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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` ...
2025-03-16rust: 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>
2025-03-08rust: 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: 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
2024-12-19rust: sync: Add lock::Backend::assert_is_held()Lyude Paul
Since we've exposed Lock::from_raw() and Guard::new() publically, we want to be able to make sure that we assert that a lock is actually held when constructing a Guard for it to handle instances of unsafe Guard::new() calls outside of our lock module. Hence add a new method assert_is_held() to Backend, which uses lockdep to check whether or not a lock has been acquired. When lockdep is disabled, this has no overhead. [Boqun: Resolve the conflicts with exposing Guard::new(), reword the commit log a bit and format "unsafe { <statement>; }" into "unsafe { <statement> }" for the consistency. ] Signed-off-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20241125204139.656801-1-lyude@redhat.com
2024-12-19rust: sync: Make Guard::new() publicLyude Paul
Since we added a `Lock::from_raw()` function previously, it makes sense to also introduce an interface for creating a `Guard` from a reference to a `Lock` for instances where we've derived the `Lock` from a raw pointer and know that the lock is already acquired, there are such usages in KMS API. [Boqun: Add backquotes to type names, reformat the commit log, reword a bit on the usage of KMS API] Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Filipe Xavier <felipe_life@live.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20241119231146.2298971-3-lyude@redhat.com
2024-12-19rust: sync: Add Lock::from_raw() for Lock<(), B>Lyude Paul
The KMS bindings [1] have a few bindings that require manually acquiring specific locks before calling certain functions. At the moment though, the only way of acquiring these locks in bindings is to simply call the C locking functions directly - since said locks are not initialized on the Rust side of things. However - if we add `#[repr(C)]` to `Lock<(), B>`, then given `()` is a ZST - `Lock<(), B>` becomes equivalent in data layout to its inner `B::State` type. Since locks in C don't have data explicitly associated with them anyway, we can take advantage of this to add a `Lock::from_raw()` function that can translate a raw pointer to `B::State` into its proper `Lock<(), B>` equivalent. This lets us simply acquire a reference to the lock in question and work with it like it was initialized on the Rust side of things, allowing us to use less unsafe code to implement bindings with lock requirements. [Boqun: Use "Link:" instead of a URL and format the commit log] Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patchwork.freedesktop.org/series/131522/ [1] Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20241119231146.2298971-2-lyude@redhat.com
2024-11-26Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Enable a series of lints, including safety-related ones, e.g. the compiler will now warn about missing safety comments, as well as unnecessary ones. How safety documentation is organized is a frequent source of review comments, thus having the compiler guide new developers on where they are expected (and where not) is very nice. - Start using '#[expect]': an interesting feature in Rust (stabilized in 1.81.0) that makes the compiler warn if an expected warning was _not_ emitted. This is useful to avoid forgetting cleaning up locally ignored diagnostics ('#[allow]'s). - Introduce '.clippy.toml' configuration file for Clippy, the Rust linter, which will allow us to tweak its behaviour. For instance, our first use cases are declaring a disallowed macro and, more importantly, enabling the checking of private items. - Lints-related fixes and cleanups related to the items above. - Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the kernel into stable Rust, one of the major pieces of the puzzle is the support to write custom types that can be used as 'self', i.e. as receivers, since the kernel needs to write types such as 'Arc' that common userspace Rust would not. 'arbitrary_self_types' has been accepted to become stable, and this is one of the steps required to get there. - Remove usage of the 'new_uninit' unstable feature. - Use custom C FFI types. Includes a new 'ffi' crate to contain our custom mapping, instead of using the standard library 'core::ffi' one. The actual remapping will be introduced in a later cycle. - Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize' instead of 32/64-bit integers. - Fix 'size_t' in bindgen generated prototypes of C builtins. - Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue in the projects, which we managed to trigger with the upcoming tracepoint support. It includes a build test since some distributions backported the fix (e.g. Debian -- thanks!). All major distributions we list should be now OK except Ubuntu non-LTS. 