/** @file
Instance of SMM memory check library.
SMM memory check library library implementation. This library consumes SMM_ACCESS2_PROTOCOL
to get SMRAM information. In order to use this library instance, the platform should produce
all SMRAM range via SMM_ACCESS2_PROTOCOL, including the range for firmware (like SMM Core
and SMM driver) and/or specific dedicated hardware.
Copyright (c) 2015 - 2016, 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
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 <PiSmm.h>
#include <Library/BaseLib.h>
#include <Library/BaseMemoryLib.h>
#include <Library/DebugLib.h>
#include <Library/MemoryAllocationLib.h>
#include <Library/UefiBootServicesTableLib.h>
#include <Library/SmmServicesTableLib.h>
#include <Library/HobLib.h>
#include <Protocol/SmmAccess2.h>
#include <Protocol/SmmReadyToLock.h>
#include <Protocol/SmmEndOfDxe.h>
#define NEXT_MEMORY_DESCRIPTOR(MemoryDescriptor, Size) \
((EFI_MEMORY_DESCRIPTOR *)((UINT8 *)(MemoryDescriptor) + (Size)))
EFI_SMRAM_DESCRIPTOR *mSmmMemLibInternalSmramRanges;
UINTN mSmmMemLibInternalSmramCount;
//
// Maximum support address used to check input buffer
//
EFI_PHYSICAL_ADDRESS mSmmMemLibInternalMaximumSupportAddress = 0;
UINTN mMemoryMapEntryCount;
EFI_MEMORY_DESCRIPTOR *mMemoryMap;
UINTN mDescriptorSize;
VOID *mRegistrationEndOfDxe;
VOID *mRegistrationReadyToLock;
BOOLEAN mSmmReadyToLock = FALSE;
/**
Calculate and save the maximum support address.
**/
VOID
SmmMemLibInternalCalculateMaximumSupportAddress (
VOID
)
{
VOID *Hob;
UINT32 RegEax;
UINT8 PhysicalAddressBits;
//
// Get physical address bits supported.
//
Hob = GetFirstHob (EFI_HOB_TYPE_CPU);
if (Hob != NULL) {
PhysicalAddressBits = ((EFI_HOB_CPU *) Hob)->SizeOfMemorySpace;
} else {
AsmCpuid (0x80000000, &RegEax, NULL, NULL, NULL);
if (RegEax >= 0x80000008) {
AsmCpuid (0x80000008, &RegEax, NULL, NULL, NULL);
PhysicalAddressBits = (UINT8) RegEax;
} else {
PhysicalAddressBits = 36;
}
}
//
// IA-32e paging translates 48-bit linear addresses to 52-bit physical addresses.
//
ASSERT (PhysicalAddressBits <= 52);
if (PhysicalAddressBits > 48) {
PhysicalAddressBits = 48;
}
//
// Save the maximum support address in one global variable
//
mSmmMemLibInternalMaximumSupportAddress = (EFI_PHYSICAL_ADDRESS)(UINTN)(LShiftU64 (1, PhysicalAddressBits) - 1);
DEBUG ((EFI_D_INFO, "mSmmMemLibInternalMaximumSupportAddress = 0x%lx\n", mSmmMemLibInternalMaximumSupportAddress));
}
/**
This function check if the buffer is valid per processor architecture and not overlap with SMRAM.
@param Buffer The buffer start address to be checked.
@param Length The buffer length to be checked.
@retval TRUE This buffer is valid per processor architecture and not overlap with SMRAM.
@retval FALSE This buffer is not valid per processor architecture or overlap with SMRAM.
**/
BOOLEAN
EFIAPI
SmmIsBufferOutsideSmmValid (
IN EFI_PHYSICAL_ADDRESS Buffer,
IN UINT64 Length
)
{
UINTN Index;
//
// Check override.
// NOTE: (B:0->L:4G) is invalid for IA32, but (B:1->L:4G-1)/(B:4G-1->L:1) is valid.
