android_kernel_motorola_sm6375/kernel/locking
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Boqun Feng 1c5b5125ac locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class()
commit 495f53d5cca0f939eaed9dca90b67e7e6fb0e30c upstream.

Currently, when a lock class is allocated, nr_unused_locks will be
increased by 1, until it gets used: nr_unused_locks will be decreased by
1 in mark_lock(). However, one scenario is missed: a lock class may be
zapped without even being used once. This could result into a situation
that nr_unused_locks != 0 but no unused lock class is active in the
system, and when `cat /proc/lockdep_stats`, a WARN_ON() will
be triggered in a CONFIG_DEBUG_LOCKDEP=y kernel:

  [...] DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused)
  [...] WARNING: CPU: 41 PID: 1121 at kernel/locking/lockdep_proc.c:283 lockdep_stats_show+0xba9/0xbd0

And as a result, lockdep will be disabled after this.

Therefore, nr_unused_locks needs to be accounted correctly at
zap_class() time.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Waiman Long <longman@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250326180831.510348-1-boqun.feng@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-05-02 07:39:15 +02:00
..
lock_events.c
lock_events.h
lock_events_list.h
lockdep.c locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class() 2025-05-02 07:39:15 +02:00
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
locktorture.c
Makefile
mcs_spinlock.h
mutex-debug.c locking/mutex: clear MUTEX_FLAGS if wait_list is empty due to signal 2021-05-26 12:05:15 +02:00
mutex-debug.h locking/mutex: clear MUTEX_FLAGS if wait_list is empty due to signal 2021-05-26 12:05:15 +02:00
mutex.c locking/mutex: Fix HANDOFF condition 2021-09-15 09:47:25 +02:00
mutex.h locking/mutex: clear MUTEX_FLAGS if wait_list is empty due to signal 2021-05-26 12:05:15 +02:00
osq_lock.c
percpu-rwsem.c
qrwlock.c
qspinlock.c
qspinlock_paravirt.h
qspinlock_stat.h
rtmutex-debug.c
rtmutex-debug.h
rtmutex.c rtmutex: Drop rt_mutex::wait_lock before scheduling 2024-09-12 11:03:57 +02:00
rtmutex.h
rtmutex_common.h
rwsem.c
rwsem.h
semaphore.c locking/semaphore: Use wake_q to wake up processes outside lock critical section 2025-04-10 14:29:42 +02:00
spinlock.c
spinlock_debug.c
test-ww_mutex.c locking/ww_mutex/test: Fix potential workqueue corruption 2023-11-28 16:50:13 +00:00