Reland 'Classify llvm-cfi-verify.'
Summary: Move llvm-cfi-verify into a class in preparation for CFI analysis to come.
Reviewers: vlad.tsyrklevich
Reviewed By: vlad.tsyrklevich
Subscribers: mgorny, llvm-commits, pcc, kcc
Differential Revision: https://reviews.llvm.org/D38379
llvm-svn: 315504
diff --git a/llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt b/llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt
new file mode 100644
index 0000000..a673d88
--- /dev/null
+++ b/llvm/tools/llvm-cfi-verify/lib/CMakeLists.txt
@@ -0,0 +1,9 @@
+add_llvm_library(LLVMCFIVerify
+ FileAnalysis.cpp
+ FileAnalysis.h
+
+ LINK_COMPONENTS
+ MC
+ MCParser
+ Object
+ Support)
diff --git a/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.cpp b/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.cpp
new file mode 100644
index 0000000..6a275ce
--- /dev/null
+++ b/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.cpp
@@ -0,0 +1,277 @@
+//===- FileAnalysis.cpp -----------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#include "FileAnalysis.h"
+
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDisassembler/MCDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstPrinter.h"
+#include "llvm/MC/MCInstrAnalysis.h"
+#include "llvm/MC/MCInstrDesc.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Object/Binary.h"
+#include "llvm/Object/COFF.h"
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/FormatVariadic.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <functional>
+
+using Instr = llvm::cfi_verify::FileAnalysis::Instr;
+
+namespace llvm {
+namespace cfi_verify {
+
+Expected<FileAnalysis> FileAnalysis::Create(StringRef Filename) {
+ // Open the filename provided.
+ Expected<object::OwningBinary<object::Binary>> BinaryOrErr =
+ object::createBinary(Filename);
+ if (!BinaryOrErr)
+ return BinaryOrErr.takeError();
+
+ // Construct the object and allow it to take ownership of the binary.
+ object::OwningBinary<object::Binary> Binary = std::move(BinaryOrErr.get());
+ FileAnalysis Analysis(std::move(Binary));
+
+ Analysis.Object = dyn_cast<object::ObjectFile>(Analysis.Binary.getBinary());
+ if (!Analysis.Object)
+ return make_error<UnsupportedDisassembly>();
+
+ Analysis.ObjectTriple = Analysis.Object->makeTriple();
+ Analysis.Features = Analysis.Object->getFeatures();
+
+ // Init the rest of the object.
+ if (auto InitResponse = Analysis.initialiseDisassemblyMembers())
+ return std::move(InitResponse);
+
+ if (auto SectionParseResponse = Analysis.parseCodeSections())
+ return std::move(SectionParseResponse);
+
+ return std::move(Analysis);
+}
+
+FileAnalysis::FileAnalysis(object::OwningBinary<object::Binary> Binary)
+ : Binary(std::move(Binary)) {}
+
+FileAnalysis::FileAnalysis(const Triple &ObjectTriple,
+ const SubtargetFeatures &Features)
+ : ObjectTriple(ObjectTriple), Features(Features) {}
+
+const Instr *
+FileAnalysis::getPrevInstructionSequential(const Instr &InstrMeta) const {
+ std::map<uint64_t, Instr>::const_iterator KV =
+ Instructions.find(InstrMeta.VMAddress);
+ if (KV == Instructions.end() || KV == Instructions.begin())
+ return nullptr;
+
+ if (!(--KV)->second.Valid)
+ return nullptr;
+
+ return &KV->second;
+}
+
+const Instr *
+FileAnalysis::getNextInstructionSequential(const Instr &InstrMeta) const {
+ std::map<uint64_t, Instr>::const_iterator KV =
+ Instructions.find(InstrMeta.VMAddress);
+ if (KV == Instructions.end() || ++KV == Instructions.end())
+ return nullptr;
+
+ if (!KV->second.Valid)
+ return nullptr;
+
+ return &KV->second;
+}
+
+bool FileAnalysis::usesRegisterOperand(const Instr &InstrMeta) const {
+ for (const auto &Operand : InstrMeta.Instruction) {
+ if (Operand.isReg())
+ return true;
+ }
+ return false;
+}
+
+const Instr *FileAnalysis::getInstruction(uint64_t Address) const {
+ const auto &InstrKV = Instructions.find(Address);
