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Date: Thu, 22 Jan 2015 11:25:02 -0600
From: Jeff Epler <jepler@unpythonic.net>
To: Anshul Garg <aksgarg1989@gmail.com>
Cc: akpm@linux-foundation.org, levex@linux.com, felipe.contreras@gmail.com,
        linux-kernel@vger.kernel.org, anshul.g@samsung.com
Subject: Re: [PATCH] lib/kstrtox.c clean kstrtoll function
Message-ID: <20150122172501.GE40116@unpythonic.net>
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On Thu, Jan 22, 2015 at 05:54:10AM -0800, Anshul Garg wrote:
> -		if ((long long)(-tmp) >= 0)
> -			return -ERANGE;
> -		*res = -tmp;
...
> +	if ((long long)tmp < 0)
> +		return -ERANGE;
> +	*res = sign * tmp;

I don't believe overflow handling is correct anymore with this patch.
Did you try with the input as the most negative possible unsigned long?

Jeff