/**
This function is called to execute an EBC CALLEX instruction.
The function check the callee's content to see whether it is common native
code or a thunk to another piece of EBC code.
If the callee is common native code, use EbcLLCAllEXASM to manipulate,
otherwise, set the VM->IP to target EBC code directly to avoid another VM
be startup which cost time and stack space.
@param VmPtr Pointer to a VM context.
@param FuncAddr Callee's address
@param NewStackPointer New stack pointer after the call
@param FramePtr New frame pointer after the call
@param Size The size of call instruction
**/
VOID
EbcLLCALLEX (
IN VM_CONTEXT *VmPtr,
IN UINTN FuncAddr,
IN UINTN NewStackPointer,
IN VOID *FramePtr,
IN UINT8 Size
)
{
CONST EBC_INSTRUCTION_BUFFER *InstructionBuffer;
//
// Processor specific code to check whether the callee is a thunk to EBC.
//
InstructionBuffer = (EBC_INSTRUCTION_BUFFER *)FuncAddr;
if (CompareMem (InstructionBuffer, &mEbcInstructionBufferTemplate,
sizeof(EBC_INSTRUCTION_BUFFER) - 2 * sizeof (UINT64)) == 0) {
//
// The callee is a thunk to EBC, adjust the stack pointer down 16 bytes and
// put our return address and frame pointer on the VM stack.
// Then set the VM's IP to new EBC code.
//
VmPtr->Gpr[0] -= 8;
VmWriteMemN (VmPtr, (UINTN) VmPtr->Gpr[0], (UINTN) FramePtr);
VmPtr->FramePtr = (VOID *) (UINTN) VmPtr->Gpr[0];
VmPtr->Gpr[0] -= 8;
VmWriteMem64 (VmPtr, (UINTN) VmPtr->Gpr[0], (UINT64) (UINTN) (VmPtr->Ip + Size));
VmPtr->Ip = (VMIP) InstructionBuffer->EbcEntryPoint;
} else {
//
// The callee is not a thunk to EBC, call native code,
// and get return value.
//
VmPtr->Gpr[7] = EbcLLCALLEXNative (FuncAddr, NewStackPointer, FramePtr);
//
// Advance the IP.
//
VmPtr->Ip += Size;
}
}
/**
This function is called to execute an EBC CALLEX instruction.
The function check the callee's content to see whether it is common native
code or a thunk to another piece of EBC code.
If the callee is common native code, use EbcLLCAllEXASM to manipulate,
otherwise, set the VM->IP to target EBC code directly to avoid another VM
be startup which cost time and stack space.
@param VmPtr Pointer to a VM context.
@param FuncAddr Callee's address
@param NewStackPointer New stack pointer after the call
@param FramePtr New frame pointer after the call
@param Size The size of call instruction
**/
VOID
EbcLLCALLEX (
IN VM_CONTEXT *VmPtr,
IN UINTN FuncAddr,
IN UINTN NewStackPointer,
IN VOID *FramePtr,
IN UINT8 Size
)
{
UINTN IsThunk;
UINTN TargetEbcAddr;
UINT8 InstructionBuffer[sizeof(mInstructionBufferTemplate)];
UINTN Index;
UINTN IndexOfEbcEntrypoint;
IsThunk = 1;
TargetEbcAddr = 0;
IndexOfEbcEntrypoint = 0;
//
// Processor specific code to check whether the callee is a thunk to EBC.
//
CopyMem (InstructionBuffer, (VOID *)FuncAddr, sizeof(InstructionBuffer));
//
// Fill the signature according to mInstructionBufferTemplate
//
for (Index = 0; Index < sizeof(mInstructionBufferTemplate) - sizeof(UINTN); Index++) {
if (*(UINTN *)&mInstructionBufferTemplate[Index] == EBC_ENTRYPOINT_SIGNATURE) {
*(UINTN *)&InstructionBuffer[Index] = EBC_ENTRYPOINT_SIGNATURE;
IndexOfEbcEntrypoint = Index;
}
if (*(UINTN *)&mInstructionBufferTemplate[Index] == EBC_LL_EBC_ENTRYPOINT_SIGNATURE) {
*(UINTN *)&InstructionBuffer[Index] = EBC_LL_EBC_ENTRYPOINT_SIGNATURE;
}
}
//
// Check if we need thunk to native
//
if (CompareMem (InstructionBuffer, mInstructionBufferTemplate, sizeof(mInstructionBufferTemplate)) != 0) {
IsThunk = 0;
}
if (IsThunk == 1){
//
// The callee is a thunk to EBC, adjust the stack pointer down 16 bytes and
// put our return address and frame pointer on the VM stack.
