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5 daysMerge tag 'rust-6.18' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux 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::<u8>().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!}` ...
2025-09-16rust: sync: use `kernel::{fmt,prelude::fmt!}`Tamir Duberstein
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 <gregkh@linuxfoundation.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-09-15rust: block: convert `block::mq` to use `Refcount`Gary Guo
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 <gary@garyguo.net> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Acked-by: Andreas Hindborg <a.hindborg@kernel.org> Tested-by: David Gow <davidgow@google.com> Link: https://lore.kernel.org/r/20250723233312.3304339-5-gary@kernel.org
2025-09-15rust: convert `Arc` to use `Refcount`Gary Guo
With `Refcount` type created, `Arc` can use `Refcount` instead of calling into FFI directly. Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/r/20250723233312.3304339-4-gary@kernel.org
2025-09-15rust: make `Arc::into_unique_or_drop` associated functionGary Guo
Make `Arc::into_unique_or_drop` to become a mere associated function instead of a method (i.e. removing the `self` receiver). It's a general convention for Rust smart pointers to avoid having methods defined on them, because if the pointee type has a method of the same name, then it is shadowed. This is normally for avoiding semver breakage, which isn't an issue for kernel codebase, but it's still generally a good practice to follow this rule, so that `ptr.foo()` would always be calling a method on the pointee type. Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/r/20250723233312.3304339-3-gary@kernel.org
2025-09-15rust: implement `kernel::sync::Refcount`Gary Guo
This is a wrapping layer of `include/linux/refcount.h`. Currently the kernel refcount has already been used in `Arc`, however it calls into FFI directly. [boqun: Add the missing <> for the link in comment] Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Fiona Behrens <me@kloenk.dev> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/r/20250723233312.3304339-2-gary@kernel.org
2025-09-15rust: sync: Add memory barriersBoqun Feng
Memory barriers are building blocks for concurrent code, hence provide a minimal set of them. The compiler barrier, barrier(), is implemented in inline asm instead of using core::sync::atomic::compiler_fence() because memory models are different: kernel's atomics are implemented in inline asm therefore the compiler barrier should be implemented in inline asm as well. Also it's currently only public to the kernel crate until there's a reasonable driver usage. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-10-boqun.feng@gmail.com/
2025-09-15rust: sync: atomic: Add Atomic<{usize,isize}>Boqun Feng
Add generic atomic support for `usize` and `isize`. Note that instead of mapping directly to `atomic_long_t`, the represention type (`AtomicType::Repr`) is selected based on CONFIG_64BIT. This reduces the necessity of creating `atomic_long_*` helpers, which could save the binary size of kernel if inline helpers are not available. To do so, an internal type `isize_atomic_repr` is defined, it's `i32` in 32bit kernel and `i64` in 64bit kernel. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-9-boqun.feng@gmail.com/
2025-09-15rust: sync: atomic: Add Atomic<u{32,64}>Boqun Feng
Add generic atomic support for basic unsigned types that have an `AtomicImpl` with the same size and alignment. Unit tests are added including Atomic<i32> and Atomic<i64>. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-8-boqun.feng@gmail.com/
2025-09-15rust: sync: atomic: Add the framework of arithmetic operationsBoqun Feng
One important set of atomic operations is the arithmetic operations, i.e. add(), sub(), fetch_add(), add_return(), etc. However it may not make senses for all the types that `AtomicType` to have arithmetic operations, for example a `Foo(u32)` may not have a reasonable add() or sub(), plus subword types (`u8` and `u16`) currently don't have atomic arithmetic operations even on C side and might not have them in the future in Rust (because they are usually suboptimal on a few architecures). Therefore the plan is to add a few subtraits of `AtomicType` describing which types have and can do atomic arithemtic operations. One trait `AtomicAdd` is added, and only add() and fetch_add() are added. The rest will be added in the future. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-7-boqun.feng@gmail.com/
2025-09-15rust: sync: atomic: Add atomic {cmp,}xchg operationsBoqun Feng
xchg() and cmpxchg() are basic operations on atomic. Provide these based on C APIs. Note that cmpxchg() use the similar function signature as compare_exchange() in Rust std: returning a `Result`, `Ok(old)` means the operation succeeds and `Err(old)` means the operation fails. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-6-boqun.feng@gmail.com/
2025-09-15rust: sync: atomic: Add generic atomicsBoqun Feng
To provide using LKMM atomics for Rust code, a generic `Atomic<T>` is added, currently `T` needs to be Send + Copy because these are the straightforward usages and all basic types support this. Implement `AtomicType` for `i32` and `i64`, and so far only basic operations load() and store() are introduced. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-5-boqun.feng@gmail.com/
2025-09-15rust: sync: atomic: Add ordering annotation typesBoqun Feng
Preparation for atomic primitives. Instead of a suffix like _acquire, a method parameter along with the corresponding generic parameter will be used to specify the ordering of an atomic operations. For example, atomic load() can be defined as: impl<T: ...> Atomic<T> { pub fn load<O: AcquireOrRelaxed>(&self, _o: O) -> T { ... } } and acquire users would do: let r = x.load(Acquire); relaxed users: let r = x.load(Relaxed); doing the following: let r = x.load(Release); will cause a compiler error. Compared to suffixes, it's easier to tell what ordering variants an operation has, and it also make it easier to unify the implementation of all ordering variants in one method via generic. The `TYPE` associate const is for generic function to pick up the particular implementation specified by an ordering annotation. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-4-boqun.feng@gmail.com/
2025-09-15rust: sync: Add basic atomic operation mapping frameworkBoqun Feng
Preparation for generic atomic implementation. To unify the implementation of a generic method over `i32` and `i64`, the C side atomic methods need to be grouped so that in a generic method, they can be referred as <type>::<method>, otherwise their parameters and return value are different between `i32` and `i64`, which would require using `transmute()` to unify the type into a `T`. Introduce `AtomicImpl` to represent a basic type in Rust that has the direct mapping to an atomic implementation from C. Use a sealed trait to restrict `AtomicImpl` to only support `i32` and `i64` for now. Further, different methods are put into different `*Ops` trait groups, and this is for the future when smaller types like `i8`/`i16` are supported but only with a limited set of API (e.g. only set(), load(), xchg() and cmpxchg(), no add() or sub() etc). While the atomic mod is introduced, documentation is also added for memory models and data races. Also bump my role to the maintainer of ATOMIC INFRASTRUCTURE to reflect my responsibility on the Rust atomic mod. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev> Link: https://lore.kernel.org/all/20250719030827.61357-3-boqun.feng@gmail.com/
2025-09-15rust: sync: extend module documentation of arefBenno Lossin
