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=-2.3 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, USER_AGENT_SANE_1 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 6B8FFC5DF60 for ; Tue, 5 Nov 2019 15:47:15 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FAD4217F5 for ; Tue, 5 Nov 2019 15:47:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="tTDRl7p0" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389592AbfKEPrO (ORCPT ); Tue, 5 Nov 2019 10:47:14 -0500 Received: from mail-pg1-f193.google.com ([209.85.215.193]:42834 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389399AbfKEPrO (ORCPT ); Tue, 5 Nov 2019 10:47:14 -0500 Received: by mail-pg1-f193.google.com with SMTP id s23so11122697pgo.9; Tue, 05 Nov 2019 07:47:14 -0800 (PST) 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:user-agent; bh=c+SKUavQ/UUT2pvxlsKyWAGVl/eUZ1sFiKjSUHD7OWM=; b=tTDRl7p0Eya+1H2H5SbkUKoE0XWcF71PfZ2sZ81JCKF8hcpj0PvtpfgwEJcIb5A2rt BXkKQOC7EIvE95H3Mu0hYRN7voHY1q2g27U4GPdQrAXqrB4p+fTgYAUwADrl9ahl2ezb uYUmbvCNGf+qzWbO0cY7zqcuZXjuj47chwEXtkGy7UiRP3LBtr3I/Cn7DG30F8dCY2CZ czRjJ2C9Ff2HJ1umguLQgkoDaCIFmlMuKv7uVAIAsFDo834KqRNURk45Uzrh2gC0rw5x dyRVpMEGAXd8YfKUZQjhd15wIffmcUPD5l4pU7AByoUIlN3U+1Si/u4MZeh/WpIxZHEv J/hA== 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:user-agent; bh=c+SKUavQ/UUT2pvxlsKyWAGVl/eUZ1sFiKjSUHD7OWM=; b=HtbKsCKvaF1fncW57rWbhN40tgYBEpyjfL4gKkHa0vIwbankC9dXD3dr6dwhWYsTIZ 7pg1ZDuzBTp43X+evTWNS3UM6Z64qex5ZPiXun7IM8sg88bBkZ7BHgLFnH1437LFbiyk qJYQdLPTSzxQA/wYkLPjMi4KiyxGB7oLzR+V3P/uZpbxmawEvrP4YWiREPoqXBHof2lw xEDYOUsKX0pxl+6kcXT/D3QTMszwajfQCRopy9qDK+iAixCuP7decGQGhgMos6UQ1dmd xHxDS0X/T3+yYoY8Ou8IRhSfh4LkMwImB3xNAMRtbfnvdcPkP6zLUvIjHMPq4OqlqqHS 4lbQ== X-Gm-Message-State: APjAAAVXs308D9cYz5afrF3ws1SYm5HDAa11Q/TUQW8OPt12bLZ4Y+s0 TJSS00iuj7mobbatirVECNM= X-Google-Smtp-Source: APXvYqzd9skRKsgAN0zqoHd1Us8MuQbRfbt9bE2FPxQNkUxx8ibqeUOlV7InWx/0LqGJSDW2uB40kg== X-Received: by 2002:a17:90a:d351:: with SMTP id i17mr7515469pjx.36.1572968833804; Tue, 05 Nov 2019 07:47:13 -0800 (PST) Received: from ast-mbp.dhcp.thefacebook.com ([2620:10d:c090:200::1:47d0]) by smtp.gmail.com with ESMTPSA id b17sm22620435pfr.17.2019.11.05.07.47.11 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 05 Nov 2019 07:47:13 -0800 (PST) Date: Tue, 5 Nov 2019 07:47:11 -0800 From: Alexei Starovoitov To: Steven Rostedt Cc: Alexei Starovoitov , davem@davemloft.net, daniel@iogearbox.net, peterz@infradead.org, x86@kernel.org, netdev@vger.kernel.org, bpf@vger.kernel.org, kernel-team@fb.com, Thomas Gleixner , Linus Torvalds Subject: Re: [PATCH bpf-next 0/7] Introduce BPF trampoline Message-ID: <20191105154709.utmzm6qvtlux4hww@ast-mbp.dhcp.thefacebook.com> References: <20191102220025.2475981-1-ast@kernel.org> <20191105143154.umojkotnvcx4yeuq@ast-mbp.dhcp.thefacebook.com> <20191105104024.4e99a630@grimm.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191105104024.4e99a630@grimm.local.home> User-Agent: NeoMutt/20180223 Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org On Tue, Nov 05, 2019 at 10:40:24AM -0500, Steven Rostedt wrote: > On Tue, 5 Nov 2019 06:31:56 -0800 > Alexei Starovoitov wrote: > > > Steven, > > look slike your branch hasn't been updated in 13 days. > > Are you still planning to fix the bugs and send it in for the merge window? > > I cannot afford to wait a full release, since I have my own follow for > > XDP/networking based on this and other folks are building their stuff on top of > > BPF trampoline too. So I'm thinking for v2 I will switch to using text_poke() > > and add appropriate guard checks, so it will be safe out of the box without > > ftrace dependency. If register_ftrace_direct() indeed comes in soon I'll > > switch to that and will make bpf trampoline to co-operate with ftrace. > > text_poke approach will make it such that what ever comes first to trace the > > fentry (either bpf trampoline or ftrace) will grab the nop and the other system > > will not be able to attach. That's safe and correct, but certainly not nice > > long term. So the fix will be needed. The key point that switching to text_poke > > will remove the register_ftrace_direct() dependency, unblock bpf developers and > > will give you time to land your stuff at your pace. > > Alexei, > > I am still working on it, and if it seems stable enough I will submit > it for this merge window, but there's no guarantees. It's ready when > it's ready. I gave 5 talks last week (4 in Lyon, and one is Sofia, > Bulgaria), thus I did not have time to work on it then. I'm currently > in the Sofia office, and I got a version working that seems to be > stable. But I still have to break it up into a patch series, and run it > through more stress tests. > > If you have to wait you may need to wait. The Linux kernel isn't > something that is suppose to put in temporary hacks, just to satisfy > someone's deadline. Ok. I will switch to text_poke and will make it hack free. ftrace mechanisms are being replaced by text_poke anyway.