#include "HeapGuard.h"

Functions
STATIC VOID	SetBits (IN EFI_PHYSICAL_ADDRESS Address, IN UINTN BitNumber, IN UINT64 *BitMap)

STATIC VOID	ClearBits (IN EFI_PHYSICAL_ADDRESS Address, IN UINTN BitNumber, IN UINT64 *BitMap)

STATIC UINT64	GetBits (IN EFI_PHYSICAL_ADDRESS Address, IN UINTN BitNumber, IN UINT64 *BitMap)

VOID *	PageAlloc (IN UINTN Pages)

UINTN	FindGuardedMemoryMap (IN EFI_PHYSICAL_ADDRESS Address, IN BOOLEAN AllocMapUnit, OUT UINT64 **BitMap)

VOID EFIAPI	SetGuardedMemoryBits (IN EFI_PHYSICAL_ADDRESS Address, IN UINTN NumberOfPages)

VOID EFIAPI	ClearGuardedMemoryBits (IN EFI_PHYSICAL_ADDRESS Address, IN UINTN NumberOfPages)

UINTN	GetGuardedMemoryBits (IN EFI_PHYSICAL_ADDRESS Address, IN UINTN NumberOfPages)

UINTN EFIAPI	GetGuardMapBit (IN EFI_PHYSICAL_ADDRESS Address)

BOOLEAN EFIAPI	IsGuardPage (IN EFI_PHYSICAL_ADDRESS Address)

BOOLEAN EFIAPI	IsMemoryGuarded (IN EFI_PHYSICAL_ADDRESS Address)

VOID EFIAPI	SetGuardPage (IN EFI_PHYSICAL_ADDRESS BaseAddress)

VOID EFIAPI	UnsetGuardPage (IN EFI_PHYSICAL_ADDRESS BaseAddress)

BOOLEAN	IsMemoryTypeToGuard (IN EFI_MEMORY_TYPE MemoryType, IN EFI_ALLOCATE_TYPE AllocateType, IN UINT8 PageOrPool)

BOOLEAN	IsPoolTypeToGuard (IN EFI_MEMORY_TYPE MemoryType)

BOOLEAN	IsPageTypeToGuard (IN EFI_MEMORY_TYPE MemoryType, IN EFI_ALLOCATE_TYPE AllocateType)

BOOLEAN	IsHeapGuardEnabled (VOID)

VOID	SetGuardForMemory (IN EFI_PHYSICAL_ADDRESS Memory, IN UINTN NumberOfPages)

VOID	UnsetGuardForMemory (IN EFI_PHYSICAL_ADDRESS Memory, IN UINTN NumberOfPages)

VOID	AdjustMemoryF (IN OUT EFI_PHYSICAL_ADDRESS Memory, IN OUT UINTN NumberOfPages)

VOID *	AdjustPoolHeadA (IN EFI_PHYSICAL_ADDRESS Memory, IN UINTN NoPages, IN UINTN Size)

VOID *	AdjustPoolHeadF (IN EFI_PHYSICAL_ADDRESS Memory)

UINTN	InternalAllocMaxAddressWithGuard (IN OUT LIST_ENTRY *FreePageList, IN UINTN NumberOfPages, IN UINTN MaxAddress, IN EFI_MEMORY_TYPE MemoryType)

EFI_STATUS	SmmInternalFreePagesExWithGuard (IN EFI_PHYSICAL_ADDRESS Memory, IN UINTN NumberOfPages, IN BOOLEAN AddRegion)

VOID	SetAllGuardPages (VOID)

VOID	SmmEntryPointMemoryManagementHook (VOID)

VOID	Uint64ToBinString (IN UINT64 Value, OUT CHAR8 *BinString)

VOID EFIAPI	DumpGuardedMemoryBitmap (VOID)

BOOLEAN	VerifyMemoryGuard (IN EFI_PHYSICAL_ADDRESS BaseAddress, IN UINTN NumberOfPages)

Variables
GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN	mOnGuarding = FALSE

GLOBAL_REMOVE_IF_UNREFERENCED UINT64	mGuardedMemoryMap = 0

GLOBAL_REMOVE_IF_UNREFERENCED UINTN	mMapLevel = 1

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

EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL *	mSmmMemoryAttribute = NULL

Detailed Description

UEFI Heap Guard functions.

Copyright (c) 2017-2018, Intel Corporation. All rights reserved.
SPDX-License-Identifier: BSD-2-Clause-Patent

Definition in file HeapGuard.c.

Function Documentation

◆ AdjustMemoryF()

VOID AdjustMemoryF	(	IN OUT EFI_PHYSICAL_ADDRESS *	Memory,
		IN OUT UINTN *	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.

