From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752478AbeCQANi (ORCPT ); Fri, 16 Mar 2018 20:13:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:55660 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751348AbeCQANh (ORCPT ); Fri, 16 Mar 2018 20:13:37 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 85C9620855 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: Sat, 17 Mar 2018 09:13:34 +0900 From: Masami Hiramatsu To: Mathieu Desnoyers Cc: rostedt , Francis Deslauriers , Masami Hiramatsu , Peter Zijlstra , linux-kernel , Linus Torvalds Subject: Re: [PATCH 2/2] kprobe: fix: Add ftrace_ops_assist_func to kprobe blacklist Message-Id: <20180317091334.55f1fc325c26deaa4d4a4d19@kernel.org> In-Reply-To: <1577244734.11604.1521222781948.JavaMail.zimbra@efficios.com> References: <1500044315-9508-1-git-send-email-francis.deslauriers@efficios.com> <1500044315-9508-3-git-send-email-francis.deslauriers@efficios.com> <20170714142900.1c91949c@gandalf.local.home> <20180316112517.66bdd85a@gandalf.local.home> <229385456.11580.1521217739037.JavaMail.zimbra@efficios.com> <20180316124134.30fa47d5@gandalf.local.home> <20180316124840.3e83bbec@gandalf.local.home> <1577244734.11604.1521222781948.JavaMail.zimbra@efficios.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 Fri, 16 Mar 2018 13:53:01 -0400 (EDT) Mathieu Desnoyers wrote: > ----- On Mar 16, 2018, at 12:48 PM, rostedt rostedt@goodmis.org wrote: > > > On Fri, 16 Mar 2018 12:41:34 -0400 > > Steven Rostedt wrote: > > > >> Yes, kprobes are dangerous. I'm not saying it shouldn't be fixed, I'm > >> saying that I don't have time to fix it now, but would be happy to > >> accept patches if someone else does so. > > > > And looking at what I replied before for the original patch. It would > > probably be a good idea to blacklist directories. Like we do with > > function tracing. We probably should black list both kernel/tracing and > > kernel/events from being probed. > > > > Did this come up at plumbers? You were there too, I don't remember > > discussing it there. > > I don't remember this coming up last Plumbers nor KS neither, given > that we were focused on other topics. > > Would the general approach you envision be based on emitting all code > generated by compilation of all objects under kernel/tracing and > kernel/events into a specific "nokprobes" text section of the kernel ? > Perhaps we could create a specific linker scripts for those directories, > or do you have in mind a neater way to do this ? .kprobes.text section still exists. As I pointed in previous mail, I don't think we have to put all those code into that section. But if you want, it is acceptable to have a kconfig which push most of those ftrace related code into .kprobes.text section. Thank, > > Thanks, > > Mathieu > > > > > -- Steve > > -- > Mathieu Desnoyers > EfficiOS Inc. > http://www.efficios.com -- Masami Hiramatsu