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SecurityPkg: Tcg2Smm: Remove Memory Clear SMI Handler

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Remove unused MemoryClear SMI Handler, which is no longer
used due to _DSM Memory Clear no longer being used.

_DSM Memory Clear was deprecated in 2019 by TCG PC Client
Platform Reset Attack Mitigation Spec Version 1.10 revision 17
Family "2.0".

Signed-off-by: Oliver Smith-Denny <osde@linux.microsoft.com>
This commit is contained in:
John Strange 2024-07-04 08:49:55 -07:00 committed by mergify[bot]
parent 559affab2e
commit a4245b265d
1 changed files with 0 additions and 85 deletions
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85
SecurityPkg/Tcg/Tcg2Smm/Tcg2Smm.c
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@ -170,81 +170,6 @@ PhysicalPresenceCallback (
return EFI_SUCCESS;
}
/**
Software SMI callback for MemoryClear which is called from ACPI method.
Caution: This function may receive untrusted input.
Variable and ACPINvs are external input, so this function will validate
its data structure to be valid value.
@param[in] DispatchHandle The unique handle assigned to this handler by SmiHandlerRegister().
@param[in] Context Points to an optional handler context which was specified when the
handler was registered.
@param[in, out] CommBuffer A pointer to a collection of data in memory that will
be conveyed from a non-SMM environment into an SMM environment.
@param[in, out] CommBufferSize The size of the CommBuffer.
@retval EFI_SUCCESS The interrupt was handled successfully.
**/
EFI_STATUS
EFIAPI
MemoryClearCallback (
IN EFI_HANDLE DispatchHandle,
IN CONST VOID *Context,
IN OUT VOID *CommBuffer,
IN OUT UINTN *CommBufferSize
)
{
EFI_STATUS Status;
UINTN DataSize;
UINT8 MorControl;
mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_SUCCESS;
if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_DSM_MEMORY_CLEAR_INTERFACE) {
MorControl = (UINT8)mTcgNvs->MemoryClear.Request;
} else if (mTcgNvs->MemoryClear.Parameter == ACPI_FUNCTION_PTS_CLEAR_MOR_BIT) {
DataSize = sizeof (UINT8);
Status = mSmmVariable->SmmGetVariable (
MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
&gEfiMemoryOverwriteControlDataGuid,
NULL,
&DataSize,
&MorControl
);
if (EFI_ERROR (Status)) {
mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
DEBUG ((DEBUG_ERROR, "[TPM] Get MOR variable failure! Status = %r\n", Status));
return EFI_SUCCESS;
}
if (MOR_CLEAR_MEMORY_VALUE (MorControl) == 0x0) {
return EFI_SUCCESS;
}
MorControl &= ~MOR_CLEAR_MEMORY_BIT_MASK;
} else {
mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
DEBUG ((DEBUG_ERROR, "[TPM] MOR Parameter error! Parameter = %x\n", mTcgNvs->MemoryClear.Parameter));
return EFI_SUCCESS;
}
DataSize = sizeof (UINT8);
Status = mSmmVariable->SmmSetVariable (
MEMORY_OVERWRITE_REQUEST_VARIABLE_NAME,
&gEfiMemoryOverwriteControlDataGuid,
EFI_VARIABLE_NON_VOLATILE | EFI_VARIABLE_BOOTSERVICE_ACCESS | EFI_VARIABLE_RUNTIME_ACCESS,
DataSize,
&MorControl
);
if (EFI_ERROR (Status)) {
mTcgNvs->MemoryClear.ReturnCode = MOR_REQUEST_GENERAL_FAILURE;
DEBUG ((DEBUG_ERROR, "[TPM] Set MOR variable failure! Status = %r\n", Status));
}
return EFI_SUCCESS;
}
/**
Notification for SMM ReadyToLock protocol.
@ -337,16 +262,6 @@ InitializeTcgCommon (
mPpSoftwareSmi = SwContext.SwSmiInputValue;
SwContext.SwSmiInputValue = (UINTN)-1;
Status = SwDispatch->Register (SwDispatch, MemoryClearCallback, &SwContext, &McSwHandle);
ASSERT_EFI_ERROR (Status);
if (EFI_ERROR (Status)) {
DEBUG ((DEBUG_ERROR, "[%a] Failed to register MC callback as SW MM handler - %r!\n", __func__, Status));
goto Cleanup;
}
mMcSoftwareSmi = SwContext.SwSmiInputValue;
//
// Locate SmmVariableProtocol.
//