diff --git a/trunk/KProcessHacker/hook.c b/trunk/KProcessHacker/hook.c
index 93b440524..660ad2e79 100644
--- a/trunk/KProcessHacker/hook.c
+++ b/trunk/KProcessHacker/hook.c
@@ -21,6 +21,7 @@
  */
 
 #include "include/hook.h"
+#include "include/sync.h"
 
 typedef struct _MAPPED_MDL
 {
@@ -38,10 +39,15 @@ VOID KphpFreeMappedMdl(
     PMAPPED_MDL MappedMdl
     );
 
+static KPH_PROCESSOR_LOCK HookProcessorLock;
+
 /* KphHook
  * 
  * Hooks a kernel-mode function.
- * WARNING: DO NOT HOOK A FUNCTION THAT IS CALLABLE ABOVE PASSIVE_LEVEL.
+ * WARNING: DO NOT HOOK A FUNCTION THAT IS CALLABLE ABOVE APC_LEVEL.
+ * 
+ * Thread safety: Full
+ * IRQL: <= APC_LEVEL
  */
 NTSTATUS KphHook(
     PKPH_HOOK Hook
@@ -62,27 +68,49 @@ NTSTATUS KphHook(
         return status;
     
     function = (PCHAR)mappedMdl.Address;
-    /* Raise to APC_LEVEL to prevent drivers calling the function while we're patching it. */
-    /* If they do, it's their problem because the function we're patching should only be 
-       called at PASSIVE_LEVEL anyway (see hook.h for definition of KPH_HOOK). */
-    KeRaiseIrql(APC_LEVEL, &oldIrql);
-    memcpy(Hook->Bytes, function, 5);
-    Hook->Hooked = TRUE;
-    /* jmp Target */
-    *function = 0xe9;
-    *(PULONG_PTR)(function + 1) = (ULONG_PTR)Hook->Target - (ULONG_PTR)Hook->Function - 5;
-    /* Lower the IRQL back. */
-    KeLowerIrql(oldIrql);
+    
+    /* Acquire a lock on all other processors. */
+    if (KphAcquireProcessorLock(&HookProcessorLock))
+    {
+        /* Patch the function. */
+        memcpy(Hook->Bytes, function, 5);
+        Hook->Hooked = TRUE;
+        /* jmp Target */
+        *function = 0xe9;
+        *(PULONG_PTR)(function + 1) = (ULONG_PTR)Hook->Target - (ULONG_PTR)Hook->Function - 5;
+        
+        /* Release the processor lock. */
+        KphReleaseProcessorLock(&HookProcessorLock);
+    }
+    else
+    {
+        dprintf("KphHook: Could not acquire processor lock!\n");
+        status = STATUS_INSUFFICIENT_RESOURCES;
+    }
     
     KphpFreeMappedMdl(&mappedMdl);
     
     return status;
 }
 
+/* KphHookInit
+ * 
+ * Initializes the hooking module.
+ */
+NTSTATUS KphHookInit()
+{
+    KphInitializeProcessorLock(&HookProcessorLock);
+    
+    return STATUS_SUCCESS;
+}
+
 /* KphUnhook
  * 
  * Unhooks a kernel-mode function.
- * WARNING: DO NOT UNHOOK A FUNCTION THAT IS CALLABLE ABOVE PASSIVE_LEVEL.
+ * WARNING: DO NOT UNHOOK A FUNCTION THAT IS CALLABLE ABOVE APC_LEVEL.
+ * 
+ * Thread safety: Full
+ * IRQL: <= APC_LEVEL
  */
 NTSTATUS KphUnhook(
     PKPH_HOOK Hook
@@ -104,10 +132,20 @@ NTSTATUS KphUnhook(
     if (!NT_SUCCESS(status))
         return status;
     
-    KeRaiseIrql(APC_LEVEL, &oldIrql);
-    memcpy(mappedMdl.Address, Hook->Bytes, 5);
-    Hook->Hooked = FALSE;
-    KeLowerIrql(oldIrql);
+    /* Acquire a lock on all other processors. */
+    if (KphAcquireProcessorLock(&HookProcessorLock))
+    {
+        /* Unpatch the function. */
+        memcpy(mappedMdl.Address, Hook->Bytes, 5);
+        Hook->Hooked = FALSE;
+        /* Release the processor lock. */
+        KphReleaseProcessorLock(&HookProcessorLock);
+    }
+    else
+    {
+        dprintf("KphUnhook: Could not acquire processor lock!\n");
+        status = STATUS_INSUFFICIENT_RESOURCES;
+    }
     
     KphpFreeMappedMdl(&mappedMdl);
     
