From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS, URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C499EC00319 for ; Fri, 22 Feb 2019 00:17:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 957F52080F for ; Fri, 22 Feb 2019 00:17:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=efficios.com header.i=@efficios.com header.b="IRDT7po5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726360AbfBVARP (ORCPT ); Thu, 21 Feb 2019 19:17:15 -0500 Received: from mail.efficios.com ([167.114.142.138]:55974 "EHLO mail.efficios.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726117AbfBVARO (ORCPT ); Thu, 21 Feb 2019 19:17:14 -0500 Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id 771E81B490F; Thu, 21 Feb 2019 19:17:12 -0500 (EST) Received: from mail.efficios.com ([IPv6:::1]) by localhost (mail02.efficios.com [IPv6:::1]) (amavisd-new, port 10032) with ESMTP id rOqzMZeZKClw; Thu, 21 Feb 2019 19:17:11 -0500 (EST) Received: from localhost (ip6-localhost [IPv6:::1]) by mail.efficios.com (Postfix) with ESMTP id CC71C1B490C; Thu, 21 Feb 2019 19:17:11 -0500 (EST) DKIM-Filter: OpenDKIM Filter v2.10.3 mail.efficios.com CC71C1B490C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=efficios.com; s=default; t=1550794631; bh=X1IaQn/z0rhMxgNYmXPodGhmYUcZTSz6kgVHCxZME4U=; h=Date:From:To:Message-ID:MIME-Version; b=IRDT7po5WpJex5TDG4EDAQGhdEYxigPQoSNJnX3fjxsBFNe9gxhJRbOyx2EZflFuO 8WsyjTOsXwjg59HqYoKQOqhdhG8WWK/Nnr1hbK4Na0HvbMO6jzxFILa3V2its3P/o5 l2A2RMQgsiS1jbvzrGxYz37pla2OHDavwlbaJGsoWUqJYbDLfjDT3o7egG68xNb/0m 6M8ipBjCiE9WQIoT1zYWg1fNDxX2j6EfuW9XEbLMBYd0C3Zh0tjzfGCgmB0ZBU5hwP U86oTsoEFUj12Yg9RC6tPT2BgFYwEDY70RxSXzhWfFJW/zhZqojt6F2HuoP0MWZM2R JMX5NzPIzpP0w== X-Virus-Scanned: amavisd-new at efficios.com Received: from mail.efficios.com ([IPv6:::1]) by localhost (mail02.efficios.com [IPv6:::1]) (amavisd-new, port 10026) with ESMTP id a2XffBRDqRW0; Thu, 21 Feb 2019 19:17:11 -0500 (EST) Received: from mail02.efficios.com (mail02.efficios.com [167.114.142.138]) by mail.efficios.com (Postfix) with ESMTP id AC9391B48FC; Thu, 21 Feb 2019 19:17:11 -0500 (EST) Date: Thu, 21 Feb 2019 19:17:11 -0500 (EST) From: Mathieu Desnoyers To: "Russell King, ARM Linux" Cc: Arnd Bergmann , Linus Torvalds , Masami Hiramatsu , Kees Cook , William Cohen , stable , Laura Abbott , linux-kernel , lttng , Greg Kroah-Hartman , Thomas Gleixner Message-ID: <622813157.4561.1550794631564.JavaMail.zimbra@efficios.com> In-Reply-To: <20190222001042.hm6j5h4hmfpwarzr@shell.armlinux.org.uk> References: <342740659.2887.1549307721609.JavaMail.zimbra@efficios.com> <20190206134115.baba291e33022a2f6b6ae5f8@kernel.org> <20190218122631.GE30260@kroah.com> <843587666.153.1550501735273.JavaMail.zimbra@efficios.com> <1829800918.4014.1550779377803.JavaMail.zimbra@efficios.com> <20190222001042.hm6j5h4hmfpwarzr@shell.armlinux.org.uk> Subject: Re: BUG: optimized kprobes illegal instructions in v4.19 stable kernels MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit X-Originating-IP: [167.114.142.138] X-Mailer: Zimbra 8.8.10_GA_3758 (ZimbraWebClient - FF65 (Linux)/8.8.10_GA_3745) Thread-Topic: optimized kprobes illegal instructions in v4.19 stable kernels Thread-Index: 5+At/aVCZETzUFh4OgPO/ag9JkcMJg== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ----- On Feb 21, 2019, at 7:10 PM, Russell King, ARM Linux linux@armlinux.org.uk wrote: > On Thu, Feb 21, 2019 at 03:02:57PM -0500, Mathieu Desnoyers wrote: >> Hi Arnd, Russell, Linus, >> >> Can we ensure the arm32 kprobes fix I submitted gets upstream before 5.0 final ? >> It takes care of an illegal instruction issue with optimized kprobes on arm32. >> >> Here is the current state of default kprobes configuration on arm32: >> using them will trigger illegal instruction OOPS on v5.0-rc7, 4.19.24, >> v4.14.102. >> >> My fix is in "accepted" state in the arm patch tracking system: >> >> https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8834/1 >> >> Should I send it directly to Linus as well ? > > Accepted means it's in my tree pending to be sent to Linus. It should > now be in mainline. Have you checked? Hrm, why did I not see it earlier today... it's embarrassing. It's there indeed, all is good! Greg, you should be able to pick it into the stable kernels now. Thanks, Mathieu > >> >> Thanks, >> >> Mathieu >> >> ----- On Feb 18, 2019, at 9:55 AM, Mathieu Desnoyers >> mathieu.desnoyers@efficios.com wrote: >> >> > ----- On Feb 18, 2019, at 7:26 AM, Greg Kroah-Hartman gregkh@linuxfoundation.org >> > wrote: >> > >> >> On Wed, Feb 06, 2019 at 01:41:15PM +0900, Masami Hiramatsu wrote: >> >>> On Tue, 5 Feb 2019 15:06:10 +0000 >> >>> Kees Cook wrote: >> >>> >> >>> > On Mon, Feb 4, 2019 at 7:15 PM Mathieu Desnoyers >> >>> > wrote: >> >>> > > >> >>> > > Hi, >> >>> > > >> >>> > > I notice this commit as a possible culprit of the illegal instructions my lttng >> >>> > > users are noticing on arm32 when using kprobes on a v4.19.13 Linux kernel >> >>> > > in a Yocto environment [1]. They were able to reproduce the issue with perf >> >>> > > as well. >> >>> > > >> >>> > > commit e46daee53bb50bde38805f1823a182979724c229 >> >>> > > Author: Kees Cook >> >>> > > Date: Tue Oct 30 22:12:56 2018 +0100 >> >>> > > >> >>> > > ARM: 8806/1: kprobes: Fix false positive with FORTIFY_SOURCE >> >>> > > >> >>> > > I *think* the intent there was to do >> >>> > > >> >>> > > - memcpy(code, &optprobe_template_entry, >> >>> > > + memcpy(code, (unsigned long *)&optprobe_template_entry, >> >>> > > >> >>> > > But if you look at the commit, the "&" seems to have been stripped away, >> >>> > > which happens to change the behavior significantly. >> >>> > >> >>> > Yeah, this was a typo on my part. :( >> >>> >> >>> Ah, I thought it had been fixed as same as x86. >> >>> On x86, all optprobe_template_* are defined as kprobe_opcode_t [], >> >>> but on arm, it still be kprobe_opcode_t. >> >>> >> >>> Hmm, but I think we should use kprobe_opcode_t [] or char[] as asm/sections.h >> >>> does. >> >>> OK, I'll prepare for the change. >> >> >> >> Did this ever get fixed in Linus's tree? If so, what is the git commit >> >> id, I can't seem to find anything... >> > >> > It seems to still be in the arm patch tracking system: >> > >> > https://www.arm.linux.org.uk/developer/patches/viewpatch.php?id=8834/1 >> > >> > If I understand its status correctly, it is applied to the arm tree, but >> > perhaps it has not been pulled by Linus yet ? The code is still broken >> > in Linus' master. >> > >> > It would be important to get this arm kprobes fix upstream before 5.0 >> > final. >> > >> > Thanks, >> > >> > Mathieu >> > >> > >> > -- >> > Mathieu Desnoyers >> > EfficiOS Inc. >> > http://www.efficios.com >> >> -- >> Mathieu Desnoyers >> EfficiOS Inc. >> http://www.efficios.com >> > > -- > RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ > FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up > According to speedtest.net: 11.9Mbps down 500kbps up -- Mathieu Desnoyers EfficiOS Inc. http://www.efficios.com