Messages in this thread | | | Subject | Re: [PATCH v2] workqueue: Fix double kfree for rescuer | From | qzhang2 <> | Date | Mon, 25 May 2020 18:19:59 +0800 |
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I see, kfree does nothing with null pointers and direct return. but again kfree is not a good suggestion.
On 5/25/20 5:50 PM, Markus Elfring wrote: >> The duplicate memory release should be deleted from the implementation >> of the callback function "rcu_free_wq". > > I tried to help with the selection of a better commit message. > I have taken another look also at the implementation of the function “destroy_workqueue”. > > * The function call “destroy_workqueue” can be performed there in an if branch > after the statement “wq->rescuer = NULL” was executed. > > * This data processing is independent from a possible call of the > function “call_rcu(&wq->rcu, rcu_free_wq)” in another if branch. > Thus it seems that a null pointer is intentionally passed by a data structure > member to this callback function on demand. > The corresponding call of the function “kfree” can tolerate this special case. > > > Now I find that the proposed change can be inappropriate. > > Regards, > Markus >
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