git.oblomov.eu Git - wine/blob - dlls/msvcrt/except.c

   1 /*
   2  * msvcrt.dll exception handling
   3  *
   4  * Copyright 2000 Jon Griffiths
   5  * Copyright 2005 Juan Lang
   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  * NOTES:
  22  *
  23  * See http://www.microsoft.com/msj/0197/exception/exception.htm,
  24  * but don't believe all of it.
  25  *
  26  * FIXME: Incomplete support for nested exceptions/try block cleanup.
  27  */
  28
  29 #include "config.h"
  30 #include "wine/port.h"
  31
  32 #include <stdarg.h>
  33
  34 #include "windef.h"
  35 #include "winbase.h"
  36 #include "winreg.h"
  37 #include "winternl.h"
  38 #include "wine/exception.h"
  39 #include "msvcrt.h"
  40 #include "excpt.h"
  41 #include "wincon.h"
  42 #include "msvcrt/float.h"
  43 #include "wine/debug.h"
  44
  45 WINE_DEFAULT_DEBUG_CHANNEL(seh);
  46
  47 /* VC++ extensions to Win32 SEH */
  48 typedef struct _SCOPETABLE
  49 {
  50   int previousTryLevel;
  51   int (*lpfnFilter)(PEXCEPTION_POINTERS);
  52   int (*lpfnHandler)(void);
  53 } SCOPETABLE, *PSCOPETABLE;
  54
  55 typedef struct _MSVCRT_EXCEPTION_FRAME
  56 {
  57   EXCEPTION_REGISTRATION_RECORD *prev;
  58   void (*handler)(PEXCEPTION_RECORD, EXCEPTION_REGISTRATION_RECORD*,
  59                   PCONTEXT, PEXCEPTION_RECORD);
  60   PSCOPETABLE scopetable;
  61   int trylevel;
  62   int _ebp;
  63   PEXCEPTION_POINTERS xpointers;
  64 } MSVCRT_EXCEPTION_FRAME;
  65
  66 #define TRYLEVEL_END (-1) /* End of trylevel list */
  67
  68 #if defined(__GNUC__) && defined(__i386__)
  69 inline static void call_finally_block( void *code_block, void *base_ptr )
  70 {
  71     __asm__ __volatile__ ("movl %1,%%ebp; call *%%eax" \
  72                           : : "a" (code_block), "g" (base_ptr));
  73 }
  74
  75 inline static DWORD call_filter( void *func, void *arg, void *ebp )
  76 {
  77     DWORD ret;
  78     __asm__ __volatile__ ("pushl %%ebp; pushl %3; movl %2,%%ebp; call *%%eax; popl %%ebp; popl %%ebp"
  79                           : "=a" (ret)
  80                           : "0" (func), "r" (ebp), "r" (arg)
  81                           : "ecx", "edx", "memory" );
  82     return ret;
  83 }
  84 #endif
  85
  86 static DWORD MSVCRT_nested_handler(PEXCEPTION_RECORD rec,
  87                                    EXCEPTION_REGISTRATION_RECORD* frame,
  88                                    PCONTEXT context,
  89                                    EXCEPTION_REGISTRATION_RECORD** dispatch)
  90 {
  91   if (rec->ExceptionFlags & 0x6)
  92     return ExceptionContinueSearch;
  93   *dispatch = frame;
  94   return ExceptionCollidedUnwind;
  95 }
  96
  97
  98 /*********************************************************************
  99  *              _EH_prolog (MSVCRT.@)
 100  */
 101 #ifdef __i386__
 102 /* Provided for VC++ binary compatibility only */
 103 __ASM_GLOBAL_FUNC(_EH_prolog,
 104                   "pushl $-1\n\t"
 105                   "pushl %eax\n\t"
 106                   "pushl %fs:0\n\t"
 107                   "movl  %esp, %fs:0\n\t"
 108                   "movl  12(%esp), %eax\n\t"
 109                   "movl  %ebp, 12(%esp)\n\t"
 110                   "leal  12(%esp), %ebp\n\t"
 111                   "pushl %eax\n\t"
 112                   "ret");
 113 #endif
 114
 115 /*******************************************************************
 116  *              _global_unwind2 (MSVCRT.@)
 117  */
 118 void CDECL _global_unwind2(EXCEPTION_REGISTRATION_RECORD* frame)
 119 {
 120     TRACE("(%p)\n",frame);
 121     RtlUnwind( frame, 0, 0, 0 );
 122 }
 123
 124 /*******************************************************************
 125  *              _local_unwind2 (MSVCRT.@)
 126  */
 127 void CDECL _local_unwind2(MSVCRT_EXCEPTION_FRAME* frame, int trylevel)
 128 {
 129   MSVCRT_EXCEPTION_FRAME *curframe = frame;
 130   EXCEPTION_REGISTRATION_RECORD reg;
 131
 132   TRACE("(%p,%d,%d)\n",frame, frame->trylevel, trylevel);
 133
 134   /* Register a handler in case of a nested exception */
 135   reg.Handler = (PEXCEPTION_HANDLER)MSVCRT_nested_handler;
 136   reg.Prev = NtCurrentTeb()->Tib.ExceptionList;
 137   __wine_push_frame(&reg);
 138
 139   while (frame->trylevel != TRYLEVEL_END && frame->trylevel != trylevel)
 140   {
 141     int curtrylevel = frame->scopetable[frame->trylevel].previousTryLevel;
 142     curframe = frame;
 143     curframe->trylevel = curtrylevel;
 144     if (!frame->scopetable[curtrylevel].lpfnFilter)
 145     {
 146       ERR("__try block cleanup not implemented - expect crash!\n");
 147       /* FIXME: Remove current frame, set ebp, call
 148        * frame->scopetable[curtrylevel].lpfnHandler()
 149        */
 150     }
 151   }
 152   __wine_pop_frame(&reg);
 153   TRACE("unwound OK\n");
 154 }
 155
 156 /*********************************************************************
 157  *              _except_handler2 (MSVCRT.@)
 158  */
 159 int CDECL _except_handler2(PEXCEPTION_RECORD rec,
 160                            EXCEPTION_REGISTRATION_RECORD* frame,
 161                            PCONTEXT context,
 162                            EXCEPTION_REGISTRATION_RECORD** dispatcher)
 163 {
 164   FIXME("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 165         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 166         frame->Handler, context, dispatcher);
 167   return ExceptionContinueSearch;
 168 }
 169
 170 /*********************************************************************
 171  *              _except_handler3 (MSVCRT.@)
 172  */
 173 int CDECL _except_handler3(PEXCEPTION_RECORD rec,
 174                            MSVCRT_EXCEPTION_FRAME* frame,
 175                            PCONTEXT context, void* dispatcher)
 176 {
 177 #if defined(__GNUC__) && defined(__i386__)
 178   long retval;
 179   int trylevel;
 180   EXCEPTION_POINTERS exceptPtrs;
 181   PSCOPETABLE pScopeTable;
 182
 183   TRACE("exception %lx flags=%lx at %p handler=%p %p %p semi-stub\n",
 184         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 185         frame->handler, context, dispatcher);
 186
 187   __asm__ __volatile__ ("cld");
 188
 189   if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 190   {
 191     /* Unwinding the current frame */
 192      _local_unwind2(frame, TRYLEVEL_END);
 193     TRACE("unwound current frame, returning ExceptionContinueSearch\n");
 194     return ExceptionContinueSearch;
 195   }
 196   else
 197   {
 198     /* Hunting for handler */
 199     exceptPtrs.ExceptionRecord = rec;
 200     exceptPtrs.ContextRecord = context;
 201     *((DWORD *)frame-1) = (DWORD)&exceptPtrs;
 202     trylevel = frame->trylevel;
 203     pScopeTable = frame->scopetable;
 204
 205     while (trylevel != TRYLEVEL_END)
 206     {
 207       if (pScopeTable[trylevel].lpfnFilter)
 208       {
 209         TRACE("filter = %p\n", pScopeTable[trylevel].lpfnFilter);
 210
 211         retval = call_filter( pScopeTable[trylevel].lpfnFilter, &exceptPtrs, &frame->_ebp );
 212
 213         TRACE("filter returned %s\n", retval == EXCEPTION_CONTINUE_EXECUTION ?
 214               "CONTINUE_EXECUTION" : retval == EXCEPTION_EXECUTE_HANDLER ?
