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2023-04-30Merge tag 'rust-6.4' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust updates from Miguel Ojeda "More additions to the Rust core. Importantly, this adds the pin-init API, which will be used by other abstractions, such as the synchronization ones added here too: - pin-init API: a solution for the safe pinned initialization problem. This allows to reduce the need for 'unsafe' code in the kernel when dealing with data structures that require a stable address. Commit 90e53c5e70a6 ("rust: add pin-init API core") contains a nice introduction -- here is an example of how it looks like: #[pin_data] struct Example { #[pin] value: Mutex<u32>, #[pin] value_changed: CondVar, } impl Example { fn new() -> impl PinInit<Self> { pin_init!(Self { value <- new_mutex!(0), value_changed <- new_condvar!(), }) } } // In a `Box`. let b = Box::pin_init(Example::new())?; // In the stack. stack_pin_init!(let s = Example::new()); - 'sync' module: New types 'LockClassKey' ('struct lock_class_key'), 'Lock', 'Guard', 'Mutex' ('struct mutex'), 'SpinLock' ('spinlock_t'), 'LockedBy' and 'CondVar' (uses 'wait_queue_head_t'), plus macros such as 'static_lock_class!' and 'new_spinlock!'. In particular, 'Lock' and 'Guard' are generic implementations that contain code that is common to all locks. Then, different backends (the new 'Backend' trait) are implemented and used to define types like 'Mutex': type Mutex<T> = Lock<T, MutexBackend>; In addition, new methods 'assume_init()', 'init_with()' and 'pin_init_with()' for 'UniqueArc<MaybeUninit<T>>' and 'downcast()' for 'Arc<dyn Any + Send + Sync>'; as well as 'Debug' and 'Display' implementations for 'Arc' and 'UniqueArc'. Reduced stack usage of 'UniqueArc::try_new_uninit()', too. - 'types' module: New trait 'AlwaysRefCounted' and new type 'ARef' (an owned reference to an always-reference-counted object, meant to be used in wrappers for C types that have their own ref counting functions). Moreover, new associated functions 'raw_get()' and 'ffi_init()' for 'Opaque'. - New 'task' module with a new type 'Task' ('struct task_struct'), and a new macro 'current!' to safely get a reference to the current one. - New 'ioctl' module with new '_IOC*' const functions (equivalent to the C macros). - New 'uapi' crate, intended to be accessible by drivers directly. - 'macros' crate: new 'quote!' macro (similar to the one provided in userspace by the 'quote' crate); and the 'module!' macro now allows specifying multiple module aliases. - 'error' module: New associated functions for the 'Error' type, such as 'from_errno()' and new functions such as 'to_result()'. - 'alloc' crate: More fallible 'Vec' methods: 'try_resize` and 'try_extend_from_slice' and the infrastructure (imported from the Rust standard library) they need" * tag 'rust-6.4' of https://github.com/Rust-for-Linux/linux: (44 commits) rust: ioctl: Add ioctl number manipulation functions rust: uapi: Add UAPI crate rust: sync: introduce `CondVar` rust: lock: add `Guard::do_unlocked` rust: sync: introduce `LockedBy` rust: introduce `current` rust: add basic `Task` rust: introduce `ARef` rust: lock: introduce `SpinLock` rust: lock: introduce `Mutex` rust: sync: introduce `Lock` and `Guard` rust: sync: introduce `LockClassKey` MAINTAINERS: add Benno Lossin as Rust reviewer rust: init: broaden the blanket impl of `Init` rust: sync: add functions for initializing `UniqueArc<MaybeUninit<T>>` rust: sync: reduce stack usage of `UniqueArc::try_new_uninit` rust: types: add `Opaque::ffi_init` rust: prelude: add `pin-init` API items to prelude rust: init: add `Zeroable` trait and `init::zeroed` function rust: init: add `stack_pin_init!` macro ...
