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1,315,249 commits

Author SHA1 Message Date
Thomas Böhler
524f6a2df7 drm/panic: correctly indent continuation of line in list item
commit 5bb698e6fc upstream.

It is common practice in Rust to indent the next line the same amount of
space as the previous one if both belong to the same list item. Clippy
checks for this with the lint `doc_lazy_continuation`.

    error: doc list item without indentation
    --> drivers/gpu/drm/drm_panic_qr.rs:979:5
        |
    979 | /// conversion to numeric segments.
        |     ^
        |
        = help: if this is supposed to be its own paragraph, add a blank line
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#doc_lazy_continuation
        = note: `-D clippy::doc-lazy-continuation` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::doc_lazy_continuation)]`
    help: indent this line
        |
    979 | ///   conversion to numeric segments.
        |     ++

Indent the offending line by 2 more spaces to remove this Clippy error.

Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-6-witcher@wiredspace.de
[ Reworded to indent Clippy's message. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:48 +01:00
Thomas Böhler
702646c7f0 drm/panic: remove redundant field when assigning value
commit da13129a3f upstream.

Rust allows initializing fields of a struct without specifying the
attribute that is assigned if the variable has the same name. In this
instance this is done for all other attributes of the struct except for
`data`. Clippy notes the redundant field name:

    error: redundant field names in struct initialization
    --> drivers/gpu/drm/drm_panic_qr.rs:495:13
        |
    495 |             data: data,
        |             ^^^^^^^^^^ help: replace it with: `data`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
        = note: `-D clippy::redundant-field-names` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::redundant_field_names)]`

Remove the redundant `data` in the assignment to be consistent.

Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-5-witcher@wiredspace.de
[ Reworded to add Clippy warning like it is done in the rest of the
  series. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:48 +01:00
Thomas Böhler
c264ae4597 drm/panic: prefer eliding lifetimes
commit ae75c40117 upstream.

Eliding lifetimes when possible instead of specifying them directly is
both shorter and easier to read. Clippy notes this in the
`needless_lifetimes` lint:

    error: the following explicit lifetimes could be elided: 'b
       --> drivers/gpu/drm/drm_panic_qr.rs:479:16
        |
    479 |     fn new<'a, 'b>(segments: &[&Segment<'b>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> {
        |                ^^                       ^^
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_lifetimes
        = note: `-D clippy::needless-lifetimes` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::needless_lifetimes)]`
    help: elide the lifetimes
        |
    479 -     fn new<'a, 'b>(segments: &[&Segment<'b>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> {
    479 +     fn new<'a>(segments: &[&Segment<'_>], data: &'a mut [u8]) -> Option<EncodedMsg<'a>> {
        |

Remove the explicit lifetime annotation in favour of an elided lifetime.

Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-4-witcher@wiredspace.de
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:47 +01:00
Thomas Böhler
c9a21ede90 drm/panic: remove unnecessary borrow in alignment_pattern
commit 7b6de57e0b upstream.

The function `alignment_pattern` returns a static reference to a `u8`
slice. The borrow of the returned element in `ALIGNMENT_PATTERNS` is
already a reference as defined in the array definition above so this
borrow is unnecessary and removed by the compiler. Clippy notes this in
`needless_borrow`:

    error: this expression creates a reference which is immediately dereferenced by the compiler
       --> drivers/gpu/drm/drm_panic_qr.rs:245:9
        |
    245 |         &ALIGNMENT_PATTERNS[self.0 - 1]
        |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: change this to: `ALIGNMENT_PATTERNS[self.0 - 1]`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrow
        = note: `-D clippy::needless-borrow` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::needless_borrow)]`

Remove the unnecessary borrow.

Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-3-witcher@wiredspace.de
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:47 +01:00
Thomas Böhler
02ea048393 drm/panic: avoid reimplementing Iterator::find
commit c408dd8167 upstream.

Rust's standard library's `std::iter::Iterator` trait provides a function
`find` that finds the first element that satisfies a predicate.
The function `Version::from_segments` is doing the same thing but is
implementing the same logic itself.

