From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758895Ab3KMR0h (ORCPT ); Wed, 13 Nov 2013 12:26:37 -0500 Received: from terminus.zytor.com ([198.137.202.10]:52936 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757859Ab3KMR01 (ORCPT ); Wed, 13 Nov 2013 12:26:27 -0500 Date: Wed, 13 Nov 2013 09:25:51 -0800 From: tip-bot for Michal Nazarewicz Message-ID: Cc: linux-kernel@vger.kernel.org, bsegall@google.com, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org, tglx@linutronix.de, mina86@mina86.com Reply-To: mingo@kernel.org, hpa@zytor.com, bsegall@google.com, linux-kernel@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de, mina86@mina86.com In-Reply-To: <1384112521-25177-1-git-send-email-mpn@google.com> References: <1384112521-25177-1-git-send-email-mpn@google.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:sched/urgent] sched/fair: Avoid integer overflow Git-Commit-ID: 85b088e934b9943322bfe37077289ae60f1b3414 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.1 (terminus.zytor.com [127.0.0.1]); Wed, 13 Nov 2013 09:25:57 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 85b088e934b9943322bfe37077289ae60f1b3414 Gitweb: http://git.kernel.org/tip/85b088e934b9943322bfe37077289ae60f1b3414 Author: Michal Nazarewicz AuthorDate: Sun, 10 Nov 2013 20:42:01 +0100 Committer: Ingo Molnar CommitDate: Wed, 13 Nov 2013 13:33:55 +0100 sched/fair: Avoid integer overflow sa->runnable_avg_sum is of type u32 but after shifting it by NICE_0_SHIFT bits it is promoted to u64. This of course makes no sense, since the result will never be more then 32-bit long. Casting sa->runnable_avg_sum to u64 before it is shifted, fixes this problem. Reviewed-by: Ben Segall Signed-off-by: Michal Nazarewicz Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1384112521-25177-1-git-send-email-mpn@google.com Signed-off-by: Ingo Molnar --- kernel/sched/fair.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c index 201be78..e8b652e 100644 --- a/kernel/sched/fair.c +++ b/kernel/sched/fair.c @@ -2178,7 +2178,7 @@ static inline void __update_tg_runnable_avg(struct sched_avg *sa, long contrib; /* The fraction of a cpu used by this cfs_rq */ - contrib = div_u64(sa->runnable_avg_sum << NICE_0_SHIFT, + contrib = div_u64((u64)sa->runnable_avg_sum << NICE_0_SHIFT, sa->runnable_avg_period + 1); contrib -= cfs_rq->tg_runnable_contrib;