Renormalized end-of-lines from master@27b044605cd5f6b33a3d231576003850b3fe305btrunk

1 files changed, 1430 insertions, 1430 deletions

diff --git a/MdeModulePkg/Core/PiSmmCore/HeapGuard.c b/MdeModulePkg/Core/PiSmmCore/HeapGuard.c
index 25310122ca..558944401f 100644
--- a/MdeModulePkg/Core/PiSmmCore/HeapGuard.c
+++ b/MdeModulePkg/Core/PiSmmCore/HeapGuard.c
@@ -1,1430 +1,1430 @@
-/** @file

-  UEFI Heap Guard functions.

-

-Copyright (c) 2017-2018, Intel Corporation. All rights reserved.<BR>

-SPDX-License-Identifier: BSD-2-Clause-Patent

-

-**/

-

-#include "HeapGuard.h"

-

-//

-// Global to avoid infinite reentrance of memory allocation when updating

-// page table attributes, which may need allocating pages for new PDE/PTE.

-//

-GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN  mOnGuarding = FALSE;

-

-//

-// Pointer to table tracking the Guarded memory with bitmap, in which  '1'

-// is used to indicate memory guarded. '0' might be free memory or Guard

-// page itself, depending on status of memory adjacent to it.

-//

-GLOBAL_REMOVE_IF_UNREFERENCED UINT64  mGuardedMemoryMap = 0;

-

-//

-// Current depth level of map table pointed by mGuardedMemoryMap.

-// mMapLevel must be initialized at least by 1. It will be automatically

-// updated according to the address of memory just tracked.

-//

-GLOBAL_REMOVE_IF_UNREFERENCED UINTN  mMapLevel = 1;

-

-//

-// Shift and mask for each level of map table

-//

-GLOBAL_REMOVE_IF_UNREFERENCED UINTN  mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH]

-  = GUARDED_HEAP_MAP_TABLE_DEPTH_SHIFTS;

-GLOBAL_REMOVE_IF_UNREFERENCED UINTN  mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH]

-  = GUARDED_HEAP_MAP_TABLE_DEPTH_MASKS;

-

-//

-// SMM memory attribute protocol

-//

-EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL  *mSmmMemoryAttribute = NULL;

-

-/**

-  Set corresponding bits in bitmap table to 1 according to the address.

-

-  @param[in]  Address     Start address to set for.

-  @param[in]  BitNumber   Number of bits to set.

-  @param[in]  BitMap      Pointer to bitmap which covers the Address.

-

-  @return VOID

-**/

-STATIC

-VOID

-SetBits (

-  IN EFI_PHYSICAL_ADDRESS  Address,

-  IN UINTN                 BitNumber,

-  IN UINT64                *BitMap

-  )

-{

-  UINTN  Lsbs;

-  UINTN  Qwords;

-  UINTN  Msbs;

-  UINTN  StartBit;

-  UINTN  EndBit;

-

-  StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);

-  EndBit   = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;

-

-  if ((StartBit + BitNumber) >= GUARDED_HEAP_MAP_ENTRY_BITS) {

-    Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) %

-           GUARDED_HEAP_MAP_ENTRY_BITS;

-    Lsbs   = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;

-    Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS;

-  } else {

-    Msbs   = BitNumber;

-    Lsbs   = 0;

-    Qwords = 0;

-  }

-

-  if (Msbs > 0) {

-    *BitMap |= LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit);

-    BitMap  += 1;

-  }

-

-  if (Qwords > 0) {

-    SetMem64 (

-      (VOID *)BitMap,

-      Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES,

-      (UINT64)-1

-      );

-    BitMap += Qwords;

-  }

-

-  if (Lsbs > 0) {

-    *BitMap |= (LShiftU64 (1, Lsbs) - 1);

-  }

-}

-

-/**

-  Set corresponding bits in bitmap table to 0 according to the address.

-

-  @param[in]  Address     Start address to set for.

-  @param[in]  BitNumber   Number of bits to set.

-  @param[in]  BitMap      Pointer to bitmap which covers the Address.

-

-  @return VOID.

-**/

-STATIC

-VOID

-ClearBits (

-  IN EFI_PHYSICAL_ADDRESS  Address,

-  IN UINTN                 BitNumber,

-  IN UINT64                *BitMap

-  )

-{

-  UINTN  Lsbs;

-  UINTN  Qwords;

-  UINTN  Msbs;

-  UINTN  StartBit;

-  UINTN  EndBit;

-

-  StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);

-  EndBit   = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;

-

-  if ((StartBit + BitNumber) >= GUARDED_HEAP_MAP_ENTRY_BITS) {

-    Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) %

-           GUARDED_HEAP_MAP_ENTRY_BITS;

-    Lsbs   = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;

-    Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS;

-  } else {

-    Msbs   = BitNumber;

-    Lsbs   = 0;

-    Qwords = 0;

-  }

-

-  if (Msbs > 0) {

-    *BitMap &= ~LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit);

-    BitMap  += 1;

-  }

-

-  if (Qwords > 0) {

-    SetMem64 ((VOID *)BitMap, Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES, 0);

-    BitMap += Qwords;

-  }

-

-  if (Lsbs > 0) {

-    *BitMap &= ~(LShiftU64 (1, Lsbs) - 1);

-  }

-}

-

-/**

-  Get corresponding bits in bitmap table according to the address.

-

-  The value of bit 0 corresponds to the status of memory at given Address.

-  No more than 64 bits can be retrieved in one call.

-

-  @param[in]  Address     Start address to retrieve bits for.

-  @param[in]  BitNumber   Number of bits to get.

-  @param[in]  BitMap      Pointer to bitmap which covers the Address.

-

-  @return An integer containing the bits information.

-**/

-STATIC

-UINT64

-GetBits (

-  IN EFI_PHYSICAL_ADDRESS  Address,

-  IN UINTN                 BitNumber,

-  IN UINT64                *BitMap

-  )

-{

-  UINTN   StartBit;

-  UINTN   EndBit;

-  UINTN   Lsbs;

-  UINTN   Msbs;

-  UINT64  Result;

-

-  ASSERT (BitNumber <= GUARDED_HEAP_MAP_ENTRY_BITS);

-

-  StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);

-  EndBit   = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;

-

-  if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) {

-    Msbs = GUARDED_HEAP_MAP_ENTRY_BITS - StartBit;

-    Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;

-  } else {

-    Msbs = BitNumber;

-    Lsbs = 0;

-  }

-

-  if ((StartBit == 0) && (BitNumber == GUARDED_HEAP_MAP_ENTRY_BITS)) {

-    Result = *BitMap;

-  } else {

-    Result = RShiftU64 ((*BitMap), StartBit) & (LShiftU64 (1, Msbs) - 1);

-    if (Lsbs > 0) {

-      BitMap += 1;

-      Result |= LShiftU64 ((*BitMap) & (LShiftU64 (1, Lsbs) - 1), Msbs);

-    }

-  }

-

-  return Result;

-}

-

-/**

-  Helper function to allocate pages without Guard for internal uses.

-

-  @param[in]  Pages       Page number.

-

-  @return Address of memory allocated.

-**/

-VOID *

-PageAlloc (

-  IN UINTN  Pages

-  )

-{

-  EFI_STATUS            Status;

-  EFI_PHYSICAL_ADDRESS  Memory;

-

-  Status = SmmInternalAllocatePages (

-             AllocateAnyPages,

-             EfiRuntimeServicesData,

-             Pages,

-             &Memory,

-             FALSE

-             );

-  if (EFI_ERROR (Status)) {

-    Memory = 0;

-  }

-

-  return (VOID *)(UINTN)Memory;

-}

-

-/**

-  Locate the pointer of bitmap from the guarded memory bitmap tables, which

-  covers the given Address.

-

-  @param[in]  Address       Start address to search the bitmap for.

-  @param[in]  AllocMapUnit  Flag to indicate memory allocation for the table.

-  @param[out] BitMap        Pointer to bitmap which covers the Address.

-

-  @return The bit number from given Address to the end of current map table.

-**/

-UINTN

-FindGuardedMemoryMap (

-  IN  EFI_PHYSICAL_ADDRESS  Address,

-  IN  BOOLEAN               AllocMapUnit,

-  OUT UINT64                **BitMap

-  )

-{

-  UINTN   Level;

-  UINT64  *GuardMap;

-  UINT64  MapMemory;

-  UINTN   Index;

-  UINTN   Size;

-  UINTN   BitsToUnitEnd;

-

-  //

-  // Adjust current map table depth according to the address to access

-  //

-  while (AllocMapUnit &&

-         mMapLevel < GUARDED_HEAP_MAP_TABLE_DEPTH &&

-         RShiftU64 (

-           Address,

-           mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1]

-           ) != 0)

-  {

-    if (mGuardedMemoryMap != 0) {

-      Size = (mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1] + 1)

-             * GUARDED_HEAP_MAP_ENTRY_BYTES;

-      MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size));

-      ASSERT (MapMemory != 0);

-

-      SetMem ((VOID *)(UINTN)MapMemory, Size, 0);

-

-      *(UINT64 *)(UINTN)MapMemory = mGuardedMemoryMap;

-      mGuardedMemoryMap           = MapMemory;

-    }

-

-    mMapLevel++;

-  }

-

-  GuardMap = &mGuardedMemoryMap;

-  for (Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;

-       Level < GUARDED_HEAP_MAP_TABLE_DEPTH;

-       ++Level)

-  {

-    if (*GuardMap == 0) {

-      if (!AllocMapUnit) {

-        GuardMap = NULL;

-        break;

-      }

-

-      Size      = (mLevelMask[Level] + 1) * GUARDED_HEAP_MAP_ENTRY_BYTES;

-      MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size));

-      ASSERT (MapMemory != 0);

-

-      SetMem ((VOID *)(UINTN)MapMemory, Size, 0);

-      *GuardMap = MapMemory;

-    }

-

-    Index    = (UINTN)RShiftU64 (Address, mLevelShift[Level]);

-    Index   &= mLevelMask[Level];

-    GuardMap = (UINT64 *)(UINTN)((*GuardMap) + Index * sizeof (UINT64));

-  }

-

-  BitsToUnitEnd = GUARDED_HEAP_MAP_BITS - GUARDED_HEAP_MAP_BIT_INDEX (Address);

-  *BitMap       = GuardMap;

-

-  return BitsToUnitEnd;

-}

-

-/**

-  Set corresponding bits in bitmap table to 1 according to given memory range.

-

-  @param[in]  Address       Memory address to guard from.

-  @param[in]  NumberOfPages Number of pages to guard.

-

-  @return VOID

-**/

-VOID

-EFIAPI

-SetGuardedMemoryBits (

-  IN EFI_PHYSICAL_ADDRESS  Address,

-  IN UINTN                 NumberOfPages

-  )

-{

-  UINT64  *BitMap;

-  UINTN   Bits;

-  UINTN   BitsToUnitEnd;

-

-  while (NumberOfPages > 0) {

-    BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap);

-    ASSERT (BitMap != NULL);

-

-    if (NumberOfPages > BitsToUnitEnd) {

-      // Cross map unit

-      Bits = BitsToUnitEnd;

-    } else {

-      Bits = NumberOfPages;

-    }

-

-    SetBits (Address, Bits, BitMap);

-

-    NumberOfPages -= Bits;

-    Address       += EFI_PAGES_TO_SIZE (Bits);

-  }

-}

-

-/**

-  Clear corresponding bits in bitmap table according to given memory range.

-

-  @param[in]  Address       Memory address to unset from.

-  @param[in]  NumberOfPages Number of pages to unset guard.

-

-  @return VOID

-**/

-VOID

-EFIAPI

-ClearGuardedMemoryBits (

-  IN EFI_PHYSICAL_ADDRESS  Address,

-  IN UINTN                 NumberOfPages

-  )

-{

-  UINT64  *BitMap;

-  UINTN   Bits;

-  UINTN   BitsToUnitEnd;

-

-  while (NumberOfPages > 0) {

-    BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap);

-    ASSERT (BitMap != NULL);

-

-    if (NumberOfPages > BitsToUnitEnd) {

-      // Cross map unit

-      Bits = BitsToUnitEnd;

-    } else {

-      Bits = NumberOfPages;

-    }

-

-    ClearBits (Address, Bits, BitMap);

-

-    NumberOfPages -= Bits;

-    Address       += EFI_PAGES_TO_SIZE (Bits);

-  }

-}

-

-/**

-  Retrieve corresponding bits in bitmap table according to given memory range.

-

-  @param[in]  Address       Memory address to retrieve from.

-  @param[in]  NumberOfPages Number of pages to retrieve.

-

-  @return An integer containing the guarded memory bitmap.

-**/

-UINTN

-GetGuardedMemoryBits (

-  IN EFI_PHYSICAL_ADDRESS  Address,

-  IN UINTN                 NumberOfPages

-  )

-{

-  UINT64  *BitMap;

-  UINTN   Bits;

-  UINTN   Result;

-  UINTN   Shift;

-  UINTN   BitsToUnitEnd;

-

-  ASSERT (NumberOfPages <= GUARDED_HEAP_MAP_ENTRY_BITS);

-

-  Result = 0;

-  Shift  = 0;

-  while (NumberOfPages > 0) {

-    BitsToUnitEnd = FindGuardedMemoryMap (Address, FALSE, &BitMap);

-

-    if (NumberOfPages > BitsToUnitEnd) {

-      // Cross map unit

-      Bits = BitsToUnitEnd;

-    } else {

-      Bits = NumberOfPages;

-    }

-

-    if (BitMap != NULL) {

-      Result |= LShiftU64 (GetBits (Address, Bits, BitMap), Shift);

-    }

-

-    Shift         += Bits;

-    NumberOfPages -= Bits;

-    Address       += EFI_PAGES_TO_SIZE (Bits);

-  }

-

-  return Result;

-}

-

-/**

-  Get bit value in bitmap table for the given address.

-

-  @param[in]  Address     The address to retrieve for.

-

-  @return 1 or 0.

-**/

-UINTN

-EFIAPI

-GetGuardMapBit (

-  IN EFI_PHYSICAL_ADDRESS  Address

-  )

-{

-  UINT64  *GuardMap;

-

-  FindGuardedMemoryMap (Address, FALSE, &GuardMap);

-  if (GuardMap != NULL) {

-    if (RShiftU64 (

-          *GuardMap,

-          GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)

-          ) & 1)

-    {

-      return 1;

-    }

-  }

-

-  return 0;

-}

-

-/**

-  Check to see if the page at the given address is a Guard page or not.

-

-  @param[in]  Address     The address to check for.

-

-  @return TRUE  The page at Address is a Guard page.

-  @return FALSE The page at Address is not a Guard page.

-**/

-BOOLEAN

-EFIAPI

-IsGuardPage (

-  IN EFI_PHYSICAL_ADDRESS  Address

-  )

-{

-  UINTN  BitMap;

-

-  //

-  // There must be at least one guarded page before and/or after given

-  // address if it's a Guard page. The bitmap pattern should be one of

-  // 001, 100 and 101

-  //

-  BitMap = GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 3);

-  return ((BitMap == BIT0) || (BitMap == BIT2) || (BitMap == (BIT2 | BIT0)));

-}

-

-/**

-  Check to see if the page at the given address is guarded or not.

-

-  @param[in]  Address     The address to check for.

-

-  @return TRUE  The page at Address is guarded.

-  @return FALSE The page at Address is not guarded.

-**/

-BOOLEAN

-EFIAPI

-IsMemoryGuarded (

-  IN EFI_PHYSICAL_ADDRESS  Address

-  )

-{

-  return (GetGuardMapBit (Address) == 1);

-}

-

-/**

-  Set the page at the given address to be a Guard page.

-

-  This is done by changing the page table attribute to be NOT PRESENT.

-

-  @param[in]  BaseAddress     Page address to Guard at.

-

-  @return VOID.

-**/

-VOID

-EFIAPI

-SetGuardPage (

-  IN  EFI_PHYSICAL_ADDRESS  BaseAddress

-  )

-{

-  EFI_STATUS  Status;

-

-  if (mSmmMemoryAttribute != NULL) {

-    mOnGuarding = TRUE;

-    Status      = mSmmMemoryAttribute->SetMemoryAttributes (

-                                         mSmmMemoryAttribute,

-                                         BaseAddress,

-                                         EFI_PAGE_SIZE,

-                                         EFI_MEMORY_RP

-                                         );

-    ASSERT_EFI_ERROR (Status);

-    mOnGuarding = FALSE;

-  }

-}

-

-/**

-  Unset the Guard page at the given address to the normal memory.

-

-  This is done by changing the page table attribute to be PRESENT.

-

-  @param[in]  BaseAddress     Page address to Guard at.

-

-  @return VOID.

-**/

-VOID

-EFIAPI

-UnsetGuardPage (

-  IN  EFI_PHYSICAL_ADDRESS  BaseAddress

-  )

-{

-  EFI_STATUS  Status;

-

-  if (mSmmMemoryAttribute != NULL) {

-    mOnGuarding = TRUE;

-    Status      = mSmmMemoryAttribute->ClearMemoryAttributes (

-                                         mSmmMemoryAttribute,

-                                         BaseAddress,

-                                         EFI_PAGE_SIZE,

-                                         EFI_MEMORY_RP|EFI_MEMORY_RO|EFI_MEMORY_XP

-                                         );

-    ASSERT_EFI_ERROR (Status);

-

-    if (gST == NULL) {

-      //

-      // Make sure EfiConventionalMemory is NX after SmmReadyToLock

-      //

-      Status = mSmmMemoryAttribute->SetMemoryAttributes (

-                                      mSmmMemoryAttribute,

-                                      BaseAddress,

-                                      EFI_PAGE_SIZE,

-                                      EFI_MEMORY_XP

-                                      );

-      ASSERT_EFI_ERROR (Status);

-    }

-

-    mOnGuarding = FALSE;

-  }

-}

-

-/**

-  Check to see if the memory at the given address should be guarded or not.

-

-  @param[in]  MemoryType      Memory type to check.

-  @param[in]  AllocateType    Allocation type to check.

-  @param[in]  PageOrPool      Indicate a page allocation or pool allocation.

-

-

-  @return TRUE  The given type of memory should be guarded.

-  @return FALSE The given type of memory should not be guarded.

-**/

-BOOLEAN

-IsMemoryTypeToGuard (

-  IN EFI_MEMORY_TYPE    MemoryType,

-  IN EFI_ALLOCATE_TYPE  AllocateType,

-  IN UINT8              PageOrPool

-  )

-{

-  UINT64  TestBit;

-  UINT64  ConfigBit;

-

-  if (  ((PcdGet8 (PcdHeapGuardPropertyMask) & PageOrPool) == 0)

-     || mOnGuarding

-     || (AllocateType == AllocateAddress))

-  {

-    return FALSE;

-  }

-

-  ConfigBit = 0;

-  if ((PageOrPool & GUARD_HEAP_TYPE_POOL) != 0) {

-    ConfigBit |= PcdGet64 (PcdHeapGuardPoolType);

-  }

-

-  if ((PageOrPool & GUARD_HEAP_TYPE_PAGE) != 0) {

-    ConfigBit |= PcdGet64 (PcdHeapGuardPageType);

-  }

-

-  if ((MemoryType == EfiRuntimeServicesData) ||

-      (MemoryType == EfiRuntimeServicesCode))

-  {

-    TestBit = LShiftU64 (1, MemoryType);

-  } else if (MemoryType == EfiMaxMemoryType) {

-    TestBit = (UINT64)-1;

-  } else {

-    TestBit = 0;

-  }

-

-  return ((ConfigBit & TestBit) != 0);

-}

-

-/**

-  Check to see if the pool at the given address should be guarded or not.

-

-  @param[in]  MemoryType      Pool type to check.

-

-

-  @return TRUE  The given type of pool should be guarded.

-  @return FALSE The given type of pool should not be guarded.

-**/

-BOOLEAN

-IsPoolTypeToGuard (

-  IN EFI_MEMORY_TYPE  MemoryType

-  )

-{

-  return IsMemoryTypeToGuard (

-           MemoryType,

-           AllocateAnyPages,

-           GUARD_HEAP_TYPE_POOL

-           );

-}

-

-/**

-  Check to see if the page at the given address should be guarded or not.

-

-  @param[in]  MemoryType      Page type to check.

-  @param[in]  AllocateType    Allocation type to check.

-

-  @return TRUE  The given type of page should be guarded.

-  @return FALSE The given type of page should not be guarded.

-**/

-BOOLEAN

-IsPageTypeToGuard (

-  IN EFI_MEMORY_TYPE    MemoryType,

-  IN EFI_ALLOCATE_TYPE  AllocateType

-  )

-{

-  return IsMemoryTypeToGuard (MemoryType, AllocateType, GUARD_HEAP_TYPE_PAGE);

-}

-

-/**

-  Check to see if the heap guard is enabled for page and/or pool allocation.

-

-  @return TRUE/FALSE.

-**/

-BOOLEAN

-IsHeapGuardEnabled (

-  VOID

-  )

-{

-  return IsMemoryTypeToGuard (

-           EfiMaxMemoryType,

-           AllocateAnyPages,

-           GUARD_HEAP_TYPE_POOL|GUARD_HEAP_TYPE_PAGE

-           );

-}

-

-/**

-  Set head Guard and tail Guard for the given memory range.

-

-  @param[in]  Memory          Base address of memory to set guard for.

-  @param[in]  NumberOfPages   Memory size in pages.

-

-  @return VOID.

-**/

-VOID

-SetGuardForMemory (

-  IN EFI_PHYSICAL_ADDRESS  Memory,

-  IN UINTN                 NumberOfPages

-  )

-{

-  EFI_PHYSICAL_ADDRESS  GuardPage;

-

-  //

-  // Set tail Guard

-  //

-  GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages);

-  if (!IsGuardPage (GuardPage)) {

-    SetGuardPage (GuardPage);

-  }

-

-  // Set head Guard

-  GuardPage = Memory - EFI_PAGES_TO_SIZE (1);

-  if (!IsGuardPage (GuardPage)) {

-    SetGuardPage (GuardPage);

-  }

-

-  //

-  // Mark the memory range as Guarded

-  //

-  SetGuardedMemoryBits (Memory, NumberOfPages);

-}

-

-/**

-  Unset head Guard and tail Guard for the given memory range.

-

-  @param[in]  Memory          Base address of memory to unset guard for.

-  @param[in]  NumberOfPages   Memory size in pages.

-

-  @return VOID.

-**/

-VOID

-UnsetGuardForMemory (

-  IN EFI_PHYSICAL_ADDRESS  Memory,

-  IN UINTN                 NumberOfPages

-  )

-{

-  EFI_PHYSICAL_ADDRESS  GuardPage;

-  UINT64                GuardBitmap;

-

-  if (NumberOfPages == 0) {

-    return;

-  }

-

-  //

-  // Head Guard must be one page before, if any.

-  //

-  //          MSB-> 1     0 <-LSB

-  //          -------------------

-  //  Head Guard -> 0     1 -> Don't free Head Guard  (shared Guard)

-  //  Head Guard -> 0     0 -> Free Head Guard either (not shared Guard)

-  //                1     X -> Don't free first page  (need a new Guard)

-  //                           (it'll be turned into a Guard page later)

-  //          -------------------

-  //      Start -> -1    -2

-  //

-  GuardPage   = Memory - EFI_PAGES_TO_SIZE (1);

-  GuardBitmap = GetGuardedMemoryBits (Memory - EFI_PAGES_TO_SIZE (2), 2);

-  if ((GuardBitmap & BIT1) == 0) {

-    //

-    // Head Guard exists.

-    //

-    if ((GuardBitmap & BIT0) == 0) {

-      //

-      // If the head Guard is not a tail Guard of adjacent memory block,

-      // unset it.

-      //

-      UnsetGuardPage (GuardPage);

-    }

-  } else {

-    //

-    // Pages before memory to free are still in Guard. It's a partial free

-    // case. Turn first page of memory block to free into a new Guard.

-    //

-    SetGuardPage (Memory);

-  }

-

-  //

-  // Tail Guard must be the page after this memory block to free, if any.

-  //

-  //   MSB-> 1     0 <-LSB

-  //  --------------------

-  //         1     0 <- Tail Guard -> Don't free Tail Guard  (shared Guard)

-  //         0     0 <- Tail Guard -> Free Tail Guard either (not shared Guard)

-  //         X     1               -> Don't free last page   (need a new Guard)

-  //                                 (it'll be turned into a Guard page later)

-  //  --------------------

-  //        +1    +0 <- End

-  //

-  GuardPage   = Memory + EFI_PAGES_TO_SIZE (NumberOfPages);

-  GuardBitmap = GetGuardedMemoryBits (GuardPage, 2);

-  if ((GuardBitmap & BIT0) == 0) {

-    //

-    // Tail Guard exists.

-    //

-    if ((GuardBitmap & BIT1) == 0) {

-      //

-      // If the tail Guard is not a head Guard of adjacent memory block,

-      // free it; otherwise, keep it.

-      //

-      UnsetGuardPage (GuardPage);

-    }

-  } else {

-    //

-    // Pages after memory to free are still in Guard. It's a partial free

-    // case. We need to keep one page to be a head Guard.

-    //

-    SetGuardPage (GuardPage - EFI_PAGES_TO_SIZE (1));

-  }

-

-  //

-  // No matter what, we just clear the mark of the Guarded memory.

-  //

-  ClearGuardedMemoryBits (Memory, NumberOfPages);

-}

-

-/**

-  Adjust the start address and number of pages to free according to Guard.

-

-  The purpose of this function is to keep the shared Guard page with adjacent

-  memory block if it's still in guard, or free it if no more sharing. Another

-  is to reserve pages as Guard pages in partial page free situation.

-

-  @param[in,out]  Memory          Base address of memory to free.

-  @param[in,out]  NumberOfPages   Size of memory to free.

-

-  @return VOID.

-**/

-VOID

-AdjustMemoryF (

-  IN OUT EFI_PHYSICAL_ADDRESS  *Memory,

-  IN OUT UINTN                 *NumberOfPages

-  )

-{

-  EFI_PHYSICAL_ADDRESS  Start;

-  EFI_PHYSICAL_ADDRESS  MemoryToTest;

-  UINTN                 PagesToFree;

-  UINT64                GuardBitmap;

-  UINT64                Attributes;

-

-  if ((Memory == NULL) || (NumberOfPages == NULL) || (*NumberOfPages == 0)) {

-    return;

-  }

-

-  Start       = *Memory;

-  PagesToFree = *NumberOfPages;

-

-  //

-  // In case the memory to free is marked as read-only (e.g. EfiRuntimeServicesCode).

-  //

-  if (mSmmMemoryAttribute != NULL) {

-    Attributes = 0;

-    mSmmMemoryAttribute->GetMemoryAttributes (

-                           mSmmMemoryAttribute,

-                           Start,

-                           EFI_PAGES_TO_SIZE (PagesToFree),

-                           &Attributes

-                           );

-    if ((Attributes & EFI_MEMORY_RO) != 0) {

-      mSmmMemoryAttribute->ClearMemoryAttributes (

-                             mSmmMemoryAttribute,

-                             Start,

-                             EFI_PAGES_TO_SIZE (PagesToFree),

-                             EFI_MEMORY_RO

-                             );

-    }

-  }

-

-  //

-  // Head Guard must be one page before, if any.

-  //

-  //          MSB-> 1     0 <-LSB

-  //          -------------------

-  //  Head Guard -> 0     1 -> Don't free Head Guard  (shared Guard)

-  //  Head Guard -> 0     0 -> Free Head Guard either (not shared Guard)

-  //                1     X -> Don't free first page  (need a new Guard)

-  //                           (it'll be turned into a Guard page later)

-  //          -------------------

-  //      Start -> -1    -2

-  //

-  MemoryToTest = Start - EFI_PAGES_TO_SIZE (2);

-  GuardBitmap  = GetGuardedMemoryBits (MemoryToTest, 2);

-  if ((GuardBitmap & BIT1) == 0) {

-    //

-    // Head Guard exists.

-    //

-    if ((GuardBitmap & BIT0) == 0) {

-      //

-      // If the head Guard is not a tail Guard of adjacent memory block,

-      // free it; otherwise, keep it.

-      //

-      Start       -= EFI_PAGES_TO_SIZE (1);

-      PagesToFree += 1;

-    }

-  } else {

-    //

-    // No Head Guard, and pages before memory to free are still in Guard. It's a

-    // partial free case. We need to keep one page to be a tail Guard.

-    //

-    Start       += EFI_PAGES_TO_SIZE (1);

-    PagesToFree -= 1;

-  }

-

-  //

-  // Tail Guard must be the page after this memory block to free, if any.

-  //

-  //   MSB-> 1     0 <-LSB

-  //  --------------------

-  //         1     0 <- Tail Guard -> Don't free Tail Guard  (shared Guard)

-  //         0     0 <- Tail Guard -> Free Tail Guard either (not shared Guard)

-  //         X     1               -> Don't free last page   (need a new Guard)

-  //                                 (it'll be turned into a Guard page later)

-  //  --------------------

-  //        +1    +0 <- End

-  //

-  MemoryToTest = Start + EFI_PAGES_TO_SIZE (PagesToFree);

-  GuardBitmap  = GetGuardedMemoryBits (MemoryToTest, 2);

-  if ((GuardBitmap & BIT0) == 0) {

-    //

-    // Tail Guard exists.

-    //

-    if ((GuardBitmap & BIT1) == 0) {

-      //

-      // If the tail Guard is not a head Guard of adjacent memory block,

-      // free it; otherwise, keep it.

-      //

-      PagesToFree += 1;

-    }

-  } else if (PagesToFree > 0) {

-    //

-    // No Tail Guard, and pages after memory to free are still in Guard. It's a

-    // partial free case. We need to keep one page to be a head Guard.

-    //

-    PagesToFree -= 1;

-  }

-

-  *Memory        = Start;

-  *NumberOfPages = PagesToFree;

-}

-

-/**

-  Adjust the pool head position to make sure the Guard page is adjavent to

-  pool tail or pool head.

-

-  @param[in]  Memory    Base address of memory allocated.

-  @param[in]  NoPages   Number of pages actually allocated.

-  @param[in]  Size      Size of memory requested.

-                        (plus pool head/tail overhead)

-

-  @return Address of pool head

-**/

-VOID *

-AdjustPoolHeadA (

-  IN EFI_PHYSICAL_ADDRESS  Memory,

-  IN UINTN                 NoPages,

-  IN UINTN                 Size

-  )

-{

-  if ((Memory == 0) || ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0)) {

-    //

-    // Pool head is put near the head Guard

-    //

-    return (VOID *)(UINTN)Memory;

-  }

-

-  //

-  // Pool head is put near the tail Guard

-  //

-  Size = ALIGN_VALUE (Size, 8);

-  return (VOID *)(UINTN)(Memory + EFI_PAGES_TO_SIZE (NoPages) - Size);

-}

-

-/**

-  Get the page base address according to pool head address.

-

-  @param[in]  Memory    Head address of pool to free.

-

-  @return Address of pool head.

-**/

-VOID *

-AdjustPoolHeadF (

-  IN EFI_PHYSICAL_ADDRESS  Memory

-  )

-{

-  if ((Memory == 0) || ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0)) {

-    //

-    // Pool head is put near the head Guard

-    //

-    return (VOID *)(UINTN)Memory;

-  }

-

-  //

-  // Pool head is put near the tail Guard

-  //

-  return (VOID *)(UINTN)(Memory & ~EFI_PAGE_MASK);

-}

-

-/**

-  Helper function of memory allocation with Guard pages.

-

-  @param  FreePageList           The free page node.

-  @param  NumberOfPages          Number of pages to be allocated.

-  @param  MaxAddress             Request to allocate memory below this address.

-  @param  MemoryType             Type of memory requested.

-

-  @return Memory address of allocated pages.

-**/

-UINTN

-InternalAllocMaxAddressWithGuard (

-  IN OUT LIST_ENTRY       *FreePageList,

-  IN     UINTN            NumberOfPages,

-  IN     UINTN            MaxAddress,

-  IN     EFI_MEMORY_TYPE  MemoryType

-

-  )

-{

-  LIST_ENTRY      *Node;

-  FREE_PAGE_LIST  *Pages;

-  UINTN           PagesToAlloc;

-  UINTN           HeadGuard;

-  UINTN           TailGuard;

-  UINTN           Address;

-

-  for (Node = FreePageList->BackLink; Node != FreePageList;

-       Node = Node->BackLink)

-  {

-    Pages = BASE_CR (Node, FREE_PAGE_LIST, Link);

-    if ((Pages->NumberOfPages >= NumberOfPages) &&

-        ((UINTN)Pages + EFI_PAGES_TO_SIZE (NumberOfPages) - 1 <= MaxAddress))

-    {

-      //

-      // We may need 1 or 2 more pages for Guard. Check it out.

-      //

-      PagesToAlloc = NumberOfPages;

-      TailGuard    = (UINTN)Pages + EFI_PAGES_TO_SIZE (Pages->NumberOfPages);

-      if (!IsGuardPage (TailGuard)) {

-        //

-        // Add one if no Guard at the end of current free memory block.

-        //

-        PagesToAlloc += 1;

-        TailGuard     = 0;

-      }

-

-      HeadGuard = (UINTN)Pages +

-                  EFI_PAGES_TO_SIZE (Pages->NumberOfPages - PagesToAlloc) -

-                  EFI_PAGE_SIZE;

-      if (!IsGuardPage (HeadGuard)) {

-        //

-        // Add one if no Guard at the page before the address to allocate

-        //

-        PagesToAlloc += 1;

-        HeadGuard     = 0;

-      }

-

-      if (Pages->NumberOfPages < PagesToAlloc) {

-        // Not enough space to allocate memory with Guards? Try next block.

-        continue;

-      }

-

-      Address = InternalAllocPagesOnOneNode (Pages, PagesToAlloc, MaxAddress);

-      ConvertSmmMemoryMapEntry (MemoryType, Address, PagesToAlloc, FALSE);

-      CoreFreeMemoryMapStack ();

-      if (HeadGuard == 0) {

-        // Don't pass the Guard page to user.

