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42 hoursMerge tag 'rust-6.17' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness', 'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and 'ref_as_ptr' These are intended to avoid type casts with the 'as' operator, which are quite powerful, into restricted variants that are less powerful and thus should help to avoid mistakes - Remove the 'author' key now that most instances were moved to the plural one in the previous cycle 'kernel' crate: - New 'bug' module: add 'warn_on!' macro which reuses the existing 'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and kernel parameters: warn_on!(value == 42); To avoid duplicating the assembly code, the same strategy is followed as for the static branch code in order to share the assembly between both C and Rust This required a few rearrangements on C arch headers -- the existing C macros should still generate the same outputs, thus no functional change expected there - 'workqueue' module: add delayed work items, including a 'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an 'enqueue_delayed' method, e.g.: /// Enqueue the struct for execution on the system workqueue, /// where its value will be printed 42 jiffies later. fn print_later(value: Arc<MyStruct>) { let _ = workqueue::system().enqueue_delayed(value, 42); } - New 'bits' module: add support for 'bit' and 'genmask' functions, with runtime- and compile-time variants, e.g.: static_assert!(0b00010000 == bit_u8(4)); static_assert!(0b00011110 == genmask_u8(1..=4)); assert!(checked_bit_u32(u32::BITS).is_none()); - 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which reads NUL-terminated strings from userspace into a '&CStr' Introduce 'UserPtr' newtype, similar in purpose to '__user' in C, to minimize mistakes handling userspace pointers, including mixing them up with integers and leaking them via the 'Debug' trait. Add it to the prelude, too - Start preparations for the replacement of our custom 'CStr' type with the analogous type in the 'core' standard library. This will take place across several cycles to make it easier. For this one, it includes a new 'fmt' module, using upstream method names and some other cleanups Replace 'fmt!' with a re-export, which helps Clippy lint properly, and clean up the found 'uninlined-format-args' instances - 'dma' module: - Clarify wording and be consistent in 'coherent' nomenclature - Convert the 'read!()' and 'write!()' macros to return a 'Result' - Add 'as_slice()', 'write()' methods in 'CoherentAllocation' - Expose 'count()' and 'size()' in 'CoherentAllocation' and add the corresponding type invariants - Implement 'CoherentAllocation::dma_handle_with_offset()' - 'time' module: - Make 'Instant' generic over clock source. This allows the compiler to assert that arithmetic expressions involving the 'Instant' use 'Instants' based on the same clock source - Make 'HrTimer' generic over the timer mode. 'HrTimer' timers take a 'Duration' or an 'Instant' when setting the expiry time, depending on the timer mode. With this change, the compiler can check the type matches the timer mode - Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep function that will select an appropriate sleep method depending on the requested sleep time - Avoid 64-bit divisions on 32-bit hardware when calculating timestamps - Seal the 'HrTimerMode' trait. This prevents users of the 'HrTimerMode' from implementing the trait on their own types - Pass the correct timer mode ID to 'hrtimer_start_range_ns()' - 'list' module: remove 'OFFSET' constants, allowing to remove pointer arithmetic; now 'impl_list_item!' invokes 'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other simplifications too - 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a constant, which avoids exposing the type of the opaque pointer, and require 'into_foreign' to return non-null Remove the 'Either<L, R>' type as well. It is unused, and we want to encourage the use of custom enums for concrete use cases - 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types to allow them to be used in generic APIs - 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>'; and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>' - 'Opaque' type: add 'cast_from' method to perform a restricted cast that cannot change the inner type and use it in callers of 'container_of!'. Rename 'raw_get' to 'cast_into' to match it - 'rbtree' module: add 'is_empty' method - 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and 'ARef', which are moved from the too general 'types' module which we want to reduce or eventually remove. Also fix a safety comment in 'static_lock_class' 'pin-init' crate: - Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are now (pin-)initializers - Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()' - New 'zeroed()', a safe version of 'mem::zeroed()' and also provide it via 'Zeroable::zeroed()' - Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for 'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for '"Rust"' and '"C"' ABIs and up to 20 arguments - Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E> [Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T' - Renamed 'zeroed()' to 'init_zeroed()' - Upstream dev news: improve CI more to deny warnings, use '--all-targets'. Check the synchronization status of the two '-next' branches in upstream and the kernel MAINTAINERS: - Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo Stoakes as reviewers (thanks everyone) And a few other cleanups and improvements" * tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits) rust: Add warn_on macro arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust rust: kernel: move ARef and AlwaysRefCounted to sync::aref rust: sync: fix safety comment for `static_lock_class` rust: types: remove `Either<L, R>` rust: kernel: use `core::ffi::CStr` method names rust: str: add `CStr` methods matching `core::ffi::CStr` rust: str: remove unnecessary qualification rust: use `kernel::{fmt,prelude::fmt!}` rust: kernel: add `fmt` module rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args scripts: rust: emit path candidates in panic message scripts: rust: replace length checks with match rust: list: remove nonexistent generic parameter in link rust: bits: add support for bits/genmask macros rust: list: remove OFFSET constants rust: list: add `impl_list_item!` examples rust: list: use fully qualified path ...