 215               "EXECUTE_HANDLER" : "CONTINUE_SEARCH");
 216
 217         if (retval == EXCEPTION_CONTINUE_EXECUTION)
 218           return ExceptionContinueExecution;
 219
 220         if (retval == EXCEPTION_EXECUTE_HANDLER)
 221         {
 222           /* Unwind all higher frames, this one will handle the exception */
 223           _global_unwind2((EXCEPTION_REGISTRATION_RECORD*)frame);
 224           _local_unwind2(frame, trylevel);
 225
 226           /* Set our trylevel to the enclosing block, and call the __finally
 227            * code, which won't return
 228            */
 229           frame->trylevel = pScopeTable->previousTryLevel;
 230           TRACE("__finally block %p\n",pScopeTable[trylevel].lpfnHandler);
 231           call_finally_block(pScopeTable[trylevel].lpfnHandler, &frame->_ebp);
 232           ERR("Returned from __finally block - expect crash!\n");
 233        }
 234       }
 235       trylevel = pScopeTable->previousTryLevel;
 236     }
 237   }
 238 #else
 239   TRACE("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 240         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 241         frame->handler, context, dispatcher);
 242 #endif
 243   TRACE("reached TRYLEVEL_END, returning ExceptionContinueSearch\n");
 244   return ExceptionContinueSearch;
 245 }
 246
 247 /*********************************************************************
 248  *              _abnormal_termination (MSVCRT.@)
 249  */
 250 int CDECL _abnormal_termination(void)
 251 {
 252   FIXME("(void)stub\n");
 253   return 0;
 254 }
 255
 256 /*
 257  * setjmp/longjmp implementation
 258  */
 259
 260 #ifdef __i386__
 261 #define MSVCRT_JMP_MAGIC 0x56433230 /* ID value for new jump structure */
 262 typedef void (*MSVCRT_unwind_function)(const void*);
 263
 264 /* define an entrypoint for setjmp/setjmp3 that stores the registers in the jmp buf */
 265 /* and then jumps to the C backend function */
 266 #define DEFINE_SETJMP_ENTRYPOINT(name) \
 267     __ASM_GLOBAL_FUNC( name, \
 268                        "movl 4(%esp),%ecx\n\t"   /* jmp_buf */      \
 269                        "movl %ebp,0(%ecx)\n\t"   /* jmp_buf.Ebp */  \
 270                        "movl %ebx,4(%ecx)\n\t"   /* jmp_buf.Ebx */  \
 271                        "movl %edi,8(%ecx)\n\t"   /* jmp_buf.Edi */  \
 272                        "movl %esi,12(%ecx)\n\t"  /* jmp_buf.Esi */  \
 273                        "movl %esp,16(%ecx)\n\t"  /* jmp_buf.Esp */  \
 274                        "movl 0(%esp),%eax\n\t"                      \
 275                        "movl %eax,20(%ecx)\n\t"  /* jmp_buf.Eip */  \
 276                        "jmp " __ASM_NAME("__regs_") # name )
 277
 278 /* restore the registers from the jmp buf upon longjmp */
 279 extern void DECLSPEC_NORETURN longjmp_set_regs( struct MSVCRT___JUMP_BUFFER *jmp, int retval );
 280 __ASM_GLOBAL_FUNC( longjmp_set_regs,
 281                    "movl 4(%esp),%ecx\n\t"   /* jmp_buf */
 282                    "movl 8(%esp),%eax\n\t"   /* retval */
 283                    "movl 0(%ecx),%ebp\n\t"   /* jmp_buf.Ebp */
 284                    "movl 4(%ecx),%ebx\n\t"   /* jmp_buf.Ebx */
 285                    "movl 8(%ecx),%edi\n\t"   /* jmp_buf.Edi */
 286                    "movl 12(%ecx),%esi\n\t"  /* jmp_buf.Esi */
 287                    "movl 16(%ecx),%esp\n\t"  /* jmp_buf.Esp */
 288                    "addl $4,%esp\n\t"        /* get rid of return address */
 289                    "jmp *20(%ecx)\n\t"       /* jmp_buf.Eip */ );
 290
 291 /*
 292  * The signatures of the setjmp/longjmp functions do not match that
 293  * declared in the setjmp header so they don't follow the regular naming
 294  * convention to avoid conflicts.
