29#define DEBUG_TYPE "x86-indirect-branch-tracking"
33 cl::desc(
"Enable X86 indirect branch tracking pass."));
35STATISTIC(NumEndBranchAdded,
"Number of ENDBR instructions added");
43 return "X86 Indirect Branch Tracking";
55 unsigned int EndbrOpcode = 0;
66char X86IndirectBranchTrackingPass::ID = 0;
69 return new X86IndirectBranchTrackingPass();
72bool X86IndirectBranchTrackingPass::addENDBR(
74 assert(
TII &&
"Target instruction info was not initialized");
75 assert((X86::ENDBR64 == EndbrOpcode || X86::ENDBR32 == EndbrOpcode) &&
76 "Unexpected Endbr opcode");
80 if (
I ==
MBB.
end() ||
I->getOpcode() != EndbrOpcode) {
91 auto *CalleeFn = dyn_cast<Function>(MOp.
getGlobal());
95 return Attrs.hasFnAttr(Attribute::ReturnsTwice);
102 if (
F.doesNoCfCheck())
111 return (
F.hasAddressTaken() || !
F.hasLocalLinkage());
115bool X86IndirectBranchTrackingPass::runOnMachineFunction(
MachineFunction &MF) {
120 Metadata *isCFProtectionSupported =
M->getModuleFlag(
"cf-protection-branch");
127 bool isJITwithCET =
TM->isJIT();
129 bool isJITwithCET =
false;
135 bool Changed =
false;
138 EndbrOpcode = SubTarget.is64Bit() ? X86::ENDBR64 : X86::ENDBR32;
146 for (
auto &
MBB : MF) {
153 if (
I->isCall() &&
I->getNumOperands() > 0 &&
155 Changed |= addENDBR(
MBB, std::next(
I));
162 if (
TM->Options.ExceptionModel == ExceptionHandling::SjLj) {
166 if (
I->isDebugInstr())
168 Changed |= addENDBR(
MBB,
I);
170 }
else if (
I->isEHLabel()) {
173 MCSymbol *Sym =
I->getOperand(0).getMCSymbol();
174 if (!MF.hasCallSiteLandingPad(Sym))
176 Changed |= addENDBR(
MBB, std::next(
I));
184 Changed |= addENDBR(
MBB, std::next(
I));
const HexagonInstrInfo * TII
const char LLVMTargetMachineRef TM
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file defines the 'Statistic' class, which is designed to be an easy way to expose various metric...
#define STATISTIC(VARNAME, DESC)
static bool needsPrologueENDBR(MachineFunction &MF, const Module *M)
static bool IsCallReturnTwice(llvm::MachineOperand &MOp)
cl::opt< bool > IndirectBranchTracking("x86-indirect-branch-tracking", cl::init(false), cl::Hidden, cl::desc("Enable X86 indirect branch tracking pass."))
FunctionPass class - This class is used to implement most global optimizations.
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
bool isEHPad() const
Returns true if the block is a landing pad.
bool hasAddressTaken() const
Test whether this block is used as as something other than the target of a terminator,...
DebugLoc findDebugLoc(instr_iterator MBBI)
Find the next valid DebugLoc starting at MBBI, skipping any DBG_VALUE and DBG_LABEL instructions.
MachineFunctionPass - This class adapts the FunctionPass interface to allow convenient creation of pa...
virtual bool runOnMachineFunction(MachineFunction &MF)=0
runOnMachineFunction - This method must be overloaded to perform the desired machine code transformat...
const TargetSubtargetInfo & getSubtarget() const
getSubtarget - Return the subtarget for which this machine code is being compiled.
Function & getFunction()
Return the LLVM function that this machine code represents.
const LLVMTargetMachine & getTarget() const
getTarget - Return the target machine this machine code is compiled with
MachineModuleInfo & getMMI() const
const Module * getModule() const
MachineOperand class - Representation of each machine instruction operand.
const GlobalValue * getGlobal() const
bool isGlobal() const
isGlobal - Tests if this is a MO_GlobalAddress operand.
A Module instance is used to store all the information related to an LLVM module.
virtual StringRef getPassName() const
getPassName - Return a nice clean name for a pass.
StringRef - Represent a constant reference to a string, i.e.
CodeModel::Model getCodeModel() const
Returns the code model.
const X86InstrInfo * getInstrInfo() const override
unsigned ID
LLVM IR allows to use arbitrary numbers as calling convention identifiers.
initializer< Ty > init(const Ty &Val)
This is an optimization pass for GlobalISel generic memory operations.
MachineInstrBuilder BuildMI(MachineFunction &MF, const MIMetadata &MIMD, const MCInstrDesc &MCID)
Builder interface. Specify how to create the initial instruction itself.
FunctionPass * createX86IndirectBranchTrackingPass()
This pass inserts ENDBR instructions before indirect jump/call destinations as part of CET IBT mechan...