From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935112AbdBQVoK (ORCPT ); Fri, 17 Feb 2017 16:44:10 -0500 Received: from mail.kernel.org ([198.145.29.136]:49306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934415AbdBQVoI (ORCPT ); Fri, 17 Feb 2017 16:44:08 -0500 Date: Sat, 18 Feb 2017 06:43:52 +0900 From: Masami Hiramatsu To: "Jon Medhurst (Tixy)" Cc: Russell King , linux-kernel@vger.kernel.org, Peter Zijlstra , Ananth N Mavinakayanahalli , Ingo Molnar , Thomas Gleixner , "H . Peter Anvin" , Wang Nan , Catalin Marinas , Will Deacon , "David A . Long" , Sandeepa Prabhu , linux-arm-kernel@lists.infradead.org Subject: Re: [BUGFIX PATCH V2 0/3] kprobes/arm: Improve kprobes implementation on arm Message-Id: <20170218064352.b1685bbd17c0189b1937ce3b@kernel.org> In-Reply-To: <1487329270.3113.5.camel@linaro.org> References: <148711844284.5814.10387227824715177703.stgit@devbox> <1487329270.3113.5.camel@linaro.org> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 17 Feb 2017 11:01:10 +0000 "Jon Medhurst (Tixy)" wrote: > On Wed, 2017-02-15 at 09:27 +0900, Masami Hiramatsu wrote: > > Hi, > > > > Here is the 2nd version of the patches which improve kprobe > > on arm implementation (a kind of bugfix). Version 1 is here; > > > > https://lkml.org/lkml/2017/2/13/538 > > > > In this version I didn't update the code, just update the > > patch description according to Tixy's comment and add his Ack. > > > > Thank you, > > > > --- > > > > Masami Hiramatsu (3): > > kprobes/arm: Allow to handle reentered kprobe on single-stepping > > kprobes/arm: Skip single-stepping in recursing path if possible > > kprobes/arm: Fix the return address of multiple kretprobes > > > > Thanks for doing these. Am I correct in assuming we don't need to > consider these fixes urgent or critical? Only the first looks like it > could be serious, and the x86 fix for that is 3 years old and ARM has > gone without it all this time. So I'm guessing it's fine to wait for the > normal development process and deal with it after the about to open > merge window is completed? Agreed. I'm not sure how frequently FIQ is used in ARM, but anyway it happens only when root user intensively uses kprobes on FIQ handlers. > If so, I propose that I put the patches in a branch for Russell to pull > later (unless he pipes up with objections or says otherwise). Meantime > I'll investigate the kprobes test failures I see (which actually looks > like cache/TLB issues and not test code problems after all). OK, btw, I couldn't reproduce the kprobes test failure with CONFIG_DEBUG_RODATA=y on qemu... > > BTW, I added the ARM kernel list to the CC. I spotted you didn't add it > to you patch postings, which means people interested in ARM (other than > Russell) wouldn't have seen them. Ah, I forgot that, Thank you! > > Thanks > > -- > Tixy -- Masami Hiramatsu