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2025-03-30Merge tag 'rust-6.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Extract the 'pin-init' API from the 'kernel' crate and make it into a standalone crate. In order to do this, the contents are rearranged so that they can easily be kept in sync with the version maintained out-of-tree that other projects have started to use too (or plan to, like QEMU). This will reduce the maintenance burden for Benno, who will now have his own sub-tree, and will simplify future expected changes like the move to use 'syn' to simplify the implementation. - Add '#[test]'-like support based on KUnit. We already had doctests support based on KUnit, which takes the examples in our Rust documentation and runs them under KUnit. Now, we are adding the beginning of the support for "normal" tests, similar to those the '#[test]' tests in userspace Rust. For instance: #[kunit_tests(my_suite)] mod tests { #[test] fn my_test() { assert_eq!(1 + 1, 2); } } Unlike with doctests, the 'assert*!'s do not map to the KUnit assertion APIs yet. - Check Rust signatures at compile time for functions called from C by name. In particular, introduce a new '#[export]' macro that can be placed in the Rust function definition. It will ensure that the function declaration on the C side matches the signature on the Rust function: #[export] pub unsafe extern "C" fn my_function(a: u8, b: i32) -> usize { // ... } The macro essentially forces the compiler to compare the types of the actual Rust function and the 'bindgen'-processed C signature. These cases are rare so far. In the future, we may consider introducing another tool, 'cbindgen', to generate C headers automatically. Even then, having these functions explicitly marked may be a good idea anyway. - Enable the 'raw_ref_op' Rust feature: it is already stable, and allows us to use the new '&raw' syntax, avoiding a couple macros. After everyone has migrated, we will disallow the macros. - Pass the correct target to 'bindgen' on Usermode Linux. - Fix 'rusttest' build in macOS. 'kernel' crate: - New 'hrtimer' module: add support for setting up intrusive timers without allocating when starting the timer. Add support for 'Pin<Box<_>>', 'Arc<_>', 'Pin<&_>' and 'Pin<&mut _>' as pointer types for use with timer callbacks. Add support for setting clock source and timer mode. - New 'dma' module: add a simple DMA coherent allocator abstraction and a test sample driver. - 'list' module: make the linked list 'Cursor' point between elements, rather than at an element, which is more convenient to us and allows for cursors to empty lists; and document it with examples of how to perform common operations with the provided methods. - 'str' module: implement a few traits for 'BStr' as well as the 'strip_prefix()' method. - 'sync' module: add 'Arc::as_ptr'. - 'alloc' module: add 'Box::into_pin'. - 'error' module: extend the 'Result' documentation, including a few examples on different ways of handling errors, a warning about using methods that may panic, and links to external documentation. 'macros' crate: - 'module' macro: add the 'authors' key to support multiple authors. The original key will be kept until everyone has migrated. Documentation: - Add error handling sections. MAINTAINERS: - Add Danilo Krummrich as reviewer of the Rust "subsystem". - Add 'RUST [PIN-INIT]' entry with Benno Lossin as maintainer. It has its own sub-tree. - Add sub-tree for 'RUST [ALLOC]'. - Add 'DMA MAPPING HELPERS DEVICE DRIVER API [RUST]' entry with Abdiel Janulgue as primary maintainer. It will go through the sub-tree of the 'RUST [ALLOC]' entry. - Add 'HIGH-RESOLUTION TIMERS [RUST]' entry with Andreas Hindborg as maintainer. It has its own sub-tree. And a few other cleanups and improvements" * tag 'rust-6.15' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (71 commits) rust: dma: add `Send` implementation for `CoherentAllocation` rust: macros: fix `make rusttest` build on macOS rust: block: refactor to use `&raw mut` rust: enable `raw_ref_op` feature rust: uaccess: name the correct function rust: rbtree: fix comments referring to Box instead of KBox rust: hrtimer: add maintainer entry rust: hrtimer: add clocksource selection through `ClockId` rust: hrtimer: add `HrTimerMode` rust: hrtimer: implement `HrTimerPointer` for `Pin<Box<T>>` rust: alloc: add `Box::into_pin` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&mut T>` rust: hrtimer: implement `UnsafeHrTimerPointer` for `Pin<&T>` rust: hrtimer: add `hrtimer::ScopedHrTimerPointer` rust: hrtimer: add `UnsafeHrTimerPointer` rust: hrtimer: allow timer restart from timer handler rust: str: implement `strip_prefix` for `BStr` rust: str: implement `AsRef<BStr>` for `[u8]` and `BStr` rust: str: implement `Index` for `BStr` rust: str: implement `PartialEq` for `BStr` ...