+ if (InstrKV == Instructions.end())
+ return nullptr;
+
+ return &InstrKV->second;
+}
+
+const Instr &FileAnalysis::getInstructionOrDie(uint64_t Address) const {
+ const auto &InstrKV = Instructions.find(Address);
+ assert(InstrKV != Instructions.end() && "Address doesn't exist.");
+ return InstrKV->second;
+}
+
+const std::set<uint64_t> &FileAnalysis::getIndirectInstructions() const {
+ return IndirectInstructions;
+}
+
+const MCRegisterInfo *FileAnalysis::getRegisterInfo() const {
+ return RegisterInfo.get();
+}
+
+const MCInstrInfo *FileAnalysis::getMCInstrInfo() const { return MII.get(); }
+
+const MCInstrAnalysis *FileAnalysis::getMCInstrAnalysis() const {
+ return MIA.get();
+}
+
+Error FileAnalysis::initialiseDisassemblyMembers() {
+ std::string TripleName = ObjectTriple.getTriple();
+ ArchName = "";
+ MCPU = "";
+ std::string ErrorString;
+
+ ObjectTarget =
+ TargetRegistry::lookupTarget(ArchName, ObjectTriple, ErrorString);
+ if (!ObjectTarget)
+ return make_error<StringError>(Twine("Couldn't find target \"") +
+ ObjectTriple.getTriple() +
+ "\", failed with error: " + ErrorString,
+ inconvertibleErrorCode());
+
+ RegisterInfo.reset(ObjectTarget->createMCRegInfo(TripleName));
+ if (!RegisterInfo)
+ return make_error<StringError>("Failed to initialise RegisterInfo.",
+ inconvertibleErrorCode());
+
+ AsmInfo.reset(ObjectTarget->createMCAsmInfo(*RegisterInfo, TripleName));
+ if (!AsmInfo)
+ return make_error<StringError>("Failed to initialise AsmInfo.",
+ inconvertibleErrorCode());
+
+ SubtargetInfo.reset(ObjectTarget->createMCSubtargetInfo(
+ TripleName, MCPU, Features.getString()));
+ if (!SubtargetInfo)
+ return make_error<StringError>("Failed to initialise SubtargetInfo.",
+ inconvertibleErrorCode());
+
+ MII.reset(ObjectTarget->createMCInstrInfo());
+ if (!MII)
+ return make_error<StringError>("Failed to initialise MII.",
+ inconvertibleErrorCode());
+
+ Context.reset(new MCContext(AsmInfo.get(), RegisterInfo.get(), &MOFI));
+
+ Disassembler.reset(
+ ObjectTarget->createMCDisassembler(*SubtargetInfo, *Context));
+
+ if (!Disassembler)
+ return make_error<StringError>("No disassembler available for target",
+ inconvertibleErrorCode());
+
+ MIA.reset(ObjectTarget->createMCInstrAnalysis(MII.get()));
+
+ Printer.reset(ObjectTarget->createMCInstPrinter(
+ ObjectTriple, AsmInfo->getAssemblerDialect(), *AsmInfo, *MII,
+ *RegisterInfo));
+
+ return Error::success();
+}
+
+Error FileAnalysis::parseCodeSections() {
+ for (const object::SectionRef &Section : Object->sections()) {
+ // Ensure only executable sections get analysed.
+ if (!(object::ELFSectionRef(Section).getFlags() & ELF::SHF_EXECINSTR))
+ continue;
+
+ StringRef SectionContents;
+ if (Section.getContents(SectionContents))
+ return make_error<StringError>("Failed to retrieve section contents",
+ inconvertibleErrorCode());
+
+ ArrayRef<uint8_t> SectionBytes((const uint8_t *)SectionContents.data(),
+ Section.getSize());
+ parseSectionContents(SectionBytes, Section.getAddress());
+ }
+ return Error::success();
+}
+
+void FileAnalysis::parseSectionContents(ArrayRef<uint8_t> SectionBytes,
+ uint64_t SectionAddress) {
+ MCInst Instruction;
+ Instr InstrMeta;
+ uint64_t InstructionSize;
+
+ for (uint64_t Byte = 0; Byte < SectionBytes.size();) {
+ bool ValidInstruction =
+ Disassembler->getInstruction(Instruction, InstructionSize,
+ SectionBytes.drop_front(Byte), 0, nulls(),
+ outs()) == MCDisassembler::Success;
+
+ Byte += InstructionSize;
+
+ uint64_t VMAddress = SectionAddress + Byte - InstructionSize;
+ InstrMeta.Instruction = Instruction;
+ InstrMeta.VMAddress = VMAddress;
+ InstrMeta.InstructionSize = InstructionSize;
+ InstrMeta.Valid = ValidInstruction;
+ addInstruction(InstrMeta);
+
+ if (!ValidInstruction)
+ continue;
+
+ // Skip additional parsing for instructions that do not affect the control
+ // flow.