2023-04-22rust: ioctl: Add ioctl number manipulation functionsAsahi Lina
Add simple 1:1 wrappers of the C ioctl number manipulation functions. Since these are macros we cannot bindgen them directly, and since they should be usable in const context we cannot use helper wrappers, so we'll have to reimplement them in Rust. Thankfully, the C headers do declare defines for the relevant bitfield positions, so we don't need to duplicate that. Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230329-rust-uapi-v2-2-bca5fb4d4a12@asahilina.net [ Moved the `#![allow(non_snake_case)]` to the usual place. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: uapi: Add UAPI crateAsahi Lina
This crate mirrors the `bindings` crate, but will contain only UAPI bindings. Unlike the bindings crate, drivers may directly use this crate if they have to interface with userspace. Initially, just bind the generic ioctl stuff. In the future, we would also like to add additional checks to ensure that all types exposed by this crate satisfy UAPI-safety guarantees (that is, they are safely castable to/from a "bag of bits"). [ Miguel: added support for the `rustdoc` and `rusttest` targets, since otherwise they fail, and we want to keep them working. ] Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230329-rust-uapi-v2-1-bca5fb4d4a12@asahilina.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `CondVar`Wedson Almeida Filho
This is the traditional condition variable or monitor synchronisation primitive. It is implemented with C's `wait_queue_head_t`. It allows users to release a lock and go to sleep while guaranteeing that notifications won't be missed. This is achieved by enqueuing a wait entry before releasing the lock. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230411054543.21278-12-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: lock: add `Guard::do_unlocked`Wedson Almeida Filho
It releases the lock, executes some function provided by the caller, then reacquires the lock. This is preparation for the implementation of condvars, which will sleep after between unlocking and relocking. We need an explicit `relock` method for primitives like `SpinLock` that have an irqsave variant: we use the guard state to determine if the lock was originally acquired with the regular `lock` function or `lock_irqsave`. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/rust-for-linux/20230412121431.41627-1-wedsonaf@gmail.com/ [ Removed the irqsave bits as discussed. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `LockedBy`Wedson Almeida Filho
This allows us to have data protected by a lock despite not being wrapped by it. Access is granted by providing evidence that the lock is held by the caller. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230411054543.21278-13-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: introduce `current`Wedson Almeida Filho
This allows Rust code to get a reference to the current task without having to increment the refcount, but still guaranteeing memory safety. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-10-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: add basic `Task`Wedson Almeida Filho
It is an abstraction for C's `struct task_struct`. It implements `AlwaysRefCounted`, so the refcount of the wrapped object is managed safely on the Rust side. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-9-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: introduce `ARef`Wedson Almeida Filho
This is an owned reference to an object that is always ref-counted. This is meant to be used in wrappers for C types that have their own ref counting functions, for example, tasks, files, inodes, dentries, etc. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230411054543.21278-8-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: lock: introduce `SpinLock`Wedson Almeida Filho
This is the `spinlock_t` lock backend and allows Rust code to use the kernel spinlock idiomatically. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230419174426.132207-1-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: lock: introduce `Mutex`Wedson Almeida Filho
This is the `struct mutex` lock backend and allows Rust code to use the kernel mutex idiomatically. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-3-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `Lock` and `Guard`Wedson Almeida Filho
They are generic Rust implementations of a lock and a lock guard that contain code that is common to all locks. Different backends will be introduced in subsequent commits. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Suggested-by: Gary Guo <gary@garyguo.net> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-2-wedsonaf@gmail.com [ Fixed typo. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-21rust: sync: introduce `LockClassKey`Wedson Almeida Filho
It is a wrapper around C's `lock_class_key`, which is used by the synchronisation primitives that are checked with lockdep. This is in preparation for introducing Rust abstractions for these primitives. 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> Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230411054543.21278-1-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-21rust: init: broaden the blanket impl of `Init`Benno Lossin
This makes it possible to use `T` as a `impl Init<T, E>` for every error type `E` instead of just `Infallible`. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230413100157.740697-1-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-19rust: allow to use INIT_STACK_ALL_ZEROAndrea Righi
