From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 32A29ECDFB8 for ; Tue, 24 Jul 2018 08:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ECD4520856 for ; Tue, 24 Jul 2018 08:46:15 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ECD4520856 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zoho.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388306AbeGXJvg (ORCPT ); Tue, 24 Jul 2018 05:51:36 -0400 Received: from sender-pp-092.zoho.com ([135.84.80.237]:25322 "EHLO sender-pp-092.zoho.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388242AbeGXJvg (ORCPT ); Tue, 24 Jul 2018 05:51:36 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=zapps768; d=zoho.com; h=from:to:cc:subject:date:message-id:in-reply-to:references; b=ol3SWcQelw6getPaZ4yqqWg8lcRMbtazynvUu06KkkiXpnLe3Rnhe39Ubd4Rm2mPnL2isMy3oVvJ xhLV4+uCLurbyjVRM0C2zdtC5Sv643QJpAuIZJ7PsEm3OdfEIzcA Received: from YEHS1XR956R00D1.lenovo.com (123.120.61.139 [123.120.61.139]) by mx.zohomail.com with SMTPS id 1532421945283221.46085617076346; Tue, 24 Jul 2018 01:45:45 -0700 (PDT) From: Huaisheng Ye To: linux-nvdimm@lists.01.org, dan.j.williams@intel.com Cc: ross.zwisler@linux.intel.com, willy@infradead.org, vishal.l.verma@intel.com, dave.jiang@intel.com, schwidefsky@de.ibm.com, heiko.carstens@de.ibm.com, viro@zeniv.linux.org.uk, martin.petersen@oracle.com, axboe@kernel.dk, gregkh@linuxfoundation.org, bart.vanassche@wdc.com, jack@suse.cz, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, linux-fsdevel@vger.kernel.org, chengnt@lenovo.com, Huaisheng Ye Subject: [PATCH 3/5] s390, dcssblk: Allow a NULL-kaddr to ->direct_access() Date: Tue, 24 Jul 2018 16:45:08 +0800 Message-Id: <20180724084510.6104-4-yehs2007@zoho.com> X-Mailer: git-send-email 2.17.0.windows.1 In-Reply-To: <20180724084510.6104-1-yehs2007@zoho.com> References: <20180724084510.6104-1-yehs2007@zoho.com> X-ZohoMailClient: External Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Huaisheng Ye dcssblk_direct_access() needs to check the validity of second rank pointer kaddr for NULL assignment. If kaddr equals to NULL, it doesn't need to calculate the value. Signed-off-by: Huaisheng Ye --- drivers/s390/block/dcssblk.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/s390/block/dcssblk.c b/drivers/s390/block/dcssblk.c index 0a312e4..9c13dc5 100644 --- a/drivers/s390/block/dcssblk.c +++ b/drivers/s390/block/dcssblk.c @@ -915,7 +915,8 @@ static DEVICE_ATTR(save, S_IWUSR | S_IRUSR, dcssblk_save_show, unsigned long dev_sz; dev_sz = dev_info->end - dev_info->start + 1; - *kaddr = (void *) dev_info->start + offset; + if (kaddr) + *kaddr = (void *) dev_info->start + offset; *pfn = __pfn_to_pfn_t(PFN_DOWN(dev_info->start + offset), PFN_DEV|PFN_SPECIAL); -- 1.8.3.1