linux-rng/rust/kernel/sync, branch master

Merge tag 'locking-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2025-12-02T03:50:58Z

Pull locking updates from Ingo Molnar: "Mutexes: - Redo __mutex_init() to reduce generated code size (Sebastian Andrzej Siewior) Seqlocks: - Introduce scoped_seqlock_read() (Peter Zijlstra) - Change thread_group_cputime() to use scoped_seqlock_read() (Oleg Nesterov) - Change do_task_stat() to use scoped_seqlock_read() (Oleg Nesterov) - Change do_io_accounting() to use scoped_seqlock_read() (Oleg Nesterov) - Fix the incorrect documentation of read_seqbegin_or_lock() / need_seqretry() (Oleg Nesterov) - Allow KASAN to fail optimizing (Peter Zijlstra) Local lock updates: - Fix all kernel-doc warnings (Randy Dunlap) - Add the headers to MAINTAINERS (Sebastian Andrzej Siewior) - Reduce the risk of shadowing via s/l/__l/ and s/tl/__tl/ (Vincent Mailhol) Lock debugging: - spinlock/debug: Fix data-race in do_raw_write_lock (Alexander Sverdlin) Atomic primitives infrastructure: - atomic: Skip alignment check for try_cmpxchg() old arg (Arnd Bergmann) Rust runtime integration: - sync: atomic: Enable generated Atomic usage (Boqun Feng) - sync: atomic: Implement Debug for Atomic (Boqun Feng) - debugfs: Remove Rust native atomics and replace them with Linux versions (Boqun Feng) - debugfs: Implement Reader for Mutex only when T is Unpin (Boqun Feng) - lock: guard: Add T: Unpin bound to DerefMut (Daniel Almeida) - lock: Pin the inner data (Daniel Almeida) - lock: Add a Pin<&mut T> accessor (Daniel Almeida)" * tag 'locking-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: locking/local_lock: Fix all kernel-doc warnings locking/local_lock: s/l/__l/ and s/tl/__tl/ to reduce the risk of shadowing locking/local_lock: Add the headers to MAINTAINERS locking/mutex: Redo __mutex_init() to reduce generated code size rust: debugfs: Replace the usage of Rust native atomics rust: sync: atomic: Implement Debug for Atomic rust: sync: atomic: Make Atomic*Ops pub(crate) seqlock: Allow KASAN to fail optimizing rust: debugfs: Implement Reader for Mutex only when T is Unpin seqlock: Change do_io_accounting() to use scoped_seqlock_read() seqlock: Change do_task_stat() to use scoped_seqlock_read() seqlock: Change thread_group_cputime() to use scoped_seqlock_read() seqlock: Introduce scoped_seqlock_read() documentation: seqlock: fix the wrong documentation of read_seqbegin_or_lock/need_seqretry atomic: Skip alignment check for try_cmpxchg() old arg rust: lock: Add a Pin<&mut T> accessor rust: lock: Pin the inner data rust: lock: guard: Add T: Unpin bound to DerefMut locking/spinlock/debug: Fix data-race in do_raw_write_lock

rust: sync: atomic: Implement Debug for Atomic

2025-11-12T16:56:41Z

If `Atomic` is `Debug` then it's a `debugfs::Writer`, therefore make it so since 1) debugfs needs to support `Atomic` and 2) it's rather trivial to implement `Debug` for `Atomic`. Tested-by: David Gow Acked-by: Greg Kroah-Hartman Signed-off-by: Boqun Feng Link: https://patch.msgid.link/20251022035324.70785-3-boqun.feng@gmail.com

rust: sync: atomic: Make Atomic*Ops pub(crate)

