dlls/ntdll/exception.c

   1 /*
   2  * NT exception handling routines
   3  *
   4  * Copyright 1999 Turchanov Sergey
   5  * Copyright 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
  22 #include "config.h"
  23 #include "wine/port.h"
  24
  25 #include <assert.h>
  26 #include <errno.h>
  27 #include <signal.h>
  28 #include <stdarg.h>
  29
  30 #include "ntstatus.h"
  31 #define WIN32_NO_STATUS
  32 #include "windef.h"
  33 #include "winternl.h"
  34 #include "wine/exception.h"
  35 #include "wine/server.h"
  36 #include "wine/list.h"
  37 #include "wine/debug.h"
  38 #include "excpt.h"
  39 #include "ntdll_misc.h"
  40
  41 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  42
  43 /* Exception record for handling exceptions happening inside exception handlers */
  44 typedef struct
  45 {
  46     EXCEPTION_REGISTRATION_RECORD frame;
  47     EXCEPTION_REGISTRATION_RECORD *prevFrame;
  48 } EXC_NESTED_FRAME;
  49
  50 typedef struct
  51 {
  52     struct list                 entry;
  53     PVECTORED_EXCEPTION_HANDLER func;
  54 } VECTORED_HANDLER;
  55
  56 static struct list vectored_handlers = LIST_INIT(vectored_handlers);
  57
  58 static RTL_CRITICAL_SECTION vectored_handlers_section;
  59 static RTL_CRITICAL_SECTION_DEBUG critsect_debug =
  60 {
  61     0, 0, &vectored_handlers_section,
  62     { &critsect_debug.ProcessLocksList, &critsect_debug.ProcessLocksList },
  63       0, 0, { (DWORD_PTR)(__FILE__ ": vectored_handlers_section") }
  64 };
  65 static RTL_CRITICAL_SECTION vectored_handlers_section = { &critsect_debug, -1, 0, 0, 0, 0 };
  66
  67 #ifdef __i386__
  68 # define GET_IP(context) ((LPVOID)(context)->Eip)
  69 #elif defined(__sparc__)
  70 # define GET_IP(context) ((LPVOID)(context)->pc)
  71 #elif defined(__powerpc__)
  72 # define GET_IP(context) ((LPVOID)(context)->Iar)
  73 #elif defined(__ALPHA__)
  74 # define GET_IP(context) ((LPVOID)(context)->Fir)
  75 #elif defined(__x86_64__)
  76 # define GET_IP(context) ((LPVOID)(context)->Rip)
  77 #else
  78 # error You must define GET_IP for this CPU
  79 #endif
  80
  81 /*******************************************************************
  82  *         EXC_RaiseHandler
  83  *
  84  * Handler for exceptions happening inside a handler.
  85  */
  86 static DWORD EXC_RaiseHandler( EXCEPTION_RECORD *rec, EXCEPTION_REGISTRATION_RECORD *frame,
  87                                CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **dispatcher )
  88 {
  89     if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
  90         return ExceptionContinueSearch;
  91     /* We shouldn't get here so we store faulty frame in dispatcher */
  92     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
  93     return ExceptionNestedException;
  94 }
  95
  96
  97 /*******************************************************************
  98  *         EXC_UnwindHandler
  99  *
 100  * Handler for exceptions happening inside an unwind handler.
 101  */
 102 static DWORD EXC_UnwindHandler( EXCEPTION_RECORD *rec, EXCEPTION_REGISTRATION_RECORD *frame,
 103                                 CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **dispatcher )
 104 {
 105     if (!(rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)))
 106         return ExceptionContinueSearch;
 107     /* We shouldn't get here so we store faulty frame in dispatcher */
 108     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
 109     return ExceptionCollidedUnwind;
 110 }
 111
 112
 113 /*******************************************************************
 114  *         EXC_CallHandler
 115  *
 116  * Call an exception handler, setting up an exception frame to catch exceptions
 117  * happening during the handler execution.
 118  *
 119  * For i386 this function is implemented in assembler in signal_i386.c.
