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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>
2025-03-16rust: pin-init: fix documentation linksBenno Lossin
Before switching to compile the `pin-init` crate directly, change any links that would be invalid to links that are valid both before and after the switch. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-12-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-08rust: lockdep: Use Pin for all LockClassKey usagesMitchell Levy
Reintroduce dynamically-allocated LockClassKeys such that they are automatically (de)registered. Require that all usages of LockClassKeys ensure that they are Pin'd. Currently, only `'static` LockClassKeys are supported, so Pin is redundant. However, it is intended that dynamically-allocated LockClassKeys will eventually be supported, so using Pin from the outset will make that change simpler. Closes: https://github.com/Rust-for-Linux/linux/issues/1102 Suggested-by: Benno Lossin <benno.lossin@proton.me> Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Mitchell Levy <levymitchell0@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20250307232717.1759087-12-boqun.feng@gmail.com
2025-03-08rust: sync: condvar: Add wait_interruptible_freezable()Alice Ryhl
To support waiting for a `CondVar` as a freezable process, add a wait_interruptible_freezable() function. Binder needs this function in the appropriate places to freeze a process where some of its threads are blocked on the Binder driver. [ Boqun: Cleaned up the changelog and documentation. ] Signed-off-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org> Link: https://lore.kernel.org/r/20250307232717.1759087-10-boqun.feng@gmail.com
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>
2024-10-07rust: 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::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>
2024-05-05rust: 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: 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>
2024-01-28rust: 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>
2023-10-05rust: 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>
2023-04-22rust: 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>