Index: /trunk/src/VBox/Runtime/Makefile.kmk
===================================================================
--- /trunk/src/VBox/Runtime/Makefile.kmk	(revision 58268)
+++ /trunk/src/VBox/Runtime/Makefile.kmk	(revision 58269)
@@ -2098,4 +2098,5 @@
 	nt/RTErrConvertFromNtStatus.cpp \
 	r0drv/generic/threadctxhooks-r0drv-generic.cpp \
+	r0drv/alloc-ef-r0drv.cpp \
 	r0drv/memobj-r0drv.cpp \
 	r0drv/mpnotification-r0drv.c \
@@ -2159,4 +2160,5 @@
 	r0drv/darwin/threadpreempt-r0drv-darwin.cpp \
 	r0drv/darwin/time-r0drv-darwin.cpp \
+	r0drv/alloc-ef-r0drv.cpp \
 	r0drv/memobj-r0drv.cpp \
 	r0drv/powernotification-r0drv.c
@@ -2255,4 +2257,5 @@
 	r0drv/freebsd/mp-r0drv-freebsd.c \
 	generic/timer-generic.cpp \
+	r0drv/alloc-ef-r0drv.cpp \
 	r0drv/memobj-r0drv.cpp \
 	r0drv/powernotification-r0drv.c
Index: /trunk/src/VBox/Runtime/include/internal/mem.h
===================================================================
--- /trunk/src/VBox/Runtime/include/internal/mem.h	(revision 58268)
+++ /trunk/src/VBox/Runtime/include/internal/mem.h	(revision 58269)
@@ -53,4 +53,20 @@
 
 
+#ifdef IN_RING0
+/** @def RTR0MEM_WITH_EF_APIS
+ * Enables the electrict fence APIs.
+ *
+ * Requires working rtR0MemObjNativeProtect implementation, thus the current
+ * OS restrictions.
+ */
+# if defined(RT_OS_DARWIN) || defined(RT_OS_FREEBSD) || defined(DOXYGEN_RUNNING)
+#  define RTR0MEM_WITH_EF_APIS
+# endif
+# ifdef RTR0MEM_WITH_EF_APIS
+DECLHIDDEN(void)    rtR0MemEfInit(void);
+DECLHIDDEN(void)    rtR0MemEfTerm(void);
+# endif
+#endif
+
 RT_C_DECLS_END
 
Index: /trunk/src/VBox/Runtime/r0drv/alloc-ef-r0drv.cpp
===================================================================
--- /trunk/src/VBox/Runtime/r0drv/alloc-ef-r0drv.cpp	(revision 58269)
+++ /trunk/src/VBox/Runtime/r0drv/alloc-ef-r0drv.cpp	(revision 58269)
@@ -0,0 +1,943 @@
+/* $Id$ */
+/** @file
+ * IPRT - Memory Allocation, electric fence for ring-0 drivers.
+ */
+
+/*
+ * Copyright (C) 2006-2015 Oracle Corporation
+ *
+ * This file is part of VirtualBox Open Source Edition (OSE), as
+ * available from http://www.virtualbox.org. This file is free software;
+ * you can redistribute it and/or modify it under the terms of the GNU
+ * General Public License (GPL) as published by the Free Software
+ * Foundation, in version 2 as it comes in the "COPYING" file of the
+ * VirtualBox OSE distribution. VirtualBox OSE is distributed in the
+ * hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
+ *
+ * The contents of this file may alternatively be used under the terms
+ * of the Common Development and Distribution License Version 1.0
+ * (CDDL) only, as it comes in the "COPYING.CDDL" file of the
+ * VirtualBox OSE distribution, in which case the provisions of the
+ * CDDL are applicable instead of those of the GPL.
+ *
+ * You may elect to license modified versions of this file under the
+ * terms and conditions of either the GPL or the CDDL or both.
+ */
+
+
+/*********************************************************************************************************************************
+*   Header Files                                                                                                                 *
+*********************************************************************************************************************************/
+#include "internal/iprt.h"
+#include <iprt/mem.h>
+#include <iprt/memobj.h>
+#include <iprt/log.h>
+#include <iprt/asm.h>
+#include <iprt/thread.h>
+#include <VBox/sup.h>
+#include <iprt/err.h>
+
+#include <iprt/alloc.h>
+#include <iprt/assert.h>
+#include <iprt/param.h>
+#include <iprt/string.h>
+
+
+
+/*******************************************************************************
+*   Defined Constants And Macros                                               *
+*******************************************************************************/
+#if defined(DOXYGEN_RUNNING)
+# define RTR0MEM_EF_IN_FRONT
+#endif
+
+/** @def RTR0MEM_EF_SIZE
+ * The size of the fence. This must be page aligned.
+ */
+#define RTR0MEM_EF_SIZE             PAGE_SIZE
+
+/** @def RTR0MEM_EF_ALIGNMENT
+ * The allocation alignment, power of two of course.
+ *
+ * Use this for working around misaligned sizes, usually stemming from
+ * allocating a string or something after the main structure.  When you
+ * encounter this, please fix the allocation to RTMemAllocVar or RTMemAllocZVar.
+ */
+#if 0
+# define RTR0MEM_EF_ALIGNMENT       (ARCH_BITS / 8)
+#else
+# define RTR0MEM_EF_ALIGNMENT       1
+#endif
+
+/** @def RTR0MEM_EF_IN_FRONT
+ * Define this to put the fence up in front of the block.
