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[2620:137:e000::3:8]) by mx.google.com with ESMTPS id bw26-20020a056a00409a00b0068fe810e8a2si13999863pfb.185.2023.10.12.02.47.12 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 12 Oct 2023 02:47:12 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) client-ip=2620:137:e000::3:8; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:8 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=huawei.com Received: from out1.vger.email (depot.vger.email [IPv6:2620:137:e000::3:0]) by fry.vger.email (Postfix) with ESMTP id 426A581DDD52; Thu, 12 Oct 2023 02:47:08 -0700 (PDT) X-Virus-Status: Clean X-Virus-Scanned: clamav-milter 0.103.10 at fry.vger.email Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235611AbjJLJqi (ORCPT + 99 others); Thu, 12 Oct 2023 05:46:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53620 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234030AbjJLJqf (ORCPT ); Thu, 12 Oct 2023 05:46:35 -0400 Received: from szxga01-in.huawei.com (szxga01-in.huawei.com [45.249.212.187]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1ED5BA9 for ; Thu, 12 Oct 2023 02:46:32 -0700 (PDT) Received: from dggpeml500002.china.huawei.com (unknown [172.30.72.54]) by szxga01-in.huawei.com (SkyGuard) with ESMTP id 4S5l8C3V6PzrT8v; Thu, 12 Oct 2023 17:43:55 +0800 (CST) Received: from localhost.localdomain (10.69.192.56) by dggpeml500002.china.huawei.com (7.185.36.158) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.31; Thu, 12 Oct 2023 17:46:30 +0800 From: Junhao He To: , CC: , , , , , , , Subject: [PATCH 2/3] coresight: ultrasoc-smb: simplify the code for check to_copy valid Date: Thu, 12 Oct 2023 17:47:05 +0800 Message-ID: <20231012094706.21565-3-hejunhao3@huawei.com> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20231012094706.21565-1-hejunhao3@huawei.com> References: <20231012094706.21565-1-hejunhao3@huawei.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Content-Type: text/plain; charset=US-ASCII X-Originating-IP: [10.69.192.56] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To dggpeml500002.china.huawei.com (7.185.36.158) X-CFilter-Loop: Reflected X-Spam-Status: No, score=-0.8 required=5.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on fry.vger.email Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-Greylist: Sender passed SPF test, not delayed by milter-greylist-4.6.4 (fry.vger.email [0.0.0.0]); Thu, 12 Oct 2023 02:47:08 -0700 (PDT) We only need to check once when before using the to_copy variable to simplify the code. Signed-off-by: Junhao He --- drivers/hwtracing/coresight/ultrasoc-smb.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/hwtracing/coresight/ultrasoc-smb.c b/drivers/hwtracing/coresight/ultrasoc-smb.c index b08a619d1116..e78edc3480ce 100644 --- a/drivers/hwtracing/coresight/ultrasoc-smb.c +++ b/drivers/hwtracing/coresight/ultrasoc-smb.c @@ -127,20 +127,15 @@ static ssize_t smb_read(struct file *file, char __user *data, size_t len, struct smb_drv_data, miscdev); struct smb_data_buffer *sdb = &drvdata->sdb; struct device *dev = &drvdata->csdev->dev; - ssize_t to_copy = 0; - - if (!len) - return 0; - - if (!sdb->data_size) - return 0; - - to_copy = min(sdb->data_size, len); + ssize_t to_copy = min(sdb->data_size, len); /* Copy parts of trace data when read pointer wrap around SMB buffer */ if (sdb->buf_rdptr + to_copy > sdb->buf_size) to_copy = sdb->buf_size - sdb->buf_rdptr; + if (!to_copy) + return 0; + if (copy_to_user(data, sdb->buf_base + sdb->buf_rdptr, to_copy)) { dev_dbg(dev, "Failed to copy data to user\n"); return -EFAULT; -- 2.33.0