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/** @file
Page table manipulation functions for IA-32 processors
Copyright (c) 2009 - 2017, Intel Corporation. All rights reserved.<BR>
Copyright (c) 2017, AMD Incorporated. 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
http://opensource.org/licenses/bsd-license.php
THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
**/
#include "PiSmmCpuDxeSmm.h"
/**
Create PageTable for SMM use.
@return PageTable Address
**/
UINT32
SmmInitPageTable (
VOID
)
{
UINTN PageFaultHandlerHookAddress;
IA32_IDT_GATE_DESCRIPTOR *IdtEntry;
EFI_STATUS Status;
//
// Initialize spin lock
//
InitializeSpinLock (mPFLock);
if (FeaturePcdGet (PcdCpuSmmProfileEnable)) {
//
// Set own Page Fault entry instead of the default one, because SMM Profile
// feature depends on IRET instruction to do Single Step
//
PageFaultHandlerHookAddress = (UINTN)PageFaultIdtHandlerSmmProfile;
IdtEntry = (IA32_IDT_GATE_DESCRIPTOR *) gcSmiIdtr.Base;
IdtEntry += EXCEPT_IA32_PAGE_FAULT;
IdtEntry->Bits.OffsetLow = (UINT16)PageFaultHandlerHookAddress;
IdtEntry->Bits.Reserved_0 = 0;
IdtEntry->Bits.GateType = IA32_IDT_GATE_TYPE_INTERRUPT_32;
IdtEntry->Bits.OffsetHigh = (UINT16)(PageFaultHandlerHookAddress >> 16);
} else {
//
// Register SMM Page Fault Handler
//
Status = SmmRegisterExceptionHandler (&mSmmCpuService, EXCEPT_IA32_PAGE_FAULT, SmiPFHandler);
ASSERT_EFI_ERROR (Status);
}
//
// Additional SMM IDT initialization for SMM stack guard
//
if (FeaturePcdGet (PcdCpuSmmStackGuard)) {
InitializeIDTSmmStackGuard ();
}
return Gen4GPageTable (TRUE);
}
/**
Page Fault handler for SMM use.
**/
VOID
SmiDefaultPFHandler (
VOID
)
{
CpuDeadLoop ();
}
/**
ThePage Fault handler wrapper for SMM use.
@param InterruptType Defines the type of interrupt or exception that
occurred on the processor.This parameter is processor architecture specific.
@param SystemContext A pointer to the processor context when
the interrupt occurred on the processor.
**/
VOID
EFIAPI
SmiPFHandler (
IN EFI_EXCEPTION_TYPE InterruptType,
IN EFI_SYSTEM_CONTEXT SystemContext
)
{
UINTN PFAddress;
UINTN GuardPageAddress;
UINTN CpuIndex;
ASSERT (InterruptType == EXCEPT_IA32_PAGE_FAULT);
AcquireSpinLock (mPFLock);
PFAddress = AsmReadCr2 ();
//
// If a page fault occurs in SMRAM range, it might be in a SMM stack guard page,
// or SMM page protection violation.
