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
  ...

17 files changed, 195 insertions, 56 deletions

diff --git a/rust/helpers/atomic.c b/rust/helpers/atomic.c
index cf06b7ef9a1c..4b24eceef5fc 100644
--- a/rust/helpers/atomic.c
+++ b/rust/helpers/atomic.c
@@ -11,11 +11,6 @@
 
 #include <linux/atomic.h>
 
-// TODO: Remove this after INLINE_HELPERS support is added.
-#ifndef __rust_helper
-#define __rust_helper
-#endif
-
 __rust_helper int
 rust_helper_atomic_read(const atomic_t *v)
 {
@@ -1037,4 +1032,4 @@ rust_helper_atomic64_dec_if_positive(atomic64_t *v)
 }
 
 #endif /* _RUST_ATOMIC_API_H */
-// 615a0e0c98b5973a47fe4fa65e92935051ca00ed
+// e4edb6174dd42a265284958f00a7cea7ddb464b1
diff --git a/rust/helpers/atomic_ext.c b/rust/helpers/atomic_ext.c
new file mode 100644
index 000000000000..7d0c2bd340da
--- /dev/null
+++ b/rust/helpers/atomic_ext.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include <asm/barrier.h>
+#include <asm/rwonce.h>
+#include <linux/atomic.h>
+
+__rust_helper s8 rust_helper_atomic_i8_read(s8 *ptr)
+{
+	return READ_ONCE(*ptr);
+}
+
+__rust_helper s8 rust_helper_atomic_i8_read_acquire(s8 *ptr)
+{
+	return smp_load_acquire(ptr);
+}
+
+__rust_helper s16 rust_helper_atomic_i16_read(s16 *ptr)
+{
+	return READ_ONCE(*ptr);
+}
+
+__rust_helper s16 rust_helper_atomic_i16_read_acquire(s16 *ptr)
+{
+	return smp_load_acquire(ptr);
+}
+
+__rust_helper void rust_helper_atomic_i8_set(s8 *ptr, s8 val)
+{
+	WRITE_ONCE(*ptr, val);
+}
+
+__rust_helper void rust_helper_atomic_i8_set_release(s8 *ptr, s8 val)
+{
+	smp_store_release(ptr, val);
+}
+
+__rust_helper void rust_helper_atomic_i16_set(s16 *ptr, s16 val)
+{
+	WRITE_ONCE(*ptr, val);
+}
+
+__rust_helper void rust_helper_atomic_i16_set_release(s16 *ptr, s16 val)
+{
+	smp_store_release(ptr, val);
+}
+
+/*
+ * xchg helpers depend on ARCH_SUPPORTS_ATOMIC_RMW and on the
+ * architecture provding xchg() support for i8 and i16.
+ *
+ * The architectures that currently support Rust (x86_64, armv7,
+ * arm64, riscv, and loongarch) satisfy these requirements.
+ */
+__rust_helper s8 rust_helper_atomic_i8_xchg(s8 *ptr, s8 new)
+{
+	return xchg(ptr, new);
+}
+
+__rust_helper s16 rust_helper_atomic_i16_xchg(s16 *ptr, s16 new)
+{
+	return xchg(ptr, new);
+}
+
+__rust_helper s8 rust_helper_atomic_i8_xchg_acquire(s8 *ptr, s8 new)
+{
+	return xchg_acquire(ptr, new);
+}
+
+__rust_helper s16 rust_helper_atomic_i16_xchg_acquire(s16 *ptr, s16 new)
+{
+	return xchg_acquire(ptr, new);
+}
+
+__rust_helper s8 rust_helper_atomic_i8_xchg_release(s8 *ptr, s8 new)
+{
+	return xchg_release(ptr, new);
+}
+
+__rust_helper s16 rust_helper_atomic_i16_xchg_release(s16 *ptr, s16 new)
+{
+	return xchg_release(ptr, new);
+}
+
+__rust_helper s8 rust_helper_atomic_i8_xchg_relaxed(s8 *ptr, s8 new)
+{
+	return xchg_relaxed(ptr, new);
+}
+
+__rust_helper s16 rust_helper_atomic_i16_xchg_relaxed(s16 *ptr, s16 new)
+{
+	return xchg_relaxed(ptr, new);
+}
+
+/*
+ * try_cmpxchg helpers depend on ARCH_SUPPORTS_ATOMIC_RMW and on the
+ * architecture provding try_cmpxchg() support for i8 and i16.
+ *
+ * The architectures that currently support Rust (x86_64, armv7,
+ * arm64, riscv, and loongarch) satisfy these requirements.
+ */
+__rust_helper bool rust_helper_atomic_i8_try_cmpxchg(s8 *ptr, s8 *old, s8 new)
+{
+	return try_cmpxchg(ptr, old, new);
+}
+
+__rust_helper bool rust_helper_atomic_i16_try_cmpxchg(s16 *ptr, s16 *old, s16 new)
+{
+	return try_cmpxchg(ptr, old, new);
+}
+
+__rust_helper bool rust_helper_atomic_i8_try_cmpxchg_acquire(s8 *ptr, s8 *old, s8 new)
+{
+	return try_cmpxchg_acquire(ptr, old, new);
+}
+
+__rust_helper bool rust_helper_atomic_i16_try_cmpxchg_acquire(s16 *ptr, s16 *old, s16 new)
+{
+	return try_cmpxchg_acquire(ptr, old, new);
+}
+
+__rust_helper bool rust_helper_atomic_i8_try_cmpxchg_release(s8 *ptr, s8 *old, s8 new)
+{
+	return try_cmpxchg_release(ptr, old, new);
+}
+
+__rust_helper bool rust_helper_atomic_i16_try_cmpxchg_release(s16 *ptr, s16 *old, s16 new)
+{
+	return try_cmpxchg_release(ptr, old, new);
+}
+
+__rust_helper bool rust_helper_atomic_i8_try_cmpxchg_relaxed(s8 *ptr, s8 *old, s8 new)
+{
+	return try_cmpxchg_relaxed(ptr, old, new);
+}
+
+__rust_helper bool rust_helper_atomic_i16_try_cmpxchg_relaxed(s16 *ptr, s16 *old, s16 new)
+{
+	return try_cmpxchg_relaxed(ptr, old, new);
+}
diff --git a/rust/helpers/barrier.c b/rust/helpers/barrier.c
index cdf28ce8e511..fed8853745c8 100644
--- a/rust/helpers/barrier.c
+++ b/rust/helpers/barrier.c
@@ -2,17 +2,17 @@
 
