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2026-06-15Merge tag 'locking-core-2026-06-14' of ↵Linus Torvalds1-0/+2
gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip Pull locking updates from Ingo Molnar: "Futex updates: - Optimize futex hash bucket access patterns (Peter Zijlstra) - Large series to address the robust futex unlock race for real, by Thomas Gleixner: "The robust futex unlock mechanism is racy in respect to the clearing of the robust_list_head::list_op_pending pointer because unlock and clearing the pointer are not atomic. The race window is between the unlock and clearing the pending op pointer. If the task is forced to exit in this window, exit will access a potentially invalid pending op pointer when cleaning up the robust list. That happens if another task manages to unmap the object containing the lock before the cleanup, which results in an UAF. In the worst case this UAF can lead to memory corruption when unrelated content has been mapped to the same address by the time the access happens. User space can't solve this problem without help from the kernel. This series provides the kernel side infrastructure to help it along: 1) Combined unlock, pointer clearing, wake-up for the contended case 2) VDSO based unlock and pointer clearing helpers with a fix-up function in the kernel when user space was interrupted within the critical section. ... with help by André Almeida: - Add a note about robust list race condition (André Almeida) - Add self-tests for robust release operations (André Almeida) Context analysis updates: - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche) - Bump required Clang version to 23 (Marco Elver) Guard infrastructure updates: - Series to remove NULL check from unconditional guards (Dmitry Ilvokhin) Lockdep updates: - Restore self-test migrate_disable() and sched_rt_mutex state on PREEMPT_RT (Karl Mehltretter) Membarriers updates: - Use per-CPU mutexes for targeted commands (Aniket Gattani) - Modernize membarrier_global_expedited with cleanup guards (Aniket Gattani) - Add rseq stress test for CFS throttle interactions (Aniket Gattani) percpu-rwsems updates: - Extract __percpu_up_read() to optimize inlining overhead (Dmitry Ilvokhin) Seqlocks updates: - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens) Lock tracing: - Add contended_release tracepoint to sleepable locks such as mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry Ilvokhin) MAINTAINERS updates: - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng) Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra, Dmitry Ilvokhin and Peter Zijlstra" * tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits) locking: Add contended_release tracepoint to sleepable locks locking/percpu-rwsem: Extract __percpu_up_read() tracing/lock: Remove unnecessary linux/sched.h include futex: Optimize futex hash bucket access patterns rust: sync: completion: Mark inline complete_all and wait_for_completion MAINTAINERS: Add RUST [SYNC] entry cleanup: Specify nonnull argument index selftests: futex: Add tests for robust release operations Documentation: futex: Add a note about robust list race condition x86/vdso: Implement __vdso_futex_robust_try_unlock() x86/vdso: Prepare for robust futex unlock support futex: Provide infrastructure to plug the non contended robust futex unlock race futex: Add robust futex unlock IP range futex: Add support for unlocking robust futexes futex: Cleanup UAPI defines x86: Select ARCH_MEMORY_ORDER_TSO uaccess: Provide unsafe_atomic_store_release_user() futex: Provide UABI defines for robust list entry modifiers futex: Move futex related mm_struct data into a struct futex: Make futex_mm_init() void ...
