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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,T_DKIMWL_WL_HIGH, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by aws-us-west-2-korg-lkml-1.web.codeaurora.org (Postfix) with ESMTP id ECE21C433EF for ; Tue, 12 Jun 2018 16:47:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A23DF208B8 for ; Tue, 12 Jun 2018 16:47:57 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="hv48kKr5" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A23DF208B8 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 S934887AbeFLQry (ORCPT ); Tue, 12 Jun 2018 12:47:54 -0400 Received: from mail.kernel.org ([198.145.29.99]:32910 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934744AbeFLQrv (ORCPT ); Tue, 12 Jun 2018 12:47:51 -0400 Received: from localhost (LFbn-1-12247-202.w90-92.abo.wanadoo.fr [90.92.61.202]) (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 74412208B7; Tue, 12 Jun 2018 16:47:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1528822071; bh=Lhsik9VY3/qtRndCmZMCs85od6fhZ7ZeI/ow8uDNJ+8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=hv48kKr5wz1OT9FVCvtZ5XN8d62YqLS6BVAOKCoTq9FrENuJ4OGYO2c943kgaM9/s UJ/x5TbNxNvi047mmgu5tu105ZTCWmfzjtkuum1x+H3Em9cxJL8tTNsuJw4HlnblCL /C3rM0UjAo3wZxgFG9P3+zZRC1XgUFPFg9wBQ6Z8= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jack Morgenstein , Tariq Toukan , "David S. Miller" Subject: [PATCH 4.9 24/31] net/mlx4: Fix irq-unsafe spinlock usage Date: Tue, 12 Jun 2018 18:46:27 +0200 Message-Id: <20180612164621.741710164@linuxfoundation.org> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180612164620.797338191@linuxfoundation.org> References: <20180612164620.797338191@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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. ------------------ From: Jack Morgenstein [ Upstream commit d546b67cda015fb92bfee93d5dc0ceadb91deaee ] spin_lock/unlock was used instead of spin_un/lock_irq in a procedure used in process space, on a spinlock which can be grabbed in an interrupt. This caused the stack trace below to be displayed (on kernel 4.17.0-rc1 compiled with Lock Debugging enabled): [ 154.661474] WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected [ 154.668909] 4.17.0-rc1-rdma_rc_mlx+ #3 Tainted: G I [ 154.675856] ----------------------------------------------------- [ 154.682706] modprobe/10159 [HC0[0]:SC0[0]:HE0:SE1] is trying to acquire: [ 154.690254] 00000000f3b0e495 (&(&qp_table->lock)->rlock){+.+.}, at: mlx4_qp_remove+0x20/0x50 [mlx4_core] [ 154.700927] and this task is already holding: [ 154.707461] 0000000094373b5d (&(&cq->lock)->rlock/1){....}, at: destroy_qp_common+0x111/0x560 [mlx4_ib] [ 154.718028] which would create a new lock dependency: [ 154.723705] (&(&cq->lock)->rlock/1){....} -> (&(&qp_table->lock)->rlock){+.+.} [ 154.731922] but this new dependency connects a SOFTIRQ-irq-safe lock: [ 154.740798] (&(&cq->lock)->rlock){..-.} [ 154.740800] ... which became SOFTIRQ-irq-safe at: [ 154.752163] _raw_spin_lock_irqsave+0x3e/0x50 [ 154.757163] mlx4_ib_poll_cq+0x36/0x900 [mlx4_ib] [ 154.762554] ipoib_tx_poll+0x4a/0xf0 [ib_ipoib] ... to a SOFTIRQ-irq-unsafe lock: [ 154.815603] (&(&qp_table->lock)->rlock){+.+.} [ 154.815604] ... which became SOFTIRQ-irq-unsafe at: [ 154.827718] ... [ 154.827720] _raw_spin_lock+0x35/0x50 [ 154.833912] mlx4_qp_lookup+0x1e/0x50 [mlx4_core] [ 154.839302] mlx4_flow_attach+0x3f/0x3d0 [mlx4_core] Since mlx4_qp_lookup() is called only in process space, we can simply replace the spin_un/lock calls with spin_un/lock_irq calls. Fixes: 6dc06c08bef1 ("net/mlx4: Fix the check in attaching steering rules") Signed-off-by: Jack Morgenstein Signed-off-by: Tariq Toukan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/mellanox/mlx4/qp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/net/ethernet/mellanox/mlx4/qp.c +++ b/drivers/net/ethernet/mellanox/mlx4/qp.c @@ -392,11 +392,11 @@ struct mlx4_qp *mlx4_qp_lookup(struct ml struct mlx4_qp_table *qp_table = &mlx4_priv(dev)->qp_table; struct mlx4_qp *qp; - spin_lock(&qp_table->lock); + spin_lock_irq(&qp_table->lock); qp = __mlx4_qp_lookup(dev, qpn); - spin_unlock(&qp_table->lock); + spin_unlock_irq(&qp_table->lock); return qp; }