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 7A4EFC04A94 for ; Sat, 12 Aug 2023 22:06:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230313AbjHLWGQ (ORCPT ); Sat, 12 Aug 2023 18:06:16 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35748 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231161AbjHLWF5 (ORCPT ); Sat, 12 Aug 2023 18:05:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F01D4198E for ; Sat, 12 Aug 2023 15:05:59 -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 8EA01620DA for ; Sat, 12 Aug 2023 22:05:59 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E05ADC433C8; Sat, 12 Aug 2023 22:05:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1691877959; bh=Y3TGFaNMhz13vJDmH7twT/AxKad3xCcByqJIV6v/sU8=; h=Date:To:From:Subject:From; b=a9ii5H+6q8DGKBZIV9ztqT1X7GlLQ6cj5NKSnDc02yAbqnbCPZYHfv56dZ9W46NP6 Cm0YIpdwnQt8Tpu73y84gJY6NcogG+pgX197RYme5mFLGdveEQ1ubJc/n8c8kiHADO KjjYen8a4yFgfORIcp54wIawlC7cg5EmB9SAfWZA= Date: Sat, 12 Aug 2023 15:05:58 -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-qs-qs_lock.patch removed from -mm tree Message-Id: <20230812220558.E05ADC433C8@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 &qs->qs_lock has been removed from the -mm tree. Its filename was ocfs2-cluster-fix-potential-deadlock-on-qs-qs_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 &qs->qs_lock Date: Wed, 2 Aug 2023 12:38:24 +0000 &qs->qs_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() -> o2quo_conn_err() -> spin_lock(&qs->qs_lock) Several lock acquisition of &qs->qs_lock under process contex do not disable irq or bottom half. The patch fixes these potential deadlocks scenerio by using spin_lock_bh() on &qs->qs_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/20230802123824.15301-1-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/quorum.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) --- a/fs/ocfs2/cluster/quorum.c~ocfs2-cluster-fix-potential-deadlock-on-qs-qs_lock +++ a/fs/ocfs2/cluster/quorum.c @@ -93,7 +93,7 @@ static void o2quo_make_decision(struct w int lowest_hb, lowest_reachable = 0, fence = 0; struct o2quo_state *qs = &o2quo_state; - spin_lock(&qs->qs_lock); + spin_lock_bh(&qs->qs_lock); lowest_hb = find_first_bit(qs->qs_hb_bm, O2NM_MAX_NODES); if (lowest_hb != O2NM_MAX_NODES) @@ -146,14 +146,14 @@ static void o2quo_make_decision(struct w out: if (fence) { - spin_unlock(&qs->qs_lock); + spin_unlock_bh(&qs->qs_lock); o2quo_fence_self(); } else { mlog(ML_NOTICE, "not fencing this node, heartbeating: %d, " "connected: %d, lowest: %d (%sreachable)\n", qs->qs_heartbeating, qs->qs_connected, lowest_hb, lowest_reachable ? "" : "un"); - spin_unlock(&qs->qs_lock); + spin_unlock_bh(&qs->qs_lock); } @@ -196,7 +196,7 @@ void o2quo_hb_up(u8 node) { struct o2quo_state *qs = &o2quo_state; - spin_lock(&qs->qs_lock); + spin_lock_bh(&qs->qs_lock); qs->qs_heartbeating++; mlog_bug_on_msg(qs->qs_heartbeating == O2NM_MAX_NODES, @@ -211,7 +211,7 @@ void o2quo_hb_up(u8 node) else o2quo_clear_hold(qs, node); - spin_unlock(&qs->qs_lock); + spin_unlock_bh(&qs->qs_lock); } /* hb going down releases any holds we might have had due to this node from @@ -220,7 +220,7 @@ void o2quo_hb_down(u8 node) { struct o2quo_state *qs = &o2quo_state; - spin_lock(&qs->qs_lock); + spin_lock_bh(&qs->qs_lock); qs->qs_heartbeating--; mlog_bug_on_msg(qs->qs_heartbeating < 0, @@ -233,7 +233,7 @@ void o2quo_hb_down(u8 node) o2quo_clear_hold(qs, node); - spin_unlock(&qs->qs_lock); + spin_unlock_bh(&qs->qs_lock); } /* this tells us that we've decided that the node is still heartbeating @@ -245,14 +245,14 @@ void o2quo_hb_still_up(u8 node) { struct o2quo_state *qs = &o2quo_state; - spin_lock(&qs->qs_lock); + spin_lock_bh(&qs->qs_lock); mlog(0, "node %u\n", node); qs->qs_pending = 1; o2quo_clear_hold(qs, node); - spin_unlock(&qs->qs_lock); + spin_unlock_bh(&qs->qs_lock); } /* This is analogous to hb_up. as a node's connection comes up we delay the @@ -264,7 +264,7 @@ void o2quo_conn_up(u8 node) { struct o2quo_state *qs = &o2quo_state; - spin_lock(&qs->qs_lock); + spin_lock_bh(&qs->qs_lock); qs->qs_connected++; mlog_bug_on_msg(qs->qs_connected == O2NM_MAX_NODES, @@ -279,7 +279,7 @@ void o2quo_conn_up(u8 node) else o2quo_clear_hold(qs, node); - spin_unlock(&qs->qs_lock); + spin_unlock_bh(&qs->qs_lock); } /* we've decided that we won't ever be connecting to the node again. if it's @@ -290,7 +290,7 @@ void o2quo_conn_err(u8 node) { struct o2quo_state *qs = &o2quo_state; - spin_lock(&qs->qs_lock); + spin_lock_bh(&qs->qs_lock); if (test_bit(node, qs->qs_conn_bm)) { qs->qs_connected--; @@ -307,7 +307,7 @@ void o2quo_conn_err(u8 node) mlog(0, "node %u, %d total\n", node, qs->qs_connected); - spin_unlock(&qs->qs_lock); + spin_unlock_bh(&qs->qs_lock); } void o2quo_init(void) _ Patches currently in -mm which might be from dg573847474@gmail.com are