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2025-03-30Merge tag 'rust-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linuxLinus Torvalds1-1/+123
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` ...
2025-03-20rust: error: Add EOVERFLOWAbdiel Janulgue1-0/+1
Trivial addition for missing EOVERFLOW error. This is used by a subsequent patch that might require returning EOVERFLOW as a result of `checked_mul`. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250317185345.2608976-2-abdiel.janulgue@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: error: extend the Result documentationDirk Behme1-1/+122
Extend the Result documentation by some guidelines and examples how to handle Result error cases gracefully. And how to not handle them. While at it fix one missing `Result` link in the existing documentation. [ Moved links out-of-line for improved readability. Fixed `srctree` link. Sorted out-of-line links. Added newlines for consistency with other docs. Applied paragraph break suggestion. Reworded slightly the docs in a couple places. Added Markdown. In addition, added `#[allow(clippy::single_match)` for the first example. It cannot be an `expect` since due to a difference introduced in Rust 1.85.0 when there are comments in the arms of the `match`. Reported it upstream, but it was intended: https://github.com/rust-lang/rust-clippy/issues/14418 Perhaps Clippy will lint about it in the future, but without autofix: https://github.com/rust-lang/rust-clippy/pull/14420 - Miguel ] Link: https://lore.kernel.org/rust-for-linux/CANiq72keOdXy0LFKk9SzYWwSjiD710v=hQO4xi+5E4xNALa6cA@mail.gmail.com/ Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Reviewed-by: Fiona Behrens <me@kloenk.dev> Link: https://lore.kernel.org/r/20250122054719.595878-1-dirk.behme@de.bosch.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-06rust: error: add missing newline to pr_warn! callsAlban Kurti1-1/+1
Added missing newline at the end of pr_warn! usage so the log is not missed. Fixes: 6551a7fe0acb ("rust: error: Add Error::from_errno{_unchecked}()") Reported-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1139 Signed-off-by: Alban Kurti <kurti@invicto.ai> Link: https://lore.kernel.org/r/20250206-printing_fix-v3-2-a85273b501ae@invicto.ai [ Replaced Closes with Link since it fixes part of the issue. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-13rust: error: import `kernel`'s `LayoutError` instead of `core`'sJimmy Ostler1-3/+4
Import the internal (`kernel::alloc`) version of `LayoutError` instead of the `core::alloc` one. In particular, this results in switching the type in the existing `From<LayoutError> for Error` implementation. Acked-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Jimmy Ostler <jtostler1@gmail.com> Link: https://lore.kernel.org/r/fe58a02189e8804a9eabdd01cb1927d4c491d79c.1734674670.git.jtostler1@gmail.com [ Reworded commit. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-12-17rust: error: modify `from_errno` to use `try_from_errno`Daniel Sedlak1-7/+4
Modify the from_errno function to use try_from_errno to reduce code duplication while still maintaining all existing behavior and error handling and also reduces unsafe code. Link: https://github.com/Rust-for-Linux/linux/issues/1125 Suggested-by: Miguel Ojeda <ojeda@kernel.org> Co-developed-by: Guilherme Augusto Martins da Silva <guilhermev2huehue@gmail.com> Signed-off-by: Guilherme Augusto Martins da Silva <guilhermev2huehue@gmail.com> Signed-off-by: Daniel Sedlak <daniel@sedlak.dev> Reviewed-by: Fiona Behrens <me@kloenk.dev> Link: https://lore.kernel.org/r/20241207112445.55502-1-daniel@sedlak.dev Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-12-16rust: map `long` to `isize` and `char` to `u8`Gary Guo1-4/+1
The following FFI types are replaced compared to `core::ffi`: 1. `char` type is now always mapped to `u8`, since kernel uses `-funsigned-char` on the C code. `core::ffi` maps it to platform default ABI, which can be either signed or unsigned. 2. `long` is now always mapped to `isize`. It's very common in the kernel to use `long` to represent a pointer-sized integer, and in fact `intptr_t` is a typedef of `long` in the kernel. Enforce this mapping rather than mapping to `i32/i64` depending on platform can save us a lot of unnecessary casts. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240913213041.395655-5-gary@garyguo.net [ Moved `uaccess` changes from the next commit, since they were irrefutable patterns that Rust >= 1.82.0 warns about. Reworded slightly and reformatted a few documentation comments. Rebased on top of `rust-next`. Added the removal of two casts to avoid Clippy warnings. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-10rust: use custom FFI integer typesGary Guo1-10/+10
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: error: check for config `test` in `Error::name`Danilo Krummrich1-2/+2
Additional to `testlib` also check for `test` in `Error::name`. This is required by a subsequent patch that (indirectly) uses `Error` in test cases. 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/20241004154149.93856-24-dakr@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15rust: error: use `core::alloc::LayoutError`Danilo Krummrich1-1/+1
Use `core::alloc::LayoutError` instead of `alloc::alloc::LayoutError` in preparation to get rid of Rust's alloc crate. 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/20241004154149.93856-23-dakr@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-10rust: error: optimize error type to use nonzeroFilipe Xavier1-9/+28
Optimize `Result<(), Error>` size by changing `Error` type to `NonZero*` for niche optimization. This reduces the space used by the `Result` type, as the `NonZero*` type enables the compiler to apply more efficient memory layout. For example, the `Result<(), Error>` changes size from 8 to 4 bytes. Link: https://github.com/Rust-for-Linux/linux/issues/1120 Signed-off-by: Filipe Xavier <felipe_life@live.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Fiona Behrens <me@kloenk.dev> Link: https://lore.kernel.org/r/BL0PR02MB4914B9B088865CF237731207E9732@BL0PR02MB4914.namprd02.prod.outlook.com [ Removed unneeded block around `match`, added backticks in panic message and added intra-doc link. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: error: make conversion functions publicFilipe Xavier1-9/+4
Change visibility to public of functions in error.rs: from_err_ptr, from_errno, from_result and to_ptr. Additionally, remove dead_code annotations. Link: https://github.com/Rust-for-Linux/linux/issues/1105 Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Filipe Xavier <felipe_life@live.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/DM4PR14MB7276E6948E67B3B23D8EA847E9652@DM4PR14MB7276.namprd14.prod.outlook.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: start using the `#[expect(...)]` attributeMiguel Ojeda1-1/+1
In Rust, it is possible to `allow` particular warnings (diagnostics, lints) locally, making the compiler ignore instances of a given warning within a given function, module, block, etc. It is similar to `#pragma GCC diagnostic push` + `ignored` + `pop` in C: #pragma GCC diagnostic push #pragma GCC diagnostic ignored "-Wunused-function" static void f(void) {} #pragma GCC diagnostic pop But way less verbose: #[allow(dead_code)] fn f() {} By that virtue, it makes it possible to comfortably enable more diagnostics by default (i.e. outside `W=` levels) that may have some false positives but that are otherwise quite useful to keep enabled to catch potential mistakes. The `#[expect(...)]` attribute [1] takes this further, and makes the compiler warn if the diagnostic was _not_ produced. For instance, the following will ensure that, when `f()` is called somewhere, we will have to remove the attribute: #[expect(dead_code)] fn f() {} If we do not, we get a warning from the compiler: warning: this lint expectation is unfulfilled --> x.rs:3:10 | 3 | #[expect(dead_code)] | ^^^^^^^^^ | = note: `#[warn(unfulfilled_lint_expectations)]` on by default This means that `expect`s do not get forgotten when they are not needed. See the next commit for more details, nuances on its usage and documentation on the feature. The attribute requires the `lint_reasons` [2] unstable feature, but it is becoming stable in 1.81.0 (to be released on 2024-09-05) and it has already been useful to clean things up in this patch series, finding cases where the `allow`s should not have been there. Thus, enable `lint_reasons` and convert some of our `allow`s to `expect`s where possible. This feature was also an example of the ongoing collaboration between Rust and the kernel -- we tested it in the kernel early on and found an issue that was quickly resolved [3]. Cc: Fridtjof Stoldt <xfrednet@gmail.com> Cc: Urgau <urgau@numericable.fr> Link: https://rust-lang.github.io/rfcs/2383-lint-reasons.html#expect-lint-attribute [1] Link: https://github.com/rust-lang/rust/issues/54503 [2] Link: https://github.com/rust-lang/rust/issues/114557 [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/20240904204347.168520-18-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: enable `clippy::undocumented_unsafe_blocks` lintMiguel Ojeda1-3/+6
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>
2024-08-18rust: error: allow `useless_conversion` for 32-bit buildsMiguel Ojeda1-1/+4
For the new Rust support for 32-bit arm [1], Clippy warns: error: useless conversion to the same type: `i32` --> rust/kernel/error.rs:139:36 | 139 | unsafe { bindings::ERR_PTR(self.0.into()) as *mut _ } | ^^^^^^^^^^^^^ help: consider removing `.into()`: `self.0` | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion = note: `-D clippy::useless-conversion` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::useless_conversion)]` The `self.0.into()` converts an `c_int` into `ERR_PTR`'s parameter which is a `c_long`. Thus, both types are `i32` in 32-bit. Therefore, allow it for those architectures. Link: https://lore.kernel.org/rust-for-linux/2dbd1491-149d-443c-9802-75786a6a3b73@gmail.com/ [1] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Christian Schrefl <chrisi.schrefl@gmail.com> Link: https://lore.kernel.org/r/20240730155702.1110144-1-ojeda@kernel.org [ Fixed typo in tag. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-06-14rust: block: introduce `kernel::block::mq` moduleAndreas Hindborg1-0/+6
