static InstTransResult doCmpxchgRR(InstPtr ip, BasicBlock *&b,
const MCOperand &dstReg,
const MCOperand &srcReg)
{
NASSERT(dstReg.isReg());
NASSERT(srcReg.isReg());
Value *acc;
switch(width) {
case 8:
acc = R_READ<width>(b, X86::AL);
break;
case 16:
acc = R_READ<width>(b, X86::AX);
break;
case 32:
acc = R_READ<width>(b, X86::EAX);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
Value *dstReg_v = R_READ<width>(b, dstReg.getReg());
Value *srcReg_v = R_READ<width>(b, srcReg.getReg());
doCmpVV<width>(ip, b, acc, dstReg_v);
Value *Cmp = new ICmpInst(*b, CmpInst::ICMP_EQ, acc, dstReg_v);
F_WRITE(b, ZF, Cmp);
///
// ZF = Acc == DST
// acc = select(ZF, acc, dst)
// dst = select(ZF, src, dst)
Value *new_acc = SelectInst::Create(Cmp, acc, dstReg_v, "", b);
Value *new_dst = SelectInst::Create(Cmp, srcReg_v, dstReg_v, "", b);
R_WRITE<width>(b, dstReg.getReg(), new_dst);
switch(width) {
case 8:
R_WRITE<width>(b, X86::AL, new_acc);
break;
case 16:
R_WRITE<width>(b, X86::AX, new_acc);
break;
case 32:
R_WRITE<width>(b, X86::EAX, new_acc);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
return ContinueBlock;
}
SystemArchType SystemArch(llvm::Module *) {
auto arch = ArchType();
if (arch == llvm::Triple::x86) {
return _X86_;
} else if (arch == llvm::Triple::x86_64) {
return _X86_64_;
} else {
throw TErr(__LINE__, __FILE__, "Unsupported architecture");
}
}
static bool LiftBlockIntoFunction(TranslationContext &ctx) {
auto didError = false;
//first, either create or look up the LLVM basic block for this native
//block. we are either creating it for the first time, or, we are
//going to look up a blank block
auto block_name = ctx.natB->get_name();
auto curLLVMBlock = ctx.va_to_bb[ctx.natB->get_base()];
//then, create a basic block for every follow of this block, if we do not
//already have that basic block in our LLVM CFG
const auto &follows = ctx.natB->get_follows();
for (auto succ_block_va : follows) {
if (!ctx.va_to_bb.count(succ_block_va)) {
throw TErr(__LINE__, __FILE__, "Missing successor block!");
}
}
//now, go through each statement and translate it into LLVM IR
//statements that branch SHOULD be the last statement in a block
for (auto inst : ctx.natB->get_insts()) {
ctx.natI = inst;
switch (LiftInstIntoBlock(ctx, curLLVMBlock, true)) {
case ContinueBlock:
break;
case EndBlock:
case EndCFG:
goto done;
case TranslateErrorUnsupported:
didError = !IgnoreUnsupportedInsts;
goto done;
case TranslateError:
didError = true;
goto done;
}
}
done:
if (curLLVMBlock->getTerminator()) {
return didError;
}
// we may need to insert a branch inst to the successor
// if the block ended on a non-terminator (this happens since we
// may split blocks in cfg recovery to avoid code duplication)
if (follows.size() == 1) {
llvm::BranchInst::Create(ctx.va_to_bb[follows.front()], curLLVMBlock);
} else {
new llvm::UnreachableInst(curLLVMBlock->getContext(), curLLVMBlock);
}
return didError;
}
NTSTATUS EXTERNAL
DriverEntry(
__in PDRIVER_OBJECT DrvObj,
__in PUNICODE_STRING RegPath
)
{
NTSTATUS status = STATUS_SUCCESS;
HID_MINIDRIVER_REGISTRATION hidMinidriverRegistration = {0};
TEnter(Func,("(DrvObj=%p,RegPath=%p)\n", DrvObj, RegPath));
gDriverObj = DrvObj;
DrvObj->MajorFunction[IRP_MJ_CREATE] =
DrvObj->MajorFunction[IRP_MJ_CLOSE] = HbtnCreateClose;
