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 <signal.h>
   9 #include "winnt.h"
  10 #include "ntddk.h"
  11 #include "process.h"
  12 #include "global.h"
  13 #include "wine/exception.h"
  14 #include "stackframe.h"
  15 #include "miscemu.h"
  16 #include "debugger.h"
  17 #include "debugtools.h"
  18
  19 DEFAULT_DEBUG_CHANNEL(seh)
  20
  21 /* Exception record for handling exceptions happening inside exception handlers */
  22 typedef struct
  23 {
  24     EXCEPTION_FRAME frame;
  25     EXCEPTION_FRAME *prevFrame;
  26 } EXC_NESTED_FRAME;
  27
  28
  29 /*******************************************************************
  30  *         EXC_RaiseHandler
  31  *
  32  * Handler for exceptions happening inside a handler.
  33  */
  34 static DWORD EXC_RaiseHandler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
  35                                CONTEXT *context, EXCEPTION_FRAME **dispatcher )
  36 {
  37     if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
  38         return ExceptionContinueSearch;
  39     /* We shouldn't get here so we store faulty frame in dispatcher */
  40     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
  41     return ExceptionNestedException;
  42 }
  43
  44
  45 /*******************************************************************
  46  *         EXC_UnwindHandler
  47  *
  48  * Handler for exceptions happening inside an unwind handler.
  49  */
  50 static DWORD EXC_UnwindHandler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
  51                                 CONTEXT *context, EXCEPTION_FRAME **dispatcher )
  52 {
  53     if (!(rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)))
  54         return ExceptionContinueSearch;
  55     /* We shouldn't get here so we store faulty frame in dispatcher */
  56     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
  57     return ExceptionCollidedUnwind;
  58 }
  59
  60
  61 /*******************************************************************
  62  *         EXC_CallHandler
  63  *
  64  * Call an exception handler, setting up an exception frame to catch exceptions
  65  * happening during the handler execution.
  66  * Please do not change the first 4 parameters order in any way - some exceptions handlers
  67  * rely on Base Pointer (EBP) to have a fixed position related to the exception frame
  68  */
  69 static DWORD EXC_CallHandler( EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
  70                               CONTEXT *context, EXCEPTION_FRAME **dispatcher,
  71                               PEXCEPTION_HANDLER handler, PEXCEPTION_HANDLER nested_handler)
  72 {
  73     EXC_NESTED_FRAME newframe;
  74     DWORD ret;
  75
  76     newframe.frame.Handler = nested_handler;
  77     newframe.prevFrame     = frame;
  78     EXC_push_frame( &newframe.frame );
  79     TRACE( "calling handler at %p code=%lx flags=%lx\n",
  80            handler, record->ExceptionCode, record->ExceptionFlags );
  81     ret = handler( record, frame, context, dispatcher );
  82     TRACE( "handler returned %lx\n", ret );
  83     EXC_pop_frame( &newframe.frame );
  84     return ret;
  85 }
  86
  87
  88 /*******************************************************************
  89  *         EXC_DefaultHandling
  90  *
  91  * Default handling for exceptions. Called when we didn't find a suitable handler.
