1 //===-- X86AsmInstrumentation.cpp - Instrument X86 inline assembly C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #include "MCTargetDesc/X86BaseInfo.h"
11 #include "X86AsmInstrumentation.h"
12 #include "X86Operand.h"
13 #include "llvm/ADT/StringExtras.h"
14 #include "llvm/MC/MCContext.h"
15 #include "llvm/MC/MCInst.h"
16 #include "llvm/MC/MCInstBuilder.h"
17 #include "llvm/MC/MCStreamer.h"
18 #include "llvm/MC/MCSubtargetInfo.h"
19 #include "llvm/Support/CommandLine.h"
20 #include "llvm/Support/Compiler.h"
21 #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
26 static cl::opt<bool> ClAsanInstrumentInlineAssembly(
27 "asan-instrument-inline-assembly", cl::desc("instrument inline assembly"),
28 cl::Hidden, cl::init(false));
30 bool IsStackReg(unsigned Reg) {
31 return Reg == X86::RSP || Reg == X86::ESP || Reg == X86::SP;
34 std::string FuncName(unsigned AccessSize, bool IsWrite) {
35 return std::string("__sanitizer_sanitize_") + (IsWrite ? "store" : "load") +
39 class X86AddressSanitizer : public X86AsmInstrumentation {
41 X86AddressSanitizer(MCSubtargetInfo &sti) : STI(sti) {}
42 virtual ~X86AddressSanitizer() {}
44 // X86AsmInstrumentation implementation:
45 virtual void InstrumentInstruction(
46 const MCInst &Inst, SmallVectorImpl<MCParsedAsmOperand *> &Operands,
47 MCContext &Ctx, MCStreamer &Out) override {
48 InstrumentMOV(Inst, Operands, Ctx, Out);
51 // Should be implemented differently in x86_32 and x86_64 subclasses.
52 virtual void InstrumentMemOperandImpl(X86Operand *Op, unsigned AccessSize,
53 bool IsWrite, MCContext &Ctx,
56 void InstrumentMemOperand(MCParsedAsmOperand *Op, unsigned AccessSize,
57 bool IsWrite, MCContext &Ctx, MCStreamer &Out);
58 void InstrumentMOV(const MCInst &Inst,
59 SmallVectorImpl<MCParsedAsmOperand *> &Operands,
60 MCContext &Ctx, MCStreamer &Out);
61 void EmitInstruction(MCStreamer &Out, const MCInst &Inst) {
62 Out.EmitInstruction(Inst, STI);
69 void X86AddressSanitizer::InstrumentMemOperand(
70 MCParsedAsmOperand *Op, unsigned AccessSize, bool IsWrite, MCContext &Ctx,
72 assert(Op && Op->isMem() && "Op should be a memory operand.");
73 assert((AccessSize & (AccessSize - 1)) == 0 && AccessSize <= 16 &&
74 "AccessSize should be a power of two, less or equal than 16.");
76 X86Operand *MemOp = static_cast<X86Operand *>(Op);
77 // FIXME: get rid of this limitation.
78 if (IsStackReg(MemOp->getMemBaseReg()) || IsStackReg(MemOp->getMemIndexReg()))
81 InstrumentMemOperandImpl(MemOp, AccessSize, IsWrite, Ctx, Out);
84 void X86AddressSanitizer::InstrumentMOV(
85 const MCInst &Inst, SmallVectorImpl<MCParsedAsmOperand *> &Operands,
86 MCContext &Ctx, MCStreamer &Out) {
87 // Access size in bytes.
88 unsigned AccessSize = 0;
89 unsigned long OpIx = Operands.size();
90 switch (Inst.getOpcode()) {
138 if (OpIx >= Operands.size())
141 const bool IsWrite = (OpIx != 1);
142 InstrumentMemOperand(Operands[OpIx], AccessSize, IsWrite, Ctx, Out);
145 class X86AddressSanitizer32 : public X86AddressSanitizer {
147 X86AddressSanitizer32(MCSubtargetInfo &sti) : X86AddressSanitizer(sti) {}
148 virtual ~X86AddressSanitizer32() {}
150 virtual void InstrumentMemOperandImpl(X86Operand *Op, unsigned AccessSize,
151 bool IsWrite, MCContext &Ctx,
152 MCStreamer &Out) override;
155 void X86AddressSanitizer32::InstrumentMemOperandImpl(
156 X86Operand *Op, unsigned AccessSize, bool IsWrite, MCContext &Ctx,
158 // FIXME: emit .cfi directives for correct stack unwinding.