With CONFIG_INIT_STACK_ALL_ZERO enabled, bindgen passes -ftrivial-auto-var-init=zero to clang, that triggers the following error: error: '-ftrivial-auto-var-init=zero' hasn't been enabled; enable it at your own peril for benchmarking purpose only with '-enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang' However, this additional option that is currently required by clang is deprecated since clang-16 and going to be removed in the future, likely with clang-18. So, make sure bindgen is using this extra option if the major version of the libclang used by bindgen is < 16. In this way we can enable CONFIG_INIT_STACK_ALL_ZERO with CONFIG_RUST without triggering any build error. Link: https://github.com/llvm/llvm-project/issues/44842 Link: https://github.com/llvm/llvm-project/blob/llvmorg-16.0.0-rc2/clang/docs/ReleaseNotes.rst#deprecated-compiler-flags Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Reviewed-by: Kees Cook <keescook@chromium.org> [Changed to < 16, added link and reworded] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: sync: add functions for initializing `UniqueArc<MaybeUninit<T>>`Benno Lossin
Add two functions `init_with` and `pin_init_with` to `UniqueArc<MaybeUninit<T>>` to initialize the memory of already allocated `UniqueArc`s. This is useful when you want to allocate memory check some condition inside of a context where allocation is forbidden and then conditionally initialize an object. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-16-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: sync: reduce stack usage of `UniqueArc::try_new_uninit`Benno Lossin
`UniqueArc::try_new_uninit` calls `Arc::try_new(MaybeUninit::uninit())`. This results in the uninitialized memory being placed on the stack, which may be arbitrarily large due to the generic `T` and thus could cause a stack overflow for large types. Change the implementation to use the pin-init API which enables in-place initialization. In particular it avoids having to first construct and then move the uninitialized memory from the stack into the final location. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-15-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: types: add `Opaque::ffi_init`Benno Lossin
This function allows to easily initialize `Opaque` with the pin-init API. `Opaque::ffi_init` takes a closure and returns a pin-initializer. This pin-initiailizer calls the given closure with a pointer to the inner `T`. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230408122429.1103522-14-y86-dev@protonmail.com [ Fixed typo. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: prelude: add `pin-init` API items to preludeBenno Lossin
Add `pin-init` API macros and traits to the prelude. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-13-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: init: add `Zeroable` trait and `init::zeroed` functionBenno Lossin
Add the `Zeroable` trait which marks types that can be initialized by writing `0x00` to every byte of the type. Also add the `init::zeroed` function that creates an initializer for a `Zeroable` type that writes `0x00` to every byte. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-12-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: init: add `stack_pin_init!` macroBenno Lossin
The `stack_pin_init!` macro allows pin-initializing a value on the stack. It accepts a `impl PinInit<T, E>` to initialize a `T`. It allows propagating any errors via `?` or handling it normally via `match`. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230408122429.1103522-11-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: init: add `PinnedDrop` trait and macrosBenno Lossin
The `PinnedDrop` trait that facilitates destruction of pinned types. It has to be implemented via the `#[pinned_drop]` macro, since the `drop` function should not be called by normal code, only by other destructors. It also only works on structs that are annotated with `#[pin_data(PinnedDrop)]`. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-10-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: init/sync: add `InPlaceInit` trait to pin-initialize smart pointersBenno Lossin
The `InPlaceInit` trait that provides two functions, for initializing using `PinInit<T, E>` and `Init<T>`. It is implemented by `Arc<T>`, `UniqueArc<T>` and `Box<T>`. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-9-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: init: add initialization macrosBenno Lossin
Add the following initializer macros: - `#[pin_data]` to annotate structurally pinned fields of structs, needed for `pin_init!` and `try_pin_init!` to select the correct initializer of fields. - `pin_init!` create a pin-initializer for a struct with the `Infallible` error type. - `try_pin_init!` create a pin-initializer for a struct with a custom error type (`kernel::error::Error` is the default). - `init!` create an in-place-initializer for a struct with the `Infallible` error type. - `try_init!` create an in-place-initializer for a struct with a custom error type (`kernel::error::Error` is the default). Also add their needed internal helper traits and structs. Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-8-y86-dev@protonmail.com [ Fixed three typos. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: add pin-init API coreBenno Lossin