+ * The default (when this isn't defined) is to up it up after the block.
+ */
+//# define RTR0MEM_EF_IN_FRONT
+
+/** @def RTR0MEM_EF_FREE_DELAYED
+ * This define will enable free() delay and protection of the freed data
+ * while it's being delayed. The value of RTR0MEM_EF_FREE_DELAYED defines
+ * the threshold of the delayed blocks.
+ * Delayed blocks does not consume any physical memory, only virtual address space.
+ */
+#define RTR0MEM_EF_FREE_DELAYED     (20 * _1M)
+
+/** @def RTR0MEM_EF_FREE_FILL
+ * This define will enable memset(,RTR0MEM_EF_FREE_FILL,)'ing the user memory
+ * in the block before freeing/decommitting it. This is useful in GDB since GDB
+ * appears to be able to read the content of the page even after it's been
+ * decommitted.
+ */
+#define RTR0MEM_EF_FREE_FILL        'f'
+
+/** @def RTR0MEM_EF_FILLER
+ * This define will enable memset(,RTR0MEM_EF_FILLER,)'ing the allocated
+ * memory when the API doesn't require it to be zero'd.
+ */
+#define RTR0MEM_EF_FILLER           0xef
+
+/** @def RTR0MEM_EF_NOMAN_FILLER
+ * This define will enable memset(,RTR0MEM_EF_NOMAN_FILLER,)'ing the
+ * unprotected but not allocated area of memory, the so called no man's land.
+ */
+#define RTR0MEM_EF_NOMAN_FILLER     0xaa
+
+/** @def RTR0MEM_EF_FENCE_FILLER
+ * This define will enable memset(,RTR0MEM_EF_FENCE_FILLER,)'ing the
+ * fence itself, as debuggers can usually read them.
+ */
+#define RTR0MEM_EF_FENCE_FILLER     0xcc
+
+
+/*******************************************************************************
+*   Header Files                                                               *
+*******************************************************************************/
+#ifdef RT_OS_WINDOWS
+# include <Windows.h>
+#else
+# include <sys/mman.h>
+#endif
+#include <iprt/avl.h>
+#include <iprt/thread.h>
+
+
+/*******************************************************************************
+*   Structures and Typedefs                                                    *
+*******************************************************************************/
+/**
+ * Allocation types.
+ */
+typedef enum RTMEMTYPE
+{
+    RTMEMTYPE_RTMEMALLOC,
+    RTMEMTYPE_RTMEMALLOCZ,
+    RTMEMTYPE_RTMEMREALLOC,
+    RTMEMTYPE_RTMEMFREE,
+
+    RTMEMTYPE_NEW,
+    RTMEMTYPE_NEW_ARRAY,
+    RTMEMTYPE_DELETE,
+    RTMEMTYPE_DELETE_ARRAY
+} RTMEMTYPE;
+
+/**
+ * Node tracking a memory allocation.
+ */
+typedef struct RTR0MEMEFBLOCK
+{
+    /** Avl node code, key is the user block pointer. */
+    AVLPVNODECORE   Core;
+    /** Allocation type. */
+    RTMEMTYPE       enmType;
+    /** The memory object. */
+    RTR0MEMOBJ      hMemObj;
+    /** The unaligned size of the block. */
+    size_t          cbUnaligned;
+    /** The aligned size of the block. */
+    size_t          cbAligned;
+    /** The allocation tag (read-only string). */
+    const char     *pszTag;
+    /** The return address of the allocator function. */
+    void           *pvCaller;
+    /** Line number of the alloc call. */
+    unsigned        iLine;
+    /** File from within the allocation was made. */
+    const char     *pszFile;
+    /** Function from within the allocation was made. */
+    const char     *pszFunction;
+} RTR0MEMEFBLOCK, *PRTR0MEMEFBLOCK;
+
+
+
+/*********************************************************************************************************************************
+*   Global Variables                                                                                                             *
+*********************************************************************************************************************************/
+/** Spinlock protecting the all the block's globals. */
+static volatile uint32_t        g_BlocksLock;
+/** Tree tracking the allocations. */
+static AVLPVTREE                g_BlocksTree;
+
+#ifdef RTR0MEM_EF_FREE_DELAYED
+/** Tail of the delayed blocks. */
+static volatile PRTR0MEMEFBLOCK g_pBlocksDelayHead;
+/** Tail of the delayed blocks. */
+static volatile PRTR0MEMEFBLOCK g_pBlocksDelayTail;
+/** Number of bytes in the delay list (includes fences). */
+static volatile size_t          g_cbBlocksDelay;
+#endif /* RTR0MEM_EF_FREE_DELAYED */
+
+/** Array of pointers free watches for. */
+void   *gapvRTMemFreeWatch[4] = {NULL, NULL, NULL, NULL};
+/** Enable logging of all freed memory. */
+bool    gfRTMemFreeLog = false;
+
+
+/*********************************************************************************************************************************
+*   Internal Functions                                                                                                           *
+*********************************************************************************************************************************/
+
+
+/**
+ * @callback_method_impl{FNRTSTROUTPUT}
+ */
+static DECLCALLBACK(size_t) rtR0MemEfWrite(void *pvArg, const char *pachChars, size_t cbChars)
+{
+    if (cbChars)
+    {
+        RTLogWriteDebugger(pachChars, cbChars);
+        RTLogWriteStdOut(pachChars, cbChars);
+        RTLogWriteUser(pachChars, cbChars);
+    }
+    return cbChars;
+}
+
+
+/**
+ * Complains about something.
