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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_2 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 24533C06513 for ; Thu, 4 Jul 2019 11:28:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00A77218A3 for ; Thu, 4 Jul 2019 11:28:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727626AbfGDL2h (ORCPT ); Thu, 4 Jul 2019 07:28:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:47984 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727560AbfGDL2h (ORCPT ); Thu, 4 Jul 2019 07:28:37 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 51968218A0; Thu, 4 Jul 2019 11:28:35 +0000 (UTC) Date: Thu, 4 Jul 2019 07:28:33 -0400 From: Steven Rostedt To: Masami Hiramatsu Cc: Ingo Molnar , linux-kernel@vger.kernel.org, Tom Zanussi , Ravi Bangoria , Namhyung Kim , Arnaldo Carvalho de Melo Subject: Re: [PATCH v2 00/12] tracing/probe: Add multi-probes per event support Message-ID: <20190704072833.4bc17d3c@gandalf.local.home> In-Reply-To: <20190704153958.16a97c881aebbc5898b1264e@kernel.org> References: <156095682948.28024.14190188071338900568.stgit@devnote2> <20190704153958.16a97c881aebbc5898b1264e@kernel.org> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 4 Jul 2019 15:39:58 +0900 Masami Hiramatsu wrote: > Hi Steve, > > Would you have any comment on this? > Hi Masami, It's on my todo list. As today is a US holiday, I'll look at this on Monday. Thanks for the reminder! -- Steve > Thank you, > > On Thu, 20 Jun 2019 00:07:09 +0900 > Masami Hiramatsu wrote: > > > Hello, > > > > This is the 2nd version of multi-probes per event support on ftrace > > and perf-tools. > > > > Previous version is here; > > https://lkml.org/lkml/2019/5/31/573 > > > > >From this version, I omitted first 9 patches which has been picked > > to Steve's tree. > > In this version, I've fixed some bugs and hardened some unexpected > > error cases according to Steve's comment. > > Here are changes in this version: > > > > - [1/12] This have below changes. > > - Warn if the primary trace_probe does not exist. > > - Fix enable_trace_kprobe() to not return error if the any probes > > are "gone" state. If all probes have gone or any other error > > reason, the event can not be enabled and return error. > > - Fix trace_probe_enable() to roll back all enabled uprobe if > > any one of uprobe is failed to enable. > > - [7/12] Swap the checking order of filename for avoiding unexpected > > memory access. > > > > > > ==== > > For trace-event, we can insert same trace-event on several places > > on the code, and those can record similar information as a same event > > with same format. > > > > This series implements similar feature on probe-event. Since the probe > > event is based on the compiled binary, sometimes we find that the target > > source line is complied into several different addresses, e.g. inlined > > function, unrolled loop, etc. In those cases, it is useful to put a > > same probe-event on different addresses. > > > > With this series, we can append multi probes on one event as below > > > > # echo p:testevent _do_fork r1=%ax r2=%dx > kprobe_events > > # echo p:testevent fork_idle r1=%ax r2=%cx >> kprobe_events > > # kprobe_events > > p:kprobes/testevent _do_fork r1=%ax r2=%dx > > p:kprobes/testevent fork_idle r1=%ax r2=%cx > > > > This means testevent is hit on both of _do_fork and fork_idle. > > As you can see, the appended event must have same number of arguments > > and those must have same 'type' and 'name' as original one. This is like > > a function signature, it checks whether the appending event has the same > > type and name of event arguments and same probe type, but doesn't care > > about the assignment. > > > > So, below appending commands will be rejected. > > > > # echo p:testevent _do_fork r1=%ax r2=%dx > kprobe_events > > # echo p:testevent fork_idle r1=%ax >> kprobe_events > > (No 2nd argument) > > # echo p:testevent fork_idle r1=%ax r2=%ax:x8 >> kprobe_events > > (The type of 2nd argument is different) > > > > If one inlined code has an argument on a register, but another > > inlined code has fixed value (as a result of optimization), > > you can also specify the fixed immediate value, e.g. > > > > # echo p:testevent _do_fork r1=%ax r2=%dx > kprobe_events > > # echo p:testevent fork_idle r1=%ax r2=\1 >> kprobe_events > > > > > > Thank you, > > > > --- > > > > Masami Hiramatsu (12): > > tracing/probe: Split trace_event related data from trace_probe > > tracing/dynevent: Delete all matched events > > tracing/dynevent: Pass extra arguments to match operation > > tracing/kprobe: Add multi-probe per event support > > tracing/uprobe: Add multi-probe per uprobe event support > > tracing/kprobe: Add per-probe delete from event > > tracing/uprobe: Add per-probe delete from event > > tracing/probe: Add immediate parameter support > > tracing/probe: Add immediate string parameter support > > selftests/ftrace: Add a testcase for kprobe multiprobe event > > selftests/ftrace: Add syntax error test for immediates > > selftests/ftrace: Add syntax error test for multiprobe > > > > > > Documentation/trace/kprobetrace.rst | 1 > > Documentation/trace/uprobetracer.rst | 1 > > kernel/trace/trace.c | 8 - > > kernel/trace/trace_dynevent.c | 10 + > > kernel/trace/trace_dynevent.h | 7 - > > kernel/trace/trace_events_hist.c | 4 > > kernel/trace/trace_kprobe.c | 241 ++++++++++++++---- > > kernel/trace/trace_probe.c | 176 +++++++++++-- > > kernel/trace/trace_probe.h | 67 ++++- > > kernel/trace/trace_uprobe.c | 263 +++++++++++++++----- > > tools/testing/selftests/ftrace/test.d/functions | 2 > > .../ftrace/test.d/kprobe/kprobe_multiprobe.tc | 35 +++ > > .../ftrace/test.d/kprobe/kprobe_syntax_errors.tc | 15 + > > 13 files changed, 665 insertions(+), 165 deletions(-) > > create mode 100644 tools/testing/selftests/ftrace/test.d/kprobe/kprobe_multiprobe.tc > > > > -- > > Masami Hiramatsu (Linaro) > >