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

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

diff --git a/kernel/futex.c b/kernel/futex.c
index be68ac0..f8614ef 100644 (file)
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -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)) {

diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index 3e99dfe..b71ad8d 100644 (file)
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -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: