HexType

Environment

Tested on Ubuntu 16.04.2 LTS 

How to build

a. Download HexType source code

git clone git@github.com:HexHive/HexType.git

b. Build HexType

run ./build.sh

How to use

a. Set HexType path

$ $BUILD_DIR/bin/export HEXTYPE_LOG_PATH="/tmp/hextype"

b. Run HexType

• Use the create-clang-typeinfo option or copy the pre-made type info (in the HexType/etc/clang_type_info) into the HexType path as typeinfo.txt file name
• Use HexType/scripts/remove_duplicated_line.py in order to remove duplicated lines when you create new type information file

  $ $BUILD_DIR/bin/clang++ test.cc -fsanitize=hextype

• Note that during various application tests, we found in a few cases that some type information was omitted during the transition from source code to LLVM IR (which can cause false positive issue). In order to solve this issue, HexType also relies on clang level type information using -mllvm -create-clang-typeinfo option.

c. Please enable/disable below #define in the lib/hextype/rbtree.h according to your purpose

HEX_LOG: print numerical statistics
PRINT_BAD_CASTING: print type confusion result
PRINT_BAD_CASTING_FILE: print type confusio result into file
PRINT_BAD_CASTING_FATAL : terminate program when HexType detects type confusion

d. Please use below additional options as compile option (with -mllvm option, e.g., -mllvm -statck-opt) according to your purpose

• Coverage

handle-reinterpret-cast : handle reinterpret_cast to increase coverage
handle-placement-new : handle placement_new to increase coverage

• Optimization

  • If you use the cast-obj-opt option, create a type casting related object list using create-cast-related-type-list option or copy the pre-made list (in the HexType/etc/typecasting_releated_type_rule) into the HexType path as casting_obj.txt file name
  • Use HexType/scripts/merge_typecasting_related_type.py in order to merge type information when you create new type casting related set

    stack-opt : apply stack optimization
    safestack-opt : apply stack optimization using safestack
    cast-obj-opt : apply only typecasting relate objects tracing optimization
    inline-opt : apply inline optimization
    compile-time-verify-opt : apply compile time verification optimization
    enhance-dynamic-cast : replace dynamic_cast`s type casting verification function

• Etc

make-loginfo : collect and print numerical statistics
make-typeinfo : print type and hash information
create-cast-releated-type-list : create typecasting related object list
create-clang-typeinfo : create clang level type info

e. HexType`s major changes

• Clang

- Handle typecasting (static_cast and C style) and reinterpret_cast
llvm/tools/clang/lib/CodeGen/CGClass.cpp
llvm/tools/clang/lib/CodeGen/CGExpr.cpp
llvm/tools/clang/lib/CodeGen/CGExprScalar.cpp
- Handle dynamic_cast
llvm/tools/clang/lib/CodeGen/ItaniumCXXABI.cpp

• LLVM Pass

llvm/lib/Transforms/Instrumentation/HexTypeTreePass.cpp : Heap object tracing and class relationship tree
llvm/lib/Transforms/Instrumentation/HexTypePass.cpp : Stack and global object tracing
llvm/lib/Transforms/Utils/HexTypeUtil.cpp : Common utils

• Runtime Library

llvm/projects/compiler-rt/lib/hextype/hextype.cc : Type casting verfication and Object tracing
llvm/projects/compiler-rt/lib/hextype/hextype.h
llvm/projects/compiler-rt/lib/hextype/hextype_rbtree.cc : RB tree implemenation
llvm/projects/compiler-rt/lib/hextype/hextype_rbtree.h
llvm/projects/compiler-rt/lib/hextype/hextype_report.cc : create HexType logs
llvm/projects/compiler-rt/lib/hextype/hextype_report.h

How to test

a. HexType testcase

make test

b. TypeSan testcase

run `test/typesancheck/hextype.py`