2025-03-16rust: make pin-init its own crateBenno Lossin
Rename relative paths inside of the crate to still refer to the same items, also rename paths inside of the kernel crate and adjust the build system to build the crate. [ Remove the `expect` (and thus the `lint_reasons` feature) since the tree now uses `quote!` from `rust/macros/export.rs`. Remove the `TokenStream` import removal, since it is now used as well. In addition, temporarily (i.e. just for this commit) use an `--extern force:alloc` to prevent an unknown `new_uninit` error in the `rustdoc` target. For context, please see a similar case in: https://lore.kernel.org/lkml/20240422090644.525520-1-ojeda@kernel.org/ And adjusted the message above. - Miguel ] Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-16-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: pin-init: move `InPlaceInit` and impls of `InPlaceWrite` into the ↵Benno Lossin
kernel crate In order to make pin-init a standalone crate, move kernel-specific code directly into the kernel crate. This includes the `InPlaceInit<T>` trait, its implementations and the implementations of `InPlaceWrite` for `Arc` and `UniqueArc`. All of these use the kernel's error type which will become unavailable in pin-init. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-9-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: pin-init: move the default error behavior of `try_[pin_]init`Benno Lossin
Move the ability to just write `try_pin_init!(Foo { a <- a_init })` (note the missing `? Error` at the end) into the kernel crate. Remove this notation from the pin-init crate, since the default when no error is specified is the kernel-internal `Error` type. Instead add two macros in the kernel crate that serve this default and are used instead of the ones from `pin-init`. This is done, because the `Error` type that is used as the default is from the kernel crate and it thus prevents making the pin-init crate standalone. In order to not cause a build error due to a name overlap, the macros in the pin-init crate are renamed, but this change is reverted in a future commit when it is a standalone crate. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-8-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: add extensions to the pin-init crate and move relevant documentation thereBenno Lossin
In preparation of splitting off the pin-init crate from the kernel crate, move all kernel-specific documentation from pin-init back into the kernel crate. Also include an example from the user-space version [1] adapted to the kernel. The new `init.rs` file will also be populated by kernel-specific extensions to the pin-init crate by the next commits. Link: https://github.com/Rust-for-Linux/pin-init/blob/c1417c64c71229f0fd444d75e88f33e3c547c829/src/lib.rs#L161 [1] Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-4-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: move pin-init API into its own directoryBenno Lossin
In preparation of splitting off the pin-init crate from the kernel crate, move all pin-init API code (including proc-macros) into `rust/pin-init`. Moved modules have their import path adjusted via the `#[path = "..."]` attribute. This allows the files to still be imported in the kernel crate even though the files are in different directories. Code that is moved out of files (but the file itself stays where it is) is imported via the `include!` macro. This also allows the code to be moved while still being part of the kernel crate. Note that this commit moves the generics parsing code out of the GPL-2.0 file `rust/macros/helpers.rs` into the Apache-2.0 OR MIT file `rust/pin_init/internal/src/helpers.rs`. I am the sole author of that code and it already is available with that license at [1]. The same is true for the entry-points of the proc-macros `pin_data`, `pinned_drop` and `derive_zeroable` in `rust/macros/lib.rs` that are moved to `rust/pin_data/internal/src/lib.rs`. Although there are some smaller patches that fix the doctests. Link: https://github.com/Rust-for-Linux/pinned-init [1] Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Fiona Behrens <me@kloenk.dev> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-3-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-16rust: init: disable doctestsBenno Lossin
The build system cannot handle doctests in the kernel crate in files outside of `rust/kernel/`. Subsequent commits will move files out of that directory, but will still compile them as part of the kernel crate. Thus ignore all doctests in the to-be-moved files. Leave tests disabled until they are separated into their own crate and they stop causing breakage. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Fiona Behrens <me@kloenk.dev> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Tested-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250308110339.2997091-2-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-06rust: init: add missing newline to pr_info! callsAlban Kurti
Several pr_info! calls in rust/kernel/init.rs (both in code examples and macro documentation) were missing a newline, causing logs to run together. This commit updates these calls to include a trailing newline, improving readability and consistency with the C side. Fixes: 6841d45a3030 ("rust: init: add `stack_pin_init!` macro") Fixes: 7f8977a7fe6d ("rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`") Fixes: d0fdc3961270 ("rust: init: add `PinnedDrop` trait and macros") Fixes: 4af84c6a85c6 ("rust: init: update expanded macro explanation") 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-v3-3-a85273b501ae@invicto.ai [ Replaced Closes with Link since it fixes part of the issue. Added one more Fixes tag (still same set of stable kernels). - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-05rust: init: fix `Zeroable` implementation for `Option<NonNull<T>>` and ↵Benno Lossin
