#include "llvm/ADT/Triple.h"
#include "llvm/CodeGen/MachineValueType.h"
#include "llvm/IR/Function.h"
+#include "llvm/MC/MCAsmInfo.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCInstBuilder.h"
#include "llvm/MC/MCTargetAsmParser.h"
#include "llvm/MC/MCTargetOptions.h"
#include "llvm/Support/CommandLine.h"
+#include <algorithm>
+#include <cassert>
+#include <vector>
+
+// Following comment describes how assembly instrumentation works.
+// Currently we have only AddressSanitizer instrumentation, but we're
+// planning to implement MemorySanitizer for inline assembly too. If
+// you're not familiar with AddressSanitizer algorithm, please, read
+// https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerAlgorithm.
+//
+// When inline assembly is parsed by an instance of X86AsmParser, all
+// instructions are emitted via EmitInstruction method. That's the
+// place where X86AsmInstrumentation analyzes an instruction and
+// decides, whether the instruction should be emitted as is or
+// instrumentation is required. The latter case happens when an
+// instruction reads from or writes to memory. Now instruction opcode
+// is explicitly checked, and if an instruction has a memory operand
+// (for instance, movq (%rsi, %rcx, 8), %rax) - it should be
+// instrumented. There're also exist instructions that modify
+// memory but don't have an explicit memory operands, for instance,
+// movs.
+//
+// Let's consider at first 8-byte memory accesses when an instruction
+// has an explicit memory operand. In this case we need two registers -
+// AddressReg to compute address of a memory cells which are accessed
+// and ShadowReg to compute corresponding shadow address. So, we need
+// to spill both registers before instrumentation code and restore them
+// after instrumentation. Thus, in general, instrumentation code will
+// look like this:
+// PUSHF # Store flags, otherwise they will be overwritten
+// PUSH AddressReg # spill AddressReg
+// PUSH ShadowReg # spill ShadowReg
+// LEA MemOp, AddressReg # compute address of the memory operand
+// MOV AddressReg, ShadowReg
+// SHR ShadowReg, 3
+// # ShadowOffset(AddressReg >> 3) contains address of a shadow
+// # corresponding to MemOp.
+// CMP ShadowOffset(ShadowReg), 0 # test shadow value
+// JZ .Done # when shadow equals to zero, everything is fine
+// MOV AddressReg, RDI
+// # Call __asan_report function with AddressReg as an argument
+// CALL __asan_report
+// .Done:
+// POP ShadowReg # Restore ShadowReg
+// POP AddressReg # Restore AddressReg
+// POPF # Restore flags
+//
+// Memory accesses with different size (1-, 2-, 4- and 16-byte) are
+// handled in a similar manner, but small memory accesses (less than 8
+// byte) require an additional ScratchReg, which is used for shadow value.
+//
+// If, suppose, we're instrumenting an instruction like movs, only
+// contents of RDI, RDI + AccessSize * RCX, RSI, RSI + AccessSize *
+// RCX are checked. In this case there're no need to spill and restore
+// AddressReg , ShadowReg or flags four times, they're saved on stack
+// just once, before instrumentation of these four addresses, and restored
+// at the end of the instrumentation.
+//
+// There exist several things which complicate this simple algorithm.
+// * Instrumented memory operand can have RSP as a base or an index
+// register. So we need to add a constant offset before computation
+// of memory address, since flags, AddressReg, ShadowReg, etc. were
+// already stored on stack and RSP was modified.
+// * Debug info (usually, DWARF) should be adjusted, because sometimes
+// RSP is used as a frame register. So, we need to select some
+// register as a frame register and temprorary override current CFA
+// register.
