[ros-diffs] [ion] 23254: - Add tracing in process/thread.c as well. - Add a new tracing class/macro for reference counts and add it in kill/process/thread.c. - Remove tracing TODO from kernel fun.

Author: ion
Date: Sun Jul 23 23:45:16 2006
New Revision: 23254

URL: http://svn.reactos.org/svn/reactos?rev=23254&view=rev
Log:
- Add tracing in process/thread.c as well.
- Add a new tracing class/macro for reference counts and add it in kill/process/thread.c.
- Remove tracing TODO from kernel fun.

Modified:
    trunk/reactos/ntoskrnl/KrnlFun.c
    trunk/reactos/ntoskrnl/include/internal/ps.h
    trunk/reactos/ntoskrnl/ps/kill.c
    trunk/reactos/ntoskrnl/ps/process.c
    trunk/reactos/ntoskrnl/ps/query.c
    trunk/reactos/ntoskrnl/ps/thread.c

Modified: trunk/reactos/ntoskrnl/KrnlFun.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/KrnlFun.c?rev=232…
==============================================================================
--- trunk/reactos/ntoskrnl/KrnlFun.c (original)
+++ trunk/reactos/ntoskrnl/KrnlFun.c Sun Jul 23 23:45:16 2006
@@ -27,7 +27,6 @@
 // Ps:
 //  - Figure out why processes don't die.
 //  - Generate process cookie for user-more thread.
-//  - Add tracing.
 //
 // Ob:
 //  - Possible bug in deferred deletion under Cc Rewrite branch.

Modified: trunk/reactos/ntoskrnl/include/internal/ps.h
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/include/internal/…
==============================================================================
--- trunk/reactos/ntoskrnl/include/internal/ps.h (original)
+++ trunk/reactos/ntoskrnl/include/internal/ps.h Sun Jul 23 23:45:16 2006
@@ -23,6 +23,7 @@
 #define PS_STATE_DEBUG                                  0x40
 #define PS_QUOTA_DEBUG                                  0x80
 #define PS_KILL_DEBUG                                   0x100
+#define PS_REF_DEBUG                                    0x200
 
 //
 // Debug/Tracing support
@@ -46,8 +47,13 @@
         DbgPrint(__VA_ARGS__);                              \
     }
 #endif
+#define PSREFTRACE(x)                                       \
+    PSTRACE(PS_REF_DEBUG,                                   \
+            "Pointer Count: %lx\n",                         \
+            OBJECT_TO_OBJECT_HEADER(x)->PointerCount);
 #else
 #define PSTRACE(x, ...) DPRINT(__VA_ARGS__);
+#define PSREFTRACE(x)
 #endif
 
 //

Modified: trunk/reactos/ntoskrnl/ps/kill.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ps/kill.c?rev=232…
==============================================================================
--- trunk/reactos/ntoskrnl/ps/kill.c (original)
+++ trunk/reactos/ntoskrnl/ps/kill.c Sun Jul 23 23:45:16 2006
@@ -85,6 +85,7 @@
     PAGED_CODE();
     PSTRACE(PS_KILL_DEBUG,
             "Process: %p ExitStatus: %p\n", Process, ExitStatus);
+    PSREFTRACE(Process);
 
     /* Check if this is a Critical Process */
     if (Process->BreakOnTermination)
@@ -103,7 +104,9 @@
     while (Thread)
     {
         /* Kill it */
+        PSREFTRACE(Thread);
         PspTerminateThreadByPointer(Thread, ExitStatus, FALSE);
+        PSREFTRACE(Thread);
         Thread = PsGetNextProcessThread(Process, Thread);
     }
 
@@ -111,6 +114,7 @@
     if (Process->ObjectTable) ObClearProcessHandleTable(Process);
 
     /* Return success*/
+    PSREFTRACE(Process);
     return STATUS_SUCCESS;
 }
 
@@ -181,6 +185,7 @@
 
             /* Dereference this thread */
             ObDereferenceObject(Thread);
+            PSREFTRACE(Thread);
         } while ((NextEntry != NULL) && (NextEntry != (PVOID)1));
 
         /* Remove magic value, keep looping if it got changed */
@@ -195,6 +200,7 @@
     KAPC_STATE ApcState;
     PAGED_CODE();
     PSTRACE(PS_KILL_DEBUG, "ObjectBody: %p\n", ObjectBody);
+    PSREFTRACE(Process);
 
     /* Check if it has an Active Process Link */
     if (Process->ActiveProcessLinks.Flink)
@@ -316,6 +322,7 @@
 
     /* Destroy the Quota Block */
     PspDestroyQuotaBlock(Process);
+    PSREFTRACE(Process);
 }
 
 VOID
@@ -326,6 +333,7 @@
     PEPROCESS Process = Thread->ThreadsProcess;
     PAGED_CODE();
     PSTRACE(PS_KILL_DEBUG, "ObjectBody: %p\n", ObjectBody);
+    PSREFTRACE(Thread);
     ASSERT(Thread->Tcb.Win32Thread == NULL);
 
     /* Check if we have a stack */
@@ -351,6 +359,7 @@
     PspDeleteThreadSecurity(Thread);
 
     /* Make sure the thread was inserted, before continuing */
+    PSREFTRACE(Thread);
     if (!Process) return;
 
     /* Check if the thread list is valid */
@@ -370,6 +379,8 @@
 
     /* Dereference the Process */
     ObDereferenceObject(Process);
+    PSREFTRACE(Thread);
+    PSREFTRACE(Process);
 }
 
 /*
@@ -401,6 +412,8 @@
     ASSERT((Thread) == PsGetCurrentThread());
 
     /* Can't terminate a thread if it attached another process */
+    PSREFTRACE(Thread);
+    PSREFTRACE(CurrentProcess);
     if (KeIsAttachedProcess())
     {
         /* Bugcheck */
@@ -624,6 +637,7 @@
                                                      PsW32ThreadCalloutExit);
 
     /* If we are the last thread and have a W32 Process */
+    PSREFTRACE(Thread);
     if ((Last) && (CurrentProcess->Win32Process))
     {
         /* Run it down too */
@@ -687,6 +701,8 @@
     ASSERT(Thread->Tcb.CombinedApcDisable == 0);
 
     /* Check if this is the final thread or not */
+    PSREFTRACE(Thread);
+    PSREFTRACE(CurrentProcess);
     if (Last)
     {
         /* Set the process exit time */
@@ -711,6 +727,7 @@
 
         /* Kill the process in the Object Manager */
         ObKillProcess(CurrentProcess);
+        PSREFTRACE(CurrentProcess);
 
         /* Check if we have a section object */
         if (CurrentProcess->SectionObject)
@@ -788,6 +805,8 @@
     if (Last) KeSetProcess(&CurrentProcess->Pcb, 0, FALSE);
 
     /* Terminate the Thread from the Scheduler */
+    PSREFTRACE(Thread);
+    PSREFTRACE(CurrentProcess);
     KeTerminateThread(0);
 }
 
@@ -868,6 +887,7 @@
     ULONG Flags;
     PAGED_CODE();
     PSTRACE(PS_KILL_DEBUG, "Thread: %p ExitStatus: %p\n", Thread, ExitStatus);
+    PSREFTRACE(Thread);
 
     /* Check if this is a Critical Thread, and Bugcheck */
     if (Thread->BreakOnTermination)
@@ -932,6 +952,7 @@
     ExFreePool(Apc);
 
     /* Return Status */
+    PSREFTRACE(Thread);
     return Status;
 }
 
@@ -944,6 +965,7 @@
     PAGED_CODE();
     PSTRACE(PS_KILL_DEBUG,
             "LastThread: %p Process: %p\n", LastThread, Process);
+    PSREFTRACE(Process);
 
     /* Set Process Exit flag */
     InterlockedOr((PLONG)&Process->Flags, PSF_PROCESS_EXITING_BIT);
@@ -975,6 +997,7 @@
     }
 
     /* Check if we are the last thread */
+    PSREFTRACE(Process);
     if (LastThread)
     {
         /* Check if we have to set the Timer Resolution */

Modified: trunk/reactos/ntoskrnl/ps/process.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ps/process.c?rev=…
==============================================================================
--- trunk/reactos/ntoskrnl/ps/process.c (original)
+++ trunk/reactos/ntoskrnl/ps/process.c Sun Jul 23 23:45:16 2006
@@ -97,6 +97,8 @@
     PETHREAD FoundThread = NULL;
     PLIST_ENTRY ListHead, Entry;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG,
+            "Process: %p Thread: %p\n", Process, Thread);
 
     /* Lock the process */
     KeEnterCriticalRegion();
@@ -147,6 +149,7 @@
     PLIST_ENTRY Entry, ListHead;
     PEPROCESS FoundProcess = NULL;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG, "Process: %p\n", OldProcess);
 
     /* Acquire the Active Process Lock */
     KeAcquireGuardedMutex(&PspActiveProcessMutex);
@@ -195,6 +198,7 @@
     ULONG i;
     UCHAR LocalQuantum, MemoryPriority;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG, "Process: %p Mode: %lx\n", Process, Mode);
 
     /* Check if this is a foreground process */
     if (Mode == PsProcessPriorityForeground)
@@ -256,6 +260,8 @@
     UCHAR Quantum;
     PCHAR QuantumTable;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG,
+            "%lx PrioritySeparation: %lx\n", Immediate, PrioritySeparation);
 
     /* Write the current priority separation */
     PsPrioritySeparation = PspPrioritySeparationFromMask(PrioritySeparation);
@@ -362,12 +368,12 @@
     PDBGK_DEBUG_OBJECT DebugObject;
     PSECTION_OBJECT SectionObject;
     NTSTATUS Status, AccessStatus;
-    KPROCESSOR_MODE PreviousMode;
-    PHYSICAL_ADDRESS DirectoryTableBase;
+    PHYSICAL_ADDRESS DirectoryTableBase = {{0}};
     KAFFINITY Affinity;
     HANDLE_TABLE_ENTRY CidEntry;
-    PETHREAD CurrentThread;
-    PEPROCESS CurrentProcess;
+    PETHREAD CurrentThread = PsGetCurrentThread();
+    KPROCESSOR_MODE PreviousMode = ExGetPreviousMode();
+    PEPROCESS CurrentProcess = PsGetCurrentProcess();
     ULONG MinWs, MaxWs;
     ACCESS_STATE LocalAccessState;
     PACCESS_STATE AccessState = &LocalAccessState;
@@ -377,14 +383,8 @@
     PSECURITY_DESCRIPTOR SecurityDescriptor;
     SECURITY_SUBJECT_CONTEXT SubjectContext;
     PAGED_CODE();
-    DirectoryTableBase.QuadPart = 0;
-
-    /* Get the current thread, process and cpu ring mode */
-    CurrentThread = PsGetCurrentThread();
-    ASSERT(&CurrentThread->Tcb == KeGetCurrentThread());
-    PreviousMode = ExGetPreviousMode();
-    ASSERT((CurrentThread) == PsGetCurrentThread());
-    CurrentProcess = (PEPROCESS)CurrentThread->Tcb.ApcState.Process;
+    PSTRACE(PS_PROCESS_DEBUG,
+            "ProcessHandle: %p Parent: %p\n", ProcessHandle, Parent);
 
     /* Validate flags */
     if (Flags & ~PS_ALL_FLAGS) return STATUS_INVALID_PARAMETER;
@@ -400,6 +400,7 @@
                                            (PVOID*)&Parent,
                                            NULL);
         if (!NT_SUCCESS(Status)) return Status;
+        PSREFTRACE(ParentProcess);
 
         /* If this process should be in a job but the parent isn't */
         if ((InJob) && (!Parent->Job))
@@ -418,7 +419,7 @@
         Parent = NULL;
 #ifdef CONFIG_SMP
         /*
-         * FIXME: Only the boot cpu is initialized in the early boot phase. 
+         * FIXME: Only the boot cpu is initialized in the early boot phase.
     */
         Affinity = 0xffffffff;
 #else
@@ -443,6 +444,7 @@
     if (!NT_SUCCESS(Status)) goto Cleanup;
 
