linux.git/rust/kernel, branch v6.6.83

rust: init: use explicit ABI to clean warning in future compilers

2025-02-17T08:40:27+00:00

commit c21bdb3d8a850afdfa4afe77eea39ae9533629b0 upstream.

Starting with Rust 1.86.0 (currently in nightly, to be released on
2025-04-03), the `missing_abi` lint is warn-by-default [1]:

    error: extern declarations without an explicit ABI are deprecated
        --> rust/doctests_kernel_generated.rs:3158:1
         |
    3158 | extern {
         | ^^^^^^ help: explicitly specify the C ABI: `extern "C"`
         |
         = note: `-D missing-abi` implied by `-D warnings`
         = help: to override `-D warnings` add `#[allow(missing_abi)]`

Thus clean it up.

Cc:  # Needed in 6.12.y and 6.13.y only (Rust is pinned in older LTSs).
Fixes: 7f8977a7fe6d ("rust: init: add `{pin_}chain` functions to `{Pin}Init`")
Link: https://github.com/rust-lang/rust/pull/132397 [1]
Reviewed-by: Gary Guo 
Reviewed-by: Alice Ryhl 
Reviewed-by: Fiona Behrens 
Link: https://lore.kernel.org/r/20250121200934.222075-1-ojeda@kernel.org
[ Added 6.13.y to Cc: stable tag. - Miguel ]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: sync: require `T: Sync` for `LockedBy::access`

2024-10-10T09:57:44+00:00

commit a8ee30f45d5d57467ddb7877ed6914d0eba0af7f upstream.

The `LockedBy::access` method only requires a shared reference to the
owner, so if we have shared access to the `LockedBy` from several
threads at once, then two threads could call `access` in parallel and
both obtain a shared reference to the inner value. Thus, require that
`T: Sync` when calling the `access` method.

An alternative is to require `T: Sync` in the `impl Sync for LockedBy`.
This patch does not choose that approach as it gives up the ability to
use `LockedBy` with `!Sync` types, which is okay as long as you only use
`access_mut`.

Cc: stable@vger.kernel.org
Fixes: 7b1f55e3a984 ("rust: sync: introduce `LockedBy`")
Signed-off-by: Alice Ryhl 
Suggested-by: Boqun Feng 
Reviewed-by: Gary Guo 
Link: https://lore.kernel.org/r/20240915-locked-by-sync-fix-v2-1-1a8d89710392@google.com
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: types: Make Opaque::get const

2024-09-12T09:11:25+00:00

commit be2ca1e03965ffb214b6cbda0ffd84daeeb5f214 upstream.

To support a potential usage:

    static foo: Opaque = ..; // Or defined in an extern block.

    ...

    fn bar() {
        let ptr = foo.get();
    }

`Opaque::get` need to be `const`, otherwise compiler will complain
because calls on statics are limited to const functions.

Also `Opaque::get` should be naturally `const` since it's a composition
of two `const` functions: `UnsafeCell::get` and `ptr::cast`.

Signed-off-by: Boqun Feng 
Reviewed-by: Alice Ryhl 
Reviewed-by: Wedson Almeida Filho 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/20240401214543.1242286-1-boqun.feng@gmail.com
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: kernel: require `Send` for `Module` implementations

2024-05-17T10:01:56+00:00

[ Upstream commit 323617f649c0966ad5e741e47e27e06d3a680d8f ]

The thread that calls the module initialisation code when a module is
loaded is not guaranteed [in fact, it is unlikely] to be the same one
that calls the module cleanup code on module unload, therefore, `Module`
implementations must be `Send` to account for them moving from one
thread to another implicitly.

Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Alice Ryhl 
Reviewed-by: Benno Lossin 
Cc: stable@vger.kernel.org # 6.8.x: df70d04d5697: rust: phy: implement `Send` for `Registration`
Cc: stable@vger.kernel.org
Fixes: 247b365dc8dc ("rust: add `kernel` crate")
Link: https://lore.kernel.org/r/20240328195457.225001-3-wedsonaf@gmail.com
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

rust: init: remove impl Zeroable for Infallible

2024-05-02T14:32:42+00:00

commit 49ceae68a0df9a92617a61e9ce8a0efcf6419585 upstream.

In Rust, producing an invalid value of any type is immediate undefined
behavior (UB); this includes via zeroing memory.  Therefore, since an
uninhabited type has no valid values, producing any values at all for it is
UB.

The Rust standard library type `core::convert::Infallible` is uninhabited,
by virtue of having been declared as an enum with no cases, which always
produces uninhabited types in Rust.

The current kernel code allows this UB to be triggered, for example by code
like `Box::::init(kernel::init::zeroed())`.

Thus, remove the implementation of `Zeroable` for `Infallible`, thereby
avoiding the unsoundness (potential for future UB).

Cc: stable@vger.kernel.org
Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function")
Closes: https://github.com/Rust-for-Linux/pinned-init/pull/13
Signed-off-by: Laine Taffin Altman 
Reviewed-by: Alice Ryhl 
Reviewed-by: Boqun Feng 
Reviewed-by: Benno Lossin 
Link: https://lore.kernel.org/r/CA160A4E-561E-4918-837E-3DCEBA74F808@me.com
[ Reformatted the comment slightly. ]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: print: use explicit link in documentation

2024-02-16T18:10:43+00:00

commit a53d8cdd5a0aec75ae32badc2d8995c59ea6e3f0 upstream.

