From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932166AbeCKPNU (ORCPT ); Sun, 11 Mar 2018 11:13:20 -0400 Received: from mail.kernel.org ([198.145.29.99]:55874 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932118AbeCKPNT (ORCPT ); Sun, 11 Mar 2018 11:13:19 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BC5421707 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=mhiramat@kernel.org Date: Mon, 12 Mar 2018 00:13:15 +0900 From: Masami Hiramatsu To: Ingo Molnar Cc: Thomas Gleixner , x86@kernel.org, Yang Bo , Ingo Molnar , "H . Peter Anvin" , linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli , Andrew Morton , Steven Rostedt , Laura Abbott , Josef Bacik , Alexei Starovoitov Subject: Re: [RFC PATCH -tip 0/9] kprobes: Cleanup jprobe implementation Message-Id: <20180312001315.7a5382b772a352919e638699@kernel.org> In-Reply-To: <20180310082444.uiy7fdqlxh6qbuwp@gmail.com> References: <152059891712.4214.9539716544254881611.stgit@devbox> <20180310082444.uiy7fdqlxh6qbuwp@gmail.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 10 Mar 2018 09:24:44 +0100 Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > > > Hello, > > > > Since we decided to remove jprobe from kernel last year, > > its APIs are disabled and we worked on moving in-kernel > > jprobe users to kprobes or trace-events. And now no jprobe > > users are here anymore. > > > > I think it is good time to get rid of jprobe implementation > > from the kernel. However, I need other arch developers help > > to complete it, since jprobe is implemented multi arch wide. > > I can remove those code, but can not test all of those. > > > > Here is the series of patches to show how to do that. > > I tried to remove it from x86 tree. Basically we need to > > do 3 things; > > > > - Remove jprobe functions (register/unregister, > > setjump/longjump) from generic/arch-dependent code. > > [1/9][2/9][3/9] > > - Remove break_handler related code. > > [4/9][5/9][6/9] > > - Do not disable preemption on exception handler > > [7/9][8/9][9/9] > > > > The [3/9] and [6/9] are destractive changes except for x86 > > (means causes build errors) since those arch still have some > > references of those functions. So we need to write patches > > similar to [2/9] and [5/9] for each arch before applying those. > > In this series I sorted it as this order just for review, > > [3/9] and [6/9] should be applied after all archs have > > been fixed. > > > > Also, [7/9] is a kind of destractive, which changes required > > behavior for the pre_handlers which changes regs->ip. > > So we also need a patch similar to [7/9] for each arch too. > > Fortunately, current in-tree such user is very limited, both > > works only on x86. So it is not hurry, but we need to change > > arch dependent code. > > > > Thank you, > > > > --- > > > > Masami Hiramatsu (9): > > kprobes: Remove jprobe API implementation > > x86: kprobes: Remove jprobe implementation > > kprobes: Remove jprobe data structure and interfaces > > kprobes: Ignore break_handler > > x86: kprobes: Ignore break_handler > > kprobes: Remove break_handler from struct kprobe > > x86: kprobes: Do not disable preempt on int3 path > > error-injection: Fix to not enabling preemption in pre_handler > > tracing: kprobes: Fix to not enabling preemption > > > > > > Documentation/kprobes.txt | 13 ++-- > > arch/x86/include/asm/kprobes.h | 3 - > > arch/x86/kernel/kprobes/common.h | 10 --- > > arch/x86/kernel/kprobes/core.c | 114 ++------------------------------------ > > arch/x86/kernel/kprobes/ftrace.c | 21 +------ > > arch/x86/kernel/kprobes/opt.c | 1 > > include/linux/kprobes.h | 54 ------------------ > > kernel/fail_function.c | 1 > > kernel/kprobes.c | 115 ++------------------------------------ > > kernel/trace/trace_kprobe.c | 3 - > > 10 files changed, 20 insertions(+), 315 deletions(-) > > Nice work, and I love the diffstat, but please do a series that works (builds and > boots and has working kprobes) at every interim step. Thank you! Yes, I'm thinking just keep header files no change (no removing API and structure) until all archs apply C file changes in next version, so that we can avoid any build error/test error. Thanks, > > Thanks, > > Ingo -- Masami Hiramatsu