SecurityPkg Variable: Remove mStorageData buffer allocation and use Scratch buffer instead to reduce SMRAM consumption.

It can reduce MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxHardwareErrorVariableSize)) size of SMRAM consumption.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Guo Dong <guo.dong@intel.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14855 6f19259b-4bc3-4df7-8a09-765794883524

4 files changed, 40 insertions, 48 deletions

diff --git a/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.c b/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.c
index 90a5d51a9e..ee45ec9776 100644
--- a/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.c
+++ b/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.c
@@ -49,14 +49,6 @@ CONST UINT8 mRsaE[] = { 0x01, 0x00, 0x01 };
 VOID  *mHashCtx = NULL;

 

 //

-// Pointer to runtime buffer.

-// For "Append" operation to an existing variable, a read/modify/write operation

-// is supported by firmware internally. Reserve runtime buffer to cache previous

-// variable data in runtime phase because memory allocation is forbidden in virtual mode.

-//

-VOID  *mStorageArea = NULL;

-

-//

 // The serialization of the values of the VariableName, VendorGuid and Attributes

 // parameters of the SetVariable() call and the TimeStamp component of the

 // EFI_VARIABLE_AUTHENTICATION_2 descriptor followed by the variable's new value

@@ -192,14 +184,6 @@ AutenticatedVariableServiceInitialize (
   }

 

   //

-  // Reserved runtime buffer for "Append" operation in virtual mode.

-  //

-  mStorageArea  = AllocateRuntimePool (MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxHardwareErrorVariableSize)));

-  if (mStorageArea == NULL) {

-    return EFI_OUT_OF_RESOURCES;

-  }

-

-  //

   // Prepare runtime buffer for serialized data of time-based authenticated

   // Variable, i.e. (VariableName, VendorGuid, Attributes, TimeStamp, Data).

   //

diff --git a/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.h b/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.h
index 1fd687b033..745e3c7d8f 100644
--- a/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.h
+++ b/SecurityPkg/VariableAuthenticated/RuntimeDxe/AuthService.h
@@ -329,7 +329,6 @@ VerifyTimeBasedPayload (
 extern UINT8  mPubKeyStore[MAX_KEYDB_SIZE];

 extern UINT32 mPubKeyNumber;

 extern VOID   *mHashCtx;

-extern VOID   *mStorageArea;

 extern UINT8  *mSerializationRuntimeBuffer;

 

 #endif

diff --git a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
index adcf25c313..28d026a0a8 100644
--- a/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
+++ b/SecurityPkg/VariableAuthenticated/RuntimeDxe/Variable.c
@@ -1752,7 +1752,9 @@ UpdateVariable (
   VARIABLE_POINTER_TRACK              NvVariable;

   VARIABLE_STORE_HEADER               *VariableStoreHeader;

   UINTN                               CacheOffset;

-  UINTN                               BufSize;

+  UINT8                               *BufferForMerge;

+  UINTN                               MergedBufSize;

+  BOOLEAN                             DataReady;

   UINTN                               DataOffset;

 

   if (mVariableModuleGlobal->FvbInstance == NULL) {

@@ -1802,7 +1804,8 @@ UpdateVariable (
   //

   NextVariable = GetEndPointer ((VARIABLE_STORE_HEADER *) ((UINTN) mVariableModuleGlobal->VariableGlobal.VolatileVariableBase));

   ScratchSize = MAX (PcdGet32 (PcdMaxVariableSize), PcdGet32 (PcdMaxHardwareErrorVariableSize));

-

+  SetMem (NextVariable, ScratchSize, 0xff);

+  DataReady = FALSE;

 

   if (Variable->CurrPtr != NULL) {

     //

@@ -1894,7 +1897,7 @@ UpdateVariable (
     // then return to the caller immediately.

     //

     if (DataSizeOfVariable (Variable->CurrPtr) == DataSize &&

-        (CompareMem (Data, GetVariableDataPtr (Variable->CurrPtr), DataSize) == 0)  &&

+        (CompareMem (Data, GetVariableDataPtr (Variable->CurrPtr), DataSize) == 0) &&

         ((Attributes & EFI_VARIABLE_APPEND_WRITE) == 0) &&

         (TimeStamp == NULL)) {

       //

@@ -1911,42 +1914,42 @@ UpdateVariable (
       //

       if ((Attributes & EFI_VARIABLE_APPEND_WRITE) != 0) {

         //

-        // Cache the previous variable data into StorageArea.

+        // NOTE: From 0 to DataOffset of NextVariable is reserved for Variable Header and Name.

+        // From DataOffset of NextVariable is to save the existing variable data.

         //

         DataOffset = sizeof (VARIABLE_HEADER) + Variable->CurrPtr->NameSize + GET_PAD_SIZE (Variable->CurrPtr->NameSize);

-        CopyMem (mStorageArea, (UINT8*)((UINTN) Variable->CurrPtr + DataOffset), Variable->CurrPtr->DataSize);

+        BufferForMerge = (UINT8 *) ((UINTN) NextVariable + DataOffset);

+        CopyMem (BufferForMerge, (UINT8 *) ((UINTN) Variable->CurrPtr + DataOffset), Variable->CurrPtr->DataSize);

 

         //

         // Set Max Common Variable Data Size as default MaxDataSize 

         //

-        MaxDataSize = PcdGet32 (PcdMaxVariableSize) - sizeof (VARIABLE_HEADER) - StrSize (VariableName) - GET_PAD_SIZE (StrSize (VariableName));

-

+        MaxDataSize = PcdGet32 (PcdMaxVariableSize) - DataOffset;

 

         if ((CompareGuid (VendorGuid, &gEfiImageSecurityDatabaseGuid) &&

             ((StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE) == 0) || (StrCmp (VariableName, EFI_IMAGE_SECURITY_DATABASE1) == 0))) ||

             (CompareGuid (VendorGuid, &gEfiGlobalVariableGuid) && (StrCmp (VariableName, EFI_KEY_EXCHANGE_KEY_NAME) == 0))) {

-

           //

           // For variables with formatted as EFI_SIGNATURE_LIST, the driver shall not perform an append of

           // EFI_SIGNATURE_DATA values that are already part of the existing variable value.

           //

           Status = AppendSignatureList (

-                     mStorageArea, 

+                     BufferForMerge,

                      Variable->CurrPtr->DataSize, 

                      MaxDataSize - Variable->CurrPtr->DataSize,

-                     Data, 

-                     DataSize, 

-                     &BufSize

+                     Data,

+                     DataSize,

+                     &MergedBufSize

                      );

           if (Status == EFI_BUFFER_TOO_SMALL) {

             //

-            // Signture List is too long, Failed to Append

+            // Signature List is too long, Failed to Append.

             //

             Status = EFI_INVALID_PARAMETER;

             goto Done;

           }

 

-          if (BufSize == Variable->CurrPtr->DataSize) {

+          if (MergedBufSize == Variable->CurrPtr->DataSize) {

             if ((TimeStamp == NULL) || CompareTimeStamp (TimeStamp, &Variable->CurrPtr->TimeStamp)) {

               //

               // New EFI_SIGNATURE_DATA is not found and timestamp is not later

@@ -1959,29 +1962,30 @@ UpdateVariable (
           }

         } else {

           //

-          // For other Variables, append the new data to the end of previous data.

+          // For other Variables, append the new data to the end of existing data.

           // Max Harware error record variable data size is different from common variable

           //

           if ((Attributes & EFI_VARIABLE_HARDWARE_ERROR_RECORD) == EFI_VARIABLE_HARDWARE_ERROR_RECORD) {

-            MaxDataSize = PcdGet32 (PcdMaxHardwareErrorVariableSize) - sizeof (VARIABLE_HEADER) - StrSize (VariableName) - GET_PAD_SIZE (StrSize (VariableName));

+            MaxDataSize = PcdGet32 (PcdMaxHardwareErrorVariableSize) - DataOffset;

           }

 

           if (Variable->CurrPtr->DataSize + DataSize > MaxDataSize) {

             //

-            // Exsiting data + Appended data exceed maximum variable size limitation 

+            // Existing data size + new data size exceed maximum variable size limitation.

             //

             Status = EFI_INVALID_PARAMETER;

             goto Done;

           }

-          CopyMem ((UINT8*)((UINTN) mStorageArea + Variable->CurrPtr->DataSize), Data, DataSize);

-          BufSize = Variable->CurrPtr->DataSize + DataSize;

+          CopyMem ((UINT8*) ((UINTN) BufferForMerge + Variable->CurrPtr->DataSize), Data, DataSize);

+          MergedBufSize = Variable->CurrPtr->DataSize + DataSize;

         }

 

         //

-        // Override Data and DataSize which are used for combined data area including previous and new data.

+        // BufferForMerge(from DataOffset of NextVariable) has included the merged existing and new data.

         //

-        Data     = mStorageArea;

-        DataSize = BufSize;

+        Data      = BufferForMerge;

+        DataSize  = MergedBufSize;

+        DataReady = TRUE;

       }

 

       //

@@ -2038,9 +2042,7 @@ UpdateVariable (
   //

   // Function part - create a new variable and copy the data.

   // Both update a variable and create a variable will come here.

-

-  SetMem (NextVariable, ScratchSize, 0xff);

-

+  //

   NextVariable->StartId     = VARIABLE_DATA;

   //

   // NextVariable->State = VAR_ADDED;

@@ -2082,11 +2084,19 @@ UpdateVariable (
     VarNameSize

     );

   VarDataOffset = VarNameOffset + VarNameSize + GET_PAD_SIZE (VarNameSize);

-  CopyMem (

-    (UINT8 *) ((UINTN) NextVariable + VarDataOffset),

-    Data,

-    DataSize

-    );

+

+  //

+  // If DataReady is TRUE, it means the variable data has been saved into

+  // NextVariable during EFI_VARIABLE_APPEND_WRITE operation preparation.

+  //

+  if (!DataReady) {

+    CopyMem (

+      (UINT8 *) ((UINTN) NextVariable + VarDataOffset),

+      Data,

+      DataSize

+      );

+  }

+

   CopyMem (&NextVariable->VendorGuid, VendorGuid, sizeof (EFI_GUID));

   //

   // There will be pad bytes after Data, the NextVariable->NameSize and

diff --git a/SecurityPkg/VariableAuthenticated/RuntimeDxe/VariableDxe.c b/SecurityPkg/VariableAuthenticated/RuntimeDxe/VariableDxe.c
index f1ba9c18f0..1d71e4f800 100644
--- a/SecurityPkg/VariableAuthenticated/RuntimeDxe/VariableDxe.c
+++ b/SecurityPkg/VariableAuthenticated/RuntimeDxe/VariableDxe.c
@@ -241,7 +241,6 @@ VariableClassAddressChangeEvent (
   EfiConvertPointer (0x0, (VOID **) &mVariableModuleGlobal->VariableGlobal.VolatileVariableBase);

   EfiConvertPointer (0x0, (VOID **) &mVariableModuleGlobal);

   EfiConvertPointer (0x0, (VOID **) &mHashCtx);

-  EfiConvertPointer (0x0, (VOID **) &mStorageArea);

   EfiConvertPointer (0x0, (VOID **) &mSerializationRuntimeBuffer);

   EfiConvertPointer (0x0, (VOID **) &mNvVariableCache);