@@ -117,6 +155,9 @@ NTSTATUS KphUnhook(
 /* KphpCreateMappedMdl
  * 
  * Creates and maps a MDL.
+ * 
+ * Thread safety: Full
+ * IRQL: Any
  */
 NTSTATUS KphpCreateMappedMdl(
     PVOID Address,
@@ -158,6 +199,9 @@ NTSTATUS KphpCreateMappedMdl(
 /* KphpFreeMappedMdl
  * 
  * Unmaps and frees a MDL.
+ * 
+ * Thread safety: Full
+ * IRQL: Any
  */
 VOID KphpFreeMappedMdl(
     PMAPPED_MDL MappedMdl
diff --git a/trunk/KProcessHacker/i386/kprocesshacker.sys b/trunk/KProcessHacker/i386/kprocesshacker.sys
index 26161fbc8..0b8610468 100644
Binary files a/trunk/KProcessHacker/i386/kprocesshacker.sys and b/trunk/KProcessHacker/i386/kprocesshacker.sys differ
diff --git a/trunk/KProcessHacker/include/debug.h b/trunk/KProcessHacker/include/debug.h
index 73572dfce..0a140616b 100644
--- a/trunk/KProcessHacker/include/debug.h
+++ b/trunk/KProcessHacker/include/debug.h
@@ -20,12 +20,16 @@
  * along with Process Hacker.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#ifndef _DEBUG_H
+#define _DEBUG_H
+
 #ifdef DBG
 #define dprintf(fs, ...) DbgPrint("KProcessHacker: " fs, __VA_ARGS__)
-#define dfprintf DbgPrint
 #else
 #define dprintf
-#define dfprintf DbgPrint
 #endif
 
+#define dfprintf(fs, ...) DbgPrint("KProcessHacker: " fs, __VA_ARGS__)
 #define dwprintf DbgPrint
+
+#endif
diff --git a/trunk/KProcessHacker/include/hook.h b/trunk/KProcessHacker/include/hook.h
index 072acc3a5..a218beba4 100644
--- a/trunk/KProcessHacker/include/hook.h
+++ b/trunk/KProcessHacker/include/hook.h
@@ -53,6 +53,8 @@ NTSTATUS KphHook(
     PKPH_HOOK Hook
     );
 
+NTSTATUS KphHookInit();
+
 NTSTATUS KphUnhook(
     PKPH_HOOK Hook
     );
diff --git a/trunk/KProcessHacker/include/sync.h b/trunk/KProcessHacker/include/sync.h
new file mode 100644
index 000000000..bb5cfebc0
--- /dev/null
+++ b/trunk/KProcessHacker/include/sync.h
@@ -0,0 +1,56 @@
+/*
+ * Process Hacker Driver - 
+ *   synchronization code
+ * 
+ * Copyright (C) 2009 wj32
+ * 
+ * This file is part of Process Hacker.
+ * 
+ * Process Hacker is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Process Hacker is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Process Hacker.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _SYNC_H
+#define _SYNC_H
+
+#include "kprocesshacker.h"
+
+typedef struct _KPH_PROCESSOR_LOCK
+{
+    /* Synchronizes access to the processor lock. */
+    FAST_MUTEX Mutex;
+    /* Storage allocated for DPCs. */
+    PKDPC Dpcs;
+    /* The number of currently acquired processors. */
+    LONG AcquiredProcessors;
+    /* The signal for acquired processors to be released. */
+    LONG ReleaseSignal;
+    /* The old IRQL. */
+    KIRQL OldIrql;
+    /* Whether the processor lock has been acquired. */
+    BOOLEAN Acquired;
+} KPH_PROCESSOR_LOCK, *PKPH_PROCESSOR_LOCK;
+
+BOOLEAN KphAcquireProcessorLock(
+    PKPH_PROCESSOR_LOCK ProcessorLock
+    );
+
+VOID KphInitializeProcessorLock(
+    PKPH_PROCESSOR_LOCK ProcessorLock
+    );
+
+VOID KphReleaseProcessorLock(
+    PKPH_PROCESSOR_LOCK ProcessorLock
+    );
+
+#endif
diff --git a/trunk/KProcessHacker/kprocesshacker.c b/trunk/KProcessHacker/kprocesshacker.c
index 567f5a4a6..c8a810682 100644
--- a/trunk/KProcessHacker/kprocesshacker.c
+++ b/trunk/KProcessHacker/kprocesshacker.c
@@ -34,10 +34,11 @@ typedef struct _KPH_CLIENT_ENTRY
     HANDLE ProcessId;
 } KPH_CLIENT_ENTRY, *PKPH_CLIENT_ENTRY;
 
