From 93dd5b7a5a4aaea69505cad2079f60f3abfda74a Mon Sep 17 00:00:00 2001
From: vanjeff <vanjeff@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Tue, 19 Apr 2011 02:50:16 +0000
Subject: sync patch r10783, r10787 from main trunk. Add security check to make
 code run safe.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/branches/UDK2010@11557 6f19259b-4bc3-4df7-8a09-765794883524
---
 UefiCpuPkg/CpuDxe/CpuDxe.c           | 2 +-
 UefiCpuPkg/CpuDxe/CpuGdt.c           | 2 +-
 UefiCpuPkg/Library/MtrrLib/MtrrLib.c | 7 ++++++-
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/UefiCpuPkg/CpuDxe/CpuDxe.c b/UefiCpuPkg/CpuDxe/CpuDxe.c
index 8d13dc13e9..a844bb9dd4 100644
--- a/UefiCpuPkg/CpuDxe/CpuDxe.c
+++ b/UefiCpuPkg/CpuDxe/CpuDxe.c
@@ -1062,7 +1062,7 @@ InitInterruptDescriptorTable (
   IdtPtrAlignmentBuffer = AllocatePool (sizeof (*IdtPtr) + 16);
   IdtPtr = ALIGN_POINTER (IdtPtrAlignmentBuffer, 16);
   IdtPtr->Base = (UINT32)(((UINTN)(VOID*) gIdtTable) & (BASE_4GB-1));
-  IdtPtr->Limit = sizeof (gIdtTable) - 1;
+  IdtPtr->Limit = (UINT16) (sizeof (gIdtTable) - 1);
 
   AsmWriteIdtr (IdtPtr);
 
diff --git a/UefiCpuPkg/CpuDxe/CpuGdt.c b/UefiCpuPkg/CpuDxe/CpuGdt.c
index b6d8ffb75d..e22b80a64f 100644
--- a/UefiCpuPkg/CpuDxe/CpuGdt.c
+++ b/UefiCpuPkg/CpuDxe/CpuGdt.c
@@ -188,7 +188,7 @@ InitGlobalDescriptorTable (
   // Write GDT register
   //
   gdtPtr.Base = (UINT32)(UINTN)(VOID*) gdt;
-  gdtPtr.Limit = sizeof (GdtTemplate) - 1;
+  gdtPtr.Limit = (UINT16) (sizeof (GdtTemplate) - 1);
   AsmWriteGdtr (&gdtPtr);
 
   //
diff --git a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
index dab0535fe9..14f7a0ad7e 100644
--- a/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
+++ b/UefiCpuPkg/Library/MtrrLib/MtrrLib.c
@@ -93,11 +93,16 @@ GetVariableMtrrCount (
   VOID
   )
 {
+  UINT32  VariableMtrrCount;
+
   if (!IsMtrrSupported ()) {
     return 0;
   }
 
-  return (UINT32)(AsmReadMsr64 (MTRR_LIB_IA32_MTRR_CAP) & MTRR_LIB_IA32_MTRR_CAP_VCNT_MASK);
+  VariableMtrrCount = (UINT32)(AsmReadMsr64 (MTRR_LIB_IA32_MTRR_CAP) & MTRR_LIB_IA32_MTRR_CAP_VCNT_MASK);
+  ASSERT (VariableMtrrCount <= MTRR_NUMBER_OF_VARIABLE_MTRR);
+
+  return VariableMtrrCount;
 }
 
 /**
-- 
cgit