created_at2021-11-15 16:48:14.915464
updated_at2023-12-19 15:33:17.483073
descriptionA Rust interface to the user-space API of the Mach 3.0 kernel that underlies OSX.
Yuki Okushi (JohnTitor)




Latest Version docs

A Rust interface to the user-space API of the Mach 3.0 kernel exposed in /usr/include/mach that underlies macOS and is linked via libSystem (and libsystem_kernel).

This library does not expose the kernel-space API of the Mach 3.0 kernel exposed in SDK/System/Library/Frameworks/Kernel.framework/Versions/A/Headers/mach.

That is, if you are writing a kernel-resident device drivers or some other kernel extensions you have to use something else. The user-space kernel API is often API-incompatible with the kernel space one, and even in the cases where they match, they are sometimes ABI incompatible such that using this library would have undefined behavior.


Add the following to your Cargo.toml to conditionally include mach on those platforms that support it.

[target.'cfg(any(target_os = "macos", target_os = "ios"))'.dependencies.mach]
version = "0.4"

Available crate feature:

  • unstable (disabled by default): Exposes newly changed APIs. Enabling this may bring breaking changes (see the breaking change policy).

Breaking change policy

We do the following steps when an item is changed/removed on latest toolchain:

  1. Deprecate an existing one
  2. Declare a new one under the unstable feature
  3. After a month or more since releasing a new version that contains that change, remove/change an older one

For instance, if const FOO value is changed from 3 to 4, we expose the newer one, i.e. 4, under unstable first. So the unstable users should notice the change on the first release since deprecating. After a month or more, all the users should notice it.


Examples can be found in the examples directory of this repository.

Since examples/ makes use of the task_for_pid() function, which requires elevated privileges, it is necessary to disable System Integrity Protection (SIP) and to be part of the admin or _developer group in order to run the example. However, do note that disabling SIP is in no way encouraged, and should only be done for development/debugging purposes.

  1. Reboot macOS in recovery mode.
  2. Click on Options.
  3. Log in to your user.
  4. In the menu click on Utilities and then Terminal.
  5. In the terminal type the following command to disable SIP: csrutil disable (csrutil enable to re-enable SIP).
  6. Reboot your machine.

To run the example, build it as follows:

cargo b --example dump_process_registers

Then run it using sudo:

sudo ./target/debug/examples/dump_process_registers

Platform support

The following table describes the current CI set-up:

Target Min. Rust XCode build ctest run
x86_64-apple-darwin 1.33.0 10.3.0 - 13.1.0
aarch64-apple-darwin nightly 13.1.0 - -
aarch64-apple-ios nightly 13.1.0 - -
aarch64-apple-ios-sim nightly 13.1.0 - -
x86_64-apple-ios nightly 13.1.0 - -


This project is licensed under either of

at your option.


Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in mach by you, as defined in the Apache-2.0 license, shall be triple licensed as above, without any additional terms or conditions.

To locally test the library, run:

TARGET=x86_64-apple-darwin RUST_VERSION=nightly ./ci/

where you can replace the TARGET and RUST_VERSION with the target you want to test (e.g. aarch64-apple-darwin) and the Rust version you want to use for the tests (e.g. stable, 1.33.0, etc.).

Commit count: 234

cargo fmt