-LIST_ENTRY ClientListHead;
-KSPIN_LOCK ClientListLock;
-NPAGED_LOOKASIDE_LIST ClientLookasideList;
+static LIST_ENTRY ClientListHead;
+static KSPIN_LOCK ClientListLock;
+static NPAGED_LOOKASIDE_LIST ClientLookasideList;
 static BOOLEAN ProtectionInitialized = FALSE;
+static FAST_MUTEX ProtectionMutex;
 
 #pragma alloc_text(PAGE, KphDispatchCreate)
 #pragma alloc_text(PAGE, KphDispatchClose)
@@ -83,6 +84,9 @@ NTSTATUS DriverEntry(PDRIVER_OBJECT DriverObject, PUNICODE_STRING RegistryPath)
         0
         );
     
+    /* Initialize process protection. */
+    ExInitializeFastMutex(&ProtectionMutex);
+    
     RtlInitUnicodeString(&deviceName, KPH_DEVICE_NAME);
     RtlInitUnicodeString(&dosDeviceName, KPH_DEVICE_DOS_NAME);
     
@@ -121,12 +125,16 @@ VOID DriverUnload(PDRIVER_OBJECT DriverObject)
     /* Destroy client list structures */
     ExDeleteNPagedLookasideList(&ClientLookasideList);
     
+    ExAcquireFastMutex(&ProtectionMutex);
+    
     if (ProtectionInitialized)
     {
         KphProtectDeinit();
         ProtectionInitialized = FALSE;
     }
     
+    ExReleaseFastMutex(&ProtectionMutex);
+    
     dprintf("Driver unloaded\n");
 }
 
@@ -161,12 +169,16 @@ NTSTATUS KphDispatchClose(PDEVICE_OBJECT DeviceObject, PIRP Irp)
 {
     NTSTATUS status = STATUS_SUCCESS;
     
+    ExAcquireFastMutex(&ProtectionMutex);
+    
     if (ProtectionInitialized)
     {
         ULONG count = KphProtectRemoveByTag(PsGetCurrentProcessId());
         dprintf("Removed %d protection entries\n", count);
     }
     
+    ExReleaseFastMutex(&ProtectionMutex);
+    
     /* Remove the client entry. */
     RemoveClientEntry(PsGetCurrentProcessId());
     
@@ -177,11 +189,15 @@ NTSTATUS KphDispatchClose(PDEVICE_OBJECT DeviceObject, PIRP Irp)
 
 VOID InitProtection()
 {
+    ExAcquireFastMutex(&ProtectionMutex);
+    
     if (!ProtectionInitialized)
     {
-        KphProtectInit();
-        ProtectionInitialized = TRUE;
+        if (NT_SUCCESS(KphProtectInit()))
+            ProtectionInitialized = TRUE;
     }
+    
+    ExReleaseFastMutex(&ProtectionMutex);
 }
 
 BOOLEAN AddClientEntry(HANDLE ProcessId)
diff --git a/trunk/KProcessHacker/protect.c b/trunk/KProcessHacker/protect.c
index a9d5a394e..f39e8593c 100644
--- a/trunk/KProcessHacker/protect.c
+++ b/trunk/KProcessHacker/protect.c
@@ -22,38 +22,38 @@
 
 #include "include/protect.h"
 
-/* ProtectedProcessRundownProtect
- * 
- * Rundown protection making sure this module doesn't deinitialize before all hook targets 
- * have finished executing and no one is accessing the lookaside list.
- */
-EX_RUNDOWN_REF ProtectedProcessRundownProtect;
-/* ProtectedProcessListHead
- * 
- * The head of the process protection linked list. Each entry stores protection 
- * information for a process.
- */
-LIST_ENTRY ProtectedProcessListHead;
-/* ProtectedProcessListLock
- * 
- * The spinlock which protects all accesses to the protected process list (even 
- * the individual entries)
- */
-KSPIN_LOCK ProtectedProcessListLock;
-/* ProtectedProcessLookasideList
- * 
- * The lookaside list for protected process entries.
- */
-NPAGED_LOOKASIDE_LIST ProtectedProcessLookasideList;
-
-KPH_HOOK ObOpenObjectByPointerHook = { 0 };
-
 BOOLEAN KphpIsCurrentProcessProtected();
 
 VOID KphpProtectRemoveEntry(
     PKPH_PROCESS_ENTRY Entry
     );
 
