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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>
2024-10-15rust: treewide: switch to the kernel `Vec` typeDanilo Krummrich
Now that we got the kernel `Vec` in place, convert all existing `Vec` users to make use of it. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20241004154149.93856-20-dakr@kernel.org [ Converted `kasan_test_rust.rs` too, as discussed. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15rust: treewide: switch to our kernel `Box` typeDanilo Krummrich
Now that we got the kernel `Box` type in place, convert all existing `Box` users to make use of it. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20241004154149.93856-13-dakr@kernel.org 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>
2024-10-08Merge patch series "File abstractions needed by Rust Binder"Christian Brauner
Alice Ryhl <aliceryhl@google.com> says: This patchset contains the file abstractions needed by the Rust implementation of the Binder driver. Please see the Rust Binder RFC for usage examples: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-0-08ba9197f637@google.com Users of "rust: types: add `NotThreadSafe`": [PATCH 5/9] rust: file: add `FileDescriptorReservation` Users of "rust: task: add `Task::current_raw`": [PATCH 7/9] rust: file: add `Kuid` wrapper [PATCH 8/9] rust: file: add `DeferredFdCloser` Users of "rust: file: add Rust abstraction for `struct file`": [PATCH RFC 02/20] rust_binder: add binderfs support to Rust binder [PATCH RFC 03/20] rust_binder: add threading support Users of "rust: cred: add Rust abstraction for `struct cred`": [PATCH RFC 05/20] rust_binder: add nodes and context managers [PATCH RFC 06/20] rust_binder: add oneway transactions [PATCH RFC 11/20] rust_binder: send nodes in transaction [PATCH RFC 13/20] rust_binder: add BINDER_TYPE_FD support Users of "rust: security: add abstraction for secctx": [PATCH RFC 06/20] rust_binder: add oneway transactions Users of "rust: file: add `FileDescriptorReservation`": [PATCH RFC 13/20] rust_binder: add BINDER_TYPE_FD support [PATCH RFC 14/20] rust_binder: add BINDER_TYPE_FDA support Users of "rust: file: add `Kuid` wrapper": [PATCH RFC 05/20] rust_binder: add nodes and context managers [PATCH RFC 06/20] rust_binder: add oneway transactions Users of "rust: file: add abstraction for `poll_table`": [PATCH RFC 07/20] rust_binder: add epoll support This patchset has some uses of read_volatile in place of READ_ONCE. Please see the following rfc for context on this: https://lore.kernel.org/all/20231025195339.1431894-1-boqun.feng@gmail.com/ * patches from https://lore.kernel.org/r/20240915-alice-file-v10-0-88484f7a3dcf@google.com: rust: file: add abstraction for `poll_table` rust: file: add `Kuid` wrapper rust: file: add `FileDescriptorReservation` rust: security: add abstraction for secctx rust: cred: add Rust abstraction for `struct cred` rust: file: add Rust abstraction for `struct file` rust: task: add `Task::current_raw` rust: types: add `NotThreadSafe` Link: https://lore.kernel.org/r/20240915-alice-file-v10-0-88484f7a3dcf@google.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-07rust: enable arbitrary_self_types and remove `Receiver`Gary Guo
The term "receiver" means that a type can be used as the type of `self`, and thus enables method call syntax `foo.bar()` instead of `Foo::bar(foo)`. Stable Rust as of today (1.81) enables a limited selection of types (primitives and types in std, e.g. `Box` and `Arc`) to be used as receivers, while custom types cannot. We want the kernel `Arc` type to have the same functionality as the Rust std `Arc`, so we use the `Receiver` trait (gated behind `receiver_trait` unstable feature) to gain the functionality. The `arbitrary_self_types` RFC [1] (tracking issue [2]) is accepted and it will allow all types that implement a new `Receiver` trait (different from today's unstable trait) to be used as receivers. This trait will be automatically implemented for all `Deref` types, which include our `Arc` type, so we no longer have to opt-in to be used as receiver. To prepare us for the change, remove the `Receiver` implementation and the associated feature. To still allow `Arc` and others to be used as method receivers, turn on `arbitrary_self_types` feature instead. This feature gate is introduced in 1.23.0. It used to enable both `Deref` types and raw pointer types to be used as receivers, but the latter is now split into a different feature gate in Rust 1.83 nightly. We do not need receivers on raw pointers so this change would not affect us and usage of `arbitrary_self_types` feature would work for all Rust versions that we support (>=1.78). Cc: Adrian Taylor <ade@hohum.me.uk> Link: https://github.com/rust-lang/rfcs/pull/3519 [1] Link: https://github.com/rust-lang/rust/issues/44874 [2] Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240915132734.1653004-1-gary@garyguo.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: provide proper code documentation titlesMiguel Ojeda
