Re: [edk2-devel] [PATCH] IntelFsp2Pkg: PeiService pointer not reset to 0 in SecMain

["Nate DeSimone" <nathaniel.l.desimone@intel.com>]

Reviewed-by: Nate DeSimone <nathaniel.l.desimone@intel.com>

-----Original Message-----
From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Chiu, Chasel
Sent: Thursday, July 25, 2019 8:51 AM
To: devel@edk2.groups.io
Cc: Desimone, Nathaniel L <nathaniel.l.desimone@intel.com>; Zeng, Star <star.zeng@intel.com>
Subject: [edk2-devel] [PATCH] IntelFsp2Pkg: PeiService pointer not reset to 0 in SecMain

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2018

Current FSP SEC_IDT_TABLE structure is not natural aligned:
  typedef struct _SEC_IDT_TABLE {
    EFI_PEI_SERVICES  *PeiService;
    UINT64            IdtTable[];
  } SEC_IDT_TABLE;
Compiler will insert DWORD padding between 2 elements and
GetPeiServicesTablePointer() in early phase then always returns padding data from stack, which was not rest to 0 in SecMain.

Solution is to align FSP SEC_IDT_TABLE structure to UefiCpuPkg to have UINT64 as PeiService field and rest it to 0.

Test: Verified on internal platform and booting successfully
      with FSP API mode.

Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Star Zeng <star.zeng@intel.com>
Signed-off-by: Chasel Chiu <chasel.chiu@intel.com>
---
 IntelFsp2Pkg/FspSecCore/SecMain.c |  2 +-  IntelFsp2Pkg/FspSecCore/SecMain.h | 10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.c b/IntelFsp2Pkg/FspSecCore/SecMain.c
index a63d1336e4..7169afc6c7 100644
--- a/IntelFsp2Pkg/FspSecCore/SecMain.c
+++ b/IntelFsp2Pkg/FspSecCore/SecMain.c
@@ -114,7 +114,7 @@ SecStartup (
   // |                   |
   // |                   |
   // |-------------------|---->  TempRamBase
-  IdtTableInStack.PeiService  = NULL;
+  IdtTableInStack.PeiService = 0;
   AsmReadIdtr (&IdtDescriptor);
   if (IdtDescriptor.Base == 0) {
     ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.h b/IntelFsp2Pkg/FspSecCore/SecMain.h
index 6fb16febab..af7f387960 100644
--- a/IntelFsp2Pkg/FspSecCore/SecMain.h
+++ b/IntelFsp2Pkg/FspSecCore/SecMain.h
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2014 - 2019, Intel Corporation. All rights 
+ reserved.<BR>
   SPDX-License-Identifier: BSD-2-Clause-Patent
 
 **/
@@ -29,7 +29,13 @@ typedef VOID (*PEI_CORE_ENTRY) ( \  );
 
 typedef struct _SEC_IDT_TABLE {
-  EFI_PEI_SERVICES  *PeiService;
+  //
+  // Reserved 8 bytes preceding IDT to store EFI_PEI_SERVICES**, since 
+ IDT base  // address should be 8-byte alignment.
+  // Note: For IA32, only the 4 bytes immediately preceding IDT is used 
+ to store  // EFI_PEI_SERVICES**  //
+  UINT64            PeiService;
   UINT64            IdtTable[FixedPcdGet8 (PcdFspMaxInterruptSupported)];
 } SEC_IDT_TABLE;
 
--
2.13.3.windows.1