convert DefaultSetInfoBufferCheck and DefaultQueryInfoBufferCheck to inlined functions
[reactos.git] / reactos / ntoskrnl / ex / event.c
index 4db20f5..2eb0ac1 100644 (file)
@@ -1,11 +1,11 @@
-/* $Id:$
- * 
+/*
  * COPYRIGHT:       See COPYING in the top level directory
  * PROJECT:         ReactOS kernel
  * FILE:            ntoskrnl/nt/event.c
  * PURPOSE:         Named event support
- * 
- * PROGRAMMERS:     Philip Susi and David Welch
+ *
+ * PROGRAMMERS:     Alex Ionescu(alex@relsoft.net) - Fixed bugs/commented
+ *                  Philip Susi and David Welch
  */
 
 /* INCLUDES *****************************************************************/
 POBJECT_TYPE EXPORTED ExEventObjectType = NULL;
 
 static GENERIC_MAPPING ExpEventMapping = {
-       STANDARD_RIGHTS_READ | SYNCHRONIZE | EVENT_QUERY_STATE,
-       STANDARD_RIGHTS_WRITE | SYNCHRONIZE | EVENT_MODIFY_STATE,
-       STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE | EVENT_QUERY_STATE,
-       EVENT_ALL_ACCESS};
+    STANDARD_RIGHTS_READ | SYNCHRONIZE | EVENT_QUERY_STATE,
+    STANDARD_RIGHTS_WRITE | SYNCHRONIZE | EVENT_MODIFY_STATE,
+    STANDARD_RIGHTS_EXECUTE | SYNCHRONIZE | EVENT_QUERY_STATE,
+    EVENT_ALL_ACCESS};
 
-static const INFORMATION_CLASS_INFO ExEventInfoClass[] =
-{
-  ICI_SQ_SAME( sizeof(EVENT_BASIC_INFORMATION), sizeof(ULONG), ICIF_QUERY ), /* EventBasicInformation */
+static const INFORMATION_CLASS_INFO ExEventInfoClass[] = {
+
+    /* EventBasicInformation */
+    ICI_SQ_SAME( sizeof(EVENT_BASIC_INFORMATION), sizeof(ULONG), ICIF_QUERY),
 };
 
 /* FUNCTIONS *****************************************************************/
 
-NTSTATUS STDCALL
-NtpCreateEvent(PVOID ObjectBody,
-              PVOID Parent,
-              PWSTR RemainingPath,
-              POBJECT_ATTRIBUTES ObjectAttributes)
-{
-  DPRINT("NtpCreateEvent(ObjectBody %x, Parent %x, RemainingPath %S)\n",
-        ObjectBody, Parent, RemainingPath);
-
-  if (RemainingPath != NULL && wcschr(RemainingPath+1, '\\') != NULL)
-    {
-      return(STATUS_UNSUCCESSFUL);
-    }
-
-  return(STATUS_SUCCESS);
-}
-
-
-VOID INIT_FUNCTION
+VOID
+INIT_FUNCTION
+STDCALL
 ExpInitializeEventImplementation(VOID)
 {
-   ExEventObjectType = ExAllocatePool(NonPagedPool,sizeof(OBJECT_TYPE));
-   
-   RtlpCreateUnicodeString(&ExEventObjectType->TypeName, L"Event", NonPagedPool);
-   
-   ExEventObjectType->Tag = TAG('E', 'V', 'T', 'T');
-   ExEventObjectType->PeakObjects = 0;
-   ExEventObjectType->PeakHandles = 0;
-   ExEventObjectType->TotalObjects = 0;
-   ExEventObjectType->TotalHandles = 0;
-   ExEventObjectType->PagedPoolCharge = 0;
-   ExEventObjectType->NonpagedPoolCharge = sizeof(KEVENT);
-   ExEventObjectType->Mapping = &ExpEventMapping;
-   ExEventObjectType->Dump = NULL;
-   ExEventObjectType->Open = NULL;
-   ExEventObjectType->Close = NULL;
-   ExEventObjectType->Delete = NULL;
-   ExEventObjectType->Parse = NULL;
-   ExEventObjectType->Security = NULL;
-   ExEventObjectType->QueryName = NULL;
-   ExEventObjectType->OkayToClose = NULL;
-   ExEventObjectType->Create = NtpCreateEvent;
-   ExEventObjectType->DuplicationNotify = NULL;
-
-   ObpCreateTypeObject(ExEventObjectType);
+  OBJECT_TYPE_INITIALIZER ObjectTypeInitializer;
+  UNICODE_STRING Name;
+
+  DPRINT("Creating Event Object Type\n");
+  
+  /* Create the Event Object Type */
+  RtlZeroMemory(&ObjectTypeInitializer, sizeof(ObjectTypeInitializer));
+  RtlInitUnicodeString(&Name, L"Event");
+  ObjectTypeInitializer.Length = sizeof(ObjectTypeInitializer);
+  ObjectTypeInitializer.DefaultNonPagedPoolCharge = sizeof(KEVENT);
+  ObjectTypeInitializer.GenericMapping = ExpEventMapping;
+  ObjectTypeInitializer.PoolType = NonPagedPool;
+  ObjectTypeInitializer.ValidAccessMask = EVENT_ALL_ACCESS;
+  ObpCreateTypeObject(&ObjectTypeInitializer, &Name, &ExEventObjectType);
 }
 
-
 /*
  * @implemented
  */
-NTSTATUS STDCALL
+NTSTATUS
+STDCALL
 NtClearEvent(IN HANDLE EventHandle)
 {
-   PKEVENT Event;
-   NTSTATUS Status;
-   
-   PAGED_CODE();
-   
-   Status = ObReferenceObjectByHandle(EventHandle,
-                                     EVENT_MODIFY_STATE,
-                                     ExEventObjectType,
-                                     ExGetPreviousMode(),
-                                     (PVOID*)&Event,
-                                     NULL);
-   if(NT_SUCCESS(Status))
-   {
-     KeClearEvent(Event);
-     ObDereferenceObject(Event);
-   }
-   
-   return Status;
+    PKEVENT Event;
+    NTSTATUS Status;
+
+    PAGED_CODE();
+
+    /* Reference the Object */
+    Status = ObReferenceObjectByHandle(EventHandle,
+                                       EVENT_MODIFY_STATE,
+                                       ExEventObjectType,
+                                       ExGetPreviousMode(),
+                                       (PVOID*)&Event,
+                                       NULL);
+
+    /* Check for Success */
+    if(NT_SUCCESS(Status)) {
+
+        /* Clear the Event and Dereference */
+        KeClearEvent(Event);
+        ObDereferenceObject(Event);
+    }
+
+    /* Return Status */
+    return Status;
 }
 