 120  */
 121 #ifndef __i386__
 122 static DWORD EXC_CallHandler( EXCEPTION_RECORD *record, EXCEPTION_REGISTRATION_RECORD *frame,
 123                               CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **dispatcher,
 124                               PEXCEPTION_HANDLER handler, PEXCEPTION_HANDLER nested_handler)
 125 {
 126     EXC_NESTED_FRAME newframe;
 127     DWORD ret;
 128
 129     newframe.frame.Handler = nested_handler;
 130     newframe.prevFrame     = frame;
 131     __wine_push_frame( &newframe.frame );
 132     ret = handler( record, frame, context, dispatcher );
 133     __wine_pop_frame( &newframe.frame );
 134     return ret;
 135 }
 136 #else
 137 /* in signal_i386.c */
 138 extern DWORD EXC_CallHandler( EXCEPTION_RECORD *record, EXCEPTION_REGISTRATION_RECORD *frame,
 139                               CONTEXT *context, EXCEPTION_REGISTRATION_RECORD **dispatcher,
 140                               PEXCEPTION_HANDLER handler, PEXCEPTION_HANDLER nested_handler);
 141 #endif
 142
 143 /**********************************************************************
 144  *           wait_suspend
 145  *
 146  * Wait until the thread is no longer suspended.
 147  */
 148 void wait_suspend( CONTEXT *context )
 149 {
 150     LARGE_INTEGER timeout;
 151     int saved_errno = errno;
 152
 153     /* store the context we got at suspend time */
 154     SERVER_START_REQ( set_thread_context )
 155     {
 156         req->handle  = wine_server_obj_handle( GetCurrentThread() );
 157         req->flags   = CONTEXT_FULL;
 158         req->suspend = 1;
 159         wine_server_add_data( req, context, sizeof(*context) );
 160         wine_server_call( req );
 161     }
 162     SERVER_END_REQ;
 163
 164     /* wait with 0 timeout, will only return once the thread is no longer suspended */
 165     timeout.QuadPart = 0;
 166     NTDLL_wait_for_multiple_objects( 0, NULL, SELECT_INTERRUPTIBLE, &timeout, 0 );
 167
 168     /* retrieve the new context */
 169     SERVER_START_REQ( get_thread_context )
 170     {
 171         req->handle  = wine_server_obj_handle( GetCurrentThread() );
 172         req->flags   = CONTEXT_FULL;
 173         req->suspend = 1;
 174         wine_server_set_reply( req, context, sizeof(*context) );
 175         wine_server_call( req );
 176     }
 177     SERVER_END_REQ;
 178
 179     errno = saved_errno;
 180 }
 181
 182
 183 /**********************************************************************
 184  *           send_debug_event
 185  *
 186  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 187  */
 188 static NTSTATUS send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 189 {
 190     int ret;
 191     DWORD i;
 192     HANDLE handle = 0;
 193     client_ptr_t params[EXCEPTION_MAXIMUM_PARAMETERS];
 194
 195     if (!NtCurrentTeb()->Peb->BeingDebugged) return 0;  /* no debugger present */
 196
 197     for (i = 0; i < min( rec->NumberParameters, EXCEPTION_MAXIMUM_PARAMETERS ); i++)
 198         params[i] = rec->ExceptionInformation[i];
 199
 200     SERVER_START_REQ( queue_exception_event )
 201     {
 202         req->first   = first_chance;
 203         req->code    = rec->ExceptionCode;
 204         req->flags   = rec->ExceptionFlags;
 205         req->record  = wine_server_client_ptr( rec->ExceptionRecord );
 206         req->address = wine_server_client_ptr( rec->ExceptionAddress );
 207         req->len     = i * sizeof(params[0]);
 208         wine_server_add_data( req, params, req->len );
 209         wine_server_add_data( req, context, sizeof(*context) );
 210         if (!wine_server_call( req )) handle = wine_server_ptr_handle( reply->handle );
 211     }
 212     SERVER_END_REQ;
 213     if (!handle) return 0;
 214
 215     NTDLL_wait_for_multiple_objects( 1, &handle, SELECT_INTERRUPTIBLE, NULL, 0 );
 216
 217     SERVER_START_REQ( get_exception_status )
 218     {
 219         req->handle = wine_server_obj_handle( handle );
 220         wine_server_set_reply( req, context, sizeof(*context) );
 221         ret = wine_server_call( req );
 222     }
 223     SERVER_END_REQ;
 224     return ret;
 225 }
 226
 227
 228 /**********************************************************************
 229  *           call_vectored_handlers
 230  *
 231  * Call the vectored handlers chain.
