https://github.com/quarkslab/QBDI

A Dynamic Binary Instrumentation framework based on LLVM.

Introduction

QuarkslaB Dynamic binary Instrumentation (QBDI) is a modular, cross-platform and cross-architecture DBI framework. It aims to support Linux, macOS, Android, iOS and Windows operating systems running on x86, x86-64, ARM and AArch64 architectures. Information about what is a DBI framework and how QBDI works can be found in the user documentation introduction (:ref:`user-introduction`).

QBDI modularity means it doesn't contain a preferred injection method and it is designed to be used in conjunction with an external injection tool. QBDI includes a tiny (LD_PRELOAD based) Linux and macOS injector for dynamic executables (QBDIPreload), which acts as the foundation for our Python bindings (pyQBDI). QBDI is also fully integrated with Frida, a reference dynamic instrumentation toolkit, allowing anybody to use their combined powers.

x86-64 support is mature (even if SIMD memory access are not yet reported). ARM architecture is a work in progress but already sufficient to execute simple CLI program like ls or cat. x86 and AArch64 are planned, but currently unsupported.

A current limitation is that QBDI doesn't handle signals, multithreading (it doesn't deal with new threads creation) and C++ exception mechanisms. However, those system-dependent features will probably not be part of the core library (KISS), and should be integrated as a new layer (to be determined how).

CPU	Operating Systems	Execution	Memory Access Information
x86-64	Linux, macOS, Windows	Supported	Partial (only non SIMD)
ARM	Linux, Android, iOS	Partial	Unsupported
AArch64	Linux, Android	Unsupported	Unsupported
x86	Linux, macOS, Windows	Unsupported	Unsupported

Compilation

To build this project the following dependencies are needed on your system: cmake, make (for Linux and macOS), ninja (for Android), Visual Studio (for Windows) and a C++11 toolchain for the platform of your choice.

The compilation is a two-step process:

• A local binary distribution of the dependencies is built.
• QBDI is built using those binaries.

The current dependencies which need to be built are LLVM and Google Test. This local built of LLVM is required because QBDI uses private APIs not exported by regular LLVM installations and because our code is only compatible with a specific version of those APIs. This first step is cached and only needs to be run once, subsequent builds only need to repeat the second step.

QBDI build system relies on CMake and requires to pass build configuration flags. To help with this step we provide shell scripts for common build configurations which follow the naming pattern config-OS-ARCH.sh. Modifying these scripts is necessary if you want to compile in debug or cross compile QBDI.

Linux

x86-64

Create a new directory at the root of the source tree, and execute the linux configuration script:

mkdir build
cd build
../cmake/config-linux-X86_64.sh

If the build script warns you of missing dependencies for your platform (in the case of a first compilation), or if you want to rebuild them, execute the following commands:

make llvm
make gtest

This will rebuild the binary distribution of those dependencies for your platform. You can then relaunch the configuration script from above and compile:

../cmake/config-linux-X86_64.sh
make -j4

Cross-compiling for ARM

The same step as above can be used but using the config-linux-ARM.sh configuration script instead. This script however needs to be customized for your cross-compilation toolchain:

• The right binaries must be exported in the AS, CC, CXX and STRIP environment variables.
• The -DCMAKE_C_FLAGS and -DCMAKE_CXX_FLAGS should contain the correct default flags for your toolchain. At least the ARM_ARCH, ARM_C_INCLUDE and ARM_CXX_INCLUDE should be modified to match your toolchain but more might be needed.

macOS

Create a new directory at the root of the source tree, and execute the linux configuration script:

mkdir build
cd build
../cmake/config-macOS-X86_64.sh

If the build script warns you of missing dependencies for your platform (in the case of a first compilation), or if you want to rebuild them, execute the following commands:

make llvm
make gtest

This will rebuild the binary distribution of those dependencies for your platform. You can then relaunch the build script from above and compile:

../cmake/config-macOS-X86_64.sh
make -j4

Windows

Building on windows requires a working bash interpreter, both Cygwin and the Windows Subsytem for Linux have been used successfully. It also requires a pure Windows installation of Python 2.

First, the config-win-X86_64.sh should be edited to use the generator (the -G flag) matching your Visual Studio installation. Then the following command should be run:

mkdir build
cd build
../cmake/config-win-X86_64.sh

If the build script warns you of missing dependencies for your platform (in the case of a first compilation), or if you want to rebuild them, execute the following commands:

MSBuild deps\llvm.vcxproj
MSBuild deps\gtest.vcxproj

This will rebuild the binary distribution of those dependencies for your platform. You can then relaunch the build script from above and compile:

../cmake/config-win-X86_64.sh
MSBuild /p:Configuration=Release ALL_BUILD.vcxproj

Android

Cross-compiling for Android requires the Android NDK and has only been tested under Linux. The config-android-ARM.sh configuration script should be customized to match your NDK installation and target platform:

• NDK_PATH should point to your Android NDK
• SDKBIN_PATH should be completed to point to the toolchain to use inside the NDK.
• API_LEVEL should match the Android API level of your target.
• The right binaries must be exported in the AS, CC, CXX and STRIP environment variables (look at what is inside your SDKBIN_PATH).

From that point on the Linux guide can be followed using this configuration script.