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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  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 "msvcrt/signal.h"
  44 #include "wine/debug.h"
  45
  46 WINE_DEFAULT_DEBUG_CHANNEL(msvcrt);
  47
  48 /* VC++ extensions to Win32 SEH */
  49 typedef struct _SCOPETABLE
  50 {
  51   int previousTryLevel;
  52   int (*lpfnFilter)(PEXCEPTION_POINTERS);
  53   int (*lpfnHandler)(void);
  54 } SCOPETABLE, *PSCOPETABLE;
  55
  56 typedef struct _MSVCRT_EXCEPTION_FRAME
  57 {
  58   EXCEPTION_REGISTRATION_RECORD *prev;
  59   void (*handler)(PEXCEPTION_RECORD, EXCEPTION_REGISTRATION_RECORD*,
  60                   PCONTEXT, PEXCEPTION_RECORD);
  61   PSCOPETABLE scopetable;
  62   int trylevel;
  63   int _ebp;
  64   PEXCEPTION_POINTERS xpointers;
  65 } MSVCRT_EXCEPTION_FRAME;
  66
  67 #define TRYLEVEL_END (-1) /* End of trylevel list */
  68
  69 #if defined(__GNUC__) && defined(__i386__)
  70 inline static void call_finally_block( void *code_block, void *base_ptr )
  71 {
  72     __asm__ __volatile__ ("movl %1,%%ebp; call *%%eax" \
  73                           : : "a" (code_block), "g" (base_ptr));
  74 }
  75
  76 inline static DWORD call_filter( void *func, void *arg, void *ebp )
  77 {
  78     DWORD ret;
  79     __asm__ __volatile__ ("pushl %%ebp; pushl %3; movl %2,%%ebp; call *%%eax; popl %%ebp; popl %%ebp"
  80                           : "=a" (ret)
  81                           : "0" (func), "r" (ebp), "r" (arg)
  82                           : "ecx", "edx", "memory" );
  83     return ret;
  84 }
  85 #endif
  86
  87 static DWORD MSVCRT_nested_handler(PEXCEPTION_RECORD rec,
  88                                    EXCEPTION_REGISTRATION_RECORD* frame,
  89                                    PCONTEXT context,
  90                                    EXCEPTION_REGISTRATION_RECORD** dispatch)
  91 {
  92   if (rec->ExceptionFlags & 0x6)
  93     return ExceptionContinueSearch;
  94   *dispatch = frame;
  95   return ExceptionCollidedUnwind;
  96 }
  97
  98
  99 /*********************************************************************
 100  *              _EH_prolog (MSVCRT.@)
 101  */
 102 #ifdef __i386__
 103 /* Provided for VC++ binary compatibility only */
 104 __ASM_GLOBAL_FUNC(_EH_prolog,
 105                   "pushl $-1\n\t"
 106                   "pushl %eax\n\t"
 107                   "pushl %fs:0\n\t"
 108                   "movl  %esp, %fs:0\n\t"
 109                   "movl  12(%esp), %eax\n\t"
 110                   "movl  %ebp, 12(%esp)\n\t"
 111                   "leal  12(%esp), %ebp\n\t"
 112                   "pushl %eax\n\t"
 113                   "ret");
 114 #endif
 115
 116 /*******************************************************************
 117  *              _global_unwind2 (MSVCRT.@)
 118  */
 119 void _global_unwind2(EXCEPTION_REGISTRATION_RECORD* frame)
 120 {
 121     TRACE("(%p)\n",frame);
 122     RtlUnwind( frame, 0, 0, 0 );
 123 }
 124
 125 /*******************************************************************
 126  *              _local_unwind2 (MSVCRT.@)
 127  */
 128 void _local_unwind2(MSVCRT_EXCEPTION_FRAME* frame, int trylevel)
 129 {
 130   MSVCRT_EXCEPTION_FRAME *curframe = frame;
