Subject: Re: [PATCH 1/8] add lib/gcd.c

From: Andrew Morton <[email-masked]>
Date: Thu, 4 Jun 2009 12:03:40 -0700

On Thu, 04 Jun 2009 08:57:24 -0700 Joe Perches <[email-masked]> wrote:

> On Thu, 2009-06-04 at 16:39 +0200, Florian Fainelli wrote:
> > diff --git a/lib/gcd.c b/lib/gcd.c
> > new file mode 100644
> > index 0000000..6634741
> > --- /dev/null
> > +++ b/lib/gcd.c
> > @@ -0,0 +1,20 @@
> > +#include <linux/gcd.h>
> > +#include <linux/module.h>
> > +
> > +/* Greatest common divisor */
> > +unsigned long gcd(unsigned long a, unsigned long b)
> > +{
> > +	unsigned long r;
> > +
> > +	if (a < b) {
> > +		r = a;
> > +		a = b;
> > +		b = r;
> 	swap(a, b)

yup

> > +	}
> > +	while ((r = a % b) != 0) {
> > +		a = b;
> > +		b = r;
> > +	}
> > +	return b;
> > +}
> > +EXPORT_SYMBOL_GPL(gcd);
> 
> Shouldn't a generic gcd protect against a div0
> if gcd(0,0)?

nope.  It's a caller bug, there's nothing the callee can do to fix it,
so an oops is a fine response.