diff options
Diffstat (limited to 'MdeModulePkg/Core/PiSmmCore/HeapGuard.c')
| -rw-r--r-- | MdeModulePkg/Core/PiSmmCore/HeapGuard.c | 2860 |
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; +} |