From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753938AbcFEWWq (ORCPT ); Sun, 5 Jun 2016 18:22:46 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:44000 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752932AbcFEWWn (ORCPT ); Sun, 5 Jun 2016 18:22:43 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Sebastian Sanchez , Mike Marciniszyn , Dennis Dalessandro , Doug Ledford Subject: [PATCH 4.6 121/121] IB/hfi1: Fix hard lockup due to not using save/restore spin lock Date: Sun, 5 Jun 2016 14:44:33 -0700 Message-Id: <20160605214421.477912937@linuxfoundation.org> X-Mailer: git-send-email 2.8.3 In-Reply-To: <20160605214417.708509043@linuxfoundation.org> References: <20160605214417.708509043@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Marciniszyn commit 7049de65c9e520886f06d6f9deceaaed5d93fb7c upstream. Commit b9b06cb6feda ("IB/hfi1: Fix missing lock/unlock in verbs drain callback") added a spin lock. Unfortunately, the new lock code can be called from a base level interrupt state, and an interrupt that can get stacked will attempt to get the same lock. Fix by using the flag save/restore spin lock variation. Cc: stable@vger.kernel.org # 4.6+ Reviewed-by: Sebastian Sanchez Signed-off-by: Mike Marciniszyn Signed-off-by: Dennis Dalessandro Signed-off-by: Doug Ledford Signed-off-by: Greg Kroah-Hartman --- drivers/staging/rdma/hfi1/qp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/staging/rdma/hfi1/qp.c +++ b/drivers/staging/rdma/hfi1/qp.c @@ -512,6 +512,7 @@ static void iowait_wakeup(struct iowait static void iowait_sdma_drained(struct iowait *wait) { struct rvt_qp *qp = iowait_to_qp(wait); + unsigned long flags; /* * This happens when the send engine notes @@ -519,12 +520,12 @@ static void iowait_sdma_drained(struct i * do the flush work until that QP's * sdma work has finished. */ - spin_lock(&qp->s_lock); + spin_lock_irqsave(&qp->s_lock, flags); if (qp->s_flags & RVT_S_WAIT_DMA) { qp->s_flags &= ~RVT_S_WAIT_DMA; hfi1_schedule_send(qp); } - spin_unlock(&qp->s_lock); + spin_unlock_irqrestore(&qp->s_lock, flags); } /**