Commit 07dad44aa9a9 ("rust: kernel: move ARef and AlwaysRefCounted to sync::aref") moved `ARef` and `AlwaysRefCounted` into their own module. In that process only a short, single line description of the module was added. Extend the description by explaining what is meant by "internal reference counting", the two items in the trait & the difference to `Arc`. Signed-off-by: Benno Lossin <lossin@kernel.org> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-09-08rust: sync: Update ARef and AlwaysRefCounted imports from sync::arefShankari Anand
Update the in-file reference of sync/aref.rs to import `ARef` and `AlwaysRefCounted` from `sync::aref` instead of `types`. This aligns with the ongoing effort to move `ARef` and `AlwaysRefCounted` to sync. Suggested-by: Benno Lossin <lossin@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1173 Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-08-15rust: alloc: take the allocator into account for FOREIGN_ALIGNAlice Ryhl
When converting a Box<T> into a void pointer, the allocator might guarantee a higher alignment than the type itself does, and in that case it is guaranteed that the void pointer has that higher alignment. This is quite useful when combined with the XArray, which you can only create using a ForeignOwnable whose FOREIGN_ALIGN is at least 4. This means that you can now always use a Box<T> with the XArray no matter the alignment of T. Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250811-align-min-allocator-v2-2-3386cc94f4fc@google.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-08-03Merge tag 'rust-6.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness', 'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and 'ref_as_ptr' These are intended to avoid type casts with the 'as' operator, which are quite powerful, into restricted variants that are less powerful and thus should help to avoid mistakes - Remove the 'author' key now that most instances were moved to the plural one in the previous cycle 'kernel' crate: - New 'bug' module: add 'warn_on!' macro which reuses the existing 'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and kernel parameters: warn_on!(value == 42); To avoid duplicating the assembly code, the same strategy is followed as for the static branch code in order to share the assembly between both C and Rust This required a few rearrangements on C arch headers -- the existing C macros should still generate the same outputs, thus no functional change expected there - 'workqueue' module: add delayed work items, including a 'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an 'enqueue_delayed' method, e.g.: /// Enqueue the struct for execution on the system workqueue, /// where its value will be printed 42 jiffies later. fn print_later(value: Arc<MyStruct>) { let _ = workqueue::system().enqueue_delayed(value, 42); } - New 'bits' module: add support for 'bit' and 'genmask' functions, with runtime- and compile-time variants, e.g.: static_assert!(0b00010000 == bit_u8(4)); static_assert!(0b00011110 == genmask_u8(1..=4)); assert!(checked_bit_u32(u32::BITS).is_none()); - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which reads NUL-terminated strings from userspace into a '&CStr' Introduce 'UserPtr' newtype, similar in purpose to '__user' in C, to minimize mistakes handling userspace pointers, including mixing them up with integers and leaking them via the 'Debug' trait. Add it to the prelude, too - Start preparations for the replacement of our custom 'CStr' type with the analogous type in the 'core' standard library. This will take place across several cycles to make it easier. For this one, it includes a new 'fmt' module, using upstream method names and some other cleanups Replace 'fmt!' with a re-export, which helps Clippy lint properly, and clean up the found 'uninlined-format-args' instances - 'dma' module: - Clarify wording and be consistent in 'coherent' nomenclature - Convert the 'read!()' and 'write!()' macros to return a 'Result' - Add 'as_slice()', 'write()' methods in 'CoherentAllocation' - Expose 'count()' and 'size()' in 'CoherentAllocation' and add the corresponding type invariants - Implement 'CoherentAllocation::dma_handle_with_offset()' - 'time' module: - Make 'Instant' generic over clock source. This allows the compiler to assert that arithmetic expressions involving the 'Instant' use 'Instants' based on the same clock source - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers take a 'Duration' or an 'Instant' when setting the expiry time, depending on the timer mode. With this change, the compiler can check the type matches the timer mode - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep function that will select an appropriate sleep method depending on the requested sleep time - Avoid 64-bit divisions on 32-bit hardware when calculating timestamps - Seal the 'HrTimerMode' trait. This prevents users of the 'HrTimerMode' from implementing the trait on their own types - Pass the correct timer mode ID to 'hrtimer_start_range_ns()' - 'list' module: remove 'OFFSET' constants, allowing to remove pointer arithmetic; now 'impl_list_item!' invokes 'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other simplifications too - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a constant, which avoids exposing the type of the opaque pointer, and require 'into_foreign' to return non-null Remove the 'Either<L, R>' type as well. It is unused, and we want to encourage the use of custom enums for concrete use cases - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types to allow them to be used in generic APIs - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>'; and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>' - 'Opaque' type: add 'cast_from' method to perform a restricted cast that cannot change the inner type and use it in callers of 'container_of!'. Rename 'raw_get' to 'cast_into' to match it - 'rbtree' module: add 'is_empty' method - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and 'ARef', which are moved from the too general 'types' module which we want to reduce or eventually remove. Also fix a safety comment in 'static_lock_class' 'pin-init' crate: - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are now (pin-)initializers - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()' - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide it via 'Zeroable::zeroed()' - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for 'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for '"Rust"' and '"C"' ABIs and up to 20 arguments - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E> [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T' - Renamed 'zeroed()' to 'init_zeroed()' - Upstream dev news: improve CI more to deny warnings, use '--all-targets'. Check the synchronization status of the two '-next' branches in upstream and the kernel MAINTAINERS: - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo Stoakes as reviewers (thanks everyone) And a few other cleanups and improvements" * tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits) rust: Add warn_on macro arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust rust: kernel: move ARef and AlwaysRefCounted to sync::aref rust: sync: fix safety comment for `static_lock_class` rust: types: remove `Either<L, R>` rust: kernel: use `core::ffi::CStr` method names rust: str: add `CStr` methods matching `core::ffi::CStr` rust: str: remove unnecessary qualification rust: use `kernel::{fmt,prelude::fmt!}` rust: kernel: add `fmt` module rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args scripts: rust: emit path candidates in panic message scripts: rust: replace length checks with match rust: list: remove nonexistent generic parameter in link rust: bits: add support for bits/genmask macros rust: list: remove OFFSET constants rust: list: add `impl_list_item!` examples rust: list: use fully qualified path ...
