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2023-08-21rust: add derive macro for `Zeroable`Benno Lossin
Add a derive proc-macro for the `Zeroable` trait. The macro supports structs where every field implements the `Zeroable` trait. This way `unsafe` implementations can be avoided. The macro is split into two parts: - a proc-macro to parse generics into impl and ty generics, - a declarative macro that expands to the impl block. Suggested-by: Asahi Lina <lina@asahilina.net> 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/20230814084602.25699-4-benno.lossin@proton.me [ Added `ignore` to the `lib.rs` example and cleaned trivial nit. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-21rust: init: make `#[pin_data]` compatible with conditional compilation of fieldsBenno Lossin
This patch allows one to write ``` #[pin_data] pub struct Foo { #[cfg(CONFIG_BAR)] a: Bar, #[cfg(not(CONFIG_BAR))] a: Baz, } ``` Before, this would result in a compile error, because `#[pin_data]` would generate two functions named `a` for both fields unconditionally. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230814084602.25699-3-benno.lossin@proton.me 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>
2023-08-20scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc`Martin Rodriguez Reboredo
Both `core` and `alloc` have their `cfgs` (such as `no_rc`) missing in `rust-project.json`. To remedy this, pass the flags to `generate_rust_analyzer.py` for them to be added to a dictionary where each key corresponds to a crate and each value to a list of `cfg`s. The dictionary is then used to pass the `cfg`s to each crate in the generated file (for `core` and `alloc` only). Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230804171448.54976-1-yakoyoku@gmail.com [ Removed `Suggested-by` as discussed in mailing list. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-15rust: bindgen: upgrade to 0.65.1Aakash Sen Sharma
In LLVM 16, anonymous items may return names like `(unnamed union at ..)` rather than empty names [1], which breaks Rust-enabled builds because bindgen assumed an empty name instead of detecting them via `clang_Cursor_isAnonymous` [2]: $ make rustdoc LLVM=1 CLIPPY=1 -j$(nproc) RUSTC L rust/core.o BINDGEN rust/bindings/bindings_generated.rs BINDGEN rust/bindings/bindings_helpers_generated.rs BINDGEN rust/uapi/uapi_generated.rs thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... thread 'main' panicked at '"ftrace_branch_data_union_(anonymous_at__/_/include/linux/compiler_types_h_146_2)" is not a valid Ident', .../proc-macro2-1.0.24/src/fallback.rs:693:9 ... This was fixed in bindgen 0.62.0. Therefore, upgrade bindgen to a more recent version, 0.65.1, to support LLVM 16. Since bindgen 0.58.0 changed the `--{white,black}list-*` flags to `--{allow,block}list-*` [3], update them on our side too. In addition, bindgen 0.61.0 moved its CLI utility into a binary crate called `bindgen-cli` [4]. Thus update the installation command in the Quick Start guide. Moreover, bindgen 0.61.0 changed the default functionality to bind `size_t` to `usize` [5] and added the `--no-size_t-is-usize` flag to not bind `size_t` as `usize`. Then bindgen 0.65.0 removed the `--size_t-is-usize` flag [6]. Thus stop passing the flag to bindgen. Finally, bindgen 0.61.0 added support for the `noreturn` attribute (in its different forms) [7]. Thus remove the infinite loop in our Rust panic handler after calling `BUG()`, since bindgen now correctly generates a `BUG()` binding that returns `!` instead of `()`. Link: https://github.com/llvm/llvm-project/commit/19e984ef8f49bc3ccced15621989fa9703b2cd5b [1] Link: https://github.com/rust-lang/rust-bindgen/pull/2319 [2] Link: https://github.com/rust-lang/rust-bindgen/pull/1990 [3] Link: https://github.com/rust-lang/rust-bindgen/pull/2284 [4] Link: https://github.com/rust-lang/rust-bindgen/commit/cc78b6fdb6e829e5fb8fa1639f2182cb49333569 [5] Link: https://github.com/rust-lang/rust-bindgen/pull/2408 [6] Link: https://github.com/rust-lang/rust-bindgen/issues/2094 [7] Signed-off-by: Aakash Sen Sharma <aakashsensharma@gmail.com> Closes: https://github.com/Rust-for-Linux/linux/issues/1013 Tested-by: Ariel Miculas <amiculas@cisco.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230612194311.24826-1-aakashsensharma@gmail.com [ Reworded commit message. Mentioned the `bindgen-cli` binary crate change, linked to it and updated the Quick Start guide. Re-added a deleted "as" word in a code comment and reflowed comment to respect the maximum length. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-14rust: upgrade to Rust 1.71.1Miguel Ojeda
