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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 03179C282CE for ; Thu, 11 Apr 2019 13:20:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C72F22077C for ; Thu, 11 Apr 2019 13:20:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726677AbfDKNT7 (ORCPT ); Thu, 11 Apr 2019 09:19:59 -0400 Received: from mail.kernel.org ([198.145.29.99]:33522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726264AbfDKNT7 (ORCPT ); Thu, 11 Apr 2019 09:19:59 -0400 Received: from gandalf.local.home (cpe-66-24-58-225.stny.res.rr.com [66.24.58.225]) (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 E3782206B7; Thu, 11 Apr 2019 13:19:57 +0000 (UTC) Date: Thu, 11 Apr 2019 09:19:55 -0400 From: Steven Rostedt To: Joel Fernandes Cc: linux-kernel@vger.kernel.org, paulmck@linux.vnet.ibm.com, keescook@chromium.org, mathieu.desnoyers@efficios.com, Jessica Yu , kernel-hardening@lists.openwall.com, kernel-team@android.com, rcu@vger.kernel.org Subject: Re: [PATCH v3 3/3] module: Make __tracepoints_ptrs as read-only Message-ID: <20190411091955.67cdd9fd@gandalf.local.home> In-Reply-To: <20190411082106.GB167446@google.com> References: <20190410195708.162185-1-joel@joelfernandes.org> <20190410195708.162185-3-joel@joelfernandes.org> <20190410161112.540017d9@gandalf.local.home> <20190410202902.GA167446@google.com> <20190410204401.62f928ca@gandalf.local.home> <20190411082106.GB167446@google.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; 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 Thu, 11 Apr 2019 04:21:06 -0400 Joel Fernandes wrote: > Patch 2/3 and 3/3 would not be nececessary if this works out. 1/3 may be a > nice clean up but is not something urgent and we could do that in the future > if needed. Well, jump_labels is "special" because it requires sorting the RO data and is done via module notify. The only other user that had to modify RO data on module load is ftrace. It had to do the nop conversions in the text area. It use to do it via module notify, but because of the hardening of the kernel, doing it there was no longer possible because everything was RO then. The solution was to call into ftrace directly from the module code instead of a notifier. This was done before sections were made RO. One option is to do the same with jump_labels and just have a call to the sorting before the notifiers and before the section gets turned into RO. Or I would say just leave it as is. As I stated, jump_labels are "special" and adding a loop of one section where I don't envision any other sections needing to do the same thing for a long time to come. I would save that patch for if there is another section that comes along that needs to be modify at module notify. -- Steve