Per secure MOR implementation document, it is not proper to add MOR lock in non-SMM version, because DXE version can not provide protection. This patch add standalone TcgMorLockDxe implementation. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: "Yao, Jiewen" <jiewen.yao@intel.com> Reviewed-by: "Zhang, Chao B" <chao.b.zhang@intel.com> Reviewed-by: "Zeng, Star" <star.zeng@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@19689 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			90 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			90 lines
		
	
	
		
			3.1 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/** @file
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  TCG MOR (Memory Overwrite Request) Lock Control support (DXE version).
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  This module clears MemoryOverwriteRequestControlLock variable to indicate
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  MOR lock control unsupported.
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Copyright (c) 2016, Intel Corporation. All rights reserved.<BR>
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This program and the accompanying materials
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are licensed and made available under the terms and conditions of the BSD License
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which accompanies this distribution.  The full text of the license may be found at
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http://opensource.org/licenses/bsd-license.php
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THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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**/
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#include <PiDxe.h>
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#include <Guid/MemoryOverwriteControl.h>
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#include <IndustryStandard/MemoryOverwriteRequestControlLock.h>
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#include <Library/DebugLib.h>
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#include <Library/BaseLib.h>
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#include <Library/BaseMemoryLib.h>
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#include "Variable.h"
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extern EDKII_VARIABLE_LOCK_PROTOCOL     mVariableLock;
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/**
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  This service is an MOR/MorLock checker handler for the SetVariable().
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  @param  VariableName the name of the vendor's variable, as a
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                       Null-Terminated Unicode String
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  @param  VendorGuid   Unify identifier for vendor.
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  @param  Attributes   Point to memory location to return the attributes of variable. If the point
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                       is NULL, the parameter would be ignored.
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  @param  DataSize     The size in bytes of Data-Buffer.
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  @param  Data         Point to the content of the variable.
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  @retval  EFI_SUCCESS            The MOR/MorLock check pass, and Variable driver can store the variable data.
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  @retval  EFI_INVALID_PARAMETER  The MOR/MorLock data or data size or attributes is not allowed for MOR variable.
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  @retval  EFI_ACCESS_DENIED      The MOR/MorLock is locked.
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  @retval  EFI_ALREADY_STARTED    The MorLock variable is handled inside this function.
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                                  Variable driver can just return EFI_SUCCESS.
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**/
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EFI_STATUS
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SetVariableCheckHandlerMor (
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  IN CHAR16     *VariableName,
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  IN EFI_GUID   *VendorGuid,
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  IN UINT32     Attributes,
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  IN UINTN      DataSize,
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  IN VOID       *Data
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  )
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{
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  //
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  // Just let it pass. No need provide protection for DXE version.
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  //
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  return EFI_SUCCESS;
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}
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/**
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  Initialization for MOR Lock Control.
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  @retval EFI_SUCEESS     MorLock initialization success.
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  @return Others          Some error occurs.
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**/
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EFI_STATUS
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MorLockInit (
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  VOID
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  )
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{
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  //
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  // Always clear variable to report unsupported to OS.
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  // The reason is that the DXE version is not proper to provide *protection*.
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  // BIOS should use SMM version variable driver to provide such capability.
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  //
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  VariableServiceSetVariable (
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    MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME,
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    &gEfiMemoryOverwriteRequestControlLockGuid,
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    EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
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    0,
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    NULL
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    );
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  //
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  // Need set this variable to be read-only to prevent other module set it.
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  //
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  VariableLockRequestToLock (&mVariableLock, MEMORY_OVERWRITE_REQUEST_CONTROL_LOCK_NAME, &gEfiMemoryOverwriteRequestControlLockGuid);
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  return EFI_SUCCESS;
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}
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