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 94BDAC001E0 for ; Sat, 12 Aug 2023 22:06:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230315AbjHLWGR (ORCPT ); Sat, 12 Aug 2023 18:06:17 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35724 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231182AbjHLWF6 (ORCPT ); Sat, 12 Aug 2023 18:05:58 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 091AF9F for ; Sat, 12 Aug 2023 15:06:01 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9C141620D7 for ; Sat, 12 Aug 2023 22:06:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id F04CEC433C7; Sat, 12 Aug 2023 22:05:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1691877960; bh=XEW8EhTz3Dv6oDtQOGDOcQzMmsEWiYw1bsoIs/YUbOY=; h=Date:To:From:Subject:From; b=YOV8zKv3bXqrX6gHh9Gg3hEznnF2t2KxaON77813UrnNEviL1pUNXGu49dDVtv6/g MFCC+Oaxm/3UkDyLoMtx8jjuYyKzY0ZeVP2zKddYoWWtz5mqYTZVfB0KIvPRXdau/8 KK/SbWjtgiXpH2OUmxO/MEMkkx4rOEFNcgFYqG6w= Date: Sat, 12 Aug 2023 15:05:59 -0700 To: mm-commits@vger.kernel.org, piaojun@huawei.com, mark@fasheh.com, junxiao.bi@oracle.com, jlbec@evilplan.org, jiangqi903@gmail.com, ghe@suse.com, dg573847474@gmail.com, akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-nonmm-stable] ocfs2-cluster-fix-potential-deadlock-on-o2net_debug_lock.patch removed from -mm tree Message-Id: <20230812220559.F04CEC433C7@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: ocfs2: cluster: fix potential deadlock on &o2net_debug_lock has been removed from the -mm tree. Its filename was ocfs2-cluster-fix-potential-deadlock-on-o2net_debug_lock.patch This patch was dropped because it was merged into the mm-nonmm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Chengfeng Ye Subject: ocfs2: cluster: fix potential deadlock on &o2net_debug_lock Date: Wed, 2 Aug 2023 13:14:36 +0000 &o2net_debug_lock is acquired by timer o2net_idle_timer() along the following call chain. Thus the acquisition of the lock under process context should disable bottom half, otherwise deadlock could happen if the timer happens to preempt the execution while the lock is held in process context on the same CPU. -> o2net_idle_timer() -> queue_delayed_work() -> sc_put() -> sc_kref_release() -> o2net_debug_del_sc() -> spin_lock(&o2net_debug_lock); Several lock acquisition of &o2net_debug_lock under process context do not disable irq or bottom half. The patch fixes these potential deadlocks scenerio by using spin_lock_bh() on &o2net_debug_lock. This flaw was found by an experimental static analysis tool I am developing for irq-related deadlock. x86_64 allmodconfig using gcc shows no new warning. Link: https://lkml.kernel.org/r/20230802131436.17765-1-dg573847474@gmail.com Signed-off-by: Chengfeng Ye Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Joseph Qi Cc: Gang He Cc: Jun Piao Signed-off-by: Andrew Morton --- fs/ocfs2/cluster/netdebug.c | 40 +++++++++++++++++----------------- 1 file changed, 20 insertions(+), 20 deletions(-) --- a/fs/ocfs2/cluster/netdebug.c~ocfs2-cluster-fix-potential-deadlock-on-o2net_debug_lock +++ a/fs/ocfs2/cluster/netdebug.c @@ -44,17 +44,17 @@ static LIST_HEAD(send_tracking); void o2net_debug_add_nst(struct o2net_send_tracking *nst) { - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); list_add(&nst->st_net_debug_item, &send_tracking); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); } void o2net_debug_del_nst(struct o2net_send_tracking *nst) { - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); if (!list_empty(&nst->st_net_debug_item)) list_del_init(&nst->st_net_debug_item); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); } static struct o2net_send_tracking @@ -84,9 +84,9 @@ static void *nst_seq_start(struct seq_fi { struct o2net_send_tracking *nst, *dummy_nst = seq->private; - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); nst = next_nst(dummy_nst); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); return nst; } @@ -95,13 +95,13 @@ static void *nst_seq_next(struct seq_fil { struct o2net_send_tracking *nst, *dummy_nst = seq->private; - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); nst = next_nst(dummy_nst); list_del_init(&dummy_nst->st_net_debug_item); if (nst) list_add(&dummy_nst->st_net_debug_item, &nst->st_net_debug_item); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); return nst; /* unused, just needs to be null when done */ } @@ -112,7 +112,7 @@ static int nst_seq_show(struct seq_file ktime_t now; s64 sock, send, status; - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); nst = next_nst(dummy_nst); if (!nst) goto out; @@ -145,7 +145,7 @@ static int nst_seq_show(struct seq_file (long long)status); out: - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); return 0; } @@ -191,16 +191,16 @@ static const struct file_operations nst_ void o2net_debug_add_sc(struct o2net_sock_container *sc) { - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); list_add(&sc->sc_net_debug_item, &sock_containers); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); } void o2net_debug_del_sc(struct o2net_sock_container *sc) { - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); list_del_init(&sc->sc_net_debug_item); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); } struct o2net_sock_debug { @@ -236,9 +236,9 @@ static void *sc_seq_start(struct seq_fil struct o2net_sock_debug *sd = seq->private; struct o2net_sock_container *sc, *dummy_sc = sd->dbg_sock; - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); sc = next_sc(dummy_sc); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); return sc; } @@ -248,12 +248,12 @@ static void *sc_seq_next(struct seq_file struct o2net_sock_debug *sd = seq->private; struct o2net_sock_container *sc, *dummy_sc = sd->dbg_sock; - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); sc = next_sc(dummy_sc); list_del_init(&dummy_sc->sc_net_debug_item); if (sc) list_add(&dummy_sc->sc_net_debug_item, &sc->sc_net_debug_item); - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); return sc; /* unused, just needs to be null when done */ } @@ -349,7 +349,7 @@ static int sc_seq_show(struct seq_file * struct o2net_sock_debug *sd = seq->private; struct o2net_sock_container *sc, *dummy_sc = sd->dbg_sock; - spin_lock(&o2net_debug_lock); + spin_lock_bh(&o2net_debug_lock); sc = next_sc(dummy_sc); if (sc) { @@ -359,7 +359,7 @@ static int sc_seq_show(struct seq_file * sc_show_sock_stats(seq, sc); } - spin_unlock(&o2net_debug_lock); + spin_unlock_bh(&o2net_debug_lock); return 0; } _ Patches currently in -mm which might be from dg573847474@gmail.com are