From: Star Zeng <star.zeng@intel.com>
Date: Mon, 7 Mar 2016 06:01:46 +0000 (+0800)
Subject: MdeModulePkg AcpiTableDxe: Use Rsdt to check against NULL
X-Git-Tag: edk2-stable201903~7673
X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=efef6ad6d7487606782a5d4aa09656fb606129d6;hp=ace1d0517b656a6d15484e875d73c0fe661ac8c7;p=mirror_edk2.git

MdeModulePkg AcpiTableDxe: Use Rsdt to check against NULL

Some static scan tool may regard CurrentRsdtEntry to be potentially
referenced to NULL pointer if CurrentRsdtEntry == NULL is used in
the right above if condition judgment.

        CopyMem (CurrentRsdtEntry, CurrentRsdtEntry + 1, (*NumberOfTableEntries - Index) * sizeof (UINT32));

It is introduced by commit f9bbb8d9c3f065faba9f266cf4e731fe2ca70c4d.
To avoid it and have same style with
"((Xsdt == NULL) || CurrentTablePointer64 == (UINT64) (UINTN) Table->Table)",
use Rsdt instead of CurrentRsdtEntry to check against NULL.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Shumin Qiu <shumin.qiu@intel.com>
Cc: Feng Tian <feng.tian@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Shumin Qiu <shumin.qiu@intel.com>
---

diff --git a/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c b/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c
index f6229ca05c..7f95b9dc70 100644
--- a/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c
+++ b/MdeModulePkg/Universal/Acpi/AcpiTableDxe/AcpiTableProtocol.c
@@ -1,7 +1,7 @@
 /** @file
   ACPI Table Protocol Implementation
 
-  Copyright (c) 2006 - 2015, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
   Copyright (c) 2016, Linaro Ltd. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
@@ -1132,7 +1132,7 @@ RemoveTableFromRsdt (
     //
     // Check if we have found the corresponding entry in both RSDT and XSDT
     //
-    if ((CurrentRsdtEntry == NULL || *CurrentRsdtEntry == (UINT32) (UINTN) Table->Table) &&
+    if (((Rsdt == NULL) || *CurrentRsdtEntry == (UINT32) (UINTN) Table->Table) &&
         ((Xsdt == NULL) || CurrentTablePointer64 == (UINT64) (UINTN) Table->Table)
         ) {
       //