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_VAR_REQ( queue_exception_event, sizeof(*rec)+sizeof(*context) )
 116     {
 117         CONTEXT *context_ptr = server_data_ptr(req);
 118         EXCEPTION_RECORD *rec_ptr = (EXCEPTION_RECORD *)(context_ptr + 1);
 119         req->first   = first_chance;
 120         *rec_ptr     = *rec;
 121         *context_ptr = *context;
 122         if (!SERVER_CALL()) handle = req->handle;
 123     }
 124     SERVER_END_VAR_REQ;
 125     if (!handle) return 0;  /* no debugger present or other error */
 126
 127     /* No need to wait on the handle since the process gets suspended
 128      * once the event is passed to the debugger, so when we get back
 129      * here the event has been continued already.
 130      */
 131     SERVER_START_VAR_REQ( get_exception_status, sizeof(*context) )
 132     {
 133         req->handle = handle;
 134         if (!SERVER_CALL()) *context = *(CONTEXT *)server_data_ptr(req);
 135         ret = req->status;
 136     }
 137     SERVER_END_VAR_REQ;
 138     NtClose( handle );
 139     return ret;
 140 }
 141
 142
 143 /*******************************************************************
 144  *         EXC_DefaultHandling
 145  *
 146  * Default handling for exceptions. Called when we didn't find a suitable handler.
 147  */
 148 static void EXC_DefaultHandling( EXCEPTION_RECORD *rec, CONTEXT *context )
 149 {
 150     if (send_debug_event( rec, FALSE, context ) == DBG_CONTINUE) return;  /* continue execution */
 151
 152     if (rec->ExceptionFlags & EH_STACK_INVALID)
 153         ERR("Exception frame is not in stack limits => unable to dispatch exception.\n");
 154     else if (rec->ExceptionCode == EXCEPTION_NONCONTINUABLE_EXCEPTION)
 155         ERR("Process attempted to continue execution after noncontinuable exception.\n");
 156     else
 157         ERR("Unhandled exception code %lx flags %lx addr %p\n",
 158             rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress );
 159     NtTerminateProcess( NtCurrentProcess(), 1 );
 160 }
 161
 162
 163 /***********************************************************************
 164  *            EXC_RtlRaiseException / RtlRaiseException (NTDLL.464)
 165  */
 166 DEFINE_REGS_ENTRYPOINT_1( RtlRaiseException, EXC_RtlRaiseException, EXCEPTION_RECORD * )
 167 void WINAPI EXC_RtlRaiseException( EXCEPTION_RECORD *rec, CONTEXT *context )
 168 {
 169     PEXCEPTION_FRAME frame, dispatch, nested_frame;
 170     EXCEPTION_RECORD newrec;
 171     DWORD res;
 172
 173     TRACE( "code=%lx flags=%lx\n", rec->ExceptionCode, rec->ExceptionFlags );
 174
 175     if (send_debug_event( rec, TRUE, context ) == DBG_CONTINUE) return;  /* continue execution */
 176
 177     frame = NtCurrentTeb()->except;
 178     nested_frame = NULL;
 179     while (frame != (PEXCEPTION_FRAME)0xFFFFFFFF)
 180     {
 181         /* Check frame address */
 182         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 183             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 184             (int)frame & 3)
 185         {
 186             rec->ExceptionFlags |= EH_STACK_INVALID;
 187             break;
 188         }
 189
 190         /* Call handler */
 191         res = EXC_CallHandler( rec, frame, context, &dispatch, frame->Handler, EXC_RaiseHandler );
 192         if (frame == nested_frame)
 193         {
 194             /* no longer nested */
 195             nested_frame = NULL;
 196             rec->ExceptionFlags &= ~EH_NESTED_CALL;
 197         }
 198
 199         switch(res)
 200         {
 201         case ExceptionContinueExecution:
 202             if (!(rec->ExceptionFlags & EH_NONCONTINUABLE)) return;
 203             newrec.ExceptionCode    = STATUS_NONCONTINUABLE_EXCEPTION;
 204             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 205             newrec.ExceptionRecord  = rec;
 206             newrec.NumberParameters = 0;
 207             RtlRaiseException( &newrec );  /* never returns */
 208             break;
 209         case ExceptionContinueSearch:
 210             break;
 211         case ExceptionNestedException:
 212             if (nested_frame < dispatch) nested_frame = dispatch;
 213             rec->ExceptionFlags |= EH_NESTED_CALL;
 214             break;
 215         default:
 216             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 217             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 218             newrec.ExceptionRecord  = rec;
 219             newrec.NumberParameters = 0;
 220             RtlRaiseException( &newrec );  /* never returns */
 221             break;
 222         }
 223         frame = frame->Prev;
 224     }
 225     EXC_DefaultHandling( rec, context );
 226 }
 227
 228
 229 /*******************************************************************
 230  *         EXC_RtlUnwind / RtlUnwind  (KERNEL32.590) (NTDLL.518)
 231  */
 232 DEFINE_REGS_ENTRYPOINT_4( RtlUnwind, EXC_RtlUnwind,
 233                           PEXCEPTION_FRAME, LPVOID, PEXCEPTION_RECORD, DWORD )
 234 void WINAPI EXC_RtlUnwind( PEXCEPTION_FRAME pEndFrame, LPVOID unusedEip,
 235                            PEXCEPTION_RECORD pRecord, DWORD returnEax,
 236                            CONTEXT *context )
 237 {
 238     EXCEPTION_RECORD record, newrec;
 239     PEXCEPTION_FRAME frame, dispatch;
 240
 241 #ifdef __i386__
 242     context->Eax = returnEax;
 243 #endif
 244
 245     /* build an exception record, if we do not have one */
 246     if (!pRecord)
 247     {
 248         record.ExceptionCode    = STATUS_UNWIND;
 249         record.ExceptionFlags   = 0;