 131   EXCEPTION_REGISTRATION_RECORD reg;
 132
 133   TRACE("(%p,%d,%d)\n",frame, frame->trylevel, trylevel);
 134
 135   /* Register a handler in case of a nested exception */
 136   reg.Handler = (PEXCEPTION_HANDLER)MSVCRT_nested_handler;
 137   reg.Prev = NtCurrentTeb()->Tib.ExceptionList;
 138   __wine_push_frame(&reg);
 139
 140   while (frame->trylevel != TRYLEVEL_END && frame->trylevel != trylevel)
 141   {
 142     int curtrylevel = frame->scopetable[frame->trylevel].previousTryLevel;
 143     curframe = frame;
 144     curframe->trylevel = curtrylevel;
 145     if (!frame->scopetable[curtrylevel].lpfnFilter)
 146     {
 147       ERR("__try block cleanup not implemented - expect crash!\n");
 148       /* FIXME: Remove current frame, set ebp, call
 149        * frame->scopetable[curtrylevel].lpfnHandler()
 150        */
 151     }
 152   }
 153   __wine_pop_frame(&reg);
 154   TRACE("unwound OK\n");
 155 }
 156
 157 /*********************************************************************
 158  *              _except_handler2 (MSVCRT.@)
 159  */
 160 int _except_handler2(PEXCEPTION_RECORD rec,
 161                      EXCEPTION_REGISTRATION_RECORD* frame,
 162                      PCONTEXT context,
 163                      EXCEPTION_REGISTRATION_RECORD** dispatcher)
 164 {
 165   FIXME("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 166         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 167         frame->Handler, context, dispatcher);
 168   return ExceptionContinueSearch;
 169 }
 170
 171 /*********************************************************************
 172  *              _except_handler3 (MSVCRT.@)
 173  */
 174 int _except_handler3(PEXCEPTION_RECORD rec,
 175                      MSVCRT_EXCEPTION_FRAME* frame,
 176                      PCONTEXT context, void* dispatcher)
 177 {
 178 #if defined(__GNUC__) && defined(__i386__)
 179   long retval;
 180   int trylevel;
 181   EXCEPTION_POINTERS exceptPtrs;
 182   PSCOPETABLE pScopeTable;
 183
 184   TRACE("exception %lx flags=%lx at %p handler=%p %p %p semi-stub\n",
 185         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 186         frame->handler, context, dispatcher);
 187
 188   __asm__ __volatile__ ("cld");
 189
 190   if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
 191   {
 192     /* Unwinding the current frame */
 193      _local_unwind2(frame, TRYLEVEL_END);
 194     TRACE("unwound current frame, returning ExceptionContinueSearch\n");
 195     return ExceptionContinueSearch;
 196   }
 197   else
 198   {
 199     /* Hunting for handler */
 200     exceptPtrs.ExceptionRecord = rec;
 201     exceptPtrs.ContextRecord = context;
 202     *((DWORD *)frame-1) = (DWORD)&exceptPtrs;
 203     trylevel = frame->trylevel;
 204     pScopeTable = frame->scopetable;
 205
 206     while (trylevel != TRYLEVEL_END)
 207     {
 208       if (pScopeTable[trylevel].lpfnFilter)
 209       {
 210         TRACE("filter = %p\n", pScopeTable[trylevel].lpfnFilter);
 211
 212         retval = call_filter( pScopeTable[trylevel].lpfnFilter, &exceptPtrs, &frame->_ebp );
 213
 214         TRACE("filter returned %s\n", retval == EXCEPTION_CONTINUE_EXECUTION ?
 215               "CONTINUE_EXECUTION" : retval == EXCEPTION_EXECUTE_HANDLER ?
