diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/cleanup.h | 69 | ||||
| -rw-r--r-- | include/linux/irqflags.h | 6 | ||||
| -rw-r--r-- | include/linux/lockdep.h | 2 | ||||
| -rw-r--r-- | include/linux/rbtree_latch.h | 20 | ||||
| -rw-r--r-- | include/linux/rwlock_rt.h | 10 | ||||
| -rw-r--r-- | include/linux/seqlock.h | 98 | ||||
| -rw-r--r-- | include/linux/spinlock_rt.h | 28 | ||||
| -rw-r--r-- | include/linux/ww_mutex.h | 14 |
8 files changed, 179 insertions, 68 deletions
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h index 875c998275c0..966fcc5ff8ef 100644 --- a/include/linux/cleanup.h +++ b/include/linux/cleanup.h @@ -273,6 +273,12 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * an anonymous instance of the (guard) class, not recommended for * conditional locks. * + * if_not_guard(name, args...) { <error handling> }: + * convenience macro for conditional guards that calls the statement that + * follows only if the lock was not acquired (typically an error return). + * + * Only 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 @@ -285,14 +291,20 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ * similar to scoped_guard(), except it does fail when the lock * acquire fails. * + * Only for conditional locks. */ +#define __DEFINE_CLASS_IS_CONDITIONAL(_name, _is_cond) \ +static __maybe_unused const bool class_##_name##_is_conditional = _is_cond + #define DEFINE_GUARD(_name, _type, _lock, _unlock) \ + __DEFINE_CLASS_IS_CONDITIONAL(_name, false); \ DEFINE_CLASS(_name, _type, if (_T) { _unlock; }, ({ _lock; _T; }), _type _T); \ static inline void * class_##_name##_lock_ptr(class_##_name##_t *_T) \ - { return *_T; } + { return (void *)(__force unsigned long)*_T; } #define DEFINE_GUARD_COND(_name, _ext, _condlock) \ + __DEFINE_CLASS_IS_CONDITIONAL(_name##_ext, true); \ EXTEND_CLASS(_name, _ext, \ ({ void *_t = _T; if (_T && !(_condlock)) _t = NULL; _t; }), \ class_##_name##_t _T) \ @@ -303,16 +315,48 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \ CLASS(_name, __UNIQUE_ID(guard)) #define __guard_ptr(_name) class_##_name##_lock_ptr +#define __is_cond_ptr(_name) class_##_name##_is_conditional -#define scoped_guard(_name, args...) \ - for (CLASS(_name, scope)(args), \ - *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 +/* + * Helper macro for scoped_guard(). + * + * Note that the "!__is_cond_ptr(_name)" part of the condition ensures that + * compiler would be sure that for the unconditional locks the body of the + * loop (caller-provided code glued to the else clause) could not be skipped. + * It is needed because the other part - "__guard_ptr(_name)(&scope)" - is too + * hard to deduce (even if could be proven true for unconditional locks). + */ +#define __scoped_guard(_name, _label, args...) \ + for (CLASS(_name, scope)(args); \ + __guard_ptr(_name)(&scope) || !__is_cond_ptr(_name); \ + ({ goto _label; })) \ + if (0) { \ +_label: \ + break; \ + } else + +#define scoped_guard(_name, args...) \ + __scoped_guard(_name, __UNIQUE_ID(label), args) + +#define __scoped_cond_guard(_name, _fail, _label, args...) \ + for (CLASS(_name, scope)(args); true; ({ goto _label; })) \ + if (!__guard_ptr(_name)(&scope)) { \ + BUILD_BUG_ON(!__is_cond_ptr(_name)); \ + _fail; \ +_label: \ + break; \ + } else + +#define scoped_cond_guard(_name, _fail, args...) \ + __scoped_cond_guard(_name, _fail, __UNIQUE_ID(label), args) + +#define __if_not_guard(_name, _id, args...) \ + BUILD_BUG_ON(!__is_cond_ptr(_name)); \ + CLASS(_name, _id)(args); \ + if (!