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 A337DC282CE for ; Thu, 11 Apr 2019 00:44:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7C98A217D4 for ; Thu, 11 Apr 2019 00:44:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726808AbfDKAoF (ORCPT ); Wed, 10 Apr 2019 20:44:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:56500 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725982AbfDKAoF (ORCPT ); Wed, 10 Apr 2019 20:44:05 -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 99BEF2133D; Thu, 11 Apr 2019 00:44:03 +0000 (UTC) Date: Wed, 10 Apr 2019 20:44:01 -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: <20190410204401.62f928ca@gandalf.local.home> In-Reply-To: <20190410202902.GA167446@google.com> References: <20190410195708.162185-1-joel@joelfernandes.org> <20190410195708.162185-3-joel@joelfernandes.org> <20190410161112.540017d9@gandalf.local.home> <20190410202902.GA167446@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 Wed, 10 Apr 2019 16:29:02 -0400 Joel Fernandes wrote: > The srcu structure pointer array is modified at module load time because the > array is fixed up by the module loader at load-time with the final locations > of the tracepoints right? Basically relocation fixups. At compile time, I > believe it is not know what the values in the ptr array are. I believe same > is true for the tracepoint ptrs array. > > Also it needs to be in a separate __tracepoint_ptrs so that this code works: > > > #ifdef CONFIG_TRACEPOINTS > mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", > sizeof(*mod->tracepoints_ptrs), > &mod->num_tracepoints); > #endif > > Did I miss some point? Thanks, But there's a lot of others too. Hmm, does this mean that the RO data sections that are in modules are not set to RO? There's a bunch of separate sections that are RO. Just look in include/asm-generic/vmlinux.lds.h under the RO_DATA_SECTION() macro. A lot of the sections saved in module.c:find_module_sections() are in that RO_DATA when compiled as a builtin. Are they not RO when loaded via a module? If this is the case, there probably is going to be a lot more sections added to your list. -- Steve