//
if ((PFAddress >= mCpuHotPlugData.SmrrBase) &&
(PFAddress < (mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize))) {
DumpCpuContext (InterruptType, SystemContext);
CpuIndex = GetCpuIndex ();
GuardPageAddress = (mSmmStackArrayBase + EFI_PAGE_SIZE + CpuIndex * mSmmStackSize);
if ((FeaturePcdGet (PcdCpuSmmStackGuard)) &&
(PFAddress >= GuardPageAddress) &&
(PFAddress < (GuardPageAddress + EFI_PAGE_SIZE))) {
DEBUG ((DEBUG_ERROR, "SMM stack overflow!\n"));
} else {
if ((SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_ID) != 0) {
DEBUG ((DEBUG_ERROR, "SMM exception at execution (0x%x)\n", PFAddress));
DEBUG_CODE (
DumpModuleInfoByIp (*(UINTN *)(UINTN)SystemContext.SystemContextIa32->Esp);
);
} else {
DEBUG ((DEBUG_ERROR, "SMM exception at access (0x%x)\n", PFAddress));
DEBUG_CODE (
DumpModuleInfoByIp ((UINTN)SystemContext.SystemContextIa32->Eip);
);
}
}
CpuDeadLoop ();
}
//
// If a page fault occurs in SMM range
//
if ((PFAddress < mCpuHotPlugData.SmrrBase) ||
(PFAddress >= mCpuHotPlugData.SmrrBase + mCpuHotPlugData.SmrrSize)) {
DumpCpuContext (InterruptType, SystemContext);
if ((SystemContext.SystemContextIa32->ExceptionData & IA32_PF_EC_ID) != 0) {
DEBUG ((DEBUG_ERROR, "Code executed on IP(0x%x) out of SMM range after SMM is locked!\n", PFAddress));
DEBUG_CODE (
DumpModuleInfoByIp (*(UINTN *)(UINTN)SystemContext.SystemContextIa32->Esp);
);
CpuDeadLoop ();
}
if (IsSmmCommBufferForbiddenAddress (PFAddress)) {
DEBUG ((DEBUG_ERROR, "Access SMM communication forbidden address (0x%x)!\n", PFAddress));
DEBUG_CODE (
DumpModuleInfoByIp ((UINTN)SystemContext.SystemContextIa32->Eip);
);
CpuDeadLoop ();
}
}
if (FeaturePcdGet (PcdCpuSmmProfileEnable)) {
SmmProfilePFHandler (
SystemContext.SystemContextIa32->Eip,
SystemContext.SystemContextIa32->ExceptionData
);
} else {
DumpCpuContext (InterruptType, SystemContext);
SmiDefaultPFHandler ();
}
ReleaseSpinLock (mPFLock);
}
/**
This function sets memory attribute for page table.
**/
VOID
SetPageTableAttributes (
VOID
)
{
UINTN Index2;
UINTN Index3;
UINT64 *L1PageTable;
UINT64 *L2PageTable;
UINT64 *L3PageTable;
BOOLEAN IsSplitted;
BOOLEAN PageTableSplitted;
DEBUG ((DEBUG_INFO, "SetPageTableAttributes\n"));
//
// Disable write protection, because we need mark page table to be write protected.
// We need *write* page table memory, to mark itself to be *read only*.
//
AsmWriteCr0 (AsmReadCr0() & ~CR0_WP);
do {
DEBUG ((DEBUG_INFO, "Start...\n"));
PageTableSplitted = FALSE;
L3PageTable = (UINT64 *)GetPageTableBase ();
SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L3PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
PageTableSplitted = (PageTableSplitted || IsSplitted);
for (Index3 = 0; Index3 < 4; Index3++) {
L2PageTable = (UINT64 *)(UINTN)(L3PageTable[Index3] & ~mAddressEncMask & PAGING_4K_ADDRESS_MASK_64);
if (L2PageTable == NULL) {
continue;
}
SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L2PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
PageTableSplitted = (PageTableSplitted || IsSplitted);
for (Index2 = 0; Index2 < SIZE_4KB/sizeof(UINT64); Index2++) {
if ((L2PageTable[Index2] & IA32_PG_PS) != 0) {
// 2M
continue;
}
L1PageTable = (UINT64 *)(UINTN)(L2PageTable[Index2] & ~mAddressEncMask & PAGING_4K_ADDRESS_MASK_64);
if (L1PageTable == NULL) {
continue;
}
SmmSetMemoryAttributesEx ((EFI_PHYSICAL_ADDRESS)(UINTN)L1PageTable, SIZE_4KB, EFI_MEMORY_RO, &IsSplitted);
PageTableSplitted = (PageTableSplitted || IsSplitted);
}
}
} while (PageTableSplitted);
//
// Enable write protection, after page table updated.
//
AsmWriteCr0 (AsmReadCr0() | CR0_WP);
return ;
}
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