+/* ProtectedProcessRundownProtect
+ * 
+ * Rundown protection making sure this module doesn't deinitialize before all hook targets 
+ * have finished executing and no one is accessing the lookaside list.
+ */
+static EX_RUNDOWN_REF ProtectedProcessRundownProtect;
+/* ProtectedProcessListHead
+ * 
+ * The head of the process protection linked list. Each entry stores protection 
+ * information for a process.
+ */
+static LIST_ENTRY ProtectedProcessListHead;
+/* ProtectedProcessListLock
+ * 
+ * The spinlock which protects all accesses to the protected process list (even 
+ * the individual entries)
+ */
+static KSPIN_LOCK ProtectedProcessListLock;
+/* ProtectedProcessLookasideList
+ * 
+ * The lookaside list for protected process entries.
+ */
+static NPAGED_LOOKASIDE_LIST ProtectedProcessLookasideList;
+
+static KPH_HOOK ObOpenObjectByPointerHook = { 0 };
+
 KPH_DEFINE_HOOK_CALL(
     NTSTATUS NTAPI KphOldObOpenObjectByPointer,
     OBOPENOBJECTBYPOINTER_ARGS,
@@ -63,6 +63,8 @@ KPH_DEFINE_HOOK_CALL(
 /* KphProtectInit
  * 
  * Initializes process protection.
+ * 
+ * IRQL: <= APC_LEVEL
  */
 NTSTATUS KphProtectInit()
 {
@@ -83,6 +85,9 @@ NTSTATUS KphProtectInit()
         0
         );
     
+    /* Initialize hooking. */
+    KphHookInit();
+    
     /* Hook various functions. */
     ObOpenObjectByPointerHook.Function = ObOpenObjectByPointer;
     ObOpenObjectByPointerHook.Target = KphNewObOpenObjectByPointer;
@@ -95,14 +100,20 @@ NTSTATUS KphProtectInit()
 /* KphProtectDeinit
  * 
  * Removes process protection and frees associated structures.
+ * 
+ * IRQL: <= APC_LEVEL
  */
 NTSTATUS KphProtectDeinit()
 {
+    NTSTATUS status = STATUS_SUCCESS;
     KIRQL oldIrql;
     LARGE_INTEGER waitLi;
     
     /* Unhook. */
-    KphUnhook(&ObOpenObjectByPointerHook);
+    status = KphUnhook(&ObOpenObjectByPointerHook);
+    
+    if (!NT_SUCCESS(status))
+        return status;
     
     /* Wait for all activity to finish. */
     ExWaitForRundownProtectionRelease(&ProtectedProcessRundownProtect);
@@ -115,12 +126,15 @@ NTSTATUS KphProtectDeinit()
     /* Free all process protection entries. */
     ExDeleteNPagedLookasideList(&ProtectedProcessLookasideList);
     
-    return STATUS_SUCCESS;
+    return status;
 }
 
 /* KphNewObOpenObjectByPointer
  * 
  * New ObOpenObjectByPointer function.
+ * 
+ * Thread safety: Full
+ * IRQL: PASSIVE_LEVEL
  */
 NTSTATUS NTAPI KphNewObOpenObjectByPointer(
     OBOPENOBJECTBYPOINTER_ARGS
@@ -210,6 +224,9 @@ NTSTATUS NTAPI KphNewObOpenObjectByPointer(
 /* KphProtectAddEntry
  * 
  * Protects the specified process.
+ * 
+ * Thread safety: Full
+ * IRQL: <= DISPATCH_LEVEL
  */
 PKPH_PROCESS_ENTRY KphProtectAddEntry(
     PEPROCESS Process,
@@ -250,6 +267,9 @@ PKPH_PROCESS_ENTRY KphProtectAddEntry(
 /* KphProtectCopyEntry
  * 
  * Copies process protection data for the specified process.
+ * 
+ * Thread safety: Full
+ * IRQL: <= DISPATCH_LEVEL
  */
 BOOLEAN KphProtectCopyEntry(
     PEPROCESS Process,
@@ -285,6 +305,10 @@ BOOLEAN KphProtectCopyEntry(
 /* KphProtectFindEntry
  * 
  * Finds process protection data.
+ * 
+ * Thread safety: Limited. The returned pointer is not guaranteed to 
+ * point to a valid process entry.
+ * IRQL: <= DISPATCH_LEVEL
  */
 PKPH_PROCESS_ENTRY KphProtectFindEntry(
     PEPROCESS Process,
@@ -322,6 +346,10 @@ PKPH_PROCESS_ENTRY KphProtectFindEntry(
 /* KphProtectRemoveByProcess
  * 
  * Removes protection from the specified process.
+ * 
+ * Thread safety: Limited. Callers must synchronize remove calls such 
+ * as KphProtectRemoveByProcess and KphProtectRemoveByTag.
+ * IRQL: <= DISPATCH_LEVEL
  */
 BOOLEAN KphProtectRemoveByProcess(
     PEPROCESS Process
@@ -340,6 +368,10 @@ BOOLEAN KphProtectRemoveByProcess(
 /* KphProtectRemoveByTag
  * 
  * Removes protection from all processes with the specified tag.
+ * 
+ * Thread safety: Limited. Callers must synchronize remove calls such 
+ * as KphProtectRemoveByProcess and KphProtectRemoveByTag.
+ * IRQL: <= DISPATCH_LEVEL
  */
 ULONG KphProtectRemoveByTag(
     HANDLE Tag
@@ -362,6 +394,9 @@ ULONG KphProtectRemoveByTag(
 /* KphpIsCurrentProcessProtected
  * 
  * Determines whether the current process is protected.
+ * 
+ * Thread safety: Full
+ * IRQL: <= DISPATCH_LEVEL
  */
 BOOLEAN KphpIsCurrentProcessProtected()
 {
@@ -371,6 +406,9 @@ BOOLEAN KphpIsCurrentProcessProtected()
 /* KphpProtectRemoveEntry
  * 
  * Removes and frees process protection data.
+ * 
+ * Thread safety: Full
+ * IRQL: <= DISPATCH_LEVEL
  */
 VOID KphpProtectRemoveEntry(
     PKPH_PROCESS_ENTRY Entry
diff --git a/trunk/KProcessHacker/sources b/trunk/KProcessHacker/sources
index d46de85aa..1be5adcb7 100644
--- a/trunk/KProcessHacker/sources
+++ b/trunk/KProcessHacker/sources
@@ -11,6 +11,7 @@ SOURCES= \
     kph.c \
     hook.c \
     protect.c \
+    sync.c \
     mm.c \
     ob.c \
     ps.c \
diff --git a/trunk/KProcessHacker/sync.c b/trunk/KProcessHacker/sync.c
new file mode 100644
index 000000000..dfabc8190
--- /dev/null
+++ b/trunk/KProcessHacker/sync.c
@@ -0,0 +1,234 @@
+/*
+ * Process Hacker Driver - 
+ *   synchronization code
+ * 
+ * Copyright (C) 2009 wj32
+ * 
+ * This file is part of Process Hacker.
+ * 
+ * Process Hacker is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Process Hacker is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Process Hacker.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "include/sync.h"
+#include "include/debug.h"
+
+ULONG KphpCountBits(
+    ULONG_PTR Number
+    );
+
+VOID KphpProcessorLockDpc(
+    PKDPC Dpc,
+    PVOID DeferredContext,
+    PVOID SystemArgument1,
+    PVOID SystemArgument2
+    );
+
+/* KphAcquireProcessorLock
+ * 
+ * Raises the IRQL to DISPATCH_LEVEL and prevents threads from 
+ * executing on other processors until the processor lock is released. 
+ * Blocks if the supplied processor lock is already in use.
+ * 
+ * ProcessorLock: A processor lock structure that is present in 
+ * non-paged memory.
+ * 
+ * Thread safety: Full
+ * IRQL: <= APC_LEVEL
+ */
+BOOLEAN KphAcquireProcessorLock(
+    PKPH_PROCESSOR_LOCK ProcessorLock
+    )
+{
+    ULONG i;
+    ULONG numberProcessors;
+    ULONG currentProcessor;
+    
+    /* Acquire the processor lock mutex. */
+    ExAcquireFastMutex(&ProcessorLock->Mutex);
+    
+    /* Reset some state. */
+    ASSERT(ProcessorLock->AcquiredProcessors == 0);
+    ProcessorLock->AcquiredProcessors = 0;
+    ProcessorLock->ReleaseSignal = 0;
+    
+    /* Get the number of processors. */
+    numberProcessors = KphpCountBits(KeQueryActiveProcessors());
+    
+    /* If there's only one processor we can simply raise the IRQL and exit. */
+    if (numberProcessors == 1)
+    {
+        dprintf("KphAcquireProcessorLock: Only one processor, raising IRQL and exiting...\n");
+        KeRaiseIrql(DISPATCH_LEVEL, &ProcessorLock->OldIrql);
+        ProcessorLock->Acquired = TRUE;
+        
+        return TRUE;
+    }
+    
+    /* Allocate storage for the DPCs. */
+    ProcessorLock->Dpcs = ExAllocatePoolWithTag(
+        NonPagedPool,
+        sizeof(KDPC) * numberProcessors,
+        KPH_TAG
+        );
+    
+    if (!ProcessorLock->Dpcs)
+    {
+        dprintf("KphAcquireProcessorLock: Could not allocate storage for DPCs!\n");
+        return FALSE;
+    }
+    
+    /* Initialize the DPCs. */
+    for (i = 0; i < numberProcessors; i++)
+    {
+        KeInitializeDpc(&ProcessorLock->Dpcs[i], KphpProcessorLockDpc, NULL);
+        KeSetTargetProcessorDpc(&ProcessorLock->Dpcs[i], (CCHAR)i);
+        KeSetImportanceDpc(&ProcessorLock->Dpcs[i], HighImportance);
+    }
+    
+    /* Raise the IRQL to DISPATCH_LEVEL to prevent context switching. */
+    KeRaiseIrql(DISPATCH_LEVEL, &ProcessorLock->OldIrql);
+    /* Get the current processor number. */
+    currentProcessor = KeGetCurrentProcessorNumber();
+    
+    /* Queue the DPCs (except on the current processor). */
+    for (i = 0; i < numberProcessors; i++)
+        if (i != currentProcessor)
+            KeInsertQueueDpc(&ProcessorLock->Dpcs[i], ProcessorLock, NULL);
+    
+    /* Spinwait for all (other) processors to be acquired. */
+    while (InterlockedCompareExchange(
+        &ProcessorLock->AcquiredProcessors,
+        numberProcessors - 1,
+        numberProcessors - 1
+        ) != numberProcessors - 1)
+        NOTHING;
+    
+    dprintf("KphAcquireProcessorLock: All processors acquired.\n");
+    ProcessorLock->Acquired = TRUE;
+    
+    return TRUE;
+}
+
+/* KphInitializeProcessorLock
+ * 
+ * Initializes a processor lock.
+ * 
+ * ProcessorLock: A processor lock structure that is present in 
+ * non-paged memory.
+ * 
+ * IRQL: Any
+ */
+VOID KphInitializeProcessorLock(
+    PKPH_PROCESSOR_LOCK ProcessorLock
+    )
+{
+    ExInitializeFastMutex(&ProcessorLock->Mutex);
+    ProcessorLock->Dpcs = NULL;
+    ProcessorLock->AcquiredProcessors = 0;
+    ProcessorLock->ReleaseSignal = 0;
+    ProcessorLock->OldIrql = PASSIVE_LEVEL;
+    ProcessorLock->Acquired = FALSE;
+}
+
+/* KphReleaseProcessorLock
+ * 
+ * Allows threads to execute on other processors and restores the IRQL.
+ * 
+ * ProcessorLock: A processor lock structure that is present in 
+ * non-paged memory.
+ * 
+ * Thread safety: Full
+ * IRQL: <= APC_LEVEL
+ */
+VOID KphReleaseProcessorLock(
+    PKPH_PROCESSOR_LOCK ProcessorLock
+    )
+{
+    if (!ProcessorLock->Acquired)
+        return;
+    
+    /* Signal for the acquired processors to be released. */
+    InterlockedExchange(&ProcessorLock->ReleaseSignal, 1);
+    
+    /* Spinwait for all acquired processors to be released. */
+    while (InterlockedCompareExchange(
+        &ProcessorLock->AcquiredProcessors,
+        0,
+        0
+        ))
+        NOTHING;
+    
+    dprintf("KphReleaseProcessorLock: All processors released.\n");
+    
+    /* Restore the old IRQL (should always be APC_LEVEL due to the 
+     * fast mutex). */
+    KeLowerIrql(ProcessorLock->OldIrql);
+    
+    /* Free the DPCs if necessary. */
+    if (ProcessorLock->Dpcs != NULL)
+    {
+        ExFreePoolWithTag(ProcessorLock->Dpcs, KPH_TAG);
+        ProcessorLock->Dpcs = NULL;
+    }
+    
+    ProcessorLock->Acquired = FALSE;
+    
+    /* Release the processor lock mutex. */
+    ExReleaseFastMutex(&ProcessorLock->Mutex);
+}
+
+ULONG KphpCountBits(
+    ULONG_PTR Number
+    )
+{
+    ULONG count = 0;
+    
+    while (Number)
+    {
+        count++;
+        Number &= Number - 1;
+    }
+    
+    return count;
+}
+
+VOID KphpProcessorLockDpc(
+    PKDPC Dpc,
+    PVOID DeferredContext,
+    PVOID SystemArgument1,
+    PVOID SystemArgument2
+    )
+{
+    PKPH_PROCESSOR_LOCK processorLock = (PKPH_PROCESSOR_LOCK)SystemArgument1;
+    
+    ASSERT(processorLock != NULL);
+    
+    dprintf("KphpProcessorLockDpc: Acquiring processor %d.\n", KeGetCurrentProcessorNumber());
+    
+    /* Increase the number of acquired processors. */
+    InterlockedIncrement(&processorLock->AcquiredProcessors);
+    
+    /* Spin until we get the signal to release the processor. */
+    while (!InterlockedCompareExchange(
+        &processorLock->ReleaseSignal,
+        1,
+        1
+        ))
+        NOTHING;
+    
+    /* Decrease the number of acquired processors. */
+    InterlockedDecrement(&processorLock->AcquiredProcessors);
+    
+    dprintf("KphpProcessorLockDpc: Releasing processor %d.\n", KeGetCurrentProcessorNumber());
+}
diff --git a/trunk/KProcessHacker/version.c b/trunk/KProcessHacker/version.c
index 79d341e75..8e26780fb 100644
--- a/trunk/KProcessHacker/version.c
+++ b/trunk/KProcessHacker/version.c
@@ -87,7 +87,7 @@ NTSTATUS KvInit()
     minorVersion = RtlWindowsVersion.dwMinorVersion;
     servicePack = RtlWindowsVersion.wServicePackMajor;
     buildNumber = RtlWindowsVersion.dwBuildNumber;
-    dprintf("Windows %d.%d, SP%d.%d, build %d\n",
+    dfprintf("Windows %d.%d, SP%d.%d, build %d\n",
         majorVersion, minorVersion, servicePack,
         RtlWindowsVersion.wServicePackMinor, buildNumber
         );
diff --git a/trunk/ProcessHacker.Native/Api/NativeDefinitions.cs b/trunk/ProcessHacker.Native/Api/NativeDefinitions.cs
index 6ff716a71..9b50a8f52 100644
--- a/trunk/ProcessHacker.Native/Api/NativeDefinitions.cs
+++ b/trunk/ProcessHacker.Native/Api/NativeDefinitions.cs
@@ -31,14 +31,23 @@ namespace ProcessHacker.Native.Api
 