This is the second upgrade to the Rust toolchain, from 1.68.2 to 1.71.1 (i.e. the latest). See the upgrade policy [1] and the comments on the first upgrade in commit 3ed03f4da06e ("rust: upgrade to Rust 1.68.2"). # Unstable features No unstable features (that we use) were stabilized. Therefore, the only unstable feature allowed to be used outside the `kernel` crate is still `new_uninit`, though other code to be upstreamed may increase the list. Please see [2] for details. # Required changes For the upgrade, this patch requires the following changes: - Removal of the `__rust_*` allocator functions, together with the addition of the `__rust_no_alloc_shim_is_unstable` static. See [3] for details. - Some more compiler builtins added due to `<f{32,64}>::midpoint()` that got added in Rust 1.71 [4]. # `alloc` upgrade and reviewing The vast majority of changes 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://github.com/rust-lang/rust/pull/86844 [3] Link: https://github.com/rust-lang/rust/pull/92048 [4] Closes: https://github.com/Rust-for-Linux/linux/issues/68 Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Trevor Gross <tmgross@umich.edu> Link: https://lore.kernel.org/r/20230729220317.416771-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-10btf, scripts: rust: drop is_rust_module.shAndrea Righi
With commit c1177979af9c ("btf, scripts: Exclude Rust CUs with pahole") we are now able to use pahole directly to identify Rust compilation units (CUs) and exclude them from generating BTF debugging information (when DEBUG_INFO_BTF is enabled). And if pahole doesn't support the --lang-exclude flag, we can't enable both RUST and DEBUG_INFO_BTF at the same time. So, in any case, the script is_rust_module.sh is just redundant and we can drop it. NOTE: we may also be able to drop the "Rust loadable module" mark inside Rust modules, but it seems safer to keep it for now to make sure we are not breaking any external tool that may potentially rely on it. Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Tested-by: Eric Curtin <ecurtin@redhat.com> Reviewed-by: Eric Curtin <ecurtin@redhat.com> Reviewed-by: Neal Gompa <neal@gompa.dev> Reviewed-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Acked-by: Daniel Xu <dxu@dxuuu.xyz> Link: https://lore.kernel.org/r/20230704052136.155445-1-andrea.righi@canonical.com [ Picked the `Reviewed-by`s from the old patch too. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-10rust: macros: add `paste!` proc macroGary Guo
This macro provides a flexible way to concatenated identifiers together and it allows the resulting identifier to be used to declare new items, which `concat_idents!` does not allow. It also allows identifiers to be transformed before concatenated. The `concat_idents!` example let x_1 = 42; let x_2 = concat_idents!(x, _1); assert!(x_1 == x_2); can be written with `paste!` macro like this: let x_1 = 42; let x_2 = paste!([<x _1>]); assert!(x_1 == x_2); However `paste!` macro is more flexible because it can be used to create a new variable: let x_1 = 42; paste!(let [<x _2>] = [<x _1>];); assert!(x_1 == x_2); While this is not possible with `concat_idents!`. This macro is similar to the `paste!` crate [1], but this is a fresh implementation to avoid vendoring large amount of code directly. Also, I have augmented it to provide a way to specify span of the resulting token, allowing precise control. For example, this code is broken because the variable is declared inside the macro, so Rust macro hygiene rules prevents access from the outside: macro_rules! m { ($id: ident) => { // The resulting token has hygiene of the macro. paste!(let [<$id>] = 1;) } } m!(a); let _ = a; In this version of `paste!` macro I added a `span` modifier to allow this: macro_rules! m { ($id: ident) => { // The resulting token has hygiene of `$id`. paste!(let [<$id:span>] = 1;) } } m!(a); let _ = a; Link: http://docs.rs/paste/ [1] Signed-off-by: Gary Guo <gary@garyguo.net> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230628171108.1150742-1-gary@garyguo.net [ Added SPDX license identifier as discussed in the list and fixed typo. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-10rust: types: make `Opaque` be `!Unpin`Benno Lossin
Adds a `PhantomPinned` field to `Opaque<T>`. This removes the last Rust guarantee: the assumption that the type `T` can be freely moved. This is not the case for many types from the C side (e.g. if they contain a `struct list_head`). This change removes the need to add a `PhantomPinned` field manually to Rust structs that contain C structs which must not be moved. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230630150216.109789-1-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-10rust: make `UnsafeCell` the outer type in `Opaque`Alice Ryhl
