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llvm/lib/Target/AArch64/AArch64BranchTargets.cpp
| Show All 10 Lines | |||||
| // trap when an indirect branch or call instruction targets an instruction | // trap when an indirect branch or call instruction targets an instruction | ||||
| // which is not a valid BTI instruction. This is intended to guard against | // which is not a valid BTI instruction. This is intended to guard against | ||||
| // control-flow hijacking attacks. Note that this does not do anything for RET | // control-flow hijacking attacks. Note that this does not do anything for RET | ||||
| // instructions, as they can be more precisely protected by return address | // instructions, as they can be more precisely protected by return address | ||||
| // signing. | // signing. | ||||
| // | // | ||||
| //===----------------------------------------------------------------------===// | //===----------------------------------------------------------------------===// | ||||
| #include "AArch64MachineFunctionInfo.h" | |||||
| #include "AArch64Subtarget.h" | #include "AArch64Subtarget.h" | ||||
| #include "llvm/CodeGen/MachineFunctionPass.h" | #include "llvm/CodeGen/MachineFunctionPass.h" | ||||
| #include "llvm/CodeGen/MachineInstrBuilder.h" | #include "llvm/CodeGen/MachineInstrBuilder.h" | ||||
| #include "llvm/CodeGen/MachineJumpTableInfo.h" | #include "llvm/CodeGen/MachineJumpTableInfo.h" | ||||
| #include "llvm/CodeGen/MachineModuleInfo.h" | #include "llvm/CodeGen/MachineModuleInfo.h" | ||||
| #include "llvm/Support/Debug.h" | #include "llvm/Support/Debug.h" | ||||
| using namespace llvm; | using namespace llvm; | ||||
| Show All 25 Lines | void AArch64BranchTargets::getAnalysisUsage(AnalysisUsage &AU) const { | ||||
| MachineFunctionPass::getAnalysisUsage(AU); | MachineFunctionPass::getAnalysisUsage(AU); | ||||
| } | } | ||||
| FunctionPass *llvm::createAArch64BranchTargetsPass() { | FunctionPass *llvm::createAArch64BranchTargetsPass() { | ||||
| return new AArch64BranchTargets(); | return new AArch64BranchTargets(); | ||||
| } | } | ||||
| bool AArch64BranchTargets::runOnMachineFunction(MachineFunction &MF) { | bool AArch64BranchTargets::runOnMachineFunction(MachineFunction &MF) { | ||||
| const Function &F = MF.getFunction(); | if (!MF.getInfo<AArch64FunctionInfo>()->branchTargetEnforcement()) | ||||
| if (!F.hasFnAttribute("branch-target-enforcement")) | |||||
| return false; | return false; | ||||
| LLVM_DEBUG( | LLVM_DEBUG( | ||||
| dbgs() << "********** AArch64 Branch Targets **********\n" | dbgs() << "********** AArch64 Branch Targets **********\n" | ||||
| << "********** Function: " << MF.getName() << '\n'); | << "********** Function: " << MF.getName() << '\n'); | ||||
| const Function &F = MF.getFunction(); | |||||
| // LLVM does not consider basic blocks which are the targets of jump tables | // LLVM does not consider basic blocks which are the targets of jump tables | ||||
| // to be address-taken (the address can't escape anywhere else), but they are | // to be address-taken (the address can't escape anywhere else), but they are | ||||
| // used for indirect branches, so need BTI instructions. | // used for indirect branches, so need BTI instructions. | ||||
| SmallPtrSet<MachineBasicBlock *, 8> JumpTableTargets; | SmallPtrSet<MachineBasicBlock *, 8> JumpTableTargets; | ||||
| if (auto *JTI = MF.getJumpTableInfo()) | if (auto *JTI = MF.getJumpTableInfo()) | ||||
| for (auto &JTE : JTI->getJumpTables()) | for (auto &JTE : JTI->getJumpTables()) | ||||
| for (auto *MBB : JTE.MBBs) | for (auto *MBB : JTE.MBBs) | ||||
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