Messages in this thread | | | Date | Mon, 3 Jan 2022 13:26:20 -0800 | Subject | Re: [PATCH] locking/lockdep: Avoid potential access of invalid memory in lock_class | From | Bart Van Assche <> |
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On 1/3/22 10:17, Waiman Long wrote: > On 1/3/22 12:47, Bart Van Assche wrote: >> On 1/2/22 18:35, Waiman Long wrote: >>> - WARN_ON_ONCE(!found); >>> - __lockdep_free_key_range(pf, key, 1); >>> - call_rcu_zapped(pf); >>> - graph_unlock(); >>> -out_irq: >>> + WARN_ON_ONCE(!found && debug_locks); >> >> lockdep_unregister_key() should only be called for a registered key so >> I'd >> like to keep the WARN_ON_ONCE(!found) here instead of changing it into >> WARN_ON_ONCE(!found && debug_locks). Otherwise this patch looks good >> to me. > > The reason for this change is to handle the case that a > lockdep_register_key()/lockdep_unregister_key() pair may be called after > debug_locks is turned off. Without that change, we are going to get the > warning in lockdep_unregister_key(). That is the motivation of your > original commit 8b39adbee805 ("locking/lockdep: Make > lockdep_unregister_key() honor 'debug_locks' again").
Ah, that's right. Hence:
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
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