[PATCH v1 4/5] MdeModulePkg: SmiHandlerProfileInfo: Updated MessageLength calculation

["Kun Qin" <kuqin12@gmail.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3398

This change replaced the calculation of communication buffer size from
explicitly adding the size of each member with the OFFSET macro function.
This will make the structure field defition change transparent to
consumers.

Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Hao A Wu <hao.a.wu@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Ray Ni <ray.ni@intel.com>

Signed-off-by: Kun Qin <kuqin12@gmail.com>
---
 MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c b/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c
index 4153074b7a80..56d80d1a9ce1 100644
--- a/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c
+++ b/MdeModulePkg/Application/SmiHandlerProfileInfo/SmiHandlerProfileInfo.c
@@ -116,7 +116,9 @@ GetSmiHandlerProfileDatabase(
   CommGetInfo->Header.ReturnStatus = (UINT64)-1;
   CommGetInfo->DataSize = 0;
 
-  CommSize = sizeof(EFI_GUID) + sizeof(UINTN) + CommHeader->MessageLength;
+  // BZ3398: Make MessageLength the same size in EFI_MM_COMMUNICATE_HEADER for both IA32 and X64.
+  // The CommHeader->MessageLength contains a definitive value, thus UINTN cast is safe here.
+  CommSize = OFFSET_OF(EFI_SMM_COMMUNICATE_HEADER, Data) + (UINTN)CommHeader->MessageLength;
   Status = SmmCommunication->Communicate(SmmCommunication, CommBuffer, &CommSize);
   if (EFI_ERROR(Status)) {
     Print(L"SmiHandlerProfile: SmmCommunication - %r\n", Status);
@@ -149,7 +151,9 @@ GetSmiHandlerProfileDatabase(
   CommGetData->Header.DataLength = sizeof(*CommGetData);
   CommGetData->Header.ReturnStatus = (UINT64)-1;
 
-  CommSize = sizeof(EFI_GUID) + sizeof(UINTN) + CommHeader->MessageLength;
+  // BZ3398: Make MessageLength the same size in EFI_MM_COMMUNICATE_HEADER for both IA32 and X64.
+  // The CommHeader->MessageLength contains a definitive value, thus UINTN cast is safe here.
+  CommSize = OFFSET_OF(EFI_SMM_COMMUNICATE_HEADER, Data) + (UINTN)CommHeader->MessageLength;
   Buffer = (UINT8 *)CommHeader + CommSize;
   Size -= CommSize;
 
-- 
2.31.1.windows.1