diff --git a/reactos/include/ddk/defines.h b/reactos/include/ddk/defines.h
index 52352569d31..05bb8ac5e77 100644
--- a/reactos/include/ddk/defines.h
+++ b/reactos/include/ddk/defines.h
@@ -207,6 +207,8 @@ enum
    IRP_MN_POWER_SEQUENCE,
 };
 
+
+/* Values returned by KeGetPreviousMode() */
 #define KernelMode (0)
 #define UserMode   (1)
 
diff --git a/reactos/include/ddk/kefuncs.h b/reactos/include/ddk/kefuncs.h
index bf89c8c75d5..bd211f110ac 100644
--- a/reactos/include/ddk/kefuncs.h
+++ b/reactos/include/ddk/kefuncs.h
@@ -44,6 +44,7 @@ KIRQL KeGetCurrentIrql(VOID);
 ULONG KeGetCurrentProcessorNumber(VOID);
 ULONG KeGetDcacheFillSize(VOID);
 PKTHREAD KeGetCurrentThread(VOID);
+ULONG KeGetPreviousMode(VOID);
 VOID KeInitializeCallbackRecord(PKBUGCHECK_CALLBACK_RECORD CallbackRecord);
 VOID KeInitializeDeviceQueue(PKDEVICE_QUEUE DeviceQueue);
 VOID KeInitializeDpc(PKDPC Dpc, PKDEFERRED_ROUTINE DeferredRoutine,
diff --git a/reactos/include/internal/ps.h b/reactos/include/internal/ps.h
index c81b1b25d96..00fbcc40d96 100644
--- a/reactos/include/internal/ps.h
+++ b/reactos/include/internal/ps.h
@@ -6,8 +6,10 @@
 extern PEPROCESS SystemProcess;
 extern HANDLE SystemProcessHandle;
 
-extern POBJECT_TYPE PsThreadType;
-extern POBJECT_TYPE PsProcessType;
+/* ntoskrnl/ps/thread.c */
+extern POBJECT_TYPE	PsThreadType;
+extern POBJECT_TYPE	PsProcessType;
+extern PETHREAD		CurrentThread;
 
 void PsInitThreadManagment(void);
 VOID PsInitProcessManagment(VOID);
diff --git a/reactos/ntoskrnl/ntoskrnl.def b/reactos/ntoskrnl/ntoskrnl.def
index db69f7e01f7..54a9751dc10 100644
--- a/reactos/ntoskrnl/ntoskrnl.def
+++ b/reactos/ntoskrnl/ntoskrnl.def
@@ -70,6 +70,7 @@ KeBugCheck
 KeBugCheckEx
 KeFlushIoBuffers
 KeGetCurrentIrql
+KeGetPreviousMode = KeGetPreviousMode@0
 KeInitializeDpc
 KeInitializeEvent
 KeInitializeSpinLock
diff --git a/reactos/ntoskrnl/ps/thread.c b/reactos/ntoskrnl/ps/thread.c
index 38e20c07c1b..e838472ba9f 100644
--- a/reactos/ntoskrnl/ps/thread.c
+++ b/reactos/ntoskrnl/ps/thread.c
@@ -50,7 +50,7 @@ static BOOLEAN DoneInitYet = FALSE;
 ULONG PiNrThreads = 0;
 ULONG PiNrRunnableThreads = 0;
 
-static PETHREAD CurrentThread = NULL;
+PETHREAD CurrentThread = NULL;
 
 static ULONG PiNextThreadUniqueId = 0;
 
diff --git a/reactos/ntoskrnl/ps/tinfo.c b/reactos/ntoskrnl/ps/tinfo.c
index 3d4de0b9f4d..0d78a079a2d 100644
--- a/reactos/ntoskrnl/ps/tinfo.c
+++ b/reactos/ntoskrnl/ps/tinfo.c
@@ -18,6 +18,7 @@
 /* FUNCTIONS *****************************************************************/
 
 NTSTATUS
+STDCALL
 NtSetInformationThread (
 	HANDLE		ThreadHandle,
 	THREADINFOCLASS	ThreadInformationClass,
@@ -25,85 +26,95 @@ NtSetInformationThread (
 	ULONG		ThreadInformationLength
 	)
 {
-   PETHREAD Thread;
-   NTSTATUS Status;
-   PTHREAD_BASIC_INFORMATION ThreadBasicInformationP;
+	PETHREAD			Thread;
+	NTSTATUS			Status;
+	PTHREAD_BASIC_INFORMATION	ThreadBasicInformationP;
    
