Lock debugging:
- Implement compiler-driven static analysis locking context
checking, using the upcoming Clang 22 compiler's context
analysis features. (Marco Elver)
We removed Sparse context analysis support, because prior to
removal even a defconfig kernel produced 1,700+ context
tracking Sparse warnings, the overwhelming majority of which
are false positives. On an allmodconfig kernel the number of
false positive context tracking Sparse warnings grows to
over 5,200... On the plus side of the balance actual locking
bugs found by Sparse context analysis is also rather ... sparse:
I found only 3 such commits in the last 3 years. So the
rate of false positives and the maintenance overhead is
rather high and there appears to be no active policy in
place to achieve a zero-warnings baseline to move the
annotations & fixers to developers who introduce new code.
Clang context analysis is more complete and more aggressive
in trying to find bugs, at least in principle. Plus it has
a different model to enabling it: it's enabled subsystem by
subsystem, which results in zero warnings on all relevant
kernel builds (as far as our testing managed to cover it).
Which allowed us to enable it by default, similar to other
compiler warnings, with the expectation that there are no
warnings going forward. This enforces a zero-warnings baseline
on clang-22+ builds. (Which are still limited in distribution,
admittedly.)
Hopefully the Clang approach can lead to a more maintainable
zero-warnings status quo and policy, with more and more
subsystems and drivers enabling the feature. Context tracking
can be enabled for all kernel code via WARN_CONTEXT_ANALYSIS_ALL=y
(default disabled), but this will generate a lot of false positives.
( Having said that, Sparse support could still be added back,
if anyone is interested - the removal patch is still
relatively straightforward to revert at this stage. )
Rust integration updates: (Alice Ryhl, Fujita Tomonori, Boqun Feng)
- Add support for Atomic<i8/i16/bool> and replace most Rust native
AtomicBool usages with Atomic<bool>
- Clean up LockClassKey and improve its documentation
- Add missing Send and Sync trait implementation for SetOnce
- Make ARef Unpin as it is supposed to be
- Add __rust_helper to a few Rust helpers as a preparation for
helper LTO
- Inline various lock related functions to avoid additional
function calls.
WW mutexes:
- Extend ww_mutex tests and other test-ww_mutex updates (John Stultz)
Misc fixes and cleanups:
- rcu: Mark lockdep_assert_rcu_helper() __always_inline
(Arnd Bergmann)
- locking/local_lock: Include more missing headers (Peter Zijlstra)
- seqlock: fix scoped_seqlock_read kernel-doc (Randy Dunlap)
- rust: sync: Replace `kernel::c_str!` with C-Strings
(Tamir Duberstein)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=N1gA
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2026-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"Lock debugging:
- Implement compiler-driven static analysis locking context checking,
using the upcoming Clang 22 compiler's context analysis features
(Marco Elver)
We removed Sparse context analysis support, because prior to
removal even a defconfig kernel produced 1,700+ context tracking
Sparse warnings, the overwhelming majority of which are false
positives. On an allmodconfig kernel the number of false positive
context tracking Sparse warnings grows to over 5,200... On the plus
side of the balance actual locking bugs found by Sparse context
analysis is also rather ... sparse: I found only 3 such commits in
the last 3 years. So the rate of false positives and the
maintenance overhead is rather high and there appears to be no
active policy in place to achieve a zero-warnings baseline to move
the annotations & fixers to developers who introduce new code.
Clang context analysis is more complete and more aggressive in
trying to find bugs, at least in principle. Plus it has a different
model to enabling it: it's enabled subsystem by subsystem, which
results in zero warnings on all relevant kernel builds (as far as
our testing managed to cover it). Which allowed us to enable it by
default, similar to other compiler warnings, with the expectation
that there are no warnings going forward. This enforces a
zero-warnings baseline on clang-22+ builds (Which are still limited
in distribution, admittedly)
Hopefully the Clang approach can lead to a more maintainable
zero-warnings status quo and policy, with more and more subsystems
and drivers enabling the feature. Context tracking can be enabled
for all kernel code via WARN_CONTEXT_ANALYSIS_ALL=y (default
disabled), but this will generate a lot of false positives.
( Having said that, Sparse support could still be added back,
if anyone is interested - the removal patch is still
relatively straightforward to revert at this stage. )
Rust integration updates: (Alice Ryhl, Fujita Tomonori, Boqun Feng)
- Add support for Atomic<i8/i16/bool> and replace most Rust native
AtomicBool usages with Atomic<bool>
- Clean up LockClassKey and improve its documentation
- Add missing Send and Sync trait implementation for SetOnce
- Make ARef Unpin as it is supposed to be
- Add __rust_helper to a few Rust helpers as a preparation for
helper LTO
- Inline various lock related functions to avoid additional function
calls
WW mutexes:
- Extend ww_mutex tests and other test-ww_mutex updates (John
Stultz)
Misc fixes and cleanups:
- rcu: Mark lockdep_assert_rcu_helper() __always_inline (Arnd
Bergmann)
- locking/local_lock: Include more missing headers (Peter Zijlstra)
- seqlock: fix scoped_seqlock_read kernel-doc (Randy Dunlap)
- rust: sync: Replace `kernel::c_str!` with C-Strings (Tamir
Duberstein)"
* tag 'locking-core-2026-02-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (90 commits)
locking/rwlock: Fix write_trylock_irqsave() with CONFIG_INLINE_WRITE_TRYLOCK
rcu: Mark lockdep_assert_rcu_helper() __always_inline
compiler-context-analysis: Remove __assume_ctx_lock from initializers
tomoyo: Use scoped init guard
crypto: Use scoped init guard
kcov: Use scoped init guard
compiler-context-analysis: Introduce scoped init guards
cleanup: Make __DEFINE_LOCK_GUARD handle commas in initializers
seqlock: fix scoped_seqlock_read kernel-doc
tools: Update context analysis macros in compiler_types.h
rust: sync: Replace `kernel::c_str!` with C-Strings
rust: sync: Inline various lock related methods
rust: helpers: Move #define __rust_helper out of atomic.c
rust: wait: Add __rust_helper to helpers
rust: time: Add __rust_helper to helpers
rust: task: Add __rust_helper to helpers
rust: sync: Add __rust_helper to helpers
rust: refcount: Add __rust_helper to helpers
rust: rcu: Add __rust_helper to helpers
rust: processor: Add __rust_helper to helpers
...
For arm32, on a x86_64 builder, running the `rusttest` target yields:
error[E0080]: evaluation of constant value failed
--> rust/kernel/static_assert.rs:37:23
|
37 | const _: () = ::core::assert!($condition $(,$arg)?);
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the evaluated program panicked at 'assertion failed: size_of::<isize>() == size_of::<isize_atomic_repr>()', rust/kernel/sync/atomic/predefine.rs:68:1
|
::: rust/kernel/sync/atomic/predefine.rs:68:1
|
68 | static_assert!(size_of::<isize>() == size_of::<isize_atomic_repr>());
| -------------------------------------------------------------------- in this macro invocation
|
= note: this error originates in the macro `::core::assert` which comes from the expansion of the macro `static_assert` (in Nightly builds, run with -Z macro-backtrace for more info)
The reason is that `rusttest` runs on the host, so for e.g. a x86_64
builder `isize` is 64 bits but it is not a `CONFIG_64BIT` build.
Fix it by providing a stub for `rusttest` as usual.
Fixes: 84c6d36bca ("rust: sync: atomic: Add Atomic<{usize,isize}>")
Cc: stable@vger.kernel.org
Reviewed-by: Onur Özkan <work@onurozkan.dev>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20260123233432.22703-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`build_assert` relies on the compiler to optimize out its error path.
Functions using it with its arguments must thus always be inlined,
otherwise the error path of `build_assert` might not be optimized out,
triggering a build error.
Cc: stable@vger.kernel.org
Fixes: bb38f35b35 ("rust: implement `kernel::sync::Refcount`")
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251208-io-build-assert-v3-5-98aded02c1ea@nvidia.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
While debugging a different issue [1], the following relocation was
noticed in the rust_binder.ko file:
R_AARCH64_CALL26 _RNvXNtNtNtCsdfZWD8DztAw_6kernel4sync4lock8spinlockNtB2_15SpinLockBackendNtB4_7Backend6unlock
This relocation (and a similar one for lock) occurred many times
throughout the module. That is not really useful because all this
function does is call spin_unlock(), so what we actually want here is
that a call to spin_unlock() dirctly is generated in favor of this
wrapper method.
Thus, mark these methods inline.
[boqun: Reword the commit message a bit]
Link: https://lore.kernel.org/p/20251111-binder-fix-list-remove-v1-0-8ed14a0da63d@google.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251218-inline-lock-unlock-v2-1-fbadac8bd61b@google.com
Add tests for Atomic<bool> operations.
Atomic<bool> does not fit into the existing u8/16/32/64 tests so
introduce a dedicated test for it.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20260101034922.2020334-3-fujita.tomonori@gmail.com
Add `bool` support, `Atomic<bool>` by using `i8` as its underlying
representation.
Rust specifies that `bool` has size 1 and alignment 1 [1], so it
matches `i8` on layout; keep `static_assert!()` checks to enforce this
assumption at build time.
