From f4a25e813f7ffa624b4868eb19fe13a34c4778ce Mon Sep 17 00:00:00 2001
From: vanjeff <vanjeff@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Thu, 16 Aug 2012 04:36:24 +0000
Subject: [PATCH] Add validation on ACPI_S3_CONTEXT.S3DebugBufferAddress,
 moreover only debug tip could override IDT entry for INT3.

Signed-off-by: Jeff Fan <jeff.fan@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>


git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@13640 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Universal/Acpi/AcpiS3SaveDxe/AcpiS3Save.c |  5 ++--
 .../BootScriptExecutorDxe/IA32/SetIdtEntry.c  | 27 ++++++++++++-----
 .../BootScriptExecutorDxe/X64/SetIdtEntry.c   | 29 ++++++++++---------
 3 files changed, 37 insertions(+), 24 deletions(-)

diff --git a/IntelFrameworkModulePkg/Universal/Acpi/AcpiS3SaveDxe/AcpiS3Save.c b/IntelFrameworkModulePkg/Universal/Acpi/AcpiS3SaveDxe/AcpiS3Save.c
index 4e36c8ae64..5a021d2caa 100644
--- a/IntelFrameworkModulePkg/Universal/Acpi/AcpiS3SaveDxe/AcpiS3Save.c
+++ b/IntelFrameworkModulePkg/Universal/Acpi/AcpiS3SaveDxe/AcpiS3Save.c
@@ -2,7 +2,7 @@
   This is an implementation of the ACPI S3 Save protocol.  This is defined in
   S3 boot path specification 0.9.
 
-Copyright (c) 2006 - 2011, Intel Corporation. All rights reserved.<BR>
+Copyright (c) 2006 - 2012, Intel Corporation. All rights reserved.<BR>
 
 This program and the accompanying materials
 are licensed and made available under the terms and conditions
@@ -453,9 +453,10 @@ S3Ready (
   ASSERT (AcpiS3Context->BootScriptStackBase != 0);
 
   //
-  // Allocate a code buffer < 4G for S3 debug to load external code
+  // Allocate a code buffer < 4G for S3 debug to load external code, set invalid code instructions in it.
   //
   AcpiS3Context->S3DebugBufferAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)AllocateAcpiNvsMemoryBelow4G (EFI_PAGE_SIZE);
+  SetMem ((VOID *)(UINTN)AcpiS3Context->S3DebugBufferAddress, EFI_PAGE_SIZE, 0xff);
 
   DEBUG((EFI_D_INFO, "AcpiS3Context: AcpiFacsTable is 0x%8x\n", AcpiS3Context->AcpiFacsTable));
   DEBUG((EFI_D_INFO, "AcpiS3Context: IdtrProfile is 0x%8x\n", AcpiS3Context->IdtrProfile));
diff --git a/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/IA32/SetIdtEntry.c b/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/IA32/SetIdtEntry.c
index 9f04959cd9..fbdf32b60b 100644
--- a/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/IA32/SetIdtEntry.c
+++ b/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/IA32/SetIdtEntry.c
@@ -50,14 +50,25 @@ SetIdtEntry (
   // Restore IDT for debug
   //
   IdtDescriptor = (IA32_DESCRIPTOR *) (UINTN) (AcpiS3Context->IdtrProfile);
-  IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
-  S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
-
-  IdtEntry->OffsetLow       = (UINT16)S3DebugBuffer;
-  IdtEntry->SegmentSelector = (UINT16)AsmReadCs ();
-  IdtEntry->Attributes      = (UINT16)INTERRUPT_GATE_ATTRIBUTE;
-  IdtEntry->OffsetHigh      = (UINT16)(S3DebugBuffer >> 16);
-
   AsmWriteIdtr (IdtDescriptor);
+
+  //
+  // Setup the default CPU exception handlers
+  //
+  SetupCpuExceptionHandlers ();
+
+  DEBUG_CODE (
+    //
+    // Update IDT entry INT3 if the instruction is valid in it
+    //
+    S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
+    if (*(UINTN *)S3DebugBuffer != (UINTN) -1) {
+      IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
+      IdtEntry->OffsetLow       = (UINT16)S3DebugBuffer;
+      IdtEntry->SegmentSelector = (UINT16)AsmReadCs ();;
+      IdtEntry->Attributes      = (UINT16)INTERRUPT_GATE_ATTRIBUTE;
+      IdtEntry->OffsetHigh      = (UINT16)(S3DebugBuffer >> 16);
+    }
+  );
 }
 
diff --git a/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/X64/SetIdtEntry.c b/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/X64/SetIdtEntry.c
index 8c34993587..40c27e4f67 100644
--- a/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/X64/SetIdtEntry.c
+++ b/MdeModulePkg/Universal/Acpi/BootScriptExecutorDxe/X64/SetIdtEntry.c
@@ -126,23 +126,24 @@ SetIdtEntry (
   //
   SetupCpuExceptionHandlers ();
 
-  //
-  // Update IDT entry INT3
-  //
-  IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
-  S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
-
-  IdtEntry->Offset15To0     = (UINT16)S3DebugBuffer;
-  IdtEntry->SegmentSelector = (UINT16)AsmReadCs ();
-  IdtEntry->Attributes      = (UINT16)INTERRUPT_GATE_ATTRIBUTE;
-  IdtEntry->Offset31To16    = (UINT16)(S3DebugBuffer >> 16);
-  IdtEntry->Offset63To32    = (UINT32)(S3DebugBuffer >> 32);
-  IdtEntry->Reserved        = 0;
+  DEBUG_CODE (
+    //
+    // Update IDT entry INT3 if the instruction is valid in it
+    //
+    S3DebugBuffer = (UINTN) (AcpiS3Context->S3DebugBufferAddress);
+    if (*(UINTN *)S3DebugBuffer != (UINTN) -1) {
+      IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (3 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
+      IdtEntry->Offset15To0     = (UINT16)S3DebugBuffer;
+      IdtEntry->SegmentSelector = (UINT16)AsmReadCs ();
+      IdtEntry->Attributes      = (UINT16)INTERRUPT_GATE_ATTRIBUTE;
+      IdtEntry->Offset31To16    = (UINT16)(S3DebugBuffer >> 16);
+      IdtEntry->Offset63To32    = (UINT32)(S3DebugBuffer >> 32);
+      IdtEntry->Reserved        = 0;
+    }
+  );
 
   IdtEntry = (INTERRUPT_GATE_DESCRIPTOR *)(IdtDescriptor->Base + (14 * sizeof (INTERRUPT_GATE_DESCRIPTOR)));
   HookPageFaultHandler (IdtEntry);
-
-  AsmWriteIdtr (IdtDescriptor);
 }
 
 /**