2025-07-29Merge tag 'locking-core-2025-07-29' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Locking primitives: - Mark devm_mutex_init() as __must_check and fix drivers that didn't check the return code (Thomas Weißschuh) - Reorganize <linux/local_lock.h> to better expose the internal APIs to local variables (Sebastian Andrzej Siewior) - Remove OWNER_SPINNABLE in rwsem (Jinliang Zheng) - Remove redundant #ifdefs in the mutex code (Ran Xiaokai) Lockdep: - Avoid returning struct in lock_stats() (Arnd Bergmann) - Change `static const` into enum for LOCKF_*_IRQ_* (Arnd Bergmann) - Temporarily use synchronize_rcu_expedited() in lockdep_unregister_key() to speed things up. (Breno Leitao) Rust runtime: - Add #[must_use] to Lock::try_lock() (Jason Devers)" * tag 'locking-core-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Speed up lockdep_unregister_key() with expedited RCU synchronization locking/mutex: Remove redundant #ifdefs locking/lockdep: Change 'static const' variables to enum values locking/lockdep: Avoid struct return in lock_stats() locking/rwsem: Use OWNER_NONSPINNABLE directly instead of OWNER_SPINNABLE rust: sync: Add #[must_use] to Lock::try_lock() locking/mutex: Mark devm_mutex_init() as __must_check leds: lp8860: Check return value of devm_mutex_init() spi: spi-nxp-fspi: Check return value of devm_mutex_init() local_lock: Move this_cpu_ptr() notation from internal to main header
2025-07-29Merge tag 'sched-core-2025-07-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler updates from Ingo Molnar: "Core scheduler changes: - Better tracking of maximum lag of tasks in presence of different slices duration, for better handling of lag in the fair scheduler (Vincent Guittot) - Clean up and standardize #if/#else/#endif markers throughout the entire scheduler code base (Ingo Molnar) - Make SMP unconditional: build the SMP scheduler's data structures and logic on UP kernel too, even though they are not used, to simplify the scheduler and remove around 200 #ifdef/[#else]/#endif blocks from the scheduler (Ingo Molnar) - Reorganize cgroup bandwidth control interface handling for better interfacing with sched_ext (Tejun Heo) Balancing: - Bump sd->max_newidle_lb_cost when newidle balance fails (Chris Mason) - Remove sched_domain_topology_level::flags to simplify the code (Prateek Nayak) - Simplify and clean up build_sched_topology() (Li Chen) - Optimize build_sched_topology() on large machines (Li Chen) Real-time scheduling: - Add initial version of proxy execution: a mechanism for mutex-owning tasks to inherit the scheduling context of higher priority waiters. Currently limited to a single runqueue and conditional on CONFIG_EXPERT, and other limitations (John Stultz, Peter Zijlstra, Valentin Schneider) - Deadline scheduler (Juri Lelli): - Fix dl_servers initialization order (Juri Lelli) - Fix DL scheduler's root domain reinitialization logic (Juri Lelli) - Fix accounting bugs after global limits change (Juri Lelli) - Fix scalability regression by implementing less agressive dl_server handling (Peter Zijlstra) PSI: - Improve scalability by optimizing psi_group_change() cpu_clock() usage (Peter Zijlstra) Rust changes: - Make Task, CondVar and PollCondVar methods inline to avoid unnecessary function calls (Kunwu Chan, Panagiotis Foliadis) - Add might_sleep() support for Rust code: Rust's "#[track_caller]" mechanism is used so that Rust's might_sleep() doesn't need to be defined as a macro (Fujita Tomonori) - Introduce file_from_location() (Boqun Feng) Debugging & instrumentation: - Make clangd usable with scheduler source code files again (Peter Zijlstra) - tools: Add root_domains_dump.py which dumps root domains info (Juri Lelli) - tools: Add dl_bw_dump.py for printing bandwidth accounting info (Juri Lelli) Misc cleanups & fixes: - Remove play_idle() (Feng Lee) - Fix check_preemption_disabled() (Sebastian Andrzej Siewior) - Do not call __put_task_struct() on RT if pi_blocked_on is set (Luis Claudio R. Goncalves) - Correct the comment in place_entity() (wang wei)" * tag 'sched-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits) sched/idle: Remove play_idle() sched: Do not call __put_task_struct() on rt if pi_blocked_on is set sched: Start blocked_on chain processing in find_proxy_task() sched: Fix proxy/current (push,pull)ability sched: Add an initial sketch of the find_proxy_task() function sched: Fix runtime accounting w/ split exec & sched contexts sched: Move update_curr_task logic into update_curr_se locking/mutex: Add p->blocked_on wrappers for correctness checks locking/mutex: Rework task_struct::blocked_on sched: Add CONFIG_SCHED_PROXY_EXEC & boot argument to enable/disable sched/topology: Remove sched_domain_topology_level::flags x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabled x86/smpboot: moves x86_topology to static initialize and truncate x86/smpboot: remove redundant CONFIG_SCHED_SMT smpboot: introduce SDTL_INIT() helper to tidy sched topology setup tools/sched: Add dl_bw_dump.py for printing bandwidth accounting info tools/sched: Add root_domains_dump.py which dumps root domains info sched/deadline: Fix accounting after global limits change sched/deadline: Reset extra_bw to max_bw when clearing root domains sched/deadline: Initialize dl_servers after SMP ...
