Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758160AbcJZBew (ORCPT ); Tue, 25 Oct 2016 21:34:52 -0400 Received: from ozlabs.org ([103.22.144.67]:40709 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754573AbcJZBeu (ORCPT ); Tue, 25 Oct 2016 21:34:50 -0400 From: Rusty Russell To: Aaron Tomlin , linux-kernel@vger.kernel.org Cc: rostedt@goodmis.org Subject: Re: [RFC PATCH 2/2] module: When modifying a module's text ignore modules which are going away too In-Reply-To: <1476980293-19062-3-git-send-email-atomlin@redhat.com> References: <1476980293-19062-1-git-send-email-atomlin@redhat.com> <1476980293-19062-3-git-send-email-atomlin@redhat.com> User-Agent: Notmuch/0.21 (http://notmuchmail.org) Emacs/24.5.1 (x86_64-pc-linux-gnu) Date: Wed, 26 Oct 2016 11:35:18 +1030 Message-ID: <87d1in538x.fsf@rustcorp.com.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1575 Lines: 48 Aaron Tomlin writes: > By default, during the access permission modification of a module's core > and init pages, we only ignore modules that are malformed. There is no > reason not to extend this to modules which are going away too. Well, it depends on all the callers (ie. ftrace): is that also ignoring modules which are going away? Otherwise, we set MODULE_STATE_GOING, ftrace walks all the modules and this one is still RO... Thanks, Rusty. > This patch makes both set_all_modules_text_rw() and > set_all_modules_text_ro() skip modules which are going away too. > > Signed-off-by: Aaron Tomlin > --- > kernel/module.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/kernel/module.c b/kernel/module.c > index ff93ab8..09c386b 100644 > --- a/kernel/module.c > +++ b/kernel/module.c > @@ -1953,7 +1953,8 @@ void set_all_modules_text_rw(void) > > mutex_lock(&module_mutex); > list_for_each_entry_rcu(mod, &modules, list) { > - if (mod->state == MODULE_STATE_UNFORMED) > + if (mod->state == MODULE_STATE_UNFORMED || > + mod->state == MODULE_STATE_GOING) > continue; > > frob_text(&mod->core_layout, set_memory_rw); > @@ -1969,7 +1970,8 @@ void set_all_modules_text_ro(void) > > mutex_lock(&module_mutex); > list_for_each_entry_rcu(mod, &modules, list) { > - if (mod->state == MODULE_STATE_UNFORMED) > + if (mod->state == MODULE_STATE_UNFORMED || > + mod->state == MODULE_STATE_GOING) > continue; > > frob_text(&mod->core_layout, set_memory_ro); > -- > 2.5.5