https://github.com/mebeim/systrack
📡🐧 Linux kernel syscall implementation tracker
https://github.com/mebeim/systrack
abi automation binary-analysis elf kconfig linux linux-kernel security-research syscall syscall-table syscalls
Last synced: 5 months ago
JSON representation
📡🐧 Linux kernel syscall implementation tracker
- Host: GitHub
- URL: https://github.com/mebeim/systrack
- Owner: mebeim
- License: gpl-3.0
- Created: 2023-02-19T23:00:50.000Z (over 2 years ago)
- Default Branch: master
- Last Pushed: 2025-03-26T23:50:46.000Z (7 months ago)
- Last Synced: 2025-04-09T05:06:50.807Z (6 months ago)
- Topics: abi, automation, binary-analysis, elf, kconfig, linux, linux-kernel, security-research, syscall, syscall-table, syscalls
- Language: Python
- Homepage: https://syscalls.mebeim.net
- Size: 2.66 MB
- Stars: 210
- Watchers: 5
- Forks: 12
- Open Issues: 1
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
Systrack
========
[![License][license-badge]](./LICENSE)
[![GitHub actions workflow status][actions-badge]][actions-link]
[![PyPI version][pypi-badge]][pypi-systrack]
[![PyPI downloads][pypi-badge2]][pypistats-systrack]
**See [mebeim/linux-syscalls](https://github.com/mebeim/linux-syscalls) for live syscall tables powered by Systrack**.
Systrack is a tool to analyze Linux kernel images (`vmlinux`) and extract
information about implemented syscalls. Given a `vmlinux` image, Systrack can
extract syscall numbers, names, symbol names, definition locations within kernel
sources, function signatures, and more.
Systrack can configure and build kernels for all its
[supported architectures](#supported-architectures-and-abis), and works best at
analyzing kernels that it has configured and built by itself.
Installation
------------
Systrack is [available on PyPI][pypi-systrack], it requires Python 3.8+ and is
installable through Pip:
```bash
pip install systrack
```
Building and installaing from source requires [`hatch`][pypi-hatch]:
```bash
hatch build
pip install dist/systrack-XXX.whl
```
Usage
-----
Systrack can mainly be used for two purposes: analyzing or building Linux
kernels. See also [Command line help](#command-line-help) (`systrack --help`)
and [Supported architectures and ABIs](#supported-architectures-and-abis)
(`systrack --arch help`) below.
- **Analyzing** a kernel image can be done given a `vmlinux` ELF with symbols,
and optionally also a kernel source directory (`--kdir`). Systrack will
extract information about implemented syscalls from the symbol table present
in the given `vmlinux` ELF, and if debugging information is present, it will
also extract file and line number information for syscall definitions.
Supplying a `--kdir` pointing Systrack to the checked-out sources for the
right kernel version (the same as the one to analyze) will help refine and/or
correct the location of the definitions.
Systrack can guess the architecture and ABI to analyze, but if the given
kernel was built with support for multiple ABIs, the right one can be selected
through `--arch`.
```none
systrack path/to/vmlinux
systrack --format json path/to/vmlinux
systrack --format html path/to/vmlinux
systrack --kdir path/to/linux_git_repo path/to/vmlinux
systrack --kdir path/to/linux_git_repo --arch x86-64-ia32 path/to/vmlinux
```
- **Building** can be done through the `--build` option. You will need to
provide a kernel source directory (`--kdir`) and an architecture/ABI
combination to build for (`--arch`).
```none
systrack --build --kdir path/to/linux_source_dir --arch x86-64
```
When building, kernel sources are configured to enable all syscalls available
for the selected architecture/ABI as to produce a `vmlinux` with a "complete"
syscall table.
Cross-compilation with GCC is possible specifying the correct toolchain prefix
with the `--cross` option, which will set the `CROSS_COMPILE` variable for the
kernel's `Makefile`. Other environment variables can also be used as usual and
are passed as is to `make`, so LLVM [cross]-compilation and custom toolchain
usage is also possible.