Rust 1.82.0's Clippy is introducing [1][2] a new warn-by-default lint, `too_long_first_doc_paragraph` [3], which is intended to catch titles of code documentation items that are too long (likely because no title was provided and the item documentation starts with a paragraph). This lint does not currently trigger anywhere, but it does detect a couple cases if checking for private items gets enabled (which we will do in the next commit): error: first doc comment paragraph is too long --> rust/kernel/init/__internal.rs:18:1 | 18 | / /// This is the module-internal type implementing `PinInit` and `Init`. It is unsafe to create this 19 | | /// type, since the closure needs to fulfill the same safety requirement as the 20 | | /// `__pinned_init`/`__init` functions. | |_ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_long_first_doc_paragraph = note: `-D clippy::too-long-first-doc-paragraph` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::too_long_first_doc_paragraph)]` error: first doc comment paragraph is too long --> rust/kernel/sync/arc/std_vendor.rs:3:1 | 3 | / //! The contents of this file come from the Rust standard library, hosted in 4 | | //! the <https://github.com/rust-lang/rust> repository, licensed under 5 | | //! "Apache-2.0 OR MIT" and adapted for kernel use. For copyright details, 6 | | //! see <https://github.com/rust-lang/rust/blob/master/COPYRIGHT>. | |_ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#too_long_first_doc_paragraph Thus clean those two instances. In addition, since we have a second `std_vendor.rs` file with a similar header, do the same there too (even if that one does not trigger the lint, because it is `doc(hidden)`). Link: https://github.com/rust-lang/rust/pull/129531 [1] Link: https://github.com/rust-lang/rust-clippy/pull/12993 [2] Link: https://rust-lang.github.io/rust-clippy/master/index.html#/too_long_first_doc_paragraph [3] Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-15-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: sync: remove unneeded `#[allow(clippy::non_send_fields_in_send_ty)]`Miguel Ojeda
Rust 1.58.0 (before Rust was merged into the kernel) made Clippy's `non_send_fields_in_send_ty` lint part of the `suspicious` lint group for a brief window of time [1] until the minor version 1.58.1 got released a week after, where the lint was moved back to `nursery`. By that time, we had already upgraded to that Rust version, and thus we had `allow`ed the lint here for `CondVar`. Nowadays, Clippy's `non_send_fields_in_send_ty` would still trigger here if it were enabled. Moreover, if enabled, `Lock<T, B>` and `Task` would also require an `allow`. Therefore, it does not seem like someone is actually enabling it (in, e.g., a custom flags build). Finally, the lint does not appear to have had major improvements since then [2]. Thus remove the `allow` since it is unneeded. Link: https://github.com/rust-lang/rust/blob/master/RELEASES.md#version-1581-2022-01-20 [1] Link: https://github.com/rust-lang/rust-clippy/issues/8045 [2] 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/20240904204347.168520-11-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: enable `clippy::unnecessary_safety_comment` lintMiguel Ojeda
In Rust 1.67.0, Clippy added the `unnecessary_safety_comment` lint [1], which is the "inverse" of `undocumented_unsafe_blocks`: it finds places where safe code has a `// SAFETY` comment attached. The lint currently finds 3 places where we had such mistakes, thus it seems already quite useful. Thus clean those and enable it. Link: https://rust-lang.github.io/rust-clippy/master/index.html#/unnecessary_safety_comment [1] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-6-ojeda@kernel.org 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: file: add abstraction for `poll_table`Alice Ryhl