DrvObj->MajorFunction[IRP_MJ_INTERNAL_DEVICE_CONTROL] = HbtnInternalIoctl;
DrvObj->MajorFunction[IRP_MJ_PNP] = HbtnPnp;
DrvObj->MajorFunction[IRP_MJ_POWER] = HbtnPower;
DrvObj->DriverUnload = HbtnUnload;
DrvObj->DriverExtension->AddDevice = HbtnAddDevice;
//
// Register with HIDCLASS.SYS module
//
RtlZeroMemory(&hidMinidriverRegistration,
sizeof(hidMinidriverRegistration));
hidMinidriverRegistration.Revision = HID_REVISION;
hidMinidriverRegistration.DriverObject = DrvObj;
hidMinidriverRegistration.RegistryPath = RegPath;
hidMinidriverRegistration.DeviceExtensionSize = sizeof(DEVICE_EXTENSION);
hidMinidriverRegistration.DevicesArePolled = FALSE;
status = HidRegisterMinidriver(&hidMinidriverRegistration);
if (!NT_SUCCESS(status))
{
LogError(ERRLOG_MINIDRV_REG_FAILED,
status,
UNIQUE_ERRID(0x10), NULL, NULL);
TErr(("failed to register mini driver.\n"));
}
TExit(Func,("=%x\n", status));
return status;
} //DriverEntry
llvm::CallingConv::ID getLLVMCC(ExternalCodeRef::CallingConvention cc) {
switch (cc) {
case ExternalCodeRef::CallerCleanup:
return llvm::CallingConv::C;
case ExternalCodeRef::CalleeCleanup:
return llvm::CallingConv::X86_StdCall;
case ExternalCodeRef::FastCall:
return llvm::CallingConv::X86_FastCall;
case ExternalCodeRef::McsemaCall:
// mcsema internal calls are cdecl with one argument
return llvm::CallingConv::C;
default:
throw TErr(__LINE__, __FILE__, "Unknown calling convention!");
break;
}
return llvm::CallingConv::C;
}
static InstTransResult doCmpxchgRM(InstPtr ip, BasicBlock *&b,
Value *dstAddr,
const MCOperand &srcReg)
{
NASSERT(dstAddr != NULL);
NASSERT(srcReg.isReg());
Value *acc;
switch(width) {
case 8:
acc = R_READ<width>(b, X86::AL);
break;
case 16:
acc = R_READ<width>(b, X86::AX);
break;
case 32:
acc = R_READ<width>(b, X86::EAX);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
//Value *mem_v = M_READ<width>(ip, b, dstAddr);
Value *m_addr = NULL;
unsigned addrspace = ip->get_addr_space();
if( dstAddr->getType()->isPointerTy() == false ) {
llvm::Type *ptrTy =
Type::getIntNPtrTy(b->getContext(), width, addrspace);
m_addr = new llvm::IntToPtrInst(dstAddr, ptrTy, "", b);
}
else if( dstAddr->getType() != Type::getIntNPtrTy(
b->getContext(), width, addrspace) )
{
//we need to bitcast the pointer value to a pointer type of the appropriate width
m_addr = CastInst::CreatePointerCast(dstAddr,
Type::getIntNPtrTy(b->getContext(), width, addrspace), "", b);
} else {
m_addr = dstAddr;
}
Value *srcReg_v = R_READ<width>(b, srcReg.getReg());
AtomicCmpXchgInst *cmpx = new AtomicCmpXchgInst(
m_addr,
acc,
srcReg_v,
llvm::SequentiallyConsistent,
llvm::SequentiallyConsistent,
llvm::CrossThread,
b);
cmpx->setVolatile(true);
Value *cmpx_val = ExtractValueInst::Create(cmpx, 0, "cmpxchg_cmpx_val", b);
Value *was_eq = ExtractValueInst::Create(cmpx, 1, "cmpxchg_was_eq", b);
doCmpVV<width>(ip, b, acc, cmpx_val);
F_WRITE(b, ZF, was_eq);
Value *new_acc = SelectInst::Create(was_eq, acc, cmpx_val, "", b);
switch(width) {
case 8:
R_WRITE<width>(b, X86::AL, new_acc);
break;
case 16:
R_WRITE<width>(b, X86::AX, new_acc);
break;
case 32:
R_WRITE<width>(b, X86::EAX, new_acc);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
return ContinueBlock;
}
VOID __cdecl
LogDbgMsg(
IN NTSTATUS ErrorCode,
IN NTSTATUS NTStatus OPTIONAL,
_In_z_ LPCSTR pszFormat,
...
