rust: remove leftover mentions of the `alloc` crate

In commit 392e34b6bc22 ("kbuild: rust: remove the `alloc` crate and
`GlobalAlloc`") we stopped using the upstream `alloc` crate.

Thus remove a fe

rust: remove leftover mentions of the `alloc` crate

In commit 392e34b6bc22 ("kbuild: rust: remove the `alloc` crate and
`GlobalAlloc`") we stopped using the upstream `alloc` crate.

Thus remove a few leftover mentions treewide.

Cc: [email protected] # Also to 6.12.y after the `alloc` backport lands
Fixes: 392e34b6bc22 ("kbuild: rust: remove the `alloc` crate and `GlobalAlloc`")
Reviewed-by: Danilo Krummrich <[email protected]>
Reviewed-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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docs: rust: quick-start: add Ubuntu

Ubuntu has changed their maintenance model for Rust toolchains and is
now providing recent Rust releases in their releases, including both
LTS and non-LTS (interi

docs: rust: quick-start: add Ubuntu

Ubuntu has changed their maintenance model for Rust toolchains and is
now providing recent Rust releases in their releases, including both
LTS and non-LTS (interim) releases.

Therefore, add instructions to the Quick Start guide for Ubuntu, like
it is done for the other distributions.

Link: https://packages.ubuntu.com/search?keywords=rustc-1
Link: https://packages.ubuntu.com/search?keywords=bindgen-0
Cc: Zixing Liu <[email protected]>
Cc: William Grant <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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docs: rust: remove unintended blockquote in Quick Start

Remove indentation within the "Hacking" section of the Rust Quick Start
guide, i.e. remove a `<blockquote>` HTML element from the rendered
doc

docs: rust: remove unintended blockquote in Quick Start

Remove indentation within the "Hacking" section of the Rust Quick Start
guide, i.e. remove a `<blockquote>` HTML element from the rendered
documentation.

Reported-by: Miguel Ojeda <[email protected]>
Closes: https://github.com/Rust-for-Linux/linux/issues/1103
Fixes: d07479b211b7 ("docs: add Rust documentation")
Signed-off-by: Jon Mulder <[email protected]>
Link: https://lore.kernel.org/r/20240826-pr-docs-rust-remove-quickstart-blockquote-v1-1-c51317d8d71a@gmail.com
[ Added Fixes tag, reworded slightly and matched title to a previous,
similar commit. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>

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docs: rust: quick-start: add Debian Testing

Debian Testing is now also providing recent Rust releases (outside of
the freeze period), like Debian Unstable (Sid).

Thus add it to the list.

Cc: Fabia

docs: rust: quick-start: add Debian Testing

Debian Testing is now also providing recent Rust releases (outside of
the freeze period), like Debian Unstable (Sid).

Thus add it to the list.

Cc: Fabian Grünbichler <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>

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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

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 <[email protected]>
Cc: Johannes Löthberg <[email protected]>
Cc: Fabian Grünbichler <[email protected]>
Cc: Josh Stone <[email protected]>
Cc: Randy Barlow <[email protected]>
Cc: Anna (navi) Figueiredo Gomes <[email protected]>
Cc: Matoro Mahri <[email protected]>
Cc: Ryan Scheel <[email protected]>
Cc: figsoda <[email protected]>
Cc: Jörg Thalheim <[email protected]>
Cc: Theodore Ni <[email protected]>
Cc: Winter <[email protected]>
Cc: William Brown <[email protected]>
Cc: Xiaoguang Wang <[email protected]>
Cc: Andrea Righi <[email protected]>
Cc: Zixing Liu <[email protected]>
Cc: Nathan Chancellor <[email protected]>
Tested-by: Benno Lossin <[email protected]>
Tested-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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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

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 <[email protected]>
Tested-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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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

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 <[email protected]>
Tested-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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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 so

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 <[email protected]>
Tested-by: Benno Lossin <[email protected]>
Tested-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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kbuild: rust: remove now-unneeded `rusttest` custom sysroot handling