The existing `CondVar` abstraction is a wrapper around `wait_queue_head`, but it does not support all use-cases of the C `wait_queue_head` type. To be specific, a `CondVar` cannot be registered with a `struct poll_table`. This limitation has the advantage that you do not need to call `synchronize_rcu` when destroying a `CondVar`. However, we need the ability to register a `poll_table` with a `wait_queue_head` in Rust Binder. To enable this, introduce a type called `PollCondVar`, which is like `CondVar` except that you can register a `poll_table`. We also introduce `PollTable`, which is a safe wrapper around `poll_table` that is intended to be used with `PollCondVar`. The destructor of `PollCondVar` unconditionally calls `synchronize_rcu` to ensure that the removal of epoll waiters has fully completed before the `wait_queue_head` is destroyed. That said, `synchronize_rcu` is rather expensive and is not needed in all cases: If we have never registered a `poll_table` with the `wait_queue_head`, then we don't need to call `synchronize_rcu`. (And this is a common case in Binder - not all processes use Binder with epoll.) The current implementation does not account for this, but if we find that it is necessary to improve this, a future patch could store a boolean next to the `wait_queue_head` to keep track of whether a `poll_table` has ever been registered. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240915-alice-file-v10-8-88484f7a3dcf@google.com Signed-off-by: Christian Brauner <brauner@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>
2024-09-26rust: sync: require `T: Sync` for `LockedBy::access`Alice Ryhl
The `LockedBy::access` method only requires a shared reference to the owner, so if we have shared access to the `LockedBy` from several threads at once, then two threads could call `access` in parallel and both obtain a shared reference to the inner value. Thus, require that `T: Sync` when calling the `access` method. An alternative is to require `T: Sync` in the `impl Sync for LockedBy`. This patch does not choose that approach as it gives up the ability to use `LockedBy` with `!Sync` types, which is okay as long as you only use `access_mut`. Cc: stable@vger.kernel.org Fixes: 7b1f55e3a984 ("rust: sync: introduce `LockedBy`") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Suggested-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240915-locked-by-sync-fix-v2-1-1a8d89710392@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18rust: Implement the smart pointer `InPlaceInit` for `Arc`Alex Mantel
For pinned and unpinned initialization of structs, a trait named `InPlaceInit` exists for uniform access. `Arc` did not implement `InPlaceInit` yet, although the functions already existed. The main reason for that, was that the trait itself returned a `Pin<Self>`. The `Arc` implementation of the kernel is already implicitly pinned. To enable `Arc` to implement `InPlaceInit` and to have uniform access, for in-place and pinned in-place initialization, an associated type is introduced for `InPlaceInit`. The new implementation of `InPlaceInit` for `Arc` sets `Arc` as the associated type. Older implementations use an explicit `Pin<T>` as the associated type. The implemented methods for `Arc` are mostly moved from a direct implementation on `Arc`. There should be no user impact. The implementation for `ListArc` is omitted, because it is not merged yet. Link: https://github.com/Rust-for-Linux/linux/issues/1079 Signed-off-by: Alex Mantel <alexmantel93@mailbox.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240727042442.682109-1-alexmantel93@mailbox.org [ Removed "Rusts" (Benno). - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@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>
2024-05-05rust: sync: add `Arc::into_unique_or_drop`Alice Ryhl
Decrement the refcount of an `Arc`, but handle the case where it hits zero by taking ownership of the now-unique `Arc`, instead of destroying and deallocating it. This is a dependency of the linked list that Rust Binder uses. The linked list uses this method as part of its `ListArc` abstraction [1]. Boqun Feng has authored the examples. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240402-linked-list-v1-1-b1c59ba7ae3b@google.com [1] Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240402-arc-for-list-v4-2-54db6440a9a9@google.com [ Replace `try_new` with `new` in example since we now have the new allocation APIs. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-05-05rust: sync: add `ArcBorrow::from_raw`Alice Ryhl