// Then set the VM's IP to new EBC code.
//
VmPtr->Gpr[0] -= 8;
VmWriteMemN (VmPtr, (UINTN) VmPtr->Gpr[0], (UINTN) FramePtr);
VmPtr->FramePtr = (VOID *) (UINTN) VmPtr->Gpr[0];
VmPtr->Gpr[0] -= 8;
VmWriteMem64 (VmPtr, (UINTN) VmPtr->Gpr[0], (UINT64) (UINTN) (VmPtr->Ip + Size));
CopyMem (&TargetEbcAddr, (UINT8 *)FuncAddr + IndexOfEbcEntrypoint, sizeof(UINTN));
VmPtr->Ip = (VMIP) (UINTN) TargetEbcAddr;
} else {
//
// The callee is not a thunk to EBC, call native code,
// and get return value.
//
VmPtr->Gpr[7] = EbcLLCALLEXNative (FuncAddr, NewStackPointer, FramePtr);
//
// Advance the IP.
//
VmPtr->Ip += Size;
}
}
/**
This function is called to execute an EBC CALLEX instruction.
The function check the callee's content to see whether it is common native
code or a thunk to another piece of EBC code.
If the callee is common native code, use EbcLLCAllEXASM to manipulate,
otherwise, set the VM->IP to target EBC code directly to avoid another VM
be startup which cost time and stack space.
@param VmPtr Pointer to a VM context.
@param FuncAddr Callee's address
@param NewStackPointer New stack pointer after the call
@param FramePtr New frame pointer after the call
@param Size The size of call instruction
**/
VOID
EbcLLCALLEX (
IN VM_CONTEXT *VmPtr,
IN UINTN FuncAddr,
IN UINTN NewStackPointer,
IN VOID *FramePtr,
IN UINT8 Size
)
{
UINTN IsThunk;
UINTN TargetEbcAddr;
IsThunk = 1;
TargetEbcAddr = 0;
//
// Processor specific code to check whether the callee is a thunk to EBC.
//
if (*((UINT8 *)FuncAddr) != 0xB8) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 1) != 0xBC) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 2) != 0x2E) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 3) != 0x11) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 4) != 0xCA) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 5) != 0xB8) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 10) != 0xB9) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 15) != 0xFF) {
IsThunk = 0;
goto Action;
}
if (*((UINT8 *)FuncAddr + 16) != 0xE1) {
IsThunk = 0;
goto Action;
}
TargetEbcAddr = ((UINTN)(*((UINT8 *)FuncAddr + 9)) << 24) + ((UINTN)(*((UINT8 *)FuncAddr + 8)) << 16) +
((UINTN)(*((UINT8 *)FuncAddr + 7)) << 8) + ((UINTN)(*((UINT8 *)FuncAddr + 6)));
Action:
if (IsThunk == 1){
//
// The callee is a thunk to EBC, adjust the stack pointer down 16 bytes and
// put our return address and frame pointer on the VM stack.
// Then set the VM's IP to new EBC code.
//
VmPtr->Gpr[0] -= 8;
VmWriteMemN (VmPtr, (UINTN) VmPtr->Gpr[0], (UINTN) FramePtr);
VmPtr->FramePtr = (VOID *) (UINTN) VmPtr->Gpr[0];
VmPtr->Gpr[0] -= 8;
VmWriteMem64 (VmPtr, (UINTN) VmPtr->Gpr[0], (UINT64) (UINTN) (VmPtr->Ip + Size));
VmPtr->Ip = (VMIP) (UINTN) TargetEbcAddr;
} else {
//
// The callee is not a thunk to EBC, call native code.
//
EbcLLCALLEXNative (FuncAddr, NewStackPointer, FramePtr);
//
// Get return value and advance the IP.
//
VmPtr->Gpr[7] = EbcLLGetReturnValue ();
VmPtr->Ip += Size;
}
}