2025-07-28Merge tag 'vfs-6.17-rc1.rust' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs rust updates from Christian Brauner: - Allow poll_table pointers to be NULL - Add Rust files to vfs MAINTAINERS entry * tag 'vfs-6.17-rc1.rust' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: vfs: add Rust files to MAINTAINERS poll: rust: allow poll_table ptrs to be null
2025-07-22rust: kernel: move ARef and AlwaysRefCounted to sync::arefShankari Anand
Move the definitions of `ARef` and `AlwaysRefCounted` from `types.rs` to a new file `sync/aref.rs`. Define the corresponding `aref` module under `rust/kernel/sync.rs`. These types are better grouped in `sync`. To avoid breaking existing imports, they are re-exported from `types.rs`. Drop unused imports `mem::ManuallyDrop`, `ptr::NonNull` from `types.rs`, they are now only used in `sync/aref.rs`, where they are already imported. Suggested-by: Benno Lossin <lossin@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1173 Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Link: https://lore.kernel.org/r/20250715110423.334744-1-shankari.ak0208@gmail.com [ Added missing `///`. Changed module title. Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-14rust: types: add FOREIGN_ALIGN to ForeignOwnableAndreas Hindborg
The current implementation of `ForeignOwnable` is leaking the type of the opaque pointer to consumers of the API. This allows consumers of the opaque pointer to rely on the information that can be extracted from the pointer type. To prevent this, change the API to the version suggested by Maira Canal (link below): Remove `ForeignOwnable::PointedTo` in favor of a constant, which specifies the alignment of the pointers returned by `into_foreign`. With this change, `ArcInner` no longer needs `pub` visibility, so change it to private. Suggested-by: Alice Ryhl <aliceryhl@google.com> Suggested-by: Maíra Canal <mcanal@igalia.com> Link: https://lore.kernel.org/r/20240309235927.168915-3-mcanal@igalia.com Acked-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250612-pointed-to-v3-1-b009006d86a1@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-14Merge branch 'tip/sched/urgent'Peter Zijlstra
Avoid merge conflicts Signed-off-by: Peter Zijlstra <peterz@infradead.org>
2025-07-14poll: rust: allow poll_table ptrs to be nullAlice Ryhl
It's possible for a poll_table to be null. This can happen if an end-user just wants to know if a resource has events right now without registering a waiter for when events become available. Furthermore, these null pointers should be handled transparently by the API, so we should not change `from_ptr` to return an `Option`. Thus, change `PollTable` to wrap a raw pointer rather than use a reference so that you can pass null. Comments mentioning `struct poll_table` are changed to just `poll_table` since `poll_table` is a typedef. (It's a typedef because it's supposed to be opaque.) Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com>
2025-07-11rust: sync: Add #[must_use] to Lock::try_lock()Jason Devers
The `Lock::try_lock()` function returns an `Option<Guard<...>>`, but it currently does not issue a warning if the return value is unused. To avoid potential bugs, the `#[must_use]` annotation is added to ensure proper usage. Note that `T` is `#[must_use]` but `Option<T>` is not. For more context, see: https://github.com/rust-lang/rust/issues/71368. Suggested-by: Alice Ryhl <aliceryhl@google.com> Link: https://github.com/Rust-for-Linux/linux/issues/1133 Signed-off-by: Jason Devers <dev.json2@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20241212154753.139563-1-dev.json2@gmail.com
2025-07-03rust: sync: implement `Borrow` and `BorrowMut` for `Arc` typesAlexandre Courbot
Implement `Borrow<T>` and `BorrowMut<T>` for `UniqueArc<T>`, and `Borrow<T>` for `Arc<T>`. This allows these containers to be used in generic APIs asking for types implementing those traits. `T` and `&mut T` also implement those traits allowing users to use either owned, shared or borrowed values. `ForeignOwnable` makes a call to its own `borrow` method which must be disambiguated. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Link: https://lore.kernel.org/r/20250616-borrow_impls-v4-2-36f9beb3fe6a@nvidia.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-24rust: sync: Mark PollCondVar::drop() inlineKunwu Chan
When building the kernel using the llvm-18.1.3-rust-1.85.0-x86_64 with ARCH=arm64, the following symbols are generated: $nm vmlinux | grep ' _R'.*PollCondVar | rustfilt ... T <kernel::sync::poll::PollCondVar as kernel::init::PinnedDrop>::drop ... This Rust symbol is trivial wrappers around the C functions __wake_up_pollfree() and synchronize_rcu(). It doesn't make sense to go through a trivial wrapper for its functions, so mark it inline. [boqun: Reword the commit title and re-format the commit log per tip tree's requirement, remove unnecessary information from "nm vmlinux" result.] Link: https://github.com/Rust-for-Linux/linux/issues/1145 Suggested-by: Alice Ryhl <aliceryhl@google.com> Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20250317025205.2366518-1-kunwu.chan@linux.dev
2025-06-24rust: sync: Mark CondVar::notify_*() inlineKunwu Chan
When build the kernel using the llvm-18.1.3-rust-1.85.0-x86_64 with ARCH=arm64, the following symbols are generated: $nm vmlinux | grep ' _R'.*CondVar | rustfilt ... T <kernel::sync::condvar::CondVar>::notify_all ... T <kernel::sync::condvar::CondVar>::notify_one ... T <kernel::sync::condvar::CondVar>::notify_sync ... These notify_*() symbols are trivial wrappers around the C functions __wake_up() and __wake_up_sync(). It doesn't make sense to go through a trivial wrapper for these functions, so mark them inline. [boqun: Reword the commit title for consistency and reformat the commit log.] Suggested-by: Alice Ryhl <aliceryhl@google.com> Link: https://github.com/Rust-for-Linux/linux/issues/1145 Co-developed-by: Grace Deng <Grace.Deng006@Gmail.com> Signed-off-by: Grace Deng <Grace.Deng006@Gmail.com> Signed-off-by: Kunwu Chan <kunwu.chan@hotmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20250324061835.1693125-1-kunwu.chan@linux.dev
2025-06-22rust: enable `clippy::ptr_as_ptr` lintTamir Duberstein
In Rust 1.51.0, Clippy introduced the `ptr_as_ptr` lint [1]: > Though `as` casts between raw pointers are not terrible, > `pointer::cast` is safer because it cannot accidentally change the > pointer's mutability, nor cast the pointer to other types like `usize`. There are a few classes of changes required: - Modules generated by bindgen are marked `#[allow(clippy::ptr_as_ptr)]`. - Inferred casts (` as _`) are replaced with `.cast()`. - Ascribed casts (` as *... T`) are replaced with `.cast::<T>()`. - Multistep casts from references (` as *const _ as *const T`) are replaced with `core::ptr::from_ref(&x).cast()` with or without `::<T>` according to the previous rules. The `core::ptr::from_ref` call is required because `(x as *const _).cast::<T>()` results in inference failure. - Native literal C strings are replaced with `c_str!().as_char_ptr()`. - `*mut *mut T as _` is replaced with `let *mut *const T = (*mut *mut T)`.cast();` since pointer to pointer can be confusing. Apply these changes and enable the lint -- no functional change intended. Link: https://rust-lang.github.io/rust-clippy/master/index.html#ptr_as_ptr [1] Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Tejun Heo <tj@kernel.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250615-ptr-as-ptr-v12-1-f43b024581e8@gmail.com [ Added `.cast()` for `opp`. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-06-13rust: completion: implement initial abstractionDanilo Krummrich
