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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, NICE_REPLY_A,SIGNED_OFF_BY,SPF_HELO_NONE,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 90408C433E8 for ; Wed, 15 Jul 2020 08:35:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 65774206F5 for ; Wed, 15 Jul 2020 08:35:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594802133; bh=Ox43SIMUWgQaXB3i+UOOy7ao2qOQdpYQtJCeLUAPGk0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:List-ID:From; b=f9xik9kPutBB15GCqtZr9J2YdSi76tZqTBVkVKgDqpuU5C8OJQAW3m4qZvuApnRu3 SvKEnbuY6Q6l/KwFwKEd2cqetdHtGQ6dJMaO5FuHEHm8us+apkwOOzE/Ulxxi9ymDM 8m96Yr0Ph5OFnpSIW4bOe/Rh1hKcbgclmEyiNIbo= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730235AbgGOIfc (ORCPT ); Wed, 15 Jul 2020 04:35:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:41670 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730224AbgGOIfa (ORCPT ); Wed, 15 Jul 2020 04:35:30 -0400 Received: from devnote2 (NE2965lan1.rev.em-net.ne.jp [210.141.244.193]) (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 BBD652065D; Wed, 15 Jul 2020 08:35:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1594802129; bh=Ox43SIMUWgQaXB3i+UOOy7ao2qOQdpYQtJCeLUAPGk0=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=LwtBgKWVLrxa9jeFRbsT9NRk351F+8baad7pbFJebQxf8s8+TVabITgJHMeWMu0fe HUCUGS/2/sOXjD99U0dJ2bWIPzS2RLkc6rSr2NzU/iY4EelmsB2idUMv7vOXWNY6Gk hvcpB7nYoPK1472Ta1KLEx4kb5A6MzuqGPr7ml80= Date: Wed, 15 Jul 2020 17:35:24 +0900 From: Masami Hiramatsu To: Jarkko Sakkinen Cc: linux-kernel@vger.kernel.org, x86@vger.kernel.org, Andi Kleen , Jessica Yu , "Naveen N. Rao" , Anil S Keshavamurthy , "David S. Miller" , Masami Hiramatsu , Steven Rostedt , Ingo Molnar Subject: Re: [PATCH v3 3/3] kprobes: Flag out CONFIG_MODULES dependent code Message-Id: <20200715173524.0f21afce3574b8e8596e751e@kernel.org> In-Reply-To: <20200714223239.1543716-4-jarkko.sakkinen@linux.intel.com> References: <20200714223239.1543716-1-jarkko.sakkinen@linux.intel.com> <20200714223239.1543716-4-jarkko.sakkinen@linux.intel.com> X-Mailer: Sylpheed 3.7.0 (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 Hi Jarkko, On Wed, 15 Jul 2020 01:32:29 +0300 Jarkko Sakkinen wrote: > Remove CONFIG_MODULES dependency by flagging out the dependent code. This > allows to use kprobes in a kernel without support for loadable modules, > which could be useful for a test kernel or perhaps an embedded kernel. > OK, looks good, I just have 2 comments below. > Cc: Andi Kleen > Signed-off-by: Jarkko Sakkinen > --- > include/linux/module.h | 14 +++++++------- > kernel/kprobes.c | 7 +++++++ > kernel/trace/trace_kprobe.c | 16 +++++++++++++++- > 3 files changed, 29 insertions(+), 8 deletions(-) > > diff --git a/include/linux/module.h b/include/linux/module.h > index 857b84bf9e90..eaa8ad02f75c 100644 > --- a/include/linux/module.h > +++ b/include/linux/module.h > @@ -290,6 +290,13 @@ extern typeof(name) __mod_##type##__##name##_device_table \ > > struct notifier_block; > > +enum module_state { > + MODULE_STATE_LIVE, /* Normal state. */ > + MODULE_STATE_COMING, /* Full formed, running module_init. */ > + MODULE_STATE_GOING, /* Going away. */ > + MODULE_STATE_UNFORMED, /* Still setting it up. */ > +}; > + > #ifdef CONFIG_MODULES > > extern int modules_disabled; /* for sysctl */ > @@ -305,13 +312,6 @@ struct module_use { > struct module *source, *target; > }; > > -enum module_state { > - MODULE_STATE_LIVE, /* Normal state. */ > - MODULE_STATE_COMING, /* Full formed, running module_init. */ > - MODULE_STATE_GOING, /* Going away. */ > - MODULE_STATE_UNFORMED, /* Still setting it up. */ > -}; > - > struct mod_tree_node { > struct module *mod; > struct latch_tree_node node; > diff --git a/kernel/kprobes.c b/kernel/kprobes.c > index b4f3c24cd2ef..3039df13d34e 100644 > --- a/kernel/kprobes.c > +++ b/kernel/kprobes.c > @@ -2225,6 +2225,7 @@ int kprobe_add_area_blacklist(unsigned long start, unsigned long end) > return 0; > } > > +#ifdef CONFIG_MODULES > /* Remove all symbols in given area from kprobe blacklist */ > static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) > { > @@ -2242,6 +2243,7 @@ static void kprobe_remove_ksym_blacklist(unsigned long entry) > { > kprobe_remove_area_blacklist(entry, entry + 1); > } > +#endif > > int __init __weak arch_populate_kprobe_blacklist(void) > { > @@ -2285,6 +2287,7 @@ static int __init populate_kprobe_blacklist(unsigned long *start, > return ret ? : arch_populate_kprobe_blacklist(); > } > > +#ifdef CONFIG_MODULES > static void add_module_kprobe_blacklist(struct module *mod) > { > unsigned long start, end; > @@ -2330,6 +2333,10 @@ static void remove_module_kprobe_blacklist(struct module *mod) > kprobe_remove_area_blacklist(start, end); > } > } > +#else > +static void add_module_kprobe_blacklist(struct module *mod) {} > +static void remove_module_kprobe_blacklist(struct module *mod) {} > +#endif /* CONFIG_MODULES */ Please feel free to move the function. I would like to see; #ifdef CONFIG_MODULES /* Remove all symbols in given area from kprobe blacklist */ static void kprobe_remove_area_blacklist(unsigned long start, unsigned long end) { ... } static void add_module_kprobe_blacklist(struct module *mod) { ... } #else static void add_module_kprobe_blacklist(struct module *mod) {} static void remove_module_kprobe_blacklist(struct module *mod) {} #endif /* CONFIG_MODULES */ Rather than split #ifdefs. > > /* Module notifier call back, checking kprobes on the module */ > static int kprobes_module_callback(struct notifier_block *nb, > diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c > index 710ec6a6aa8f..7fcd1bf2d96e 100644 > --- a/kernel/trace/trace_kprobe.c > +++ b/kernel/trace/trace_kprobe.c > @@ -103,8 +103,9 @@ static nokprobe_inline bool trace_kprobe_has_gone(struct trace_kprobe *tk) > return !!(kprobe_gone(&tk->rp.kp)); > } > > +#ifdef CONFIG_MODULES > static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, > - struct module *mod) > + struct module *mod) > { > int len = strlen(mod->name); > const char *name = trace_kprobe_symbol(tk); > @@ -129,6 +130,17 @@ static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > > return ret; > } > +#else > +static nokprobe_inline bool trace_kprobe_within_module(struct trace_kprobe *tk, > + struct module *mod) > +{ > + return false; > +} > +static nokprobe_inline bool trace_kprobe_module_exist(struct trace_kprobe *tk) > +{ > + return false; > +} > +#endif > > static bool trace_kprobe_is_busy(struct dyn_event *ev) > { > @@ -685,10 +697,12 @@ static int trace_kprobe_module_callback(struct notifier_block *nb, > /* Don't need to check busy - this should have gone. */ > __unregister_trace_kprobe(tk); > ret = __register_trace_kprobe(tk); > +#ifdef CONFIG_MODULES > if (ret) > pr_warn("Failed to re-register probe %s on %s: %d\n", > trace_probe_name(&tk->tp), > mod->name, ret); > +#endif I guess this CONFIG_MODULES is for avoiding build error according to mod->name, if so, please use module_name(mod) macro instead of this #ifdef. > } > } > mutex_unlock(&event_mutex); > -- > 2.25.1 > -- Masami Hiramatsu