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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 594C1C433E2 for ; Wed, 27 May 2020 12:20:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 36B69207D8 for ; Wed, 27 May 2020 12:20:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728501AbgE0MU2 (ORCPT ); Wed, 27 May 2020 08:20:28 -0400 Received: from alexa-out-blr-01.qualcomm.com ([103.229.18.197]:52008 "EHLO alexa-out-blr-01.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726785AbgE0MU0 (ORCPT ); Wed, 27 May 2020 08:20:26 -0400 Received: from ironmsg01-blr.qualcomm.com ([10.86.208.130]) by alexa-out-blr-01.qualcomm.com with ESMTP/TLS/AES256-SHA; 27 May 2020 17:49:42 +0530 Received: from sartgarg-linux.qualcomm.com ([10.206.24.245]) by ironmsg01-blr.qualcomm.com with ESMTP; 27 May 2020 17:49:29 +0530 Received: by sartgarg-linux.qualcomm.com (Postfix, from userid 2339771) id 215AC17B2; Wed, 27 May 2020 17:49:28 +0530 (IST) From: Sarthak Garg To: stable@vger.kernel.org Cc: adrian.hunter@intel.com, ulf.hansson@linaro.org, vbadigan@codeaurora.org, stummala@codeaurora.org, linux-mmc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org Subject: [4.19.124 V1] mmc: core: Fix recursive locking issue in CQE recovery path Date: Wed, 27 May 2020 17:49:02 +0530 Message-Id: <1590581942-24283-1-git-send-email-sartgarg@codeaurora.org> X-Mailer: git-send-email 2.7.4 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [ Upstream commit 39a22f73744d5baee30b5f134ae2e30b668b66ed ] Consider the following stack trace -001|raw_spin_lock_irqsave -002|mmc_blk_cqe_complete_rq -003|__blk_mq_complete_request(inline) -003|blk_mq_complete_request(rq) -004|mmc_cqe_timed_out(inline) -004|mmc_mq_timed_out mmc_mq_timed_out acquires the queue_lock for the first time. The mmc_blk_cqe_complete_rq function also tries to acquire the same queue lock resulting in recursive locking where the task is spinning for the same lock which it has already acquired leading to watchdog bark. Fix this issue with the lock only for the required critical section. Cc: Fixes: 1e8e55b67030 ("mmc: block: Add CQE support") Suggested-by: Sahitya Tummala Signed-off-by: Sarthak Garg Acked-by: Adrian Hunter Link: https://lore.kernel.org/r/1588868135-31783-1-git-send-email-vbadigan@codeaurora.org Signed-off-by: Ulf Hansson --- drivers/mmc/core/queue.c | 13 ++++--------- 1 file changed, 4 insertions(+), 9 deletions(-) diff --git a/drivers/mmc/core/queue.c b/drivers/mmc/core/queue.c index 03f3d9c..2a78816 100644 --- a/drivers/mmc/core/queue.c +++ b/drivers/mmc/core/queue.c @@ -108,7 +108,7 @@ static enum blk_eh_timer_return mmc_cqe_timed_out(struct request *req) case MMC_ISSUE_DCMD: if (host->cqe_ops->cqe_timeout(host, mrq, &recovery_needed)) { if (recovery_needed) - __mmc_cqe_recovery_notifier(mq); + mmc_cqe_recovery_notifier(mrq); return BLK_EH_RESET_TIMER; } /* The request has gone already */ @@ -125,18 +125,13 @@ static enum blk_eh_timer_return mmc_mq_timed_out(struct request *req, struct request_queue *q = req->q; struct mmc_queue *mq = q->queuedata; unsigned long flags; - int ret; + bool ignore_tout; spin_lock_irqsave(q->queue_lock, flags); - - if (mq->recovery_needed || !mq->use_cqe) - ret = BLK_EH_RESET_TIMER; - else - ret = mmc_cqe_timed_out(req); - + ignore_tout = mq->recovery_needed || !mq->use_cqe; spin_unlock_irqrestore(q->queue_lock, flags); - return ret; + return ignore_tout ? BLK_EH_RESET_TIMER : mmc_cqe_timed_out(req); } static void mmc_mq_recovery_handler(struct work_struct *work) -- 2.7.4