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//**********************************************************************
//**********************************************************************
//** **
//** (C)Copyright 1985-2014, American Megatrends, Inc. **
//** **
//** All Rights Reserved. **
//** **
//** 5555 Oakbrook Parkway, Suite 200, Norcross, GA 30093 **
//** **
//** Phone: (770)-246-8600 **
//** **
//**********************************************************************
//**********************************************************************
//**********************************************************************
// $Header: /Alaska/SOURCE/Modules/AmiBufferValidationLib/SmmAmiBufferValidationLib.c 4 1/06/15 10:21a Aaronp $
//
// $Revision: 4 $
//
// $Date: 1/06/15 10:21a $
//**********************************************************************
// Revision History
// ----------------
// $Log: /Alaska/SOURCE/Modules/AmiBufferValidationLib/SmmAmiBufferValidationLib.c $
//
// 4 1/06/15 10:21a Aaronp
// [TAG] EIP198890
// [Category] Improvement
// [Description] Use of CORE_COMBINED_VERSION requires Token.h to be
// included.
//
// 3 12/30/14 4:08p Aaronp
// [TAG] EIP198005
// [Category] Improvement
// [Description] Added support for pre PI 1.2
//
// 2 11/26/14 10:33a Aaronp
// Updated function headers with additional information that was added to
// the AptioV component.
//
// 1 11/07/14 12:07p Aaronp
// Initial addition of AmiBufferValidationLib
//
//**********************************************************************
//**********************************************************************
//<AMI_FHDR_START>
//
// Name: SmmAmiBufferValidationLib.c
//
// Description: Source file that defines the AmiBufferValidationLib functions
// used for validating that buffer addresses and MMIO addreses
// do not reside in SMM. The file also provides a function to
// validate that a buffer does reside in SMM.
//
//<AMI_FHDR_END>
//**********************************************************************
#include <Token.h>
#include <AmiDxeLib.h>
#if defined(PI_SPECIFICATION_VERSION)&&(PI_SPECIFICATION_VERSION>=0x0001000A)
#include <Protocol/SmmAccess2.h>
#else
#include <Protocol/SmmAccess.h>
#endif
/// Internal list of SMRAM regions
EFI_SMRAM_DESCRIPTOR *SmmAmiBufferValidationLibSmramRanges = NULL;
/// Number of SMRAM regions in the internal list
UINTN SmmAmiBufferValidationLibNumberOfSmramRange = 0;
//<AMI_PHDR_START>
//----------------------------------------------------------------------------
// Procedure: AmiValidateMemoryBuffer
//
// Description: Function verifies the buffer to make sure its address range is legal for a memory buffer. A legal memory
// buffer is one that lies entirely outside of SMRAM. SMI handlers that receive buffer address and/or size
// from outside of SMM at runtime must validate the buffer using this function prior to using it or passing
// to other SMM interfaces.
//
// Input:
// VOID *Buffer - Buffer address
// UINTN BufferSize - Size of the Buffer
//
// Output:
// EFI_SUCCESS - The buffer address range is valid and can be safely used.
// EFI_ACCESS_DENIED - The buffer can't be used because its address range overlaps with protected area such as SMRAM.
// EFI_INVALID_PARAMETER - The buffer can't be used because its address range is invalid.
// EFI_NOT_FOUND - The buffer can't be used because its validity cannot be verified. Normally due to the SMRAM ranges were not available.
//----------------------------------------------------------------------------
//<AMI_PHDR_END>
EFI_STATUS AmiValidateMemoryBuffer(VOID* Buffer, UINTN BufferSize){
UINTN i;
UINTN BufferAddress;
if (SmmAmiBufferValidationLibNumberOfSmramRange==0) return EFI_NOT_FOUND;
BufferAddress = (UINTN)Buffer;
if (BufferAddress + BufferSize < BufferAddress) return EFI_INVALID_PARAMETER; // overflow
for (i = 0; i < SmmAmiBufferValidationLibNumberOfSmramRange; i ++) {
if ( BufferAddress >= SmmAmiBufferValidationLibSmramRanges[i].CpuStart
&& BufferAddress < SmmAmiBufferValidationLibSmramRanges[i].CpuStart + SmmAmiBufferValidationLibSmramRanges[i].PhysicalSize
) return EFI_ACCESS_DENIED; // Buffer starts in SMRAM
if ( BufferAddress < SmmAmiBufferValidationLibSmramRanges[i].CpuStart
&& BufferAddress+BufferSize > SmmAmiBufferValidationLibSmramRanges[i].CpuStart
) return EFI_ACCESS_DENIED; // Buffer overlaps with SMRAM
}
return EFI_SUCCESS;
}
//<AMI_PHDR_START>
//----------------------------------------------------------------------------
// Procedure: AmiValidateMmioBuffer
//
// Description: Function verifies the buffer to make sure its address range is legal for a MMIO buffer. A legal MMIO buffer is one that lies
// entirely outside of SMRAM. SMI handlers that receive a buffer address and/or size from outside of SMM at runtime must validate
// the buffer using this function prior to using the MMIO Buffer or passing to other SMM interfaces.
//
// Input:
// VOID *Buffer - Buffer address
// UINTN BufferSize - Size of the Buffer
//
// Output:
// EFI_SUCCESS - The buffer address range is valid and can be safely used.
// EFI_ACCESS_DENIED - The buffer can't be used because its address range overlaps with protected area such as SMRAM.
// EFI_INVALID_PARAMETER - The buffer can't be used because its address range is invalid.
