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Merge branch into tip/master: 'locking/core'

Browse Source 
# New commits in locking/core:
    cb4ccc70344c ("MAINTAINERS: Add static_call_inline.c to STATIC BRANCH/CALL")
    a937f384c9da ("cleanup, tags: Create tags for the cleanup primitives")
    abfdccd6af2b ("sched/wake_q: Add helper to call wake_up_q after unlock with preemption disabled")
    fbd7a5a0359b ("rust: sync: Add lock::Backend::assert_is_held()")
    eb5ccb038284 ("rust: sync: Add SpinLockGuard type alias")
    37624dde4768 ("rust: sync: Add MutexGuard type alias")
    daa03fe50ec3 ("rust: sync: Make Guard::new() public")
    15abc88057ee ("rust: sync: Add Lock::from_raw() for Lock<(), B>")
    9793c9bb91f1 ("locking: MAINTAINERS: Start watching Rust locking primitives")
    343060092585 ("lockdep: Move lockdep_assert_locked() under #ifdef CONFIG_PROVE_LOCKING")
    8148fa2e022b ("lockdep: Mark chain_hlock_class_idx() with __maybe_unused")
    bd7b5ae26618 ("lockdep: Document MAX_LOCKDEP_CHAIN_HLOCKS calculation")
    88a79e88a97c ("lockdep: Clarify size for LOCKDEP_*_BITS configs")
    e638072e6172 ("lockdep: Fix upper limit for LOCKDEP_*_BITS configs")
    0d3547df6934 ("locking/ww_mutex/test: Use swap() macro")
    63a48181fbcd ("smp/scf: Evaluate local cond_func() before IPI side-effects")
    d387ceb17149 ("locking/lockdep: Enforce PROVE_RAW_LOCK_NESTING only if ARCH_SUPPORTS_RT")

Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Ingo Molnar 2025-01-13 18:13:42 +01:00
commit 90df9792d9
17 changed files with 152 additions and 69 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

9
MAINTAINERS
View File

@ -13429,8 +13429,8 @@ LOCKING PRIMITIVES
M: Peter Zijlstra <peterz@infradead.org>
M: Ingo Molnar <mingo@redhat.com>
M: Will Deacon <will@kernel.org>
M: Boqun Feng <boqun.feng@gmail.com> (LOCKDEP & RUST)
R: Waiman Long <longman@redhat.com>
R: Boqun Feng <boqun.feng@gmail.com> (LOCKDEP)
L: linux-kernel@vger.kernel.org
S: Maintained
T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git locking/core
@ -13444,6 +13444,11 @@ F: include/linux/seqlock.h
F: include/linux/spinlock*.h
F: kernel/locking/
F: lib/locking*.[ch]
F: rust/helpers/mutex.c
F: rust/helpers/spinlock.c
F: rust/kernel/sync/lock.rs
F: rust/kernel/sync/lock/
F: rust/kernel/sync/locked_by.rs
X: kernel/locking/locktorture.c
LOGICAL DISK MANAGER SUPPORT (LDM, Windows 2000/XP/Vista Dynamic Disks)
@ -22450,7 +22455,7 @@ F: arch/*/kernel/static_call.c
F: include/linux/jump_label*.h
F: include/linux/static_call*.h
F: kernel/jump_label.c
F: kernel/static_call.c
F: kernel/static_call*.c
STI AUDIO (ASoC) DRIVERS
M: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>

34
include/linux/sched/wake_q.h
View File

@ -63,4 +63,38 @@ extern void wake_q_add(struct wake_q_head *head, struct task_struct *task);
extern void wake_q_add_safe(struct wake_q_head *head, struct task_struct *task);
extern void wake_up_q(struct wake_q_head *head);
/* Spin unlock helpers to unlock and call wake_up_q with preempt disabled */
static inline
void raw_spin_unlock_wake(raw_spinlock_t *lock, struct wake_q_head *wake_q)
{
guard(preempt)();
raw_spin_unlock(lock);
if (wake_q) {
wake_up_q(wake_q);
wake_q_init(wake_q);
}
}
static inline
void raw_spin_unlock_irq_wake(raw_spinlock_t *lock, struct wake_q_head *wake_q)
{
guard(preempt)();
raw_spin_unlock_irq(lock);
if (wake_q) {
wake_up_q(wake_q);
wake_q_init(wake_q);
}
}
static inline
void raw_spin_unlock_irqrestore_wake(raw_spinlock_t *lock, unsigned long flags,
struct wake_q_head *wake_q)
{
guard(preempt)();
raw_spin_unlock_irqrestore(lock, flags);
if (wake_q) {
wake_up_q(wake_q);
wake_q_init(wake_q);
}
}
#endif /* _LINUX_SCHED_WAKE_Q_H */