```none
systrack --build --kdir path/to/linux_source --arch arm64 --cross aarch64-linux-gnu-
```
Supported architectures and ABIs
--------------------------------
Here's a list of supported arch/ABI combinations accepted via `--arch` (values
are case-insensitive). This information is also available running
`systrack --arch help`.
| Value | Aliases | Arch | Kernel | Syscall ABI | Build based on | Notes |
|:----------------|:-------------------|:--------|:-------|:---------------|:------------------------------|:--------|
| `arm` | `arm-eabi`, `eabi` | ARM | 32-bit | 32-bit EABI | `multi_v7_defconfig` | *[2]* |
| `arm-oabi` | `oabi` | ARM | 32-bit | 32-bit OABI | `multi_v7_defconfig` | *[2,4]* |
| `arm64` | `aarch64` | ARM | 64-bit | 64-bit AArch64 | `defconfig` | |
| `arm64-aarch32` | `aarch32` | ARM | 64-bit | 32-bit AArch32 | `defconfig` | *[1]* |
| `mips` | `mips32`, `o32` | MIPS | 32-bit | 32-bit O32 | `defconfig` | |
| `mips64` | `n64` | MIPS | 64-bit | 64-bit N64 | `ip27_defconfig` | *[1]* |
| `mips64-n32` | `n32` | MIPS | 64-bit | 64-bit N32 | `ip27_defconfig` | *[1]* |
| `mips64-o32` | `o32-64` | MIPS | 64-bit | 32-bit O32 | `ip27_defconfig` | *[1]* |
| `powerpc` | `ppc`, `ppc32` | PowerPC | 32-bit | 32-bit PPC32 | `ppc64_defconfig` | |
| `powerpc64` | `ppc64` | PowerPC | 64-bit | 64-bit PPC64 | `ppc64_defconfig` | *[1]* |
| `powerpc64-32` | `ppc64-32` | PowerPC | 64-bit | 32-bit PPC32 | `ppc64_defconfig` | *[1]* |
| `powerpc64-spu` | `ppc64-spu`, `spu` | PowerPC | 64-bit | 64-bit "SPU" | `ppc64_defconfig` | *[1,5]* |
| `riscv` | `riscv32`, `rv32` | RISC-V | 32-bit | 32-bit "RV32" | `defconfig` + `32-bit.config` | *[3,6]* |
| `riscv64` | `rv64` | RISC-V | 64-bit | 64-bit "RV64" | `defconfig` | *[1,6]* |
| `riscv64-32` | `rv64-32` | RISC-V | 64-bit | 32-bit "RV32" | `defconfig` | *[1,6]* |
| `x86` | `i386`, `ia32` | x86 | 32-bit | 32-bit IA32 | `i386_defconfig` | |
| `x86-64` | `x64` | x86 | 64-bit | 64-bit x86-64 | `x86_64_defconfig` | *[1]* |
| `x86-64-x32` | `x32` | x86 | 64-bit | 64-bit x32 | `x86_64_defconfig` | *[1]* |
| `x86-64-ia32` | `ia32-64` | x86 | 64-bit | 32-bit IA32 | `x86_64_defconfig` | *[1]* |
Notes:
1. Building creates a kernel supporting all ABIs for this architecture.
2. Build based on `defconfig` for Linux <= v3.7.
3. Build based on `rv32_defconfig` for Linux <= v6.7 and `defconfig` for
Linux <= v5.0.
4. Building creates an EABI kernel with compat OABI support. Building an
OABI-only kernel is NOT supported. The seccomp filter system will be missing.
5. "SPU" is not a real ABI. It indicates a Cell processor SPU (Synergistic
Processing Unit). The ABI is really PPC64, but SPUs can only use a subset of
syscalls.
6. "RV32" and "RV64" are not real ABIs, but rather ISAs. The RISC-V syscall
ABI is the same for 32-bit and 64-bit (only register size differs). These
names are only used for clarity.
Runtime dependencies
--------------------
External (non-Python) runtime dependencies are:
- **Required**: `readelf` (from GNU binutils) is used to parse and extract ELF
metadata such as symbols and sections. This is currently the only *compulsory*
external dependency of Systrack.
