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=-14.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 034F2C433DB for ; Sun, 7 Feb 2021 17:50:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C01F964E26 for ; Sun, 7 Feb 2021 17:50:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229715AbhBGRu3 (ORCPT ); Sun, 7 Feb 2021 12:50:29 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60174 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229506AbhBGRuZ (ORCPT ); Sun, 7 Feb 2021 12:50:25 -0500 Received: from mail-ot1-x32b.google.com (mail-ot1-x32b.google.com [IPv6:2607:f8b0:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 569A4C061756 for ; Sun, 7 Feb 2021 09:49:45 -0800 (PST) Received: by mail-ot1-x32b.google.com with SMTP id d7so9787827otq.6 for ; Sun, 07 Feb 2021 09:49:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=kjF32x+g63Mhbkv+V5xB1MnzYdIbawp2tYWaemr5LkM=; b=WFEp5x4q+0sXS7gFfs14ExT0SFo9H1X65E1OoNACPF6Kqi87HxY0D/1zCG1jpe6qQ8 1TRHrOoHhHSv1PKHUyiPDv5vytQZLskL9DlnTU+pXtHAGOrMKttXcqgt/KZ9WoE39Z/L ikVLzxoXsac/Secxzr+VCNOK870kiQfO0/+lImSX0H2G15deUA7aZODS2RLo9FHXElBg mvDUZ/Y/GuItRPDeP6FvMY25+oaiPAKVIicWf5qhI2O0XYBYIVPBHD7NuKGRqMrKu8UX ti4vT3bVtXIlpu/hQAnix06hl7n4ptAmU5tV24y2JGVEy8FQQACIsN47+oiusGIaIi+M hWPQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=kjF32x+g63Mhbkv+V5xB1MnzYdIbawp2tYWaemr5LkM=; b=iTRy939jCktt3iPa5LDuNfddc6Ed3u7oe2we5AFWyZCanrmyn6nOmSWfDnNTne2sJO 5Xxdh2vcmyc28WhoT/JWRQDcoslkuI8MpcJ5PRghBvWrOSknhWbYOGKqNpjR3Tt+RAt+ eVqF44Ts3ncznT6FMJd3yiMlg59SVObUTop7fQBn8xmfR7xGXLD1YIFc9kOnVaFdr08I Qs6LmoPFygezeP9Js1S/9/0Aa9/sEr+LZn9g9J7+/ZWUwL3zcsnA0NH2TKgY+5sWvChA rTEO4M/hYICITr/oohylu+RuHfbqNnre6hN1sLpDqvwqzAR3wOz7knJYz03ZPkcB3jpt BJXQ== X-Gm-Message-State: AOAM5316EoKgGYS3uyQmwP+JB0N330Cb0m35MedQtyIOck+O+UbVynOC WejZGF+/pcEx8d0O2CzZ+yQ= X-Google-Smtp-Source: ABdhPJzTbZEL8JoVD7ZzlPbgc5H2uDRTplsnwWHKeojePM8OoLFZ4hp0FMWp6Lcx3WTDl4QBvsQrRQ== X-Received: by 2002:a9d:6290:: with SMTP id x16mr10294196otk.109.1612720184586; Sun, 07 Feb 2021 09:49:44 -0800 (PST) Received: from Davids-MacBook-Pro.local ([8.48.134.33]) by smtp.googlemail.com with ESMTPSA id t3sm165792otb.36.2021.02.07.09.49.42 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 07 Feb 2021 09:49:43 -0800 (PST) Subject: Re: [net-next v2] tcp: Explicitly mark reserved field in tcp_zerocopy_receive args. To: Arjun Roy , davem@davemloft.net, netdev@vger.kernel.org Cc: arjunroy@google.com, edumazet@google.com, soheil@google.com, Leon Romanovsky , Jakub Kicinski References: <20210206203648.609650-1-arjunroy.kdev@gmail.com> From: David Ahern Message-ID: Date: Sun, 7 Feb 2021 10:49:41 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.16; rv:78.0) Gecko/20100101 Thunderbird/78.7.0 MIME-Version: 1.0 In-Reply-To: <20210206203648.609650-1-arjunroy.kdev@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2/6/21 1:36 PM, Arjun Roy wrote: > From: Arjun Roy > > Explicitly define reserved field and require it to be 0-valued. > > Fixes: 7eeba1706eba ("tcp: Add receive timestamp support for receive zerocopy.") > Signed-off-by: Arjun Roy > Signed-off-by: Eric Dumazet > Signed-off-by: Soheil Hassas Yeganeh > Suggested-by: David Ahern > Suggested-by: Leon Romanovsky > Suggested-by: Jakub Kicinski > --- > include/uapi/linux/tcp.h | 2 +- > net/ipv4/tcp.c | 2 ++ > 2 files changed, 3 insertions(+), 1 deletion(-) > > diff --git a/include/uapi/linux/tcp.h b/include/uapi/linux/tcp.h > index 42fc5a640df4..8fc09e8638b3 100644 > --- a/include/uapi/linux/tcp.h > +++ b/include/uapi/linux/tcp.h > @@ -357,6 +357,6 @@ struct tcp_zerocopy_receive { > __u64 msg_control; /* ancillary data */ > __u64 msg_controllen; > __u32 msg_flags; > - /* __u32 hole; Next we must add >1 u32 otherwise length checks fail. */ > + __u32 reserved; /* set to 0 for now */ > }; > #endif /* _UAPI_LINUX_TCP_H */ > diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c > index e1a17c6b473c..c8469c579ed8 100644 > --- a/net/ipv4/tcp.c > +++ b/net/ipv4/tcp.c > @@ -4159,6 +4159,8 @@ static int do_tcp_getsockopt(struct sock *sk, int level, > } > if (copy_from_user(&zc, optval, len)) > return -EFAULT; > + if (zc.reserved) > + return -EINVAL; > lock_sock(sk); > err = tcp_zerocopy_receive(sk, &zc, &tss); > release_sock(sk); > The 'switch (len)' statement needs to be updated now that 'len' is not going to end on the 'msg_flags' boundary? But then, how did that work before if there was 4 byte padding? Maybe I am missing something here. You currently have: switch (len) { case offsetofend(struct tcp_zerocopy_receive, msg_flags): which should == 60, yet the struct size is 64 with 4-bytes of padding. A user doing int optlen = sizeof(struct tcp_zerocopy_receive); getsockopt(...., &optlen) would pass in a value of 64, right?