2025-07-15rust: types: add Opaque::cast_fromAlice Ryhl
Since commit b20fbbc08a36 ("rust: check type of `$ptr` in `container_of!`") we have enforced that the field pointer passed to container_of! must match the declared field. This caused mismatches when using a pointer to bindings::x for fields of type Opaque<bindings::x>. This situation encourages the user to simply pass field.cast() to the container_of! macro, but this is not great because you might accidentally pass a *mut bindings::y when the field type is Opaque<bindings::x>, which would be wrong. To help catch this kind of mistake, add a new Opaque::cast_from that wraps a raw pointer in Opaque without changing the inner type. Also update the docs to reflect this as well as some existing users. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Andreas Hindborg <a.hindborg@kernel.org> Acked-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250624-opaque-from-raw-v2-1-e4da40bdc59c@google.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-07-11drm: rust: rename as_ref() to from_raw() for drm constructorsAlice Ryhl
The prefix as_* should not be used for a constructor. Constructors usually use the prefix from_* instead. Some prior art in the stdlib: Box::from_raw, CString::from_raw, Rc::from_raw, Arc::from_raw, Waker::from_raw, File::from_raw_fd. There is also prior art in the kernel crate: cpufreq::Policy::from_raw, fs::File::from_raw_file, Kuid::from_raw, ARef::from_raw, SeqFile::from_raw, VmaNew::from_raw, Io::from_raw. Link: https://lore.kernel.org/r/aCd8D5IA0RXZvtcv@pollux Signed-off-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250711-device-as-ref-v2-2-1b16ab6402d7@google.com
2025-06-04Merge tag 'rust-6.16' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull Rust updates from Miguel Ojeda: "Toolchain and infrastructure: - KUnit '#[test]'s: - Support KUnit-mapped 'assert!' macros. The support that landed last cycle was very basic, and the 'assert!' macros panicked since they were the standard library ones. Now, they are mapped to the KUnit ones in a similar way to how is done for doctests, reusing the infrastructure there. With this, a failing test like: #[test] fn my_first_test() { assert_eq!(42, 43); } will report: # my_first_test: ASSERTION FAILED at rust/kernel/lib.rs:251 Expected 42 == 43 to be true, but is false # my_first_test.speed: normal not ok 1 my_first_test - Support tests with checked 'Result' return types. The return value of test functions that return a 'Result' will be checked, thus one can now easily catch errors when e.g. using the '?' operator in tests. With this, a failing test like: #[test] fn my_test() -> Result { f()?; Ok(()) } will report: # my_test: ASSERTION FAILED at rust/kernel/lib.rs:321 Expected is_test_result_ok(my_test()) to be true, but is false # my_test.speed: normal not ok 1 my_test - Add 'kunit_tests' to the prelude. - Clarify the remaining language unstable features in use. - Compile 'core' with edition 2024 for Rust >= 1.87. - Workaround 'bindgen' issue with forward references to 'enum' types. - objtool: relax slice condition to cover more 'noreturn' functions. - Use absolute paths in macros referencing 'core' and 'kernel' crates. - Skip '-mno-fdpic' flag for bindgen in GCC 32-bit arm builds. - Clean some 'doc_markdown' lint hits -- we may enable it later on. 'kernel' crate: - 'alloc' module: - 'Box': support for type coercion, e.g. 