 216               "EXECUTE_HANDLER" : "CONTINUE_SEARCH");
 217
 218         if (retval == EXCEPTION_CONTINUE_EXECUTION)
 219           return ExceptionContinueExecution;
 220
 221         if (retval == EXCEPTION_EXECUTE_HANDLER)
 222         {
 223           /* Unwind all higher frames, this one will handle the exception */
 224           _global_unwind2((EXCEPTION_REGISTRATION_RECORD*)frame);
 225           _local_unwind2(frame, trylevel);
 226
 227           /* Set our trylevel to the enclosing block, and call the __finally
 228            * code, which won't return
 229            */
 230           frame->trylevel = pScopeTable->previousTryLevel;
 231           TRACE("__finally block %p\n",pScopeTable[trylevel].lpfnHandler);
 232           call_finally_block(pScopeTable[trylevel].lpfnHandler, &frame->_ebp);
 233           ERR("Returned from __finally block - expect crash!\n");
 234        }
 235       }
 236       trylevel = pScopeTable->previousTryLevel;
 237     }
 238   }
 239 #else
 240   TRACE("exception %lx flags=%lx at %p handler=%p %p %p stub\n",
 241         rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress,
 242         frame->handler, context, dispatcher);
 243 #endif
 244   TRACE("reached TRYLEVEL_END, returning ExceptionContinueSearch\n");
 245   return ExceptionContinueSearch;
 246 }
 247
 248 /*********************************************************************
 249  *              _abnormal_termination (MSVCRT.@)
 250  */
 251 int _abnormal_termination(void)
 252 {
 253   FIXME("(void)stub\n");
 254   return 0;
 255 }
 256
 257 /*
 258  * setjmp/longjmp implementation
 259  */
 260
 261 #ifdef __i386__
 262 #define MSVCRT_JMP_MAGIC 0x56433230 /* ID value for new jump structure */
 263 typedef void (*MSVCRT_unwind_function)(const void*);
 264
 265 /*
 266  * The signatures of the setjmp/longjmp functions do not match that
 267  * declared in the setjmp header so they don't follow the regular naming
 268  * convention to avoid conflicts.
 269  */
 270
 271 /*******************************************************************
 272  *              _setjmp (MSVCRT.@)
 273  */
 274 DEFINE_REGS_ENTRYPOINT( MSVCRT__setjmp, 4, 0 );
 275 void WINAPI __regs_MSVCRT__setjmp(struct MSVCRT___JUMP_BUFFER *jmp, CONTEXT86* context)
 276 {
 277     TRACE("(%p)\n",jmp);
 278     jmp->Ebp = context->Ebp;
 279     jmp->Ebx = context->Ebx;
 280     jmp->Edi = context->Edi;
 281     jmp->Esi = context->Esi;
 282     jmp->Esp = context->Esp;
 283     jmp->Eip = context->Eip;
 284     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 285     if (jmp->Registration == TRYLEVEL_END)
 286         jmp->TryLevel = TRYLEVEL_END;
 287     else
 288         jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 289     TRACE("returning 0\n");
 290     context->Eax=0;
 291 }
 292
 293 /*******************************************************************
 294  *              _setjmp3 (MSVCRT.@)
 295  */
 296 DEFINE_REGS_ENTRYPOINT( MSVCRT__setjmp3, 8, 0 );
 297 void WINAPI __regs_MSVCRT__setjmp3(struct MSVCRT___JUMP_BUFFER *jmp, int nb_args, CONTEXT86* context)
 298 {
 299     TRACE("(%p,%d)\n",jmp,nb_args);
 300     jmp->Ebp = context->Ebp;
 301     jmp->Ebx = context->Ebx;
 302     jmp->Edi = context->Edi;
 303     jmp->Esi = context->Esi;
 304     jmp->Esp = context->Esp;
 305     jmp->Eip = context->Eip;
 306     jmp->Cookie = MSVCRT_JMP_MAGIC;
 307     jmp->UnwindFunc = 0;
 308     jmp->Registration = (unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 309     if (jmp->Registration == TRYLEVEL_END)
 310     {
 311         jmp->TryLevel = TRYLEVEL_END;
 312     }
 313     else
 314     {
 315         void **args = ((void**)context->Esp)+2;
 316
 317         if (nb_args > 0) jmp->UnwindFunc = (unsigned long)*args++;
 318         if (nb_args > 1) jmp->TryLevel = (unsigned long)*args++;
 319         else jmp->TryLevel = ((MSVCRT_EXCEPTION_FRAME*)jmp->Registration)->trylevel;
 320         if (nb_args > 2)
 321         {