Implement a minimal abstraction for the completion synchronization primitive. This initial abstraction only adds complete_all() and wait_for_completion(), since that is what is required for the subsequent Devres patch. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Juri Lelli <juri.lelli@redhat.com> Cc: Vincent Guittot <vincent.guittot@linaro.org> Cc: Dietmar Eggemann <dietmar.eggemann@arm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Ben Segall <bsegall@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Valentin Schneider <vschneid@redhat.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <lossin@kernel.org> Acked-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20250612121817.1621-2-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-06-04Merge tag 'rust-6.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - KUnit '#[test]'s: - Support KUnit-mapped 'assert!' macros. The support that landed last cycle was very basic, and the 'assert!' macros panicked since they were the standard library ones. Now, they are mapped to the KUnit ones in a similar way to how is done for doctests, reusing the infrastructure there. With this, a failing test like: #[test] fn my_first_test() { assert_eq!(42, 43); } will report: # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251 Expected 42 == 43 to be true, but is false # my_first_test.speed: normal not ok 1 my_first_test - Support tests with checked 'Result' return types. The return value of test functions that return a 'Result' will be checked, thus one can now easily catch errors when e.g. using the '?' operator in tests. With this, a failing test like: #[test] fn my_test() -> Result { f()?; Ok(()) } will report: # my_test: ASSERTION FAILED at rust/kernel/lib.rs:321 Expected is_test_result_ok(my_test()) to be true, but is false # my_test.speed: normal not ok 1 my_test - Add 'kunit_tests' to the prelude. - Clarify the remaining language unstable features in use. - Compile 'core' with edition 2024 for Rust >= 1.87. - Workaround 'bindgen' issue with forward references to 'enum' types. - objtool: relax slice condition to cover more 'noreturn' functions. - Use absolute paths in macros referencing 'core' and 'kernel' crates. - Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds. - Clean some 'doc_markdown' lint hits -- we may enable it later on. 'kernel' crate: - 'alloc' module: - 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>' if 'T' implements 'U'. - 'Vec': implement new methods (prerequisites for nova-core and binder): 'truncate', 'resize', 'clear', 'pop', 'push_within_capacity' (with new error type 'PushError'), 'drain_all', 'retain', 'remove' (with new error type 'RemoveError'), insert_within_capacity' (with new error type 'InsertError'). In addition, simplify 'push' using 'spare_capacity_mut', split 'set_len' into 'inc_len' and 'dec_len', add type invariant 'len <= capacity' and simplify 'truncate' using 'dec_len'. - 'time' module: - Morph the Rust hrtimer subsystem into the Rust timekeeping subsystem, covering delay, sleep, timekeeping, timers. This new subsystem has all the relevant timekeeping C maintainers listed in the entry. - Replace 'Ktime' with 'Delta' and 'Instant' types to represent a duration of time and a point in time. - Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer' to delay converting to 'Instant' and 'Delta'. - 'xarray' module: - Add a Rust abstraction for the 'xarray' data structure. This abstraction allows Rust code to leverage the 'xarray' to store types that implement 'ForeignOwnable'. This support is a dependency for memory backing feature of the Rust null block driver, which is waiting to be merged. - Set up an entry in 'MAINTAINERS' for the XArray Rust support. Patches will go to the new Rust XArray tree and then via the Rust subsystem tree for now. - Allow 'ForeignOwnable' to carry information about the pointed-to type. This helps asserting alignment requirements for the pointer passed to the foreign language. - 'container_of!': retain pointer mut-ness and add a compile-time check of the type of the first parameter ('$field_ptr'). - Support optional message in 'static_assert!'. - Add C FFI types (e.g. 'c_int') to the prelude. - 'str' module: simplify KUnit tests 'format!' macro, convert 'rusttest' tests into KUnit, take advantage of the '-> Result' support in KUnit '#[test]'s. - 'list' module: add examples for 'List', fix path of 'assert_pinned!' (so far unused macro rule). - 'workqueue' module: remove 'HasWork::OFFSET'. - 'page' module: add 'inline' attribute. 'macros' crate: - 'module' macro: place 'cleanup_module()' in '.exit.text' section. 'pin-init' crate: - Add 'Wrapper<T>' trait for creating pin-initializers for wrapper structs with a structurally pinned value such as 'UnsafeCell<T>' or 'MaybeUninit<T>'. - Add 'MaybeZeroable' derive macro to try to derive 'Zeroable', but not error if not all fields implement it. This is needed to derive 'Zeroable' for all bindgen-generated structs. - Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the initialized type of an initializer. These are utilized by the 'Wrapper<T>' implementations. - Add support for visibility in 'Zeroable' derive macro. - Add support for 'union's in 'Zeroable' derive macro. - Upstream dev news: streamline CI, fix some bugs. Add new workflows to check if the user-space version and the one in the kernel tree have diverged. Use the issues tab [1] to track them, which should help folks report and diagnose issues w.r.t. 'pin-init' better. [1] https://github.com/rust-for-linux/pin-init/issues Documentation: - Testing: add docs on the new KUnit '#[test]' tests. - Coding guidelines: explain that '///' vs. '//' applies to private items too. Add section on C FFI types. - Quick Start guide: update Ubuntu instructions and split them into "25.04" and "24.04 LTS and older". And a few other cleanups and improvements" * tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (78 commits) rust: list: Fix typo `much` in arc.rs rust: check type of `$ptr` in `container_of!` rust: workqueue: remove HasWork::OFFSET rust: retain pointer mut-ness in `container_of!` Documentation: rust: testing: add docs on the new KUnit `#[test]` tests Documentation: rust: rename `#[test]`s to "`rusttest` host tests" rust: str: take advantage of the `-> Result` support in KUnit `#[test]`'s rust: str: simplify KUnit tests `format!` macro rust: str: convert `rusttest` tests into KUnit rust: add `kunit_tests` to the prelude rust: kunit: support checked `-> Result`s in KUnit `#[test]`s rust: kunit: support KUnit-mapped `assert!` macros in `#[test]`s rust: make section names plural rust: list: fix path of `assert_pinned!` rust: compile libcore with edition 2024 for 1.87+ rust: dma: add missing Markdown code span rust: task: add missing Markdown code spans and intra-doc links rust: pci: fix docs related to missing Markdown code spans rust: alloc: add missing Markdown code span rust: alloc: add missing Markdown code spans ...
2025-05-26rust: make section names pluralPatrick Miller
Clean Rust documentation section headers to use plural names. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1110 Signed-off-by: Patrick Miller <paddymills@proton.me> Link: https://lore.kernel.org/r/20241002022749.390836-1-paddymills@proton.me [ Removed the `init` one that doesn't apply anymore and reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-18Merge tag 'rust-xarray-for-v6.16' of https://github.com/Rust-for-Linux/linux ↵Miguel Ojeda
into rust-next Pull XArray updates from Andreas Hindborg: "Introduce Rust support for the 'xarray' data structure: - Add a Rust abstraction for the 'xarray' data structure. This abstraction allows Rust code to leverage the 'xarray' to store types that implement 'ForeignOwnable'. This support is a dependency for memory backing feature of the Rust null block driver, which is waiting to be merged. - Set up an entry in MAINTAINERS for the XArray Rust support. Patches will go to the new Rust XArray tree and then via the Rust subsystem tree for now. 'kernel' crate: - Allow 'ForeignOwnable' to carry information about the pointed-to type. This helps asserting alignment requirements for the pointer passed to the foreign language." * tag 'rust-xarray-for-v6.16' of https://github.com/Rust-for-Linux/linux: MAINTAINERS: add entry for Rust XArray API rust: xarray: Add an abstraction for XArray rust: types: add `ForeignOwnable::PointedTo`
2025-05-16rust: sync: rcu: Mark Guard methods as inlineI Hsin Cheng
Currently the implementation of "Guard" methods are basically wrappers around rcu's function within kernel. Building the kernel with llvm 18.1.8 on x86_64 machine will generate the following symbols: $ nm vmlinux | grep ' _R'.*Guard | rustfilt ffffffff817b6c90 T <kernel::sync::rcu::Guard>::new ffffffff817b6cb0 T <kernel::sync::rcu::Guard>::unlock ffffffff817b6cd0 T <kernel::sync::rcu::Guard as core::ops::drop::Drop>::drop ffffffff817b6c90 T <kernel::sync::rcu::Guard as core::default::Default>::default These Rust symbols are basically wrappers around functions "rcu_read_lock" and "rcu_read_unlock". Marking them as inline can reduce the generation of these symbols, and saves the size of code generation for 132 bytes. $ ./scripts/bloat-o-meter vmlinux_old vmlinux_new (Output is demangled for readability) add/remove: 0/10 grow/shrink: 0/1 up/down: 0/-132 (-132) Function old new delta rust_driver_pci::SampleDriver::probe 1041 1034 -7 kernel::sync::rcu::Guard::default 9 - -9 kernel::sync::rcu::Guard::drop 9 - -9 kernel::sync::rcu::read_lock 9 - -9 kernel::sync::rcu::Guard::unlock 9 - -9 kernel::sync::rcu::Guard::new 9 - -9 __pfx__kernel::sync::rcu::Guard::default 16 - -16 __pfx__kernel::sync::rcu::Guard::drop 16 - -16 __pfx__kernel::sync::rcu::read_lock 16 - -16 __pfx__kernel::sync::rcu::Guard::unlock 16 - -16 __pfx__kernel::sync::rcu::Guard::new 16 - -16 Total: Before=23365955, After=23365823, chg -0.00% Link: https://github.com/Rust-for-Linux/linux/issues/1145 Signed-off-by: I Hsin Cheng <richard120310@gmail.com> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Charalampos Mitrodimas <charmitro@posteo.net> Acked-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Joel Fernandes <joelagnelf@nvidia.com>
2025-05-12rust: convert raw URLs to Markdown autolinks in commentsXizhe Yin
Some comments in Rust files use raw URLs (http://example.com) rather than Markdown autolinks <URL>. This inconsistency makes the documentation less uniform and harder to maintain. This patch converts all remaining raw URLs in Rust code comments to use the Markdown autolink format, maintaining consistency with the rest of the codebase which already uses this style. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1153 Signed-off-by: Xizhe Yin <xizheyin@smail.nju.edu.cn> Link: https://lore.kernel.org/r/509F0B66E3C1575D+20250407033441.5567-1-xizheyin@smail.nju.edu.cn [ Used From form for Signed-off-by. Sorted tags. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-01rust: types: add `ForeignOwnable::PointedTo`Tamir Duberstein
Allow implementors to specify the foreign pointer type; this exposes information about the pointed-to type such as its alignment. This requires the trait to be `unsafe` since it is now possible for implementors to break soundness by returning a misaligned pointer. Encoding the pointer type in the trait (and avoiding pointer casts) allows the compiler to check that implementors return the correct pointer type. This is preferable to directly encoding the alignment in the trait using a constant as the compiler would be unable to check it. Acked-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250423-rust-xarray-bindings-v19-1-83cdcf11c114@gmail.com Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-03-30Merge tag 'rust-6.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Extract the 'pin-init' API from the 'kernel' crate and make it into a standalone crate. In order to do this, the contents are rearranged so that they can easily be kept in sync with the version maintained out-of-tree that other projects have started to use too (or plan to, like QEMU). This will reduce the maintenance burden for Benno, who will now have his own sub-tree, and will simplify future expected changes like the move to use 'syn' to simplify the implementation. - Add '#[test]'-like support based on KUnit. We already had doctests support based on KUnit, which takes the examples in our Rust documentation and runs them under KUnit. Now, we are adding the beginning of the support for "normal" tests, similar to those the '#[test]' tests in userspace Rust. For instance: #[kunit_tests(my_suite)] mod tests { #[test] fn my_test() { assert_eq!