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2026-02-10Merge tag 'rust-6.20-7.0' of ↵Linus Torvalds-4/+4
git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux Pull rust updates from Miguel Ojeda: "Toolchain and infrastructure: - Add '__rust_helper' annotation to the C helpers This is needed to inline these helpers into Rust code - Remove imports available via the prelude, treewide This was possible thanks to a new lint in Klint that Gary has implemented -- more Klint-related changes, including initial upstream support, are coming - Deduplicate pin-init flags 'kernel' crate: - Add support for calling a function exactly once with the new 'do_once_lite!' macro (and 'OnceLite' type) Based on this, add 'pr_*_once!' macros to print only once - Add 'impl_flags!' macro for defining common bitflags operations: impl_flags!( /// Represents multiple permissions. #[derive(Debug, Clone, Default, Copy, PartialEq, Eq)] pub struct Permissions(u32); /// Represents a single permission. #[derive(Debug, Clone, Copy, PartialEq, Eq)] pub enum Permission { /// Read permission. Read = 1 << 0, /// Write permission. Write = 1 << 1, /// Execute permission. Execute = 1 << 2, } ); let mut f: Permissions = Permission::Read | Permission::Write; assert!(f.contains(Permission::Read)); assert!(!f.contains(Permission::Execute)); f |= Permission::Execute; assert!(f.contains(Permission::Execute)); let f2: Permissions = Permission::Write | Permission::Execute; assert!((f ^ f2).contains(Permission::Read)); assert!(!(f ^ f2).contains(Permission::Write)); - 'bug' module: support 'CONFIG_DEBUG_BUGVERBOSE_DETAILED' in the 'warn_on!' macro in order to show the evaluated condition alongside the file path: ------------[ cut here ]------------ WARNING: [val == 1] linux/samples/rust/rust_minimal.rs:27 at ... Modules linked in: rust_minimal(+) - Add safety module with 'unsafe_precondition_assert!' macro, currently a wrapper for 'debug_assert!', intended to mark the validation of safety preconditions where possible: /// # Safety /// /// The caller must ensure that `index` is less than `N`. unsafe fn set_unchecked(&mut self, index: usize, value: T) { unsafe_precondition_assert!( index < N, "set_unchecked() requires index ({index}) < N ({N})" ); ... } - Add instructions to 'build_assert!' documentation requesting to always inline functions when used with function arguments - 'ptr' module: replace 'build_assert!' with a 'const' one - 'rbtree' module: reduce unsafe blocks on pointer derefs - 'transmute' module: implement 'FromBytes' and 'AsBytes' for inhabited ZSTs, and use it in Nova - More treewide replacements of 'c_str!' with C string literals 'macros' crate: - Rewrite most procedural macros ('module!', 'concat_idents!', '#[export]', '#[vtable]', '#[kunit_tests]') to use the 'syn' parsing library which we introduced last cycle, with better diagnostics This also allows to support '#[cfg]' properly in the '#[vtable]' macro, to support arbitrary types in 'module!' macro (not just an identifier) and to remove several custom parsing helpers we had - Use 'quote!' from the recently vendored 'quote' library and remove our custom one The vendored one also allows us to avoid quoting '"' and '{}' inside the template anymore and editors can now highlight it. In addition, it improves robustness as it eliminates the need for string quoting and escaping - Use 'pin_init::zeroed()' to simplify KUnit code 'pin-init' crate: - Rewrite all procedural macros ('[pin_]init!', '#[pin_data]', '#[pinned_drop]', 'derive([Maybe]Zeroable)') to use the 'syn' parsing library which we introduced last cycle, with better diagnostics - Implement 'InPlaceWrite' for '&'static mut MaybeUninit<T>'. This enables users to use external allocation mechanisms such as 'static_cell' - Support tuple structs in 'derive([Maybe]Zeroable)' - Support attributes on fields in '[pin_]init!' (such as '#[cfg(...)]') - Add a '#[default_error(<type>)]' attribute to '[pin_]init!' to override the default error (when no '? Error' is specified) - Support packed structs in '[pin_]init!' with '#[disable_initialized_field_access]' - Remove 'try_[pin_]init!' in favor of merging their feature with '[pin_]init!'. Update the kernel's own 'try_[pin_]init!' macros to use the 'default_error' attribute - Correct 'T: Sized' bounds to 'T: ?Sized' in the generated 'PinnedDrop' check by '#[pin_data]' Documentation: - Conclude the Rust experiment MAINTAINERS: - Add "RUST [RUST-ANALYZER]" entry for the rust-analyzer support. Tamir and Jesung will take care of it. They have both been active around it for a while. The new tree will flow through the Rust one - Add Gary as maintainer for "RUST [PIN-INIT]" - Update Boqun and Tamir emails to their kernel.org accounts And a few other cleanups and improvements" * tag 'rust-6.20-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (59 commits) rust: safety: introduce `unsafe_precondition_assert!` macro rust: add `impl_flags!` macro for defining common bitflag operations rust: print: Add pr_*_once macros rust: bug: Support DEBUG_BUGVERBOSE_DETAILED option rust: print: Add support for calling a function exactly once rust: kbuild: deduplicate pin-init flags gpu: nova-core: remove imports available via prelude rust: clk: replace `kernel::c_str!` with C-Strings MAINTAINERS: Update my email address to @kernel.org rust: macros: support `#[cfg]` properly in `#[vtable]` macro. rust: kunit: use `pin_init::zeroed` instead of custom null value rust: macros: rearrange `#[doc(hidden)]` in `module!` macro rust: macros: allow arbitrary types to be used in `module!` macro rust: macros: convert `#[kunit_tests]` macro to use `syn` rust: macros: convert `concat_idents!` to use `syn` rust: macros: convert `#[export]` to use `syn` rust: macros: use `quote!` for `module!` macro rust: macros: use `syn` to parse `module!` macro rust: macros: convert `#[vtable]` macro to use `syn` rust: macros: use `quote!` from vendored crate ...
2026-01-19rust: i2c: replace `kernel::c_str!` with C-StringsTamir Duberstein-4/+4
C-String literals were added in Rust 1.77. Replace instances of `kernel::c_str!` with C-String literals where possible. Signed-off-by: Tamir Duberstein <tamird@gmail.com> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://patch.msgid.link/20251222-cstr-i2c-v1-1-df1c258d4615@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-01-16rust: driver: drop device private data post unbindDanilo Krummrich-2/+2
Currently, the driver's device private data is allocated and initialized from driver core code called from bus abstractions after the driver's probe() callback returned the corresponding initializer. Similarly, the driver's device private data is dropped within the remove() callback of bus abstractions after calling the remove() callback of the corresponding driver. However, commit 6f61a2637abe ("rust: device: introduce Device::drvdata()") introduced an accessor for the driver's device private data for a Device<Bound>, i.e. a device that is currently bound to a driver. Obviously, this is in conflict with dropping the driver's device private data in remove(), since a device can not be considered to be fully unbound after remove() has finished: We also have to consider registrations guarded by devres - such as IRQ or class device registrations - which are torn down after remove() in devres_release_all(). Thus, it can happen that, for instance, a class device or IRQ callback still calls Device::drvdata(), which then runs concurrently to remove() (which sets dev->driver_data to NULL and drops the driver's device private data), before devres_release_all() started to tear down the corresponding registration. This is because devres guarded registrations can, as expected, access the corresponding Device<Bound> that defines their scope. In C it simply is the driver's responsibility to ensure that its device private data is freed after e.g. an IRQ registration is unregistered. Typically, C drivers achieve this by allocating their device private data with e.g. devm_kzalloc() before doing anything else, i.e. before e.g. registering an IRQ with devm_request_threaded_irq(), relying on the reverse order cleanup of devres. Technically, we could do something similar in Rust. However, the resulting code would be pretty messy: In Rust we have to differentiate between allocated but uninitialized memory and initialized memory in the type system. Thus, we would need to somehow keep track of whether the driver's device private data object has been initialized (i.e. probe() was successful and returned a valid initializer for this memory) and conditionally call the destructor of the corresponding object when it is freed. This is because we'd need to allocate and register the memory of the driver's device private data *before* it is initialized by the initializer returned by the driver's probe() callback, because the driver could already register devres guarded registrations within probe() outside of the driver's device private data initializer. Luckily there is a much simpler solution: Instead of dropping the driver's device private data at the end of remove(), we just drop it after the device has been fully unbound, i.e. after all devres callbacks have been processed. For this, we introduce a new post_unbind() callback private to the driver-core, i.e. the callback is neither exposed to drivers, nor to bus abstractions. This way, the driver-core code can simply continue to conditionally allocate the memory for the driver's device private data when the driver's initializer is returned from probe() - no change needed - and drop it when the driver-core code receives the post_unbind() callback. Closes: https://lore.kernel.org/all/DEZMS6Y4A7XE.XE7EUBT5SJFJ@kernel.org/ Fixes: 6f61a2637abe ("rust: device: introduce Device::drvdata()") Acked-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20260107103511.570525-7-dakr@kernel.org [ Remove #ifdef CONFIG_RUST, rename post_unbind() to post_unbind_rust(). - Danilo] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16rust: driver: add DriverData type to the DriverLayout traitDanilo Krummrich-0/+2
Add an associated type DriverData to the DriverLayout trait indicating the type of the driver's device private data. Acked-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20260107103511.570525-6-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16rust: driver: add DEVICE_DRIVER_OFFSET to the DriverLayout traitDanilo Krummrich-0/+3
Add an associated const DEVICE_DRIVER_OFFSET to the DriverLayout trait indicating the offset of the embedded struct device_driver within Self::DriverType, i.e. the specific driver structs, such as struct pci_driver or struct platform_driver. Acked-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20260107103511.570525-5-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16rust: driver: introduce a DriverLayout traitDanilo Krummrich-7/+11
