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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,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 89466C433E0 for ; Sat, 16 May 2020 18:29:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 73B3A207C4 for ; Sat, 16 May 2020 18:29:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726718AbgEPS3a (ORCPT ); Sat, 16 May 2020 14:29:30 -0400 Received: from mga05.intel.com ([192.55.52.43]:56285 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726298AbgEPS3X (ORCPT ); Sat, 16 May 2020 14:29:23 -0400 IronPort-SDR: TfY2BZCu06WlrN0Ey/UH/24aXYdrDOoWG064xZFZ79eIrDdOvky63XJOMgpCz+WYYue/JllW7c jCbnCf6H11iA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 May 2020 11:29:20 -0700 IronPort-SDR: MzVdcs248i3MjTjkHHeBODWbsp/ohHaSFgOKTXHnytAbE8rkyOilMYMQhn6jxTB7Ul/+eFihfw hCmnew2PG4/A== X-IronPort-AV: E=Sophos;i="5.73,400,1583222400"; d="scan'208";a="281563333" Received: from rchatre-s.jf.intel.com ([10.54.70.76]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 May 2020 11:29:19 -0700 From: Reinette Chatre To: tglx@linutronix.de, fenghua.yu@intel.com, bp@alien8.de, tony.luck@intel.com Cc: kuo-lang.tseng@intel.com, ravi.v.shankar@intel.com, mingo@redhat.com, babu.moger@amd.com, hpa@zytor.com, x86@kernel.org, linux-kernel@vger.kernel.org, Reinette Chatre , Andy Shevchenko Subject: [PATCH V4 4/4] x86/resctrl: Use appropriate API for strings terminated by newline Date: Sat, 16 May 2020 11:28:41 -0700 Message-Id: <0c04b58148f181ba182b9a487465e4853e4eadbb.1589652468.git.reinette.chatre@intel.com> X-Mailer: git-send-email 2.21.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The user input to files in the resctrl filesystem are expected to be terminated with a newline. Testing the user input includes a test for the presence of a newline and then replacing the newline with NUL byte followed by comparison using strcmp(). sysfs_streq() exists to test if strings are equal, treating both NUL and newline-then-NUL as equivalent string terminations. Even more, sysfs_match_string() exists to match a given string in an array using sysfs_streq(). Replace existing strcmp() comparisons of strings that are terminated with a newline with more appropriate sysfs_streq() via the sysfs_match_string() API that can perform the match across the different mode strings that are already maintained in an array. Suggested-by: Andy Shevchenko Signed-off-by: Reinette Chatre --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 32 ++++++++++++++------------ 1 file changed, 17 insertions(+), 15 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index 088a1536bccc..0e302d3c44e6 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -1415,12 +1415,11 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, { struct rdtgroup *rdtgrp; enum rdtgrp_mode mode; - int ret = 0; + int user_m; + int ret; - /* Valid input requires a trailing newline */ - if (nbytes == 0 || buf[nbytes - 1] != '\n') + if (nbytes == 0) return -EINVAL; - buf[nbytes - 1] = '\0'; rdtgrp = rdtgroup_kn_lock_live(of->kn); if (!rdtgrp) { @@ -1432,11 +1431,17 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, mode = rdtgrp->mode; - if ((!strcmp(buf, "shareable") && mode == RDT_MODE_SHAREABLE) || - (!strcmp(buf, "exclusive") && mode == RDT_MODE_EXCLUSIVE) || - (!strcmp(buf, "pseudo-locksetup") && - mode == RDT_MODE_PSEUDO_LOCKSETUP) || - (!strcmp(buf, "pseudo-locked") && mode == RDT_MODE_PSEUDO_LOCKED)) + ret = sysfs_match_string(rdt_mode_str, buf); + if (ret < 0) { + rdt_last_cmd_puts("Unknown or unsupported mode\n"); + goto out; + } + + user_m = ret; + ret = 0; + + /* Do nothing and return success if user asks for current mode */ + if (user_m == mode) goto out; if (mode == RDT_MODE_PSEUDO_LOCKED) { @@ -1445,14 +1450,14 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, goto out; } - if (!strcmp(buf, "shareable")) { + if (user_m == RDT_MODE_SHAREABLE) { if (rdtgrp->mode == RDT_MODE_PSEUDO_LOCKSETUP) { ret = rdtgroup_locksetup_exit(rdtgrp); if (ret) goto out; } rdtgrp->mode = RDT_MODE_SHAREABLE; - } else if (!strcmp(buf, "exclusive")) { + } else if (user_m == RDT_MODE_EXCLUSIVE) { if (!rdtgroup_mode_test_exclusive(rdtgrp)) { ret = -EINVAL; goto out; @@ -1463,14 +1468,11 @@ static ssize_t rdtgroup_mode_write(struct kernfs_open_file *of, goto out; } rdtgrp->mode = RDT_MODE_EXCLUSIVE; - } else if (!strcmp(buf, "pseudo-locksetup")) { + } else if (user_m == RDT_MODE_PSEUDO_LOCKSETUP) { ret = rdtgroup_locksetup_enter(rdtgrp); if (ret) goto out; rdtgrp->mode = RDT_MODE_PSEUDO_LOCKSETUP; - } else { - rdt_last_cmd_puts("Unknown or unsupported mode\n"); - ret = -EINVAL; } out: -- 2.21.0