`Option<KBox<T>>` According to [1], `NonNull<T>` and `#[repr(transparent)]` wrapper types such as our custom `KBox<T>` have the null pointer optimization only if `T: Sized`. Thus remove the `Zeroable` implementation for the unsized case. Link: https://doc.rust-lang.org/stable/std/option/index.html#representation [1] Reported-by: Alice Ryhl <aliceryhl@google.com> Closes: https://lore.kernel.org/rust-for-linux/CAH5fLghL+qzrD8KiCF1V3vf2YcC6aWySzkmaE2Zzrnh1gKj-hw@mail.gmail.com/ Cc: stable@vger.kernel.org # v6.12+ (a custom patch will be needed for 6.6.y) Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function") Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250305132836.2145476-1-benno.lossin@proton.me [ Added Closes tag and moved up the Reported-by one. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-02-06rust: init: use explicit ABI to clean warning in future compilersMiguel Ojeda
Starting with Rust 1.86.0 (currently in nightly, to be released on 2025-04-03), the `missing_abi` lint is warn-by-default [1]: error: extern declarations without an explicit ABI are deprecated --> rust/doctests_kernel_generated.rs:3158:1 | 3158 | extern { | ^^^^^^ help: explicitly specify the C ABI: `extern "C"` | = note: `-D missing-abi` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(missing_abi)]` Thus clean it up. Cc: <stable@vger.kernel.org> # Needed in 6.12.y and 6.13.y only (Rust is pinned in older LTSs). Fixes: 7f8977a7fe6d ("rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`") Link: https://github.com/rust-lang/rust/pull/132397 [1] 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/20250121200934.222075-1-ojeda@kernel.org [ Added 6.13.y to Cc: stable tag. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-13rust: init: update `stack_try_pin_init` examplesJimmy Ostler
Change documentation imports to use `kernel::alloc::AllocError`, because `KBox::new()` now returns that, instead of the `core`'s `AllocError`. Reviewed-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Jimmy Ostler <jtostler1@gmail.com> Link: https://lore.kernel.org/r/ec8badbe94c5e78f22315325a7f2ae96129d6a65.1734674670.git.jtostler1@gmail.com [ Fixed formatting of imports (still unordered). Slightly reworded commit. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-13rust: init: replace unwraps with question mark operatorsDaniel Sedlak
Use `?` operator in the doctests. Since it is in the examples, using unwraps can convey a wrong impression that unwrapping is fine in general, thus this patch removes this unwrapping. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/rust-for-linux/CANiq72nsK1D4NuQ1U7NqMWoYjXkqQSj4QuUEL98OmFbq022Z9A@mail.gmail.com/ Signed-off-by: Daniel Sedlak <daniel@sedlak.dev> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20241123095033.41240-2-daniel@sedlak.dev [ Reworded commit slightly. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-11-10rust: use custom FFI integer typesGary Guo
Currently FFI integer types are defined in libcore. This commit creates the `ffi` crate and asks bindgen to use that crate for FFI integer types instead of `core::ffi`. This commit is preparatory and no type changes are made in this commit yet. Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240913213041.395655-4-gary@garyguo.net [ Added `rustdoc`, `rusttest` and KUnit tests support. Rebased on top of `rust-next` (e.g. migrated more `core::ffi` cases). Reworded crate docs slightly and formatted. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15rust: alloc: remove extension of std's `Box`Danilo Krummrich
Now that all existing `Box` users were moved to the kernel `Box` type, remove the `BoxExt` extension and all other related extensions. 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/20241004154149.93856-14-dakr@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15rust: treewide: switch to our kernel `Box` typeDanilo Krummrich
Now that we got the kernel `Box` type in place, convert all existing `Box` users to make use of it. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20241004154149.93856-13-dakr@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-07rust: 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: init: remove unneeded `#[allow(clippy::disallowed_names)]`Miguel Ojeda
These few cases, unlike others in the same file, did not need the `allow`. Thus clean them up. 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/20240904204347.168520-10-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>
2024-08-23rust: init: add `assert_pinned` macroBenno Lossin
Add a macro to statically check if a field of a struct is marked with `#[pin]` ie that it is structurally pinned. This can be used when `unsafe` code needs to rely on fields being structurally pinned. The macro has a special "inline" mode for the case where the type depends on generic parameters from the surrounding scope. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Co-developed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240814-linked-list-v5-1-f5f5e8075da0@google.com [ Replaced `compile_fail` with `ignore` and a TODO note. Removed `pub` from example to clean `unreachable_pub` lint. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-22rust: init: add `write_[pin_]init` functionsBenno Lossin
Sometimes it is necessary to split allocation and initialization into two steps. One such situation is when reusing existing allocations obtained via `Box::drop_contents`. See [1] for an example. In order to support this use case add `write_[pin_]init` functions to the pin-init API. These functions operate on already allocated smart pointers that wrap `MaybeUninit<T>`. Link: https://lore.kernel.org/rust-for-linux/f026532f-8594-4f18-9aa5-57ad3f5bc592@proton.me/ [1] Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20240819112415.99810-2-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-08-18rust: Implement the smart pointer `InPlaceInit` for `Arc`Alex Mantel
