From patchwork Fri Jan 24 09:28:13 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 233238 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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 679A4C32771 for ; Fri, 24 Jan 2020 09:48:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3C0BD208C4 for ; Fri, 24 Jan 2020 09:48:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579859306; bh=N7QHR2jrNoMngVyO6iNc7LKzLtL4/IfjdgirWTNdVJQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=uI/EX1wW/bJm/dyDZVIMZEProTuK3bF9zP6u867hsd07EMoP+oP/ukZ/1AzLWUI6/ qnqAIgKTnO5d1y4Fa/kgrqdV+MbuaO0ykkk0Th6+G6XiG7KHBlMZdE0iTP4b92IwJT u5t2HUKGJeQ7Vw9FqxSaLKrW8JFZLoP46chOkV6k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732478AbgAXJsZ (ORCPT ); Fri, 24 Jan 2020 04:48:25 -0500 Received: from mail.kernel.org ([198.145.29.99]:48490 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730051AbgAXJsZ (ORCPT ); Fri, 24 Jan 2020 04:48:25 -0500 Received: from localhost (unknown [145.15.244.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3917A20718; Fri, 24 Jan 2020 09:48:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579859304; bh=N7QHR2jrNoMngVyO6iNc7LKzLtL4/IfjdgirWTNdVJQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jf0iG4SKkcMUo2JrKSrWWEcsdgGKSTT8Hvmqd8qqQOpCE6Wzv73pQNydE+duRPTvq 7YXUzTgf4nJ7Jg3mDflXz8sylCmcVxU2ydfba9+umRKlJqyOBLu2CItH5ldRYoBoSD E9PFXuVsHJmg6FxU2FLh5tcrqkYb0PCJmZd0pqEI= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Moni Shoua , Leon Romanovsky , Saeed Mahameed , Sasha Levin Subject: [PATCH 4.14 075/343] net/mlx5: Take lock with IRQs disabled to avoid deadlock Date: Fri, 24 Jan 2020 10:28:13 +0100 Message-Id: <20200124092929.705750893@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124092919.490687572@linuxfoundation.org> References: <20200124092919.490687572@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Moni Shoua [ Upstream commit 33814e5d127e21f53b52e17b0722c1b57d4f4d29 ] The lock in qp_table might be taken from process context or from interrupt context. This may lead to a deadlock unless it is taken with IRQs disabled. Discovered by lockdep ================================ WARNING: inconsistent lock state 4.20.0-rc6 -------------------------------- inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} python/12572 [HC1[1]:SC0[0]:HE0:SE1] takes: 00000000052a4df4 (&(&table->lock)->rlock#2){?.+.}, /0x50 [mlx5_core] {HARDIRQ-ON-W} state was registered at: _raw_spin_lock+0x33/0x70 mlx5_get_rsc+0x1a/0x50 [mlx5_core] mlx5_ib_eqe_pf_action+0x493/0x1be0 [mlx5_ib] process_one_work+0x90c/0x1820 worker_thread+0x87/0xbb0 kthread+0x320/0x3e0 ret_from_fork+0x24/0x30 irq event stamp: 103928 hardirqs last enabled at (103927): [] nk+0x1a/0x1c hardirqs last disabled at (103928): [] unk+0x1a/0x1c softirqs last enabled at (103924): [] tcp_sendmsg+0x31/0x40 softirqs last disabled at (103922): [] 80 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&(&table->lock)->rlock#2); lock(&(&table->lock)->rlock#2); *** DEADLOCK *** Fixes: 032080ab43ac ("IB/mlx5: Lock QP during page fault handling") Signed-off-by: Moni Shoua Reviewed-by: Leon Romanovsky Signed-off-by: Saeed Mahameed Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/qp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/qp.c b/drivers/net/ethernet/mellanox/mlx5/core/qp.c index 5f091c6ea049d..b92d5690287b5 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/qp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/qp.c @@ -44,14 +44,15 @@ static struct mlx5_core_rsc_common *mlx5_get_rsc(struct mlx5_core_dev *dev, { struct mlx5_qp_table *table = &dev->priv.qp_table; struct mlx5_core_rsc_common *common; + unsigned long flags; - spin_lock(&table->lock); + spin_lock_irqsave(&table->lock, flags); common = radix_tree_lookup(&table->tree, rsn); if (common) atomic_inc(&common->refcount); - spin_unlock(&table->lock); + spin_unlock_irqrestore(&table->lock, flags); if (!common) { mlx5_core_warn(dev, "Async event for bogus resource 0x%x\n",