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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7B301CD98E6 for ; Wed, 11 Oct 2023 02:21:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344821AbjJKCVS (ORCPT ); Tue, 10 Oct 2023 22:21:18 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344739AbjJKCVQ (ORCPT ); Tue, 10 Oct 2023 22:21:16 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:3::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5144B94; Tue, 10 Oct 2023 19:21:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=ECF3/1WilG3oPuCuQT95CHRb45iMre03wS/vbNRxGFU=; b=MyVIx+klhdf+TiAhgT+Rt8tolB vCapYA9ODnH0R/7PAEM1nJC1uN27r3bDSc3yDt+P2Aw9NTrQUXiM6qyZwQm7/pjADj8FC7LciRwEC 664mxoRJzI8Xj8m3PBh0aY7+ZC6s7U77HEDTju9qCnVtLdA0Q7+QMTRbng8UQkKKab1sfNOuLGW3z ebN0CWekKymRFWshTAlTEkXoLHMvgPzHwkd7cgembcawXDiS5spd9i8eRm6+IN1royT+QFABenq1r +Wg2EETZ4kE4kG3wtiVxKFD18/O+zWVOJ2bW4cRaCf4xQVQ+WQOn5nZxBimqJpdXzq2fVdsRoS2rN l5ReAb3A==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1qqOqX-00EZyf-0C; Wed, 11 Oct 2023 02:21:13 +0000 Date: Tue, 10 Oct 2023 19:21:13 -0700 From: Luis Chamberlain To: "Joey Jiao (QUIC)" Cc: "linux-modules@vger.kernel.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH] module: Add CONFIG_MODULE_LOAD_IN_SEQUENCE option Message-ID: References: <20231009045636.4143-1-quic_jiangenj@quicinc.com> <49a0f7c36d8d41abb1204b0780667fe0@quicinc.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <49a0f7c36d8d41abb1204b0780667fe0@quicinc.com> Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Please find a good email client to reply to patches. On Wed, Oct 11, 2023 at 01:57:58AM +0000, Joey Jiao (QUIC) wrote: > Hi Luis, > > > How is ignoring an error ensuring ordering? > The change is just to disable the schedule_work. That's different and can be made clearer. Try: if (!IS_ENABLED(CONFIG_FOO)) schedule_stuff > > Why are you making this only now be called with this new kconfig option? > This sequence loading is especially helpful for syzkaller coverage decoding. > When kaslr is disabled, address inside core kernel is fixed, so syzkaller can always get right function/line number from addr2line. > But module address keeps change across rebooting, in first booting, it might be loaded at X1, and at X2 after reboot, and at X3 after another reboot. > In this way, syzkaller just can't decode correctly for module address. And syzkaller currently uses PC and branch info for coverage guided things. > > There was a discussion previously here https://groups.google.com/g/syzkaller/c/1Pnm_BjrZO8/m/WOyAKx8ZAgAJ for modprobe. You are missing my point, you are disabling in effect a piece of code where it was not before. Luis