Parameters

[in,out]	Memory	Base address of memory to free.
[in,out]	NumberOfPages	Size of memory to free.

Returns: VOID.

Definition at line 825 of file HeapGuard.c.

◆ AdjustPoolHeadA()

VOID * AdjustPoolHeadA	(	IN EFI_PHYSICAL_ADDRESS	Memory,
		IN UINTN	NoPages,
		IN UINTN	Size
	)

Adjust the pool head position to make sure the Guard page is adjavent to pool tail or pool head.

Parameters

[in]	Memory	Base address of memory allocated.
[in]	NoPages	Number of pages actually allocated.
[in]	Size	Size of memory requested. (plus pool head/tail overhead)

Returns: Address of pool head

Definition at line 948 of file HeapGuard.c.

◆ AdjustPoolHeadF()

VOID * AdjustPoolHeadF ( IN EFI_PHYSICAL_ADDRESS Memory )

Get the page base address according to pool head address.

Parameters

[in] Memory Head address of pool to free.

Returns: Address of pool head.

Definition at line 976 of file HeapGuard.c.

◆ ClearBits()

STATIC VOID ClearBits	(	IN EFI_PHYSICAL_ADDRESS	Address,
		IN UINTN	BitNumber,
		IN UINT64 *	BitMap
	)

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

Parameters

[in]	Address	Start address to set for.
[in]	BitNumber	Number of bits to set.
[in]	BitMap	Pointer to bitmap which covers the Address.

Returns: VOID.

Definition at line 111 of file HeapGuard.c.

◆ ClearGuardedMemoryBits()

VOID EFIAPI ClearGuardedMemoryBits	(	IN EFI_PHYSICAL_ADDRESS	Address,
		IN UINTN	NumberOfPages
	)

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

Parameters

[in]	Address	Memory address to unset from.
[in]	NumberOfPages	Number of pages to unset guard.

Returns: VOID

Definition at line 359 of file HeapGuard.c.

◆ DumpGuardedMemoryBitmap()

VOID EFIAPI DumpGuardedMemoryBitmap ( VOID )

Dump the guarded memory bit map.

Definition at line 1269 of file HeapGuard.c.

◆ FindGuardedMemoryMap()

UINTN FindGuardedMemoryMap	(	IN EFI_PHYSICAL_ADDRESS	Address,
		IN BOOLEAN	AllocMapUnit,
		OUT UINT64 **	BitMap
	)

Locate the pointer of bitmap from the guarded memory bitmap tables, which covers the given Address.

Parameters

[in]	Address	Start address to search the bitmap for.
[in]	AllocMapUnit	Flag to indicate memory allocation for the table.
[out]	BitMap	Pointer to bitmap which covers the Address.

Returns: The bit number from given Address to the end of current map table.

Definition at line 244 of file HeapGuard.c.

◆ GetBits()

STATIC UINT64 GetBits	(	IN EFI_PHYSICAL_ADDRESS	Address,
		IN UINTN	BitNumber,
		IN UINT64 *	BitMap
	)

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.

Parameters

[in]	Address	Start address to retrieve bits for.
[in]	BitNumber	Number of bits to get.
[in]	BitMap	Pointer to bitmap which covers the Address.

Returns: An integer containing the bits information.

Definition at line 166 of file HeapGuard.c.

◆ GetGuardedMemoryBits()

UINTN GetGuardedMemoryBits	(	IN EFI_PHYSICAL_ADDRESS	Address,
		IN UINTN	NumberOfPages
	)

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

Parameters

[in]	Address	Memory address to retrieve from.
[in]	NumberOfPages	Number of pages to retrieve.

Returns: An integer containing the guarded memory bitmap.

Definition at line 395 of file HeapGuard.c.

◆ GetGuardMapBit()

UINTN EFIAPI GetGuardMapBit ( IN EFI_PHYSICAL_ADDRESS Address )

Get bit value in bitmap table for the given address.

Parameters

[in] Address The address to retrieve for.

Returns: 1 or 0.

Definition at line 441 of file HeapGuard.c.

◆ InternalAllocMaxAddressWithGuard()

UINTN InternalAllocMaxAddressWithGuard	(	IN OUT LIST_ENTRY *	FreePageList,
		IN UINTN	NumberOfPages,
		IN UINTN	MaxAddress,
		IN EFI_MEMORY_TYPE	MemoryType
	)

Helper function of memory allocation with Guard pages.

Parameters

FreePageList	The free page node.
NumberOfPages	Number of pages to be allocated.
MaxAddress	Request to allocate memory below this address.
MemoryType	Type of memory requested.

Returns: Memory address of allocated pages.

Definition at line 1004 of file HeapGuard.c.

◆ IsGuardPage()

BOOLEAN EFIAPI IsGuardPage ( IN EFI_PHYSICAL_ADDRESS Address )

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

Parameters

[in] Address The address to check for.

