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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 6FCE1C10F0E for ; Mon, 15 Apr 2019 17:05:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 48EA02075B for ; Mon, 15 Apr 2019 17:05:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727744AbfDORFu (ORCPT ); Mon, 15 Apr 2019 13:05:50 -0400 Received: from mail-pf1-f193.google.com ([209.85.210.193]:36033 "EHLO mail-pf1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725798AbfDORFt (ORCPT ); Mon, 15 Apr 2019 13:05:49 -0400 Received: by mail-pf1-f193.google.com with SMTP id z5so8915501pfn.3 for ; Mon, 15 Apr 2019 10:05:49 -0700 (PDT) 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=PqPF6cVkRaWxPUG61WHSdVmGRxrRtg3EbV3y1hjxGxY=; b=L6odk70cd+d/crDQqWpCdMIwXMYynjsRXxSjvuPHxR+uUSYS8l6iTzI4bkTyzKwoZs oo+0BuCnDqCjyZSvnC/Tpx/46v9KOTPNO2lqy5qcoOgiXJA+Oc2J92IaozLKCctqodqO wHHXTRbBrwddkhcCgt4zzN+micrhBkwrsZ6DHq5wtHpcQBKzKVl0kGQGUtlecHfaowZh j+uwvBBhiZa3+pxrSJL6V5cskZU3PbbKHk8XDkNBkFZOL4Ib+CF2d7qpcXBsuctiebcn ydGdKeWn88lwkd2j3VxAIPAVaD9LNIOwvuKu6tEkJdWqwmNzzjYZmyzdOLV4U2FbA/DK 0CHQ== X-Gm-Message-State: APjAAAUuhGc9gbhLMrdo+YRMIo+7dXbgafeNFJ1uzJgTyG3U23xnsPmT 7DMVMlzX1ishv977HA1XtqwgB5A616U= X-Google-Smtp-Source: APXvYqyiMPe7Joju60HTakSRAr8rfO81BjzaMzBkFcsoMFDxTo4SW02kpskOLDLn4N28rsa04QOr/A== X-Received: by 2002:a63:360c:: with SMTP id d12mr67685333pga.404.1555347948914; Mon, 15 Apr 2019 10:05:48 -0700 (PDT) Received: from desktop-bart.svl.corp.google.com ([2620:15c:2cd:203:5cdc:422c:7b28:ebb5]) by smtp.gmail.com with ESMTPSA id j19sm61312568pfh.41.2019.04.15.10.05.47 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 15 Apr 2019 10:05:47 -0700 (PDT) From: Bart Van Assche To: Peter Zijlstra Cc: Ingo Molnar , Thomas Gleixner , linux-kernel@vger.kernel.org, Bart Van Assche , Will Deacon , Waiman Long , shenghui Subject: [PATCH] locking/lockdep: Make lockdep_unregister_key() honor 'debug_locks' again Date: Mon, 15 Apr 2019 10:05:38 -0700 Message-Id: <20190415170538.23491-1-bvanassche@acm.org> X-Mailer: git-send-email 2.20.GIT 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 If lockdep_register_key() and lockdep_unregister_key() are called with debug_locks == false then the following warning is reported: WARNING: CPU: 2 PID: 15145 at kernel/locking/lockdep.c:4920 lockdep_unregister_key+0x1ad/0x240 That warning is reported because lockdep_unregister_key() ignores the value of 'debug_locks' and because the behavior of lockdep_register_key() depends on whether or not 'debug_locks' is set. Fix this inconsistency by making lockdep_unregister_key() take 'debug_locks' again into account. Cc: Thomas Gleixner Cc: Will Deacon Cc: Waiman Long Cc: shenghui Fixes: 90c1cba2b3b3 ("locking/lockdep: Zap lock classes even with lock debugging disabled") Signed-off-by: Bart Van Assche --- kernel/locking/lockdep.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index e16766ff184b..e221be724fe8 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -4907,8 +4907,9 @@ void lockdep_unregister_key(struct lock_class_key *key) return; raw_local_irq_save(flags); - arch_spin_lock(&lockdep_lock); - current->lockdep_recursion = 1; + if (!graph_lock()) + goto out_irq; + pf = get_pending_free(); hlist_for_each_entry_rcu(k, hash_head, hash_entry) { if (k == key) { @@ -4920,8 +4921,8 @@ void lockdep_unregister_key(struct lock_class_key *key) WARN_ON_ONCE(!found); __lockdep_free_key_range(pf, key, 1); call_rcu_zapped(pf); - current->lockdep_recursion = 0; - arch_spin_unlock(&lockdep_lock); + graph_unlock(); +out_irq: raw_local_irq_restore(flags); /* Wait until is_dynamic_key() has finished accessing k->hash_entry. */ -- 2.21.0.196.g041f5ea1cf98