- Updates to our vectored exception handling:

- KiUserExceptionDispatcher: RtlDispatchException directly
- RtlDispatchException: Call vectored exception handlers before doing anything else
- Rename RtlpExecuteVectoredExceptionHandlers to RtlCallVectoredExceptionHandlers as this is the real name
- References: "New Vectored Exception Handling in Windows XP" by Matt Pietrek

svn path=/trunk/; revision=35812

reactos/dll/ntdll/dispatch/dispatch.c

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

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

@@ -183,43 +183,13 @@ _KiRaiseUserExceptionDispatcher@0:
 .globl _KiUserExceptionDispatcher@8
 _KiUserExceptionDispatcher@8:
 
-    /* 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.
-     */
-     
+    /* Clear direction flag */
     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
@@ -228,7 +198,6 @@ _KiUserExceptionDispatcher@8:
     or al, al
     jz RaiseException
 
-ContinueExecution:
     /* Pop off the records */
     pop ebx
     pop ecx

reactos/lib/rtl/i386/except.c

@@ -74,6 +74,13 @@ 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

@@ -37,6 +37,13 @@ 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

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