summaryrefslogtreecommitdiff
path: root/rust/kernel/lib.rs
AgeCommit message (Collapse)Author
2025-05-20rust: opp: Add initial abstractions for OPP frameworkViresh Kumar
Introduce initial Rust abstractions for the Operating Performance Points (OPP) framework. This includes bindings for `struct dev_pm_opp` and `struct dev_pm_opp_data`, laying the groundwork for further OPP integration. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-20rust: cpu: Add from_cpu()Viresh Kumar
This implements cpu::from_cpu(), which returns a reference to Device for a CPU. The C struct is created at initialization time for CPUs and is never freed and so ARef isn't returned from this function. The new helper will be used by Rust based cpufreq drivers. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-19rust: clk: Add initial abstractionsViresh Kumar
Add initial abstractions for the clk APIs. These provide the minimal functionality needed for common use cases, making them straightforward to introduce in the first iteration. These will be used by Rust based cpufreq / OPP layers to begin with. Tested-by: Daniel Almeida <daniel.almeida@collabora.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
2025-05-19rust: cpumask: Add initial abstractionsViresh Kumar
Add initial Rust abstractions for struct cpumask, covering a subset of its APIs. Additional APIs can be added as needed. These abstractions will be used in upcoming Rust support for cpufreq and OPP frameworks. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Yury Norov [NVIDIA] <yury.norov@gmail.com>
2025-05-18Merge tag 'rust-xarray-for-v6.16' of https://github.com/Rust-for-Linux/linux ↵Miguel Ojeda
into rust-next Pull XArray updates from Andreas Hindborg: "Introduce Rust support for the 'xarray' data structure: - 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. 'kernel' crate: - Allow 'ForeignOwnable' to carry information about the pointed-to type. This helps asserting alignment requirements for the pointer passed to the foreign language." * tag 'rust-xarray-for-v6.16' of https://github.com/Rust-for-Linux/linux: MAINTAINERS: add entry for Rust XArray API rust: xarray: Add an abstraction for XArray rust: types: add `ForeignOwnable::PointedTo`
2025-05-12rust: configfs: introduce rust support for configfsAndreas Hindborg
Add a Rust API for configfs, thus allowing Rust modules to use configfs for configuration. Make the implementation a shim on top of the C configfs implementation, allowing safe use of the C infrastructure from Rust. Link: https://lore.kernel.org/r/20250508-configfs-v8-1-8ebde6180edc@kernel.org Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-05-11mm: rust: add abstraction for struct mm_structAlice Ryhl
Patch series "Rust support for mm_struct, vm_area_struct, and mmap", v16. This updates the vm_area_struct support to use the approach we discussed at LPC where there are several different Rust wrappers for vm_area_struct depending on the kind of access you have to the vma. Each case allows a different set of operations on the vma. This includes an MM MAINTAINERS entry as proposed by Lorenzo: https://lore.kernel.org/all/33e64b12-aa07-4e78-933a-b07c37ff1d84@lucifer.local/ This patch (of 9): These abstractions allow you to reference a `struct mm_struct` using both mmgrab and mmget refcounts. This is done using two Rust types: * Mm - represents an mm_struct where you don't know anything about the value of mm_users. * MmWithUser - represents an mm_struct where you know at compile time that mm_users is non-zero. This allows us to encode in the type system whether a method requires that mm_users is non-zero or not. For instance, you can always call `mmget_not_zero` but you can only call `mmap_read_lock` when mm_users is non-zero. The struct is called Mm to keep consistency with the C side. The ability to obtain `current->mm` is added later in this series. The mm module is defined to only exist when CONFIG_MMU is set. This avoids various errors due to missing types and functions when CONFIG_MMU is disabled. More fine-grained cfgs can be considered in the future. See the thread at [1] for more info. Link: https://lkml.kernel.org/r/20250408-vma-v16-9-d8b446e885d9@google.com Link: https://lkml.kernel.org/r/20250408-vma-v16-1-d8b446e885d9@google.com Link: https://lore.kernel.org/all/202503091916.QousmtcY-lkp@intel.com/ Signed-off-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Liam R. Howlett <Liam.Howlett@Oracle.com> Acked-by: Balbir Singh <balbirs@nvidia.com> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Gary Guo <gary@garyguo.net> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benno Lossin <benno.lossin@proton.me> Cc: Björn Roy Baron <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jann Horn <jannh@google.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Trevor Gross <tmgross@umich.edu> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-12rust: clarify the language unstable features in useMiguel Ojeda
We track the details of which Rust features we use at our usual "live list" [1] (and its sub-lists), but in light of a discussion in the LWN article [2], it would help to clarify it in the source code. In particular, we are very close to rely only on stable Rust language-wise -- essentially only two language features remain (including the `kernel` crate). Thus add some details in both the feature list of the `kernel` crate as well as the list of allowed features. This does not over every single feature, and there are quite a few non-language features that we use too. To have the full picture, please refer to [1]. Link: https://github.com/Rust-for-Linux/linux/issues/2 [1] Link: https://lwn.net/Articles/1015409/ [2] Suggested-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20250327211302.286313-1-ojeda@kernel.org [ Improved comments with suggestions from the list. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-05-01rust: xarray: Add an abstraction for XArrayTamir Duberstein
`XArray` is an efficient sparse array of pointers. Add a Rust abstraction for this type. This implementation bounds the element type on `ForeignOwnable` and requires explicit locking for all operations. Future work may leverage RCU to enable lockless operation. Inspired-by: Maíra Canal <mcanal@igalia.com> Inspired-by: Asahi Lina <lina@asahilina.net> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Tamir Duberstein <tamird@gmail.com> Link: https://lore.kernel.org/r/20250423-rust-xarray-bindings-v19-2-83cdcf11c114@gmail.com Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
2025-04-24rust: drm: ioctl: Add DRM ioctl abstractionAsahi Lina
DRM drivers need to be able to declare which driver-specific ioctls they support. Add an abstraction implementing the required types and a helper macro to generate the ioctl definition inside the DRM driver. Note that this macro is not usable until further bits of the abstraction are in place (but it will not fail to compile on its own, if not called). 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/20250410235546.43736-3-dakr@kernel.org [ MISC fixes * wrap raw_data in Opaque to avoid UB when creating a reference * fix IOCTL sample declaration * fix safety comment of IOCTL argument * original source archive: https://archive.is/LqHDQ - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-04-19rust: auxiliary: add auxiliary device / driver abstractionsDanilo Krummrich
Implement the basic auxiliary abstractions required to implement a driver matching an auxiliary device. The design and implementation is analogous to PCI and platform and is based on the generic device / driver abstractions. Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20250414131934.28418-4-dakr@kernel.org [ Fix typos, `let _ =` => `drop()`, use `kernel::ffi`. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
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` ...
