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 "server.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_SendEvent
  90  *
  91  * Send an EXCEPTION_DEBUG_EVENT event to the debugger.
  92  */
  93 static inline int send_debug_event( EXCEPTION_RECORD *rec, int first_chance, CONTEXT *context )
  94 {
  95     struct exception_event_request *req = get_req_buffer();
  96     req->record  = *rec;
  97     req->first   = first_chance;
  98     req->context = *context;
  99     if (!server_call_noerr( REQ_EXCEPTION_EVENT )) *context = req->context;
 100     return req->status;
 101 }
 102
 103
 104 /*******************************************************************
 105  *         EXC_DefaultHandling
 106  *
 107  * Default handling for exceptions. Called when we didn't find a suitable handler.
 108  */
 109 static void EXC_DefaultHandling( EXCEPTION_RECORD *rec, CONTEXT *context )
 110 {
 111     if (send_debug_event( rec, FALSE, context ) == DBG_CONTINUE) return;  /* continue execution */
 112
 113     if (rec->ExceptionFlags & EH_STACK_INVALID)
 114         ERR("Exception frame is not in stack limits => unable to dispatch exception.\n");
 115     else if (rec->ExceptionCode == EXCEPTION_NONCONTINUABLE_EXCEPTION)
 116         ERR("Process attempted to continue execution after noncontinuable exception.\n");
 117     else
 118         ERR("Unhandled exception code %lx flags %lx addr %p\n",
 119             rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress );
 120     TerminateProcess( GetCurrentProcess(), 1 );
 121 }
 122
 123
 124 /***********************************************************************
 125  *            EXC_RtlRaiseException / RtlRaiseException (NTDLL.464)
 126  */
 127 DEFINE_REGS_ENTRYPOINT_1( RtlRaiseException, EXC_RtlRaiseException, EXCEPTION_RECORD * )
 128 void WINAPI EXC_RtlRaiseException( EXCEPTION_RECORD *rec, CONTEXT *context )
 129 {
 130     PEXCEPTION_FRAME frame, dispatch, nested_frame;
 131     EXCEPTION_RECORD newrec;
 132     DWORD res;
 133
 134     TRACE( "code=%lx flags=%lx\n", rec->ExceptionCode, rec->ExceptionFlags );
 135
 136     if (send_debug_event( rec, TRUE, context ) == DBG_CONTINUE) return;  /* continue execution */
 137
 138     frame = NtCurrentTeb()->except;
 139     nested_frame = NULL;
 140     while (frame != (PEXCEPTION_FRAME)0xFFFFFFFF)
 141     {
 142         /* Check frame address */
 143         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 144             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 145             (int)frame & 3)
 146         {
 147             rec->ExceptionFlags |= EH_STACK_INVALID;
 148             break;
 149         }
 150
 151         /* Call handler */
 152         res = EXC_CallHandler( rec, frame, context, &dispatch, frame->Handler, EXC_RaiseHandler );
 153         if (frame == nested_frame)
 154         {
 155             /* no longer nested */
 156             nested_frame = NULL;
 157             rec->ExceptionFlags &= ~EH_NESTED_CALL;
 158         }
 159
 160         switch(res)
 161         {
 162         case ExceptionContinueExecution:
 163             if (!(rec->ExceptionFlags & EH_NONCONTINUABLE)) return;
 164             newrec.ExceptionCode    = STATUS_NONCONTINUABLE_EXCEPTION;
 165             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 166             newrec.ExceptionRecord  = rec;
 167             newrec.NumberParameters = 0;
 168             RtlRaiseException( &newrec );  /* never returns */
 169             break;
 170         case ExceptionContinueSearch:
 171             break;
 172         case ExceptionNestedException:
 173             if (nested_frame < dispatch) nested_frame = dispatch;
 174             rec->ExceptionFlags |= EH_NESTED_CALL;
 175             break;
 176         default:
 177             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 178             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 179             newrec.ExceptionRecord  = rec;
 180             newrec.NumberParameters = 0;
 181             RtlRaiseException( &newrec );  /* never returns */
 182             break;
 183         }
 184         frame = frame->Prev;
 185     }
 186     EXC_DefaultHandling( rec, context );
 187 }