-        Address += EFI_PAGE_SIZE;

-      }

-

-      SetGuardForMemory (Address, NumberOfPages);

-      return Address;

-    }

-  }

-

-  return (UINTN)(-1);

-}

-

-/**

-  Helper function of memory free with Guard pages.

-

-  @param[in]  Memory                 Base address of memory being freed.

-  @param[in]  NumberOfPages          The number of pages to free.

-  @param[in]  AddRegion              If this memory is new added region.

-

-  @retval EFI_NOT_FOUND          Could not find the entry that covers the range.

-  @retval EFI_INVALID_PARAMETER  Address not aligned, Address is zero or NumberOfPages is zero.

-  @return EFI_SUCCESS            Pages successfully freed.

-**/

-EFI_STATUS

-SmmInternalFreePagesExWithGuard (

-  IN EFI_PHYSICAL_ADDRESS  Memory,

-  IN UINTN                 NumberOfPages,

-  IN BOOLEAN               AddRegion

-  )

-{

-  EFI_PHYSICAL_ADDRESS  MemoryToFree;

-  UINTN                 PagesToFree;

-

-  if (((Memory & EFI_PAGE_MASK) != 0) || (Memory == 0) || (NumberOfPages == 0)) {

-    return EFI_INVALID_PARAMETER;

-  }

-

-  MemoryToFree = Memory;

-  PagesToFree  = NumberOfPages;

-

-  AdjustMemoryF (&MemoryToFree, &PagesToFree);

-  UnsetGuardForMemory (Memory, NumberOfPages);

-  if (PagesToFree == 0) {

-    return EFI_SUCCESS;

-  }

-

-  return SmmInternalFreePagesEx (MemoryToFree, PagesToFree, AddRegion);

-}

-

-/**

-  Set all Guard pages which cannot be set during the non-SMM mode time.

-**/

-VOID

-SetAllGuardPages (

-  VOID

-  )

-{

-  UINTN    Entries[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINTN    Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINTN    Indices[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINT64   Tables[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINT64   Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINT64   TableEntry;

-  UINT64   Address;

-  UINT64   GuardPage;

-  INTN     Level;

-  UINTN    Index;

-  BOOLEAN  OnGuarding;

-

-  if ((mGuardedMemoryMap == 0) ||

-      (mMapLevel == 0) ||

-      (mMapLevel > GUARDED_HEAP_MAP_TABLE_DEPTH))

-  {

-    return;

-  }

-

-  CopyMem (Entries, mLevelMask, sizeof (Entries));

-  CopyMem (Shifts, mLevelShift, sizeof (Shifts));

-

-  SetMem (Tables, sizeof (Tables), 0);

-  SetMem (Addresses, sizeof (Addresses), 0);

-  SetMem (Indices, sizeof (Indices), 0);

-

-  Level         = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;

-  Tables[Level] = mGuardedMemoryMap;

-  Address       = 0;

-  OnGuarding    = FALSE;

-

-  DEBUG_CODE (

-    DumpGuardedMemoryBitmap ();

-    );

-

-  while (TRUE) {

-    if (Indices[Level] > Entries[Level]) {

-      Tables[Level] = 0;

-      Level        -= 1;

-    } else {

-      TableEntry = ((UINT64 *)(UINTN)(Tables[Level]))[Indices[Level]];

-      Address    = Addresses[Level];

-

-      if (TableEntry == 0) {

-        OnGuarding = FALSE;

-      } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {

-        Level           += 1;

-        Tables[Level]    = TableEntry;

-        Addresses[Level] = Address;

-        Indices[Level]   = 0;

-

-        continue;

-      } else {

-        Index = 0;

-        while (Index < GUARDED_HEAP_MAP_ENTRY_BITS) {

-          if ((TableEntry & 1) == 1) {

-            if (OnGuarding) {

-              GuardPage = 0;

-            } else {

-              GuardPage = Address - EFI_PAGE_SIZE;

-            }

-

-            OnGuarding = TRUE;

-          } else {

-            if (OnGuarding) {

-              GuardPage = Address;

-            } else {

-              GuardPage = 0;

-            }

-

-            OnGuarding = FALSE;

-          }

-

-          if (GuardPage != 0) {

-            SetGuardPage (GuardPage);

-          }

-

-          if (TableEntry == 0) {

-            break;

-          }

-

-          TableEntry = RShiftU64 (TableEntry, 1);

-          Address   += EFI_PAGE_SIZE;

-          Index     += 1;

-        }

-      }

-    }

-

-    if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) {

-      break;

-    }

-

-    Indices[Level]  += 1;

-    Address          = (Level == 0) ? 0 : Addresses[Level - 1];

-    Addresses[Level] = Address | LShiftU64 (Indices[Level], Shifts[Level]);

-  }

-}

-

-/**

-  Hook function used to set all Guard pages after entering SMM mode.

-**/

-VOID

-SmmEntryPointMemoryManagementHook (

-  VOID

-  )

-{

-  EFI_STATUS  Status;

-

-  if (mSmmMemoryAttribute == NULL) {

-    Status = SmmLocateProtocol (

-               &gEdkiiSmmMemoryAttributeProtocolGuid,

-               NULL,

-               (VOID **)&mSmmMemoryAttribute

-               );

-    if (!EFI_ERROR (Status)) {

-      SetAllGuardPages ();

-    }

-  }

-}

-

-/**

-  Helper function to convert a UINT64 value in binary to a string.

-

-  @param[in]  Value       Value of a UINT64 integer.

-  @param[out] BinString   String buffer to contain the conversion result.

-

-  @return VOID.

-**/

-VOID

-Uint64ToBinString (

-  IN  UINT64  Value,

-  OUT CHAR8   *BinString

-  )

-{

-  UINTN  Index;

-

-  if (BinString == NULL) {

-    return;

-  }

-

-  for (Index = 64; Index > 0; --Index) {

-    BinString[Index - 1] = '0' + (Value & 1);

-    Value                = RShiftU64 (Value, 1);

-  }

-

-  BinString[64] = '\0';

-}

-

-/**

-  Dump the guarded memory bit map.

-**/

-VOID

-EFIAPI

-DumpGuardedMemoryBitmap (

-  VOID

-  )

-{

-  UINTN   Entries[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINTN   Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINTN   Indices[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINT64  Tables[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINT64  Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH];

-  UINT64  TableEntry;

-  UINT64  Address;

-  INTN    Level;

-  UINTN   RepeatZero;

-  CHAR8   String[GUARDED_HEAP_MAP_ENTRY_BITS + 1];

-  CHAR8   *Ruler1;

-  CHAR8   *Ruler2;

-

-  if ((mGuardedMemoryMap == 0) ||

-      (mMapLevel == 0) ||

-      (mMapLevel > GUARDED_HEAP_MAP_TABLE_DEPTH))

-  {

-    return;

-  }

-

-  Ruler1 = "               3               2               1               0";

-  Ruler2 = "FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210";

-

-  DEBUG ((

-    HEAP_GUARD_DEBUG_LEVEL,

-    "============================="

-    " Guarded Memory Bitmap "

-    "==============================\r\n"

-    ));

-  DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "                  %a\r\n", Ruler1));

-  DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "                  %a\r\n", Ruler2));

-

-  CopyMem (Entries, mLevelMask, sizeof (Entries));

-  CopyMem (Shifts, mLevelShift, sizeof (Shifts));

-

-  SetMem (Indices, sizeof (Indices), 0);

-  SetMem (Tables, sizeof (Tables), 0);

-  SetMem (Addresses, sizeof (Addresses), 0);

-

-  Level         = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;

-  Tables[Level] = mGuardedMemoryMap;

-  Address       = 0;

-  RepeatZero    = 0;

-

-  while (TRUE) {

-    if (Indices[Level] > Entries[Level]) {

-      Tables[Level] = 0;

-      Level        -= 1;

-      RepeatZero    = 0;

-

-      DEBUG ((

-        HEAP_GUARD_DEBUG_LEVEL,

-        "========================================="

-        "=========================================\r\n"

-        ));

-    } else {

-      TableEntry = ((UINT64 *)(UINTN)Tables[Level])[Indices[Level]];

-      Address    = Addresses[Level];

-

-      if (TableEntry == 0) {

-        if (Level == GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {

-          if (RepeatZero == 0) {

-            Uint64ToBinString (TableEntry, String);

-            DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String));

-          } else if (RepeatZero == 1) {

-            DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "...             : ...\r\n"));

-          }

-

-          RepeatZero += 1;

-        }

-      } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {

-        Level           += 1;

-        Tables[Level]    = TableEntry;

-        Addresses[Level] = Address;

-        Indices[Level]   = 0;

-        RepeatZero       = 0;

-

-        continue;

-      } else {

-        RepeatZero = 0;

-        Uint64ToBinString (TableEntry, String);

-        DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String));

-      }

-    }

-

-    if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) {

-      break;

-    }

-

-    Indices[Level]  += 1;

-    Address          = (Level == 0) ? 0 : Addresses[Level - 1];

-    Addresses[Level] = Address | LShiftU64 (Indices[Level], Shifts[Level]);

-  }

-}

-

-/**

-  Debug function used to verify if the Guard page is well set or not.

-

-  @param[in]  BaseAddress     Address of memory to check.

-  @param[in]  NumberOfPages   Size of memory in pages.

-

-  @return TRUE    The head Guard and tail Guard are both well set.

-  @return FALSE   The head Guard and/or tail Guard are not well set.

-**/

-BOOLEAN

-VerifyMemoryGuard (

-  IN  EFI_PHYSICAL_ADDRESS  BaseAddress,

-  IN  UINTN                 NumberOfPages

-  )

-{

-  EFI_STATUS            Status;

-  UINT64                Attribute;

-  EFI_PHYSICAL_ADDRESS  Address;

-

-  if (mSmmMemoryAttribute == NULL) {

-    return TRUE;

-  }

-

-  Attribute = 0;

-  Address   = BaseAddress - EFI_PAGE_SIZE;

-  Status    = mSmmMemoryAttribute->GetMemoryAttributes (

-                                     mSmmMemoryAttribute,

-                                     Address,

-                                     EFI_PAGE_SIZE,

-                                     &Attribute

-                                     );

-  if (EFI_ERROR (Status) || ((Attribute & EFI_MEMORY_RP) == 0)) {

-    DEBUG ((

-      DEBUG_ERROR,

-      "Head Guard is not set at: %016lx (%016lX)!!!\r\n",

-      Address,

-      Attribute

-      ));

-    DumpGuardedMemoryBitmap ();

-    return FALSE;

-  }

-

-  Attribute = 0;

-  Address   = BaseAddress + EFI_PAGES_TO_SIZE (NumberOfPages);

-  Status    = mSmmMemoryAttribute->GetMemoryAttributes (

-                                     mSmmMemoryAttribute,

-                                     Address,

-                                     EFI_PAGE_SIZE,

-                                     &Attribute

-                                     );

-  if (EFI_ERROR (Status) || ((Attribute & EFI_MEMORY_RP) == 0)) {

-    DEBUG ((

-      DEBUG_ERROR,

-      "Tail Guard is not set at: %016lx (%016lX)!!!\r\n",

-      Address,

-      Attribute

-      ));

-    DumpGuardedMemoryBitmap ();

-    return FALSE;

-  }

-

-  return TRUE;

