Re: [PATCH] kfence: add kfence.fault parameter

[Rik van Riel <riel@surriel.com>]

On Wed, 2026-02-25 at 21:36 +0100, Marco Elver wrote:
> 
> +static int __init early_kfence_fault(char *arg)
> +{
> +	if (!arg)
> +		return -EINVAL;
> +
> +	if (!strcmp(arg, "report"))
> +		kfence_fault = KFENCE_FAULT_REPORT;
> +	else if (!strcmp(arg, "oops"))
> +		kfence_fault = KFENCE_FAULT_OOPS;
> +	else if (!strcmp(arg, "panic"))
> +		kfence_fault = KFENCE_FAULT_PANIC;
> +	else
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +early_param("kfence.fault", early_kfence_fault);

The other parameters in mm/kfence/ seem to be module_param,
which make them tunable at run time through
/sys/module/kfence/parameters/*

Why is this one different?

And, does this one show up as /sys/module/kfence/parameters/fault?

Having the ability to tweak this behavior at run time, without
requiring a system reboot, could be really useful for people
unexpectedly triggering kernel panics across a fleet of servers,
and deciding they would rather not.

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