 250         record.ExceptionRecord  = NULL;
 251         record.ExceptionAddress = GET_IP(context);
 252         record.NumberParameters = 0;
 253         pRecord = &record;
 254     }
 255
 256     pRecord->ExceptionFlags |= EH_UNWINDING | (pEndFrame ? 0 : EH_EXIT_UNWIND);
 257
 258     TRACE( "code=%lx flags=%lx\n", pRecord->ExceptionCode, pRecord->ExceptionFlags );
 259
 260     /* get chain of exception frames */
 261     frame = NtCurrentTeb()->except;
 262     while ((frame != (PEXCEPTION_FRAME)0xffffffff) && (frame != pEndFrame))
 263     {
 264         /* Check frame address */
 265         if (pEndFrame && (frame > pEndFrame))
 266         {
 267             newrec.ExceptionCode    = STATUS_INVALID_UNWIND_TARGET;
 268             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 269             newrec.ExceptionRecord  = pRecord;
 270             newrec.NumberParameters = 0;
 271             RtlRaiseException( &newrec );  /* never returns */
 272         }
 273         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 274             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 275             (int)frame & 3)
 276         {
 277             newrec.ExceptionCode    = STATUS_BAD_STACK;
 278             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 279             newrec.ExceptionRecord  = pRecord;
 280             newrec.NumberParameters = 0;
 281             RtlRaiseException( &newrec );  /* never returns */
 282         }
 283
 284         /* Call handler */
 285         switch(EXC_CallHandler( pRecord, frame, context, &dispatch,
 286                                 frame->Handler, EXC_UnwindHandler ))
 287         {
 288         case ExceptionContinueSearch:
 289             break;
 290         case ExceptionCollidedUnwind:
 291             frame = dispatch;
 292             break;
 293         default:
 294             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 295             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 296             newrec.ExceptionRecord  = pRecord;
 297             newrec.NumberParameters = 0;
 298             RtlRaiseException( &newrec );  /* never returns */
 299             break;
 300         }
 301         frame = __wine_pop_frame( frame );
 302     }
 303 }
 304
 305
 306 /*******************************************************************
 307  *            EXC_NtRaiseException / NtRaiseException  (NTDLL.175)
 308  */
 309 DEFINE_REGS_ENTRYPOINT_3( NtRaiseException, EXC_NtRaiseException,
 310                           EXCEPTION_RECORD *, CONTEXT *, BOOL )
 311 void WINAPI EXC_NtRaiseException( EXCEPTION_RECORD *rec, CONTEXT *ctx,
 312                                   BOOL first, CONTEXT *context )
 313 {
 314     EXC_RtlRaiseException( rec, ctx );
 315     *context = *ctx;
 316 }
 317
 318
 319 /***********************************************************************
 320  *            RtlRaiseStatus  (NTDLL.465)
 321  *
 322  * Raise an exception with ExceptionCode = status
 323  */
 324 void WINAPI RtlRaiseStatus( NTSTATUS status )
 325 {
 326     EXCEPTION_RECORD ExceptionRec;
 327
 328     ExceptionRec.ExceptionCode    = status;
 329     ExceptionRec.ExceptionFlags   = EH_NONCONTINUABLE;
 330     ExceptionRec.ExceptionRecord  = NULL;
 331     ExceptionRec.NumberParameters = 0;
 332     RtlRaiseException( &ExceptionRec );
 333 }
 334
 335
 336 /*************************************************************
 337  *            __wine_exception_handler
 338  *
 339  * Exception handler for exception blocks declared in Wine code.
 340  */
 341 DWORD __wine_exception_handler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
 342                                 CONTEXT *context, LPVOID pdispatcher )
 343 {
 344     __WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
 345
 346     if (record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND | EH_NESTED_CALL))
 347         return ExceptionContinueSearch;
 348     if (wine_frame->u.filter)
 349     {
 350         EXCEPTION_POINTERS ptrs;
 351         ptrs.ExceptionRecord = record;
 352         ptrs.ContextRecord = context;
 353         switch(wine_frame->u.filter( &ptrs ))
 354         {
 355         case EXCEPTION_CONTINUE_SEARCH:
 356             return ExceptionContinueSearch;
 357         case EXCEPTION_CONTINUE_EXECUTION:
 358             return ExceptionContinueExecution;
 359         case EXCEPTION_EXECUTE_HANDLER:
 360             break;
 361         default:
 362             MESSAGE( "Invalid return value from exception filter\n" );
 363             assert( FALSE );
 364         }
 365     }
 366     /* hack to make GetExceptionCode() work in handler */
 367     wine_frame->ExceptionCode   = record->ExceptionCode;
 368     wine_frame->ExceptionRecord = wine_frame;
 369
 370     RtlUnwind( frame, 0, record, 0 );
 371     __wine_pop_frame( frame );
 372     longjmp( wine_frame->jmp, 1 );
 373 }
 374
 375
 376 /*************************************************************
 377  *            __wine_finally_handler
 378  *
 379  * Exception handler for try/finally blocks declared in Wine code.
 380  */
 381 DWORD __wine_finally_handler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
 382                               CONTEXT *context, LPVOID pdispatcher )
 383 {
 384     __WINE_FRAME *wine_frame = (__WINE_FRAME *)frame;
 385
 386     if (!(record->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)))
 387         return ExceptionContinueSearch;
 388     wine_frame->u.finally_func( FALSE );
 389     return ExceptionContinueSearch;
 390 }