Add initial abstractions for working with blk-mq. This patch is a maintained, refactored subset of code originally published by Wedson Almeida Filho <wedsonaf@gmail.com> [1]. [1] https://github.com/wedsonaf/linux/tree/f2cfd2fe0e2ca4e90994f96afe268bbd4382a891/rust/kernel/blk/mq.rs Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240611114551.228679-2-nmi@metaspace.dk Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-05-05rust: kernel: remove redundant importsMiguel Ojeda1-1/+0
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: kernel: remove usage of `allocator_api` unstable featureWedson Almeida Filho1-2/+2
With the adoption of `BoxExt` and `VecExt`, we don't need the functions provided by this feature (namely the methods prefixed with `try_` and different allocator per collection instance). We do need `AllocError`, but we define our own as it is a trivial empty struct. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20240328013603.206764-11-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: alloc: update `VecExt` to take allocation flagsWedson Almeida Filho1-10/+1
We also rename the methods by removing the `try_` prefix since the names are available due to our usage of the `no_global_oom_handling` config when building the `alloc` crate. Reviewed-by: Boqun Feng <boqun.feng@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/20240328013603.206764-8-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: error: improve unsafe code in exampleValentin Obst1-7/+3
The `from_err_ptr` function is safe. There is no need for the call to it to be inside the unsafe block. Reword the SAFETY comment to provide a better justification of why the FFI call is safe. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-2-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-12-21rust: support `srctree`-relative linksMiguel Ojeda1-1/+1
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>
2023-12-14rust: macros: improve `#[vtable]` documentationBenno Lossin1-0/+4
Traits marked with `#[vtable]` need to provide default implementations for optional functions. The C side represents these with `NULL` in the vtable, so the default functions are never actually called. We do not want to replicate the default behavior from C in Rust, because that is not maintainable. Therefore we should use `build_error` in those default implementations. The error message for that is provided at `kernel::error::VTABLE_DEFAULT_ERROR`. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Finn Behrens <me@kloenk.dev> Link: https://lore.kernel.org/r/20231026201855.1497680-1-benno.lossin@proton.me [ Wrapped paragraph to 80 as requested and capitalized sentence. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-12rust: error: Markdown style nitManmohan Shukla1-1/+1
This patch fixes a trivial markdown style nit in the `SAFETY` comment. Signed-off-by: Manmohan Shukla <manmshuk@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Jianguo Bao <roidinev@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Fixes: c7e20faa5fca ("rust: error: Add Error::to_ptr()") Link: https://lore.kernel.org/r/20230906204857.85619-1-manmshuk@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-12rust: error: fix the description for `ECHILD`Wedson Almeida Filho1-1/+1
A mistake was made and the description of `ECHILD` is wrong (it reuses the description of `ENOEXEC`). This fixes it to reflect what's in `errno-base.h`. Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Fixes: 266def2a0f5b ("rust: error: add codes from `errno-base.h`") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20230930144958.46051-1-wedsonaf@gmail.com [ Use the plural, as noticed by Benno. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-06-13rust: error: `impl Debug` for `Error` with `errname()` integrationGary Guo1-0/+39
Integrate the `Error` type with `errname()` by providing a new `name()` method. Then, implement `Debug` for the type using the new method. [ Miguel: under `CONFIG_SYMBOLIC_ERRNAME=n`, `errname()` is a `static inline`, so added a helper to support that case, like we had in the `rust` branch. Also moved `#include` up and reworded commit message for clarity. ] Co-developed-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com> Signed-off-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230531174450.3733220-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: error: add missing error codesAlice Ryhl1-0/+20
This adds the error codes from `include/linux/errno.h` to the list of Rust error constants. These errors were not included originally, because they are not supposed to be visible from userspace. However, they are still a perfectly valid error to use when writing a kernel driver. For example, you might want to return ERESTARTSYS if you receive a signal during a call to `schedule`. This patch inserts an annotation to skip rustfmt on the list of error codes. Without it, three of the error codes are split over several lines, which looks terribly inconsistent. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230504064854.774820-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: error: allow specifying error type on `Result`Alice Ryhl1-1/+1
