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 "debugtools.h"
  17
  18 DEFAULT_DEBUG_CHANNEL(seh)
  19
  20 /* Exception record for handling exceptions happening inside exception handlers */
  21 typedef struct
  22 {
  23     EXCEPTION_FRAME frame;
  24     EXCEPTION_FRAME *prevFrame;
  25 } EXC_NESTED_FRAME;
  26
  27
  28 #ifdef __i386__
  29 # define GET_IP(context) ((LPVOID)(context)->Eip)
  30 #else
  31 # error You must define GET_IP for this CPU
  32 #endif  /* __i386__ */
  33
  34 /* Default hook for built-in debugger */
  35 static DWORD default_hook( EXCEPTION_RECORD *rec, CONTEXT *ctx, BOOL first )
  36 {
  37     if (!first)
  38     {
  39         DPRINTF( "stopping process due to unhandled exception %08lx.\n",
  40                  rec->ExceptionCode );
  41         raise( SIGSTOP );
  42     }
  43     return 0;  /* not handled */
  44 }
  45 static DEBUGHOOK debug_hook = default_hook;
  46
  47 /*******************************************************************
  48  *         EXC_SetDebugEventHook
  49  *         EXC_GetDebugEventHook
  50  *
  51  * Set/Get the hook for the built-in debugger.
  52  *
  53  * FIXME: the built-in debugger should use the normal debug events.
  54  */
  55 void EXC_SetDebugEventHook( DEBUGHOOK hook )
  56 {
  57     debug_hook = hook;
  58 }
  59 DEBUGHOOK EXC_GetDebugEventHook(void)
  60 {
  61     return debug_hook;
  62 }
  63
  64 /*******************************************************************
  65  *         EXC_RaiseHandler
  66  *
  67  * Handler for exceptions happening inside a handler.
  68  */
  69 static DWORD CALLBACK EXC_RaiseHandler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
  70                                         CONTEXT *context, EXCEPTION_FRAME **dispatcher )
  71 {
  72     if (rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND))
  73         return ExceptionContinueSearch;
  74     /* We shouldn't get here so we store faulty frame in dispatcher */
  75     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
  76     return ExceptionNestedException;
  77 }
  78
  79
  80 /*******************************************************************
  81  *         EXC_UnwindHandler
  82  *
  83  * Handler for exceptions happening inside an unwind handler.
  84  */
  85 static DWORD CALLBACK EXC_UnwindHandler( EXCEPTION_RECORD *rec, EXCEPTION_FRAME *frame,
  86                                          CONTEXT *context, EXCEPTION_FRAME **dispatcher )
  87 {
  88     if (!(rec->ExceptionFlags & (EH_UNWINDING | EH_EXIT_UNWIND)))
  89         return ExceptionContinueSearch;
  90     /* We shouldn't get here so we store faulty frame in dispatcher */
  91     *dispatcher = ((EXC_NESTED_FRAME*)frame)->prevFrame;
  92     return ExceptionCollidedUnwind;
  93 }
  94
  95
  96 /*******************************************************************
  97  *         EXC_CallHandler
  98  *
  99  * Call an exception handler, setting up an exception frame to catch exceptions
 100  * happening during the handler execution.
 101  */
 102 static DWORD EXC_CallHandler( PEXCEPTION_HANDLER handler, PEXCEPTION_HANDLER nested_handler,
 103                               EXCEPTION_RECORD *record, EXCEPTION_FRAME *frame,
 104                               CONTEXT *context, EXCEPTION_FRAME **dispatcher )
 105 {
 106     EXC_NESTED_FRAME newframe;
 107     DWORD ret;
 108
 109     newframe.frame.Handler = nested_handler;
 110     newframe.prevFrame     = frame;
 111     EXC_push_frame( &newframe.frame );
 112     TRACE( "calling handler at %p code=%lx flags=%lx\n",
 113            handler, record->ExceptionCode, record->ExceptionFlags );
 114     ret = handler( record, frame, context, dispatcher );
 115     TRACE( "handler returned %lx\n", ret );
 116     EXC_pop_frame( &newframe.frame );
 117     return ret;
 118 }
 119
 120
 121 /*******************************************************************
 122  *         EXC_DefaultHandling
 123  *
 124  * Default handling for exceptions. Called when we didn't find a suitable handler.