     /* Clean up the Object */
+    PSREFTRACE(Process);
     RtlZeroMemory(Process, sizeof(EPROCESS));
 
     /* Initialize pushlock and rundown protection */
@@ -590,7 +592,8 @@
     Process->PriorityClass = PROCESS_PRIORITY_CLASS_NORMAL;
 
     /* Create the Process' Address Space */
-    Status = MmCreateProcessAddressSpace(Process, (PROS_SECTION_OBJECT)SectionObject);
+    Status = MmCreateProcessAddressSpace(Process,
+                                         (PROS_SECTION_OBJECT)SectionObject);
     if (!NT_SUCCESS(Status)) goto CleanupWithRef;
 
     /* Check for parent again */
@@ -690,6 +693,7 @@
     if (AccessState) SeDeleteAccessState(AccessState);
 
     /* Cleanup on failure */
+    PSREFTRACE(Process);
     if (!NT_SUCCESS(Status)) goto Cleanup;
 
     /* Compute Quantum and Priority */
@@ -762,6 +766,7 @@
     KeQuerySystemTime(&Process->CreateTime);
 
     /* Protect against bad user-mode pointer */
+    PSREFTRACE(Process);
     _SEH_TRY
     {
         /* Save the process handle */
@@ -787,10 +792,12 @@
     if (Parent) ObDereferenceObject(Parent);
 
     /* Return status to caller */
+    PSREFTRACE(Process);
+    if (Parent) PSREFTRACE(Parent);
     return Status;
 }
 
-/* PUBLIC FUNCTIONS *****************************************************************/
+/* PUBLIC FUNCTIONS **********************************************************/
 
 /*
  * @implemented
@@ -825,6 +832,7 @@
     PEPROCESS FoundProcess;
     NTSTATUS Status = STATUS_INVALID_PARAMETER;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG, "ProcessId: %p\n", ProcessId);
     KeEnterCriticalRegion();
 
     /* Get the CID Handle Entry */
@@ -867,6 +875,7 @@
     PETHREAD FoundThread;
     NTSTATUS Status = STATUS_INVALID_CID;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG, "Cid: %p\n", Cid);
     KeEnterCriticalRegion();
 
     /* Get the CID Handle Entry */
@@ -1158,6 +1167,7 @@
 {
     UCHAR Quantum;
     ULONG Priority;
+    PSTRACE(PS_PROCESS_DEBUG, "Process: %p Type: %lx\n", Process, Type);
 
     /* Compute quantum and priority */
     Priority = PspComputeQuantumAndPriority(Process, Type, &Quantum);
@@ -1173,7 +1183,7 @@
 NTAPI
 NtCreateProcessEx(OUT PHANDLE ProcessHandle,
                   IN ACCESS_MASK DesiredAccess,
-                  IN POBJECT_ATTRIBUTES ObjectAttributes  OPTIONAL,
+                  IN POBJECT_ATTRIBUTES ObjectAttributes OPTIONAL,
                   IN HANDLE ParentProcess,
                   IN ULONG Flags,
                   IN HANDLE SectionHandle OPTIONAL,
@@ -1184,6 +1194,8 @@
     KPROCESSOR_MODE PreviousMode  = ExGetPreviousMode();
     NTSTATUS Status = STATUS_SUCCESS;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG,
+            "ParentProcess: %p Flags: %lx\n", ParentProcess, Flags);
 
     /* Check if we came from user mode */
     if(PreviousMode != KernelMode)
@@ -1241,6 +1253,8 @@
                 IN HANDLE ExceptionPort OPTIONAL)
 {
     ULONG Flags = 0;
+    PSTRACE(PS_PROCESS_DEBUG,
+            "Parent: %p Attributes: %p\n", ParentProcess, ObjectAttributes);
 
     /* Set new-style flags */
     if ((ULONG)SectionHandle & 1) Flags = PS_REQUEST_BREAKAWAY;
@@ -1280,6 +1294,8 @@
     ACCESS_STATE AccessState;
     AUX_DATA AuxData;
     PAGED_CODE();
+    PSTRACE(PS_PROCESS_DEBUG,
+            "ClientId: %p Attributes: %p\n", ClientId, ObjectAttributes);
 