Currently, if the `kernel::error::Result` type is in scope (which is often is, since it's in the kernel's prelude), you cannot write `Result<T, SomeOtherErrorType>` when you want to use a different error type than `kernel::error::Error`. To solve this we change the error type from being hard-coded to just being a default generic parameter. This still lets you write `Result<T>` when you just want to use the `Error` error type, but also lets you write `Result<T, SomeOtherErrorType>` when necessary. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230502124015.356001-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-12rust: error: Add from_result() helperWedson Almeida Filho1-0/+39
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 Asbroeck1-1/+49
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 Filho1-1/+10
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 Ojeda1-0/+32
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 Lina1-0/+7
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 Lina1-1/+1
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>
2022-12-04rust: error: add `From` implementations for `Error`Wedson Almeida Filho1-1/+44
Add a set of `From` implementations for the `Error` kernel type. These implementations allow to easily convert from standard Rust error types to the usual kernel errors based on one of the `E*` integer codes. On top of that, the question mark Rust operator (`?`) implicitly performs a conversion on the error value using the `From` trait when propagating. Thus it is extra convenient to use. For instance, a kernel function that needs to convert a `i64` into a `i32` and to bubble up the error as a kernel error may write: fn f(x: i64) -> Result<...> { ... let y = i32::try_from(x)?; ... } which will transform the `TryFromIntError` into an `Err(EINVAL)`. Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com> Co-developed-by: Nándor István Krácser <bonifaido@gmail.com> Signed-off-by: Nándor István Krácser <bonifaido@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reviewed-by: Finn Behrens <me@kloenk.dev> [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04rust: error: add codes from `errno-base.h`Viktor Garske1-0/+33
Only a few codes were added so far. With the `declare_err!` macro in place, add the remaining ones (which is most of them) from `include/uapi/asm-generic/errno-base.h`. Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Viktor Garske <viktor@v-gar.de> Reviewed-by: Gary Guo <gary@garyguo.net> [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-04rust: error: declare errors using macroFinn Behrens1-2/+10
Add a macro to declare errors, which simplifies the work needed to add each one, avoids repetition of the code and makes it easier to change the way they are declared. Signed-off-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Gary Guo <gary@garyguo.net> [Reworded, adapted for upstream and applied latest changes] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28rust: add `kernel` crateWedson Almeida Filho1-0/+59
The `kernel` crate currently includes all the abstractions that wrap kernel features written in C. These abstractions call the C side of the kernel via the generated bindings with the `bindgen` tool. Modules developed in Rust should never call the bindings themselves. In the future, as the abstractions grow in number, we may need to split this crate into several, possibly following a similar subdivision in subsystems as the kernel itself and/or moving the code to the actual subsystems. Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Co-developed-by: Alex Gaynor <alex.gaynor@gmail.com> Signed-off-by: Alex Gaynor <alex.gaynor@gmail.com> Co-developed-by: Geoffrey Thomas <geofft@ldpreload.com> Signed-off-by: Geoffrey Thomas <geofft@ldpreload.com> Co-developed-by: Finn Behrens <me@kloenk.de> Signed-off-by: Finn Behrens <me@kloenk.de> Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com> Co-developed-by: Sven Van Asbroeck <thesven73@gmail.com> Signed-off-by: Sven Van Asbroeck <thesven73@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Boris-Chengbiao Zhou <bobo1239@web.de> Signed-off-by: Boris-Chengbiao Zhou <bobo1239@web.de> Co-developed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Co-developed-by: Fox Chen <foxhlchen@gmail.com> Signed-off-by: Fox Chen <foxhlchen@gmail.com> Co-developed-by: Viktor Garske <viktor@v-gar.de> Signed-off-by: Viktor Garske <viktor@v-gar.de> Co-developed-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl> Signed-off-by: Dariusz Sosnowski <dsosnowski@dsosnowski.pl> Co-developed-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com> Signed-off-by: Léo Lanteri Thauvin <leseulartichaut@gmail.com> Co-developed-by: Niklas Mohrin <dev@niklasmohrin.de> Signed-off-by: Niklas Mohrin <dev@niklasmohrin.de> Co-developed-by: Milan Landaverde <milan@mdaverde.com> Signed-off-by: Milan Landaverde <milan@mdaverde.com> Co-developed-by: Morgan Bartlett <mjmouse9999@gmail.com> Signed-off-by: Morgan Bartlett <mjmouse9999@gmail.com> Co-developed-by: Maciej Falkowski <m.falkowski@samsung.com> Signed-off-by: Maciej Falkowski <m.falkowski@samsung.com> Co-developed-by: Nándor István Krácser <bonifaido@gmail.com> Signed-off-by: Nándor István Krácser <bonifaido@gmail.com> Co-developed-by: David Gow <davidgow@google.com> Signed-off-by: David Gow <davidgow@google.com> Co-developed-by: John Baublitz <john.m.baublitz@gmail.com> Signed-off-by: John Baublitz <john.m.baublitz@gmail.com> Co-developed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@google.com> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>