[boqun: Remove the unnecessary impl AtomicImpl for bool]
Link: https://doc.rust-lang.org/reference/types/boolean.html [1]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20260101034922.2020334-2-fujita.tomonori@gmail.com
Add atomic xchg and cmpxchg operation support for i8 and i16 types
with tests.
Note that since the current implementation of
Atomic::<{i8,i16}>::{load,store}() is READ_ONCE()/WRITE_ONCE()-based.
The atomicity between load/store and xchg/cmpxchg is only guaranteed if
the architecture has native RmW support, hence i8/i16 is currently
AtomicImpl only when CONFIG_ARCH_SUPPORTS_ATOMIC_RWM=y.
[boqun: Make i8/i16 AtomicImpl only when
CONFIG_ARCH_SUPPORTS_ATOMIC_RWM=y]
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251228120546.1602275-4-fujita.tomonori@gmail.com
Rework the internal AtomicOps macro plumbing to generate per-type
implementations from a mapping list.
Capture the trait definition once and reuse it for both declaration
and per-type impl expansion to reduce duplication and keep future
extensions simple.
This is a preparatory refactor for enabling i8/i16 atomics cleanly.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251228120546.1602275-2-fujita.tomonori@gmail.com
The default implementation of Unpin for ARef<T> is conditional on T
being Unpin due to its PhantomData<T> field. However, this is overly
strict as pointers to T are legal to move even if T itself cannot move.
Since commit 66f1ea83d9 ("rust: lock: Add a Pin<&mut T> accessor")
this causes build failures when combined with a Mutex that contains an
field ARef<T>, because almost any type that ARef is used with is !Unpin.
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251218-unpin-for-aref-v2-1-30d77129cbc6@google.com
Implement Send and Sync for SetOnce<T> to allow it to be used across
thread boundaries.
Send: SetOnce<T> can be transferred across threads when T: Send, as
the contained value is also transferred and will be dropped on the
destination thread.
Sync: SetOnce<T> can be shared across threads when T: Sync, as
as_ref() provides shared references &T and atomic operations ensure
proper synchronization. Since the inner T may be dropped on any
thread, we also require T: Send.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251216000901.221375-1-fujita.tomonori@gmail.com
Commit 14e9a18b07 ("rust: sync: atomic: Make Atomic*Ops pub(crate)")
added a `pub(crate)` import in the same "block" as the `pub` one,
without running `rustfmt`, which would sort them differently.
Instead of running `rustfmt` as-is, add a newline to keep the import
"blocks" with different visibilities separate.
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Rust module parameter support:
- Add Rust module parameter support, enabling Rust kernel modules to declare
and use module parameters. The rust_minimal sample module demonstrates this,
and the rust null block driver will be the first to use it in the next cycle.
This also adds the Rust module files under the modules subsystem as agreed
between the Rust and modules maintainers.
Hardening:
- Add compile-time check for embedded NUL characters in MODULE_*() macros. This
module metadata was once used (and maybe still) to bypass license enforcement
(LWN article [1] from 2003). This change required a sparse fix [2] which you
reviewed.
MAINTAINERS:
- Add Aaron Tomlin as reviewer for the Modules subsystem.
The changes have been in linux-next for 4 weeks. Recent 0day reports for UM [3]
and arm64 [4] builds were not reproducible and traced to a buggy bindgen version
combined with unreleased clang-22 in 0day. The Rust team has reported this to
0day.
As discussed previously, we rotate module maintainership among co-maintainers
every 6 months. Sami Tolvanen is next in line and will send the next pull
request. As a reminder, Luis has already announced [5] he will gradually step
away as maintainer.
Link: https://lwn.net/Articles/82305/ [1]
Link: https://lore.kernel.org/linux-sparse/CACePvbVG2KrGQq4cNKV=wbO5h=jp3M0RO1SdfX8kV4OukjPG8A@mail.gmail.com/T/#mf838b3e2e3245d88c30a801ea7473d5a5c0eb121 [2]
Link: https://lore.kernel.org/oe-kbuild-all/202511210858.uwVivgvn-lkp@intel.com/ [3]
Link: https://lore.kernel.org/oe-kbuild-all/202512020454.Tf36WHw5-lkp@intel.com/ [4]
Link: https://lore.kernel.org/linux-modules/aGiAF8IQ4PRYn0th@bombadil.infradead.org/ [5]
Signed-off-by: Daniel Gomez <da.gomez@samsung.com>
-----BEGIN PGP SIGNATURE-----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=ujQB
-----END PGP SIGNATURE-----
Merge tag 'modules-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux
Pull module updates from Daniel Gomez:
"Rust module parameter support:
- Add Rust module parameter support, enabling Rust kernel modules to
declare and use module parameters. The rust_minimal sample module
demonstrates this, and the rust null block driver will be the first
to use it in the next cycle. This also adds the Rust module files
under the modules subsystem as agreed between the Rust and modules
maintainers.
Hardening:
- Add compile-time check for embedded NUL characters in MODULE_*()
macros. This module metadata was once used (and maybe still) to
bypass license enforcement (LWN article from 2003):
https://lwn.net/Articles/82305/ [1]
MAINTAINERS:
- Add Aaron Tomlin as reviewer for the Modules subsystem"
* tag 'modules-6.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/modules/linux:
MAINTAINERS: Add myself as reviewer for module support
module: Add compile-time check for embedded NUL characters
media: radio: si470x: Fix DRIVER_AUTHOR macro definition
media: dvb-usb-v2: lmedm04: Fix firmware macro definitions
modules: add rust modules files to MAINTAINERS
rust: samples: add a module parameter to the rust_minimal sample
rust: module: update the module macro with module parameter support
rust: module: use a reference in macros::module::module
rust: introduce module_param module
rust: str: add radix prefixed integer parsing functions
rust: sync: add `SetOnce`
Toolchain and infrastructure:
- Add support for 'syn'.
Syn is a parsing library for parsing a stream of Rust tokens into a
syntax tree of Rust source code.
Currently this library is geared toward use in Rust procedural
macros, but contains some APIs that may be useful more generally.
'syn' allows us to greatly simplify writing complex macros such as
'pin-init' (Benno has already prepared the 'syn'-based version). We
will use it in the 'macros' crate too.
'syn' is the most downloaded Rust crate (according to crates.io), and
it is also used by the Rust compiler itself. While the amount of code
is substantial, there should not be many updates needed for these
crates, and even if there are, they should not be too big, e.g. +7k
-3k lines across the 3 crates in the last year.
'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
I only modified their code to remove a third dependency
('unicode-ident') and to add the SPDX identifiers. The code can be
easily verified to exactly match upstream with the provided scripts.
They are all licensed under "Apache-2.0 OR MIT", like the other
vendored 'alloc' crate we had for a while.
Please see the merge commit with the cover letter for more context.
- Allow 'unreachable_pub' and 'clippy::disallowed_names' for doctests.
Examples (i.e. doctests) may want to do things like show public items
and use names such as 'foo'.
Nevertheless, we still try to keep examples as close to real code as
possible (this is part of why running Clippy on doctests is important
for us, e.g. for safety comments, which userspace Rust does not
support yet but we are stricter).
'kernel' crate:
- Replace our custom 'CStr' type with 'core::ffi::CStr'.
Using the standard library type reduces our custom code footprint,
and we retain needed custom functionality through an extension trait
and a new 'fmt!' macro which replaces the previous 'core' import.
This started in 6.17 and continued in 6.18, and we finally land the
replacement now. This required quite some stamina from Tamir, who
split the changes in steps to prepare for the flag day change here.
- Replace 'kernel::c_str!' with C string literals.
C string literals were added in Rust 1.77, which produce '&CStr's
(the 'core' one), so now we can write:
c"hi"
instead of:
c_str!("hi")
- Add 'num' module for numerical features.
It includes the 'Integer' trait, implemented for all primitive
integer types.
It also includes the 'Bounded' integer wrapping type: an integer
value that requires only the 'N' less significant bits of the wrapped
type to be encoded:
// An unsigned 8-bit integer, of which only the 4 LSBs are used.
let v = Bounded::<u8, 4>:🆕:<15>();
assert_eq!(v.get(), 15);
'Bounded' is useful to e.g. enforce guarantees when working with
bitfields that have an arbitrary number of bits.
Values can be constructed from simple non-constant expressions or,
for more complex ones, validated at runtime.
'Bounded' also comes with comparison and arithmetic operations (with
both their backing type and other 'Bounded's with a compatible
backing type), casts to change the backing type, extending/shrinking
and infallible/fallible conversions from/to primitives as applicable.
- 'rbtree' module: add immutable cursor ('Cursor').
It enables to use just an immutable tree reference where appropriate.
The existing fully-featured mutable cursor is renamed to 'CursorMut'.
kallsyms:
- Fix wrong "big" kernel symbol type read from procfs.
'pin-init' crate:
- A couple minor fixes (Benno asked me to pick these patches up for
him this cycle).
Documentation:
- Quick Start guide: add Debian 13 (Trixie).
Debian Stable is now able to build Linux, since Debian 13 (released
2025-08-09) packages Rust 1.85.0, which is recent enough.
We are planning to propose that the minimum supported Rust version in
Linux follows Debian Stable releases, with Debian 13 being the first
one we upgrade to, i.e. Rust 1.85.
MAINTAINERS:
- Add entry for the new 'num' module.