     /* Check if we were called from user mode */
     if (PreviousMode != KernelMode)
@@ -1409,6 +1425,8 @@
 
         /* Dereference the Process */
         ObDereferenceObject(Process);
+        PSREFTRACE(Process);
+        PSREFTRACE(Thread);
     }
     else
     {

Modified: trunk/reactos/ntoskrnl/ps/query.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ps/query.c?rev=23…
==============================================================================
--- trunk/reactos/ntoskrnl/ps/query.c (original)
+++ trunk/reactos/ntoskrnl/ps/query.c Sun Jul 23 23:45:16 2006
@@ -17,7 +17,7 @@
 #include "internal/ps_i.h"
 
 /* Debugging Level */
-ULONG PspTraceLevel = 0; //PS_KILL_DEBUG | PS_SECURITY_DEBUG;
+ULONG PspTraceLevel = 0; //PS_KILL_DEBUG | PS_REF_DEBUG;
 
 /* PRIVATE FUNCTIONS *********************************************************/
 

Modified: trunk/reactos/ntoskrnl/ps/thread.c
URL:
http://svn.reactos.org/svn/reactos/trunk/reactos/ntoskrnl/ps/thread.c?rev=2…
==============================================================================
--- trunk/reactos/ntoskrnl/ps/thread.c (original)
+++ trunk/reactos/ntoskrnl/ps/thread.c Sun Jul 23 23:45:16 2006
@@ -30,6 +30,8 @@
     PTEB Teb;
     BOOLEAN DeadThread = FALSE;
     PAGED_CODE();
+    PSTRACE(PS_THREAD_DEBUG,
+            "StartRoutine: %p StartContext: %p\n", StartRoutine,
StartContext);
 
     /* Go to Passive Level */
     KeLowerIrql(PASSIVE_LEVEL);
@@ -50,6 +52,7 @@
     }
 
     /* Check if this is a system thread, or if we're hiding */
+    PSREFTRACE(Thread);
     if (!(Thread->SystemThread) && !(Thread->HideFromDebugger))
     {
         /* We're not, so notify the debugger */
@@ -108,12 +111,15 @@
                        IN PVOID StartContext)
 {
     PETHREAD Thread;
+    PSTRACE(PS_THREAD_DEBUG,
+            "StartRoutine: %p StartContext: %p\n", StartRoutine,
StartContext);
 
     /* Unlock the dispatcher Database */
     KeLowerIrql(PASSIVE_LEVEL);
     Thread = PsGetCurrentThread();
 
     /* Make sure the thread isn't gone */
+    PSREFTRACE(Thread);
     if (!(Thread->Terminated) && !(Thread->DeadThread))
     {
         /* Call it the Start Routine */
@@ -128,7 +134,7 @@
 NTAPI
 PspCreateThread(OUT PHANDLE ThreadHandle,
                 IN ACCESS_MASK DesiredAccess,
-                IN POBJECT_ATTRIBUTES ObjectAttributes  OPTIONAL,
+                IN POBJECT_ATTRIBUTES ObjectAttributes OPTIONAL,
                 IN HANDLE ProcessHandle,
                 IN PEPROCESS TargetProcess,
                 OUT PCLIENT_ID ClientId,
@@ -153,6 +159,9 @@
     PSECURITY_DESCRIPTOR SecurityDescriptor;
     SECURITY_SUBJECT_CONTEXT SubjectContext;
     PAGED_CODE();
+    PSTRACE(PS_THREAD_DEBUG,
+            "ThreadContext: %p TargetProcess: %p ProcessHandle: %p\n",
+            ThreadContext, TargetProcess, ProcessHandle);
 