For pinned and unpinned initialization of structs, a trait named `InPlaceInit` exists for uniform access. `Arc` did not implement `InPlaceInit` yet, although the functions already existed. The main reason for that, was that the trait itself returned a `Pin<Self>`. The `Arc` implementation of the kernel is already implicitly pinned. To enable `Arc` to implement `InPlaceInit` and to have uniform access, for in-place and pinned in-place initialization, an associated type is introduced for `InPlaceInit`. The new implementation of `InPlaceInit` for `Arc` sets `Arc` as the associated type. Older implementations use an explicit `Pin<T>` as the associated type. The implemented methods for `Arc` are mostly moved from a direct implementation on `Arc`. There should be no user impact. The implementation for `ListArc` is omitted, because it is not merged yet. Link: https://github.com/Rust-for-Linux/linux/issues/1079 Signed-off-by: Alex Mantel <alexmantel93@mailbox.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240727042442.682109-1-alexmantel93@mailbox.org [ Removed "Rusts" (Benno). - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-07-10rust: init: simplify from `map_err` to `inspect_err`Miguel Ojeda
A new complexity lint, `manual_inspect` [1], has been introduced in the upcoming Rust 1.81 (currently in nightly), which checks for uses of `map*` which return the original item: error: --> rust/kernel/init.rs:846:23 | 846 | (self.1)(val).map_err(|e| { | ^^^^^^^ | = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_inspect = note: `-D clippy::manual-inspect` implied by `-D warnings` = help: to override `-D warnings` add `#[allow(clippy::manual_inspect)]` help: try | 846 ~ (self.1)(val).inspect_err(|e| { 847 | // SAFETY: `slot` was initialized above. 848 ~ unsafe { core::ptr::drop_in_place(slot) }; | Thus clean them up. Link: https://rust-lang.github.io/rust-clippy/master/index.html#/manual_inspect [1] Tested-by: Benno Lossin <benno.lossin@proton.me> Tested-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20240709160615.998336-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-05-13Merge tag 'rust-6.10' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull Rust updates from Miguel Ojeda: "The most notable change is the drop of the 'alloc' in-tree fork. This is nicely reflected in the diffstat as a ~10k lines drop. In turn, this makes the version upgrades way simpler and smaller in the future, e.g. the latest one in commit 56f64b370612 ("rust: upgrade to Rust 1.78.0"). More importantly, this increases the chances that a newer compiler version just works, which in turn means supporting several compiler versions is easier now. Thus we will look into finally setting a minimum version in the near future. Toolchain and infrastructure: - Upgrade to Rust 1.78.0 This time around, due to how the kernel and Rust schedules have aligned, there are two upgrades in fact. These allow us to remove one more unstable feature ('offset_of') from the list, among other improvements - Drop 'alloc' in-tree fork of the standard library crate, which means all the unstable features used by 'alloc' (~30 language ones, ~60 library ones) are not a concern anymore - Support DWARFv5 via the '-Zdwarf-version' flag - Support zlib and zstd debuginfo compression via the '-Zdebuginfo-compression' flag 'kernel' crate: - Support allocation flags ('GFP_*'), particularly in 'Box' (via 'BoxExt'), 'Vec' (via 'VecExt'), 'Arc' and 'UniqueArc', as well as in the 'init' module APIs - Remove usage of the 'allocator_api' unstable feature - Remove 'try_' prefix in allocation APIs' names - Add 'VecExt' (an extension trait) to be able to drop the 'alloc' fork - Add the '{make,to}_{upper,lower}case()' methods to 'CStr'/'CString' - Add the 'as_ptr' method to 'ThisModule' - Add the 'from_raw' method to 'ArcBorrow' - Add the 'into_unique_or_drop' method to 'Arc' - Display column number in the 'dbg!' macro output by applying the equivalent change done to the standard library one - Migrate 'Work' to '#[pin_data]' thanks to the changes in the 'macros' crate, which allows to remove an unsafe call in its 'new' associated function - Prevent namespacing issues when using the '[try_][pin_]init!' macros by changing the generated name of guard variables - Make the 'get' method in 'Opaque' const - Implement the 'Default' trait for 'LockClassKey' - Remove unneeded 'kernel::prelude' imports from doctests - Remove redundant imports 'macros' crate: - Add 'decl_generics' to 'parse_generics()' to support default values, and use that to allow them in '#[pin_data]' Helpers: - Trivial English grammar fix Documentation: - Add section on Rust Kselftests to the 'Testing' document - Expand the 'Abstractions vs. bindings' section of the 'General Information' document" * tag 'rust-6.10' of https://github.com/Rust-for-Linux/linux: (31 commits) rust: alloc: fix dangling pointer in VecExt<T>::reserve() rust: upgrade to Rust 1.78.0 rust: kernel: remove redundant imports rust: sync: implement `Default` for `LockClassKey` docs: rust: extend abstraction and binding documentation docs: rust: Add instructions for the Rust kselftest rust: remove unneeded `kernel::prelude` imports from doctests rust: update `dbg!()` to format column number rust: helpers: Fix grammar in comment rust: init: change the generated name of guard variables rust: sync: add `Arc::into_unique_or_drop` rust: sync: add `ArcBorrow::from_raw` rust: types: Make Opaque::get const rust: kernel: remove usage of `allocator_api` unstable feature rust: init: update `init` module to take allocation flags rust: sync: update `Arc` and `UniqueArc` to take allocation flags rust: alloc: update `VecExt` to take allocation flags rust: alloc: introduce the `BoxExt` trait rust: alloc: introduce allocation flags rust: alloc: remove our fork of the `alloc` crate ...
