llvm-project/llvm/lib/Target/X86/X86TargetMachine.h
Xiang1 Zhang 43f031d312 Enable IBT(Indirect Branch Tracking) in JIT with CET(Control-flow Enforcement Technology)
Summary:
This patch comes from H.J.'s 2bd54ce7fa

**This patch fix the failed llvm unit tests which running on CET machine. **(e.g. ExecutionEngine/MCJIT/MCJITTests)

The reason we enable IBT at "JIT compiled with CET" is mainly that:  the JIT don't know the its caller program is CET enable or not.
If JIT's caller program is non-CET, it is no problem JIT generate CET code or not.
But if JIT's caller program is CET enabled,  JIT must generate CET code or it will cause Control protection exceptions.

I have test the patch at llvm-unit-test and llvm-test-suite at CET machine. It passed.
and H.J. also test it at building and running VNCserver(Virtual Network Console), it works too.
(if not apply this patch, VNCserver will crash at CET machine.)

Reviewers: hjl.tools, craig.topper, LuoYuanke, annita.zhang, pengfei

Subscribers: tstellar, efriedma, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D76900
2020-04-03 11:44:07 +08:00

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2.1 KiB
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//===-- X86TargetMachine.h - Define TargetMachine for the X86 ---*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file declares the X86 specific subclass of TargetMachine.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_LIB_TARGET_X86_X86TARGETMACHINE_H
#define LLVM_LIB_TARGET_X86_X86TARGETMACHINE_H
#include "X86Subtarget.h"
#include "llvm/ADT/Optional.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/Support/CodeGen.h"
#include "llvm/Target/TargetMachine.h"
#include <memory>
namespace llvm {
class StringRef;
class X86Subtarget;
class X86RegisterBankInfo;
class TargetTransformInfo;
class X86TargetMachine final : public LLVMTargetMachine {
std::unique_ptr<TargetLoweringObjectFile> TLOF;
mutable StringMap<std::unique_ptr<X86Subtarget>> SubtargetMap;
// True if this is used in JIT.
bool IsJIT;
public:
X86TargetMachine(const Target &T, const Triple &TT, StringRef CPU,
StringRef FS, const TargetOptions &Options,
Optional<Reloc::Model> RM, Optional<CodeModel::Model> CM,
CodeGenOpt::Level OL, bool JIT);
~X86TargetMachine() override;
const X86Subtarget *getSubtargetImpl(const Function &F) const override;
// DO NOT IMPLEMENT: There is no such thing as a valid default subtarget,
// subtargets are per-function entities based on the target-specific
// attributes of each function.
const X86Subtarget *getSubtargetImpl() const = delete;
TargetTransformInfo getTargetTransformInfo(const Function &F) override;
// Set up the pass pipeline.
TargetPassConfig *createPassConfig(PassManagerBase &PM) override;
TargetLoweringObjectFile *getObjFileLowering() const override {
return TLOF.get();
}
bool isJIT() const { return IsJIT; }
};
} // end namespace llvm
#endif // LLVM_LIB_TARGET_X86_X86TARGETMACHINE_H