2025-11-12T16:56:38Z

In order to write code over a generate Atomic we need to make Atomic*Ops public so that functions like `.load()` and `.store()` are available. Make these pub(crate) at the beginning so the usage in kernel crate is supported. Tested-by: David Gow Acked-by: Greg Kroah-Hartman Signed-off-by: Boqun Feng Link: https://patch.msgid.link/20251022035324.70785-2-boqun.feng@gmail.com

rust: condvar: fix broken intra-doc link

2025-11-02T22:18:42Z

The future move of pin-init to `syn` uncovers the following broken intra-doc link: error: unresolved link to `crate::pin_init` --> rust/kernel/sync/condvar.rs:39:40 | 39 | /// instances is with the [`pin_init`](crate::pin_init!) and [`new_condvar`] macros. | ^^^^^^^^^^^^^^^^ no item named `pin_init` in module `kernel` | = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]` Currently, when rendered, the link points to a literal `crate::pin_init!` URL. Thus fix it. Cc: stable@vger.kernel.org Fixes: 129e97be8e28 ("rust: pin-init: fix documentation links") Reviewed-by: Alice Ryhl Link: https://patch.msgid.link/20251029073344.349341-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda

rust: lock: Add a Pin<&mut T> accessor

2025-10-21T10:31:56Z

In order for callers to be able to access the inner T safely if T: !Unpin, there needs to be a way to get a Pin<&mut T>. Add this accessor and a corresponding example to tell users how it works. This requires the pin projection functionality [1] for better ergonomic. [boqun: Apply Daniel's fix to the code example, add the reference to pin projection patch and remove out-of-date part in the commit log] Suggested-by: Benno Lossin Suggested-by: Boqun Feng Signed-off-by: Daniel Almeida Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Link: https://github.com/Rust-for-Linux/linux/issues/1181 Link: https://lore.kernel.org/rust-for-linux/20250912174148.373530-1-lossin@kernel.org/ [1]

rust: lock: Pin the inner data

2025-10-21T10:31:55Z

In preparation to support Lock where T is pinned, the first thing that needs to be done is to structurally pin the 'data' member. This switches the 't' parameter in Lock::new() to take in an impl PinInit instead of a plain T. This in turn uses the blanket implementation "impl PinInit for T". Subsequent patches will touch on Guard. Suggested-by: Benno Lossin Suggested-by: Boqun Feng Signed-off-by: Daniel Almeida Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Benno Lossin Reviewed-by: Alice Ryhl Link: https://github.com/Rust-for-Linux/linux/issues/1181

rust: lock: guard: Add T: Unpin bound to DerefMut

2025-10-21T10:31:55Z

A core property of pinned types is not handing a mutable reference to the inner data in safe code, as this trivially allows that data to be moved. Enforce this condition by adding a bound on lock::Guard's DerefMut implementation, so that it's only implemented for pinning-agnostic types. Suggested-by: Benno Lossin Suggested-by: Boqun Feng Signed-off-by: Daniel Almeida Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Benno Lossin Reviewed-by: Alice Ryhl Link: https://github.com/Rust-for-Linux/linux/issues/1181

