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![]() 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> |
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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 | ||
locktorture.c | ||
Makefile | ||
mcs_spinlock.h | ||
mutex-debug.c | ||
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 | ||
rwbase_rt.c | ||
rwsem.c | ||
semaphore.c | ||
spinlock_debug.c | ||
spinlock_rt.c | ||
spinlock.c | ||
test-ww_mutex.c | ||
ww_mutex.h | ||
ww_rt_mutex.c |