From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752300AbaLIVDa (ORCPT ); Tue, 9 Dec 2014 16:03:30 -0500 Received: from mail-lb0-f169.google.com ([209.85.217.169]:47300 "EHLO mail-lb0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751828AbaLIVD3 (ORCPT ); Tue, 9 Dec 2014 16:03:29 -0500 From: Rasmus Villemoes To: Andrew Morton Cc: Rasmus Villemoes , linux-kernel@vger.kernel.org Subject: [PATCH 1/2] lib/lcm.c: Ensure correct result whenever it fits Date: Tue, 9 Dec 2014 22:03:03 +0100 Message-Id: <1418158984-25546-1-git-send-email-linux@rasmusvillemoes.dk> X-Mailer: git-send-email 2.1.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Ensure that lcm(a,b) returns the mathematically correct result, provided it fits in an unsigned long. The current version returns garbage if a*b overflows, even if the final result would fit. Signed-off-by: Rasmus Villemoes --- lib/lcm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/lcm.c b/lib/lcm.c index b9c8de461e9e..01b3aa922dda 100644 --- a/lib/lcm.c +++ b/lib/lcm.c @@ -7,7 +7,7 @@ unsigned long lcm(unsigned long a, unsigned long b) { if (a && b) - return (a * b) / gcd(a, b); + return (a / gcd(a, b)) * b; else if (b) return b; -- 2.1.3