Re: [RFC PATCH v2 05/20] tracing/filters: Optimise cpumask vs cpumask filtering when user mask is a single CPU

[Steven Rostedt]

On Thu, 20 Jul 2023 17:30:41 +0100
Valentin Schneider <vschneid@xxxxxxxxxx> wrote:

>  		/* Move along */
>  		i++;
> +
> +		/*
> +		 * Optimisation: if the user-provided mask has a weight of one
> +		 * then we can treat it as a scalar input.
> +		 */
> +		single = cpumask_weight(pred->mask) == 1;
> +		if (single && field->filter_type == FILTER_CPUMASK) {
> +			pred->val = cpumask_first(pred->mask);
> +			kfree(pred->mask);

Don't we need:
			pred->mask = NULL;

here, or the free_predicate() will cause a double free?

-- Steve

> +		}
> +