 188
 189
 190 /*******************************************************************
 191  *         EXC_RtlUnwind / RtlUnwind  (KERNEL32.590) (NTDLL.518)
 192  */
 193 DEFINE_REGS_ENTRYPOINT_4( RtlUnwind, EXC_RtlUnwind,
 194                           PEXCEPTION_FRAME, LPVOID, PEXCEPTION_RECORD, DWORD )
 195 void WINAPI EXC_RtlUnwind( PEXCEPTION_FRAME pEndFrame, LPVOID unusedEip,
 196                            PEXCEPTION_RECORD pRecord, DWORD returnEax,
 197                            CONTEXT *context )
 198 {
 199     EXCEPTION_RECORD record, newrec;
 200     PEXCEPTION_FRAME frame, dispatch;
 201
 202 #ifdef __i386__
 203     context->Eax = returnEax;
 204 #endif
 205
 206     /* build an exception record, if we do not have one */
 207     if (!pRecord)
 208     {
 209         record.ExceptionCode    = STATUS_UNWIND;
 210         record.ExceptionFlags   = 0;
 211         record.ExceptionRecord  = NULL;
 212         record.ExceptionAddress = GET_IP(context);
 213         record.NumberParameters = 0;
 214         pRecord = &record;
 215     }
 216
 217     pRecord->ExceptionFlags |= EH_UNWINDING | (pEndFrame ? 0 : EH_EXIT_UNWIND);
 218
 219     TRACE( "code=%lx flags=%lx\n", pRecord->ExceptionCode, pRecord->ExceptionFlags );
 220
 221     /* get chain of exception frames */
 222     frame = NtCurrentTeb()->except;
 223     while ((frame != (PEXCEPTION_FRAME)0xffffffff) && (frame != pEndFrame))
 224     {
 225         /* Check frame address */
 226         if (pEndFrame && (frame > pEndFrame))
 227         {
 228             newrec.ExceptionCode    = STATUS_INVALID_UNWIND_TARGET;
 229             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 230             newrec.ExceptionRecord  = pRecord;
 231             newrec.NumberParameters = 0;
 232             RtlRaiseException( &newrec );  /* never returns */
 233         }
 234         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 235             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 236             (int)frame & 3)
 237         {
 238             newrec.ExceptionCode    = STATUS_BAD_STACK;
 239             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 240             newrec.ExceptionRecord  = pRecord;
 241             newrec.NumberParameters = 0;
 242             RtlRaiseException( &newrec );  /* never returns */
 243         }
 244
 245         /* Call handler */
 246         switch(EXC_CallHandler( pRecord, frame, context, &dispatch,
 247                                 frame->Handler, EXC_UnwindHandler ))
 248         {
 249         case ExceptionContinueSearch:
 250             break;
 251         case ExceptionCollidedUnwind:
 252             frame = dispatch;
 253             break;
 254         default:
 255             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 256             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 257             newrec.ExceptionRecord  = pRecord;
 258             newrec.NumberParameters = 0;
 259             RtlRaiseException( &newrec );  /* never returns */
 260             break;
 261         }
 262         frame = EXC_pop_frame( frame );
 263     }
 264 }
 265
 266
 267 /*******************************************************************
 268  *            EXC_NtRaiseException / NtRaiseException  (NTDLL.175)
 269  */
 270 DEFINE_REGS_ENTRYPOINT_3( NtRaiseException, EXC_NtRaiseException,
 271                           EXCEPTION_RECORD *, CONTEXT *, BOOL )
 272 void WINAPI EXC_NtRaiseException( EXCEPTION_RECORD *rec, CONTEXT *ctx,
 273                                   BOOL first, CONTEXT *context )
 274 {
 275     EXC_RtlRaiseException( rec, ctx );
 276     *context = *ctx;
 277 }
 278
 279
 280 /***********************************************************************
 281  *            RtlRaiseStatus  (NTDLL.465)
 282  *
 283  * Raise an exception with ExceptionCode = status
 284  */
 285 void WINAPI RtlRaiseStatus( NTSTATUS status )
 286 {
 287     EXCEPTION_RECORD ExceptionRec;
 288
 289     ExceptionRec.ExceptionCode    = status;
 290     ExceptionRec.ExceptionFlags   = EH_NONCONTINUABLE;
 291     ExceptionRec.ExceptionRecord  = NULL;
 292     ExceptionRec.NumberParameters = 0;
 293     RtlRaiseException( &ExceptionRec );
 294 }