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 12FD3C2D0CE for ; Tue, 21 Jan 2020 13:12:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DA7C421569 for ; Tue, 21 Jan 2020 13:12:28 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Z8J8xUgv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728803AbgAUNM2 (ORCPT ); Tue, 21 Jan 2020 08:12:28 -0500 Received: from mail-pj1-f66.google.com ([209.85.216.66]:54590 "EHLO mail-pj1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725890AbgAUNM1 (ORCPT ); Tue, 21 Jan 2020 08:12:27 -0500 Received: by mail-pj1-f66.google.com with SMTP id kx11so1347618pjb.4 for ; Tue, 21 Jan 2020 05:12:27 -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=mV1qixM+hRHgqOUWXlliAy9s0rAvz7UfT2PUrmz0Bbg=; b=Z8J8xUgv8y94kuhtX71q1/CgB8A/sNC1KYd1fA4XQ8dsGsaiP8ZgINBuCPnzRg4jHV CderUAy51B78k5hydIFo8YC5g4HekpmRgr3HyEQaYAgvf6qtS8Aji3Xgdw3dAdkh7Lu9 rbyrLtr0sphBHAJXTzNAIU/PPtgvQu1s9enlYvGdqLY7A+118uke39A8zjn1l+gy0Csu u1H7QAonjdPZPsxVEQjA9Cq5C0irlKLA3lGcMYyt7ZKo4oSVRQtsag//IGj7nJHYLaXg C5a0GPYzOBtZkQzlXuV2WhmR17axvDCbDCM8N3tX/9uSQmdOy+L85hYnf/5L1kItG67Y FSEQ== 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=mV1qixM+hRHgqOUWXlliAy9s0rAvz7UfT2PUrmz0Bbg=; b=S7TZl+bSRqBCDdkD3T8Whu9ZJ4Jodhn766uy5uVlBSA03AdnJh9sgcx0iXozc+3AZZ W6FjJbhUZoxjLMV4RDJ+qlZyXi3iNSCS3A2wlBPEd/b2mRrerJLGF6l1t9b+4YAmH/Ks TxjXTd8SyuFZdGbD+kSldNjhTYT8jXoLZoCEd1U9jAK2ZXiHCZ+rxOegJ+w//oUCxiqM yTOotlQ+7wVPnEyhVNaQoQrssYI4sjfCj1H+pS56z0EIijDMbfCu+jLYm8xyJB4N6Daa 1z1rkaRuYFltcHQ7H8nbSx/MezyUL9O0mtbIou9gfSwyhuBJbN4+ldoNv6p9boSEsquy 6/hA== X-Gm-Message-State: APjAAAWmSSiGPMkLHd/bSONqQs+r6HZpmrOZ2zXxwvW8/CGWCPRIRXFQ fE9jqEBf1THdj9U9QjYwkI8= X-Google-Smtp-Source: APXvYqyEZrfngkxRMK2d39FAOYp9BghixyVDEshJdO27mt1aBls2Y29kbpl7VvmR8iQqVYQg2VnG/Q== X-Received: by 2002:a17:90a:1697:: with SMTP id o23mr5418876pja.62.1579612347118; Tue, 21 Jan 2020 05:12:27 -0800 (PST) Received: from localhost.localdomain ([146.196.37.201]) by smtp.googlemail.com with ESMTPSA id i8sm44027333pfa.109.2020.01.21.05.12.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 21 Jan 2020 05:12:26 -0800 (PST) From: Amol Grover To: Thomas Gleixner Cc: linux-kernel@vger.kernel.org, linux-kernel-mentees@lists.linuxfoundation.org, Joel Fernandes , Madhuparna Bhowmik , "Paul E . McKenney" , Amol Grover Subject: [PATCH] kernel: time: posix-timers: Pass lockdep expression to RCU lists Date: Tue, 21 Jan 2020 18:41:33 +0530 Message-Id: <20200121131132.15830-1-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 head is traversed using hlist_for_each_entry_rcu outside an RCU read-side critical section but under the protection of hash_lock. Hence, add corresponding lockdep expression to silence false-positive lockdep warnings, and harden RCU lists. Add macro for the corresponding lockdep expression. Signed-off-by: Amol Grover --- kernel/time/posix-timers.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 0ec5b7a1d769..2ccce00af177 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -50,6 +50,8 @@ static struct kmem_cache *posix_timers_cache; static DEFINE_HASHTABLE(posix_timers_hashtable, 9); static DEFINE_SPINLOCK(hash_lock); +#define hash_lock_held() \ + lockdep_is_held(&hash_lock) static const struct k_clock * const posix_clocks[]; static const struct k_clock *clockid_to_kclock(const clockid_t id); @@ -120,7 +122,7 @@ static struct k_itimer *__posix_timers_find(struct hlist_head *head, { struct k_itimer *timer; - hlist_for_each_entry_rcu(timer, head, t_hash) { + hlist_for_each_entry_rcu(timer, head, t_hash, hash_lock_held()) { if ((timer->it_signal == sig) && (timer->it_id == id)) return timer; } -- 2.24.1