/** @file
Locate, get and update PE/COFF permissions during Standalone MM
Foundation Entry point on ARM platforms.
Copyright (c) 2017 - 2021, Arm Ltd. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
**/
#include <PiMm.h>
#include <PiPei.h>
#include <Guid/MmramMemoryReserve.h>
#include <Guid/MpInformation.h>
#include <Library/AArch64/StandaloneMmCoreEntryPoint.h>
#include <Library/ArmMmuLib.h>
#include <Library/ArmSvcLib.h>
#include <Library/DebugLib.h>
#include <Library/HobLib.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/SerialPortLib.h>
#include <IndustryStandard/ArmStdSmc.h>
/**
Privileged firmware assigns RO & Executable attributes to all memory occupied
by the Boot Firmware Volume. This function sets the correct permissions of
sections in the Standalone MM Core module to be able to access RO and RW data
and make further progress in the boot process.
@param [in] ImageContext Pointer to PE/COFF image context
@param [in] ImageBase Base of image in memory
@param [in] SectionHeaderOffset Offset of PE/COFF image section header
@param [in] NumberOfSections Number of Sections
@param [in] TextUpdater Function to change code permissions
@param [in] ReadOnlyUpdater Function to change RO permissions
@param [in] ReadWriteUpdater Function to change RW permissions
**/
EFI_STATUS
EFIAPI
UpdateMmFoundationPeCoffPermissions (
IN CONST PE_COFF_LOADER_IMAGE_CONTEXT *ImageContext,
IN EFI_PHYSICAL_ADDRESS ImageBase,
IN UINT32 SectionHeaderOffset,
IN CONST UINT16 NumberOfSections,
IN REGION_PERMISSION_UPDATE_FUNC TextUpdater,
IN REGION_PERMISSION_UPDATE_FUNC ReadOnlyUpdater,
IN REGION_PERMISSION_UPDATE_FUNC ReadWriteUpdater
)
{
EFI_IMAGE_SECTION_HEADER SectionHeader;
RETURN_STATUS Status;
EFI_PHYSICAL_ADDRESS Base;
UINTN Size;
UINTN ReadSize;
UINTN Index;
ASSERT (ImageContext != NULL);
//
// Iterate over the sections
//
for (Index = 0; Index < NumberOfSections; Index++) {
//
// Read section header from file
//
Size = sizeof (EFI_IMAGE_SECTION_HEADER);
ReadSize = Size;
Status = ImageContext->ImageRead (
ImageContext->Handle,
SectionHeaderOffset,
&Size,
&SectionHeader
);
if (RETURN_ERROR (Status) || (Size != ReadSize)) {
DEBUG ((DEBUG_ERROR,
"%a: ImageContext->ImageRead () failed (Status = %r)\n",
__FUNCTION__, Status));
return Status;
}
DEBUG ((DEBUG_INFO,
"%a: Section %d of image at 0x%lx has 0x%x permissions\n",
__FUNCTION__, Index, ImageContext->ImageAddress, SectionHeader.Characteristics));
DEBUG ((DEBUG_INFO,
"%a: Section %d of image at 0x%lx has %a name\n",
__FUNCTION__, Index, ImageContext->ImageAddress, SectionHeader.Name));
DEBUG ((DEBUG_INFO,
"%a: Section %d of image at 0x%lx has 0x%x address\n",
__FUNCTION__, Index, ImageContext->ImageAddress,
ImageContext->ImageAddress + SectionHeader.VirtualAddress));
DEBUG ((DEBUG_INFO,
"%a: Section %d of image at 0x%lx has 0x%x data\n",
__FUNCTION__, Index, ImageContext->ImageAddress, SectionHeader.PointerToRawData));
//
// If the section is marked as XN then remove the X attribute. Furthermore,
// if it is a writeable section then mark it appropriately as well.