Returns: TRUE The page at Address is a Guard page.; FALSE The page at Address is not a Guard page.

Definition at line 471 of file HeapGuard.c.

◆ IsHeapGuardEnabled()

BOOLEAN IsHeapGuardEnabled ( VOID )

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

Returns: TRUE/FALSE.

Definition at line 672 of file HeapGuard.c.

◆ IsMemoryGuarded()

BOOLEAN EFIAPI IsMemoryGuarded ( IN EFI_PHYSICAL_ADDRESS Address )

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

Parameters

[in] Address The address to check for.

Returns: TRUE The page at Address is guarded.; FALSE The page at Address is not guarded.

Definition at line 496 of file HeapGuard.c.

◆ IsMemoryTypeToGuard()

BOOLEAN IsMemoryTypeToGuard	(	IN EFI_MEMORY_TYPE	MemoryType,
		IN EFI_ALLOCATE_TYPE	AllocateType,
		IN UINT8	PageOrPool
	)

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

Parameters

[in]	MemoryType	Memory type to check.
[in]	AllocateType	Allocation type to check.
[in]	PageOrPool	Indicate a page allocation or pool allocation.

Returns: TRUE The given type of memory should be guarded.; FALSE The given type of memory should not be guarded.

Definition at line 589 of file HeapGuard.c.

◆ IsPageTypeToGuard()

BOOLEAN IsPageTypeToGuard	(	IN EFI_MEMORY_TYPE	MemoryType,
		IN EFI_ALLOCATE_TYPE	AllocateType
	)

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

Parameters

[in]	MemoryType	Page type to check.
[in]	AllocateType	Allocation type to check.

Returns: TRUE The given type of page should be guarded.; FALSE The given type of page should not be guarded.

Definition at line 658 of file HeapGuard.c.

◆ IsPoolTypeToGuard()

BOOLEAN IsPoolTypeToGuard ( IN EFI_MEMORY_TYPE MemoryType )

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

Parameters

[in] MemoryType Pool type to check.

Returns: TRUE The given type of pool should be guarded.; FALSE The given type of pool should not be guarded.

Definition at line 637 of file HeapGuard.c.

◆ PageAlloc()

VOID * PageAlloc ( IN UINTN Pages )

Helper function to allocate pages without Guard for internal uses.

Parameters

[in] Pages Page number.

Returns: Address of memory allocated.

Definition at line 212 of file HeapGuard.c.

◆ SetAllGuardPages()

VOID SetAllGuardPages ( VOID )

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

Definition at line 1112 of file HeapGuard.c.

◆ SetBits()

STATIC VOID SetBits	(	IN EFI_PHYSICAL_ADDRESS	Address,
		IN UINTN	BitNumber,
		IN UINT64 *	BitMap
	)

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

Parameters

[in]	Address	Start address to set for.
[in]	BitNumber	Number of bits to set.
[in]	BitMap	Pointer to bitmap which covers the Address.

Returns: VOID

Definition at line 55 of file HeapGuard.c.

◆ SetGuardedMemoryBits()

VOID EFIAPI SetGuardedMemoryBits	(	IN EFI_PHYSICAL_ADDRESS	Address,
		IN UINTN	NumberOfPages
	)

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

Parameters

[in]	Address	Memory address to guard from.
[in]	NumberOfPages	Number of pages to guard.

Returns: VOID

Definition at line 322 of file HeapGuard.c.

◆ SetGuardForMemory()

VOID SetGuardForMemory	(	IN EFI_PHYSICAL_ADDRESS	Memory,
		IN UINTN	NumberOfPages
	)

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

Parameters

[in]	Memory	Base address of memory to set guard for.
[in]	NumberOfPages	Memory size in pages.

Returns: VOID.

Definition at line 692 of file HeapGuard.c.

◆ SetGuardPage()

VOID EFIAPI SetGuardPage ( IN EFI_PHYSICAL_ADDRESS BaseAddress )

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.

Parameters

[in] BaseAddress Page address to Guard at.

Returns: VOID.

Definition at line 514 of file HeapGuard.c.

◆ SmmEntryPointMemoryManagementHook()

VOID SmmEntryPointMemoryManagementHook ( VOID )

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

Definition at line 1218 of file HeapGuard.c.

◆ SmmInternalFreePagesExWithGuard()

EFI_STATUS SmmInternalFreePagesExWithGuard	(	IN EFI_PHYSICAL_ADDRESS	Memory,
		IN UINTN	NumberOfPages,
		IN BOOLEAN	AddRegion
	)

Helper function of memory free with Guard pages.

Parameters

[in]	Memory	Base address of memory being freed.
[in]	NumberOfPages	The number of pages to free.
[in]	AddRegion	If this memory is new added region.

Return values

EFI_NOT_FOUND	Could not find the entry that covers the range.
EFI_INVALID_PARAMETER	Address not aligned, Address is zero or NumberOfPages is zero.

Returns: EFI_SUCCESS Pages successfully freed.

Definition at line 1083 of file HeapGuard.c.

◆ Uint64ToBinString()

VOID Uint64ToBinString	(	IN UINT64	Value,
		OUT CHAR8 *	BinString
	)

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

Parameters

[in]	Value	Value of a UINT64 integer.
[out]	BinString	String buffer to contain the conversion result.

Returns: VOID.

Definition at line 1245 of file HeapGuard.c.

◆ UnsetGuardForMemory()

VOID UnsetGuardForMemory	(	IN EFI_PHYSICAL_ADDRESS	Memory,
		IN UINTN	NumberOfPages
	)

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

Parameters

[in]	Memory	Base address of memory to unset guard for.
[in]	NumberOfPages	Memory size in pages.

Returns: VOID.

Definition at line 728 of file HeapGuard.c.

◆ UnsetGuardPage()

VOID EFIAPI UnsetGuardPage ( IN EFI_PHYSICAL_ADDRESS BaseAddress )

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

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

Parameters

[in] BaseAddress Page address to Guard at.

Returns: VOID.

Definition at line 544 of file HeapGuard.c.

◆ VerifyMemoryGuard()

BOOLEAN VerifyMemoryGuard	(	IN EFI_PHYSICAL_ADDRESS	BaseAddress,
		IN UINTN	NumberOfPages
	)

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

Parameters

[in]	BaseAddress	Address of memory to check.
[in]	NumberOfPages	Size of memory in pages.

Returns: TRUE The head Guard and tail Guard are both well set.; FALSE The head Guard and/or tail Guard are not well set.

Definition at line 1378 of file HeapGuard.c.

Variable Documentation

◆ mGuardedMemoryMap

GLOBAL_REMOVE_IF_UNREFERENCED UINT64 mGuardedMemoryMap = 0

Definition at line 22 of file HeapGuard.c.

◆ mLevelMask

GLOBAL_REMOVE_IF_UNREFERENCED UINTN mLevelMask[GUARDED_HEAP_MAP_TABLE_DEPTH] = GUARDED_HEAP_MAP_TABLE_DEPTH_MASKS

Definition at line 36 of file HeapGuard.c.

◆ mLevelShift

GLOBAL_REMOVE_IF_UNREFERENCED UINTN mLevelShift[GUARDED_HEAP_MAP_TABLE_DEPTH] = GUARDED_HEAP_MAP_TABLE_DEPTH_SHIFTS

Definition at line 34 of file HeapGuard.c.

◆ mMapLevel

GLOBAL_REMOVE_IF_UNREFERENCED UINTN mMapLevel = 1

Definition at line 29 of file HeapGuard.c.

◆ mOnGuarding

GLOBAL_REMOVE_IF_UNREFERENCED BOOLEAN mOnGuarding = FALSE

Definition at line 15 of file HeapGuard.c.

◆ mSmmMemoryAttribute

EDKII_SMM_MEMORY_ATTRIBUTE_PROTOCOL* mSmmMemoryAttribute = NULL

Definition at line 42 of file HeapGuard.c.

Functions

Variables

Detailed Description

Function Documentation

◆ AdjustMemoryF()

◆ AdjustPoolHeadA()

◆ AdjustPoolHeadF()

◆ ClearBits()

◆ ClearGuardedMemoryBits()

◆ DumpGuardedMemoryBitmap()

◆ FindGuardedMemoryMap()

◆ GetBits()

◆ GetGuardedMemoryBits()

◆ GetGuardMapBit()

◆ InternalAllocMaxAddressWithGuard()

◆ IsGuardPage()

◆ IsHeapGuardEnabled()

◆ IsMemoryGuarded()

◆ IsMemoryTypeToGuard()

◆ IsPageTypeToGuard()

◆ IsPoolTypeToGuard()

◆ PageAlloc()

◆ SetAllGuardPages()

◆ SetBits()

◆ SetGuardedMemoryBits()

◆ SetGuardForMemory()

◆ SetGuardPage()

◆ SmmEntryPointMemoryManagementHook()

◆ SmmInternalFreePagesExWithGuard()

◆ Uint64ToBinString()

◆ UnsetGuardForMemory()

◆ UnsetGuardPage()

◆ VerifyMemoryGuard()

Variable Documentation

◆ mGuardedMemoryMap

◆ mLevelMask

◆ mLevelShift

◆ mMapLevel

◆ mOnGuarding

◆ mSmmMemoryAttribute