  92  */
  93 static void EXC_DefaultHandling( EXCEPTION_RECORD *rec, CONTEXT *context )
  94 {
  95     if ((PROCESS_Current()->flags & PDB32_DEBUGGED) &&
  96         (DEBUG_SendExceptionEvent( rec, FALSE, context ) == DBG_CONTINUE))
  97         return;  /* continue execution */
  98
  99     if (wine_debugger( rec, context, FALSE ) == DBG_CONTINUE)
 100         return;  /* continue execution */
 101
 102     if (rec->ExceptionFlags & EH_STACK_INVALID)
 103         ERR("Exception frame is not in stack limits => unable to dispatch exception.\n");
 104     else if (rec->ExceptionCode == EXCEPTION_NONCONTINUABLE_EXCEPTION)
 105         ERR("Process attempted to continue execution after noncontinuable exception.\n");
 106     else
 107         ERR("Unhandled exception code %lx flags %lx addr %p\n",
 108             rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress );
 109     TerminateProcess( GetCurrentProcess(), 1 );
 110 }
 111
 112
 113 /***********************************************************************
 114  *            EXC_RtlRaiseException / RtlRaiseException (NTDLL.464)
 115  */
 116 DEFINE_REGS_ENTRYPOINT_1( RtlRaiseException, EXC_RtlRaiseException, EXCEPTION_RECORD * )
 117 void WINAPI EXC_RtlRaiseException( EXCEPTION_RECORD *rec, CONTEXT *context )
 118 {
 119     PEXCEPTION_FRAME frame, dispatch, nested_frame;
 120     EXCEPTION_RECORD newrec;
 121     DWORD res;
 122
 123     TRACE( "code=%lx flags=%lx\n", rec->ExceptionCode, rec->ExceptionFlags );
 124
 125     if ((PROCESS_Current()->flags & PDB32_DEBUGGED) &&
 126         (DEBUG_SendExceptionEvent( rec, TRUE, context ) == DBG_CONTINUE))
 127         return;  /* continue execution */
 128
 129     if (wine_debugger( rec, context, TRUE ) == DBG_CONTINUE)
 130         return;  /* continue execution */
 131
 132     frame = NtCurrentTeb()->except;
 133     nested_frame = NULL;
 134     while (frame != (PEXCEPTION_FRAME)0xFFFFFFFF)
 135     {
 136         /* Check frame address */
 137         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 138             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 139             (int)frame & 3)
 140         {
 141             rec->ExceptionFlags |= EH_STACK_INVALID;
 142             break;
 143         }
 144
 145         /* Call handler */
 146         res = EXC_CallHandler( rec, frame, context, &dispatch, frame->Handler, EXC_RaiseHandler );
 147         if (frame == nested_frame)
 148         {
 149             /* no longer nested */
 150             nested_frame = NULL;
 151             rec->ExceptionFlags &= ~EH_NESTED_CALL;
 152         }
 153
 154         switch(res)
 155         {
 156         case ExceptionContinueExecution:
 157             if (!(rec->ExceptionFlags & EH_NONCONTINUABLE)) return;
 158             newrec.ExceptionCode    = STATUS_NONCONTINUABLE_EXCEPTION;
 159             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 160             newrec.ExceptionRecord  = rec;
 161             newrec.NumberParameters = 0;
 162             RtlRaiseException( &newrec );  /* never returns */
 163             break;
 164         case ExceptionContinueSearch:
 165             break;
 166         case ExceptionNestedException:
 167             if (nested_frame < dispatch) nested_frame = dispatch;
 168             rec->ExceptionFlags |= EH_NESTED_CALL;
 169             break;
 170         default:
 171             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 172             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 173             newrec.ExceptionRecord  = rec;
 174             newrec.NumberParameters = 0;
 175             RtlRaiseException( &newrec );  /* never returns */
 176             break;
 177         }
 178         frame = frame->Prev;
 179     }
 180     EXC_DefaultHandling( rec, context );
 181 }
 182
 183
 184 /*******************************************************************
 185  *         EXC_RtlUnwind / RtlUnwind  (KERNEL32.590) (NTDLL.518)
 186  */
 187 DEFINE_REGS_ENTRYPOINT_4( RtlUnwind, EXC_RtlUnwind,
 188                           PEXCEPTION_FRAME, LPVOID, PEXCEPTION_RECORD, DWORD )
 189 void WINAPI EXC_RtlUnwind( PEXCEPTION_FRAME pEndFrame, LPVOID unusedEip,
 190                            PEXCEPTION_RECORD pRecord, DWORD returnEax,
 191                            CONTEXT *context )
 192 {
 193     EXCEPTION_RECORD record, newrec;
 194     PEXCEPTION_FRAME frame, dispatch;
 195
 196 #ifdef __i386__