- Remove Alex as Rust maintainer: he hasn't had the time to contribute
for a few years now, so it is a no-op change in practice.
And a few other cleanups and improvements.
-----BEGIN PGP SIGNATURE-----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=9nM+
-----END PGP SIGNATURE-----
Merge tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Add support for 'syn'.
Syn is a parsing library for parsing a stream of Rust tokens into a
syntax tree of Rust source code.
Currently this library is geared toward use in Rust procedural
macros, but contains some APIs that may be useful more generally.
'syn' allows us to greatly simplify writing complex macros such as
'pin-init' (Benno has already prepared the 'syn'-based version). We
will use it in the 'macros' crate too.
'syn' is the most downloaded Rust crate (according to crates.io),
and it is also used by the Rust compiler itself. While the amount
of code is substantial, there should not be many updates needed for
these crates, and even if there are, they should not be too big,
e.g. +7k -3k lines across the 3 crates in the last year.
'syn' requires two smaller dependencies: 'quote' and 'proc-macro2'.
I only modified their code to remove a third dependency
('unicode-ident') and to add the SPDX identifiers. The code can be
easily verified to exactly match upstream with the provided
scripts.
They are all licensed under "Apache-2.0 OR MIT", like the other
vendored 'alloc' crate we had for a while.
Please see the merge commit with the cover letter for more context.
- Allow 'unreachable_pub' and 'clippy::disallowed_names' for
doctests.
Examples (i.e. doctests) may want to do things like show public
items and use names such as 'foo'.
Nevertheless, we still try to keep examples as close to real code
as possible (this is part of why running Clippy on doctests is
important for us, e.g. for safety comments, which userspace Rust
does not support yet but we are stricter).
'kernel' crate:
- Replace our custom 'CStr' type with 'core::ffi::CStr'.
Using the standard library type reduces our custom code footprint,
and we retain needed custom functionality through an extension
trait and a new 'fmt!' macro which replaces the previous 'core'
import.
This started in 6.17 and continued in 6.18, and we finally land the
replacement now. This required quite some stamina from Tamir, who
split the changes in steps to prepare for the flag day change here.
- Replace 'kernel::c_str!' with C string literals.
C string literals were added in Rust 1.77, which produce '&CStr's
(the 'core' one), so now we can write:
c"hi"
instead of:
c_str!("hi")
- Add 'num' module for numerical features.
It includes the 'Integer' trait, implemented for all primitive
integer types.
It also includes the 'Bounded' integer wrapping type: an integer
value that requires only the 'N' least significant bits of the
wrapped type to be encoded:
// An unsigned 8-bit integer, of which only the 4 LSBs are used.
let v = Bounded::<u8, 4>:🆕:<15>();
assert_eq!(v.get(), 15);
'Bounded' is useful to e.g. enforce guarantees when working with
bitfields that have an arbitrary number of bits.
Values can also be constructed from simple non-constant expressions
or, for more complex ones, validated at runtime.
'Bounded' also comes with comparison and arithmetic operations
(with both their backing type and other 'Bounded's with a
compatible backing type), casts to change the backing type,
extending/shrinking and infallible/fallible conversions from/to
primitives as applicable.
- 'rbtree' module: add immutable cursor ('Cursor').
It enables to use just an immutable tree reference where
appropriate. The existing fully-featured mutable cursor is renamed
to 'CursorMut'.
kallsyms:
- Fix wrong "big" kernel symbol type read from procfs.
'pin-init' crate:
- A couple minor fixes (Benno asked me to pick these patches up for
him this cycle).
Documentation:
- Quick Start guide: add Debian 13 (Trixie).
Debian Stable is now able to build Linux, since Debian 13 (released
2025-08-09) packages Rust 1.85.0, which is recent enough.
We are planning to propose that the minimum supported Rust version
in Linux follows Debian Stable releases, with Debian 13 being the
first one we upgrade to, i.e. Rust 1.85.
MAINTAINERS:
- Add entry for the new 'num' module.
- Remove Alex as Rust maintainer: he hasn't had the time to
contribute for a few years now, so it is a no-op change in
practice.
And a few other cleanups and improvements"
* tag 'rust-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (53 commits)
rust: macros: support `proc-macro2`, `quote` and `syn`
rust: syn: enable support in kbuild
rust: syn: add `README.md`
rust: syn: remove `unicode-ident` dependency
rust: syn: add SPDX License Identifiers
rust: syn: import crate
rust: quote: enable support in kbuild
rust: quote: add `README.md`
rust: quote: add SPDX License Identifiers
rust: quote: import crate
rust: proc-macro2: enable support in kbuild
rust: proc-macro2: add `README.md`
rust: proc-macro2: remove `unicode_ident` dependency
rust: proc-macro2: add SPDX License Identifiers
rust: proc-macro2: import crate
rust: kbuild: support using libraries in `rustc_procmacro`
rust: kbuild: support skipping flags in `rustc_test_library`
rust: kbuild: add proc macro library support
rust: kbuild: simplify `--cfg` handling
rust: kbuild: introduce `core-flags` and `core-skip_flags`
...
Mutexes:
- Redo __mutex_init() to reduce generated code size
(Sebastian Andrzej Siewior)
Seqlocks:
- Introduce scoped_seqlock_read() (Peter Zijlstra)
- Change thread_group_cputime() to use scoped_seqlock_read()
(Oleg Nesterov)
- Change do_task_stat() to use scoped_seqlock_read()
(Oleg Nesterov)
- Change do_io_accounting() to use scoped_seqlock_read()
(Oleg Nesterov)
- Fix the incorrect documentation of read_seqbegin_or_lock() /
need_seqretry() (Oleg Nesterov)
- Allow KASAN to fail optimizing (Peter Zijlstra)
Local lock updates:
- Fix all kernel-doc warnings (Randy Dunlap)
- Add the <linux/local_lock*.h> headers to MAINTAINERS
(Sebastian Andrzej Siewior)
- Reduce the risk of shadowing via s/l/__l/ and s/tl/__tl/
(Vincent Mailhol)
Lock debugging:
- spinlock/debug: Fix data-race in do_raw_write_lock
(Alexander Sverdlin)
Atomic primitives infrastructure:
- atomic: Skip alignment check for try_cmpxchg() old arg
(Arnd Bergmann)
Rust runtime integration:
- sync: atomic: Enable generated Atomic<T> usage (Boqun Feng)
- sync: atomic: Implement Debug for Atomic<Debug> (Boqun Feng)
- debugfs: Remove Rust native atomics and replace them with
Linux versions (Boqun Feng)
- debugfs: Implement Reader for Mutex<T> only when T is Unpin
(Boqun Feng)
- lock: guard: Add T: Unpin bound to DerefMut (Daniel Almeida)
- lock: Pin the inner data (Daniel Almeida)
- lock: Add a Pin<&mut T> accessor (Daniel Almeida)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----
iQJFBAABCgAvFiEEBpT5eoXrXCwVQwEKEnMQ0APhK1gFAmktVmgRHG1pbmdvQGtl
cm5lbC5vcmcACgkQEnMQ0APhK1hDqw//e9BTs9Yx6yLxZVRDagS7KrDKy3V3OMg1
9h+tXzCosGeNz7XwVzt590wsACJvX7/QtqgTFQy/GPYBW56WeVOSYSpA6I4s43G1
sz+EAc4BYPBWEwBQxCfPDwHI/M0MD0Im6mjpATc6Uv1Ct0+KS8iFXRnGUALe4bis
8aKV8ZHo81Wnu6v1B8GroExHolL/AMORYfEYHABpWEe+GpwxqQcRdZjc/eiEUzOg
umwMC9bNc5FAiPlku9Mh6pcBPjkMd9bGjVEIG8deJhm/aD8f/b0mgaxyaKgoHx8J
ptauY3kLYBLuV793U37SXuQVw6o2LGHCYvN1fX+g1D0YTIuqIq9Pz7ObZs7w4xDd
6iIK4QYP4Gjkvn0ZA275eI3ItcBEjJ2FD3ZDbkXNj+O4vEOrmG/OX4h2H5WGq/AU
zr9YfmkRn0InPeHeLU1UM3NdbKgwc/Bd6MubSwX4v7G7ws4CGDtlvA2d3xg5q8Ls
MQoAV+9QtiZ9prQjtd8nukgmh/+okPmCcnuEVXhSOZHpPjqXXnyUCTPyKXVkltdF
1u4oUHiQY7Jydfn0wZgEV4nASDeV2gz5BwKoSAuKvYc5HGhXnXxvzyJyHJy3dL8R
afGGQ3XfQhA0hUKoMiQFUk7p7dvjdAiHxN1EcvxxJqWVsaE/Gpik1GOm+FRn7Oqs
UMvspgGrbI4=
=KPgY
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"Mutexes:
- Redo __mutex_init() to reduce generated code size (Sebastian
Andrzej Siewior)
Seqlocks:
- Introduce scoped_seqlock_read() (Peter Zijlstra)
- Change thread_group_cputime() to use scoped_seqlock_read() (Oleg
Nesterov)
- Change do_task_stat() to use scoped_seqlock_read() (Oleg Nesterov)
- Change do_io_accounting() to use scoped_seqlock_read() (Oleg
Nesterov)
- Fix the incorrect documentation of read_seqbegin_or_lock() /
need_seqretry() (Oleg Nesterov)
- Allow KASAN to fail optimizing (Peter Zijlstra)
Local lock updates:
- Fix all kernel-doc warnings (Randy Dunlap)
- Add the <linux/local_lock*.h> headers to MAINTAINERS (Sebastian
Andrzej Siewior)
- Reduce the risk of shadowing via s/l/__l/ and s/tl/__tl/ (Vincent
Mailhol)
Lock debugging:
- spinlock/debug: Fix data-race in do_raw_write_lock (Alexander
Sverdlin)
Atomic primitives infrastructure:
- atomic: Skip alignment check for try_cmpxchg() old arg (Arnd
