diff --git a/drivers/leds/leds-lp8860.c b/drivers/leds/leds-lp8860.c index 52b97c9..0962c00 100644 --- a/drivers/leds/leds-lp8860.c +++ b/drivers/leds/leds-lp8860.c @@ -307,7 +307,9 @@ static int lp8860_probe(struct i2c_client *client) led->client = client; led->led_dev.brightness_set_blocking = lp8860_brightness_set; - devm_mutex_init(&client->dev, &led->lock); + ret = devm_mutex_init(&client->dev, &led->lock); + if (ret) + return dev_err_probe(&client->dev, ret, "Failed to initialize lock\n"); led->regmap = devm_regmap_init_i2c(client, &lp8860_regmap_config); if (IS_ERR(led->regmap)) { diff --git a/drivers/spi/spi-nxp-fspi.c b/drivers/spi/spi-nxp-fspi.c index e63c77e..f3d5765 100644 --- a/drivers/spi/spi-nxp-fspi.c +++ b/drivers/spi/spi-nxp-fspi.c @@ -1273,7 +1273,9 @@ static int nxp_fspi_probe(struct platform_device *pdev) if (ret) return dev_err_probe(dev, ret, "Failed to request irq\n"); - devm_mutex_init(dev, &f->lock); + ret = devm_mutex_init(dev, &f->lock); + if (ret) + return dev_err_probe(dev, ret, "Failed to initialize lock\n"); ctlr->bus_num = -1; ctlr->num_chipselect = NXP_FSPI_MAX_CHIPSELECT; diff --git a/include/linux/lockdep_types.h b/include/linux/lockdep_types.h index 9f361d3..eae115a 100644 --- a/include/linux/lockdep_types.h +++ b/include/linux/lockdep_types.h @@ -175,7 +175,7 @@ struct lock_class_stats { unsigned long bounces[nr_bounce_types]; }; -struct lock_class_stats lock_stats(struct lock_class *class); +void lock_stats(struct lock_class *class, struct lock_class_stats *stats); void clear_lock_stats(struct lock_class *class); #endif diff --git a/include/linux/mutex.h b/include/linux/mutex.h index a039fa8..00afd34 100644 --- a/include/linux/mutex.h +++ b/include/linux/mutex.h @@ -126,11 +126,11 @@ do { \ #ifdef CONFIG_DEBUG_MUTEXES -int __devm_mutex_init(struct device *dev, struct mutex *lock); +int __must_check __devm_mutex_init(struct device *dev, struct mutex *lock); #else -static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) +static inline int __must_check __devm_mutex_init(struct device *dev, struct mutex *lock) { /* * When CONFIG_DEBUG_MUTEXES is off mutex_destroy() is just a nop so @@ -141,14 +141,17 @@ static inline int __devm_mutex_init(struct device *dev, struct mutex *lock) #endif -#define devm_mutex_init(dev, mutex) \ +#define __mutex_init_ret(mutex) \ ({ \ typeof(mutex) mutex_ = (mutex); \ \ mutex_init(mutex_); \ - __devm_mutex_init(dev, mutex_); \ + mutex_; \ }) +#define devm_mutex_init(dev, mutex) \ + __devm_mutex_init(dev, __mutex_init_ret(mutex)) + /* * See kernel/locking/mutex.c for detailed documentation of these APIs. * Also see Documentation/locking/mutex-design.rst. diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index dd2bbf7..2d4c5ba 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -297,33 +297,30 @@ static inline void lock_time_add(struct lock_time *src, struct lock_time *dst) dst->nr += src->nr; } -struct lock_class_stats lock_stats(struct lock_class *class) +void lock_stats(struct lock_class *class, struct lock_class_stats *stats) { - struct lock_class_stats stats; int cpu, i; - memset(&stats, 0, sizeof(struct lock_class_stats)); + memset(stats, 0, sizeof(struct lock_class_stats)); for_each_possible_cpu(cpu) { struct lock_class_stats *pcs = &per_cpu(cpu_lock_stats, cpu)[class - lock_classes]; - for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++) - stats.contention_point[i] += pcs->contention_point[i]; + for (i = 0; i < ARRAY_SIZE(stats->contention_point); i++) + stats->contention_point[i] += pcs->contention_point[i]; - for (i = 0; i < ARRAY_SIZE(stats.contending_point); i++) - stats.contending_point[i] += pcs->contending_point[i]; + for (i = 0; i < ARRAY_SIZE(stats->contending_point); i++) + stats->contending_point[i] += pcs->contending_point[i]; - lock_time_add(&pcs->read_waittime, &stats.read_waittime); - lock_time_add(&pcs->write_waittime, &stats.write_waittime); + lock_time_add(&pcs->read_waittime, &stats->read_waittime); + lock_time_add(&pcs->write_waittime, &stats->write_waittime); - lock_time_add(&pcs->read_holdtime, &stats.read_holdtime); - lock_time_add(&pcs->write_holdtime, &stats.write_holdtime); + lock_time_add(&pcs->read_holdtime, &stats->read_holdtime); + lock_time_add(&pcs->write_holdtime, &stats->write_holdtime); - for (i = 0; i < ARRAY_SIZE(stats.bounces); i++) - stats.bounces[i] += pcs->bounces[i]; + for (i = 