The DriverLayout trait describes the layout of a specific driver structure, such as `struct pci_driver` or `struct platform_driver`. In a first step, this replaces the associated type RegType of the RegistrationOps with the DriverLayout::DriverType associated type. Acked-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20260107103511.570525-4-dakr@kernel.org [ Rename driver::Driver to driver::DriverLayout, as it represents the layout of a driver structure rather than the driver structure itself. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-15rust: i2c: do not drop device private data on shutdown()Danilo Krummrich-2/+2
We must not drop the device private data on shutdown(); none of the registrations attached to devres that might access the device private data are released before shutdown() is called. Hence, freeing the device private data on shutdown() can cause UAF bugs. Fixes: 57c5bd9aee94 ("rust: i2c: add basic I2C device and driver abstractions") Acked-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20260107103511.570525-2-dakr@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-24rust: i2c: prepare for `core::ffi::CStr`Miguel Ojeda-10/+4
The rust-next tree contains commit: 3b83f5d5e78a ("rust: replace `CStr` with `core::ffi::CStr`") which, when merged together with commits: 57c5bd9aee94 ("rust: i2c: add basic I2C device and driver abstractions") f3cc26a417b7 ("rust: i2c: add manual I2C device creation abstractions") from this tree (driver-core), produces errors like the following: error[E0599]: no method named `len_with_nul` found for reference `&'static ffi::CStr` in the current scope --> rust/kernel/i2c.rs:48:16 | 48 | id.len_with_nul() <= Self::I2C_NAME_SIZE, | ^^^^^^^^^^^^ method not found in `&CStr` error[E0599]: no method named `as_bytes_with_nul` found for reference `&'static ffi::CStr` in the current scope --> rust/kernel/i2c.rs:51:22 | 51 | let src = id.as_bytes_with_nul(); | ^^^^^^^^^^^^^^^^^ | help: there is a method `to_bytes_with_nul` with a similar name | 51 | let src = id.to_bytes_with_nul(); | ~~~~~~~~~~~~~~~~~ which were detected in linux-next by Stephen [1]. The `i2c` code can be independently prepared to be ready for the change, thus do so. The change is similar to the one done by Tamir in commit 657403637f7d ("rust: acpi: use `core::ffi::CStr` method names"). Link: https://lore.kernel.org/all/20251120181111.65ce75a0@canb.auug.org.au/ [1] Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Link: https://patch.msgid.link/20251123163536.1771801-1-ojeda@kernel.org Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-18rust: Add trait to convert a device reference to a bus device referenceMarkus Probst-0/+7
Implement the `AsBusDevice` trait for converting a `Device` reference to a bus device reference for all bus devices. The `AsBusDevice` trait allows abstractions to provide the bus device in class device callbacks. It must not be used by drivers and is intended for bus and class device abstractions only. Signed-off-by: Markus Probst <markus.probst@posteo.de> Link: https://patch.msgid.link/20251027200547.1038967-2-markus.probst@posteo.de [ * Remove unused import. * Change visibility of AsBusDevice to public. * Fix build for USB. * Add impl for I2cClient. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-18rust: i2c: add manual I2C device creation abstractionsIgor Korotin-1/+152
In addition to the basic I2C device support, add rust abstractions upon `i2c_new_client_device`/`i2c_unregister_device` C functions. Implement the core abstractions needed for manual creation/deletion of I2C devices, including: * `i2c::Registration` — a NonNull pointer created by the function `i2c_new_client_device` * `i2c::I2cAdapter` — a ref counted wrapper around `struct i2c_adapter` * `i2c::I2cBoardInfo` — a safe wrapper around `struct i2c_board_info` Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20251116162154.171493-1-igor.korotin.linux@gmail.com [ Remove unnecessary safety comment. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2025-11-18rust: i2c: add basic I2C device and driver abstractionsIgor Korotin-0/+434
Implement the core abstractions needed for I2C drivers, including: * `i2c::Driver` — the trait drivers must implement, including `probe` * `i2c::I2cClient` — a safe wrapper around `struct i2c_client` * `i2c::Adapter` — implements `driver::RegistrationOps` to hook into the generic `driver::Registration` machinery * `i2c::DeviceId` — a `RawDeviceIdIndex` implementation for I2C device IDs Acked-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Igor Korotin <igor.korotin.linux@gmail.com> Link: https://patch.msgid.link/20251116162144.171469-1-igor.korotin.linux@gmail.com [ Remove unnecessary safety comment; fix rustdoc `Device` -> `I2cClient`. - Danilo ] Signed-off-by: Danilo Krummrich <dakr@kernel.org>