Clippy complains about this in the `manual_find` lint:

    error: manual implementation of `Iterator::find`
       --> drivers/gpu/drm/drm_panic_qr.rs:212:9
        |
    212 | /         for v in (1..=40).map(|k| Version(k)) {
    213 | |             if v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum() {
    214 | |                 return Some(v);
    215 | |             }
    216 | |         }
    217 | |         None
        | |____________^ help: replace with an iterator: `(1..=40).map(|k| Version(k)).find(|&v| v.max_data() * 8 >= segments.iter().map(|s| s.total_size_bits(v)).sum())`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_find
        = note: `-D clippy::manual-find` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::manual_find)]`

Use `Iterator::find` instead to make the intention clearer.

At the same time, clean up the redundant closure that Clippy warns
about too:

    error: redundant closure
    --> drivers/gpu/drm/drm_panic_qr.rs:212:31
        |
    212 |         for v in (1..=40).map(|k| Version(k)) {
        |                               ^^^^^^^^^^^^^^ help: replace the closure with the function itself: `Version`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_closure
        = note: `-D clippy::redundant-closure` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(clippy::redundant_closure)]`

Fixes: cb5164ac43 ("drm/panic: Add a QR code panic screen")
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1123
Signed-off-by: Thomas Böhler <witcher@wiredspace.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20241019084048.22336-2-witcher@wiredspace.de
[ Reworded to mention the redundant closure cleanup too. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:47 +01:00
Danilo Krummrich
14b6c04327 MAINTAINERS: add entry for the Rust alloc module
commit 6ce162a002 upstream.

Add maintainers entry for the Rust `alloc` module.

Currently, this includes the `Allocator` API itself, `Allocator`
implementations, such as `Kmalloc` or `Vmalloc`, as well as the kernel's
implementation of the primary memory allocation data structures, `Box`
and `Vec`.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-30-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:47 +01:00
Danilo Krummrich
298be04c03 kbuild: rust: remove the alloc crate and GlobalAlloc
commit 392e34b6bc upstream.

Now that we have our own `Allocator`, `Box` and `Vec` types we can remove
Rust's `alloc` crate and the `new_uninit` unstable feature.

Also remove `Kmalloc`'s `GlobalAlloc` implementation -- we can't remove
this in a separate patch, since the `alloc` crate requires a
`#[global_allocator]` to set, that implements `GlobalAlloc`.

Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-29-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:47 +01:00
Danilo Krummrich
1ef4cf5f98 rust: alloc: update module comment of alloc.rs
commit 8ae740c391 upstream.

Before we remove Rust's alloc crate, rewrite the module comment in
alloc.rs to avoid a rustdoc warning.

Besides that, the module comment in alloc.rs isn't correct anymore,
we're no longer extending Rust's alloc crate.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-28-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:47 +01:00
Danilo Krummrich
ec50a634be rust: str: test: replace alloc::format
commit eb6f92cd3f upstream.

The current implementation of tests in str.rs use `format!` to format
strings for comparison, which, internally, creates a new `String`.

In order to prepare for getting rid of Rust's alloc crate, we have to
cut this dependency. Instead, implement `format!` for `CString`.

Note that for userspace tests, `Kmalloc`, which is backing `CString`'s
memory, is just a type alias to `Cmalloc`.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-27-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:47 +01:00
Danilo Krummrich
575f8f4711 rust: alloc: implement Cmalloc in module allocator_test
commit dd09538fb4 upstream.

So far the kernel's `Box` and `Vec` types can't be used by userspace
test cases, since all users of those types (e.g. `CString`) use kernel
allocators for instantiation.

In order to allow userspace test cases to make use of such types as
well, implement the `Cmalloc` allocator within the allocator_test module
and type alias all kernel allocators to `Cmalloc`. The `Cmalloc`
allocator uses libc's `realloc()` function as allocator backend.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-26-dakr@kernel.org
[ Removed the temporary `allow(dead_code)` as discussed in the list and
  fixed typo, added backticks. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:46 +01:00
Danilo Krummrich
8079b1b73c rust: alloc: implement contains for Flags
commit 909037ce03 upstream.

Provide a simple helper function to check whether given flags do
contain one or multiple other flags.

This is used by a subsequent patch implementing the Cmalloc `Allocator`
to check for __GFP_ZERO.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-25-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:46 +01:00
Danilo Krummrich
f261b3ae28 rust: error: check for config test in Error::name
commit 4a28ab469f upstream.

