From patchwork Mon Mar 15 13:53:15 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 401327 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=-19.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 3C453C4646C for ; Mon, 15 Mar 2021 14:05:04 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26E6D64F13 for ; Mon, 15 Mar 2021 14:05:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230513AbhCOOEs (ORCPT ); Mon, 15 Mar 2021 10:04:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:37582 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232979AbhCOOA3 (ORCPT ); Mon, 15 Mar 2021 10:00:29 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2748B64F06; Mon, 15 Mar 2021 13:59:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615816800; bh=D1PiA+M4iRzzEEoFXNnIFPKLpdvVYmCc9yT9KFEC9VU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FcJ3jNcwUK6F+GPxb2Fen0Qqxb4lB8LiUjqaHPdwnw2APoKhPfAwXABmiY6wh5yRf oh/NQOotlpLwMJX0LqOnbO1UK1FfdmrEQYL6nPpLcMC/PdYW9FEkNbUalN9vTxoYvb LaZ8GuxwzDMPR6ekx/viDj0JbMa5jjFTE1cxqlck= From: gregkh@linuxfoundation.org To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Chaotian Jing , Ulf Hansson , Sasha Levin Subject: [PATCH 5.11 132/306] mmc: mediatek: fix race condition between msdc_request_timeout and irq Date: Mon, 15 Mar 2021 14:53:15 +0100 Message-Id: <20210315135512.114324488@linuxfoundation.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210315135507.611436477@linuxfoundation.org> References: <20210315135507.611436477@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Greg Kroah-Hartman From: Chaotian Jing [ Upstream commit 0354ca6edd464a2cf332f390581977b8699ed081 ] when get request SW timeout, if CMD/DAT xfer done irq coming right now, then there is race between the msdc_request_timeout work and irq handler, and the host->cmd and host->data may set to NULL in irq handler. also, current flow ensure that only one path can go to msdc_request_done(), so no need check the return value of cancel_delayed_work(). Signed-off-by: Chaotian Jing Link: https://lore.kernel.org/r/20201218071611.12276-1-chaotian.jing@mediatek.com Signed-off-by: Ulf Hansson Signed-off-by: Sasha Levin --- drivers/mmc/host/mtk-sd.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/drivers/mmc/host/mtk-sd.c b/drivers/mmc/host/mtk-sd.c index de09c6347524..898ed1b023df 100644 --- a/drivers/mmc/host/mtk-sd.c +++ b/drivers/mmc/host/mtk-sd.c @@ -1127,13 +1127,13 @@ static void msdc_track_cmd_data(struct msdc_host *host, static void msdc_request_done(struct msdc_host *host, struct mmc_request *mrq) { unsigned long flags; - bool ret; - ret = cancel_delayed_work(&host->req_timeout); - if (!ret) { - /* delay work already running */ - return; - } + /* + * No need check the return value of cancel_delayed_work, as only ONE + * path will go here! + */ + cancel_delayed_work(&host->req_timeout); + spin_lock_irqsave(&host->lock, flags); host->mrq = NULL; spin_unlock_irqrestore(&host->lock, flags); @@ -1155,7 +1155,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events, bool done = false; bool sbc_error; unsigned long flags; - u32 *rsp = cmd->resp; + u32 *rsp; if (mrq->sbc && cmd == mrq->cmd && (events & (MSDC_INT_ACMDRDY | MSDC_INT_ACMDCRCERR @@ -1176,6 +1176,7 @@ static bool msdc_cmd_done(struct msdc_host *host, int events, if (done) return true; + rsp = cmd->resp; sdr_clr_bits(host->base + MSDC_INTEN, cmd_ints_mask); @@ -1363,7 +1364,7 @@ static void msdc_data_xfer_next(struct msdc_host *host, static bool msdc_data_xfer_done(struct msdc_host *host, u32 events, struct mmc_request *mrq, struct mmc_data *data) { - struct mmc_command *stop = data->stop; + struct mmc_command *stop; unsigned long flags; bool done; unsigned int check_data = events & @@ -1379,6 +1380,7 @@ static bool msdc_data_xfer_done(struct msdc_host *host, u32 events, if (done) return true; + stop = data->stop; if (check_data || (stop && stop->error)) { dev_dbg(host->dev, "DMA status: 0x%8X\n",