linux.git/rust/kernel, branch v6.6.131

rust: pin-init: internal: init: document load-bearing fact of field accessors

2026-04-02T11:07:30+00:00

[ Upstream commit 580cc37b1de4fcd9997c48d7080e744533f09f36 ]

The functions `[Pin]Init::__[pinned_]init` and `ptr::write` called from
the `init!` macro require the passed pointer to be aligned. This fact is
ensured by the creation of field accessors to previously initialized
fields.

Since we missed this very important fact from the beginning [1],
document it in the code.

Link: https://rust-for-linux.zulipchat.com/#narrow/channel/561532-pin-init/topic/initialized.20field.20accessor.20detection/with/576210658 [1]
Fixes: 90e53c5e70a6 ("rust: add pin-init API core")
Cc:  # 6.6.y, 6.12.y: 42415d163e5d: rust: pin-init: add references to previously initialized fields
Cc:  # 6.6.y, 6.12.y, 6.18.y, 6.19.y
Signed-off-by: Benno Lossin 
Reviewed-by: Gary Guo 
Link: https://patch.msgid.link/20260302140424.4097655-2-lossin@kernel.org
[ Updated Cc: stable@ tags as discussed. - Miguel ]
Signed-off-by: Miguel Ojeda 
[ Moved changes to the declarative macro, because 6.19.y and earlier do not
  have `syn`. Also duplicated the comment for all field accessor creations.
  - Benno ]
Signed-off-by: Benno Lossin 
Signed-off-by: Greg Kroah-Hartman

rust: pin-init: add references to previously initialized fields

2026-04-02T11:07:29+00:00

[ Upstream commit 42415d163e5df6db799c7de6262d707e402c2c7e ]

After initializing a field in an initializer macro, create a variable
holding a reference that points at that field. The type is either
`Pin<&mut T>` or `&mut T` depending on the field's structural pinning
kind.

[ Applied fixes to devres and rust_driver_pci sample - Benno]
Reviewed-by: Danilo Krummrich 
Signed-off-by: Benno Lossin 
[ Removed the devres changes, because devres is not present in 6.12.y and
  earlier. Also adjusted paths in the macro to account for the fact that
  pin-init is part of the kernel crate in 6.12.y and earlier. - Benno ]
Signed-off-by: Benno Lossin 
Signed-off-by: Greg Kroah-Hartman

rust: kunit: fix warning when !CONFIG_PRINTK

2026-03-25T10:05:40+00:00

[ Upstream commit 7dd34dfc8dfa92a7244242098110388367996ac3 ]

If `CONFIG_PRINTK` is not set, then the following warnings are issued
during build:

  warning: unused variable: `args`
    --> ../rust/kernel/kunit.rs:16:12
    |
  16 | pub fn err(args: fmt::Arguments<'_>) {
    |            ^^^^ help: if this is intentional, prefix it with an underscore: `_args`
    |
    = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default

  warning: unused variable: `args`
    --> ../rust/kernel/kunit.rs:32:13
    |
  32 | pub fn info(args: fmt::Arguments<'_>) {
    |             ^^^^ help: if this is intentional, prefix it with an underscore: `_args`

Fix this by adding a no-op assignment using `args` when `CONFIG_PRINTK`
is not set.

Fixes: a66d733da801 ("rust: support running Rust documentation tests as KUnit ones")
Signed-off-by: Alexandre Courbot 
Reviewed-by: Alice Ryhl 
Reviewed-by: David Gow 
Signed-off-by: Shuah Khan 
Signed-off-by: Sasha Levin

rust: lockdep: Remove support for dynamically allocated LockClassKeys

2025-03-22T19:50:50+00:00

commit 966944f3711665db13e214fef6d02982c49bb972 upstream.

Currently, dynamically allocated LockCLassKeys can be used from the Rust
side without having them registered. This is a soundness issue, so
remove them.

Fixes: 6ea5aa08857a ("rust: sync: introduce `LockClassKey`")
Suggested-by: Alice Ryhl 
Signed-off-by: Mitchell Levy 
Signed-off-by: Boqun Feng 
Signed-off-by: Ingo Molnar 
Reviewed-by: Benno Lossin 
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250307232717.1759087-11-boqun.feng@gmail.com
Signed-off-by: Boqun Feng 
Signed-off-by: Greg Kroah-Hartman

rust: init: add missing newline to pr_info! calls

2025-03-22T19:50:48+00:00

[ Upstream commit 6933c1067fe6df8ddb34dd68bdb2aa172cbd08c8 ]

Several pr_info! calls in rust/kernel/init.rs (both in code examples
and macro documentation) were missing a newline, causing logs to
run together. This commit updates these calls to include a trailing
newline, improving readability and consistency with the C side.

Fixes: 6841d45a3030 ("rust: init: add `stack_pin_init!` macro")
Fixes: 7f8977a7fe6d ("rust: init: add `{pin_}chain` functions to `{Pin}Init`")
Fixes: d0fdc3961270 ("rust: init: add `PinnedDrop` trait and macros")
Fixes: 4af84c6a85c6 ("rust: init: update expanded macro explanation")
Reported-by: Miguel Ojeda 
Link: https://github.com/Rust-for-Linux/linux/issues/1139
Signed-off-by: Alban Kurti 
Link: https://lore.kernel.org/r/20250206-printing_fix-v3-3-a85273b501ae@invicto.ai
[ Replaced Closes with Link since it fixes part of the issue. Added
  one more Fixes tag (still same set of stable kernels). - Miguel ]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

rust: error: add missing newline to pr_warn! calls

2025-03-22T19:50:48+00:00

[ Upstream commit 6f5c36f56d475732981dcf624e0ac0cc7c8984c8 ]

Added missing newline at the end of pr_warn! usage
so the log is not missed.

Fixes: 6551a7fe0acb ("rust: error: Add Error::from_errno{_unchecked}()")
Reported-by: Miguel Ojeda 
Link: https://github.com/Rust-for-Linux/linux/issues/1139
Signed-off-by: Alban Kurti 
Link: https://lore.kernel.org/r/20250206-printing_fix-v3-2-a85273b501ae@invicto.ai
[ Replaced Closes with Link since it fixes part of the issue. - Miguel ]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

rust: init: fix `Zeroable` implementation for `Option>` and `Option>`

2025-03-22T19:50:48+00:00

commit df27cef153603b18a7d094b53cc3d5264ff32797 upstream.

According to [1], `NonNull` and `#[repr(transparent)]` wrapper types
such as our custom `KBox` have the null pointer optimization only if
`T: Sized`. Thus remove the `Zeroable` implementation for the unsized
case.

Link: https://doc.rust-lang.org/stable/std/option/index.html#representation [1]
Reported-by: Alice Ryhl 
Closes: https://lore.kernel.org/rust-for-linux/CAH5fLghL+qzrD8KiCF1V3vf2YcC6aWySzkmaE2Zzrnh1gKj-hw@mail.gmail.com/
Cc: stable@vger.kernel.org # v6.12+ (a custom patch will be needed for 6.6.y)
Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function")
Signed-off-by: Benno Lossin 
Reviewed-by: Alice Ryhl 
Reviewed-by: Andreas Hindborg 
Link: https://lore.kernel.org/r/20250305132836.2145476-1-benno.lossin@proton.me
[ Added Closes tag and moved up the Reported-by one. - Miguel ]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

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