5
kernel/futex/pi.c
View File

@ -1020,10 +1020,7 @@ retry_private:
* it sees the futex_q::pi_state.
*/
ret = __rt_mutex_start_proxy_lock(&q.pi_state->pi_mutex, &rt_waiter, current, &wake_q);
preempt_disable();
raw_spin_unlock_irq(&q.pi_state->pi_mutex.wait_lock);
wake_up_q(&wake_q);
preempt_enable();
raw_spin_unlock_irq_wake(&q.pi_state->pi_mutex.wait_lock, &wake_q);
if (ret) {
if (ret == 1)

4
kernel/locking/lockdep.c
View File

@ -157,10 +157,12 @@ static inline void lockdep_unlock(void)
__this_cpu_dec(lockdep_recursion);
}
#ifdef CONFIG_PROVE_LOCKING
static inline bool lockdep_assert_locked(void)
{
return DEBUG_LOCKS_WARN_ON(__owner != current);
}
#endif
static struct task_struct *lockdep_selftest_task_struct;
@ -430,7 +432,7 @@ static inline u16 hlock_id(struct held_lock *hlock)
return (hlock->class_idx | (hlock->read << MAX_LOCKDEP_KEYS_BITS));
}
static inline unsigned int chain_hlock_class_idx(u16 hlock_id)
static inline __maybe_unused unsigned int chain_hlock_class_idx(u16 hlock_id)
{
return hlock_id & (MAX_LOCKDEP_KEYS - 1);
}

3
kernel/locking/lockdep_internals.h
View File

@ -119,7 +119,8 @@ static const unsigned long LOCKF_USED_IN_IRQ_READ =
#define MAX_LOCKDEP_CHAINS (1UL << MAX_LOCKDEP_CHAINS_BITS)
#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS*5)
#define AVG_LOCKDEP_CHAIN_DEPTH 5
#define MAX_LOCKDEP_CHAIN_HLOCKS (MAX_LOCKDEP_CHAINS * AVG_LOCKDEP_CHAIN_DEPTH)
extern struct lock_chain lock_chains[];

16
kernel/locking/mutex.c
View File

@ -657,10 +657,7 @@ __mutex_lock_common(struct mutex *lock, unsigned int state, unsigned int subclas
goto err;
}
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
/* Make sure we do wakeups before calling schedule */
wake_up_q(&wake_q);
wake_q_init(&wake_q);
raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
schedule_preempt_disabled();
@ -710,8 +707,7 @@ skip_wait:
if (ww_ctx)
ww_mutex_lock_acquired(ww, ww_ctx);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
wake_up_q(&wake_q);
raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
preempt_enable();
return 0;
@ -720,10 +716,9 @@ err:
__mutex_remove_waiter(lock, &waiter);
err_early_kill:
trace_contention_end(lock, ret);
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
debug_mutex_free_waiter(&waiter);
mutex_release(&lock->dep_map, ip);
wake_up_q(&wake_q);
preempt_enable();
return ret;
}
@ -935,10 +930,7 @@ static noinline void __sched __mutex_unlock_slowpath(struct mutex *lock, unsigne
if (owner & MUTEX_FLAG_HANDOFF)
__mutex_handoff(lock, next);
preempt_disable();
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
wake_up_q(&wake_q);
preempt_enable();
raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
}
#ifndef CONFIG_DEBUG_LOCK_ALLOC