Additional to `testlib` also check for `test` in `Error::name`. This is
required by a subsequent patch that (indirectly) uses `Error` in test
cases.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-24-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:46 +01:00
Danilo Krummrich
9c330479d7 rust: error: use core::alloc::LayoutError
commit 29a48d25ff upstream.

Use `core::alloc::LayoutError` instead of `alloc::alloc::LayoutError` in
preparation to get rid of Rust's alloc crate.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-23-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:46 +01:00
Danilo Krummrich
718900ae1b rust: alloc: add Vec to prelude
commit 3145dc91c3 upstream.

Now that we removed `VecExt` and the corresponding includes in
prelude.rs, add the new kernel `Vec` type instead.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-22-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:46 +01:00
Danilo Krummrich
61e82d643c rust: alloc: remove VecExt extension
commit 405966efc7 upstream.

Now that all existing `Vec` users were moved to the kernel `Vec` type,
remove the `VecExt` extension.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-21-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:46 +01:00
Danilo Krummrich
e64a79b9a5 rust: treewide: switch to the kernel Vec type
commit 58eff8e872 upstream.

Now that we got the kernel `Vec` in place, convert all existing `Vec`
users to make use of it.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-20-dakr@kernel.org
[ Converted `kasan_test_rust.rs` too, as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:46 +01:00
Danilo Krummrich
0a798a23bb rust: alloc: implement collect for IntoIter
commit 93e602310f upstream.

Currently, we can't implement `FromIterator`. There are a couple of
issues with this trait in the kernel, namely:

  - Rust's specialization feature is unstable. This prevents us to
    optimize for the special case where `I::IntoIter` equals `Vec`'s
    `IntoIter` type.
  - We also can't use `I::IntoIter`'s type ID either to work around this,
    since `FromIterator` doesn't require this type to be `'static`.
  - `FromIterator::from_iter` does return `Self` instead of
    `Result<Self, AllocError>`, hence we can't properly handle allocation
    failures.
  - Neither `Iterator::collect` nor `FromIterator::from_iter` can handle
    additional allocation flags.

Instead, provide `IntoIter::collect`, such that we can at least convert
`IntoIter` into a `Vec` again.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-19-dakr@kernel.org
[ Added newline in documentation, changed case of section to be
  consistent with an existing one, fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:45 +01:00
Danilo Krummrich
94091ef3d5 rust: alloc: implement IntoIterator for Vec
commit 1d1d223aa3 upstream.

Implement `IntoIterator` for `Vec`, `Vec`'s `IntoIter` type, as well as
`Iterator` for `IntoIter`.

`Vec::into_iter` disassembles the `Vec` into its raw parts; additionally,
`IntoIter` keeps track of a separate pointer, which is incremented
correspondingly as the iterator advances, while the length, or the count
of elements, is decremented.

This also means that `IntoIter` takes the ownership of the backing
buffer and is responsible to drop the remaining elements and free the
backing buffer, if it's dropped.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-18-dakr@kernel.org
[ Fixed typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:45 +01:00
Danilo Krummrich
0ca66a44e2 rust: alloc: implement kernel Vec type
commit 2aac4cd7da upstream.

`Vec` provides a contiguous growable array type with contents allocated
with the kernel's allocators (e.g. `Kmalloc`, `Vmalloc` or `KVmalloc`).

In contrast to Rust's stdlib `Vec` type, the kernel `Vec` type considers
the kernel's GFP flags for all appropriate functions, always reports
allocation failures through `Result<_, AllocError>` and remains
independent from unstable features.

[ This patch starts using a new unstable feature, `inline_const`, but
  it was stabilized in Rust 1.79.0, i.e. the next version after the
  minimum one, thus it will not be an issue. - Miguel ]

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-17-dakr@kernel.org
[ Cleaned `rustdoc` unescaped backtick warning, added a couple more
  backticks elsewhere, fixed typos, sorted `feature`s, rewrapped
  documentation lines. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:45 +01:00
Benno Lossin
2dbf251264 rust: alloc: introduce ArrayLayout
commit 9e7bbfa182 upstream.

When allocating memory for arrays using allocators, the `Layout::array`
function is typically used. It returns a result, since the given size
might be too big. However, `Vec` and its iterators store their allocated
capacity and thus they already did check that the size is not too big.