 #include <asm/barrier.h>
 
-void rust_helper_smp_mb(void)
+__rust_helper void rust_helper_smp_mb(void)
 {
 	smp_mb();
 }
 
-void rust_helper_smp_wmb(void)
+__rust_helper void rust_helper_smp_wmb(void)
 {
 	smp_wmb();
 }
 
-void rust_helper_smp_rmb(void)
+__rust_helper void rust_helper_smp_rmb(void)
 {
 	smp_rmb();
 }
diff --git a/rust/helpers/blk.c b/rust/helpers/blk.c
index cc9f4e6a2d23..20c512e46a7a 100644
--- a/rust/helpers/blk.c
+++ b/rust/helpers/blk.c
@@ -3,12 +3,12 @@
 #include <linux/blk-mq.h>
 #include <linux/blkdev.h>
 
-void *rust_helper_blk_mq_rq_to_pdu(struct request *rq)
+__rust_helper void *rust_helper_blk_mq_rq_to_pdu(struct request *rq)
 {
 	return blk_mq_rq_to_pdu(rq);
 }
 
-struct request *rust_helper_blk_mq_rq_from_pdu(void *pdu)
+__rust_helper struct request *rust_helper_blk_mq_rq_from_pdu(void *pdu)
 {
 	return blk_mq_rq_from_pdu(pdu);
 }
diff --git a/rust/helpers/completion.c b/rust/helpers/completion.c
index b2443262a2ae..0126767cc3be 100644
--- a/rust/helpers/completion.c
+++ b/rust/helpers/completion.c
@@ -2,7 +2,7 @@
 