-}

+/** @file
+  UEFI Heap Guard functions.
+
+Copyright (c) 2017-2018, Intel Corporation. All rights reserved.<BR>
+SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#include "HeapGuard.h"
+
+//
+// Global to avoid infinite reentrance of memory allocation when updating
+// page table attributes, which may need allocating pages for new PDE/PTE.
+//
+GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN  mOnGuarding = FALSE;
+
+//
+// Pointer to table tracking the Guarded memory with bitmap, in which  '1'
+// is used to indicate memory guarded. '0' might be free memory or Guard
+// page itself, depending on status of memory adjacent to it.
+//
+GLOBAL_REMOVE_IF_UNREFERENCED UINT64  mGuardedMemoryMap = 0;
+
+//
+// Current depth level of map table pointed by mGuardedMemoryMap.
+// mMapLevel must be initialized at least by 1. It will be automatically
+// updated according to the address of memory just tracked.
+//
+GLOBAL_REMOVE_IF_UNREFERENCED UINTN  mMapLevel = 1;
+
+//
+// Shift and mask for each level of map table
+//
+GLOBAL_REMOVE_IF_UNREFERENCED UINTN  mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH]
+  = GUARDED_HEAP_MAP_TABLE_DEPTH_SHIFTS;
+GLOBAL_REMOVE_IF_UNREFERENCED UINTN  mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH]
+  = GUARDED_HEAP_MAP_TABLE_DEPTH_MASKS;
+
+//
+// SMM memory attribute protocol
+//
+EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL  *mSmmMemoryAttribute = NULL;
+
+/**
+  Set corresponding bits in bitmap table to 1 according to the address.
+
+  @param[in]  Address     Start address to set for.
+  @param[in]  BitNumber   Number of bits to set.
+  @param[in]  BitMap      Pointer to bitmap which covers the Address.
+
+  @return VOID
+**/
+STATIC
+VOID
+SetBits (
+  IN EFI_PHYSICAL_ADDRESS  Address,
+  IN UINTN                 BitNumber,
+  IN UINT64                *BitMap
+  )
+{
+  UINTN  Lsbs;
+  UINTN  Qwords;
+  UINTN  Msbs;
+  UINTN  StartBit;
+  UINTN  EndBit;
+
+  StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);
+  EndBit   = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;
+
+  if ((StartBit + BitNumber) >= GUARDED_HEAP_MAP_ENTRY_BITS) {
+    Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) %
+           GUARDED_HEAP_MAP_ENTRY_BITS;
+    Lsbs   = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;
+    Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS;
+  } else {
+    Msbs   = BitNumber;
+    Lsbs   = 0;
+    Qwords = 0;
+  }
+
+  if (Msbs > 0) {
+    *BitMap |= LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit);
+    BitMap  += 1;
+  }
+
+  if (Qwords > 0) {
+    SetMem64 (
+      (VOID *)BitMap,
+      Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES,
+      (UINT64)-1
+      );
+    BitMap += Qwords;
+  }
+
+  if (Lsbs > 0) {
+    *BitMap |= (LShiftU64 (1, Lsbs) - 1);
+  }
+}
+
+/**
+  Set corresponding bits in bitmap table to 0 according to the address.
+
+  @param[in]  Address     Start address to set for.
+  @param[in]  BitNumber   Number of bits to set.
+  @param[in]  BitMap      Pointer to bitmap which covers the Address.
+
+  @return VOID.
+**/
+STATIC
+VOID
+ClearBits (
+  IN EFI_PHYSICAL_ADDRESS  Address,
+  IN UINTN                 BitNumber,
+  IN UINT64                *BitMap
+  )
+{
+  UINTN  Lsbs;
+  UINTN  Qwords;
+  UINTN  Msbs;
+  UINTN  StartBit;
+  UINTN  EndBit;
+
+  StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);
+  EndBit   = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;
+
+  if ((StartBit + BitNumber) >= GUARDED_HEAP_MAP_ENTRY_BITS) {
+    Msbs = (GUARDED_HEAP_MAP_ENTRY_BITS - StartBit) %
+           GUARDED_HEAP_MAP_ENTRY_BITS;
+    Lsbs   = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;
+    Qwords = (BitNumber - Msbs) / GUARDED_HEAP_MAP_ENTRY_BITS;
+  } else {
+    Msbs   = BitNumber;
+    Lsbs   = 0;
+    Qwords = 0;
+  }
+
+  if (Msbs > 0) {
+    *BitMap &= ~LShiftU64 (LShiftU64 (1, Msbs) - 1, StartBit);
+    BitMap  += 1;
+  }
+
+  if (Qwords > 0) {
+    SetMem64 ((VOID *)BitMap, Qwords * GUARDED_HEAP_MAP_ENTRY_BYTES, 0);
+    BitMap += Qwords;
+  }
+
+  if (Lsbs > 0) {
+    *BitMap &= ~(LShiftU64 (1, Lsbs) - 1);
+  }
+}
+
+/**
+  Get corresponding bits in bitmap table according to the address.
+
+  The value of bit 0 corresponds to the status of memory at given Address.
+  No more than 64 bits can be retrieved in one call.
+
+  @param[in]  Address     Start address to retrieve bits for.
+  @param[in]  BitNumber   Number of bits to get.
+  @param[in]  BitMap      Pointer to bitmap which covers the Address.
+
+  @return An integer containing the bits information.
+**/
+STATIC
+UINT64
+GetBits (
+  IN EFI_PHYSICAL_ADDRESS  Address,
+  IN UINTN                 BitNumber,
+  IN UINT64                *BitMap
+  )
+{
+  UINTN   StartBit;
+  UINTN   EndBit;
+  UINTN   Lsbs;
+  UINTN   Msbs;
+  UINT64  Result;
+
+  ASSERT (BitNumber <= GUARDED_HEAP_MAP_ENTRY_BITS);
+
+  StartBit = (UINTN)GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address);
+  EndBit   = (StartBit + BitNumber - 1) % GUARDED_HEAP_MAP_ENTRY_BITS;
+
+  if ((StartBit + BitNumber) > GUARDED_HEAP_MAP_ENTRY_BITS) {
+    Msbs = GUARDED_HEAP_MAP_ENTRY_BITS - StartBit;
+    Lsbs = (EndBit + 1) % GUARDED_HEAP_MAP_ENTRY_BITS;
+  } else {
+    Msbs = BitNumber;
+    Lsbs = 0;
+  }
+
+  if ((StartBit == 0) && (BitNumber == GUARDED_HEAP_MAP_ENTRY_BITS)) {
+    Result = *BitMap;
+  } else {
+    Result = RShiftU64 ((*BitMap), StartBit) & (LShiftU64 (1, Msbs) - 1);
+    if (Lsbs > 0) {
+      BitMap += 1;
+      Result |= LShiftU64 ((*BitMap) & (LShiftU64 (1, Lsbs) - 1), Msbs);
+    }
+  }
+
+  return Result;
+}
+
+/**
+  Helper function to allocate pages without Guard for internal uses.
+
+  @param[in]  Pages       Page number.
+
+  @return Address of memory allocated.
+**/
+VOID *
+PageAlloc (
+  IN UINTN  Pages
+  )
+{
+  EFI_STATUS            Status;
+  EFI_PHYSICAL_ADDRESS  Memory;
+
+  Status = SmmInternalAllocatePages (
+             AllocateAnyPages,
+             EfiRuntimeServicesData,
+             Pages,
+             &Memory,
+             FALSE
+             );
+  if (EFI_ERROR (Status)) {
+    Memory = 0;
+  }
+
+  return (VOID *)(UINTN)Memory;
+}
+
+/**
+  Locate the pointer of bitmap from the guarded memory bitmap tables, which
+  covers the given Address.
+
+  @param[in]  Address       Start address to search the bitmap for.
+  @param[in]  AllocMapUnit  Flag to indicate memory allocation for the table.
+  @param[out] BitMap        Pointer to bitmap which covers the Address.
+
+  @return The bit number from given Address to the end of current map table.
+**/
+UINTN
+FindGuardedMemoryMap (
+  IN  EFI_PHYSICAL_ADDRESS  Address,
+  IN  BOOLEAN               AllocMapUnit,
+  OUT UINT64                **BitMap
+  )
+{
+  UINTN   Level;
+  UINT64  *GuardMap;
+  UINT64  MapMemory;
+  UINTN   Index;
+  UINTN   Size;
+  UINTN   BitsToUnitEnd;
+
+  //
+  // Adjust current map table depth according to the address to access
+  //
+  while (AllocMapUnit &&
+         mMapLevel < GUARDED_HEAP_MAP_TABLE_DEPTH &&
+         RShiftU64 (
+           Address,
+           mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1]
+           ) != 0)
+  {
+    if (mGuardedMemoryMap != 0) {
+      Size = (mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel - 1] + 1)
+             * GUARDED_HEAP_MAP_ENTRY_BYTES;
+      MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size));
+      ASSERT (MapMemory != 0);
+
+      SetMem ((VOID *)(UINTN)MapMemory, Size, 0);
+
+      *(UINT64 *)(UINTN)MapMemory = mGuardedMemoryMap;
+      mGuardedMemoryMap           = MapMemory;
+    }
+
+    mMapLevel++;
+  }
+
+  GuardMap = &mGuardedMemoryMap;
+  for (Level = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;
+       Level < GUARDED_HEAP_MAP_TABLE_DEPTH;
+       ++Level)
+  {
+    if (*GuardMap == 0) {
+      if (!AllocMapUnit) {
+        GuardMap = NULL;
+        break;
+      }
+
+      Size      = (mLevelMask[Level] + 1) * GUARDED_HEAP_MAP_ENTRY_BYTES;
+      MapMemory = (UINT64)(UINTN)PageAlloc (EFI_SIZE_TO_PAGES (Size));
+      ASSERT (MapMemory != 0);
+
+      SetMem ((VOID *)(UINTN)MapMemory, Size, 0);
+      *GuardMap = MapMemory;
+    }
+
+    Index    = (UINTN)RShiftU64 (Address, mLevelShift[Level]);
+    Index   &= mLevelMask[Level];
+    GuardMap = (UINT64 *)(UINTN)((*GuardMap) + Index * sizeof (UINT64));
+  }
+
+  BitsToUnitEnd = GUARDED_HEAP_MAP_BITS - GUARDED_HEAP_MAP_BIT_INDEX (Address);
+  *BitMap       = GuardMap;
+
+  return BitsToUnitEnd;
+}
+
+/**
+  Set corresponding bits in bitmap table to 1 according to given memory range.
+
+  @param[in]  Address       Memory address to guard from.
+  @param[in]  NumberOfPages Number of pages to guard.
+
+  @return VOID
+**/
+VOID
+EFIAPI
+SetGuardedMemoryBits (
+  IN EFI_PHYSICAL_ADDRESS  Address,
+  IN UINTN                 NumberOfPages
+  )
+{
+  UINT64  *BitMap;
+  UINTN   Bits;
+  UINTN   BitsToUnitEnd;
+
+  while (NumberOfPages > 0) {
+    BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap);
+    ASSERT (BitMap != NULL);
+
+    if (NumberOfPages > BitsToUnitEnd) {
+      // Cross map unit
+      Bits = BitsToUnitEnd;
+    } else {
+      Bits = NumberOfPages;
+    }
+
+    SetBits (Address, Bits, BitMap);
+
+    NumberOfPages -= Bits;
+    Address       += EFI_PAGES_TO_SIZE (Bits);
+  }
+}
+
+/**
+  Clear corresponding bits in bitmap table according to given memory range.
+
+  @param[in]  Address       Memory address to unset from.
+  @param[in]  NumberOfPages Number of pages to unset guard.
+
+  @return VOID
+**/
+VOID
+EFIAPI
+ClearGuardedMemoryBits (
+  IN EFI_PHYSICAL_ADDRESS  Address,
+  IN UINTN                 NumberOfPages
+  )
+{
+  UINT64  *BitMap;
+  UINTN   Bits;
+  UINTN   BitsToUnitEnd;
+
+  while (NumberOfPages > 0) {
