Boqun Feng a9e4bebec6 locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class() ... commit 495f53d5cc 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>		2025-04-25 10:43:41 +02:00
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irqflag-debug.c
lock_events_list.h
lock_events.c
lock_events.h
lockdep_internals.h
lockdep_proc.c
lockdep_states.h
lockdep.c	locking/lockdep: Decrease nr_unused_locks if lock unused in zap_class()	2025-04-25 10:43:41 +02:00
locktorture.c
Makefile
mcs_spinlock.h
mutex-debug.c	locking/mutex: Introduce devm_mutex_init()	2024-07-11 12:47:04 +02:00
mutex.c
mutex.h
osq_lock.c
percpu-rwsem.c
qrwlock.c
qspinlock_paravirt.h
qspinlock_stat.h
qspinlock.c
rtmutex_api.c
rtmutex_common.h
rtmutex.c	rtmutex: Drop rt_mutex::wait_lock before scheduling	2024-09-12 11:10:17 +02:00
rwbase_rt.c
rwsem.c	locking/rwsem: Add __always_inline annotation to __down_write_common() and inlined callers	2024-08-03 08:49:08 +02:00
semaphore.c	locking/semaphore: Use wake_q to wake up processes outside lock critical section	2025-04-10 14:33:39 +02:00
spinlock_debug.c
spinlock_rt.c
spinlock.c
test-ww_mutex.c	locking/ww_mutex/test: Fix potential workqueue corruption	2023-11-28 17:06:54 +00:00
ww_mutex.h
ww_rt_mutex.c