When combining `UnsafeCell` with `MaybeUninit`, it is idiomatic to use `UnsafeCell` as the outer type. Intuitively, this is because a `MaybeUninit<T>` might not contain a `T`, but we always want the effect of the `UnsafeCell`, even if the inner value is uninitialized. Now, strictly speaking, this doesn't really make a difference. The compiler will always apply the `UnsafeCell` effect even if the inner value is uninitialized. But I think we should follow the convention here. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-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/20230614115328.2825961-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-09rust: macros: vtable: fix `HAS_*` redefinition (`gen_const_name`)Qingsong Chen
If we define the same function name twice in a trait (using `#[cfg]`), the `vtable` macro will redefine its `gen_const_name`, e.g. this will define `HAS_BAR` twice: #[vtable] pub trait Foo { #[cfg(CONFIG_X)] fn bar(); #[cfg(not(CONFIG_X))] fn bar(x: usize); } Fixes: b44becc5ee80 ("rust: macros: add `#[vtable]` proc macro") Signed-off-by: Qingsong Chen <changxian.cqs@antgroup.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Sergio González Collado <sergio.collado@gmail.com> Link: https://lore.kernel.org/r/20230808025404.2053471-1-changxian.cqs@antgroup.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07scripts: `make rust-analyzer` for out-of-tree modulesVinay Varma
Adds support for out-of-tree rust modules to use the `rust-analyzer` make target to generate the rust-project.json file. The change involves adding an optional parameter `external_src` to the `generate_rust_analyzer.py` which expects the path to the out-of-tree module's source directory. When this parameter is passed, I have chosen not to add the non-core modules (samples and drivers) into the result since these are not expected to be used in third party modules. Related changes are also made to the Makefile and rust/Makefile allowing the `rust-analyzer` target to be used for out-of-tree modules as well. Link: https://github.com/Rust-for-Linux/linux/pull/914 Link: https://github.com/Rust-for-Linux/rust-out-of-tree-module/pull/2 Signed-off-by: Vinay Varma <varmavinaym@gmail.com> Link: https://lore.kernel.org/r/20230411091714.130525-1-varmavinaym@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07rust: alloc: Add realloc and alloc_zeroed to the GlobalAlloc implBjörn Roy Baron
While there are default impls for these methods, using the respective C api's is faster. Currently neither the existing nor these new GlobalAlloc method implementations are actually called. Instead the __rust_* function defined below the GlobalAlloc impl are used. With rustc 1.71 these functions will be gone and all allocation calls will go through the GlobalAlloc implementation. Link: https://github.com/Rust-for-Linux/linux/issues/68 Signed-off-by: Björn Roy Baron <bjorn3_gh@protonmail.com> [boqun: add size adjustment for alignment requirement] Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230730012905.643822-4-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07rust: allocator: Use krealloc_aligned() in KernelAllocator::allocBoqun Feng
This fixes the potential issue that when KernelAllocator is used, the allocation may be mis-aligned due to SLAB's alignment guarantee. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230730012905.643822-3-boqun.feng@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07rust: helpers: sort includes alphabetically in rust/helpers.cAriel Miculas
Sort the #include directives of rust/helpers.c alphabetically and add a comment specifying this. The reason for this is to improve readability and to be consistent with the other files with a similar approach within 'rust/'. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Link: https://github.com/Rust-for-Linux/linux/issues/1003 Signed-off-by: Ariel Miculas <amiculas@cisco.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230426204923.16195-1-amiculas@cisco.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-07rust: lock: Add intra-doc links to the Backend traitBen Gooding
Add missing intra-doc links to the Backend trait to make navigating the documentation easier. Suggested-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/rust-for-linux/94625fe6-b87a-a8f0-5b2a-a8152d5f7436@proton.me/ Link: https://github.com/Rust-for-Linux/linux/issues/1001 Signed-off-by: Ben Gooding <ben.gooding.dev@gmail.com> Link: https://lore.kernel.org/r/20230509202314.8248-1-ben.gooding.dev@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-04rust: fix bindgen build error with UBSAN_BOUNDS_STRICTAndrea Righi
With commit 2d47c6956ab3 ("ubsan: Tighten UBSAN_BOUNDS on GCC") if CONFIG_UBSAN is enabled and gcc supports -fsanitize=bounds-strict, we can trigger the following build error due to bindgen lacking support for this additional build option: BINDGEN rust/bindings/bindings_generated.rs error: unsupported argument 'bounds-strict' to option '-fsanitize=' Fix by adding -fsanitize=bounds-strict to the list of skipped gcc flags for bindgen. Fixes: 2d47c6956ab3 ("ubsan: Tighten UBSAN_BOUNDS on GCC") Signed-off-by: Andrea Righi <andrea.righi@canonical.com> Acked-by: Kees Cook <keescook@chromium.org> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230711071914.133946-1-andrea.righi@canonical.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-04rust: delete `ForeignOwnable::borrow_mut`Alice Ryhl