+    BitsToUnitEnd = FindGuardedMemoryMap (Address, TRUE, &BitMap);
+    ASSERT (BitMap != NULL);
+
+    if (NumberOfPages > BitsToUnitEnd) {
+      // Cross map unit
+      Bits = BitsToUnitEnd;
+    } else {
+      Bits = NumberOfPages;
+    }
+
+    ClearBits (Address, Bits, BitMap);
+
+    NumberOfPages -= Bits;
+    Address       += EFI_PAGES_TO_SIZE (Bits);
+  }
+}
+
+/**
+  Retrieve corresponding bits in bitmap table according to given memory range.
+
+  @param[in]  Address       Memory address to retrieve from.
+  @param[in]  NumberOfPages Number of pages to retrieve.
+
+  @return An integer containing the guarded memory bitmap.
+**/
+UINTN
+GetGuardedMemoryBits (
+  IN EFI_PHYSICAL_ADDRESS  Address,
+  IN UINTN                 NumberOfPages
+  )
+{
+  UINT64  *BitMap;
+  UINTN   Bits;
+  UINTN   Result;
+  UINTN   Shift;
+  UINTN   BitsToUnitEnd;
+
+  ASSERT (NumberOfPages <= GUARDED_HEAP_MAP_ENTRY_BITS);
+
+  Result = 0;
+  Shift  = 0;
+  while (NumberOfPages > 0) {
+    BitsToUnitEnd = FindGuardedMemoryMap (Address, FALSE, &BitMap);
+
+    if (NumberOfPages > BitsToUnitEnd) {
+      // Cross map unit
+      Bits = BitsToUnitEnd;
+    } else {
+      Bits = NumberOfPages;
+    }
+
+    if (BitMap != NULL) {
+      Result |= LShiftU64 (GetBits (Address, Bits, BitMap), Shift);
+    }
+
+    Shift         += Bits;
+    NumberOfPages -= Bits;
+    Address       += EFI_PAGES_TO_SIZE (Bits);
+  }
+
+  return Result;
+}
+
+/**
+  Get bit value in bitmap table for the given address.
+
+  @param[in]  Address     The address to retrieve for.
+
+  @return 1 or 0.
+**/
+UINTN
+EFIAPI
+GetGuardMapBit (
+  IN EFI_PHYSICAL_ADDRESS  Address
+  )
+{
+  UINT64  *GuardMap;
+
+  FindGuardedMemoryMap (Address, FALSE, &GuardMap);
+  if (GuardMap != NULL) {
+    if (RShiftU64 (
+          *GuardMap,
+          GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address)
+          ) & 1)
+    {
+      return 1;
+    }
+  }
+
+  return 0;
+}
+
+/**
+  Check to see if the page at the given address is a Guard page or not.
+
+  @param[in]  Address     The address to check for.
+
+  @return TRUE  The page at Address is a Guard page.
+  @return FALSE The page at Address is not a Guard page.
+**/
+BOOLEAN
+EFIAPI
+IsGuardPage (
+  IN EFI_PHYSICAL_ADDRESS  Address
+  )
+{
+  UINTN  BitMap;
+
+  //
+  // There must be at least one guarded page before and/or after given
+  // address if it's a Guard page. The bitmap pattern should be one of
+  // 001, 100 and 101
+  //
+  BitMap = GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 3);
+  return ((BitMap == BIT0) || (BitMap == BIT2) || (BitMap == (BIT2 | BIT0)));
+}
+
+/**
+  Check to see if the page at the given address is guarded or not.
+
+  @param[in]  Address     The address to check for.
+
+  @return TRUE  The page at Address is guarded.
+  @return FALSE The page at Address is not guarded.
+**/
+BOOLEAN
+EFIAPI
+IsMemoryGuarded (
+  IN EFI_PHYSICAL_ADDRESS  Address
+  )
+{
+  return (GetGuardMapBit (Address) == 1);
+}
+
+/**
+  Set the page at the given address to be a Guard page.
+
+  This is done by changing the page table attribute to be NOT PRESENT.
+
+  @param[in]  BaseAddress     Page address to Guard at.
+
+  @return VOID.
+**/
+VOID
+EFIAPI
+SetGuardPage (
+  IN  EFI_PHYSICAL_ADDRESS  BaseAddress
+  )
+{
+  EFI_STATUS  Status;
+
+  if (mSmmMemoryAttribute != NULL) {
+    mOnGuarding = TRUE;
+    Status      = mSmmMemoryAttribute->SetMemoryAttributes (
+                                         mSmmMemoryAttribute,
+                                         BaseAddress,
+                                         EFI_PAGE_SIZE,
+                                         EFI_MEMORY_RP
+                                         );
+    ASSERT_EFI_ERROR (Status);
+    mOnGuarding = FALSE;
+  }
+}
+
+/**
+  Unset the Guard page at the given address to the normal memory.
+
+  This is done by changing the page table attribute to be PRESENT.
+
+  @param[in]  BaseAddress     Page address to Guard at.
+
+  @return VOID.
+**/
+VOID
+EFIAPI
+UnsetGuardPage (
+  IN  EFI_PHYSICAL_ADDRESS  BaseAddress
+  )
+{
+  EFI_STATUS  Status;
+
+  if (mSmmMemoryAttribute != NULL) {
+    mOnGuarding = TRUE;
+    Status      = mSmmMemoryAttribute->ClearMemoryAttributes (
+                                         mSmmMemoryAttribute,
+                                         BaseAddress,
+                                         EFI_PAGE_SIZE,
+                                         EFI_MEMORY_RP|EFI_MEMORY_RO|EFI_MEMORY_XP
+                                         );
+    ASSERT_EFI_ERROR (Status);
+
+    if (gST == NULL) {
+      //
+      // Make sure EfiConventionalMemory is NX after SmmReadyToLock
+      //
+      Status = mSmmMemoryAttribute->SetMemoryAttributes (
+                                      mSmmMemoryAttribute,
+                                      BaseAddress,
+                                      EFI_PAGE_SIZE,
+                                      EFI_MEMORY_XP
+                                      );
+      ASSERT_EFI_ERROR (Status);
+    }
+
+    mOnGuarding = FALSE;
+  }
+}
+
+/**
+  Check to see if the memory at the given address should be guarded or not.
+
+  @param[in]  MemoryType      Memory type to check.
+  @param[in]  AllocateType    Allocation type to check.
+  @param[in]  PageOrPool      Indicate a page allocation or pool allocation.
+
+
+  @return TRUE  The given type of memory should be guarded.
+  @return FALSE The given type of memory should not be guarded.
+**/
+BOOLEAN
+IsMemoryTypeToGuard (
+  IN EFI_MEMORY_TYPE    MemoryType,
+  IN EFI_ALLOCATE_TYPE  AllocateType,
+  IN UINT8              PageOrPool
+  )
+{
+  UINT64  TestBit;
+  UINT64  ConfigBit;
+
+  if (  ((PcdGet8 (PcdHeapGuardPropertyMask) & PageOrPool) == 0)
+     || mOnGuarding
+     || (AllocateType == AllocateAddress))
+  {
+    return FALSE;
+  }
+
+  ConfigBit = 0;
+  if ((PageOrPool & GUARD_HEAP_TYPE_POOL) != 0) {
+    ConfigBit |= PcdGet64 (PcdHeapGuardPoolType);
+  }
+
+  if ((PageOrPool & GUARD_HEAP_TYPE_PAGE) != 0) {
+    ConfigBit |= PcdGet64 (PcdHeapGuardPageType);
+  }
+
+  if ((MemoryType == EfiRuntimeServicesData) ||
+      (MemoryType == EfiRuntimeServicesCode))
+  {
+    TestBit = LShiftU64 (1, MemoryType);
+  } else if (MemoryType == EfiMaxMemoryType) {
+    TestBit = (UINT64)-1;
+  } else {
+    TestBit = 0;
+  }
+
+  return ((ConfigBit & TestBit) != 0);
+}
+
+/**
+  Check to see if the pool at the given address should be guarded or not.
+
+  @param[in]  MemoryType      Pool type to check.
+
+
+  @return TRUE  The given type of pool should be guarded.
+  @return FALSE The given type of pool should not be guarded.
+**/
+BOOLEAN
+IsPoolTypeToGuard (
+  IN EFI_MEMORY_TYPE  MemoryType
+  )
+{
+  return IsMemoryTypeToGuard (
+           MemoryType,
+           AllocateAnyPages,
+           GUARD_HEAP_TYPE_POOL
+           );
+}
+
+/**
+  Check to see if the page at the given address should be guarded or not.
+
+  @param[in]  MemoryType      Page type to check.
+  @param[in]  AllocateType    Allocation type to check.
+
+  @return TRUE  The given type of page should be guarded.
+  @return FALSE The given type of page should not be guarded.
+**/
+BOOLEAN
+IsPageTypeToGuard (
+  IN EFI_MEMORY_TYPE    MemoryType,
+  IN EFI_ALLOCATE_TYPE  AllocateType
+  )
+{
+  return IsMemoryTypeToGuard (MemoryType, AllocateType, GUARD_HEAP_TYPE_PAGE);
+}
+
+/**
+  Check to see if the heap guard is enabled for page and/or pool allocation.
+
+  @return TRUE/FALSE.
+**/
+BOOLEAN
+IsHeapGuardEnabled (
+  VOID
+  )
+{
+  return IsMemoryTypeToGuard (
+           EfiMaxMemoryType,
+           AllocateAnyPages,
+           GUARD_HEAP_TYPE_POOL|GUARD_HEAP_TYPE_PAGE
+           );
+}
+
+/**
+  Set head Guard and tail Guard for the given memory range.
+
+  @param[in]  Memory          Base address of memory to set guard for.
+  @param[in]  NumberOfPages   Memory size in pages.
+
+  @return VOID.
+**/
+VOID
+SetGuardForMemory (
+  IN EFI_PHYSICAL_ADDRESS  Memory,
+  IN UINTN                 NumberOfPages
+  )
+{
+  EFI_PHYSICAL_ADDRESS  GuardPage;
+
+  //
+  // Set tail Guard
+  //
+  GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages);
+  if (!IsGuardPage (GuardPage)) {
+    SetGuardPage (GuardPage);
+  }
+
+  // Set head Guard
+  GuardPage = Memory - EFI_PAGES_TO_SIZE (1);
+  if (!IsGuardPage (GuardPage)) {
+    SetGuardPage (GuardPage);
+  }
+
+  //
+  // Mark the memory range as Guarded
+  //
+  SetGuardedMemoryBits (Memory, NumberOfPages);
+}
+
+/**
+  Unset head Guard and tail Guard for the given memory range.
+
+  @param[in]  Memory          Base address of memory to unset guard for.
+  @param[in]  NumberOfPages   Memory size in pages.
+
+  @return VOID.
+**/
+VOID
+UnsetGuardForMemory (
+  IN EFI_PHYSICAL_ADDRESS  Memory,
+  IN UINTN                 NumberOfPages
+  )
+{
+  EFI_PHYSICAL_ADDRESS  GuardPage;
+  UINT64                GuardBitmap;
+
+  if (NumberOfPages == 0) {
+    return;
+  }
+
+  //
+  // Head Guard must be one page before, if any.
+  //
+  //          MSB-> 1     0 <-LSB
+  //          -------------------
+  //  Head Guard -> 0     1 -> Don't free Head Guard  (shared Guard)
+  //  Head Guard -> 0     0 -> Free Head Guard either (not shared Guard)
+  //                1     X -> Don't free first page  (need a new Guard)
+  //                           (it'll be turned into a Guard page later)
+  //          -------------------
+  //      Start -> -1    -2
+  //
+  GuardPage   = Memory - EFI_PAGES_TO_SIZE (1);
+  GuardBitmap = GetGuardedMemoryBits (Memory - EFI_PAGES_TO_SIZE (2), 2);
+  if ((GuardBitmap & BIT1) == 0) {
+    //
+    // Head Guard exists.
+    //
+    if ((GuardBitmap & BIT0) == 0) {
+      //
+      // If the head Guard is not a tail Guard of adjacent memory block,
+      // unset it.
+      //
+      UnsetGuardPage (GuardPage);
+    }
+  } else {
+    //
+    // Pages before memory to free are still in Guard. It's a partial free
+    // case. Turn first page of memory block to free into a new Guard.
+    //
+    SetGuardPage (Memory);
+  }
+
+  //
+  // Tail Guard must be the page after this memory block to free, if any.
+  //
+  //   MSB-> 1     0 <-LSB
+  //  --------------------
+  //         1     0 <- Tail Guard -> Don't free Tail Guard  (shared Guard)
+  //         0     0 <- Tail Guard -> Free Tail Guard either (not shared Guard)
+  //         X     1               -> Don't free last page   (need a new Guard)
+  //                                 (it'll be turned into a Guard page later)
+  //  --------------------
+  //        +1    +0 <- End
+  //
+  GuardPage   = Memory + EFI_PAGES_TO_SIZE (NumberOfPages);
+  GuardBitmap = GetGuardedMemoryBits (GuardPage, 2);
+  if ((GuardBitmap & BIT0) == 0) {
+    //
+    // Tail Guard exists.
+    //
+    if ((GuardBitmap & BIT1) == 0) {
+      //
+      // If the tail Guard is not a head Guard of adjacent memory block,
+      // free it; otherwise, keep it.
+      //
+      UnsetGuardPage (GuardPage);
+    }
+  } else {
+    //
+    // Pages after memory to free are still in Guard. It's a partial free
+    // case. We need to keep one page to be a head Guard.
+    //
+    SetGuardPage (GuardPage - EFI_PAGES_TO_SIZE (1));
+  }
+
+  //
+  // No matter what, we just clear the mark of the Guarded memory.
+  //
+  ClearGuardedMemoryBits (Memory, NumberOfPages);
+}
+
+/**
+  Adjust the start address and number of pages to free according to Guard.
+
+  The purpose of this function is to keep the shared Guard page with adjacent
+  memory block if it's still in guard, or free it if no more sharing. Another
+  is to reserve pages as Guard pages in partial page free situation.
+
+  @param[in,out]  Memory          Base address of memory to free.
+  @param[in,out]  NumberOfPages   Size of memory to free.
+
+  @return VOID.
+**/
+VOID
+AdjustMemoryF (
+  IN OUT EFI_PHYSICAL_ADDRESS  *Memory,
+  IN OUT UINTN                 *NumberOfPages
+  )
+{
+  EFI_PHYSICAL_ADDRESS  Start;
+  EFI_PHYSICAL_ADDRESS  MemoryToTest;
+  UINTN                 PagesToFree;
+  UINT64                GuardBitmap;
+  UINT64                Attributes;
+
+  if ((Memory == NULL) || (NumberOfPages == NULL) || (*NumberOfPages == 0)) {
+    return;
+  }
+
+  Start       = *Memory;
+  PagesToFree = *NumberOfPages;
+
+  //
+  // In case the memory to free is marked as read-only (e.g. EfiRuntimeServicesCode).
+  //
+  if (mSmmMemoryAttribute != NULL) {
+    Attributes = 0;
+    mSmmMemoryAttribute->GetMemoryAttributes (
+                           mSmmMemoryAttribute,
+                           Start,
+                           EFI_PAGES_TO_SIZE (PagesToFree),
+                           &Attributes
+                           );
+    if ((Attributes & EFI_MEMORY_RO) != 0) {
+      mSmmMemoryAttribute->ClearMemoryAttributes (
+                             mSmmMemoryAttribute,
+                             Start,
+                             EFI_PAGES_TO_SIZE (PagesToFree),
+                             EFI_MEMORY_RO
+                             );
+    }
+  }
+
+  //
+  // Head Guard must be one page before, if any.
+  //
+  //          MSB-> 1     0 <-LSB
+  //          -------------------
+  //  Head Guard -> 0     1 -> Don't free Head Guard  (shared Guard)
+  //  Head Guard -> 0     0 -> Free Head Guard either (not shared Guard)
+  //                1     X -> Don't free first page  (need a new Guard)
+  //                           (it'll be turned into a Guard page later)
+  //          -------------------
+  //      Start -> -1    -2
+  //
+  MemoryToTest = Start - EFI_PAGES_TO_SIZE (2);
+  GuardBitmap  = GetGuardedMemoryBits (MemoryToTest, 2);
+  if ((GuardBitmap & BIT1) == 0) {
+    //
+    // Head Guard exists.
+    //
+    if ((GuardBitmap & BIT0) == 0) {
+      //
+      // If the head Guard is not a tail Guard of adjacent memory block,
+      // free it; otherwise, keep it.
+      //
+      Start       -= EFI_PAGES_TO_SIZE (1);
+      PagesToFree += 1;
+    }
+  } else {
+    //
+    // No Head Guard, and pages before memory to free are still in Guard. It's a
+    // partial free case. We need to keep one page to be a tail Guard.
+    //
+    Start       += EFI_PAGES_TO_SIZE (1);
+    PagesToFree -= 1;
+  }
+
+  //
+  // Tail Guard must be the page after this memory block to free, if any.
+  //
+  //   MSB-> 1     0 <-LSB
+  //  --------------------
+  //         1     0 <- Tail Guard -> Don't free Tail Guard  (shared Guard)
+  //         0     0 <- Tail Guard -> Free Tail Guard either (not shared Guard)
+  //         X     1               -> Don't free last page   (need a new Guard)
+  //                                 (it'll be turned into a Guard page later)
+  //  --------------------
+  //        +1    +0 <- End
+  //
+  MemoryToTest = Start + EFI_PAGES_TO_SIZE (PagesToFree);
+  GuardBitmap  = GetGuardedMemoryBits (MemoryToTest, 2);
+  if ((GuardBitmap & BIT0) == 0) {
+    //
+    // Tail Guard exists.
+    //
+    if ((GuardBitmap & BIT1) == 0) {
+      //
+      // If the tail Guard is not a head Guard of adjacent memory block,
+      // free it; otherwise, keep it.
+      //
+      PagesToFree += 1;
+    }
+  } else if (PagesToFree > 0) {
+    //
+    // No Tail Guard, and pages after memory to free are still in Guard. It's a
+    // partial free case. We need to keep one page to be a head Guard.
+    //
+    PagesToFree -= 1;
+  }
+
+  *Memory        = Start;
+  *NumberOfPages = PagesToFree;
+}
+
+/**
+  Adjust the pool head position to make sure the Guard page is adjavent to
+  pool tail or pool head.
+
+  @param[in]  Memory    Base address of memory allocated.
+  @param[in]  NoPages   Number of pages actually allocated.
+  @param[in]  Size      Size of memory requested.
+                        (plus pool head/tail overhead)
+
+  @return Address of pool head
+**/
+VOID *
+AdjustPoolHeadA (
+  IN EFI_PHYSICAL_ADDRESS  Memory,
+  IN UINTN                 NoPages,
+  IN UINTN                 Size
+  )
+{
+  if ((Memory == 0) || ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0)) {
+    //
+    // Pool head is put near the head Guard
+    //
+    return (VOID *)(UINTN)Memory;
+  }
+
+  //
+  // Pool head is put near the tail Guard
+  //
+  Size = ALIGN_VALUE (Size, 8);
+  return (VOID *)(UINTN)(Memory + EFI_PAGES_TO_SIZE (NoPages) - Size);
+}
+
+/**
+  Get the page base address according to pool head address.
+
+  @param[in]  Memory    Head address of pool to free.
+
+  @return Address of pool head.
+**/
+VOID *
+AdjustPoolHeadF (
+  IN EFI_PHYSICAL_ADDRESS  Memory
+  )
+{
+  if ((Memory == 0) || ((PcdGet8 (PcdHeapGuardPropertyMask) & BIT7) != 0)) {
+    //
+    // Pool head is put near the head Guard
+    //
+    return (VOID *)(UINTN)Memory;
+  }
+
+  //
+  // Pool head is put near the tail Guard
+  //
+  return (VOID *)(UINTN)(Memory & ~EFI_PAGE_MASK);
+}
+
+/**
+  Helper function of memory allocation with Guard pages.
+
+  @param  FreePageList           The free page node.
+  @param  NumberOfPages          Number of pages to be allocated.
+  @param  MaxAddress             Request to allocate memory below this address.
+  @param  MemoryType             Type of memory requested.
+
+  @return Memory address of allocated pages.
+**/
+UINTN
+InternalAllocMaxAddressWithGuard (
+  IN OUT LIST_ENTRY       *FreePageList,
+  IN     UINTN            NumberOfPages,
+  IN     UINTN            MaxAddress,
+  IN     EFI_MEMORY_TYPE  MemoryType
+
+  )
+{
+  LIST_ENTRY      *Node;
+  FREE_PAGE_LIST  *Pages;
+  UINTN           PagesToAlloc;
+  UINTN           HeadGuard;
+  UINTN           TailGuard;
+  UINTN           Address;
+
+  for (Node = FreePageList->BackLink; Node != FreePageList;
+       Node = Node->BackLink)
+  {
+    Pages = BASE_CR (Node, FREE_PAGE_LIST, Link);
+    if ((Pages->NumberOfPages >= NumberOfPages) &&
+        ((UINTN)Pages + EFI_PAGES_TO_SIZE (NumberOfPages) - 1 <= MaxAddress))
+    {
+      //
+      // We may need 1 or 2 more pages for Guard. Check it out.
+      //
+      PagesToAlloc = NumberOfPages;
+      TailGuard    = (UINTN)Pages + EFI_PAGES_TO_SIZE (Pages->NumberOfPages);
+      if (!IsGuardPage (TailGuard)) {
+        //
+        // Add one if no Guard at the end of current free memory block.
+        //
+        PagesToAlloc += 1;
+        TailGuard     = 0;
+      }
+
+      HeadGuard = (UINTN)Pages +
+                  EFI_PAGES_TO_SIZE (Pages->NumberOfPages - PagesToAlloc) -
+                  EFI_PAGE_SIZE;
+      if (!IsGuardPage (HeadGuard)) {
+        //
+        // Add one if no Guard at the page before the address to allocate
+        //
+        PagesToAlloc += 1;
+        HeadGuard     = 0;
+      }
+
+      if (Pages->NumberOfPages < PagesToAlloc) {
+        // Not enough space to allocate memory with Guards? Try next block.
+        continue;
+      }
+
+      Address = InternalAllocPagesOnOneNode (Pages, PagesToAlloc, MaxAddress);
+      ConvertSmmMemoryMapEntry (MemoryType, Address, PagesToAlloc, FALSE);
+      CoreFreeMemoryMapStack ();
+      if (HeadGuard == 0) {
+        // Don't pass the Guard page to user.
+        Address += EFI_PAGE_SIZE;
+      }
+
+      SetGuardForMemory (Address, NumberOfPages);
+      return Address;
+    }
+  }
+
+  return (UINTN)(-1);
+}
+
+/**
+  Helper function of memory free with Guard pages.
+
+  @param[in]  Memory                 Base address of memory being freed.
+  @param[in]  NumberOfPages          The number of pages to free.
+  @param[in]  AddRegion              If this memory is new added region.
+
+  @retval EFI_NOT_FOUND          Could not find the entry that covers the range.