-   Status = ObReferenceObjectByHandle(ThreadHandle,
-				      THREAD_SET_INFORMATION,
-				      PsThreadType,
-				      UserMode,
-				      (PVOID*)&Thread,
-				      NULL);
-   if (Status != STATUS_SUCCESS)
-     {
-	return(Status);
-     }
+	Status = ObReferenceObjectByHandle(
+			ThreadHandle,
+			THREAD_SET_INFORMATION,
+			PsThreadType,
+			UserMode,
+			(PVOID*) & Thread,
+			NULL
+			);
+	if (Status != STATUS_SUCCESS)
+	{
+		return Status;
+	}
    
-   switch (ThreadInformationClass)
-     {
-      case ThreadBasicInformation:
-	ThreadBasicInformationP = (PTHREAD_BASIC_INFORMATION)ThreadInformation;
-	ThreadBasicInformationP->ExitStatus = Thread->ExitStatus;
-	ThreadBasicInformationP->TebBaseAddress = Thread->Tcb.Teb;
-	ThreadBasicInformationP->AffinityMask = Thread->Tcb.Affinity;
-	ThreadBasicInformationP->BasePriority = Thread->Tcb.BasePriority;
-	ThreadBasicInformationP->UniqueThreadId = (ULONG)
-	  Thread->Cid.UniqueThread;
-	Status = STATUS_SUCCESS;
-	break;
+	switch (ThreadInformationClass)
+	{
+	case ThreadBasicInformation:
+		ThreadBasicInformationP = 
+			(PTHREAD_BASIC_INFORMATION) ThreadInformation;
+		ThreadBasicInformationP->ExitStatus = 
+			Thread->ExitStatus;
+		ThreadBasicInformationP->TebBaseAddress = 
+			Thread->Tcb.Teb;
+		ThreadBasicInformationP->AffinityMask = 
+			Thread->Tcb.Affinity;
+		ThreadBasicInformationP->BasePriority = 
+			Thread->Tcb.BasePriority;
+		ThreadBasicInformationP->UniqueThreadId = 
+			(ULONG) Thread->Cid.UniqueThread;
+		Status = STATUS_SUCCESS;
+		break;
 	
-      case ThreadTimes:
-	break;
+	case ThreadTimes:
+		break;
 	
-      case ThreadPriority:
-	KeSetPriorityThread(&Thread->Tcb,*(KPRIORITY *)ThreadInformation);
-	Status = STATUS_SUCCESS;
-	break;
+	case ThreadPriority:
+		KeSetPriorityThread(
+			& Thread->Tcb,
+			* (KPRIORITY *) ThreadInformation 
+			);
+		Status = STATUS_SUCCESS;
+		break;
 	  
-      case ThreadBasePriority:
-	break;
+	case ThreadBasePriority:
+		break;
 	
-      case ThreadAffinityMask:
-	break;
+	case ThreadAffinityMask:
+		break;
 	
-      case ThreadImpersonationToken:
-	break;
+	case ThreadImpersonationToken:
+		break;
 	
-      case ThreadDescriptorTableEntry:
-	UNIMPLEMENTED;
-	break;
+	case ThreadDescriptorTableEntry:
+		UNIMPLEMENTED;
+		break;
 	
-      case ThreadEventPair:
-	UNIMPLEMENTED;
-	break;
+	case ThreadEventPair:
+		UNIMPLEMENTED;
+		break;
 	
-      case ThreadQuerySetWin32StartAddress:
-	break;
+	case ThreadQuerySetWin32StartAddress:
+		break;
 	
-      case ThreadZeroTlsCell:
-	break;
+	case ThreadZeroTlsCell:
+		break;
 	
-      case ThreadPerformanceCount:
-	break;
+	case ThreadPerformanceCount:
+		break;
 	
-      case ThreadAmILastThread:
-	break;	
+	case ThreadAmILastThread:
+		break;	
 	
-      case ThreadPriorityBoost:
-	break;
+	case ThreadPriorityBoost:
+		break;
 	
-      default:
-	Status = STATUS_UNSUCCESSFUL;
-     }
-   ObDereferenceObject(Thread);
-   return(Status);
+	default:
+		Status = STATUS_UNSUCCESSFUL;
+	}
+	ObDereferenceObject(Thread);
+	return Status;
 }
 
 
 NTSTATUS
 STDCALL
-NtQueryInformationThread(
+NtQueryInformationThread (
 	IN	HANDLE		ThreadHandle,
 	IN	THREADINFOCLASS	ThreadInformationClass,
 	OUT	PVOID		ThreadInformation,
@@ -112,3 +123,15 @@ NtQueryInformationThread(
 {
 	UNIMPLEMENTED
 }
+
+
+ULONG
+STDCALL
+KeGetPreviousMode (VOID)
+{
+	/* CurrentThread is in ntoskrnl/ps/thread.c */
+	return (ULONG) CurrentThread->Tcb.PreviousMode;
+}
+
+
+/* EOF */