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=-10.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 677E8C433DB for ; Fri, 29 Jan 2021 03:38:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3141064DFB for ; Fri, 29 Jan 2021 03:38:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231816AbhA2Die (ORCPT ); Thu, 28 Jan 2021 22:38:34 -0500 Received: from szxga06-in.huawei.com ([45.249.212.32]:11906 "EHLO szxga06-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231593AbhA2Di3 (ORCPT ); Thu, 28 Jan 2021 22:38:29 -0500 Received: from DGGEMS402-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga06-in.huawei.com (SkyGuard) with ESMTP id 4DRjgf3NsYzjDdN; Fri, 29 Jan 2021 11:36:46 +0800 (CST) Received: from [10.174.178.52] (10.174.178.52) by DGGEMS402-HUB.china.huawei.com (10.3.19.202) with Microsoft SMTP Server id 14.3.498.0; Fri, 29 Jan 2021 11:37:40 +0800 Subject: Re: [PATCH] kretprobe: avoid re-registration of the same kretprobe earlier To: Masami Hiramatsu CC: Steven Rostedt , , , , , , References: <20201124115719.11799-1-bobo.shaobowang@huawei.com> <20201130161850.34bcfc8a@gandalf.local.home> <20201202083253.9dbc76704149261e131345bf@kernel.org> <9dff21f8-4ab9-f9b2-64fd-cc8c5f731932@huawei.com> <20201215123119.35258dd5006942be247600db@kernel.org> <20201222200356.6910b42c165b8756878cc9b0@kernel.org> From: "Wangshaobo (bobo)" Message-ID: Date: Fri, 29 Jan 2021 11:37:39 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101 Thunderbird/68.1.0 MIME-Version: 1.0 In-Reply-To: <20201222200356.6910b42c165b8756878cc9b0@kernel.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.178.52] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Dear Masami and Steve, I have sent v2 but still have confusions: > OK, I think it is simpler to check the rp->kp.addr && rp->kp.symbol_name > because it is not allowed (it can lead inconsistent setting). > > How about this code? Is this work for you? > > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index 41fdbb7953c6..73500be564be 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -2103,6 +2103,14 @@ int register_kretprobe(struct kretprobe *rp) > int i; > void *addr; > > + /* It is not allowed to specify addr and symbol_name at the same time */ > + if (rp->kp.addr && rp->kp.symbol_name) > + return -EINVAL; > + above sentence can be removed because of kprobe_on_func_entry() do it: kprobe_on_func_entry()      -=>_kprobe_addr() {if (rp->kp.addr && rp->kp.symbol_name) ...} > + /* If only rp->kp.addr is specified, check reregistering kprobes */ > + if (rp->kp.addr && check_kprobe_rereg(&rp->kp)) > + return -EINVAL; for arch arm64，x86_64, above sentence can be moved behind following sentence. kprobe_on_func_entry()     -=>arch_kprobe_on_func_entry() {kp->offset can not be 0 ; ...} So if offset of kprobe if not 0, do not waste time to excute above sentence. But for Arch ppc64,  I still not figure out better one solution. Thank you -- Wang ShaoBo > if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset)) > return -EINVAL; > > > Thank you, >