2025-03-23rust: enable `raw_ref_op` featureAntonio Hickey
Since Rust 1.82.0 the `raw_ref_op` feature is stable [1]. By enabling this feature we can use `&raw const place` and `&raw mut place` instead of using `addr_of!(place)` and `addr_of_mut!(place)` macros. Allowing us to reduce macro complexity, and improve consistency with existing reference syntax as `&raw const`, `&raw mut` are similar to `&`, `&mut` making it fit more naturally with other existing code. Suggested-by: Benno Lossin <benno.lossin@proton.me> Link: https://github.com/Rust-for-Linux/linux/issues/1148 Link: https://blog.rust-lang.org/2024/10/17/Rust-1.82.0.html#native-syntax-for-creating-a-raw-pointer [1] Signed-off-by: Antonio Hickey <contact@antoniohickey.com> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Tamir Duberstein <tamird@gmail.com> Link: https://lore.kernel.org/r/20250320020740.1631171-2-contact@antoniohickey.com [ Removed dashed line change as discussed. Added Link to the explanation of the feature in the Rust 1.82.0 release blog post. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-03-20rust: add dma coherent allocator abstractionAbdiel Janulgue
Add a simple dma coherent allocator rust abstraction. Based on Andreas Hindborg's dma abstractions from the rnvme driver, which was also based on earlier work by Wedson Almeida Filho. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Abdiel Janulgue <abdiel.janulgue@gmail.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250317185345.2608976-3-abdiel.janulgue@gmail.com Nacked-by: Christoph Hellwig <hch@lst.de> [ Removed period. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
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: 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>
2025-03-05rust: remove leftover mentions of the `alloc` crateMiguel Ojeda
In commit 392e34b6bc22 ("kbuild: rust: remove the `alloc` crate and `GlobalAlloc`") we stopped using the upstream `alloc` crate. Thus remove a few leftover mentions treewide. Cc: stable@vger.kernel.org # Also to 6.12.y after the `alloc` backport lands Fixes: 392e34b6bc22 ("kbuild: rust: remove the `alloc` crate and `GlobalAlloc`") Reviewed-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://lore.kernel.org/r/20250303171030.1081134-1-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-02-13rust/kernel: Add faux device bindingsLyude Paul
This introduces a module for working with faux devices in rust, along with adding sample code to show how the API is used. Unlike other types of devices, we don't provide any hooks for device probe/removal - since these are optional for the faux API and are unnecessary in rust. Signed-off-by: Lyude Paul <lyude@redhat.com> Cc: Maíra Canal <mairacanal@riseup.net> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com> Acked-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/2025021026-exert-accent-b4c6@gregkh Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-28Merge tag 'driver-core-6.14-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core and debugfs updates from Greg KH: "Here is the big set of driver core and debugfs updates for 6.14-rc1. Included in here is a bunch of driver core, PCI, OF, and platform rust bindings (all acked by the different subsystem maintainers), hence the merge conflict with the rust tree, and some driver core api updates to mark things as const, which will also require some fixups due to new stuff coming in through other trees in this merge window. There are also a bunch of debugfs updates from Al, and there is at least one user that does have a regression with these, but Al is working on tracking down the fix for it. In my use (and everyone else's linux-next use), it does not seem like a big issue at the moment. Here's a short list of the things in here: - driver core rust bindings for PCI, platform, OF, and some i/o functions. We are almost at the "write a real driver in rust" stage now, depending on what you want to do. - misc device rust bindings and a sample driver to show how to use them - debugfs cleanups in the fs as well as the users of the fs api for places where drivers got it wrong or were unnecessarily doing things in complex ways. - driver core const work, making more of the api take const * for different parameters to make the rust bindings easier overall. - other small fixes and updates All of these have been in linux-next with all of the aforementioned merge conflicts, and the one debugfs issue, which looks to be resolved "soon"" * tag 'driver-core-6.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (95 commits) rust: device: Use as_char_ptr() to avoid explicit cast rust: device: Replace CString with CStr in property_present() devcoredump: Constify 'struct bin_attribute' devcoredump: Define 'struct bin_attribute' through macro rust: device: Add property_present() saner replacement for debugfs_rename() orangefs-debugfs: don't mess with ->d_name octeontx2: don't mess with ->d_parent or ->d_parent->d_name arm_scmi: don't mess with ->d_parent->d_name slub: don't mess with ->d_name sof-client-ipc-flood-test: don't mess with ->d_name qat: don't mess with ->d_name xhci: don't mess with ->d_iname mtu3: don't mess wiht ->d_iname greybus/camera - stop messing with ->d_iname mediatek: stop messing with ->d_iname netdevsim: don't embed file_operations into your structs b43legacy: make use of debugfs_get_aux() b43: stop embedding struct file_operations into their objects carl9170: stop embedding file_operations into their objects ...