namespace llvm {
namespace {
cl::desc("instrument assembly with AddressSanitizer checks"), cl::Hidden,
cl::init(false));
-bool IsStackReg(unsigned Reg) {
- return Reg == X86::RSP || Reg == X86::ESP || Reg == X86::SP;
+const int64_t MinAllowedDisplacement = std::numeric_limits<int32_t>::min();
+const int64_t MaxAllowedDisplacement = std::numeric_limits<int32_t>::max();
+
+int64_t ApplyDisplacementBounds(int64_t Displacement) {
+ return std::max(std::min(MaxAllowedDisplacement, Displacement),
+ MinAllowedDisplacement);
+}
+
+void CheckDisplacementBounds(int64_t Displacement) {
+ assert(Displacement >= MinAllowedDisplacement &&
+ Displacement <= MaxAllowedDisplacement);
}
+bool IsStackReg(unsigned Reg) { return Reg == X86::RSP || Reg == X86::ESP; }
+
bool IsSmallMemAccess(unsigned AccessSize) { return AccessSize < 8; }
std::string FuncName(unsigned AccessSize, bool IsWrite) {
class X86AddressSanitizer : public X86AsmInstrumentation {
public:
struct RegisterContext {
+ private:
+ enum RegOffset {
+ REG_OFFSET_ADDRESS = 0,
+ REG_OFFSET_SHADOW,
+ REG_OFFSET_SCRATCH
+ };
+
+ public:
RegisterContext(unsigned AddressReg, unsigned ShadowReg,
- unsigned ScratchReg)
- : AddressReg(AddressReg), ShadowReg(ShadowReg), ScratchReg(ScratchReg) {
+ unsigned ScratchReg) {
+ BusyRegs.push_back(convReg(AddressReg, MVT::i64));
+ BusyRegs.push_back(convReg(ShadowReg, MVT::i64));
+ BusyRegs.push_back(convReg(ScratchReg, MVT::i64));
+ }
+
+ unsigned AddressReg(MVT::SimpleValueType VT) const {
+ return convReg(BusyRegs[REG_OFFSET_ADDRESS], VT);
+ }
+
+ unsigned ShadowReg(MVT::SimpleValueType VT) const {
+ return convReg(BusyRegs[REG_OFFSET_SHADOW], VT);
+ }
+
+ unsigned ScratchReg(MVT::SimpleValueType VT) const {
+ return convReg(BusyRegs[REG_OFFSET_SCRATCH], VT);
}
- unsigned addressReg(MVT::SimpleValueType VT) const {
- return getX86SubSuperRegister(AddressReg, VT);
+ void AddBusyReg(unsigned Reg) {
+ if (Reg != X86::NoRegister)
+ BusyRegs.push_back(convReg(Reg, MVT::i64));
}
- unsigned shadowReg(MVT::SimpleValueType VT) const {
- return getX86SubSuperRegister(ShadowReg, VT);
+ void AddBusyRegs(const X86Operand &Op) {
+ AddBusyReg(Op.getMemBaseReg());
+ AddBusyReg(Op.getMemIndexReg());
}
- unsigned scratchReg(MVT::SimpleValueType VT) const {
- return getX86SubSuperRegister(ScratchReg, VT);
+ unsigned ChooseFrameReg(MVT::SimpleValueType VT) const {
+ static const unsigned Candidates[] = { X86::RBP, X86::RAX, X86::RBX,
+ X86::RCX, X86::RDX, X86::RDI,
+ X86::RSI };
+ for (unsigned Reg : Candidates) {
+ if (!std::count(BusyRegs.begin(), BusyRegs.end(), Reg))
+ return convReg(Reg, VT);
+ }
+ return X86::NoRegister;
+ }
+
+ private:
+ unsigned convReg(unsigned Reg, MVT::SimpleValueType VT) const {
+ return Reg == X86::NoRegister ? Reg : getX86SubSuperRegister(Reg, VT);
}
- const unsigned AddressReg;
- const unsigned ShadowReg;
- const unsigned ScratchReg;
+ std::vector<unsigned> BusyRegs;
};
X86AddressSanitizer(const MCSubtargetInfo &STI)
- : X86AsmInstrumentation(STI), RepPrefix(false) {}
+ : X86AsmInstrumentation(STI), RepPrefix(false), OrigSPOffset(0) {}
+
virtual ~X86AddressSanitizer() {}
// X86AsmInstrumentation implementation:
EmitInstruction(Out, Inst);
}
- // Should be implemented differently in x86_32 and x86_64 subclasses.
- virtual void StoreFlags(MCStreamer &Out) = 0;
-
- virtual void RestoreFlags(MCStreamer &Out) = 0;
-
// Adjusts up stack and saves all registers used in instrumentation.
virtual void InstrumentMemOperandPrologue(const RegisterContext &RegCtx,
MCContext &Ctx,
protected:
void EmitLabel(MCStreamer &Out, MCSymbol *Label) { Out.EmitLabel(Label); }
+ void EmitLEA(X86Operand &Op, MVT::SimpleValueType VT, unsigned Reg,
+ MCStreamer &Out) {
+ assert(VT == MVT::i32 || VT == MVT::i64);
+ MCInst Inst;
+ Inst.setOpcode(VT == MVT::i32 ? X86::LEA32r : X86::LEA64r);
+ Inst.addOperand(MCOperand::CreateReg(getX86SubSuperRegister(Reg, VT)));
+ Op.addMemOperands(Inst, 5);
+ EmitInstruction(Out, Inst);
+ }
+
+ void ComputeMemOperandAddress(X86Operand &Op, MVT::SimpleValueType VT,
+ unsigned Reg, MCContext &Ctx, MCStreamer &Out);
+
+ // Creates new memory operand with Displacement added to an original
+ // displacement. Residue will contain a residue which could happen when the
+ // total displacement exceeds 32-bit limitation.