2024-05-05rust: remove unneeded `kernel::prelude` imports from doctestsNell Shamrell-Harrington
Rust doctests implicitly include `kernel::prelude::*`. Removes explicit `kernel::prelude` imports from doctests. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1064 Signed-off-by: Nell Shamrell-Harrington <nells@linux.microsoft.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240411225331.274662-1-nells@linux.microsoft.com [ Add it back for `module_phy_driver`'s example since it is within a `mod`, and thus it cannot be removed. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: kernel: remove usage of `allocator_api` unstable featureWedson Almeida Filho
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: init: update `init` module to take allocation flagsWedson Almeida Filho
This is the last component in the conversion for allocators to take allocation flags as parameters. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20240328013603.206764-10-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: sync: update `Arc` and `UniqueArc` to take allocation flagsWedson Almeida Filho
We also remove the `try_` prefix to align with how `Box` and `Vec` are providing methods now. `init` is temporarily updated with uses of GFP_KERNEL. These will be updated in a subsequent patch to take flags as well. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20240328013603.206764-9-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-16rust: alloc: introduce the `BoxExt` traitWedson Almeida Filho
Make fallible versions of `new` and `new_uninit` methods available in `Box` even though it doesn't implement them because we build `alloc` with the `no_global_oom_handling` config. They also have an extra `flags` parameter that allows callers to pass flags to the allocator. Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240328013603.206764-7-wedsonaf@gmail.com [ Used `Box::write()` to avoid one `unsafe` block as suggested by Boqun. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-04-04rust: init: remove impl Zeroable for InfallibleLaine Taffin Altman
In Rust, producing an invalid value of any type is immediate undefined behavior (UB); this includes via zeroing memory. Therefore, since an uninhabited type has no valid values, producing any values at all for it is UB. The Rust standard library type `core::convert::Infallible` is uninhabited, by virtue of having been declared as an enum with no cases, which always produces uninhabited types in Rust. The current kernel code allows this UB to be triggered, for example by code like `Box::<core::convert::Infallible>::init(kernel::init::zeroed())`. Thus, remove the implementation of `Zeroable` for `Infallible`, thereby avoiding the unsoundness (potential for future UB). Cc: stable@vger.kernel.org Fixes: 38cde0bd7b67 ("rust: init: add `Zeroable` trait and `init::zeroed` function") Closes: https://github.com/Rust-for-Linux/pinned-init/pull/13 Signed-off-by: Laine Taffin Altman <alexanderaltman@me.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/CA160A4E-561E-4918-837E-3DCEBA74F808@me.com [ Reformatted the comment slightly. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: add reexports for macrosAlice Ryhl
Currently, all macros are reexported with #[macro_export] only, which means that to access `new_work!` from the workqueue, you need to import it from the path `kernel::new_work` instead of importing it from the workqueue module like all other items in the workqueue. By adding reexports of the macros, it becomes possible to import the macros from the correct modules. It's still possible to import the macros from the root, but I don't think we can do anything about that. There is no functional change. This is merely a code cleanliness improvement. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20240129145837.1419880-1-aliceryhl@google.com [ Removed new `use kernel::prelude::*`s, reworded title. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-02-18rust: kernel: fix multiple typos in documentationValentin Obst
Fixes multiple trivial typos in documentation and comments of the kernel crate. allocator: - Fix a trivial list item alignment issue in the last SAFETY comment of `krealloc_aligned`. init: - Replace 'type' with 'trait' in the doc comments of the `PinInit` and `Init` traits. - Add colons before starting lists. - Add spaces between the type and equal sign to respect the code formatting rules in example code. - End a sentence with a full stop instead of a colon. ioctl: - Replace 'an' with 'a' where appropriate. str: - Replace 'Return' with 'Returns' in the doc comment of `bytes_written` as the text describes what the function does. sync/lock: - Fix a trivial list item alignment issue in the Safety section of the `Backend` trait's description. sync/lock/spinlock: - The code in this module operates on spinlocks, not mutexes. Thus, replace 'mutex' with 'spinlock' in the SAFETY comment of `unlock`. workqueue: - Replace "wont" with "won't" in the doc comment of `__enqueue`. Signed-off-by: Valentin Obst <kernel@valentinobst.de> Reviewed-by: Trevor Gross <tmgross@umich.edu> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20240131-doc-fixes-v3-v3-1-0c8af94ed7de@valentinobst.de Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-10-05rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`Gary Guo