We discovered that the current design of `borrow_mut` is problematic. This patch removes it until a better solution can be found. Specifically, the current design gives you access to a `&mut T`, which lets you change where the `ForeignOwnable` points (e.g., with `core::mem::swap`). No upcoming user of this API intended to make that possible, making all of them unsound. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Fixes: 0fc4424d24a2 ("rust: types: introduce `ForeignOwnable`") Link: https://lore.kernel.org/r/20230706094615.3080784-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-08-04rust: allocator: Prevent mis-aligned allocationBoqun Feng
Currently the rust allocator simply passes the size of the type Layout to krealloc(), and in theory the alignment requirement from the type Layout may be larger than the guarantee provided by SLAB, which means the allocated object is mis-aligned. Fix this by adjusting the allocation size to the nearest power of two, which SLAB always guarantees a size-aligned allocation. And because Rust guarantees that the original size must be a multiple of alignment and the alignment must be a power of two, then the alignment requirement is satisfied. Suggested-by: Vlastimil Babka <vbabka@suse.cz> Co-developed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk> Signed-off-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Cc: stable@vger.kernel.org # v6.1+ Acked-by: Vlastimil Babka <vbabka@suse.cz> Fixes: 247b365dc8dc ("rust: add `kernel` crate") Link: https://github.com/Rust-for-Linux/linux/issues/974 Link: https://lore.kernel.org/r/20230730012905.643822-2-boqun.feng@gmail.com [ Applied rewording of comment as discussed in the mailing list. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-07-21docs: Move rustdoc output, cross-reference itCarlos Bilbao
Generate rustdoc documentation with the rest of subsystem's documentation in Documentation/output. Add a cross reference to the generated rustdoc in Documentation/rust/index.rst if Sphinx target rustdoc is set. Reviewed-by: Akira Yokosawa <akiyks@gmail.com> Signed-off-by: Carlos Bilbao <carlos.bilbao@amd.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20230718151534.4067460-2-carlos.bilbao@amd.com
2023-07-19rust: support running Rust documentation tests as KUnit onesMiguel Ojeda
Rust has documentation tests: these are typically examples of usage of any item (e.g. function, struct, module...). They are very convenient because they are just written alongside the documentation. For instance: /// Sums two numbers. /// /// ``` /// assert_eq!(mymod::f(10, 20), 30); /// ``` pub fn f(a: i32, b: i32) -> i32 { a + b } In userspace, the tests are collected and run via `rustdoc`. Using the tool as-is would be useful already, since it allows to compile-test most tests (thus enforcing they are kept in sync with the code they document) and run those that do not depend on in-kernel APIs. However, by transforming the tests into a KUnit test suite, they can also be run inside the kernel. Moreover, the tests get to be compiled as other Rust kernel objects instead of targeting userspace. On top of that, the integration with KUnit means the Rust support gets to reuse the existing testing facilities. For instance, the kernel log would look like: KTAP version 1 1..1 KTAP version 1 # Subtest: rust_doctests_kernel 1..59 # rust_doctest_kernel_build_assert_rs_0.location: rust/kernel/build_assert.rs:13 ok 1 rust_doctest_kernel_build_assert_rs_0 # rust_doctest_kernel_build_assert_rs_1.location: rust/kernel/build_assert.rs:56 ok 2 rust_doctest_kernel_build_assert_rs_1 # rust_doctest_kernel_init_rs_0.location: rust/kernel/init.rs:122 ok 3 rust_doctest_kernel_init_rs_0 ... # rust_doctest_kernel_types_rs_2.location: rust/kernel/types.rs:150 ok 59 rust_doctest_kernel_types_rs_2 # rust_doctests_kernel: pass:59 fail:0 skip:0 total:59 # Totals: pass:59 fail:0 skip:0 total:59 ok 1 rust_doctests_kernel Therefore, add support for running Rust documentation tests in KUnit. Some other notes about the current implementation and support follow. The transformation is performed by a couple scripts written as Rust hostprogs. Tests using the `?` operator are also supported as usual, e.g.: /// ``` /// # use kernel::{spawn_work_item, workqueue}; /// spawn_work_item!(workqueue::system(), || pr_info!