Bergmann)
Rust runtime integration:
- sync: atomic: Enable generated Atomic<T> usage (Boqun Feng)
- sync: atomic: Implement Debug for Atomic<Debug> (Boqun Feng)
- debugfs: Remove Rust native atomics and replace them with Linux
versions (Boqun Feng)
- debugfs: Implement Reader for Mutex<T> only when T is Unpin (Boqun
Feng)
- lock: guard: Add T: Unpin bound to DerefMut (Daniel Almeida)
- lock: Pin the inner data (Daniel Almeida)
- lock: Add a Pin<&mut T> accessor (Daniel Almeida)"
* tag 'locking-core-2025-12-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/local_lock: Fix all kernel-doc warnings
locking/local_lock: s/l/__l/ and s/tl/__tl/ to reduce the risk of shadowing
locking/local_lock: Add the <linux/local_lock*.h> headers to MAINTAINERS
locking/mutex: Redo __mutex_init() to reduce generated code size
rust: debugfs: Replace the usage of Rust native atomics
rust: sync: atomic: Implement Debug for Atomic<Debug>
rust: sync: atomic: Make Atomic*Ops pub(crate)
seqlock: Allow KASAN to fail optimizing
rust: debugfs: Implement Reader for Mutex<T> only when T is Unpin
seqlock: Change do_io_accounting() to use scoped_seqlock_read()
seqlock: Change do_task_stat() to use scoped_seqlock_read()
seqlock: Change thread_group_cputime() to use scoped_seqlock_read()
seqlock: Introduce scoped_seqlock_read()
documentation: seqlock: fix the wrong documentation of read_seqbegin_or_lock/need_seqretry
atomic: Skip alignment check for try_cmpxchg() old arg
rust: lock: Add a Pin<&mut T> accessor
rust: lock: Pin the inner data
rust: lock: guard: Add T: Unpin bound to DerefMut
locking/spinlock/debug: Fix data-race in do_raw_write_lock
If `Atomic<T>` is `Debug` then it's a `debugfs::Writer`, therefore make
it so since 1) debugfs needs to support `Atomic<T>` and 2) it's rather
trivial to implement `Debug` for `Atomic<Debug>`.
Tested-by: David Gow <davidgow@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251022035324.70785-3-boqun.feng@gmail.com
In order to write code over a generate Atomic<T> we need to make
Atomic*Ops public so that functions like `.load()` and `.store()` are
available. Make these pub(crate) at the beginning so the usage in kernel
crate is supported.
Tested-by: David Gow <davidgow@google.com>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://patch.msgid.link/20251022035324.70785-2-boqun.feng@gmail.com
Introduce the `SetOnce` type, a container that can only be written once.
The container uses an internal atomic to synchronize writes to the internal
value.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: Daniel Gomez <da.gomez@samsung.com>
Signed-off-by: Daniel Gomez <da.gomez@kernel.org>
The future move of pin-init to `syn` uncovers the following broken
intra-doc link:
error: unresolved link to `crate::pin_init`
--> rust/kernel/sync/condvar.rs:39:40
|
39 | /// instances is with the [`pin_init`](crate::pin_init!) and [`new_condvar`] macros.
| ^^^^^^^^^^^^^^^^ no item named `pin_init` in module `kernel`
|
= note: `-D rustdoc::broken-intra-doc-links` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(rustdoc::broken_intra_doc_links)]`
Currently, when rendered, the link points to a literal `crate::pin_init!`
URL.
Thus fix it.
Cc: stable@vger.kernel.org
Fixes: 129e97be8e ("rust: pin-init: fix documentation links")
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20251029073344.349341-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
`kernel::ffi::CStr` was introduced in commit d126d23801 ("rust: str:
add `CStr` type") in November 2022 as an upstreaming of earlier work
that was done in May 2021[0]. That earlier work, having predated the
inclusion of `CStr` in `core`, largely duplicated the implementation of
`std::ffi::CStr`.
`std::ffi::CStr` was moved to `core::ffi::CStr` in Rust 1.64 in
September 2022. Hence replace `kernel::str::CStr` with `core::ffi::CStr`
to reduce our custom code footprint, and retain needed custom
functionality through an extension trait.
Add `CStr` to `ffi` and the kernel prelude.
Link: faa3cbcca0 [0]
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Link: https://patch.msgid.link/20251018-cstr-core-v18-16-9378a54385f8@gmail.com
[ Removed assert that would now depend on the Rust version. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
In order for callers to be able to access the inner T safely if T:
!Unpin, there needs to be a way to get a Pin<&mut T>. Add this accessor
and a corresponding example to tell users how it works.
This requires the pin projection functionality [1] for better ergonomic.
[boqun: Apply Daniel's fix to the code example, add the reference to pin
projection patch and remove out-of-date part in the commit log]
Suggested-by: Benno Lossin <lossin@kernel.org>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1181
Link: https://lore.kernel.org/rust-for-linux/20250912174148.373530-1-lossin@kernel.org/ [1]
In preparation to support Lock<T> where T is pinned, the first thing
that needs to be done is to structurally pin the 'data' member. This
switches the 't' parameter in Lock<T>::new() to take in an impl
PinInit<T> instead of a plain T. This in turn uses the blanket
implementation "impl PinInit<T> for T".
Subsequent patches will touch on Guard<T>.
Suggested-by: Benno Lossin <lossin@kernel.org>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1181
A core property of pinned types is not handing a mutable reference to
the inner data in safe code, as this trivially allows that data to be
moved.
Enforce this condition by adding a bound on lock::Guard's DerefMut
implementation, so that it's only implemented for pinning-agnostic
types.
Suggested-by: Benno Lossin <lossin@kernel.org>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1181
Toolchain and infrastructure:
- Derive 'Zeroable' for all structs and unions generated by 'bindgen'
where possible and corresponding cleanups. To do so, add the
'pin-init' crate as a dependency to 'bindings' and 'uapi'.
It also includes its first use in the 'cpufreq' module, with more to
come in the next cycle.
- Add warning to the 'rustdoc' target to detect broken 'srctree/' links
and fix existing cases.
- Remove support for unused (since v6.16) host '#[test]'s, simplifying
the 'rusttest' target. Tests should generally run within KUnit.
'kernel' crate:
- Add 'ptr' module with a new 'Alignment' type, which is always a power
of two and is used to validate that a given value is a valid
alignment and to perform masking and alignment operations:
// Checked at build time.
assert_eq!(Alignment:🆕:<16>().as_usize(), 16);
// Checked at runtime.
assert_eq!(Alignment::new_checked(15), None);
assert_eq!(Alignment::of::<u8>().log2(), 0);
assert_eq!(0x25u8.align_down(Alignment:🆕:<0x10>()), 0x20);
assert_eq!(0x5u8.align_up(Alignment:🆕:<0x10>()), Some(0x10));
assert_eq!(u8::MAX.align_up(Alignment:🆕:<0x10>()), None);
It also includes its first use in Nova.
- Add 'core::mem::{align,size}_of{,_val}' to the prelude, matching
Rust 1.80.0.
- Keep going with the steps on our migration to the standard library
'core::ffi::CStr' type (use 'kernel::{fmt, prelude::fmt!}' and use
upstream method names).
- 'error' module: improve 'Error::from_errno' and 'to_result'
documentation, including examples/tests.
- 'sync' module: extend 'aref' submodule documentation now that it
exists, and more updates to complete the ongoing move of 'ARef' and
'AlwaysRefCounted' to 'sync::aref'.
- 'list' module: add an example/test for 'ListLinksSelfPtr' usage.
- 'alloc' module:
- Implement 'Box::pin_slice()', which constructs a pinned slice of
elements.
- Provide information about the minimum alignment guarantees of
'Kmalloc', 'Vmalloc' and 'KVmalloc'.
- Take minimum alignment guarantees of allocators for
'ForeignOwnable' into account.
- Remove the 'allocator_test' (including 'Cmalloc').
- Add doctest for 'Vec::as_slice()'.
- Constify various methods.
- 'time' module:
- Add methods on 'HrTimer' that can only be called with exclusive
access to an unarmed timer, or from timer callback context.
- Add arithmetic operations to 'Instant' and 'Delta'.
- Add a few convenience and access methods to 'HrTimer' and
'Instant'.
'macros' crate:
- Reduce collections in 'quote!' macro.
And a few other cleanups and improvements.
-----BEGIN PGP SIGNATURE-----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=+VG2
-----END PGP SIGNATURE-----
Merge tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Derive 'Zeroable' for all structs and unions generated by 'bindgen'
where possible and corresponding cleanups. To do so, add the
'pin-init' crate as a dependency to 'bindings' and 'uapi'.