//
if ((SectionHeader.Characteristics & EFI_IMAGE_SCN_MEM_EXECUTE) == 0) {
Base = ImageBase + SectionHeader.VirtualAddress;
TextUpdater (Base, SectionHeader.Misc.VirtualSize);
if ((SectionHeader.Characteristics & EFI_IMAGE_SCN_MEM_WRITE) != 0) {
ReadWriteUpdater (Base, SectionHeader.Misc.VirtualSize);
DEBUG ((DEBUG_INFO,
"%a: Mapping section %d of image at 0x%lx with RW-XN permissions\n",
__FUNCTION__, Index, ImageContext->ImageAddress));
} else {
DEBUG ((DEBUG_INFO,
"%a: Mapping section %d of image at 0x%lx with RO-XN permissions\n",
__FUNCTION__, Index, ImageContext->ImageAddress));
}
} else {
DEBUG ((DEBUG_INFO,
"%a: Ignoring section %d of image at 0x%lx with 0x%x permissions\n",
__FUNCTION__, Index, ImageContext->ImageAddress, SectionHeader.Characteristics));
}
SectionHeaderOffset += sizeof (EFI_IMAGE_SECTION_HEADER);
}
return RETURN_SUCCESS;
}
/**
Privileged firmware assigns RO & Executable attributes to all memory occupied
by the Boot Firmware Volume. This function locates the Standalone MM Core
module PE/COFF image in the BFV and returns this information.
@param [in] BfvAddress Base Address of Boot Firmware Volume
@param [in, out] TeData Pointer to address for allocating memory
for PE/COFF image data
@param [in, out] TeDataSize Pointer to size of PE/COFF image data
**/
EFI_STATUS
EFIAPI
LocateStandaloneMmCorePeCoffData (
IN EFI_FIRMWARE_VOLUME_HEADER *BfvAddress,
IN OUT VOID **TeData,
IN OUT UINTN *TeDataSize
)
{
EFI_FFS_FILE_HEADER *FileHeader;
EFI_STATUS Status;
FileHeader = NULL;
Status = FfsFindNextFile (
EFI_FV_FILETYPE_SECURITY_CORE,
BfvAddress,
&FileHeader
);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "Unable to locate Standalone MM FFS file - 0x%x\n",
Status));
return Status;
}
Status = FfsFindSectionData (EFI_SECTION_PE32, FileHeader, TeData, TeDataSize);
if (EFI_ERROR (Status)) {
Status = FfsFindSectionData (EFI_SECTION_TE, FileHeader, TeData, TeDataSize);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "Unable to locate Standalone MM Section data - %r\n",
Status));
return Status;
}
}
DEBUG ((DEBUG_INFO, "Found Standalone MM PE data - 0x%x\n", *TeData));
return Status;
}
/**
Returns the PC COFF section information.
@param [in, out] ImageContext Pointer to PE/COFF image context
@param [out] ImageBase Base of image in memory
@param [out] SectionHeaderOffset Offset of PE/COFF image section header
@param [out] NumberOfSections Number of Sections
**/
STATIC
EFI_STATUS
GetPeCoffSectionInformation (
IN OUT PE_COFF_LOADER_IMAGE_CONTEXT *ImageContext,
OUT EFI_PHYSICAL_ADDRESS *ImageBase,
OUT UINT32 *SectionHeaderOffset,
OUT UINT16 *NumberOfSections
)
{
RETURN_STATUS Status;
EFI_IMAGE_OPTIONAL_HEADER_PTR_UNION Hdr;
EFI_IMAGE_OPTIONAL_HEADER_UNION HdrData;
UINTN Size;
UINTN ReadSize;
ASSERT (ImageContext != NULL);
ASSERT (SectionHeaderOffset != NULL);
ASSERT (NumberOfSections != NULL);
Status = PeCoffLoaderGetImageInfo (ImageContext);
if (RETURN_ERROR (Status)) {
DEBUG ((DEBUG_ERROR,
"%a: PeCoffLoaderGetImageInfo () failed (Status == %r)\n",
__FUNCTION__, Status));
return Status;
}
if (ImageContext->SectionAlignment < EFI_PAGE_SIZE) {
//
// The sections need to be at least 4 KB aligned, since that is the
// granularity at which we can tighten permissions.
