X86SpeculativeExecutionSideEffectSuppression.cpp File Reference

This file contains the X86 implementation of the speculative execution side effect suppression mitigation. More...

#include "X86.h"
#include "X86InstrInfo.h"
#include "X86Subtarget.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/CodeGen/MachineInstrBuilder.h"
#include "llvm/Pass.h"
#include "llvm/Target/TargetMachine.h"

Go to the source code of this file.

Macros
#define	DEBUG_TYPE   "x86-seses"

Functions
	STATISTIC (NumLFENCEsInserted, "Number of lfence instructions inserted")
static bool	hasConstantAddressingMode (const MachineInstr &MI)
bool	runX86SpeculativeExecutionSideEffectSuppression (MachineFunction &MF)

Variables
static cl::opt< bool >	EnableSpeculativeExecutionSideEffectSuppression ("x86-seses-enable-without-lvi-cfi", cl::desc("Force enable speculative execution side effect suppression. " "(Note: User must pass -mlvi-cfi in order to mitigate indirect " "branches and returns.)"), cl::init(false), cl::Hidden)
static cl::opt< bool >	OneLFENCEPerBasicBlock ("x86-seses-one-lfence-per-bb", cl::desc("Omit all lfences other than the first to be placed in a basic block."), cl::init(false), cl::Hidden)
static cl::opt< bool >	OnlyLFENCENonConst ("x86-seses-only-lfence-non-const", cl::desc("Only lfence before groups of terminators where at least one " "branch instruction has an input to the addressing mode that is a " "register other than %rip."), cl::init(false), cl::Hidden)
static cl::opt< bool >	OmitBranchLFENCEs ("x86-seses-omit-branch-lfences", cl::desc("Omit all lfences before branch instructions."), cl::init(false), cl::Hidden)

Detailed Description

This file contains the X86 implementation of the speculative execution side effect suppression mitigation.

This must be used with the -mlvi-cfi flag in order to mitigate indirect branches and returns.

Definition in file X86SpeculativeExecutionSideEffectSuppression.cpp.

Macro Definition Documentation

DEBUG_TYPE

#define DEBUG_TYPE   "x86-seses"

Definition at line 28 of file X86SpeculativeExecutionSideEffectSuppression.cpp.

Function Documentation

hasConstantAddressingMode()

bool hasConstantAddressingMode ( const MachineInstr & MI )

static

Definition at line 83 of file X86SpeculativeExecutionSideEffectSuppression.cpp.

References MI.

Referenced by runX86SpeculativeExecutionSideEffectSuppression().

runX86SpeculativeExecutionSideEffectSuppression()

bool runX86SpeculativeExecutionSideEffectSuppression

(

MachineFunction &

MF

)

Definition at line 90 of file X86SpeculativeExecutionSideEffectSuppression.cpp.

References assert(), llvm::BuildMI(), llvm::dbgs(), llvm::dwarf_linker::DebugLoc, EnableSpeculativeExecutionSideEffectSuppression, llvm::X86Subtarget::getInstrInfo(), llvm::MachineFunction::getName(), llvm::TargetMachine::getOptLevel(), llvm::MachineFunction::getSubtarget(), llvm::MachineFunction::getTarget(), hasConstantAddressingMode(), LLVM_DEBUG, MBB, MI, Modified, llvm::None, OmitBranchLFENCEs, OneLFENCEPerBasicBlock, OnlyLFENCENonConst, and TII.

Referenced by llvm::X86SpeculativeExecutionSideEffectSuppressionPass::run().

STATISTIC()

STATISTIC	(	NumLFENCEsInserted	,
		"Number of lfence instructions inserted"	)

Variable Documentation

EnableSpeculativeExecutionSideEffectSuppression

cl::opt< bool > EnableSpeculativeExecutionSideEffectSuppression("x86-seses-enable-without-lvi-cfi", cl::desc("Force enable speculative execution side effect suppression. " "(Note: User must pass -mlvi-cfi in order to mitigate indirect " "branches and returns.)"), cl::init(false), cl::Hidden) ( "x86-seses-enable-without-lvi-cfi" , cl::desc("Force enable speculative execution side effect suppression. " "(Note: User must pass -mlvi-cfi in order to mitigate indirect " "branches and returns.)") , cl::init(false) , cl::Hidden  )

static

Referenced by runX86SpeculativeExecutionSideEffectSuppression().

OmitBranchLFENCEs

cl::opt< bool > OmitBranchLFENCEs("x86-seses-omit-branch-lfences", cl::desc("Omit all lfences before branch instructions."), cl::init(false), cl::Hidden) ( "x86-seses-omit-branch-lfences" , cl::desc("Omit all lfences before branch instructions.") , cl::init(false) , cl::Hidden  )

static

Referenced by runX86SpeculativeExecutionSideEffectSuppression().

OneLFENCEPerBasicBlock

cl::opt< bool > OneLFENCEPerBasicBlock("x86-seses-one-lfence-per-bb", cl::desc( "Omit all lfences other than the first to be placed in a basic block."), cl::init(false), cl::Hidden) ( "x86-seses-one-lfence-per-bb" , cl::desc( "Omit all lfences other than the first to be placed in a basic block.") , cl::init(false) , cl::Hidden  )

static

Referenced by runX86SpeculativeExecutionSideEffectSuppression().

OnlyLFENCENonConst

cl::opt< bool > OnlyLFENCENonConst("x86-seses-only-lfence-non-const", cl::desc("Only lfence before groups of terminators where at least one " "branch instruction has an input to the addressing mode that is a " "register other than %rip."), cl::init(false), cl::Hidden) ( "x86-seses-only-lfence-non-const" , cl::desc("Only lfence before groups of terminators where at least one " "branch instruction has an input to the addressing mode that is a " "register other than %rip.") , cl::init(false) , cl::Hidden  )

static

Referenced by runX86SpeculativeExecutionSideEffectSuppression().