From 6e601a4109d4a998596986718653048ae23de0a6 Mon Sep 17 00:00:00 2001
From: Star Zeng <star.zeng@intel.com>
Date: Thu, 11 Jan 2018 18:27:12 +0800
Subject: UefiCpuPkg PiSmmCpuDxeSmm: Fixed #double fault on #page fault for
 IA32

When StackGuard is enabled on IA32, the #double fault exception
is reported instead of #page fault.

This issue does not exist on X64, or IA32 without StackGuard.

The fix at e4435f710cea2d2f10cd7343d545920867780086 was incomplete.

It is because AllocateCodePages() is used to allocate buffer for
GDT and TSS, the code pages will be set to RO in SetMemMapAttributes().
But IA32 Stack Guard need use task switch to switch stack that need
write GDT and TSS, so AllocateCodePages() could not be used.

This patch uses AllocatePages() instead of AllocateCodePages() to
allocate buffer for GDT and TSS if StackGuard is enabled on IA32.

Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Jian J Wang <jian.j.wang@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
---
 UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c | 49 +++++++++++++++++++++-
 1 file changed, 48 insertions(+), 1 deletion(-)

(limited to 'UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c')

diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
index 2d7dba59bf..16664f304c 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
@@ -1,6 +1,6 @@
 /** @file
 
-Copyright (c) 2016 - 2017, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2016 - 2018, Intel Corporation. All rights reserved.<BR>
 This program and the accompanying materials
 are licensed and made available under the terms and conditions of the BSD License
 which accompanies this distribution.  The full text of the license may be found at
@@ -768,6 +768,53 @@ PatchSmmSaveStateMap (
     );
 }
 
+/**
+  This function sets GDT/IDT buffer to be RO and XP.
+**/
+VOID
+PatchGdtIdtMap (
+  VOID
+  )
+{
+  EFI_PHYSICAL_ADDRESS       BaseAddress;
+  UINTN                      Size;
+
+  //
+  // GDT
+  //
+  DEBUG ((DEBUG_INFO, "PatchGdtIdtMap - GDT:\n"));
+
+  BaseAddress = mGdtBuffer;
+  Size = ALIGN_VALUE(mGdtBufferSize, SIZE_4KB);
+  //
+  // The range should have been set to RO
+  // if it is allocated with EfiRuntimeServicesCode.
+  //
+  SmmSetMemoryAttributes (
+    BaseAddress,
+    Size,
+    EFI_MEMORY_XP
+    );
+
+  //
+  // IDT
+  //
+  DEBUG ((DEBUG_INFO, "PatchGdtIdtMap - IDT:\n"));
+
+  BaseAddress = gcSmiIdtr.Base;
+  Size = ALIGN_VALUE(gcSmiIdtr.Limit + 1, SIZE_4KB);
+  SmmSetMemoryAttributes (
+    BaseAddress,
+    Size,
+    EFI_MEMORY_RO
+    );
+  SmmSetMemoryAttributes (
+    BaseAddress,
+    Size,
+    EFI_MEMORY_XP
+    );
+}
+
 /**
   This function sets memory attribute according to MemoryAttributesTable.
 **/
-- 
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