2025-01-13rust: use derive(CoercePointee) on rustc >= 1.84.0Xiangfei Ding
The `kernel` crate relies on both `coerce_unsized` and `dispatch_from_dyn` unstable features. Alice Ryhl has proposed [1] the introduction of the unstable macro `SmartPointer` to reduce such dependence, along with a RFC patch [2]. Since Rust 1.81.0 this macro, later renamed to `CoercePointee` in Rust 1.84.0 [3], has been fully implemented with the naming discussion resolved. This feature is now on track to stabilization in the language. In order to do so, we shall start using this macro in the `kernel` crate to prove the functionality and utility of the macro as the justification of its stabilization. This patch makes this switch in such a way that the crate remains backward compatible with older Rust compiler versions, via the new Kconfig option `RUSTC_HAS_COERCE_POINTEE`. A minimal demonstration example is added to the `samples/rust/rust_print_main.rs` module. Link: https://rust-lang.github.io/rfcs/3621-derive-smart-pointer.html [1] Link: https://lore.kernel.org/all/20240823-derive-smart-pointer-v1-1-53769cd37239@google.com/ [2] Link: https://github.com/rust-lang/rust/pull/131284 [3] Signed-off-by: Xiangfei Ding <dingxiangfei2009@gmail.com> Reviewed-by: Fiona Behrens <me@kloenk.dev> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20241203205050.679106-2-dingxiangfei2009@gmail.com [ Fixed version to 1.84. Renamed option to `RUSTC_HAS_COERCE_POINTEE` to match `CC_HAS_*` ones. Moved up new config option, closer to the `CC_HAS_*` ones. Simplified Kconfig line. Fixed typos and slightly reworded example and commit. Added Link to PR. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-10rust: kernel: move `build_error` hidden function to prevent mistakesMiguel Ojeda
Users were using the hidden exported `kernel::build_error` function instead of the intended `kernel::build_error!` macro, e.g. see the previous commit. To force to use the macro, move it into the `build_assert` module, thus making it a compilation error and avoiding a collision in the same "namespace". Using the function now would require typing the module name (which is hidden), not just a single character. Now attempting to use the function will trigger this error with the right suggestion by the compiler: error[E0423]: expected function, found macro `kernel::build_error` --> samples/rust/rust_minimal.rs:29:9 | 29 | kernel::build_error(); | ^^^^^^^^^^^^^^^^^^^ not a function | help: use `!` to invoke the macro | 29 | kernel::build_error!(); | + An alternative would be using an alias, but it would be more complex and moving it into the module seems right since it belongs there and reduces the amount of code at the crate root. Keep the `#[doc(hidden)]` inside `build_assert` in case the module is not hidden in the future. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20241123222849.350287-2-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2025-01-07rust: io: move module entry to its correct locationDanilo Krummrich
The module entry of `io` falsely ended up in the "use" block instead of the "mod" block, hence move it to its correct location. Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250103164655.96590-3-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-01-07rust: pci: do not depend on CONFIG_PCI_MSIDanilo Krummrich
The PCI abstractions do not actually depend on CONFIG_PCI_MSI; it also breaks drivers that only depend on CONFIG_PCI, hence drop it. While at it, move the module entry to its correct location. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202501030744.4ucqC1cB-lkp@intel.com/ Fixes: 1bd8b6b2c5d3 ("rust: pci: add basic PCI device / driver abstractions") Signed-off-by: Danilo Krummrich <dakr@kernel.org> Link: https://lore.kernel.org/r/20250103164655.96590-2-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: platform: add basic platform device / driver abstractionsDanilo Krummrich
Implement the basic platform bus abstractions required to write a basic platform driver. This includes the following data structures: The `platform::Driver` trait represents the interface to the driver and provides `platform::Driver::probe` for the driver to implement. The `platform::Device` abstraction represents a `struct platform_device`. In order to provide the platform bus specific parts to a generic `driver::Registration` the `driver::RegistrationOps` trait is implemented by `platform::Adapter`. Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-15-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: of: add `of::DeviceId` abstractionDanilo Krummrich
`of::DeviceId` is an abstraction around `struct of_device_id`. This is used by subsequent patches, in particular the platform bus abstractions, to create OF device ID tables. Reviewed-by: Rob Herring (Arm) <robh@kernel.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Tested-by: Fabien Parent <fabien.parent@linaro.org> Link: https://lore.kernel.org/r/20241219170425.12036-13-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: pci: add basic PCI device / driver abstractionsDanilo Krummrich
Implement the basic PCI abstractions required to write a basic PCI driver. This includes the following data structures: The `pci::Driver` trait represents the interface to the driver and provides `pci::Driver::probe` for the driver to implement. The `pci::Device` abstraction represents a `struct pci_dev` and provides abstractions for common functions, such as `pci::Device::set_master`. In order to provide the PCI specific parts to a generic `driver::Registration` the `driver::RegistrationOps` trait is implemented by `pci::Adapter`. `pci::DeviceId` implements PCI device IDs based on the generic `device_id::RawDevceId` abstraction. Co-developed-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-10-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: add devres abstractionDanilo Krummrich
Add a Rust abstraction for the kernel's devres (device resource management) implementation. The Devres type acts as a container to manage the lifetime and accessibility of device bound resources. Therefore it registers a devres callback and revokes access to the resource on invocation. Users of the Devres abstraction can simply free the corresponding resources in their Drop implementation, which is invoked when either the Devres instance goes out of scope or the devres callback leads to the resource being revoked, which implies a call to drop_in_place(). Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-9-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: add `io::{Io, IoRaw}` base typesDanilo Krummrich