This API is used to facilitate safe pinned initialization of structs. It replaces cumbersome `unsafe` manual initialization with elegant safe macro invocations. Due to the size of this change it has been split into six commits: 1. This commit introducing the basic public interface: traits and functions to represent and create initializers. 2. Adds the `#[pin_data]`, `pin_init!`, `try_pin_init!`, `init!` and `try_init!` macros along with their internal types. 3. Adds the `InPlaceInit` trait that allows using an initializer to create an object inside of a `Box<T>` and other smart pointers. 4. Adds the `PinnedDrop` trait and adds macro support for it in the `#[pin_data]` macro. 5. Adds the `stack_pin_init!` macro allowing to pin-initialize a struct on the stack. 6. Adds the `Zeroable` trait and `init::zeroed` function to initialize types that have `0x00` in all bytes as a valid bit pattern. -- In this section the problem that the new pin-init API solves is outlined. This message describes the entirety of the API, not just the parts introduced in this commit. For a more granular explanation and additional information on pinning and this issue, view [1]. Pinning is Rust's way of enforcing the address stability of a value. When a value gets pinned it will be impossible for safe code to move it to another location. This is done by wrapping pointers to said object with `Pin<P>`. This wrapper prevents safe code from creating mutable references to the object, preventing mutable access, which is needed to move the value. `Pin<P>` provides `unsafe` functions to circumvent this and allow modifications regardless. It is then the programmer's responsibility to uphold the pinning guarantee. Many kernel data structures require a stable address, because there are foreign pointers to them which would get invalidated by moving the structure. Since these data structures are usually embedded in structs to use them, this pinning property propagates to the container struct. Resulting in most structs in both Rust and C code needing to be pinned. So if we want to have a `mutex` field in a Rust struct, this struct also needs to be pinned, because a `mutex` contains a `list_head`. Additionally initializing a `list_head` requires already having the final memory location available, because it is initialized by pointing it to itself. But this presents another challenge in Rust: values have to be initialized at all times. There is the `MaybeUninit<T>` wrapper type, which allows handling uninitialized memory, but this requires using the `unsafe` raw pointers and a casting the type to the initialized variant. This problem gets exacerbated when considering encapsulation and the normal safety requirements of Rust code. The fields of the Rust `Mutex<T>` should not be accessible to normal driver code. After all if anyone can modify the fields, there is no way to ensure the invariants of the `Mutex<T>` are upheld. But if the fields are inaccessible, then initialization of a `Mutex<T>` needs to be somehow achieved via a function or a macro. Because the `Mutex<T>` must be pinned in memory, the function cannot return it by value. It also cannot allocate a `Box` to put the `Mutex<T>` into, because that is an unnecessary allocation and indirection which would hurt performance. The solution in the rust tree (e.g. this commit: [2]) that is replaced by this API is to split this function into two parts: 1. A `new` function that returns a partially initialized `Mutex<T>`, 2. An `init` function that requires the `Mutex<T>` to be pinned and that fully initializes the `Mutex<T>`. Both of these functions have to be marked `unsafe`, since a call to `new` needs to be accompanied with a call to `init`, otherwise using the `Mutex<T>` could result in UB. And because calling `init` twice also is not safe. While `Mutex<T>` initialization cannot fail, other structs might also have to allocate memory, which would result in conditional successful initialization requiring even more manual accommodation work. Combine this with the problem of pin-projections -- the way of accessing fields of a pinned struct -- which also have an `unsafe` API, pinned initialization is riddled with `unsafe` resulting in very poor ergonomics. Not only that, but also having to call two functions possibly multiple lines apart makes it very easy to forget it outright or during refactoring. Here is an example of the current way of initializing a struct with two synchronization primitives (see [3] for the full example): struct SharedState { state_changed: CondVar, inner: Mutex<SharedStateInner>, } impl SharedState { fn try_new() -> Result<Arc<Self>> { let mut state = Pin::from(UniqueArc::try_new(Self { // SAFETY: `condvar_init!` is called below. state_changed: unsafe { CondVar::new() }, // SAFETY: `mutex_init!` is called below. inner: unsafe { Mutex::new(SharedStateInner { token_count: 0 }) }, })?); // SAFETY: `state_changed` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.state_changed) }; kernel::condvar_init!(pinned, "SharedState::state_changed"); // SAFETY: `inner` is pinned when `state` is. let pinned = unsafe { state.as_mut().map_unchecked_mut(|s| &mut s.inner) }; kernel::mutex_init!(pinned, "SharedState::inner"); Ok(state.into()) } } The pin-init API of this patch solves this issue by providing a comprehensive solution comprised of macros and traits. Here is the example from above using the pin-init API: #[pin_data] struct SharedState { #[pin] state_changed: CondVar, #[pin] inner: Mutex<SharedStateInner>, } impl SharedState { fn new() -> impl PinInit<Self> { pin_init!(Self { state_changed <- new_condvar!("SharedState::state_changed"), inner <- new_mutex!( SharedStateInner { token_count: 0 }, "SharedState::inner", ), }) } } Notably the way the macro is used here requires no `unsafe` and thus comes with the usual Rust promise of safe code not introducing any memory violations. Additionally it is now up to the caller of `new()` to decide the memory location of the `SharedState`. They can choose at the moment `Arc<T>`, `Box<T>` or the stack. -- The API has the following architecture: 1. Initializer traits `PinInit<T, E>` and `Init<T, E>` that act like closures. 2. Macros to create these initializer traits safely. 3. Functions to allow manually writing initializers. The initializers (an `impl PinInit<T, E>`) receive a raw pointer pointing to uninitialized memory and their job is to fully initialize a `T` at that location. If initialization fails, they return an error (`E`) by value. This way of initializing cannot be safely exposed to the user, since it relies upon these properties outside of the control of the trait: - the memory location (slot) needs to be valid memory, - if initialization fails, the slot should not be read from, - the value in the slot should be pinned, so it cannot move and the memory cannot be deallocated until the value is dropped. This is why using an initializer is facilitated by another trait that ensures these requirements. These initializers can be created manually by just supplying a closure that fulfills the same safety requirements as `PinInit<T, E>`. But this is an `unsafe` operation. To allow safe initializer creation, the `pin_init!` is provided along with three other variants: `try_pin_init!`, `try_init!` and `init!`. These take a modified struct initializer as a parameter and generate a closure that initializes the fields in sequence. The macros take great care in upholding the safety requirements: - A shadowed struct type is used as the return type of the closure instead of `()`. This is to prevent early returns, as these would prevent full initialization. - To ensure every field is only initialized once, a normal struct initializer is placed in unreachable code. The type checker will emit errors if a field is missing or specified multiple times. - When initializing a field fails, the whole initializer will fail and automatically drop fields that have been initialized earlier. - Only the correct initializer type is allowed for unpinned fields. You cannot use a `impl PinInit<T, E>` to initialize a structurally not pinned field. To ensure the last point, an additional macro `#[pin_data]` is needed. This macro annotates the struct itself and the user specifies structurally pinned and not pinned fields. Because dropping a pinned struct is also not allowed to break the pinning invariants, another macro attribute `#[pinned_drop]` is needed. This macro is introduced in a following commit. These two macros also have mechanisms to ensure the overall safety of the API. Additionally, they utilize a combined proc-macro, declarative macro design: first a proc-macro enables the outer attribute syntax `#[...]` and does some important pre-parsing. Notably this prepares the generics such that the declarative macro can handle them using token trees. Then the actual parsing of the structure and the emission of code is handled by a declarative macro. For pin-projections the crates `pin-project` [4] and `pin-project-lite` [5] had been considered, but were ultimately rejected: - `pin-project` depends on `syn` [6] which is a very big dependency, around 50k lines of code. - `pin-project-lite` is a more reasonable 5k lines of code, but contains a very complex declarative macro to parse generics. On top of that it would require modification that would need to be maintained independently. Link: https://rust-for-linux.com/the-safe-pinned-initialization-problem [1] Link: https://github.com/Rust-for-Linux/linux/tree/0a04dc4ddd671efb87eef54dde0fb38e9074f4be [2] Link: https://github.com/Rust-for-Linux/linux/blob/f509ede33fc10a07eba3da14aa00302bd4b5dddd/samples/rust/rust_miscdev.rs [3] Link: https://crates.io/crates/pin-project [4] Link: https://crates.io/crates/pin-project-lite [5] Link: https://crates.io/crates/syn [6] Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230408122429.1103522-7-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: types: add `Opaque::raw_get`Benno Lossin
This function mirrors `UnsafeCell::raw_get`. It avoids creating a reference and allows solely using raw pointers. The `pin-init` API will be using this, since uninitialized memory requires raw pointers. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230408122429.1103522-6-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: sync: change error type of constructor functionsBenno Lossin
Change the error type of the constructors of `Arc` and `UniqueArc` to be `AllocError` instead of `Error`. This makes the API more clear as to what can go wrong when calling `try_new` or its variants. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230408122429.1103522-4-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: macros: add `quote!` macroGary Guo
Add the `quote!` macro for creating `TokenStream`s directly via the given Rust tokens. It also supports repetitions using iterators. It will be used by the pin-init API proc-macros to generate code. Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230408122429.1103522-3-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: enable the `pin_macro` featureBenno Lossin
