+/** @file
+ UEFI Heap Guard functions.
+
+Copyright (c) 2017, Intel Corporation. All rights reserved.<BR>
+This program and the accompanying materials
+are licensed and made available under the terms and conditions of the BSD License
+which accompanies this distribution. The full text of the license may be found at
+http://opensource.org/licenses/bsd-license.php
+
+THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
+WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include "DxeMain.h"
+#include "Imem.h"
+#include "HeapGuard.h"
+
+//
+// Global to avoid infinite reentrance of memory allocation when updating
+// page table attributes, which may need allocate 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;
+
+/**
+ 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;
+ }
+
+ Result = RShiftU64 ((*BitMap), StartBit) & (LShiftU64 (1, Msbs) - 1);
+ if (Lsbs > 0) {
+ BitMap += 1;
+ Result |= LShiftU64 ((*BitMap) & (LShiftU64 (1, Lsbs) - 1), Msbs);
+ }
+
+ return Result;
+}
+
+/**
+ 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;
+ EFI_STATUS Status;
+
+ //
+ // Adjust current map table depth according to the address to access
+ //
+ while (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;
+ Status = CoreInternalAllocatePages (
+ AllocateAnyPages,
+ EfiBootServicesData,
+ EFI_SIZE_TO_PAGES (Size),
+ &MapMemory,
+ FALSE
+ );
+ ASSERT_EFI_ERROR (Status);
+ 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;
+ Status = CoreInternalAllocatePages (
+ AllocateAnyPages,
+ EfiBootServicesData,
+ EFI_SIZE_TO_PAGES (Size),
+ &MapMemory,
+ FALSE
+ );
+ ASSERT_EFI_ERROR (Status);
+ 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 VOID.
+**/
+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;
+}
+
+/**
+ Set the bit in bitmap table for the given address.
+
+ @param[in] Address The address to set for.
+
+ @return VOID.
+**/
+VOID
+EFIAPI
+SetGuardMapBit (
+ IN EFI_PHYSICAL_ADDRESS Address
+ )
+{
+ UINT64 *GuardMap;
+ UINT64 BitMask;
+
+ FindGuardedMemoryMap (Address, TRUE, &GuardMap);
+ if (GuardMap != NULL) {
+ BitMask = LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address));
+ *GuardMap |= BitMask;
+ }
+}
+
+/**
+ Clear the bit in bitmap table for the given address.
+
+ @param[in] Address The address to clear for.
+
+ @return VOID.
+**/
+VOID
+EFIAPI
+ClearGuardMapBit (
+ IN EFI_PHYSICAL_ADDRESS Address
+ )
+{
+ UINT64 *GuardMap;
+ UINT64 BitMask;
+
+ FindGuardedMemoryMap (Address, TRUE, &GuardMap);
+ if (GuardMap != NULL) {
+ BitMask = LShiftU64 (1, GUARDED_HEAP_MAP_ENTRY_BIT_INDEX (Address));
+ *GuardMap &= ~BitMask;
+ }
+}
+
+/**
+ 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;
+
+ BitMap = GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 3);
+ return ((BitMap == 0b001) || (BitMap == 0b100) || (BitMap == 0b101));
+}
+
+/**
+ Check to see if the page at the given address is a head Guard page or not.
+
+ @param[in] Address The address to check for
+
+ @return TRUE The page at Address is a head Guard page
+ @return FALSE The page at Address is not a head Guard page
+**/
+BOOLEAN
+EFIAPI
+IsHeadGuard (
+ IN EFI_PHYSICAL_ADDRESS Address
+ )
+{
+ return (GetGuardedMemoryBits (Address, 2) == 0b10);
+}
+
+/**
+ Check to see if the page at the given address is a tail Guard page or not.
+
+ @param[in] Address The address to check for.
+
+ @return TRUE The page at Address is a tail Guard page.
+ @return FALSE The page at Address is not a tail Guard page.
+**/
+BOOLEAN
+EFIAPI
+IsTailGuard (
+ IN EFI_PHYSICAL_ADDRESS Address
+ )
+{
+ return (GetGuardedMemoryBits (Address - EFI_PAGE_SIZE, 2) == 0b01);
+}
+
+/**
+ 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 PRSENT.
+
+ @param[in] BaseAddress Page address to Guard at
+
+ @return VOID
+**/
+VOID
+EFIAPI
+SetGuardPage (
+ IN EFI_PHYSICAL_ADDRESS BaseAddress
+ )
+{
+ //
+ // Set flag to make sure allocating memory without GUARD for page table
+ // operation; otherwise infinite loops could be caused.
+ //
+ mOnGuarding = TRUE;
+ //
+ // Note: This might overwrite other attributes needed by other features,
+ // such as memory protection (NX). Please make sure they are not enabled
+ // at the same time.
+ //
+ gCpu->SetMemoryAttributes (gCpu, BaseAddress, EFI_PAGE_SIZE, EFI_MEMORY_RP);
+ 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 PRSENT.
+
+ @param[in] BaseAddress Page address to Guard at.
+
+ @return VOID.
+**/
+VOID
+EFIAPI
+UnsetGuardPage (
+ IN EFI_PHYSICAL_ADDRESS BaseAddress
+ )
+{
+ //
+ // Set flag to make sure allocating memory without GUARD for page table
+ // operation; otherwise infinite loops could be caused.
+ //
+ mOnGuarding = TRUE;
+ //
+ // Note: This might overwrite other attributes needed by other features,
+ // such as memory protection (NX). Please make sure they are not enabled
+ // at the same time.
+ //
+ gCpu->SetMemoryAttributes (gCpu, BaseAddress, EFI_PAGE_SIZE, 0);
+ 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;
+ BOOLEAN InSmm;
+
+ if (gCpu == NULL || AllocateType == AllocateAddress) {
+ return FALSE;
+ }
+
+ InSmm = FALSE;
+ if (gSmmBase2 != NULL) {
+ gSmmBase2->InSmm (gSmmBase2, &InSmm);
+ }
+
+ if (InSmm) {
+ return FALSE;
+ }
+
+ if ((PcdGet8 (PcdHeapGuardPropertyMask) & PageOrPool) == 0) {
+ return FALSE;
+ }
+
+ if (PageOrPool == GUARD_HEAP_TYPE_POOL) {
+ ConfigBit = PcdGet64 (PcdHeapGuardPoolType);
+ } else if (PageOrPool == GUARD_HEAP_TYPE_PAGE) {
+ ConfigBit = PcdGet64 (PcdHeapGuardPageType);
+ } else {
+ ConfigBit = (UINT64)-1;
+ }
+
+ if ((UINT32)MemoryType >= MEMORY_TYPE_OS_RESERVED_MIN) {
+ TestBit = BIT63;
+ } else if ((UINT32) MemoryType >= MEMORY_TYPE_OEM_RESERVED_MIN) {
+ TestBit = BIT62;
+ } else if (MemoryType < EfiMaxMemoryType) {
+ 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);
+}
+
+/**
+ 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;
+
+ if (NumberOfPages == 0) {
+ return;
+ }
+
+ //
+ // Head Guard must be one page before, if any.
+ //
+ GuardPage = Memory - EFI_PAGES_TO_SIZE (1);
+ if (IsHeadGuard (GuardPage)) {
+ if (!IsMemoryGuarded (GuardPage - EFI_PAGES_TO_SIZE (1))) {
+ //
+ // If the head Guard is not a tail Guard of adjacent memory block,
+ // unset it.
+ //
+ UnsetGuardPage (GuardPage);
+ }
+ } else if (IsMemoryGuarded (GuardPage)) {
+ //
+ // 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.
+ //
+ GuardPage = Memory + EFI_PAGES_TO_SIZE (NumberOfPages);
+ if (IsTailGuard (GuardPage)) {
+ if (!IsMemoryGuarded (GuardPage + EFI_PAGES_TO_SIZE (1))) {
+ //
+ // If the tail Guard is not a head Guard of adjacent memory block,
+ // free it; otherwise, keep it.
+ //
+ UnsetGuardPage (GuardPage);
+ }
+ } else if (IsMemoryGuarded (GuardPage)) {
+ //
+ // 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 address of free memory according to existing and/or required Guard.
+
+ This function will check if there're existing Guard pages of adjacent
+ memory blocks, and try to use it as the Guard page of the memory to be
+ allocated.
+
+ @param[in] Start Start address of free memory block.
+ @param[in] Size Size of free memory block.
+ @param[in] SizeRequested Size of memory to allocate.
+
+ @return The end address of memory block found.
+ @return 0 if no enough space for the required size of memory and its Guard.