+ std::unique_ptr<X86Operand> AddDisplacement(X86Operand &Op,
+ int64_t Displacement,
+ MCContext &Ctx, int64_t *Residue);
+
// True when previous instruction was actually REP prefix.
bool RepPrefix;
+
+ // Offset from the original SP register.
+ int64_t OrigSPOffset;
};
void X86AddressSanitizer::InstrumentMemOperand(
IsSmallMemAccess(AccessSize)
? X86::RBX
: X86::NoRegister /* ScratchReg */);
+ RegCtx.AddBusyReg(DstReg);
+ RegCtx.AddBusyReg(SrcReg);
+ RegCtx.AddBusyReg(CntReg);
InstrumentMemOperandPrologue(RegCtx, Ctx, Out);
}
const bool IsWrite = MII.get(Inst.getOpcode()).mayStore();
- RegisterContext RegCtx(X86::RDI /* AddressReg */, X86::RAX /* ShadowReg */,
- IsSmallMemAccess(AccessSize)
- ? X86::RCX
- : X86::NoRegister /* ScratchReg */);
for (unsigned Ix = 0; Ix < Operands.size(); ++Ix) {
assert(Operands[Ix]);
MCParsedAsmOperand &Op = *Operands[Ix];
if (Op.isMem()) {
X86Operand &MemOp = static_cast<X86Operand &>(Op);
- // FIXME: get rid of this limitation.
- if (IsStackReg(MemOp.getMemBaseReg()) ||
- IsStackReg(MemOp.getMemIndexReg())) {
- continue;
- }
-
+ RegisterContext RegCtx(
+ X86::RDI /* AddressReg */, X86::RAX /* ShadowReg */,
+ IsSmallMemAccess(AccessSize) ? X86::RCX
+ : X86::NoRegister /* ScratchReg */);
+ RegCtx.AddBusyRegs(MemOp);
InstrumentMemOperandPrologue(RegCtx, Ctx, Out);
InstrumentMemOperand(MemOp, AccessSize, IsWrite, RegCtx, Ctx, Out);
InstrumentMemOperandEpilogue(RegCtx, Ctx, Out);
}
}
+void X86AddressSanitizer::ComputeMemOperandAddress(X86Operand &Op,
+ MVT::SimpleValueType VT,
+ unsigned Reg, MCContext &Ctx,
+ MCStreamer &Out) {
+ int64_t Displacement = 0;
+ if (IsStackReg(Op.getMemBaseReg()))
+ Displacement -= OrigSPOffset;
+ if (IsStackReg(Op.getMemIndexReg()))
+ Displacement -= OrigSPOffset * Op.getMemScale();
+
+ assert(Displacement >= 0);
+
+ // Emit Op as is.
+ if (Displacement == 0) {
+ EmitLEA(Op, VT, Reg, Out);
+ return;
+ }
+
+ int64_t Residue;
+ std::unique_ptr<X86Operand> NewOp =
+ AddDisplacement(Op, Displacement, Ctx, &Residue);
+ EmitLEA(*NewOp, VT, Reg, Out);
+
+ while (Residue != 0) {
+ const MCConstantExpr *Disp =
+ MCConstantExpr::Create(ApplyDisplacementBounds(Residue), Ctx);
+ std::unique_ptr<X86Operand> DispOp =
+ X86Operand::CreateMem(0, Disp, Reg, 0, 1, SMLoc(), SMLoc());
+ EmitLEA(*DispOp, VT, Reg, Out);
+ Residue -= Disp->getValue();
+ }
+}
+
+std::unique_ptr<X86Operand>
+X86AddressSanitizer::AddDisplacement(X86Operand &Op, int64_t Displacement,
+ MCContext &Ctx, int64_t *Residue) {
+ assert(Displacement >= 0);
+
+ if (Displacement == 0 ||
+ (Op.getMemDisp() && Op.getMemDisp()->getKind() != MCExpr::Constant)) {
+ *Residue = Displacement;
+ return X86Operand::CreateMem(Op.getMemSegReg(), Op.getMemDisp(),
+ Op.getMemBaseReg(), Op.getMemIndexReg(),
+ Op.getMemScale(), SMLoc(), SMLoc());
+ }
+
+ int64_t OrigDisplacement =
+ static_cast<const MCConstantExpr *>(Op.getMemDisp())->getValue();
+ CheckDisplacementBounds(OrigDisplacement);
+ Displacement += OrigDisplacement;
+
