dlls/ntdll/exception.c

   1 /*
   2  * NT exception handling routines
   3  *
   4  * Copyright 1999 Turchanov Sergey
   5  * Copyright 1999 Alexandre Julliard
   6  */
   7
   8 #include <assert.h>
   9 #include <signal.h>
  10
  11 #include "config.h"
  12 #include "winnt.h"
  13 #include "ntddk.h"
  14 #include "global.h"
  15 #include "wine/exception.h"
  16 #include "stackframe.h"
  17 #include "miscemu.h"
  18 #include "server.h"
  19 #include "debugtools.h"
  20
  21 DEFAULT_DEBUG_CHANNEL(seh);
  22
  23 /* Exception record for handling exceptions happening inside exception handlers */
  24 typedef struct
  25 {
  26     EXCEPTION_FRAME frame;
  27     EXCEPTION_FRAME *prevFrame;
  28 } EXC_NESTED_FRAME;
  29
  30 #ifdef __i386__
  31 # define GET_IP(context) ((LPVOID)(context)->Eip)
  32 #endif
  33 #ifdef __sparc__
  34 # define GET_IP(context) ((LPVOID)(context)->pc)
  35 #endif
  36 #ifndef GET_IP
  37 # error You must define GET_IP for this CPU
  38 #endif
  39
  40 void WINAPI EXC_RtlRaiseException( PEXCEPTION_RECORD, PCONTEXT );
  41 void WINAPI EXC_RtlUnwind( PEXCEPTION_FRAME, LPVOID,
  42                            PEXCEPTION_RECORD, DWORD, PCONTEXT );
  43 void WINAPI EXC_NtRaiseException( PEXCEPTION_RECORD, PCONTEXT,
  44                                   BOOL, PCONTEXT );
  45
  46 /*******************************************************************
  47  *         EXC_RaiseHandler
  48  *
  49  * Handler for exceptions happening inside a handler.
  50  */
  51 static DWORD EXC_RaiseHandler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
  52                                CONTEXT *context, EXCEPTION_FRAME **dispatcher )
  53 {
  54     if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
  55         return ExceptionContinueSearch;
  56     /* We shouldn't get here so we store faulty frame in dispatcher */
  57     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
  58     return ExceptionNestedException;
  59 }
  60
  61
  62 /*******************************************************************
  63  *         EXC_UnwindHandler
  64  *
  65  * Handler for exceptions happening inside an unwind handler.
  66  */
  67 static DWORD EXC_UnwindHandler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
  68                                 CONTEXT *context, EXCEPTION_FRAME **dispatcher )
  69 {
  70     if (!(rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)))
  71         return ExceptionContinueSearch;
  72     /* We shouldn't get here so we store faulty frame in dispatcher */
  73     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
  74     return ExceptionCollidedUnwind;
  75 }
  76
  77
  78 /*******************************************************************
  79  *         EXC_CallHandler
  80  *
  81  * Call an exception handler, setting up an exception frame to catch exceptions
  82  * happening during the handler execution.
