diff options
Diffstat (limited to 'contrib/llvm-project/llvm/lib/CodeGen/SanitizerBinaryMetadata.cpp')
-rw-r--r-- | contrib/llvm-project/llvm/lib/CodeGen/SanitizerBinaryMetadata.cpp | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/contrib/llvm-project/llvm/lib/CodeGen/SanitizerBinaryMetadata.cpp b/contrib/llvm-project/llvm/lib/CodeGen/SanitizerBinaryMetadata.cpp new file mode 100644 index 000000000000..cc29bdce1210 --- /dev/null +++ b/contrib/llvm-project/llvm/lib/CodeGen/SanitizerBinaryMetadata.cpp @@ -0,0 +1,87 @@ +//===- SanitizerBinaryMetadata.cpp +//----------------------------------------------===// +// +// 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 is a part of SanitizerBinaryMetadata. +// +//===----------------------------------------------------------------------===// + +#include "llvm/Transforms/Instrumentation/SanitizerBinaryMetadata.h" +#include "llvm/CodeGen/MachineFrameInfo.h" +#include "llvm/CodeGen/MachineFunction.h" +#include "llvm/CodeGen/MachineFunctionPass.h" +#include "llvm/CodeGen/Passes.h" +#include "llvm/IR/IRBuilder.h" +#include "llvm/IR/MDBuilder.h" +#include "llvm/InitializePasses.h" +#include "llvm/Pass.h" +#include <algorithm> + +using namespace llvm; + +namespace { +class MachineSanitizerBinaryMetadata : public MachineFunctionPass { +public: + static char ID; + + MachineSanitizerBinaryMetadata(); + bool runOnMachineFunction(MachineFunction &F) override; +}; +} // namespace + +INITIALIZE_PASS(MachineSanitizerBinaryMetadata, "machine-sanmd", + "Machine Sanitizer Binary Metadata", false, false) + +char MachineSanitizerBinaryMetadata::ID = 0; +char &llvm::MachineSanitizerBinaryMetadataID = + MachineSanitizerBinaryMetadata::ID; + +MachineSanitizerBinaryMetadata::MachineSanitizerBinaryMetadata() + : MachineFunctionPass(ID) { + initializeMachineSanitizerBinaryMetadataPass( + *PassRegistry::getPassRegistry()); +} + +bool MachineSanitizerBinaryMetadata::runOnMachineFunction(MachineFunction &MF) { + MDNode *MD = MF.getFunction().getMetadata(LLVMContext::MD_pcsections); + if (!MD) + return false; + const auto &Section = *cast<MDString>(MD->getOperand(0)); + if (!Section.getString().startswith(kSanitizerBinaryMetadataCoveredSection)) + return false; + auto &AuxMDs = *cast<MDTuple>(MD->getOperand(1)); + // Assume it currently only has features. + assert(AuxMDs.getNumOperands() == 1); + Constant *Features = + cast<ConstantAsMetadata>(AuxMDs.getOperand(0))->getValue(); + if (!Features->getUniqueInteger()[kSanitizerBinaryMetadataUARBit]) + return false; + // Calculate size of stack args for the function. + int64_t Size = 0; + uint64_t Align = 0; + const MachineFrameInfo &MFI = MF.getFrameInfo(); + for (int i = -1; i >= (int)-MFI.getNumFixedObjects(); --i) { + Size = std::max(Size, MFI.getObjectOffset(i) + MFI.getObjectSize(i)); + Align = std::max(Align, MFI.getObjectAlign(i).value()); + } + Size = (Size + Align - 1) & ~(Align - 1); + if (!Size) + return false; + // Non-zero size, update metadata. + auto &F = MF.getFunction(); + IRBuilder<> IRB(F.getContext()); + MDBuilder MDB(F.getContext()); + // Keep the features and append size of stack args to the metadata. + APInt NewFeatures = Features->getUniqueInteger(); + NewFeatures.setBit(kSanitizerBinaryMetadataUARHasSizeBit); + F.setMetadata( + LLVMContext::MD_pcsections, + MDB.createPCSections({{Section.getString(), + {IRB.getInt(NewFeatures), IRB.getInt32(Size)}}})); + return false; +} |