region-rs

Cross-platform virtual memory API

This crate provides a cross-platform Rust API for allocating, querying and manipulating virtual memory. It is a thin abstraction over platform APIs such as VirtualQuery/VirtualAlloc/VirtualLock on Windows and mprotect/mmap/mlock (and friends) on Unix-like systems.

Platforms

Continuously tested against:

• Linux (gnu / musl)
• Windows (gnu / msvc)
• macOS
• FreeBSD
• OpenBSD
• NetBSD

Also checked / supported where practical:

• Android (compile-checked; full cross tests currently blocked by toolchain linking)
• Illumos
• GNU/Hurd (compile-checked via nightly -Zbuild-std=core,alloc; no prebuilt rust-std)
• Redox (allocation/protection; region querying is not yet available)

Installation

[dependencies]
region = "4.0.0"

The default feature set includes std. Disable it to use the crate as #![no_std] + alloc:

region = { version = "4.0.0", default-features = false }

Example

use region::Protection;

let data = [0xDE, 0xAD, 0xBE, 0xEF];

// Page size
let pz = region::page::size();

// VirtualQuery | '/proc/self/maps'
let q  = region::query(data.as_ptr())?;
let qr = region::query_range(data.as_ptr(), data.len())?;

// VirtualAlloc | mmap
let alloc = region::alloc(100, Protection::READ_WRITE)?;

// VirtualProtect | mprotect
unsafe {
  region::protect(data.as_ptr(), data.len(), Protection::READ_WRITE_EXECUTE)?;
}

// Temporarily change one or more pages' protection
let handle = unsafe {
  region::protect_with_handle(data.as_ptr(), data.len(), Protection::READ_WRITE_EXECUTE)?
};

// VirtualLock | mlock
let guard = region::lock(data.as_ptr(), data.len())?;

Compatibility notes

• This is a major release (4.0.0): Rust edition is 2024, MSRV is 1.85, and a few APIs/error types changed for no_std friendliness and safer locking semantics.
• bitflags is now 2.x. Prefer Protection::from_bits_retain over the deprecated from_bits_unchecked.
• windows-sys accepts >=0.52, <=0.61 so dependents can unify versions.