  83  * Please do not change the first 4 parameters order in any way - some exceptions handlers
  84  * rely on Base Pointer (EBP) to have a fixed position related to the exception frame
  85  */
  86 static DWORD EXC_CallHandler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
  87                               CONTEXT *context, EXCEPTION_FRAME **dispatcher,
  88                               PEXCEPTION_HANDLER handler, PEXCEPTION_HANDLER nested_handler)
  89 {
  90     EXC_NESTED_FRAME newframe;
  91     DWORD ret;
  92
  93     newframe.frame.Handler = nested_handler;
  94     newframe.prevFrame     = frame;
  95     __wine_push_frame( &newframe.frame );
  96     TRACE( "calling handler at %p code=%lx flags=%lx\n",
  97            handler, record->ExceptionCode, record->ExceptionFlags );
  98     ret = handler( record, frame, context, dispatcher );
  99     TRACE( "handler returned %lx\n", ret );
 100     __wine_pop_frame( &newframe.frame );
 101     return ret;
 102 }
 103
 104
 105 /**********************************************************************
 106  *           send_debug_event
 107  *
 108  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
 109  */
 110 static int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
 111 {
 112     int ret;
 113     HANDLE handle = 0;
 114
 115     SERVER_START_REQ
 116     {
 117         struct queue_exception_event_request *req = server_alloc_req( sizeof(*req),
 118                                                                       sizeof(*rec)+sizeof(*context) );
 119         CONTEXT *context_ptr = server_data_ptr(req);
 120         EXCEPTION_RECORD *rec_ptr = (EXCEPTION_RECORD *)(context_ptr + 1);
 121         req->first   = first_chance;
 122         *rec_ptr     = *rec;
 123         *context_ptr = *context;
 124         if (!server_call_noerr( REQ_QUEUE_EXCEPTION_EVENT )) handle = req->handle;
 125     }
 126     SERVER_END_REQ;
 127     if (!handle) return 0;  /* no debugger present or other error */
 128
 129     /* No need to wait on the handle since the process gets suspended
 130      * once the event is passed to the debugger, so when we get back
 131      * here the event has been continued already.
 132      */
 133     SERVER_START_REQ
 134     {
 135         struct get_exception_status_request *req = server_alloc_req( sizeof(*req), sizeof(*context) );
 136         req->handle = handle;
 137         if (!server_call_noerr( REQ_GET_EXCEPTION_STATUS ))
 138             *context = *(CONTEXT *)server_data_ptr(req);
 139         ret = req->status;
 140     }
 141     SERVER_END_REQ;
 142     NtClose( handle );
 143     return ret;
 144 }
 145
 146
 147 /*******************************************************************
 148  *         EXC_DefaultHandling
 149  *
 150  * Default handling for exceptions. Called when we didn't find a suitable handler.
 151  */
 152 static void EXC_DefaultHandling( EXCEPTION_RECORD *rec, CONTEXT *context )
 153 {
 154     if (send_debug_event( rec, FALSE, context ) == DBG_CONTINUE) return;  /* continue execution */
 155
 156     if (rec->ExceptionFlags & EH_STACK_INVALID)
 157         ERR("Exception frame is not in stack limits => unable to dispatch exception.\n");
 158     else if (rec->ExceptionCode == EXCEPTION_NONCONTINUABLE_EXCEPTION)
 159         ERR("Process attempted to continue execution after noncontinuable exception.\n");
 160     else
 161         ERR("Unhandled exception code %lx flags %lx addr %p\n",
 162             rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress );
 163     NtTerminateProcess( NtCurrentProcess(), 1 );
 164 }
 165
 166
 167 /***********************************************************************
 168  *            EXC_RtlRaiseException / RtlRaiseException (NTDLL.464)
 169  */
 170 DEFINE_REGS_ENTRYPOINT_1( RtlRaiseException, EXC_RtlRaiseException, EXCEPTION_RECORD * )
 171 void WINAPI EXC_RtlRaiseException( EXCEPTION_RECORD *rec, CONTEXT *context )
 172 {
 173     PEXCEPTION_FRAME frame, dispatch, nested_frame;
 174     EXCEPTION_RECORD newrec;
 175     DWORD res;
 176
 177     TRACE( "code=%lx flags=%lx\n", rec->ExceptionCode, rec->ExceptionFlags );
 178
 179     if (send_debug_event( rec, TRUE, context ) == DBG_CONTINUE) return;  /* continue execution */
