#include <PiDxe.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/DxeServicesTableLib.h>
#include <Library/DebugLib.h>
#include <Library/UefiLib.h>
#include <Library/ImagePropertiesRecordLib.h>
#include <Guid/EventGroup.h>
#include <Guid/MemoryAttributesTable.h>
#include <Protocol/FirmwareVolume2.h>
#include <Protocol/SimpleFileSystem.h>
#include "DxeMain.h"
#include "Mem/HeapGuard.h"

Macros
#define	IMAGE_UNKNOWN 0x00000001

#define	IMAGE_FROM_FV 0x00000002

#define	DO_NOT_PROTECT 0x00000000

#define	PROTECT_IF_ALIGNED_ELSE_ALLOW 0x00000001

#define	MEMORY_TYPE_OS_RESERVED_MIN 0x80000000

#define	MEMORY_TYPE_OEM_RESERVED_MIN 0x70000000

#define	PREVIOUS_MEMORY_DESCRIPTOR(MemoryDescriptor, Size) ((EFI_MEMORY_DESCRIPTOR )((UINT8 )(MemoryDescriptor) - (Size)))

Functions
UINT32	GetImageType (IN CONST EFI_DEVICE_PATH_PROTOCOL *File)

UINT32	GetProtectionPolicyFromImageType (IN UINT32 ImageType)

UINT32	GetUefiImageProtectionPolicy (IN EFI_LOADED_IMAGE_PROTOCOL LoadedImage, IN EFI_DEVICE_PATH_PROTOCOL LoadedImageDevicePath)

VOID	SetUefiImageMemoryAttributes (IN UINT64 BaseAddress, IN UINT64 Length, IN UINT64 Attributes)

VOID	SetUefiImageProtectionAttributes (IN IMAGE_PROPERTIES_RECORD *ImageRecord)

STATIC UINT32	GetMemoryProtectionSectionAlignment (IN EFI_MEMORY_TYPE MemoryType)

VOID	ProtectUefiImage (IN EFI_LOADED_IMAGE_PROTOCOL LoadedImage, IN EFI_DEVICE_PATH_PROTOCOL LoadedImageDevicePath)

VOID	UnprotectUefiImage (IN EFI_LOADED_IMAGE_PROTOCOL LoadedImage, IN EFI_DEVICE_PATH_PROTOCOL LoadedImageDevicePath)

STATIC UINT64	GetPermissionAttributeForMemoryType (IN EFI_MEMORY_TYPE MemoryType)

STATIC VOID	SortMemoryMap (IN OUT EFI_MEMORY_DESCRIPTOR *MemoryMap, IN UINTN MemoryMapSize, IN UINTN DescriptorSize)

STATIC VOID	MergeMemoryMapForProtectionPolicy (IN OUT EFI_MEMORY_DESCRIPTOR MemoryMap, IN OUT UINTN MemoryMapSize, IN UINTN DescriptorSize)

STATIC VOID	InitializeDxeNxMemoryProtectionPolicy (VOID)

VOID EFIAPI	MemoryProtectionCpuArchProtocolNotify (IN EFI_EVENT Event, IN VOID *Context)

VOID	MemoryProtectionExitBootServicesCallback (VOID)

VOID EFIAPI	DisableNullDetectionAtTheEndOfDxe (EFI_EVENT Event, VOID *Context)

VOID EFIAPI	CoreInitializeMemoryProtection (VOID)

STATIC BOOLEAN	IsInSmm (VOID)

EFI_STATUS EFIAPI	ApplyMemoryProtectionPolicy (IN EFI_MEMORY_TYPE OldType, IN EFI_MEMORY_TYPE NewType, IN EFI_PHYSICAL_ADDRESS Memory, IN UINT64 Length)

Variables
UINT32	mImageProtectionPolicy

LIST_ENTRY	mGcdMemorySpaceMap

STATIC LIST_ENTRY	mProtectedImageRecordList

Detailed Description

UEFI Memory Protection support.

If the UEFI image is page aligned, the image code section is set to read only and the image data section is set to non-executable.

1) This policy is applied for all UEFI image including boot service driver, runtime driver or application. 2) This policy is applied only if the UEFI image meets the page alignment requirement. 3) This policy is applied only if the Source UEFI image matches the PcdImageProtectionPolicy definition. 4) This policy is not applied to the non-PE image region.

The DxeCore calls CpuArchProtocol->SetMemoryAttributes() to protect the image. If the CpuArch protocol is not installed yet, the DxeCore enqueues the protection request. Once the CpuArch is installed, the DxeCore dequeues the protection request and applies policy.

Once the image is unloaded, the protection is removed automatically.

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

Definition in file MemoryProtection.c.

Macro Definition Documentation

◆ DO_NOT_PROTECT

#define DO_NOT_PROTECT 0x00000000

Definition at line 55 of file MemoryProtection.c.

◆ IMAGE_FROM_FV

#define IMAGE_FROM_FV 0x00000002

Definition at line 50 of file MemoryProtection.c.

◆ IMAGE_UNKNOWN

#define IMAGE_UNKNOWN 0x00000001

Definition at line 49 of file MemoryProtection.c.

◆ MEMORY_TYPE_OEM_RESERVED_MIN

#define MEMORY_TYPE_OEM_RESERVED_MIN 0x70000000

Definition at line 59 of file MemoryProtection.c.

◆ MEMORY_TYPE_OS_RESERVED_MIN

#define MEMORY_TYPE_OS_RESERVED_MIN 0x80000000

Definition at line 58 of file MemoryProtection.c.

◆ PREVIOUS_MEMORY_DESCRIPTOR

#define PREVIOUS_MEMORY_DESCRIPTOR	(	MemoryDescriptor,
		Size
	)	((EFI_MEMORY_DESCRIPTOR )((UINT8 )(MemoryDescriptor) - (Size)))

Definition at line 61 of file MemoryProtection.c.

◆ PROTECT_IF_ALIGNED_ELSE_ALLOW

#define PROTECT_IF_ALIGNED_ELSE_ALLOW 0x00000001

Definition at line 56 of file MemoryProtection.c.

Function Documentation

◆ ApplyMemoryProtectionPolicy()

EFI_STATUS EFIAPI ApplyMemoryProtectionPolicy	(	IN EFI_MEMORY_TYPE	OldType,
		IN EFI_MEMORY_TYPE	NewType,
		IN EFI_PHYSICAL_ADDRESS	Memory,
		IN UINT64	Length
	)

Manage memory permission attributes on a memory range, according to the configured DXE memory protection policy.

Parameters

OldType	The old memory type of the range
NewType	The new memory type of the range
Memory	The base address of the range
Length	The size of the range (in bytes)

Returns: EFI_SUCCESS If we are executing in SMM mode. No permission attributes are updated in this case; EFI_SUCCESS If the the CPU arch protocol is not installed yet; EFI_SUCCESS If no DXE memory protection policy has been configured; EFI_SUCCESS If OldType and NewType use the same permission attributes; other Return value of gCpu->SetMemoryAttributes()

Definition at line 1035 of file MemoryProtection.c.

◆ CoreInitializeMemoryProtection()

VOID EFIAPI CoreInitializeMemoryProtection ( VOID )

Initialize Memory Protection support.

Definition at line 931 of file MemoryProtection.c.

◆ DisableNullDetectionAtTheEndOfDxe()

VOID EFIAPI DisableNullDetectionAtTheEndOfDxe	(	EFI_EVENT	Event,
		VOID *	Context
	)

Disable NULL pointer detection after EndOfDxe. This is a workaround resort in order to skip unfixable NULL pointer access issues detected in OptionROM or boot loaders.

Parameters

[in]	Event	The Event this notify function registered to.
[in]	Context	Pointer to the context data registered to the Event.

Definition at line 884 of file MemoryProtection.c.

◆ GetImageType()

UINT32 GetImageType ( IN CONST EFI_DEVICE_PATH_PROTOCOL * File )

Get the image type.