 125  */
 126 static void EXC_DefaultHandling( EXCEPTION_RECORD *rec, CONTEXT *context )
 127 {
 128     if ((PROCESS_Current()->flags & PDB32_DEBUGGED) &&
 129         (DEBUG_SendExceptionEvent( rec, FALSE ) == DBG_CONTINUE))
 130         return;  /* continue execution */
 131
 132     if (debug_hook( rec, context, FALSE ) == DBG_CONTINUE)
 133         return;  /* continue execution */
 134
 135     if (rec->ExceptionFlags & EH_STACK_INVALID)
 136         ERR("Exception frame is not in stack limits => unable to dispatch exception.\n");
 137     else if (rec->ExceptionCode == EXCEPTION_NONCONTINUABLE_EXCEPTION)
 138         ERR("Process attempted to continue execution after noncontinuable exception.\n");
 139     else
 140         ERR("Unhandled exception code %lx flags %lx addr %p\n",
 141             rec->ExceptionCode, rec->ExceptionFlags, rec->ExceptionAddress );
 142     TerminateProcess( GetCurrentProcess(), 1 );
 143 }
 144
 145
 146 /***********************************************************************
 147  *            RtlRaiseException  (NTDLL.464)
 148  */
 149 void WINAPI REGS_FUNC(RtlRaiseException)( EXCEPTION_RECORD *rec, CONTEXT *context )
 150 {
 151     PEXCEPTION_FRAME frame, dispatch, nested_frame;
 152     EXCEPTION_RECORD newrec;
 153     DWORD res;
 154
 155     TRACE( "code=%lx flags=%lx\n", rec->ExceptionCode, rec->ExceptionFlags );
 156
 157     if ((PROCESS_Current()->flags & PDB32_DEBUGGED) &&
 158         (DEBUG_SendExceptionEvent( rec, TRUE ) == DBG_CONTINUE))
 159         return;  /* continue execution */
 160
 161     if (debug_hook( rec, context, TRUE ) == DBG_CONTINUE)
 162         return;  /* continue execution */
 163
 164     frame = NtCurrentTeb()->except;
 165     nested_frame = NULL;
 166     while (frame != (PEXCEPTION_FRAME)0xFFFFFFFF)
 167     {
 168         /* Check frame address */
 169         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 170             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 171             (int)frame & 3)
 172         {
 173             rec->ExceptionFlags |= EH_STACK_INVALID;
 174             break;
 175         }
 176
 177         /* Call handler */
 178         res = EXC_CallHandler( frame->Handler, EXC_RaiseHandler, rec, frame, context, &dispatch );
 179         if (frame == nested_frame)
 180         {
 181             /* no longer nested */
 182             nested_frame = NULL;
 183             rec->ExceptionFlags &= ~EH_NESTED_CALL;
 184         }
 185
 186         switch(res)
 187         {
 188         case ExceptionContinueExecution:
 189             if (!(rec->ExceptionFlags & EH_NONCONTINUABLE)) return;
 190             newrec.ExceptionCode    = STATUS_NONCONTINUABLE_EXCEPTION;
 191             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 192             newrec.ExceptionRecord  = rec;
 193             newrec.NumberParameters = 0;
 194             RtlRaiseException( &newrec );  /* never returns */
 195             break;
 196         case ExceptionContinueSearch:
 197             break;
 198         case ExceptionNestedException:
 199             if (nested_frame < dispatch) nested_frame = dispatch;
 200             rec->ExceptionFlags |= EH_NESTED_CALL;
 201             break;
 202         default:
 203             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 204             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 205             newrec.ExceptionRecord  = rec;
 206             newrec.NumberParameters = 0;
 207             RtlRaiseException( &newrec );  /* never returns */
 208             break;
 209         }
 210         frame = frame->Prev;
 211     }
 212     EXC_DefaultHandling( rec, context );
 213 }
 214
 215
 216 /*******************************************************************
 217  *         RtlUnwind  (KERNEL32.590) (NTDLL.518)
 218  */
 219 void WINAPI REGS_FUNC(RtlUnwind)( PEXCEPTION_FRAME pEndFrame, LPVOID unusedEip,
 220                                   PEXCEPTION_RECORD pRecord, DWORD returnEax,
 221                                   CONTEXT *context )
 222 {
 223     EXCEPTION_RECORD record, newrec;
 224     PEXCEPTION_FRAME frame, dispatch;
 225
 226 #ifdef __i386__
 227     context->Eax = returnEax;
 228 #endif
 229
 230     /* build an exception record, if we do not have one */