Allows access to a value in an `Arc` that is currently held as a raw pointer due to use of `Arc::into_raw`, without destroying or otherwise consuming that raw pointer. This is a dependency of the linked list that Rust Binder uses. The linked list uses this method when iterating over the linked list [1]. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240402-linked-list-v1-6-b1c59ba7ae3b@google.com [1] Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240402-arc-for-list-v4-1-54db6440a9a9@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: kernel: remove usage of `allocator_api` unstable featureWedson Almeida Filho
With the adoption of `BoxExt` and `VecExt`, we don't need the functions provided by this feature (namely the methods prefixed with `try_` and different allocator per collection instance). We do need `AllocError`, but we define our own as it is a trivial empty struct. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20240328013603.206764-11-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: init: update `init` module to take allocation flagsWedson Almeida Filho
This is the last component in the conversion for allocators to take allocation flags as parameters. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20240328013603.206764-10-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: sync: update `Arc` and `UniqueArc` to take allocation flagsWedson Almeida Filho
We also remove the `try_` prefix to align with how `Box` and `Vec` are providing methods now. `init` is temporarily updated with uses of GFP_KERNEL. These will be updated in a subsequent patch to take flags as well. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20240328013603.206764-9-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: alloc: introduce the `BoxExt` traitWedson Almeida Filho
Make fallible versions of `new` and `new_uninit` methods available in `Box` even though it doesn't implement them because we build `alloc` with the `no_global_oom_handling` config. They also have an extra `flags` parameter that allows callers to pass flags to the allocator. Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240328013603.206764-7-wedsonaf@gmail.com [ Used `Box::write()` to avoid one `unsafe` block as suggested by Boqun. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: stop using ptr_metadata featureAlice Ryhl
The `byte_sub` method was stabilized in Rust 1.75.0. By using that method, we no longer need the unstable `ptr_metadata` feature for implementing `Arc::from_raw`. This brings us one step closer towards not using unstable compiler features. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240215104601.1267763-1-aliceryhl@google.com [ Reworded title. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add reexports for macrosAlice Ryhl
Currently, all macros are reexported with #[macro_export] only, which means that to access `new_work!` from the workqueue, you need to import it from the path `kernel::new_work` instead of importing it from the workqueue module like all other items in the workqueue. By adding reexports of the macros, it becomes possible to import the macros from the correct modules. It's still possible to import the macros from the root, but I don't think we can do anything about that. There is no functional change. This is merely a code cleanliness improvement. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240129145837.1419880-1-aliceryhl@google.com [ Removed new `use kernel::prelude::*`s, reworded title. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: locked_by: shorten doclink previewValentin Obst
Increases readability by removing `super::` from the link preview text. 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-v3-12-0c8af94ed7de@valentinobst.de 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: unify spelling of refcount in docsValentin Obst
Replace instances of 'ref-count[ed]' with 'refcount[ed]' to increase consistency within the Rust documentation. The latter form is used more widely in the rest of the kernel: ```console $ rg '(\*|//).*?\srefcount(|ed)[\s,.]' | wc -l 1605 $ rg '(\*|//).*?\sref-count(|ed)[\s,.]' | wc -l 43 ``` (numbers are for commit 052d534373b7 ("Merge tag 'exfat-for-6.8-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat")) 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-v3-7-0c8af94ed7de@valentinobst.de [ Reworded to use the kernel's commit description style. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add srctree-relative doclinksValentin Obst
