From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751839Ab3HTClJ (ORCPT ); Mon, 19 Aug 2013 22:41:09 -0400 Received: from intranet.asianux.com ([58.214.24.6]:28285 "EHLO intranet.asianux.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751254Ab3HTClI (ORCPT ); Mon, 19 Aug 2013 22:41:08 -0400 X-Spam-Score: -101.1 Message-ID: <5212D703.5080405@asianux.com> Date: Tue, 20 Aug 2013 10:40:03 +0800 From: Chen Gang User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130110 Thunderbird/17.0.2 MIME-Version: 1.0 To: bsingharora@gmail.com CC: "linux-kernel@vger.kernel.org" Subject: [PATCH] kernel/delayacct.c: check NULL for member variable 'delays' in all extern functions. Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The member variable 'delays' may be NULL, so need check NULL before use it for all extern functions, just like __delayacct_tsk_init() and __delayacct_add_tsk() have already done. Signed-off-by: Chen Gang --- kernel/delayacct.c | 10 ++++++++++ 1 files changed, 10 insertions(+), 0 deletions(-) diff --git a/kernel/delayacct.c b/kernel/delayacct.c index d473988..10cddce 100644 --- a/kernel/delayacct.c +++ b/kernel/delayacct.c @@ -81,11 +81,15 @@ static void delayacct_end(struct timespec *start, struct timespec *end, void __delayacct_blkio_start(void) { + if (!current->delays) + return; delayacct_start(¤t->delays->blkio_start); } void __delayacct_blkio_end(void) { + if (!current->delays) + return; if (current->delays->flags & DELAYACCT_PF_SWAPIN) /* Swapin block I/O */ delayacct_end(¤t->delays->blkio_start, @@ -167,6 +171,8 @@ __u64 __delayacct_blkio_ticks(struct task_struct *tsk) __u64 ret; unsigned long flags; + if (!tsk->delays) + return 0; spin_lock_irqsave(&tsk->delays->lock, flags); ret = nsec_to_clock_t(tsk->delays->blkio_delay + tsk->delays->swapin_delay); @@ -176,11 +182,15 @@ __u64 __delayacct_blkio_ticks(struct task_struct *tsk) void __delayacct_freepages_start(void) { + if (!current->delays) + return; delayacct_start(¤t->delays->freepages_start); } void __delayacct_freepages_end(void) { + if (!current->delays) + return; delayacct_end(¤t->delays->freepages_start, ¤t->delays->freepages_end, ¤t->delays->freepages_delay, -- 1.7.7.6