 232  */
 233 static LONG call_vectored_handlers( EXCEPTION_RECORD *rec, CONTEXT *context )
 234 {
 235     struct list *ptr;
 236     LONG ret = EXCEPTION_CONTINUE_SEARCH;
 237     EXCEPTION_POINTERS except_ptrs;
 238
 239     except_ptrs.ExceptionRecord = rec;
 240     except_ptrs.ContextRecord = context;
 241
 242     RtlEnterCriticalSection( &vectored_handlers_section );
 243     LIST_FOR_EACH( ptr, &vectored_handlers )
 244     {
 245         VECTORED_HANDLER *handler = LIST_ENTRY( ptr, VECTORED_HANDLER, entry );
 246         TRACE( "calling handler at %p code=%x flags=%x\n",
 247                handler->func, rec->ExceptionCode, rec->ExceptionFlags );
 248         ret = handler->func( &except_ptrs );
 249         TRACE( "handler at %p returned %x\n", handler->func, ret );
 250         if (ret == EXCEPTION_CONTINUE_EXECUTION) break;
 251     }
 252     RtlLeaveCriticalSection( &vectored_handlers_section );
 253     return ret;
 254 }
 255
 256
 257 /**********************************************************************
 258  *           call_stack_handlers
 259  *
 260  * Call the stack handlers chain.
 261  */
 262 static NTSTATUS call_stack_handlers( EXCEPTION_RECORD *rec, CONTEXT *context )
 263 {
 264     EXCEPTION_REGISTRATION_RECORD *frame, *dispatch, *nested_frame;
 265     DWORD res;
 266
 267     frame = NtCurrentTeb()->Tib.ExceptionList;
 268     nested_frame = NULL;
 269     while (frame != (EXCEPTION_REGISTRATION_RECORD*)~0UL)
 270     {
 271         /* Check frame address */
 272         if (((void*)frame < NtCurrentTeb()->Tib.StackLimit) ||
 273             ((void*)(frame+1) > NtCurrentTeb()->Tib.StackBase) ||
 274             (ULONG_PTR)frame & 3)
 275         {
 276             rec->ExceptionFlags |= EH_STACK_INVALID;
 277             break;
 278         }
 279
 280         /* Call handler */
 281         TRACE( "calling handler at %p code=%x flags=%x\n",
 282                frame->Handler, rec->ExceptionCode, rec->ExceptionFlags );
 283         res = EXC_CallHandler( rec, frame, context, &dispatch, frame->Handler, EXC_RaiseHandler );
 284         TRACE( "handler at %p returned %x\n", frame->Handler, res );
 285
 286         if (frame == nested_frame)
 287         {
 288             /* no longer nested */
 289             nested_frame = NULL;
 290             rec->ExceptionFlags &= ~EH_NESTED_CALL;
 291         }
 292
 293         switch(res)
 294         {
 295         case ExceptionContinueExecution:
 296             if (!(rec->ExceptionFlags & EH_NONCONTINUABLE)) return STATUS_SUCCESS;
 297             return STATUS_NONCONTINUABLE_EXCEPTION;
 298         case ExceptionContinueSearch:
 299             break;
 300         case ExceptionNestedException:
 301             if (nested_frame < dispatch) nested_frame = dispatch;
 302             rec->ExceptionFlags |= EH_NESTED_CALL;
 303             break;
 304         default:
 305             return STATUS_INVALID_DISPOSITION;
 306         }
 307         frame = frame->Prev;
 308     }
 309     return STATUS_UNHANDLED_EXCEPTION;
 310 }
 311
 312
 313 /*******************************************************************
 314  *              raise_exception
 315  *
 316  * Implementation of NtRaiseException.
