Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932653Ab3CULkF (ORCPT ); Thu, 21 Mar 2013 07:40:05 -0400 Received: from mail-ee0-f43.google.com ([74.125.83.43]:52515 "EHLO mail-ee0-f43.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932215Ab3CULkB (ORCPT ); Thu, 21 Mar 2013 07:40:01 -0400 Date: Thu, 21 Mar 2013 12:39:57 +0100 From: Ingo Molnar To: Masami Hiramatsu Cc: Timo Juhani Lindfors , 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: [PATCH -tip ] [BUGFIX] kprobes: Move hash_64() into .text.kprobe section Message-ID: <20130321113957.GA2659@gmail.com> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5147D318.9060400@hitachi.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1849 Lines: 52 * 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 ... symbol name and annotation should go hand in hand. Thanks, Ingo -- 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/