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Date: Wed, 12 Sep 2012 12:10:55 -0700
From: Andrew Morton <akpm@linux-foundation.org>
To: dave@gnu.org
Cc: Eric Dumazet <eric.dumazet@gmail.com>, lkml <linux-kernel@vger.kernel.org>,
        stable@vger.kernel.org
Subject: Re: [PATCH v2] lib: gcd: prevent possible div by 0
Message-Id: <20120912121055.bd417043.akpm@linux-foundation.org>
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On Mon, 10 Sep 2012 16:35:19 +0200
Davidlohr Bueso <dave@gnu.org> wrote:

> Account for all properties when a and/or b are 0:
> gcd(0, 0) = 0
> gcd(a, 0) = a
> gcd(0, b) = b
> 
> Cc: stable@vger.kernel.org

Why cc:stable?  If this patch fixes some known problem in the current
kernel then that really really should have been described in the
changelog.  Always.  Please.

> ...
> --- a/lib/gcd.c
> +++ b/lib/gcd.c
> @@ -9,6 +9,9 @@ unsigned long gcd(unsigned long a, unsigned long b)
>  
>  	if (a < b)
>  		swap(a, b);
> +
> +	if (!b)
> +		return a;
>  	while ((r = a % b) != 0) {
>  		a = b;
>  		b = r;
> -- 
> 1.7.9.5
> 
>