+**/
+UINT64
+AdjustMemoryS (
+ IN UINT64 Start,
+ IN UINT64 Size,
+ IN UINT64 SizeRequested
+ )
+{
+ UINT64 Target;
+
+ Target = Start + Size - SizeRequested;
+
+ //
+ // At least one more page needed for Guard page.
+ //
+ if (Size < (SizeRequested + EFI_PAGES_TO_SIZE (1))) {
+ return 0;
+ }
+
+ if (!IsGuardPage (Start + Size)) {
+ // No Guard at tail to share. One more page is needed.
+ Target -= EFI_PAGES_TO_SIZE (1);
+ }
+
+ // Out of range?
+ if (Target < Start) {
+ return 0;
+ }
+
+ // At the edge?
+ if (Target == Start) {
+ if (!IsGuardPage (Target - EFI_PAGES_TO_SIZE (1))) {
+ // No enough space for a new head Guard if no Guard at head to share.
+ return 0;
+ }
+ }
+
+ // OK, we have enough pages for memory and its Guards. Return the End of the
+ // free space.
+ return Target + SizeRequested - 1;
+}
+
+/**
+ 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;
+
+ if (Memory == NULL || NumberOfPages == NULL || *NumberOfPages == 0) {
+ return;
+ }
+
+ Start = *Memory;
+ PagesToFree = *NumberOfPages;
+
+ //
+ // Head Guard must be one page before, if any.
+ //
+ MemoryToTest = Start - EFI_PAGES_TO_SIZE (1);
+ if (IsHeadGuard (MemoryToTest)) {
+ if (!IsMemoryGuarded (MemoryToTest - EFI_PAGES_TO_SIZE (1))) {
+ //
+ // 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 if (IsMemoryGuarded (MemoryToTest)) {
+ //
+ // 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.
+ //
+ MemoryToTest = Start + EFI_PAGES_TO_SIZE (PagesToFree);
+ if (IsTailGuard (MemoryToTest)) {
+ if (!IsMemoryGuarded (MemoryToTest + EFI_PAGES_TO_SIZE (1))) {
+ //
+ // If the tail Guard is not a head Guard of adjacent memory block,
+ // free it; otherwise, keep it.
+ //
+ PagesToFree += 1;
+ }
+ } else if (IsMemoryGuarded (MemoryToTest)) {
+ //
+ // 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 base and number of pages to really allocate according to Guard.
+
+ @param[in,out] Memory Base address of free memory.
+ @param[in,out] NumberOfPages Size of memory to allocate.
+
+ @return VOID.
+**/
+VOID
+AdjustMemoryA (
+ IN OUT EFI_PHYSICAL_ADDRESS *Memory,
+ IN OUT UINTN *NumberOfPages
+ )
+{
+ //
+ // FindFreePages() has already taken the Guard into account. It's safe to
+ // adjust the start address and/or number of pages here, to make sure that
+ // the Guards are also "allocated".
+ //
+ if (!IsGuardPage (*Memory + EFI_PAGES_TO_SIZE (*NumberOfPages))) {
+ // No tail Guard, add one.
+ *NumberOfPages += 1;
+ }
+
+ if (!IsGuardPage (*Memory - EFI_PAGE_SIZE)) {
+ // No head Guard, add one.
+ *Memory -= EFI_PAGE_SIZE;
+ *NumberOfPages += 1;
+ }
+}
+
+/**
+ 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 ((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_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 ((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);
+}
+
+/**
+ Allocate or free guarded memory.
+
+ @param[in] Start Start address of memory to allocate or free.
+ @param[in] NumberOfPages Memory size in pages.
+ @param[in] NewType Memory type to convert to.
+
+ @return VOID.
+**/
+EFI_STATUS
+CoreConvertPagesWithGuard (
+ IN UINT64 Start,
+ IN UINTN NumberOfPages,
+ IN EFI_MEMORY_TYPE NewType
+ )
+{
+ if (NewType == EfiConventionalMemory) {
+ AdjustMemoryF (&Start, &NumberOfPages);
+ } else {
+ AdjustMemoryA (&Start, &NumberOfPages);
+ }
+
+ return CoreConvertPages(Start, NumberOfPages, NewType);
+}
+
+/**
+ 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) {
+ 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]);
+
+ }
+}
+
projects / mirror_edk2.git / commitdiff