Parameters

[in] File This is a pointer to the device path of the file that is being dispatched.

Returns: UINT32 Image Type

Definition at line 79 of file MemoryProtection.c.

◆ GetMemoryProtectionSectionAlignment()

STATIC UINT32 GetMemoryProtectionSectionAlignment ( IN EFI_MEMORY_TYPE MemoryType )

Return the section alignment requirement for the PE image section type.

Parameters

[in] MemoryType PE/COFF image memory type

Return values

The	required section alignment for this memory type

Definition at line 293 of file MemoryProtection.c.

◆ GetPermissionAttributeForMemoryType()

STATIC UINT64 GetPermissionAttributeForMemoryType ( IN EFI_MEMORY_TYPE MemoryType )

Return the EFI memory permission attribute associated with memory type 'MemoryType' under the configured DXE memory protection policy.

Parameters

MemoryType Memory type.

Definition at line 440 of file MemoryProtection.c.

◆ GetProtectionPolicyFromImageType()

UINT32 GetProtectionPolicyFromImageType ( IN UINT32 ImageType )

Get UEFI image protection policy based upon image type.

Parameters

[in] ImageType The UEFI image type

Returns: UEFI image protection policy

Definition at line 126 of file MemoryProtection.c.

◆ GetUefiImageProtectionPolicy()

UINT32 GetUefiImageProtectionPolicy	(	IN EFI_LOADED_IMAGE_PROTOCOL *	LoadedImage,
		IN EFI_DEVICE_PATH_PROTOCOL *	LoadedImageDevicePath
	)

Get UEFI image protection policy based upon loaded image device path.

Parameters

[in]	LoadedImage	The loaded image protocol
[in]	LoadedImageDevicePath	The loaded image device path protocol

Returns: UEFI image protection policy

Definition at line 146 of file MemoryProtection.c.

◆ InitializeDxeNxMemoryProtectionPolicy()

STATIC VOID InitializeDxeNxMemoryProtectionPolicy ( VOID )

Remove exec permissions from all regions whose type is identified by PcdDxeNxMemoryProtectionPolicy.

Definition at line 572 of file MemoryProtection.c.

◆ IsInSmm()

STATIC BOOLEAN IsInSmm ( VOID )

Returns whether we are currently executing in SMM mode.

Definition at line 1002 of file MemoryProtection.c.

◆ MemoryProtectionCpuArchProtocolNotify()

VOID EFIAPI MemoryProtectionCpuArchProtocolNotify	(	IN EFI_EVENT	Event,
		IN VOID *	Context
	)

A notification for CPU_ARCH protocol.

Parameters

[in]	Event	Event whose notification function is being invoked.
[in]	Context	Pointer to the notification function's context, which is implementation-dependent.

Definition at line 773 of file MemoryProtection.c.

◆ MemoryProtectionExitBootServicesCallback()

VOID MemoryProtectionExitBootServicesCallback ( VOID )

ExitBootServices Callback function for memory protection.

Definition at line 850 of file MemoryProtection.c.

◆ MergeMemoryMapForProtectionPolicy()

STATIC VOID MergeMemoryMapForProtectionPolicy	(	IN OUT EFI_MEMORY_DESCRIPTOR *	MemoryMap,
		IN OUT UINTN *	MemoryMapSize,
		IN UINTN	DescriptorSize
	)

Merge adjacent memory map entries if they use the same memory protection policy

Parameters

[in,out]	MemoryMap	A pointer to the buffer in which firmware places the current memory map.
[in,out]	MemoryMapSize	A pointer to the size, in bytes, of the MemoryMap buffer. On input, this is the size of the current memory map. On output, it is the size of new memory map after merge.
[in]	DescriptorSize	Size, in bytes, of an individual EFI_MEMORY_DESCRIPTOR.

Definition at line 514 of file MemoryProtection.c.

◆ ProtectUefiImage()

VOID ProtectUefiImage	(	IN EFI_LOADED_IMAGE_PROTOCOL *	LoadedImage,
		IN EFI_DEVICE_PATH_PROTOCOL *	LoadedImageDevicePath
	)

Protect UEFI PE/COFF image.

