From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751967AbaCWICv (ORCPT ); Sun, 23 Mar 2014 04:02:51 -0400 Received: from szxga01-in.huawei.com ([119.145.14.64]:53746 "EHLO szxga01-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750974AbaCWICp (ORCPT ); Sun, 23 Mar 2014 04:02:45 -0400 From: Liu Hua To: CC: , , , , , Liu Hua , Subject: [PATCH v2] hung_task : check the value of "sysctl_hung_task_timeout_sec" Date: Sun, 23 Mar 2014 15:54:04 +0800 Message-ID: <1395561244-69173-1-git-send-email-sdu.liu@huawei.com> X-Mailer: git-send-email 1.9.0 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.107.197.247] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org As sysctl_hung_task_timeout_sec is unsigned long, when this value is larger then LONG_MAX/HZ, the function schedule_timeout_interruptible in watchdog will return immediately without sleep and with print : [ 205.452934] schedule_timeout: wrong timeout value ffffffffffffff83 and then the funtion watchdog will call schedule_timeout_interruptible again and again. The screen will be filled with "schedule_timeout: wrong timeout value ffffffffffffff83" This patch does some check and correction in timeout_jiffies, to let the function schedule_timeout_interruptible allways get the valid parameter. Cc: Signed-off-by: Liu Hua --- kernel/hung_task.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/hung_task.c b/kernel/hung_task.c index 6df6149..f992286 100644 --- a/kernel/hung_task.c +++ b/kernel/hung_task.c @@ -174,8 +174,12 @@ static void check_hung_uninterruptible_tasks(unsigned long timeout) static unsigned long timeout_jiffies(unsigned long timeout) { - /* timeout of 0 will disable the watchdog */ - return timeout ? timeout * HZ : MAX_SCHEDULE_TIMEOUT; + /* timeout of 0 or >= LONG_MAX/HZ will disable the watchdog */ + if ((timeout == 0) || (timeout > MAX_SCHEDULE_TIMEOUT)) + return MAX_SCHEDULE_TIMEOUT; + + return (timeout * HZ) < MAX_SCHEDULE_TIMEOUT ? + timeout * HZ : MAX_SCHEDULE_TIMEOUT; } /* -- 1.9.0