("x"))?; /// # Ok::<(), Error>(()) /// ``` The tests are also compiled with Clippy under `CLIPPY=1`, just like normal code, thus also benefitting from extra linting. The names of the tests are currently automatically generated. This allows to reduce the burden for documentation writers, while keeping them fairly stable for bisection. This is an improvement over the `rustdoc`-generated names, which include the line number; but ideally we would like to get `rustdoc` to provide the Rust item path and a number (for multiple examples in a single documented Rust item). In order for developers to easily see from which original line a failed doctests came from, a KTAP diagnostic line is printed to the log, containing the location (file and line) of the original test (i.e. instead of the location in the generated Rust file): # rust_doctest_kernel_types_rs_2.location: rust/kernel/types.rs:150 This line follows the syntax for declaring test metadata in the proposed KTAP v2 spec [1], which may be used for the proposed KUnit test attributes API [2]. Thus hopefully this will make migration easier later on (suggested by David [3]). The original line in that test attribute is figured out by providing an anchor (suggested by Boqun [4]). The original file is found by walking the filesystem, checking directory prefixes to reduce the amount of combinations to check, and it is only done once per file. Ambiguities are detected and reported. A notable difference from KUnit C tests is that the Rust tests appear to assert using the usual `assert!` and `assert_eq!` macros from the Rust standard library (`core`). We provide a custom version that forwards the call to KUnit instead. Importantly, these macros do not require passing context, unlike the KUnit C ones (i.e. `struct kunit *`). This makes them easier to use, and readers of the documentation do not need to care about which testing framework is used. In addition, it may allow us to test third-party code more easily in the future. However, a current limitation is that KUnit does not support assertions in other tasks. Thus we presently simply print an error to the kernel log if an assertion actually failed. This should be revisited to properly fail the test, perhaps saving the context somewhere else, or letting KUnit handle it. Link: https://lore.kernel.org/lkml/20230420205734.1288498-1-rmoar@google.com/ [1] Link: https://lore.kernel.org/linux-kselftest/20230707210947.1208717-1-rmoar@google.com/ [2] Link: https://lore.kernel.org/rust-for-linux/CABVgOSkOLO-8v6kdAGpmYnZUb+LKOX0CtYCo-Bge7r_2YTuXDQ@mail.gmail.com/ [3] Link: https://lore.kernel.org/rust-for-linux/ZIps86MbJF%2FiGIzd@boqun-archlinux/ [4] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-07-19rust: types: 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: David Gow <davidgow@google.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-07-19rust: sync: 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: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2023-07-19rust: str: 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: Björn Roy Baron <bjorn3_gh@protonmail.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> Reviewed-by: David Gow <davidgow@google.com> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Shuah Khan <skhan@linuxfoundation.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>
2023-06-13rust: error: `impl Debug` for `Error` with `errname()` integrationGary Guo
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: task: add `Send` marker to `Task`Alice Ryhl
When a type also implements `Sync`, the meaning of `Send` is just "this type may be accessed mutably from threads other than the one it is created on". That's ok for this type. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230531145939.3714886-5-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: specify when `ARef` is thread safeAlice Ryhl
An `ARef` behaves just like the `Arc` when it comes to thread safety, so we can reuse the thread safety comments from `Arc` here. This is necessary because without this change, the Rust compiler will assume that things are not thread safe even though they are. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230531145939.3714886-4-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: sync: reword the `Arc` safety comment for `Sync`Alice Ryhl
The safety comment on `impl Sync for Arc` references the Send safety comment. This commit avoids that in case the two comments drift apart in the future. Suggested-by: Andreas Hindborg <a.hindborg@samsung.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230531145939.3714886-3-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: sync: reword the `Arc` safety comment for `Send`Alice Ryhl
The safety comment on `impl Send for Arc` talks about "directly" accessing the value, when it really means "accessing the value with a mutable reference". This commit clarifies that. Suggested-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230531145939.3714886-2-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: sync: implement `AsRef<T>` for `Arc<T>`Alice Ryhl
