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 22AB2C55194 for ; Fri, 24 Apr 2020 14:03:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 025CF2075A for ; Fri, 24 Apr 2020 14:03:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="R55GRcqE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727863AbgDXODz (ORCPT ); Fri, 24 Apr 2020 10:03:55 -0400 Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120]:47365 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727921AbgDXODz (ORCPT ); Fri, 24 Apr 2020 10:03:55 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1587737033; 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=R55GRcqEX4TM0eJoTC/rW/2Ou8pu8DZX0bXaX+TdZ7mBdOyyPahVFtMqMpV7J+/X8INaML MkzspGFzY/jPwDB/fTkLPuzx4hBUOhFTF7RWKlJjYGPmEB7VghKJTcnsu/JmBoxUpXn1ht nLGcsbq+u5975pZo+rrceOJR6eXU7X0= Received: from mail-lf1-f70.google.com (mail-lf1-f70.google.com [209.85.167.70]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-499-GeTXm1eHMDyWtub1VxeKGQ-1; Fri, 24 Apr 2020 10:03:52 -0400 X-MC-Unique: GeTXm1eHMDyWtub1VxeKGQ-1 Received: by mail-lf1-f70.google.com with SMTP id d5so3948704lfb.5 for ; Fri, 24 Apr 2020 07:03:51 -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=m6A4f9lJU0+XB2FWyYiV1O5un9rYZZIAcIH+Ex5OWSiysUouKGlhj+OiQw6z6Jd6dz 35261J0BZh2InJbAKNNLexfxBeBOMJ45VlWnmLLn1KtOVt7khj3EhRpbBQiFs0+mtQTx 7TMt4OnsXhPa0Makf6rb/M21vIiy1mqylk67rJUdXmtV827OGg3QnR5gS4LFIEmfIF0v IVR3rD40v2V8V3PqleHhH2/Z1cq9aL020JxyqB52Rtac50Hj28rGmsZ5Ey8m+MGk8iio SfbXL1Koc4zGxK2CjwvFk89LMUuAShtEN9+4RaqUzU3v3sDWc5zeXbfDowT6BSEclEd2 Cydw== X-Gm-Message-State: AGi0PuazfnqOP/1Gco4GQmtqiuWO6SYOPWxpR/VqXFUFb+NKO99/PMc3 ZNURo5DyOKlQf8dcuzfBMTFpbT0LDoIMKOBFPTeyydWSojAAqQ2DZEGCyGj3M+mzKG2UZHxy/L2 Q+4mndnEog5f5 X-Received: by 2002:a2e:97d3:: with SMTP id m19mr5838020ljj.136.1587737029538; 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: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@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