Messages in this thread | | | Subject | Re: [PATCH v4] workqueue: Remove unnecessary kfree() call in rcu_free_wq() | From | Markus Elfring <> | Date | Wed, 27 May 2020 08:40:12 +0200 |
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> The callback function "rcu_free_wq" could be called after memory > was released for "wq->rescuer" already and assignment is empty. so > remove unnecessary kfree(NULL).
I have got the impression that also this wording approach contains weaknesses. How do you think about a wording variant like the following?
The data structure member “wq->rescuer” was reset to a null pointer in one if branch. It was passed to a call of the function “kfree” in the callback function “rcu_free_wq” (which was eventually executed). The function “kfree” does not perform more meaningful data processing for a passed null pointer (besides immediately returning from such a call). Thus delete this function call which became unnecessary with the referenced software update.
> Fixes: def98c84b6cd ("workqueue: Fix spurious sanity check failures in destroy_workqueue()")
This change triggered another collateral evolution finally. Would you like to detect similarly questionable function calls by advanced source code analysis?
> Fixes: 8efe1223d73c ("workqueue: Fix missing kfree(rescuer) in destroy_workqueue()")
Please delete this tag from the change description (because I find that it is not so relevant here.)
> v1->v2->v3->v4: > Modify wrong submission information.
Will it be nicer to mention the adjustment of the commit message?
Regards, Markus
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