     public partial class Win32
     {
+        public const int FlsMaximumAvailable = 128;
+#if _X64
+        public const int GdiHandleBufferSize = 60;
+#else
+        public const int GdiHandleBufferSize = 34;
+#endif
         public const int MaximumSupportedExtension = 512;
         public const int SecurityDescriptorMinLength = 20;
         public const int SecurityDescriptorRevision = 1;
-        public readonly int SecurityMaxSidSize =
+        public static readonly int SecurityMaxSidSize =
             Marshal.SizeOf(typeof(Sid)) - sizeof(int) + (SidMaxSubAuthorities * sizeof(int));
         public const int SidMaxSubAuthorities = 15;
         public const int SidRecommendedSubAuthorities = 1;
         public const int SidRevision = 1;
         public const int SizeOf80387Registers = 80;
+
+        public static readonly IntPtr PebLdrOffset = Marshal.OffsetOf(typeof(Peb), "Ldr");
+        public static readonly IntPtr PebProcessParametersOffset = Marshal.OffsetOf(typeof(Peb), "ProcessParameters");
     }
 }
diff --git a/trunk/ProcessHacker.Native/Api/NativeStructs.cs b/trunk/ProcessHacker.Native/Api/NativeStructs.cs
index 05e80422c..e39f0e785 100644
--- a/trunk/ProcessHacker.Native/Api/NativeStructs.cs
+++ b/trunk/ProcessHacker.Native/Api/NativeStructs.cs
@@ -392,6 +392,98 @@ namespace ProcessHacker.Native.Api
         public int NonPagedPoolUsage;
     }
 