+ const auto &InstrDesc = MII->get(Instruction.getOpcode());
+ if (!InstrDesc.mayAffectControlFlow(Instruction, *RegisterInfo))
+ continue;
+
+ uint64_t Target;
+ if (MIA->evaluateBranch(Instruction, VMAddress, InstructionSize, Target)) {
+ // If the target can be evaluated, it's not indirect.
+ StaticBranchTargetings[Target].push_back(VMAddress);
+ continue;
+ }
+
+ if (!usesRegisterOperand(InstrMeta))
+ continue;
+
+ IndirectInstructions.insert(VMAddress);
+ }
+}
+
+void FileAnalysis::addInstruction(const Instr &Instruction) {
+ const auto &KV =
+ Instructions.insert(std::make_pair(Instruction.VMAddress, Instruction));
+ if (!KV.second) {
+ errs() << "Failed to add instruction at address "
+ << format_hex(Instruction.VMAddress, 2)
+ << ": Instruction at this address already exists.\n";
+ exit(EXIT_FAILURE);
+ }
+}
+
+char UnsupportedDisassembly::ID;
+void UnsupportedDisassembly::log(raw_ostream &OS) const {
+ OS << "Dissassembling of non-objects not currently supported.\n";
+}
+
+std::error_code UnsupportedDisassembly::convertToErrorCode() const {
+ return std::error_code();
+}
+
+} // namespace cfi_verify
+} // namespace llvm
diff --git a/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.h b/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.h
new file mode 100644
index 0000000..80e3256
--- /dev/null
+++ b/llvm/tools/llvm-cfi-verify/lib/FileAnalysis.h
@@ -0,0 +1,157 @@
+//===- FileAnalysis.h -------------------------------------------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_CFI_VERIFY_FILE_ANALYSIS_H
+#define LLVM_CFI_VERIFY_FILE_ANALYSIS_H
+
+#include "llvm/BinaryFormat/ELF.h"
+#include "llvm/MC/MCAsmInfo.h"
+#include "llvm/MC/MCContext.h"
+#include "llvm/MC/MCDisassembler/MCDisassembler.h"
+#include "llvm/MC/MCInst.h"
+#include "llvm/MC/MCInstPrinter.h"
+#include "llvm/MC/MCInstrAnalysis.h"
+#include "llvm/MC/MCInstrDesc.h"
+#include "llvm/MC/MCInstrInfo.h"
+#include "llvm/MC/MCObjectFileInfo.h"
+#include "llvm/MC/MCRegisterInfo.h"
+#include "llvm/MC/MCSubtargetInfo.h"
+#include "llvm/Object/Binary.h"
+#include "llvm/Object/COFF.h"
+#include "llvm/Object/ELFObjectFile.h"
+#include "llvm/Object/ObjectFile.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/Support/Error.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/TargetRegistry.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Support/raw_ostream.h"
+
+#include <functional>
+#include <set>
+#include <string>
+#include <unordered_map>
+
+namespace llvm {
+namespace cfi_verify {
+
+// Disassembler and analysis tool for machine code files. Keeps track of non-
+// sequential control flows, including indirect control flow instructions.
+class FileAnalysis {
+public:
+ // A metadata struct for an instruction.
+ struct Instr {
+ uint64_t VMAddress; // Virtual memory address of this instruction.
+ MCInst Instruction; // Instruction.
+ uint64_t InstructionSize; // Size of this instruction.
+ bool Valid; // Is this a valid instruction? If false, Instr::Instruction is
+ // undefined.
+ };
+
+ // Construct a FileAnalysis from a file path.
+ static Expected<FileAnalysis> Create(StringRef Filename);
+
+ // Construct and take ownership of the supplied object. Do not use this
+ // constructor, prefer to use FileAnalysis::Create instead.
+ FileAnalysis(object::OwningBinary<object::Binary> Binary);
+ FileAnalysis() = delete;
+ FileAnalysis(const FileAnalysis &) = delete;
+ FileAnalysis(FileAnalysis &&Other) = default;
+
+ // Returns the instruction at the provided address. Returns nullptr if there
+ // is no instruction at the provided address.
+ const Instr *getInstruction(uint64_t Address) const;
+
+ // Returns the instruction at the provided adress, dying if the instruction is
+ // not found.
+ const Instr &getInstructionOrDie(uint64_t Address) const;
+
+ // Returns a pointer to the previous/next instruction in sequence,
+ // respectively. Returns nullptr if the next/prev instruction doesn't exist,
+ // or if the provided instruction doesn't exist.