Clippy triggered a false positive on its `new_ret_no_self` lint when using the `pin_init!` macro. Since Rust 1.67.0, that does not happen anymore, since Clippy learnt to not warn about `-> impl Trait<Self>` [1][2]. The kernel nowadays uses Rust 1.72.1, thus remove the `#[allow]`. Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Finn Behrens <me@kloenk.dev> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://github.com/rust-lang/rust-clippy/issues/7344 [1] Link: https://github.com/rust-lang/rust-clippy/pull/9733 [2] Link: https://lore.kernel.org/r/20230923024707.47610-1-gary@garyguo.net [ Reworded slightly and added a couple `Link`s. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-29Merge tag 'rust-6.6' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust updates from Miguel Ojeda: "In terms of lines, most changes this time are on the pinned-init API and infrastructure. While we have a Rust version upgrade, and thus a bunch of changes from the vendored 'alloc' crate as usual, this time those do not account for many lines. Toolchain and infrastructure: - Upgrade to Rust 1.71.1. This is the second such upgrade, which is a smaller jump compared to the last time. This version allows us to remove the '__rust_*' allocator functions -- the compiler now generates them as expected, thus now our 'KernelAllocator' is used. It also introduces the 'offset_of!' macro in the standard library (as an unstable feature) which we will need soon. So far, we were using a declarative macro as a prerequisite in some not-yet-landed patch series, which did not support sub-fields (i.e. nested structs): #[repr(C)] struct S { a: u16, b: (u8, u8), } assert_eq!(offset_of!(S, b.1), 3); - Upgrade to bindgen 0.65.1. This is the first time we upgrade its version. Given it is a fairly big jump, it comes with a fair number of improvements/changes that affect us, such as a fix needed to support LLVM 16 as well as proper support for '__noreturn' C functions, which are now mapped to return the '!' type in Rust: void __noreturn f(void); // C pub fn f() -> !; // Rust - 'scripts/rust_is_available.sh' improvements and fixes. This series takes care of all the issues known so far and adds a few new checks to cover for even more cases, plus adds some more help texts. All this together will hopefully make problematic setups easier to identify and to be solved by users building the kernel. In addition, it adds a test suite which covers all branches of the shell script, as well as tests for the issues found so far. - Support rust-analyzer for out-of-tree modules too. - Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates. - Drop 'scripts/is_rust_module.sh' since it is not needed anymore. Macros crate: - New 'paste!' proc macro. This macro is a more flexible version of 'concat_idents!': it allows the resulting identifier to be used to declare new items and it allows to transform the identifiers before concatenating them, e.g. let x_1 = 42; paste!(let [<x _2>] = [<x _1>];); assert!(x_1 == x_2); The macro is then used for several of the pinned-init API changes in this pull. Pinned-init API: - Make '#[pin_data]' compatible with conditional compilation of fields, allowing to write code like: #[pin_data] pub struct Foo { #[cfg(CONFIG_BAR)] a: Bar, #[cfg(not(CONFIG_BAR))] a: Baz, } - New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait, which allows 'unsafe' implementations for structs where every field implements the 'Zeroable' trait, e.g.: #[derive(Zeroable)] pub struct DriverData { id: i64, buf_ptr: *mut u8, len: usize, } - Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for zeroing all other fields, e.g.: pin_init!(Buf { buf: [1; 64], ..Zeroable::zeroed() }); - New '{,pin_}init_array_from_fn()' functions to create array initializers given a generator function, e.g.: let b: Box<[usize; 1_000]> = Box::init::<Error>( init_array_from_fn(|i| i) ).unwrap(); assert_eq!(b.len(), 1_000); assert_eq!(b[123], 123); - New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to execute a closure on the value directly after initialization, e.g.: let foo = init!(Foo { buf <- init::zeroed() }).chain(|foo| { foo.setup(); Ok(()) }); - Support arbitrary paths in init macros, instead of just identifiers and generic types. - Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and 'Opaque<T>' types. - Make initializer values inaccessible after initialization. - Make guards in the init macros hygienic. 'allocator' module: - Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing misaligned allocations when the Rust 1.71.1 upgrade is applied later in this pull. The equivalent fix for the previous compiler version (where 'KernelAllocator' is not yet used) was merged into 6.5 already, which added the 'krealloc_aligned()' function used here. - Implement 'KernelAllocator::{realloc, alloc_zeroed}' for performance, using 'krealloc_aligned()' too, which forwards the call to the C API. 'types' module: - Make 'Opaque' be '!Unpin', removing the need to add a 'PhantomPinned' field to Rust structs that contain C structs which must not be moved. - Make 'Opaque' use 'UnsafeCell' as the outer type, rather than inner. Documentation: - Suggest obtaining the source code of the Rust's 'core' library using the tarball instead of the repository. MAINTAINERS: - Andreas and Alice, from Samsung and Google respectively, are joining as reviewers of the "RUST" entry. As well as a few other minor changes and cleanups" * tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits) rust: init: update expanded macro explanation rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>` rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>` rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>` rust: init: add support for arbitrary paths in init macros rust: init: add functions to create array initializers rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields rust: init: make initializer values inaccessible after initializing rust: init: wrap type checking struct initializers in a closure rust: init: make guards in the init macros hygienic rust: add derive macro for `Zeroable` rust: init: make `#[pin_data]` compatible with conditional compilation of fields rust: init: consolidate init macros docs: rust: clarify what 'rustup override' does docs: rust: update instructions for obtaining 'core' source docs: rust: add command line to rust-analyzer section scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc` rust: bindgen: upgrade to 0.65.1 rust: enable `no_mangle_with_rust_abi` Clippy lint rust: upgrade to Rust 1.71.1 ...
