Commit 431f288e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull locking fixes from Thomas Gleixner:
 "A set of locking fixes:

   - Address the fallout of the rwsem rework. Missing ACQUIREs and a
     sanity check to prevent a use-after-free

   - Add missing checks for unitialized mutexes when mutex debugging is
     enabled.

   - Remove the bogus code in the generic SMP variant of
     arch_futex_atomic_op_inuser()

   - Fixup the #ifdeffery in lockdep to prevent compile warnings"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/mutex: Test for initialized mutex
  locking/lockdep: Clean up #ifdef checks
  locking/lockdep: Hide unused 'class' variable
  locking/rwsem: Add ACQUIRE comments
  tty/ldsem, locking/rwsem: Add missing ACQUIRE to read_failed sleep loop
  lcoking/rwsem: Add missing ACQUIRE to read_slowpath sleep loop
  locking/rwsem: Add missing ACQUIRE to read_slowpath exit when queue is empty
  locking/rwsem: Don't call owner_on_cpu() on read-owner
  futex: Cleanup generic SMP variant of arch_futex_atomic_op_inuser()
parents 13fbe991 6c11c6e3

drivers/tty/tty_ldsem.c

+2 −3
Original line number Diff line number Diff line
@@ -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;

include/asm-generic/futex.h

+1 −20
Original line number Diff line number Diff line
@@ -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

kernel/locking/lockdep.c

+6 −7
Original line number Diff line number Diff line
@@ -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;

kernel/locking/lockdep_proc.c

+2 −1
Original line number Diff line number Diff line
@@ -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)

kernel/locking/mutex.c

+10 −1
Original line number Diff line number Diff line
@@ -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_);

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