This feature enables the use of the `pin!` macro for the `stack_pin_init!` macro. This feature is already stabilized in Rust version 1.68. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Acked-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20230408122429.1103522-2-y86-dev@protonmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: error: Add from_result() helperWedson Almeida Filho
Add a helper function to easily return C result codes from a Rust function that calls functions which return a Result<T>. Lina: Imported from rust-for-linux/rust, originally developed by Wedson as part of file_operations.rs. Added the allow() flags since there is no user in the kernel crate yet and fixed a typo in a comment. Replaced the macro with a function taking a closure, per discussion on the ML. Co-developed-by: Fox Chen <foxhlchen@gmail.com> Signed-off-by: Fox Chen <foxhlchen@gmail.com> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-error-v3-6-03779bddc02b@asahilina.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: error: Add a helper to convert a C ERR_PTR to a `Result`Sven Van Asbroeck
Some kernel C API functions return a pointer which embeds an optional `errno`. Callers are supposed to check the returned pointer with `IS_ERR()` and if this returns `true`, retrieve the `errno` using `PTR_ERR()`. Create a Rust helper function to implement the Rust equivalent: transform a `*mut T` to `Result<*mut T>`. Lina: Imported from rust-for-linux/linux, with subsequent refactoring and contributions squashed in and attributed below. Renamed the function to from_err_ptr(). Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Co-developed-by: Fox Chen <foxhlchen@gmail.com> Signed-off-by: Fox Chen <foxhlchen@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-error-v3-5-03779bddc02b@asahilina.net [ Add a removal of `#[allow(dead_code)]`. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: error: Add to_result() helperWedson Almeida Filho
Add a to_result() helper to convert kernel C return values to a Rust Result, mapping >=0 values to Ok(()) and negative values to Err(...), with Error::from_errno() ensuring that the errno is within range. Lina: Imported from rust-for-linux/rust, originally developed by Wedson as part of the AMBA device driver support. Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-error-v3-4-03779bddc02b@asahilina.net [ Add a removal of `#[allow(dead_code)]`. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: error: Add Error::from_errno{_unchecked}()Miguel Ojeda
Add a function to create `Error` values out of a kernel error return, which safely upholds the invariant that the error code is well-formed (negative and greater than -MAX_ERRNO). If a malformed code is passed in, it will be converted to EINVAL. Lina: Imported from rust-for-linux/rust as authored by Miguel and Fox with refactoring from Wedson, renamed from_kernel_errno() to from_errno(). Co-developed-by: Fox Chen <foxhlchen@gmail.com> Signed-off-by: Fox Chen <foxhlchen@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-error-v3-3-03779bddc02b@asahilina.net [ Mark the new associated functions as `#[allow(dead_code)]`. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: error: Add Error::to_ptr()Asahi Lina
This is the Rust equivalent to ERR_PTR(), for use in C callbacks. Marked as #[allow(dead_code)] for now, since it does not have any consumers yet. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230224-rust-error-v3-2-03779bddc02b@asahilina.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: error: Rename to_kernel_errno() -> to_errno()Asahi Lina
This is kernel code, so specifying "kernel" is redundant. Let's simplify things and just call it to_errno(). Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-error-v3-1-03779bddc02b@asahilina.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: sync: arc: Add UniqueArc<MaybeUninit<T>::assume_init()Asahi Lina
We can already create `UniqueArc<MaybeUninit<T>>` instances with `UniqueArc::try_new_uninit()` and write to them with `write()`. Add the missing unsafe `assume_init()` function to promote it to `UniqueArc<T>`, so users can do piece-wise initialization of the contents instead of doing it all at once as long as they keep the invariants (the same requirements as `MaybeUninit::assume_init()`). This mirrors the std `Arc::assume_init()` function. In the kernel, since we have `UniqueArc`, arguably this only belongs there since most use cases will initialize it immediately after creating it, before demoting it to `Arc` to share it. [ Miguel: The "Rust pin-init API for pinned initialization of structs" patch series [1] from Benno Lossin contains a very similar patch: rust: sync: add `assume_init` to `UniqueArc` Adds the `assume_init` function to `UniqueArc<MaybeUninit<T>>` that unsafely assumes the value to be initialized and yields a value of type `UniqueArc<T>`. This function is used when manually initializing the pointee of an `UniqueArc`. To make that patch a noop and thus drop it, I adjusted the `SAFETY` comment here to be the same as in the current latest version of that series (v7). I have also brought the `Reviewed-by`s there into here, and reworded the `Co-authored-by` into `Co-developed-by`. ] Link: https://lore.kernel.org/r/20230408122429.1103522-5-y86-dev@protonmail.com [1] Co-developed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230224-rust-arc-v2-2-5c97a865b276@asahilina.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: sync: arc: Implement Arc<dyn Any + Send + Sync>::downcast()Asahi Lina