This trait lets you use `Arc<T>` in code that is generic over smart pointer types. The `AsRef` trait should be implemented on all smart pointers. The standard library also implements it on the ordinary `Arc`. Co-developed-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230517200814.3157916-2-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: sync: add `Arc::ptr_eq`Alice Ryhl
Add a method for comparing whether two `Arc` pointers reference the same underlying object. This comparison can already be done by getting a reference to the inner values and comparing whether the references have the same address. However, writing `Arc::ptr_eq(a, b)` is generally less error-prone than doing the same check on the references, since you might otherwise accidentally compare the two `&Arc<T>` references instead, which wont work because those are pointers to pointers to the inner value, when you just want to compare the pointers to the inner value. Also, this method might optimize better because getting a reference to the inner value involves offsetting the pointer, which this method does not need to do. Co-developed-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230517200814.3157916-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: error: add missing error codesAlice Ryhl
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: str: add conversion from `CStr` to `CString`Alice Ryhl
These methods can be used to copy the data in a temporary c string into a separate allocation, so that it can be accessed later even if the original is deallocated. The API in this change mirrors the standard library API for the `&str` and `String` types. The `ToOwned` trait is not implemented because it assumes that allocations are infallible. Reviewed-by: Benno Lossin <benno.lossin@proton.me> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com> Link: https://lore.kernel.org/r/20230503141016.683634-1-aliceryhl@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: error: allow specifying error type on `Result`Alice Ryhl
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>
2023-05-31rust: init: update macro expansion example in docsBenno Lossin
Also improve the explaining comments. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230424081112.99890-4-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: macros: replace Self with the concrete type in #[pin_data]Benno Lossin
When using `#[pin_data]` on a struct that used `Self` in the field types, a type error would be emitted when trying to use `pin_init!`. Since an internal type would be referenced by `Self` instead of the defined struct. This patch fixes this issue by replacing all occurrences of `Self` in the `#[pin_data]` macro with the concrete type circumventing the issue. Since rust allows type definitions inside of blocks, which are expressions, the macro also checks for these and emits a compile error when it finds `trait`, `enum`, `union`, `struct` or `impl`. These keywords allow creating new `Self` contexts, which conflicts with the current implementation of replacing every `Self` ident. If these were allowed, some `Self` idents would be replaced incorrectly. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reported-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230424081112.99890-3-benno.lossin@proton.me [ Added newline in commit message ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: macros: refactor generics parsing of `#[pin_data]` into its own functionBenno Lossin
Other macros might also want to parse generics. Additionally this makes the code easier to read, as the next commit will introduce more code in `#[pin_data]`. Also add more comments to explain how parsing generics work. 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: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Link: https://lore.kernel.org/r/20230424081112.99890-2-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: macros: fix usage of `#[allow]` in `quote!`Benno Lossin
When using `quote!` as part of an expression that was not the last one in a function, the `#[allow(clippy::vec_init_then_push)]` attribute would be present on an expression, which is not allowed. This patch refactors that part of the macro to use a statement instead. Signed-off-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://lore.kernel.org/r/20230424081112.99890-1-benno.lossin@proton.me Signed-off-by: Miguel Ojeda <ojeda@kernel.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>
2023-05-31rust: arc: fix intra-doc link in `Arc<T>::init`Miguel Ojeda