+ const Instr *getPrevInstructionSequential(const Instr &InstrMeta) const;
+ const Instr *getNextInstructionSequential(const Instr &InstrMeta) const;
+
+ // Returns whether this instruction uses a register operand.
+ bool usesRegisterOperand(const Instr &InstrMeta) const;
+
+ // Returns the list of indirect instructions.
+ const std::set<uint64_t> &getIndirectInstructions() const;
+
+ const MCRegisterInfo *getRegisterInfo() const;
+ const MCInstrInfo *getMCInstrInfo() const;
+ const MCInstrAnalysis *getMCInstrAnalysis() const;
+
+protected:
+ // Construct a blank object with the provided triple and features. Used in
+ // testing, where a sub class will dependency inject protected methods to
+ // allow analysis of raw binary, without requiring a fully valid ELF file.
+ FileAnalysis(const Triple &ObjectTriple, const SubtargetFeatures &Features);
+
+ // Add an instruction to this object.
+ void addInstruction(const Instr &Instruction);
+
+ // Disassemble and parse the provided bytes into this object. Instruction
+ // address calculation is done relative to the provided SectionAddress.
+ void parseSectionContents(ArrayRef<uint8_t> SectionBytes,
+ uint64_t SectionAddress);
+
+ // Constructs and initialises members required for disassembly.
+ Error initialiseDisassemblyMembers();
+
+ // Parses code sections from the internal object file. Saves them into the
+ // internal members. Should only be called once by Create().
+ Error parseCodeSections();
+
+private:
+ // Members that describe the input file.
+ object::OwningBinary<object::Binary> Binary;
+ const object::ObjectFile *Object = nullptr;
+ Triple ObjectTriple;
+ std::string ArchName;
+ std::string MCPU;
+ const Target *ObjectTarget = nullptr;
+ SubtargetFeatures Features;
+
+ // Members required for disassembly.
+ std::unique_ptr<const MCRegisterInfo> RegisterInfo;
+ std::unique_ptr<const MCAsmInfo> AsmInfo;
+ std::unique_ptr<MCSubtargetInfo> SubtargetInfo;
+ std::unique_ptr<const MCInstrInfo> MII;
+ MCObjectFileInfo MOFI;
+ std::unique_ptr<MCContext> Context;
+ std::unique_ptr<const MCDisassembler> Disassembler;
+ std::unique_ptr<const MCInstrAnalysis> MIA;
+ std::unique_ptr<MCInstPrinter> Printer;
+
+ // A mapping between the virtual memory address to the instruction metadata
+ // struct.
+ std::map<uint64_t, Instr> Instructions;
+
+ // Contains a mapping between a specific address, and a list of instructions
+ // that use this address as a branch target (including call instructions).
+ std::unordered_map<uint64_t, std::vector<uint64_t>> StaticBranchTargetings;
+
+ // A list of addresses of indirect control flow instructions.
+ std::set<uint64_t> IndirectInstructions;
+};
+
+class UnsupportedDisassembly : public ErrorInfo<UnsupportedDisassembly> {
+public:
+ static char ID;
+
+ void log(raw_ostream &OS) const override;
+ std::error_code convertToErrorCode() const override;
+};
+
+} // namespace cfi_verify
+} // namespace llvm
+
+#endif // LLVM_CFI_VERIFY_FILE_ANALYSIS_H
diff --git a/llvm/tools/llvm-cfi-verify/lib/LLVMBuild.txt b/llvm/tools/llvm-cfi-verify/lib/LLVMBuild.txt
new file mode 100644
index 0000000..39537f5
--- /dev/null
+++ b/llvm/tools/llvm-cfi-verify/lib/LLVMBuild.txt
@@ -0,0 +1,22 @@
+;===- ./tools/llvm-cfi-verify/lib/LLVMBuild.txt ----------------*- Conf -*--===;
+;
+; The LLVM Compiler Infrastructure
+;
+; This file is distributed under the University of Illinois Open Source
+; License. See LICENSE.TXT for details.
+;
+;===------------------------------------------------------------------------===;
+;
+; This is an LLVMBuild description file for the components in this subdirectory.
+;
+; For more information on the LLVMBuild system, please see:
+;
+; http://llvm.org/docs/LLVMBuild.html
+;
+;===------------------------------------------------------------------------===;
+
+[component_0]
+type = Library
+name = CFIVerify
+parent = Libraries
+required_libraries = MC MCDisassembler MCParser Support