The `ArrayLayout` type provides this exact behavior, as it can be
infallibly converted into a `Layout`. Instead of a `usize` capacity,
`Vec` and other similar array-storing types can use `ArrayLayout`
instead.

Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-16-dakr@kernel.org
[ Formatted a few comments. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:45 +01:00
Danilo Krummrich
22e1e850e2 rust: alloc: add Box to prelude
commit e1044c2238 upstream.

Now that we removed `BoxExt` and the corresponding includes in
prelude.rs, add the new kernel `Box` type instead.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-15-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:45 +01:00
Danilo Krummrich
34eb8dcb62 rust: alloc: remove extension of std's Box
commit e8c6ccdbca upstream.

Now that all existing `Box` users were moved to the kernel `Box` type,
remove the `BoxExt` extension and all other related extensions.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-14-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:45 +01:00
Danilo Krummrich
17bb4365ec rust: treewide: switch to our kernel Box type
commit 8373147ce4 upstream.

Now that we got the kernel `Box` type in place, convert all existing
`Box` users to make use of it.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-13-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:44 +01:00
Danilo Krummrich
3ca8b102ef rust: alloc: implement kernel Box
commit c8cfa8d0c0 upstream.

`Box` provides the simplest way to allocate memory for a generic type
with one of the kernel's allocators, e.g. `Kmalloc`, `Vmalloc` or
`KVmalloc`.

In contrast to Rust's `Box` type, the kernel `Box` type considers the
kernel's GFP flags for all appropriate functions, always reports
allocation failures through `Result<_, AllocError>` and remains
independent from unstable features.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-12-dakr@kernel.org
[ Added backticks, fixed typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:44 +01:00
Danilo Krummrich
10027707e1 rust: alloc: add __GFP_NOWARN to Flags
commit 01b2196e5a upstream.

Some test cases in subsequent patches provoke allocation failures. Add
`__GFP_NOWARN` to enable test cases to silence unpleasant warnings.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-11-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:44 +01:00
Danilo Krummrich
b1ae22456a rust: alloc: implement KVmalloc allocator
commit 8362c2608b upstream.

Implement `Allocator` for `KVmalloc`, an `Allocator` that tries to
allocate memory with `kmalloc` first and, on failure, falls back to
`vmalloc`.

All memory allocations made with `KVmalloc` end up in
`kvrealloc_noprof()`; all frees in `kvfree()`.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-10-dakr@kernel.org
[ Reworded typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:44 +01:00
Danilo Krummrich
88c5feb07a rust: alloc: implement Vmalloc allocator
commit 61c004781d upstream.

Implement `Allocator` for `Vmalloc`, the kernel's virtually contiguous
allocator, typically used for larger objects, (much) larger than page
size.

All memory allocations made with `Vmalloc` end up in `vrealloc()`.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-9-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:44 +01:00
Danilo Krummrich
a03b5e77db rust: alloc: add module allocator_test
commit 5a888c28e3 upstream.

`Allocator`s, such as `Kmalloc`, will be used by e.g. `Box` and `Vec` in
subsequent patches, and hence this dependency propagates throughout the
whole kernel.

Add the `allocator_test` module that provides an empty implementation
for all `Allocator`s in the kernel, such that we don't break the
`rusttest` make target in subsequent patches.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-8-dakr@kernel.org
[ Added missing `_old_layout` parameter as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:44 +01:00
Danilo Krummrich
dcaf3206d9 rust: alloc: implement Allocator for Kmalloc
commit a34822d1c4 upstream.

Implement `Allocator` for `Kmalloc`, the kernel's default allocator,
typically used for objects smaller than page size.

All memory allocations made with `Kmalloc` end up in `krealloc()`.

It serves as allocator for the subsequently introduced types `KBox` and
`KVec`.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-7-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:44 +01:00
Danilo Krummrich
594134eb9c rust: alloc: make allocator module public
commit a87a36f0bf upstream.

Subsequent patches implement allocators such as `Kmalloc`, `Vmalloc`,
`KVmalloc`; we need them to be available outside of the kernel crate as
well.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-6-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:43 +01:00
Danilo Krummrich
e19e92087a rust: alloc: implement ReallocFunc
commit 8a799831fc upstream.

