Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933516Ab3FRX6o (ORCPT ); Tue, 18 Jun 2013 19:58:44 -0400 Received: from mail-pa0-f49.google.com ([209.85.220.49]:59797 "EHLO mail-pa0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755322Ab3FRX6k (ORCPT ); Tue, 18 Jun 2013 19:58:40 -0400 From: Kevin Hilman To: Frederic Weisbecker Cc: linaro-kernel@lists.linaro.org, Ingo Molnar , Peter Zijlstra , linux-kernel@vger.kernel.org (open list) Subject: [PATCH 2/2] sched/nohz: fix overflow error in scheduler_tick_max_deferment() Date: Tue, 18 Jun 2013 16:58:29 -0700 Message-Id: <1371599913-1232-2-git-send-email-khilman@linaro.org> X-Mailer: git-send-email 1.8.3 In-Reply-To: <1371599913-1232-1-git-send-email-khilman@linaro.org> References: <1371599913-1232-1-git-send-email-khilman@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1078 Lines: 34 The conversion of the max deferment from usecs to nsecs can easily overflow on platforms where a long is 32-bits. To fix, cast the usecs value to u64 before multiplying by NSECS_PER_USEC. This was discovered on 32-bit ARM platform when extending the max deferment value. Cc: Frederic Weisbecker Signed-off-by: Kevin Hilman --- kernel/sched/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/sched/core.c b/kernel/sched/core.c index b5d3f99..b506722 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -2765,7 +2765,7 @@ u64 scheduler_tick_max_deferment(void) if (time_before_eq(next, now)) return 0; - return jiffies_to_usecs(next - now) * NSEC_PER_USEC; + return (u64)jiffies_to_usecs(next - now) * NSEC_PER_USEC; } #endif -- 1.8.3 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/