[PATCH v2] lib: gcd: prevent possible div by 0

From: Davidlohr Bueso
Date: Mon Sep 10 2012 - 10:35:21 EST


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@xxxxxxxxxxxxxxx
Signed-off-by: Davidlohr Bueso <dave@xxxxxxx>
---
V2: simplified checking with b = 0 (Eric)

lib/gcd.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/lib/gcd.c b/lib/gcd.c
index cce4f3c..3657f12 100644
--- 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



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