[PATCH v9 00/27] Rust support

Miguel Ojeda
2022-08-05T15:43:03Z

Rust support

This is the patch series (v9) to add support for Rust as a second
language to the Linux kernel.

If you are interested in following this effort, please join us in
the mailing list at:

rust-for-linux@vger.kernel.org

and take a look at the project itself at:

https://github.com/Rust-for-Linux

As usual, special thanks go to ISRG (Internet Security Research Group)
and Google for their financial support on this endeavor.

Cheers,
Miguel

--

# Rust support

This cover letter explains the major changes and updates done since
the previous ones. For those, please see:

RFC: https://lore.kernel.org/lkml/20210414184604.23473-1-ojeda@kernel.org/
v1: https://lore.kernel.org/lkml/20210704202756.29107-1-ojeda@kernel.org/
v2: https://lore.kernel.org/lkml/20211206140313.5653-1-ojeda@kernel.org/
v3: https://lore.kernel.org/lkml/20220117053349.6804-1-ojeda@kernel.org/
v4: https://lore.kernel.org/lkml/20220212130410.6901-1-ojeda@kernel.org/
v5: https://lore.kernel.org/lkml/20220317181032.15436-1-ojeda@kernel.org/
v6: https://lore.kernel.org/lkml/20220507052451.12890-1-ojeda@kernel.org/
v7: https://lore.kernel.org/lkml/20220523020209.11810-1-ojeda@kernel.org/
v8: https://lore.kernel.org/lkml/20220802015052.10452-1-ojeda@kernel.org/

This is a trimmed down v8. It has enough support to compile a minimal
Rust kernel module, with the aim to get the "core" support in first
and then start upstreaming the rest piece by piece.

The kernel module is able to create a `Vec<i32>` (a contiguous,
growable array type), push some numbers and print them on unload to
the kernel log with the `pr_info!` macro.

The patch series could be made even more minimal by removing some of
that too, but this seemed like a good balance.

After the diet regime, 3% of the `kernel` crate remains (down to 500
lines), 60% of `alloc`, and the "adapt `alloc`" commit is 100 lines.
Overall, we went from 40 to 13 klines.

Most of the code has been around in linux-next for some months now,
but to trim down things I had to do minor changes. In any case, please
let me know if this selection is in line with what you expected.

## Patch series status

The Rust support is still to be considered experimental. However,
support is good enough that kernel developers can start working on the
Rust abstractions for subsystems and write drivers and other modules.

The current series will appear in the next `linux-next`, as usual.

I have kept the docs as they were in v8 since they showcase best what
the docs would eventually look like:

https://rust-for-linux.github.io/docs/kernel/

As usual, please see the following link for the live list of unstable
Rust features we are using (note that this trimmed version does not
require all of them):

https://github.com/Rust-for-Linux/linux/issues/2

## Conferences, meetings and liaisons

Join us in LPC 2022 (Linux Plumbers Conference) for the Rust MC
(microconference)! The schedule is available at:

https://lpc.events/event/16/sessions/150/

We will be talking about GCC Rust (the Rust frontend for GCC),
`rustc_codegen_gcc` (the GCC backend for `rustc`), Rust for Linux,
the Rust NVMe driver, the integration of Rust with the Kernel Testing
Service and Rust in the Kernel (via eBPF).

In addition, I would like to personally thank Google and ISRG
(Internet Security Research Group) for sponsoring Kangrejos,
the Rust for Linux workshop:

https://kangrejos.com

## Acknowledgements

The signatures in the main commits correspond to the people that
wrote code that has ended up in them at the present time. For details
on contributions to code and discussions, please see our repository:

https://github.com/Rust-for-Linux/linux

However, we would like to give credit to everyone that has contributed
in one way or another to the Rust for Linux project. Since the
previous cover letter:

- Boqun Feng, Konstantin Shelekhin and David Laight for their
reviews of some of the v8 patches.

- Matthew Wilcox, Greg Kroah-Hartman, Rasmus Villemoes and Christoph
Hellwig for their feedback on v8.

- Björn Roy Baron, Gary Guo and Boqun Feng for stepping up as
reviewers in `MAINTAINERS`.

- Jon Olson for working on a `cpu` module with utilities for
SMP systems.

- Alice Ryhl for working on adding `BINDER_TYPE_PTR` support.

- FUJITA Tomonori for working on PCI support for a NVMe Rust driver.

- Andreas Reindl for working on adding missing `SAFETY` comments.

- Wei Liu for taking the time to answer questions from newcomers
in Zulip.

- Philip Li, Yujie Liu et al. for continuing their work on adding
Rust support to the Intel 0DAY/LKP kernel test robot.

- Philip Herron and Arthur Cohen (and his supporters Open Source
Security and Embecosm) et al. for their ongoing work on GCC Rust.

- Antoni Boucher (and his supporters) et al. for their ongoing
work on `rustc_codegen_gcc`.

- Emilio Cobos Álvarez et al. for their work on `bindgen`, including
on issues that affect the kernel.

- Mats Larsen, Marc Poulhiès et al. for their ongoing work on
improving Rust support in Compiler Explorer.

- Many folks that have reported issues, tested the project,
helped spread the word, joined discussions and contributed in
other ways!

Please see also the acknowledgements on the previous cover letters.

Boqun Feng (2):
kallsyms: use `sizeof` instead of hardcoded size
kallsyms: avoid hardcoding buffer size

Daniel Xu (1):
scripts: add `is_rust_module.sh`

Gary Guo (1):
vsprintf: add new `%pA` format specifier

Miguel Ojeda (22):
kallsyms: add static relationship between `KSYM_NAME_LEN{,_BUFFER}`
kallsyms: support "big" kernel symbols
kallsyms: increase maximum kernel symbol length to 512
rust: add C helpers
rust: import upstream `alloc` crate
rust: adapt `alloc` crate to the kernel
rust: add `compiler_builtins` crate
rust: add `macros` crate
rust: add `bindings` crate
rust: export generated symbols
scripts: checkpatch: diagnose uses of `%pA` in the C side as errors
scripts: checkpatch: enable language-independent checks for Rust
scripts: decode_stacktrace: demangle Rust symbols
scripts: add `generate_rust_analyzer.py`
scripts: add `generate_rust_target.rs`
scripts: add `rust_is_available.sh`
rust: add `.rustfmt.toml`
Kbuild: add Rust support
docs: add Rust documentation
x86: enable initial Rust support
samples: add first Rust examples
MAINTAINERS: Rust

