f133eae70c
Didn't find a test for this (but there are tests for the `Function` version of this pass)
110 lines
3.8 KiB
C++
110 lines
3.8 KiB
C++
//===- SanitizerBinaryMetadata.cpp
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//----------------------------------------------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file is a part of SanitizerBinaryMetadata.
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//
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//===----------------------------------------------------------------------===//
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#include "llvm/CodeGen/SanitizerBinaryMetadata.h"
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#include "llvm/CodeGen/MachineFrameInfo.h"
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#include "llvm/CodeGen/MachineFunction.h"
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#include "llvm/CodeGen/MachineFunctionPass.h"
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#include "llvm/CodeGen/Passes.h"
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#include "llvm/IR/IRBuilder.h"
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#include "llvm/IR/MDBuilder.h"
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#include "llvm/InitializePasses.h"
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#include "llvm/Pass.h"
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#include "llvm/Transforms/Instrumentation/SanitizerBinaryMetadata.h"
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#include <algorithm>
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using namespace llvm;
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namespace {
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// FIXME: This pass modifies Function metadata, which is not to be done in
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// MachineFunctionPass. It should probably be moved to a FunctionPass.
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class MachineSanitizerBinaryMetadataLegacy : public MachineFunctionPass {
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public:
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static char ID;
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MachineSanitizerBinaryMetadataLegacy();
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bool runOnMachineFunction(MachineFunction &F) override;
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};
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struct MachineSanitizerBinaryMetadata {
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bool run(MachineFunction &MF);
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};
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} // namespace
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INITIALIZE_PASS(MachineSanitizerBinaryMetadataLegacy, "machine-sanmd",
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"Machine Sanitizer Binary Metadata", false, false)
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char MachineSanitizerBinaryMetadataLegacy::ID = 0;
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char &llvm::MachineSanitizerBinaryMetadataID =
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MachineSanitizerBinaryMetadataLegacy::ID;
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MachineSanitizerBinaryMetadataLegacy::MachineSanitizerBinaryMetadataLegacy()
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: MachineFunctionPass(ID) {
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initializeMachineSanitizerBinaryMetadataLegacyPass(
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*PassRegistry::getPassRegistry());
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}
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bool MachineSanitizerBinaryMetadataLegacy::runOnMachineFunction(
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MachineFunction &MF) {
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return MachineSanitizerBinaryMetadata().run(MF);
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}
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PreservedAnalyses
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MachineSanitizerBinaryMetadataPass::run(MachineFunction &MF,
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MachineFunctionAnalysisManager &MFAM) {
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if (!MachineSanitizerBinaryMetadata().run(MF))
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return PreservedAnalyses::all();
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return getMachineFunctionPassPreservedAnalyses();
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}
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bool MachineSanitizerBinaryMetadata::run(MachineFunction &MF) {
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MDNode *MD = MF.getFunction().getMetadata(LLVMContext::MD_pcsections);
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if (!MD)
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return false;
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const auto &Section = *cast<MDString>(MD->getOperand(0));
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if (!Section.getString().starts_with(kSanitizerBinaryMetadataCoveredSection))
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return false;
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auto &AuxMDs = *cast<MDTuple>(MD->getOperand(1));
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// Assume it currently only has features.
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assert(AuxMDs.getNumOperands() == 1);
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Constant *Features =
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cast<ConstantAsMetadata>(AuxMDs.getOperand(0))->getValue();
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if (!Features->getUniqueInteger()[kSanitizerBinaryMetadataUARBit])
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return false;
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// Calculate size of stack args for the function.
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int64_t Size = 0;
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uint64_t Align = 0;
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const MachineFrameInfo &MFI = MF.getFrameInfo();
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for (int i = -1; i >= (int)-MFI.getNumFixedObjects(); --i) {
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Size = std::max(Size, MFI.getObjectOffset(i) + MFI.getObjectSize(i));
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Align = std::max(Align, MFI.getObjectAlign(i).value());
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}
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Size = (Size + Align - 1) & ~(Align - 1);
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if (!Size)
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return false;
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// Non-zero size, update metadata.
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auto &F = MF.getFunction();
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IRBuilder<> IRB(F.getContext());
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MDBuilder MDB(F.getContext());
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// Keep the features and append size of stack args to the metadata.
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APInt NewFeatures = Features->getUniqueInteger();
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NewFeatures.setBit(kSanitizerBinaryMetadataUARHasSizeBit);
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F.setMetadata(
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LLVMContext::MD_pcsections,
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MDB.createPCSections({{Section.getString(),
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{IRB.getInt(NewFeatures), IRB.getInt32(Size)}}}));
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return false;
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}
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