 #include <linux/completion.h>
 
-void rust_helper_init_completion(struct completion *x)
+__rust_helper void rust_helper_init_completion(struct completion *x)
 {
 	init_completion(x);
 }
diff --git a/rust/helpers/cpu.c b/rust/helpers/cpu.c
index 824e0adb19d4..5759349b2c88 100644
--- a/rust/helpers/cpu.c
+++ b/rust/helpers/cpu.c
@@ -2,7 +2,7 @@
 
 #include <linux/smp.h>
 
-unsigned int rust_helper_raw_smp_processor_id(void)
+__rust_helper unsigned int rust_helper_raw_smp_processor_id(void)
 {
 	return raw_smp_processor_id();
 }
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 79c72762ad9c..a3c42e51f00a 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -7,7 +7,10 @@
  * Sorted alphabetically.
  */
 
+#define __rust_helper
+
 #include "atomic.c"
+#include "atomic_ext.c"
 #include "auxiliary.c"
 #include "barrier.c"
 #include "binder.c"
diff --git a/rust/helpers/mutex.c b/rust/helpers/mutex.c
index e487819125f0..1b07d6e64299 100644
--- a/rust/helpers/mutex.c
+++ b/rust/helpers/mutex.c
@@ -2,28 +2,29 @@
 
 #include <linux/mutex.h>
 
-void rust_helper_mutex_lock(struct mutex *lock)
+__rust_helper void rust_helper_mutex_lock(struct mutex *lock)
 {
 	mutex_lock(lock);
 }
 
-int rust_helper_mutex_trylock(struct mutex *lock)
+__rust_helper int rust_helper_mutex_trylock(struct mutex *lock)
 {
 	return mutex_trylock(lock);
 }
 
-void rust_helper___mutex_init(struct mutex *mutex, const char *name,
-			      struct lock_class_key *key)
+__rust_helper void rust_helper___mutex_init(struct mutex *mutex,
+					    const char *name,
+					    struct lock_class_key *key)
 {
 	__mutex_init(mutex, name, key);
 }
 
-void rust_helper_mutex_assert_is_held(struct mutex *mutex)
+__rust_helper void rust_helper_mutex_assert_is_held(struct mutex *mutex)
 {
 	lockdep_assert_held(mutex);
 }
 
-void rust_helper_mutex_destroy(struct mutex *lock)
+__rust_helper void rust_helper_mutex_destroy(struct mutex *lock)
 {
 	mutex_destroy(lock);
 }
diff --git a/rust/helpers/processor.c b/rust/helpers/processor.c
index d41355e14d6e..76fadbb647c5 100644
--- a/rust/helpers/processor.c
+++ b/rust/helpers/processor.c
@@ -2,7 +2,7 @@
 
 #include <linux/processor.h>
 
-void rust_helper_cpu_relax(void)
+__rust_helper void rust_helper_cpu_relax(void)
 {
 	cpu_relax();
 }
diff --git a/rust/helpers/rcu.c b/rust/helpers/rcu.c
index f1cec6583513..481274c05857 100644
--- a/rust/helpers/rcu.c
+++ b/rust/helpers/rcu.c
@@ -2,12 +2,12 @@
 
 #include <linux/rcupdate.h>
 
-void rust_helper_rcu_read_lock(void)
+__rust_helper void rust_helper_rcu_read_lock(void)
 {
 	rcu_read_lock();
 }
 
-void rust_helper_rcu_read_unlock(void)
+__rust_helper void rust_helper_rcu_read_unlock(void)
 {
 	rcu_read_unlock();
 }
diff --git a/rust/helpers/refcount.c b/rust/helpers/refcount.c
index d175898ad7b8..36334a674ee4 100644
--- a/rust/helpers/refcount.c
+++ b/rust/helpers/refcount.c
@@ -2,27 +2,27 @@
 
 #include <linux/refcount.h>
 
-refcount_t rust_helper_REFCOUNT_INIT(int n)
+__rust_helper refcount_t rust_helper_REFCOUNT_INIT(int n)
 {
 	return (refcount_t)REFCOUNT_INIT(n);
 }
 
-void rust_helper_refcount_set(refcount_t *r, int n)
+__rust_helper void rust_helper_refcount_set(refcount_t *r, int n)
 {
 	refcount_set(r, n);
 }
 