159 EmitInstruction(Out, MCInstBuilder(X86::PUSH32r).addReg(X86::EAX));
162 Inst.setOpcode(X86::LEA32r);
163 Inst.addOperand(MCOperand::CreateReg(X86::EAX));
164 Op->addMemOperands(Inst, 5);
165 EmitInstruction(Out, Inst);
167 EmitInstruction(Out, MCInstBuilder(X86::PUSH32r).addReg(X86::EAX));
169 const std::string Func = FuncName(AccessSize, IsWrite);
170 const MCSymbol *FuncSym = Ctx.GetOrCreateSymbol(StringRef(Func));
171 const MCSymbolRefExpr *FuncExpr =
172 MCSymbolRefExpr::Create(FuncSym, MCSymbolRefExpr::VK_PLT, Ctx);
173 EmitInstruction(Out, MCInstBuilder(X86::CALLpcrel32).addExpr(FuncExpr));
175 EmitInstruction(Out, MCInstBuilder(X86::ADD32ri).addReg(X86::ESP)
176 .addReg(X86::ESP).addImm(4));
177 EmitInstruction(Out, MCInstBuilder(X86::POP32r).addReg(X86::EAX));
180 class X86AddressSanitizer64 : public X86AddressSanitizer {
182 X86AddressSanitizer64(MCSubtargetInfo &sti) : X86AddressSanitizer(sti) {}
183 virtual ~X86AddressSanitizer64() {}
185 virtual void InstrumentMemOperandImpl(X86Operand *Op, unsigned AccessSize,
186 bool IsWrite, MCContext &Ctx,
187 MCStreamer &Out) override;
190 void X86AddressSanitizer64::InstrumentMemOperandImpl(
191 X86Operand *Op, unsigned AccessSize, bool IsWrite, MCContext &Ctx,
193 // FIXME: emit .cfi directives for correct stack unwinding.
194 // Set %rsp below current red zone (128 bytes wide)
195 EmitInstruction(Out, MCInstBuilder(X86::SUB64ri32).addReg(X86::RSP)
196 .addReg(X86::RSP).addImm(128));
197 EmitInstruction(Out, MCInstBuilder(X86::PUSH64r).addReg(X86::RDI));
200 Inst.setOpcode(X86::LEA64r);
201 Inst.addOperand(MCOperand::CreateReg(X86::RDI));
202 Op->addMemOperands(Inst, 5);
203 EmitInstruction(Out, Inst);
206 const std::string Func = FuncName(AccessSize, IsWrite);
207 const MCSymbol *FuncSym = Ctx.GetOrCreateSymbol(StringRef(Func));
208 const MCSymbolRefExpr *FuncExpr =
209 MCSymbolRefExpr::Create(FuncSym, MCSymbolRefExpr::VK_PLT, Ctx);
210 EmitInstruction(Out, MCInstBuilder(X86::CALL64pcrel32).addExpr(FuncExpr));
212 EmitInstruction(Out, MCInstBuilder(X86::POP64r).addReg(X86::RDI));
213 EmitInstruction(Out, MCInstBuilder(X86::ADD64ri32).addReg(X86::RSP)
214 .addReg(X86::RSP).addImm(128));
217 } // End anonymous namespace
219 X86AsmInstrumentation::X86AsmInstrumentation() {}
220 X86AsmInstrumentation::~X86AsmInstrumentation() {}
222 void X86AsmInstrumentation::InstrumentInstruction(
223 const MCInst &Inst, SmallVectorImpl<MCParsedAsmOperand *> &Operands,
224 MCContext &Ctx, MCStreamer &Out) {}
226 X86AsmInstrumentation *CreateX86AsmInstrumentation(MCSubtargetInfo &STI) {
227 if (ClAsanInstrumentInlineAssembly) {
228 if ((STI.getFeatureBits() & X86::Mode32Bit) != 0)
229 return new X86AddressSanitizer32(STI);
230 if ((STI.getFeatureBits() & X86::Mode64Bit) != 0)
231 return new X86AddressSanitizer64(STI);
233 return new X86AsmInstrumentation();
236 } // End llvm namespace