 317  */
 318 static NTSTATUS raise_exception( EXCEPTION_RECORD *rec, CONTEXT *context, BOOL first_chance )
 319 {
 320     NTSTATUS status;
 321
 322     if (first_chance)
 323     {
 324         DWORD c;
 325
 326         TRACE( "code=%x flags=%x addr=%p ip=%p tid=%04x\n",
 327                rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 328                GET_IP(context), GetCurrentThreadId() );
 329         for (c = 0; c < rec->NumberParameters; c++)
 330             TRACE( " info[%d]=%08lx\n", c, rec->ExceptionInformation[c] );
 331         if (rec->ExceptionCode == EXCEPTION_WINE_STUB)
 332         {
 333             if (rec->ExceptionInformation[1] >> 16)
 334                 MESSAGE( "wine: Call from %p to unimplemented function %s.%s, aborting\n",
 335                          rec->ExceptionAddress,
 336                          (char*)rec->ExceptionInformation[0], (char*)rec->ExceptionInformation[1] );
 337             else
 338                 MESSAGE( "wine: Call from %p to unimplemented function %s.%ld, aborting\n",
 339                          rec->ExceptionAddress,
 340                          (char*)rec->ExceptionInformation[0], rec->ExceptionInformation[1] );
 341         }
 342         else
 343         {
 344 #ifdef __i386__
 345             TRACE(" eax=%08x ebx=%08x ecx=%08x edx=%08x esi=%08x edi=%08x\n",
 346                   context->Eax, context->Ebx, context->Ecx,
 347                   context->Edx, context->Esi, context->Edi );
 348             TRACE(" ebp=%08x esp=%08x cs=%04x ds=%04x es=%04x fs=%04x gs=%04x flags=%08x\n",
 349                   context->Ebp, context->Esp, context->SegCs, context->SegDs,
 350                   context->SegEs, context->SegFs, context->SegGs, context->EFlags );
 351 #elif defined(__x86_64__)
 352             TRACE(" rax=%016lx rbx=%016lx rcx=%016lx rdx=%016lx\n",
 353                   context->Rax, context->Rbx, context->Rcx, context->Rdx );
 354             TRACE(" rsi=%016lx rdi=%016lx rbp=%016lx rsp=%016lx\n",
 355                   context->Rsi, context->Rdi, context->Rbp, context->Rsp );
 356             TRACE("  r8=%016lx  r9=%016lx r10=%016lx r11=%016lx\n",
 357                   context->R8, context->R9, context->R10, context->R11 );
 358             TRACE(" r12=%016lx r13=%016lx r14=%016lx r15=%016lx\n",
 359                   context->R12, context->R13, context->R14, context->R15 );
 360 #endif
 361         }
 362         status = send_debug_event( rec, TRUE, context );
 363         if (status == DBG_CONTINUE || status == DBG_EXCEPTION_HANDLED)
 364             return STATUS_SUCCESS;
 365
 366 #ifdef __i386__
 367         /* fix up instruction pointer in context for EXCEPTION_BREAKPOINT */
 368         if (rec->ExceptionCode == EXCEPTION_BREAKPOINT) context->Eip--;
 369 #endif
 370
 371         if (call_vectored_handlers( rec, context ) == EXCEPTION_CONTINUE_EXECUTION)
 372             return STATUS_SUCCESS;
 373
 374         if ((status = call_stack_handlers( rec, context )) != STATUS_UNHANDLED_EXCEPTION)
 375             return status;
 376     }
 377
 378     /* last chance exception */
 379
 380     status = send_debug_event( rec, FALSE, context );
 381     if (status != DBG_CONTINUE)
 382     {
 383         if (rec->ExceptionFlags & EH_STACK_INVALID)
 384             ERR("Exception frame is not in stack limits => unable to dispatch exception.\n");
 385         else if (rec->ExceptionCode == STATUS_NONCONTINUABLE_EXCEPTION)
 386             ERR("Process attempted to continue execution after noncontinuable exception.\n");
 387         else
 388             ERR("Unhandled exception code %x flags %x addr %p\n",
 389                 rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress );
 390         NtTerminateProcess( NtCurrentProcess(), 1 );
 391     }
 392     return STATUS_SUCCESS;
 393 }
 394
 395
 396 /*******************************************************************
 397  *              NtRaiseException (NTDLL.@)
 398  */
 399 NTSTATUS WINAPI NtRaiseException( EXCEPTION_RECORD *rec, CONTEXT *context, BOOL first_chance )
 400 {
 401     NTSTATUS status = raise_exception( rec, context, first_chance );
 402     if (status == STATUS_SUCCESS) NtSetContextThread( GetCurrentThread(), context );
 403     return status;
 404 }
 405
 406
