Traits marked with `#[vtable]` need to provide default implementations
for optional functions. The C side represents these with `NULL` in the
vtable, so the default functions are never actually called. We do not
want to replicate the default behavior from C in Rust, because that is
not maintainable. Therefore we should use `build_error` in those default
implementations. The error message for that is provided at
`kernel::error::VTABLE_DEFAULT_ERROR`.
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Link: https://lore.kernel.org/r/20231026201855.1497680-1-benno.lossin@proton.me
[ Wrapped paragraph to 80 as requested and capitalized sentence. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Currently, for `const`s that bindgen doesn't recognise, we define a
helper constant with
const <TYPE> BINDINGS_<NAME> = <NAME>;
in `bindings_helper.h` and then we put
pub const <NAME>: <TYPE> = BINDINGS_<NAME>;
in `bindings/lib.rs`. This is fine since we currently only have 3
constants that are defined this way, but is going to be more annoying
when more constants are added since every new constant needs to be
defined in two places.
This patch changes the way we define constant helpers to
const <TYPE> RUST_CONST_HELPER_<NAME> = <NAME>;
and then use `sed` to postprocess Rust code generated by bindgen to
remove the distinct prefix, so users of the `bindings` crate can refer
to the name directly.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20231104145700.2495176-1-gary@garyguo.net
[ Reworded for typos. ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Pull workqueue rust bindings from Tejun Heo:
"Add rust bindings to allow rust code to schedule work items on
workqueues.
While the current bindings don't cover all of the workqueue API, it
provides enough for basic usage and can be expanded as needed"
* tag 'wq-for-6.7-rust-bindings' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
rust: workqueue: add examples
rust: workqueue: add `try_spawn` helper method
rust: workqueue: implement `WorkItemPointer` for pointer types
rust: workqueue: add helper for defining work_struct fields
rust: workqueue: define built-in queues
rust: workqueue: add low-level workqueue bindings
rust: sync: add `Arc::{from_raw, into_raw}`
Pull rust updates from Miguel Ojeda:
"A small one compared to the previous one in terms of features. In
terms of lines, as usual, the 'alloc' version upgrade accounts for
most of them.
Toolchain and infrastructure:
- Upgrade to Rust 1.73.0
This time around, due to how the kernel and Rust schedules have
aligned, there are two upgrades in fact. They contain the fixes for
a few issues we reported to the Rust project.
In addition, a few cleanups indicated by the upgraded compiler or
possible thanks to it. For instance, the compiler now detects
redundant explicit links.
- A couple changes to the Rust 'Makefile' so that it can be used with
toybox tools, allowing Rust to be used in the Android kernel build.
x86:
- Enable IBT if enabled in C
Documentation:
- Add "The Rust experiment" section to the Rust index page
MAINTAINERS:
- Add Maintainer Entry Profile field ('P:').
- Update our 'W:' field to point to the webpage we have been building
this year"
* tag 'rust-6.7' of https://github.com/Rust-for-Linux/linux:
docs: rust: add "The Rust experiment" section
x86: Enable IBT in Rust if enabled in C
rust: Use grep -Ev rather than relying on GNU grep
rust: Use awk instead of recent xargs
rust: upgrade to Rust 1.73.0
rust: print: use explicit link in documentation
rust: task: remove redundant explicit link
rust: kernel: remove `#[allow(clippy::new_ret_no_self)]`
MAINTAINERS: add Maintainer Entry Profile field for Rust
MAINTAINERS: update Rust webpage
rust: upgrade to Rust 1.72.1
rust: arc: add explicit `drop()` around `Box::from_raw()`
The future `rustdoc` in the Rust 1.73.0 upgrade requires an explicit
link for `pr_info!`:
error: unresolved link to `pr_info`
--> rust/kernel/print.rs:395:63
|
395 | /// Use only when continuing a previous `pr_*!` macro (e.g. [`pr_info!`]).
| ^^^^^^^^ no item named `pr_info` in scope
|
= note: `macro_rules` named `pr_info` exists in this crate, but it is not in scope at this link's location
= note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
Thus do so to avoid a broken link while upgrading.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Reviewed-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Link: https://lore.kernel.org/r/20231005210556.466856-3-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Starting with Rust 1.73.0, `rustdoc` detects redundant explicit
links with its new lint `redundant_explicit_links` [1]:
error: redundant explicit link target
--> rust/kernel/task.rs:85:21
|
85 | /// [`current`](crate::current) macro because it is safe.
| --------- ^^^^^^^^^^^^^^ explicit target is redundant
| |
| because label contains path that resolves to same destination
|
= note: when a link's destination is not specified,
the label is used to resolve intra-doc links
= note: `-D rustdoc::redundant-explicit-links` implied by `-D warnings`
help: remove explicit link target
|
85 | /// [`current`] macro because it is safe.