It also includes its first use in the 'cpufreq' module, with more
to come in the next cycle.
- Add warning to the 'rustdoc' target to detect broken 'srctree/'
links and fix existing cases.
- Remove support for unused (since v6.16) host '#[test]'s,
simplifying the 'rusttest' target. Tests should generally run
within KUnit.
'kernel' crate:
- Add 'ptr' module with a new 'Alignment' type, which is always a
power of two and is used to validate that a given value is a valid
alignment and to perform masking and alignment operations:
// Checked at build time.
assert_eq!(Alignment:🆕:<16>().as_usize(), 16);
// Checked at runtime.
assert_eq!(Alignment::new_checked(15), None);
assert_eq!(Alignment::of::<u8>().log2(), 0);
assert_eq!(0x25u8.align_down(Alignment:🆕:<0x10>()), 0x20);
assert_eq!(0x5u8.align_up(Alignment:🆕:<0x10>()), Some(0x10));
assert_eq!(u8::MAX.align_up(Alignment:🆕:<0x10>()), None);
It also includes its first use in Nova.
- Add 'core::mem::{align,size}_of{,_val}' to the prelude, matching
Rust 1.80.0.
- Keep going with the steps on our migration to the standard library
'core::ffi::CStr' type (use 'kernel::{fmt, prelude::fmt!}' and use
upstream method names).
- 'error' module: improve 'Error::from_errno' and 'to_result'
documentation, including examples/tests.
- 'sync' module: extend 'aref' submodule documentation now that it
exists, and more updates to complete the ongoing move of 'ARef' and
'AlwaysRefCounted' to 'sync::aref'.
- 'list' module: add an example/test for 'ListLinksSelfPtr' usage.
- 'alloc' module:
- Implement 'Box::pin_slice()', which constructs a pinned slice of
elements.
- Provide information about the minimum alignment guarantees of
'Kmalloc', 'Vmalloc' and 'KVmalloc'.
- Take minimum alignment guarantees of allocators for
'ForeignOwnable' into account.
- Remove the 'allocator_test' (including 'Cmalloc').
- Add doctest for 'Vec::as_slice()'.
- Constify various methods.
- 'time' module:
- Add methods on 'HrTimer' that can only be called with exclusive
access to an unarmed timer, or from timer callback context.
- Add arithmetic operations to 'Instant' and 'Delta'.
- Add a few convenience and access methods to 'HrTimer' and
'Instant'.
'macros' crate:
- Reduce collections in 'quote!' macro.
And a few other cleanups and improvements"
* tag 'rust-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (58 commits)
gpu: nova-core: use Alignment for alignment-related operations
rust: add `Alignment` type
rust: macros: reduce collections in `quote!` macro
rust: acpi: use `core::ffi::CStr` method names
rust: of: use `core::ffi::CStr` method names
rust: net: use `core::ffi::CStr` method names
rust: miscdevice: use `core::ffi::CStr` method names
rust: kunit: use `core::ffi::CStr` method names
rust: firmware: use `core::ffi::CStr` method names
rust: drm: use `core::ffi::CStr` method names
rust: cpufreq: use `core::ffi::CStr` method names
rust: configfs: use `core::ffi::CStr` method names
rust: auxiliary: use `core::ffi::CStr` method names
drm/panic: use `core::ffi::CStr` method names
rust: device: use `kernel::{fmt,prelude::fmt!}`
rust: sync: use `kernel::{fmt,prelude::fmt!}`
rust: seq_file: use `kernel::{fmt,prelude::fmt!}`
rust: kunit: use `kernel::{fmt,prelude::fmt!}`
rust: file: use `kernel::{fmt,prelude::fmt!}`
rust: device: use `kernel::{fmt,prelude::fmt!}`
...
Reduce coupling to implementation details of the formatting machinery by
avoiding direct use for `core`'s formatting traits and macros.
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Tamir Duberstein <tamird@gmail.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Currently there's a custom reference counting in `block::mq`, which uses
`AtomicU64` Rust atomics, and this type doesn't exist on some 32-bit
architectures. We cannot just change it to use 32-bit atomics, because
doing so will make it vulnerable to refcount overflow. So switch it to
use the kernel refcount `kernel::sync::Refcount` instead.
There is an operation needed by `block::mq`, atomically decreasing
refcount from 2 to 0, which is not available through refcount.h, so
I exposed `Refcount::as_atomic` which allows accessing the refcount
directly.
[boqun: Adopt the LKMM atomic API]
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Acked-by: Andreas Hindborg <a.hindborg@kernel.org>
Tested-by: David Gow <davidgow@google.com>
Link: https://lore.kernel.org/r/20250723233312.3304339-5-gary@kernel.org
With `Refcount` type created, `Arc` can use `Refcount` instead of
calling into FFI directly.
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/r/20250723233312.3304339-4-gary@kernel.org
Make `Arc::into_unique_or_drop` to become a mere associated function
instead of a method (i.e. removing the `self` receiver).
It's a general convention for Rust smart pointers to avoid having
methods defined on them, because if the pointee type has a method of the
same name, then it is shadowed. This is normally for avoiding semver
breakage, which isn't an issue for kernel codebase, but it's still
generally a good practice to follow this rule, so that `ptr.foo()` would
always be calling a method on the pointee type.
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/r/20250723233312.3304339-3-gary@kernel.org
This is a wrapping layer of `include/linux/refcount.h`. Currently the
kernel refcount has already been used in `Arc`, however it calls into
FFI directly.
[boqun: Add the missing <> for the link in comment]
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Fiona Behrens <me@kloenk.dev>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/r/20250723233312.3304339-2-gary@kernel.org
Memory barriers are building blocks for concurrent code, hence provide
a minimal set of them.
The compiler barrier, barrier(), is implemented in inline asm instead of
using core::sync::atomic::compiler_fence() because memory models are
different: kernel's atomics are implemented in inline asm therefore the
compiler barrier should be implemented in inline asm as well. Also it's
currently only public to the kernel crate until there's a reasonable
driver usage.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-10-boqun.feng@gmail.com/
Add generic atomic support for `usize` and `isize`. Note that instead of
mapping directly to `atomic_long_t`, the represention type
(`AtomicType::Repr`) is selected based on CONFIG_64BIT. This reduces
the necessity of creating `atomic_long_*` helpers, which could save
the binary size of kernel if inline helpers are not available. To do so,
an internal type `isize_atomic_repr` is defined, it's `i32` in 32bit
kernel and `i64` in 64bit kernel.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-9-boqun.feng@gmail.com/
Add generic atomic support for basic unsigned types that have an
`AtomicImpl` with the same size and alignment.
Unit tests are added including Atomic<i32> and Atomic<i64>.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-8-boqun.feng@gmail.com/
One important set of atomic operations is the arithmetic operations,
i.e. add(), sub(), fetch_add(), add_return(), etc. However it may not
make senses for all the types that `AtomicType` to have arithmetic
operations, for example a `Foo(u32)` may not have a reasonable add() or
sub(), plus subword types (`u8` and `u16`) currently don't have
atomic arithmetic operations even on C side and might not have them in
the future in Rust (because they are usually suboptimal on a few
architecures). Therefore the plan is to add a few subtraits of
`AtomicType` describing which types have and can do atomic arithemtic
operations.
One trait `AtomicAdd` is added, and only add() and fetch_add() are
added. The rest will be added in the future.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-7-boqun.feng@gmail.com/
xchg() and cmpxchg() are basic operations on atomic. Provide these based
on C APIs.
Note that cmpxchg() use the similar function signature as
compare_exchange() in Rust std: returning a `Result`, `Ok(old)` means
the operation succeeds and `Err(old)` means the operation fails.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-6-boqun.feng@gmail.com/
To provide using LKMM atomics for Rust code, a generic `Atomic<T>` is
added, currently `T` needs to be Send + Copy because these are the
straightforward usages and all basic types support this.
Implement `AtomicType` for `i32` and `i64`, and so far only basic
operations load() and store() are introduced.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-5-boqun.feng@gmail.com/
Preparation for atomic primitives. Instead of a suffix like _acquire, a
method parameter along with the corresponding generic parameter will be
used to specify the ordering of an atomic operations. For example,
atomic load() can be defined as:
impl<T: ...> Atomic<T> {
pub fn load<O: AcquireOrRelaxed>(&self, _o: O) -> T { ... }
}
and acquire users would do:
let r = x.load(Acquire);
relaxed users:
let r = x.load(Relaxed);
doing the following:
let r = x.load(Release);
will cause a compiler error.
Compared to suffixes, it's easier to tell what ordering variants an
operation has, and it also make it easier to unify the implementation of
all ordering variants in one method via generic. The `TYPE` associate
const is for generic function to pick up the particular implementation
specified by an ordering annotation.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-4-boqun.feng@gmail.com/
Preparation for generic atomic implementation. To unify the
implementation of a generic method over `i32` and `i64`, the C side
atomic methods need to be grouped so that in a generic method, they can
be referred as <type>::<method>, otherwise their parameters and return
value are different between `i32` and `i64`, which would require using
`transmute()` to unify the type into a `T`.
Introduce `AtomicImpl` to represent a basic type in Rust that has the
direct mapping to an atomic implementation from C. Use a sealed trait to
restrict `AtomicImpl` to only support `i32` and `i64` for now.