`ReallocFunc` is an abstraction for the kernel's realloc derivates, such
as `krealloc`, `vrealloc` and `kvrealloc`.

All of the named functions share the same function signature and
implement the same semantics. The `ReallocFunc` abstractions provides a
generalized wrapper around those, to trivialize the implementation of
`Kmalloc`, `Vmalloc` and `KVmalloc` in subsequent patches.

Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-5-dakr@kernel.org
[ Added temporary `allow(dead_code)` for `dangling_from_layout` to clean
  warning in `rusttest` target as discussed in the list (but it is
  needed earlier, i.e. in this patch already). Added colon. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:43 +01:00
Danilo Krummrich
b3b7ea4b0d rust: alloc: rename KernelAllocator to Kmalloc
commit 941e655314 upstream.

Subsequent patches implement `Vmalloc` and `KVmalloc` allocators, hence
align `KernelAllocator` to this naming scheme.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-4-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:43 +01:00
Danilo Krummrich
e40d06619c rust: alloc: separate aligned_size from krealloc_aligned
commit a654a6e096 upstream.

Separate `aligned_size` from `krealloc_aligned`.

Subsequent patches implement `Allocator` derivates, such as `Kmalloc`,
that require `aligned_size` and replace the original `krealloc_aligned`.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-3-dakr@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:43 +01:00
Danilo Krummrich
4b773fe566 rust: alloc: add Allocator trait
commit b7a084ba4f upstream.

Add a kernel specific `Allocator` trait, that in contrast to the one in
Rust's core library doesn't require unstable features and supports GFP
flags.

Subsequent patches add the following trait implementors: `Kmalloc`,
`Vmalloc` and `KVmalloc`.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Link: https://lore.kernel.org/r/20241004154149.93856-2-dakr@kernel.org
[ Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:43 +01:00
Filipe Xavier
311d5ecf16 rust: error: optimize error type to use nonzero
commit e9759c5b9e upstream.

Optimize `Result<(), Error>` size by changing `Error` type to
`NonZero*` for niche optimization.

This reduces the space used by the `Result` type, as the `NonZero*`
type enables the compiler to apply more efficient memory layout.
For example, the `Result<(), Error>` changes size from 8 to 4 bytes.

Link: https://github.com/Rust-for-Linux/linux/issues/1120
Signed-off-by: Filipe Xavier <felipe_life@live.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/BL0PR02MB4914B9B088865CF237731207E9732@BL0PR02MB4914.namprd02.prod.outlook.com
[ Removed unneeded block around `match`, added backticks in panic
  message and added intra-doc link. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:43 +01:00
Filipe Xavier
6e5a4992d1 rust: error: make conversion functions public
commit 5ed1474734 upstream.

Change visibility to public of functions in error.rs:
from_err_ptr, from_errno, from_result and to_ptr.
Additionally, remove dead_code annotations.

Link: https://github.com/Rust-for-Linux/linux/issues/1105
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Filipe Xavier <felipe_life@live.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/DM4PR14MB7276E6948E67B3B23D8EA847E9652@DM4PR14MB7276.namprd14.prod.outlook.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:43 +01:00
Miguel Ojeda
cf1cdd56d3 Documentation: rust: discuss #[expect(...)] in the guidelines
commit 04866494e9 upstream.

Discuss `#[expect(...)]` in the Lints sections of the coding guidelines
document, which is an upcoming feature in Rust 1.81.0, and explain that
it is generally to be preferred over `allow` unless there is a reason
not to use it (e.g. conditional compilation being involved).

Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-19-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:42 +01:00
Miguel Ojeda
706d4296b8 rust: start using the #[expect(...)] attribute
commit 1f9ed17254 upstream.

In Rust, it is possible to `allow` particular warnings (diagnostics,
lints) locally, making the compiler ignore instances of a given warning
within a given function, module, block, etc.

It is similar to `#pragma GCC diagnostic push` + `ignored` + `pop` in C:

    #pragma GCC diagnostic push
    #pragma GCC diagnostic ignored "-Wunused-function"
    static void f(void) {}
    #pragma GCC diagnostic pop

But way less verbose:

    #[allow(dead_code)]
    fn f() {}

By that virtue, it makes it possible to comfortably enable more
diagnostics by default (i.e. outside `W=` levels) that may have some
false positives but that are otherwise quite useful to keep enabled to
catch potential mistakes.