     /* If we were called from PsCreateSystemThread, then we're kernel mode */
     if (StartRoutine) PreviousMode = KernelMode;
@@ -167,6 +176,7 @@
                                            PreviousMode,
                                            (PVOID*)&Process,
                                            NULL);
+        PSREFTRACE(Process);
     }
     else
     {
@@ -175,6 +185,7 @@
         {
             /* Reference the Process by Pointer */
             ObReferenceObject(TargetProcess);
+            PSREFTRACE(TargetProcess);
             Process = TargetProcess;
             Status = STATUS_SUCCESS;
         }
@@ -191,6 +202,7 @@
     /* Also make sure that User-Mode isn't trying to create a system thread */
     if ((PreviousMode != KernelMode) && (Process == PsInitialSystemProcess))
     {
+        /* Fail */
         ObDereferenceObject(Process);
         return STATUS_INVALID_HANDLE;
     }
@@ -213,6 +225,7 @@
     }
 
     /* Zero the Object entirely */
+    PSREFTRACE(Thread);
     RtlZeroMemory(Thread, sizeof(ETHREAD));
 
     /* Initialize rundown protection */
@@ -294,6 +307,7 @@
     }
 
     /* Check if we failed */
+    PSREFTRACE(Thread);
     if (!NT_SUCCESS(Status))
     {
         /* Delete the TEB if we had done */
@@ -389,6 +403,7 @@
                             &hThread);
 
     /* Delete the access state if we had one */
+    PSREFTRACE(Thread);
     if (AccessState) SeDeleteAccessState(AccessState);
 
     /* Check for success */
@@ -440,6 +455,7 @@
     ASSERT(!(Thread->CreateTime.HighPart & 0xF0000000));
 
     /* Make sure the thread isn't dead */
+    PSREFTRACE(Thread);
     if (!Thread->DeadThread)
     {
         /* Get the thread's SD */
@@ -505,6 +521,7 @@
     }
 
     /* Dispatch thread */
+    PSREFTRACE(Thread);
     OldIrql = KeAcquireDispatcherDatabaseLock ();
     KiReadyThread(&Thread->Tcb);
     KeReleaseDispatcherDatabaseLock(OldIrql);
@@ -513,6 +530,7 @@
     ObDereferenceObject(Thread);
 
     /* Return */
+    PSREFTRACE(Thread);
     return Status;
 
     /* Most annoying failure case ever, where we undo almost all manually */
@@ -521,6 +539,7 @@
     ExReleasePushLockExclusive(&Process->ProcessLock);
 
     /* Uninitailize it */
+    PSREFTRACE(Thread);
     KeUninitThread(&Thread->Tcb);
 
     /* If we had a TEB, delete it */
@@ -531,6 +550,7 @@
 
     /* Dereference the thread and return failure */
     ObDereferenceObject(Thread);
+    PSREFTRACE(Thread);
     return STATUS_PROCESS_IS_TERMINATING;
 }
 
@@ -552,6 +572,9 @@
     PEPROCESS TargetProcess = NULL;
     HANDLE Handle = ProcessHandle;
     PAGED_CODE();
+    PSTRACE(PS_THREAD_DEBUG,
+            "ProcessHandle: %p StartRoutine: %p StartContext: %p\n",
+            ProcessHandle, StartRoutine, StartContext);
 
     /* Check if we have a handle. If not, use the System Process */
     if (!ProcessHandle)
@@ -586,6 +609,7 @@
     PETHREAD FoundThread;
     NTSTATUS Status = STATUS_INVALID_PARAMETER;
     PAGED_CODE();
+    PSTRACE(PS_THREAD_DEBUG, "ThreadId: %p\n", ThreadId);
     KeEnterCriticalRegion();
 
     /* Get the CID Handle Entry */
@@ -811,6 +835,8 @@
     INITIAL_TEB SafeInitialTeb;
     NTSTATUS Status = STATUS_SUCCESS;
     PAGED_CODE();
+    PSTRACE(PS_THREAD_DEBUG,
+            "ProcessHandle: %p Context: %p\n", ProcessHandle, ThreadContext);
 
     /* Check if this was from user-mode */
     if(KeGetPreviousMode() != KernelMode)
@@ -887,6 +913,8 @@
     ACCESS_STATE AccessState;
     AUX_DATA AuxData;
     PAGED_CODE();
+    PSTRACE(PS_THREAD_DEBUG,
+            "ClientId: %p ObjectAttributes: %p\n", ClientId,
ObjectAttributes);
 
     /* Check if we were called from user mode */
     if (PreviousMode != KernelMode)