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2025-03-09print: use new #[export] macro for rust_fmt_argumentAlice Ryhl
This moves the rust_fmt_argument function over to use the new #[export] macro, which will verify at compile-time that the function signature matches what is in the header file. Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250303-export-macro-v3-4-41fbad85a27f@google.com [ Removed period as requested by Andy. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-09rust: fix signature of rust_fmt_argumentAlice Ryhl
Without this change, the rest of this series will emit the following error message: error[E0308]: `if` and `else` have incompatible types --> <linux>/rust/kernel/print.rs:22:22 | 21 | #[export] | --------- expected because of this 22 | unsafe extern "C" fn rust_fmt_argument( | ^^^^^^^^^^^^^^^^^ expected `u8`, found `i8` | = note: expected fn item `unsafe extern "C" fn(*mut u8, *mut u8, *mut c_void) -> *mut u8 {bindings::rust_fmt_argument}` found fn item `unsafe extern "C" fn(*mut i8, *mut i8, *const c_void) -> *mut i8 {print::rust_fmt_argument}` The error may be different depending on the architecture. To fix this, change the void pointer argument to use a const pointer, and change the imports to use crate::ffi instead of core::ffi for integer types. Fixes: 787983da7718 ("vsprintf: add new `%pA` format specifier") Reviewed-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Petr Mladek <pmladek@suse.com> Link: https://lore.kernel.org/r/20250303-export-macro-v3-1-41fbad85a27f@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-12-16rust: cleanup unnecessary castsGary Guo
With `long` mapped to `isize`, `size_t`/`__kernel_size_t` mapped to `usize` and `char` mapped to `u8`, many of the existing casts are no longer necessary. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240913213041.395655-6-gary@garyguo.net [ Moved `uaccess` changes to the previous commit, since they were irrefutable patterns that Rust >= 1.82.0 warns about. Removed a couple casts that now use `c""` literals. Rebased on top of `rust-next`. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: start using the `#[expect(...)]` attributeMiguel Ojeda
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's `check-private-items`Miguel Ojeda
In Rust 1.76.0, Clippy added the `check-private-items` lint configuration option. When turned on (the default is off), it makes several lints check private items as well. In our case, it affects two lints we have enabled [1]: `missing_safety_doc` and `unnecessary_safety_doc`. It also seems to affect the new `too_long_first_doc_paragraph` lint [2], even though the documentation does not mention it. Thus allow the few instances remaining we currently hit and enable the lint. Link: https://doc.rust-lang.org/nightly/clippy/lint_configuration.html#check-private-items [1] Link: https://rust-lang.github.io/rust-clippy/master/index.html#/too_long_first_doc_paragraph [2] Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Gary Guo <gary@garyguo.net> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240904204347.168520-16-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>
2024-08-25rust: kernel: use docs.kernel.org links in code documentationMichael Vetter
Use links to docs.kernel.org instead of www.kernel.org/doc/html/latest in the code documentation. The links are shorter and cleaner. Link: https://github.com/Rust-for-Linux/linux/issues/1101 Signed-off-by: Michael Vetter <jubalh@iodoru.org> [ Reworded slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-05-05rust: kernel: remove redundant importsMiguel Ojeda
Rust's `unused_imports` lint covers both unused and redundant imports. In the upcoming 1.78.0, the lint detects more cases of redundant imports [1], e.g.: error: the item `bindings` is imported redundantly --> rust/kernel/print.rs:38:9 | 38 | use crate::bindings; | ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude Most cases are `use crate::bindings`, plus a few other items like `Box`. Thus clean them up. Note that, in the `bindings` case, the message "defined by prelude" above means the extern prelude, i.e. the `--extern` flags we pass. Link: https://github.com/rust-lang/rust/pull/117772 [1] Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240401212303.537355-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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>
2023-10-15rust: print: use explicit link in documentationMiguel Ojeda
The future `rustdoc` in the Rust 1.73.0 upgrade requires an explicit link for `pr_info!`: error: unresolved link to `pr_info` --> rust/kernel/print.rs:395:63 | 395 | /// Use only when continuing a previous `pr_*!` macro (e.g. [`pr_info!`]). | ^^^^^^^^ no item named `pr_info` in scope | = note: `macro_rules` named `pr_info` exists in this crate, but it is not in scope at this link's location = note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings` Thus do so to avoid a broken link while upgrading. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20231005210556.466856-3-ojeda@kernel.org 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>
2023-01-16rust: print: avoid evaluating arguments in `pr_*` macros in `unsafe` blocksMiguel Ojeda
At the moment it is possible to perform unsafe operations in the arguments of `pr_*` macros since they are evaluated inside an `unsafe` block: let x = &10u32 as *const u32; pr_info!("{}", *x); In other words, this is a soundness issue. Fix it so that it requires an explicit `unsafe` block. Reported-by: Wedson Almeida Filho <wedsonaf@gmail.com> Reported-by: Domen Puncer Kugler <domen.puncerkugler@nccgroup.com> Link: https://github.com/Rust-for-Linux/linux/issues/479 Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
2022-12-01rust: print: add `pr_cont!` macroMiguel Ojeda
This level is a bit different from the rest since it does not pass the module name to the `_printk()` call. Thus add a new parameter to the general `print_macro!` to handle it differently. Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Sergio González Collado <sergio.collado@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-12-01rust: print: add more `pr_*!` levelsMiguel Ojeda
Currently, only `pr_info!` (for the minimal sample) and `pr_emerg!` (for the panic handler) are there. Add the other levels as new macros, i.e. `pr_alert!`, `pr_crit!`, `pr_err!`, `pr_warn!`, `pr_notice!` and `pr_debug!`. Co-developed-by: Adam Bratschi-Kaye <ark.email@gmail.com> Signed-off-by: Adam Bratschi-Kaye <ark.email@gmail.com> Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Sergio Gonzalez Collado <sergio.collado@gmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2022-09-28rust: add `kernel` crateWedson Almeida Filho
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>