+    [StructLayout(LayoutKind.Sequential)]
+    public struct Peb
+    {
+        [MarshalAs(UnmanagedType.I1)]
+        public bool InheritedAddressSpace;
+        [MarshalAs(UnmanagedType.I1)]
+        public bool ReadImageFileExecOptions;
+        [MarshalAs(UnmanagedType.I1)]
+        public bool BeingDebugged;
+        [MarshalAs(UnmanagedType.I1)]
+        public bool BitField;
+        public IntPtr Mutant;
+
+        public IntPtr ImageBaseAddress;
+        public IntPtr Ldr; // ptr to PebLdrData
+        public IntPtr ProcessParameters; // ptr to RtlUserProcessParameters
+        public IntPtr SubSystemData;
+        public IntPtr ProcessHeap;
+        public IntPtr FastPebLock;
+        public IntPtr AtlThunkSListPtr;
+        public IntPtr SparePrt2;
+        public int EnvironmentUpdateCount;
+        public IntPtr KernelCallbackTable;
+        public int SystemReserved;
+        public int SpareUlong;
+        public IntPtr FreeList;
+        public int TlsExpansionCounter;
+        public IntPtr TlsBitmap;
+        public unsafe fixed int TlsBitmapBits[2];
+        public IntPtr ReadOnlySharedMemoryBase;
+        public IntPtr ReadOnlySharedMemoryHeap;
+        public IntPtr ReadOnlyStaticServerData;
+        public IntPtr AnsiCodePageData;
+        public IntPtr OemCodePageData;
+        public IntPtr UnicodeCaseTableData;
+
+        public int NumberOfProcessors;
+        public int NtGlobalFlag;
+
+        public long CriticalSectionTimeout;
+        public IntPtr HeapSegmentReserve;
+        public IntPtr HeapSegmentCommit;
+        public IntPtr HeapDeCommitTotalFreeThreshold;
+        public IntPtr HeapDeCommitFreeBlockThreshold;
+
+        public int NumberOfHeaps;
+        public int MaximumNumberOfHeaps;
+        public IntPtr ProcessHeaps;
+
+        public IntPtr GdiSharedHandleTable;
+        public IntPtr ProcessStarterHelper;
+        public int GdiDCAttributeList;
+        public IntPtr LoaderLock;
+
+        public int OSMajorVersion;
+        public int OSMinorVersion;
+        public short OSBuildNumber;
+        public short OSCSDVersion;
+        public int OSPlatformId;
+        public int ImageSubsystem;
+        public int ImageSubsystemMajorVersion;
+        public int ImageSubsystemMinorVersion;
+        public IntPtr ImageProcessAffinityMask;
+        public unsafe fixed byte GdiHandleBuffer[Win32.GdiHandleBufferSize];
+        public IntPtr PostProcessInitRoutine;
+
+        public IntPtr TlsExpansionBitmap;
+        public unsafe fixed int TlsExpansionBitmapBits[32];
+
+        public int SessionId;
+
+        public long AppCompatFlags;
+        public long AppCompatFlagsUser;
+        public IntPtr pShimData;
+        public IntPtr AppCompatInfo;
+
+        public UnicodeString CSDVersion;
+
+        public IntPtr ActivationContextData;
+        public IntPtr ProcessAssemblyStorageMap;
+        public IntPtr SystemDefaultActivationContextData;
+        public IntPtr SystemAssemblyStorageMap;
+
+        public IntPtr MinimumStackCommit;
+
+        public IntPtr FlsCallback;
+        public ListEntry FlsListHead;
+        public IntPtr FlsBitmap;
+        public unsafe fixed int FlsBitmapBits[Win32.FlsMaximumAvailable / (sizeof(int) * 8)];
+        public int FlsHighIndex;
+    }
+
     [StructLayout(LayoutKind.Sequential)]
     public struct PebLdrData
     {
diff --git a/trunk/ProcessHacker.Native/Objects/ProcessHandle.cs b/trunk/ProcessHacker.Native/Objects/ProcessHandle.cs
index b01926d8b..1b8a32305 100644
--- a/trunk/ProcessHacker.Native/Objects/ProcessHandle.cs
+++ b/trunk/ProcessHacker.Native/Objects/ProcessHandle.cs
@@ -401,11 +401,11 @@ namespace ProcessHacker.Native.Objects
 