 322             size_t size = (nb_args - 2) * sizeof(DWORD);
 323             memcpy( jmp->UnwindData, args, min( size, sizeof(jmp->UnwindData) ));
 324         }
 325     }
 326     TRACE("returning 0\n");
 327     context->Eax = 0;
 328 }
 329
 330 /*********************************************************************
 331  *              longjmp (MSVCRT.@)
 332  */
 333 DEFINE_REGS_ENTRYPOINT( MSVCRT_longjmp, 8, 0 );
 334 void WINAPI __regs_MSVCRT_longjmp(struct MSVCRT___JUMP_BUFFER *jmp, int retval, CONTEXT86* context)
 335 {
 336     unsigned long cur_frame = 0;
 337
 338     TRACE("(%p,%d)\n", jmp, retval);
 339
 340     cur_frame=(unsigned long)NtCurrentTeb()->Tib.ExceptionList;
 341     TRACE("cur_frame=%lx\n",cur_frame);
 342
 343     if (cur_frame != jmp->Registration)
 344         _global_unwind2((EXCEPTION_REGISTRATION_RECORD*)jmp->Registration);
 345
 346     if (jmp->Registration)
 347     {
 348         if (!IsBadReadPtr(&jmp->Cookie, sizeof(long)) &&
 349             jmp->Cookie == MSVCRT_JMP_MAGIC && jmp->UnwindFunc)
 350         {
 351             MSVCRT_unwind_function unwind_func;
 352
 353             unwind_func=(MSVCRT_unwind_function)jmp->UnwindFunc;
 354             unwind_func(jmp);
 355         }
 356         else
 357             _local_unwind2((MSVCRT_EXCEPTION_FRAME*)jmp->Registration,
 358                            jmp->TryLevel);
 359     }
 360
 361     if (!retval)
 362         retval = 1;
 363
 364     TRACE("Jump to %lx returning %d\n",jmp->Eip,retval);
 365     context->Ebp = jmp->Ebp;
 366     context->Ebx = jmp->Ebx;
 367     context->Edi = jmp->Edi;
 368     context->Esi = jmp->Esi;
 369     context->Esp = jmp->Esp;
 370     context->Eip = jmp->Eip;
 371     context->Eax = retval;
 372 }
 373
 374 /*********************************************************************
 375  *              _seh_longjmp_unwind (MSVCRT.@)
 376  */
 377 void __stdcall _seh_longjmp_unwind(struct MSVCRT___JUMP_BUFFER *jmp)
 378 {
 379     _local_unwind2( (MSVCRT_EXCEPTION_FRAME *)jmp->Registration, jmp->TryLevel );
 380 }
 381 #endif /* i386 */
 382
 383 static __sighandler_t sighandlers[NSIG] = { SIG_DFL };
 384
 385 static BOOL WINAPI msvcrt_console_handler(DWORD ctrlType)
 386 {
 387     BOOL ret = FALSE;
 388
 389     switch (ctrlType)
 390     {
 391     case CTRL_C_EVENT:
 392         if (sighandlers[SIGINT])
 393         {
 394             if (sighandlers[SIGINT] != SIG_IGN)
 395                 sighandlers[SIGINT](SIGINT);
 396             ret = TRUE;
 397         }
 398         break;
 399     }
 400     return ret;
 401 }
 402
 403 typedef void (*float_handler)(int, int);
 404
 405 /* The exception codes are actually NTSTATUS values */
 406 struct
 407 {
 408     NTSTATUS status;
 409     int signal;
 410 } float_exception_map[] = {
 411  { EXCEPTION_FLT_DENORMAL_OPERAND, _FPE_DENORMAL },
 412  { EXCEPTION_FLT_DIVIDE_BY_ZERO, _FPE_ZERODIVIDE },
 413  { EXCEPTION_FLT_INEXACT_RESULT, _FPE_INEXACT },
 414  { EXCEPTION_FLT_INVALID_OPERATION, _FPE_INVALID },
 415  { EXCEPTION_FLT_OVERFLOW, _FPE_OVERFLOW },
 416  { EXCEPTION_FLT_STACK_CHECK, _FPE_STACKOVERFLOW },
 417  { EXCEPTION_FLT_UNDERFLOW, _FPE_UNDERFLOW },
 418 };
 419
 420 static LONG WINAPI msvcrt_exception_filter(struct _EXCEPTION_POINTERS *except)
 421 {
 422     LONG ret = EXCEPTION_CONTINUE_SEARCH;
 423
 424     if (!except || !except->ExceptionRecord)
 425         return EXCEPTION_CONTINUE_SEARCH;
 426
 427     switch (except->ExceptionRecord->ExceptionCode)
 428     {
 429     case EXCEPTION_ACCESS_VIOLATION:
 430         if (sighandlers[SIGSEGV])
 431         {
 432             if (sighandlers[SIGSEGV] != SIG_IGN)
 433                 sighandlers[SIGSEGV](SIGSEGV);
 434             ret = EXCEPTION_CONTINUE_EXECUTION;
 435         }
 436         break;
 437     /* According to
 438      * http://msdn.microsoft.com/library/en-us/vclib/html/_CRT_signal.asp
 439      * the FPE signal handler takes as a second argument the type of
 440      * floating point exception.
