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=-13.6 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 65781C43381 for ; Fri, 15 Jan 2021 08:13:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 385C123119 for ; Fri, 15 Jan 2021 08:13:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732387AbhAOINA (ORCPT ); Fri, 15 Jan 2021 03:13:00 -0500 Received: from forward4-smtp.messagingengine.com ([66.111.4.238]:34127 "EHLO forward4-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730858AbhAOINA (ORCPT ); Fri, 15 Jan 2021 03:13:00 -0500 Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailforward.nyi.internal (Postfix) with ESMTP id B73EE19C3DB6; Fri, 15 Jan 2021 03:11:46 -0500 (EST) Received: from mailfrontend2 ([10.202.2.163]) by compute4.internal (MEProxy); Fri, 15 Jan 2021 03:11:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:content-transfer-encoding:content-type :date:from:message-id:mime-version:subject:to:x-me-proxy :x-me-proxy:x-me-sender:x-me-sender:x-sasl-enc; s=fm1; bh=C1zoH7 9H4UJydk/cjFcyiPVxoRqFbHIPkxVDhggtUP4=; b=TU21hE18HFGO6HAYIONTXE JS+iQDW2n2GjdXh6Ei+A3KFNylUfe5qv+D6v5Nt1QHrAKDq01c3CAmO+vPc+eTIE qw1QIoqHGBRnwznYZ4IwSBqg3evGkasLeczu2OO8u3oB2jhwMexVlf/lkSp7WhLo ad4mdCbW/Sf33kNKvBLUxESN5IqFEFrw9oQ1wCEb8UFC3YO10sASPirhsdJuLQyg 8GjqSjEmbBa8B1vb23Vr18Jx1y36/D19KxNob01jEicMYQnalsqsKjmbvhsVNvfy aXc6YG/1+gnPRObOrQf6diXMoOOIrwjiaNMtzLN5zFwgndcdT9CNw9JMyv51U/eQ == X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeduledrtddugdduudeiucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucenucfjughrpefuvffhfffkgggtgfesthekredttd dtlfenucfhrhhomhepoehgrhgvghhkhheslhhinhhugihfohhunhgurghtihhonhdrohhr gheqnecuggftrfgrthhtvghrnhepieetveehuedvhfdtgfdvieeiheehfeelveevheejud etveeuveeludejjefgteehnecukfhppeekfedrkeeirdejgedrieegnecuvehluhhsthgv rhfuihiivgepgeenucfrrghrrghmpehmrghilhhfrhhomhepghhrvghgsehkrhhorghhrd gtohhm X-ME-Proxy: Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) by mail.messagingengine.com (Postfix) with ESMTPA id 6871E108005F; Fri, 15 Jan 2021 03:11:46 -0500 (EST) Subject: FAILED: patch "[PATCH] s390/qeth: fix locking for discipline setup / removal" failed to apply to 4.14-stable tree To: jwi@linux.ibm.com, kuba@kernel.org, wintera@linux.ibm.com Cc: From: Date: Fri, 15 Jan 2021 09:11:44 +0100 Message-ID: <161069830426197@kroah.com> 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 4.14-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 . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From b41b554c1ee75070a14c02a88496b1f231c7eacc Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Thu, 7 Jan 2021 18:24:41 +0100 Subject: [PATCH] s390/qeth: fix locking for discipline setup / removal Due to insufficient locking, qeth_core_set_online() and qeth_dev_layer2_store() can run in parallel, both attempting to load & setup the discipline (and stepping on each other toes along the way). A similar race can also occur between qeth_core_remove_device() and qeth_dev_layer2_store(). Access to .discipline is meant to be protected by the discipline_mutex, so add/expand the locking in qeth_core_remove_device() and qeth_core_set_online(). Adjust the locking in qeth_l*_remove_device() accordingly, as it's now handled by the callers in a consistent manner. Based on an initial patch by Ursula Braun. Fixes: 9dc48ccc68b9 ("qeth: serialize sysfs-triggered device configurations") Signed-off-by: Julian Wiedmann Reviewed-by: Alexandra Winter Signed-off-by: Jakub Kicinski diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index d45e223fc521..cf18d87da41e 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -6585,6 +6585,7 @@ static int qeth_core_probe_device(struct ccwgroup_device *gdev) break; default: card->info.layer_enforced = true; + /* It's so early that we don't need the discipline_mutex yet. */ rc = qeth_core_load_discipline(card, enforced_disc); if (rc) goto err_load; @@ -6617,10 +6618,12 @@ static void qeth_core_remove_device(struct ccwgroup_device *gdev) QETH_CARD_TEXT(card, 2, "removedv"); + mutex_lock(&card->discipline_mutex); if (card->discipline) { card->discipline->remove(gdev); qeth_core_free_discipline(card); } + mutex_unlock(&card->discipline_mutex); qeth_free_qdio_queues(card); @@ -6635,6 +6638,7 @@ static int qeth_core_set_online(struct ccwgroup_device *gdev) int rc = 0; enum qeth_discipline_id def_discipline; + mutex_lock(&card->discipline_mutex); if (!card->discipline) { def_discipline = IS_IQD(card) ? QETH_DISCIPLINE_LAYER3 : QETH_DISCIPLINE_LAYER2; @@ -6648,11 +6652,10 @@ static int qeth_core_set_online(struct ccwgroup_device *gdev) } } - mutex_lock(&card->discipline_mutex); rc = qeth_set_online(card, card->discipline); - mutex_unlock(&card->discipline_mutex); err: + mutex_unlock(&card->discipline_mutex); return rc; } diff --git a/drivers/s390/net/qeth_l2_main.c b/drivers/s390/net/qeth_l2_main.c index 37279b1e29f6..4254caf1d9b6 100644 --- a/drivers/s390/net/qeth_l2_main.c +++ b/drivers/s390/net/qeth_l2_main.c @@ -2207,11 +2207,8 @@ static void qeth_l2_remove_device(struct ccwgroup_device *gdev) qeth_set_allowed_threads(card, 0, 1); wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0); - if (gdev->state == CCWGROUP_ONLINE) { - mutex_lock(&card->discipline_mutex); + if (gdev->state == CCWGROUP_ONLINE) qeth_set_offline(card, card->discipline, false); - mutex_unlock(&card->discipline_mutex); - } cancel_work_sync(&card->close_dev_work); if (card->dev->reg_state == NETREG_REGISTERED) diff --git a/drivers/s390/net/qeth_l3_main.c b/drivers/s390/net/qeth_l3_main.c index 8d474179ce98..6970597bc885 100644 --- a/drivers/s390/net/qeth_l3_main.c +++ b/drivers/s390/net/qeth_l3_main.c @@ -1970,11 +1970,8 @@ static void qeth_l3_remove_device(struct ccwgroup_device *cgdev) qeth_set_allowed_threads(card, 0, 1); wait_event(card->wait_q, qeth_threads_running(card, 0xffffffff) == 0); - if (cgdev->state == CCWGROUP_ONLINE) { - mutex_lock(&card->discipline_mutex); + if (cgdev->state == CCWGROUP_ONLINE) qeth_set_offline(card, card->discipline, false); - mutex_unlock(&card->discipline_mutex); - } cancel_work_sync(&card->close_dev_work); if (card->dev->reg_state == NETREG_REGISTERED)