 174                         (DWORD)ptr->ExceptionRecord->ExceptionAddress);
 175     if ((len2<0) || (len>=size-len))
 176         return -1;
 177     return len+len2;
 178 }
 179
 180
 181 /**********************************************************************
 182  *           send_debug_event
 183  *
 184  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 185  */
 186 static NTSTATUS send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 187 {
 188     NTSTATUS ret;
 189     HANDLE handle = 0;
 190
 191     SERVER_START_REQ( queue_exception_event )
 192     {
 193         req->first   = first_chance;
 194         wine_server_add_data( req, context, sizeof(*context) );
 195         wine_server_add_data( req, rec, sizeof(*rec) );
 196         if (!(ret = wine_server_call( req ))) handle = reply->handle;
 197     }
 198     SERVER_END_REQ;
 199     if (ret) return ret;
 200
 201     /* No need to wait on the handle since the process gets suspended
 202      * once the event is passed to the debugger, so when we get back
 203      * here the event has been continued already.
 204      */
 205     SERVER_START_REQ( get_exception_status )
 206     {
 207         req->handle = handle;
 208         wine_server_set_reply( req, context, sizeof(*context) );
 209         wine_server_call( req );
 210         ret = reply->status;
 211     }
 212     SERVER_END_REQ;
 213     NtClose( handle );
 214     return ret;
 215 }
 216
 217 /******************************************************************
 218  *              start_debugger
 219  *
 220  * Does the effective debugger startup according to 'format'
 221  */
 222 static BOOL     start_debugger(PEXCEPTION_POINTERS epointers, HANDLE hEvent)
 223 {
 224     OBJECT_ATTRIBUTES attr;
 225     UNICODE_STRING nameW;
 226     char *cmdline, *env, *p;
 227     HKEY                hDbgConf;
 228     DWORD               bAuto = FALSE;
 229     PROCESS_INFORMATION info;
 230     STARTUPINFOA        startup;
 231     char*               format = NULL;
 232     BOOL                ret = FALSE;
 233
 234     static const WCHAR AeDebugW[] = {'M','a','c','h','i','n','e','\\',
 235                                      'S','o','f','t','w','a','r','e','\\',
 236                                      'M','i','c','r','o','s','o','f','t','\\',
 237                                      'W','i','n','d','o','w','s',' ','N','T','\\',
 238                                      'C','u','r','r','e','n','t','V','e','r','s','i','o','n','\\',
 239                                      'A','e','D','e','b','u','g',0};
 240     static const WCHAR DebuggerW[] = {'D','e','b','u','g','g','e','r',0};
 241     static const WCHAR AutoW[] = {'A','u','t','o',0};
 242
 243     MESSAGE("wine: Unhandled exception (thread %04lx), starting debugger...\n", GetCurrentThreadId());
 244
 245     attr.Length = sizeof(attr);
 246     attr.RootDirectory = 0;
 247     attr.ObjectName = &nameW;
 248     attr.Attributes = 0;
 249     attr.SecurityDescriptor = NULL;
 250     attr.SecurityQualityOfService = NULL;
 251     RtlInitUnicodeString( &nameW, AeDebugW );
 252
 253     if (!NtOpenKey( &hDbgConf, KEY_ALL_ACCESS, &attr ))
 254     {
 255         char buffer[64];
 256         KEY_VALUE_PARTIAL_INFORMATION *info;
 257         DWORD format_size = 0;
 258
 259         RtlInitUnicodeString( &nameW, DebuggerW );
 260         if (NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 261                              NULL, 0, &format_size ) == STATUS_BUFFER_OVERFLOW)
 262         {
 263             char *data = HeapAlloc(GetProcessHeap(), 0, format_size);
 264             NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 265                              data, format_size, &format_size );
