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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 8C918C1B087 for ; Mon, 7 Dec 2020 15:56:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 69FAB23877 for ; Mon, 7 Dec 2020 15:56:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726840AbgLGP4T (ORCPT ); Mon, 7 Dec 2020 10:56:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726487AbgLGP4S (ORCPT ); Mon, 7 Dec 2020 10:56:18 -0500 Received: from mail-lf1-x12f.google.com (mail-lf1-x12f.google.com [IPv6:2a00:1450:4864:20::12f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 58F68C061793 for ; Mon, 7 Dec 2020 07:55:38 -0800 (PST) Received: by mail-lf1-x12f.google.com with SMTP id s30so18792470lfc.4 for ; Mon, 07 Dec 2020 07:55:38 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=2ns4l6DTJ6AHFucdrrlh89ycXS4RQATDPRF8fpv/tss=; b=Z7Gt8elzv7yMIf6fXrAuEAN0o955Dx7qICBcGktU3KsuYPCBES2WQrcixsnCro/yac aDdnNWmcFfClJwfJjtUaTYpFP+zxk+yuraLVIgbjdkWCkrTqo4ViYOxrzT3nug1Dp/ue SWocKXYRQ+6kS4P2gNBZwLRS4ez3+zUfn9DEZbz6nF+wX6xNV4MJYmywXx4yNanUb5eg Nw9/FJU1sS5MpuLRSYcT7qagTpkrPycEfg7FFODMGEmsFNUBNnQW/7Bd50r3gnRVU5ZN MWkQFICVKdT+Q9/tfBDxqdeAc8DiYD1sM6JCim3cOG02aWb6WX/ScPPwTwoxz3ywT8Dw 4buw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=2ns4l6DTJ6AHFucdrrlh89ycXS4RQATDPRF8fpv/tss=; b=OqTTWtD1YytBctUPzWi5hgTKUAX1lH57I+xOzVUDc3XX8lugvowNluEpJNc2Bi+oS6 REQ/Q9U8saL+28k9/7g9h2edNJY+o5Nh1MGo5jfWIZwQzOpARdWtVFIG5hqVxZ2UazkJ CfN+zpTMfRIAUN8/6EF5JkKERB8pQDCDNB8Cr4AQ+5QAEeYGhKq/t5d+kT+fSEkOjOdH oP+CBl0rPidbmu4bPDIQXp0PayjQga9o3CPPKXhl+zXy7JIPTrgDln/nyt4QPiAJh5iR Mee1C4AiclvY2moV3NFlmdIQE5QZKIjGQenpYBhnKMvHrNgjpAbJoBfA5OsXcCH5Cox4 YTCw== X-Gm-Message-State: AOAM533EVXHP6Clt/bTN6Vm1Ufms1ynyG1DQCn6tbY+nurx2tlPw89or +feflx9RG7jbY/3wLR2jrotoyrWa5D/Qijjk3cQ= X-Google-Smtp-Source: ABdhPJyVn90ZGeQ4Z9iqucHOBpRtkkm9pUM31bpGrKDhQ39Y62wXIA/3FsCRcK4VFNnCnOH79jsdU48/nWNkZUNcN5M= X-Received: by 2002:a05:6512:3227:: with SMTP id f7mr9229109lfe.119.1607356536841; Mon, 07 Dec 2020 07:55:36 -0800 (PST) MIME-Version: 1.0 References: <87lfeebwpu.fsf@toke.dk> <10679e62-50a2-4c01-31d2-cb79c01e4cbf@fb.com> <87r1o59aoc.fsf@toke.dk> <6801fcdb-932e-c185-22db-89987099b553@fb.com> <875z5d7ufl.fsf@toke.dk> In-Reply-To: <875z5d7ufl.fsf@toke.dk> From: Alexei Starovoitov Date: Mon, 7 Dec 2020 07:55:25 -0800 Message-ID: Subject: Re: Latest libbpf fails to load programs compiled with old LLVM To: =?UTF-8?B?VG9rZSBIw7hpbGFuZC1Kw7hyZ2Vuc2Vu?= Cc: Andrii Nakryiko , Yonghong Song , bpf Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Mon, Dec 7, 2020 at 3:03 AM Toke H=C3=B8iland-J=C3=B8rgensen wrote: > > Wait, what? This is a regression that *breaks people's programs* on > compiler versions that are still very much in the wild! I mean, fine if > you don't want to support new features on such files, but then surely we > can at least revert back to the old behaviour? Those folks that care about compiling with old llvm would have to stick to whatever loader they have instead of using libbpf. It's not a backward compatibility breakage. > I used "prog" because that's what iproute2 looks for if you don't supply Please don't use iproute2 as a reason to do anything in libbpf. It won't fl= y.