+ */
+static void rtR0MemComplain(const char *pszOp, const char *pszFormat, ...)
+{
+    va_list args;
+    RTStrFormat(rtR0MemEfWrite, NULL, NULL, NULL, "RTMem error: %s: ", pszOp);
+    va_start(args, pszFormat);
+    RTStrFormatV(rtR0MemEfWrite, NULL, NULL, NULL, pszFormat, args);
+    va_end(args);
+    RTAssertDoPanic();
+}
+
+/**
+ * Log an event.
+ */
+DECLINLINE(void) rtR0MemLog(const char *pszOp, const char *pszFormat, ...)
+{
+#if 0
+    va_list args;
+    RTStrFormat(rtR0MemEfWrite, NULL, NULL, NULL, "RTMem info: %s: ", pszOp);
+    va_start(args, pszFormat);
+    RTStrFormatV(rtR0MemEfWrite, NULL, NULL, NULL, pszFormat, args);
+    va_end(args);
+#else
+    NOREF(pszOp); NOREF(pszFormat);
+#endif
+}
+
+
+
+/**
+ * Acquires the lock.
+ */
+DECLINLINE(RTCCUINTREG) rtR0MemBlockLock(void)
+{
+    RTCCUINTREG uRet;
+    unsigned c = 0;
+    if (RTThreadPreemptIsEnabled(NIL_RTTHREAD))
+    {
+        for (;;)
+        {
+            uRet = ASMIntDisableFlags();
+            if (ASMAtomicCmpXchgU32(&g_BlocksLock, 1, 0))
+                break;
+            ASMSetFlags(uRet);
+            RTThreadSleepNoLog(((++c) >> 2) & 31);
+        }
+    }
+    else
+    {
+        for (;;)
+        {
+            uRet = ASMIntDisableFlags();
+            if (ASMAtomicCmpXchgU32(&g_BlocksLock, 1, 0))
+                break;
+            ASMSetFlags(uRet);
+            ASMNopPause();
+            if (++c & 3)
+                ASMNopPause();
+        }
+    }
+    return uRet;
+}
+
+
+/**
+ * Releases the lock.
+ */
+DECLINLINE(void) rtR0MemBlockUnlock(RTCCUINTREG fSavedIntFlags)
+{
+    Assert(g_BlocksLock == 1);
+    ASMAtomicXchgU32(&g_BlocksLock, 0);
+    ASMSetFlags(fSavedIntFlags);
+}
+
+
+/**
+ * Creates a block.
+ */
+DECLINLINE(PRTR0MEMEFBLOCK) rtR0MemBlockCreate(RTMEMTYPE enmType, size_t cbUnaligned, size_t cbAligned,
+                                               const char *pszTag, void *pvCaller, RT_SRC_POS_DECL)
+{
+    PRTR0MEMEFBLOCK pBlock = (PRTR0MEMEFBLOCK)RTMemAlloc(sizeof(*pBlock));
+    if (pBlock)
+    {
+        pBlock->enmType     = enmType;
+        pBlock->cbUnaligned = cbUnaligned;
+        pBlock->cbAligned   = cbAligned;
+        pBlock->pszTag      = pszTag;
+        pBlock->pvCaller    = pvCaller;
+        pBlock->iLine       = iLine;
+        pBlock->pszFile     = pszFile;
+        pBlock->pszFunction = pszFunction;
+    }
+    return pBlock;
+}
+
+
+/**
+ * Frees a block.
+ */
+DECLINLINE(void) rtR0MemBlockFree(PRTR0MEMEFBLOCK pBlock)
+{
+    RTMemFree(pBlock);
+}
+
+
+/**
+ * Insert a block from the tree.
+ */
+DECLINLINE(void) rtR0MemBlockInsert(PRTR0MEMEFBLOCK pBlock, void *pv, RTR0MEMOBJ hMemObj)
+{
+    pBlock->Core.Key = pv;
+    pBlock->hMemObj  = hMemObj;
+    RTCCUINTREG fSavedIntFlags = rtR0MemBlockLock();
+    bool fRc = RTAvlPVInsert(&g_BlocksTree, &pBlock->Core);
+    rtR0MemBlockUnlock(fSavedIntFlags);
+    AssertRelease(fRc);
+}
+
+
+/**
+ * Remove a block from the tree and returns it to the caller.
+ */
+DECLINLINE(PRTR0MEMEFBLOCK) rtR0MemBlockRemove(void *pv)
+{
+    RTCCUINTREG fSavedIntFlags = rtR0MemBlockLock();
+    PRTR0MEMEFBLOCK pBlock = (PRTR0MEMEFBLOCK)RTAvlPVRemove(&g_BlocksTree, pv);
+    rtR0MemBlockUnlock(fSavedIntFlags);
+    return pBlock;
+}
+
+
+/**
+ * Gets a block.
