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`
...
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/[email protected]/
And adjusted the message above. - Miguel ]
Signed-off-by: Benno Lossin <[email protected]>
Reviewed-by: Fiona Behrens <[email protected]>
Tested-by: Andreas Hindborg <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
Reintroduce dynamically-allocated LockClassKeys such that they are
automatically (de)registered. Require that all usages of LockClassKeys
ensure that they are Pin'd.
Currently, only `'static` LockClassKeys are supported, so Pin is
redundant. However, it is intended that dynamically-allocated
LockClassKeys will eventually be supported, so using Pin from the outset
will make that change simpler.
Closes: https://github.com/Rust-for-Linux/linux/issues/1102
Suggested-by: Benno Lossin <[email protected]>
Suggested-by: Boqun Feng <[email protected]>
Signed-off-by: Mitchell Levy <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Since we've exposed Lock::from_raw() and Guard::new() publically, we
want to be able to make sure that we assert that a lock is actually held
when constructing a Guard for it to handle instances of unsafe
Guard::new() calls outside of our lock module.
Hence add a new method assert_is_held() to Backend, which uses lockdep
to check whether or not a lock has been acquired. When lockdep is
disabled, this has no overhead.
[Boqun: Resolve the conflicts with exposing Guard::new(), reword the
commit log a bit and format "unsafe { <statement>; }" into "unsafe {
<statement> }" for the consistency. ]
Signed-off-by: Lyude Paul <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
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 <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ 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 <[email protected]>
Add support for creating global variables that are wrapped in a mutex or
spinlock.
The implementation here is intended to replace the global mutex
workaround found in the Rust Binder RFC [1]. In both cases, the global
lock must be initialized before first use. The macro is unsafe to use
for the same reason.
The separate initialization step is required because it is tricky to
access the value of __ARCH_SPIN_LOCK_UNLOCKED from Rust. Doing so will
require changes to the C side. That change will happen as a follow-up to
this patch.
Link: https://lore.kernel.org/rust-for-linux/[email protected]/#Z31drivers:android:context.rs [1]
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Boqun Feng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Simplified a few intra-doc links. Formatted a few comments. Reworded
title. - Miguel ]
Signed-off-by: Miguel Ojeda <[email protected]>
Rust's `unused_imports` lint covers both unused and redundant imports.
In the upcoming 1.78.0, the lint detects more cases of redundant imports
[1], e.g.:
error: the item `bindings` is imported redundantly
--> rust/kernel/print.rs:38:9
|
38 | use crate::bindings;
| ^^^^^^^^^^^^^^^ the item `bindings` is already defined by prelude
Most cases are `use crate::bindings`, plus a few other items like `Box`.
Thus clean them up.
Note that, in the `bindings` case, the message "defined by prelude"
above means the extern prelude, i.e. the `--extern` flags we pass.
Link: https://github.com/rust-lang/rust/pull/117772 [1]
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
Currently, all macros are reexported with #[macro_export] only, which
means that to access `new_work!` from the workqueue, you need to import
it from the path `kernel::new_work` instead of importing it from the
workqueue module like all other items in the workqueue. By adding
reexports of the macros, it becomes possible to import the macros from
the correct modules.
It's still possible to import the macros from the root, but I don't
think we can do anything about that.
There is no functional change. This is merely a code cleanliness
improvement.
Signed-off-by: Alice Ryhl <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Tested-by: Boqun Feng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[ Removed new `use kernel::prelude::*`s, reworded title. ]
Signed-off-by: Miguel Ojeda <[email protected]>
Fixes multiple trivial typos in documentation and comments of the
kernel crate.
allocator:
- Fix a trivial list item alignment issue in the last SAFETY comment of
`krealloc_aligned`.
init:
- Replace 'type' with 'trait' in the doc comments of the `PinInit` and
`Init` traits.
- Add colons before starting lists.
- Add spaces between the type and equal sign to respect the code
formatting rules in example code.
- End a sentence with a full stop instead of a colon.
ioctl:
- Replace 'an' with 'a' where appropriate.
str:
- Replace 'Return' with 'Returns' in the doc comment of `bytes_written`
as the text describes what the function does.
sync/lock:
- Fix a trivial list item alignment issue in the Safety section of the
`Backend` trait's description.
sync/lock/spinlock:
- The code in this module operates on spinlocks, not mutexes. Thus,
replace 'mutex' with 'spinlock' in the SAFETY comment of `unlock`.
workqueue:
- Replace "wont" with "won't" in the doc comment of `__enqueue`.
Signed-off-by: Valentin Obst <[email protected]>
Reviewed-by: Trevor Gross <[email protected]>
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
Some of our links use relative paths in order to point to files in the
source tree, e.g.:
//! C header: [`include/linux/printk.h`](../../../../include/linux/printk.h)
/// [`struct mutex`]: ../../../../include/linux/mutex.h
These are problematic because they are hard to maintain and do not support
`O=` builds.
Instead, provide support for `srctree`-relative links, e.g.:
//! C header: [`include/linux/printk.h`](srctree/include/linux/printk.h)
/// [`struct mutex`]: srctree/include/linux/mutex.h
The links are fixed after `rustdoc` generation to be based on the absolute
path to the source tree.
Essentially, this is the automatic version of Tomonori's fix [1],
suggested by Gary [2].
Suggested-by: Gary Guo <[email protected]>
Reported-by: FUJITA Tomonori <[email protected]>
Closes: https://lore.kernel.org/r/[email protected] [1]
Fixes: 48fadf4400 ("docs: Move rustdoc output, cross-reference it")
Link: https://lore.kernel.org/rust-for-linux/20231026154525.6d14b495@eugeo/ [2]
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Benno Lossin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Miguel Ojeda <[email protected]>
Rust documentation tests are going to be build/run-tested
with the KUnit integration added in a future patch, thus
update them to make them compilable/testable so that we
may start enforcing it.
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Reviewed-by: Björn Roy Baron <[email protected]>
Reviewed-by: Alice Ryhl <[email protected]>
Reviewed-by: David Gow <[email protected]>
Signed-off-by: Miguel Ojeda <[email protected]>
Signed-off-by: Shuah Khan <[email protected]>
It releases the lock, executes some function provided by the caller,
then reacquires the lock. This is preparation for the implementation of
condvars, which will sleep after between unlocking and relocking.
We need an explicit `relock` method for primitives like `SpinLock` that
have an irqsave variant: we use the guard state to determine if the lock
was originally acquired with the regular `lock` function or
`lock_irqsave`.
Reviewed-by: Martin Rodriguez Reboredo <[email protected]>
Signed-off-by: Wedson Almeida Filho <[email protected]>
Link: https://lore.kernel.org/rust-for-linux/[email protected]/
[ Removed the irqsave bits as discussed. ]
Signed-off-by: Miguel Ojeda <[email protected]>
Linus Torvalds