From mboxrd@z Thu Jan  1 00:00:00 1970
From: Joe Perches <joe@perches.com>
Subject: Re: [PATCH v5 3/3] PM: Introduce Intel PowerClamp Driver
Date: Thu, 03 Jan 2013 19:51:04 -0800
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To: Jacob Pan <jacob.jun.pan@linux.intel.com>
Cc: Linux PM <linux-pm@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>, Rafael Wysocki <rafael.j.wysocki@intel.com>, Len Brown <len.brown@intel.com>, Thomas Gleixner <tglx@linutronix.de>, "H. Peter Anvin" <hpa@zytor.com>, Ingo Molnar <mingo@elte.hu>, Zhang Rui <rui.zhang@intel.com>, Rob Landley <rob@landley.net>, Arjan van de Ven <arjan@linux.intel.com>, Paul McKenney <paulmck@linux.vnet.ibm.com>

On Thu, 2013-01-03 at 07:10 -0800, Jacob Pan wrote:
> Intel PowerClamp driver performs synchronized idle injection across
> all online CPUs. The goal is to maintain a given package level C-state
> ratio.

[]

> +static int window_size_set(const char *arg, const struct kernel_param *kp)
> +{
> +	int ret = 0;
> +	unsigned long new_window_size;
> +
> +	ret = kstrtoul(arg, 10, &new_window_size);
> +	if (ret)
> +		goto exit_win;
> +	if (new_window_size > 10 || new_window_size < 2) {
> +		pr_err("Invalid window size %lu, between 2-10\n",
> +			new_window_size);
> +		ret = -EINVAL;
> +	}
> +
> +	window_size = new_window_size;

Possible assignment of known invalid windows size?
Maybe you should add
	goto exit;
after
	ret = -EINVAL;

or add
	new_window_size = clamp(new_window_size, 2ul, 10ul);