+ */
+DECLINLINE(PRTR0MEMEFBLOCK) rtR0MemBlockGet(void *pv)
+{
+    RTCCUINTREG fSavedIntFlags = rtR0MemBlockLock();
+    PRTR0MEMEFBLOCK pBlock = (PRTR0MEMEFBLOCK)RTAvlPVGet(&g_BlocksTree, pv);
+    rtR0MemBlockUnlock(fSavedIntFlags);
+    return pBlock;
+}
+
+
+/**
+ * Dumps one allocation.
+ */
+static DECLCALLBACK(int) RTMemDumpOne(PAVLPVNODECORE pNode, void *pvUser)
+{
+    PRTR0MEMEFBLOCK pBlock = (PRTR0MEMEFBLOCK)pNode;
+    RTStrFormat(rtR0MemEfWrite, NULL, NULL, NULL, "%p %08lx(+%02lx) %p\n",
+                pBlock->Core.Key,
+                (unsigned long)pBlock->cbUnaligned,
+                (unsigned long)(pBlock->cbAligned - pBlock->cbUnaligned),
+                pBlock->pvCaller);
+    NOREF(pvUser);
+    return 0;
+}
+
+
+/**
+ * Dumps the allocated blocks.
+ * This is something which you should call from gdb.
+ */
+extern "C" void RTMemDump(void);
+void RTMemDump(void)
+{
+    RTStrFormat(rtR0MemEfWrite, NULL, NULL, NULL, "address  size(alg)     caller\n");
+    RTAvlPVDoWithAll(&g_BlocksTree, true, RTMemDumpOne, NULL);
+}
+
+#ifdef RTR0MEM_EF_FREE_DELAYED
+
+/**
+ * Insert a delayed block.
+ */
+DECLINLINE(void) rtR0MemBlockDelayInsert(PRTR0MEMEFBLOCK pBlock)
+{
+    size_t cbBlock = RT_ALIGN_Z(pBlock->cbAligned, PAGE_SIZE) + RTR0MEM_EF_SIZE;
+    pBlock->Core.pRight = NULL;
+    pBlock->Core.pLeft = NULL;
+    RTCCUINTREG fSavedIntFlags = rtR0MemBlockLock();
+    if (g_pBlocksDelayHead)
+    {
+        g_pBlocksDelayHead->Core.pLeft = (PAVLPVNODECORE)pBlock;
+        pBlock->Core.pRight = (PAVLPVNODECORE)g_pBlocksDelayHead;
+        g_pBlocksDelayHead = pBlock;
+    }
+    else
+    {
+        g_pBlocksDelayTail = pBlock;
+        g_pBlocksDelayHead = pBlock;
+    }
+    g_cbBlocksDelay += cbBlock;
+    rtR0MemBlockUnlock(fSavedIntFlags);
+}
+
+/**
+ * Removes a delayed block.
+ */
+DECLINLINE(PRTR0MEMEFBLOCK) rtR0MemBlockDelayRemove(void)
+{
+    PRTR0MEMEFBLOCK pBlock = NULL;
+    RTCCUINTREG fSavedIntFlags = rtR0MemBlockLock();
+    if (g_cbBlocksDelay > RTR0MEM_EF_FREE_DELAYED)
+    {
+        pBlock = g_pBlocksDelayTail;
+        if (pBlock)
+        {
+            g_pBlocksDelayTail = (PRTR0MEMEFBLOCK)pBlock->Core.pLeft;
+            if (pBlock->Core.pLeft)
+                pBlock->Core.pLeft->pRight = NULL;
+            else
+                g_pBlocksDelayHead = NULL;
+            g_cbBlocksDelay -= RT_ALIGN_Z(pBlock->cbAligned, PAGE_SIZE) + RTR0MEM_EF_SIZE;
+        }
+    }
+    rtR0MemBlockUnlock(fSavedIntFlags);
+    return pBlock;
+}
+
+#endif  /* RTR0MEM_EF_FREE_DELAYED */
+
+
+static void rtR0MemFreeBlock(PRTR0MEMEFBLOCK pBlock, const char *pszOp)
+{
+    void  *pv      = pBlock->Core.Key;
+# ifdef RTR0MEM_EF_IN_FRONT
+    void  *pvBlock = (char *)pv - RTR0MEM_EF_SIZE;
+# else
+    void  *pvBlock = (void *)((uintptr_t)pv & ~(uintptr_t)PAGE_OFFSET_MASK);
+# endif
+    size_t cbBlock = RT_ALIGN_Z(pBlock->cbAligned, PAGE_SIZE) + RTR0MEM_EF_SIZE;
+
+    int rc = RTR0MemObjProtect(pBlock->hMemObj, 0 /*offSub*/, cbBlock, RTMEM_PROT_READ | RTMEM_PROT_WRITE);
+    if (RT_FAILURE(rc))
+        rtR0MemComplain(pszOp, "RTR0MemObjProtect([%p], 0, %#x, RTMEM_PROT_READ | RTMEM_PROT_WRITE) -> %Rrc\n",
+                        pvBlock, cbBlock, rc);
+
+    rc = RTR0MemObjFree(pBlock->hMemObj, true /*fFreeMappings*/);
+    if (RT_FAILURE(rc))
+        rtR0MemComplain(pszOp, "RTR0MemObjFree([%p LB %#x]) -> %Rrc\n", pvBlock, cbBlock, rc);
+    pBlock->hMemObj = NIL_RTR0MEMOBJ;
+
+    rtR0MemBlockFree(pBlock);
+}
+
+
+/**
+ * Initialize call, we shouldn't fail here.
