linux-stable.git/rust/kernel, branch v6.12.97

rust: block: fix GenDisk cleanup paths

2026-07-24T14:11:47+00:00

[ Upstream commit 2957771379fa335103a4b539db57bb2271e12142 ]

GenDiskBuilder::build() still has fallible work after
__blk_mq_alloc_disk(), but its error path only recovers the
foreign queue data. That leaks the temporary gendisk and
request_queue until later teardown. If the caller moved the last
Arc> into build(), the leaked queue can retain blk-mq
state after the tag set is dropped.

Fix the pre-registration failure path by dropping the temporary
gendisk reference with put_disk() before recovering queue_data,
so disk_release() can tear down the owned queue.

Also pair GenDisk::drop() with put_disk() after del_gendisk().
Once a Rust GenDisk has been added with device_add_disk(),
del_gendisk() only unregisters it; the final gendisk reference
still has to be dropped to complete the release path.

Fixes: 3253aba3408a ("rust: block: introduce `kernel::block::mq` module")
Cc: stable@kernel.org
Reported-by: Yuan Tan 
Reported-by: Xin Liu 
Reviewed-by: Andreas Hindborg 
Signed-off-by: Haoze Xie 
Signed-off-by: Ren Wei 
Link: https://patch.msgid.link/b70aff9a920cc42110fe5cf454c3099561863519.1780063368.git.royenheart@gmail.com
Signed-off-by: Jens Axboe 
[ no queue-data recovery or recover_data.dismiss() in 6.12 ]
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

rust: block: `allow(deprecated)` for `fetch_update` for Rust >= 1.99.0

2026-07-24T14:11:42+00:00

Starting with Rust 1.99.0 (expected 2026-10-01), the
`Atomic*::fetch_update` method is deprecated, with the compiler suggesting
the `try_update` alias instead:

    error: use of deprecated method `core::sync::atomic::Atomic::::fetch_update`: renamed to `try_update` for consistency
       --> rust/kernel/block/mq/request.rs:206:22
        |
    206 |     let old = target.fetch_update(Ordering::Relaxed, Ordering::Relaxed, |x| Some(op(x)));
        |                      ^^^^^^^^^^^^
        |
        = note: `-D deprecated` implied by `-D warnings`
        = help: to override `-D warnings` add `#[allow(deprecated)]`
    help: replace the use of the deprecated method
        |
    206 -     let old = target.fetch_update(Ordering::Relaxed, Ordering::Relaxed, |x| Some(op(x)));
    206 +     let old = target.try_update(Ordering::Relaxed, Ordering::Relaxed, |x| Some(op(x)));
        |

The deprecation was added in Rust 1.95.0 [1], but only triggers starting
with Rust 1.99.0.

However, we cannot use the alias since our minimum in 6.12.y is Rust
1.78.0 -- `try_update` was added in Rust 1.86.0 [2].

Thus just allow the lint.

Cc: Andreas Hindborg 
Cc: Boqun Feng 
Cc: Jens Axboe 
Link: https://github.com/rust-lang/rust/pull/148590 [1]
Link: https://github.com/rust-lang/rust/pull/133829 [2]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

rust: alloc: fix assert in `Vec::reserve` doc test

2026-07-24T14:11:05+00:00

[ Upstream commit 75619f2df7a5da6ffb61eedc2a73fdf70c65471c ]

The assert in the doctest used `>= 10`, which only checks that the
capacity can hold `additional` elements, ignoring the existing length
of `v`. The correct check should ensure there is room for `additional`
*extra* elements on top of what is already in the vector.

Fix the assert to use `>= v.len() + 10` so the example accurately
reflects the actual semantics of the function.

Reported-by: Miguel Ojeda 
Closes: https://lore.kernel.org/rust-for-linux/CANiq72nkXWhjK9iFRrhGtkMZGsvNE_zVsu4JnxaFRfxWL7RRdg@mail.gmail.com/
Fixes: 2aac4cd7dae3d ("rust: alloc: implement kernel `Vec` type")
Signed-off-by: Hsiu Che Yu 
Reviewed-by: Alice Ryhl 
Reviewed-by: Alexandre Courbot 
Link: https://patch.msgid.link/20260427-doctest-kvec-reserve-v1-1-0623abcd9c2e@gmail.com
Signed-off-by: Danilo Krummrich 
Signed-off-by: Sasha Levin

rust: alloc: fix `Vec::extend_with` SAFETY comment

2026-07-24T14:10:46+00:00

[ Upstream commit f497aae6ded43f91b1dbf29a35d7062823635640 ]

Fix an incorrect operator in the SAFETY comment, changing `<` to `<=`,
since `Vec::reserve` guarantees capacity for exactly n additional elements,
so the equal case should be included.

