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=-9.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 20264C33CA2 for ; Fri, 10 Jan 2020 12:18:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E10732072A for ; Fri, 10 Jan 2020 12:18:44 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="AyJDmw1n" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728071AbgAJMSo (ORCPT ); Fri, 10 Jan 2020 07:18:44 -0500 Received: from mail-pl1-f194.google.com ([209.85.214.194]:35156 "EHLO mail-pl1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727720AbgAJMSn (ORCPT ); Fri, 10 Jan 2020 07:18:43 -0500 Received: by mail-pl1-f194.google.com with SMTP id g6so809792plt.2 for ; Fri, 10 Jan 2020 04:18:43 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=34rCBCNBrLFlE6OZuubd6Z6OlOWhV0HGucVsYoePbqA=; b=AyJDmw1nfTmU38bLxh+Zgeu6ZVenlE9iZh5wgKN+xTCCcVbRXd9o/heLIU/pN6gucy +x5Tsci0dO8ZhS0dQsBFg5t6DZIgfpU5hJ3dQgkh4Hr0FvQ3c1MCVSdIux67XzFt1JAN swqPk6+jTakkB2XfeIbBenGxQxjLc+3Vu0tDUnHnT0MFTrjWU9bMvxEumVbT2V0IH2k3 NKMn8E3yiX+w12LiWcL2SWzxnYU4T0LCidiwLYIKi9lxQzBvfqDxICtapnipP+9jxEuS TohB1N+FcisEX8rLBfH9FIqKIemfV8QvJoxW17SQIC8NKLfxpFYpoySyD9/uqs5nLHRv HPEQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=34rCBCNBrLFlE6OZuubd6Z6OlOWhV0HGucVsYoePbqA=; b=BKxksYhafmuwAt+6GT/rmpEJx04lLTeC5faIBmblfZMX4RDbQwLJcs+4EtgnElSJ3Y 4aX3y2nkj6rtkqaeVLHOnKn2Ouhq1/xLAqH2twIFfjBr48ZI6Wl30vNSTDdNshUVr2PY idFO6deBjUQNDJvEoIywwTAVOldtNykdBQl7raR28M9SNgAkUJZWThPcROJIzhp8fDnk lMsV8xttLTHCzZUpNo7U7GkHmt/4FyYgc6ZYB+aabm0L6uxSEZWjUqHKTtKwoMYwV73H 2mkD2K8Mqw72fCt4fmaGsKl3jTLaithVN45esKjct3xLxYbRzurNXa1ri6amM12bJoC9 VbDQ== X-Gm-Message-State: APjAAAXKuXjE0t++QjOjjwIotzjK89t/mTqAcORRAI/FXEtt0LhH2+UH QFxRSulqsTPpg7QN7vQXGuc= X-Google-Smtp-Source: APXvYqwC+PRY9JeuUX6ytka2wfVtRm/TMSWCLgftycjUZOj9TUHFQKY/Dli2kVHoe5tJT3gd4K9HVw== X-Received: by 2002:a17:90a:10c8:: with SMTP id b8mr4336581pje.92.1578658722987; Fri, 10 Jan 2020 04:18:42 -0800 (PST) Received: from localhost.localdomain ([103.211.17.220]) by smtp.googlemail.com with ESMTPSA id m128sm2774523pfm.183.2020.01.10.04.18.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 10 Jan 2020 04:18:42 -0800 (PST) From: Amol Grover To: Corey Minyard , Arnd Bergmann , Greg Kroah-Hartman Cc: openipmi-developer@lists.sourceforge.net, linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, Joel Fernandes , Madhuparna Bhowmik , "Paul E . McKenney" , Amol Grover Subject: [PATCH] drivers: char: ipmi: ipmi_msghandler: Pass lockdep expression to RCU lists Date: Fri, 10 Jan 2020 17:43:42 +0530 Message-Id: <20200110121341.31522-1-frextrite@gmail.com> X-Mailer: git-send-email 2.24.1 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 intf->cmd_rcvrs is traversed with list_for_each_entry_rcu outside an RCU read-side critical section but under the protection of intf->cmd_rcvrs_mutex. ipmi_interfaces is traversed using list_for_each_entry_rcu outside an RCU read-side critical section but under the protection of ipmi_interfaces_mutex. Hence, add the corresponding lockdep expression to the list traversal primitive to silence false-positive lockdep warnings, and harden RCU lists. Add macro for the corresponding lockdep expression to make the code clean and concise. Signed-off-by: Amol Grover --- drivers/char/ipmi/ipmi_msghandler.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index cad9563f8f48..7eff0335bc82 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -35,6 +35,8 @@ #include #define IPMI_DRIVER_VERSION "39.2" +#define cmd_rcvrs_mutex_held() \ + lockdep_is_held(&intf->cmd_rcvrs_mutex) static struct ipmi_recv_msg *ipmi_alloc_recv_msg(void); static int ipmi_init_msghandler(void); @@ -618,6 +620,8 @@ static DEFINE_MUTEX(ipmidriver_mutex); static LIST_HEAD(ipmi_interfaces); static DEFINE_MUTEX(ipmi_interfaces_mutex); +#define ipmi_interfaces_mutex_held() \ + lockdep_is_held(&ipmi_interfaces_mutex) static struct srcu_struct ipmi_interfaces_srcu; /* @@ -1321,7 +1325,8 @@ static void _ipmi_destroy_user(struct ipmi_user *user) * synchronize_srcu()) then free everything in that list. */ mutex_lock(&intf->cmd_rcvrs_mutex); - list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) { + list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link, + cmd_rcvrs_mutex_held()) { if (rcvr->user == user) { list_del_rcu(&rcvr->link); rcvr->next = rcvrs; @@ -1599,7 +1604,8 @@ static struct cmd_rcvr *find_cmd_rcvr(struct ipmi_smi *intf, { struct cmd_rcvr *rcvr; - list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) { + list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link, + rcu_read_lock_held() || cmd_rcvrs_mutex_held()) { if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd) && (rcvr->chans & (1 << chan))) return rcvr; @@ -1614,7 +1620,8 @@ static int is_cmd_rcvr_exclusive(struct ipmi_smi *intf, { struct cmd_rcvr *rcvr; - list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link) { + list_for_each_entry_rcu(rcvr, &intf->cmd_rcvrs, link, + cmd_rcvrs_mutex_held()) { if ((rcvr->netfn == netfn) && (rcvr->cmd == cmd) && (rcvr->chans & chans)) return 0; @@ -3450,7 +3457,8 @@ int ipmi_add_smi(struct module *owner, /* Look for a hole in the numbers. */ i = 0; link = &ipmi_interfaces; - list_for_each_entry_rcu(tintf, &ipmi_interfaces, link) { + list_for_each_entry_rcu(tintf, &ipmi_interfaces, link, + ipmi_interfaces_mutex_held()) { if (tintf->intf_num != i) { link = &tintf->link; break; -- 2.24.1