)
{
#define MAX_ERRMSG_LEN ((ERROR_LOG_MAXIMUM_SIZE - \
FIELD_OFFSET(IO_ERROR_LOG_PACKET, DumpData)) \
/sizeof(WCHAR))
static char szErrMsg[MAX_ERRMSG_LEN] = {0};
TEnter(Func, ("(ErrorCode=%x,NTStatus=%x,Format=%s)",
ErrorCode, NTStatus, pszFormat));
TAssert(gDriverObj != NULL);
if (gDriverObj != NULL)
{
va_list arglist;
NTSTATUS status;
size_t iLen = 0;
ULONG_PTR iTotalLen;
PIO_ERROR_LOG_PACKET ErrEntry;
va_start(arglist, pszFormat);
status = RtlStringCchVPrintfA(szErrMsg,
ARRAYSIZE(szErrMsg),
pszFormat,
arglist);
va_end(arglist);
if (NT_SUCCESS(status))
{
status = RtlStringCchLengthA(szErrMsg, ARRAYSIZE(szErrMsg), &iLen);
}
if (NT_SUCCESS(status))
{
iTotalLen = FIELD_OFFSET(IO_ERROR_LOG_PACKET, DumpData) +
(iLen + 1)*sizeof(WCHAR);
iTotalLen = max(iTotalLen, sizeof(IO_ERROR_LOG_PACKET));
ErrEntry = IoAllocateErrorLogEntry(gDriverObj, (UCHAR)iTotalLen);
if (ErrEntry)
{
ErrEntry->NumberOfStrings = 1;
ErrEntry->ErrorCode = ErrorCode;
ErrEntry->StringOffset = FIELD_OFFSET(IO_ERROR_LOG_PACKET,
DumpData);
mbstowcs((WCHAR *)ErrEntry->DumpData, szErrMsg, iLen);
ErrEntry->FinalStatus = NTStatus;
IoWriteErrorLogEntry(ErrEntry);
}
else
{
TWarn(("Failed to allocate error log entry (len=%d).",
(int)iTotalLen));
}
if (ErrorCode == ERRLOG_DEBUG_INFORMATION)
{
TInfo(("%s", szErrMsg));
}
else if (ErrorCode == ERRLOG_DEBUG_WARNING)
{
TWarn(("%s", szErrMsg));
}
else if (ErrorCode == ERRLOG_DEBUG_ERROR)
{
TErr(("%s", szErrMsg));
}
}
}
TExit(Func, ("!"));
return;
} //LogDbgMsg
// Iterate over the list of external functions and insert them as
// global functions.
static void InitExternalCode(NativeModulePtr natMod, llvm::Module *M) {
for (auto e : natMod->getExtCalls()) {
auto conv = e->getCallingConvention();
auto argCount = e->getNumArgs();
auto symName = e->getSymbolName();
auto funcSign = e->getFunctionSignature();
// Create the function if it is not already there.
auto &C = M->getContext();
auto F = M->getFunction(symName);
if (F) {
continue;
}
if (ExternalCodeRef::McsemaCall == conv) {
// normal mcsema function prototypes
F = llvm::dyn_cast<llvm::Function>(M->getOrInsertFunction(
ArchNameMcSemaCall(symName), LiftedFunctionType()));
ArchSetCallingConv(M, F);
F->setLinkage(llvm::GlobalValue::ExternalLinkage);
continue;
}
std::vector<llvm::Type *> arguments;
llvm::Type *returnType = nullptr;
// Create arguments.