32
kernel/locking/rtmutex.c
View File

@ -1292,13 +1292,7 @@ static int __sched task_blocks_on_rt_mutex(struct rt_mutex_base *lock,
*/
get_task_struct(owner);
preempt_disable();
raw_spin_unlock_irq(&lock->wait_lock);
/* wake up any tasks on the wake_q before calling rt_mutex_adjust_prio_chain */
wake_up_q(wake_q);
wake_q_init(wake_q);
preempt_enable();
raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
res = rt_mutex_adjust_prio_chain(owner, chwalk, lock,
next_lock, waiter, task);
@ -1642,13 +1636,7 @@ static int __sched rt_mutex_slowlock_block(struct rt_mutex_base *lock,
owner = rt_mutex_owner(lock);
else
owner = NULL;
preempt_disable();
raw_spin_unlock_irq(&lock->wait_lock);
if (wake_q) {
wake_up_q(wake_q);
wake_q_init(wake_q);
}
preempt_enable();
raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
if (!owner || !rtmutex_spin_on_owner(lock, waiter, owner))
rt_mutex_schedule();
@ -1799,10 +1787,7 @@ static int __sched rt_mutex_slowlock(struct rt_mutex_base *lock,
*/
raw_spin_lock_irqsave(&lock->wait_lock, flags);
ret = __rt_mutex_slowlock_locked(lock, ww_ctx, state, &wake_q);
preempt_disable();
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
wake_up_q(&wake_q);
preempt_enable();
raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
rt_mutex_post_schedule();
return ret;
@ -1860,11 +1845,7 @@ static void __sched rtlock_slowlock_locked(struct rt_mutex_base *lock,
owner = rt_mutex_owner(lock);
else
owner = NULL;
preempt_disable();
raw_spin_unlock_irq(&lock->wait_lock);
wake_up_q(wake_q);
wake_q_init(wake_q);
preempt_enable();
raw_spin_unlock_irq_wake(&lock->wait_lock, wake_q);
if (!owner || !rtmutex_spin_on_owner(lock, &waiter, owner))
schedule_rtlock();
@ -1893,10 +1874,7 @@ static __always_inline void __sched rtlock_slowlock(struct rt_mutex_base *lock)
raw_spin_lock_irqsave(&lock->wait_lock, flags);
rtlock_slowlock_locked(lock, &wake_q);
preempt_disable();
raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
wake_up_q(&wake_q);
preempt_enable();
raw_spin_unlock_irqrestore_wake(&lock->wait_lock, flags, &wake_q);
}
#endif /* RT_MUTEX_BUILD_SPINLOCKS */

9
kernel/locking/test-ww_mutex.c
View File

@ -404,7 +404,7 @@ static inline u32 prandom_u32_below(u32 ceil)
static int *get_random_order(int count)
{
int *order;
int n, r, tmp;
int n, r;
order = kmalloc_array(count, sizeof(*order), GFP_KERNEL);
if (!order)
@ -415,11 +415,8 @@ static int *get_random_order(int count)
for (n = count - 1; n > 1; n--) {
r = prandom_u32_below(n + 1);
if (r != n) {
tmp = order[n];
order[n] = order[r];
order[r] = tmp;
}
if (r != n)
swap(order[n], order[r]);
}
return order;

5
kernel/smp.c
View File

@ -815,7 +815,8 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
WARN_ON_ONCE(!in_task());
/* Check if we need local execution. */
if ((scf_flags & SCF_RUN_LOCAL) && cpumask_test_cpu(this_cpu, mask))
if ((scf_flags & SCF_RUN_LOCAL) && cpumask_test_cpu(this_cpu, mask) &&
(!cond_func || cond_func(this_cpu, info)))
run_local = true;
/* Check if we need remote execution, i.e., any CPU excluding this one. */
@ -868,7 +869,7 @@ static void smp_call_function_many_cond(const struct cpumask *mask,
send_call_function_ipi_mask(cfd->cpumask_ipi);
}
if (run_local && (!cond_func || cond_func(this_cpu, info))) {
if (run_local) {
unsigned long flags;
local_irq_save(flags);