 197     context->Eax = returnEax;
 198 #endif
 199
 200     /* build an exception record, if we do not have one */
 201     if (!pRecord)
 202     {
 203         record.ExceptionCode    = STATUS_UNWIND;
 204         record.ExceptionFlags   = 0;
 205         record.ExceptionRecord  = NULL;
 206         record.ExceptionAddress = GET_IP(context);
 207         record.NumberParameters = 0;
 208         pRecord = &record;
 209     }
 210
 211     pRecord->ExceptionFlags |= EH_UNWINDING | (pEndFrame ? 0 : EH_EXIT_UNWIND);
 212
 213     TRACE( "code=%lx flags=%lx\n", pRecord->ExceptionCode, pRecord->ExceptionFlags );
 214
 215     /* get chain of exception frames */
 216     frame = NtCurrentTeb()->except;
 217     while ((frame != (PEXCEPTION_FRAME)0xffffffff) && (frame != pEndFrame))
 218     {
 219         /* Check frame address */
 220         if (pEndFrame && (frame > pEndFrame))
 221         {
 222             newrec.ExceptionCode    = STATUS_INVALID_UNWIND_TARGET;
 223             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 224             newrec.ExceptionRecord  = pRecord;
 225             newrec.NumberParameters = 0;
 226             RtlRaiseException( &newrec );  /* never returns */
 227         }
 228         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 229             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 230             (int)frame & 3)
 231         {
 232             newrec.ExceptionCode    = STATUS_BAD_STACK;
 233             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 234             newrec.ExceptionRecord  = pRecord;
 235             newrec.NumberParameters = 0;
 236             RtlRaiseException( &newrec );  /* never returns */
 237         }
 238
 239         /* Call handler */
 240         switch(EXC_CallHandler( pRecord, frame, context, &dispatch,
 241                                 frame->Handler, EXC_UnwindHandler ))
 242         {
 243         case ExceptionContinueSearch:
 244             break;
 245         case ExceptionCollidedUnwind:
 246             frame = dispatch;
 247             break;
 248         default:
 249             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 250             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 251             newrec.ExceptionRecord  = pRecord;
 252             newrec.NumberParameters = 0;
 253             RtlRaiseException( &newrec );  /* never returns */
 254             break;
 255         }
 256         frame = EXC_pop_frame( frame );
 257     }
 258 }
 259
 260
 261 /*******************************************************************
 262  *            EXC_NtRaiseException / NtRaiseException  (NTDLL.175)
 263  */
 264 DEFINE_REGS_ENTRYPOINT_3( NtRaiseException, EXC_NtRaiseException,
 265                           EXCEPTION_RECORD *, CONTEXT *, BOOL )
 266 void WINAPI EXC_NtRaiseException( EXCEPTION_RECORD *rec, CONTEXT *ctx,
 267                                   BOOL first, CONTEXT *context )
 268 {
 269     EXC_RtlRaiseException( rec, ctx );
 270     *context = *ctx;
 271 }
 272
 273
 274 /***********************************************************************
 275  *            RtlRaiseStatus  (NTDLL.465)
 276  *
 277  * Raise an exception with ExceptionCode = status
 278  */
 279 void WINAPI RtlRaiseStatus( NTSTATUS status )
 280 {
 281     EXCEPTION_RECORD ExceptionRec;
 282
 283     ExceptionRec.ExceptionCode    = status;
 284     ExceptionRec.ExceptionFlags   = EH_NONCONTINUABLE;
 285     ExceptionRec.ExceptionRecord  = NULL;
 286     ExceptionRec.NumberParameters = 0;
 287     RtlRaiseException( &ExceptionRec );
 288 }
 289
 290
 291 /***********************************************************************
 292  *           EXC_DebugBreak / DebugBreak (KERNEL32.181)
 293  */
 294 DEFINE_REGS_ENTRYPOINT_0( DebugBreak, EXC_DebugBreak )
 295 void WINAPI EXC_DebugBreak( CONTEXT *context )
 296 {
 297     EXCEPTION_RECORD rec;
 298
 299     rec.ExceptionCode    = EXCEPTION_BREAKPOINT;
 300     rec.ExceptionFlags   = 0;
 301     rec.ExceptionRecord  = NULL;
 302     rec.NumberParameters = 0;
 303     EXC_RtlRaiseException( &rec, context );
 304 }
 305
 306
 307 /***********************************************************************
 308  *           DebugBreak16   (KERNEL.203)
 309  */
 310 void WINAPI DebugBreak16( CONTEXT86 *context )
 311 {
 312 #ifdef __i386__
 313     EXC_DebugBreak( context );
 314 #endif  /* defined(__i386__) */
 315 }