 266             info = (KEY_VALUE_PARTIAL_INFORMATION *)data;
 267             RtlUnicodeToMultiByteSize( &format_size, (WCHAR *)info->Data, info->DataLength );
 268             format = HeapAlloc( GetProcessHeap(), 0, format_size+1 );
 269             RtlUnicodeToMultiByteN( format, format_size, NULL,
 270                                     (WCHAR *)info->Data, info->DataLength );
 271             format[format_size] = 0;
 272
 273             if (info->Type == REG_EXPAND_SZ)
 274             {
 275                 char* tmp;
 276
 277                 /* Expand environment variable references */
 278                 format_size=ExpandEnvironmentStringsA(format,NULL,0);
 279                 tmp=HeapAlloc(GetProcessHeap(), 0, format_size);
 280                 ExpandEnvironmentStringsA(format,tmp,format_size);
 281                 HeapFree(GetProcessHeap(), 0, format);
 282                 format=tmp;
 283             }
 284             HeapFree( GetProcessHeap(), 0, data );
 285         }
 286
 287         RtlInitUnicodeString( &nameW, AutoW );
 288         if (!NtQueryValueKey( hDbgConf, &nameW, KeyValuePartialInformation,
 289                               buffer, sizeof(buffer)-sizeof(WCHAR), &format_size ))
 290        {
 291            info = (KEY_VALUE_PARTIAL_INFORMATION *)buffer;
 292            if (info->Type == REG_DWORD) memcpy( &bAuto, info->Data, sizeof(DWORD) );
 293            else if (info->Type == REG_SZ)
 294            {
 295                WCHAR *str = (WCHAR *)info->Data;
 296                str[info->DataLength/sizeof(WCHAR)] = 0;
 297                bAuto = atoiW( str );
 298            }
 299        }
 300        else bAuto = TRUE;
 301
 302        NtClose(hDbgConf);
 303     }
 304
 305     if (format)
 306     {
 307         cmdline = HeapAlloc(GetProcessHeap(), 0, strlen(format) + 2*20);
 308         sprintf(cmdline, format, GetCurrentProcessId(), hEvent);
 309         HeapFree(GetProcessHeap(), 0, format);
 310     }
 311     else
 312     {
 313         cmdline = HeapAlloc(GetProcessHeap(), 0, 80);
 314         sprintf(cmdline, "winedbg --auto %ld %ld",
 315                 GetCurrentProcessId(), (ULONG_PTR)hEvent);
 316     }
 317
 318     if (!bAuto)
 319     {
 320         HMODULE                 mod = GetModuleHandleA( "user32.dll" );
 321         MessageBoxA_funcptr     pMessageBoxA = NULL;
 322
 323         if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 324         if (pMessageBoxA)
 325         {
 326             char buffer[256];
 327             format_exception_msg( epointers, buffer, sizeof(buffer) );
 328             if (pMessageBoxA( 0, buffer, "Exception raised", MB_YESNO | MB_ICONHAND ) == IDNO)
 329             {
 330                 TRACE("Killing process\n");
 331                 goto EXIT;
 332             }
 333         }
 334     }
 335
 336     /* remove WINEDEBUG from the environment */
 337     env = GetEnvironmentStringsA();
 338     for (p = env; *p; p += strlen(p) + 1)
 339     {
 340         if (!memcmp( p, "WINEDEBUG=", sizeof("WINEDEBUG=")-1 ))
 341         {
 342             char *next = p + strlen(p) + 1;
 343             char *end = next;
 344             while (*end) end += strlen(end) + 1;
 345             memmove( p, next, end + 1 - next );
 346             break;
 347         }
 348     }
 349
 350     TRACE("Starting debugger %s\n", debugstr_a(cmdline));
 351     memset(&startup, 0, sizeof(startup));
 352     startup.cb = sizeof(startup);
 353     startup.dwFlags = STARTF_USESHOWWINDOW;
 354     startup.wShowWindow = SW_SHOWNORMAL;
 355     ret = CreateProcessA(NULL, cmdline, NULL, NULL, TRUE, 0, env, NULL, &startup, &info);
 356     FreeEnvironmentStringsA( env );
 357
 358     if (ret) WaitForSingleObject(hEvent, INFINITE);  /* wait for debugger to come up... */