 180
 181     frame = NtCurrentTeb()->except;
 182     nested_frame = NULL;
 183     while (frame != (PEXCEPTION_FRAME)0xFFFFFFFF)
 184     {
 185         /* Check frame address */
 186         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 187             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 188             (int)frame & 3)
 189         {
 190             rec->ExceptionFlags |= EH_STACK_INVALID;
 191             break;
 192         }
 193
 194         /* Call handler */
 195         res = EXC_CallHandler( rec, frame, context, &dispatch, frame->Handler, EXC_RaiseHandler );
 196         if (frame == nested_frame)
 197         {
 198             /* no longer nested */
 199             nested_frame = NULL;
 200             rec->ExceptionFlags &= ~EH_NESTED_CALL;
 201         }
 202
 203         switch(res)
 204         {
 205         case ExceptionContinueExecution:
 206             if (!(rec->ExceptionFlags & EH_NONCONTINUABLE)) return;
 207             newrec.ExceptionCode    = STATUS_NONCONTINUABLE_EXCEPTION;
 208             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 209             newrec.ExceptionRecord  = rec;
 210             newrec.NumberParameters = 0;
 211             RtlRaiseException( &newrec );  /* never returns */
 212             break;
 213         case ExceptionContinueSearch:
 214             break;
 215         case ExceptionNestedException:
 216             if (nested_frame < dispatch) nested_frame = dispatch;
 217             rec->ExceptionFlags |= EH_NESTED_CALL;
 218             break;
 219         default:
 220             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 221             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 222             newrec.ExceptionRecord  = rec;
 223             newrec.NumberParameters = 0;
 224             RtlRaiseException( &newrec );  /* never returns */
 225             break;
 226         }
 227         frame = frame->Prev;
 228     }
 229     EXC_DefaultHandling( rec, context );
 230 }
 231
 232
 233 /*******************************************************************
 234  *         EXC_RtlUnwind / RtlUnwind  (KERNEL32.590) (NTDLL.518)
 235  */
 236 DEFINE_REGS_ENTRYPOINT_4( RtlUnwind, EXC_RtlUnwind,
 237                           PEXCEPTION_FRAME, LPVOID, PEXCEPTION_RECORD, DWORD )
 238 void WINAPI EXC_RtlUnwind( PEXCEPTION_FRAME pEndFrame, LPVOID unusedEip,
 239                            PEXCEPTION_RECORD pRecord, DWORD returnEax,
 240                            CONTEXT *context )
 241 {
 242     EXCEPTION_RECORD record, newrec;
 243     PEXCEPTION_FRAME frame, dispatch;
 244
 245 #ifdef __i386__
 246     context->Eax = returnEax;
 247 #endif
 248
 249     /* build an exception record, if we do not have one */
 250     if (!pRecord)
 251     {
 252         record.ExceptionCode    = STATUS_UNWIND;
 253         record.ExceptionFlags   = 0;
 254         record.ExceptionRecord  = NULL;
 255         record.ExceptionAddress = GET_IP(context);
 256         record.NumberParameters = 0;
 257         pRecord = &record;
 258     }
 259
 260     pRecord->ExceptionFlags |= EH_UNWINDING | (pEndFrame ? 0 : EH_EXIT_UNWIND);
 261
 262     TRACE( "code=%lx flags=%lx\n", pRecord->ExceptionCode, pRecord->ExceptionFlags );
 263
 264     /* get chain of exception frames */
 265     frame = NtCurrentTeb()->except;
 266     while ((frame != (PEXCEPTION_FRAME)0xffffffff) && (frame != pEndFrame))
 267     {
 268         /* Check frame address */
 269         if (pEndFrame && (frame > pEndFrame))
 270         {
 271             newrec.ExceptionCode    = STATUS_INVALID_UNWIND_TARGET;
 272             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 273             newrec.ExceptionRecord  = pRecord;
 274             newrec.NumberParameters = 0;
 275             RtlRaiseException( &newrec );  /* never returns */
 276         }
 277         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 278             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 279             (int)frame & 3)
 280         {
 281             newrec.ExceptionCode    = STATUS_BAD_STACK;
 282             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 283             newrec.ExceptionRecord  = pRecord;