'Box<T>' to 'Box<dyn U>' if 'T' implements 'U'. - 'Vec': implement new methods (prerequisites for nova-core and binder): 'truncate', 'resize', 'clear', 'pop', 'push_within_capacity' (with new error type 'PushError'), 'drain_all', 'retain', 'remove' (with new error type 'RemoveError'), insert_within_capacity' (with new error type 'InsertError'). In addition, simplify 'push' using 'spare_capacity_mut', split 'set_len' into 'inc_len' and 'dec_len', add type invariant 'len <= capacity' and simplify 'truncate' using 'dec_len'. - 'time' module: - Morph the Rust hrtimer subsystem into the Rust timekeeping subsystem, covering delay, sleep, timekeeping, timers. This new subsystem has all the relevant timekeeping C maintainers listed in the entry. - Replace 'Ktime' with 'Delta' and 'Instant' types to represent a duration of time and a point in time. - Temporarily add 'Ktime' to 'hrtimer' module to allow 'hrtimer' to delay converting to 'Instant' and 'Delta'. - 'xarray' module: - Add a Rust abstraction for the 'xarray' data structure. This abstraction allows Rust code to leverage the 'xarray' to store types that implement 'ForeignOwnable'. This support is a dependency for memory backing feature of the Rust null block driver, which is waiting to be merged. - Set up an entry in 'MAINTAINERS' for the XArray Rust support. Patches will go to the new Rust XArray tree and then via the Rust subsystem tree for now. - Allow 'ForeignOwnable' to carry information about the pointed-to type. This helps asserting alignment requirements for the pointer passed to the foreign language. - 'container_of!': retain pointer mut-ness and add a compile-time check of the type of the first parameter ('$field_ptr'). - Support optional message in 'static_assert!'. - Add C FFI types (e.g. 'c_int') to the prelude. - 'str' module: simplify KUnit tests 'format!' macro, convert 'rusttest' tests into KUnit, take advantage of the '-> Result' support in KUnit '#[test]'s. - 'list' module: add examples for 'List', fix path of 'assert_pinned!' (so far unused macro rule). - 'workqueue' module: remove 'HasWork::OFFSET'. - 'page' module: add 'inline' attribute. 'macros' crate: - 'module' macro: place 'cleanup_module()' in '.exit.text' section. 'pin-init' crate: - Add 'Wrapper<T>' trait for creating pin-initializers for wrapper structs with a structurally pinned value such as 'UnsafeCell<T>' or 'MaybeUninit<T>'. - Add 'MaybeZeroable' derive macro to try to derive 'Zeroable', but not error if not all fields implement it. This is needed to derive 'Zeroable' for all bindgen-generated structs. - Add 'unsafe fn cast_[pin_]init()' functions to unsafely change the initialized type of an initializer. These are utilized by the 'Wrapper<T>' implementations. - Add support for visibility in 'Zeroable' derive macro. - Add support for 'union's in 'Zeroable' derive macro. - Upstream dev news: streamline CI, fix some bugs. Add new workflows to check if the user-space version and the one in the kernel tree have diverged. Use the issues tab [1] to track them, which should help folks report and diagnose issues w.r.t. 'pin-init' better. [1] https://github.com/rust-for-linux/pin-init/issues Documentation: - Testing: add docs on the new KUnit '#[test]' tests. - Coding guidelines: explain that '///' vs. '//' applies to private items too. Add section on C FFI types. - Quick Start guide: update Ubuntu instructions and split them into "25.04" and "24.04 LTS and older". And a few other cleanups and improvements" * tag 'rust-6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (78 commits) rust: list: Fix typo `much` in arc.rs rust: check type of `$ptr` in `container_of!` rust: workqueue: remove HasWork::OFFSET rust: retain pointer mut-ness in `container_of!` Documentation: rust: testing: add docs on the new KUnit `#[test]` tests Documentation: rust: rename `#[test]`s to "`rusttest` host tests" rust: str: take advantage of the `-> Result` support in KUnit `#[test]`'s rust: str: simplify KUnit tests `format!` macro rust: str: convert `rusttest` tests into KUnit rust: add `kunit_tests` to the prelude rust: kunit: support checked `-> Result`s in KUnit `#[test]`s rust: kunit: support KUnit-mapped `assert!` macros in `#[test]`s rust: make section names plural rust: list: fix path of `assert_pinned!` rust: compile libcore with edition 2024 for 1.87+ rust: dma: add missing Markdown code span rust: task: add missing Markdown code spans and intra-doc links rust: pci: fix docs related to missing Markdown code spans rust: alloc: add missing Markdown code span rust: alloc: add missing Markdown code spans ...