The future `rustdoc` in the Rust 1.73.0 upgrade requires an explicit
link for `pr_info!`:

    error: unresolved link to `pr_info`
       --> rust/kernel/print.rs:395:63
        |
    395 | /// Use only when continuing a previous `pr_*!` macro (e.g. [`pr_info!`]).
        |                                                               ^^^^^^^^ no item named `pr_info` in scope
        |
        = note: `macro_rules` named `pr_info` exists in this crate, but it is not in scope at this link's location
        = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`

Thus do so to avoid a broken link while upgrading.

Reviewed-by: Alice Ryhl 
Reviewed-by: Vincenzo Palazzo 
Reviewed-by: Finn Behrens 
Reviewed-by: Martin Rodriguez Reboredo 
Link: https://lore.kernel.org/r/20231005210556.466856-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: task: remove redundant explicit link

2024-02-16T18:10:43+00:00

commit c61bcc278b1924da13fd52edbd46b08a518c11ef upstream.

Starting with Rust 1.73.0, `rustdoc` detects redundant explicit
links with its new lint `redundant_explicit_links` [1]:

    error: redundant explicit link target
      --> rust/kernel/task.rs:85:21
       |
    85 |     /// [`current`](crate::current) macro because it is safe.
       |          ---------  ^^^^^^^^^^^^^^ explicit target is redundant
       |          |
       |          because label contains path that resolves to same destination
       |
       = note: when a link's destination is not specified,
               the label is used to resolve intra-doc links
       = note: `-D rustdoc::redundant-explicit-links` implied by `-D warnings`
    help: remove explicit link target
       |
    85 |     /// [`current`] macro because it is safe.

In order to avoid the warning in the compiler upgrade commit,
make it an intra-doc link as the tool suggests.

Link: https://github.com/rust-lang/rust/pull/113167 [1]
Reviewed-by: Finn Behrens 
Reviewed-by: Alice Ryhl 
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Vincenzo Palazzo 
Link: https://lore.kernel.org/r/20231005210556.466856-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: arc: add explicit `drop()` around `Box::from_raw()`

2024-02-16T18:10:43+00:00

commit 828176d037e29f813792a8b3ac1591834240e96f upstream.

`Box::from_raw()` is `#[must_use]`, which means the result cannot
go unused.

In Rust 1.71.0, this was not detected because the block expression
swallows the diagnostic [1]:

    unsafe { Box::from_raw(self.ptr.as_ptr()) };

It would have been detected, however, if the line had been instead:

    unsafe { Box::from_raw(self.ptr.as_ptr()); }

i.e. the semicolon being inside the `unsafe` block, rather than
outside.

In Rust 1.72.0, the compiler started warning about this [2], so
without this patch we will get:

        error: unused return value of `alloc::boxed::Box::::from_raw` that must be used
        --> rust/kernel/sync/arc.rs:302:22
        |
    302 |             unsafe { Box::from_raw(self.ptr.as_ptr()) };
        |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        |
        = note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`
        = note: `-D unused-must-use` implied by `-D warnings`
    help: use `let _ = ...` to ignore the resulting value
        |
    302 |             unsafe { let _ = Box::from_raw(self.ptr.as_ptr()); };
        |                      +++++++                                 +

Thus add an add an explicit `drop()` as the `#[must_use]`'s
annotation suggests (instead of the more general help line).

Link: https://github.com/rust-lang/rust/issues/104253 [1]
Link: https://github.com/rust-lang/rust/pull/112529 [2]
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Gary Guo 
Reviewed-by: Alice Ryhl 
Reviewed-by: Andreas Hindborg 
Reviewed-by: Björn Roy Baron 
Link: https://lore.kernel.org/r/20230823160244.188033-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

rust: error: Markdown style nit

2023-10-12T20:58:52+00:00

This patch fixes a trivial markdown style nit in the `SAFETY` comment.

Signed-off-by: Manmohan Shukla 
Reviewed-by: Alice Ryhl 
Reviewed-by: Jianguo Bao 
Reviewed-by: Vincenzo Palazzo 
Reviewed-by: Finn Behrens 
Reviewed-by: Benno Lossin 
Reviewed-by: Andreas Hindborg 
Fixes: c7e20faa5fca ("rust: error: Add Error::to_ptr()")
Link: https://lore.kernel.org/r/20230906204857.85619-1-manmshuk@gmail.com
Signed-off-by: Miguel Ojeda

rust: error: fix the description for `ECHILD`

2023-10-12T20:58:28+00:00

A mistake was made and the description of `ECHILD` is wrong (it reuses
the description of `ENOEXEC`). This fixes it to reflect what's in
`errno-base.h`.

Signed-off-by: Wedson Almeida Filho 
Reviewed-by: Martin Rodriguez Reboredo 
Reviewed-by: Trevor Gross 
Reviewed-by: Finn Behrens 
Reviewed-by: Alice Ryhl 
Fixes: 266def2a0f5b ("rust: error: add codes from `errno-base.h`")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230930144958.46051-1-wedsonaf@gmail.com
[ Use the plural, as noticed by Benno. ]
Signed-off-by: Miguel Ojeda