In order to avoid the warning in the compiler upgrade commit,
make it an intra-doc link as the tool suggests.
Link: https://github.com/rust-lang/rust/pull/113167 [1]
Reviewed-by: Finn Behrens <me@kloenk.dev>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com>
Link: https://lore.kernel.org/r/20231005210556.466856-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`Box::from_raw()` is `#[must_use]`, which means the result cannot
go unused.
In Rust 1.71.0, this was not detected because the block expression
swallows the diagnostic [1]:
unsafe { Box::from_raw(self.ptr.as_ptr()) };
It would have been detected, however, if the line had been instead:
unsafe { Box::from_raw(self.ptr.as_ptr()); }
i.e. the semicolon being inside the `unsafe` block, rather than
outside.
In Rust 1.72.0, the compiler started warning about this [2], so
without this patch we will get:
error: unused return value of `alloc::boxed::Box::<T>::from_raw` that must be used
--> rust/kernel/sync/arc.rs:302:22
|
302 | unsafe { Box::from_raw(self.ptr.as_ptr()) };
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
|
= note: call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`
= note: `-D unused-must-use` implied by `-D warnings`
help: use `let _ = ...` to ignore the resulting value
|
302 | unsafe { let _ = Box::from_raw(self.ptr.as_ptr()); };
| +++++++ +
Thus add an add an explicit `drop()` as the `#[must_use]`'s
annotation suggests (instead of the more general help line).
Link: https://github.com/rust-lang/rust/issues/104253 [1]
Link: https://github.com/rust-lang/rust/pull/112529 [2]
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Link: https://lore.kernel.org/r/20230823160244.188033-2-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
This adds two examples of how to use the workqueue. The first example
shows how to use it when you only have one `work_struct` field, and the
second example shows how to use it when you have multiple `work_struct`
fields.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This adds a convenience method that lets you spawn a closure for
execution on a workqueue. This will be the most convenient way to use
workqueues, but it is fallible because it needs to allocate memory.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
This implements the `WorkItemPointer` trait for the pointer types that
you are likely to use the workqueue with. The `Arc` type is for
reference counted objects, and the `Pin<Box<T>>` type is for objects
where the caller has exclusive ownership of the object.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
The main challenge with defining `work_struct` fields is making sure
that the function pointer stored in the `work_struct` is appropriate for
the work item type it is embedded in. It needs to know the offset of the
`work_struct` field being used (even if there are several!) so that it
can do a `container_of`, and it needs to know the type of the work item
so that it can call into the right user-provided code. All of this needs
to happen in a way that provides a safe API to the user, so that users
of the workqueue cannot mix up the function pointers.
There are three important pieces that are relevant when doing this:
* The pointer type.
* The work item struct. This is what the pointer points at.
* The `work_struct` field. This is a field of the work item struct.
This patch introduces a separate trait for each piece. The pointer type
is given a `WorkItemPointer` trait, which pointer types need to
implement to be usable with the workqueue. This trait will be
implemented for `Arc` and `Box` in a later patch in this patchset.
Implementing this trait is unsafe because this is where the
`container_of` operation happens, but user-code will not need to
implement it themselves.
The work item struct should then implement the `WorkItem` trait. This
trait is where user-code specifies what they want to happen when a work
item is executed. It also specifies what the correct pointer type is.
Finally, to make the work item struct know the offset of its
`work_struct` field, we use a trait called `HasWork<T, ID>`. If a type
implements this trait, then the type declares that, at the given offset,
there is a field of type `Work<T, ID>`. The trait is marked unsafe
because the OFFSET constant must be correct, but we provide an
`impl_has_work!` macro that can safely implement `HasWork<T>` on a type.