+ int64_t NewDisplacement = ApplyDisplacementBounds(Displacement);
+ CheckDisplacementBounds(NewDisplacement);
+
+ *Residue = Displacement - NewDisplacement;
+ const MCExpr *Disp = MCConstantExpr::Create(NewDisplacement, Ctx);
+ return X86Operand::CreateMem(Op.getMemSegReg(), Disp, Op.getMemBaseReg(),
+ Op.getMemIndexReg(), Op.getMemScale(), SMLoc(),
+ SMLoc());
+}
+
class X86AddressSanitizer32 : public X86AddressSanitizer {
public:
static const long kShadowOffset = 0x20000000;
virtual ~X86AddressSanitizer32() {}
- virtual void StoreFlags(MCStreamer &Out) override {
+ unsigned GetFrameReg(const MCContext &Ctx, MCStreamer &Out) {
+ unsigned FrameReg = GetFrameRegGeneric(Ctx, Out);
+ if (FrameReg == X86::NoRegister)
+ return FrameReg;
+ return getX86SubSuperRegister(FrameReg, MVT::i32);
+ }
+
+ void SpillReg(MCStreamer &Out, unsigned Reg) {
+ EmitInstruction(Out, MCInstBuilder(X86::PUSH32r).addReg(Reg));
+ OrigSPOffset -= 4;
+ }
+
+ void RestoreReg(MCStreamer &Out, unsigned Reg) {
+ EmitInstruction(Out, MCInstBuilder(X86::POP32r).addReg(Reg));
+ OrigSPOffset += 4;
+ }
+
+ void StoreFlags(MCStreamer &Out) {
EmitInstruction(Out, MCInstBuilder(X86::PUSHF32));
+ OrigSPOffset -= 4;
}
- virtual void RestoreFlags(MCStreamer &Out) override {
+ void RestoreFlags(MCStreamer &Out) {
EmitInstruction(Out, MCInstBuilder(X86::POPF32));
+ OrigSPOffset += 4;
}
virtual void InstrumentMemOperandPrologue(const RegisterContext &RegCtx,
MCContext &Ctx,
MCStreamer &Out) override {
- const MCRegisterInfo* MRI = Ctx.getRegisterInfo();
+ unsigned LocalFrameReg = RegCtx.ChooseFrameReg(MVT::i32);
+ assert(LocalFrameReg != X86::NoRegister);
+
+ const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
+ unsigned FrameReg = GetFrameReg(Ctx, Out);
if (MRI && FrameReg != X86::NoRegister) {
- EmitInstruction(
- Out, MCInstBuilder(X86::PUSH32r).addReg(X86::EBP));
+ SpillReg(Out, LocalFrameReg);
if (FrameReg == X86::ESP) {
- Out.EmitCFIAdjustCfaOffset(4 /* byte size of the FrameReg */);
+ Out.EmitCFIAdjustCfaOffset(4 /* byte size of the LocalFrameReg */);
Out.EmitCFIRelOffset(
- MRI->getDwarfRegNum(X86::EBP, true /* IsEH */), 0);
+ MRI->getDwarfRegNum(LocalFrameReg, true /* IsEH */), 0);
}
EmitInstruction(
- Out, MCInstBuilder(X86::MOV32rr).addReg(X86::EBP).addReg(FrameReg));
+ Out,
+ MCInstBuilder(X86::MOV32rr).addReg(LocalFrameReg).addReg(FrameReg));
Out.EmitCFIRememberState();
Out.EmitCFIDefCfaRegister(
- MRI->getDwarfRegNum(X86::EBP, true /* IsEH */));
+ MRI->getDwarfRegNum(LocalFrameReg, true /* IsEH */));
}
- EmitInstruction(
- Out, MCInstBuilder(X86::PUSH32r).addReg(RegCtx.addressReg(MVT::i32)));
- EmitInstruction(
- Out, MCInstBuilder(X86::PUSH32r).addReg(RegCtx.shadowReg(MVT::i32)));
- if (RegCtx.ScratchReg != X86::NoRegister) {
- EmitInstruction(
- Out, MCInstBuilder(X86::PUSH32r).addReg(RegCtx.scratchReg(MVT::i32)));
- }
+ SpillReg(Out, RegCtx.AddressReg(MVT::i32));
+ SpillReg(Out, RegCtx.ShadowReg(MVT::i32));
+ if (RegCtx.ScratchReg(MVT::i32) != X86::NoRegister)
+ SpillReg(Out, RegCtx.ScratchReg(MVT::i32));
