Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757992Ab2B2NUu (ORCPT ); Wed, 29 Feb 2012 08:20:50 -0500 Received: from mail7.hitachi.co.jp ([133.145.228.42]:53287 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754620Ab2B2NUt (ORCPT ); Wed, 29 Feb 2012 08:20:49 -0500 X-AuditID: b753bd60-9a2c4ba00000029c-4d-4f4e262e8368 X-AuditID: b753bd60-9a2c4ba00000029c-4d-4f4e262e8368 Message-ID: <4F4E262B.9030806@hitachi.com> Date: Wed, 29 Feb 2012 22:20:43 +0900 From: Masami Hiramatsu Organization: Hitachi, Ltd., Japan User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:10.0.2) Gecko/20120216 Thunderbird/10.0.2 MIME-Version: 1.0 To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, yrl.pp-manager.tt@hitachi.com, systemtap@sourceware.org, anderson@redhat.com, Thomas Gleixner , "H. Peter Anvin" , Ananth N Mavinakayanahalli Subject: Re: [PATCH v3 -tip] [BUGFIX] x86/kprobes: Fix to recover instructions on optimized path References: <20120223083703.GA26781@elte.hu> <20120224095412.8462.55698.stgit@localhost.localdomain> <20120227093421.GA10078@elte.hu> <4F4C4182.1040706@hitachi.com> <20120228084828.GK21106@elte.hu> <4F4CA3BC.7050909@hitachi.com> <20120228095953.GA17149@elte.hu> In-Reply-To: <20120228095953.GA17149@elte.hu> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2458 Lines: 70 (2012/02/28 18:59), Ingo Molnar wrote: > > * Masami Hiramatsu wrote: > >> (2012/02/28 17:48), Ingo Molnar wrote: >>> >>> * Masami Hiramatsu wrote: >>> >>>> (2012/02/27 18:34), Ingo Molnar wrote: >>>>> >>>>> * Masami Hiramatsu wrote: >>>>> >>>>>> + >>>>>> +#ifdef CONFIG_OPTPROBES >>>>>> +static unsigned long __recover_optprobed_insn(struct kprobe *kp, >>>>>> + kprobe_opcode_t *buf, >>>>>> + unsigned long addr) >>>>>> +{ >>>>>> + long offs = addr - (unsigned long)kp->addr - 1; >>>>>> + struct optimized_kprobe *op = container_of(kp, struct optimized_kprobe, kp); >>>>>> + >>>>>> + /* >>>>>> + * If the kprobe can be optimized, original bytes which can be >>>>>> + * overwritten by jump destination address. In this case, original >>>>>> + * bytes must be recovered from op->optinsn.copied_insn buffer. >>>>>> + */ >>>>>> + memcpy(buf, (void *)addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); >>>>>> + if (addr == (unsigned long)kp->addr) { >>>>>> + buf[0] = kp->opcode; >>>>>> + memcpy(buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE); >>>>>> + } else >>>>>> + memcpy(buf, op->optinsn.copied_insn + offs, RELATIVE_ADDR_SIZE - offs); >>>>>> + >>>>>> + return (unsigned long)buf; >>>>>> +} >>>>>> +#endif >>>>> >>>>> Why not stick this into a new kprobes-opt.c file? >>>> >>>> Would you mean that I should split all optprobe stuffs into >>>> new file? >>> >>> Yeah, that would be sensible I think - and it might help avoid >>> similar complications in the future. >>> >>> Could (and probably should) be done in a separate patch - to >>> keep the bits that you already fixed and tested intact. >> >> OK, I'll make a separate patch. > > Could be done on top of your existing patch, to keep things > simpler for you - a split-up patch done before your fix would > create a lot of conflicts in the fix patch. I see. And in the previous patch, I've just find a small racing bug. I'll update it too. Thank you, -- Masami HIRAMATSU Software Platform 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/