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=-3.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 88967C54FD0 for ; Fri, 24 Apr 2020 14:03:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5C1B921473 for ; Fri, 24 Apr 2020 14:03:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="a3XaaelA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728576AbgDXODy (ORCPT ); Fri, 24 Apr 2020 10:03:54 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:49979 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727863AbgDXODy (ORCPT ); Fri, 24 Apr 2020 10:03:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587737032; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=86M4xLQmCX1+Kj9jFqVw76Vk3b/HPyVBNV1KeyvfXH8=; b=a3XaaelA4epJrbJCVSKB3FtMFoxviho57uk87hb8FEJ4R1yDi1bDXIb7a5P/NrNJ9p3wAH bFxX4a99lhPAd8QkqFEvtJQIS3W4M2QOl7TtiefHkoUTz9o/T0x8vfA6/5whGUjRAQMhRw k7ZlfjXk4g1ZcaKRcXd7+3WTOpbfUb4= Received: from mail-lf1-f69.google.com (mail-lf1-f69.google.com [209.85.167.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-92-mBOgew2HMb64Ee5DWAbo8g-1; Fri, 24 Apr 2020 10:03:51 -0400 X-MC-Unique: mBOgew2HMb64Ee5DWAbo8g-1 Received: by mail-lf1-f69.google.com with SMTP id g5so3935624lfh.9 for ; Fri, 24 Apr 2020 07:03:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:in-reply-to:references:date :message-id:mime-version:content-transfer-encoding; bh=86M4xLQmCX1+Kj9jFqVw76Vk3b/HPyVBNV1KeyvfXH8=; b=A0ugrg273JFmy8u8sOt714ksl939D4yyvP9ZyhZyW9IjQcmcRvM/OcPHOFQ6R9fNdA Hvb/0Qaf9F+5peLNT0cGDL1vAtgkNUUKrUHm7yDEAIaMomY1jNwycGpGIDQ5S+rV+0QV 0+TXiczkc7v1GgpdA8MKX0Z5c7MEo5ojaGF3oftAkC6LRcx5lkXT+w374lM0JdnoJHLp gWG857vbr6loixm8w5y1F1cegfTigf8dOuNyUrUZ3l+hwOzN3Pn3lCbtAbG8U3FyCVT6 LpaeG5EP69PN/+CB+YIXzD2C0E6+O1X+x1dkUf/2/4G0p/u5NLsb2zStXtLAqkFQMHdI oohg== X-Gm-Message-State: AGi0PubONN/e3iUauLl6nSXDOkW43pPvajeGT5E9fMF4Ybv265SRvS6S mY10RTYex4bOtU3dh0rKPVtPo0KPbbZvsFbekVkcGnerN9ABp2X9de6JQUVTZv8x/7uk1vDqlM/ k0d9oxSyo3XNWOJ9n X-Received: by 2002:a2e:97d3:: with SMTP id m19mr5838013ljj.136.1587737029525; Fri, 24 Apr 2020 07:03:49 -0700 (PDT) X-Google-Smtp-Source: APiQypJMYfs1sZxGBXbruY1FnOCks0xsAgGNnkQ+l8pOrzapO4B0sM0RXjSKiML1hjyB3FQOYpf72Q== X-Received: by 2002:a2e:97d3:: with SMTP id m19mr5837996ljj.136.1587737029225; Fri, 24 Apr 2020 07:03:49 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id l7sm4944371lfg.79.2020.04.24.07.03.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 24 Apr 2020 07:03:38 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id B91671814FF; Fri, 24 Apr 2020 16:03:23 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Jesper Dangaard Brouer , sameehj@amazon.com Cc: Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, zorik@amazon.com, akiyano@amazon.com, gtzalik@amazon.com, Daniel Borkmann , Alexei Starovoitov , John Fastabend , Alexander Duyck , Jeff Kirsher , David Ahern , Willem de Bruijn , Ilias Apalodimas , Lorenzo Bianconi , Saeed Mahameed , steffen.klassert@secunet.com Subject: Re: [PATCH net-next 06/33] net: XDP-generic determining XDP frame size In-Reply-To: <158757167152.1370371.9610663437543094071.stgit@firesoul> References: <158757160439.1370371.13213378122947426220.stgit@firesoul> <158757167152.1370371.9610663437543094071.stgit@firesoul> X-Clacks-Overhead: GNU Terry Pratchett Date: Fri, 24 Apr 2020 16:03:23 +0200 Message-ID: <87blnh3rro.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Jesper Dangaard Brouer writes: > The SKB "head" pointer points to the data area that contains > skb_shared_info, that can be found via skb_end_pointer(). Given > xdp->data_hard_start have been established (basically pointing to > skb->head), frame size is between skb_end_pointer() and data_hard_start, > plus the size reserved to skb_shared_info. > > Change the bpf_xdp_adjust_tail offset adjust of skb->len, to be a positive > offset number on grow, and negative number on shrink. As this seems more > natural when reading the code. > > Signed-off-by: Jesper Dangaard Brouer Acked-by: Toke H=C3=B8iland-J=C3=B8rgensen