+  @retval EFI_INVALID_PARAMETER  Address not aligned, Address is zero or NumberOfPages is zero.
+  @return EFI_SUCCESS            Pages successfully freed.
+**/
+EFI_STATUS
+SmmInternalFreePagesExWithGuard (
+  IN EFI_PHYSICAL_ADDRESS  Memory,
+  IN UINTN                 NumberOfPages,
+  IN BOOLEAN               AddRegion
+  )
+{
+  EFI_PHYSICAL_ADDRESS  MemoryToFree;
+  UINTN                 PagesToFree;
+
+  if (((Memory & EFI_PAGE_MASK) != 0) || (Memory == 0) || (NumberOfPages == 0)) {
+    return EFI_INVALID_PARAMETER;
+  }
+
+  MemoryToFree = Memory;
+  PagesToFree  = NumberOfPages;
+
+  AdjustMemoryF (&MemoryToFree, &PagesToFree);
+  UnsetGuardForMemory (Memory, NumberOfPages);
+  if (PagesToFree == 0) {
+    return EFI_SUCCESS;
+  }
+
+  return SmmInternalFreePagesEx (MemoryToFree, PagesToFree, AddRegion);
+}
+
+/**
+  Set all Guard pages which cannot be set during the non-SMM mode time.
+**/
+VOID
+SetAllGuardPages (
+  VOID
+  )
+{
+  UINTN    Entries[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINTN    Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINTN    Indices[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINT64   Tables[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINT64   Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINT64   TableEntry;
+  UINT64   Address;
+  UINT64   GuardPage;
+  INTN     Level;
+  UINTN    Index;
+  BOOLEAN  OnGuarding;
+
+  if ((mGuardedMemoryMap == 0) ||
+      (mMapLevel == 0) ||
+      (mMapLevel > GUARDED_HEAP_MAP_TABLE_DEPTH))
+  {
+    return;
+  }
+
+  CopyMem (Entries, mLevelMask, sizeof (Entries));
+  CopyMem (Shifts, mLevelShift, sizeof (Shifts));
+
+  SetMem (Tables, sizeof (Tables), 0);
+  SetMem (Addresses, sizeof (Addresses), 0);
+  SetMem (Indices, sizeof (Indices), 0);
+
+  Level         = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;
+  Tables[Level] = mGuardedMemoryMap;
+  Address       = 0;
+  OnGuarding    = FALSE;
+
+  DEBUG_CODE (
+    DumpGuardedMemoryBitmap ();
+    );
+
+  while (TRUE) {
+    if (Indices[Level] > Entries[Level]) {
+      Tables[Level] = 0;
+      Level        -= 1;
+    } else {
+      TableEntry = ((UINT64 *)(UINTN)(Tables[Level]))[Indices[Level]];
+      Address    = Addresses[Level];
+
+      if (TableEntry == 0) {
+        OnGuarding = FALSE;
+      } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {
+        Level           += 1;
+        Tables[Level]    = TableEntry;
+        Addresses[Level] = Address;
+        Indices[Level]   = 0;
+
+        continue;
+      } else {
+        Index = 0;
+        while (Index < GUARDED_HEAP_MAP_ENTRY_BITS) {
+          if ((TableEntry & 1) == 1) {
+            if (OnGuarding) {
+              GuardPage = 0;
+            } else {
+              GuardPage = Address - EFI_PAGE_SIZE;
+            }
+
+            OnGuarding = TRUE;
+          } else {
+            if (OnGuarding) {
+              GuardPage = Address;
+            } else {
+              GuardPage = 0;
+            }
+
+            OnGuarding = FALSE;
+          }
+
+          if (GuardPage != 0) {
+            SetGuardPage (GuardPage);
+          }
+
+          if (TableEntry == 0) {
+            break;
+          }
+
+          TableEntry = RShiftU64 (TableEntry, 1);
+          Address   += EFI_PAGE_SIZE;
+          Index     += 1;
+        }
+      }
+    }
+
+    if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) {
+      break;
+    }
+
+    Indices[Level]  += 1;
+    Address          = (Level == 0) ? 0 : Addresses[Level - 1];
+    Addresses[Level] = Address | LShiftU64 (Indices[Level], Shifts[Level]);
+  }
+}
+
+/**
+  Hook function used to set all Guard pages after entering SMM mode.
+**/
+VOID
+SmmEntryPointMemoryManagementHook (
+  VOID
+  )
+{
+  EFI_STATUS  Status;
+
+  if (mSmmMemoryAttribute == NULL) {
+    Status = SmmLocateProtocol (
+               &gEdkiiSmmMemoryAttributeProtocolGuid,
+               NULL,
+               (VOID **)&mSmmMemoryAttribute
+               );
+    if (!EFI_ERROR (Status)) {
+      SetAllGuardPages ();
+    }
+  }
+}
+
+/**
+  Helper function to convert a UINT64 value in binary to a string.
+
+  @param[in]  Value       Value of a UINT64 integer.
+  @param[out] BinString   String buffer to contain the conversion result.
+
+  @return VOID.
+**/
+VOID
+Uint64ToBinString (
+  IN  UINT64  Value,
+  OUT CHAR8   *BinString
+  )
+{
+  UINTN  Index;
+
+  if (BinString == NULL) {
+    return;
+  }
+
+  for (Index = 64; Index > 0; --Index) {
+    BinString[Index - 1] = '0' + (Value & 1);
+    Value                = RShiftU64 (Value, 1);
+  }
+
+  BinString[64] = '\0';
+}
+
+/**
+  Dump the guarded memory bit map.
+**/
+VOID
+EFIAPI
+DumpGuardedMemoryBitmap (
+  VOID
+  )
+{
+  UINTN   Entries[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINTN   Shifts[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINTN   Indices[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINT64  Tables[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINT64  Addresses[GUARDED_HEAP_MAP_TABLE_DEPTH];
+  UINT64  TableEntry;
+  UINT64  Address;
+  INTN    Level;
+  UINTN   RepeatZero;
+  CHAR8   String[GUARDED_HEAP_MAP_ENTRY_BITS + 1];
+  CHAR8   *Ruler1;
+  CHAR8   *Ruler2;
+
+  if ((mGuardedMemoryMap == 0) ||
+      (mMapLevel == 0) ||
+      (mMapLevel > GUARDED_HEAP_MAP_TABLE_DEPTH))
+  {
+    return;
+  }
+
+  Ruler1 = "               3               2               1               0";
+  Ruler2 = "FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210FEDCBA9876543210";
+
+  DEBUG ((
+    HEAP_GUARD_DEBUG_LEVEL,
+    "============================="
+    " Guarded Memory Bitmap "
+    "==============================\r\n"
+    ));
+  DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "                  %a\r\n", Ruler1));
+  DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "                  %a\r\n", Ruler2));
+
+  CopyMem (Entries, mLevelMask, sizeof (Entries));
+  CopyMem (Shifts, mLevelShift, sizeof (Shifts));
+
+  SetMem (Indices, sizeof (Indices), 0);
+  SetMem (Tables, sizeof (Tables), 0);
+  SetMem (Addresses, sizeof (Addresses), 0);
+
+  Level         = GUARDED_HEAP_MAP_TABLE_DEPTH - mMapLevel;
+  Tables[Level] = mGuardedMemoryMap;
+  Address       = 0;
+  RepeatZero    = 0;
+
+  while (TRUE) {
+    if (Indices[Level] > Entries[Level]) {
+      Tables[Level] = 0;
+      Level        -= 1;
+      RepeatZero    = 0;
+
+      DEBUG ((
+        HEAP_GUARD_DEBUG_LEVEL,
+        "========================================="
+        "=========================================\r\n"
+        ));
+    } else {
+      TableEntry = ((UINT64 *)(UINTN)Tables[Level])[Indices[Level]];
+      Address    = Addresses[Level];
+
+      if (TableEntry == 0) {
+        if (Level == GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {
+          if (RepeatZero == 0) {
+            Uint64ToBinString (TableEntry, String);
+            DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String));
+          } else if (RepeatZero == 1) {
+            DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "...             : ...\r\n"));
+          }
+
+          RepeatZero += 1;
+        }
+      } else if (Level < GUARDED_HEAP_MAP_TABLE_DEPTH - 1) {
+        Level           += 1;
+        Tables[Level]    = TableEntry;
+        Addresses[Level] = Address;
+        Indices[Level]   = 0;
+        RepeatZero       = 0;
+
+        continue;
+      } else {
+        RepeatZero = 0;
+        Uint64ToBinString (TableEntry, String);
+        DEBUG ((HEAP_GUARD_DEBUG_LEVEL, "%016lx: %a\r\n", Address, String));
+      }
+    }
+
+    if (Level < (GUARDED_HEAP_MAP_TABLE_DEPTH - (INTN)mMapLevel)) {
+      break;
+    }
+
+    Indices[Level]  += 1;
+    Address          = (Level == 0) ? 0 : Addresses[Level - 1];
+    Addresses[Level] = Address | LShiftU64 (Indices[Level], Shifts[Level]);
+  }
+}
+
+/**
+  Debug function used to verify if the Guard page is well set or not.
+
+  @param[in]  BaseAddress     Address of memory to check.
+  @param[in]  NumberOfPages   Size of memory in pages.
+
+  @return TRUE    The head Guard and tail Guard are both well set.
+  @return FALSE   The head Guard and/or tail Guard are not well set.
+**/
+BOOLEAN
+VerifyMemoryGuard (
+  IN  EFI_PHYSICAL_ADDRESS  BaseAddress,
+  IN  UINTN                 NumberOfPages
+  )
+{
+  EFI_STATUS            Status;
+  UINT64                Attribute;
+  EFI_PHYSICAL_ADDRESS  Address;
+
+  if (mSmmMemoryAttribute == NULL) {
+    return TRUE;
+  }
+
+  Attribute = 0;
+  Address   = BaseAddress - EFI_PAGE_SIZE;
+  Status    = mSmmMemoryAttribute->GetMemoryAttributes (
+                                     mSmmMemoryAttribute,
+                                     Address,
+                                     EFI_PAGE_SIZE,
+                                     &Attribute
+                                     );
+  if (EFI_ERROR (Status) || ((Attribute & EFI_MEMORY_RP) == 0)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "Head Guard is not set at: %016lx (%016lX)!!!\r\n",
+      Address,
+      Attribute
+      ));
+    DumpGuardedMemoryBitmap ();
+    return FALSE;
+  }
+
+  Attribute = 0;
+  Address   = BaseAddress + EFI_PAGES_TO_SIZE (NumberOfPages);
+  Status    = mSmmMemoryAttribute->GetMemoryAttributes (
+                                     mSmmMemoryAttribute,
+                                     Address,
+                                     EFI_PAGE_SIZE,
+                                     &Attribute
+                                     );
+  if (EFI_ERROR (Status) || ((Attribute & EFI_MEMORY_RP) == 0)) {
+    DEBUG ((
+      DEBUG_ERROR,
+      "Tail Guard is not set at: %016lx (%016lX)!!!\r\n",
+      Address,
+      Attribute
+      ));
+    DumpGuardedMemoryBitmap ();
+    return FALSE;
+  }
+
+  return TRUE;
+}