//
if (!ImageContext->IsTeImage) {
DEBUG ((DEBUG_WARN,
"%a: non-TE Image at 0x%lx has SectionAlignment < 4 KB (%lu)\n",
__FUNCTION__, ImageContext->ImageAddress, ImageContext->SectionAlignment));
return RETURN_UNSUPPORTED;
}
ImageContext->SectionAlignment = EFI_PAGE_SIZE;
}
//
// Read the PE/COFF Header. For PE32 (32-bit) this will read in too much
// data, but that should not hurt anything. Hdr.Pe32->OptionalHeader.Magic
// determines if this is a PE32 or PE32+ image. The magic is in the same
// location in both images.
//
Hdr.Union = &HdrData;
Size = sizeof (EFI_IMAGE_OPTIONAL_HEADER_UNION);
ReadSize = Size;
Status = ImageContext->ImageRead (
ImageContext->Handle,
ImageContext->PeCoffHeaderOffset,
&Size,
Hdr.Pe32
);
if (RETURN_ERROR (Status) || (Size != ReadSize)) {
DEBUG ((DEBUG_ERROR,
"%a: TmpContext->ImageRead () failed (Status = %r)\n",
__FUNCTION__, Status));
return Status;
}
*ImageBase = ImageContext->ImageAddress;
if (!ImageContext->IsTeImage) {
ASSERT (Hdr.Pe32->Signature == EFI_IMAGE_NT_SIGNATURE);
*SectionHeaderOffset = ImageContext->PeCoffHeaderOffset + sizeof (UINT32) +
sizeof (EFI_IMAGE_FILE_HEADER);
*NumberOfSections = Hdr.Pe32->FileHeader.NumberOfSections;
switch (Hdr.Pe32->OptionalHeader.Magic) {
case EFI_IMAGE_NT_OPTIONAL_HDR32_MAGIC:
*SectionHeaderOffset += Hdr.Pe32->FileHeader.SizeOfOptionalHeader;
break;
case EFI_IMAGE_NT_OPTIONAL_HDR64_MAGIC:
*SectionHeaderOffset += Hdr.Pe32Plus->FileHeader.SizeOfOptionalHeader;
break;
default:
ASSERT (FALSE);
}
} else {
*SectionHeaderOffset = (UINTN)(sizeof (EFI_TE_IMAGE_HEADER));
*NumberOfSections = Hdr.Te->NumberOfSections;
*ImageBase -= (UINT32)Hdr.Te->StrippedSize - sizeof (EFI_TE_IMAGE_HEADER);
}
return RETURN_SUCCESS;
}
/**
Privileged firmware assigns RO & Executable attributes to all memory occupied
by the Boot Firmware Volume. This function locates the section information of
the Standalone MM Core module to be able to change permissions of the
individual sections later in the boot process.
@param [in] TeData Pointer to PE/COFF image data
@param [in, out] ImageContext Pointer to PE/COFF image context
@param [out] ImageBase Pointer to ImageBase variable
@param [in, out] SectionHeaderOffset Offset of PE/COFF image section header
@param [in, out] NumberOfSections Number of Sections
**/
EFI_STATUS
EFIAPI
GetStandaloneMmCorePeCoffSections (
IN VOID *TeData,
IN OUT PE_COFF_LOADER_IMAGE_CONTEXT *ImageContext,
OUT EFI_PHYSICAL_ADDRESS *ImageBase,
IN OUT UINT32 *SectionHeaderOffset,
IN OUT UINT16 *NumberOfSections
)
{
EFI_STATUS Status;
// Initialize the Image Context
ZeroMem (ImageContext, sizeof (PE_COFF_LOADER_IMAGE_CONTEXT));
ImageContext->Handle = TeData;
ImageContext->ImageRead = PeCoffLoaderImageReadFromMemory;
DEBUG ((DEBUG_INFO, "Found Standalone MM PE data - 0x%x\n", TeData));
Status = GetPeCoffSectionInformation (ImageContext, ImageBase,
SectionHeaderOffset, NumberOfSections);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "Unable to locate Standalone MM Core PE-COFF Section information - %r\n", Status));
return Status;
}
DEBUG ((DEBUG_INFO, "Standalone MM Core PE-COFF SectionHeaderOffset - 0x%x, NumberOfSections - %d\n",
*SectionHeaderOffset, *NumberOfSections));
return Status;
}