 407 /***********************************************************************
 408  *              RtlRaiseException (NTDLL.@)
 409  */
 410 void WINAPI __regs_RtlRaiseException( EXCEPTION_RECORD *rec, CONTEXT *context )
 411 {
 412     NTSTATUS status = raise_exception( rec, context, TRUE );
 413     if (status != STATUS_SUCCESS)
 414     {
 415         EXCEPTION_RECORD newrec;
 416         newrec.ExceptionCode    = status;
 417         newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 418         newrec.ExceptionRecord  = rec;
 419         newrec.NumberParameters = 0;
 420         RtlRaiseException( &newrec );  /* never returns */
 421     }
 422 }
 423
 424 /**********************************************************************/
 425
 426 #ifdef DEFINE_REGS_ENTRYPOINT
 427 DEFINE_REGS_ENTRYPOINT( RtlRaiseException, 1 )
 428 #else
 429 void WINAPI RtlRaiseException( EXCEPTION_RECORD *rec )
 430 {
 431     CONTEXT context;
 432     RtlCaptureContext( &context );
 433     __regs_RtlRaiseException( rec, &context );
 434 }
 435 #endif
 436
 437
 438 /*******************************************************************
 439  *              RtlUnwind (NTDLL.@)
 440  */
 441 void WINAPI __regs_RtlUnwind( EXCEPTION_REGISTRATION_RECORD* pEndFrame, PVOID unusedEip,
 442                               PEXCEPTION_RECORD pRecord, PVOID returnEax, CONTEXT *context )
 443 {
 444     EXCEPTION_RECORD record, newrec;
 445     EXCEPTION_REGISTRATION_RECORD *frame, *dispatch;
 446     DWORD res;
 447
 448 #ifdef __i386__
 449     context->Eax = (DWORD)returnEax;
 450 #endif
 451
 452     /* build an exception record, if we do not have one */
 453     if (!pRecord)
 454     {
 455         record.ExceptionCode    = STATUS_UNWIND;
 456         record.ExceptionFlags   = 0;
 457         record.ExceptionRecord  = NULL;
 458         record.ExceptionAddress = GET_IP(context);
 459         record.NumberParameters = 0;
 460         pRecord = &record;
 461     }
 462
 463     pRecord->ExceptionFlags |= EH_UNWINDING | (pEndFrame ? 0 : EH_EXIT_UNWIND);
 464
 465     TRACE( "code=%x flags=%x\n", pRecord->ExceptionCode, pRecord->ExceptionFlags );
 466
 467     /* get chain of exception frames */
 468     frame = NtCurrentTeb()->Tib.ExceptionList;
 469     while ((frame != (EXCEPTION_REGISTRATION_RECORD*)~0UL) && (frame != pEndFrame))
 470     {
 471         /* Check frame address */
 472         if (pEndFrame && (frame > pEndFrame))
 473         {
 474             newrec.ExceptionCode    = STATUS_INVALID_UNWIND_TARGET;
 475             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 476             newrec.ExceptionRecord  = pRecord;
 477             newrec.NumberParameters = 0;
 478             RtlRaiseException( &newrec );  /* never returns */
 479         }
 480         if (((void*)frame < NtCurrentTeb()->Tib.StackLimit) ||
 481             ((void*)(frame+1) > NtCurrentTeb()->Tib.StackBase) ||
 482             (UINT_PTR)frame & 3)
 483         {
 484             newrec.ExceptionCode    = STATUS_BAD_STACK;
 485             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 486             newrec.ExceptionRecord  = pRecord;
 487             newrec.NumberParameters = 0;
 488             RtlRaiseException( &newrec );  /* never returns */
 489         }
 490
 491         /* Call handler */
 492         TRACE( "calling handler at %p code=%x flags=%x\n",
 493                frame->Handler, pRecord->ExceptionCode, pRecord->ExceptionFlags );
 494         res = EXC_CallHandler( pRecord, frame, context, &dispatch, frame->Handler, EXC_UnwindHandler );
 495         TRACE( "handler at %p returned %x\n", frame->Handler, res );
 496
 497         switch(res)
 498         {
 499         case ExceptionContinueSearch:
 500             break;
 501         case ExceptionCollidedUnwind:
 502             frame = dispatch;
 503             break;
 504         default:
 505             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 506             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 507             newrec.ExceptionRecord  = pRecord;
 508             newrec.NumberParameters = 0;
 509             RtlRaiseException( &newrec );  /* never returns */
 510             break;
 511         }
 512         frame = __wine_pop_frame( frame );
 513     }
 514 }
 515
