# rawsys-linux
[](https://crates.io/crates/rawsys-linux)
[](https://docs.rs/rawsys-linux)
[](https://doc.rust-lang.org/edition-guide/)
[README.ko.md](README.ko.md)
**Call the Linux kernel directly without libc.**
> This is a low-level library to enumerate and invoke raw Linux system calls.
> Key changes are summarized in [CHANGELOG.md](CHANGELOG.md). Highlights in v1.0.0:
* Raw call number types are now fixed-width to the architecture (`u32`/`u64`) and exposed via the `SyscallWord` alias.
* Migrated to Rust 2024 edition and reduced compiler warnings.
* Kernel version tables can be selected at build time via features.
---
* [Introduction](#introduction)
* [Installation](#installation)
* [Quick Start](#quick-start)
* [Features & Configuration](#features--configuration)
* [no_std](#no_std)
* [Kernel Version Selection (mutually exclusive)](#kernel-version-selection-mutually-exclusive)
* [Serde](#serde)
* [Build Examples](#build-examples)
* [Architecture Support](#architecture-support)
* [Updating the syscall list](#updating-the-syscall-list)
* [About contributing](#about-contributing)
* [License & Acknowledgements](#license--acknowledgements)
## Introduction
`rawsys-linux` exposes:
- A `Sysno` enum per architecture with syscall IDs and names.
- Inlinable raw syscall functions for several architectures.
- `Errno`, `SysnoSet`, and `SysnoMap` utilities for ergonomic and fast lookup.
## Installation
Using a Git dependency:
```toml
[dependencies]
rawsys-linux = { git = "https://github.com/sonjaehyuk/rawsys-linux" }
```
In code, `rawsys-linux` is imported as `rawsys_linux` (hyphen → underscore):
```rust
use rawsys_linux::{syscall, Sysno, SyscallWord};
```
## Quick Start
Unsafe by nature: invoking syscalls bypasses libc. Use with care.
```rust
use rawsys_linux::{syscall, Sysno, SyscallWord};
fn main() {
unsafe {
// openat(AT_FDCWD, "/dev/null", O_RDONLY, 0)
let fd = syscall(Sysno::openat, &rawsys_linux::SyscallArgs::from(&[
(-100isize) as SyscallWord,
"/dev/null\0".as_ptr() as SyscallWord,
0,
0,
]))?;
// close(fd)
let _ = syscall(Sysno::close, &rawsys_linux::SyscallArgs::from(&[fd]))?;
}
}
```
Macro form is also available:
```rust
use rawsys_linux::syscall;
fn main() {
unsafe {
let tid = syscall!(Sysno::gettid)?;
let _ = tid;
}
}
```
## Features & Configuration
Default features: `std`, `serde`.
Additional features:
- `full`: Enables all optional features.
- `all`: Exposes syscall tables for all architectures.
- Per-architecture: `aarch64`, `arm`, `loongarch64`, `mips`, `mips64`, `powerpc`, `powerpc64`, `riscv32`, `riscv64`, `s390x`, `sparc`, `sparc64`, `x86`, `x86_64`.
- Kernel versions: `default_kernel_5_4`, `default_kernel_5_10`, `default_kernel_5_15`, `default_kernel_6_1`, `default_kernel_6_6`, `default_kernel_6_10`, `default_kernel_6_12`.
**kernel versions selects the kernel version exposed by default, not the available kernels. All versions are available via modules.**
### no_std
Disable default features and choose exactly one kernel version:
```toml
[dependencies]
rawsys-linux = { git = "https://github.com/sonjaehyuk/rawsys-linux", default-features = false, features = ["default_kernel_6_12", "serde"] }
```
Notes:
- Syscall invocation works without `std`. Error handling (`Errno`) and internals are `no_std`-friendly.
- Some architectures require nightly due to inline assembly constraints (see Architecture Support).
### Kernel Version Selection (mutually exclusive)
Pick exactly one kernel version to lock syscall tables. If none is chosen, the latest (`default_kernel_6_12`) is used by default.
```bash
cargo build --features "default_kernel_5_10"
cargo build --features "default_kernel_6_6 aarch64"
```
Enabling multiple `default_kernel_*` features simultaneously will cause duplicate symbol errors. Choose exactly one.
### Serde
`Sysno`, `SysnoSet`, and related types implement Serde. To disable Serde, turn off default features and opt-in only what you need.
```toml
[dependencies]
rawsys-linux = { git = "https://github.com/sonjaehyuk/rawsys-linux", default-features = false, features = ["default_kernel_6_12"] }
```
## Build Examples
```bash
# x86-64 target with kernel 6.1 tables
cargo build --features "default_kernel_6_1"
# Cross-compile: expose aarch64 tables + kernel 5.15
cargo build --features "aarch64 default_kernel_5_15"
# All architectures + kernel 6.12
cargo build --features "all default_kernel_6_12"
```
## Architecture Support
The *Enum* column means that a `Sysno` enum is implemented for this
architecture.
The *Invoke* column means that syscalls can be invoked for this architecture.
The *Stable Rust?* column means that syscall invocation only requires stable Rust. Some architectures require nightly Rust because inline assembly [is not yet stabilized for all architectures][asm_experimental_arch].
[asm_experimental_arch]: https://github.com/rust-lang/rust/issues/93335
| `arm`\* | ✅ | ✅ | Yes ✅ |
| `aarch64` | ✅ | ✅ | Yes ✅ |
| `mips` | ✅ | ✅ | No ❌ |
| `mips64` | ✅ | ✅ | No ❌ |
| `powerpc` | ✅ | ✅ | No ❌ |
| `powerpc64` | ✅ | ✅ | No ❌ |
| `riscv32` | ✅ | ❌† | No ❌ |
| `riscv64` | ✅ | ✅ | Yes ✅ |
| `s390x` | ✅ | ✅ | No ❌ |
| `sparc` | ✅ | ❌ | N/A |
| `sparc64` | ✅ | ❌ | N/A |
| `x86` | ✅ | ✅ | Yes ✅ |
| `x86_64` | ✅ | ✅ | Yes ✅ |
\* Includes ARM thumb mode support.
† Rust does not support riscv32 Linux targets, but syscall functions are
implemented if you're feeling adventurous.
## Updating the syscall list
Updates are pulled from the Linux source tree (tables or unistd headers).
- Generate syscalls for a specific version:
- `cd syscalls-gen && cargo run -- --version v6.10`
- Generate multiple versions and/or specific archs:
- `cd syscalls-gen && cargo run -- --versions v6.8,v6.10 --archs x86_64,aarch64`
This will add files under `src/arch/<arch>/vX_Y.rs` (e.g., `src/arch/x86_64/v6_10.rs`).
When adding a new version, declare the module in each architecture’s `mod.rs` and update the selection logic as needed.
## About contributing
Check out [CONTRIBUTING.md](CONTRIBUTING.md)
## License & Acknowledgements
- License: [BSD-2-Clause](LICENSE)
- Acknowledgements: Thanks to Jason White’s original `syscalls` project.