 441      */
 442     case EXCEPTION_FLT_DENORMAL_OPERAND:
 443     case EXCEPTION_FLT_DIVIDE_BY_ZERO:
 444     case EXCEPTION_FLT_INEXACT_RESULT:
 445     case EXCEPTION_FLT_INVALID_OPERATION:
 446     case EXCEPTION_FLT_OVERFLOW:
 447     case EXCEPTION_FLT_STACK_CHECK:
 448     case EXCEPTION_FLT_UNDERFLOW:
 449         if (sighandlers[SIGFPE])
 450         {
 451             if (sighandlers[SIGFPE] != SIG_IGN)
 452             {
 453                 int i, float_signal = _FPE_INVALID;
 454
 455                 float_handler handler = (float_handler)sighandlers[SIGFPE];
 456                 for (i = 0; i < sizeof(float_exception_map) /
 457                  sizeof(float_exception_map[0]); i++)
 458                     if (float_exception_map[i].status ==
 459                      except->ExceptionRecord->ExceptionCode)
 460                     {
 461                         float_signal = float_exception_map[i].signal;
 462                         break;
 463                     }
 464                 handler(SIGFPE, float_signal);
 465             }
 466             ret = EXCEPTION_CONTINUE_EXECUTION;
 467         }
 468         break;
 469     case EXCEPTION_ILLEGAL_INSTRUCTION:
 470         if (sighandlers[SIGILL])
 471         {
 472             if (sighandlers[SIGILL] != SIG_IGN)
 473                 sighandlers[SIGILL](SIGILL);
 474             ret = EXCEPTION_CONTINUE_EXECUTION;
 475         }
 476         break;
 477     }
 478     return ret;
 479 }
 480
 481 void msvcrt_init_signals(void)
 482 {
 483     SetConsoleCtrlHandler(msvcrt_console_handler, TRUE);
 484     SetUnhandledExceptionFilter(msvcrt_exception_filter);
 485 }
 486
 487 void msvcrt_free_signals(void)
 488 {
 489     SetConsoleCtrlHandler(msvcrt_console_handler, FALSE);
 490     SetUnhandledExceptionFilter(NULL);
 491 }
 492
 493 /*********************************************************************
 494  *              signal (MSVCRT.@)
 495  * MS signal handling is described here:
 496  * http://msdn.microsoft.com/library/en-us/vclib/html/_CRT_signal.asp
 497  * Some signals may never be generated except through an explicit call to
 498  * raise.
 499  */
 500 __sighandler_t MSVCRT_signal(int sig, __sighandler_t func)
 501 {
 502     __sighandler_t ret = SIG_ERR;
 503
 504     TRACE("(%d, %p)\n", sig, func);
 505
 506     if (func == SIG_ERR) return SIG_ERR;
 507
 508     switch (sig)
 509     {
 510     /* Cases handled internally.  Note SIGTERM is never generated by Windows,
 511      * so we effectively mask it.
 512      */
 513     case SIGABRT:
 514     case SIGFPE:
 515     case SIGILL:
 516     case SIGSEGV:
 517     case SIGINT:
 518     case SIGTERM:
 519         ret = sighandlers[sig];
 520         sighandlers[sig] = func;
 521         break;
 522     default:
 523         ret = SIG_ERR;
 524     }
 525     return ret;
 526 }
 527
 528 /*********************************************************************
 529  *              _XcptFilter (MSVCRT.@)
 530  */
 531 int _XcptFilter(NTSTATUS ex, PEXCEPTION_POINTERS ptr)
 532 {
 533     TRACE("(%ld,%p)\n", ex, ptr);
 534     /* I assume ptr->ExceptionRecord->ExceptionCode is the same as ex */
 535     return msvcrt_exception_filter(ptr);
 536 }