 295  */
 296
 297 /*******************************************************************
 298  *              _setjmp (MSVCRT.@)
 299  */
 300 DEFINE_SETJMP_ENTRYPOINT(MSVCRT__setjmp);
 301 int CDECL __regs_MSVCRT__setjmp(struct MSVCRT___JUMP_BUFFER *jmp)
 302 {
 303     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 304     if (jmp->Registration == TRYLEVEL_END)
 305         jmp->TryLevel = TRYLEVEL_END;
 306     else
 307         jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 308
 309     TRACE("buf=%p ebx=%08lx esi=%08lx edi=%08lx ebp=%08lx esp=%08lx eip=%08lx frame=%08lx\n",
 310           jmp, jmp->Ebx, jmp->Esi, jmp->Edi, jmp->Ebp, jmp->Esp, jmp->Eip, jmp->Registration );
 311     return 0;
 312 }
 313
 314 /*******************************************************************
 315  *              _setjmp3 (MSVCRT.@)
 316  */
 317 DEFINE_SETJMP_ENTRYPOINT( MSVCRT__setjmp3 );
 318 int CDECL __regs_MSVCRT__setjmp3(struct MSVCRT___JUMP_BUFFER *jmp, int nb_args, ...)
 319 {
 320     jmp->Cookie = MSVCRT_JMP_MAGIC;
 321     jmp->UnwindFunc = 0;
 322     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 323     if (jmp->Registration == TRYLEVEL_END)
 324     {
 325         jmp->TryLevel = TRYLEVEL_END;
 326     }
 327     else
 328     {
 329         int i;
 330         va_list args;
 331
 332         va_start( args, nb_args );
 333         if (nb_args > 0) jmp->UnwindFunc = va_arg( args, unsigned long );
 334         if (nb_args > 1) jmp->TryLevel = va_arg( args, unsigned long );
 335         else jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 336         for (i = 0; i < 6 && i < nb_args - 2; i++)
 337             jmp->UnwindData[i] = va_arg( args, unsigned long );
 338         va_end( args );
 339     }
 340
 341     TRACE("buf=%p ebx=%08lx esi=%08lx edi=%08lx ebp=%08lx esp=%08lx eip=%08lx frame=%08lx\n",
 342           jmp, jmp->Ebx, jmp->Esi, jmp->Edi, jmp->Ebp, jmp->Esp, jmp->Eip, jmp->Registration );
 343     return 0;
 344 }
 345
 346 /*********************************************************************
 347  *              longjmp (MSVCRT.@)
 348  */
 349 int CDECL MSVCRT_longjmp(struct MSVCRT___JUMP_BUFFER *jmp, int retval)
 350 {
 351     unsigned long cur_frame = 0;
 352
 353     TRACE("buf=%p ebx=%08lx esi=%08lx edi=%08lx ebp=%08lx esp=%08lx eip=%08lx frame=%08lx retval=%08x\n",
 354           jmp, jmp->Ebx, jmp->Esi, jmp->Edi, jmp->Ebp, jmp->Esp, jmp->Eip, jmp->Registration, retval );
 355
 356     cur_frame=(unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 357     TRACE("cur_frame=%lx\n",cur_frame);
 358
 359     if (cur_frame != jmp->Registration)
 360         _global_unwind2((EXCEPTION_REGISTRATION_RECORD*)jmp->Registration);
 361
 362     if (jmp->Registration)
 363     {
 364         if (!IsBadReadPtr(&jmp->Cookie, sizeof(long)) &&