 359     else ERR("Couldn't start debugger (%s) (%ld)\n"
 360              "Read the Wine Developers Guide on how to set up winedbg or another debugger\n",
 361              debugstr_a(cmdline), GetLastError());
 362 EXIT:
 363     HeapFree(GetProcessHeap(), 0, cmdline);
 364     return ret;
 365 }
 366
 367 /******************************************************************
 368  *              start_debugger_atomic
 369  *
 370  * starts the debugger in an atomic way:
 371  *      - either the debugger is not started and it is started
 372  *      - or the debugger has already been started by another thread
 373  *      - or the debugger couldn't be started
 374  *
 375  * returns TRUE for the two first conditions, FALSE for the last
 376  */
 377 static  int     start_debugger_atomic(PEXCEPTION_POINTERS epointers)
 378 {
 379     static HANDLE       hRunOnce /* = 0 */;
 380
 381     if (hRunOnce == 0)
 382     {
 383         OBJECT_ATTRIBUTES       attr;
 384         HANDLE                  hEvent;
 385
 386         attr.Length                   = sizeof(attr);
 387         attr.RootDirectory            = 0;
 388         attr.Attributes               = OBJ_INHERIT;
 389         attr.ObjectName               = NULL;
 390         attr.SecurityDescriptor       = NULL;
 391         attr.SecurityQualityOfService = NULL;
 392
 393         /* ask for manual reset, so that once the debugger is started,
 394          * every thread will know it */
 395         NtCreateEvent( &hEvent, EVENT_ALL_ACCESS, &attr, TRUE, FALSE );
 396         if (InterlockedCompareExchangePointer( (PVOID)&hRunOnce, hEvent, 0 ) == 0)
 397         {
 398             /* ok, our event has been set... we're the winning thread */
 399             BOOL        ret = start_debugger( epointers, hRunOnce );
 400             DWORD       tmp;
 401
 402             if (!ret)
 403             {
 404                 /* so that the other threads won't be stuck */
 405                 NtSetEvent( hRunOnce, &tmp );
 406             }
 407             return ret;
 408         }
 409
 410         /* someone beat us here... */
 411         CloseHandle( hEvent );
 412     }
 413
 414     /* and wait for the winner to have actually created the debugger */
 415     WaitForSingleObject( hRunOnce, INFINITE );
 416     /* in fact, here, we only know that someone has tried to start the debugger,
 417      * we'll know by reposting the exception if it has actually attached
 418      * to the current process */
 419     return TRUE;
 420 }
 421
 422
 423 /*******************************************************************
 424  *         check_resource_write
 425  *
 426  * Check if the exception is a write attempt to the resource data.
 427  * If yes, we unprotect the resources to let broken apps continue
 428  * (Windows does this too).
 429  */
 430 inline static BOOL check_resource_write( const EXCEPTION_RECORD *rec )
 431 {
 432     void *addr, *rsrc;
 433     DWORD size;
 434     MEMORY_BASIC_INFORMATION info;
 435
 436     if (rec->ExceptionCode != EXCEPTION_ACCESS_VIOLATION) return FALSE;
 437     if (rec->NumberParameters < 2) return FALSE;
 438     if (!rec->ExceptionInformation[0]) return FALSE;  /* not a write access */
 439     addr = (void *)rec->ExceptionInformation[1];
 440     if (!VirtualQuery( addr, &info, sizeof(info) )) return FALSE;
 441     if (!(rsrc = RtlImageDirectoryEntryToData( (HMODULE)info.AllocationBase, TRUE,
 442                                               IMAGE_DIRECTORY_ENTRY_RESOURCE, &size )))
 443         return FALSE;
 444     if (addr < rsrc || (char *)addr >= (char *)rsrc + size) return FALSE;
 445     TRACE( "Broken app is writing to the resource data, enabling work-around\n" );
 446     VirtualProtect( rsrc, size, PAGE_WRITECOPY, NULL );