Convert existing references to C header files to make use of Commit bc2e7d5c298a ("rust: support `srctree`-relative links"). 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-v3-4-0c8af94ed7de@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: update integer types in CondVarAlice Ryhl
Reduce the chances of compilation failures due to integer type mismatches in `CondVar`. When an integer is defined using a #define in C, bindgen doesn't know which integer type it is supposed to be, so it will just use `u32` by default (if it fits in an u32). Whenever the right type is something else, we insert a cast in Rust. However, this means that the code has a lot of extra casts, and sometimes the code will be missing casts if u32 happens to be correct on the developer's machine, even though the type might be something else on a different platform. This patch updates all uses of such constants in `rust/kernel/sync/condvar.rs` to use constants defined with the right type. This allows us to remove various unnecessary casts, while also future-proofing for the case where `unsigned int != u32` (even though that is unlikely to ever happen in the kernel). I wrote this patch at the suggestion of Benno in [1]. Link: https://lore.kernel.org/all/nAEg-6vbtX72ZY3oirDhrSEf06TBWmMiTt73EklMzEAzN4FD4mF3TPEyAOxBZgZtjzoiaBYtYr3s8sa9wp1uYH9vEWRf2M-Lf4I0BY9rAgk=@proton.me/ [1] Suggested-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-4-88e0c871cc05@google.com [ Added note on the unlikeliness of `sizeof(int)` changing. ] 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>
2024-01-28rust: sync: add `CondVar::notify_sync`Alice Ryhl
Wake up another thread synchronously. This method behaves like `notify_one`, except that it hints to the scheduler that the current thread is about to go to sleep, so it should schedule the target thread on the same CPU. This is used by Rust Binder as a performance optimization. When sending a transaction to a different process, we usually know which thread will handle it, so we can schedule that thread for execution next on this CPU for better cache locality. Reviewed-by: Benno Lossin <benno.lossin@proton.me> 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> Link: https://lore.kernel.org/r/20240108-rb-new-condvar-methods-v4-1-88e0c871cc05@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-01-22rust: sync: `CondVar` rename "wait_list" to "wait_queue_head"Charalampos Mitrodimas
Fields named "wait_list" usually are of type "struct list_head". To avoid confusion and because it is of type "Opaque<bindings::wait_queue_head>" we are renaming "wait_list" to "wait_queue_head". Signed-off-by: Charalampos Mitrodimas <charmitro@posteo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240105012930.1426214-1-charmitro@posteo.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21rust: support `srctree`-relative linksMiguel Ojeda
Some of our links use relative paths in order to point to files in the source tree, e.g.: //! C header: [`include/linux/printk.h`](../../../../include/linux/printk.h) /// [`struct mutex`]: ../../../../include/linux/mutex.h These are problematic because they are hard to maintain and do not support `O=` builds. Instead, provide support for `srctree`-relative links, e.g.: //! C header: [`include/linux/printk.h`](srctree/include/linux/printk.h) /// [`struct mutex`]: srctree/include/linux/mutex.h The links are fixed after `rustdoc` generation to be based on the absolute path to the source tree. Essentially, this is the automatic version of Tomonori's fix [1], suggested by Gary [2]. Suggested-by: Gary Guo <gary@garyguo.net> Reported-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Closes: https://lore.kernel.org/r/20231026.204058.2167744626131849993.fujita.tomonori@gmail.com [1] Fixes: 48fadf440075 ("docs: Move rustdoc output, cross-reference it") Link: https://lore.kernel.org/rust-for-linux/20231026154525.6d14b495@eugeo/ [2] Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20231215235428.243211-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21rust: sync: Makes `CondVar::wait()` an uninterruptible waitBoqun Feng
