Reverted r35812 because of unwanted triple fault bug.

See issue #3704,3706 for more details.

svn path=/trunk/; revision=35846

reactos/dll/ntdll/dispatch/dispatch.c

@@ -15,6 +15,10 @@
 
 typedef NTSTATUS (NTAPI *USER_CALL)(PVOID Argument, ULONG ArgumentLength);
 
+EXCEPTION_DISPOSITION NTAPI
+RtlpExecuteVectoredExceptionHandlers(IN PEXCEPTION_RECORD  ExceptionRecord,
+                                     IN PCONTEXT  Context);
+
 /* FUNCTIONS ****************************************************************/
 
 /*
@@ -28,16 +32,26 @@ KiUserExceptionDispatcher(PEXCEPTION_RECORD ExceptionRecord,
     EXCEPTION_RECORD NestedExceptionRecord;
     NTSTATUS Status;
 
-    /* Dispatch the exception and check the result */
+    /* call the vectored exception handlers */
-    if (RtlDispatchException(ExceptionRecord, Context))
+    if(RtlpExecuteVectoredExceptionHandlers(ExceptionRecord,
+                                            Context) != ExceptionContinueExecution)
     {
-        /* Continue executing */
+        goto ContinueExecution;
-        Status = NtContinue(Context, FALSE);
     }
     else
     {
-        /* Raise an exception */
+        /* Dispatch the exception and check the result */
-        Status = NtRaiseException(ExceptionRecord, Context, FALSE);
+        if(RtlDispatchException(ExceptionRecord, Context))
+        {
+ContinueExecution:
+            /* Continue executing */
+            Status = NtContinue(Context, FALSE);
+        }
+        else
+        {
+            /* Raise an exception */
+            Status = NtRaiseException(ExceptionRecord, Context, FALSE);
+        }
     }
 
     /* Setup the Exception record */

reactos/dll/ntdll/dispatch/i386/dispatch.S

@@ -183,13 +183,43 @@ _KiRaiseUserExceptionDispatcher@0:
 .globl _KiUserExceptionDispatcher@8
 _KiUserExceptionDispatcher@8:
 
-    /* Clear direction flag */
+    /* clear the direct flag 
+     * text from bug 2279
+     * if it not clear it means that if an exception occurs while
+     * the direction flag is set (typically inside memmove), the 
+     * exception handlers will be called with the direction flag still
+     * set.  The Windows x86-32 and x86-64 ABI requires that the 
+     * direction flag be Calling memset() with a compile-time constant 
+     * size on both GCC and MSVC will result in inlining a "rep stosd" 
+     * instruction.  Because of the ABI, they will assume that the 
+     * direction flag is clear and not emit a "cld" instruction. 
+     * Using memset() in an exception handler therefore will 
+     * corrupt memory if the exception occurred during a reverse copy 
+     * such as a forward overlapping memmove().
+     *
+     * For reliability and ease of debugging, please add "cld" to the beginning of
+     * KiUserExceptionDispatcher.  Note that the same will be true of x86-64 whenever
+     * that happens.  This does not affect continuing execution; the CONTEXT of the
+     * exception has the direction flag set and will be restored upon NtContinue. 
+     * KiUserApcDispatcher and KiUserCallbackDispatcher need to be evaluated for this
+     * issue.
+     */
+     
     cld
 
     /* Save the Context and Exception Records */
     mov ecx, [esp+4]
     mov ebx, [esp]
 
+    /* Call the vectored exception handler */
+    push ecx
+    push ebx
+    call _RtlpExecuteVectoredExceptionHandlers@8
+
+    /* Check for success */
+    or al, al
+    jnz ContinueExecution
+
     /* Dispatch the exception */
     sub esp, 8
     call _RtlDispatchException@8
@@ -198,6 +228,7 @@ _KiUserExceptionDispatcher@8:
     or al, al
     jz RaiseException
 
+ContinueExecution:
     /* Pop off the records */
     pop ebx
     pop ecx

reactos/lib/rtl/i386/except.c

@@ -74,13 +74,6 @@ RtlDispatchException(IN PEXCEPTION_RECORD ExceptionRecord,
     ULONG_PTR StackLow, StackHigh;
     ULONG_PTR RegistrationFrameEnd;
 
-    /* Call any registered vectored handlers */
-    if (RtlCallVectoredExceptionHandlers(ExceptionRecord, Context))
-    {
-        /* Exception handled, continue execution */
-        return TRUE;
-    }
-
     /* Get the current stack limits and registration frame */
     RtlpGetStackLimits(&StackLow, &StackHigh);
     RegistrationFrame = RtlpGetExceptionList();

reactos/lib/rtl/rtlp.h

@@ -37,13 +37,6 @@ VOID
 NTAPI
 RtlpSetExceptionList(PEXCEPTION_REGISTRATION_RECORD NewExceptionList);
 
-BOOLEAN
-NTAPI
-RtlCallVectoredExceptionHandlers(
-  IN PEXCEPTION_RECORD ExceptionRecord,
-  IN PCONTEXT Context
-);
-
 typedef struct _DISPATCHER_CONTEXT
 {
     PEXCEPTION_REGISTRATION_RECORD RegistrationPointer;

reactos/lib/rtl/vectoreh.c

@@ -28,10 +28,9 @@ typedef struct _RTL_VECTORED_EXCEPTION_HANDLER
 
 /* FUNCTIONS ***************************************************************/
 
-BOOLEAN
+EXCEPTION_DISPOSITION NTAPI
-NTAPI
+RtlpExecuteVectoredExceptionHandlers(IN PEXCEPTION_RECORD  ExceptionRecord,
-RtlCallVectoredExceptionHandlers(IN PEXCEPTION_RECORD  ExceptionRecord,
+                                     IN PCONTEXT  Context)
-                                 IN PCONTEXT  Context)
 {
   PLIST_ENTRY CurrentEntry;
   PRTL_VECTORED_EXCEPTION_HANDLER veh;
@@ -56,7 +55,7 @@ RtlCallVectoredExceptionHandlers(IN PEXCEPTION_RECORD  ExceptionRecord,
 
       if(VectoredHandler(&ExceptionInfo) == EXCEPTION_CONTINUE_EXECUTION)
       {
-        return TRUE;
+        return ExceptionContinueSearch;
       }
 
       RtlEnterCriticalSection(&RtlpVectoredExceptionLock);
@@ -64,7 +63,7 @@ RtlCallVectoredExceptionHandlers(IN PEXCEPTION_RECORD  ExceptionRecord,
     RtlLeaveCriticalSection(&RtlpVectoredExceptionLock);
   }
 
-  return FALSE;
+  return ExceptionContinueExecution;
 }
 
 VOID