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SecurityPkg: Variable drivers robustly handle crashes during Reclaim().

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PEI variable implementation checks only the variable header signature for validity. This does not seem robust if system crash occurred during previous Reclaim() operation. If the crash occurred while FTW was rewriting the variable FV, the signature could be valid even though the rest of the FV isn't valid.
Solution: PEI variable and early phase(before FTW protocol ready) of DXE variable can check the FTW last write status provided by FaultTolerantWritePei and determine if all or partial variable data has been backed up in spare block, and then use the backed up data.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14455 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Star Zeng
2013-07-03 09:09:42 +00:00
committed by lzeng14
parent 3e02ebb2bb
commit 039a40aa3b
7 changed files with 514 additions and 198 deletions
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14
SecurityPkg/VariableAuthenticated/Pei/Variable.h
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@@ -2,7 +2,7 @@
The internal header file includes the common header files, defines
internal structure and functions used by PeiVariable module.
Copyright (c) 2009 - 2011, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2009 - 2013, Intel Corporation. All rights reserved.<BR>
This program and the accompanying materials
are licensed and made available under the terms and conditions of the BSD License
which accompanies this distribution. The full text of the license may be found at
@@ -30,6 +30,7 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
#include <Guid/AuthenticatedVariableFormat.h>
#include <Guid/VariableIndexTable.h>
#include <Guid/SystemNvDataGuid.h>
#include <Guid/FaultTolerantWrite.h>
typedef enum {
VariableStoreTypeHob,
@@ -37,6 +38,17 @@ typedef enum {
VariableStoreTypeMax
} VARIABLE_STORE_TYPE;
typedef struct {
VARIABLE_STORE_HEADER *VariableStoreHeader;
VARIABLE_INDEX_TABLE *IndexTable;
//
// If it is not NULL, it means there may be an inconsecutive variable whose
// partial content is still in NV storage, but another partial content is backed up
// in spare block.
//
FAULT_TOLERANT_WRITE_LAST_WRITE_DATA *FtwLastWriteData;
} VARIABLE_STORE_INFO;
//
// Functions
//