| Age | Commit message (Collapse) | Author | Files | Lines |
|---|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"Mutexes:
- Add killable flavor to guard definitions (Davidlohr Bueso)
- Remove the list_head from struct mutex (Matthew Wilcox)
- Rename mutex_init_lockep() (Davidlohr Bueso)
rwsems:
- Remove the list_head from struct rw_semaphore and
replace it with a single pointer (Matthew Wilcox)
- Fix logic error in rwsem_del_waiter() (Andrei Vagin)
Semaphores:
- Remove the list_head from struct semaphore (Matthew Wilcox)
Jump labels:
- Use ATOMIC_INIT() for initialization of .enabled (Thomas Weißschuh)
- Remove workaround for old compilers in initializations
(Thomas Weißschuh)
Lock context analysis changes and improvements:
- Add context analysis for rwsems (Peter Zijlstra)
- Fix rwlock and spinlock lock context annotations (Bart Van Assche)
- Fix rwlock support in <linux/spinlock_up.h> (Bart Van Assche)
- Add lock context annotations in the spinlock implementation
(Bart Van Assche)
- signal: Fix the lock_task_sighand() annotation (Bart Van Assche)
- ww-mutex: Fix the ww_acquire_ctx function annotations
(Bart Van Assche)
- Add lock context support in do_raw_{read,write}_trylock()
(Bart Van Assche)
- arm64, compiler-context-analysis: Permit alias analysis through
__READ_ONCE() with CONFIG_LTO=y (Marco Elver)
- Add __cond_releases() (Peter Zijlstra)
- Add context analysis for mutexes (Peter Zijlstra)
- Add context analysis for rtmutexes (Peter Zijlstra)
- Convert futexes to compiler context analysis (Peter Zijlstra)
Rust integration updates:
- Add atomic fetch_sub() implementation (Andreas Hindborg)
- Refactor various rust_helper_ methods for expansion (Boqun Feng)
- Add Atomic<*{mut,const} T> support (Boqun Feng)
- Add atomic operation helpers over raw pointers (Boqun Feng)
- Add performance-optimal Flag type for atomic booleans, to avoid
slow byte-sized RMWs on architectures that don't support them.
(FUJITA Tomonori)
- Misc cleanups and fixes (Andreas Hindborg, Boqun Feng, FUJITA
Tomonori)
LTO support updates:
- arm64: Optimize __READ_ONCE() with CONFIG_LTO=y (Marco Elver)
- compiler: Simplify generic RELOC_HIDE() (Marco Elver)
Miscellaneous fixes and cleanups by Peter Zijlstra, Randy Dunlap,
Thomas Weißschuh, Davidlohr Bueso and Mikhail Gavrilov"
* tag 'locking-core-2026-04-13' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (39 commits)
compiler: Simplify generic RELOC_HIDE()
locking: Add lock context annotations in the spinlock implementation
locking: Add lock context support in do_raw_{read,write}_trylock()
locking: Fix rwlock support in <linux/spinlock_up.h>
lockdep: Raise default stack trace limits when KASAN is enabled
cleanup: Optimize guards
jump_label: remove workaround for old compilers in initializations
jump_label: use ATOMIC_INIT() for initialization of .enabled
futex: Convert to compiler context analysis
locking/rwsem: Fix logic error in rwsem_del_waiter()
locking/rwsem: Add context analysis
locking/rtmutex: Add context analysis
locking/mutex: Add context analysis
compiler-context-analysys: Add __cond_releases()
locking/mutex: Remove the list_head from struct mutex
locking/semaphore: Remove the list_head from struct semaphore
locking/rwsem: Remove the list_head from struct rw_semaphore
rust: atomic: Update a safety comment in impl of `fetch_add()`
rust: sync: atomic: Update documentation for `fetch_add()`
rust: sync: atomic: Add fetch_sub()
...
|
|
With the Rust version bump in place, the `RUSTC_HAS_COERCE_POINTEE`
Kconfig (automatic) option is always true.
Thus remove the option and simplify the code.
In particular, this includes removing our use of the predecessor unstable
features we used with Rust < 1.84.0 (`coerce_unsized`, `dispatch_from_dyn`
and `unsize`).
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
Due to Rust macro scoping rules, all macros defined in a crate using
`#[macro_export]` end up in the top-level. For the list macros, we
re-export them inside the list module, and expect users to use
`kernel::list::macro_name!()`.
Use `#[doc(hidden)]` on the macro definition, and use `#[doc(inline)]` on
the re-export to make the macro appear to be defined at module-level inside
documentation.
