[PATCH v3 2/3] MdeModulePkg VariablePei: Return GetVariable() attr if EFI_BUFFER_TOO_SMALL

["Michael Kubacki" <michael.kubacki@outlook.com>]

From: Michael Kubacki <michael.kubacki@microsoft.com>

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=2062

This commit makes the behavior for PeiGetVariable() match the following
specification-defined behavior. It is now consistent with the DXE/SMM
variable driver implementation.

The UEFI specification v2.8 Errata A Section 8.2 "GetVariable()"
"Attributes" parameter description states:

"If not NULL, a pointer to the memory location to return the
 attributes bitmask for the variable. See 'Related Definitions.'
 If not NULL, then Attributes is set on output both when
 EFI_SUCCESS and when EFI_BUFFER_TOO_SMALL is returned."

The attributes were previously only returned from the implementation
in Variable.c on EFI_SUCCESS. They are now returned on EFI_SUCCESS or
EFI_BUFFER_TOO_SMALL according to spec.

Cc: Bret Barkelew <Bret.Barkelew@microsoft.com>
Cc: Liming Gao <liming.gao@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
---
 MdeModulePkg/Universal/Variable/Pei/Variable.c | 19 ++++++++++---------
 1 file changed, 10 insertions(+), 9 deletions(-)

diff --git a/MdeModulePkg/Universal/Variable/Pei/Variable.c b/MdeModulePkg/Universal/Variable/Pei/Variable.c
index f61465fc3045..f420b58165b7 100644
--- a/MdeModulePkg/Universal/Variable/Pei/Variable.c
+++ b/MdeModulePkg/Universal/Variable/Pei/Variable.c
@@ -3,6 +3,7 @@
   PEI ReadOnly Varaiable2 PPI. These services operates the non volatile storage space.
 
 Copyright (c) 2006 - 2019, Intel Corporation. All rights reserved.<BR>
+Copyright (c) Microsoft Corporation.<BR>
 SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -1047,17 +1048,17 @@ PeiGetVariable (
     }
 
     GetVariableNameOrData (&StoreInfo, GetVariableDataPtr (Variable.CurrPtr, VariableHeader, StoreInfo.AuthFlag), VarDataSize, Data);
-
-    if (Attributes != NULL) {
-      *Attributes = VariableHeader->Attributes;
-    }
-
-    *DataSize = VarDataSize;
-    return EFI_SUCCESS;
+    Status = EFI_SUCCESS;
   } else {
-    *DataSize = VarDataSize;
-    return EFI_BUFFER_TOO_SMALL;
+    Status = EFI_BUFFER_TOO_SMALL;
   }
+
+  if (Attributes != NULL) {
+    *Attributes = VariableHeader->Attributes;
+  }
+  *DataSize = VarDataSize;
+
+  return Status;
 }
 
 /**
-- 
2.16.3.windows.1