0; i < ARRAY_SIZE(stats->bounces); i++) + stats->bounces[i] += pcs->bounces[i]; } - - return stats; } void clear_lock_stats(struct lock_class *class) @@ -6619,8 +6616,16 @@ void lockdep_unregister_key(struct lock_class_key *key) if (need_callback) call_rcu(&delayed_free.rcu_head, free_zapped_rcu); - /* Wait until is_dynamic_key() has finished accessing k->hash_entry. */ - synchronize_rcu(); + /* + * Wait until is_dynamic_key() has finished accessing k->hash_entry. + * + * Some operations like __qdisc_destroy() will call this in a debug + * kernel, and the network traffic is disabled while waiting, hence + * the delay of the wait matters in debugging cases. Currently use a + * synchronize_rcu_expedited() to speed up the wait at the cost of + * system IPIs. TODO: Replace RCU with hazptr for this. + */ + synchronize_rcu_expedited(); } EXPORT_SYMBOL_GPL(lockdep_unregister_key); diff --git a/kernel/locking/lockdep_internals.h b/kernel/locking/lockdep_internals.h index 82156ca..0e5e6ff 100644 --- a/kernel/locking/lockdep_internals.h +++ b/kernel/locking/lockdep_internals.h @@ -47,29 +47,31 @@ enum { __LOCKF(USED_READ) }; +enum { #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE | -static const unsigned long LOCKF_ENABLED_IRQ = + LOCKF_ENABLED_IRQ = #include "lockdep_states.h" - 0; + 0, #undef LOCKDEP_STATE #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE | -static const unsigned long LOCKF_USED_IN_IRQ = + LOCKF_USED_IN_IRQ = #include "lockdep_states.h" - 0; + 0, #undef LOCKDEP_STATE #define LOCKDEP_STATE(__STATE) LOCKF_ENABLED_##__STATE##_READ | -static const unsigned long LOCKF_ENABLED_IRQ_READ = + LOCKF_ENABLED_IRQ_READ = #include "lockdep_states.h" - 0; + 0, #undef LOCKDEP_STATE #define LOCKDEP_STATE(__STATE) LOCKF_USED_IN_##__STATE##_READ | -static const unsigned long LOCKF_USED_IN_IRQ_READ = + LOCKF_USED_IN_IRQ_READ = #include "lockdep_states.h" - 0; + 0, #undef LOCKDEP_STATE +}; #define LOCKF_ENABLED_IRQ_ALL (LOCKF_ENABLED_IRQ | LOCKF_ENABLED_IRQ_READ) #define LOCKF_USED_IN_IRQ_ALL (LOCKF_USED_IN_IRQ | LOCKF_USED_IN_IRQ_READ) diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index b52c07c..1916db9 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -657,7 +657,7 @@ static int lock_stat_open(struct inode *inode, struct file *file) if (!test_bit(idx, lock_classes_in_use)) continue; iter->class = class; - iter->stats = lock_stats(class); + lock_stats(class, &iter->stats); iter++; } diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index a39eccc..d4210dc 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -191,9 +191,7 @@ static void __mutex_add_waiter(struct mutex *lock, struct mutex_waiter *waiter, struct list_head *list) { -#ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER hung_task_set_blocker(lock, BLOCKER_TYPE_MUTEX); -#endif debug_mutex_add_waiter(lock, waiter, current); list_add_tail(&waiter->list, list); @@ -209,9 +207,7 @@ __mutex_remove_waiter(struct mutex *lock, struct mutex_waiter *waiter) __mutex_clear_flag(lock, MUTEX_FLAGS); debug_mutex_remove_waiter(lock, waiter, current); -#ifdef CONFIG_DETECT_HUNG_TASK_BLOCKER hung_task_clear_blocker(); -#endif } /* diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 2ddb827..8572dba 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -727,8 +727,6 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem) return ret; } -#define OWNER_SPINNABLE (OWNER_NULL | OWNER_WRITER | OWNER_READER) - static inline enum owner_state rwsem_owner_state(struct task_struct *owner, unsigned long flags) { @@ -835,7 +833,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem) enum owner_state owner_state; owner_state = rwsem_spin_on_owner(sem); - if (!(owner_state & OWNER_SPINNABLE)) + if (owner_state == OWNER_NONSPINNABLE) break; /* diff --git a/rust/kernel/sync/lock.rs b/rust/kernel/sync/lock.rs index e82fa5b..27202be 100644 --- a/rust/kernel/sync/lock.rs +++ b/rust/kernel/sync/lock.rs @@ -175,6 +175,8 @@ impl Lock { /// Tries to acquire the lock. /// /// Returns a guard that can be used to access the data protected by the lock if successful. + // `Option` is not `#[must_use]` even if `T` is, thus the attribute is needed here. + #[must_use = "if unused, the lock will be immediately unlocked"] pub fn try_lock(&self) -> Option> { // SAFETY: The constructor of the type calls `init`, so the existence of the object proves // that `init` was called.