const auto Arch = SystemArch(M);
const auto OS = SystemOS(M);
for (auto i = 0; i < argCount; i++) {
if (_X86_64_ == Arch) {
if (llvm::Triple::Win32 == OS) {
if (funcSign.c_str()[i] == 'F') {
arguments.push_back(llvm::Type::getDoubleTy(C));
} else {
arguments.push_back(llvm::Type::getInt64Ty(C));
}
} else if (llvm::Triple::Linux == OS) {
arguments.push_back(llvm::Type::getInt64Ty(C));
} else {
TASSERT(false, "Unknown OS Type!");
}
} else {
arguments.push_back(llvm::Type::getInt32Ty(C));
}
}
//create function type
switch (e->getReturnType()) {
case ExternalCodeRef::NoReturn:
case ExternalCodeRef::VoidTy:
returnType = llvm::Type::getVoidTy(C);
break;
case ExternalCodeRef::Unknown:
case ExternalCodeRef::IntTy:
if (natMod->is64Bit()) {
returnType = llvm::Type::getInt64Ty(C);
} else {
returnType = llvm::Type::getInt32Ty(C);
}
break;
default:
throw TErr(
__LINE__, __FILE__,
"Encountered an unknown return type while translating function");
}
auto FTy = llvm::FunctionType::get(returnType, arguments, false);
if (e->isWeak()) {
F = llvm::Function::Create(FTy, llvm::GlobalValue::ExternalWeakLinkage,
symName, M);
} else {
F = llvm::Function::Create(FTy, llvm::GlobalValue::ExternalLinkage,
symName, M);
}
if (e->getReturnType() == ExternalCodeRef::NoReturn) {
F->setDoesNotReturn();
}
//set calling convention
if (natMod->is64Bit()) {
ArchSetCallingConv(M, F);
} else {
F->setCallingConv(getLLVMCC(conv));
}
}
}
static bool InsertFunctionIntoModule(NativeModulePtr mod,
NativeFunctionPtr func, llvm::Module *M) {
auto &C = M->getContext();
auto F = M->getFunction(func->get_name());
if (!F) {
throw TErr(__LINE__, __FILE__, "Could not get func " + func->get_name());
}
if (!F->empty()) {
std::cout << "WARNING: Asking to re-insert function: " << func->get_name()
<< std::endl << "\tReturning current function instead"
<< std::endl;
return true;
}
auto entryBlock = llvm::BasicBlock::Create(F->getContext(), "entry", F);
ArchAllocRegisterVars(entryBlock);
TranslationContext ctx;
ctx.natM = mod;
ctx.natF = func;
ctx.natI = nullptr;
ctx.M = M;
ctx.F = F;
// Create basic blocks for each basic block in the original function.
for (auto block_info : func->get_blocks()) {
ctx.va_to_bb[block_info.first] = llvm::BasicBlock::Create(
C, block_info.second->get_name(), F);
}
// Create a branch from the end of the entry block to the first block
llvm::BranchInst::Create(ctx.va_to_bb[func->get_start()], entryBlock);
try {
// Lift every basic block into the functions.
auto error = false;
for (auto block_info : func->get_blocks()) {
ctx.natB = block_info.second;
error = LiftBlockIntoFunction(ctx) || error;
ctx.natB = nullptr;
}
// For ease of debugging generated code, don't allow lifted functions to
// be inlined. This will make lifted and native call graphs one-to-one.