StoreFlags(Out);
}
virtual void InstrumentMemOperandEpilogue(const RegisterContext &RegCtx,
MCContext &Ctx,
MCStreamer &Out) override {
+ unsigned LocalFrameReg = RegCtx.ChooseFrameReg(MVT::i32);
+ assert(LocalFrameReg != X86::NoRegister);
+
RestoreFlags(Out);
- if (RegCtx.ScratchReg != X86::NoRegister) {
- EmitInstruction(
- Out, MCInstBuilder(X86::POP32r).addReg(RegCtx.scratchReg(MVT::i32)));
- }
- EmitInstruction(
- Out, MCInstBuilder(X86::POP32r).addReg(RegCtx.shadowReg(MVT::i32)));
- EmitInstruction(
- Out, MCInstBuilder(X86::POP32r).addReg(RegCtx.addressReg(MVT::i32)));
+ if (RegCtx.ScratchReg(MVT::i32) != X86::NoRegister)
+ RestoreReg(Out, RegCtx.ScratchReg(MVT::i32));
+ RestoreReg(Out, RegCtx.ShadowReg(MVT::i32));
+ RestoreReg(Out, RegCtx.AddressReg(MVT::i32));
+ unsigned FrameReg = GetFrameReg(Ctx, Out);
if (Ctx.getRegisterInfo() && FrameReg != X86::NoRegister) {
- EmitInstruction(
- Out, MCInstBuilder(X86::POP32r).addReg(X86::EBP));
+ RestoreReg(Out, LocalFrameReg);
Out.EmitCFIRestoreState();
if (FrameReg == X86::ESP)
- Out.EmitCFIAdjustCfaOffset(-4 /* byte size of the FrameReg */);
+ Out.EmitCFIAdjustCfaOffset(-4 /* byte size of the LocalFrameReg */);
}
}
.addReg(X86::ESP)
.addImm(-16));
EmitInstruction(
- Out, MCInstBuilder(X86::PUSH32r).addReg(RegCtx.addressReg(MVT::i32)));
+ Out, MCInstBuilder(X86::PUSH32r).addReg(RegCtx.AddressReg(MVT::i32)));
const std::string &Fn = FuncName(AccessSize, IsWrite);
MCSymbol *FnSym = Ctx.GetOrCreateSymbol(StringRef(Fn));
void X86AddressSanitizer32::InstrumentMemOperandSmall(
X86Operand &Op, unsigned AccessSize, bool IsWrite,
const RegisterContext &RegCtx, MCContext &Ctx, MCStreamer &Out) {
- unsigned AddressRegI32 = RegCtx.addressReg(MVT::i32);
- unsigned ShadowRegI32 = RegCtx.shadowReg(MVT::i32);
- unsigned ShadowRegI8 = RegCtx.shadowReg(MVT::i8);
+ unsigned AddressRegI32 = RegCtx.AddressReg(MVT::i32);
+ unsigned ShadowRegI32 = RegCtx.ShadowReg(MVT::i32);
+ unsigned ShadowRegI8 = RegCtx.ShadowReg(MVT::i8);
- assert(RegCtx.ScratchReg != X86::NoRegister);
- unsigned ScratchRegI32 = RegCtx.scratchReg(MVT::i32);
+ assert(RegCtx.ScratchReg(MVT::i32) != X86::NoRegister);
+ unsigned ScratchRegI32 = RegCtx.ScratchReg(MVT::i32);
- {
- MCInst Inst;
- Inst.setOpcode(X86::LEA32r);
- Inst.addOperand(MCOperand::CreateReg(AddressRegI32));
- Op.addMemOperands(Inst, 5);
- EmitInstruction(Out, Inst);
- }
+ ComputeMemOperandAddress(Op, MVT::i32, AddressRegI32, Ctx, Out);
EmitInstruction(Out, MCInstBuilder(X86::MOV32rr).addReg(ShadowRegI32).addReg(
AddressRegI32));
case 1:
break;
case 2: {
- MCInst Inst;
- Inst.setOpcode(X86::LEA32r);
- Inst.addOperand(MCOperand::CreateReg(ScratchRegI32));
-
const MCExpr *Disp = MCConstantExpr::Create(1, Ctx);
std::unique_ptr<X86Operand> Op(
X86Operand::CreateMem(0, Disp, ScratchRegI32, 0, 1, SMLoc(), SMLoc()));
- Op->addMemOperands(Inst, 5);
- EmitInstruction(Out, Inst);
+ EmitLEA(*Op, MVT::i32, ScratchRegI32, Out);
break;
}
case 4:
void X86AddressSanitizer32::InstrumentMemOperandLarge(