 231     if (!pRecord)
 232     {
 233         record.ExceptionCode    = STATUS_UNWIND;
 234         record.ExceptionFlags   = 0;
 235         record.ExceptionRecord  = NULL;
 236         record.ExceptionAddress = GET_IP(context);
 237         record.NumberParameters = 0;
 238         pRecord = &record;
 239     }
 240
 241     pRecord->ExceptionFlags |= EH_UNWINDING | (pEndFrame ? 0 : EH_EXIT_UNWIND);
 242
 243     TRACE( "code=%lx flags=%lx\n", pRecord->ExceptionCode, pRecord->ExceptionFlags );
 244
 245     /* get chain of exception frames */
 246     frame = NtCurrentTeb()->except;
 247     while ((frame != (PEXCEPTION_FRAME)0xffffffff) && (frame != pEndFrame))
 248     {
 249         /* Check frame address */
 250         if (pEndFrame && (frame > pEndFrame))
 251         {
 252             newrec.ExceptionCode    = STATUS_INVALID_UNWIND_TARGET;
 253             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 254             newrec.ExceptionRecord  = pRecord;
 255             newrec.NumberParameters = 0;
 256             RtlRaiseException( &newrec );  /* never returns */
 257         }
 258         if (((void*)frame < NtCurrentTeb()->stack_low) ||
 259             ((void*)(frame+1) > NtCurrentTeb()->stack_top) ||
 260             (int)frame & 3)
 261         {
 262             newrec.ExceptionCode    = STATUS_BAD_STACK;
 263             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 264             newrec.ExceptionRecord  = pRecord;
 265             newrec.NumberParameters = 0;
 266             RtlRaiseException( &newrec );  /* never returns */
 267         }
 268
 269         /* Call handler */
 270         switch(EXC_CallHandler( frame->Handler, EXC_UnwindHandler, pRecord,
 271                                 frame, context, &dispatch ))
 272         {
 273         case ExceptionContinueSearch:
 274             break;
 275         case ExceptionCollidedUnwind:
 276             frame = dispatch;
 277             break;
 278         default:
 279             newrec.ExceptionCode    = STATUS_INVALID_DISPOSITION;
 280             newrec.ExceptionFlags   = EH_NONCONTINUABLE;
 281             newrec.ExceptionRecord  = pRecord;
 282             newrec.NumberParameters = 0;
 283             RtlRaiseException( &newrec );  /* never returns */
 284             break;
 285         }
 286         frame = EXC_pop_frame( frame );
 287     }
 288 }
 289
 290
 291 /*******************************************************************
 292  *         NtRaiseException    (NTDLL.175)
 293  *
 294  * Real prototype:
 295  *    DWORD WINAPI NtRaiseException( EXCEPTION_RECORD *rec, CONTEXT *ctx, BOOL first );
 296  */
 297 void WINAPI REGS_FUNC(NtRaiseException)( EXCEPTION_RECORD *rec, CONTEXT *ctx,
 298                                          BOOL first, CONTEXT *context )
 299 {
 300     REGS_FUNC(RtlRaiseException)( rec, ctx );
 301     *context = *ctx;
 302 }
 303
 304
 305 /***********************************************************************
 306  *            RtlRaiseStatus  (NTDLL.465)
 307  *
 308  * Raise an exception with ExceptionCode = status
 309  */
 310 void WINAPI RtlRaiseStatus( NTSTATUS status )
 311 {
 312     EXCEPTION_RECORD ExceptionRec;
 313
 314     ExceptionRec.ExceptionCode    = status;
 315     ExceptionRec.ExceptionFlags   = EH_NONCONTINUABLE;
 316     ExceptionRec.ExceptionRecord  = NULL;
 317     ExceptionRec.NumberParameters = 0;
 318     RtlRaiseException( &ExceptionRec );
 319 }
 320
 321
 322 /***********************************************************************
 323  *           DebugBreak   (KERNEL32.181)
 324  */
 325 void WINAPI REGS_FUNC(DebugBreak)( CONTEXT *context )
 326 {
 327     EXCEPTION_RECORD rec;
 328
 329     rec.ExceptionCode    = EXCEPTION_BREAKPOINT;
 330     rec.ExceptionFlags   = 0;
 331     rec.ExceptionRecord  = NULL;
 332     rec.NumberParameters = 0;
 333     REGS_FUNC(RtlRaiseException)( &rec, context );
 334 }
 335
 336
 337 /***********************************************************************
 338  *           DebugBreak16   (KERNEL.203)
 339  */
 340 void WINAPI DebugBreak16( CONTEXT86 *context )
 341 {
 342 #ifdef __i386__
 343     REGS_FUNC(DebugBreak)( context );
 344 #endif  /* defined(__i386__) */
 345 }