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4 daysrust: add pr_*_ratelimited! macros for printingAlice Ryhl
Printing can be very expensive if it occurs often, so printing that can be triggered by userspace should be rate limited. For this purpose, add a Rust wrapper around `struct ratelimit_state` and use it in the new macros. The new files will fall under the catch-all RUST maintainers entry. Tested-by: Alvin Sun <alvin.sun@linux.dev> Reviewed-by: Carlos Llamas <cmllamas@google.com> Link: https://github.com/Rust-for-Linux/linux/issues/122 Acked-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20261007-pr-ratelimited-v6-3-f14accd4ea3b@google.com [ Removed unused link reference definitions. On the `static`, allowed the `non_upper_case_globals` lint so that `kernel` users (and users providing their own name) do not warn. Reworded title for typo. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
4 daysrust: sync: add const constructor for raw_spinlock_tAlice Ryhl
The abstractions for pr_*_ratelimited! need to construct a global `struct ratelimit_state`, which contains a `raw_spinlock_t` field. Thus, add a const constructor for the `raw_spinlock_t` type. The SPINLOCK_OWNER_INIT constant isn't mirrored via a const helper because bindgen generates a 'static mut' instead of a constant from the pointer constant., The __ARCH_SPIN_LOCK_UNLOCKED constant cannot be translated by bindgen because it's a define for a struct without type annotations, so it's explicitly declared in Rust. Reviewed-by: Boqun Feng <boqun@kernel.org> Reviewed-by: Carlos Llamas <cmllamas@google.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20261007-pr-ratelimited-v6-2-f14accd4ea3b@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-08-10rust: sync: Introduce SpinLockIrq::lock_with() and friendsLyude Paul
`SpinLockIrq` and `SpinLock` use the exact same underlying C structure, with the only real difference being that the former uses the irq_disable() and irq_enable() variants for locking/unlocking. These variants can introduce some minor overhead in contexts where we already know that local processor interrupts are disabled, and as such we want a way to be able to skip modifying processor interrupt state in said contexts in order to avoid some overhead - just like the current C API allows us to do. In order to do this, we add some special functions for SpinLockIrq: lock_with() and try_lock_with(), which allow acquiring the lock without changing the interrupt state - as long as the caller can provide a LocalInterruptDisabled reference to prove that local processor interrupts have been disabled. In some hacked-together benchmarks we ran, most of the time this did actually seem to lead to a noticeable difference in overhead: From an aarch64 VM running on a MacBook M4: lock() when irq is disabled, 100 times cost Delta { nanos: 500 } lock_with() when irq is disabled, 100 times cost Delta { nanos: 292 } lock() when irq is enabled, 100 times cost Delta { nanos: 834 } lock() when irq is disabled, 100 times cost Delta { nanos: 459 } lock_with() when irq is disabled, 100 times cost Delta { nanos: 291 } lock() when irq is enabled, 100 times cost Delta { nanos: 709 } From an x86_64 VM (qemu/kvm) running on a i7-13700H lock() when irq is disabled, 100 times cost Delta { nanos: 1002 } lock_with() when irq is disabled, 100 times cost Delta { nanos: 729 } lock() when irq is enabled, 100 times cost Delta { nanos: 1516 } lock() when irq is disabled, 100 times cost Delta { nanos: 754 } lock_with() when irq is disabled, 100 times cost Delta { nanos: 966 } lock() when irq is enabled, 100 times cost Delta { nanos: 1227 } (note that there were some runs on x86_64 where lock() on irq disabled vs. lock_with() on irq disabled had equivalent benchmarks, but it very much appeared to be a minority of test runs.) While it's not clear how this affects real-world workloads yet, let's add this for the time being so we can find out. This makes it so that a `SpinLockIrq` will work like a `SpinLock` if interrupts are disabled. So a function: (&'a SpinLockIrq, &'a LocalInterruptDisabled) -> Guard<'a, .., SpinLockBackend> makes sense. Note that due to `Guard` and `LocalInterruptDisabled` having the same lifetime, interrupts cannot be enabled while the Guard exists. Signed-off-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260807070218.27144-19-boqun@kernel.org
2026-08-10rust: sync: Add SpinLockIrqLyude Paul
A variant of `SpinLock` that ensures interrupts are disabled in the critical section. `lock()` will ensure that either interrupts are already disabled or disable them. `unlock()` will reverse the respective operation. [Boqun: Port to use spin_lock_irq_disable() and spin_unlock_irq_enable()] Signed-off-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260807070218.27144-18-boqun@kernel.org
2026-08-10rust: sync: Use super::* in spinlock.rsLyude Paul
No functional changes. Signed-off-by: Lyude Paul <lyude@redhat.com> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://patch.msgid.link/20260807070218.27144-17-boqun@kernel.org
2026-01-10rust: sync: Inline various lock related methodsAlice Ryhl
While debugging a different issue [1], the following relocation was noticed in the rust_binder.ko file: R_AARCH64_CALL26 _RNvXNtNtNtCsdfZWD8DztAw_6kernel4sync4lock8spinlockNtB2_15SpinLockBackendNtB4_7Backend6unlock This relocation (and a similar one for lock) occurred many times throughout the module. That is not really useful because all this function does is call spin_unlock(), so what we actually want here is that a call to spin_unlock() dirctly is generated in favor of this wrapper method. Thus, mark these methods inline. [boqun: Reword the commit message a bit] Link: https://lore.kernel.org/p/20251111-binder-fix-list-remove-v1-0-8ed14a0da63d@google.com Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://patch.msgid.link/20251218-inline-lock-unlock-v2-1-fbadac8bd61b@google.com
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>
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: Add SpinLockGuard type aliasLyude Paul
A simple helper alias for code that needs to deal with Guard types returned from SpinLocks. Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20241120222742.2490495-3-lyude@redhat.com
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>
2024-10-15rust: 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>
2024-05-05rust: 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>
2024-04-16rust: 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>
2024-02-18rust: 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: 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>
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>
2023-07-19rust: 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>
2023-04-22rust: 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: 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>