X86Operand &Op, unsigned AccessSize, bool IsWrite,
const RegisterContext &RegCtx, MCContext &Ctx, MCStreamer &Out) {
- unsigned AddressRegI32 = RegCtx.addressReg(MVT::i32);
- unsigned ShadowRegI32 = RegCtx.shadowReg(MVT::i32);
+ unsigned AddressRegI32 = RegCtx.AddressReg(MVT::i32);
+ unsigned ShadowRegI32 = RegCtx.ShadowReg(MVT::i32);
- {
- MCInst Inst;
- Inst.setOpcode(X86::LEA32r);
- Inst.addOperand(MCOperand::CreateReg(AddressRegI32));
- Op.addMemOperands(Inst, 5);
- EmitInstruction(Out, Inst);
- }
+ ComputeMemOperandAddress(Op, MVT::i32, AddressRegI32, Ctx, Out);
EmitInstruction(Out, MCInstBuilder(X86::MOV32rr).addReg(ShadowRegI32).addReg(
AddressRegI32));
virtual ~X86AddressSanitizer64() {}
- virtual void StoreFlags(MCStreamer &Out) override {
+ unsigned GetFrameReg(const MCContext &Ctx, MCStreamer &Out) {
+ unsigned FrameReg = GetFrameRegGeneric(Ctx, Out);
+ if (FrameReg == X86::NoRegister)
+ return FrameReg;
+ return getX86SubSuperRegister(FrameReg, MVT::i64);
+ }
+
+ void SpillReg(MCStreamer &Out, unsigned Reg) {
+ EmitInstruction(Out, MCInstBuilder(X86::PUSH64r).addReg(Reg));
+ OrigSPOffset -= 8;
+ }
+
+ void RestoreReg(MCStreamer &Out, unsigned Reg) {
+ EmitInstruction(Out, MCInstBuilder(X86::POP64r).addReg(Reg));
+ OrigSPOffset += 8;
+ }
+
+ void StoreFlags(MCStreamer &Out) {
EmitInstruction(Out, MCInstBuilder(X86::PUSHF64));
+ OrigSPOffset -= 8;
}
- virtual void RestoreFlags(MCStreamer &Out) override {
+ void RestoreFlags(MCStreamer &Out) {
EmitInstruction(Out, MCInstBuilder(X86::POPF64));
+ OrigSPOffset += 8;
}
virtual void InstrumentMemOperandPrologue(const RegisterContext &RegCtx,
MCContext &Ctx,
MCStreamer &Out) override {
- const MCRegisterInfo *RegisterInfo = Ctx.getRegisterInfo();
- if (RegisterInfo && FrameReg != X86::NoRegister) {
- EmitInstruction(Out, MCInstBuilder(X86::PUSH64r).addReg(X86::RBP));
+ unsigned LocalFrameReg = RegCtx.ChooseFrameReg(MVT::i64);
+ assert(LocalFrameReg != X86::NoRegister);
+
+ const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
+ unsigned FrameReg = GetFrameReg(Ctx, Out);
+ if (MRI && FrameReg != X86::NoRegister) {
+ SpillReg(Out, X86::RBP);
if (FrameReg == X86::RSP) {
- Out.EmitCFIAdjustCfaOffset(8 /* byte size of the FrameReg */);
+ Out.EmitCFIAdjustCfaOffset(8 /* byte size of the LocalFrameReg */);
Out.EmitCFIRelOffset(
- RegisterInfo->getDwarfRegNum(X86::RBP, true /* IsEH */), 0);
+ MRI->getDwarfRegNum(LocalFrameReg, true /* IsEH */), 0);
}
EmitInstruction(
- Out, MCInstBuilder(X86::MOV64rr).addReg(X86::RBP).addReg(FrameReg));
+ Out,
+ MCInstBuilder(X86::MOV64rr).addReg(LocalFrameReg).addReg(FrameReg));
Out.EmitCFIRememberState();
Out.EmitCFIDefCfaRegister(
- RegisterInfo->getDwarfRegNum(X86::RBP, true /* IsEH */));
+ MRI->getDwarfRegNum(LocalFrameReg, true /* IsEH */));
}
EmitAdjustRSP(Ctx, Out, -128);
- EmitInstruction(
- Out, MCInstBuilder(X86::PUSH64r).addReg(RegCtx.shadowReg(MVT::i64)));
- EmitInstruction(
- Out, MCInstBuilder(X86::PUSH64r).addReg(RegCtx.addressReg(MVT::i64)));
