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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 17529C04AB5 for ; Thu, 6 Jun 2019 18:19:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F276F2083D for ; Thu, 6 Jun 2019 18:19:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730532AbfFFST4 (ORCPT ); Thu, 6 Jun 2019 14:19:56 -0400 Received: from shards.monkeyblade.net ([23.128.96.9]:55336 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727559AbfFFSTz (ORCPT ); Thu, 6 Jun 2019 14:19:55 -0400 Received: from localhost (unknown [IPv6:2601:601:9f80:35cd::3d5]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id 50D1914DE1037; Thu, 6 Jun 2019 11:19:55 -0700 (PDT) Date: Thu, 06 Jun 2019 11:19:54 -0700 (PDT) Message-Id: <20190606.111954.2036000288766363267.davem@davemloft.net> To: fw@strlen.de Cc: john.hurley@netronome.com, netdev@vger.kernel.org, simon.horman@netronome.com, jakub.kicinski@netronome.com, jhs@mojatatu.com, oss-drivers@netronome.com Subject: Re: [RFC net-next v2 1/1] net: sched: protect against loops in TC filter hooks From: David Miller In-Reply-To: <20190606125818.bvo5im2wqj365tai@breakpoint.cc> References: <1559825374-32117-1-git-send-email-john.hurley@netronome.com> <20190606125818.bvo5im2wqj365tai@breakpoint.cc> X-Mailer: Mew version 6.8 on Emacs 26.1 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 06 Jun 2019 11:19:55 -0700 (PDT) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Florian Westphal Date: Thu, 6 Jun 2019 14:58:18 +0200 >> @@ -827,6 +828,7 @@ struct sk_buff { >> __u8 tc_at_ingress:1; >> __u8 tc_redirected:1; >> __u8 tc_from_ingress:1; >> + __u8 tc_hop_count:2; > > I dislike this, why can't we just use a pcpu counter? I understand that it's because the only precise context is per-SKB not per-cpu doing packet processing. This has been discussed before.