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 24134C4741F for ; Mon, 9 Nov 2020 13:25:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C440520663 for ; Mon, 9 Nov 2020 13:25:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604928350; bh=81AaFuK1HpKyNz0GTHs3QANVJVpbojE6iqbD9c855H0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=DdJgWfDCmruflElkzUI3q7H1QYDfGL6tIcS2LP1m+PYnwyAOvh6IA2Ah2yGKwsM5n glGiJTw3zT6BAaTEU4Gwtx46AimUddu9djaCMFGYmDnZAFjmElFQJD+0R0AmnPTiuI mtmQB10Sw6GzE1y1rrVcM706FiOn0I5/FmfwXJOA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732379AbgKINR1 (ORCPT ); Mon, 9 Nov 2020 08:17:27 -0500 Received: from mail.kernel.org ([198.145.29.99]:44342 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732327AbgKINRN (ORCPT ); Mon, 9 Nov 2020 08:17:13 -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 4FF2C206D8; Mon, 9 Nov 2020 13:17:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1604927833; bh=81AaFuK1HpKyNz0GTHs3QANVJVpbojE6iqbD9c855H0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=zkG7L6SBbp8WeBy26NDDwi/ghlBBD2UGiTsZgu7I+8+NPW/MyTpAXpzWu/UqOxY2k VRwdo9EYj5TsY/nDQ03myVDk7kZ1G8PdohEtfqI/FqxmIegYq2O5m9YzR+AvnGHEPX D+sopWjWVRs2+zoQRwq9RFckECVLGN9297bEv2nE= 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 5.9 029/133] gianfar: Account for Tx PTP timestamp in the skb headroom Date: Mon, 9 Nov 2020 13:54:51 +0100 Message-Id: <20201109125032.121468721@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201109125030.706496283@linuxfoundation.org> References: <20201109125030.706496283@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: linux-kernel@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 @@ -3372,7 +3372,7 @@ 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++) {