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=-5.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 B0699C433FE for ; Mon, 7 Dec 2020 16:16:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7EA9A2376F for ; Mon, 7 Dec 2020 16:16:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726197AbgLGQQ7 (ORCPT ); Mon, 7 Dec 2020 11:16:59 -0500 Received: from us-smtp-delivery-124.mimecast.com ([63.128.21.124]:53502 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726141AbgLGQQ7 (ORCPT ); Mon, 7 Dec 2020 11:16:59 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607357732; 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=XGOBTSRTM9+tAuCjeJvzx4ZaxY4e+O+c9GUP2xJoJgw=; b=D4mLbskKF8OHYdIYDjrFl+uaFrAUMYnWCZksa6UOXRFuWDzrns8oDobzQaBY1VqgQ9QF4O lM06qimDspc18q5n3JGjmAV5bvb8fgbzywFNRwAUECNIFiffJYsL+OuNhu++j1Zv6o7U1y vXEUojKZJDMuny+H0dzyAZQdHPwHp0s= Received: from mail-wm1-f71.google.com (mail-wm1-f71.google.com [209.85.128.71]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-6-2HPbCSXjM-69ITbhC6OBSQ-1; Mon, 07 Dec 2020 11:15:30 -0500 X-MC-Unique: 2HPbCSXjM-69ITbhC6OBSQ-1 Received: by mail-wm1-f71.google.com with SMTP id u123so4295741wmu.5 for ; Mon, 07 Dec 2020 08:15:30 -0800 (PST) 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=XGOBTSRTM9+tAuCjeJvzx4ZaxY4e+O+c9GUP2xJoJgw=; b=X/ssEhnmmdf7ZIXOhJNqHV8Wob4D+WGSQdYxz9DRjCF0XchVETvZi4aCaXmc3B4EeD o3iokkRLOpVh+QwbNnm9MlKxsiGr5s58TdDMiAw9hAeWDYeuXPVnhVq4+r6tOEf7j+vA QleL+K795g2dPTKm6hrXRwoJOToYgQFCNj46JRly+lrmvQwyARVaZPHffyq5ABxwWM2A W+kqThKYyx0T7eg2iv+/ep8bHZAWYK4/EfQUNE6+Nmiy5LofFGR97/aZ17WhrgEgn43R 0AbH6imgvybMYHhDiNzPNhvgC75Kej9CZf1kehDZq9UJw5L6fUVWtWqvlGapaDPcbya+ kQpQ== X-Gm-Message-State: AOAM531KmAvHhe4dNM3nTSmeCJ9wD/9f9FyTUX5l8Dv3or99HyXo7B6s HO7L3+T1MHMynXDtJn+Mp0f7SUAQWcMXwu9FJmU21cn01pmq6+q6YDY6oZXM9YS1aTIzeswwB+L n7m7G/iURWWPv X-Received: by 2002:a5d:4586:: with SMTP id p6mr21186841wrq.308.1607357729066; Mon, 07 Dec 2020 08:15:29 -0800 (PST) X-Google-Smtp-Source: ABdhPJzfI4RZGHd6D/kw6tCcjmBDVCB5z3aDm5GYfb8Phhn8jgCzvJ4L7SXeLWXK5w2RDEsKyglQOQ== X-Received: by 2002:a5d:4586:: with SMTP id p6mr21186820wrq.308.1607357728860; Mon, 07 Dec 2020 08:15:28 -0800 (PST) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id j13sm14774907wmi.36.2020.12.07.08.15.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Dec 2020 08:15:28 -0800 (PST) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id F38951843F5; Mon, 7 Dec 2020 17:15:26 +0100 (CET) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Alexei Starovoitov Cc: Andrii Nakryiko , Yonghong Song , bpf Subject: Re: Latest libbpf fails to load programs compiled with old LLVM In-Reply-To: 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> X-Clacks-Overhead: GNU Terry Pratchett Date: Mon, 07 Dec 2020 17:15:26 +0100 Message-ID: <878sa9619d.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Alexei Starovoitov writes: > 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. What? It's a change in libbpf that breaks loading of existing BPF object files that were working (with libbpf) before. If that's not a backward compatibility break then that term has lost all meaning. >> 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 = fly. Eh? Did you even read the email you're replying to? This issue has nothing to do with iproute2, that was an unrelated thing Andrii asked me to change when he was looking at my example... -Toke