__guard_ptr(_name)(&_id)) + +#define if_not_guard(_name, args...) \ + __if_not_guard(_name, __UNIQUE_ID(guard), args) /* * Additional helper macros for generating lock guards with types, either for @@ -347,7 +391,7 @@ static inline void class_##_name##_destructor(class_##_name##_t *_T) \ \ static inline void *class_##_name##_lock_ptr(class_##_name##_t *_T) \ { \ - return _T->lock; \ + return (void *)(__force unsigned long)_T->lock; \ } @@ -369,14 +413,17 @@ static inline class_##_name##_t class_##_name##_constructor(void) \ } #define DEFINE_LOCK_GUARD_1(_name, _type, _lock, _unlock, ...) \ +__DEFINE_CLASS_IS_CONDITIONAL(_name, false); \ __DEFINE_UNLOCK_GUARD(_name, _type, _unlock, __VA_ARGS__) \ __DEFINE_LOCK_GUARD_1(_name, _type, _lock) #define DEFINE_LOCK_GUARD_0(_name, _lock, _unlock, ...) \ +__DEFINE_CLASS_IS_CONDITIONAL(_name, false); \ __DEFINE_UNLOCK_GUARD(_name, void, _unlock, __VA_ARGS__) \ __DEFINE_LOCK_GUARD_0(_name, _lock) #define DEFINE_LOCK_GUARD_1_COND(_name, _ext, _condlock) \ + __DEFINE_CLASS_IS_CONDITIONAL(_name##_ext, true); \ EXTEND_CLASS(_name, _ext, \ ({ class_##_name##_t _t = { .lock = l }, *_T = &_t;\ if (_T->lock && !(_condlock)) _T->lock = NULL; \ diff --git a/include/linux/irqflags.h b/include/linux/irqflags.h index 3f003d5fde53..57b074e0cfbb 100644 --- a/include/linux/irqflags.h +++ b/include/linux/irqflags.h @@ -18,6 +18,8 @@ #include <asm/irqflags.h> #include <asm/percpu.h> +struct task_struct; + /* Currently lockdep_softirqs_on/off is used only by lockdep */ #ifdef CONFIG_PROVE_LOCKING extern void lockdep_softirqs_on(unsigned long ip); @@ -25,12 +27,16 @@ extern void lockdep_hardirqs_on_prepare(void); extern void lockdep_hardirqs_on(unsigned long ip); extern void lockdep_hardirqs_off(unsigned long ip); + extern void lockdep_cleanup_dead_cpu(unsigned int cpu, + struct task_struct *idle); #else static inline void lockdep_softirqs_on(unsigned long ip) { } static inline void lockdep_softirqs_off(unsigned long ip) { } static inline void lockdep_hardirqs_on_prepare(void) { } static inline void lockdep_hardirqs_on(unsigned long ip) { } static inline void lockdep_hardirqs_off(unsigned long ip) { } + static inline void lockdep_cleanup_dead_cpu(unsigned int cpu, + struct task_struct *idle) {} #endif #ifdef CONFIG_TRACE_IRQFLAGS diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 217f7abf2cbf..67964dc4db95 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -173,7 +173,7 @@ static inline void lockdep_init_map(struct lockdep_map *lock, const char *name, (lock)->dep_map.lock_type) #define lockdep_set_subclass(lock, sub) \ - lockdep_init_map_type(&(lock)->dep_map, #lock, (lock)->dep_map.key, sub,\ + lockdep_init_map_type(&(lock)->dep_map, (lock)->dep_map.name, (lock)->dep_map.key, sub,\ (lock)->dep_map.wait_type_inner, \ (lock)->dep_map.wait_type_outer, \ (lock)->dep_map.lock_type) diff --git a/include/linux/rbtree_latch.h b/include/linux/rbtree_latch.h index 6a0999c26c7c..2f630eb8307e 100644 --- a/include/linux/rbtree_latch.h +++ b/include/linux/rbtree_latch.h @@ -14,7 +14,7 @@ * * If we need to allow unconditional lookups (say as required for NMI context * usage) we need a more complex setup; this data structure provides this by - * employing the latch technique -- see @raw_write_seqcount_latch -- to + * employing the latch technique -- see @write_seqcount_latch_begin -- to * implement a latched RB-tree which does allow for unconditional lookups by * virtue of always having (at least) one stable copy of the tree. * @@ -132,7 +132,7 @@ __lt_find(void *key, struct latch_tree_root *ltr, int idx, * @ops: operators defining the node order * * It inserts @node into @root in an ordered fashion such that we can always - * observe one complete tree. See the comment for raw_write_seqcount_latch(). + * observe one complete tree. See the comment for write_seqcount_latch_begin(). * * The inserts use rcu_assign_pointer() to publish the element such that the * tree structure is stored before we can observe the new @node. @@ -145,10 +145,11 @@ latch_tree_insert(struct latch_tree_node *node, struct latch_tree_root *root, const struct latch_tree_ops *ops) { - raw_write_seqcount_latch(&root->seq); + write_seqcount_latch_begin(&root->seq); __lt_insert(node, root, 0, ops->less); - raw_write_seqcount_latch(&root->seq); + write_seqcount_latch(&root->seq); __lt_insert(node, root, 1, ops->less); + write_seqcount_latch_end(&root->seq); } /** @@ -159,7 +160,7 @@ latch_tree_insert(struct latch_tree_node *node, * * Removes @node from the trees @root in an ordered fashion such that we can * always observe one complete tree. See the comment for - * raw_write_seqcount_latch(). + * write_seqcount_latch_begin(). * * It is assumed that @node will observe one RCU quiescent state before being * reused of freed. @@ -172,10 +173,11 @@ latch_tree_erase(struct latch_tree_node *node, struct latch_tree_root *root, const struct latch_tree_ops *ops) { - raw_write_seqcount_latch(&root->seq); + write_seqcount_latch_begin(&root->seq); __lt_erase(node, root, 0); - raw_write_seqcount_latch(&root->seq); + write_seqcount_latch(&root->seq); __lt_erase(node, root, 1); + write_seqcount_latch_end(&root->seq); } /** @@ -204,9 +206,9 @@ latch_tree_find(void *key, struct latch_tree_root *root, unsigned int seq; do { - seq = raw_read_seqcount_latch(&root->seq); + seq = read_seqcount_latch(&root->seq); node = __lt_find(key, root, seq & 1, ops->comp); - } while (raw_read_seqcount_latch_retry(&root->seq, seq)); + } while (read_seqcount_latch_retry(&root->seq, seq)); return node; } diff --git a/include/linux/rwlock_rt.h b/include/linux/rwlock_rt.h index 8544ff05e594..7d81fc6918ee 100644 --- a/include/linux/rwlock_rt.h +++ b/include/linux/rwlock_rt.h @@ -24,13 +24,13 @@ do { \ __rt_rwlock_init(rwl, #rwl, &__key); \ } while (0) -extern void rt_read_lock(rwlock_t *rwlock); +extern void rt_read_lock(rwlock_t *rwlock) __acquires(rwlock); extern int rt_read_trylock(rwlock_t *rwlock); -extern void rt_read_unlock(rwlock_t *rwlock); -extern void rt_write_lock(rwlock_t *rwlock); -extern void rt_write_lock_nested(rwlock_t *rwlock, int subclass); +extern void rt_read_unlock(rwlock_t *rwlock) __releases(rwlock); +extern void rt_write_lock(rwlock_t *rwlock) __acquires(rwlock); +extern void rt_write_lock_nested(rwlock_t *rwlock, int subclass) __acquires(rwlock); extern int rt_write_trylock(rwlock_t *rwlock); -extern void rt_write_unlock(rwlock_t *rwlock); +extern void rt_write_unlock(rwlock_t *rwlock) __releases(rwlock); static __always_inline void read_lock(rwlock_t *rwlock) { diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h index fffeb754880f..5298765d6ca4 100644 --- a/include/linux/seqlock.h +++ b/include/linux/seqlock.h @@ -622,6 +622,23 @@ static __always_inline unsigned raw_read_seqcount_latch(const seqcount_latch_t * } /** + * read_seqcount_latch() - pick even/odd latch data copy + * @s: Pointer to seqcount_latch_t + * + * See write_seqcount_latch() for details and a full reader/writer usage + * example. + * + * Return: sequence counter raw value. Use the lowest bit as an index for + * picking which data copy to read. The full counter must then be checked + * with read_seqcount_latch_retry(). + */ +static __always_inline unsigned read_seqcount_latch(const seqcount_latch_t *s) +{ + kcsan_atomic_next(KCSAN_SEQLOCK_REGION_MAX); + return raw_read_seqcount_latch(s); +} + +/** * raw_read_seqcount_latch_retry() - end a seqcount_latch_t read section * @s: Pointer to seqcount_latch_t * @start: count, from raw_read_seqcount_latch() @@ -636,8 +653,33 @@ raw_read_seqcount_latch_retry(const seqcount_latch_t *s, unsigned start) } /** + * read_seqcount_latch_retry() - end a seqcount_latch_t read section + * @s: Pointer to seqcount_latch_t + * @start: count, from read_seqcount_latch() + * + * Return: true if a read section retry is required, else false + */ +static __always_inline int +read_seqcount_latch_retry(const seqcount_latch_t *s, unsigned start) +{ + kcsan_atomic_next(0); + return