 
 /*
  * @implemented
  */
-NTSTATUS STDCALL
+NTSTATUS
+STDCALL
 NtCreateEvent(OUT PHANDLE EventHandle,
-             IN ACCESS_MASK DesiredAccess,
-             IN POBJECT_ATTRIBUTES ObjectAttributes  OPTIONAL,
-             IN EVENT_TYPE EventType,
-             IN BOOLEAN InitialState)
+              IN ACCESS_MASK DesiredAccess,
+              IN POBJECT_ATTRIBUTES ObjectAttributes  OPTIONAL,
+              IN EVENT_TYPE EventType,
+              IN BOOLEAN InitialState)
 {
-   KPROCESSOR_MODE PreviousMode;
-   PKEVENT Event;
-   HANDLE hEvent;
-   NTSTATUS Status = STATUS_SUCCESS;
-   
-   PAGED_CODE();
-   PreviousMode = ExGetPreviousMode();
-   if(PreviousMode == UserMode)
-   {
-     _SEH_TRY
-     {
-       ProbeForWrite(EventHandle,
-                     sizeof(HANDLE),
-                     sizeof(ULONG));
-     }
-     _SEH_HANDLE
-     {
-       Status = _SEH_GetExceptionCode();
-     }
-     _SEH_END;
-     
-     if(!NT_SUCCESS(Status))
-     {
-       return Status;
-     }
-   }
-   Status = ObCreateObject(PreviousMode,
-                           ExEventObjectType,
-                           ObjectAttributes,
-                           PreviousMode,
-                           NULL,
-                           sizeof(KEVENT),
-                           0,
-                           0,
-                           (PVOID*)&Event);
-   if(NT_SUCCESS(Status))
-   {
-     KeInitializeEvent(Event,
-                       EventType,
-                       InitialState);
-     Status = ObInsertObject((PVOID)Event,
-                             NULL,
-                             DesiredAccess,
-                             0,
-                             NULL,
-                             &hEvent);
-     ObDereferenceObject(Event);
-     if(NT_SUCCESS(Status))
-     {
-       _SEH_TRY
-       {
-         *EventHandle = hEvent;
-       }
-       _SEH_HANDLE
-       {
-         Status = _SEH_GetExceptionCode();
-       }
-       _SEH_END;
-     }
-   }
-   return Status;
-}
+    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
+    PKEVENT Event;
+    HANDLE hEvent;
+    NTSTATUS Status = STATUS_SUCCESS;
+
+    PAGED_CODE();
+    DPRINT("NtCreateEvent(0x%p, 0x%x, 0x%p)\n", EventHandle, DesiredAccess, ObjectAttributes);
+
+    /* Check Output Safety */
+    if(PreviousMode != KernelMode) {
+
+        _SEH_TRY {
+
+            ProbeForWriteHandle(EventHandle);
+        } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+            Status = _SEH_GetExceptionCode();
+
+        } _SEH_END;
+
+        if(!NT_SUCCESS(Status)) return Status;
+    }
+
+    /* Create the Object */
+    Status = ObCreateObject(PreviousMode,
+                            ExEventObjectType,
+                            ObjectAttributes,
+                            PreviousMode,
+                            NULL,
+                            sizeof(KEVENT),
+                            0,
+                            0,
+                            (PVOID*)&Event);
+
+    /* Check for Success */
+    if(NT_SUCCESS(Status)) {
 
+        /* Initalize the Event */
+        KeInitializeEvent(Event,
+                          EventType,
+                          InitialState);
+
+        /* Insert it */
+        Status = ObInsertObject((PVOID)Event,
+                                 NULL,
+                                 DesiredAccess,
+                                 0,
+                                 NULL,
+                                 &hEvent);
+        ObDereferenceObject(Event);
+
+        /* Check for success and return handle */
+        if(NT_SUCCESS(Status)) {
+
+            _SEH_TRY {
+
+                *EventHandle = hEvent;
+
+            } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+                Status = _SEH_GetExceptionCode();
+
+            } _SEH_END;
+        }
+    }
+
+    /* Return Status */
+    return Status;
+}
 
 /*
  * @implemented
  */
-NTSTATUS STDCALL
+NTSTATUS
+STDCALL
 NtOpenEvent(OUT PHANDLE EventHandle,
-           IN ACCESS_MASK DesiredAccess,
-           IN POBJECT_ATTRIBUTES ObjectAttributes)
+            IN ACCESS_MASK DesiredAccess,
+            IN POBJECT_ATTRIBUTES ObjectAttributes)
 {
-   HANDLE hEvent;
-   KPROCESSOR_MODE PreviousMode;
-   NTSTATUS Status = STATUS_SUCCESS;
-   
-   PAGED_CODE();
-   
-   DPRINT("NtOpenEvent(0x%x, 0x%x, 0x%x)\n", EventHandle, DesiredAccess, ObjectAttributes);
-
-   PreviousMode = ExGetPreviousMode();
-   
-   if(PreviousMode == UserMode)
-   {
-     _SEH_TRY
-     {
-       ProbeForWrite(EventHandle,
-                     sizeof(HANDLE),
-                     sizeof(ULONG));
-     }
-     _SEH_HANDLE
-     {
-       Status = _SEH_GetExceptionCode();
-     }
-     _SEH_END;
-     
-     if(!NT_SUCCESS(Status))
-     {
-       return Status;
-     }
-   }
+    HANDLE hEvent;
+    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
+    NTSTATUS Status = STATUS_SUCCESS;
 
