From patchwork Thu Apr 30 08:39:43 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hanjun Guo X-Patchwork-Id: 11519521 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 38C7992C for ; Thu, 30 Apr 2020 08:46:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 21D5D20838 for ; Thu, 30 Apr 2020 08:46:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727094AbgD3Iqb (ORCPT ); Thu, 30 Apr 2020 04:46:31 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:3395 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726766AbgD3Iqb (ORCPT ); Thu, 30 Apr 2020 04:46:31 -0400 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 557EB5F83E79386DA22A; Thu, 30 Apr 2020 16:46:20 +0800 (CST) Received: from linux-ibm.site (10.175.102.37) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.487.0; Thu, 30 Apr 2020 16:46:11 +0800 From: Hanjun Guo To: "Rafael J. Wysocki" , Daniel Lezcano , Doug Smythies CC: , Jonathan Corbet , Hanjun Guo Subject: [RFC v2 PATCH 2/6] cpuidle: sysfs: Accept governor name with 15 characters Date: Thu, 30 Apr 2020 16:39:43 +0800 Message-ID: <1588235987-12300-3-git-send-email-guohanjun@huawei.com> X-Mailer: git-send-email 1.7.12.4 In-Reply-To: <1588235987-12300-1-git-send-email-guohanjun@huawei.com> References: <1588235987-12300-1-git-send-email-guohanjun@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.102.37] X-CFilter-Loop: Reflected Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org CPUIDLE_NAME_LEN is 16, so it's possible to accept governor name with 15 characters, but now store_current_governor() rejects governor name with 15 characters as it returns -EINVAL if count equals CPUIDLE_NAME_LEN. Refactor the code to accept such case and simplify the code. Signed-off-by: Hanjun Guo --- drivers/cpuidle/sysfs.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/drivers/cpuidle/sysfs.c b/drivers/cpuidle/sysfs.c index 3485210..af5a65f 100644 --- a/drivers/cpuidle/sysfs.c +++ b/drivers/cpuidle/sysfs.c @@ -85,34 +85,25 @@ static ssize_t store_current_governor(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { - char gov_name[CPUIDLE_NAME_LEN]; - int ret = -EINVAL; - size_t len = count; + char gov_name[CPUIDLE_NAME_LEN + 1]; + int ret; struct cpuidle_governor *gov; - if (!len || len >= sizeof(gov_name)) + ret = sscanf(buf, "%" __stringify(CPUIDLE_NAME_LEN) "s", gov_name); + if (ret != 1) return -EINVAL; - memcpy(gov_name, buf, len); - gov_name[len] = '\0'; - if (gov_name[len - 1] == '\n') - gov_name[--len] = '\0'; - mutex_lock(&cpuidle_lock); - + ret = -EINVAL; list_for_each_entry(gov, &cpuidle_governors, governor_list) { - if (strlen(gov->name) == len && !strcmp(gov->name, gov_name)) { + if (!strncmp(gov->name, gov_name, CPUIDLE_NAME_LEN)) { ret = cpuidle_switch_governor(gov); break; } } - mutex_unlock(&cpuidle_lock); - if (ret) - return ret; - else - return count; + return ret ? ret : count; } static DEVICE_ATTR(current_driver, 0444, show_current_driver, NULL);