         private unsafe void EnumModulesNative(EnumModulesDelegate enumModulesCallback)
         {
-            byte* buffer = stackalloc byte[4];
+            byte* buffer = stackalloc byte[IntPtr.Size];
 
-            this.ReadMemory(this.GetBasicInformation().PebBaseAddress.Increment(0xc), buffer, 4);
+            this.ReadMemory(this.GetBasicInformation().PebBaseAddress.Increment(Win32.PebLdrOffset), buffer, IntPtr.Size);
 
-            IntPtr loaderData = new IntPtr(*(int*)buffer);
+            IntPtr loaderData = *(IntPtr*)buffer;
 
             PebLdrData* data = stackalloc PebLdrData[1];
             this.ReadMemory(loaderData, data, Marshal.SizeOf(typeof(PebLdrData)));
@@ -925,7 +925,7 @@ namespace ProcessHacker.Native.Objects
              * +0c PVOID LoaderData;
              * +10 PRTL_USER_PROCESS_PARAMETERS ProcessParameters; 
              */
-            this.ReadMemory(pebBaseAddress.Increment(0x10), buffer, IntPtr.Size);
+            this.ReadMemory(pebBaseAddress.Increment(Win32.PebProcessParametersOffset), buffer, IntPtr.Size);
             IntPtr processParameters = *(IntPtr*)buffer;
 
             // Read length (in bytes) of string. The offset of the UNICODE_STRING structure is 
@@ -941,7 +941,7 @@ namespace ProcessHacker.Native.Objects
             byte[] stringData = new byte[stringLength];
 
             // read address of string
-            this.ReadMemory(processParameters.Increment((int)offset + 0x4), buffer, 4);
+            this.ReadMemory(processParameters.Increment((int)offset + 0x4), buffer, IntPtr.Size);
             IntPtr stringAddr = *(IntPtr*)buffer;
 
             // read string and decode it