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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A4329C4740A for ; Tue, 10 Sep 2019 14:32:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B08521479 for ; Tue, 10 Sep 2019 14:32:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=kroah.com header.i=@kroah.com header.b="owh93KPM"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="KGOayJ6s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732771AbfIJOcr (ORCPT ); Tue, 10 Sep 2019 10:32:47 -0400 Received: from wout4-smtp.messagingengine.com ([64.147.123.20]:33441 "EHLO wout4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731630AbfIJOcr (ORCPT ); Tue, 10 Sep 2019 10:32:47 -0400 Received: from compute6.internal (compute6.nyi.internal [10.202.2.46]) by mailout.west.internal (Postfix) with ESMTP id 0CBCD49F; Tue, 10 Sep 2019 10:32:45 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute6.internal (MEProxy); Tue, 10 Sep 2019 10:32:46 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kroah.com; h= date:from:to:cc:subject:message-id:references:mime-version :content-type:in-reply-to; s=fm1; bh=+wxplw0ClvEAab2tmMcZITn+xly 4Zj9SPax4wW8MTSo=; b=owh93KPMm8nhZ33EL1kORO2mCAT9hvldORO0T1s6qHj ZHbwBvhRvHHnPnNSj7/Mg5RYwVeMpIXU07Yu0xyx7jJgMNinN9lRLrCv9UJh5cmb 66WIkTYAPVJBJePOZLjV7nP+FXvqZfIgwLUCtgdY+1t8KbS18tZL9cV2Dm6cJs6N KKroUVQP/doAwOFHinib/sUg3KVu2ScvHKHdAbhT0qa8r55oIlzhPn+JQApwE5CK 75i1rgR7G9sOeo0aAKpYwKs7bTCiH87WB2i2DypvNSkerEgZR2IzPtX/sb+0A7C2 VQsXZ6P+Q0AgM8zz55zFDvcoHKJ5xgBXuryXKsFGwHQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm3; bh=+wxplw 0ClvEAab2tmMcZITn+xly4Zj9SPax4wW8MTSo=; b=KGOayJ6s8mADctJuo1Yp9p 2++i8E96Gc7GsLD+gZkfFvJYhSQpfAkiChviD2S1PnNGRI38MzQtcue2Sh0vfXu0 vItrK4XFJygZHVahon8FiIQccMQgwOP63rQA8q/YAmU+9Pdw67bQChv1tZi6QkAt hyL+RGnysRVdxG9lzcjG0i9ETmKt8tiOL50XUAfkN1aGFExK0ikRGszC+9xz3yOF CR3IOdchGTgnVgOVwKeWv9bp8w7e2wp44LY9E8pdYsTAU27kr/7wGT88gRg6Udlo 8KageuMj3KHHHmRGVZd8nxHLANmDQVK2CO5Qyp+DOFHbnrKIZZczgBmRG6V3xWmQ == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedufedrtddtgdehhecutefuodetggdotefrodftvf curfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfghnecu uegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenuc fjughrpeffhffvuffkfhggtggujggfsehttdertddtredvnecuhfhrohhmpefirhgvghcu mffjuceoghhrvghgsehkrhhorghhrdgtohhmqeenucffohhmrghinhepkhgvrhhnvghlrd horhhgnecukfhppedvudefrdeftddrkedruddutdenucfrrghrrghmpehmrghilhhfrhho mhepghhrvghgsehkrhhorghhrdgtohhmnecuvehluhhsthgvrhfuihiivgeptd X-ME-Proxy: Received: from localhost (110.8.30.213.rev.vodafone.pt [213.30.8.110]) by mail.messagingengine.com (Postfix) with ESMTPA id 8BDB58005B; Tue, 10 Sep 2019 10:32:44 -0400 (EDT) Date: Tue, 10 Sep 2019 15:32:42 +0100 From: Greg KH To: Baolin Wang Cc: stable@vger.kernel.org, peterz@infradead.org, mingo@redhat.com, longman@redhat.com, arnd@arndb.de, orsonzhai@gmail.com, vincent.guittot@linaro.org, linux-kernel@vger.kernel.org Subject: Re: [BACKPORT 4.14.y v2 2/6] locking/lockdep: Add debug_locks check in __lock_downgrade() Message-ID: <20190910143242.GB3362@kroah.com> References: <7d3d221015cd343df47de4a68ed4776aca2ca0ab.1567649729.git.baolin.wang@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <7d3d221015cd343df47de4a68ed4776aca2ca0ab.1567649729.git.baolin.wang@linaro.org> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Thu, Sep 05, 2019 at 11:07:14AM +0800, Baolin Wang wrote: > From: Waiman Long > > [Upstream commit 513e1073d52e55b8024b4f238a48de7587c64ccf] > > Tetsuo Handa had reported he saw an incorrect "downgrading a read lock" > warning right after a previous lockdep warning. It is likely that the > previous warning turned off lock debugging causing the lockdep to have > inconsistency states leading to the lock downgrade warning. > > Fix that by add a check for debug_locks at the beginning of > __lock_downgrade(). > > Reported-by: Tetsuo Handa > Reported-by: syzbot+53383ae265fb161ef488@syzkaller.appspotmail.com > Signed-off-by: Waiman Long > Signed-off-by: Peter Zijlstra (Intel) > Cc: Andrew Morton > Cc: Linus Torvalds > Cc: Paul E. McKenney > Cc: Peter Zijlstra > Cc: Thomas Gleixner > Cc: Will Deacon > Link: https://lkml.kernel.org/r/1547093005-26085-1-git-send-email-longman@redhat.com > Signed-off-by: Ingo Molnar > Signed-off-by: Baolin Wang > --- > kernel/locking/lockdep.c | 3 +++ > 1 file changed, 3 insertions(+) Why isn't this relevant for 4.19.y? I can't add a patch to 4.14.y and then have someone upgrade to 4.19.y and not have the same fix in there, that would be a regression. So can you redo this series also with a 4.19.y set at the same so we don't get out of sync? I've queued up your first patch already as that was in 4.19.y (and also needed in 4.9.y). thanks, greg k-h