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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C9501C54EBE for ; Mon, 16 Jan 2023 11:34:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229588AbjAPLeO (ORCPT ); Mon, 16 Jan 2023 06:34:14 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56386 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229545AbjAPLeN (ORCPT ); Mon, 16 Jan 2023 06:34:13 -0500 Received: from mail-ed1-x52a.google.com (mail-ed1-x52a.google.com [IPv6:2a00:1450:4864:20::52a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5854210E6 for ; Mon, 16 Jan 2023 03:34:12 -0800 (PST) Received: by mail-ed1-x52a.google.com with SMTP id v10so39108580edi.8 for ; Mon, 16 Jan 2023 03:34:12 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cloudflare.com; s=google; h=mime-version:message-id:in-reply-to:date:subject:cc:to:from :user-agent:references:from:to:cc:subject:date:message-id:reply-to; bh=musiU/xa+beV5wDQ+48J+naON4JvwF6zzi8se9Hs4H8=; b=GDWE2ZkJ1iQzUoNKqyzh3ULBoNfQV2zOsFJTiUgf7xglDzXrJPons73dgXabJICmRR Qiiw05I6DwZoglyT8q8Mgy0c4jXXQUrTV5vxrUL1CFpBNCSR96ZsykrAyRN338svAsTn 01/h+Exdhl1hGM3yHasawzVPtKmoVArpB1iI8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:message-id:in-reply-to:date:subject:cc:to:from :user-agent:references:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=musiU/xa+beV5wDQ+48J+naON4JvwF6zzi8se9Hs4H8=; b=BIBOenXrP5gw1ZL4xTRv/R4tFzokXy28fP0rHEvVAcsjM7oLcT4ng1Lu6BLi9WeyVV FARmVLlpLwiwb0/Mg88eAlxJvF+N2G6jlKaiWQLX+3uT9mbOSldzLjMYnov71019aQjn ZMm+5bMnzUPHiegbHB3GJ51sdUUf1dRgANHtGhLpvSstHfEf7rSTg+LiyAPzw6izvf3m O41kp4l3yYAebvBSZOWExEHD+u5vEEo2uibfmuM7cd116w6bJQnUoeAA5L8tCqsGoitb rfhZ1uERNCliYdEMm+neB4nAMmSTsvI2cFm5Lpxnssf4UpEelIO6VWWHuy8vVKvuvxrW 3kBg== X-Gm-Message-State: AFqh2koWGgeEjV5FI0B0AcBzziC71MatqdZMYexOjcqqAQd14PaFpeqT G3cdCNJ93I6EmLfIXFchn7xIz+YskVT2CGQ5 X-Google-Smtp-Source: AMrXdXsq9l0PKkMRmShnI9epkwxkBKszmh/AV9Wan3qmM5TCqZMCQeMSkTSAUPyWaAekGUl6xN0Bgg== X-Received: by 2002:aa7:c716:0:b0:479:8313:3008 with SMTP id i22-20020aa7c716000000b0047983133008mr9172281edq.0.1673868850923; Mon, 16 Jan 2023 03:34:10 -0800 (PST) Received: from cloudflare.com (79.184.151.107.ipv4.supernova.orange.pl. [79.184.151.107]) by smtp.gmail.com with ESMTPSA id da11-20020a056402176b00b0049b5c746df7sm4838006edb.0.2023.01.16.03.34.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 16 Jan 2023 03:34:10 -0800 (PST) References: <20230113-sockmap-fix-v1-1-d3cad092ee10@cloudflare.com> <202301141018.w4fQc4gd-lkp@intel.com> <87sfgayeg9.fsf@cloudflare.com> User-agent: mu4e 1.6.10; emacs 28.2 From: Jakub Sitnicki To: Dan Carpenter Cc: oe-kbuild@lists.linux.dev, netdev@vger.kernel.org, lkp@intel.com, oe-kbuild-all@lists.linux.dev, kernel-team@cloudflare.com, John Fastabend , Eric Dumazet , Daniel Borkmann , Alexei Starovoitov , Andrii Nakryiko , syzbot+04c21ed96d861dccc5cd@syzkaller.appspotmail.com Subject: Re: [PATCH bpf 1/3] bpf, sockmap: Check for any of tcp_bpf_prots when cloning a listener Date: Mon, 16 Jan 2023 12:31:11 +0100 In-reply-to: Message-ID: <87h6wqyaq6.fsf@cloudflare.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Jan 16, 2023 at 02:13 PM +03, Dan Carpenter wrote: > On Mon, Jan 16, 2023 at 11:09:02AM +0100, Jakub Sitnicki wrote: [...] >> Smatch doesn't seem to graps the 2D array concept here. We can make it >> happy by being explicit but harder on the eyes: >> >> if (&tcp_bpf_prots[0][0] <= prot && prot < &tcp_bpf_prots[ARRAY_SIZE(tcp_bpf_prots)][0]) >> newsk->sk_prot = sk->sk_prot_creator; > > Huh. I can silence this false positive in Smatch... It never even > occured to me that this was a two dimensional array (I only have the > information in the email). > No need. Eric's macro helper makes Smatch happy. I'll use it in v2. >> >> Clang can do pointer arithmetic on 2D arrays just fine :-) > > Heh. I must have an older version of Clang. > > CC net/ipv4/tcp_bpf.o > net/ipv4/tcp_bpf.c:644:41: warning: array index 2 is past the end of the array (that has type 'struct proto[2][4]') [-Warray-bounds] > if (tcp_bpf_prots[0] <= prot && prot < tcp_bpf_prots[ARRAY_SIZE(tcp_bpf_prots)]) > ^ ~~~~~~~~~~~~~~~~~~~~~~~~~ > net/ipv4/tcp_bpf.c:544:1: note: array 'tcp_bpf_prots' declared here > static struct proto tcp_bpf_prots[TCP_BPF_NUM_PROTS][TCP_BPF_NUM_CFGS]; > ^ > 1 warning generated. FWIW, I've checked against: $ clang --version clang version 15.0.6 (Fedora 15.0.6-2.fc37) Gotta keep it fresh to be able to build bpf selftests ;-) But I sure don't want to break builds with older Clangs. Thanks for pointing it out.