Further, different methods are put into different `*Ops` trait groups,
and this is for the future when smaller types like `i8`/`i16` are
supported but only with a limited set of API (e.g. only set(), load(),
xchg() and cmpxchg(), no add() or sub() etc).
While the atomic mod is introduced, documentation is also added for
memory models and data races.
Also bump my role to the maintainer of ATOMIC INFRASTRUCTURE to reflect
my responsibility on the Rust atomic mod.
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Elle Rhumsaa <elle@weathered-steel.dev>
Link: https://lore.kernel.org/all/20250719030827.61357-3-boqun.feng@gmail.com/
Commit 07dad44aa9 ("rust: kernel: move ARef and AlwaysRefCounted to
sync::aref") moved `ARef` and `AlwaysRefCounted` into their own module.
In that process only a short, single line description of the module was
added. Extend the description by explaining what is meant by "internal
reference counting", the two items in the trait & the difference to
`Arc`.
Signed-off-by: Benno Lossin <lossin@kernel.org>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Update the in-file reference of sync/aref.rs to import `ARef` and
`AlwaysRefCounted` from `sync::aref` instead of `types`.
This aligns with the ongoing effort to move `ARef` and
`AlwaysRefCounted` to sync.
Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
When converting a Box<T> into a void pointer, the allocator might
guarantee a higher alignment than the type itself does, and in that case
it is guaranteed that the void pointer has that higher alignment.
This is quite useful when combined with the XArray, which you can only
create using a ForeignOwnable whose FOREIGN_ALIGN is at least 4. This
means that you can now always use a Box<T> with the XArray no matter the
alignment of T.
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://lore.kernel.org/r/20250811-align-min-allocator-v2-2-3386cc94f4fc@google.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
Toolchain and infrastructure:
- Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and 'ref_as_ptr'.
These are intended to avoid type casts with the 'as' operator, which
are quite powerful, into restricted variants that are less powerful
and thus should help to avoid mistakes.
- Remove the 'author' key now that most instances were moved to the
plural one in the previous cycle.
'kernel' crate:
- New 'bug' module: add 'warn_on!' macro which reuses the existing
'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
kernel parameters:
warn_on!(value == 42);
To avoid duplicating the assembly code, the same strategy is followed
as for the static branch code in order to share the assembly between
both C and Rust. This required a few rearrangements on C arch headers
-- the existing C macros should still generate the same outputs, thus
no functional change expected there.
- 'workqueue' module: add delayed work items, including a 'DelayedWork'
struct, a 'impl_has_delayed_work!' macro and an 'enqueue_delayed'
method, e.g.:
/// Enqueue the struct for execution on the system workqueue,
/// where its value will be printed 42 jiffies later.
fn print_later(value: Arc<MyStruct>) {
let _ = workqueue::system().enqueue_delayed(value, 42);
}
- New 'bits' module: add support for 'bit' and 'genmask' functions,
with runtime- and compile-time variants, e.g.:
static_assert!(0b00010000 == bit_u8(4));
static_assert!(0b00011110 == genmask_u8(1..=4));
assert!(checked_bit_u32(u32::BITS).is_none());
- 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which reads
NUL-terminated strings from userspace into a '&CStr'.
Introduce 'UserPtr' newtype, similar in purpose to '__user' in C, to
minimize mistakes handling userspace pointers, including mixing them
up with integers and leaking them via the 'Debug' trait. Add it to
the prelude, too.
- Start preparations for the replacement of our custom 'CStr' type
with the analogous type in the 'core' standard library. This will
take place across several cycles to make it easier. For this one,
it includes a new 'fmt' module, using upstream method names and some
other cleanups.
Replace 'fmt!' with a re-export, which helps Clippy lint properly,
and clean up the found 'uninlined-format-args' instances.
- 'dma' module:
- Clarify wording and be consistent in 'coherent' nomenclature.
- Convert the 'read!()' and 'write!()' macros to return a 'Result'.
- Add 'as_slice()', 'write()' methods in 'CoherentAllocation'.
- Expose 'count()' and 'size()' in 'CoherentAllocation' and add the
corresponding type invariants.
- Implement 'CoherentAllocation::dma_handle_with_offset()'.
- 'time' module:
- Make 'Instant' generic over clock source. This allows the compiler
to assert that arithmetic expressions involving the 'Instant' use
'Instants' based on the same clock source.
- Make 'HrTimer' generic over the timer mode. 'HrTimer' timers take a
'Duration' or an 'Instant' when setting the expiry time, depending
on the timer mode. With this change, the compiler can check the
type matches the timer mode.
- Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
function that will select an appropriate sleep method depending on
the requested sleep time.
- Avoid 64-bit divisions on 32-bit hardware when calculating
timestamps.
- Seal the 'HrTimerMode' trait. This prevents users of the
'HrTimerMode' from implementing the trait on their own types.
- Pass the correct timer mode ID to 'hrtimer_start_range_ns()'.
- 'list' module: remove 'OFFSET' constants, allowing to remove pointer
arithmetic; now 'impl_list_item!' invokes 'impl_has_list_links!' or
'impl_has_list_links_self_ptr!'. Other simplifications too.
- 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
constant, which avoids exposing the type of the opaque pointer, and
require 'into_foreign' to return non-null.
Remove the 'Either<L, R>' type as well. It is unused, and we want to
encourage the use of custom enums for concrete use cases.
- 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
to allow them to be used in generic APIs.
- 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'.
- 'Opaque' type: add 'cast_from' method to perform a restricted cast
that cannot change the inner type and use it in callers of
'container_of!'. Rename 'raw_get' to 'cast_into' to match it.
- 'rbtree' module: add 'is_empty' method.
- 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
'ARef', which are moved from the too general 'types' module which we
want to reduce or eventually remove. Also fix a safety comment in
'static_lock_class'.
'pin-init' crate:
- Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are now
(pin-)initializers.
- Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'.
- New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
it via 'Zeroable::zeroed()'.
- Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for '"Rust"'
and '"C"' ABIs and up to 20 arguments.
- Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
[Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'.
- Renamed 'zeroed()' to 'init_zeroed()'.
- Upstream dev news: improve CI more to deny warnings, use
'--all-targets'. Check the synchronization status of the two '-next'
branches in upstream and the kernel.
MAINTAINERS:
- Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
Stoakes as reviewers (thanks everyone).
And a few other cleanups and improvements.
-----BEGIN PGP SIGNATURE-----
iQIzBAABCgAdFiEEPjU5OPd5QIZ9jqqOGXyLc2htIW0FAmiOWREACgkQGXyLc2ht
IW39Ig/9E0ExSiBgNKdkCOaULMq31wAxnu3iWoVVisFndlh/Inv+JlaLrmA57BCi
xXgBwVZ1GoMsG8Fzt6gT+gyhGYi8waNd+5KXr/WJZVTaJ9v1KpdvxuCnSz0DjCbk
GaKfAfxvJ5GAOEwiIIX8X0TFu6kx911DCJY387/VrqZQ7Msh1QSM3tcZeir/EV4w
lPjUdlOh1FnLJLI9CGuW20d1IhQUP7K3pdoywgJPpCZV0I8QCyMlMqCEael8Tw2S
r/PzRaQtiIzk5HTx06V8paK+nEn0K2vQXqW2kV56Y6TNm1Zcv6dES/8hCITsISs2
nwney3vXEwvoZX+YkQRffZddY4i6YenWMrtLgVxZzdshBL3bn6eHqBL04Nfix+p7
pQe3qMH3G8UBtX1lugBE7RrWGWcz9ARN8sK12ClmpAUnKJOwTpo97kpqXP7pDme8
Buh/oV3voAMsqwooSbVBzuUUWnbGaQ5Oj6CiiosSadfNh6AxJLYLKHtRLKJHZEw3
0Ob/1HhoWS6JSvYKVjMyD19qcH7O8ThZE+83CfMAkI4KphXJarWhpSmN4cHkFn/v
0clQ7Y5m+up9v1XWTaEq0Biqa6CaxLQwm/qW5WU0Y/TiovmvxAFdCwsQqDkRoJNx
9kNfMJRvNl78KQxrjEDz9gl7/ajgqX1KkqP8CQbGjv29cGzFlVE=
=5Wt9
-----END PGP SIGNATURE-----
Merge tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux
Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Enable a set of Clippy lints: 'ptr_as_ptr', 'ptr_cast_constness',
'as_ptr_cast_mut', 'as_underscore', 'cast_lossless' and
'ref_as_ptr'
These are intended to avoid type casts with the 'as' operator,
which are quite powerful, into restricted variants that are less
powerful and thus should help to avoid mistakes
- Remove the 'author' key now that most instances were moved to the
plural one in the previous cycle
'kernel' crate:
- New 'bug' module: add 'warn_on!' macro which reuses the existing
'BUG'/'WARN' infrastructure, i.e. it respects the usual sysctls and
kernel parameters:
warn_on!(value == 42);
To avoid duplicating the assembly code, the same strategy is
followed as for the static branch code in order to share the
assembly between both C and Rust
This required a few rearrangements on C arch headers -- the
existing C macros should still generate the same outputs, thus no
functional change expected there
- 'workqueue' module: add delayed work items, including a
'DelayedWork' struct, a 'impl_has_delayed_work!' macro and an
'enqueue_delayed' method, e.g.:
/// Enqueue the struct for execution on the system workqueue,
/// where its value will be printed 42 jiffies later.