I/O memory is typically either mapped through direct calls to ioremap() or subsystem / bus specific ones such as pci_iomap(). Even though subsystem / bus specific functions to map I/O memory are based on ioremap() / iounmap() it is not desirable to re-implement them in Rust. Instead, implement a base type for I/O mapped memory, which generically provides the corresponding accessors, such as `Io::readb` or `Io:try_readb`. `Io` supports an optional const generic, such that a driver can indicate the minimal expected and required size of the mapping at compile time. Correspondingly, calls to the 'non-try' accessors, support compile time checks of the I/O memory offset to read / write, while the 'try' accessors, provide boundary checks on runtime. `IoRaw` is meant to be embedded into a structure (e.g. pci::Bar or io::IoMem) which creates the actual I/O memory mapping and initializes `IoRaw` accordingly. To ensure that I/O mapped memory can't out-live the device it may be bound to, subsystems must embed the corresponding I/O memory type (e.g. pci::Bar) into a `Devres` container, such that it gets revoked once the device is unbound. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Tested-by: Daniel Almeida <daniel.almeida@collabora.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-8-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: add `Revocable` typeWedson Almeida Filho
Revocable allows access to objects to be safely revoked at run time. This is useful, for example, for resources allocated during device probe; when the device is removed, the driver should stop accessing the device resources even if another state is kept in memory due to existing references (i.e., device context data is ref-counted and has a non-zero refcount after removal of the device). Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Co-developed-by: Danilo Krummrich <dakr@kernel.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Link: https://lore.kernel.org/r/20241219170425.12036-7-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: implement `IdArray`, `IdTable` and `RawDeviceId`Danilo Krummrich
Most subsystems use some kind of ID to match devices and drivers. Hence, we have to provide Rust drivers an abstraction to register an ID table for the driver to match. Generally, those IDs are subsystem specific and hence need to be implemented by the corresponding subsystem. However, the `IdArray`, `IdTable` and `RawDeviceId` types provide a generalized implementation that makes the life of subsystems easier to do so. Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Co-developed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Gary Guo <gary@garyguo.net> Co-developed-by: Fabien Parent <fabien.parent@linaro.org> Signed-off-by: Fabien Parent <fabien.parent@linaro.org> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Tested-by: Fabien Parent <fabien.parent@linaro.org> Link: https://lore.kernel.org/r/20241219170425.12036-4-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: implement generic driver registrationDanilo Krummrich
Implement the generic `Registration` type and the `RegistrationOps` trait. The `Registration` structure is the common type that represents a driver registration and is typically bound to the lifetime of a module. However, it doesn't implement actual calls to the kernel's driver core to register drivers itself. Instead the `RegistrationOps` trait is provided to subsystems, which have to implement `RegistrationOps::register` and `RegistrationOps::unregister`. Subsystems have to provide an implementation for both of those methods where the subsystem specific variants to register / unregister a driver have to implemented. For instance, the PCI subsystem would call __pci_register_driver() from `RegistrationOps::register` and pci_unregister_driver() from `DrvierOps::unregister`. Co-developed-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Tested-by: Fabien Parent <fabien.parent@linaro.org> Link: https://lore.kernel.org/r/20241219170425.12036-3-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-12-20rust: module: add trait `ModuleMetadata`Danilo Krummrich
In order to access static metadata of a Rust kernel module, add the `ModuleMetadata` trait. In particular, this trait provides the name of a Rust kernel module as specified by the `module!` macro. Signed-off-by: Danilo Krummrich <dakr@kernel.org> Tested-by: Dirk Behme <dirk.behme@de.bosch.com> Tested-by: Fabien Parent <fabien.parent@linaro.org> Link: https://lore.kernel.org/r/20241219170425.12036-2-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-29Merge tag 'char-misc-6.13-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc/IIO/whatever driver subsystem updates from Greg KH: "Here is the 'big and hairy' char/misc/iio and other small driver subsystem updates for 6.13-rc1. Loads of things in here, and even a fun merge conflict! - rust misc driver bindings and other rust changes to make misc drivers actually possible. I think this is the tipping point, expect to see way more rust drivers going forward now that these bindings are present. Next merge window hopefully we will have pci and platform drivers working, which will fully enable almost all driver subsystems to start accepting (or at least getting) rust drivers. This is the end result of a lot of work from a lot of people, congrats to all of them for getting this far, you've proved many of us wrong in the best way possible, working code :) - IIO driver updates, too many to list individually, that subsystem keeps growing and growing... - Interconnect driver updates - nvmem driver updates - pwm driver updates - platform_driver::remove() fixups, loads of them - counter driver updates - misc driver updates (keba?) - binder driver updates and fixes - loads of other small char/misc/etc driver updates and additions, full details in the shortlog. All of these have been in linux-next for a while, with no other reported issues other than that merge conflict" * tag 'char-misc-6.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (401 commits) mei: vsc: Fix typo "maintstepping" -> "mainstepping" firmware: Switch back to struct platform_driver::remove() misc: isl29020: Fix the wrong format specifier scripts/tags.sh: Don't tag usages of DEFINE_MUTEX fpga: Switch back to struct platform_driver::remove() mei: vsc: Improve error logging in vsc_identify_silicon() mei: vsc: Do not re-enable interrupt from vsc_tp_reset() dt-bindings: spmi: qcom,x1e80100-spmi-pmic-arb: Add SAR2130P compatible dt-bindings: spmi: spmi-mtk-pmif: Add compatible for MT8188 spmi: pmic-arb: fix return path in for_each_available_child_of_node() iio: Move __private marking before struct element priv in struct iio_dev docs: iio: ad7380: add adaq4370-4 and adaq4380-4 iio: adc: ad7380: add support for adaq4370-4 and adaq4380-4 iio: adc: ad7380: use local dev variable to shorten long lines iio: adc: ad7380: fix oversampling formula dt-bindings: iio: adc: ad7380: add adaq4370-4 and adaq4380-4 compatible parts bus: mhi: host: pci_generic: Use pcim_iomap_region() to request and map MHI BAR bus: mhi: host: Switch trace_mhi_gen_tre fields to native endian misc: atmel-ssc: Use of_property_present() for non-boolean properties misc: keba: Add hardware dependency ...
2024-11-26Merge tag 'rust-6.13' of https://github.com/Rust-for-Linux/linuxLinus Torvalds
Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Enable a series of lints, including safety-related ones, e.g. the compiler will now warn about missing safety comments, as well as unnecessary ones. How safety documentation is organized is a frequent source of review comments, thus having the compiler guide new developers on where they are expected (and where not) is very nice. - Start using '#[expect]': an interesting feature in Rust (stabilized in 1.81.0) that makes the compiler warn if an expected warning was _not_ emitted. This is useful to avoid forgetting cleaning up locally ignored diagnostics ('#[allow]'s). - Introduce '.clippy.toml' configuration file for Clippy, the Rust linter, which will allow us to tweak its behaviour. For instance, our first use cases are declaring a disallowed macro and, more importantly, enabling the checking of private items. - Lints-related fixes and cleanups related to the items above. - Migrate from 'receiver_trait' to 'arbitrary_self_types': to get the kernel into stable Rust, one of the major pieces of the puzzle is the support to write custom types that can be used as 'self', i.e. as receivers, since the kernel needs to write types such as 'Arc' that common userspace Rust would not. 'arbitrary_self_types' has been accepted to become stable, and this is one of the steps required to get there. - Remove usage of the 'new_uninit' unstable feature. - Use custom C FFI types. Includes a new 'ffi' crate to contain our custom mapping, instead of using the standard library 'core::ffi' one. The actual remapping will be introduced in a later cycle. - Map '__kernel_{size_t,ssize_t,ptrdiff_t}' to 'usize'/'isize' instead of 32/64-bit integers. - Fix 'size_t' in bindgen generated prototypes of C builtins. - Warn on bindgen < 0.69.5 and libclang >= 19.1 due to a double issue in the projects, which we managed to trigger with the upcoming tracepoint support. It includes a build test since some distributions backported the fix (e.g. Debian -- thanks!). All major distributions we list should be now OK except Ubuntu non-LTS. 'macros' crate: - Adapt the build system to be able run the doctests there too; and clean up and enable the corresponding doctests. 'kernel' crate: - Add 'alloc' module with generic kernel allocator support and remove the dependency on the Rust standard library 'alloc' and the extension traits we used to provide fallible methods with flags. Add the 'Allocator' trait and its implementations '{K,V,KV}malloc'. Add the 'Box' type (a heap allocation for a single value of type 'T' that is also generic over an allocator and considers the kernel's GFP flags) and its shorthand aliases '{K,V,KV}Box'. Add 'ArrayLayout' type. Add 'Vec' (a contiguous growable array type) and its shorthand aliases '{K,V,KV}Vec', including iterator support. For instance, now we may write code such as: let mut v = KVec::new(); v.push(1, GFP_KERNEL)?; assert_eq!(&v, &[1]); Treewide, move as well old users to these new types. - 'sync' module: add global lock support, including the 'GlobalLockBackend' trait; the 'Global{Lock,Guard,LockedBy}' types and the 'global_lock!' macro. Add the 'Lock::try_lock' method. - 'error' module: optimize 'Error' type to use 'NonZeroI32' and make conversion functions public. - 'page' module: add 'page_align' function. - Add 'transmute' module with the existing 'FromBytes' and 'AsBytes' traits. - 'block::mq::request' module: improve rendered documentation. - 'types' module: extend 'Opaque' type documentation and add simple examples for the 'Either' types. drm/panic: - Clean up a series of Clippy warnings. Documentation: - Add coding guidelines for lints and the '#[expect]' feature. - Add Ubuntu to the list of distributions in the Quick Start guide. MAINTAINERS: - Add Danilo Krummrich as maintainer of the new 'alloc' module. And a few other small cleanups and fixes" * tag 'rust-6.13' of https://github.com/Rust-for-Linux/linux: (82 commits) rust: alloc: Fix `ArrayLayout` allocations docs: rust: remove spurious item in `expect` list rust: allow `clippy::needless_lifetimes` rust: warn on bindgen < 0.69.5 and libclang >= 19.1 rust: use custom FFI integer types rust: map `__kernel_size_t` and friends also to usize/isize rust: fix size_t in bindgen prototypes of C builtins rust: sync: add global lock support rust: macros: enable the rest of the tests rust: macros: enable paste! use from macro_rules! rust: enable macros::module! tests rust: kbuild: expand rusttest target for macros rust: types: extend `Opaque` documentation rust: block: fix formatting of `kernel::block::mq::request` module rust: macros: fix documentation of the paste! macro rust: kernel: fix THIS_MODULE header path in ThisModule doc comment rust: page: add Rust version of PAGE_ALIGN rust: helpers: remove unnecessary header includes rust: exports: improve grammar in commentary drm/panic: allow verbose version check ...
2024-11-26Merge tag 'vfs-6.13.rust.pid_namespace' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull pid_namespace rust bindings from Christian Brauner: "This contains my Rust bindings for pid namespaces needed for various rust drivers. Here's a description of the basic C semantics and how they are mapped to Rust. The pid namespace of a task doesn't ever change once the task is alive. A unshare(CLONE_NEWPID) or setns(fd_pidns/pidfd, CLONE_NEWPID) will not have an effect on the calling task's pid namespace. It will only effect the pid namespace of children created by the calling task. This invariant guarantees that after having acquired a reference to a task's pid namespace it will remain unchanged. When a task has exited and been reaped release_task() will be called. This will set the pid namespace of the task to NULL. So retrieving the pid namespace of a task that is dead will return NULL. Note, that neither holding the RCU lock nor holding a reference count to the task will prevent release_task() from being called. In order to retrieve the pid namespace of a task the task_active_pid_ns() function can be used. There are two cases to consider: (1) retrieving the pid namespace of the current task (2) retrieving the pid namespace of a non-current task From system call context retrieving the pid namespace for case (1) is always safe and requires neither RCU locking nor a reference count to be held. Retrieving the pid namespace after release_task() for current will return NULL but no codepath like that is exposed to Rust. Retrieving the pid namespace from system call context for (2) requires RCU protection. Accessing a pid namespace outside of RCU protection requires a reference count that must've been acquired while holding the RCU lock. Note that accessing a non-current task means NULL can be returned as the non-current task could have already passed through release_task(). To retrieve (1) the current_pid_ns!() macro should be used. It ensures that the returned pid namespace cannot outlive the calling scope. The associated current_pid_ns() function should not be called directly as it could be abused to created an unbounded lifetime for the pid namespace. The current_pid_ns!() macro allows Rust to handle the common case of accessing current's pid namespace without RCU protection and without having to acquire a reference count. For (2) the task_get_pid_ns() method must be used. This will always acquire a reference on the pid namespace and will return an Option to force the caller to explicitly handle the case where pid namespace is None. Something that tends to be forgotten when doing the equivalent operation in C. Missing RCU primitives make it difficult to perform operations that are otherwise safe without holding a reference count as long as RCU protection is guaranteed. But it is not important currently. But we do want it in the future. Note that for (2) the required RCU protection around calling task_active_pid_ns() synchronizes against putting the last reference of the associated struct pid of task->thread_pid. The struct pid stored in that field is used to retrieve the pid namespace of the caller. When release_task() is called task->thread_pid will be NULLed and put_pid() on said struct pid will be delayed in free_pid() via call_rcu() allowing everyone with an RCU protected access to the struct pid acquired from task->thread_pid to finish" * tag 'vfs-6.13.rust.pid_namespace' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: rust: add PidNamespace
2024-11-25Merge tag 'trace-rust-v6.13' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull rust trace event support from Steven Rostedt: "Allow Rust code to have trace events Trace events is a popular way to debug what is happening inside the kernel or just to find out what is happening. Rust code is being added to the Linux kernel but it currently does not support the tracing infrastructure. Add support of trace events inside Rust code" * tag 'trace-rust-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: rust: jump_label: skip formatting generated file jump_label: rust: pass a mut ptr to `static_key_count` samples: rust: fix `rust_print` build making it a combined module rust: add arch_static_branch jump_label: adjust inline asm to be consistent rust: samples: add tracepoint to Rust sample rust: add tracepoint support rust: add static_branch_unlikely for static_key_false
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>
2024-11-05rust: introduce `InPlaceModule`Wedson Almeida Filho
This allows modules to be initialised in-place in pinned memory, which enables the usage of pinned types (e.g., mutexes, spinlocks, driver registrations, etc.) in modules without any extra allocations. Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com> Signed-off-by: Danilo Krummrich <dakr@kernel.org> Acked-by: Miguel Ojeda <ojeda@kernel.org> Link: https://lore.kernel.org/r/20241022213221.2383-3-dakr@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-04rust: add arch_static_branchAlice Ryhl
To allow the Rust implementation of static_key_false to use runtime code patching instead of the generic implementation, pull in the relevant inline assembly from the jump_label.h header by running the C preprocessor on a .rs.S file. Build rules are added for .rs.S files. Since the relevant inline asm has been adjusted to export the inline asm via the ARCH_STATIC_BRANCH_ASM macro in a consistent way, the Rust side does not need architecture specific code to pull in the asm. It is not possible to use the existing C implementation of arch_static_branch via a Rust helper because it passes the argument `key` to inline assembly as an 'i' parameter. Any attempt to add a C helper for this function will fail to compile because the value of `key` must be known at compile-time. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Cc: Gary Guo <gary@garyguo.net> Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <bjorn3_gh@protonmail.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: Andreas Hindborg <a.hindborg@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Fuad Tabba <tabba@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anup Patel <apatel@ventanamicro.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Conor Dooley <conor.dooley@microchip.com> Cc: Samuel Holland <samuel.holland@sifive.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Bibo Mao <maobibo@loongson.cn> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tianrui Zhao <zhaotianrui@loongson.cn> Link: https://lore.kernel.org/20241030-tracepoint-v12-5-eec7f0f8ad22@google.com Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Co-developed-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-04rust: add tracepoint supportAlice Ryhl
Make it possible to have Rust code call into tracepoints defined by C code. It is still required that the tracepoint is declared in a C header, and that this header is included in the input to bindgen. Instead of calling __DO_TRACE directly, the exported rust_do_trace_ function calls an inline helper function. This is because the `cond` argument does not exist at the callsite of DEFINE_RUST_DO_TRACE. __DECLARE_TRACE always emits an inline static and an extern declaration that is only used when CREATE_RUST_TRACE_POINTS is set. These should not end up in the final binary so it is not a problem that they sometimes are emitted without a user. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <bjorn3_gh@protonmail.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: Andreas Hindborg <a.hindborg@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Fuad Tabba <tabba@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anup Patel <apatel@ventanamicro.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Conor Dooley <conor.dooley@microchip.com> Cc: Samuel Holland <samuel.holland@sifive.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Bibo Mao <maobibo@loongson.cn> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tianrui Zhao <zhaotianrui@loongson.cn> Link: https://lore.kernel.org/20241030-tracepoint-v12-2-eec7f0f8ad22@google.com Reviewed-by: Carlos Llamas <cmllamas@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-11-04rust: add static_branch_unlikely for static_key_falseAlice Ryhl
Add just enough support for static key so that we can use it from tracepoints. Tracepoints rely on `static_branch_unlikely` with a `struct static_key_false`, so we add the same functionality to Rust. This patch only provides a generic implementation without code patching (matching the one used when CONFIG_JUMP_LABEL is disabled). Later patches add support for inline asm implementations that use runtime patching. When CONFIG_JUMP_LABEL is unset, `static_key_count` is a static inline function, so a Rust helper is defined for `static_key_count` in this case. If Rust is compiled with LTO, this call should get inlined. The helper can be eliminated once we have the necessary inline asm to make atomic operations from Rust. Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Jason Baron <jbaron@akamai.com> Cc: Ard Biesheuvel <ardb@kernel.org> Cc: Miguel Ojeda <ojeda@kernel.org> Cc: Alex Gaynor <alex.gaynor@gmail.com> Cc: Wedson Almeida Filho <wedsonaf@gmail.com> Cc: " =?utf-8?q?Bj=C3=B6rn_Roy_Baron?= " <bjorn3_gh@protonmail.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: Andreas Hindborg <a.hindborg@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Uros Bizjak <ubizjak@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: Oliver Upton <oliver.upton@linux.dev> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Fuad Tabba <tabba@google.com> Cc: Paul Walmsley <paul.walmsley@sifive.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Anup Patel <apatel@ventanamicro.com> Cc: Andrew Jones <ajones@ventanamicro.com> Cc: Alexandre Ghiti <alexghiti@rivosinc.com> Cc: Conor Dooley <conor.dooley@microchip.com> Cc: Samuel Holland <samuel.holland@sifive.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Bibo Mao <maobibo@loongson.cn> Cc: Tiezhu Yang <yangtiezhu@loongson.cn> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Tianrui Zhao <zhaotianrui@loongson.cn> Link: https://lore.kernel.org/20241030-tracepoint-v12-1-eec7f0f8ad22@google.com Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-10-21rust: kernel: fix THIS_MODULE header path in ThisModule doc commentYutaro Ohno
The doc comment for `ThisModule` incorrectly states the C header file for `THIS_MODULE` as `include/linux/export.h`, while the correct path is `include/linux/init.h`. This is because `THIS_MODULE` was moved in commit 5b20755b7780 ("init: move THIS_MODULE from <linux/export.h> to <linux/init.h>"). Update the doc comment for `ThisModule` to reflect the correct header file path for `THIS_MODULE`. Fixes: 5b20755b7780 ("init: move THIS_MODULE from <linux/export.h> to <linux/init.h>") Signed-off-by: Yutaro Ohno <yutaro.ono.418@gmail.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/ZxXDZwxWgoEiIYkj@ohnotp Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-15rust: alloc: implement kernel `Vec` typeDanilo Krummrich
`Vec` provides a contiguous growable array type with contents allocated with the kernel's allocators (e.g. `Kmalloc`, `Vmalloc` or `KVmalloc`). In contrast to Rust's stdlib `Vec` type, the kernel `Vec` type considers the kernel's GFP flags for all appropriate functions, always reports allocation failures through `Result<_, AllocError>` and remains independent from unstable features. [ This patch starts using a new unstable feature, `inline_const`, but it was stabilized in Rust 1.79.0, i.e. the next version after the minimum one, thus it will not be an issue. - Miguel ] 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/20241004154149.93856-17-dakr@kernel.org [ Cleaned `rustdoc` unescaped backtick warning, added a couple more backticks elsewhere, fixed typos, sorted `feature`s, rewrapped documentation lines. - 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>
2024-10-10rust: kernel: move `FromBytes` and `AsBytes` traits to a new `transmute` moduleAliet Exposito Garcia
Refactor the `FromBytes` and `AsBytes` traits from `types.rs` into a new `transmute.rs` module: - Add `rust/kernel/transmute.rs` with the definitions of `FromBytes` and `AsBytes`. - Remove the same trait definitions from `rust/kernel/types.rs`. - Update `rust/kernel/uaccess.rs` to import `AsBytes` and `FromBytes` from `transmute.rs`. The traits and their implementations remain unchanged. Suggested-by: Benno Lossin <benno.lossin@proton.me> Link: https://github.com/Rust-for-Linux/linux/issues/1117 Signed-off-by: Aliet Exposito Garcia <aliet.exposito@gmail.com> Reviewed-by: Fiona Behrens <me@kloenk.dev> Reviewed-by: Benno Lossin <benno.lossin@proton.me> Link: https://lore.kernel.org/r/20240918225115.2309224-2-aliet.exposito@gmail.com [ Rebased on top of the lints series and slightly reworded. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2024-10-09rust: miscdevice: add base miscdevice abstractionAlice Ryhl
Provide a `MiscDevice` trait that lets you specify the file operations that you wish to provide for your misc device. For now, only three file operations are provided: open, close, ioctl. These abstractions only support MISC_DYNAMIC_MINOR. This enforces that new miscdevices should not hard-code a minor number. When implementing ioctl, the Result type is used. This means that you can choose to return either of: * An integer of type isize. * An errno using the kernel::error::Error type. When returning an isize, the integer is returned verbatim. It's mainly intended for returning positive integers to userspace. However, it is technically possible to return errors via the isize return value too. To avoid having a dependency on files, this patch does not provide the file operations callbacks a pointer to the file. This means that they cannot check file properties such as O_NONBLOCK (which Binder needs). Support for that can be added as a follow-up. To avoid having a dependency on vma, this patch does not provide any way to implement mmap (which Binder needs). Support for that can be added as a follow-up. Rust Binder will use these abstractions to create the /dev/binder file when binderfs is disabled. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/rust-for-linux/20240328195457.225001-1-wedsonaf@gmail.com/ Link: https://lore.kernel.org/r/20241001-b4-miscdevice-v2-2-330d760041fa@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-10-08rust: add PidNamespaceChristian Brauner