`Arc<T>::init` refers to `Arc<T>::pin_init` via an intra-doc link using the text `pin_init`, rather than more explicitly, which makes `rustdoc` point it to the `pin_init!` macro instead. This is required for the compiler upgrade since the newer `rustdoc` would trigger the `broken_intra_doc_links` lint [1], but in this case the macro was not the intended target to begin with, and so the actual fix is to make it point to the right place, regardless of the upgrade. Thus make it more explicit. Fixes: 92c4a1e7e81c ("rust: init/sync: add `InPlaceInit` trait to pin-initialize smart pointers") Link: https://github.com/rust-lang/rust/issues/106142 [1] Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.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/20230418214347.324156-3-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-05-31rust: alloc: clarify what is the upstream versionMiguel Ojeda
It may be unclear for readers which upstream Rust version these files are based on. They may be unaware that they are intended to match the minimum (and only, so far) supported version of Rust in the kernel. Thus clarify it. Reviewed-by: Benno Lossin <benno.lossin@proton.me> 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/20230418214347.324156-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-30Merge tag 'rust-6.4' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust updates from Miguel Ojeda "More additions to the Rust core. Importantly, this adds the pin-init API, which will be used by other abstractions, such as the synchronization ones added here too: - pin-init API: a solution for the safe pinned initialization problem. This allows to reduce the need for 'unsafe' code in the kernel when dealing with data structures that require a stable address. Commit 90e53c5e70a6 ("rust: add pin-init API core") contains a nice introduction -- here is an example of how it looks like: #[pin_data] struct Example { #[pin] value: Mutex<u32>, #[pin] value_changed: CondVar, } impl Example { fn new() -> impl PinInit<Self> { pin_init!(Self { value <- new_mutex!(0), value_changed <- new_condvar!(), }) } } // In a `Box`. let b = Box::pin_init(Example::new())?; // In the stack. stack_pin_init!(let s = Example::new()); - 'sync' module: New types 'LockClassKey' ('struct lock_class_key'), 'Lock', 'Guard', 'Mutex' ('struct mutex'), 'SpinLock' ('spinlock_t'), 'LockedBy' and 'CondVar' (uses 'wait_queue_head_t'), plus macros such as 'static_lock_class!' and 'new_spinlock!'. In particular, 'Lock' and 'Guard' are generic implementations that contain code that is common to all locks. Then, different backends (the new 'Backend' trait) are implemented and used to define types like 'Mutex': type Mutex<T> = Lock<T, MutexBackend>; In addition, new methods 'assume_init()', 'init_with()' and 'pin_init_with()' for 'UniqueArc<MaybeUninit<T>>' and 'downcast()' for 'Arc<dyn Any + Send + Sync>'; as well as 'Debug' and 'Display' implementations for 'Arc' and 'UniqueArc'. Reduced stack usage of 'UniqueArc::try_new_uninit()', too. - 'types' module: New trait 'AlwaysRefCounted' and new type 'ARef' (an owned reference to an always-reference-counted object, meant to be used in wrappers for C types that have their own ref counting functions). Moreover, new associated functions 'raw_get()' and 'ffi_init()' for 'Opaque'. - New 'task' module with a new type 'Task' ('struct task_struct'), and a new macro 'current!' to safely get a reference to the current one. - New 'ioctl' module with new '_IOC*' const functions (equivalent to the C macros). - New 'uapi' crate, intended to be accessible by drivers directly. - 'macros' crate: new 'quote!' macro (similar to the one provided in userspace by the 'quote' crate); and the 'module!' macro now allows specifying multiple module aliases. - 'error' module: New associated functions for the 'Error' type, such as 'from_errno()' and new functions such as 'to_result()'. - 'alloc' crate: More fallible 'Vec' methods: 'try_resize` and 'try_extend_from_slice' and the infrastructure (imported from the Rust standard library) they need" * tag 'rust-6.4' of https://github.com/Rust-for-Linux/linux: (44 commits) rust: ioctl: Add ioctl number manipulation functions rust: uapi: Add UAPI crate rust: sync: introduce `CondVar` rust: lock: add `Guard::do_unlocked` rust: sync: introduce `LockedBy` rust: introduce `current` rust: add basic `Task` rust: introduce `ARef` rust: lock: introduce `SpinLock` rust: lock: introduce `Mutex` rust: sync: introduce `Lock` and `Guard` rust: sync: introduce `LockClassKey` MAINTAINERS: add Benno Lossin as Rust reviewer rust: init: broaden the blanket impl of `Init` rust: sync: add functions for initializing `UniqueArc<MaybeUninit<T>>` rust: sync: reduce stack usage of `UniqueArc::try_new_uninit` rust: types: add `Opaque::ffi_init` rust: prelude: add `pin-init` API items to prelude rust: init: add `Zeroable` trait and `init::zeroed` function rust: init: add `stack_pin_init!` macro ...
