Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758209Ab3CUNXa (ORCPT ); Thu, 21 Mar 2013 09:23:30 -0400 Received: from mail9.hitachi.co.jp ([133.145.228.44]:43251 "EHLO mail9.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756329Ab3CUNX3 (ORCPT ); Thu, 21 Mar 2013 09:23:29 -0400 Message-ID: <514B09D5.4090004@hitachi.com> Date: Thu, 21 Mar 2013 22:23:33 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.2; rv:13.0) Gecko/20120614 Thunderbird/13.0.1 MIME-Version: 1.0 To: Ingo Molnar , Timo Juhani Lindfors Cc: Linus Torvalds , Ingo Molnar , Linux Kernel Mailing List , Ananth N Mavinakayanahalli , Pavel Emelyanov , Jiri Kosina , Nadia Yvette Chambers , yrl.pp-manager.tt@hitachi.com, "David S. Miller" Subject: Re: Re: Re: [PATCH -tip ] [BUGFIX] kprobes: Move hash_64() into .text.kprobe section References: <20130311142233.19885.10567.stgit@mhiramat-M0-7522> <514023AA.4070004@hitachi.com> <847glb8m4i.fsf@sauna.l.org> <51408349.8080800@hitachi.com> <84li9ke88w.fsf@sauna.l.org> <5147D318.9060400@hitachi.com> <20130321113957.GA2659@gmail.com> In-Reply-To: <20130321113957.GA2659@gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2274 Lines: 67 (2013/03/21 20:39), Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > >> (2013/03/19 5:57), Timo Juhani Lindfors wrote: >>> Masami Hiramatsu writes: >>>> Thank you for reporting!! >>> >>> Thanks for fixing these! I spent some time trying to automate the >>> process of finding sensitive functions and eventually resorted into >>> booting a kvm instance with a minimal initrd to test every single >>> function in a clean and reproducible environment. >>> >>> I found 7 more cases where calling register_kprobe() leads to an instant >>> kernel panic: >>> >>> __flush_tlb_single >>> native_flush_tlb >>> native_safe_halt >>> native_set_pgd >>> native_set_pmd >>> native_set_pud >>> native_write_cr0 >> >> Ah, right and Great! these native_* things are too fundamental one. >> Hmm, curiously, those are defined as inline functions, and >> I also couldn't find some of those symbols even with your previous >> kconfig. >> >>> You can see full kernel console output for each function at >>> http://lindi.iki.fi/lindi/linux/kprobes/panics_2013-03-18/ >> >> As you can see, your panic messages, most of them caused GFP. >> This may mean that int3 software exception must not happened >> on those sites. Not the recursive call. >> >> Perhaps, I'd better add those native_* things into symbol-name >> based blacklist, instead of adding __kprobes, because those >> are not related to kprobes recursion. > > Blacklists are not really good in general - it's easy for a symbol to be > renamed and the blacklist misses them silently ... Ah, right. > > symbol name and annotation should go hand in hand. Thus, I think we'd better moving __kprobes into compiler.h first. Anyway, I'm still waiting for the actual kconfig from Timo, because I couldn't reproduce the problem yet (no such symbols). Thank you, -- Masami HIRAMATSU IT Management Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/