2023-08-21rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`Benno Lossin
The `{pin_}chain` functions extend an initializer: it not only initializes the value, but also executes a closure taking a reference to the initialized value. This allows to do something with a value directly after initialization. Suggested-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230814084602.25699-13-benno.lossin@proton.me [ Cleaned a few trivial nits. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>`Benno Lossin
Remove the blanket implementation of `PinInit<T, E> for I where I: Init<T, E>`. This blanket implementation prevented custom types that implement `PinInit`. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-12-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`Benno Lossin
`UnsafeCell<T>` and `T` have the same layout so if `T` is `Zeroable` then so should `UnsafeCell<T>` be. This allows using the derive macro for `Zeroable` on types that contain an `UnsafeCell<T>`. Since `Opaque<T>` contains a `MaybeUninit<T>`, all bytes zero is a valid bit pattern for that type. Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-11-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21rust: init: add functions to create array initializersBenno Lossin
Add two functions `pin_init_array_from_fn` and `init_array_from_fn` that take a function that generates initializers for `T` from `usize`, the added functions then return an initializer for `[T; N]` where every element is initialized by an element returned from the generator function. Suggested-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-9-benno.lossin@proton.me [ Cleaned a couple trivial nits. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fieldsBenno Lossin
Add the struct update syntax to the init macros, but only for `..Zeroable::zeroed()`. Adding this at the end of the struct initializer allows one to omit fields from the initializer, these fields will be initialized with 0x00 set to every byte. Only types that implement the `Zeroable` trait can utilize this. Suggested-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-8-benno.lossin@proton.me [ Rebased on `rust-next` and cleaned a few trivial nits. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21rust: init: make guards in the init macros hygienicBenno Lossin
Use hygienic identifiers for the guards instead of the field names. This makes the init macros feel more like normal struct initializers, since assigning identifiers with the name of a field does not create conflicts. Also change the internals of the guards, no need to make the `forget` function `unsafe`, since users cannot access the guards anyways. Now the guards are carried directly on the stack and have no extra `Cell<bool>` field that marks if they have been forgotten or not, instead they are just forgotten via `mem::forget`. Suggested-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-5-benno.lossin@proton.me [ Cleaned a few trivial nits. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21rust: init: consolidate init macrosBenno Lossin
Merges the implementations of `try_init!` and `try_pin_init!`. These two macros are very similar, but use different traits. The new macro `__init_internal!` that is now the implementation for both takes these traits as parameters. This change does not affect any users, as no public API has been changed, but it should simplify maintaining the init macros. Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-2-benno.lossin@proton.me [ Cleaned a couple trivial nits. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-07-18rust: init: make doctests compilable/testableMiguel Ojeda
Rust documentation tests are going to be build/run-tested with the KUnit integration added in a future patch, thus update them to make them compilable/testable so that we may start enforcing it. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: David Gow <davidgow@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-05-31rust: upgrade to Rust 1.68.2Miguel Ojeda
This is the first upgrade to the Rust toolchain since the initial Rust merge, from 1.62.0 to 1.68.2 (i.e. the latest). # Context The kernel currently supports only a single Rust version [1] (rather than a minimum) given our usage of some "unstable" Rust features [2] which do not promise backwards compatibility. The goal is to reach a point where we can declare a minimum version for the toolchain. For instance, by waiting for some of the features to be stabilized. Therefore, the first minimum Rust version that the kernel will support is "in the future". # Upgrade policy Given we will eventually need to reach that minimum version, it would be ideal to upgrade the compiler from time to time to be as close as possible to that goal and find any issues sooner. In the extreme, we could upgrade as soon as a new Rust release is out. Of course, upgrading so often is in stark contrast to what one normally would need for GCC and LLVM, especially given the release schedule: 6 weeks for Rust vs. half a year for LLVM and a year for GCC. Having said that, there is no particular advantage to updating slowly either: kernel developers in "stable" distributions are unlikely to be able to use their distribution-provided Rust toolchain for the kernel anyway [3]. Instead, by routinely upgrading to the latest instead, kernel developers using Linux distributions that