- if (RegCtx.ScratchReg != X86::NoRegister) {
- EmitInstruction(
- Out, MCInstBuilder(X86::PUSH64r).addReg(RegCtx.scratchReg(MVT::i64)));
- }
+ SpillReg(Out, RegCtx.ShadowReg(MVT::i64));
+ SpillReg(Out, RegCtx.AddressReg(MVT::i64));
+ if (RegCtx.ScratchReg(MVT::i64) != X86::NoRegister)
+ SpillReg(Out, RegCtx.ScratchReg(MVT::i64));
StoreFlags(Out);
}
virtual void InstrumentMemOperandEpilogue(const RegisterContext &RegCtx,
MCContext &Ctx,
MCStreamer &Out) override {
+ unsigned LocalFrameReg = RegCtx.ChooseFrameReg(MVT::i64);
+ assert(LocalFrameReg != X86::NoRegister);
+
RestoreFlags(Out);
- if (RegCtx.ScratchReg != X86::NoRegister) {
- EmitInstruction(
- Out, MCInstBuilder(X86::POP64r).addReg(RegCtx.scratchReg(MVT::i64)));
- }
- EmitInstruction(
- Out, MCInstBuilder(X86::POP64r).addReg(RegCtx.addressReg(MVT::i64)));
- EmitInstruction(
- Out, MCInstBuilder(X86::POP64r).addReg(RegCtx.shadowReg(MVT::i64)));
+ if (RegCtx.ScratchReg(MVT::i64) != X86::NoRegister)
+ RestoreReg(Out, RegCtx.ScratchReg(MVT::i64));
+ RestoreReg(Out, RegCtx.AddressReg(MVT::i64));
+ RestoreReg(Out, RegCtx.ShadowReg(MVT::i64));
EmitAdjustRSP(Ctx, Out, 128);
+ unsigned FrameReg = GetFrameReg(Ctx, Out);
if (Ctx.getRegisterInfo() && FrameReg != X86::NoRegister) {
- EmitInstruction(
- Out, MCInstBuilder(X86::POP64r).addReg(X86::RBP));
+ RestoreReg(Out, LocalFrameReg);
Out.EmitCFIRestoreState();
if (FrameReg == X86::RSP)
- Out.EmitCFIAdjustCfaOffset(-8 /* byte size of the FrameReg */);
+ Out.EmitCFIAdjustCfaOffset(-8 /* byte size of the LocalFrameReg */);
}
}
private:
void EmitAdjustRSP(MCContext &Ctx, MCStreamer &Out, long Offset) {
- MCInst Inst;
- Inst.setOpcode(X86::LEA64r);
- Inst.addOperand(MCOperand::CreateReg(X86::RSP));
-
const MCExpr *Disp = MCConstantExpr::Create(Offset, Ctx);
std::unique_ptr<X86Operand> Op(
X86Operand::CreateMem(0, Disp, X86::RSP, 0, 1, SMLoc(), SMLoc()));
- Op->addMemOperands(Inst, 5);
- EmitInstruction(Out, Inst);
+ EmitLEA(*Op, MVT::i64, X86::RSP, Out);
+ OrigSPOffset += Offset;
}
void EmitCallAsanReport(unsigned AccessSize, bool IsWrite, MCContext &Ctx,
.addReg(X86::RSP)
.addImm(-16));
- if (RegCtx.AddressReg != X86::RDI) {
+ if (RegCtx.AddressReg(MVT::i64) != X86::RDI) {
EmitInstruction(Out, MCInstBuilder(X86::MOV64rr).addReg(X86::RDI).addReg(
- RegCtx.addressReg(MVT::i64)));
+ RegCtx.AddressReg(MVT::i64)));
}
const std::string &Fn = FuncName(AccessSize, IsWrite);
MCSymbol *FnSym = Ctx.GetOrCreateSymbol(StringRef(Fn));
void X86AddressSanitizer64::InstrumentMemOperandSmall(
X86Operand &Op, unsigned AccessSize, bool IsWrite,
const RegisterContext &RegCtx, MCContext &Ctx, MCStreamer &Out) {
- unsigned AddressRegI64 = RegCtx.addressReg(MVT::i64);
- unsigned AddressRegI32 = RegCtx.addressReg(MVT::i32);
- unsigned ShadowRegI64 = RegCtx.shadowReg(MVT::i64);
- unsigned ShadowRegI32 = RegCtx.shadowReg(MVT::i32);
- unsigned ShadowRegI8 = RegCtx.shadowReg(MVT::i8);
+ unsigned AddressRegI64 = RegCtx.AddressReg(MVT::i64);
+ unsigned AddressRegI32 = RegCtx.AddressReg(MVT::i32);