//
if ((Length > mSmmMemLibInternalMaximumSupportAddress) ||
(Buffer > mSmmMemLibInternalMaximumSupportAddress) ||
((Length != 0) && (Buffer > (mSmmMemLibInternalMaximumSupportAddress - (Length - 1)))) ) {
//
// Overflow happen
//
DEBUG ((
EFI_D_ERROR,
"SmmIsBufferOutsideSmmValid: Overflow: Buffer (0x%lx) - Length (0x%lx), MaximumSupportAddress (0x%lx)\n",
Buffer,
Length,
mSmmMemLibInternalMaximumSupportAddress
));
return FALSE;
}
for (Index = 0; Index < mSmmMemLibInternalSmramCount; Index ++) {
if (((Buffer >= mSmmMemLibInternalSmramRanges[Index].CpuStart) && (Buffer < mSmmMemLibInternalSmramRanges[Index].CpuStart + mSmmMemLibInternalSmramRanges[Index].PhysicalSize)) ||
((mSmmMemLibInternalSmramRanges[Index].CpuStart >= Buffer) && (mSmmMemLibInternalSmramRanges[Index].CpuStart < Buffer + Length))) {
DEBUG ((
EFI_D_ERROR,
"SmmIsBufferOutsideSmmValid: Overlap: Buffer (0x%lx) - Length (0x%lx), ",
Buffer,
Length
));
DEBUG ((
EFI_D_ERROR,
"CpuStart (0x%lx) - PhysicalSize (0x%lx)\n",
mSmmMemLibInternalSmramRanges[Index].CpuStart,
mSmmMemLibInternalSmramRanges[Index].PhysicalSize
));
return FALSE;
}
}
//
// Check override for Valid Communication Region
//
if (mSmmReadyToLock) {
EFI_MEMORY_DESCRIPTOR *MemoryMap;
BOOLEAN InValidCommunicationRegion;
InValidCommunicationRegion = FALSE;
MemoryMap = mMemoryMap;
for (Index = 0; Index < mMemoryMapEntryCount; Index++) {
if ((Buffer >= MemoryMap->PhysicalStart) &&
(Buffer + Length <= MemoryMap->PhysicalStart + LShiftU64 (MemoryMap->NumberOfPages, EFI_PAGE_SHIFT))) {
InValidCommunicationRegion = TRUE;
}
MemoryMap = NEXT_MEMORY_DESCRIPTOR(MemoryMap, mDescriptorSize);
}
if (!InValidCommunicationRegion) {
DEBUG ((
EFI_D_ERROR,
"SmmIsBufferOutsideSmmValid: Not in ValidCommunicationRegion: Buffer (0x%lx) - Length (0x%lx), ",
Buffer,
Length
));
ASSERT (FALSE);
return FALSE;
}
}
return TRUE;
}
/**
Copies a source buffer (non-SMRAM) to a destination buffer (SMRAM).
This function copies a source buffer (non-SMRAM) to a destination buffer (SMRAM).
It checks if source buffer is valid per processor architecture and not overlap with SMRAM.
If the check passes, it copies memory and returns EFI_SUCCESS.
If the check fails, it return EFI_SECURITY_VIOLATION.
The implementation must be reentrant.
@param DestinationBuffer The pointer to the destination buffer of the memory copy.
@param SourceBuffer The pointer to the source buffer of the memory copy.
@param Length The number of bytes to copy from SourceBuffer to DestinationBuffer.
@retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with SMRAM.
@retval EFI_SUCCESS Memory is copied.
**/
EFI_STATUS
EFIAPI
SmmCopyMemToSmram (
OUT VOID *DestinationBuffer,
IN CONST VOID *SourceBuffer,
IN UINTN Length
)
{
if (!SmmIsBufferOutsideSmmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
DEBUG ((EFI_D_ERROR, "SmmCopyMemToSmram: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
return EFI_SECURITY_VIOLATION;
}
CopyMem (DestinationBuffer, SourceBuffer, Length);
return EFI_SUCCESS;
}
/**
Copies a source buffer (SMRAM) to a destination buffer (NON-SMRAM).
This function copies a source buffer (non-SMRAM) to a destination buffer (SMRAM).
It checks if destination buffer is valid per processor architecture and not overlap with SMRAM.
If the check passes, it copies memory and returns EFI_SUCCESS.
If the check fails, it returns EFI_SECURITY_VIOLATION.
The implementation must be reentrant.
@param DestinationBuffer The pointer to the destination buffer of the memory copy.
@param SourceBuffer The pointer to the source buffer of the memory copy.
@param Length The number of bytes to copy from SourceBuffer to DestinationBuffer.
@retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per processor architecture or overlap with SMRAM.
@retval EFI_SUCCESS Memory is copied.
**/
EFI_STATUS
EFIAPI
SmmCopyMemFromSmram (
OUT VOID *DestinationBuffer,
IN CONST VOID *SourceBuffer,
IN UINTN Length
)
{
if (!SmmIsBufferOutsideSmmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
DEBUG ((EFI_D_ERROR, "SmmCopyMemFromSmram: Security Violation: Destination (0x%x), Length (0x%x)\n", DestinationBuffer, Length));
return EFI_SECURITY_VIOLATION;
}
CopyMem (DestinationBuffer, SourceBuffer, Length);
return EFI_SUCCESS;
}
/**
Copies a source buffer (NON-SMRAM) to a destination buffer (NON-SMRAM).
This function copies a source buffer (non-SMRAM) to a destination buffer (SMRAM).
It checks if source buffer and destination buffer are valid per processor architecture and not overlap with SMRAM.
If the check passes, it copies memory and returns EFI_SUCCESS.
If the check fails, it returns EFI_SECURITY_VIOLATION.
The implementation must be reentrant, and it must handle the case where source buffer overlaps destination buffer.
@param DestinationBuffer The pointer to the destination buffer of the memory copy.
@param SourceBuffer The pointer to the source buffer of the memory copy.
@param Length The number of bytes to copy from SourceBuffer to DestinationBuffer.
@retval EFI_SECURITY_VIOLATION The DesinationBuffer is invalid per processor architecture or overlap with SMRAM.
@retval EFI_SECURITY_VIOLATION The SourceBuffer is invalid per processor architecture or overlap with SMRAM.
@retval EFI_SUCCESS Memory is copied.
**/
EFI_STATUS
EFIAPI
SmmCopyMem (
OUT VOID *DestinationBuffer,
IN CONST VOID *SourceBuffer,
IN UINTN Length
)
{
if (!SmmIsBufferOutsideSmmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)DestinationBuffer, Length)) {
DEBUG ((EFI_D_ERROR, "SmmCopyMem: Security Violation: Destination (0x%x), Length (0x%x)\n", DestinationBuffer, Length));
return EFI_SECURITY_VIOLATION;
}
if (!SmmIsBufferOutsideSmmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)SourceBuffer, Length)) {
DEBUG ((EFI_D_ERROR, "SmmCopyMem: Security Violation: Source (0x%x), Length (0x%x)\n", SourceBuffer, Length));
return EFI_SECURITY_VIOLATION;
}
CopyMem (DestinationBuffer, SourceBuffer, Length);
return EFI_SUCCESS;
}
/**
Fills a target buffer (NON-SMRAM) with a byte value.
This function fills a target buffer (non-SMRAM) with a byte value.
It checks if target buffer is valid per processor architecture and not overlap with SMRAM.
If the check passes, it fills memory and returns EFI_SUCCESS.
If the check fails, it returns EFI_SECURITY_VIOLATION.
@param Buffer The memory to set.
@param Length The number of bytes to set.
@param Value The value with which to fill Length bytes of Buffer.
@retval EFI_SECURITY_VIOLATION The Buffer is invalid per processor architecture or overlap with SMRAM.
@retval EFI_SUCCESS Memory is set.
**/
EFI_STATUS
EFIAPI
SmmSetMem (
OUT VOID *Buffer,
IN UINTN Length,
IN UINT8 Value
)
{
if (!SmmIsBufferOutsideSmmValid ((EFI_PHYSICAL_ADDRESS)(UINTN)Buffer, Length)) {
DEBUG ((EFI_D_ERROR, "SmmSetMem: Security Violation: Source (0x%x), Length (0x%x)\n", Buffer, Length));
return EFI_SECURITY_VIOLATION;
}
SetMem (Buffer, Length, Value);
return EFI_SUCCESS;
}
/**
Notification for SMM EndOfDxe protocol.
@param[in] Protocol Points to the protocol's unique identifier.
@param[in] Interface Points to the interface instance.
@param[in] Handle The handle on which the interface was installed.
@retval EFI_SUCCESS Notification runs successfully.
**/
EFI_STATUS
EFIAPI
SmmLibInternalEndOfDxeNotify (
IN CONST EFI_GUID *Protocol,
IN VOID *Interface,
IN EFI_HANDLE Handle
)
{
EFI_STATUS Status;
UINTN MapKey;
UINTN MemoryMapSize;
EFI_MEMORY_DESCRIPTOR *MemoryMap;
EFI_MEMORY_DESCRIPTOR *MemoryMapStart;
EFI_MEMORY_DESCRIPTOR *SmmMemoryMapStart;
UINTN MemoryMapEntryCount;
UINTN DescriptorSize;
UINT32 DescriptorVersion;
UINTN Index;
MemoryMapSize = 0;
MemoryMap = NULL;
Status = gBS->GetMemoryMap (
&MemoryMapSize,
MemoryMap,
&MapKey,
&DescriptorSize,
&DescriptorVersion
);
ASSERT (Status == EFI_BUFFER_TOO_SMALL);
do {
Status = gBS->AllocatePool (EfiBootServicesData, MemoryMapSize, (VOID **)&MemoryMap);
ASSERT (MemoryMap != NULL);
Status = gBS->GetMemoryMap (
&MemoryMapSize,
MemoryMap,
&MapKey,
&DescriptorSize,
&DescriptorVersion
);
if (EFI_ERROR (Status)) {
gBS->FreePool (MemoryMap);
}
} while (Status == EFI_BUFFER_TOO_SMALL);
//
// Get Count
//
mDescriptorSize = DescriptorSize;
MemoryMapEntryCount = MemoryMapSize/DescriptorSize;
MemoryMapStart = MemoryMap;
mMemoryMapEntryCount = 0;
for (Index = 0; Index < MemoryMapEntryCount; Index++) {
switch (MemoryMap->Type) {
case EfiReservedMemoryType:
case EfiRuntimeServicesCode:
case EfiRuntimeServicesData:
case EfiACPIMemoryNVS:
mMemoryMapEntryCount++;
break;
}
MemoryMap = NEXT_MEMORY_DESCRIPTOR(MemoryMap, DescriptorSize);
}
MemoryMap = MemoryMapStart;
//
// Get Data
//
mMemoryMap = AllocatePool (mMemoryMapEntryCount*DescriptorSize);
ASSERT (mMemoryMap != NULL);
SmmMemoryMapStart = mMemoryMap;
for (Index = 0; Index < MemoryMapEntryCount; Index++) {
switch (MemoryMap->Type) {
case EfiReservedMemoryType:
case EfiRuntimeServicesCode:
case EfiRuntimeServicesData:
case EfiACPIMemoryNVS:
CopyMem (mMemoryMap, MemoryMap, DescriptorSize);
mMemoryMap = NEXT_MEMORY_DESCRIPTOR(mMemoryMap, DescriptorSize);
break;
}
MemoryMap = NEXT_MEMORY_DESCRIPTOR(MemoryMap, DescriptorSize);
}
mMemoryMap = SmmMemoryMapStart;
MemoryMap = MemoryMapStart;
gBS->FreePool (MemoryMap);
return EFI_SUCCESS;
}
/**
Notification for SMM ReadyToLock protocol.
@param[in] Protocol Points to the protocol's unique identifier.
@param[in] Interface Points to the interface instance.
@param[in] Handle The handle on which the interface was installed.
@retval EFI_SUCCESS Notification runs successfully.
**/
EFI_STATUS
EFIAPI
SmmLibInternalReadyToLockNotify (
IN CONST EFI_GUID *Protocol,
IN VOID *Interface,
IN EFI_HANDLE Handle
)
{
mSmmReadyToLock = TRUE;
return EFI_SUCCESS;
}
/**
The constructor function initializes the Smm Mem library
@param ImageHandle The firmware allocated handle for the EFI image.
@param SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The constructor always returns EFI_SUCCESS.
**/
EFI_STATUS
EFIAPI
SmmMemLibConstructor (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
EFI_STATUS Status;
EFI_SMM_ACCESS2_PROTOCOL *SmmAccess;
UINTN Size;
//
// Get SMRAM information
//
Status = gBS->LocateProtocol (&gEfiSmmAccess2ProtocolGuid, NULL, (VOID **)&SmmAccess);
ASSERT_EFI_ERROR (Status);
Size = 0;
Status = SmmAccess->GetCapabilities (SmmAccess, &Size, NULL);
ASSERT (Status == EFI_BUFFER_TOO_SMALL);
mSmmMemLibInternalSmramRanges = AllocatePool (Size);
ASSERT (mSmmMemLibInternalSmramRanges != NULL);
Status = SmmAccess->GetCapabilities (SmmAccess, &Size, mSmmMemLibInternalSmramRanges);
ASSERT_EFI_ERROR (Status);
mSmmMemLibInternalSmramCount = Size / sizeof (EFI_SMRAM_DESCRIPTOR);
//
// Calculate and save maximum support address
//
SmmMemLibInternalCalculateMaximumSupportAddress ();
//
// Register EndOfDxe to get UEFI memory map
//
Status = gSmst->SmmRegisterProtocolNotify (&gEfiSmmEndOfDxeProtocolGuid, SmmLibInternalEndOfDxeNotify, &mRegistrationEndOfDxe);
ASSERT_EFI_ERROR (Status);
//
// Register ready to lock so that we can know when to check valid SMRAM region
//
Status = gSmst->SmmRegisterProtocolNotify (&gEfiSmmReadyToLockProtocolGuid, SmmLibInternalReadyToLockNotify, &mRegistrationReadyToLock);
ASSERT_EFI_ERROR (Status);
return EFI_SUCCESS;
}
/**
The destructor function frees resource used in the Smm Mem library
@param[in] ImageHandle The firmware allocated handle for the EFI image.
@param[in] SystemTable A pointer to the EFI System Table.
@retval EFI_SUCCESS The deconstructor always returns EFI_SUCCESS.
**/
EFI_STATUS
EFIAPI
SmmMemLibDestructor (
IN EFI_HANDLE ImageHandle,
IN EFI_SYSTEM_TABLE *SystemTable
)
{
FreePool (mSmmMemLibInternalSmramRanges);
gSmst->SmmRegisterProtocolNotify (&gEfiSmmEndOfDxeProtocolGuid, NULL, &mRegistrationEndOfDxe);
gSmst->SmmRegisterProtocolNotify (&gEfiSmmReadyToLockProtocolGuid, NULL, &mRegistrationReadyToLock);
return EFI_SUCCESS;
}