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

From: Thomas Gleixner
Date: Sun Nov 01 2020 - 08:56:54 EST


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: