linux-kernel - [PATCH] lib: gcd: prevent possible div by 0

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Date:	Sun, 09 Sep 2012 17:03:58 +0200
From:	Davidlohr Bueso <dave@....org>
To:	lkml <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>
Cc:	stable@...r.kernel.org
Subject: [PATCH] lib: gcd: prevent possible div by 0

Account for properties when a and/or b are 0:
gcd(0, 0) = 0
gcd(a, 0) = a
gcd(0, b) = b

Cc: stable@...r.kernel.org
Signed-off-by: Davidlohr Bueso <dave@....org>
---
 lib/gcd.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/lib/gcd.c b/lib/gcd.c
index cce4f3c..7e163c6 100644
--- a/lib/gcd.c
+++ b/lib/gcd.c
@@ -7,6 +7,9 @@ unsigned long gcd(unsigned long a, unsigned long b)
 {
 	unsigned long r;
 
+	if (!a || !b)
+		return a | b;
+
 	if (a < b)
 		swap(a, b);
 	while ((r = a % b) != 0) {
-- 
1.7.9.5



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