The other exported types are already automatically `#[doc(inline)]` because
they are defined in a non-public module, so there is no need to split the
macro re-exports out.
Signed-off-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260312174700.4016015-1-gary@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
Make AtomicTracker use AtomicFlag instead of Atomic<bool> to avoid
slow byte-sized RMWs on architectures that don't support them.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: Boqun Feng <boqun@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260129122622.3896144-3-tomo@aliasing.net
Link: https://patch.msgid.link/20260303201701.12204-10-boqun@kernel.org
|
|
Convert uses of `AtomicBool` to `Atomic<bool>`.
Note that the compare_exchange migration simplifies to
`try_cmpxchg()`, since `try_cmpxchg()` provides relaxed ordering on
failure, making the explicit failure ordering unnecessary.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251230093718.1852322-3-fujita.tomonori@gmail.com
|
|
Correct the typo (s/much/must) in the ListArc documentation.
Reported-by: Miguel Ojeda <ojeda@kernel.org>
Closes: https://github.com/Rust-for-Linux/linux/issues/1166
Fixes: a48026315cd7 ("rust: list: add tracking for ListArc")
Signed-off-by: Sylvan Smit <sylvan@sylvansmit.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250529162923.434978-1-sylvan@sylvansmit.com
[ Changed tag to "Reported-by" and sorted. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
Clean Rust documentation section headers to use plural names.
Suggested-by: Miguel Ojeda <ojeda@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1110
Signed-off-by: Patrick Miller <paddymills@proton.me>
Link: https://lore.kernel.org/r/20241002022749.390836-1-paddymills@proton.me
[ Removed the `init` one that doesn't apply anymore and
reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
Commit dbd5058ba60c ("rust: make pin-init its own crate") moved all
items from pin-init into the pin-init crate, including the
`assert_pinned!` macro.
Thus fix the path of the sole user of the `assert_pinned!` macro.
This occurrence was missed in the commit above, since it is in a macro
rule that has no current users (although binder is a future user).
Cc: stable@kernel.org
Fixes: dbd5058ba60c ("rust: make pin-init its own crate")
Signed-off-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250525173450.853413-1-lossin@kernel.org
[ Reworded slightly as discussed in the list. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
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>
|
|
The term "receiver" means that a type can be used as the type of `self`,
and thus enables method call syntax `foo.bar()` instead of
`Foo::bar(foo)`. Stable Rust as of today (1.81) enables a limited
selection of types (primitives and types in std, e.g. `Box` and `Arc`)
to be used as receivers, while custom types cannot.
We want the kernel `Arc` type to have the same functionality as the Rust
std `Arc`, so we use the `Receiver` trait (gated behind `receiver_trait`
unstable feature) to gain the functionality.
The `arbitrary_self_types` RFC [1] (tracking issue [2]) is accepted and
it will allow all types that implement a new `Receiver` trait (different
from today's unstable trait) to be used as receivers. This trait will be
automatically implemented for all `Deref` types, which include our `Arc`
type, so we no longer have to opt-in to be used as receiver. To prepare
us for the change, remove the `Receiver` implementation and the
associated feature. To still allow `Arc` and others to be used as method
receivers, turn on `arbitrary_self_types` feature instead.
This feature gate is introduced in 1.23.0. It used to enable both
`Deref` types and raw pointer types to be used as receivers, but the
latter is now split into a different feature gate in Rust 1.83 nightly.
We do not need receivers on raw pointers so this change would not affect
us and usage of `arbitrary_self_types` feature would work for all Rust
versions that we support (>=1.78).
Cc: Adrian Taylor <ade@hohum.me.uk>
Link: https://github.com/rust-lang/rfcs/pull/3519 [1]
Link: https://github.com/rust-lang/rust/issues/44874 [2]
Signed-off-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915132734.1653004-1-gary@garyguo.net
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
Add the actual linked list itself.
The linked list uses the following design: The List type itself just has
a single pointer to the first element of the list. And the actual list
items then form a cycle. So the last item is `first->prev`.
This is slightly different from the usual kernel linked list. Matching
that exactly would amount to giving List two pointers, and having it be
part of the cycle of items. This alternate design has the advantage that
the cycle is never completely empty, which can reduce the number of
branches in some cases. However, it also has the disadvantage that List
must be pinned, which this design is trying to avoid.
Having the list items form a cycle rather than having null pointers at
the beginning/end is convenient for several reasons. For one, it lets us
store only one pointer in List, and it simplifies the implementation of
several functions.
