If lockdep_register_key() and lockdep_unregister_key() are called with debug_locks == false then the following warning is reported:
WARNING: CPU: 2 PID: 15145 at kernel/locking/lockdep.c:4920 lockdep_unregister_key+0x1ad/0x240 That warning is reported because lockdep_unregister_key() ignores the value of 'debug_locks' and because the behavior of lockdep_register_key() depends on whether or not 'debug_locks' is set. Fix this inconsistency by making lockdep_register_key() unconditionally register lock keys. Cc: Thomas Gleixner <[email protected]> Cc: Will Deacon <[email protected]> Cc: Waiman Long <[email protected]> Cc: shenghui <[email protected]> Reported-by: shenghui <[email protected]> Fixes: a0b0fd53e1e6 ("locking/lockdep: Free lock classes that are no longer in use") # v5.1-rc1. Signed-off-by: Bart Van Assche <[email protected]> --- kernel/locking/lockdep.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index d2d65bbfae01..a228509b62f1 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1027,15 +1027,16 @@ void lockdep_register_key(struct lock_class_key *key) hash_head = keyhashentry(key); raw_local_irq_save(flags); - if (!graph_lock()) - goto restore_irqs; + arch_spin_lock(&lockdep_lock); + current->lockdep_recursion = 1; hlist_for_each_entry_rcu(k, hash_head, hash_entry) { if (WARN_ON_ONCE(k == key)) goto out_unlock; } hlist_add_head_rcu(&key->hash_entry, hash_head); out_unlock: - graph_unlock(); + current->lockdep_recursion = 0; + arch_spin_unlock(&lockdep_lock); restore_irqs: raw_local_irq_restore(flags); } -- 2.21.0.196.g041f5ea1cf98