The macro expands to something that only compiles if the specified field
really has the type `Work<T>`. It is used like this:
```
struct MyWorkItem {
work_field: Work<MyWorkItem, 1>,
}
impl_has_work! {
impl HasWork<MyWorkItem, 1> for MyWorkItem { self.work_field }
}
```
Note that since the `Work` type is annotated with an id, you can have
several `work_struct` fields by using a different id for each one.
Co-developed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
We provide these methods because it lets us access these queues from
Rust without using unsafe code.
These methods return `&'static Queue`. References annotated with the
'static lifetime are used when the referent will stay alive forever.
That is ok for these queues because they are global variables and cannot
be destroyed.
Signed-off-by: Wedson Almeida Filho <walmeida@microsoft.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: "Andreas Hindborg (Samsung)" <nmi@metaspace.dk>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull rust updates from Miguel Ojeda:
"In terms of lines, most changes this time are on the pinned-init API
and infrastructure. While we have a Rust version upgrade, and thus a
bunch of changes from the vendored 'alloc' crate as usual, this time
those do not account for many lines.
Toolchain and infrastructure:
- Upgrade to Rust 1.71.1. This is the second such upgrade, which is a
smaller jump compared to the last time.
This version allows us to remove the '__rust_*' allocator functions
-- the compiler now generates them as expected, thus now our
'KernelAllocator' is used.
It also introduces the 'offset_of!' macro in the standard library
(as an unstable feature) which we will need soon. So far, we were
using a declarative macro as a prerequisite in some not-yet-landed
patch series, which did not support sub-fields (i.e. nested
structs):
#[repr(C)]
struct S {
a: u16,
b: (u8, u8),
}
assert_eq!(offset_of!(S, b.1), 3);
- Upgrade to bindgen 0.65.1. This is the first time we upgrade its
version.
Given it is a fairly big jump, it comes with a fair number of
improvements/changes that affect us, such as a fix needed to
support LLVM 16 as well as proper support for '__noreturn' C
functions, which are now mapped to return the '!' type in Rust:
void __noreturn f(void); // C
pub fn f() -> !; // Rust
- 'scripts/rust_is_available.sh' improvements and fixes.
This series takes care of all the issues known so far and adds a
few new checks to cover for even more cases, plus adds some more
help texts. All this together will hopefully make problematic
setups easier to identify and to be solved by users building the
kernel.
In addition, it adds a test suite which covers all branches of the
shell script, as well as tests for the issues found so far.
- Support rust-analyzer for out-of-tree modules too.
- Give 'cfg's to rust-analyzer for the 'core' and 'alloc' crates.
- Drop 'scripts/is_rust_module.sh' since it is not needed anymore.
Macros crate:
- New 'paste!' proc macro.
This macro is a more flexible version of 'concat_idents!': it
allows the resulting identifier to be used to declare new items and
it allows to transform the identifiers before concatenating them,
e.g.
let x_1 = 42;
paste!(let [<x _2>] = [<x _1>];);
assert!(x_1 == x_2);
The macro is then used for several of the pinned-init API changes
in this pull.
Pinned-init API:
- Make '#[pin_data]' compatible with conditional compilation of
fields, allowing to write code like:
#[pin_data]
pub struct Foo {
#[cfg(CONFIG_BAR)]
a: Bar,
#[cfg(not(CONFIG_BAR))]
a: Baz,
}
- New '#[derive(Zeroable)]' proc macro for the 'Zeroable' trait,
which allows 'unsafe' implementations for structs where every field
implements the 'Zeroable' trait, e.g.:
#[derive(Zeroable)]
pub struct DriverData {
id: i64,
buf_ptr: *mut u8,
len: usize,
}
- Add '..Zeroable::zeroed()' syntax to the 'pin_init!' macro for
zeroing all other fields, e.g.:
pin_init!(Buf {
buf: [1; 64],
..Zeroable::zeroed()
});
- New '{,pin_}init_array_from_fn()' functions to create array
initializers given a generator function, e.g.:
let b: Box<[usize; 1_000]> = Box::init::<Error>(
init_array_from_fn(|i| i)
).unwrap();
assert_eq!(b.len(), 1_000);
assert_eq!(b[123], 123);
- New '{,pin_}chain' methods for '{,Pin}Init<T, E>' that allow to
execute a closure on the value directly after initialization, e.g.:
let foo = init!(Foo {
buf <- init::zeroed()
}).chain(|foo| {
foo.setup();
Ok(())
});
- Support arbitrary paths in init macros, instead of just identifiers
and generic types.
