[GIT pull] locking/urgent for v5.10-rc2

[Thomas Gleixner]

Linus,

please pull the latest locking/urgent branch from:

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

up to:  1a39340865ce: lockdep: Fix nr_unused_locks accounting


A couple of locking fixes:

 - Fix incorrect failure injection handling on 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.

Thanks,

	tglx

------------------>
Mateusz Nosek (1):
      futex: Fix incorrect should_fail_futex() handling

Peter Zijlstra (3):
      lockdep: Fix preemption WARN for spurious IRQ-enable
      locking/lockdep: Remove more raw_cpu_read() usage
      lockdep: Fix nr_unused_locks accounting


 kernel/futex.c           |  4 +++-
 kernel/locking/lockdep.c | 20 +++++++-------------
 2 files changed, 10 insertions(+), 14 deletions(-)

diff --git a/kernel/futex.c b/kernel/futex.c
index a5876694a60e..39681bf8b06c 100644
--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -1502,8 +1502,10 @@ 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 3e99dfef8408..b71ad8d9f1c9 100644
--- 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: