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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 D8477C388F7 for ; Mon, 9 Nov 2020 13:45:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8A46E206ED for ; Mon, 9 Nov 2020 13:45:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604929524; bh=kOandtB1ZMev2Spg8KASy1z02WsLM2ai2Cy10DWXrx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DzoDoBALYD6WHhy5BhAq8W5c+tjZMVCtm+NIkKybvPTcsRHImWWpYukdV1+HpReGG 4q6cNCBFmVhWWts7Tfzh6aqq91xt5L5QxKmHaujYGbIHdSm/qbBWVD7U2stk0g9zaT h762c1DyXFMu7ZOk3PiL2DWkFsspyzXzZ1mhJg+M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730169AbgKIM6k (ORCPT ); Mon, 9 Nov 2020 07:58:40 -0500 Received: from mail.kernel.org ([198.145.29.99]:52876 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730158AbgKIM6k (ORCPT ); Mon, 9 Nov 2020 07:58:40 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 18C9320789; Mon, 9 Nov 2020 12:58:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604926719; bh=kOandtB1ZMev2Spg8KASy1z02WsLM2ai2Cy10DWXrx0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=R6QHAwXBge6T/ti3YMExfezJlPpBcoMa/ox5BH7OaFSg4NMSMqbi3UMrokIlmhuQw DTm9EeJjR9ayZpp4RDvBaETcd2aLgc9+D56udGxqZHaEWhoZOB8i9bykYDgQRlzsTy jLGxUlN83GU9BStlnfcd4lpKdDrSJ7gmn7Yvv7jA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, James Jurack , Claudiu Manoil , Jakub Kicinski Subject: [PATCH 4.4 67/86] gianfar: Account for Tx PTP timestamp in the skb headroom Date: Mon, 9 Nov 2020 13:55:14 +0100 Message-Id: <20201109125023.994044097@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201109125020.852643676@linuxfoundation.org> References: <20201109125020.852643676@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Claudiu Manoil [ Upstream commit d6a076d68c6b5d6a5800f3990a513facb7016dea ] When PTP timestamping is enabled on Tx, the controller inserts the Tx timestamp at the beginning of the frame buffer, between SFD and the L2 frame header. This means that the skb provided by the stack is required to have enough headroom otherwise a new skb needs to be created by the driver to accommodate the timestamp inserted by h/w. Up until now the driver was relying on the second option, using skb_realloc_headroom() to create a new skb to accommodate PTP frames. Turns out that this method is not reliable, as reallocation of skbs for PTP frames along with the required overhead (skb_set_owner_w, consume_skb) is causing random crashes in subsequent skb_*() calls, when multiple concurrent TCP streams are run at the same time on the same device (as seen in James' report). Note that these crashes don't occur with a single TCP stream, nor with multiple concurrent UDP streams, but only when multiple TCP streams are run concurrently with the PTP packet flow (doing skb reallocation). This patch enforces the first method, by requesting enough headroom from the stack to accommodate PTP frames, and so avoiding skb_realloc_headroom() & co, and the crashes no longer occur. There's no reason not to set needed_headroom to a large enough value to accommodate PTP frames, so in this regard this patch is a fix. Reported-by: James Jurack Fixes: bee9e58c9e98 ("gianfar:don't add FCB length to hard_header_len") Signed-off-by: Claudiu Manoil Link: https://lore.kernel.org/r/20201020173605.1173-1-claudiu.manoil@nxp.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/ethernet/freescale/gianfar.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/net/ethernet/freescale/gianfar.c +++ b/drivers/net/ethernet/freescale/gianfar.c @@ -1385,7 +1385,7 @@ static int gfar_probe(struct platform_de if (dev->features & NETIF_F_IP_CSUM || priv->device_flags & FSL_GIANFAR_DEV_HAS_TIMER) - dev->needed_headroom = GMAC_FCB_LEN; + dev->needed_headroom = GMAC_FCB_LEN + GMAC_TXPAL_LEN; /* Initializing some of the rx/tx queue level parameters */ for (i = 0; i < priv->num_tx_queues; i++) {