Signed-off-by: Hsiu Che Yu 
Reviewed-by: Alexandre Courbot 
Fixes: 2aac4cd7dae3d ("rust: alloc: implement kernel `Vec` type")
Link: https://patch.msgid.link/18fc8eee2f057a6bfbcadae156d1d0b7c40d0077.1777111268.git.yu.whisper.personal@gmail.com
Signed-off-by: Danilo Krummrich 
Signed-off-by: Sasha Levin

rust: pin-init: fix incorrect accessor reference lifetime

2026-05-17T15:14:34+00:00

commit 68bf102226cf2199dc609b67c1e847cad4de4b57 upstream

When a field has been initialized, `init!`/`pin_init!` create a reference
or pinned reference to the field so it can be accessed later during the
initialization of other fields. However, the reference it created is
incorrectly `&'static` rather than just the scope of the initializer.

This means that you can do

    init!(Foo {
        a: 1,
        _: {
            let b: &'static u32 = a;
        }
    })

which is unsound.

This is caused by `&mut (*$slot).$ident`, which actually allows arbitrary
lifetime, so this is effectively `'static`.

Fix it by adding `let_binding` method on `DropGuard` to shorten lifetime.
This results in exactly what we want for these accessors. The safety and
invariant comments of `DropGuard` have been reworked; instead of reasoning
about what caller can do with the guard, express it in a way that the
ownership is transferred to the guard and `forget` takes it back, so the
unsafe operations within the `DropGuard` can be more easily justified.

Assisted-by: Claude:claude-3-opus
Signed-off-by: Gary Guo 
Signed-off-by: Greg Kroah-Hartman

rust: init: fix `clippy::undocumented_unsafe_blocks` warnings

2026-05-07T04:09:25+00:00

The stable backport in commit acc105db0826 ("rust: pin-init:
add references to previously initialized fields") introduced some
`clippy::undocumented_unsafe_blocks` warnings [1], e.g.

    error: unsafe block missing a safety comment
        --> rust/kernel/init/macros.rs:1015:25

As well as:

    --> rust/kernel/init/macros.rs:1243:45
    --> rust/kernel/init/macros.rs:1286:22
    --> rust/kernel/init/macros.rs:1374:45

After discussing it with Benno and Gary, we decided to clean the build
log by doing a minimal targeted stable commit.

Thus, depending on the case:

  - Reorder the attributes so that the existing `// SAFETY:` comments
    may be seen by Clippy.

  - Add a placeholder `// SAFETY: TODO.` comment.

Cc: Benno Lossin 
Cc: Gary Guo 
Fixes: acc105db0826 ("rust: pin-init: add references to previously initialized fields")
Link: https://lore.kernel.org/stable/20260421111111.57059-1-ojeda@kernel.org/ [1]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Sasha Levin

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

2026-04-02T11:09:50+00:00

commit 580cc37b1de4fcd9997c48d7080e744533f09f36 upstream.

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

2026-04-02T11:09:50+00:00

commit 42415d163e5df6db799c7de6262d707e402c2c7e upstream.

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

2026-03-13T16:20:40+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: rbtree: fix documentation typo in CursorMut peek_next method

2026-02-06T15:55:44+00:00

commit 45f6aed8a835ee2bdd0a5d5ee626a91fe285014f upstream.

The peek_next method's doc comment incorrectly stated it accesses the
"previous" node when it actually accesses the next node.

Fix the documentation to accurately reflect the method's behavior.

Fixes: 98c14e40e07a ("rust: rbtree: add cursor")
Reviewed-by: Alice Ryhl 
Signed-off-by: Hang Shu 
Reported-by: Miguel Ojeda 
Closes: https://github.com/Rust-for-Linux/linux/issues/1205
Cc: stable@vger.kernel.org
Reviewed-by: Gary Guo 
Link: https://patch.msgid.link/20251107093921.3379954-1-m18080292938@163.com
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman