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[BOLT][AArch64] Handle PAuth call instructions in isIndirectCall #133227

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Merged
merged 1 commit into from
Apr 8, 2025
Merged

[BOLT][AArch64] Handle PAuth call instructions in isIndirectCall #133227

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10 changes: 5 additions & 5 deletions bolt/include/bolt/Core/MCPlusBuilder.h
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Original file line number Diff line number Diff line change
Expand Up @@ -577,12 +577,12 @@ class MCPlusBuilder {
return getNoRegister();
}

/// Returns the register used as call destination, or no-register, if not
/// an indirect call. Sets IsAuthenticatedInternally if the instruction
/// accepts a signed pointer as its operand and authenticates it internally.
/// Returns the register used as the destination of an indirect branch or call
/// instruction. Sets IsAuthenticatedInternally if the instruction accepts
/// a signed pointer as its operand and authenticates it internally.
virtual MCPhysReg
getRegUsedAsCallDest(const MCInst &Inst,
bool &IsAuthenticatedInternally) const {
getRegUsedAsIndirectBranchDest(const MCInst &Inst,
bool &IsAuthenticatedInternally) const {
llvm_unreachable("not implemented");
return getNoRegister();
}
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8 changes: 5 additions & 3 deletions bolt/lib/Passes/PAuthGadgetScanner.cpp
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Expand Up @@ -457,14 +457,16 @@ static std::shared_ptr<Report>
shouldReportCallGadget(const BinaryContext &BC, const MCInstReference &Inst,
const State &S) {
static const GadgetKind CallKind("non-protected call found");
if (!BC.MIB->isCall(Inst) && !BC.MIB->isBranch(Inst))
if (!BC.MIB->isIndirectCall(Inst) && !BC.MIB->isIndirectBranch(Inst))
return nullptr;

bool IsAuthenticated = false;
MCPhysReg DestReg = BC.MIB->getRegUsedAsCallDest(Inst, IsAuthenticated);
if (IsAuthenticated || DestReg == BC.MIB->getNoRegister())
MCPhysReg DestReg =
BC.MIB->getRegUsedAsIndirectBranchDest(Inst, IsAuthenticated);
if (IsAuthenticated)
return nullptr;

assert(DestReg != BC.MIB->getNoRegister());
LLVM_DEBUG({
traceInst(BC, "Found call inst", Inst);
traceReg(BC, "Call destination reg", DestReg);
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16 changes: 7 additions & 9 deletions bolt/lib/Target/AArch64/AArch64MCPlusBuilder.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@
//
//===----------------------------------------------------------------------===//

#include "AArch64InstrInfo.h"
#include "AArch64MCSymbolizer.h"
#include "MCTargetDesc/AArch64AddressingModes.h"
#include "MCTargetDesc/AArch64FixupKinds.h"
Expand Down Expand Up @@ -277,15 +278,14 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
}
}

MCPhysReg
getRegUsedAsCallDest(const MCInst &Inst,
bool &IsAuthenticatedInternally) const override {
assert(isCall(Inst) || isBranch(Inst));
IsAuthenticatedInternally = false;
MCPhysReg getRegUsedAsIndirectBranchDest(
const MCInst &Inst, bool &IsAuthenticatedInternally) const override {
assert(isIndirectCall(Inst) || isIndirectBranch(Inst));

switch (Inst.getOpcode()) {
case AArch64::BR:
case AArch64::BLR:
IsAuthenticatedInternally = false;
return Inst.getOperand(0).getReg();
case AArch64::BRAA:
case AArch64::BRAB:
Expand All @@ -298,9 +298,7 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
IsAuthenticatedInternally = true;
return Inst.getOperand(0).getReg();
default:
if (isIndirectCall(Inst) || isIndirectBranch(Inst))
llvm_unreachable("Unhandled indirect branch");
return getNoRegister();
llvm_unreachable("Unhandled indirect branch or call");
}
}

Expand Down Expand Up @@ -662,7 +660,7 @@ class AArch64MCPlusBuilder : public MCPlusBuilder {
}

bool isIndirectCall(const MCInst &Inst) const override {
return Inst.getOpcode() == AArch64::BLR;
return isIndirectCallOpcode(Inst.getOpcode());
}

MCPhysReg getSpRegister(int Size) const {
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13 changes: 13 additions & 0 deletions llvm/lib/Target/AArch64/AArch64InstrInfo.h
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Expand Up @@ -726,6 +726,19 @@ static inline bool isIndirectBranchOpcode(int Opc) {
return false;
}

static inline bool isIndirectCallOpcode(unsigned Opc) {
switch (Opc) {
case AArch64::BLR:
case AArch64::BLRAA:
case AArch64::BLRAB:
case AArch64::BLRAAZ:
case AArch64::BLRABZ:
return true;
default:
return false;
}
}

static inline bool isPTrueOpcode(unsigned Opc) {
switch (Opc) {
case AArch64::PTRUE_B:
Expand Down