2026-06-10rust: make `build_assert` module the home of related macrosGary Guo4-10/+13
Given the macro scoping rules, all macros are rendered twice, in the module and in the top-level of kernel crate. Add `#[doc(hidden)]` to the macro definition and `#[doc(inline)]` to the re-export inside `build_assert` module so the top-level items are hidden. [ Sadly, because the definition is hidden, `rustdoc` decides to not list them as re-exports in the `prelude` page anymore, even if we refer to the not-actually-hidden item. - Miguel ] Acked-by: Danilo Krummrich <dakr@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Acked-by: Alexandre Courbot <acourbot@nvidia.com> Acked-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Acked-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260609142637.373347-1-gary@kernel.org [ Kept a single declaration in the prelude, and reworded since they already had `no_inline`. Removed other imports from `predefine` since we now use the prelude. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-10rust: aref: use the "kernel vertical" imports styleAndreas Hindborg1-1/+6
Convert the imports to use the "kernel vertical" imports style [1]. No functional changes intended. Link: https://docs.kernel.org/rust/coding-guidelines.html#imports [1] Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> Link: https://patch.msgid.link/20260604-unique-ref-v17-8-7b4c3d2930b9@kernel.org [ Picked from larger series and reworded. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-09rust: sync: completion: Mark inline complete_all and wait_for_completionFabricio Parra1-0/+2
When building the kernel using the llvm-22.1.0-rust-1.93.1-x86_64 toolchain provided by kernel.org with ARCH=x86_64, the following symbols are generated: $ nm vmlinux | grep ' _R'.*Completion | rustfilt ffffffff81827930 T <kernel::sync::completion::Completion>::complete_all ffffffff81827950 T <kernel::sync::completion::Completion>::wait_for_completion These Rust methods are thin wrappers around the C completion helpers `complete_all` and `wait_for_completion`. Mark them `#[inline]` to keep the wrapper pattern consistent with other small Rust helper methods. After applying this patch, the above command will produce no output. Suggested-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Fabricio Parra <a@alice0.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://github.com/Rust-for-Linux/linux/issues/1145 Link: https://patch.msgid.link/20260316151056.287-1-a@alice0.com Link: https://patch.msgid.link/20260605052331.1628-4-boqun@kernel.org
2026-06-09rust: sync: add `UniqueArc::as_ptr`Andreas Hindborg1-0/+8
Add an associated function to `UniqueArc` for getting a raw pointer. The implementation defers to the `Arc` implementation. Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20260605-unique-arc-as-ptr-v2-1-425476d2abdb@kernel.org [ Relaxed bound moving it to new `T: ?Sized` impl block. Reworded since it is not a method anymore. Added intra-doc link. - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-09rust: inline some init methodsAlexandre Courbot1-0/+4
These methods should be inlined for optimization reasons. Failure to do so can also produce symbol names larger than what `modpost` or `objtool` can handle. Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260605-nova-exports-v4-1-e948c287407c@nvidia.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-08rust: tests: add Kconfig for KUnit testYury Norov1-0/+1
There are 6 individual Rust KUnit test suites (plus the doctests one). All the tests are compiled unconditionally now, which adds ~200 kB to the kernel image for me on x86_64. As Rust matures, this bloating will inevitably grow. Add Kconfig.test which includes a RUST_KUNIT_TESTS menu, and all individual tests under it. As usual, new tests are all enabled if KUNIT_ALL_TESTS=y. Suggested-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Yury Norov <ynorov@nvidia.com> Reviewed-by: David Gow <david@davidgow.net> Acked-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260417031531.315281-3-ynorov@nvidia.com [ Fixed capitalization. Used singular for "API" for consistency. Reworded to clarify these are suites and that there exists the doctests one (which is the biggest at the moment by far). - Miguel ] Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-08rust: tests: drop 'use crate' in bitmap and atomic KUnit testsYury Norov1-3/+1
The following patch makes usage of macros::kunit_tests crate conditional on the corresponding configs. When the configs are disabled, compiler warns on unused crate. So, embed it in unit test declaration. Signed-off-by: Yury Norov <ynorov@nvidia.com> Reviewed-by: David Gow <david@davidgow.net> Acked-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260417031531.315281-2-ynorov@nvidia.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-04rust: sync: add #[must_use] to GlobalGuard and GlobalLock::try_lockAshutosh Desai1-0/+2
Guard is marked #[must_use] since dropping it releases the lock. GlobalGuard wraps Guard with identical semantics but was missing the annotation, so discarding it would silently compile without warning. Similarly, GlobalLock::try_lock was missing #[must_use]. Option<T> does not propagate #[must_use] from T, so the attribute needs to be on the function directly - same reason Lock::try_lock has it. Reviewed-by: Alice Ryhl <aliceryhl@google.com> Signed-off-by: Ashutosh Desai <ashutoshdesai993@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260502160057.3402896-1-ashutoshdesai993@gmail.com Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-24Merge tag 'char-misc-7.1-rc1' of ↵Linus Torvalds1-0/+22
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char / misc / IIO / and others driver updates from Greg KH: "Here is the char/misc/iio and other smaller driver subsystem updates for 7.1-rc1. Lots of stuff in here, all tiny, but relevant for the different drivers they touch. Major points in here is: - the usual large set of new IIO drivers and updates for that subsystem (the large majority of this diffstat) - lots of comedi driver updates and bugfixes - coresight driver updates - interconnect driver updates and additions - mei driver updates - binder (both rust and C versions) updates and fixes - lots of other smaller driver subsystem updates and additions All of these have been in linux-next for a while with no reported issues" * tag 'char-misc-7.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (405 commits) coresight: tpdm: fix invalid MMIO access issue mei: me: add nova lake point H DID mei: lb: add late binding version 2 mei: bus: add mei_cldev_uuid w1: ds2490: drop redundant device reference bus: mhi: host: pci_generic: Add Telit FE912C04 modem support mei: csc: wake device while reading firmware status mei: csc: support controller with separate PCI device mei: convert PCI error to common errno mei: trace: print return value of pci_cfg_read mei: me: move trace into firmware status read mei: fix idle print specifiers mei: me: use PCI_DEVICE_DATA macro sonypi: Convert ACPI driver to a platform one misc: apds990x: fix all kernel-doc warnings most: usb: Use kzalloc_objs for endpoint address array hpet: Convert ACPI driver to a platform one misc: vmw_vmci: Fix spelling mistakes in comments parport: Remove completed item from to-do list char: remove unnecessary module_init/exit functions ...