The `#[expect(...)]` attribute [1] takes this further, and makes the
compiler warn if the diagnostic was _not_ produced. For instance, the
following will ensure that, when `f()` is called somewhere, we will have
to remove the attribute:

    #[expect(dead_code)]
    fn f() {}

If we do not, we get a warning from the compiler:

    warning: this lint expectation is unfulfilled
     --> x.rs:3:10
      |
    3 | #[expect(dead_code)]
      |          ^^^^^^^^^
      |
      = note: `#[warn(unfulfilled_lint_expectations)]` on by default

This means that `expect`s do not get forgotten when they are not needed.

See the next commit for more details, nuances on its usage and
documentation on the feature.

The attribute requires the `lint_reasons` [2] unstable feature, but it
is becoming stable in 1.81.0 (to be released on 2024-09-05) and it has
already been useful to clean things up in this patch series, finding
cases where the `allow`s should not have been there.

Thus, enable `lint_reasons` and convert some of our `allow`s to `expect`s
where possible.

This feature was also an example of the ongoing collaboration between
Rust and the kernel -- we tested it in the kernel early on and found an
issue that was quickly resolved [3].

Cc: Fridtjof Stoldt <xfrednet@gmail.com>
Cc: Urgau <urgau@numericable.fr>
Link: https://rust-lang.github.io/rfcs/2383-lint-reasons.html#expect-lint-attribute [1]
Link: https://github.com/rust-lang/rust/issues/54503 [2]
Link: https://github.com/rust-lang/rust/issues/114557 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-18-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:42 +01:00
Miguel Ojeda
a24a26adba Documentation: rust: add coding guidelines on lints
commit 139d396572 upstream.

In the C side, disabling diagnostics locally, i.e. within the source code,
is rare (at least in the kernel). Sometimes warnings are manipulated
via the flags at the translation unit level, but that is about it.

In Rust, it is easier to change locally the "level" of lints
(e.g. allowing them locally). In turn, this means it is easier to
globally enable more lints that may trigger a few false positives here
and there that need to be allowed locally, but that generally can spot
issues or bugs.

Thus document this.

Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-17-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:42 +01:00
Miguel Ojeda
87052e24eb rust: enable Clippy's check-private-items
commit 624063b9ac upstream.

In Rust 1.76.0, Clippy added the `check-private-items` lint configuration
option. When turned on (the default is off), it makes several lints
check private items as well.

In our case, it affects two lints we have enabled [1]:
`missing_safety_doc` and `unnecessary_safety_doc`.

It also seems to affect the new `too_long_first_doc_paragraph` lint [2],
even though the documentation does not mention it.

Thus allow the few instances remaining we currently hit and enable
the lint.

Link: https://doc.rust-lang.org/nightly/clippy/lint_configuration.html#check-private-items [1]
Link: https://rust-lang.github.io/rust-clippy/master/index.html#/too_long_first_doc_paragraph [2]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-16-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:42 +01:00
Miguel Ojeda
9dd2e0358b rust: provide proper code documentation titles
commit 2f390cc589 upstream.

Rust 1.82.0's Clippy is introducing [1][2] a new warn-by-default lint,
`too_long_first_doc_paragraph` [3], which is intended to catch titles
of code documentation items that are too long (likely because no title
was provided and the item documentation starts with a paragraph).

This lint does not currently trigger anywhere, but it does detect a couple
cases if checking for private items gets enabled (which we will do in
the next commit):

    error: first doc comment paragraph is too long
      --> rust/kernel/init/__internal.rs:18:1
       |
    18 | / /// This is the module-internal type implementing `PinInit` and `Init`. It is unsafe to create this
    19 | | /// type, since the closure needs to fulfill the same safety requirement as the
    20 | | /// `__pinned_init`/`__init` functions.
       | |_
       |
       = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_long_first_doc_paragraph
       = note: `-D clippy::too-long-first-doc-paragraph` implied by `-D warnings`
       = help: to override `-D warnings` add `#[allow(clippy::too_long_first_doc_paragraph)]`

    error: first doc comment paragraph is too long
     --> rust/kernel/sync/arc/std_vendor.rs:3:1
      |
    3 | / //! The contents of this file come from the Rust standard library, hosted in
    4 | | //! the <https://github.com/rust-lang/rust> repository, licensed under
    5 | | //! "Apache-2.0 OR MIT" and adapted for kernel use. For copyright details,
    6 | | //! see <https://github.com/rust-lang/rust/blob/master/COPYRIGHT>.
      | |_
      |
      = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_long_first_doc_paragraph

Thus clean those two instances.

In addition, since we have a second `std_vendor.rs` file with a similar
header, do the same there too (even if that one does not trigger the lint,
because it is `doc(hidden)`).

Link: https://github.com/rust-lang/rust/pull/129531 [1]
Link: https://github.com/rust-lang/rust-clippy/pull/12993 [2]
Link: https://rust-lang.github.io/rust-clippy/master/index.html#/too_long_first_doc_paragraph [3]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-15-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:42 +01:00
Miguel Ojeda
a01b7b2c1e rust: replace clippy::dbg_macro with disallowed_macros
commit 8577c9dca7 upstream.

Back when we used Rust 1.60.0 (before Rust was merged in the kernel),
we added `-Wclippy::dbg_macro` to the compilation flags. This worked
great with our custom `dbg!` macro (vendored from `std`, but slightly
modified to use the kernel printing facilities).

However, in the very next version, 1.61.0, it stopped working [1] since
the lint started to use a Rust diagnostic item rather than a path to find
the `dbg!` macro [1]. This behavior remains until the current nightly
(1.83.0).

Therefore, currently, the `dbg_macro` is not doing anything, which
explains why we can invoke `dbg!` in samples/rust/rust_print.rs`, as well
as why changing the `#[allow()]`s to `#[expect()]`s in `std_vendor.rs`
doctests does not work since they are not fulfilled.

One possible workaround is using `rustc_attrs` like the standard library
does. However, this is intended to be internal, and we just started
supporting several Rust compiler versions, so it is best to avoid it.

Therefore, instead, use `disallowed_macros`. It is a stable lint and
is more flexible (in that we can provide different macros), although
its diagnostic message(s) are not as nice as the specialized one (yet),
and does not allow to set different lint levels per macro/path [2].

In turn, this requires allowing the (intentional) `dbg!` use in the
sample, as one would have expected.

Finally, in a single case, the `allow` is fixed to be an inner attribute,
since otherwise it was not being applied.

Link: https://github.com/rust-lang/rust-clippy/issues/11303 [1]
Link: https://github.com/rust-lang/rust-clippy/issues/11307 [2]
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-13-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:42 +01:00
Miguel Ojeda
503e18c448 rust: introduce .clippy.toml
commit 7d56786edc upstream.

Some Clippy lints can be configured/tweaked. We will use these knobs to
our advantage in later commits.

This is done via a configuration file, `.clippy.toml` [1]. The file is
currently unstable. This may be a problem in the future, but we can adapt
as needed. In addition, we proposed adding Clippy to the Rust CI's RFL
job [2], so we should be able to catch issues pre-merge.

Thus introduce the file.

Link: https://doc.rust-lang.org/clippy/configuration.html [1]
Link: https://github.com/rust-lang/rust/pull/128928 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-12-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:42 +01:00
Miguel Ojeda
b212da6fdf rust: sync: remove unneeded #[allow(clippy::non_send_fields_in_send_ty)]
commit 5e7c9b84ad upstream.

Rust 1.58.0 (before Rust was merged into the kernel) made Clippy's
`non_send_fields_in_send_ty` lint part of the `suspicious` lint group for
a brief window of time [1] until the minor version 1.58.1 got released
a week after, where the lint was moved back to `nursery`.

By that time, we had already upgraded to that Rust version, and thus we
had `allow`ed the lint here for `CondVar`.

Nowadays, Clippy's `non_send_fields_in_send_ty` would still trigger here
if it were enabled.

Moreover, if enabled, `Lock<T, B>` and `Task` would also require an
`allow`. Therefore, it does not seem like someone is actually enabling it
(in, e.g., a custom flags build).

Finally, the lint does not appear to have had major improvements since
then [2].

Thus remove the `allow` since it is unneeded.

Link: https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1581-2022-01-20 [1]
Link: https://github.com/rust-lang/rust-clippy/issues/8045 [2]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:41 +01:00
Miguel Ojeda
d09e7c93df rust: init: remove unneeded #[allow(clippy::disallowed_names)]
commit d5cc7ab0a0 upstream.

These few cases, unlike others in the same file, did not need the `allow`.

Thus clean them up.

Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-10-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:41 +01:00
Miguel Ojeda
85ad471366 rust: enable rustdoc::unescaped_backticks lint
commit bef83245f5 upstream.

In Rust 1.71.0, `rustdoc` added the `unescaped_backticks` lint, which
detects what are typically typos in Markdown formatting regarding inline
code [1], e.g. from the Rust standard library:

    /// ... to `deref`/`deref_mut`` must ...

    /// ... use [`from_mut`]`. Specifically, ...

It does not seem to have almost any false positives, from the experience
of enabling it in the Rust standard library [2], which will be checked
starting with Rust 1.82.0. The maintainers also confirmed it is ready
to be used.

Thus enable it.

Link: https://doc.rust-lang.org/rustdoc/lints.html#unescaped_backticks [1]
Link: https://github.com/rust-lang/rust/pull/128307 [2]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:41 +01:00
Miguel Ojeda
c6447d4d83 rust: enable clippy::ignored_unit_patterns lint
commit 3fcc233976 upstream.

In Rust 1.73.0, Clippy introduced the `ignored_unit_patterns` lint [1]:

> Matching with `()` explicitly instead of `_` outlines the fact that
> the pattern contains no data. Also it would detect a type change
> that `_` would ignore.

There is only a single case that requires a change:

    error: matching over `()` is more explicit
       --> rust/kernel/types.rs:176:45
        |
    176 |         ScopeGuard::new_with_data((), move |_| cleanup())
        |                                             ^ help: use `()` instead of `_`: `()`
        |
        = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ignored_unit_patterns
        = note: requested on the command line with `-D clippy::ignored-unit-patterns`

Thus clean it up and enable the lint -- no functional change intended.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#/ignored_unit_patterns [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-8-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:41 +01:00
Miguel Ojeda
f07f6c135d rust: enable clippy::unnecessary_safety_doc lint
commit 23f42dc054 upstream.

In Rust 1.67.0, Clippy added the `unnecessary_safety_doc` lint [1],
which is similar to `unnecessary_safety_comment`, but for `# Safety`
sections, i.e. safety preconditions in the documentation.

This is something that should not happen with our coding guidelines in
mind. Thus enable the lint to have it machine-checked.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#/unnecessary_safety_doc [1]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-7-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:41 +01:00
Miguel Ojeda
c778ec35c3 rust: enable clippy::unnecessary_safety_comment lint
commit c28bfe76e4 upstream.

In Rust 1.67.0, Clippy added the `unnecessary_safety_comment` lint [1],
which is the "inverse" of `undocumented_unsafe_blocks`: it finds places
where safe code has a `// SAFETY` comment attached.

The lint currently finds 3 places where we had such mistakes, thus it
seems already quite useful.

Thus clean those and enable it.

Link: https://rust-lang.github.io/rust-clippy/master/index.html#/unnecessary_safety_comment [1]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-6-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:41 +01:00
Miguel Ojeda
4e7072490d rust: enable clippy::undocumented_unsafe_blocks lint
commit db4f72c904 upstream.

Checking that we are not missing any `// SAFETY` comments in our `unsafe`
blocks is something we have wanted to do for a long time, as well as
cleaning up the remaining cases that were not documented [1].

Back when Rust for Linux started, this was something that could have
been done via a script, like Rust's `tidy`. Soon after, in Rust 1.58.0,
Clippy implemented the `undocumented_unsafe_blocks` lint [2].

Even though the lint has a few false positives, e.g. in some cases where
attributes appear between the comment and the `unsafe` block [3], there
are workarounds and the lint seems quite usable already.

Thus enable the lint now.

We still have a few cases to clean up, so just allow those for the moment
by writing a `TODO` comment -- some of those may be good candidates for
new contributors.

Link: https://github.com/Rust-for-Linux/linux/issues/351 [1]
Link: https://rust-lang.github.io/rust-clippy/master/#/undocumented_unsafe_blocks [2]
Link: https://github.com/rust-lang/rust-clippy/issues/13189 [3]
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Tested-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240904204347.168520-5-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-03-13 13:01:41 +01:00