(1 + 1, 2); } } Unlike with doctests, the 'assert*!'s do not map to the KUnit assertion APIs yet. - Check Rust signatures at compile time for functions called from C by name. In particular, introduce a new '#[export]' macro that can be placed in the Rust function definition. It will ensure that the function declaration on the C side matches the signature on the Rust function: #[export] pub unsafe extern "C" fn my_function(a: u8, b: i32) -> usize { // ... } The macro essentially forces the compiler to compare the types of the actual Rust function and the 'bindgen'-processed C signature. These cases are rare so far. In the future, we may consider introducing another tool, 'cbindgen', to generate C headers automatically. Even then, having these functions explicitly marked may be a good idea anyway. - Enable the 'raw_ref_op' Rust feature: it is already stable, and allows us to use the new '&raw' syntax, avoiding a couple macros. After everyone has migrated, we will disallow the macros. - Pass the correct target to 'bindgen' on Usermode Linux. - Fix 'rusttest' build in macOS. 'kernel' crate: - New 'hrtimer' module: add support for setting up intrusive timers without allocating when starting the timer. Add support for 'Pin<Box<_>>', 'Arc<_>', 'Pin<&_>' and 'Pin<&mut _>' as pointer types for use with timer callbacks. Add support for setting clock source and timer mode. - New 'dma' module: add a simple DMA coherent allocator abstraction and a test sample driver. - 'list' module: make the linked list 'Cursor' point between elements, rather than at an element, which is more convenient to us and allows for cursors to empty lists; and document it with examples of how to perform common operations with the provided methods. - 'str' module: implement a few traits for 'BStr' as well as the 'strip_prefix()' method. - 'sync' module: add 'Arc::as_ptr'. - 'alloc' module: add 'Box::into_pin'. - 'error' module: extend the 'Result' documentation, including a few examples on different ways of handling errors, a warning about using methods that may panic, and links to external documentation. 'macros' crate: - 'module' macro: add the 'authors' key to support multiple authors. The original key will be kept until everyone has migrated. Documentation: - Add error handling sections. MAINTAINERS: - Add Danilo Krummrich as reviewer of the Rust "subsystem". - Add 'RUST [PIN-INIT]' entry with Benno Lossin as maintainer. It has its own sub-tree. - Add sub-tree for 'RUST [ALLOC]'. - Add 'DMA MAPPING HELPERS DEVICE DRIVER API [RUST]' entry with Abdiel Janulgue as primary maintainer. It will go through the sub-tree of the 'RUST [ALLOC]' entry. - Add 'HIGH-RESOLUTION TIMERS [RUST]' entry with Andreas Hindborg as maintainer. It has its own sub-tree. And a few other cleanups and improvements" * tag 'rust-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (71 commits) rust: dma: add `Send` implementation for `CoherentAllocation` rust: macros: fix `make rusttest` build on macOS rust: block: refactor to use `&raw mut` rust: enable `raw_ref_op` feature rust: uaccess: name the correct function rust: rbtree: fix comments referring to Box instead of KBox rust: hrtimer: add maintainer entry rust: hrtimer: add clocksource selection through `ClockId` rust: hrtimer: add `HrTimerMode` rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>` rust: alloc: add `Box::into_pin` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>` rust: hrtimer: add `hrtimer::ScopedHrTimerPointer` rust: hrtimer: add `UnsafeHrTimerPointer` rust: hrtimer: allow timer restart from timer handler rust: str: implement `strip_prefix` for `BStr` rust: str: implement `AsRef<BStr>` for `[u8]` and `BStr` rust: str: implement `Index` for `BStr` rust: str: implement `PartialEq` for `BStr` ...
2025-03-25Merge tag 'rust-hrtimer-for-v6.15-v3' of ↵Miguel Ojeda
https://github.com/Rust-for-Linux/linux into rust-next Pull rust-hrtimer updates from Andreas Hindborg: "Introduce Rust support for the 'hrtimer' subsystem: - Add a way to use the 'hrtimer' subsystem from Rust. Rust code can now set up intrusive timers without allocating when starting the timer. - Add support for 'Pin<Box<_>>', 'Arc<_>', 'Pin<&_>' and 'Pin<&mut _>' as pointer types for use with timer callbacks. - Add support for setting clock source and timer mode. 'kernel' crate: - Add 'Arc::as_ptr' for converting an 'Arc' to a raw pointer. This is a dependency for the 'hrtimer' API. - Add 'Box::into_pin' for converting a 'Box<_>' into a 'Pin<Box<_>>' to align with Rust 'alloc'. This is a dependency for the 'hrtimer' API." * tag 'rust-hrtimer-for-v6.15-v3' of https://github.com/Rust-for-Linux/linux: rust: hrtimer: add maintainer entry rust: hrtimer: add clocksource selection through `ClockId` rust: hrtimer: add `HrTimerMode` rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>` rust: alloc: add `Box::into_pin` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>` rust: hrtimer: add `hrtimer::ScopedHrTimerPointer` rust: hrtimer: add `UnsafeHrTimerPointer` rust: hrtimer: allow timer restart from timer handler rust: hrtimer: implement `HrTimerPointer` for `Arc` rust: sync: add `Arc::as_ptr` rust: hrtimer: introduce hrtimer support
2025-03-24Merge tag 'locking-core-2025-03-22' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Locking primitives: - Micro-optimize percpu_{,try_}cmpxchg{64,128}_op() and {,try_}cmpxchg{64,128} on x86 (Uros Bizjak) - mutexes: extend debug checks in mutex_lock() (Yunhui Cui) - Misc cleanups (Uros Bizjak) Lockdep: - Fix might_fault() lockdep check of current->mm->mmap_lock (Peter Zijlstra) - Don't disable interrupts on RT in disable_irq_nosync_lockdep.*() (Sebastian Andrzej Siewior) - Disable KASAN instrumentation of lockdep.c (Waiman Long) - Add kasan_check_byte() check in lock_acquire() (Waiman Long) - Misc cleanups (Sebastian Andrzej Siewior) Rust runtime integration: - Use Pin for all LockClassKey usages (Mitchell Levy) - sync: Add accessor for the lock behind a given guard (Alice Ryhl) - sync: condvar: Add wait_interruptible_freezable() (Alice Ryhl) - sync: lock: Add an example for Guard:: Lock_ref() (Boqun Feng) Split-lock detection feature (x86): - Fix warning mode with disabled mitigation mode (Maksim Davydov) Locking events: - Add locking events for rtmutex slow paths (Waiman Long) - Add locking events for lockdep (Waiman Long)" * tag 'locking-core-2025-03-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: lockdep: Remove disable_irq_lockdep() lockdep: Don't disable interrupts on RT in disable_irq_nosync_lockdep.*() rust: lockdep: Use Pin for all LockClassKey usages rust: sync: condvar: Add wait_interruptible_freezable() rust: sync: lock: Add an example for Guard:: Lock_ref() rust: sync: Add accessor for the lock behind a given guard locking/lockdep: Add kasan_check_byte() check in lock_acquire() locking/lockdep: Disable KASAN instrumentation of lockdep.c locking/lock_events: Add locking events for lockdep locking/lock_events: Add locking events for rtmutex slow paths x86/split_lock: Fix the delayed detection logic lockdep/mm: Fix might_fault() lockdep check of current->mm->mmap_lock x86/locking: Remove semicolon from "lock" prefix locking/mutex: Add MUTEX_WARN_ON() into fast path x86/locking: Use asm_inline for {,try_}cmpxchg{64,128} emulations x86/locking: Use ALT_OUTPUT_SP() for percpu_{,try_}cmpxchg{64,128}_op()