Merge tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

2025-10-01T02:12:49Z

Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Derive 'Zeroable' for all structs and unions generated by 'bindgen' where possible and corresponding cleanups. To do so, add the 'pin-init' crate as a dependency to 'bindings' and 'uapi'. It also includes its first use in the 'cpufreq' module, with more to come in the next cycle. - Add warning to the 'rustdoc' target to detect broken 'srctree/' links and fix existing cases. - Remove support for unused (since v6.16) host '#[test]'s, simplifying the 'rusttest' target. Tests should generally run within KUnit. 'kernel' crate: - Add 'ptr' module with a new 'Alignment' type, which is always a power of two and is used to validate that a given value is a valid alignment and to perform masking and alignment operations: // Checked at build time. assert_eq!(Alignment::new::<16>().as_usize(), 16); // Checked at runtime. assert_eq!(Alignment::new_checked(15), None); assert_eq!(Alignment::of::().log2(), 0); assert_eq!(0x25u8.align_down(Alignment::new::<0x10>()), 0x20); assert_eq!(0x5u8.align_up(Alignment::new::<0x10>()), Some(0x10)); assert_eq!(u8::MAX.align_up(Alignment::new::<0x10>()), None); It also includes its first use in Nova. - Add 'core::mem::{align,size}_of{,_val}' to the prelude, matching Rust 1.80.0. - Keep going with the steps on our migration to the standard library 'core::ffi::CStr' type (use 'kernel::{fmt, prelude::fmt!}' and use upstream method names). - 'error' module: improve 'Error::from_errno' and 'to_result' documentation, including examples/tests. - 'sync' module: extend 'aref' submodule documentation now that it exists, and more updates to complete the ongoing move of 'ARef' and 'AlwaysRefCounted' to 'sync::aref'. - 'list' module: add an example/test for 'ListLinksSelfPtr' usage. - 'alloc' module: - Implement 'Box::pin_slice()', which constructs a pinned slice of elements. - Provide information about the minimum alignment guarantees of 'Kmalloc', 'Vmalloc' and 'KVmalloc'. - Take minimum alignment guarantees of allocators for 'ForeignOwnable' into account. - Remove the 'allocator_test' (including 'Cmalloc'). - Add doctest for 'Vec::as_slice()'. - Constify various methods. - 'time' module: - Add methods on 'HrTimer' that can only be called with exclusive access to an unarmed timer, or from timer callback context. - Add arithmetic operations to 'Instant' and 'Delta'. - Add a few convenience and access methods to 'HrTimer' and 'Instant'. 'macros' crate: - Reduce collections in 'quote!' macro. And a few other cleanups and improvements" * tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (58 commits) gpu: nova-core: use Alignment for alignment-related operations rust: add `Alignment` type rust: macros: reduce collections in `quote!` macro rust: acpi: use `core::ffi::CStr` method names rust: of: use `core::ffi::CStr` method names rust: net: use `core::ffi::CStr` method names rust: miscdevice: use `core::ffi::CStr` method names rust: kunit: use `core::ffi::CStr` method names rust: firmware: use `core::ffi::CStr` method names rust: drm: use `core::ffi::CStr` method names rust: cpufreq: use `core::ffi::CStr` method names rust: configfs: use `core::ffi::CStr` method names rust: auxiliary: use `core::ffi::CStr` method names drm/panic: use `core::ffi::CStr` method names rust: device: use `kernel::{fmt,prelude::fmt!}` rust: sync: use `kernel::{fmt,prelude::fmt!}` rust: seq_file: use `kernel::{fmt,prelude::fmt!}` rust: kunit: use `kernel::{fmt,prelude::fmt!}` rust: file: use `kernel::{fmt,prelude::fmt!}` rust: device: use `kernel::{fmt,prelude::fmt!}` ...

rust: sync: use `kernel::{fmt,prelude::fmt!}`

2025-09-16T07:26:59Z

Reduce coupling to implementation details of the formatting machinery by avoiding direct use for `core`'s formatting traits and macros. Acked-by: Greg Kroah-Hartman Reviewed-by: Alice Ryhl Reviewed-by: Benno Lossin Signed-off-by: Tamir Duberstein Signed-off-by: Miguel Ojeda

rust: block: convert `block::mq` to use `Refcount`

2025-09-15T07:38:36Z

Currently there's a custom reference counting in `block::mq`, which uses `AtomicU64` Rust atomics, and this type doesn't exist on some 32-bit architectures. We cannot just change it to use 32-bit atomics, because doing so will make it vulnerable to refcount overflow. So switch it to use the kernel refcount `kernel::sync::Refcount` instead. There is an operation needed by `block::mq`, atomically decreasing refcount from 2 to 0, which is not available through refcount.h, so I exposed `Refcount::as_atomic` which allows accessing the refcount directly. [boqun: Adopt the LKMM atomic API] Signed-off-by: Gary Guo Signed-off-by: Boqun Feng Signed-off-by: Peter Zijlstra (Intel) Reviewed-by: Benno Lossin Reviewed-by: Elle Rhumsaa Acked-by: Andreas Hindborg Tested-by: David Gow Link: https://lore.kernel.org/r/20250723233312.3304339-5-gary@kernel.org