Commit Graph

15 Commits

Author SHA1 Message Date
Miguel Ojeda
b126341111 docs: rust: quick-start: add section on Linux distributions
Now that we are starting to support several Rust compiler and `bindgen`
versions, there is a good chance some Linux distributions work out of
the box.

Thus, provide some instructions on how to set the toolchain up for a
few major Linux distributions. This simplifies the setup users need to
build the kernel.

In addition, add an introduction to the document so that it is easier
to understand its structure and move the LLVM+Rust kernel.org toolchains
paragraph there (removing "depending on the Linux version"). We may want
to reorganize the document or split it in the future, but I wanted to
focus this commit on the new information added about each particular
distribution.

Finally, remove the `rustup`'s components mention in `changes.rst` since
users do not need it if they install the toolchain via the distributions
(and anyway it was too detailed for that main document).

Cc: Jan Alexander Steffens <heftig@archlinux.org>
Cc: Johannes Löthberg <johannes@kyriasis.com>
Cc: Fabian Grünbichler <debian@fabian.gruenbichler.email>
Cc: Josh Stone <jistone@redhat.com>
Cc: Randy Barlow <randy@electronsweatshop.com>
Cc: Anna (navi) Figueiredo Gomes <navi@vlhl.dev>
Cc: Matoro Mahri <matoro_gentoo@matoro.tk>
Cc: Ryan Scheel <ryan.havvy@gmail.com>
Cc: figsoda <figsoda@pm.me>
Cc: Jörg Thalheim <joerg@thalheim.io>
Cc: Theodore Ni <43ngvg@masqt.com>
Cc: Winter <nixos@winter.cafe>
Cc: William Brown <wbrown@suse.de>
Cc: Xiaoguang Wang <xiaoguang.wang@suse.com>
Cc: Andrea Righi <andrea.righi@canonical.com>
Cc: Zixing Liu <zixing.liu@canonical.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-14-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:29:55 +02:00
Miguel Ojeda
c844fa64a2 rust: start supporting several bindgen versions
With both the workaround for `bindgen` 0.69.0 and the warning about
0.66.0 and 0.66.1 in place, start supporting several `bindgen` versions,
like it was done for the Rust compiler in a previous patch.

All other versions, including the latest 0.69.4, build without errors.

The `bindgen` project, like Rust, has also agreed to have the kernel
in their CI [1] -- thanks! This should help both projects: `bindgen`
will be able to detect early issues like those mentioned above, and the
kernel will be very likely build with new releases (at least for the
basic configuration being tested).

Link: https://github.com/rust-lang/rust-bindgen/pull/2851 [1]
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-10-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:52 +02:00
Miguel Ojeda
d49082faf6 rust: avoid assuming a particular bindgen build
`bindgen`'s logic to find `libclang` (via `clang-sys`) may change over
time, and depends on how it was built (e.g. Linux distributions may decide
to build it differently, and we are going to provide documentation on
installing it via distributions later in this series).

Therefore, clarify that `bindgen` may be built in several ways and
simplify the documentation by only mentioning the most prominent
environment variable (`LIBCLANG_PATH`) as an example on how to tweak the
search of the library at runtime (i.e. when `bindgen` is built as our
documentation explains). This also avoids duplicating the documentation,
like `bindgen` itself does (i.e. it refers to `clang-sys`).

Similarly, replace the test we had for this (which used the real program)
with a mocked one, to avoid depending on the particular build as well.

Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-8-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:52 +02:00
Miguel Ojeda
63b27f4a00 rust: start supporting several compiler versions
It is time to start supporting several Rust compiler versions and thus
establish a minimum Rust version.

We may still want to upgrade the minimum sometimes in the beginning since
there may be important features coming into the language that improve
how we write code (e.g. field projections), which may or may not make
sense to support conditionally.

We will start with a window of two stable releases, and widen it over
time. Thus this patch does not move the current minimum (1.78.0), but
instead adds support for the recently released 1.79.0.

This should already be enough for kernel developers in distributions that
provide recent Rust compiler versions routinely, such as Arch Linux,
Debian Unstable (outside the freeze period), Fedora Linux, Gentoo
Linux (especially the testing channel), Nix (unstable) and openSUSE
Tumbleweed. See the documentation patch about it later in this series.

In addition, Rust for Linux is now being built-tested in Rust's pre-merge
CI [1]. That is, every change that is attempting to land into the Rust
compiler is tested against the kernel, and it is merged only if it passes
-- thanks to the Rust project for that!

Thus, with the pre-merge CI in place, both projects hope to avoid
unintentional changes to Rust that break the kernel. This means that,
in general, apart from intentional changes on their side (that we will
need to workaround conditionally on our side), the upcoming Rust compiler
versions should generally work.

For instance, currently, the beta (1.80.0) and nightly (1.81.0) branches
work as well.

Of course, the Rust for Linux CI job in the Rust toolchain may still need
to be temporarily disabled for different reasons, but the intention is
to help bring Rust for Linux into stable Rust.

Link: https://github.com/rust-lang/rust/pull/125209 [1]
Reviewed-by: Finn Behrens <me@kloenk.dev>
Tested-by: Benno Lossin <benno.lossin@proton.me>
Tested-by: Andreas Hindborg <a.hindborg@samsung.com>
Link: https://lore.kernel.org/r/20240709160615.998336-7-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10 10:28:52 +02:00
Miguel Ojeda
9ffc80c819 kbuild: rust: remove now-unneeded rusttest custom sysroot handling
Since we dropped our custom `alloc` in commit 9d0441bab7 ("rust: alloc:
remove our fork of the `alloc` crate"), there is no need anymore to keep
the custom sysroot hack.

Thus delete it, which makes the target way simpler and faster too.

This also means we are not using Cargo for anything at the moment,
and that no download is required anymore, so update the main `Makefile`
and the documentation accordingly.

Link: https://lore.kernel.org/r/20240528163502.411600-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:39:39 +02:00
Nathan Chancellor
526c539452 docs: rust: introduce the new kernel.org LLVM+Rust toolchains
These combined LLVM+Rust toolchains are now available, thanks to Nathan
Chancellor (ClangBuiltLinux).

Thus introduce them in the Rust Quick Start guide.

Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240517170615.377786-1-ojeda@kernel.org
Co-developed-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-08 22:39:29 +02:00
Viresh Kumar
711cbfc717 docs: rust: Clarify that 'rustup override' applies to build directory
'rustup override' is required to be set for the build directory and not
necessarily the kernel source tree (unless the build directory is its
subdir).

Clarify the same in the Quick Start guide.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Originally-pointed-out-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/commit/f2238e7
Link: https://lore.kernel.org/r/e2b943eca92abebbf035447b3569f09a7176c770.1702366951.git.viresh.kumar@linaro.org
[ Reworded and fixed quotes for `--path` and `set`. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21 22:47:40 +01:00
Miguel Ojeda
7583ce66dd docs: rust: remove CC=clang mentions
Nowadays all architectures except s390 recommend using `LLVM=1` instead of
`CC=clang`, and since commit a3c6bfba44 ("Documentation/llvm: refresh
docs") the Kbuild LLVM documentation makes `LLVM=1` the way to go:

    We want to encourage the use of ``LLVM=1`` rather than just
    ``CC=clang``. Make that suggestion "above the fold" and "front and
    center" in our docs.

In particular, that commit removes the examples with `CC=clang`.

Thus do the same in the Rust Quick Start guide, i.e. remove the `CC=clang`
mentions, especially since the architectures that have had their Rust
support upstreamed (or soon to be upstreamed) are all `LLVM=1` ones.
And perhaps by the time Rust is supported for s390 (or new architectures),
it may have moved to `LLVM=1` anyway. Otherwise, this can be added back
if needed (or perhaps an extra link to Documentation/kbuild/llvm.rst).

This should also help avoiding potential confusion around `CC=clang` [1].

Link: https://lore.kernel.org/rust-for-linux/6df6e8e5-8d5b-4d3d-91b5-bc0e90c424ea@nvidia.com/ [1]
Reviewed-by: Ariel Miculas <amiculas@cisco.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Justin Stitt <justinstitt@google.com>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20231215124751.175191-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21 22:47:09 +01:00
Trevor Gross
2285eb2f24 docs: rust: clarify what 'rustup override' does
The behavior of 'rustup override' is not very well known. Add a small
note about what it does, so users have a better understanding of how it
affects their system toolchain (i.e., it does not affect system
toolchain and only sets a directory-specific override).

Signed-off-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230803060437.12157-3-tmgross@umich.edu
[ Undid the `:` to `::` change. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21 00:36:41 +02:00
Trevor Gross
8cb40124cf docs: rust: update instructions for obtaining 'core' source
The source for Rust's 'core' library is needed to build the kernel with
Rust support. This sometimes needs to be obtained by hand when using a
standalone version of 'rustc' not managed by 'rustup'. Currently, the
documentation suggests cloning the 'rust' repository to obtain these
sources, but this is quite slow (on the order of a multiple minutes).

Change this documentation to suggest using the source tarball instead.
The tarball includes only needed files (<5M) and is significantly faster
to download; this is more in line with what 'rustup' does.

Also simplify wording of the relevant section.

Link: https://github.com/Rust-for-Linux/linux/pull/1024
Signed-off-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20230803060437.12157-2-tmgross@umich.edu
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-20 23:16:39 +02:00
Guillaume Plourde
b603c6cc40 docs: rust: add command line to rust-analyzer section
Add command line to rust-analyzer section for convenience purposes.

Signed-off-by: Guillaume Plourde <gplourde@protonmail.com>
Link: https://lore.kernel.org/r/y4jBalhfESeCZDShmVaGwrdlIRoIHroqNVUUYLck6qGNwB5e7wbIJO5DoiLBTPpTNYtdneWRODjhXwlIl9VzokqxffdNU7y__1wIa7BBl94=@protonmail.com
[ Fixed indentation to tab and reworded title. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-20 23:16:39 +02:00
Aakash Sen Sharma
08ab786556 rust: bindgen: upgrade to 0.65.1
In LLVM 16, anonymous items may return names like `(unnamed union at ..)`
rather than empty names [1], which breaks Rust-enabled builds because
bindgen assumed an empty name instead of detecting them via
`clang_Cursor_isAnonymous` [2]:

    $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc)
      RUSTC L rust/core.o
      BINDGEN rust/bindings/bindings_generated.rs
      BINDGEN rust/bindings/bindings_helpers_generated.rs
      BINDGEN rust/uapi/uapi_generated.rs
    thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9
    ...
    thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9
    ...

This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to
a more recent version, 0.65.1, to support LLVM 16.

Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to
`--{allow,block}list-*` [3], update them on our side too.

In addition, bindgen 0.61.0 moved its CLI utility into a binary crate
called `bindgen-cli` [4]. Thus update the installation command in the
Quick Start guide.

Moreover, bindgen 0.61.0 changed the default functionality to bind
`size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag
to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed
the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen.

Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in
its different forms) [7]. Thus remove the infinite loop in our Rust
panic handler after calling `BUG()`, since bindgen now correctly
generates a `BUG()` binding that returns `!` instead of `()`.

Link: 19e984ef8f [1]
Link: https://github.com/rust-lang/rust-bindgen/pull/2319 [2]
Link: https://github.com/rust-lang/rust-bindgen/pull/1990 [3]
Link: https://github.com/rust-lang/rust-bindgen/pull/2284 [4]
Link: cc78b6fdb6 [5]
Link: https://github.com/rust-lang/rust-bindgen/pull/2408 [6]
Link: https://github.com/rust-lang/rust-bindgen/issues/2094 [7]
Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com>
Closes: https://github.com/Rust-for-Linux/linux/issues/1013
Tested-by: Ariel Miculas <amiculas@cisco.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com
[ Reworded commit message. Mentioned the `bindgen-cli` binary crate
  change, linked to it and updated the Quick Start guide. Re-added a
  deleted "as" word in a code comment and reflowed comment to respect
  the maximum length. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-15 00:37:22 +02:00
Miguel Ojeda
eae90172c5 docs: rust: add paragraph about finding a suitable libclang
Sometimes users need to tweak the finding process of `libclang`
for `bindgen` via the `clang-sys`-provided environment variables.

Thus add a paragraph to the setting up guide, including a reference
to `clang-sys`'s relevant documentation.

Link: https://lore.kernel.org/rust-for-linux/CAKwvOdm5JT4wbdQQYuW+RT07rCi6whGBM2iUAyg8A1CmLXG6Nw@mail.gmail.com/
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20230616001631.463536-4-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-09 19:33:31 +02:00
Miguel Ojeda
6883b29c6c docs: rust: point directly to the standalone installers
The Quick Start guide points to the Rust programming language front
page when it mentions the possibility of using the standalone
installers instead of `rustup`.

This was done to have a hopefully stable link, but it is not too
helpful: readers need to figure out how to reach the standalone
installers from there.

Thus point directly to the page (and anchor) with the table that
contains the standalone installers (plus signing key etc.).

If the link breaks in the future, we can always update it as
needed. And anyway having the full link includes the domain and
gives more information about where the old docs were in such
a broken link case, which may help.

Link: https://lore.kernel.org/linux-doc/CANiq72=gpzQyh1ExGbBWWNdgH-mTATdG5F600jKD1=NLLCn7wg@mail.gmail.com/
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Link: https://lore.kernel.org/r/20230306220959.240235-1-ojeda@kernel.org
[ Removed "install ``rustup``" ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31 18:52:35 +02:00
Miguel Ojeda
d07479b211 docs: add Rust documentation
Most of the documentation for Rust is written within the source code
itself, as it is idiomatic for Rust projects. This applies to both
the shared infrastructure at `rust/` as well as any other Rust module
(e.g. drivers) written across the kernel.

However, these documents contain general information that does not
fit particularly well in the source code, like the Quick Start guide.

It also contains a few other small changes elsewhere in the
documentation folder.

Reviewed-by: Kees Cook <keescook@chromium.org>
Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com>
Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com>
Co-developed-by: Finn Behrens <me@kloenk.de>
Signed-off-by: Finn Behrens <me@kloenk.de>
Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com>
Co-developed-by: Wedson Almeida Filho <wedsonaf@google.com>
Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com>
Co-developed-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com>
Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com>
Co-developed-by: Wu XiangCheng <bobwxc@email.cn>
Signed-off-by: Wu XiangCheng <bobwxc@email.cn>
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de>
Co-developed-by: Yuki Okushi <jtitor@2k36.org>
Signed-off-by: Yuki Okushi <jtitor@2k36.org>
Co-developed-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Co-developed-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Co-developed-by: Julian Merkle <me@jvmerkle.de>
Signed-off-by: Julian Merkle <me@jvmerkle.de>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28 09:02:45 +02:00