- Implement the 'Zeroable' trait for the 'UnsafeCell<T>' and
'Opaque<T>' types.
- Make initializer values inaccessible after initialization.
- Make guards in the init macros hygienic.
'allocator' module:
- Use 'krealloc_aligned()' in 'KernelAllocator::alloc' preventing
misaligned allocations when the Rust 1.71.1 upgrade is applied
later in this pull.
The equivalent fix for the previous compiler version (where
'KernelAllocator' is not yet used) was merged into 6.5 already,
which added the 'krealloc_aligned()' function used here.
- Implement 'KernelAllocator::{realloc, alloc_zeroed}' for
performance, using 'krealloc_aligned()' too, which forwards the
call to the C API.
'types' module:
- Make 'Opaque' be '!Unpin', removing the need to add a
'PhantomPinned' field to Rust structs that contain C structs which
must not be moved.
- Make 'Opaque' use 'UnsafeCell' as the outer type, rather than
inner.
Documentation:
- Suggest obtaining the source code of the Rust's 'core' library
using the tarball instead of the repository.
MAINTAINERS:
- Andreas and Alice, from Samsung and Google respectively, are
joining as reviewers of the "RUST" entry.
As well as a few other minor changes and cleanups"
* tag 'rust-6.6' of https://github.com/Rust-for-Linux/linux: (42 commits)
rust: init: update expanded macro explanation
rust: init: add `{pin_}chain` functions to `{Pin}Init<T, E>`
rust: init: make `PinInit<T, E>` a supertrait of `Init<T, E>`
rust: init: implement `Zeroable` for `UnsafeCell<T>` and `Opaque<T>`
rust: init: add support for arbitrary paths in init macros
rust: init: add functions to create array initializers
rust: init: add `..Zeroable::zeroed()` syntax for zeroing all missing fields
rust: init: make initializer values inaccessible after initializing
rust: init: wrap type checking struct initializers in a closure
rust: init: make guards in the init macros hygienic
rust: add derive macro for `Zeroable`
rust: init: make `#[pin_data]` compatible with conditional compilation of fields
rust: init: consolidate init macros
docs: rust: clarify what 'rustup override' does
docs: rust: update instructions for obtaining 'core' source
docs: rust: add command line to rust-analyzer section
scripts: generate_rust_analyzer: provide `cfg`s for `core` and `alloc`
rust: bindgen: upgrade to 0.65.1
rust: enable `no_mangle_with_rust_abi` Clippy lint
rust: upgrade to Rust 1.71.1
...
Pull kunit updates from Shuah Khan:
- add support for running Rust documentation tests as KUnit tests
- make init, str, sync, types doctests compilable/testable
- add support for attributes API which include speed, modules
attributes, ability to filter and report attributes
- add support for marking tests slow using attributes API
- add attributes API documentation
- fix a wild-memory-access bug in kunit_filter_suites() and a possible
memory leak in kunit_filter_suites()
- add support for counting number of test suites in a module, list
action to kunit test modules, and test filtering on module tests
* tag 'linux-kselftest-kunit-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (25 commits)
kunit: fix struct kunit_attr header
kunit: replace KUNIT_TRIGGER_STATIC_STUB maro with KUNIT_STATIC_STUB_REDIRECT
kunit: Allow kunit test modules to use test filtering
kunit: Make 'list' action available to kunit test modules
kunit: Report the count of test suites in a module
kunit: fix uninitialized variables bug in attributes filtering
kunit: fix possible memory leak in kunit_filter_suites()
kunit: fix wild-memory-access bug in kunit_filter_suites()
kunit: Add documentation of KUnit test attributes
kunit: add tests for filtering attributes
kunit: time: Mark test as slow using test attributes
kunit: memcpy: Mark tests as slow using test attributes
kunit: tool: Add command line interface to filter and report attributes
kunit: Add ability to filter attributes
kunit: Add module attribute
kunit: Add speed attribute
kunit: Add test attributes API structure
MAINTAINERS: add Rust KUnit files to the KUnit entry
rust: support running Rust documentation tests as KUnit ones
rust: types: make doctests compilable/testable
...