 516 /**********************************************************************/
 517
 518 #ifdef DEFINE_REGS_ENTRYPOINT
 519 DEFINE_REGS_ENTRYPOINT( RtlUnwind, 4 )
 520 #else
 521 void WINAPI RtlUnwind( PVOID pEndFrame, PVOID unusedEip,
 522                        PEXCEPTION_RECORD pRecord, PVOID returnEax )
 523 {
 524     CONTEXT context;
 525     RtlCaptureContext( &context );
 526     __regs_RtlUnwind( pEndFrame, unusedEip, pRecord, returnEax, &context );
 527 }
 528 #endif
 529
 530
 531 /***********************************************************************
 532  *            RtlRaiseStatus  (NTDLL.@)
 533  *
 534  * Raise an exception with ExceptionCode = status
 535  */
 536 void WINAPI RtlRaiseStatus( NTSTATUS status )
 537 {
 538     EXCEPTION_RECORD ExceptionRec;
 539
 540     ExceptionRec.ExceptionCode    = status;
 541     ExceptionRec.ExceptionFlags   = EH_NONCONTINUABLE;
 542     ExceptionRec.ExceptionRecord  = NULL;
 543     ExceptionRec.NumberParameters = 0;
 544     RtlRaiseException( &ExceptionRec );
 545 }
 546
 547
 548 /*******************************************************************
 549  *         RtlAddVectoredExceptionHandler   (NTDLL.@)
 550  */
 551 PVOID WINAPI RtlAddVectoredExceptionHandler( ULONG first, PVECTORED_EXCEPTION_HANDLER func )
 552 {
 553     VECTORED_HANDLER *handler = RtlAllocateHeap( GetProcessHeap(), 0, sizeof(*handler) );
 554     if (handler)
 555     {
 556         handler->func = func;
 557         RtlEnterCriticalSection( &vectored_handlers_section );
 558         if (first) list_add_head( &vectored_handlers, &handler->entry );
 559         else list_add_tail( &vectored_handlers, &handler->entry );
 560         RtlLeaveCriticalSection( &vectored_handlers_section );
 561     }
 562     return handler;
 563 }
 564
 565
 566 /*******************************************************************
 567  *         RtlRemoveVectoredExceptionHandler   (NTDLL.@)
 568  */
 569 ULONG WINAPI RtlRemoveVectoredExceptionHandler( PVOID handler )
 570 {
 571     struct list *ptr;
 572     ULONG ret = FALSE;
 573
 574     RtlEnterCriticalSection( &vectored_handlers_section );
 575     LIST_FOR_EACH( ptr, &vectored_handlers )
 576     {
 577         VECTORED_HANDLER *curr_handler = LIST_ENTRY( ptr, VECTORED_HANDLER, entry );
 578         if (curr_handler == handler)
 579         {
 580             list_remove( ptr );
 581             ret = TRUE;
 582             break;
 583         }
 584     }
 585     RtlLeaveCriticalSection( &vectored_handlers_section );
 586     if (ret) RtlFreeHeap( GetProcessHeap(), 0, handler );
 587     return ret;
 588 }
 589
 590
 591 /*************************************************************************
 592  * RtlCaptureStackBackTrace   [NTDLL.@]
 593  *
 594  * Captures stack backtrace
 595  *
 596  * PARAMS
 597  *  Skip   [I] Number of stack frames to skip before starting a capture
 598  *  Count  [I] Number of stack frames to capture into Buffer
 599  *  Buffer [O] Array of backtrace pointers captured from stack
 600  *  Hash   [O] Optional pointer to variable where backtrace hash should be stored
 601  *
 602  * RETURNS
 603  *  Number of captured stack frames or 0 if error occurred
 604  *
 605  * NOTES
 606  *   Unimplemented
 607  */
 608 USHORT WINAPI RtlCaptureStackBackTrace(ULONG Skip, ULONG Count, PVOID *Buffer, ULONG *Hash)
 609 {
 610     FIXME("(%d, %d, %p, %p) stub!\n", Skip, Count, Buffer, Hash);
 611     return 0;
 612 }
 613
 614
 615 /*************************************************************
 616  *            __wine_spec_unimplemented_stub
 617  *
 618  * ntdll-specific implementation to avoid depending on kernel functions.
 619  * Can be removed once ntdll.spec no longer contains stubs.
 620  */
 621 void __wine_spec_unimplemented_stub( const char *module, const char *function )
 622 {
 623     EXCEPTION_RECORD record;
 624
 625     record.ExceptionCode    = EXCEPTION_WINE_STUB;
 626     record.ExceptionFlags   = EH_NONCONTINUABLE;
 627     record.ExceptionRecord  = NULL;
 628     record.ExceptionAddress = __wine_spec_unimplemented_stub;
 629     record.NumberParameters = 2;
 630     record.ExceptionInformation[0] = (ULONG_PTR)module;
 631     record.ExceptionInformation[1] = (ULONG_PTR)function;
 632     for (;;) RtlRaiseException( &record );
 633 }