 284             newrec.NumberParameters = 0;
 285             RtlRaiseException( &newrec );  /* never returns */
 286         }
 287
 288         /* Call handler */
 289         switch(EXC_CallHandler( pRecord, frame, context, &dispatch,
 290                                 frame->Handler, EXC_UnwindHandler ))
 291         {
 292         case ExceptionContinueSearch:
 293             break;
 294         case ExceptionCollidedUnwind:
 295             frame = dispatch;
 296             break;
 297         default:
 298             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 299             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 300             newrec.ExceptionRecord  = pRecord;
 301             newrec.NumberParameters = 0;
 302             RtlRaiseException( &newrec );  /* never returns */
 303             break;
 304         }
 305         frame = __wine_pop_frame( frame );
 306     }
 307 }
 308
 309
 310 /*******************************************************************
 311  *            EXC_NtRaiseException / NtRaiseException  (NTDLL.175)
 312  */
 313 DEFINE_REGS_ENTRYPOINT_3( NtRaiseException, EXC_NtRaiseException,
 314                           EXCEPTION_RECORD *, CONTEXT *, BOOL )
 315 void WINAPI EXC_NtRaiseException( EXCEPTION_RECORD *rec, CONTEXT *ctx,
 316                                   BOOL first, CONTEXT *context )
 317 {
 318     EXC_RtlRaiseException( rec, ctx );
 319     *context = *ctx;
 320 }
 321
 322
 323 /***********************************************************************
 324  *            RtlRaiseStatus  (NTDLL.465)
 325  *
 326  * Raise an exception with ExceptionCode = status
 327  */
 328 void WINAPI RtlRaiseStatus( NTSTATUS status )
 329 {
 330     EXCEPTION_RECORD ExceptionRec;
 331
 332     ExceptionRec.ExceptionCode    = status;
 333     ExceptionRec.ExceptionFlags   = EH_NONCONTINUABLE;
 334     ExceptionRec.ExceptionRecord  = NULL;
 335     ExceptionRec.NumberParameters = 0;
 336     RtlRaiseException( &ExceptionRec );
 337 }
 338
 339
 340 /*************************************************************
 341  *            __wine_exception_handler
 342  *
 343  * Exception handler for exception blocks declared in Wine code.
 344  */
 345 DWORD __wine_exception_handler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
 346                                 CONTEXT *context, LPVOID pdispatcher )
 347 {
 348     __WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
 349
 350     if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND | EH_NESTED_CALL))
 351         return ExceptionContinueSearch;
 352     if (wine_frame->u.filter)
 353     {
 354         EXCEPTION_POINTERS ptrs;
 355         ptrs.ExceptionRecord = record;
 356         ptrs.ContextRecord = context;
 357         switch(wine_frame->u.filter( &ptrs ))
 358         {
 359         case EXCEPTION_CONTINUE_SEARCH:
 360             return ExceptionContinueSearch;
 361         case EXCEPTION_CONTINUE_EXECUTION:
 362             return ExceptionContinueExecution;
 363         case EXCEPTION_EXECUTE_HANDLER:
 364             break;
 365         default:
 366             MESSAGE( "Invalid return value from exception filter\n" );
 367             assert( FALSE );
 368         }
 369     }
 370     /* hack to make GetExceptionCode() work in handler */
 371     wine_frame->ExceptionCode   = record->ExceptionCode;
 372     wine_frame->ExceptionRecord = wine_frame;
 373
 374     RtlUnwind( frame, 0, record, 0 );
 375     __wine_pop_frame( frame );
 376     longjmp( wine_frame->jmp, 1 );
 377 }
 378
 379
 380 /*************************************************************
 381  *            __wine_finally_handler
 382  *
 383  * Exception handler for try/finally blocks declared in Wine code.
 384  */
 385 DWORD __wine_finally_handler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
 386                               CONTEXT *context, LPVOID pdispatcher )
 387 {
 388     __WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
 389
 390     if (!(record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)))
 391         return ExceptionContinueSearch;
 392     wine_frame->u.finally_func( FALSE );
 393     return ExceptionContinueSearch;
 394 }