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UefiCpuPkg/PiSmmCpu: Check for untested memory in GCD
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It treats GCD untested memory as invalid SMM
communication buffer.

Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jiewen Yao <[email protected]>
Reviewed-by: Star Zeng <[email protected]>
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@jyao1
jyao1 committed Jul 26, 2018
1 parent 233ffa9 commit ac6613d
Showing 1 changed file with 120 additions and 24 deletions.
144 changes: 120 additions & 24 deletions UefiCpuPkg/PiSmmCpuDxeSmm/SmmCpuMemoryManagement.c
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Original file line number Diff line number Diff line change
Expand Up @@ -13,6 +13,13 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.

#include "PiSmmCpuDxeSmm.h"

//
// attributes for reserved memory before it is promoted to system memory
//
#define EFI_MEMORY_PRESENT 0x0100000000000000ULL
#define EFI_MEMORY_INITIALIZED 0x0200000000000000ULL
#define EFI_MEMORY_TESTED 0x0400000000000000ULL

#define NEXT_MEMORY_DESCRIPTOR(MemoryDescriptor, Size) \
((EFI_MEMORY_DESCRIPTOR *)((UINT8 *)(MemoryDescriptor) + (Size)))

Expand All @@ -23,6 +30,9 @@ EFI_MEMORY_DESCRIPTOR *mUefiMemoryMap;
UINTN mUefiMemoryMapSize;
UINTN mUefiDescriptorSize;

EFI_GCD_MEMORY_SPACE_DESCRIPTOR *mGcdMemSpace = NULL;
UINTN mGcdMemNumberOfDesc = 0;

PAGE_ATTRIBUTE_TABLE mPageAttributeTable[] = {
{Page4K, SIZE_4KB, PAGING_4K_ADDRESS_MASK_64},
{Page2M, SIZE_2MB, PAGING_2M_ADDRESS_MASK_64},
Expand Down Expand Up @@ -1022,6 +1032,60 @@ MergeMemoryMapForNotPresentEntry (
return ;
}

/**
This function caches the GCD memory map information.
**/
VOID
GetGcdMemoryMap (
VOID
)
{
UINTN NumberOfDescriptors;
EFI_GCD_MEMORY_SPACE_DESCRIPTOR *MemSpaceMap;
EFI_STATUS Status;
UINTN Index;

Status = gDS->GetMemorySpaceMap (&NumberOfDescriptors, &MemSpaceMap);
if (EFI_ERROR (Status)) {
return ;
}

mGcdMemNumberOfDesc = 0;
for (Index = 0; Index < NumberOfDescriptors; Index++) {
if (MemSpaceMap[Index].GcdMemoryType == EfiGcdMemoryTypeReserved &&
(MemSpaceMap[Index].Capabilities & (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED | EFI_MEMORY_TESTED)) ==
(EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED)
) {
mGcdMemNumberOfDesc++;
}
}

mGcdMemSpace = AllocateZeroPool (mGcdMemNumberOfDesc * sizeof (EFI_GCD_MEMORY_SPACE_DESCRIPTOR));
ASSERT (mGcdMemSpace != NULL);
if (mGcdMemSpace == NULL) {
mGcdMemNumberOfDesc = 0;
gBS->FreePool (MemSpaceMap);
return ;
}

mGcdMemNumberOfDesc = 0;
for (Index = 0; Index < NumberOfDescriptors; Index++) {
if (MemSpaceMap[Index].GcdMemoryType == EfiGcdMemoryTypeReserved &&
(MemSpaceMap[Index].Capabilities & (EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED | EFI_MEMORY_TESTED)) ==
(EFI_MEMORY_PRESENT | EFI_MEMORY_INITIALIZED)
) {
CopyMem (
&mGcdMemSpace[mGcdMemNumberOfDesc],
&MemSpaceMap[Index],
sizeof(EFI_GCD_MEMORY_SPACE_DESCRIPTOR)
);
mGcdMemNumberOfDesc++;
}
}

gBS->FreePool (MemSpaceMap);
}

/**
This function caches the UEFI memory map information.
**/
Expand Down Expand Up @@ -1081,6 +1145,11 @@ GetUefiMemoryMap (
ASSERT (mUefiMemoryMap != NULL);

gBS->FreePool (MemoryMap);

