From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751878AbeCJIYu (ORCPT ); Sat, 10 Mar 2018 03:24:50 -0500 Received: from mail-wr0-f196.google.com ([209.85.128.196]:42529 "EHLO mail-wr0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750829AbeCJIYs (ORCPT ); Sat, 10 Mar 2018 03:24:48 -0500 X-Google-Smtp-Source: AG47ELv4B+wnXfDb8qUqR/nwvujkYi6c2I7OKp0hIYFwInmWiFLcGiAtTiNLgMevigEdWtVXsveYVw== Date: Sat, 10 Mar 2018 09:24:44 +0100 From: Ingo Molnar To: Masami Hiramatsu 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: <20180310082444.uiy7fdqlxh6qbuwp@gmail.com> References: <152059891712.4214.9539716544254881611.stgit@devbox> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <152059891712.4214.9539716544254881611.stgit@devbox> User-Agent: NeoMutt/20170609 (1.8.3) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * 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. Thanks, Ingo