 365             jmp->Cookie == MSVCRT_JMP_MAGIC && jmp->UnwindFunc)
 366         {
 367             MSVCRT_unwind_function unwind_func;
 368
 369             unwind_func=(MSVCRT_unwind_function)jmp->UnwindFunc;
 370             unwind_func(jmp);
 371         }
 372         else
 373             _local_unwind2((MSVCRT_EXCEPTION_FRAME*)jmp->Registration,
 374                            jmp->TryLevel);
 375     }
 376
 377     if (!retval)
 378         retval = 1;
 379
 380     longjmp_set_regs( jmp, retval );
 381 }
 382
 383 /*********************************************************************
 384  *              _seh_longjmp_unwind (MSVCRT.@)
 385  */
 386 void __stdcall _seh_longjmp_unwind(struct MSVCRT___JUMP_BUFFER *jmp)
 387 {
 388     _local_unwind2( (MSVCRT_EXCEPTION_FRAME *)jmp->Registration, jmp->TryLevel );
 389 }
 390 #endif /* i386 */
 391
 392 static MSVCRT___sighandler_t sighandlers[MSVCRT_NSIG] = { MSVCRT_SIG_DFL };
 393
 394 static BOOL WINAPI msvcrt_console_handler(DWORD ctrlType)
 395 {
 396     BOOL ret = FALSE;
 397
 398     switch (ctrlType)
 399     {
 400     case CTRL_C_EVENT:
 401         if (sighandlers[MSVCRT_SIGINT])
 402         {
 403             if (sighandlers[MSVCRT_SIGINT] != MSVCRT_SIG_IGN)
 404                 sighandlers[MSVCRT_SIGINT](MSVCRT_SIGINT);
 405             ret = TRUE;
 406         }
 407         break;
 408     }
 409     return ret;
 410 }
 411
 412 typedef void (*float_handler)(int, int);
 413
 414 /* The exception codes are actually NTSTATUS values */
 415 struct
 416 {
 417     NTSTATUS status;
 418     int signal;
 419 } float_exception_map[] = {
 420  { EXCEPTION_FLT_DENORMAL_OPERAND, _FPE_DENORMAL },
 421  { EXCEPTION_FLT_DIVIDE_BY_ZERO, _FPE_ZERODIVIDE },
 422  { EXCEPTION_FLT_INEXACT_RESULT, _FPE_INEXACT },
 423  { EXCEPTION_FLT_INVALID_OPERATION, _FPE_INVALID },
 424  { EXCEPTION_FLT_OVERFLOW, _FPE_OVERFLOW },
 425  { EXCEPTION_FLT_STACK_CHECK, _FPE_STACKOVERFLOW },
 426  { EXCEPTION_FLT_UNDERFLOW, _FPE_UNDERFLOW },
 427 };
 428
 429 static LONG WINAPI msvcrt_exception_filter(struct _EXCEPTION_POINTERS *except)
 430 {
 431     LONG ret = EXCEPTION_CONTINUE_SEARCH;
 432
 433     if (!except || !except->ExceptionRecord)
 434         return EXCEPTION_CONTINUE_SEARCH;
 435
 436     switch (except->ExceptionRecord->ExceptionCode)
 437     {
 438     case EXCEPTION_ACCESS_VIOLATION:
 439         if (sighandlers[MSVCRT_SIGSEGV])
 440         {
 441             if (sighandlers[MSVCRT_SIGSEGV] != MSVCRT_SIG_IGN)
 442                 sighandlers[MSVCRT_SIGSEGV](MSVCRT_SIGSEGV);
 443             ret = EXCEPTION_CONTINUE_EXECUTION;
 444         }
 445         break;
 446     /* According to
 447      * http://msdn.microsoft.com/library/en-us/vclib/html/_CRT_signal.asp
 448      * the FPE signal handler takes as a second argument the type of
 449      * floating point exception.