//
// Get additional information from GCD memory map.
//
GetGcdMemoryMap ();
}

/**
Expand All @@ -1102,33 +1171,52 @@ SetUefiMemMapAttributes (

DEBUG ((DEBUG_INFO, "SetUefiMemMapAttributes\n"));

if (mUefiMemoryMap == NULL) {
DEBUG ((DEBUG_INFO, "UefiMemoryMap - NULL\n"));
return ;
if (mUefiMemoryMap != NULL) {
MemoryMapEntryCount = mUefiMemoryMapSize/mUefiDescriptorSize;
MemoryMap = mUefiMemoryMap;
for (Index = 0; Index < MemoryMapEntryCount; Index++) {
if (IsUefiPageNotPresent(MemoryMap)) {
Status = SmmSetMemoryAttributes (
MemoryMap->PhysicalStart,
EFI_PAGES_TO_SIZE((UINTN)MemoryMap->NumberOfPages),
EFI_MEMORY_RP
);
DEBUG ((
DEBUG_INFO,
"UefiMemory protection: 0x%lx - 0x%lx %r\n",
MemoryMap->PhysicalStart,
MemoryMap->PhysicalStart + (UINT64)EFI_PAGES_TO_SIZE((UINTN)MemoryMap->NumberOfPages),
Status
));
}
MemoryMap = NEXT_MEMORY_DESCRIPTOR(MemoryMap, mUefiDescriptorSize);
}
}
//
// Do not free mUefiMemoryMap, it will be checked in IsSmmCommBufferForbiddenAddress().
//

MemoryMapEntryCount = mUefiMemoryMapSize/mUefiDescriptorSize;
MemoryMap = mUefiMemoryMap;
for (Index = 0; Index < MemoryMapEntryCount; Index++) {
if (IsUefiPageNotPresent(MemoryMap)) {
//
// Set untested memory as not present.
//
if (mGcdMemSpace != NULL) {
for (Index = 0; Index < mGcdMemNumberOfDesc; Index++) {
Status = SmmSetMemoryAttributes (
MemoryMap->PhysicalStart,
EFI_PAGES_TO_SIZE((UINTN)MemoryMap->NumberOfPages),
mGcdMemSpace[Index].BaseAddress,
mGcdMemSpace[Index].Length,
EFI_MEMORY_RP
);
DEBUG ((
DEBUG_INFO,
"UefiMemory protection: 0x%lx - 0x%lx %r\n",
MemoryMap->PhysicalStart,
MemoryMap->PhysicalStart + (UINT64)EFI_PAGES_TO_SIZE((UINTN)MemoryMap->NumberOfPages),
"GcdMemory protection: 0x%lx - 0x%lx %r\n",
mGcdMemSpace[Index].BaseAddress,
mGcdMemSpace[Index].BaseAddress + mGcdMemSpace[Index].Length,
Status
));
}
MemoryMap = NEXT_MEMORY_DESCRIPTOR(MemoryMap, mUefiDescriptorSize);
}

//
// Do free mUefiMemoryMap, it will be checked in IsSmmCommBufferForbiddenAddress().
// Do not free mGcdMemSpace, it will be checked in IsSmmCommBufferForbiddenAddress().
//
}

Expand All @@ -1149,21 +1237,29 @@ IsSmmCommBufferForbiddenAddress (
UINTN MemoryMapEntryCount;
UINTN Index;

if (mUefiMemoryMap == NULL) {
return FALSE;
if (mUefiMemoryMap != NULL) {
MemoryMap = mUefiMemoryMap;
MemoryMapEntryCount = mUefiMemoryMapSize/mUefiDescriptorSize;
for (Index = 0; Index < MemoryMapEntryCount; Index++) {
if (IsUefiPageNotPresent (MemoryMap)) {
if ((Address >= MemoryMap->PhysicalStart) &&
(Address < MemoryMap->PhysicalStart + EFI_PAGES_TO_SIZE((UINTN)MemoryMap->NumberOfPages)) ) {
return TRUE;
}
}
MemoryMap = NEXT_MEMORY_DESCRIPTOR(MemoryMap, mUefiDescriptorSize);
}
}

MemoryMap = mUefiMemoryMap;
MemoryMapEntryCount = mUefiMemoryMapSize/mUefiDescriptorSize;
for (Index = 0; Index < MemoryMapEntryCount; Index++) {
if (IsUefiPageNotPresent (MemoryMap)) {
if ((Address >= MemoryMap->PhysicalStart) &&
(Address < MemoryMap->PhysicalStart + EFI_PAGES_TO_SIZE((UINTN)MemoryMap->NumberOfPages)) ) {
if (mGcdMemSpace != NULL) {
for (Index = 0; Index < mGcdMemNumberOfDesc; Index++) {
if ((Address >= mGcdMemSpace[Index].BaseAddress) &&
(Address < mGcdMemSpace[Index].BaseAddress + mGcdMemSpace[Index].Length) ) {
return TRUE;
}
}
MemoryMap = NEXT_MEMORY_DESCRIPTOR(MemoryMap, mUefiDescriptorSize);
}

return FALSE;
}

Expand Down

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