Relink

Relink: Rust ELF Loader and Runtime Linker

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Load, link, and rewrite ELF in no_std environments.

Relink is a highly customizable, high-performance Rust ELF loading and runtime linking library. It can load .so files, executables, and object files from disk or memory, then resolve dependencies, apply relocations, and look up symbols. It also exposes observer hooks for load, relocation, symbol binding, and lifecycle events.

When To Use It

• Load plugins, JIT artifacts, or hot-reload modules at runtime.
• Control DT_NEEDED dependencies, symbol scopes, or relocation handling yourself.
• Track or customize load, relocation, symbol binding, and init/fini flow through observer hooks.
• Load ELF from memory, or plug in your own mmap or memory-management backend.
• Scan dependencies and sections first, then reorder layout, pack hot code, use huge pages, or run custom handling.
• Load relocatable ELF files such as .o / .ko.
• Keep ELF loading available in no_std, kernels, embedded systems, or non-standard runtimes.

What It Loads

• Shared objects / dynamic libraries (ET_DYN)
• Executables and PIE-style images (ET_EXEC, plus executable-style ET_DYN)
• Relocatable object files (ET_REL, for example .o / .ko)

Compared With dlopen

Quick Start

The default feature set is full, which is suitable for loading dynamic libraries, executables, relocatable objects, TLS, and lazy binding:

[dependencies]
elf_loader = "0.16.0"

For a smaller build, disable default features and opt in only to what you need:

[dependencies]
elf_loader = { version = "0.16.0", default-features = false, features = ["libc"] }

Use Linker to Load Dependencies

use elf_loader::{
    LinkContext, Linker, Result,
    input::PathBuf,
    linker::SearchPathResolver,
};

const LINKER: Linker<'static, PathBuf> = Linker::new();

fn main() -> Result<()> {
    let root = PathBuf::from("path/to/plugin.so");
    let mut context: LinkContext<PathBuf, ()> = LinkContext::new();

    let loaded = LINKER
        .resolver(SearchPathResolver::new())
        .load(&mut context, root)?;

    let run = unsafe {
        loaded
            .get::<extern "C" fn() -> i32>("run")
            .expect("symbol `run` not found")
    };
    let _ = run();

    Ok(())
}

Benchmarks

The table below is a GitHub Actions performance snapshot. Use it only as a reference for the current test suite. Full environment details are in actions/runs/25632675040/job/75239090388. The fixture is the repository’s libc -> libb -> liba test chain, not the system C library.

Lower is better for loading. scan_first includes dependency scanning and section planning, so it is not a direct dlopen replacement.

Symbol lookup was measured after both loaders had already loaded the fixture chain:

Feature Flags

Notes:

• The default feature set is full, equivalent to tls + lazy-binding + object + libc.
• tls only provides the default resolver; custom TLS resolvers do not need this feature.
• load_object() is still controlled by the object feature. Default builds include it; with --no-default-features, enable it explicitly.

Platform Support

Legend: ✅ supported, 🔧 basic support, 🚧 pending. Complex section-reorder repair and .o / ET_REL support are currently centered on x86_64 and riscv64 relocation handling; contributions for the other architectures are welcome.

Contributing

Issues and pull requests are welcome. Star the project if it is useful in your work.

License

This project is dual-licensed under either of the following:

• MIT License
• Apache License 2.0

Contributors