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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 77F3FC7EE23 for ; Sun, 11 Jun 2023 13:12:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233630AbjFKNMp (ORCPT ); Sun, 11 Jun 2023 09:12:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55278 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232910AbjFKNMo (ORCPT ); Sun, 11 Jun 2023 09:12:44 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8BC259F for ; Sun, 11 Jun 2023 06:12:43 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 1FAF761087 for ; Sun, 11 Jun 2023 13:12:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0EE21C433EF; Sun, 11 Jun 2023 13:12:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1686489162; bh=STNAJtrjagubnl0A10nnDXRy2p1RvWWdnMKqRNWJTFY=; h=Subject:To:Cc:From:Date:From; b=f5/fiQ1fKxTvbSp5I5+DrgRTQBgjzqAQJy3ynWl8UbgN2e/ci6+UhmMDJ8+YIl41n mVI+eqrJIjRPrKMhz92XMYGkVQynW74+vJBLQdMs9ZY/xE0cyn9VQf6/tIylag71nA 6Jp8V+55vFir6Qb1+ZOn1tZkLsIdjKJDY6NEKG3Y= Subject: FAILED: patch "[PATCH] cgroup: fix missing cpus_read_{lock,unlock}() in" failed to apply to 6.3-stable tree To: zhengqi.arch@bytedance.com, songmuchun@bytedance.com, tj@kernel.org, zhaogongyi@bytedance.com Cc: From: Date: Sun, 11 Jun 2023 15:12:33 +0200 Message-ID: <2023061132-curator-unbent-d3ad@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.3-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.3.y git checkout FETCH_HEAD git cherry-pick -x ab1de7ead871ebe6d12a774c3c25de0388cde082 # git commit -s git send-email --to '' --in-reply-to '2023061132-curator-unbent-d3ad@gregkh' --subject-prefix 'PATCH 6.3.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From ab1de7ead871ebe6d12a774c3c25de0388cde082 Mon Sep 17 00:00:00 2001 From: Qi Zheng Date: Wed, 17 May 2023 07:45:45 +0000 Subject: [PATCH] cgroup: fix missing cpus_read_{lock,unlock}() in cgroup_transfer_tasks() The commit 4f7e7236435c ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock") fixed the deadlock between cgroup_threadgroup_rwsem and cpus_read_lock() by introducing cgroup_attach_{lock,unlock}() and removing cpus_read_{lock,unlock}() from cpuset_attach(). But cgroup_transfer_tasks() was missed and not handled, which will cause th following warning: WARNING: CPU: 0 PID: 589 at kernel/cpu.c:526 lockdep_assert_cpus_held+0x32/0x40 CPU: 0 PID: 589 Comm: kworker/1:4 Not tainted 6.4.0-rc2-next-20230517 #50 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: events cpuset_hotplug_workfn RIP: 0010:lockdep_assert_cpus_held+0x32/0x40 <...> Call Trace: cpuset_attach+0x40/0x240 cgroup_migrate_execute+0x452/0x5e0 ? _raw_spin_unlock_irq+0x28/0x40 cgroup_transfer_tasks+0x1f3/0x360 ? find_held_lock+0x32/0x90 ? cpuset_hotplug_workfn+0xc81/0xed0 cpuset_hotplug_workfn+0xcb1/0xed0 ? process_one_work+0x248/0x5b0 process_one_work+0x2b9/0x5b0 worker_thread+0x56/0x3b0 ? process_one_work+0x5b0/0x5b0 kthread+0xf1/0x120 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 So just use the cgroup_attach_{lock,unlock}() helper to fix it. Reported-by: Zhao Gongyi Signed-off-by: Qi Zheng Acked-by: Muchun Song Fixes: 05c7b7a92cc8 ("cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug") Cc: stable@vger.kernel.org # v5.17+ Signed-off-by: Tejun Heo diff --git a/kernel/cgroup/cgroup-v1.c b/kernel/cgroup/cgroup-v1.c index aeef06c465ef..5407241dbb45 100644 --- a/kernel/cgroup/cgroup-v1.c +++ b/kernel/cgroup/cgroup-v1.c @@ -108,7 +108,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) cgroup_lock(); - percpu_down_write(&cgroup_threadgroup_rwsem); + cgroup_attach_lock(true); /* all tasks in @from are being moved, all csets are source */ spin_lock_irq(&css_set_lock); @@ -144,7 +144,7 @@ int cgroup_transfer_tasks(struct cgroup *to, struct cgroup *from) } while (task && !ret); out_err: cgroup_migrate_finish(&mgctx); - percpu_up_write(&cgroup_threadgroup_rwsem); + cgroup_attach_unlock(true); cgroup_unlock(); return ret; }