 450      */
 451     case EXCEPTION_FLT_DENORMAL_OPERAND:
 452     case EXCEPTION_FLT_DIVIDE_BY_ZERO:
 453     case EXCEPTION_FLT_INEXACT_RESULT:
 454     case EXCEPTION_FLT_INVALID_OPERATION:
 455     case EXCEPTION_FLT_OVERFLOW:
 456     case EXCEPTION_FLT_STACK_CHECK:
 457     case EXCEPTION_FLT_UNDERFLOW:
 458         if (sighandlers[MSVCRT_SIGFPE])
 459         {
 460             if (sighandlers[MSVCRT_SIGFPE] != MSVCRT_SIG_IGN)
 461             {
 462                 int i, float_signal = _FPE_INVALID;
 463
 464                 float_handler handler = (float_handler)sighandlers[MSVCRT_SIGFPE];
 465                 for (i = 0; i < sizeof(float_exception_map) /
 466                  sizeof(float_exception_map[0]); i++)
 467                     if (float_exception_map[i].status ==
 468                      except->ExceptionRecord->ExceptionCode)
 469                     {
 470                         float_signal = float_exception_map[i].signal;
 471                         break;
 472                     }
 473                 handler(MSVCRT_SIGFPE, float_signal);
 474             }
 475             ret = EXCEPTION_CONTINUE_EXECUTION;
 476         }
 477         break;
 478     case EXCEPTION_ILLEGAL_INSTRUCTION:
 479         if (sighandlers[MSVCRT_SIGILL])
 480         {
 481             if (sighandlers[MSVCRT_SIGILL] != MSVCRT_SIG_IGN)
 482                 sighandlers[MSVCRT_SIGILL](MSVCRT_SIGILL);
 483             ret = EXCEPTION_CONTINUE_EXECUTION;
 484         }
 485         break;
 486     }
 487     return ret;
 488 }
 489
 490 void msvcrt_init_signals(void)
 491 {
 492     SetConsoleCtrlHandler(msvcrt_console_handler, TRUE);
 493     SetUnhandledExceptionFilter(msvcrt_exception_filter);
 494 }
 495
 496 void msvcrt_free_signals(void)
 497 {
 498     SetConsoleCtrlHandler(msvcrt_console_handler, FALSE);
 499     SetUnhandledExceptionFilter(NULL);
 500 }
 501
 502 /*********************************************************************
 503  *              signal (MSVCRT.@)
 504  * MS signal handling is described here:
 505  * http://msdn.microsoft.com/library/en-us/vclib/html/_CRT_signal.asp
 506  * Some signals may never be generated except through an explicit call to
 507  * raise.
 508  */
 509 MSVCRT___sighandler_t CDECL MSVCRT_signal(int sig, MSVCRT___sighandler_t func)
 510 {
 511     MSVCRT___sighandler_t ret = MSVCRT_SIG_ERR;
 512
 513     TRACE("(%d, %p)\n", sig, func);
 514
 515     if (func == MSVCRT_SIG_ERR) return MSVCRT_SIG_ERR;
 516
 517     switch (sig)
 518     {
 519     /* Cases handled internally.  Note SIGTERM is never generated by Windows,
 520      * so we effectively mask it.
 521      */
 522     case MSVCRT_SIGABRT:
 523     case MSVCRT_SIGFPE:
 524     case MSVCRT_SIGILL:
 525     case MSVCRT_SIGSEGV:
 526     case MSVCRT_SIGINT:
 527     case MSVCRT_SIGTERM:
 528         ret = sighandlers[sig];
 529         sighandlers[sig] = func;
 530         break;
 531     default:
 532         ret = MSVCRT_SIG_ERR;
 533     }
 534     return ret;
 535 }
 536
 537 /*********************************************************************
 538  *              _XcptFilter (MSVCRT.@)
 539  */
 540 int CDECL _XcptFilter(NTSTATUS ex, PEXCEPTION_POINTERS ptr)
 541 {
 542     TRACE("(%08lx,%p)\n", ex, ptr);
 543     /* I assume ptr->ExceptionRecord->ExceptionCode is the same as ex */
 544     return msvcrt_exception_filter(ptr);
 545 }