This mirrors the standard library's alloc::sync::Arc::downcast(). Based on the Rust standard library implementation, ver 1.62.0, licensed under "Apache-2.0 OR MIT", from: https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src For copyright details, please see: https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-arc-v2-1-5c97a865b276@asahilina.net [ Moved `mod std_vendor;` up. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: macros: Allow specifying multiple module aliasesAsahi Lina
Modules can (and usually do) have multiple alias tags, in order to specify multiple possible device matches for autoloading. Allow this by changing the alias ModuleInfo field to an Option<Vec<String>>. Note: For normal device IDs this is autogenerated by modpost (which is not properly integrated with Rust support yet), so it is useful to be able to manually add device match aliases for now, and should still be useful in the future for corner cases that modpost does not handle. This pulls in the expect_group() helper from the rfl/rust branch (with credit to authors). Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Co-developed-by: Finn Behrens <me@kloenk.dev> Signed-off-by: Finn Behrens <me@kloenk.dev> Co-developed-by: Sumera Priyadarsini <sylphrenadin@gmail.com> Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-macros-v2-1-7396e8b7018d@asahilina.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: alloc: vec: Add some try_* methods we needMiguel Ojeda
Add some missing fallible methods that we need. They are all marked as: #[stable(feature = "kernel", since = "1.0.0")] for easy identification. Lina: Extracted from commit 487d7578bd03 ("rust: alloc: add some `try_*` methods we need") in rust-for-linux/rust. Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://github.com/Rust-for-Linux/linux/commit/487d7578bd03 Link: https://lore.kernel.org/r/20230224-rust-vec-v1-4-733b5b5a57c5@asahilina.net [ Match the non-fallible methods from version 1.62.0, since those in commit 487d7578bd03 were written for 1.54.0-beta.1. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: Add SPDX headers to alloc::vec::{spec_extend, set_len_on_drop}Asahi Lina
Add the missing SPDX headers to these modules, which were just imported from the Rust stdlib. Doing this in a separate commit makes it easier to audit that the files have not been modified in the original import. See the preceding two commits for attribution and licensing details. Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-vec-v1-3-733b5b5a57c5@asahilina.net [ Reworded for typo. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: Import upstream `alloc::vec::spec_extend` moduleAsahi Lina
This is a subset of the Rust standard library `alloc` crate, version 1.62.0, licensed under "Apache-2.0 OR MIT", from: https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src The file is copied as-is, with no modifications whatsoever (not even adding the SPDX identifiers). For copyright details, please see: https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-vec-v1-2-733b5b5a57c5@asahilina.net [ Import version 1.62.0 instead, to match the one in mainline. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: Import upstream `alloc::vec::set_len_on_drop` moduleAsahi Lina
This is a subset of the Rust standard library `alloc` crate, version 1.62.0, licensed under "Apache-2.0 OR MIT", from: https://github.com/rust-lang/rust/tree/1.62.0/library/alloc/src The file is copied as-is, with no modifications whatsoever (not even adding the SPDX identifiers). For copyright details, please see: https://github.com/rust-lang/rust/blob/1.62.0/COPYRIGHT Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230224-rust-vec-v1-1-733b5b5a57c5@asahilina.net [ Import version 1.62.0 instead, to match the one in mainline. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: Enable the new_uninit feature for kernel and driver cratesAsahi Lina
The unstable new_uninit feature enables various library APIs to create uninitialized containers, such as `Box::assume_init()`. This is necessary to build abstractions that directly initialize memory at the target location, instead of doing copies through the stack. Will be used by the DRM scheduler abstraction in the kernel crate, and by field-wise initialization (e.g. using `place!()` or a future replacement macro which may itself live in `kernel`) in driver crates. Link: https://github.com/Rust-for-Linux/linux/issues/879 Link: https://github.com/Rust-for-Linux/linux/issues/2 Link: https://github.com/rust-lang/rust/issues/63291 Signed-off-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Link: https://lore.kernel.org/r/20230224-rust-new_uninit-v1-1-c951443d9e26@asahilina.net [ Reworded to use `Link` tags. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-10rust: sync: impl {Debug,Display} for {Unique,}ArcBoqun Feng
This allows printing the inner data of `Arc` and its friends if the inner data implements `Display` or `Debug`. It's useful for logging and debugging purpose. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Link: https://lore.kernel.org/r/20230207185216.1314638-2-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-07rust: build: Fix grep warningVincenzo Palazzo
Fix grep warning during the build, with GNU grep 3.8 with the following command `grep -v '^\#\|^$$' rust/bindgen_parameters` I see the following warning ``` grep: warning: stray \ before # --opaque-type xregs_state --opaque-type desc_struct --opaque-type arch_lbr_state --opaque-type local_apic --opaque-type x86_msi_data --opaque-type x86_msi_addr_lo --opaque-type kunit_try_catch --opaque-type spinlock --no-doc-comments ``` Signed-off-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Tested-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-06rust: kernel: Mark rust_fmt_argument as extern "C"David Gow
The rust_fmt_argument function is called from printk() to handle the %pA format specifier. Since it's called from C, we should mark it extern "C" to make sure it's ABI compatible. Cc: stable@vger.kernel.org Fixes: 247b365dc8dc ("rust: add `kernel` crate") Signed-off-by: David Gow <davidgow@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> [Applied `rustfmt`] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-06rust: str: fix requierments->requirements typoPatrick Blass
Fix a trivial spelling error in the `rust/kernel/str.rs` file. Fixes: 247b365dc8dc ("rust: add `kernel` crate") Reported-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/978 Signed-off-by: Patrick Blass <patrickblass@mailbox.org> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> [Reworded slightly] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-03-03Merge tag 'rust-fixes-6.3-rc1' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull Rust fix from Miguel Ojeda: "A single build error fix: there was a change during the merge window to a C header parsed by the Rust bindings generator, introducing a type that it does not handle well. The fix tells the generator to treat the type as opaque (for now)" * tag 'rust-fixes-6.3-rc1' of https://github.com/Rust-for-Linux/linux: rust: bindgen: Add `alt_instr` as opaque type
2023-03-02rust: bindgen: Add `alt_instr` as opaque typeArnaldo Carvalho de Melo
To address this build error: BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs EXPORTS rust/exports_core_generated.h RUSTC P rust/libmacros.so RUSTC L rust/compiler_builtins.o RUSTC L rust/alloc.o RUSTC L rust/bindings.o RUSTC L rust/build_error.o EXPORTS rust/exports_alloc_generated.h error[E0588]: packed type cannot transitively contain a `#[repr(align)]` type --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10094:1 | 10094 | / pub struct alt_instr { 10095 | | pub instr_offset: s32, 10096 | | pub repl_offset: s32, 10097 | | pub __bindgen_anon_1: alt_instr__bindgen_ty_1, 10098 | | pub instrlen: u8_, 10099 | | pub replacementlen: u8_, 10100 | | } | |_^ | note: `alt_instr__bindgen_ty_1__bindgen_ty_1` has a `#[repr(align)]` attribute --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10111:1 | 10111 | / pub struct alt_instr__bindgen_ty_1__bindgen_ty_1 { 10112 | | pub _bitfield_1: __BindgenBitfieldUnit<[u8; 4usize], u16>, 10113 | | } | |_^ note: `alt_instr` contains a field of type `alt_instr__bindgen_ty_1` --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10097:9 | 10097 | pub __bindgen_anon_1: alt_instr__bindgen_ty_1, | ^^^^^^^^^^^^^^^^ note: ...which contains a field of type `alt_instr__bindgen_ty_1__bindgen_ty_1` --> /var/home/acme/git/linux/rust/bindings/bindings_generated.rs:10104:9 | 10104 | pub __bindgen_anon_1: alt_instr__bindgen_ty_1__bindgen_ty_1, | ^^^^^^^^^^^^^^^^ error: aborting due to previous error For more information about this error, try `rustc --explain E0588`. make[1]: *** [rust/Makefile:389: rust/bindings.o] Error 1 make: *** [Makefile:1293: prepare] Error 2 Cc: Derek Barbosa <debarbos@redhat.com> Cc: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Fixes: 5d1dd961e743 ("x86/alternatives: Add alt_instr.flags") Reported-by: kernel test robot <lkp@intel.com> Reported-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-02-26Merge tag 'kbuild-v6.3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Change V=1 option to print both short log and full command log - Allow V=1 and V=2 to be combined as V=12 - Make W=1 detect wrong .gitignore files - Tree-wide cleanups for unused command line arguments passed to Clang - Stop using -Qunused-arguments with Clang - Make scripts/setlocalversion handle only correct release tags instead of any arbitrary annotated tag - Create Debian and RPM source packages without cleaning the source tree - Various cleanups for packaging * tag 'kbuild-v6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (74 commits) kbuild: rpm-pkg: remove unneeded KERNELRELEASE from modules/headers_install docs: kbuild: remove description of KBUILD_LDS_MODULE .gitattributes: use 'dts' diff driver for *.dtso files kbuild: deb-pkg: improve the usability of source package kbuild: deb-pkg: fix binary-arch and clean in debian/rules kbuild: tar-pkg: use tar rules in scripts/Makefile.package kbuild: make perf-tar*-src-pkg work without relying on git kbuild: deb-pkg: switch over to source format 3.0 (quilt) kbuild: deb-pkg: make .orig tarball a hard link if possible kbuild: deb-pkg: hide KDEB_SOURCENAME from Makefile kbuild: srcrpm-pkg: create source package without cleaning kbuild: rpm-pkg: build binary packages from source rpm kbuild: deb-pkg: create source package without cleaning kbuild: add a tool to list files ignored by git Documentation/llvm: add Chimera Linux, Google and Meta datacenters setlocalversion: use only the correct release tag for git-describe setlocalversion: clean up the construction of version output .gitignore: ignore *.cover and *.mbx kbuild: remove --include-dir MAKEFLAG from top Makefile kbuild: fix trivial typo in comment ...