-void rust_helper_refcount_inc(refcount_t *r)
+__rust_helper void rust_helper_refcount_inc(refcount_t *r)
 {
 	refcount_inc(r);
 }
 
-void rust_helper_refcount_dec(refcount_t *r)
+__rust_helper void rust_helper_refcount_dec(refcount_t *r)
 {
 	refcount_dec(r);
 }
 
-bool rust_helper_refcount_dec_and_test(refcount_t *r)
+__rust_helper bool rust_helper_refcount_dec_and_test(refcount_t *r)
 {
 	return refcount_dec_and_test(r);
 }
diff --git a/rust/helpers/signal.c b/rust/helpers/signal.c
index 1a6bbe9438e2..85111186cf3d 100644
--- a/rust/helpers/signal.c
+++ b/rust/helpers/signal.c
@@ -2,7 +2,7 @@
 
 #include <linux/sched/signal.h>
 
-int rust_helper_signal_pending(struct task_struct *t)
+__rust_helper int rust_helper_signal_pending(struct task_struct *t)
 {
 	return signal_pending(t);
 }
diff --git a/rust/helpers/spinlock.c b/rust/helpers/spinlock.c
index 42c4bf01a23e..4d13062cf253 100644
--- a/rust/helpers/spinlock.c
+++ b/rust/helpers/spinlock.c
@@ -2,8 +2,9 @@
 
 #include <linux/spinlock.h>
 
-void rust_helper___spin_lock_init(spinlock_t *lock, const char *name,
-				  struct lock_class_key *key)
+__rust_helper void rust_helper___spin_lock_init(spinlock_t *lock,
+						const char *name,
+						struct lock_class_key *key)
 {
 #ifdef CONFIG_DEBUG_SPINLOCK
 # if defined(CONFIG_PREEMPT_RT)
@@ -16,22 +17,22 @@ void rust_helper___spin_lock_init(spinlock_t *lock, const char *name,
 #endif /* CONFIG_DEBUG_SPINLOCK */
 }
 
-void rust_helper_spin_lock(spinlock_t *lock)
+__rust_helper void rust_helper_spin_lock(spinlock_t *lock)
 {
 	spin_lock(lock);
 }
 
-void rust_helper_spin_unlock(spinlock_t *lock)
+__rust_helper void rust_helper_spin_unlock(spinlock_t *lock)
 {
 	spin_unlock(lock);
 }
 
-int rust_helper_spin_trylock(spinlock_t *lock)
+__rust_helper int rust_helper_spin_trylock(spinlock_t *lock)
 {
 	return spin_trylock(lock);
 }
 
-void rust_helper_spin_assert_is_held(spinlock_t *lock)
+__rust_helper void rust_helper_spin_assert_is_held(spinlock_t *lock)
 {
 	lockdep_assert_held(lock);
 }
diff --git a/rust/helpers/sync.c b/rust/helpers/sync.c
index ff7e68b48810..82d6aff73b04 100644
--- a/rust/helpers/sync.c
+++ b/rust/helpers/sync.c
@@ -2,12 +2,12 @@
 
 #include <linux/lockdep.h>
 
-void rust_helper_lockdep_register_key(struct lock_class_key *k)
+__rust_helper void rust_helper_lockdep_register_key(struct lock_class_key *k)
 {
 	lockdep_register_key(k);
 }
 
-void rust_helper_lockdep_unregister_key(struct lock_class_key *k)
+__rust_helper void rust_helper_lockdep_unregister_key(struct lock_class_key *k)
 {
 	lockdep_unregister_key(k);
 }
diff --git a/rust/helpers/task.c b/rust/helpers/task.c
index 2c85bbc2727e..c0e1a06ede78 100644
--- a/rust/helpers/task.c
+++ b/rust/helpers/task.c
@@ -3,60 +3,60 @@
 #include <linux/kernel.h>
 #include <linux/sched/task.h>
 
-void rust_helper_might_resched(void)
+__rust_helper void rust_helper_might_resched(void)
 {
 	might_resched();
 }
 
-struct task_struct *rust_helper_get_current(void)
+__rust_helper struct task_struct *rust_helper_get_current(void)
 {
 	return current;
 }
 