 447     return TRUE;
 448 }
 449
 450
 451 /*******************************************************************
 452  *         UnhandledExceptionFilter   (KERNEL32.@)
 453  */
 454 DWORD WINAPI UnhandledExceptionFilter(PEXCEPTION_POINTERS epointers)
 455 {
 456     NTSTATUS status;
 457
 458     if (check_resource_write( epointers->ExceptionRecord )) return EXCEPTION_CONTINUE_EXECUTION;
 459
 460     if (!NtCurrentTeb()->Peb->BeingDebugged)
 461     {
 462         if (epointers->ExceptionRecord->ExceptionCode == CONTROL_C_EXIT)
 463         {
 464             /* do not launch the debugger on ^C, simply terminate the process */
 465             TerminateProcess( GetCurrentProcess(), 1 );
 466         }
 467
 468         if (top_filter)
 469         {
 470             DWORD ret = top_filter( epointers );
 471             if (ret != EXCEPTION_CONTINUE_SEARCH) return ret;
 472         }
 473
 474         /* FIXME: Should check the current error mode */
 475
 476         if (!start_debugger_atomic( epointers ) || !NtCurrentTeb()->Peb->BeingDebugged)
 477             return EXCEPTION_EXECUTE_HANDLER;
 478     }
 479
 480     /* send a last chance event to the debugger */
 481     status = send_debug_event( epointers->ExceptionRecord, FALSE, epointers->ContextRecord );
 482     switch (status)
 483     {
 484     case DBG_CONTINUE:
 485         return EXCEPTION_CONTINUE_EXECUTION;
 486     case DBG_EXCEPTION_NOT_HANDLED:
 487         TerminateProcess( GetCurrentProcess(), epointers->ExceptionRecord->ExceptionCode );
 488         break; /* not reached */
 489     default:
 490         FIXME("Unhandled error on debug event: %lx\n", status);
 491         break;
 492     }
 493     return EXCEPTION_EXECUTE_HANDLER;
 494 }
 495
 496
 497 /***********************************************************************
 498  *            SetUnhandledExceptionFilter   (KERNEL32.@)
 499  */
 500 LPTOP_LEVEL_EXCEPTION_FILTER WINAPI SetUnhandledExceptionFilter(
 501                                           LPTOP_LEVEL_EXCEPTION_FILTER filter )
 502 {
 503     LPTOP_LEVEL_EXCEPTION_FILTER old = top_filter;
 504     top_filter = filter;
 505     return old;
 506 }
 507
 508
 509 /**************************************************************************
 510  *           FatalAppExitA   (KERNEL32.@)
 511  */
 512 void WINAPI FatalAppExitA( UINT action, LPCSTR str )
 513 {
 514     HMODULE mod = GetModuleHandleA( "user32.dll" );
 515     MessageBoxA_funcptr pMessageBoxA = NULL;
 516
 517     WARN("AppExit\n");
 518
 519     if (mod) pMessageBoxA = (MessageBoxA_funcptr)GetProcAddress( mod, "MessageBoxA" );
 520     if (pMessageBoxA) pMessageBoxA( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 521     else ERR( "%s\n", debugstr_a(str) );
 522     ExitProcess(0);
 523 }
 524
 525
 526 /**************************************************************************
 527  *           FatalAppExitW   (KERNEL32.@)
 528  */
 529 void WINAPI FatalAppExitW( UINT action, LPCWSTR str )
 530 {
 531     static const WCHAR User32DllW[] = {'u','s','e','r','3','2','.','d','l','l',0};
 532
 533     HMODULE mod = GetModuleHandleW( User32DllW );
 534     MessageBoxW_funcptr pMessageBoxW = NULL;
 535
 536     WARN("AppExit\n");
 537
 538     if (mod) pMessageBoxW = (MessageBoxW_funcptr)GetProcAddress( mod, "MessageBoxW" );
 539     if (pMessageBoxW) pMessageBoxW( 0, str, NULL, MB_SYSTEMMODAL | MB_OK );
 540     else ERR( "%s\n", debugstr_w(str) );
 541     ExitProcess(0);
 542 }
 543
 544
 545 /**************************************************************************
 546  *           FatalExit   (KERNEL32.@)
 547  */
 548 void WINAPI FatalExit(int ExitCode)
 549 {
 550     WARN("FatalExit\n");
 551     ExitProcess(ExitCode);
 552 }