Since we dropped our custom `alloc` in commit 9d0441bab775 ("rust: alloc:
remove our fork of the `alloc` crate"), there is no nee

kbuild: rust: remove now-unneeded `rusttest` custom sysroot handling

Since we dropped our custom `alloc` in commit 9d0441bab775 ("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/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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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 Q

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Co-developed-by: Miguel Ojeda <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>

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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 dir

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 <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Originally-pointed-out-by: Masahiro Yamada <[email protected]>
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 <[email protected]>

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docs: rust: remove `CC=clang` mentions

Nowadays all architectures except s390 recommend using `LLVM=1` instead of
`CC=clang`, and since commit a3c6bfba4429 ("Documentation/llvm: refresh
docs") the K

docs: rust: remove `CC=clang` mentions

Nowadays all architectures except s390 recommend using `LLVM=1` instead of
`CC=clang`, and since commit a3c6bfba4429 ("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/[email protected]/ [1]
Reviewed-by: Ariel Miculas <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Reviewed-by: Justin Stitt <[email protected]>
Reviewed-by: John Hubbard <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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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

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 <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Undid the `:` to `::` change. ]
Signed-off-by: Miguel Ojeda <[email protected]>

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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 usi

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 <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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docs: rust: add command line to rust-analyzer section

Add command line to rust-analyzer section for convenience purposes.

Signed-off-by: Guillaume Plourde <[email protected]>
Link: https://lo

docs: rust: add command line to rust-analyzer section

Add command line to rust-analyzer section for convenience purposes.

Signed-off-by: Guillaume Plourde <[email protected]>
Link: https://lore.kernel.org/r/y4jBalhfESeCZDShmVaGwrdlIRoIHroqNVUUYLck6qGNwB5e7wbIJO5DoiLBTPpTNYtdneWRODjhXwlIl9VzokqxffdNU7y__1wIa7BBl94=@protonmail.com
[ Fixed indentation to tab and reworded title. ]
Signed-off-by: Miguel Ojeda <[email protected]>

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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 em

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: https://github.com/llvm/llvm-project/commit/19e984ef8f49bc3ccced15621989fa9703b2cd5b [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: https://github.com/rust-lang/rust-bindgen/commit/cc78b6fdb6e829e5fb8fa1639f2182cb49333569 [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 <[email protected]>
Closes: https://github.com/Rust-for-Linux/linux/issues/1013
Tested-by: Ariel Miculas <[email protected]>
Reviewed-by: Gary Guo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ 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 <[email protected]>

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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

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 <[email protected]>
Reviewed-by: Nathan Chancellor <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>

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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 i

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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Removed "install ``rustup``" ]
Signed-off-by: Miguel Ojeda <[email protected]>

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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 `rus

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 <[email protected]>
Co-developed-by: Alex Gaynor <[email protected]>
Signed-off-by: Alex Gaynor <[email protected]>
Co-developed-by: Finn Behrens <[email protected]>
Signed-off-by: Finn Behrens <[email protected]>
Co-developed-by: Adam Bratschi-Kaye <[email protected]>
Signed-off-by: Adam Bratschi-Kaye <[email protected]>
Co-developed-by: Wedson Almeida Filho <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Co-developed-by: Michael Ellerman <[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Co-developed-by: Sven Van Asbroeck <[email protected]>
Signed-off-by: Sven Van Asbroeck <[email protected]>
Co-developed-by: Wu XiangCheng <[email protected]>
Signed-off-by: Wu XiangCheng <[email protected]>
Co-developed-by: Gary Guo <[email protected]>
Signed-off-by: Gary Guo <[email protected]>
Co-developed-by: Boris-Chengbiao Zhou <[email protected]>
Signed-off-by: Boris-Chengbiao Zhou <[email protected]>
Co-developed-by: Yuki Okushi <[email protected]>
Signed-off-by: Yuki Okushi <[email protected]>
Co-developed-by: Wei Liu <[email protected]>
Signed-off-by: Wei Liu <[email protected]>
Co-developed-by: Daniel Xu <[email protected]>
Signed-off-by: Daniel Xu <[email protected]>
Co-developed-by: Julian Merkle <[email protected]>
Signed-off-by: Julian Merkle <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>

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