2026-04-14Merge tag 'locking-core-2026-04-13' of ↵Linus Torvalds3-24/+439
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() ...
2026-04-07rust: remove `RUSTC_HAS_COERCE_POINTEE` and simplify codeMiguel Ojeda1-19/+2
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>
2026-04-01rust: sync: implement == operator for ARefAlice Ryhl1-0/+22
Rust Binder wants to perform a comparison between ARef<Task> and &Task, so define the == operator for ARef<_> when compared with another ARef<_> or just a reference. The operator is implemented in terms of the same operator applied to the inner type. Note that PartialEq<U> cannot be implemented because it would overlap with the impl for ARef<U>. Reviewed-by: Gary Guo <gary@garyguo.net> Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20260324-close-fd-check-current-v3-1-b94274bedac7@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-03-08rust: atomic: Update a safety comment in impl of `fetch_add()`Andreas Hindborg1-1/+1
The safety comment used in the implementation of `fetch_add()` could be read as just saying something it is true without justifying it. Update the safety comment to include justification. Suggested-by: Miguel Ojeda <ojeda@kernel.org> Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20260220-atomic-sub-v3-3-e63cbed1d2aa@kernel.org Link: https://patch.msgid.link/20260303201701.12204-14-boqun@kernel.org
2026-03-08rust: sync: atomic: Update documentation for `fetch_add()`Andreas Hindborg1-6/+4
The documentation for `fetch_add()` does not indicate that the original value is returned by `fetch_add()`. Update the documentation so this is clear. Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20260220-atomic-sub-v3-2-e63cbed1d2aa@kernel.org Link: https://patch.msgid.link/20260303201701.12204-13-boqun@kernel.org
2026-03-08rust: sync: atomic: Add fetch_sub()Andreas Hindborg2-0/+48
Add `Atomic::fetch_sub()` with implementation and documentation in line with existing `Atomic::fetch_add()` implementation. Signed-off-by: Andreas Hindborg <a.hindborg@kernel.org> Signed-off-by: Boqun Feng <boqun@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20260220-atomic-sub-v3-1-e63cbed1d2aa@kernel.org Link: https://patch.msgid.link/20260303201701.12204-12-boqun@kernel.org
2026-03-08rust: sync: atomic: Add atomic operation helpers over raw pointersBoqun Feng2-0/+150
In order to synchronize with C or external memory, atomic operations over raw pointers are need. Although there is already an `Atomic::from_ptr()` to provide a `&Atomic<T>`, it's more convenient to have helpers that directly perform atomic operations on raw pointers. Hence a few are added, which are basically an `Atomic::from_ptr().op()` wrapper. Note: for naming, since `atomic_xchg()` and `atomic_cmpxchg()` have a conflict naming to 32bit C atomic xchg/cmpxchg, hence the helpers are just named as `xchg()` and `cmpxchg()`. For `atomic_load()` and `atomic_store()`, their 32bit C counterparts are `atomic_read()` and `atomic_set()`, so keep the `atomic_` prefix. [boqun: Fix typo spotted by Alice and fix broken sentence spotted by Gary] 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: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260120115207.55318-3-boqun.feng@gmail.com Link: https://patch.msgid.link/20260303201701.12204-11-boqun@kernel.org
2026-03-08rust: sync: atomic: Add performance-optimal Flag type for atomic booleansFUJITA Tomonori2-0/+142
Add AtomicFlag type for boolean flags. Document when AtomicFlag is generally preferable to Atomic<bool>: in particular, when RMW operations such as xchg()/cmpxchg() may be used and minimizing memory usage is not the top priority. On some architectures without byte-sized RMW instructions, Atomic<bool> can be slower for RMW operations. 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/20260129122622.3896144-2-tomo@aliasing.net Link: https://patch.msgid.link/20260303201701.12204-9-boqun@kernel.org
2026-03-08rust: sync: atomic: Add Atomic<*{mut,const} T> supportBoqun Feng3-10/+72
Atomic pointer support is an important piece of synchronization algorithm, e.g. RCU, hence provide the support for that. Note that instead of relying on atomic_long or the implementation of `Atomic<usize>`, a new set of helpers (atomic_ptr_*) is introduced for atomic pointer specifically, this is because ptr2int casting would lose the provenance of a pointer and even though in theory there are a few tricks the provenance can be restored, it'll still be a simpler implementation if C could provide atomic pointers directly. The side effects of this approach are: we don't have the arithmetic and logical operations for pointers yet and the current implementation only works on ARCH_SUPPORTS_ATOMIC_RMW architectures, but these are implementation issues and can be added later. Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Link: https://patch.msgid.link/20260120140503.62804-3-boqun.feng@gmail.com Link: https://patch.msgid.link/20260303201701.12204-8-boqun@kernel.org