22
lib/Kconfig.debug
View File

@ -1397,9 +1397,9 @@ config PROVE_LOCKING
For more details, see Documentation/locking/lockdep-design.rst.
config PROVE_RAW_LOCK_NESTING
bool
bool "Enable raw_spinlock - spinlock nesting checks" if !ARCH_SUPPORTS_RT
depends on PROVE_LOCKING
default y
default y if ARCH_SUPPORTS_RT
help
Enable the raw_spinlock vs. spinlock nesting checks which ensure
that the lock nesting rules for PREEMPT_RT enabled kernels are
@ -1502,15 +1502,15 @@ config LOCKDEP_SMALL
bool
config LOCKDEP_BITS
int "Bitsize for MAX_LOCKDEP_ENTRIES"
int "Size for MAX_LOCKDEP_ENTRIES (as Nth power of 2)"
depends on LOCKDEP && !LOCKDEP_SMALL
range 10 30
range 10 24
default 15
help
Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
config LOCKDEP_CHAINS_BITS
int "Bitsize for MAX_LOCKDEP_CHAINS"
int "Size for MAX_LOCKDEP_CHAINS (as Nth power of 2)"
depends on LOCKDEP && !LOCKDEP_SMALL
range 10 21
default 16
@ -1518,25 +1518,25 @@ config LOCKDEP_CHAINS_BITS
Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
config LOCKDEP_STACK_TRACE_BITS
int "Bitsize for MAX_STACK_TRACE_ENTRIES"
int "Size for MAX_STACK_TRACE_ENTRIES (as Nth power of 2)"
depends on LOCKDEP && !LOCKDEP_SMALL
range 10 30
range 10 26
default 19
help
Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
config LOCKDEP_STACK_TRACE_HASH_BITS
int "Bitsize for STACK_TRACE_HASH_SIZE"
int "Size for STACK_TRACE_HASH_SIZE (as Nth power of 2)"
depends on LOCKDEP && !LOCKDEP_SMALL
range 10 30
range 10 26
default 14
help
Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
config LOCKDEP_CIRCULAR_QUEUE_BITS
int "Bitsize for elements in circular_queue struct"
int "Size for elements in circular_queue struct (as Nth power of 2)"
depends on LOCKDEP
range 10 30
range 10 26
default 12
help
Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.

5
rust/helpers/mutex.c
View File

@ -12,3 +12,8 @@ void rust_helper___mutex_init(struct mutex *mutex, const char *name,
{
__mutex_init(mutex, name, key);
}
void rust_helper_mutex_assert_is_held(struct mutex *mutex)
{
lockdep_assert_held(mutex);
}

5
rust/helpers/spinlock.c
View File

@ -30,3 +30,8 @@ int rust_helper_spin_trylock(spinlock_t *lock)
{
return spin_trylock(lock);
}
void rust_helper_spin_assert_is_held(spinlock_t *lock)
{
lockdep_assert_held(lock);
}

4
rust/kernel/sync.rs
View File

@ -16,8 +16,8 @@ pub mod poll;
pub use arc::{Arc, ArcBorrow, UniqueArc};
pub use condvar::{new_condvar, CondVar, CondVarTimeoutResult};
pub use lock::global::{global_lock, GlobalGuard, GlobalLock, GlobalLockBackend, GlobalLockedBy};
pub use lock::mutex::{new_mutex, Mutex};
pub use lock::spinlock::{new_spinlock, SpinLock};
pub use lock::mutex::{new_mutex, Mutex, MutexGuard};
pub use lock::spinlock::{new_spinlock, SpinLock, SpinLockGuard};
pub use locked_by::LockedBy;
/// Represents a lockdep class. It's a wrapper around C's `lock_class_key`.

35
rust/kernel/sync/lock.rs
View File

@ -90,12 +90,20 @@ pub unsafe trait Backend {
// SAFETY: The safety requirements ensure that the lock is initialised.
*guard_state = unsafe { Self::lock(ptr) };
}
/// Asserts that the lock is held using lockdep.
///
/// # Safety
///
/// Callers must ensure that [`Backend::init`] has been previously called.
unsafe fn assert_is_held(ptr: *mut Self::State);
}
/// A mutual exclusion primitive.
///
/// Exposes one of the kernel locking primitives. Which one is exposed depends on the lock
/// [`Backend`] specified as the generic parameter `B`.
#[repr(C)]
#[pin_data]
pub struct Lock<T: ?Sized, B: Backend> {
/// The kernel lock object.
@ -134,6 +142,28 @@ impl<T, B: Backend> Lock<T, B> {
}
}
impl<B: Backend> Lock<(), B> {
/// Constructs a [`Lock`] from a raw pointer.
///
/// This can be useful for interacting with a lock which was initialised outside of Rust.
///
/// # Safety
///
/// The caller promises that `ptr` points to a valid initialised instance of [`State`] during
/// the whole lifetime of `'a`.
///
/// [`State`]: Backend::State
pub unsafe fn from_raw<'a>(ptr: *mut B::State) -> &'a Self {
// SAFETY:
// - By the safety contract `ptr` must point to a valid initialised instance of `B::State`
// - Since the lock data type is `()` which is a ZST, `state` is the only non-ZST member of
// the struct
// - Combined with `#[repr(C)]`, this guarantees `Self` has an equivalent data layout to
// `B::State`.
unsafe { &*ptr.cast() }
}
}
impl<T: ?Sized, B: Backend> Lock<T, B> {
/// Acquires the lock and gives the caller access to the data protected by it.
pub fn lock(&self) -> Guard<'_, T, B> {
@ -211,7 +241,10 @@ impl<'a, T: ?Sized, B: Backend> Guard<'a, T, B> {
/// # Safety
///
/// The caller must ensure that it owns the lock.
pub(crate) unsafe fn new(lock: &'a Lock<T, B>, state: B::GuardState) -> Self {
pub unsafe fn new(lock: &'a Lock<T, B>, state: B::GuardState) -> Self {
// SAFETY: The caller can only hold the lock if `Backend::init` has already been called.
unsafe { B::assert_is_held(lock.state.get()) };
Self {
lock,
state,

