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=-3.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=no 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 632D7C433FF for ; Wed, 14 Aug 2019 22:01:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31EE92133F for ; Wed, 14 Aug 2019 22:01:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=netronome-com.20150623.gappssmtp.com header.i=@netronome-com.20150623.gappssmtp.com header.b="r/fxvywn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729390AbfHNWBj (ORCPT ); Wed, 14 Aug 2019 18:01:39 -0400 Received: from mail-qk1-f193.google.com ([209.85.222.193]:41432 "EHLO mail-qk1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728583AbfHNWBj (ORCPT ); Wed, 14 Aug 2019 18:01:39 -0400 Received: by mail-qk1-f193.google.com with SMTP id g17so325855qkk.8 for ; Wed, 14 Aug 2019 15:01:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netronome-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:in-reply-to:references :organization:mime-version:content-transfer-encoding; bh=jnzlZ6m4MyBxiN6dXhfXGdbsyLhcPOPGv61CSnzfC+A=; b=r/fxvywngqCj51PhCj37ngMB4xdglQXrSEZWUwJQGToBavgm0YUXJH/dZZb3sRhMSa 4XdBcej/gP8n2ywM/WYTbJQyhogVOj0HNnbJGWNegWHQHSpTynmdFvdMqwwALj4F1gp7 0w1QKvqUMeLRhbFVXfob6wnOs2TsqdVdfUOECgdNykLDS1opGxonLPw41BqlwriC1gza jixtbKZoTs/K+iMJ4t8m+eQqqL7TwY6UBO3O7BbenB7+UvQRiDdDfaBAEjHgNVSR5ulZ l3McWlEvyI1bdjmQ0r7UEsIdcKbJCEJmBTTRjbFfmnFkZRdEcsVXpfDhfN4cXdkZYYmj Km8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:in-reply-to :references:organization:mime-version:content-transfer-encoding; bh=jnzlZ6m4MyBxiN6dXhfXGdbsyLhcPOPGv61CSnzfC+A=; b=ic76JpHvjUt+siJ4iMNCB6eB471B1O6eCJFRHU7X+3kUBPuQqa3DdeM+r3Rck9guwb AAfl5LhYE6I6ufrGePTI5++n6EwpqxK+uGbc2lEzPJvpfOJvCqdJ3bUoExvJuoAF7xGA yaY/ltkmpv9j0dh4wRxnWYP5Aq4lRKme08tvz149gDtyACPPSWanzYjP/9wto3prG5jS b/d93peVFrS5UJxHJrxq3RZpm5VpTANmiCzcfvdePKAjERb+sLYdYH2L+OZuUk6QP13Z JY9nuh+9W+vDYO5ud0ve7jv6+nqU/QXzvPISD5/+2x2JYB5Xr6UwmQM3pbdTRyXxw8x7 7EJw== X-Gm-Message-State: APjAAAU6kRfO6iCLSlCmlqjgdAhRQFJXVYpOFt32HUYQoiAbVZtzmRhB MbDo3Mw73uTY8LoI06HuChWoXQ== X-Google-Smtp-Source: APXvYqyevbHlwujs+qIs2fF8/38hu1aCZhxdWs5ZHvmvdjmB2g6RzytsVXv5cXSc7L03g/nXtTIcqg== X-Received: by 2002:a37:bcc:: with SMTP id 195mr1339307qkl.115.1565820098385; Wed, 14 Aug 2019 15:01:38 -0700 (PDT) Received: from cakuba.netronome.com ([66.60.152.14]) by smtp.gmail.com with ESMTPSA id p201sm511922qke.6.2019.08.14.15.01.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Aug 2019 15:01:38 -0700 (PDT) Date: Wed, 14 Aug 2019 15:01:23 -0700 From: Jakub Kicinski To: Maxim Mikityanskiy Cc: Alexei Starovoitov , Daniel Borkmann , "bpf@vger.kernel.org" , "netdev@vger.kernel.org" , "David S. Miller" , =?UTF-8?B?QmrDtnJuIFTDtnBlbA==?= , Saeed Mahameed , Jesper Dangaard Brouer , John Fastabend , Martin KaFai Lau , Song Liu , Yonghong Song Subject: Re: [PATCH bpf-next v2] net: Don't call XDP_SETUP_PROG when nothing is changed Message-ID: <20190814150123.6b5124e8@cakuba.netronome.com> In-Reply-To: <20190814143352.3759-1-maximmi@mellanox.com> References: <5b123e9a-095f-1db4-da6e-5af6552430e1@iogearbox.net> <20190814143352.3759-1-maximmi@mellanox.com> Organization: Netronome Systems, Ltd. MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 14 Aug 2019 14:34:06 +0000, Maxim Mikityanskiy wrote: > Don't uninstall an XDP program when none is installed, and don't install > an XDP program that has the same ID as the one already installed. > > dev_change_xdp_fd doesn't perform any checks in case it uninstalls an > XDP program. It means that the driver's ndo_bpf can be called with > XDP_SETUP_PROG asking to set it to NULL even if it's already NULL. This > case happens if the user runs `ip link set eth0 xdp off` when there is > no XDP program attached. > > The symmetrical case is possible when the user tries to set the program > that is already set. > > The drivers typically perform some heavy operations on XDP_SETUP_PROG, > so they all have to handle these cases internally to return early if > they happen. This patch puts this check into the kernel code, so that > all drivers will benefit from it. > > Signed-off-by: Maxim Mikityanskiy Reviewed-by: Jakub Kicinski