Commit 8d99084e authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

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

   - Fix incorrect failure injection handling in the fuxtex code

   - Prevent a preemption warning in lockdep when tracking
     local_irq_enable() and interrupts are already enabled

   - Remove more raw_cpu_read() usage from lockdep which causes state
     corruption on !X86 architectures.

   - Make the nr_unused_locks accounting in lockdep correct again"

* tag 'locking-urgent-2020-11-01' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix nr_unused_locks accounting
  locking/lockdep: Remove more raw_cpu_read() usage
  futex: Fix incorrect should_fail_futex() handling
  lockdep: Fix preemption WARN for spurious IRQ-enable
parents 31f02006 1a393408

kernel/futex.c

+3 −1
Original line number Diff line number Diff line
@@ -1503,8 +1503,10 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_pi_state *pi_ 
	 */

	newval = FUTEX_WAITERS | task_pid_vnr(new_owner);



	if (unlikely(should_fail_futex(true)))

	if (unlikely(should_fail_futex(true))) {

		ret = -EFAULT;

		goto out_unlock;

	}



	ret = cmpxchg_futex_value_locked(&curval, uaddr, uval, newval);

	if (!ret && (curval != uval)) {

kernel/locking/lockdep.c

+7 −13
Original line number Diff line number Diff line
@@ -84,7 +84,7 @@ static inline bool lockdep_enabled(void) 
	if (!debug_locks)

		return false;



	if (raw_cpu_read(lockdep_recursion))

	if (this_cpu_read(lockdep_recursion))

		return false;



	if (current->lockdep_recursion)
@@ -4057,7 +4057,7 @@ void lockdep_hardirqs_on_prepare(unsigned long ip) 
	if (unlikely(in_nmi()))

		return;



	if (unlikely(__this_cpu_read(lockdep_recursion)))

	if (unlikely(this_cpu_read(lockdep_recursion)))

		return;



	if (unlikely(lockdep_hardirqs_enabled())) {
@@ -4126,7 +4126,7 @@ void noinstr lockdep_hardirqs_on(unsigned long ip) 
		goto skip_checks;

	}



	if (unlikely(__this_cpu_read(lockdep_recursion)))

	if (unlikely(this_cpu_read(lockdep_recursion)))

		return;



	if (lockdep_hardirqs_enabled()) {
@@ -4396,6 +4396,9 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, 
	if (unlikely(hlock_class(this)->usage_mask & new_mask))

		goto unlock;



	if (!hlock_class(this)->usage_mask)

		debug_atomic_dec(nr_unused_locks);



	hlock_class(this)->usage_mask |= new_mask;



	if (new_bit < LOCK_TRACE_STATES) {
@@ -4403,19 +4406,10 @@ static int mark_lock(struct task_struct *curr, struct held_lock *this, 
			return 0;

	}



	switch (new_bit) {

	case 0 ... LOCK_USED-1:

	if (new_bit < LOCK_USED) {

		ret = mark_lock_irq(curr, this, new_bit);

		if (!ret)

			return 0;

		break;



	case LOCK_USED:

		debug_atomic_dec(nr_unused_locks);

		break;



	default:

		break;

	}



unlock:

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