Parameters

[in]	LoadedImage	The loaded image protocol
[in]	LoadedImageDevicePath	The loaded image device path protocol

Definition at line 330 of file MemoryProtection.c.

◆ SetUefiImageMemoryAttributes()

VOID SetUefiImageMemoryAttributes	(	IN UINT64	BaseAddress,
		IN UINT64	Length,
		IN UINT64	Attributes
	)

Set UEFI image memory attributes.

Parameters

[in]	BaseAddress	Specified start address
[in]	Length	Specified length
[in]	Attributes	Specified attributes

Definition at line 188 of file MemoryProtection.c.

◆ SetUefiImageProtectionAttributes()

VOID SetUefiImageProtectionAttributes ( IN IMAGE_PROPERTIES_RECORD * ImageRecord )

Set UEFI image protection attributes.

Parameters

[in] ImageRecord A UEFI image record

Definition at line 215 of file MemoryProtection.c.

◆ SortMemoryMap()

STATIC VOID SortMemoryMap	(	IN OUT EFI_MEMORY_DESCRIPTOR *	MemoryMap,
		IN UINTN	MemoryMapSize,
		IN UINTN	DescriptorSize
	)

Sort memory map entries based upon PhysicalStart, from low to high.

Parameters

MemoryMap	A pointer to the buffer in which firmware places the current memory map.
MemoryMapSize	Size, in bytes, of the MemoryMap buffer.
DescriptorSize	Size, in bytes, of an individual EFI_MEMORY_DESCRIPTOR.

Definition at line 471 of file MemoryProtection.c.

◆ UnprotectUefiImage()

VOID UnprotectUefiImage	(	IN EFI_LOADED_IMAGE_PROTOCOL *	LoadedImage,
		IN EFI_DEVICE_PATH_PROTOCOL *	LoadedImageDevicePath
	)

Unprotect UEFI image.

Parameters

[in]	LoadedImage	The loaded image protocol
[in]	LoadedImageDevicePath	The loaded image device path protocol

Definition at line 399 of file MemoryProtection.c.

Variable Documentation

◆ mGcdMemorySpaceMap

LIST_ENTRY mGcdMemorySpaceMap

extern

Definition at line 45 of file Gcd.c.

◆ mImageProtectionPolicy

UINT32 mImageProtectionPolicy

Definition at line 64 of file MemoryProtection.c.

◆ mProtectedImageRecordList

STATIC LIST_ENTRY mProtectedImageRecordList

Definition at line 68 of file MemoryProtection.c.

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ DO_NOT_PROTECT

◆ IMAGE_FROM_FV

◆ IMAGE_UNKNOWN

◆ MEMORY_TYPE_OEM_RESERVED_MIN

◆ MEMORY_TYPE_OS_RESERVED_MIN

◆ PREVIOUS_MEMORY_DESCRIPTOR

◆ PROTECT_IF_ALIGNED_ELSE_ALLOW

Function Documentation

◆ ApplyMemoryProtectionPolicy()

◆ CoreInitializeMemoryProtection()

◆ DisableNullDetectionAtTheEndOfDxe()

◆ GetImageType()

◆ GetMemoryProtectionSectionAlignment()

◆ GetPermissionAttributeForMemoryType()

◆ GetProtectionPolicyFromImageType()

◆ GetUefiImageProtectionPolicy()

◆ InitializeDxeNxMemoryProtectionPolicy()

◆ IsInSmm()

◆ MemoryProtectionCpuArchProtocolNotify()

◆ MemoryProtectionExitBootServicesCallback()

◆ MergeMemoryMapForProtectionPolicy()

◆ ProtectUefiImage()

◆ SetUefiImageMemoryAttributes()

◆ SetUefiImageProtectionAttributes()

◆ SortMemoryMap()

◆ UnprotectUefiImage()

Variable Documentation

◆ mGcdMemorySpaceMap

◆ mImageProtectionPolicy

◆ mProtectedImageRecordList