From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.5 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 373CEC433E1 for ; Wed, 26 Aug 2020 10:25:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0A6FD2071E for ; Wed, 26 Aug 2020 10:25:54 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="R0WUt2Nv" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728419AbgHZKZw (ORCPT ); Wed, 26 Aug 2020 06:25:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728132AbgHZKZw (ORCPT ); Wed, 26 Aug 2020 06:25:52 -0400 Received: from merlin.infradead.org (merlin.infradead.org [IPv6:2001:8b0:10b:1231::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07DDAC061574 for ; Wed, 26 Aug 2020 03:25:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=8e7m1CkmXpgJBEIhBkOz8FSttb96UAPZGvqZLIsdgA0=; b=R0WUt2Nv3A5DmntgkldazUgIsg +wipts7wLWsx8Ee7V08Zf1SIPg+bl58SHK44F/NQGL4q1OY5eQiPjAQcbNISnhblKl6loFFtt8kfk sStiby/f6BiBrh4Y029E0Z+nD1M8HKbkK48mlqYY/hekPwLSlSiGIRb6N39Z5nocpmMaCm3AaxrB4 Cnongp00g9pjTOTzECeVMET2NsTyL0mVLmmACRp3vccGpeAYi7ic9RQQb+DIxMIgIgDEHh2L05Ejm BbjUfz752681Q7l7WTCe9VXH2/T1iCNCJZEkUXoTqxFfGlWqL2eyib1U2pJk28DxKzljWfOuVnKTc 3Xd73iTQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kAsck-0006eU-QK; Wed, 26 Aug 2020 10:25:47 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 99111301A66; Wed, 26 Aug 2020 12:25:45 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 823BA2C016759; Wed, 26 Aug 2020 12:25:45 +0200 (CEST) Date: Wed, 26 Aug 2020 12:25:45 +0200 From: peterz@infradead.org To: Masami Hiramatsu Cc: "Eddy_Wu@trendmicro.com" , "linux-kernel@vger.kernel.org" , "x86@kernel.org" Subject: Re: x86/kprobes: kretprobe fails to triggered if kprobe at function entry is not optimized (trigger by int3 breakpoint) Message-ID: <20200826102545.GF1362448@hirez.programming.kicks-ass.net> References: <8816bdbbc55c4d2397e0b02aad2825d3@trendmicro.com> <20200825005426.f592075d13be740cb3c9aa77@kernel.org> <7396e7b2079644a6aafd9670a111232b@trendmicro.com> <20200825151538.f856d701a34f4e0561a64932@kernel.org> <20200825120911.GX1362448@hirez.programming.kicks-ass.net> <20200826172239.ff175be78ee5f3a4380579c3@kernel.org> <20200826180645.9b609fc05df2a149564df1b8@kernel.org> <20200826190041.2d0ff0fbe154ba62163b0c00@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200826190041.2d0ff0fbe154ba62163b0c00@kernel.org> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 26, 2020 at 07:00:41PM +0900, Masami Hiramatsu wrote: > Of course, this doesn't solve the llist_del_first() contention in the > pre_kretprobe_handler(). So anyway we need a lock for per-probe llist > (if I understand llist.h comment correctly.) Bah, lemme think about that. Kprobes really shouldn't be using locks :/