Currently, `CondVar::wait()` is an interruptible wait, and this is different than `wait_event()` in include/linux/wait.h (which is an uninterruptible wait). To avoid confusion between different APIs on the interruptible/uninterruptible, make `CondVar::wait()` an uninterruptible wait same as `wait_event()`, also rename the old `wait()` to `CondVar::wait_interruptible()`. Spotted-by: Tiago Lam <tiagolam@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Tiago Lam <tiagolam@gmail.com> Link: https://lore.kernel.org/r/20231214200421.690629-1-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-30Merge tag 'wq-for-6.7-rust-bindings' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue rust bindings from Tejun Heo: "Add rust bindings to allow rust code to schedule work items on workqueues. While the current bindings don't cover all of the workqueue API, it provides enough for basic usage and can be expanded as needed" * tag 'wq-for-6.7-rust-bindings' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: rust: workqueue: add examples rust: workqueue: add `try_spawn` helper method rust: workqueue: implement `WorkItemPointer` for pointer types rust: workqueue: add helper for defining work_struct fields rust: workqueue: define built-in queues rust: workqueue: add low-level workqueue bindings rust: sync: add `Arc::{from_raw, into_raw}`
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>
2023-10-05rust: arc: add explicit `drop()` around `Box::from_raw()`Miguel Ojeda
`Box::from_raw()` is `#[must_use]`, which means the result cannot go unused. In Rust 1.71.0, this was not detected because the block expression swallows the diagnostic [1]: unsafe { Box::from_raw(self.ptr.as_ptr()) }; It would have been detected, however, if the line had been instead: unsafe { Box::from_raw(self.ptr.as_ptr()); } i.e. the semicolon being inside the `unsafe` block, rather than outside. In Rust 1.72.0, the compiler started warning about this [2], so without this patch we will get: error: unused return value of `alloc::boxed::Box::<T>::from_raw` that must be used --> rust/kernel/sync/arc.rs:302:22 | 302 | unsafe { Box::from_raw(self.ptr.as_ptr()) }; | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ | = note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box` = note: `-D unused-must-use` implied by `-D warnings` help: use `let _ = ...` to ignore the resulting value | 302 | unsafe { let _ = Box::from_raw(self.ptr.as_ptr()); }; | +++++++ + Thus add an add an explicit `drop()` as the `#[must_use]`'s annotation suggests (instead of the more general help line). Link: https://github.com/rust-lang/rust/issues/104253 [1] Link: https://github.com/rust-lang/rust/pull/112529 [2] Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Link: https://lore.kernel.org/r/20230823160244.188033-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-09-25rust: sync: add `Arc::{from_raw, into_raw}`Wedson Almeida Filho
These methods can be used to turn an `Arc` into a raw pointer and back, in a way that preserves the metadata for fat pointers. This is done using the unstable ptr_metadata feature [1]. However, it could also be done using the unstable pointer_byte_offsets feature [2], which is likely to have a shorter path to stabilization than ptr_metadata. Link: https://github.com/rust-lang/rust/issues/81513 [1] Link: https://github.com/rust-lang/rust/issues/96283 [2] Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Co-developed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2023-08-29Merge tag 'rust-6.6' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust updates from Miguel Ojeda: "In terms of lines, most changes this time are on the pinned-init API and infrastructure. While we have a Rust version upgrade, and thus a bunch of changes from the vendored 'alloc' crate as usual, this time those do not account for many lines. Toolchain and infrastructure: - Upgrade to Rust 1.71.1. This is the second such upgrade, which is a smaller jump compared to the last time. This version allows us to remove the '__rust_*' allocator functions -- the compiler now generates them as expected, thus now our 'KernelAllocator' is used. It also introduces the 'offset_of!' macro in the standard library (as an unstable feature) which we will need soon. So far, we were using a declarative macro as a prerequisite in some not-yet-landed patch series, which did not support sub-fields (i.e. nested structs): #[repr(C)] struct S { a: u16, b: (u8, u8), } assert_eq!(offset_of!(S, b.1), 3); - Upgrade to bindgen 0.65.1. This is the first time we upgrade its version. Given it is a fairly big jump, it comes with a fair number of improvements/changes that affect us, such as a fix needed to support LLVM 16 as well as proper support for '__noreturn' C functions, which are now mapped to return the '!' type in Rust: void __noreturn f(void); // C pub fn f() -> !; // Rust - 'scripts/rust_is_available.sh' improvements and fixes. This series takes care of all the issues known so far and adds a few new checks to cover for even more cases, plus adds some more help texts. All this together will hopefully make problematic setups easier to identify and to be solved by users building the kernel. In addition, it adds a test suite which covers all branches of the shell script, as well as tests for the issues found so far. - Support rust-analyzer for out-of-tree modules too. - Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates. - Drop 'scripts/is_rust_module.sh' since it is not needed anymore. Macros crate: - New 'paste!' proc macro. This macro is a more flexible version of 'concat_idents!': it allows the resulting identifier to be used to declare new items and it allows to transform the identifiers before concatenating them, e.g. let x_1 = 42; paste!(let [<x _2>] = [<x _1>];); assert!(x_1 == x_2); The macro is then used for several of the pinned-init API changes in this pull. Pinned-init API: - Make '#[pin_data]' compatible with conditional compilation of fields, allowing to write code like: #[pin_data] pub struct Foo { #[cfg(CONFIG_BAR)] a: Bar, #[cfg(not(CONFIG_BAR))] a: Baz, } - New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait, which allows 'unsafe' implementations for structs where every field implements the 'Zeroable' trait, e.g.: #[derive(Zeroable)] pub struct DriverData { id: i64, buf_ptr: *mut u8, len: usize, } - Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for zeroing all other fields, e.g.: pin_init!(Buf { buf: [1; 64], ..Zeroable::zeroed() }); - New '{,pin_}init_array_from_fn()' functions to create array initializers given a generator function, e.g.: let b: Box<[usize; 1_000]> = Box::init::<Error>( init_array_from_fn(|i| i) ).unwrap(); assert_eq!(b.len(), 1_000); assert_eq!(b[123], 123); - New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to execute a closure on the value directly after initialization, e.g.: let foo = init!(Foo { buf <- init::zeroed() }).chain(|foo| { foo.setup(); Ok(()) }); - Support arbitrary paths in init macros, instead of just identifiers and generic types. - Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and 'Opaque<T>' types. - Make initializer values inaccessible after initialization. - Make guards in the init macros hygienic. 'allocator' module: - Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing misaligned allocations when the Rust 1.71.1 upgrade is applied later in this pull. The equivalent fix for the previous compiler version (where 'KernelAllocator' is not yet used) was merged into 6.5 already, which added the 'krealloc_aligned()' function used here. - Implement 'KernelAllocator::{realloc, alloc_zeroed}' for performance, using 'krealloc_aligned()' too, which forwards the call to the C API. 'types' module: - Make 'Opaque' be '!Unpin', removing the need to add a 'PhantomPinned' field to Rust structs that contain C structs which must not be moved. - Make 'Opaque' use 'UnsafeCell' as the outer type, rather than inner. Documentation: - Suggest obtaining the source code of the Rust's 'core' library using the tarball instead of the repository. MAINTAINERS: - Andreas and Alice, from Samsung and Google respectively, are joining as reviewers of the "RUST" entry. As well as a few other minor changes and cleanups" * tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits) rust: init: update expanded macro explanation rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>` rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>` rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>` rust: init: add support for arbitrary paths in init macros rust: init: add functions to create array initializers rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields rust: init: make initializer values inaccessible after initializing rust: init: wrap type checking struct initializers in a closure rust: init: make guards in the init macros hygienic rust: add derive macro for `Zeroable` rust: init: make `#[pin_data]` compatible with conditional compilation of fields rust: init: consolidate init macros docs: rust: clarify what 'rustup override' does docs: rust: update instructions for obtaining 'core' source docs: rust: add command line to rust-analyzer section scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc` rust: bindgen: upgrade to 0.65.1 rust: enable `no_mangle_with_rust_abi` Clippy lint rust: upgrade to Rust 1.71.1 ...