2025-03-16rust: make pin-init its own crateBenno Lossin
Rename relative paths inside of the crate to still refer to the same items, also rename paths inside of the kernel crate and adjust the build system to build the crate. [ Remove the `expect` (and thus the `lint_reasons` feature) since the tree now uses `quote!` from `rust/macros/export.rs`. Remove the `TokenStream` import removal, since it is now used as well. In addition, temporarily (i.e. just for this commit) use an `--extern force:alloc` to prevent an unknown `new_uninit` error in the `rustdoc` target. For context, please see a similar case in: https://lore.kernel.org/lkml/20240422090644.525520-1-ojeda@kernel.org/ And adjusted the message above. - Miguel ] Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-16-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: pin-init: fix documentation linksBenno Lossin
Before switching to compile the `pin-init` crate directly, change any links that would be invalid to links that are valid both before and after the switch. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-12-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: pin-init: move `InPlaceInit` and impls of `InPlaceWrite` into the ↵Benno Lossin
kernel crate In order to make pin-init a standalone crate, move kernel-specific code directly into the kernel crate. This includes the `InPlaceInit<T>` trait, its implementations and the implementations of `InPlaceWrite` for `Arc` and `UniqueArc`. All of these use the kernel's error type which will become unavailable in pin-init. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-9-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-11rust: sync: add `Arc::as_ptr`Andreas Hindborg
Add a method to get a pointer to the data contained in an `Arc`. Reviewed-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20250309-hrtimer-v3-v6-12-rc2-v12-2-73586e2bd5f1@kernel.org Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-03-08rust: improve lifetimes markupBorys Tyran
Improve lifetimes markup; e.g. from: /// ... 'a ... to: /// ... `'a` ... This will make lifetimes display as code span with Markdown and make it more consistent with rest of the docs. Link: https://github.com/Rust-for-Linux/linux/issues/1138 Signed-off-by: Borys Tyran <borys.tyran@protonmail.com> Link: https://lore.kernel.org/r/20250207142437.112435-1-borys.tyran@protonmail.com [ Reworded and changed Closes tag to Link. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-08rust: lockdep: Use Pin for all LockClassKey usagesMitchell Levy
Reintroduce dynamically-allocated LockClassKeys such that they are automatically (de)registered. Require that all usages of LockClassKeys ensure that they are Pin'd. Currently, only `'static` LockClassKeys are supported, so Pin is redundant. However, it is intended that dynamically-allocated LockClassKeys will eventually be supported, so using Pin from the outset will make that change simpler. Closes: https://github.com/Rust-for-Linux/linux/issues/1102 Suggested-by: Benno Lossin <benno.lossin@proton.me> Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Mitchell Levy <levymitchell0@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20250307232717.1759087-12-boqun.feng@gmail.com
2025-03-08rust: sync: condvar: Add wait_interruptible_freezable()Alice Ryhl
To support waiting for a `CondVar` as a freezable process, add a wait_interruptible_freezable() function. Binder needs this function in the appropriate places to freeze a process where some of its threads are blocked on the Binder driver. [ Boqun: Cleaned up the changelog and documentation. ] Signed-off-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250307232717.1759087-10-boqun.feng@gmail.com
2025-03-08rust: sync: lock: Add an example for Guard:: Lock_ref()Boqun Feng
To provide examples on usage of `Guard::lock_ref()` along with the unit test, an "assert a lock is held by a guard" example is added. (Also apply feedback from Benno.) Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250223072114.3715-1-boqun.feng@gmail.com Link: https://lore.kernel.org/r/20250307232717.1759087-9-boqun.feng@gmail.com
2025-03-08rust: sync: Add accessor for the lock behind a given guardAlice Ryhl
In order to assert a particular `Guard` is associated with a particular `Lock`, add an accessor to obtain a reference to the underlying `Lock` of a `Guard`. Binder needs this assertion to ensure unsafe list operations are done with the correct lock held. [Boqun: Capitalize the title and reword the commit log] Signed-off-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Fiona Behrens <me@kloenk.dev> Link: https://lore.kernel.org/r/20250205-guard-get-lock-v2-1-ba32a8c1d5b7@google.com Link: https://lore.kernel.org/r/20250307232717.1759087-8-boqun.feng@gmail.com
2025-03-06rust: sync: add missing newline in locked_by log exampleAlban Kurti
The pr_info! example in rust/kernel/sync/locked_by.rs was missing a newline. This patch appends the missing newline to ensure that log messages for locked resources display correctly. Fixes: 7b1f55e3a984 ("rust: sync: introduce `LockedBy`") Reported-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1139 Signed-off-by: Alban Kurti <kurti@invicto.ai> Link: https://lore.kernel.org/r/20250206-printing_fix-v3-4-a85273b501ae@invicto.ai [ Replaced Closes with Link since it fixes part of the issue. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>