+ */
+void rtR0MemEfInit(void)
+{
+
+}
+
+/**
+ * @callback_method_impl{AVLPVCALLBACK}
+ */
+static DECLCALLBACK(int) rtR0MemEfDestroyBlock(PAVLPVNODECORE pNode, void *pvUser)
+{
+    PRTR0MEMEFBLOCK pBlock = (PRTR0MEMEFBLOCK)pNode;
+
+    /* Note! pszFile and pszFunction may be invalid at this point. */
+    rtR0MemComplain("rtR0MemEfDestroyBlock", "Leaking %zu bytes at %p (iLine=%u pvCaller=%p)\n",
+                    pBlock->cbAligned, pBlock->Core.Key, pBlock->iLine, pBlock->pvCaller);
+
+    rtR0MemFreeBlock(pBlock, "rtR0MemEfDestroyBlock");
+
+    NOREF(pvUser);
+    return VINF_SUCCESS;
+}
+
+
+/**
+ * Termination call.
+ *
+ * Will check and free memory.
+ */
+void rtR0MemEfTerm(void)
+{
+#ifdef RTR0MEM_EF_FREE_DELAYED
+    /*
+     * Release delayed frees.
+     */
+    RTCCUINTREG fSavedIntFlags = rtR0MemBlockLock();
+    for (;;)
+    {
+        PRTR0MEMEFBLOCK pBlock = g_pBlocksDelayTail;
+        g_pBlocksDelayTail = (PRTR0MEMEFBLOCK)pBlock->Core.pLeft;
+        if (pBlock->Core.pLeft)
+            pBlock->Core.pLeft->pRight = NULL;
+        else
+            g_pBlocksDelayHead = NULL;
+        rtR0MemBlockUnlock(fSavedIntFlags);
+
+        rtR0MemFreeBlock(pBlock, "rtR0MemEfTerm");
+
+        rtR0MemBlockLock();
+    }
+    g_cbBlocksDelay = 0;
+    rtR0MemBlockUnlock(fSavedIntFlags);
+#endif
+
+    /*
+     * Complain about leaks. Then release them.
+     */
+    RTAvlPVDestroy(&g_BlocksTree, rtR0MemEfDestroyBlock, NULL);
+}
+
+
+/**
+ * Internal allocator.
+ */
+static void * rtR0MemAlloc(const char *pszOp, RTMEMTYPE enmType, size_t cbUnaligned, size_t cbAligned,
+                           const char *pszTag, void *pvCaller, RT_SRC_POS_DECL)
+{
+    /*
+     * Sanity.
+     */
+    if (    RT_ALIGN_Z(RTR0MEM_EF_SIZE, PAGE_SIZE) != RTR0MEM_EF_SIZE
+        &&  RTR0MEM_EF_SIZE <= 0)
+    {
+        rtR0MemComplain(pszOp, "Invalid E-fence size! %#x\n", RTR0MEM_EF_SIZE);
+        return NULL;
+    }
+    if (!cbUnaligned)
+    {
+#if 1
+        rtR0MemComplain(pszOp, "Request of ZERO bytes allocation!\n");
+        return NULL;
+#else
+        cbAligned = cbUnaligned = 1;
+#endif
+    }
+
+#ifndef RTR0MEM_EF_IN_FRONT
+    /* Alignment decreases fence accuracy, but this is at least partially
+     * counteracted by filling and checking the alignment padding. When the
+     * fence is in front then then no extra alignment is needed. */
+    cbAligned = RT_ALIGN_Z(cbAligned, RTR0MEM_EF_ALIGNMENT);
+#endif
+
+    /*
+     * Allocate the trace block.
+     */
+    PRTR0MEMEFBLOCK pBlock = rtR0MemBlockCreate(enmType, cbUnaligned, cbAligned, pszTag, pvCaller, RT_SRC_POS_ARGS);
+    if (!pBlock)
+    {
+        rtR0MemComplain(pszOp, "Failed to allocate trace block!\n");
+        return NULL;
+    }
+
+    /*
+     * Allocate a block with page alignment space + the size of the E-fence.
+     */
+    void       *pvBlock = NULL;
+    RTR0MEMOBJ  hMemObj;
+    size_t      cbBlock = RT_ALIGN_Z(cbAligned, PAGE_SIZE) + RTR0MEM_EF_SIZE;
+    int rc = RTR0MemObjAllocPage(&hMemObj, cbBlock, false /*fExecutable*/);
+    if (RT_SUCCESS(rc))
+        pvBlock = RTR0MemObjAddress(hMemObj);
+    if (pvBlock)
+    {
+        /*
+         * Calc the start of the fence and the user block
+         * and then change the page protection of the fence.