Wedson Almeida Filho (1):
rust: add `kernel` crate

.gitignore | 6 +
.rustfmt.toml | 12 +
Documentation/core-api/printk-formats.rst | 10 +
Documentation/doc-guide/kernel-doc.rst | 3 +
Documentation/index.rst | 1 +
Documentation/kbuild/kbuild.rst | 17 +
Documentation/kbuild/makefiles.rst | 50 +-
Documentation/process/changes.rst | 41 +
Documentation/rust/arch-support.rst | 19 +
Documentation/rust/coding-guidelines.rst | 216 ++
Documentation/rust/general-information.rst | 79 +
Documentation/rust/index.rst | 22 +
Documentation/rust/quick-start.rst | 232 ++
MAINTAINERS | 18 +
Makefile | 172 +-
arch/Kconfig | 6 +
arch/x86/Kconfig | 1 +
arch/x86/Makefile | 10 +
include/linux/compiler_types.h | 6 +-
include/linux/kallsyms.h | 2 +-
init/Kconfig | 46 +-
kernel/configs/rust.config | 1 +
kernel/kallsyms.c | 26 +-
kernel/livepatch/core.c | 4 +-
lib/Kconfig.debug | 34 +
lib/vsprintf.c | 13 +
rust/.gitignore | 8 +
rust/Makefile | 381 +++
rust/alloc/README.md | 33 +
rust/alloc/alloc.rs | 440 +++
rust/alloc/borrow.rs | 498 +++
rust/alloc/boxed.rs | 2028 +++++++++++
rust/alloc/collections/mod.rs | 156 +
rust/alloc/lib.rs | 244 ++
rust/alloc/raw_vec.rs | 527 +++
rust/alloc/slice.rs | 1204 +++++++
rust/alloc/vec/drain.rs | 186 ++
rust/alloc/vec/drain_filter.rs | 145 +
rust/alloc/vec/into_iter.rs | 366 ++
rust/alloc/vec/is_zero.rs | 120 +
rust/alloc/vec/mod.rs | 3140 ++++++++++++++++++
rust/alloc/vec/partial_eq.rs | 49 +
rust/bindgen_parameters | 21 +
rust/bindings/bindings_helper.h | 13 +
rust/bindings/lib.rs | 53 +
rust/compiler_builtins.rs | 63 +
rust/exports.c | 21 +
rust/helpers.c | 51 +
rust/kernel/allocator.rs | 64 +
rust/kernel/error.rs | 59 +
rust/kernel/lib.rs | 78 +
rust/kernel/prelude.rs | 20 +
rust/kernel/print.rs | 198 ++
rust/kernel/str.rs | 72 +
rust/macros/helpers.rs | 51 +
rust/macros/lib.rs | 72 +
rust/macros/module.rs | 282 ++
samples/Kconfig | 2 +
samples/Makefile | 1 +
samples/rust/Kconfig | 30 +
samples/rust/Makefile | 5 +
samples/rust/hostprogs/.gitignore | 3 +
samples/rust/hostprogs/Makefile | 5 +
samples/rust/hostprogs/a.rs | 7 +
samples/rust/hostprogs/b.rs | 5 +
samples/rust/hostprogs/single.rs | 12 +
samples/rust/rust_minimal.rs | 38 +
scripts/.gitignore | 1 +
scripts/Kconfig.include | 6 +-
scripts/Makefile | 3 +
scripts/Makefile.build | 60 +
scripts/Makefile.debug | 10 +
scripts/Makefile.host | 34 +-
scripts/Makefile.lib | 12 +
scripts/Makefile.modfinal | 8 +-
scripts/cc-version.sh | 12 +-
scripts/checkpatch.pl | 12 +-
scripts/decode_stacktrace.sh | 14 +
scripts/generate_rust_analyzer.py | 135 +
scripts/generate_rust_target.rs | 182 +
scripts/is_rust_module.sh | 16 +
scripts/kallsyms.c | 47 +-
scripts/kconfig/confdata.c | 75 +
scripts/min-tool-version.sh | 6 +
scripts/rust_is_available.sh | 160 +
scripts/rust_is_available_bindgen_libclang.h | 2 +
tools/include/linux/kallsyms.h | 2 +-
tools/lib/perf/include/perf/event.h | 2 +-
tools/lib/symbol/kallsyms.h | 2 +-
89 files changed, 12548 insertions(+), 51 deletions(-)
create mode 100644 .rustfmt.toml
create mode 100644 Documentation/rust/arch-support.rst
create mode 100644 Documentation/rust/coding-guidelines.rst
create mode 100644 Documentation/rust/general-information.rst
create mode 100644 Documentation/rust/index.rst
create mode 100644 Documentation/rust/quick-start.rst
create mode 100644 kernel/configs/rust.config
create mode 100644 rust/.gitignore
create mode 100644 rust/Makefile
create mode 100644 rust/alloc/README.md
create mode 100644 rust/alloc/alloc.rs
create mode 100644 rust/alloc/borrow.rs
create mode 100644 rust/alloc/boxed.rs
create mode 100644 rust/alloc/collections/mod.rs
create mode 100644 rust/alloc/lib.rs
create mode 100644 rust/alloc/raw_vec.rs
create mode 100644 rust/alloc/slice.rs
create mode 100644 rust/alloc/vec/drain.rs
create mode 100644 rust/alloc/vec/drain_filter.rs
create mode 100644 rust/alloc/vec/into_iter.rs
create mode 100644 rust/alloc/vec/is_zero.rs
create mode 100644 rust/alloc/vec/mod.rs
create mode 100644 rust/alloc/vec/partial_eq.rs
create mode 100644 rust/bindgen_parameters
create mode 100644 rust/bindings/bindings_helper.h
create mode 100644 rust/bindings/lib.rs
create mode 100644 rust/compiler_builtins.rs
create mode 100644 rust/exports.c
create mode 100644 rust/helpers.c
create mode 100644 rust/kernel/allocator.rs
create mode 100644 rust/kernel/error.rs
create mode 100644 rust/kernel/lib.rs
create mode 100644 rust/kernel/prelude.rs
create mode 100644 rust/kernel/print.rs
create mode 100644 rust/kernel/str.rs
create mode 100644 rust/macros/helpers.rs
create mode 100644 rust/macros/lib.rs
create mode 100644 rust/macros/module.rs
create mode 100644 samples/rust/Kconfig
create mode 100644 samples/rust/Makefile
create mode 100644 samples/rust/hostprogs/.gitignore
create mode 100644 samples/rust/hostprogs/Makefile
create mode 100644 samples/rust/hostprogs/a.rs
create mode 100644 samples/rust/hostprogs/b.rs
create mode 100644 samples/rust/hostprogs/single.rs
create mode 100644 samples/rust/rust_minimal.rs
create mode 100755 scripts/generate_rust_analyzer.py
create mode 100644 scripts/generate_rust_target.rs
create mode 100755 scripts/is_rust_module.sh
create mode 100755 scripts/rust_is_available.sh
create mode 100644 scripts/rust_is_available_bindgen_libclang.h

base-commit: 3d7cb6b04c3f3115719235cc6866b10326de34cd
--
2.37.1