From patchwork Tue Jul 24 08:45:08 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Huaisheng Ye X-Patchwork-Id: 10541675 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8B7B790E3 for ; Tue, 24 Jul 2018 08:46:10 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 78DE028787 for ; Tue, 24 Jul 2018 08:46:10 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 6CE862878F; Tue, 24 Jul 2018 08:46:10 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, FREEMAIL_FROM,MAILING_LIST_MULTI,RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from ml01.01.org (ml01.01.org [198.145.21.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 29F142879B for ; Tue, 24 Jul 2018 08:46:10 +0000 (UTC) Received: from [127.0.0.1] (localhost [IPv6:::1]) by ml01.01.org (Postfix) with ESMTP id 2216F210C125F; Tue, 24 Jul 2018 01:46:10 -0700 (PDT) X-Original-To: linux-nvdimm@lists.01.org Delivered-To: linux-nvdimm@lists.01.org Received-SPF: Pass (sender SPF authorized) identity=mailfrom; client-ip=135.84.80.237; helo=sender-pp-092.zoho.com; envelope-from=yehs2007@zoho.com; receiver=linux-nvdimm@lists.01.org Received: from sender-pp-092.zoho.com (sender-pp-092.zoho.com [135.84.80.237]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id 19FE5210C1251 for ; Tue, 24 Jul 2018 01:46:09 -0700 (PDT) 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 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 X-BeenThere: linux-nvdimm@lists.01.org X-Mailman-Version: 2.1.27 Precedence: list List-Id: "Linux-nvdimm developer list." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: axboe@kernel.dk, linux-s390@vger.kernel.org, chengnt@lenovo.com, linux-fsdevel@vger.kernel.org, heiko.carstens@de.ibm.com, linux-kernel@vger.kernel.org, willy@infradead.org, bart.vanassche@wdc.com, viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org, schwidefsky@de.ibm.com, jack@suse.cz MIME-Version: 1.0 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" X-Virus-Scanned: ClamAV using ClamSMTP 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);