Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965415AbbEMOO2 (ORCPT ); Wed, 13 May 2015 10:14:28 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38870 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965377AbbEMOOX (ORCPT ); Wed, 13 May 2015 10:14:23 -0400 Date: Wed, 13 May 2015 09:14:15 -0500 From: Josh Poimboeuf To: Minfei Huang Cc: mbenes@suse.cz, sjenning@redhat.com, jkosina@suse.cz, vojtech@suse.cz, live-patching@vger.kernel.org, linux-kernel@vger.kernel.org, mhuang@redhat.com Subject: Re: [PATCH v3] livepatch: Prevent to apply the patch once coming module notifier fails Message-ID: <20150513141415.GB28284@treble.redhat.com> References: <1431439484-44530-1-git-send-email-mnfhuang@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <1431439484-44530-1-git-send-email-mnfhuang@gmail.com> User-Agent: Mutt/1.5.23.1-rc1 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2818 Lines: 90 On Tue, May 12, 2015 at 10:04:44PM +0800, Minfei Huang wrote: > @@ -883,7 +883,7 @@ int klp_register_patch(struct klp_patch *patch) > } > EXPORT_SYMBOL_GPL(klp_register_patch); > > -static void klp_module_notify_coming(struct klp_patch *patch, > +static int klp_module_notify_coming(struct klp_patch *patch, > struct klp_object *obj) > { > struct module *pmod = patch->mod; > @@ -891,22 +891,24 @@ static void klp_module_notify_coming(struct klp_patch *patch, > int ret; > > ret = klp_init_object_loaded(patch, obj); > - if (ret) > - goto err; > + if (ret) { > + pr_warn("failed to initialize the patch '%s' (%d)\n", > + pmod->name, ret); > + goto out; > + } Can you change it to: "failed to initialize the patch '%s' for module '%s' (%d)\n" ? That would make it more consistent with the other error message and identify the failing module. Also, the indentation should be fixed on the second pr_warn() line. > > if (patch->state == KLP_DISABLED) > - return; > + goto out; > > pr_notice("applying patch '%s' to loading module '%s'\n", > pmod->name, mod->name); > > ret = klp_enable_object(obj); > - if (!ret) > - return; > - > -err: > - pr_warn("failed to apply patch '%s' to module '%s' (%d)\n", > - pmod->name, mod->name, ret); > + if (ret) > + pr_warn("failed to apply patch '%s' to module '%s' (%d)\n", > + pmod->name, mod->name, ret); Bad indentation here too. > @@ -930,6 +932,7 @@ disabled: > static int klp_module_notify(struct notifier_block *nb, unsigned long action, > void *data) > { > + int ret; > struct module *mod = data; > struct klp_patch *patch; > struct klp_object *obj; > @@ -955,7 +958,13 @@ static int klp_module_notify(struct notifier_block *nb, unsigned long action, > > if (action == MODULE_STATE_COMING) { > obj->mod = mod; > - klp_module_notify_coming(patch, obj); > + ret = klp_module_notify_coming(patch, obj); > + if (ret) { > + obj->mod = NULL; > + pr_warn("patch '%s' is dead, remove it " > + "or re-install the module '%s'\n", > + patch->mod->name, obj->name); > + } The patch isn't necessarily dead, since it might also include previously enabled changes for vmlinux or other modules. It can actually be a dangerous condition if there's a mismatch between old code in the module and new code elsewhere. How about something like: "patch '%s' is in an inconsistent state!\n" Also, there's no need to split up the string literal into two lines. It's ok for a line to have more than 80 columns in that case. -- Josh -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/