Implement the newly defined PPI that permits the PEI core and DXE IPL to
manage memory permissions on ranges of DRAM, for doing things like
mapping the stack non-executable, or granting executable permissions to
shadowed PEIMs.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
ArmPkg/Drivers/CpuPei/CpuPei.c | 76 ++++++++++++++++++++
ArmPkg/Drivers/CpuPei/CpuPei.inf | 4 ++
2 files changed, 80 insertions(+)
diff --git a/ArmPkg/Drivers/CpuPei/CpuPei.c b/ArmPkg/Drivers/CpuPei/CpuPei.c
index 85ef5ec07b9fdafa..1c2b53100f6a424e 100644
--- a/ArmPkg/Drivers/CpuPei/CpuPei.c
+++ b/ArmPkg/Drivers/CpuPei/CpuPei.c
@@ -3,6 +3,7 @@
Copyright (c) 2006, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2011 Hewlett Packard Corporation. All rights reserved.<BR>
Copyright (c) 2011-2013, ARM Limited. All rights reserved.<BR>
+Copyright (c) 2023, Google, LLC. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -24,6 +25,7 @@ Module Name:
// The protocols, PPI and GUID definitions for this module
//
#include <Ppi/ArmMpCoreInfo.h>
+#include <Ppi/MemoryAttribute.h>
//
// The Library classes this module consumes
@@ -34,6 +36,77 @@ Module Name:
#include <Library/PcdLib.h>
#include <Library/HobLib.h>
#include <Library/ArmLib.h>
+#include <Library/ArmMmuLib.h>
+
+/**
+ Set the requested memory permission attributes on a region of memory.
+
+ BaseAddress and Length must be aligned to EFI_PAGE_SIZE.
+
+ Attributes must contain a combination of EFI_MEMORY_RP, EFI_MEMORY_RO and
+ EFI_MEMORY_XP, and specifies the attributes that must be set for the
+ region in question. Attributes that are omitted will be cleared from the
+ region only if they are set in AttributeMask.
+
+ AttributeMask must contain a combination of EFI_MEMORY_RP, EFI_MEMORY_RO and
+ EFI_MEMORY_XP, and specifies the attributes that the call will operate on.
+ AttributeMask must not be 0x0, and must contain at least the bits set in
+ Attributes.
+
+ @param[in] This The protocol instance pointer.
+ @param[in] BaseAddress The physical address that is the start address
+ of a memory region.
+ @param[in] Length The size in bytes of the memory region.
+ @param[in] Attributes Memory attributes to set or clear.
+ @param[in] AttributeMask Mask of memory attributes to operate on.
+
+ @retval EFI_SUCCESS The attributes were set for the memory region.
+ @retval EFI_INVALID_PARAMETER Length is zero.
+ AttributeMask is zero.
+ AttributeMask lacks bits set in Attributes.
+ BaseAddress or Length is not suitably aligned.
+ @retval EFI_UNSUPPORTED The processor does not support one or more
+ bytes of the memory resource range specified
+ by BaseAddress and Length.
+ The bit mask of attributes is not supported for
+ the memory resource range specified by
+ BaseAddress and Length.
+ @retval EFI_OUT_OF_RESOURCES Requested attributes cannot be applied due to
+ lack of system resources.
+
+**/
+STATIC
+EFI_STATUS
+EFIAPI
+SetMemoryPermissions (
+ IN EDKII_MEMORY_ATTRIBUTE_PPI *This,
+ IN EFI_PHYSICAL_ADDRESS BaseAddress,
+ IN UINT64 Length,
+ IN UINT64 Attributes,
+ IN UINT64 AttributeMask
+ )
+{
+ if ((Length == 0) ||
+ (AttributeMask == 0) ||
+ ((AttributeMask & (EFI_MEMORY_RP | EFI_MEMORY_RO | EFI_MEMORY_XP)) == 0) ||
+ ((Attributes & ~AttributeMask) != 0) ||
+ (((BaseAddress | Length) & EFI_PAGE_MASK) != 0))
+ {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ return ArmSetMemoryAttributes (BaseAddress, Length, Attributes, AttributeMask);
+}
+
+STATIC CONST EDKII_MEMORY_ATTRIBUTE_PPI mMemoryAttributePpi = {
+ SetMemoryPermissions
+};
+
+STATIC CONST EFI_PEI_PPI_DESCRIPTOR mMemoryAttributePpiDesc = {
+ (EFI_PEI_PPI_DESCRIPTOR_PPI | EFI_PEI_PPI_DESCRIPTOR_TERMINATE_LIST),
+ &gEdkiiMemoryAttributePpiGuid,
+ (VOID *)&mMemoryAttributePpi
+};
/*++
@@ -79,5 +152,8 @@ InitializeCpuPeim (
}
}
+ Status = PeiServicesInstallPpi (&mMemoryAttributePpiDesc);
+ ASSERT_EFI_ERROR (Status);
+
return EFI_SUCCESS;
}
diff --git a/ArmPkg/Drivers/CpuPei/CpuPei.inf b/ArmPkg/Drivers/CpuPei/CpuPei.inf
index a9f85cbc68b1c52e..49b67077ec6166f1 100644
--- a/ArmPkg/Drivers/CpuPei/CpuPei.inf
+++ b/ArmPkg/Drivers/CpuPei/CpuPei.inf
@@ -3,6 +3,7 @@
#
# This module provides platform specific function to detect boot mode.
# Copyright (c) 2006 - 2010, Intel Corporation. All rights reserved.<BR>
+# Copyright (c) 2023, Google, LLC. All rights reserved.<BR>
#
# SPDX-License-Identifier: BSD-2-Clause-Patent
#
@@ -28,6 +29,7 @@ [Sources]
CpuPei.c
[Packages]
+ MdeModulePkg/MdeModulePkg.dec
MdePkg/MdePkg.dec
EmbeddedPkg/EmbeddedPkg.dec
ArmPkg/ArmPkg.dec
@@ -37,9 +39,11 @@ [LibraryClasses]
DebugLib
HobLib
ArmLib
+ ArmMmuLib
[Ppis]
gArmMpCoreInfoPpiGuid
+ gEdkiiMemoryAttributePpiGuid
[Guids]
gArmMpCoreInfoGuid
--
2.39.2
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