-   Status = ObOpenObjectByName(ObjectAttributes,
-                              ExEventObjectType,
-                              NULL,
-                              PreviousMode,
-                              DesiredAccess,
-                              NULL,
-                              &hEvent);
-             
-   if(NT_SUCCESS(Status))
-   {
-     _SEH_TRY
-     {
-       *EventHandle = hEvent;
-     }
-     _SEH_HANDLE
-     {
-       Status = _SEH_GetExceptionCode();
-     }
-     _SEH_END;
-   }
-   
-   return Status;
-}
+    PAGED_CODE();
+    DPRINT("NtOpenEvent(0x%p, 0x%x, 0x%p)\n", EventHandle, DesiredAccess, ObjectAttributes);
+
+    /* Check Output Safety */
+    if(PreviousMode != KernelMode) {
+
+        _SEH_TRY {
+
+            ProbeForWriteHandle(EventHandle);
+        } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
 
+            Status = _SEH_GetExceptionCode();
+
+        } _SEH_END;
+
+        if(!NT_SUCCESS(Status)) return Status;
+    }
+
+    /* Open the Object */
+    Status = ObOpenObjectByName(ObjectAttributes,
+                                ExEventObjectType,
+                                NULL,
+                                PreviousMode,
+                                DesiredAccess,
+                                NULL,
+                                &hEvent);
+
+    /* Check for success and return handle */
+    if(NT_SUCCESS(Status)) {
+
+        _SEH_TRY {
+
+            *EventHandle = hEvent;
+
+        } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+            Status = _SEH_GetExceptionCode();
+
+        } _SEH_END;
+    }
+
+    /* Return status */
+    return Status;
+}
 
 /*
  * @implemented
  */
-NTSTATUS STDCALL
+NTSTATUS
+STDCALL
 NtPulseEvent(IN HANDLE EventHandle,
-            OUT PLONG PreviousState  OPTIONAL)
+             OUT PLONG PreviousState OPTIONAL)
 {
-   PKEVENT Event;
-   KPROCESSOR_MODE PreviousMode;
-   NTSTATUS Status = STATUS_SUCCESS;
-   
-   PAGED_CODE();
-
-   DPRINT("NtPulseEvent(EventHandle 0%x PreviousState 0%x)\n",
-         EventHandle, PreviousState);
-
-   PreviousMode = ExGetPreviousMode();
-   
-   if(PreviousState != NULL && PreviousMode == UserMode)
-   {
-     _SEH_TRY
-     {
-       ProbeForWrite(PreviousState,
-                     sizeof(LONG),
-                     sizeof(ULONG));
-     }
-     _SEH_HANDLE
-     {
-       Status = _SEH_GetExceptionCode();
-     }
-     _SEH_END;
-     
-     if(!NT_SUCCESS(Status))
-     {
-       return Status;
-     }
-   }
+    PKEVENT Event;
+    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
+    NTSTATUS Status = STATUS_SUCCESS;
+
+    PAGED_CODE();
+    DPRINT("NtPulseEvent(EventHandle 0%x PreviousState 0%x)\n",
+            EventHandle, PreviousState);
+
+    /* Check buffer validity */
+    if(PreviousState && PreviousMode != KernelMode) {
 
-   Status = ObReferenceObjectByHandle(EventHandle,
-                                     EVENT_MODIFY_STATE,
-                                     ExEventObjectType,
-                                     PreviousMode,
-                                     (PVOID*)&Event,
-                                     NULL);
-   if(NT_SUCCESS(Status))
-   {
-     LONG Prev = KePulseEvent(Event, EVENT_INCREMENT, FALSE);
-     ObDereferenceObject(Event);
-     
-     if(PreviousState != NULL)
-     {
-       _SEH_TRY
-       {
-         *PreviousState = Prev;
-       }
-       _SEH_HANDLE
-       {
-         Status = _SEH_GetExceptionCode();
-       }
-       _SEH_END;
-     }
+        _SEH_TRY {
+
+            ProbeForWriteLong(PreviousState);
+         } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+            Status = _SEH_GetExceptionCode();
+
+        } _SEH_END;
+
+        if(!NT_SUCCESS(Status)) return Status;
+    }
+
+    /* Open the Object */
+    Status = ObReferenceObjectByHandle(EventHandle,
+                                       EVENT_MODIFY_STATE,
+                                       ExEventObjectType,
+                                       PreviousMode,
+                                       (PVOID*)&Event,
+                                       NULL);
+
+    /* Check for success */
+    if(NT_SUCCESS(Status)) {
+
+        /* Pulse the Event */
+        LONG Prev = KePulseEvent(Event, EVENT_INCREMENT, FALSE);
+        ObDereferenceObject(Event);
+
+        /* Return it */
+        if(PreviousState) {
+
+            _SEH_TRY {
+
+                *PreviousState = Prev;
+
+            } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+                Status = _SEH_GetExceptionCode();
+
+            } _SEH_END;
+        }
    }
 
