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author | Linus Torvalds <torvalds@linux-foundation.org> | 2024-01-09 05:19:44 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2024-01-09 05:19:44 +0300 |
commit | 6cbf5b3105f31217053570e7ca722b739a9242a4 (patch) | |
tree | 6e2cdd781c14ae73e6afe5034a2ae1d131781a69 /include | |
parent | f0a78b3e2a0c842cc7b4c2686f4a35681f02ca72 (diff) | |
parent | 2b9d9e0a9ba0e24cb9c78336481f0ed8b2bc1ff2 (diff) | |
download | linux-6cbf5b3105f31217053570e7ca722b739a9242a4.tar.xz |
Merge tag 'locking-core-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molar:
"Lock guards:
- Use lock guards in the ptrace code
- Introduce conditional guards to extend to conditional lock
primitives like mutex_trylock()/mutex_lock_interruptible()/etc.
lockdep:
- Optimize 'struct lock_class' to be smaller
- Update file patterns in MAINTAINERS
mutexes:
- Document mutex lifetime rules a bit more"
* tag 'locking-core-2024-01-08' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/mutex: Clarify that mutex_unlock(), and most other sleeping locks, can still use the lock object after it's unlocked
locking/mutex: Document that mutex_unlock() is non-atomic
ptrace: Convert ptrace_attach() to use lock guards
locking/lockdep: Slightly reorder 'struct lock_class' to save some memory
MAINTAINERS: Add include/linux/lockdep*.h
cleanup: Add conditional guard support
Diffstat (limited to 'include')
-rw-r--r-- | include/linux/cleanup.h | 52 | ||||
-rw-r--r-- | include/linux/lockdep_types.h | 2 | ||||
-rw-r--r-- | include/linux/mutex.h | 3 | ||||
-rw-r--r-- | include/linux/rwsem.h | 8 | ||||
-rw-r--r-- | include/linux/sched/task.h | 2 | ||||
-rw-r--r-- | include/linux/spinlock.h | 41 |
6 files changed, 99 insertions, 9 deletions
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index 9f1a9c455b68..c2d09bc4f976 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -125,25 +125,55 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * trivial wrapper around DEFINE_CLASS() above specifically * for locks. * + * DEFINE_GUARD_COND(name, ext, condlock) + * wrapper around EXTEND_CLASS above to add conditional lock + * variants to a base class, eg. mutex_trylock() or + * mutex_lock_interruptible(). + * * guard(name): - * an anonymous instance of the (guard) class + * an anonymous instance of the (guard) class, not recommended for + * conditional locks. * * scoped_guard (name, args...) { }: * similar to CLASS(name, scope)(args), except the variable (with the * explicit name 'scope') is declard in a for-loop such that its scope is * bound to the next (compound) statement. * + * for conditional locks the loop body is skipped when the lock is not + * acquired. + * + * scoped_cond_guard (name, fail, args...) { }: + * similar to scoped_guard(), except it does fail when the lock + * acquire fails. + * */ #define DEFINE_GUARD(_name, _type, _lock, _unlock) \ - DEFINE_CLASS(_name, _type, _unlock, ({ _lock; _T; }), _type _T) + DEFINE_CLASS(_name, _type, if (_T) { _unlock; }, ({ _lock; _T; }), _type _T); \ + static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \ + { return *_T; } + +#define DEFINE_GUARD_COND(_name, _ext, _condlock) \ + EXTEND_CLASS(_name, _ext, \ + ({ void *_t = _T; if (_T && !(_condlock)) _t = NULL; _t; }), \ + class_##_name##_t _T) \ + static inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ + { return class_##_name##_lock_ptr(_T); } #define guard(_name) \ CLASS(_name, __UNIQUE_ID(guard)) +#define __guard_ptr(_name) class_##_name##_lock_ptr + #define scoped_guard(_name, args...) \ for (CLASS(_name, scope)(args), \ - *done = NULL; !done; done = (void *)1) + *done = NULL; __guard_ptr(_name)(&scope) && !done; done = (void *)1) + +#define scoped_cond_guard(_name, _fail, args...) \ + for (CLASS(_name, scope)(args), \ + *done = NULL; !done; done = (void *)1) \ + if (!__guard_ptr(_name)(&scope)) _fail; \ + else /* * Additional helper macros for generating lock guards with types, either for @@ -152,6 +182,7 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * * DEFINE_LOCK_GUARD_0(name, lock, unlock, ...) * DEFINE_LOCK_GUARD_1(name, type, lock, unlock, ...) + * DEFINE_LOCK_GUARD_1_COND(name, ext, condlock) * * will result in the following type: * @@ -173,6 +204,11 @@ typedef struct { \ static inline void class_##_name##_destructor(class_##_name##_t *_T) \ { \ if (_T->lock) { _unlock; } \ +} \ + \ +static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T) \ +{ \ + return _T->lock; \ } @@ -201,4 +237,14 @@ __DEFINE_LOCK_GUARD_1(_name, _type, _lock) __DEFINE_UNLOCK_GUARD(_name, void, _unlock, __VA_ARGS__) \ __DEFINE_LOCK_GUARD_0(_name, _lock) +#define DEFINE_LOCK_GUARD_1_COND(_name, _ext, _condlock) \ + EXTEND_CLASS(_name, _ext, \ + ({ class_##_name##_t _t = { .lock = l }, *_T = &_t;\ + if (_T->lock && !(_condlock)) _T->lock = NULL; \ + _t; }), \ + typeof_member(class_##_name##_t, lock) l) \ + static inline void * class_##_name##_ext##_lock_ptr(class_##_name##_t *_T) \ + { return class_##_name##_lock_ptr(_T); } + + #endif /* __LINUX_GUARDS_H */ diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h index 2ebc323d345a..857d785e89e6 100644 --- a/include/linux/lockdep_types.h +++ b/include/linux/lockdep_types.h @@ -127,12 +127,12 @@ struct lock_class { unsigned long usage_mask; const struct lock_trace *usage_traces[LOCK_TRACE_STATES]; + const char *name; /* * Generation counter, when doing certain classes of graph walking, * to ensure that we check one node only once: */ int name_version; - const char *name; u8 wait_type_inner; u8 wait_type_outer; diff --git a/include/linux/mutex.h b/include/linux/mutex.h index a33aa9eb9fc3..95d11308f995 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -221,6 +221,7 @@ extern void mutex_unlock(struct mutex *lock); extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock); DEFINE_GUARD(mutex, struct mutex *, mutex_lock(_T), mutex_unlock(_T)) -DEFINE_FREE(mutex, struct mutex *, if (_T) mutex_unlock(_T)) +DEFINE_GUARD_COND(mutex, _try, mutex_trylock(_T)) +DEFINE_GUARD_COND(mutex, _intr, mutex_lock_interruptible(_T) == 0) #endif /* __LINUX_MUTEX_H */ diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 1dd530ce8b45..9c29689ff505 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -203,11 +203,11 @@ extern void up_read(struct rw_semaphore *sem); extern void up_write(struct rw_semaphore *sem); DEFINE_GUARD(rwsem_read, struct rw_semaphore *, down_read(_T), up_read(_T)) -DEFINE_GUARD(rwsem_write, struct rw_semaphore *, down_write(_T), up_write(_T)) - -DEFINE_FREE(up_read, struct rw_semaphore *, if (_T) up_read(_T)) -DEFINE_FREE(up_write, struct rw_semaphore *, if (_T) up_write(_T)) +DEFINE_GUARD_COND(rwsem_read, _try, down_read_trylock(_T)) +DEFINE_GUARD_COND(rwsem_read, _intr, down_read_interruptible(_T) == 0) +DEFINE_GUARD(rwsem_write, struct rw_semaphore *, down_write(_T), up_write(_T)) +DEFINE_GUARD_COND(rwsem_write, _try, down_write_trylock(_T)) /* * downgrade write lock to read lock diff --git a/include/linux/sched/task.h b/include/linux/sched/task.h index a23af225c898..4f3dca353556 100644 --- a/include/linux/sched/task.h +++ b/include/linux/sched/task.h @@ -226,4 +226,6 @@ static inline void task_unlock(struct task_struct *p) spin_unlock(&p->alloc_lock); } +DEFINE_GUARD(task_lock, struct task_struct *, task_lock(_T), task_unlock(_T)) + #endif /* _LINUX_SCHED_TASK_H */ diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 31d3d747a9db..90bc853cafb6 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -507,6 +507,8 @@ DEFINE_LOCK_GUARD_1(raw_spinlock, raw_spinlock_t, raw_spin_lock(_T->lock), raw_spin_unlock(_T->lock)) +DEFINE_LOCK_GUARD_1_COND(raw_spinlock, _try, raw_spin_trylock(_T->lock)) + DEFINE_LOCK_GUARD_1(raw_spinlock_nested, raw_spinlock_t, raw_spin_lock_nested(_T->lock, SINGLE_DEPTH_NESTING), raw_spin_unlock(_T->lock)) @@ -515,23 +517,62 @@ DEFINE_LOCK_GUARD_1(raw_spinlock_irq, raw_spinlock_t, raw_spin_lock_irq(_T->lock), raw_spin_unlock_irq(_T->lock)) +DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irq, _try, raw_spin_trylock_irq(_T->lock)) + DEFINE_LOCK_GUARD_1(raw_spinlock_irqsave, raw_spinlock_t, raw_spin_lock_irqsave(_T->lock, _T->flags), raw_spin_unlock_irqrestore(_T->lock, _T->flags), unsigned long flags) +DEFINE_LOCK_GUARD_1_COND(raw_spinlock_irqsave, _try, + raw_spin_trylock_irqsave(_T->lock, _T->flags)) + DEFINE_LOCK_GUARD_1(spinlock, spinlock_t, spin_lock(_T->lock), spin_unlock(_T->lock)) +DEFINE_LOCK_GUARD_1_COND(spinlock, _try, spin_trylock(_T->lock)) + DEFINE_LOCK_GUARD_1(spinlock_irq, spinlock_t, spin_lock_irq(_T->lock), spin_unlock_irq(_T->lock)) +DEFINE_LOCK_GUARD_1_COND(spinlock_irq, _try, + spin_trylock_irq(_T->lock)) + DEFINE_LOCK_GUARD_1(spinlock_irqsave, spinlock_t, spin_lock_irqsave(_T->lock, _T->flags), spin_unlock_irqrestore(_T->lock, _T->flags), unsigned long flags) +DEFINE_LOCK_GUARD_1_COND(spinlock_irqsave, _try, + spin_trylock_irqsave(_T->lock, _T->flags)) + +DEFINE_LOCK_GUARD_1(read_lock, rwlock_t, + read_lock(_T->lock), + read_unlock(_T->lock)) + +DEFINE_LOCK_GUARD_1(read_lock_irq, rwlock_t, + read_lock_irq(_T->lock), + read_unlock_irq(_T->lock)) + +DEFINE_LOCK_GUARD_1(read_lock_irqsave, rwlock_t, + read_lock_irqsave(_T->lock, _T->flags), + read_unlock_irqrestore(_T->lock, _T->flags), + unsigned long flags) + +DEFINE_LOCK_GUARD_1(write_lock, rwlock_t, + write_lock(_T->lock), + write_unlock(_T->lock)) + +DEFINE_LOCK_GUARD_1(write_lock_irq, rwlock_t, + write_lock_irq(_T->lock), + write_unlock_irq(_T->lock)) + +DEFINE_LOCK_GUARD_1(write_lock_irqsave, rwlock_t, + write_lock_irqsave(_T->lock, _T->flags), + write_unlock_irqrestore(_T->lock, _T->flags), + unsigned long flags) + #undef __LINUX_INSIDE_SPINLOCK_H #endif /* __LINUX_SPINLOCK_H */ |