From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 12027 invoked by alias); 20 Dec 2013 02:38:00 -0000 Mailing-List: contact systemtap-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: systemtap-owner@sourceware.org Received: (qmail 12017 invoked by uid 89); 20 Dec 2013 02:37:59 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.8 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS autolearn=ham version=3.3.2 X-HELO: mail4.hitachi.co.jp Received: from mail4.hitachi.co.jp (HELO mail4.hitachi.co.jp) (133.145.228.5) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 20 Dec 2013 02:37:58 +0000 Received: from mlsv1.hitachi.co.jp (unknown [133.144.234.166]) by mail4.hitachi.co.jp (Postfix) with ESMTP id 2E37733CC9; Fri, 20 Dec 2013 11:37:56 +0900 (JST) Received: from mfilter05.hitachi.co.jp by mlsv1.hitachi.co.jp (8.13.1/8.13.1) id rBK2bu9u018469; Fri, 20 Dec 2013 11:37:56 +0900 Received: from vshuts02.hitachi.co.jp (vshuts02.hitachi.co.jp [10.201.6.84]) by mfilter05.hitachi.co.jp (Switch-3.3.4/Switch-3.3.4) with ESMTP id rBK2bs72005956; Fri, 20 Dec 2013 11:37:55 +0900 Received: from gxml20a.ad.clb.hitachi.co.jp (unknown [158.213.157.160]) by vshuts02.hitachi.co.jp (Postfix) with ESMTP id 377AF490042; Fri, 20 Dec 2013 11:37:54 +0900 (JST) Received: from [10.198.212.163] by gxml20a.ad.clb.hitachi.co.jp (Switch-3.1.10/Switch-3.1.9) id 5BK231HFJ00007708; Fri, 20 Dec 2013 11:37:53 +0900 Message-ID: <52B3AD7D.2020104@hitachi.com> Date: Fri, 20 Dec 2013 02:38:00 -0000 From: Masami Hiramatsu User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Jovi Zhangwei Cc: Ingo Molnar , linux-arch@vger.kernel.org, Ananth N Mavinakayanahalli , Sandeepa Prabhu , x86@kernel.org, lkml , "Steven Rostedt (Red Hat)" , Ingo Molnar , systemtap@sourceware.org, "H. Peter Anvin" , Thomas Gleixner , "David S. Miller" Subject: Re: [PATCH -tip v6 06/22] [BUGFIX] x86: Prohibit probing on memcpy/memset References: <20131219090353.14309.15496.stgit@kbuild-fedora.novalocal> <20131219090409.14309.25677.stgit@kbuild-fedora.novalocal> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2013-q4/txt/msg00454.txt.bz2 Hi Jovi, (2013/12/19 18:37), Jovi Zhangwei wrote: > Hi Masami, > > On Thu, Dec 19, 2013 at 5:04 PM, Masami Hiramatsu > wrote: >> memcpy/memset functions are fundamental functions and >> those are involved in kprobe's exception handling. >> Prohibit probing on them to avoid kernel crash. >> > Would you please let me know the LKML link of that bugfix, I cannot > find it in my LKML fold. Yeah, that was found in my testing environment. > No objection on this patch. :) just want to know more, It seems there > have no problem to probe memcpy in my box, maybe I didn't hit the > crash code path. Ah, I see. Originally the problem happened when I put a probe on __memcpy. And it looks the instances of memcpy and __memcpy are same on x86-64. Thus I decided to blacklist both. (memset/__memset too) Have you ever tried to probe __memcpy on your box? Thank you, -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com