Unfortunately, the `remove` function that removes an arbitrary element
from the list has to be unsafe. This is needed because there is no way
to handle the case where you pass an element from the wrong list. For
example, if it is the first element of some other list, then that other
list's `first` pointer would not be updated. Similarly, it could be a
data race if you try to remove it from two different lists in parallel.
(There's no problem with passing `remove` an item that's not in any
list. Additionally, other removal methods such as `pop_front` need not
be unsafe, as they can't be used to remove items from another list.)
A future patch in this series will introduce support for cursors that
can be used to remove arbitrary items without unsafe code.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-6-f5f5e8075da0@google.com
[ Fixed a few typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
Add the ability to track whether a ListArc exists for a given value,
allowing for the creation of ListArcs without going through UniqueArc.
The `impl_list_arc_safe!` macro is extended with a `tracked_by` strategy
that defers the tracking of ListArcs to a field of the struct.
Additionally, the AtomicListArcTracker type is introduced, which can
track whether a ListArc exists using an atomic. By deferring the
tracking to a field of type AtomicListArcTracker, structs gain the
ability to create ListArcs without going through a UniqueArc.
Rust Binder uses this for some objects where we want to be able to
insert them into a linked list at any time. Using the
AtomicListArcTracker, we are able to check whether an item is already in
the list, and if not, we can create a `ListArc` and push it.
The macro has the ability to defer the tracking of ListArcs to a field,
using whatever strategy that field has. Since we don't add any
strategies other than AtomicListArcTracker, another similar option would
be to hard-code that the field should be an AtomicListArcTracker.
However, Rust Binder has a case where the AtomicListArcTracker is not
stored directly in the struct, but in a sub-struct. Furthermore, the
outer struct is generic:
struct Wrapper<T: ?Sized> {
links: ListLinks,
inner: T,
}
Here, the Wrapper struct implements ListArcSafe with `tracked_by inner`,
and then the various types used with `inner` also uses the macro to
implement ListArcSafe. Some of them use the untracked strategy, and some
of them use tracked_by with an AtomicListArcTracker. This way, Wrapper
just inherits whichever choice `inner` has made.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-3-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
|
The `ListArc` type can be thought of as a special reference to a
refcounted object that owns the permission to manipulate the
`next`/`prev` pointers stored in the refcounted object. By ensuring that
each object has only one `ListArc` reference, the owner of that
reference is assured exclusive access to the `next`/`prev` pointers.
When a `ListArc` is inserted into a `List`, the `List` takes ownership
of the `ListArc` reference.
There are various strategies for ensuring that a value has only one
`ListArc` reference. The simplest is to convert a `UniqueArc` into a
`ListArc`. However, the refcounted object could also keep track of
whether a `ListArc` exists using a boolean, which could allow for the
creation of new `ListArc` references from an `Arc` reference. Whatever
strategy is used, the relevant tracking is referred to as "the tracking
inside `T`", and the `ListArcSafe` trait (and its subtraits) are used to
update the tracking when a `ListArc` is created or destroyed.
Note that we allow the case where the tracking inside `T` thinks that a
`ListArc` exists, but actually, there isn't a `ListArc`. However, we do
not allow the opposite situation where a `ListArc` exists, but the
tracking thinks it doesn't. This is because the former can at most
result in us failing to create a `ListArc` when the operation could
succeed, whereas the latter can result in the creation of two `ListArc`
references. Only the latter situation can lead to memory safety issues.
This patch introduces the `impl_list_arc_safe!` macro that allows you to
implement `ListArcSafe` for types using the strategy where a `ListArc`
can only be created from a `UniqueArc`. Other strategies are introduced
in later patches.
This is part of the linked list that Rust Binder will use for many
different things. The strategy where a `ListArc` can only be created
from a `UniqueArc` is actually sufficient for most of the objects that
Rust Binder needs to insert into linked lists. Usually, these are todo
items that are created and then immediately inserted into a queue.
The const generic ID allows objects to have several prev/next pointer
pairs so that the same object can be inserted into several different
lists. You are able to have several `ListArc` references as long as they
correspond to different pointer pairs. The ID itself is purely a
compile-time concept and will not be present in the final binary. Both
the `List` and the `ListArc` will need to agree on the ID for them to
work together. Rust Binder uses this in a few places (e.g. death
recipients) where the same object can be inserted into both generic todo
lists and some other lists for tracking the status of the object.
The ID is a const generic rather than a type parameter because the
`pair_from_unique` method needs to be able to assert that the two ids
are different. There's no easy way to assert that when using types
instead of integers.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-2-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
|