13
rust/kernel/sync/lock/mutex.rs
View File

@ -86,6 +86,14 @@ pub use new_mutex;
/// [`struct mutex`]: srctree/include/linux/mutex.h
pub type Mutex<T> = super::Lock<T, MutexBackend>;
/// A [`Guard`] acquired from locking a [`Mutex`].
///
/// This is simply a type alias for a [`Guard`] returned from locking a [`Mutex`]. It will unlock
/// the [`Mutex`] upon being dropped.
///
/// [`Guard`]: super::Guard
pub type MutexGuard<'a, T> = super::Guard<'a, T, MutexBackend>;
/// A kernel `struct mutex` lock backend.
pub struct MutexBackend;
@ -126,4 +134,9 @@ unsafe impl super::Backend for MutexBackend {
None
}
}
unsafe fn assert_is_held(ptr: *mut Self::State) {
// SAFETY: The `ptr` pointer is guaranteed to be valid and initialized before use.
unsafe { bindings::mutex_assert_is_held(ptr) }
}
}

13
rust/kernel/sync/lock/spinlock.rs
View File

@ -87,6 +87,14 @@ pub type SpinLock<T> = super::Lock<T, SpinLockBackend>;
/// A kernel `spinlock_t` lock backend.
pub struct SpinLockBackend;
/// A [`Guard`] acquired from locking a [`SpinLock`].
///
/// This is simply a type alias for a [`Guard`] returned from locking a [`SpinLock`]. It will unlock
/// the [`SpinLock`] upon being dropped.
///
/// [`Guard`]: super::Guard
pub type SpinLockGuard<'a, T> = super::Guard<'a, T, SpinLockBackend>;
// SAFETY: The underlying kernel `spinlock_t` object ensures mutual exclusion. `relock` uses the
// default implementation that always calls the same locking method.
unsafe impl super::Backend for SpinLockBackend {
@ -125,4 +133,9 @@ unsafe impl super::Backend for SpinLockBackend {
None
}
}
unsafe fn assert_is_held(ptr: *mut Self::State) {
// SAFETY: The `ptr` pointer is guaranteed to be valid and initialized before use.
unsafe { bindings::spin_assert_is_held(ptr) }
}
}

7
scripts/tags.sh
View File

@ -212,6 +212,13 @@ regex_c=(
'/^SEQCOUNT_LOCKTYPE(\([^,]*\),[[:space:]]*\([^,]*\),[^)]*)/seqcount_\2_init/'
'/^\<DECLARE_IDTENTRY[[:alnum:]_]*([^,)]*,[[:space:]]*\([[:alnum:]_]\+\)/\1/'
'/^\<DEFINE_IDTENTRY[[:alnum:]_]*([[:space:]]*\([[:alnum:]_]\+\)/\1/'
'/^\<DEFINE_FREE(\([[:alnum:]_]\+\)/cleanup_\1/'
'/^\<DEFINE_CLASS(\([[:alnum:]_]\+\)/class_\1/'
'/^\<EXTEND_CLASS(\([[:alnum:]_]\+\),[[:space:]]*\([[:alnum:]_]\+\)/class_\1\2/'
'/^\<DEFINE_GUARD(\([[:alnum:]_]\+\)/class_\1/'
'/^\<DEFINE_GUARD_COND(\([[:alnum:]_]\+\),[[:space:]]*\([[:alnum:]_]\+\)/class_\1\2/'
'/^\<DEFINE_LOCK_GUARD_[[:digit:]](\([[:alnum:]_]\+\)/class_\1/'
'/^\<DEFINE_LOCK_GUARD_[[:digit:]]_COND(\([[:alnum:]_]\+\),[[:space:]]*\([[:alnum:]_]\+\)/class_\1\2/'
)
regex_kconfig=(
'/^[[:blank:]]*\(menu\|\)config[[:blank:]]\+\([[:alnum:]_]\+\)/\2/'