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=-13.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,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 6A004C43457 for ; Mon, 27 Jul 2020 23:26:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47E8820786 for ; Mon, 27 Jul 2020 23:26:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595892415; bh=XTzEKkCiT3hDLUuKnQImLhNJnYrQpx71QkDX6t+ecwA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=IQcPfXWuLM6H1kRMFHpOuut7ezTQu4SBjglpxxvjvffZ8Lkti/dXRLwWY1zwOtftX 3glU+YlfoUiwJAbwnJ9QQoa3sbk6FLFHNwL3R3ADfdR8ArrBuH4L2pBpSaP/AOheXA 57Zqqp4e5RuOyuVhXQRHgRWA4JnNzbBE+RIvyWZM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728761AbgG0X0x (ORCPT ); Mon, 27 Jul 2020 19:26:53 -0400 Received: from mail.kernel.org ([198.145.29.99]:36354 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728498AbgG0XZH (ORCPT ); Mon, 27 Jul 2020 19:25:07 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5906C20786; Mon, 27 Jul 2020 23:25:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1595892306; bh=XTzEKkCiT3hDLUuKnQImLhNJnYrQpx71QkDX6t+ecwA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=1PDYGTYNNPjuItrs1mQ40wf1Pl5ga2XC2+aHXrhbpNbdpbCgeRLU8ueYmtSCvNDER GKa+6dLZqKmCkxjsZMJgTX0rYENFLIIkCEkPP2A71JZU+F9iIQMYEODnAuxeggrpbB uP6kkbGQJyrS1jArCxcWW3FtD+MtOMoHk7uid50E= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Yoshihiro Shimoda , Dirk Behme , Sergei Shtylyov , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org, linux-renesas-soc@vger.kernel.org Subject: [PATCH AUTOSEL 4.14 05/10] net: ethernet: ravb: exit if re-initialization fails in tx timeout Date: Mon, 27 Jul 2020 19:24:53 -0400 Message-Id: <20200727232458.718131-5-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200727232458.718131-1-sashal@kernel.org> References: <20200727232458.718131-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Yoshihiro Shimoda [ Upstream commit 015c5d5e6aa3523c758a70eb87b291cece2dbbb4 ] According to the report of [1], this driver is possible to cause the following error in ravb_tx_timeout_work(). ravb e6800000.ethernet ethernet: failed to switch device to config mode This error means that the hardware could not change the state from "Operation" to "Configuration" while some tx and/or rx queue are operating. After that, ravb_config() in ravb_dmac_init() will fail, and then any descriptors will be not allocaled anymore so that NULL pointer dereference happens after that on ravb_start_xmit(). To fix the issue, the ravb_tx_timeout_work() should check the return values of ravb_stop_dma() and ravb_dmac_init(). If ravb_stop_dma() fails, ravb_tx_timeout_work() re-enables TX and RX and just exits. If ravb_dmac_init() fails, just exits. [1] https://lore.kernel.org/linux-renesas-soc/20200518045452.2390-1-dirk.behme@de.bosch.com/ Reported-by: Dirk Behme Signed-off-by: Yoshihiro Shimoda Reviewed-by: Sergei Shtylyov Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- drivers/net/ethernet/renesas/ravb_main.c | 26 ++++++++++++++++++++++-- 1 file changed, 24 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index d73617cc3b159..9f4d93a16b7e5 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -1482,6 +1482,7 @@ static void ravb_tx_timeout_work(struct work_struct *work) struct ravb_private *priv = container_of(work, struct ravb_private, work); struct net_device *ndev = priv->ndev; + int error; netif_tx_stop_all_queues(ndev); @@ -1490,15 +1491,36 @@ static void ravb_tx_timeout_work(struct work_struct *work) ravb_ptp_stop(ndev); /* Wait for DMA stopping */ - ravb_stop_dma(ndev); + if (ravb_stop_dma(ndev)) { + /* If ravb_stop_dma() fails, the hardware is still operating + * for TX and/or RX. So, this should not call the following + * functions because ravb_dmac_init() is possible to fail too. + * Also, this should not retry ravb_stop_dma() again and again + * here because it's possible to wait forever. So, this just + * re-enables the TX and RX and skip the following + * re-initialization procedure. + */ + ravb_rcv_snd_enable(ndev); + goto out; + } ravb_ring_free(ndev, RAVB_BE); ravb_ring_free(ndev, RAVB_NC); /* Device init */ - ravb_dmac_init(ndev); + error = ravb_dmac_init(ndev); + if (error) { + /* If ravb_dmac_init() fails, descriptors are freed. So, this + * should return here to avoid re-enabling the TX and RX in + * ravb_emac_init(). + */ + netdev_err(ndev, "%s: ravb_dmac_init() failed, error %d\n", + __func__, error); + return; + } ravb_emac_init(ndev); +out: /* Initialise PTP Clock driver */ if (priv->chip_id == RCAR_GEN2) ravb_ptp_init(ndev, priv->pdev); -- 2.25.1