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=-9.7 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 33199C5DF63 for ; Wed, 6 Nov 2019 22:04:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F3D06217D7 for ; Wed, 6 Nov 2019 22:04:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732472AbfKFWEK (ORCPT ); Wed, 6 Nov 2019 17:04:10 -0500 Received: from mga12.intel.com ([192.55.52.136]:17526 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726912AbfKFWEK (ORCPT ); Wed, 6 Nov 2019 17:04:10 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 06 Nov 2019 14:04:10 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,275,1569308400"; d="scan'208";a="205969023" Received: from xshen14-linux.bj.intel.com ([10.238.155.105]) by orsmga006.jf.intel.com with ESMTP; 06 Nov 2019 14:04:07 -0800 From: Xiaochen Shen To: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, hpa@zytor.com, tony.luck@intel.com, fenghua.yu@intel.com, reinette.chatre@intel.com Cc: x86@kernel.org, linux-kernel@vger.kernel.org, pei.p.jia@intel.com, xiaochen.shen@intel.com Subject: [PATCH] x86/resctrl: Fix potential lockdep warning Date: Thu, 7 Nov 2019 06:36:36 +0800 Message-Id: <1573079796-11713-1-git-send-email-xiaochen.shen@intel.com> X-Mailer: git-send-email 1.8.3.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org rdtgroup_cpus_write() and mkdir_rdt_prepare() call rdtgroup_kn_lock_live() -> kernfs_to_rdtgroup() to get 'rdtgrp', and then call rdt_last_cmd_xxx() functions which will check if rdtgroup_mutex is held/requires its caller to hold rdtgroup_mutex. But if 'rdtgrp' returned from kernfs_to_rdtgroup() is NULL, rdtgroup_mutex is not held and calling rdt_last_cmd_xxx() will result in a lockdep warning. Remove rdt_last_cmd_xxx() in these two paths. Just returning error should be sufficient to report to the user that the entry doesn't exist any more. Fixes: 94457b36e8a5 ("x86/intel_rdt: Add diagnostics when writing the cpus file") Fixes: cfd0f34e4cd5 ("x86/intel_rdt: Add diagnostics when making directories") Signed-off-by: Xiaochen Shen Reviewed-by: Tony Luck Reviewed-by: Fenghua Yu Reviewed-by: Reinette Chatre --- arch/x86/kernel/cpu/resctrl/rdtgroup.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c index a46dee8e78db..2e3b06d6bbc6 100644 --- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c +++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c @@ -461,10 +461,8 @@ static ssize_t rdtgroup_cpus_write(struct kernfs_open_file *of, } rdtgrp = rdtgroup_kn_lock_live(of->kn); - rdt_last_cmd_clear(); if (!rdtgrp) { ret = -ENOENT; - rdt_last_cmd_puts("Directory was removed\n"); goto unlock; } @@ -2648,10 +2646,8 @@ static int mkdir_rdt_prepare(struct kernfs_node *parent_kn, int ret; prdtgrp = rdtgroup_kn_lock_live(prgrp_kn); - rdt_last_cmd_clear(); if (!prdtgrp) { ret = -ENODEV; - rdt_last_cmd_puts("Directory was removed\n"); goto out_unlock; } -- 1.8.3.1