track the latest Rust release may be able to use those rather than Rust-provided ones, especially if their package manager allows to pin / hold back / downgrade the version for some days during windows where the version may not match. For instance, Arch, Fedora, Gentoo and openSUSE all provide and track the latest version of Rust as they get released every 6 weeks. Then, when the minimum version is reached, we will stop upgrading and decide how wide the window of support will be. For instance, a year of Rust versions. We will probably want to start small, and then widen it over time, just like the kernel did originally for LLVM, see commit 3519c4d6e08e ("Documentation: add minimum clang/llvm version"). # Unstable features stabilized This upgrade allows us to remove the following unstable features since they were stabilized: - `feature(explicit_generic_args_with_impl_trait)` (1.63). - `feature(core_ffi_c)` (1.64). - `feature(generic_associated_types)` (1.65). - `feature(const_ptr_offset_from)` (1.65, *). - `feature(bench_black_box)` (1.66, *). - `feature(pin_macro)` (1.68). The ones marked with `*` apply only to our old `rust` branch, not mainline yet, i.e. only for code that we may potentially upstream. With this patch applied, the only unstable feature allowed to be used outside the `kernel` crate is `new_uninit`, though other code to be upstreamed may increase the list. Please see [2] for details. # Other required changes Since 1.63, `rustdoc` triggers the `broken_intra_doc_links` lint for links pointing to exported (`#[macro_export]`) `macro_rules`. An issue was opened upstream [4], but it turns out it is intended behavior. For the moment, just add an explicit reference for each link. Later we can revisit this if `rustdoc` removes the compatibility measure. Nevertheless, this was helpful to discover a link that was pointing to the wrong place unintentionally. Since that one was actually wrong, it is fixed in a previous commit independently. Another change was the addition of `cfg(no_rc)` and `cfg(no_sync)` in upstream [5], thus remove our original changes for that. Similarly, upstream now tests that it compiles successfully with `#[cfg(not(no_global_oom_handling))]` [6], which allow us to get rid of some changes, such as an `#[allow(dead_code)]`. In addition, remove another `#[allow(dead_code)]` due to new uses within the standard library. Finally, add `try_extend_trusted` and move the code in `spec_extend.rs` since upstream moved it for the infallible version. # `alloc` upgrade and reviewing There are a large amount of changes, but the vast majority of them are due to our `alloc` fork being upgraded at once. There are two kinds of changes to be aware of: the ones coming from upstream, which we should follow as closely as possible, and the updates needed in our added fallible APIs to keep them matching the newer infallible APIs coming from upstream. Instead of taking a look at the diff of this patch, an alternative approach is reviewing a diff of the changes between upstream `alloc` and the kernel's. This allows to easily inspect the kernel additions only, especially to check if the fallible methods we already have still match the infallible ones in the new version coming from upstream. Another approach is reviewing the changes introduced in the additions in the kernel fork between the two versions. This is useful to spot potentially unintended changes to our additions. To apply these approaches, one may follow steps similar to the following to generate a pair of patches that show the differences between upstream Rust and the kernel (for the subset of `alloc` we use) before and after applying this patch: # Get the difference with respect to the old version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > old.patch git -C linux restore rust/alloc # Apply this patch. git -C linux am rust-upgrade.patch # Get the difference with respect to the new version. git -C rust checkout $(linux/scripts/min-tool-version.sh rustc) git -C linux ls-tree -r --name-only HEAD -- rust/alloc | cut -d/ -f3- | grep -Fv README.md | xargs -IPATH cp rust/library/alloc/src/PATH linux/rust/alloc/PATH git -C linux diff --patch-with-stat --summary -R > new.patch git -C linux restore rust/alloc Now one may check the `new.patch` to take a look at the additions (first approach) or at the difference between those two patches (second approach). For the latter, a side-by-side tool is recommended. Link: https://rust-for-linux.com/rust-version-policy [1] Link: https://github.com/Rust-for-Linux/linux/issues/2 [2] Link: https://lore.kernel.org/rust-for-linux/CANiq72mT3bVDKdHgaea-6WiZazd8Mvurqmqegbe5JZxVyLR8Yg@mail.gmail.com/ [3] Link: https://github.com/rust-lang/rust/issues/106142 [4] Link: https://github.com/rust-lang/rust/pull/89891 [5] Link: https://github.com/rust-lang/rust/pull/98652 [6] Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-By: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Tested-by: Ariel Miculas <amiculas@cisco.com> Tested-by: David Gow <davidgow@google.com> Tested-by: Boqun Feng <boqun.feng@gmail.com> Link: https://lore.kernel.org/r/20230418214347.324156-4-ojeda@kernel.org [ Removed `feature(core_ffi_c)` from `uapi` ] 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>
2023-04-12rust: 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: 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>