+ unsigned ShadowRegI64 = RegCtx.ShadowReg(MVT::i64);
+ unsigned ShadowRegI32 = RegCtx.ShadowReg(MVT::i32);
+ unsigned ShadowRegI8 = RegCtx.ShadowReg(MVT::i8);
- assert(RegCtx.ScratchReg != X86::NoRegister);
- unsigned ScratchRegI32 = RegCtx.scratchReg(MVT::i32);
+ assert(RegCtx.ScratchReg(MVT::i32) != X86::NoRegister);
+ unsigned ScratchRegI32 = RegCtx.ScratchReg(MVT::i32);
+
+ ComputeMemOperandAddress(Op, MVT::i64, AddressRegI64, Ctx, Out);
- {
- MCInst Inst;
- Inst.setOpcode(X86::LEA64r);
- Inst.addOperand(MCOperand::CreateReg(AddressRegI64));
- Op.addMemOperands(Inst, 5);
- EmitInstruction(Out, Inst);
- }
EmitInstruction(Out, MCInstBuilder(X86::MOV64rr).addReg(ShadowRegI64).addReg(
AddressRegI64));
EmitInstruction(Out, MCInstBuilder(X86::SHR64ri)
case 1:
break;
case 2: {
- MCInst Inst;
- Inst.setOpcode(X86::LEA32r);
- Inst.addOperand(MCOperand::CreateReg(ScratchRegI32));
-
const MCExpr *Disp = MCConstantExpr::Create(1, Ctx);
std::unique_ptr<X86Operand> Op(
X86Operand::CreateMem(0, Disp, ScratchRegI32, 0, 1, SMLoc(), SMLoc()));
- Op->addMemOperands(Inst, 5);
- EmitInstruction(Out, Inst);
+ EmitLEA(*Op, MVT::i32, ScratchRegI32, Out);
break;
}
case 4:
void X86AddressSanitizer64::InstrumentMemOperandLarge(
X86Operand &Op, unsigned AccessSize, bool IsWrite,
const RegisterContext &RegCtx, MCContext &Ctx, MCStreamer &Out) {
- unsigned AddressRegI64 = RegCtx.addressReg(MVT::i64);
- unsigned ShadowRegI64 = RegCtx.shadowReg(MVT::i64);
+ unsigned AddressRegI64 = RegCtx.AddressReg(MVT::i64);
+ unsigned ShadowRegI64 = RegCtx.ShadowReg(MVT::i64);
+
+ ComputeMemOperandAddress(Op, MVT::i64, AddressRegI64, Ctx, Out);
- {
- MCInst Inst;
- Inst.setOpcode(X86::LEA64r);
- Inst.addOperand(MCOperand::CreateReg(AddressRegI64));
- Op.addMemOperands(Inst, 5);
- EmitInstruction(Out, Inst);
- }
EmitInstruction(Out, MCInstBuilder(X86::MOV64rr).addReg(ShadowRegI64).addReg(
AddressRegI64));
EmitInstruction(Out, MCInstBuilder(X86::SHR64ri)
} // End anonymous namespace
X86AsmInstrumentation::X86AsmInstrumentation(const MCSubtargetInfo &STI)
- : STI(STI), FrameReg(X86::NoRegister) {}
+ : STI(STI), InitialFrameReg(0) {}
X86AsmInstrumentation::~X86AsmInstrumentation() {}
Out.EmitInstruction(Inst, STI);
}
+unsigned X86AsmInstrumentation::GetFrameRegGeneric(const MCContext &Ctx,
+ MCStreamer &Out) {
+ if (!Out.getNumFrameInfos()) // No active dwarf frame
+ return X86::NoRegister;
+ const MCDwarfFrameInfo &Frame = Out.getDwarfFrameInfos().back();
+ if (Frame.End) // Active dwarf frame is closed
+ return X86::NoRegister;
+ const MCRegisterInfo *MRI = Ctx.getRegisterInfo();
+ if (!MRI) // No register info
+ return X86::NoRegister;
+
+ if (InitialFrameReg) {
+ // FrameReg is set explicitly, we're instrumenting a MachineFunction.
+ return InitialFrameReg;
+ }
+
+ return MRI->getLLVMRegNum(Frame.CurrentCfaRegister, true /* IsEH */);
+}
+
X86AsmInstrumentation *
CreateX86AsmInstrumentation(const MCTargetOptions &MCOptions,
const MCContext &Ctx, const MCSubtargetInfo &STI) {