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MdeModulePkg/Core: Fix feature conflict between NX and Stack guard 

If enabled, NX memory protection feature will mark some types of active
memory as NX (non-executable), which includes the first page of the stack.
This will overwrite the attributes of the first page of the stack if the
stack guard feature is also enabled.

The solution is to override the attributes setting to the first page of
the stack by adding back the 'EFI_MEMORY_RP' attribute when the stack
guard feature is enabled.

Cc: Star Zeng <star.zeng@intel.com>
Cc: Eric Dong <eric.dong@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Reviewed-by: Jiewen Yao <jiewen.yao@intel.com>
Reviewed-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Ruiyu Ni <ruiyu.ni@intel.com>
This commit is contained in:
Hao Wu 2018-03-06 19:34:38 +08:00
parent a10acf0e20
commit 7db1458f75
2 changed files with 61 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
MdeModulePkg/Core/Dxe/DxeMain.inf
View File

@ -3,7 +3,7 @@
#
# It provides an implementation of DXE Core that is compliant with DXE CIS.
#
# Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.<BR>
# Copyright (c) 2006 - 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
@ -130,6 +130,7 @@
gEfiPropertiesTableGuid ## SOMETIMES_PRODUCES ## SystemTable
gEfiMemoryAttributesTableGuid ## SOMETIMES_PRODUCES ## SystemTable
gEfiEndOfDxeEventGroupGuid ## SOMETIMES_CONSUMES ## Event
gEfiHobMemoryAllocStackGuid ## SOMETIMES_CONSUMES ## SystemTable
[Ppis]
gEfiVectorHandoffInfoPpiGuid ## UNDEFINED # HOB
@ -198,6 +199,7 @@
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPageType ## CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPoolType ## CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask ## CONSUMES
gEfiMdeModulePkgTokenSpaceGuid.PcdCpuStackGuard ## CONSUMES
# [Hob]
# RESOURCE_DESCRIPTOR ## CONSUMES

62
MdeModulePkg/Core/Dxe/Misc/MemoryProtection.c
View File

@ -801,6 +801,9 @@ InitializeDxeNxMemoryProtectionPolicy (
UINT64 Attributes;
LIST_ENTRY *Link;
EFI_GCD_MAP_ENTRY *Entry;
EFI_PEI_HOB_POINTERS Hob;
EFI_HOB_MEMORY_ALLOCATION *MemoryHob;
EFI_PHYSICAL_ADDRESS StackBase;
//
// Get the EFI memory map.
@ -832,6 +835,40 @@ InitializeDxeNxMemoryProtectionPolicy (
} while (Status == EFI_BUFFER_TOO_SMALL);
ASSERT_EFI_ERROR (Status);
StackBase = 0;
if (PcdGetBool (PcdCpuStackGuard)) {
//
// Get the base of stack from Hob.
//
Hob.Raw = GetHobList ();
while ((Hob.Raw = GetNextHob (EFI_HOB_TYPE_MEMORY_ALLOCATION, Hob.Raw)) != NULL) {
MemoryHob = Hob.MemoryAllocation;
if (CompareGuid(&gEfiHobMemoryAllocStackGuid, &MemoryHob->AllocDescriptor.Name)) {
DEBUG ((
DEBUG_INFO,
"%a: StackBase = 0x%016lx StackSize = 0x%016lx\n",
__FUNCTION__,
MemoryHob->AllocDescriptor.MemoryBaseAddress,
MemoryHob->AllocDescriptor.MemoryLength
));
StackBase = MemoryHob->AllocDescriptor.MemoryBaseAddress;
//
// Ensure the base of the stack is page-size aligned.
//
ASSERT ((StackBase & EFI_PAGE_MASK) == 0);
break;
}
Hob.Raw = GET_NEXT_HOB (Hob);
}
//
// Ensure the base of stack can be found from Hob when stack guard is
// enabled.
//
ASSERT (StackBase != 0);
}
DEBUG ((
DEBUG_INFO,
"%a: applying strict permissions to active memory regions\n",
@ -851,19 +888,36 @@ InitializeDxeNxMemoryProtectionPolicy (
LShiftU64 (MemoryMapEntry->NumberOfPages, EFI_PAGE_SHIFT),
Attributes);
if (MemoryMapEntry->PhysicalStart == 0 &&
PcdGet8 (PcdNullPointerDetectionPropertyMask) != 0) {
ASSERT (MemoryMapEntry->NumberOfPages > 0);
//
// Add EFI_MEMORY_RP attribute for page 0 if NULL pointer detection is
// enabled.
//
if (MemoryMapEntry->PhysicalStart == 0 &&
PcdGet8 (PcdNullPointerDetectionPropertyMask) != 0) {
ASSERT (MemoryMapEntry->NumberOfPages > 0);
SetUefiImageMemoryAttributes (
0,
EFI_PAGES_TO_SIZE (1),
EFI_MEMORY_RP | Attributes);
}
//
// Add EFI_MEMORY_RP attribute for the first page of the stack if stack
// guard is enabled.
//
if (StackBase != 0 &&
(StackBase >= MemoryMapEntry->PhysicalStart &&
StackBase < MemoryMapEntry->PhysicalStart +
LShiftU64 (MemoryMapEntry->NumberOfPages, EFI_PAGE_SHIFT)) &&
PcdGetBool (PcdCpuStackGuard)) {
SetUefiImageMemoryAttributes (
StackBase,
EFI_PAGES_TO_SIZE (1),
EFI_MEMORY_RP | Attributes);
}
}
MemoryMapEntry = NEXT_MEMORY_DESCRIPTOR (MemoryMapEntry, DescriptorSize);
}