diff options
| -rw-r--r-- | drivers/tty/tty_ldsem.c | 5 | ||||
| -rw-r--r-- | include/asm-generic/futex.h | 21 | ||||
| -rw-r--r-- | kernel/locking/lockdep.c | 13 | ||||
| -rw-r--r-- | kernel/locking/lockdep_proc.c | 3 | ||||
| -rw-r--r-- | kernel/locking/mutex.c | 11 | ||||
| -rw-r--r-- | kernel/locking/rwsem.c | 28 |
6 files changed, 43 insertions, 38 deletions
diff --git a/drivers/tty/tty_ldsem.c b/drivers/tty/tty_ldsem.c index 717292c1c0df..60ff236a3d63 100644 --- a/drivers/tty/tty_ldsem.c +++ b/drivers/tty/tty_ldsem.c @@ -93,8 +93,7 @@ static void __ldsem_wake_readers(struct ld_semaphore *sem) list_for_each_entry_safe(waiter, next, &sem->read_wait, list) { tsk = waiter->task; - smp_mb(); - waiter->task = NULL; + smp_store_release(&waiter->task, NULL); wake_up_process(tsk); put_task_struct(tsk); } @@ -194,7 +193,7 @@ down_read_failed(struct ld_semaphore *sem, long count, long timeout) for (;;) { set_current_state(TASK_UNINTERRUPTIBLE); - if (!waiter.task) + if (!smp_load_acquire(&waiter.task)) break; if (!timeout) break; diff --git a/include/asm-generic/futex.h b/include/asm-generic/futex.h index 8666fe7f35d7..02970b11f71f 100644 --- a/include/asm-generic/futex.h +++ b/include/asm-generic/futex.h @@ -118,26 +118,7 @@ futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr, static inline int arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr) { - int oldval = 0, ret; - - pagefault_disable(); - - switch (op) { - case FUTEX_OP_SET: - case FUTEX_OP_ADD: - case FUTEX_OP_OR: - case FUTEX_OP_ANDN: - case FUTEX_OP_XOR: - default: - ret = -ENOSYS; - } - - pagefault_enable(); - - if (!ret) - *oval = oldval; - - return ret; + return -ENOSYS; } static inline int diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index 341f52117f88..4861cf8e274b 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -448,7 +448,7 @@ static void print_lockdep_off(const char *bug_msg) unsigned long nr_stack_trace_entries; -#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) +#ifdef CONFIG_PROVE_LOCKING /* * Stack-trace: tightly packed array of stack backtrace * addresses. Protected by the graph_lock. @@ -491,7 +491,7 @@ unsigned int max_lockdep_depth; DEFINE_PER_CPU(struct lockdep_stats, lockdep_stats); #endif -#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) +#ifdef CONFIG_PROVE_LOCKING /* * Locking printouts: */ @@ -2969,7 +2969,7 @@ static void check_chain_key(struct task_struct *curr) #endif } -#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) +#ifdef CONFIG_PROVE_LOCKING static int mark_lock(struct task_struct *curr, struct held_lock *this, enum lock_usage_bit new_bit); @@ -3608,7 +3608,7 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, return ret; } -#else /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */ +#else /* CONFIG_PROVE_LOCKING */ static inline int mark_usage(struct task_struct *curr, struct held_lock *hlock, int check) @@ -3627,7 +3627,7 @@ static inline int separate_irq_context(struct task_struct *curr, return 0; } -#endif /* defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_PROVE_LOCKING) */ +#endif /* CONFIG_PROVE_LOCKING */ /* * Initialize a lock instance's lock-class mapping info: @@ -4321,8 +4321,7 @@ static void __lock_unpin_lock(struct lockdep_map *lock, struct pin_cookie cookie */ static void check_flags(unsigned long flags) { -#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP) && \ - defined(CONFIG_TRACE_IRQFLAGS) +#if defined(CONFIG_PROVE_LOCKING) && defined(CONFIG_DEBUG_LOCKDEP) if (!debug_locks) return; diff --git a/kernel/locking/lockdep_proc.c b/kernel/locking/lockdep_proc.c index 65b6a1600c8f..bda006f8a88b 100644 --- a/kernel/locking/lockdep_proc.c +++ b/kernel/locking/lockdep_proc.c @@ -200,7 +200,6 @@ static void lockdep_stats_debug_show(struct seq_file *m) static int lockdep_stats_show(struct seq_file *m, void *v) { - struct lock_class *class; unsigned long nr_unused = 0, nr_uncategorized = 0, nr_irq_safe = 0, nr_irq_unsafe = 0, nr_softirq_safe = 0, nr_softirq_unsafe = 0, @@ -211,6 +210,8 @@ static int lockdep_stats_show(struct seq_file *m, void *v) sum_forward_deps = 0; #ifdef CONFIG_PROVE_LOCKING + struct lock_class *class; + list_for_each_entry(class, &all_lock_classes, lock_entry) { if (class->usage_mask == 0) diff --git a/kernel/locking/mutex.c b/kernel/locking/mutex.c index edd1c082dbf5..5e069734363c 100644 --- a/kernel/locking/mutex.c +++ b/kernel/locking/mutex.c @@ -908,6 +908,10 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, might_sleep(); +#ifdef CONFIG_DEBUG_MUTEXES + DEBUG_LOCKS_WARN_ON(lock->magic != lock); +#endif + ww = container_of(lock, struct ww_mutex, base); if (use_ww_ctx && ww_ctx) { if (unlikely(ww_ctx == READ_ONCE(ww->ctx))) @@ -1379,8 +1383,13 @@ __ww_mutex_lock_interruptible_slowpath(struct ww_mutex *lock, */ int __sched mutex_trylock(struct mutex *lock) { - bool locked = __mutex_trylock(lock); + bool locked; + +#ifdef CONFIG_DEBUG_MUTEXES + DEBUG_LOCKS_WARN_ON(lock->magic != lock); +#endif + locked = __mutex_trylock(lock); if (locked) mutex_acquire(&lock->dep_map, 0, 1, _RET_IP_); diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index 37524a47f002..bd0f0d05724c 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -666,7 +666,11 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem, preempt_disable(); rcu_read_lock(); owner = rwsem_owner_flags(sem, &flags); - if ((flags & nonspinnable) || (owner && !owner_on_cpu(owner))) + /* + * Don't check the read-owner as the entry may be stale. + */ + if ((flags & nonspinnable) || + (owner && !(flags & RWSEM_READER_OWNED) && !owner_on_cpu(owner))) ret = false; rcu_read_unlock(); preempt_enable(); @@ -1000,6 +1004,7 @@ rwsem_down_read_slowpath(struct rw_semaphore *sem, int state) atomic_long_add(-RWSEM_READER_BIAS, &sem->count); adjustment = 0; if (rwsem_optimistic_spin(sem, false)) { + /* rwsem_optimistic_spin() implies ACQUIRE on success */ /* * Wake up other readers in the wait list if the front * waiter is a reader. @@ -1014,6 +1019,7 @@ rwsem_down_read_slowpath(struct rw_semaphore *sem, int state) } return sem; } else if (rwsem_reader_phase_trylock(sem, waiter.last_rowner)) { + /* rwsem_reader_phase_trylock() implies ACQUIRE on success */ return sem; } @@ -1032,6 +1038,8 @@ queue: */ if (adjustment && !(atomic_long_read(&sem->count) & (RWSEM_WRITER_MASK | RWSEM_FLAG_HANDOFF))) { + /* Provide lock ACQUIRE */ + smp_acquire__after_ctrl_dep(); raw_spin_unlock_irq(&sem->wait_lock); rwsem_set_reader_owned(sem); lockevent_inc(rwsem_rlock_fast); @@ -1065,15 +1073,18 @@ queue: wake_up_q(&wake_q); /* wait to be given the lock */ - while (true) { + for (;;) { set_current_state(state); - if (!waiter.task) + if (!smp_load_acquire(&waiter.task)) { + /* Matches rwsem_mark_wake()'s smp_store_release(). */ break; + } if (signal_pending_state(state, current)) { raw_spin_lock_irq(&sem->wait_lock); if (waiter.task) goto out_nolock; raw_spin_unlock_irq(&sem->wait_lock); + /* Ordered by sem->wait_lock against rwsem_mark_wake(). */ break; } schedule(); @@ -1083,6 +1094,7 @@ queue: __set_current_state(TASK_RUNNING); lockevent_inc(rwsem_rlock); return sem; + out_nolock: list_del(&waiter.list); if (list_empty(&sem->wait_list)) { @@ -1123,8 +1135,10 @@ rwsem_down_write_slowpath(struct rw_semaphore *sem, int state) /* do optimistic spinning and steal lock if possible */ if (rwsem_can_spin_on_owner(sem, RWSEM_WR_NONSPINNABLE) && - rwsem_optimistic_spin(sem, true)) + rwsem_optimistic_spin(sem, true)) { + /* rwsem_optimistic_spin() implies ACQUIRE on success */ return sem; + } /* * Disable reader optimistic spinning for this rwsem after @@ -1184,9 +1198,11 @@ rwsem_down_write_slowpath(struct rw_semaphore *sem, int state) wait: /* wait until we successfully acquire the lock */ set_current_state(state); - while (true) { - if (rwsem_try_write_lock(sem, wstate)) + for (;;) { + if (rwsem_try_write_lock(sem, wstate)) { + /* rwsem_try_write_lock() implies ACQUIRE on success */ break; + } raw_spin_unlock_irq(&sem->wait_lock); |