F->addFnAttr(llvm::Attribute::NoInline);
//we should be done, having inserted every block into the module
return !error;
} catch (std::exception &e) {
std::cerr << "error: " << std::endl << e.what() << std::endl
<< "in function " << std::hex
<< ctx.natF->get_start() << std::endl;
if (ctx.natB) {
std::cerr << "in block " << std::hex << ctx.natB->get_base() << std::endl;
if (ctx.natI) {
std::cerr << "in inst " << std::hex << ctx.natI->get_loc() << std::endl;
}
}
return false;
}
}
static InstTransResult doCmpxchgRR(InstPtr ip, BasicBlock *&b,
const MCOperand &dstReg,
const MCOperand &srcReg)
{
NASSERT(dstReg.isReg());
NASSERT(srcReg.isReg());
Function *F = b->getParent();
BasicBlock *AccEQDest =
BasicBlock::Create(b->getContext(), "AccEQDest", F);
BasicBlock *AccNEDest =
BasicBlock::Create(b->getContext(), "AccNEDest", F);
BasicBlock *done =
BasicBlock::Create(b->getContext(), "done", F);
Value *acc;
switch(width) {
case 8:
acc = R_READ<width>(b, X86::AL);
break;
case 16:
acc = R_READ<width>(b, X86::AX);
break;
case 32:
acc = R_READ<width>(b, X86::EAX);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
Value *dstReg_v = R_READ<width>(b, dstReg.getReg());
Value *srcReg_v = R_READ<width>(b, srcReg.getReg());
doCmpVV<width>(ip, b, acc, dstReg_v);
Value *Cmp = new ICmpInst(*b, CmpInst::ICMP_EQ, acc, dstReg_v);
BranchInst::Create(AccEQDest, AccNEDest, Cmp, b);
// Acc == Dst
F_SET(AccEQDest, "ZF");
R_WRITE<width>(AccEQDest, dstReg.getReg(), srcReg_v);
BranchInst::Create(done, AccEQDest);
// Acc != Dst
F_CLEAR(AccNEDest, "ZF");
switch(width) {
case 8:
R_WRITE<width>(AccNEDest, X86::AL, dstReg_v);
break;
case 16:
R_WRITE<width>(AccNEDest, X86::AX, dstReg_v);
break;
case 32:
R_WRITE<width>(AccNEDest, X86::EAX, dstReg_v);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
BranchInst::Create(done, AccNEDest);
b = done;
return ContinueBlock;
}
static InstTransResult doCmpxchgRM(InstPtr ip, BasicBlock *&b,
Value *dstAddr,
const MCOperand &srcReg)
{
NASSERT(dstAddr != NULL);
NASSERT(srcReg.isReg());
Function *F = b->getParent();
BasicBlock *AccEQDest =
BasicBlock::Create(b->getContext(), "AccEQDest", F);
BasicBlock *AccNEDest =
BasicBlock::Create(b->getContext(), "AccNEDest", F);
BasicBlock *done =
BasicBlock::Create(b->getContext(), "done", F);
Value *acc;
switch(width) {
case 8:
acc = R_READ<width>(b, X86::AL);
break;
case 16:
acc = R_READ<width>(b, X86::AX);
break;
case 32:
acc = R_READ<width>(b, X86::EAX);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
//Value *mem_v = M_READ<width>(ip, b, dstAddr);
Value *m_addr = NULL;
unsigned addrspace = ip->get_addr_space();
if( dstAddr->getType()->isPointerTy() == false ) {
llvm::Type *ptrTy =
Type::getIntNPtrTy(b->getContext(), width, addrspace);
m_addr = new llvm::IntToPtrInst(dstAddr, ptrTy, "", b);
}
else if( dstAddr->getType() != Type::getIntNPtrTy(
b->getContext(), width, addrspace) )
{
//we need to bitcast the pointer value to a pointer type of the appropriate width
m_addr = CastInst::CreatePointerCast(dstAddr,
Type::getIntNPtrTy(b->getContext(), width, addrspace), "", b);
} else {
m_addr = dstAddr;
}
Value *srcReg_v = R_READ<width>(b, srcReg.getReg());
AtomicCmpXchgInst *cmpx = new AtomicCmpXchgInst(
m_addr,
acc,
srcReg_v,
llvm::SequentiallyConsistent,
llvm::CrossThread,
b);
cmpx->setVolatile(true);
// needed for flags settings
doCmpVV<width>(ip, b, acc, cmpx);
Value *Cmp = new ICmpInst(*b, CmpInst::ICMP_EQ, cmpx, acc);
