From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751448AbbLNOfe (ORCPT ); Mon, 14 Dec 2015 09:35:34 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:39106 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750924AbbLNOfd (ORCPT ); Mon, 14 Dec 2015 09:35:33 -0500 Date: Mon, 14 Dec 2015 15:35:28 +0100 From: Peter Zijlstra To: Andrey Ryabinin Cc: mingo@redhat.com, bsegall@google.com, dietmar.eggemann@arm.com, linux-kernel@vger.kernel.org, yuyang.du@intel.com, pjt@google.com, morten.rasmussen@arm.com Subject: Re: [PATCH v2] sched/fair: fix mul overflow on 32-bit systems Message-ID: <20151214143528.GP6357@twins.programming.kicks-ass.net> References: <1450097243-30137-1-git-send-email-aryabinin@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1450097243-30137-1-git-send-email-aryabinin@virtuozzo.com> User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Dec 14, 2015 at 03:47:23PM +0300, Andrey Ryabinin wrote: > Make 'r' 64-bit type to avoid overflow in 'r * LOAD_AVG_MAX' > on 32-bit systems: > UBSAN: Undefined behaviour in kernel/sched/fair.c:2785:18 > signed integer overflow: > 87950 * 47742 cannot be represented in type 'int' > > Fixes: 9d89c257dfb9 ("sched/fair: Rewrite runnable load and utilization average tracking") > Signed-off-by: Andrey Ryabinin Thanks!