From mboxrd@z Thu Jan 1 00:00:00 1970 From: Masami Hiramatsu Subject: Re: [PATCH -tip v6 06/22] [BUGFIX] x86: Prohibit probing on memcpy/memset Date: Fri, 20 Dec 2013 11:37:49 +0900 Message-ID: <52B3AD7D.2020104@hitachi.com> References: <20131219090353.14309.15496.stgit@kbuild-fedora.novalocal> <20131219090409.14309.25677.stgit@kbuild-fedora.novalocal> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail4.hitachi.co.jp ([133.145.228.5]:47000 "EHLO mail4.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755938Ab3LTCh5 (ORCPT ); Thu, 19 Dec 2013 21:37:57 -0500 In-Reply-To: Sender: linux-arch-owner@vger.kernel.org List-ID: 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" 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