'macros' crate: - Adapt the build system to be able run the doctests there too; and clean up and enable the corresponding doctests. 'kernel' crate: - Add 'alloc' module with generic kernel allocator support and remove the dependency on the Rust standard library 'alloc' and the extension traits we used to provide fallible methods with flags. Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'. Add the 'Box' type (a heap allocation for a single value of type 'T' that is also generic over an allocator and considers the kernel's GFP flags) and its shorthand aliases '{K,V,KV}Box'. Add 'ArrayLayout' type. Add 'Vec' (a contiguous growable array type) and its shorthand aliases '{K,V,KV}Vec', including iterator support. For instance, now we may write code such as: let mut v = KVec::new(); v.push(1, GFP_KERNEL)?; assert_eq!(&v, &[1]); Treewide, move as well old users to these new types. - 'sync' module: add global lock support, including the 'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types and the 'global_lock!' macro. Add the 'Lock::try_lock' method. - 'error' module: optimize 'Error' type to use 'NonZeroI32' and make conversion functions public. - 'page' module: add 'page_align' function. - Add 'transmute' module with the existing 'FromBytes' and 'AsBytes' traits. - 'block::mq::request' module: improve rendered documentation. - 'types' module: extend 'Opaque' type documentation and add simple examples for the 'Either' types. drm/panic: - Clean up a series of Clippy warnings. Documentation: - Add coding guidelines for lints and the '#[expect]' feature. - Add Ubuntu to the list of distributions in the Quick Start guide. MAINTAINERS: - Add Danilo Krummrich as maintainer of the new 'alloc' module. And a few other small cleanups and fixes" * tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux: (82 commits) rust: alloc: Fix `ArrayLayout` allocations docs: rust: remove spurious item in `expect` list rust: allow `clippy::needless_lifetimes` rust: warn on bindgen < 0.69.5 and libclang >= 19.1 rust: use custom FFI integer types rust: map `__kernel_size_t` and friends also to usize/isize rust: fix size_t in bindgen prototypes of C builtins rust: sync: add global lock support rust: macros: enable the rest of the tests rust: macros: enable paste! use from macro_rules! rust: enable macros::module! tests rust: kbuild: expand rusttest target for macros rust: types: extend `Opaque` documentation rust: block: fix formatting of `kernel::block::mq::request` module rust: macros: fix documentation of the paste! macro rust: kernel: fix THIS_MODULE header path in ThisModule doc comment rust: page: add Rust version of PAGE_ALIGN rust: helpers: remove unnecessary header includes rust: exports: improve grammar in commentary drm/panic: allow verbose version check ...
2024-11-10rust: use custom FFI integer typesGary Guo
Currently FFI integer types are defined in libcore. This commit creates the `ffi` crate and asks bindgen to use that crate for FFI integer types instead of `core::ffi`. This commit is preparatory and no type changes are made in this commit yet. Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240913213041.395655-4-gary@garyguo.net [ Added `rustdoc`, `rusttest` and KUnit tests support. Rebased on top of `rust-next` (e.g. migrated more `core::ffi` cases). Reworded crate docs slightly and formatted. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-10rust: sync: add global lock supportAlice Ryhl
Add support for creating global variables that are wrapped in a mutex or spinlock. The implementation here is intended to replace the global mutex workaround found in the Rust Binder RFC [1]. In both cases, the global lock must be initialized before first use. The macro is unsafe to use for the same reason. The separate initialization step is required because it is tricky to access the value of __ARCH_SPIN_LOCK_UNLOCKED from Rust. Doing so will require changes to the C side. That change will happen as a follow-up to this patch. Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-2-08ba9197f637@google.com/#Z31drivers:android:context.rs [1] Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20241023-static-mutex-v6-1-d7efdadcc84f@google.com [ Simplified a few intra-doc links. Formatted a few comments. Reworded title. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-10rust: lock: add trylock method support for lock backendFilipe Xavier
Add a non-blocking trylock method to lock backend interface, mutex and spinlock implementations. It includes a C helper for spin_trylock. Rust Binder will use this method together with the new shrinker abstractions to avoid deadlocks in the memory shrinker. Link: https://lore.kernel.org/all/20240912-shrinker-v1-1-18b7f1253553@google.com Signed-off-by: Filipe Xavier <felipe_life@live.com> Reviewed-by: Fiona Behrens <me@kloenk.dev> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/BL0PR02MB4914579914884B5D7473B3D6E96A2@BL0PR02MB4914.namprd02.prod.outlook.com [ Slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: enable `clippy::undocumented_unsafe_blocks` lintMiguel Ojeda
Checking that we are not missing any `// SAFETY` comments in our `unsafe` blocks is something we have wanted to do for a long time, as well as cleaning up the remaining cases that were not documented [1]. Back when Rust for Linux started, this was something that could have been done via a script, like Rust's `tidy`. Soon after, in Rust 1.58.0, Clippy implemented the `undocumented_unsafe_blocks` lint [2]. Even though the lint has a few false positives, e.g. in some cases where attributes appear between the comment and the `unsafe` block [3], there are workarounds and the lint seems quite usable already. Thus enable the lint now. We still have a few cases to clean up, so just allow those for the moment by writing a `TODO` comment -- some of those may be good candidates for new contributors. Link: https://github.com/Rust-for-Linux/linux/issues/351 [1] Link: https://rust-lang.github.io/rust-clippy/master/#/undocumented_unsafe_blocks [2] Link: https://github.com/rust-lang/rust-clippy/issues/13189 [3] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-5-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-09-30rust: types: add `NotThreadSafe`Alice Ryhl
This introduces a new marker type for types that shouldn't be thread safe. By adding a field of this type to a struct, it becomes non-Send and non-Sync, which means that it cannot be accessed in any way from threads other than the one it was created on. This is useful for APIs that require globals such as `current` to remain constant while the value exists. We update two existing users in the Kernel to use this helper: * `Task::current()` - moving the return type of this value to a different thread would not be safe as you can no longer be guaranteed that the `current` pointer remains valid. * Lock guards. Mutexes and spinlocks should be unlocked on the same thread as where they were locked, so we enforce this using the Send trait. There are also additional users in later patches of this patchset. See [1] and [2] for the discussion that led to the introduction of this patch. Link: https://lore.kernel.org/all/nFDPJFnzE9Q5cqY7FwSMByRH2OAn_BpI4H53NQfWIlN6I2qfmAqnkp2wRqn0XjMO65OyZY4h6P4K2nAGKJpAOSzksYXaiAK_FoH_8QbgBI4=@proton.me/ [1] Link: https://lore.kernel.org/all/nFDPJFnzE9Q5cqY7FwSMByRH2OAn_BpI4H53NQfWIlN6I2qfmAqnkp2wRqn0XjMO65OyZY4h6P4K2nAGKJpAOSzksYXaiAK_FoH_8QbgBI4=@proton.me/ [2] Suggested-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240915-alice-file-v10-1-88484f7a3dcf@google.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-05-05rust: kernel: remove redundant importsMiguel Ojeda
Rust's `unused_imports` lint covers both unused and redundant imports. In the upcoming 1.78.0, the lint detects more cases of redundant imports [1], e.g.: error: the item `bindings` is imported redundantly --> rust/kernel/print.rs:38:9 | 38 | use crate::bindings; | ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude Most cases are `use crate::bindings`, plus a few other items like `Box`. Thus clean them up. Note that, in the `bindings` case, the message "defined by prelude" above means the extern prelude, i.e. the `--extern` flags we pass. Link: https://github.com/rust-lang/rust/pull/117772 [1] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240401212303.537355-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add doclinksValentin Obst
Add doclinks to existing documentation. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-10-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: mark code fragments in docs with backticksValentin Obst
Fix places where comments include code fragments that are not enclosed in backticks. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-8-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: fix multiple typos in documentationValentin Obst
Fixes multiple trivial typos in documentation and comments of the kernel crate. allocator: - Fix a trivial list item alignment issue in the last SAFETY comment of `krealloc_aligned`. init: - Replace 'type' with 'trait' in the doc comments of the `PinInit` and `Init` traits. - Add colons before starting lists. - Add spaces between the type and equal sign to respect the code formatting rules in example code. - End a sentence with a full stop instead of a colon. ioctl: - Replace 'an' with 'a' where appropriate. str: - Replace 'Return' with 'Returns' in the doc comment of `bytes_written` as the text describes what the function does. sync/lock: - Fix a trivial list item alignment issue in the Safety section of the `Backend` trait's description. sync/lock/spinlock: - The code in this module operates on spinlocks, not mutexes. Thus, replace 'mutex' with 'spinlock' in the SAFETY comment of `unlock`. workqueue: - Replace "wont" with "won't" in the doc comment of `__enqueue`. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-1-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-28rust: sync: add `CondVar::wait_timeout`Alice Ryhl
Sleep on a condition variable with a timeout. This is used by Rust Binder for process freezing. There, we want to sleep until the freeze operation completes, but we want to be able to abort the process freezing if it doesn't complete within some timeout. Note that it is not enough to avoid jiffies by introducing a variant of `CondVar::wait_timeout` that takes the timeout in msecs because we need to be able to restart the sleep with the remaining sleep duration if it is interrupted, and if the API takes msecs rather than jiffies, then that would require a conversion roundtrip jiffies->msecs->jiffies that is best avoided. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-3-88e0c871cc05@google.com [ Added `CondVarTimeoutResult` re-export and fixed typo. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-05rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`Gary Guo
Clippy triggered a false positive on its `new_ret_no_self` lint when using the `pin_init!` macro. Since Rust 1.67.0, that does not happen anymore, since Clippy learnt to not warn about `-> impl Trait<Self>` [1][2]. The kernel nowadays uses Rust 1.72.1, thus remove the `#[allow]`. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://github.com/rust-lang/rust-clippy/issues/7344 [1] Link: https://github.com/rust-lang/rust-clippy/pull/9733 [2] Link: https://lore.kernel.org/r/20230923024707.47610-1-gary@garyguo.net [ Reworded slightly and added a couple `Link`s. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07rust: lock: Add intra-doc links to the Backend traitBen Gooding
Add missing intra-doc links to the Backend trait to make navigating the documentation easier. Suggested-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/rust-for-linux/94625fe6-b87a-a8f0-5b2a-a8152d5f7436@proton.me/ Link: https://github.com/Rust-for-Linux/linux/issues/1001 Signed-off-by: Ben Gooding <ben.gooding.dev@gmail.com> Link: https://lore.kernel.org/r/20230509202314.8248-1-ben.gooding.dev@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `CondVar`Wedson Almeida Filho
This is the traditional condition variable or monitor synchronisation primitive. It is implemented with C's `wait_queue_head_t`. It allows users to release a lock and go to sleep while guaranteeing that notifications won't be missed. This is achieved by enqueuing a wait entry before releasing the lock. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230411054543.21278-12-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: lock: add `Guard::do_unlocked`Wedson Almeida Filho
It releases the lock, executes some function provided by the caller, then reacquires the lock. This is preparation for the implementation of condvars, which will sleep after between unlocking and relocking. We need an explicit `relock` method for primitives like `SpinLock` that have an irqsave variant: we use the guard state to determine if the lock was originally acquired with the regular `lock` function or `lock_irqsave`. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/rust-for-linux/20230412121431.41627-1-wedsonaf@gmail.com/ [ Removed the irqsave bits as discussed. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `LockedBy`Wedson Almeida Filho
This allows us to have data protected by a lock despite not being wrapped by it. Access is granted by providing evidence that the lock is held by the caller. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230411054543.21278-13-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: lock: introduce `SpinLock`Wedson Almeida Filho
This is the `spinlock_t` lock backend and allows Rust code to use the kernel spinlock idiomatically. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230419174426.132207-1-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: lock: introduce `Mutex`Wedson Almeida Filho
This is the `struct mutex` lock backend and allows Rust code to use the kernel mutex idiomatically. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-3-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `Lock` and `Guard`Wedson Almeida Filho
They are generic Rust implementations of a lock and a lock guard that contain code that is common to all locks. Different backends will be introduced in subsequent commits. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Suggested-by: Gary Guo <gary@garyguo.net> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-2-wedsonaf@gmail.com [ Fixed typo. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>