BranchInst::Create(AccEQDest, AccNEDest, Cmp, b);
// Acc == Dst
F_SET(AccEQDest, "ZF");
//M_WRITE<width>(ip, AccEQDest, dstAddr, srcReg_v);
BranchInst::Create(done, AccEQDest);
// Acc != Dst
F_CLEAR(AccNEDest, "ZF");
switch(width) {
case 8:
R_WRITE<width>(AccNEDest, X86::AL, cmpx);
break;
case 16:
R_WRITE<width>(AccNEDest, X86::AX, cmpx);
break;
case 32:
R_WRITE<width>(AccNEDest, X86::EAX, cmpx);
break;
default:
throw TErr(__LINE__, __FILE__, "Width not supported");
}
BranchInst::Create(done, AccNEDest);
b = done;
return ContinueBlock;
}
Value *getAddrFromExpr( BasicBlock *b,
NativeModulePtr mod,
const MCOperand &Obase,
const MCOperand &Oscale,
const MCOperand &Oindex,
const int64_t Odisp,
const MCOperand &Oseg,
bool dataOffset)
{
TASSERT(Obase.isReg(), "");
TASSERT(Oscale.isImm(), "");
TASSERT(Oindex.isReg(), "");
TASSERT(Oseg.isReg(), "");
unsigned baseReg = Obase.getReg();
int64_t disp = Odisp;
// specific function for 64 bit
Value *d = NULL;
IntegerType *iTy = IntegerType::getInt64Ty(b->getContext());
if( dataOffset ||
(mod && disp && baseReg != X86::RBP && baseReg!= X86::RSP) )
{
VA baseGlobal;
if( addrIsInData(disp, mod, baseGlobal, dataOffset ? 0 : 0x1000) ) {
//we should be able to find a reference to this in global data
Module *M = b->getParent()->getParent();
string sn = "data_0x" + to_string<VA>(baseGlobal, hex);
GlobalVariable *gData = M->getNamedGlobal(sn);
//if we thought it was a global, we should be able to
//pin it to a global array we made during module setup
if( gData == NULL)
throw TErr(__LINE__, __FILE__, "Global variable not found");
// since globals are now a structure
// we cannot simply slice into them.
// Need to get ptr and then add integer displacement to ptr
Value *globalGEPV[] =
{ ConstantInt::get(Type::getInt64Ty(b->getContext()), 0),
ConstantInt::get(Type::getInt32Ty(b->getContext()), 0)};
Instruction *globalGEP =
GetElementPtrInst::Create(gData, globalGEPV, "", b);
Type *ty = Type::getInt64Ty(b->getContext());
Value *intVal = new PtrToIntInst(globalGEP, ty, "", b);
uint32_t addr_offset = disp-baseGlobal;
Value *int_adjusted =
BinaryOperator::CreateAdd(intVal, CONST_V<64>(b, addr_offset), "", b);
//then, assign this to the outer 'd' so that the rest of the
//logic picks up on that address instead of another address
d = int_adjusted;
}
} else {
//there is no disp value, or its relative to esp/ebp in which case
//we might not want to do anything
}
if( d == NULL ) {
//create a constant integer out of the raw displacement
//we were unable to assign the displacement to an address
d = ConstantInt::getSigned(iTy, disp);
}
Value *rVal = NULL;
//read the base register (if given)
if( baseReg != X86::NoRegister && baseReg != X86::RIP) {
rVal = R_READ<64>(b, baseReg);
} else {
//if the base is not present, just use 0
rVal = CONST_V<64>(b, 0);
}
Value *dispComp;
dispComp =
BinaryOperator::Create( Instruction::Add, rVal, d, "", b);
//add the index amount, if present
if( Oindex.getReg() != X86::NoRegister ) {
Value *index = R_READ<64>(b, Oindex.getReg());
int64_t scaleAmt = Oscale.getImm();
if( scaleAmt > 1 ) {
index =
BinaryOperator::CreateMul(index,CONST_V<64>(b, scaleAmt),"",b);
}
dispComp =
BinaryOperator::CreateAdd(dispComp, index, "", b);
}
//convert the resulting integer into a pointer type
PointerType *piTy = Type::getInt64PtrTy(b->getContext());
Value *dispPtr = new IntToPtrInst(dispComp, piTy, "", b);
return dispPtr;
}