2025-05-14rust: drm: gem: Implement AlwaysRefCounted for all gem objects automaticallyLyude Paul
Currently we are requiring AlwaysRefCounted in most trait bounds for gem objects, and implementing it by hand for our only current type of gem object. However, all gem objects use the same functions for reference counting - and all gem objects support reference counting. We're planning on adding support for shmem gem objects, let's move this around a bit by instead making IntoGEMObject require AlwaysRefCounted as a trait bound, and then provide a blanket AlwaysRefCounted implementation for any object that implements IntoGEMObject so all gem object types can use the same AlwaysRefCounted implementation. This also makes things less verbose by making the AlwaysRefCounted trait bound implicit for any IntoGEMObject bound. Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://lore.kernel.org/r/20250513221046.903358-5-lyude@redhat.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-05-14rust: drm: gem: s/into_gem_obj()/as_raw()/Lyude Paul
There's a few changes here: * The rename, of course (this should also let us drop the clippy annotation here) * Return *mut bindings::drm_gem_object instead of &Opaque<bindings::drm_gem_object> - the latter doesn't really have any benefit and just results in conversion from the rust type to the C type having to be more verbose than necessary. Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://lore.kernel.org/r/20250513221046.903358-4-lyude@redhat.com [ Fixup s/into_gem_obj()/as_raw()/ in safety comment. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-05-14rust: drm: gem: Refactor IntoGEMObject::from_gem_obj() to as_ref()Lyude Paul
There's a few issues with this function, mainly: * This function -probably- should have been unsafe from the start. Pointers are not always necessarily valid, but you want a function that does field-projection for a pointer that can travel outside of the original struct to be unsafe, at least if I understand properly. * *mut Self is not terribly useful in this context, the majority of uses of from_gem_obj() grab a *mut Self and then immediately convert it into a &'a Self. It also goes against the ffi conventions we've set in the rest of the kernel thus far. * from_gem_obj() also doesn't follow the naming conventions in the rest of the DRM bindings at the moment, as_ref() would be a better name. So, let's: * Make from_gem_obj() unsafe * Convert it to return &'a Self * Rename it to as_ref() * Update all call locations Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://lore.kernel.org/r/20250513221046.903358-3-lyude@redhat.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-05-14rust: drm: gem: Use NonNull for Object::devLyude Paul
There is usually not much of a reason to use a raw pointer in a data struct, so move this to NonNull instead. Signed-off-by: Lyude Paul <lyude@redhat.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://lore.kernel.org/r/20250513221046.903358-2-lyude@redhat.com Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-04-28rust: drm: gem: Add GEM object abstractionAsahi Lina
DRM GEM is the DRM memory management subsystem used by most modern drivers; add a Rust abstraction for DRM GEM. This includes the BaseObject trait, which contains operations shared by all GEM object classes. Signed-off-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Alyssa Rosenzweig <alyssa@rosenzweig.io> Reviewed-by: Lyude Paul <lyude@redhat.com> Link: https://lore.kernel.org/r/20250410235546.43736-8-dakr@kernel.org [ Rework of GEM object abstractions * switch to the Opaque<T> type * fix (mutable) references to struct drm_gem_object (which in this context is UB) * drop all custom reference types in favor of AlwaysRefCounted * bunch of minor changes and simplifications (e.g. IntoGEMObject trait) * write and fix safety and invariant comments * remove necessity for and convert 'as' casts * original source archive: https://archive.is/dD5SL - Danilo ] [ Fix missing CONFIG_DRM guards in rust/helpers/drm.c. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>