-void rust_helper_get_task_struct(struct task_struct *t)
+__rust_helper void rust_helper_get_task_struct(struct task_struct *t)
 {
 	get_task_struct(t);
 }
 
-void rust_helper_put_task_struct(struct task_struct *t)
+__rust_helper void rust_helper_put_task_struct(struct task_struct *t)
 {
 	put_task_struct(t);
 }
 
-kuid_t rust_helper_task_uid(struct task_struct *task)
+__rust_helper kuid_t rust_helper_task_uid(struct task_struct *task)
 {
 	return task_uid(task);
 }
 
-kuid_t rust_helper_task_euid(struct task_struct *task)
+__rust_helper kuid_t rust_helper_task_euid(struct task_struct *task)
 {
 	return task_euid(task);
 }
 
 #ifndef CONFIG_USER_NS
-uid_t rust_helper_from_kuid(struct user_namespace *to, kuid_t uid)
+__rust_helper uid_t rust_helper_from_kuid(struct user_namespace *to, kuid_t uid)
 {
 	return from_kuid(to, uid);
 }
 #endif /* CONFIG_USER_NS */
 
-bool rust_helper_uid_eq(kuid_t left, kuid_t right)
+__rust_helper bool rust_helper_uid_eq(kuid_t left, kuid_t right)
 {
 	return uid_eq(left, right);
 }
 
-kuid_t rust_helper_current_euid(void)
+__rust_helper kuid_t rust_helper_current_euid(void)
 {
 	return current_euid();
 }
 
-struct user_namespace *rust_helper_current_user_ns(void)
+__rust_helper struct user_namespace *rust_helper_current_user_ns(void)
 {
 	return current_user_ns();
 }
 
-pid_t rust_helper_task_tgid_nr_ns(struct task_struct *tsk,
-				  struct pid_namespace *ns)
+__rust_helper pid_t rust_helper_task_tgid_nr_ns(struct task_struct *tsk,
+						struct pid_namespace *ns)
 {
 	return task_tgid_nr_ns(tsk, ns);
 }
diff --git a/rust/helpers/time.c b/rust/helpers/time.c
index 67a36ccc3ec4..32f495970493 100644
--- a/rust/helpers/time.c
+++ b/rust/helpers/time.c
@@ -4,37 +4,37 @@
 #include <linux/ktime.h>
 #include <linux/timekeeping.h>
 
-void rust_helper_fsleep(unsigned long usecs)
+__rust_helper void rust_helper_fsleep(unsigned long usecs)
 {
 	fsleep(usecs);
 }
 
-ktime_t rust_helper_ktime_get_real(void)
+__rust_helper ktime_t rust_helper_ktime_get_real(void)
 {
 	return ktime_get_real();
 }
 
-ktime_t rust_helper_ktime_get_boottime(void)
+__rust_helper ktime_t rust_helper_ktime_get_boottime(void)
 {
 	return ktime_get_boottime();
 }
 
-ktime_t rust_helper_ktime_get_clocktai(void)
+__rust_helper ktime_t rust_helper_ktime_get_clocktai(void)
 {
 	return ktime_get_clocktai();
 }
 
-s64 rust_helper_ktime_to_us(const ktime_t kt)
+__rust_helper s64 rust_helper_ktime_to_us(const ktime_t kt)
 {
 	return ktime_to_us(kt);
 }
 
-s64 rust_helper_ktime_to_ms(const ktime_t kt)
+__rust_helper s64 rust_helper_ktime_to_ms(const ktime_t kt)
 {
 	return ktime_to_ms(kt);
 }
 
-void rust_helper_udelay(unsigned long usec)
+__rust_helper void rust_helper_udelay(unsigned long usec)
 {
 	udelay(usec);
 }
diff --git a/rust/helpers/wait.c b/rust/helpers/wait.c
index ae48e33d9da3..2dde1e451780 100644
--- a/rust/helpers/wait.c
+++ b/rust/helpers/wait.c
@@ -2,7 +2,7 @@
 
 #include <linux/wait.h>
 
-void rust_helper_init_wait(struct wait_queue_entry *wq_entry)
+__rust_helper void rust_helper_init_wait(struct wait_queue_entry *wq_entry)
 {
 	init_wait(wq_entry);
 }