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=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 93368C43441 for ; Thu, 8 Nov 2018 22:21:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5428320818 for ; Thu, 8 Nov 2018 22:21:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="WJ4OhMsJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5428320818 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731273AbeKIH6y (ORCPT ); Fri, 9 Nov 2018 02:58:54 -0500 Received: from mail.kernel.org ([198.145.29.99]:35818 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727227AbeKIHn0 (ORCPT ); Fri, 9 Nov 2018 02:43:26 -0500 Received: from localhost (unknown [208.72.13.198]) (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 2E2E220892; Thu, 8 Nov 2018 22:05:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1541714756; bh=DVoUi4tWamRKu1Czsfrvv9+rJkWxgCXhZEymfhVMqG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WJ4OhMsJBmuczmnjuQa6O/pSnfcHt8tWNJ4dVn2714G87nNTNgZprvHKtpPR5Kvkf B9mi54UazFxkvLupYo+/iqLGJ8i07Ykdzhl86iiDvhzuN7ulqFV5Vbrn1NzhZf9Eg0 BWwxIWFVzoowC/cQ7Hq4Xsmb/gJa+CPENrbU1C0g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Moshe Shemesh , Saeed Mahameed , Sasha Levin Subject: [PATCH 4.9 078/171] net/mlx5: Fix health work queue spin lock to IRQ safe Date: Thu, 8 Nov 2018 13:50:48 -0800 Message-Id: <20181108215133.199210073@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181108215127.257643509@linuxfoundation.org> References: <20181108215127.257643509@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 6377ed0bbae6fa28853e1679d068a9106c8a8908 ] spin_lock/unlock of health->wq_lock should be IRQ safe. It was changed to spin_lock_irqsave since adding commit 0179720d6be2 ("net/mlx5: Introduce trigger_health_work function") which uses spin_lock from asynchronous event (IRQ) context. Thus, all spin_lock/unlock of health->wq_lock should have been moved to IRQ safe mode. However, one occurrence on new code using this lock missed that change, resulting in possible deadlock: kernel: Possible unsafe locking scenario: kernel: CPU0 kernel: ---- kernel: lock(&(&health->wq_lock)->rlock); kernel: kernel: lock(&(&health->wq_lock)->rlock); kernel: #012 *** DEADLOCK *** Fixes: 2a0165a034ac ("net/mlx5: Cancel delayed recovery work when unloading the driver") Signed-off-by: Moshe Shemesh Signed-off-by: Saeed Mahameed Signed-off-by: Sasha Levin --- drivers/net/ethernet/mellanox/mlx5/core/health.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/health.c b/drivers/net/ethernet/mellanox/mlx5/core/health.c index 448e71e07668..264f51b3409d 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/health.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/health.c @@ -369,10 +369,11 @@ void mlx5_drain_health_wq(struct mlx5_core_dev *dev) void mlx5_drain_health_recovery(struct mlx5_core_dev *dev) { struct mlx5_core_health *health = &dev->priv.health; + unsigned long flags; - spin_lock(&health->wq_lock); + spin_lock_irqsave(&health->wq_lock, flags); set_bit(MLX5_DROP_NEW_RECOVERY_WORK, &health->flags); - spin_unlock(&health->wq_lock); + spin_unlock_irqrestore(&health->wq_lock, flags); cancel_delayed_work_sync(&dev->priv.health.recover_work); } -- 2.17.1