The lifetime of `PidNamespace` is bound to `Task` and `struct pid`. The `PidNamespace` of a `Task` doesn't ever change once the `Task` is alive. A `unshare(CLONE_NEWPID)` or `setns(fd_pidns/pidfd, CLONE_NEWPID)` will not have an effect on the calling `Task`'s pid namespace. It will only effect the pid namespace of children created by the calling `Task`. This invariant guarantees that after having acquired a reference to a `Task`'s pid namespace it will remain unchanged. When a task has exited and been reaped `release_task()` will be called. This will set the `PidNamespace` of the task to `NULL`. So retrieving the `PidNamespace` of a task that is dead will return `NULL`. Note, that neither holding the RCU lock nor holding a referencing count to the `Task` will prevent `release_task()` being called. In order to retrieve the `PidNamespace` of a `Task` the `task_active_pid_ns()` function can be used. There are two cases to consider: (1) retrieving the `PidNamespace` of the `current` task (2) retrieving the `PidNamespace` of a non-`current` task From system call context retrieving the `PidNamespace` for case (1) is always safe and requires neither RCU locking nor a reference count to be held. Retrieving the `PidNamespace` after `release_task()` for current will return `NULL` but no codepath like that is exposed to Rust. Retrieving the `PidNamespace` from system call context for (2) requires RCU protection. Accessing `PidNamespace` outside of RCU protection requires a reference count that must've been acquired while holding the RCU lock. Note that accessing a non-`current` task means `NULL` can be returned as the non-`current` task could have already passed through `release_task()`. To retrieve (1) the `current_pid_ns!()` macro should be used which ensure that the returned `PidNamespace` cannot outlive the calling scope. The associated `current_pid_ns()` function should not be called directly as it could be abused to created an unbounded lifetime for `PidNamespace`. The `current_pid_ns!()` macro allows Rust to handle the common case of accessing `current`'s `PidNamespace` without RCU protection and without having to acquire a reference count. For (2) the `task_get_pid_ns()` method must be used. This will always acquire a reference on `PidNamespace` and will return an `Option` to force the caller to explicitly handle the case where `PidNamespace` is `None`, something that tends to be forgotten when doing the equivalent operation in `C`. Missing RCU primitives make it difficult to perform operations that are otherwise safe without holding a reference count as long as RCU protection is guaranteed. But it is not important currently. But we do want it in the future. Note for (2) the required RCU protection around calling `task_active_pid_ns()` synchronizes against putting the last reference of the associated `struct pid` of `task->thread_pid`. The `struct pid` stored in that field is used to retrieve the `PidNamespace` of the caller. When `release_task()` is called `task->thread_pid` will be `NULL`ed and `put_pid()` on said `struct pid` will be delayed in `free_pid()` via `call_rcu()` allowing everyone with an RCU protected access to the `struct pid` acquired from `task->thread_pid` to finish. Link: https://lore.kernel.org/r/20241002-brauner-rust-pid_namespace-v5-1-a90e70d44fde@kernel.org Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-08rust: add seqfile abstractionAlice Ryhl
This adds a simple seq file abstraction that lets you print to a seq file using ordinary Rust printing syntax. An example user from Rust Binder: pub(crate) fn full_debug_print( &self, m: &SeqFile, owner_inner: &mut ProcessInner, ) -> Result<()> { let prio = self.node_prio(); let inner = self.inner.access_mut(owner_inner); seq_print!( m, " node {}: u{:016x} c{:016x} pri {}:{} hs {} hw {} cs {} cw {}", self.debug_id, self.ptr, self.cookie, prio.sched_policy, prio.prio, inner.strong.has_count, inner.weak.has_count, inner.strong.count, inner.weak.count, ); if !inner.refs.is_empty() { seq_print!(m, " proc"); for node_ref in &inner.refs { seq_print!(m, " {}", node_ref.process.task.pid()); } } seq_print!(m, "\n"); for t in &inner.oneway_todo { t.debug_print_inner(m, " pending async transaction "); } Ok(()) } The `SeqFile` type is marked not thread safe so that `call_printf` can be a `&self` method. The alternative is to use `self: Pin<&mut Self>` which is inconvenient, or to have `SeqFile` wrap a pointer instead of wrapping the C struct directly. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://lore.kernel.org/r/20241001-seqfile-v1-1-dfcd0fc21e96@google.com Signed-off-by: Christian Brauner <brauner@kernel.org>
2024-10-08Merge patch series "File abstractions needed by Rust Binder"Christian Brauner
Alice Ryhl <aliceryhl@google.com> says: This patchset contains the file abstractions needed by the Rust implementation of the Binder driver. Please see the Rust Binder RFC for usage examples: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-0-08ba9197f637@google.com Users of "rust: types: add `NotThreadSafe`": [PATCH 5/9] rust: file: add `FileDescriptorReservation` Users of "rust: task: add `Task::current_raw`": [PATCH 7/9] rust: file: add `Kuid` wrapper [PATCH 8/9] rust: file: add `DeferredFdCloser` Users of "rust: file: add Rust abstraction for `struct file`": [PATCH RFC 02/20] rust_binder: add binderfs support to Rust binder [PATCH RFC 03/20] rust_binder: add threading support Users of "rust: cred: add Rust abstraction for `struct cred`": [PATCH RFC 05/20] rust_binder: add nodes and context managers [PATCH RFC 06/20] rust_binder: add oneway transactions [PATCH RFC 11/20] rust_binder: send nodes in transaction [PATCH RFC 13/20] rust_binder: add BINDER_TYPE_FD support Users of "rust: security: add abstraction for secctx": [PATCH RFC 06/20] rust_binder: add oneway transactions Users of "rust: file: add `FileDescriptorReservation`": [PATCH RFC 13/20] rust_binder: add BINDER_TYPE_FD support [PATCH RFC 14/20] rust_binder: add BINDER_TYPE_FDA support Users of "rust: file: add `Kuid` wrapper": [PATCH RFC 05/20] rust_binder: add nodes and context managers [PATCH RFC 06/20] rust_binder: add oneway transactions Users of "rust: file: add abstraction for `poll_table`": [PATCH RFC 07/20] rust_binder: add epoll support This patchset has some uses of read_volatile in place of READ_ONCE. Please see the following rfc for context on this: https://lore.kernel.org/all/20231025195339.1431894-1-boqun.feng@gmail.com/ * patches from https://lore.kernel.org/r/20240915-alice-file-v10-0-88484f7a3dcf@google.com: rust: file: add abstraction for `poll_table` rust: file: add `Kuid` wrapper rust: file: add `FileDescriptorReservation` rust: security: add abstraction for secctx rust: cred: add Rust abstraction for `struct cred` rust: file: add Rust abstraction for `struct file` rust: task: add `Task::current_raw` rust: types: add `NotThreadSafe` Link: https://lore.kernel.org/r/20240915-alice-file-v10-0-88484f7a3dcf@google.com Signed-off-by: Christian Brauner <brauner@kernel.org>