2026-03-08rust: sync: atomic: Clarify the need of CONFIG_ARCH_SUPPORTS_ATOMIC_RMWBoqun Feng1-6/+13
Currently, since all the architectures that support Rust all have CONFIG_ARCH_SUPPORTS_ATOMIC_RMW selected, the helpers of atomic load/store on i8 and i16 relies on CONFIG_ARCH_SUPPORTS_ATOMIC_RMW=y. It's generally fine since most of architectures support that. The plan for CONFIG_ARCH_SUPPORTS_ATOMIC_RMW=n architectures is adding their (probably lock-based) atomic load/store for i8 and i16 as their atomic_{read,set}() and atomic64_{read,set}() counterpart when they plans to support Rust. Hence use a statis_assert!() to check this and remind the future us the need of the helpers. This is more clear than the #[cfg] on impl blocks of i8 and i16. Suggested-by: Dirk Behme <dirk.behme@gmail.com> Suggested-by: Benno Lossin <lossin@kernel.org> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260120140503.62804-2-boqun.feng@gmail.com Link: https://patch.msgid.link/20260303201701.12204-7-boqun@kernel.org
2026-03-08rust: sync: atomic: Add example for Atomic::get_mut()FUJITA Tomonori1-0/+11
Add an example for Atomic::get_mut(). No functional change. 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: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260128123313.3850604-1-tomo@aliasing.net Link: https://patch.msgid.link/20260303201701.12204-3-boqun@kernel.org
2026-03-08rust: sync: atomic: Remove bound `T: Sync` for `Atomic::from_ptr()`Boqun Feng1-4/+1
Originally, `Atomic::from_ptr()` requires `T` being a `Sync` because I thought having the ability to do `from_ptr()` meant multiplle `&Atomic<T>`s shared by different threads, which was identical (or similar) to multiple `&T`s shared by different threads. Hence `T` was required to be `Sync`. However this is not true, since `&Atomic<T>` is not the same at `&T`. Moreover, having this bound makes `Atomic::<*mut T>::from_ptr()` impossible, which is definitely not intended. Therefore remove the `T: Sync` bound. [boqun: Fix title typo spotted by Alice & Gary] Fixes: 29c32c405e53 ("rust: sync: atomic: Add generic atomics") 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: Gary Guo <gary@garyguo.net> Link: https://patch.msgid.link/20260120115207.55318-2-boqun.feng@gmail.com Link: https://patch.msgid.link/20260303201701.12204-2-boqun@kernel.org
2026-02-17Merge tag 'char-misc-7.0-rc1' of ↵Linus Torvalds1-0/+3
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc/IIO driver updates from Greg KH: "Here is the big set of char/misc/iio and other smaller driver subsystem changes for 7.0-rc1. Lots of little things in here, including: - Loads of iio driver changes and updates and additions - gpib driver updates - interconnect driver updates - i3c driver updates - hwtracing (coresight and intel) driver updates - deletion of the obsolete mwave driver - binder driver updates (rust and c versions) - mhi driver updates (causing a merge conflict, see below) - mei driver updates - fsi driver updates - eeprom driver updates - lots of other small char and misc driver updates and cleanups All of these have been in linux-next for a while, with no reported issues" * tag 'char-misc-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (297 commits) mux: mmio: fix regmap leak on probe failure rust_binder: return p from rust_binder_transaction_target_node() drivers: android: binder: Update ARef imports from sync::aref rust_binder: fix needless borrow in context.rs iio: magn: mmc5633: Fix Kconfig for combination of I3C as module and driver builtin iio: sca3000: Fix a resource leak in sca3000_probe() iio: proximity: rfd77402: Add interrupt handling support iio: proximity: rfd77402: Document device private data structure iio: proximity: rfd77402: Use devm-managed mutex initialization iio: proximity: rfd77402: Use kernel helper for result polling iio: proximity: rfd77402: Align polling timeout with datasheet iio: cros_ec: Allow enabling/disabling calibration mode iio: frequency: ad9523: correct kernel-doc bad line warning iio: buffer: buffer_impl.h: fix kernel-doc warnings iio: gyro: itg3200: Fix unchecked return value in read_raw MAINTAINERS: add entry for ADE9000 driver iio: accel: sca3000: remove unused last_timestamp field iio: accel: adxl372: remove unused int2_bitmask field iio: adc: ad7766: Use iio_trigger_generic_data_rdy_poll() iio: magnetometer: Remove IRQF_ONESHOT ...
