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=-1.1 required=3.0 tests=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 E09B6C433E0 for ; Sat, 4 Jul 2020 00:06:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ABD3F20747 for ; Sat, 4 Jul 2020 00:06:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="sayvllZq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726455AbgGDAGV (ORCPT ); Fri, 3 Jul 2020 20:06:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47282 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726379AbgGDAGV (ORCPT ); Fri, 3 Jul 2020 20:06:21 -0400 Received: from mail-pl1-x642.google.com (mail-pl1-x642.google.com [IPv6:2607:f8b0:4864:20::642]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3E40C061794; Fri, 3 Jul 2020 17:06:20 -0700 (PDT) Received: by mail-pl1-x642.google.com with SMTP id 72so2562957ple.0; Fri, 03 Jul 2020 17:06:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=7UMg+mEjzy3xVimDZCzvYsyI12zw07nNUOKb1rhadCM=; b=sayvllZqvov9e1fBu22meYNRdjUMDn7kR+eHeA+zCkmpQ1hH75bbCfWMT9uV+l2/JT bbZX3yaouonPtVmBq9qu/58Rac7ivp+cspN2kpdMNJYsdaSwIviXmsq0i1YDxWwly+7s MwQOY/TNQXc8mIOXVLW5o7yJs2aO3WE6fK+kl1CXf88Oqgck/JLHv72y+Y4ZOrgYYTmk JoZhGW7tl6Gr21ddt/AWAgtswVpxcRaPFg2s4g2la8oGj9dEzbSVLM7WwbC3xxp4WCli dShIbfw82q8uYSY5dHHx+OYfLFEftAVUfbDFKPNJQ0w1H4rC4L0x4HkDGVTJjM/atJfY oTgA== 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:references :mime-version:content-disposition:in-reply-to; bh=7UMg+mEjzy3xVimDZCzvYsyI12zw07nNUOKb1rhadCM=; b=ewYIDYY2U35ilkA2DOxrdIpVkYf/JqKDLT+pEdk+7Q5m/LqEdQnXO1a99doWUBt8OA fXg55HOqFN22NeSFlQuzIme8ZT3/FU9eb+qJhF5e1WEdDxZVPoBCYdvg6sKZlnBaFIYe 9d9igf5g+l/H/W4RGhFNUYg8QBLV5bguL/u5RUXFYb/h62UkepGaqtLO8pEnWmlVrjHt 9Iunu/Oiaroj+JcZEeeAoHP7vyApF9ICaLPTrxXATehXTpFWOq6G/aRQ/E6AgwQ2lDiS uee6FJiJR2or9PiFxU89xuHWYbyu40T+U5DgHOmsTSj3dpkyaCCORjhImSBrv3PnFLwB LsBA== X-Gm-Message-State: AOAM5339Ufj35Ma2hpOcin7njyp2e8jZSTSUBQ40ozOlx5cDyt2QzOwR psa31vnMkAmW7rW9LRpVVf8= X-Google-Smtp-Source: ABdhPJwdQsoe3BLy3+8W8uel5KTOJGL6fkyp92gLyek3RevEayrbei+Bg+lwJvyxXugERCBTrz2sZg== X-Received: by 2002:a17:90a:ae14:: with SMTP id t20mr38057450pjq.184.1593821180297; Fri, 03 Jul 2020 17:06:20 -0700 (PDT) Received: from ast-mbp.dhcp.thefacebook.com ([2620:10d:c090:400::5:d8c2]) by smtp.gmail.com with ESMTPSA id q92sm12186901pjh.12.2020.07.03.17.06.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Jul 2020 17:06:19 -0700 (PDT) Date: Fri, 3 Jul 2020 17:06:17 -0700 From: Alexei Starovoitov To: Linus Torvalds Cc: David Miller , Daniel Borkmann , "Eric W. Biederman" , Netdev , bpf , kernel-team@fb.com Subject: Re: [PATCH bpf-next 3/3] bpf: Add kernel module with user mode driver that populates bpffs. Message-ID: <20200704000617.mrkwrta2gwywgb7l@ast-mbp.dhcp.thefacebook.com> References: <20200702200329.83224-1-alexei.starovoitov@gmail.com> <20200702200329.83224-4-alexei.starovoitov@gmail.com> <20200703023547.qpu74obn45qvb2k7@ast-mbp.dhcp.thefacebook.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Thu, Jul 02, 2020 at 08:34:17PM -0700, Linus Torvalds wrote: > On Thu, Jul 2, 2020 at 7:35 PM Alexei Starovoitov > wrote: > > > > On Thu, Jul 02, 2020 at 06:05:29PM -0700, Linus Torvalds wrote: > > > On Thu, Jul 2, 2020 at 1:03 PM Alexei Starovoitov > > > wrote: > > > > > > > > The BPF program dump_bpf_prog() in iterators.bpf.c is printing this data about > > > > all BPF programs currently loaded in the system. This information is unstable > > > > and will change from kernel to kernel. > > > > > > If so, it should probably be in debugfs, not in /sys/fs/ > > > > /sys/fs/bpf/ is just a historic location where we chose to mount bpffs. > > It's more the "information is unstable and will change from kernel to kernel" > > No such interfaces exist. If people start parsing it and depending it, > it's suddenly an ABI, whether you want to or not (and whether you > documented it or not). > > At least if it's in /sys/kernel/debug/bpf/ or something, it's less > likely that anybody will do that. I think I will go with "debug" mount option then. By default nothing will be preloaded, so de-facto /sys/fs/bpf/ will stay empty.