fn print_later(value: Arc<MyStruct>) {
let _ = workqueue::system().enqueue_delayed(value, 42);
}
- New 'bits' module: add support for 'bit' and 'genmask' functions,
with runtime- and compile-time variants, e.g.:
static_assert!(0b00010000 == bit_u8(4));
static_assert!(0b00011110 == genmask_u8(1..=4));
assert!(checked_bit_u32(u32::BITS).is_none());
- 'uaccess' module: add 'UserSliceReader::strcpy_into_buf', which
reads NUL-terminated strings from userspace into a '&CStr'
Introduce 'UserPtr' newtype, similar in purpose to '__user' in C,
to minimize mistakes handling userspace pointers, including mixing
them up with integers and leaking them via the 'Debug' trait. Add
it to the prelude, too
- Start preparations for the replacement of our custom 'CStr' type
with the analogous type in the 'core' standard library. This will
take place across several cycles to make it easier. For this one,
it includes a new 'fmt' module, using upstream method names and
some other cleanups
Replace 'fmt!' with a re-export, which helps Clippy lint properly,
and clean up the found 'uninlined-format-args' instances
- 'dma' module:
- Clarify wording and be consistent in 'coherent' nomenclature
- Convert the 'read!()' and 'write!()' macros to return a 'Result'
- Add 'as_slice()', 'write()' methods in 'CoherentAllocation'
- Expose 'count()' and 'size()' in 'CoherentAllocation' and add
the corresponding type invariants
- Implement 'CoherentAllocation::dma_handle_with_offset()'
- 'time' module:
- Make 'Instant' generic over clock source. This allows the
compiler to assert that arithmetic expressions involving the
'Instant' use 'Instants' based on the same clock source
- Make 'HrTimer' generic over the timer mode. 'HrTimer' timers
take a 'Duration' or an 'Instant' when setting the expiry time,
depending on the timer mode. With this change, the compiler can
check the type matches the timer mode
- Add an abstraction for 'fsleep'. 'fsleep' is a flexible sleep
function that will select an appropriate sleep method depending
on the requested sleep time
- Avoid 64-bit divisions on 32-bit hardware when calculating
timestamps
- Seal the 'HrTimerMode' trait. This prevents users of the
'HrTimerMode' from implementing the trait on their own types
- Pass the correct timer mode ID to 'hrtimer_start_range_ns()'
- 'list' module: remove 'OFFSET' constants, allowing to remove
pointer arithmetic; now 'impl_list_item!' invokes
'impl_has_list_links!' or 'impl_has_list_links_self_ptr!'. Other
simplifications too
- 'types' module: remove 'ForeignOwnable::PointedTo' in favor of a
constant, which avoids exposing the type of the opaque pointer, and
require 'into_foreign' to return non-null
Remove the 'Either<L, R>' type as well. It is unused, and we want
to encourage the use of custom enums for concrete use cases
- 'sync' module: implement 'Borrow' and 'BorrowMut' for 'Arc' types
to allow them to be used in generic APIs
- 'alloc' module: implement 'Borrow' and 'BorrowMut' for 'Box<T, A>';
and 'Borrow', 'BorrowMut' and 'Default' for 'Vec<T, A>'
- 'Opaque' type: add 'cast_from' method to perform a restricted cast
that cannot change the inner type and use it in callers of
'container_of!'. Rename 'raw_get' to 'cast_into' to match it
- 'rbtree' module: add 'is_empty' method
- 'sync' module: new 'aref' submodule to hold 'AlwaysRefCounted' and
'ARef', which are moved from the too general 'types' module which
we want to reduce or eventually remove. Also fix a safety comment
in 'static_lock_class'
'pin-init' crate:
- Add 'impl<T, E> [Pin]Init<T, E> for Result<T, E>', so results are
now (pin-)initializers
- Add 'Zeroable::init_zeroed()' that delegates to 'init_zeroed()'
- New 'zeroed()', a safe version of 'mem::zeroed()' and also provide
it via 'Zeroable::zeroed()'
- Implement 'Zeroable' for 'Option<&T>', 'Option<&mut T>' and for
'Option<[unsafe] [extern "abi"] fn(...args...) -> ret>' for
'"Rust"' and '"C"' ABIs and up to 20 arguments
- Changed blanket impls of 'Init' and 'PinInit' from 'impl<T, E>
[Pin]Init<T, E> for T' to 'impl<T> [Pin]Init<T> for T'
- Renamed 'zeroed()' to 'init_zeroed()'
- Upstream dev news: improve CI more to deny warnings, use
'--all-targets'. Check the synchronization status of the two
'-next' branches in upstream and the kernel
MAINTAINERS:
- Add Vlastimil Babka, Liam R. Howlett, Uladzislau Rezki and Lorenzo
Stoakes as reviewers (thanks everyone)
And a few other cleanups and improvements"
* tag 'rust-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (76 commits)
rust: Add warn_on macro
arm64/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
riscv/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
x86/bug: Add ARCH_WARN_ASM macro for BUG/WARN asm code sharing with Rust
rust: kernel: move ARef and AlwaysRefCounted to sync::aref
rust: sync: fix safety comment for `static_lock_class`
rust: types: remove `Either<L, R>`
rust: kernel: use `core::ffi::CStr` method names
rust: str: add `CStr` methods matching `core::ffi::CStr`
rust: str: remove unnecessary qualification
rust: use `kernel::{fmt,prelude::fmt!}`
rust: kernel: add `fmt` module
rust: kernel: remove `fmt!`, fix clippy::uninlined-format-args
scripts: rust: emit path candidates in panic message
scripts: rust: replace length checks with match
rust: list: remove nonexistent generic parameter in link
rust: bits: add support for bits/genmask macros
rust: list: remove OFFSET constants
rust: list: add `impl_list_item!` examples
rust: list: use fully qualified path
...
Locking primitives:
- Mark devm_mutex_init() as __must_check and fix drivers
that didn't check the return code. (Thomas Weißschuh)
- Reorganize <linux/local_lock.h> to better expose the
internal APIs to local variables. (Sebastian Andrzej Siewior)
- Remove OWNER_SPINNABLE in rwsem (Jinliang Zheng)
- Remove redundant #ifdefs in the mutex code (Ran Xiaokai)
Lockdep:
- Avoid returning struct in lock_stats() (Arnd Bergmann)
- Change `static const` into enum for LOCKF_*_IRQ_*
(Arnd Bergmann)
- Temporarily use synchronize_rcu_expedited() in
lockdep_unregister_key() to speed things up.
(Breno Leitao)
Rust runtime:
- Add #[must_use] to Lock::try_lock() (Jason Devers)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=RExf
-----END PGP SIGNATURE-----
Merge tag 'locking-core-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
"Locking primitives:
- Mark devm_mutex_init() as __must_check and fix drivers that didn't
check the return code (Thomas Weißschuh)
- Reorganize <linux/local_lock.h> to better expose the internal APIs
to local variables (Sebastian Andrzej Siewior)
- Remove OWNER_SPINNABLE in rwsem (Jinliang Zheng)
- Remove redundant #ifdefs in the mutex code (Ran Xiaokai)
Lockdep:
- Avoid returning struct in lock_stats() (Arnd Bergmann)
- Change `static const` into enum for LOCKF_*_IRQ_* (Arnd Bergmann)
- Temporarily use synchronize_rcu_expedited() in
lockdep_unregister_key() to speed things up. (Breno Leitao)
Rust runtime:
- Add #[must_use] to Lock::try_lock() (Jason Devers)"
* tag 'locking-core-2025-07-29' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
lockdep: Speed up lockdep_unregister_key() with expedited RCU synchronization
locking/mutex: Remove redundant #ifdefs
locking/lockdep: Change 'static const' variables to enum values
locking/lockdep: Avoid struct return in lock_stats()
locking/rwsem: Use OWNER_NONSPINNABLE directly instead of OWNER_SPINNABLE
rust: sync: Add #[must_use] to Lock::try_lock()
locking/mutex: Mark devm_mutex_init() as __must_check
leds: lp8860: Check return value of devm_mutex_init()
spi: spi-nxp-fspi: Check return value of devm_mutex_init()
local_lock: Move this_cpu_ptr() notation from internal to main header
Core scheduler changes:
- Better tracking of maximum lag of tasks in presence of different
slices duration, for better handling of lag in the fair
scheduler. (Vincent Guittot)
- Clean up and standardize #if/#else/#endif markers throughout
the entire scheduler code base (Ingo Molnar)
- Make SMP unconditional: build the SMP scheduler's
data structures and logic on UP kernel too, even though
they are not used, to simplify the scheduler and remove
around 200 #ifdef/[#else]/#endif blocks from the
scheduler. (Ingo Molnar)
- Reorganize cgroup bandwidth control interface handling
for better interfacing with sched_ext (Tejun Heo)
Balancing:
- Bump sd->max_newidle_lb_cost when newidle balance fails (Chris Mason)
- Remove sched_domain_topology_level::flags to simplify the code (Prateek Nayak)
- Simplify and clean up build_sched_topology() (Li Chen)
- Optimize build_sched_topology() on large machines (Li Chen)
Real-time scheduling:
- Add initial version of proxy execution: a mechanism for mutex-owning
tasks to inherit the scheduling context of higher priority waiters.