raw_read_seqcount_latch_retry(s, start); +} + +/** * raw_write_seqcount_latch() - redirect latch readers to even/odd copy * @s: Pointer to seqcount_latch_t + */ +static __always_inline void raw_write_seqcount_latch(seqcount_latch_t *s) +{ + smp_wmb(); /* prior stores before incrementing "sequence" */ + s->seqcount.sequence++; + smp_wmb(); /* increment "sequence" before following stores */ +} + +/** + * write_seqcount_latch_begin() - redirect latch readers to odd copy + * @s: Pointer to seqcount_latch_t * * The latch technique is a multiversion concurrency control method that allows * queries during non-atomic modifications. If you can guarantee queries never @@ -665,17 +707,11 @@ raw_read_seqcount_latch_retry(const seqcount_latch_t *s, unsigned start) * * void latch_modify(struct latch_struct *latch, ...) * { - * smp_wmb(); // Ensure that the last data[1] update is visible - * latch->seq.sequence++; - * smp_wmb(); // Ensure that the seqcount update is visible - * + * write_seqcount_latch_begin(&latch->seq); * modify(latch->data[0], ...); - * - * smp_wmb(); // Ensure that the data[0] update is visible - * latch->seq.sequence++; - * smp_wmb(); // Ensure that the seqcount update is visible - * + * write_seqcount_latch(&latch->seq); * modify(latch->data[1], ...); + * write_seqcount_latch_end(&latch->seq); * } * * The query will have a form like:: @@ -686,13 +722,13 @@ raw_read_seqcount_latch_retry(const seqcount_latch_t *s, unsigned start) * unsigned seq, idx; * * do { - * seq = raw_read_seqcount_latch(&latch->seq); + * seq = read_seqcount_latch(&latch->seq); * * idx = seq & 0x01; * entry = data_query(latch->data[idx], ...); * * // This includes needed smp_rmb() - * } while (raw_read_seqcount_latch_retry(&latch->seq, seq)); + * } while (read_seqcount_latch_retry(&latch->seq, seq)); * * return entry; * } @@ -716,11 +752,31 @@ raw_read_seqcount_latch_retry(const seqcount_latch_t *s, unsigned start) * When data is a dynamic data structure; one should use regular RCU * patterns to manage the lifetimes of the objects within. */ -static inline void raw_write_seqcount_latch(seqcount_latch_t *s) +static __always_inline void write_seqcount_latch_begin(seqcount_latch_t *s) { - smp_wmb(); /* prior stores before incrementing "sequence" */ - s->seqcount.sequence++; - smp_wmb(); /* increment "sequence" before following stores */ + kcsan_nestable_atomic_begin(); + raw_write_seqcount_latch(s); +} + +/** + * write_seqcount_latch() - redirect latch readers to even copy + * @s: Pointer to seqcount_latch_t + */ +static __always_inline void write_seqcount_latch(seqcount_latch_t *s) +{ + raw_write_seqcount_latch(s); +} + +/** + * write_seqcount_latch_end() - end a seqcount_latch_t write section + * @s: Pointer to seqcount_latch_t + * + * Marks the end of a seqcount_latch_t writer section, after all copies of the + * latch-protected data have been updated. + */ +static __always_inline void write_seqcount_latch_end(seqcount_latch_t *s) +{ + kcsan_nestable_atomic_end(); } #define __SEQLOCK_UNLOCKED(lockname) \ @@ -754,11 +810,7 @@ static inline void raw_write_seqcount_latch(seqcount_latch_t *s) */ static inline unsigned read_seqbegin(const seqlock_t *sl) { - unsigned ret = read_seqcount_begin(&sl->seqcount); - - kcsan_atomic_next(0); /* non-raw usage, assume closing read_seqretry() */ - kcsan_flat_atomic_begin(); - return ret; + return read_seqcount_begin(&sl->seqcount); } /** @@ -774,12 +826,6 @@ static inline unsigned read_seqbegin(const seqlock_t *sl) */ static inline unsigned read_seqretry(const seqlock_t *sl, unsigned start) { - /* - * Assume not nested: read_seqretry() may be called multiple times when - * completing read critical section. - */ - kcsan_flat_atomic_end(); - return read_seqcount_retry(&sl->seqcount, start); } diff --git a/include/linux/spinlock_rt.h b/include/linux/spinlock_rt.h index 61c49b16f69a..f6499c37157d 100644 --- a/include/linux/spinlock_rt.h +++ b/include/linux/spinlock_rt.h @@ -16,26 +16,25 @@ static inline void __rt_spin_lock_init(spinlock_t *lock, const char *name, } #endif -#define spin_lock_init(slock) \ +#define __spin_lock_init(slock, name, key, percpu) \ do { \ - static struct lock_class_key __key; \ - \ rt_mutex_base_init(&(slock)->lock); \ - __rt_spin_lock_init(slock, #slock, &__key, false); \ + __rt_spin_lock_init(slock, name, key, percpu); \ } while (0) -#define local_spin_lock_init(slock) \ +#define _spin_lock_init(slock, percpu) \ do { \ static struct lock_class_key __key; \ - \ - rt_mutex_base_init(&(slock)->lock); \ - __rt_spin_lock_init(slock, #slock, &__key, true); \ + __spin_lock_init(slock, #slock, &__key, percpu); \ } while (0) -extern void rt_spin_lock(spinlock_t *lock); -extern void rt_spin_lock_nested(spinlock_t *lock, int subclass); -extern void rt_spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *nest_lock); -extern void rt_spin_unlock(spinlock_t *lock); +#define spin_lock_init(slock) _spin_lock_init(slock, false) +#define local_spin_lock_init(slock) _spin_lock_init(slock, true) + +extern void rt_spin_lock(spinlock_t *lock) __acquires(lock); +extern void rt_spin_lock_nested(spinlock_t *lock, int subclass) __acquires(lock); +extern void rt_spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *nest_lock) __acquires(lock); +extern void rt_spin_unlock(spinlock_t *lock) __releases(lock); extern void rt_spin_lock_unlock(spinlock_t *lock); extern int rt_spin_trylock_bh(spinlock_t *lock); extern int rt_spin_trylock(spinlock_t *lock); @@ -132,7 +131,7 @@ static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, #define spin_trylock_irq(lock) \ __cond_lock(lock, rt_spin_trylock(lock)) -#define __spin_trylock_irqsave(lock, flags) \ +#define spin_trylock_irqsave(lock, flags) \ ({ \ int __locked; \ \ @@ -142,9 +141,6 @@ static __always_inline void spin_unlock_irqrestore(spinlock_t *lock, __locked; \ }) -#define spin_trylock_irqsave(lock, flags) \ - __cond_lock(lock, __spin_trylock_irqsave(lock, flags)) - #define spin_is_contended(lock) (((void)(lock), 0)) static inline int spin_is_locked(spinlock_t *lock) diff --git a/include/linux/ww_mutex.h b/include/linux/ww_mutex.h index bb763085479a..a401a2f31a77 100644 --- a/include/linux/ww_mutex.h +++ b/include/linux/ww_mutex.h @@ -65,6 +65,16 @@ struct ww_acquire_ctx { #endif #ifdef CONFIG_DEBUG_LOCK_ALLOC struct lockdep_map dep_map; + /** + * @first_lock_dep_map: fake lockdep_map for first locked ww_mutex. + * + * lockdep requires the lockdep_map for the first locked ww_mutex + * in a ww transaction to remain in memory until all ww_mutexes of + * the transaction have been unlocked. Ensure this by keeping a + * fake locked ww_mutex lockdep map between ww_acquire_init() and + * ww_acquire_fini(). + */ + struct lockdep_map first_lock_dep_map; #endif #ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH unsigned int deadlock_inject_interval; @@ -146,7 +156,10 @@ static inline void ww_acquire_init(struct ww_acquire_ctx *ctx, debug_check_no_locks_freed((void *)ctx, sizeof(*ctx)); lockdep_init_map(&ctx->dep_map, ww_class->acquire_name, &ww_class->acquire_key, 0); + lockdep_init_map(&ctx->first_lock_dep_map, ww_class->mutex_name, + &ww_class->mutex_key, 0); mutex_acquire(&ctx->dep_map, 0, 0, _RET_IP_); + mutex_acquire_nest(&ctx->first_lock_dep_map, 0, 0, &ctx->dep_map, _RET_IP_); #endif #ifdef CONFIG_DEBUG_WW_MUTEX_SLOWPATH ctx->deadlock_inject_interval = 1; @@ -185,6 +198,7 @@ static inline void ww_acquire_done(struct ww_acquire_ctx *ctx) static inline void ww_acquire_fini(struct ww_acquire_ctx *ctx) { #ifdef CONFIG_DEBUG_LOCK_ALLOC + mutex_release(&ctx->first_lock_dep_map, _THIS_IP_); mutex_release(&ctx->dep_map, _THIS_IP_); #endif #ifdef DEBUG_WW_MUTEXES |