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=-2.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 C5260C43387 for ; Tue, 15 Jan 2019 05:50:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8B59920656 for ; Tue, 15 Jan 2019 05:50:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547531401; bh=OsNbKiOw4wC2BGgc0y+q1WmevhGN5MS5HBVUsKEr3Ao=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=UWyR6a64gfIb9SRV+HpT4VGSBMxIN68akqmnYizF1GsZwwmayqyY27Dzud1jyp3vN idK5qgH8kcAhVWnlcbvI5PDhMfhiLIMg5IA2RnIJNmBoylcBX6KaCnVOY41HTWBAr8 c93k81Def3vtLYTdKvcSzproMlbFlvf0vid1PD2k= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728241AbfAOFt7 (ORCPT ); Tue, 15 Jan 2019 00:49:59 -0500 Received: from mail.kernel.org ([198.145.29.99]:58728 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725929AbfAOFt7 (ORCPT ); Tue, 15 Jan 2019 00:49:59 -0500 Received: from devnote (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9678B20656; Tue, 15 Jan 2019 05:49:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1547531398; bh=OsNbKiOw4wC2BGgc0y+q1WmevhGN5MS5HBVUsKEr3Ao=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=YD/aV1bYlT9JBqyuX7FQozAs4TTkv/t4gLaNQr6DdeJLSC/50wtmS2upU9/fBZCaL gPyViv5g/QDVmYvtA9NvI0QNxfAnOEvk85lRPaMEZ4ewCCA03LMADru3uT7/OjNX/m 26UlNHYNoeafYBNg5lDIPwEQtDg5hXKQ1u6Bc8jE= Date: Tue, 15 Jan 2019 14:49:55 +0900 From: Masami Hiramatsu To: James Morse Cc: Catalin Marinas , Will Deacon , Pratyush Anand , "David A . Long" , linux-arm-kernel@lists.infradead.org, linux-kernel Subject: Re: [PATCH 1/3] arm64: kprobes: Move extable address check into arch_prepare_kprobe() Message-Id: <20190115144955.b3a6cfae18035ae46ffdcfc2@kernel.org> In-Reply-To: <92c160a8-7627-0c64-ed73-df616e9c057d@arm.com> References: <154502881646.30629.9938335052821665530.stgit@devbox> <154502884653.30629.3172839440883293817.stgit@devbox> <20190108113953.8bc0cc7d196ddba370377217@kernel.org> <20190109110500.b4b5049f4c67dfc85b9ced4e@kernel.org> <92c160a8-7627-0c64-ed73-df616e9c057d@arm.com> X-Mailer: Sylpheed 3.5.0 (GTK+ 2.24.30; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 11 Jan 2019 18:22:38 +0000 James Morse wrote: > Hi, > > On 09/01/2019 02:05, Masami Hiramatsu wrote: > > On Tue, 8 Jan 2019 17:13:36 +0000 > > James Morse wrote: > >> On 08/01/2019 02:39, Masami Hiramatsu wrote: > >>> On Thu, 3 Jan 2019 17:05:18 +0000 > >>> James Morse wrote: > >>>> On 17/12/2018 06:40, Masami Hiramatsu wrote: > >>>>> Move extable address check into arch_prepare_kprobe() from > >>>>> arch_within_kprobe_blacklist(). > >>>> > >>>> I'm trying to work out the pattern for what should go in the blacklist, and what > >>>> should be rejected by the arch code. > >>>> > >>>> It seems address-ranges should be blacklisted as the contents don't matter. > >>>> easy-example: the idmap text. > >>> > >>> Yes, more precisely, the code smaller than a function (symbol), it must be > >>> rejected by arch_prepare_kprobe(), since blacklist is poplated based on > >>> kallsyms. > >> > >> Ah, okay, so the pattern is the blacklist should only be for whole symbols, > >> (which explains why its usually based on sections). > > > > Correct. Actually, the blacklist is generated based on the symbol info > > from symbol address. > > > >> I see kprobe_add_ksym_blacklist() would go wrong if you give it something like: > >> platform_drv_probe+0x50/0xb0, as it will log platform_drv_probe+0x50 as the > >> start_addr and platform_drv_probe+0x50+0xb0 as the end. > > > > Yes, it expects given address is the entry of a symbol. > > >> But how does anything from the arch code's blacklist get into the > >> kprobe_blacklist list? > > > > It should be done via arch_populate_kprobe_blacklist(). > > >> We don't have an arch_populate_kprobe_blacklist(), so rely on > >> within_kprobe_blacklist() calling arch_within_kprobe_blacklist() with the > >> address, as well as walking kprobe_blacklist. > >> > >> Is this cleanup ahead of a series that does away with > >> arch_within_kprobe_blacklist() so that debugfs list is always complete? > > > > Right, after this cleanup, I will send arch_populate_kprobe_blacklist() > > patch for arm64 and others. My plan is to move all arch_within_kprobe_blacklist() > > to arch_populate_kprobe_blacklist() so that user can get more precise blacklist > > via debugfs. > > Thanks, now it all makes sense! > > Reviewed-by: James Morse Thanks! > > > Could you include a paragraph like that in the cover-letter or commit-message? > The 'fix' in the cover-letter subject had me looking for the bug! Ok, I'll update commit message with your reviewed-by. Thank you! > > > Thanks, > > James -- Masami Hiramatsu