- Optional: `addr2line` (from GNU binutils) is used to extract location
information from DWARF debug info. Without this program, Systrack will not
output any information about syscall definition locations.
- Optional: `rg` ([ripgrep][ripgrep]) is used for much faster recursive
grepping of syscall definition locations within kernel sources when needed.
Otherwise, a slower pure-Python implementation is used.
- Optional: a working compiler toolchain and
[kernel build dependencies](https://www.kernel.org/doc/html/latest/process/changes.html)
are obviously needed if you want Systrack to *build* kernels from source.
Limitations
-----------
- Supported kernel images: Systrack works with regular *uncompressed* `vmlinux`
ELF images and *needs* ELF symbols. Compressed and stripped kernel images are
not supported. Tools such as
[`vmlinux-to-elf`](https://github.com/marin-m/vmlinux-to-elf) can be used to
uncompress and unstrip kernel images, after which Systrack will be able to
analyze them.
- Old kernel versions: Systrack was mainly designed for and tested on modern
kernels (>= v4.0) and has not been tested on older kernels. It should still
*somewhat* work on older kernels, but without the same level of guarantee on
the correctness of the output. Support for old kernels may come gradually in
the future.
- Relocatable kernels: Systrack does not currently parse and apply ELF
relocations. This means that Systrack does not support kernels using
relocation entries for the syscall table. On some architectures (notably MIPS)
if the kernel is relocatable the syscall table is relocated at startup and
does not contain valid virtual addresses: Systrack will currently fail to
analyze such kernels.
Command line help
-----------------
```none
$ systrack --help
usage: systrack [OPTIONS...] [VMLINUX]
Analyze a Linux kernel image and extract information about implemented syscalls
positional arguments:
VMLINUX path to vmlinux, if not inside KDIR or no KDIR supplied
options:
-h, --help show this help message and exit
-k KDIR, --kdir KDIR kernel source directory
-a ARCH, --arch ARCH kernel architecture/ABI combination; pass "help" for a list
(default: autodetect)
-b, --build configure and build kernel and exit
-c, --config configure kernel and exit
-C, --clean clean kernel sources (make distclean) and exit
-x PREFIX, --cross PREFIX
toolchain prefix for cross-compilation; use with -b/-c/-C
-o OUTDIR, --out OUTDIR
output directory for out-of-tree kernel build (make O=...); only
meaningful with -b/-c/-C
-f FMT, --format FMT output format: text, json or html (default: text)
--absolute-paths output absolute paths instead of paths relative to KDIR
--remap ORIG_KDIR replace ORIG_KDIR with the KDIR provided with -k/--kdir for paths
obtained from ELF debug information; needed if the kernel was
built with ORIG_KDIR as source directory instead of KDIR, and
debug info contains absolute paths to ORIG_KDIR
--checkout REF git checkout to REF inside KDIR before doing anything; the
special value "auto" can be used to checkout to the tag
corresponding to the detected kernel version from VMLINUX
--disable-opt try building kernel with reduced/disabled optimizations for more
reliable location results; only meaningful with -b
-q, --quiet quietness level:
-q = no info, -qq = no warnings, -qqq = no errors
-qqqq = no standard error output whatsoever
-v, --verbose verbosity level:
-v = info, -vv = debug, -vvv = more debug
-V, --version show version information and exit
```
---
*Copyright © 2023-2025 Marco Bonelli. Licensed under the GNU General Public License v3.0.*
[license-badge]: https://img.shields.io/github/license/mebeim/systrack?color=blue
[actions-badge]: https://img.shields.io/github/actions/workflow/status/mebeim/systrack/publish.yml?event=release&label=publish
[actions-link]: https://github.com/mebeim/systrack/actions/workflows/publish.yml
[pypi-badge]: https://img.shields.io/pypi/v/systrack
[pypi-badge2]: https://img.shields.io/pypi/dm/systrack
[pypi-systrack]: https://pypi.org/project/systrack/
[pypistats-systrack]: https://pypistats.org/packages/systrack
[pypi-hatch]: https://pypi.org/project/hatch
[ripgrep]: https://github.com/BurntSushi/ripgrep