From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from youngberry.canonical.com ([91.189.89.112]:46722 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933049AbbI3JyV (ORCPT ); Wed, 30 Sep 2015 05:54:21 -0400 From: Luis Henriques To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Jack Morgenstein , Or Gerlitz , Doug Ledford , Luis Henriques Subject: [PATCH 3.16.y-ckt 110/133] IB/mlx4: Fix potential deadlock when sending mad to wire Date: Wed, 30 Sep 2015 10:50:58 +0100 Message-Id: <1443606681-7124-111-git-send-email-luis.henriques@canonical.com> In-Reply-To: <1443606681-7124-1-git-send-email-luis.henriques@canonical.com> References: <1443606681-7124-1-git-send-email-luis.henriques@canonical.com> Sender: stable-owner@vger.kernel.org List-ID: 3.16.7-ckt18 -stable review patch. If anyone has any objections, please let me know. ------------------ From: Jack Morgenstein commit 90c1d8b6350cca9d8a234f03c77a317a7613bcee upstream. send_mad_to_wire takes the same spinlock that is taken in the interrupt context. Therefore, it needs irqsave/restore. Fixes: b9c5d6a64358 ('IB/mlx4: Add multicast group (MCG) paravirtualization for SR-IOV') Signed-off-by: Jack Morgenstein Signed-off-by: Or Gerlitz Signed-off-by: Doug Ledford Signed-off-by: Luis Henriques --- drivers/infiniband/hw/mlx4/mcg.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/infiniband/hw/mlx4/mcg.c b/drivers/infiniband/hw/mlx4/mcg.c index ed327e6c8fdc..a0559a8af4f4 100644 --- a/drivers/infiniband/hw/mlx4/mcg.c +++ b/drivers/infiniband/hw/mlx4/mcg.c @@ -206,15 +206,16 @@ static int send_mad_to_wire(struct mlx4_ib_demux_ctx *ctx, struct ib_mad *mad) { struct mlx4_ib_dev *dev = ctx->dev; struct ib_ah_attr ah_attr; + unsigned long flags; - spin_lock(&dev->sm_lock); + spin_lock_irqsave(&dev->sm_lock, flags); if (!dev->sm_ah[ctx->port - 1]) { /* port is not yet Active, sm_ah not ready */ - spin_unlock(&dev->sm_lock); + spin_unlock_irqrestore(&dev->sm_lock, flags); return -EAGAIN; } mlx4_ib_query_ah(dev->sm_ah[ctx->port - 1], &ah_attr); - spin_unlock(&dev->sm_lock); + spin_unlock_irqrestore(&dev->sm_lock, flags); return mlx4_ib_send_to_wire(dev, mlx4_master_func_num(dev->dev), ctx->port, IB_QPT_GSI, 0, 1, IB_QP1_QKEY, &ah_attr, NULL, mad);