From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752705AbbIOBHc (ORCPT ); Mon, 14 Sep 2015 21:07:32 -0400 Received: from mail-pa0-f46.google.com ([209.85.220.46]:33826 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751601AbbIOBFd (ORCPT ); Mon, 14 Sep 2015 21:05:33 -0400 From: John Stultz To: LKML Cc: John Stultz , Prarit Bhargava , Richard Cochran , Ingo Molnar , Thomas Gleixner Subject: [RFC][PATCH 1/5] clocksource: Fix abs() usage w/ 64bit values Date: Mon, 14 Sep 2015 18:05:20 -0700 Message-Id: <1442279124-7309-2-git-send-email-john.stultz@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1442279124-7309-1-git-send-email-john.stultz@linaro.org> References: <1442279124-7309-1-git-send-email-john.stultz@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch fixes one cases where abs() was being used with 64-bit nanosecond values, where the result may be capped at 32-bits. This potentially could cause watchdog false negatives on 32-bit systems, so this patch addresses the issue by using abs64(). Cc: Prarit Bhargava Cc: Richard Cochran Cc: Ingo Molnar Cc: Thomas Gleixner Signed-off-by: John Stultz --- kernel/time/clocksource.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 841b72f..3a38775 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -217,7 +217,7 @@ static void clocksource_watchdog(unsigned long data) continue; /* Check the deviation from the watchdog clocksource. */ - if ((abs(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD)) { + if (abs64(cs_nsec - wd_nsec) > WATCHDOG_THRESHOLD) { pr_warn("timekeeping watchdog: Marking clocksource '%s' as unstable because the skew is too large:\n", cs->name); pr_warn(" '%s' wd_now: %llx wd_last: %llx mask: %llx\n", -- 1.9.1