+   /* Return Status */
    return Status;
 }
 
@@ -320,230 +294,199 @@ NtPulseEvent(IN HANDLE EventHandle,
 /*
  * @implemented
  */
-NTSTATUS STDCALL
+NTSTATUS
+STDCALL
 NtQueryEvent(IN HANDLE EventHandle,
-            IN EVENT_INFORMATION_CLASS EventInformationClass,
-            OUT PVOID EventInformation,
-            IN ULONG EventInformationLength,
-            OUT PULONG ReturnLength  OPTIONAL)
+             IN EVENT_INFORMATION_CLASS EventInformationClass,
+             OUT PVOID EventInformation,
+             IN ULONG EventInformationLength,
+             OUT PULONG ReturnLength  OPTIONAL)
 {
-   PKEVENT Event;
-   KPROCESSOR_MODE PreviousMode;
-   NTSTATUS Status = STATUS_SUCCESS;
-   
-   PAGED_CODE();
-
-   PreviousMode = ExGetPreviousMode();
-   
-   DefaultQueryInfoBufferCheck(EventInformationClass,
-                               ExEventInfoClass,
-                               EventInformation,
-                               EventInformationLength,
-                               ReturnLength,
-                               PreviousMode,
-                               &Status);
-   if(!NT_SUCCESS(Status))
-   {
-     DPRINT1("NtQueryEvent() failed, Status: 0x%x\n", Status);
-     return Status;
-   }
+    PKEVENT Event;
+    KPROCESSOR_MODE PreviousMode  = ExGetPreviousMode();
+    NTSTATUS Status = STATUS_SUCCESS;
+    PEVENT_BASIC_INFORMATION BasicInfo = (PEVENT_BASIC_INFORMATION)EventInformation;
+
+    PAGED_CODE();
+    DPRINT("NtQueryEvent(0x%p, 0x%x)\n", EventHandle, EventInformationClass);
+
+    /* Check buffers and class validity */
+    Status = DefaultQueryInfoBufferCheck(EventInformationClass,
+                                         ExEventInfoClass,
+                                         sizeof(ExEventInfoClass) / sizeof(ExEventInfoClass[0]),
+                                         EventInformation,
+                                         EventInformationLength,
+                                         ReturnLength,
+                                         PreviousMode);
+    if(!NT_SUCCESS(Status)) {
+
+        /* Invalid buffers */
+        DPRINT("NtQuerySemaphore() failed, Status: 0x%x\n", Status);
+        return Status;
+    }
+
+    /* Get the Object */
+    Status = ObReferenceObjectByHandle(EventHandle,
+                                       EVENT_QUERY_STATE,
+                                       ExEventObjectType,
+                                       PreviousMode,
+                                       (PVOID*)&Event,
+                                       NULL);
 
-   Status = ObReferenceObjectByHandle(EventHandle,
-                                     EVENT_QUERY_STATE,
-                                     ExEventObjectType,
-                                     PreviousMode,
-                                     (PVOID*)&Event,
-                                     NULL);
-   if(NT_SUCCESS(Status))
-   {
-     switch(EventInformationClass)
-     {
-       case EventBasicInformation:
-       {
-         PEVENT_BASIC_INFORMATION BasicInfo = (PEVENT_BASIC_INFORMATION)EventInformation;
-         
-         _SEH_TRY
-         {
-           if (Event->Header.Type == InternalNotificationEvent)
-             BasicInfo->EventType = NotificationEvent;
-           else
-             BasicInfo->EventType = SynchronizationEvent;
-           BasicInfo->EventState = KeReadStateEvent(Event);
-
-           if(ReturnLength != NULL)
-           {
-             *ReturnLength = sizeof(EVENT_BASIC_INFORMATION);
-           }
-         }
-         _SEH_HANDLE
-         {
-           Status = _SEH_GetExceptionCode();
-         }
-         _SEH_END;
-         break;
-       }
-
-       default:
-         Status = STATUS_NOT_IMPLEMENTED;
-         break;
-     }
-
-     ObDereferenceObject(Event);
+    /* Check for success */
+    if(NT_SUCCESS(Status)) {
+
+        _SEH_TRY {
+
+            /* Return Event Type and State */
+            BasicInfo->EventType = Event->Header.Type;
+            BasicInfo->EventState = KeReadStateEvent(Event);
+
+            /* Return length */
+            if(ReturnLength) *ReturnLength = sizeof(EVENT_BASIC_INFORMATION);
+
+        } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+            Status = _SEH_GetExceptionCode();
+
+        } _SEH_END;
+
+        /* Dereference the Object */
+        ObDereferenceObject(Event);
    }
 
+   /* Return status */
    return Status;
 }
 
-
 /*
  * @implemented
  */
-NTSTATUS STDCALL
+NTSTATUS
+STDCALL
 NtResetEvent(IN HANDLE EventHandle,
-            OUT PLONG PreviousState  OPTIONAL)
+             OUT PLONG PreviousState OPTIONAL)
 {
-   PKEVENT Event;
-   KPROCESSOR_MODE PreviousMode;
-   NTSTATUS Status = STATUS_SUCCESS;
-   
-   PAGED_CODE();
-
-   DPRINT("NtResetEvent(EventHandle 0%x PreviousState 0%x)\n",
-         EventHandle, PreviousState);
-
-   PreviousMode = ExGetPreviousMode();
-
-   if(PreviousState != NULL && PreviousMode == UserMode)
-   {
-     _SEH_TRY
-     {
-       ProbeForWrite(PreviousState,
-                     sizeof(LONG),
-                     sizeof(ULONG));
-     }
-     _SEH_HANDLE
-     {
-       Status = _SEH_GetExceptionCode();
-     }
-     _SEH_END;
-     
-     if(!NT_SUCCESS(Status))
-     {
-       return Status;
-     }
-   }
+    PKEVENT Event;
+    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
+    NTSTATUS Status = STATUS_SUCCESS;
 
-   Status = ObReferenceObjectByHandle(EventHandle,
-                                     EVENT_MODIFY_STATE,
-                                     ExEventObjectType,
-                                     PreviousMode,
-                                     (PVOID*)&Event,
-                                     NULL);
-   if(NT_SUCCESS(Status))
-   {
-     LONG Prev = KeResetEvent(Event);
-     ObDereferenceObject(Event);
-     
-     if(PreviousState != NULL)
-     {
-       _SEH_TRY
-       {
-         *PreviousState = Prev;
-       }
-       _SEH_HANDLE
-       {
-         Status = _SEH_GetExceptionCode();
-       }
-       _SEH_END;
-     }
-   }
+    PAGED_CODE();
+    DPRINT("NtResetEvent(EventHandle 0%x PreviousState 0%x)\n",
+            EventHandle, PreviousState);
 
-   return Status;
-}
+    /* Check buffer validity */
+    if(PreviousState && PreviousMode != KernelMode) {
 
+        _SEH_TRY {
 
-/*
- * @implemented
- */
-NTSTATUS STDCALL
-NtSetEvent(IN HANDLE EventHandle,
-          OUT PLONG PreviousState  OPTIONAL)
-{
-   PKEVENT Event;
-   KPROCESSOR_MODE PreviousMode;
-   NTSTATUS Status = STATUS_SUCCESS;
-   
-   PAGED_CODE();
-
-   DPRINT("NtSetEvent(EventHandle 0%x PreviousState 0%x)\n",
-         EventHandle, PreviousState);
-
-   PreviousMode = ExGetPreviousMode();
-
-   if(PreviousState != NULL && PreviousMode == UserMode)
-   {
-     _SEH_TRY
-     {
-       ProbeForWrite(PreviousState,
-                     sizeof(LONG),
-                     sizeof(ULONG));
-     }
-     _SEH_HANDLE
-     {
-       Status = _SEH_GetExceptionCode();
-     }
-     _SEH_END;
-     
-     if(!NT_SUCCESS(Status))
-     {
-       return Status;
-     }
-   }
+            ProbeForWriteLong(PreviousState);
+         } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+            Status = _SEH_GetExceptionCode();
+
+        } _SEH_END;
+
+        if(!NT_SUCCESS(Status)) return Status;
+    }
+
+    /* Open the Object */
+    Status = ObReferenceObjectByHandle(EventHandle,
+                                       EVENT_MODIFY_STATE,
+                                       ExEventObjectType,
+                                       PreviousMode,
+                                       (PVOID*)&Event,
+                                       NULL);
+
+    /* Check for success */
+    if(NT_SUCCESS(Status)) {
+
+        /* Reset the Event */
+        LONG Prev = KeResetEvent(Event);
+        ObDereferenceObject(Event);
+
+        /* Return it */
+        if(PreviousState) {
+
+            _SEH_TRY {
 
-   Status = ObReferenceObjectByHandle(EventHandle,
-                                     EVENT_MODIFY_STATE,
-                                     ExEventObjectType,
-                                     PreviousMode,
-                                     (PVOID*)&Event,
-                                     NULL);
-   if(NT_SUCCESS(Status))
-   {
-     LONG Prev = KeSetEvent(Event, EVENT_INCREMENT, FALSE);
-     ObDereferenceObject(Event);
-
-     if(PreviousState != NULL)
-     {
-       _SEH_TRY
-       {
-         *PreviousState = Prev;
-       }
-       _SEH_HANDLE
-       {
-         Status = _SEH_GetExceptionCode();
-       }
-       _SEH_END;
-     }
+                *PreviousState = Prev;
+
+            } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+                Status = _SEH_GetExceptionCode();
+
+            } _SEH_END;
+        }
    }
 
+   /* Return Status */
    return Status;
 }
 
-
 /*
- * @unimplemented
+ * @implemented
  */
 NTSTATUS
 STDCALL
-NtTraceEvent(
-       IN ULONG TraceHandle,
-       IN ULONG Flags,
-       IN ULONG TraceHeaderLength,
-       IN struct _EVENT_TRACE_HEADER* TraceHeader
-       )
+NtSetEvent(IN HANDLE EventHandle,
+           OUT PLONG PreviousState  OPTIONAL)
 {
-       UNIMPLEMENTED;
-       return STATUS_NOT_IMPLEMENTED;
-}
+    PKEVENT Event;
+    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
+    NTSTATUS Status = STATUS_SUCCESS;
+
+    PAGED_CODE();
+    DPRINT("NtSetEvent(EventHandle 0%x PreviousState 0%x)\n",
+           EventHandle, PreviousState);
+
+    /* Check buffer validity */
+    if(PreviousState != NULL && PreviousMode != KernelMode) {
 
+        _SEH_TRY {
+
+            ProbeForWriteLong(PreviousState);
+         } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+            Status = _SEH_GetExceptionCode();
+
+        } _SEH_END;
+
+        if(!NT_SUCCESS(Status)) return Status;
+    }
+
+    /* Open the Object */
+    Status = ObReferenceObjectByHandle(EventHandle,
+                                       EVENT_MODIFY_STATE,
+                                       ExEventObjectType,
+                                       PreviousMode,
+                                       (PVOID*)&Event,
+                                       NULL);
+
+    /* Check for success */
+    if(NT_SUCCESS(Status)) {
+
+        /* Set the Event */
+        LONG Prev = KeSetEvent(Event, EVENT_INCREMENT, FALSE);
+        ObDereferenceObject(Event);
+
+        /* Return it */
+        if(PreviousState) {
+
+            _SEH_TRY {
+
+                *PreviousState = Prev;
+
+            } _SEH_EXCEPT(_SEH_ExSystemExceptionFilter) {
+
+                Status = _SEH_GetExceptionCode();
+
+            } _SEH_END;
+        }
+   }
+
+   /* Return Status */
+   return Status;
+}
 
 /* EOF */