+         */
+#ifdef RTR0MEM_EF_IN_FRONT
+        void *pvEFence = pvBlock;
+        void *pv       = (char *)pvEFence + RTR0MEM_EF_SIZE;
+# ifdef RTR0MEM_EF_NOMAN_FILLER
+        memset((char *)pv + cbUnaligned, RTR0MEM_EF_NOMAN_FILLER, cbBlock - RTR0MEM_EF_SIZE - cbUnaligned);
+# endif
+#else
+        void *pvEFence = (char *)pvBlock + (cbBlock - RTR0MEM_EF_SIZE);
+        void *pv       = (char *)pvEFence - cbAligned;
+# ifdef RTR0MEM_EF_NOMAN_FILLER
+        memset(pvBlock, RTR0MEM_EF_NOMAN_FILLER, cbBlock - RTR0MEM_EF_SIZE - cbAligned);
+        memset((char *)pv + cbUnaligned, RTR0MEM_EF_NOMAN_FILLER, cbAligned - cbUnaligned);
+# endif
+#endif
+
+#ifdef RTR0MEM_EF_FENCE_FILLER
+        memset(pvEFence, RTR0MEM_EF_FENCE_FILLER, RTR0MEM_EF_SIZE);
+#endif
+        rc = RTR0MemObjProtect(hMemObj, (uint8_t *)pvEFence - (uint8_t *)pvBlock, RTR0MEM_EF_SIZE, RTMEM_PROT_NONE);
+        if (!rc)
+        {
+            rtR0MemBlockInsert(pBlock, pv, hMemObj);
+            if (enmType == RTMEMTYPE_RTMEMALLOCZ)
+                memset(pv, 0, cbUnaligned);
+#ifdef RTR0MEM_EF_FILLER
+            else
+                memset(pv, RTR0MEM_EF_FILLER, cbUnaligned);
+#endif
+
+            rtR0MemLog(pszOp, "returns %p (pvBlock=%p cbBlock=%#x pvEFence=%p cbUnaligned=%#x)\n", pv, pvBlock, cbBlock, pvEFence, cbUnaligned);
+            return pv;
+        }
+        rtR0MemComplain(pszOp, "RTMemProtect failed, pvEFence=%p size %d, rc=%d\n", pvEFence, RTR0MEM_EF_SIZE, rc);
+        RTR0MemObjFree(hMemObj, true /*fFreeMappings*/);
+    }
+    else
+    {
+        rtR0MemComplain(pszOp, "Failed to allocated %zu (%zu) bytes (rc=%Rrc).\n", cbBlock, cbUnaligned, rc);
+        if (RT_SUCCESS(rc))
+            RTR0MemObjFree(hMemObj, true /*fFreeMappings*/);
+    }
+
+    rtR0MemBlockFree(pBlock);
+    return NULL;
+}
+
+
+/**
+ * Internal free.
+ */
+static void rtR0MemFree(const char *pszOp, RTMEMTYPE enmType, void *pv, void *pvCaller, RT_SRC_POS_DECL)
+{
+    NOREF(enmType); RT_SRC_POS_NOREF();
+
+    /*
+     * Simple case.
+     */
+    if (!pv)
+        return;
+
+    /*
+     * Check watch points.
+     */
+    for (unsigned i = 0; i < RT_ELEMENTS(gapvRTMemFreeWatch); i++)
+        if (gapvRTMemFreeWatch[i] == pv)
+            RTAssertDoPanic();
+
+    /*
+     * Find the block.
+     */
+    PRTR0MEMEFBLOCK pBlock = rtR0MemBlockRemove(pv);
+    if (pBlock)
+    {
+        if (gfRTMemFreeLog)
+            RTLogPrintf("RTMem %s: pv=%p pvCaller=%p cbUnaligned=%#x\n", pszOp, pv, pvCaller, pBlock->cbUnaligned);
+
+#ifdef RTR0MEM_EF_NOMAN_FILLER
+        /*
+         * Check whether the no man's land is untouched.
+         */
+# ifdef RTR0MEM_EF_IN_FRONT
+        void *pvWrong = ASMMemIsAll8((char *)pv + pBlock->cbUnaligned,
+                                     RT_ALIGN_Z(pBlock->cbAligned, PAGE_SIZE) - pBlock->cbUnaligned,
+                                     RTR0MEM_EF_NOMAN_FILLER);
+# else
+        /* Alignment must match allocation alignment in rtMemAlloc(). */
+        void *pvWrong = ASMMemIsAll8((char *)pv + pBlock->cbUnaligned,
+                                     pBlock->cbAligned - pBlock->cbUnaligned,
+                                     RTR0MEM_EF_NOMAN_FILLER);
+        if (pvWrong)
+            RTAssertDoPanic();
+        pvWrong = ASMMemIsAll8((void *)((uintptr_t)pv & ~(uintptr_t)PAGE_OFFSET_MASK),
+                               RT_ALIGN_Z(pBlock->cbAligned, PAGE_SIZE) - pBlock->cbAligned,
+                               RTR0MEM_EF_NOMAN_FILLER);
+# endif
+        if (pvWrong)
+            RTAssertDoPanic();
+#endif
+
+#ifdef RTR0MEM_EF_FREE_FILL
+        /*
+         * Fill the user part of the block.
+         */
+        memset(pv, RTR0MEM_EF_FREE_FILL, pBlock->cbUnaligned);
+#endif
+
+#if defined(RTR0MEM_EF_FREE_DELAYED) && RTR0MEM_EF_FREE_DELAYED > 0
+        /*
+         * We're doing delayed freeing.
+         * That means we'll expand the E-fence to cover the entire block.
+         */
+# ifdef RTR0MEM_EF_IN_FRONT
+        int rc = RTR0MemObjProtect(pBlock->hMemObj, RTR0MEM_EF_SIZE /*offSub*/, pBlock->cbAligned, RTMEM_PROT_NONE);
+# else
+        int rc = RTR0MemObjProtect(pBlock->hMemObj, 0 /*offSub*/,               pBlock->cbAligned, RTMEM_PROT_NONE);
+# endif
+        if (RT_SUCCESS(rc))
+        {
+            /*
+             * Insert it into the free list and process pending frees.
+             */
+            rtR0MemBlockDelayInsert(pBlock);
+            while ((pBlock = rtR0MemBlockDelayRemove()) != NULL)
+                rtR0MemFreeBlock(pBlock, pszOp);
+        }
+        else
+            rtR0MemComplain(pszOp, "Failed to expand the efence of pv=%p cb=%d, rc=%d.\n", pv, pBlock, rc);
+
+#else  /* !RTR0MEM_EF_FREE_DELAYED */
+        rtR0MemFreeBlock(pBlock, pszOp);
+#endif /* !RTR0MEM_EF_FREE_DELAYED */
+    }
+    else
+        rtR0MemComplain(pszOp, "pv=%p not found! Incorrect free!\n", pv);
+}
+
+
+/**
+ * Internal realloc.
+ */
+static void *rtR0MemRealloc(const char *pszOp, RTMEMTYPE enmType, void *pvOld, size_t cbNew,
+                            const char *pszTag, void *pvCaller, RT_SRC_POS_DECL)
+{
+    /*
+     * Allocate new and copy.
+     */
+    if (!pvOld)
+        return rtR0MemAlloc(pszOp, enmType, cbNew, cbNew, pszTag, pvCaller, RT_SRC_POS_ARGS);
+    if (!cbNew)
+    {
+        rtR0MemFree(pszOp, RTMEMTYPE_RTMEMREALLOC, pvOld, pvCaller, RT_SRC_POS_ARGS);
+        return NULL;
+    }
+
+    /*
+     * Get the block, allocate the new, copy the data, free the old one.
+     */
+    PRTR0MEMEFBLOCK pBlock = rtR0MemBlockGet(pvOld);
+    if (pBlock)
+    {
+        void *pvRet = rtR0MemAlloc(pszOp, enmType, cbNew, cbNew, pszTag, pvCaller, RT_SRC_POS_ARGS);
+        if (pvRet)
+        {
+            memcpy(pvRet, pvOld, RT_MIN(cbNew, pBlock->cbUnaligned));
+            rtR0MemFree(pszOp, RTMEMTYPE_RTMEMREALLOC, pvOld, pvCaller, RT_SRC_POS_ARGS);
+        }
+        return pvRet;
+    }
+    rtR0MemComplain(pszOp, "pvOld=%p was not found!\n", pvOld);
+    return NULL;
+}
+
+
+
+
+RTDECL(void *)  RTMemEfTmpAlloc(size_t cb, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("TmpAlloc", RTMEMTYPE_RTMEMALLOC, cb, cb, pszTag, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void *)  RTMemEfTmpAllocZ(size_t cb, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("TmpAlloc", RTMEMTYPE_RTMEMALLOCZ, cb, cb, pszTag, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void)    RTMemEfTmpFree(void *pv, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    if (pv)
+        rtR0MemFree("Free", RTMEMTYPE_RTMEMFREE, pv, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void *)  RTMemEfAlloc(size_t cb, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("Alloc", RTMEMTYPE_RTMEMALLOC, cb, cb, pszTag, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void *)  RTMemEfAllocZ(size_t cb, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("AllocZ", RTMEMTYPE_RTMEMALLOCZ, cb, cb, pszTag, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void *)  RTMemEfAllocVar(size_t cbUnaligned, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    size_t cbAligned;
+    if (cbUnaligned >= 16)
+        cbAligned = RT_ALIGN_Z(cbUnaligned, 16);
+    else
+        cbAligned = RT_ALIGN_Z(cbUnaligned, sizeof(void *));
+    return rtR0MemAlloc("Alloc", RTMEMTYPE_RTMEMALLOC, cbUnaligned, cbAligned, pszTag, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void *)  RTMemEfAllocZVar(size_t cbUnaligned, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    size_t cbAligned;
+    if (cbUnaligned >= 16)
+        cbAligned = RT_ALIGN_Z(cbUnaligned, 16);
+    else
+        cbAligned = RT_ALIGN_Z(cbUnaligned, sizeof(void *));
+    return rtR0MemAlloc("AllocZ", RTMEMTYPE_RTMEMALLOCZ, cbUnaligned, cbAligned, pszTag, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void *)  RTMemEfRealloc(void *pvOld, size_t cbNew, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    return rtR0MemRealloc("Realloc", RTMEMTYPE_RTMEMREALLOC, pvOld, cbNew, pszTag, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void)    RTMemEfFree(void *pv, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    if (pv)
+        rtR0MemFree("Free", RTMEMTYPE_RTMEMFREE, pv, ASMReturnAddress(), RT_SRC_POS_ARGS);
+}
+
+
+RTDECL(void *) RTMemEfDup(const void *pvSrc, size_t cb, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    void *pvDst = RTMemEfAlloc(cb, pszTag, RT_SRC_POS_ARGS);
+    if (pvDst)
+        memcpy(pvDst, pvSrc, cb);
+    return pvDst;
+}
+
+
+RTDECL(void *) RTMemEfDupEx(const void *pvSrc, size_t cbSrc, size_t cbExtra, const char *pszTag, RT_SRC_POS_DECL) RT_NO_THROW_DEF
+{
+    void *pvDst = RTMemEfAlloc(cbSrc + cbExtra, pszTag, RT_SRC_POS_ARGS);
+    if (pvDst)
+    {
+        memcpy(pvDst, pvSrc, cbSrc);
+        memset((uint8_t *)pvDst + cbSrc, 0, cbExtra);
+    }
+    return pvDst;
+}
+
+
+
+
+/*
+ *
+ * The NP (no position) versions.