2026-02-10Merge tag 'locking-core-2026-02-08' of ↵Linus Torvalds8-27/+172
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 ...
2026-01-26rust: sync: atomic: Provide stub for `rusttest` 32-bit hostsMiguel Ojeda1-0/+11
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: 84c6d36bcaf9 ("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>
2026-01-18rust: sync: refcount: always inline functions using build_assert with argumentsAlexandre Courbot1-1/+2
`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: bb38f35b35f9 ("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>
2026-01-10rust: sync: Inline various lock related methodsAlice Ryhl4-0/+19
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
2026-01-09rust: sync: atomic: Add atomic bool testsFUJITA Tomonori1-0/+16
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
2026-01-09rust: sync: atomic: Add atomic bool support via i8 representationFUJITA Tomonori1-0/+11
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
2026-01-09rust: sync: atomic: Add i8/i16 xchg and cmpxchg supportFUJITA Tomonori2-3/+9
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
2026-01-09rust: sync: atomic: Add store_release/load_acquire testsFUJITA Tomonori1-0/+10
Add minimum store_release/load_acquire tests. Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://patch.msgid.link/20251211113826.1299077-5-fujita.tomonori@gmail.com
2026-01-09rust: sync: atomic: Add i8/i16 load and store supportFUJITA Tomonori2-7/+32
Add atomic operation support for i8 and i16 types using volatile read/write and smp_load_acquire/smp_store_release helpers. [boqun: Adjust [1] to avoid introduction of impl_atomic_only_load_and_store_ops!() in the middle] Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com> Reviewed-by: Gary Guo <gary@garyguo.net> Reviewed-by: Joel Fernandes <joelagnelf@nvidia.com> Link: https://lore.kernel.org/all/20251228120546.1602275-1-fujita.tomonori@gmail.com/ [1] Signed-off-by: Boqun Feng <boqun.feng@gmail.com> Link: https://patch.msgid.link/20251211113826.1299077-4-fujita.tomonori@gmail.com
2026-01-09rust: sync: atomic: Prepare AtomicOps macros for i8/i16 supportFUJITA Tomonori1-19/+66
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
2026-01-09rust: sync: Implement Unpin for ARefAlice Ryhl1-0/+3
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 66f1ea83d9f8 ("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
2026-01-09rust: sync: set_once: Implement Send and SyncFUJITA Tomonori1-0/+8
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
2025-12-29rust: sync: add Arc::DATA_OFFSETAlice Ryhl1-0/+3
This constant will be used to expose some offset constants from the Rust Binder driver to tracepoints which are implemented in C. The constant is usually equal to sizeof(refcount_t), but may be larger if T has a large alignment. Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com> Link: https://patch.msgid.link/20251203-binder-trace1-v1-1-22d3ffddb44e@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-06rust: sync: atomic: separate import "blocks"Miguel Ojeda1-0/+1
Commit 14e9a18b07ec ("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>
2025-12-06Merge tag 'modules-6.19-rc1' of ↵Linus Torvalds1-0/+125
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`
2025-12-03Merge tag 'rust-6.19' of ↵Linus Torvalds3-3/+3
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 f