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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id F1159C19F2A for ; Fri, 29 Jul 2022 00:02:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232968AbiG2ACq (ORCPT ); Thu, 28 Jul 2022 20:02:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232909AbiG2ACl (ORCPT ); Thu, 28 Jul 2022 20:02:41 -0400 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 361FD4C62D; Thu, 28 Jul 2022 17:02:41 -0700 (PDT) Received: from kbox (unknown [76.135.27.191]) by linux.microsoft.com (Postfix) with ESMTPSA id C693820FE893; Thu, 28 Jul 2022 17:02:40 -0700 (PDT) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com C693820FE893 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1659052960; bh=5HsiSU6m/N6TMarfRdE3+yKjdjkRJvzIxn0ww+MA5EQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=G3wnN+IxGKceZ3K5xAhgyW4p7SUtOA5jHr6JAFv1X7+vk02/skz386Uve2498aWq7 LiObo1cOVNJrUHdjfE1jJdKCqpjuVWW6DVONZrS6MIDdozga1kI8x8bdqJFc7IoDD2 iVsQw6wmdjvybihrILNDnuSbu29/vnz6mZ4wB52I= Date: Thu, 28 Jul 2022 17:02:34 -0700 From: Beau Belgrave To: rostedt@goodmis.org, mhiramat@kernel.org, mathieu.desnoyers@efficios.com Cc: linux-trace-devel@vger.kernel.org, linux-kernel@vger.kernel.org, beaub@linux.microsoft.com Subject: Re: tracing/user_events: Tracking broken status and feedback Message-ID: <20220729000234.GA2746@kbox> References: <20220725231900.GA2389@kbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220725231900.GA2389@kbox> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 25, 2022 at 04:19:00PM -0700, Beau Belgrave wrote: > To help keep track of what is required to remove the broken status from > user_events I am starting this thread. I would like to use this thread > to provide status on the work that has been done so far and to have a > discussion about when the broken status can be removed. > > Feedback threads from 5.18 version of user_events: > 1. https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/ > 2. https://lore.kernel.org/all/1651771383.54437.1652370439159.JavaMail.zimbra@efficios.com/ > > All the feedback has been addressed in the patchsets 1 and 2 (see below). > Here are the details: > > 1. Use bits vs bytes in event enabled memory mappings. > Fixed in patchset 1. > > 2. Pack ABI structures where size is used. > Fixed in patchset 1. > > 3. Don't trust user strings for string formatting. > Fixed in patchset 1. > > 4. Move to refcount APIs vs atomic for tracking references. > Fixed in patchset 1. > > 5. Ensure event_mutex is held during registration. > Fixed in patchset 2. > > With these, I believe I have addressed all issues to remove the > "broken status". > > Here is the list of additional feedback (and status) that I don't believe > should have a bearing on removing the "broken status": > > 1. Kernel vs user tracers in ABI. > This is not done, the plan is to build a libtracepoint library that allows > working with both kernel and user tracers in user programs. Steven is > working on this at the moment. I don't believe this is required to remove > the broken status, but it will help prove the ABI by having it. > > No patchset yet. > > 2. Container/namespace isolation of events. > user_events utilizes tracefs for user facing files in the ABI. I've created > an RFC patchset showing how if tracefs offered an isolated directory > structure per-namespace the user_events ABI is unaffected. This is true for > other ABIs that tracefs hosts, if they would like to integrate. I don't > believe this is required to remove the broken status, however, it's useful > to have to see how the ABI is unaffected while we work toward enabling > isolation within tracing. > > See patchset 3. > > Patchsets: > 1. https://lore.kernel.org/all/20220425184631.2068-1-beaub@linux.microsoft.com/ > 2. https://lore.kernel.org/all/20220328223225.1992-1-beaub@linux.microsoft.com/ > 3. https://lore.kernel.org/all/20220707215828.2021-1-beaub@linux.microsoft.com/ > > Thanks, > -Beau Steven had feedback on patchset 1 here: https://lore.kernel.org/all/20220726180115.69320865@gandalf.local.home/ I've updated patchset 1 and 3 to address this feedback. Updated patchsets: 1. https://lore.kernel.org/all/20220728233309.1896-1-beaub@linux.microsoft.com/ 3. https://lore.kernel.org/all/20220728235241.2249-1-beaub@linux.microsoft.com/ Thanks, -Beau