+ *
+ */
+
+
+
+RTDECL(void *)  RTMemEfTmpAllocNP(size_t cb, const char *pszTag) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("TmpAlloc", RTMEMTYPE_RTMEMALLOC, cb, cb, pszTag, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void *)  RTMemEfTmpAllocZNP(size_t cb, const char *pszTag) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("TmpAllocZ", RTMEMTYPE_RTMEMALLOCZ, cb, cb, pszTag, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void)    RTMemEfTmpFreeNP(void *pv) RT_NO_THROW_DEF
+{
+    if (pv)
+        rtR0MemFree("Free", RTMEMTYPE_RTMEMFREE, pv, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void *)  RTMemEfAllocNP(size_t cb, const char *pszTag) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("Alloc", RTMEMTYPE_RTMEMALLOC, cb, cb, pszTag, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void *)  RTMemEfAllocZNP(size_t cb, const char *pszTag) RT_NO_THROW_DEF
+{
+    return rtR0MemAlloc("AllocZ", RTMEMTYPE_RTMEMALLOCZ, cb, cb, pszTag, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void *)  RTMemEfAllocVarNP(size_t cbUnaligned, const char *pszTag) RT_NO_THROW_DEF
+{
+    size_t cbAligned;
+    if (cbUnaligned >= 16)
+        cbAligned = RT_ALIGN_Z(cbUnaligned, 16);
+    else
+        cbAligned = RT_ALIGN_Z(cbUnaligned, sizeof(void *));
+    return rtR0MemAlloc("Alloc", RTMEMTYPE_RTMEMALLOC, cbUnaligned, cbAligned, pszTag, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void *)  RTMemEfAllocZVarNP(size_t cbUnaligned, const char *pszTag) RT_NO_THROW_DEF
+{
+    size_t cbAligned;
+    if (cbUnaligned >= 16)
+        cbAligned = RT_ALIGN_Z(cbUnaligned, 16);
+    else
+        cbAligned = RT_ALIGN_Z(cbUnaligned, sizeof(void *));
+    return rtR0MemAlloc("AllocZ", RTMEMTYPE_RTMEMALLOCZ, cbUnaligned, cbAligned, pszTag, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void *)  RTMemEfReallocNP(void *pvOld, size_t cbNew, const char *pszTag) RT_NO_THROW_DEF
+{
+    return rtR0MemRealloc("Realloc", RTMEMTYPE_RTMEMREALLOC, pvOld, cbNew, pszTag, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void)    RTMemEfFreeNP(void *pv) RT_NO_THROW_DEF
+{
+    if (pv)
+        rtR0MemFree("Free", RTMEMTYPE_RTMEMFREE, pv, ASMReturnAddress(), NULL, 0, NULL);
+}
+
+
+RTDECL(void *) RTMemEfDupNP(const void *pvSrc, size_t cb, const char *pszTag) RT_NO_THROW_DEF
+{
+    void *pvDst = RTMemEfAlloc(cb, pszTag, NULL, 0, NULL);
+    if (pvDst)
+        memcpy(pvDst, pvSrc, cb);
+    return pvDst;
+}
+
+
+RTDECL(void *) RTMemEfDupExNP(const void *pvSrc, size_t cbSrc, size_t cbExtra, const char *pszTag) RT_NO_THROW_DEF
+{
+    void *pvDst = RTMemEfAlloc(cbSrc + cbExtra, pszTag, NULL, 0, NULL);
+    if (pvDst)
+    {
+        memcpy(pvDst, pvSrc, cbSrc);
+        memset((uint8_t *)pvDst + cbSrc, 0, cbExtra);
+    }
+    return pvDst;
+}
+
Index: /trunk/src/VBox/Runtime/r0drv/initterm-r0drv.cpp
===================================================================
--- /trunk/src/VBox/Runtime/r0drv/initterm-r0drv.cpp	(revision 58268)
+++ /trunk/src/VBox/Runtime/r0drv/initterm-r0drv.cpp	(revision 58269)
@@ -43,4 +43,5 @@
 
 #include "internal/initterm.h"
+#include "internal/mem.h"
 #include "internal/thread.h"
 
@@ -88,4 +89,7 @@
     if (RT_SUCCESS(rc))
     {
+#ifdef RTR0MEM_WITH_EF_APIS
+        rtR0MemEfInit();
+#endif
         rc = rtThreadInit();
         if (RT_SUCCESS(rc))
@@ -106,4 +110,7 @@
             rtThreadTerm();
         }
+#ifdef RTR0MEM_WITH_EF_APIS
+        rtR0MemEfTerm();
+#endif
         rtR0TermNative();
     }
@@ -119,4 +126,7 @@
     rtR0PowerNotificationTerm();
     rtR0MpNotificationTerm();
+#endif
+#ifdef RTR0MEM_WITH_EF_APIS
+    rtR0MemEfTerm();
 #endif
     rtR0TermNative();