Currently limited to a single runqueue and conditional on CONFIG_EXPERT,
and other limitations. (John Stultz, Peter Zijlstra, Valentin Schneider)
- Deadline scheduler (Juri Lelli):
- Fix dl_servers initialization order (Juri Lelli)
- Fix DL scheduler's root domain reinitialization logic (Juri Lelli)
- Fix accounting bugs after global limits change (Juri Lelli)
- Fix scalability regression by implementing less agressive dl_server handling
(Peter Zijlstra)
PSI:
- Improve scalability by optimizing psi_group_change() cpu_clock() usage
(Peter Zijlstra)
Rust changes:
- Make Task, CondVar and PollCondVar methods inline to avoid unnecessary
function calls (Kunwu Chan, Panagiotis Foliadis)
- Add might_sleep() support for Rust code: Rust's "#[track_caller]"
mechanism is used so that Rust's might_sleep() doesn't need to be
defined as a macro (Fujita Tomonori)
- Introduce file_from_location() (Boqun Feng)
Debugging & instrumentation:
- Make clangd usable with scheduler source code files again (Peter Zijlstra)
- tools: Add root_domains_dump.py which dumps root domains info (Juri Lelli)
- tools: Add dl_bw_dump.py for printing bandwidth accounting info (Juri Lelli)
Misc cleanups & fixes:
- Remove play_idle() (Feng Lee)
- Fix check_preemption_disabled() (Sebastian Andrzej Siewior)
- Do not call __put_task_struct() on RT if pi_blocked_on is set
(Luis Claudio R. Goncalves)
- Correct the comment in place_entity() (wang wei)
Signed-off-by: Ingo Molnar <mingo@kernel.org>
-----BEGIN PGP SIGNATURE-----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=8T0v
-----END PGP SIGNATURE-----
Merge tag 'sched-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
"Core scheduler changes:
- Better tracking of maximum lag of tasks in presence of different
slices duration, for better handling of lag in the fair scheduler
(Vincent Guittot)
- Clean up and standardize #if/#else/#endif markers throughout the
entire scheduler code base (Ingo Molnar)
- Make SMP unconditional: build the SMP scheduler's data structures
and logic on UP kernel too, even though they are not used, to
simplify the scheduler and remove around 200 #ifdef/[#else]/#endif
blocks from the scheduler (Ingo Molnar)
- Reorganize cgroup bandwidth control interface handling for better
interfacing with sched_ext (Tejun Heo)
Balancing:
- Bump sd->max_newidle_lb_cost when newidle balance fails (Chris
Mason)
- Remove sched_domain_topology_level::flags to simplify the code
(Prateek Nayak)
- Simplify and clean up build_sched_topology() (Li Chen)
- Optimize build_sched_topology() on large machines (Li Chen)
Real-time scheduling:
- Add initial version of proxy execution: a mechanism for
mutex-owning tasks to inherit the scheduling context of higher
priority waiters.
Currently limited to a single runqueue and conditional on
CONFIG_EXPERT, and other limitations (John Stultz, Peter Zijlstra,
Valentin Schneider)
- Deadline scheduler (Juri Lelli):
- Fix dl_servers initialization order (Juri Lelli)
- Fix DL scheduler's root domain reinitialization logic (Juri
Lelli)
- Fix accounting bugs after global limits change (Juri Lelli)
- Fix scalability regression by implementing less agressive
dl_server handling (Peter Zijlstra)
PSI:
- Improve scalability by optimizing psi_group_change() cpu_clock()
usage (Peter Zijlstra)
Rust changes:
- Make Task, CondVar and PollCondVar methods inline to avoid
unnecessary function calls (Kunwu Chan, Panagiotis Foliadis)
- Add might_sleep() support for Rust code: Rust's "#[track_caller]"
mechanism is used so that Rust's might_sleep() doesn't need to be
defined as a macro (Fujita Tomonori)
- Introduce file_from_location() (Boqun Feng)
Debugging & instrumentation:
- Make clangd usable with scheduler source code files again (Peter
Zijlstra)
- tools: Add root_domains_dump.py which dumps root domains info (Juri
Lelli)
- tools: Add dl_bw_dump.py for printing bandwidth accounting info
(Juri Lelli)
Misc cleanups & fixes:
- Remove play_idle() (Feng Lee)
- Fix check_preemption_disabled() (Sebastian Andrzej Siewior)
- Do not call __put_task_struct() on RT if pi_blocked_on is set (Luis
Claudio R. Goncalves)
- Correct the comment in place_entity() (wang wei)"
* tag 'sched-core-2025-07-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (84 commits)
sched/idle: Remove play_idle()
sched: Do not call __put_task_struct() on rt if pi_blocked_on is set
sched: Start blocked_on chain processing in find_proxy_task()
sched: Fix proxy/current (push,pull)ability
sched: Add an initial sketch of the find_proxy_task() function
sched: Fix runtime accounting w/ split exec & sched contexts
sched: Move update_curr_task logic into update_curr_se
locking/mutex: Add p->blocked_on wrappers for correctness checks
locking/mutex: Rework task_struct::blocked_on
sched: Add CONFIG_SCHED_PROXY_EXEC & boot argument to enable/disable
sched/topology: Remove sched_domain_topology_level::flags
x86/smpboot: avoid SMT domain attach/destroy if SMT is not enabled
x86/smpboot: moves x86_topology to static initialize and truncate
x86/smpboot: remove redundant CONFIG_SCHED_SMT
smpboot: introduce SDTL_INIT() helper to tidy sched topology setup
tools/sched: Add dl_bw_dump.py for printing bandwidth accounting info
tools/sched: Add root_domains_dump.py which dumps root domains info
sched/deadline: Fix accounting after global limits change
sched/deadline: Reset extra_bw to max_bw when clearing root domains
sched/deadline: Initialize dl_servers after SMP
...
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCaINClgAKCRCRxhvAZXjc
otDpAQCvI4ASuGHsDY7NMF/sOjVeeXIAQHNaxfrVnYzppqZw1wD+IFhE//BIyJoC
22zmr/o72h4YH0PazIl85NuVS2n9UA4=
=EFWZ
-----END PGP SIGNATURE-----
Merge tag 'vfs-6.17-rc1.rust' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs rust updates from Christian Brauner:
- Allow poll_table pointers to be NULL
- Add Rust files to vfs MAINTAINERS entry
* tag 'vfs-6.17-rc1.rust' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
vfs: add Rust files to MAINTAINERS
poll: rust: allow poll_table ptrs to be null
Move the definitions of `ARef` and `AlwaysRefCounted` from `types.rs`
to a new file `sync/aref.rs`. Define the corresponding `aref` module
under `rust/kernel/sync.rs`. These types are better grouped in `sync`.
To avoid breaking existing imports, they are re-exported from `types.rs`.
Drop unused imports `mem::ManuallyDrop`, `ptr::NonNull` from `types.rs`,
they are now only used in `sync/aref.rs`, where they are already imported.
Suggested-by: Benno Lossin <lossin@kernel.org>
Link: https://github.com/Rust-for-Linux/linux/issues/1173
Signed-off-by: Shankari Anand <shankari.ak0208@gmail.com>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Link: https://lore.kernel.org/r/20250715110423.334744-1-shankari.ak0208@gmail.com
[ Added missing `///`. Changed module title. Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The current implementation of `ForeignOwnable` is leaking the type of the
opaque pointer to consumers of the API. This allows consumers of the opaque
pointer to rely on the information that can be extracted from the pointer
type.
To prevent this, change the API to the version suggested by Maira
Canal (link below): Remove `ForeignOwnable::PointedTo` in favor of a
constant, which specifies the alignment of the pointers returned by
`into_foreign`.
With this change, `ArcInner` no longer needs `pub` visibility, so change it
to private.
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Suggested-by: Maíra Canal <mcanal@igalia.com>
Link: https://lore.kernel.org/r/20240309235927.168915-3-mcanal@igalia.com
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20250612-pointed-to-v3-1-b009006d86a1@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
It's possible for a poll_table to be null. This can happen if an
end-user just wants to know if a resource has events right now without
registering a waiter for when events become available. Furthermore,
these null pointers should be handled transparently by the API, so we
should not change `from_ptr` to return an `Option`. Thus, change
`PollTable` to wrap a raw pointer rather than use a reference so that
you can pass null.
Comments mentioning `struct poll_table` are changed to just `poll_table`
since `poll_table` is a typedef. (It's a typedef because it's supposed
to be opaque.)
Reviewed-by: Benno Lossin <lossin@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
The `Lock::try_lock()` function returns an `Option<Guard<...>>`, but it
currently does not issue a warning if the return value is unused.
To avoid potential bugs, the `#[must_use]` annotation is added to ensure
proper usage.
Note that `T` is `#[must_use]` but `Option<T>` is not.
For more context, see: https://github.com/rust-lang/rust/issues/71368.
Suggested-by: Alice Ryhl <aliceryhl@google.com>
Link: https://github.com/Rust-for-Linux/linux/issues/1133
Signed-off-by: Jason Devers <dev.json2@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20241212154753.139563-1-dev.json2@gmail.com
Linus Torvalds