// EFI_NOT_FOUND - The buffer can't be used because its validity cannot be verified. Normally due to the SMRAM ranges were not available.
//----------------------------------------------------------------------------
//<AMI_PHDR_END>
EFI_STATUS AmiValidateMmioBuffer(VOID* Buffer, UINTN BufferSize){
return AmiValidateMemoryBuffer(Buffer,BufferSize);
}
//<AMI_PHDR_START>
//----------------------------------------------------------------------------
// Procedure: AmiValidateSmramBuffer
//
// Description: Function verifies the buffer to make sure it wholly resides in the SMRAM.
//
// Input:
// IN VOID *Buffer - Buffer address
// IN UINTN BufferSize - Size of the Buffer
//
// Output:
// EFI_SUCCESS - The buffer resides in the SMRAM and can be safely used.
// EFI_ACCESS_DENIED - The buffer can't be used because at least one byte of the buffer is outside of SMRAM.
// EFI_INVALID_PARAMETER - The buffer can't be used because its address range is invalid.
// EFI_NOT_FOUND - The buffer can't be used because its validity cannot be verified. Normally due to the SMRAM ranges were not available.
//----------------------------------------------------------------------------
//<AMI_PHDR_END>
EFI_STATUS AmiValidateSmramBuffer(VOID* Buffer, UINTN BufferSize){
UINTN i;
UINTN BufferAddress;
if (SmmAmiBufferValidationLibNumberOfSmramRange==0) return EFI_NOT_FOUND;
BufferAddress = (UINTN)Buffer;
if (BufferAddress + BufferSize < BufferAddress) return EFI_INVALID_PARAMETER; // overflow
for (i = 0; i < SmmAmiBufferValidationLibNumberOfSmramRange; i ++) {
if ( BufferAddress >= SmmAmiBufferValidationLibSmramRanges[i].CpuStart
&& BufferAddress+BufferSize <= SmmAmiBufferValidationLibSmramRanges[i].CpuStart + SmmAmiBufferValidationLibSmramRanges[i].PhysicalSize
) return EFI_SUCCESS; // Entire Buffer is in SMRAM
}
return EFI_ACCESS_DENIED;
}
//<AMI_PHDR_START>
//----------------------------------------------------------------------------
// Procedure: InitAmiBufferValidationLib
//
// Description: Performs the necessary initialization so that the buffer validation functions will operate
// correctly when they are called.
//
// Input:
// IN EFI_HANDLE ImageHandle - The handle of this image
// IN EFI_SYSTEM_TABLE *SystemTable - Pointer to the EFI_SYSTEM_TABLE
//
// Output:
// EFI_NOT_FOUND - The Smm Access protocol could not be found
// EFI_OUT_OF_RESOURCES - An allocation failed because it could not find any memory resources
// EFI_INVALID_PARAMETER - An invalid parameter was passed to one of the functions
// EFI_SUCCESS - The necessary functions were initialized
//----------------------------------------------------------------------------
//<AMI_PHDR_END>
EFI_STATUS EFIAPI InitAmiBufferValidationLib(IN EFI_HANDLE ImageHandle, IN EFI_SYSTEM_TABLE *SystemTable){
EFI_STATUS Status;
#if defined(PI_SPECIFICATION_VERSION)&&(PI_SPECIFICATION_VERSION>=0x0001000A)
EFI_SMM_ACCESS2_PROTOCOL *SmmAccess;
#else
EFI_SMM_ACCESS_PROTOCOL *SmmAccess;
#endif
UINTN Size;
#if defined(CORE_COMBINED_VERSION)&&(CORE_COMBINED_VERSION>0x4028a)
InitAmiSmmLib(ImageHandle,SystemTable);
#endif
// Get SMRAM information
#if defined(PI_SPECIFICATION_VERSION)&&(PI_SPECIFICATION_VERSION>=0x0001000A)
Status = pBS->LocateProtocol (&gEfiSmmAccess2ProtocolGuid, NULL, (VOID **)&SmmAccess);
#else
Status = pBS->LocateProtocol (&gEfiSmmAccessProtocolGuid, NULL, (VOID **)&SmmAccess);
#endif
if (EFI_ERROR(Status)) return Status;
Size = 0;
Status = SmmAccess->GetCapabilities (SmmAccess, &Size, NULL);
if (Status != EFI_BUFFER_TOO_SMALL) return Status;
Status = pSmst->SmmAllocatePool (EfiRuntimeServicesData, Size, (VOID **)&SmmAmiBufferValidationLibSmramRanges);
if (EFI_ERROR(Status)){
SmmAmiBufferValidationLibSmramRanges = NULL;
return Status;
}
Status = SmmAccess->GetCapabilities (SmmAccess, &Size, SmmAmiBufferValidationLibSmramRanges);
if (EFI_ERROR(Status)){
pSmst->SmmFreePool (SmmAmiBufferValidationLibSmramRanges);
SmmAmiBufferValidationLibSmramRanges = NULL;
return Status;
}
SmmAmiBufferValidationLibNumberOfSmramRange = Size / sizeof (EFI_SMRAM_DESCRIPTOR);
return EFI_SUCCESS;
}
//**********************************************************************
//**********************************************************************
//** **
//** (C)Copyright 1985-2014, American Megatrends, Inc. **
//** **
//** All Rights Reserved. **
//** **
//** 5555 Oakbrook Parkway, Suite 200, Norcross, GA 30093 **
//** **
//** Phone: (770)-246-8600 **
//** **
//**********************************************************************
//**********************************************************************
|