2023-04-22rust: ioctl: Add ioctl number manipulation functionsAsahi Lina
Add simple 1:1 wrappers of the C ioctl number manipulation functions. Since these are macros we cannot bindgen them directly, and since they should be usable in const context we cannot use helper wrappers, so we'll have to reimplement them in Rust. Thankfully, the C headers do declare defines for the relevant bitfield positions, so we don't need to duplicate that. Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230329-rust-uapi-v2-2-bca5fb4d4a12@asahilina.net [ Moved the `#![allow(non_snake_case)]` to the usual place. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: uapi: Add UAPI crateAsahi Lina
This crate mirrors the `bindings` crate, but will contain only UAPI bindings. Unlike the bindings crate, drivers may directly use this crate if they have to interface with userspace. Initially, just bind the generic ioctl stuff. In the future, we would also like to add additional checks to ensure that all types exposed by this crate satisfy UAPI-safety guarantees (that is, they are safely castable to/from a "bag of bits"). [ Miguel: added support for the `rustdoc` and `rusttest` targets, since otherwise they fail, and we want to keep them working. ] Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Asahi Lina <lina@asahilina.net> Link: https://lore.kernel.org/r/20230329-rust-uapi-v2-1-bca5fb4d4a12@asahilina.net Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `CondVar`Wedson Almeida Filho
This is the traditional condition variable or monitor synchronisation primitive. It is implemented with C's `wait_queue_head_t`. It allows users to release a lock and go to sleep while guaranteeing that notifications won't be missed. This is achieved by enqueuing a wait entry before releasing the lock. Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Will Deacon <will@kernel.org> Cc: Waiman Long <longman@redhat.com> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20230411054543.21278-12-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: lock: add `Guard::do_unlocked`Wedson Almeida Filho
It releases the lock, executes some function provided by the caller, then reacquires the lock. This is preparation for the implementation of condvars, which will sleep after between unlocking and relocking. We need an explicit `relock` method for primitives like `SpinLock` that have an irqsave variant: we use the guard state to determine if the lock was originally acquired with the regular `lock` function or `lock_irqsave`. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/rust-for-linux/20230412121431.41627-1-wedsonaf@gmail.com/ [ Removed the irqsave bits as discussed. ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: sync: introduce `LockedBy`Wedson Almeida Filho
This allows us to have data protected by a lock despite not being wrapped by it. Access is granted by providing evidence that the lock is held by the caller. Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20230411054543.21278-13-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: introduce `current`Wedson Almeida Filho
This allows Rust code to get a reference to the current task without having to increment the refcount, but still guaranteeing memory safety. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-10-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2023-04-22rust: add basic `Task`Wedson Almeida Filho
It is an abstraction for C's `struct task_struct`. It implements `AlwaysRefCounted`, so the refcount of the wrapped object is managed safely on the Rust side. Cc: Ingo Molnar <mingo@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com> Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Link: https://lore.kernel.org/r/20230411054543.21278-9-wedsonaf@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>