From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S936439AbdAKJ6f (ORCPT ); Wed, 11 Jan 2017 04:58:35 -0500 Received: from mail.kernel.org ([198.145.29.136]:60172 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936245AbdAKJ6b (ORCPT ); Wed, 11 Jan 2017 04:58:31 -0500 Date: Wed, 11 Jan 2017 18:57:45 +0900 From: Masami Hiramatsu To: Josh Poimboeuf Cc: Peter Zijlstra , Masami Hiramatsu , Ingo Molnar , linux-kernel@vger.kernel.org, Ananth N Mavinakayanahalli , Thomas Gleixner , "H . Peter Anvin" , Andrey Konovalov , Andy Lutomirski Subject: Re: [PATCH tip/master v4] kprobes: extable: Identify kprobes' insn-slots as kernel text area Message-Id: <20170111185745.66af396b4b2bacc02ac343fb@kernel.org> In-Reply-To: <20170110214207.dd52me5mtz6hhuzb@treble> References: <20170104100102.GE25813@worktop.programming.kicks-ass.net> <148388747896.6869.6354262871751682264.stgit@devbox> <20170109173648.k7dxu7nz22qc6upq@treble> <20170110085923.GD3092@twins.programming.kicks-ass.net> <20170110214207.dd52me5mtz6hhuzb@treble> X-Mailer: Sylpheed 3.5.0 (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 Tue, 10 Jan 2017 15:42:07 -0600 Josh Poimboeuf wrote: > On Tue, Jan 10, 2017 at 09:59:23AM +0100, Peter Zijlstra wrote: > > On Mon, Jan 09, 2017 at 11:36:48AM -0600, Josh Poimboeuf wrote: > > > BTW, I think we'll have more problems with generated code if/when we > > > move to an x86 DWARF unwinder, because it won't have any idea how to > > > unwind past generated code. Long term I wonder if it would make sense > > > to create some kind of framework for creating or registering generated > > > code, so we can solve these types of problems in a single place. > > > > Yes, this seems like a good idea. Maybe we could pull the rbtree thing > > from modules and make that a more generic interface for code > > registration. > > Yeah, a generic fast lookup for module+generated code could be useful. > It would also be nice to associate names with generated functions and > integrate that with kallsyms. For DWARF we would also need a way to > associate CFI metadata with address ranges. >>From the kprobe point of view, kallsyms and DWARF seems a bit overkill. At least for kprobe insn slots, I think one symbol per page instead of each entry will be better and CFI also should be generated for each call. Thank you, -- Masami Hiramatsu