2023-08-28Merge tag 'linux-kselftest-kunit-6.6-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest Pull kunit updates from Shuah Khan: - add support for running Rust documentation tests as KUnit tests - make init, str, sync, types doctests compilable/testable - add support for attributes API which include speed, modules attributes, ability to filter and report attributes - add support for marking tests slow using attributes API - add attributes API documentation - fix a wild-memory-access bug in kunit_filter_suites() and a possible memory leak in kunit_filter_suites() - add support for counting number of test suites in a module, list action to kunit test modules, and test filtering on module tests * tag 'linux-kselftest-kunit-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits) kunit: fix struct kunit_attr header kunit: replace KUNIT_TRIGGER_STATIC_STUB maro with KUNIT_STATIC_STUB_REDIRECT kunit: Allow kunit test modules to use test filtering kunit: Make 'list' action available to kunit test modules kunit: Report the count of test suites in a module kunit: fix uninitialized variables bug in attributes filtering kunit: fix possible memory leak in kunit_filter_suites() kunit: fix wild-memory-access bug in kunit_filter_suites() kunit: Add documentation of KUnit test attributes kunit: add tests for filtering attributes kunit: time: Mark test as slow using test attributes kunit: memcpy: Mark tests as slow using test attributes kunit: tool: Add command line interface to filter and report attributes kunit: Add ability to filter attributes kunit: Add module attribute kunit: Add speed attribute kunit: Add test attributes API structure MAINTAINERS: add Rust KUnit files to the KUnit entry rust: support running Rust documentation tests as KUnit ones rust: types: make doctests compilable/testable ...
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>
2023-08-04rust: delete `ForeignOwnable::borrow_mut`Alice Ryhl
We discovered that the current design of `borrow_mut` is problematic. This patch removes it until a better solution can be found. Specifically, the current design gives you access to a `&mut T`, which lets you change where the `ForeignOwnable` points (e.g., with `core::mem::swap`). No upcoming user of this API intended to make that possible, making all of them unsound. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Fixes: 0fc4424d24a2 ("rust: types: introduce `ForeignOwnable`") Link: https://lore.kernel.org/r/20230706094615.3080784-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-07-19rust: sync: make doctests compilable/testableMiguel Ojeda
Rust documentation tests are going to be build/run-tested with the KUnit integration added in a future patch, thus update them to make them compilable/testable so that we may start enforcing it. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-05-31rust: sync: reword the `Arc` safety comment for `Sync`Alice Ryhl
The safety comment on `impl Sync for Arc` references the Send safety comment. This commit avoids that in case the two comments drift apart in the future. Suggested-by: Andreas Hindborg <a.hindborg@samsung.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230531145939.3714886-3-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: sync: reword the `Arc` safety comment for `Send`Alice Ryhl
The safety comment on `impl Send for Arc` talks about "directly" accessing the value, when it really means "accessing the value with a mutable reference". This commit clarifies that. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230531145939.3714886-2-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: sync: implement `AsRef<T>` for `Arc<T>`Alice Ryhl
This trait lets you use `Arc<T>` in code that is generic over smart pointer types. The `AsRef` trait should be implemented on all smart pointers. The standard library also implements it on the ordinary `Arc`. Co-developed-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230517200814.3157916-2-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: sync: add `Arc::ptr_eq`Alice Ryhl
Add a method for comparing whether two `Arc` pointers reference the same underlying object. This comparison can already be done by getting a reference to the inner values and comparing whether the references have the same address. However, writing `Arc::ptr_eq(a, b)` is generally less error-prone than doing the same check on the references, since you might otherwise accidentally compare the two `&Arc<T>` references instead, which wont work because those are pointers to pointers to the inner value, when you just want to compare the pointers to the inner value. Also, this method might optimize better because getting a reference to the inner value involves offsetting the pointer, which this method does not need to do. Co-developed-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230517200814.3157916-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>