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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BF9A1C433EF for ; Fri, 15 Jul 2022 11:47:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232763AbiGOLrk (ORCPT ); Fri, 15 Jul 2022 07:47:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230055AbiGOLrj (ORCPT ); Fri, 15 Jul 2022 07:47:39 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 66E4E88F0B; Fri, 15 Jul 2022 04:47:38 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id F203562304; Fri, 15 Jul 2022 11:47:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1ACD8C3411E; Fri, 15 Jul 2022 11:47:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1657885657; bh=bOhZ+ZI4CCMrYCxTvYYbqkus2jBN41LpMcdBoZMKp/g=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=SDERY9zqlsrtHlvd/ExgvUcaD4kQ7ZZyzri8/3NQv5dDaUmjeTI8fcSj2HCegu/rP ParWgDunpLCv4CdUCPloAJh5r+witRQgOLd5pBTI+RRRf6GO59dwT7B+qvnEyxY0TH MdTultRbNQ7f6hBEe2na8NbKiNLlePVOnPCIXGImYeNk4sNXNiEpaUqt+110dm/AJd kpT9bvs87G59/CEALa8mJLmKqmY47FQRwTrigRUx2FrXMW8KtLZFC/ieZQ80qJyFfX g1Ynll8wssHbduvEcrfdWL/0c3LVMYxBKfrizfRPI3g9gqgB4y2k1sdekQ1+buwjuq e1qT0xLPbdcpQ== Message-ID: <3758d3bd-7272-e907-a51a-44a21d757674@kernel.org> Date: Fri, 15 Jul 2022 13:47:28 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.11.0 Subject: Re: [PATCH V5 01/16] rv: Add Runtime Verification (RV) interface Content-Language: en-US To: Tao Zhou Cc: Steven Rostedt , Wim Van Sebroeck , Guenter Roeck , Jonathan Corbet , Ingo Molnar , Thomas Gleixner , Peter Zijlstra , Will Deacon , Catalin Marinas , Marco Elver , Dmitry Vyukov , "Paul E. McKenney" , Shuah Khan , Gabriele Paoloni , Juri Lelli , Clark Williams , Randy Dunlap , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-trace-devel@vger.kernel.org References: <442b03c687c298b25c79aa5a16ec7fb2aef0f2c9.1657745645.git.bristot@kernel.org> From: Daniel Bristot de Oliveira In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-trace-devel@vger.kernel.org On 7/14/22 09:46, Tao Zhou wrote: > On Wed, Jul 13, 2022 at 11:17:17PM +0200, > Daniel Bristot de Oliveira wrote: > > [...] > >> +void put_task_monitor_slot(int slot) >> +{ >> + lockdep_assert_held(&rv_interface_lock); >> + >> + if (slot < 0 || slot > RV_PER_TASK_MONITORS) { > > slot is the array index that should be 0 here. The up bound is not bigger > than 0 because the element of array now is RV_PER_TASK_MONITORS. > > So up bound check is 'slot > RV_PER_TASK_MONITORS-1'. fixed! (slot >= RV...) > [...] > >> +/* >> + * interface for enabling/disabling a monitor. >> + */ >> +static ssize_t monitor_enable_write_data(struct file *filp, const char __user *user_buf, >> + size_t count, loff_t *ppos) >> +{ >> + struct rv_monitor_def *mdef = filp->private_data; >> + int retval; >> + bool val; >> + >> + retval = kstrtobool_from_user(user_buf, count, &val); >> + if (retval) >> + return retval; >> + >> + retval = count; >> + >> + mutex_lock(&rv_interface_lock); >> + >> + if (val) >> + retval = enable_monitor(mdef); >> + else >> + retval = disable_monitor(mdef); >> + >> + mutex_unlock(&rv_interface_lock); >> + >> + return retval ? retval : count; > > Feel that this can be written `return retval ? : count;` why not... > [...] > >> +static void *enabled_monitors_start(struct seq_file *m, loff_t *pos) >> +{ >> + struct rv_monitor_def *m_def; >> + loff_t l; >> + >> + mutex_lock(&rv_interface_lock); >> + >> + if (list_empty(&rv_monitors_list)) >> + return NULL; >> + >> + m_def = list_entry(&rv_monitors_list, struct rv_monitor_def, list); >> + >> + for (l = 0; l <= *pos; ) { >> + m_def = enabled_monitors_next(m, m_def, &l); >> + if (!m_def) >> + break; > > Is this check is inversed. enabled_monitors_start() will stop at first > enabled monitor, then enabled_monitors_next() do loop to next. Check > like the above, enabled_monitors_start() will loop to the last monitor. > But I doubt myself I do not mention/see it. Sorry for these. > > the check is: > > if (m_def) > break; > > [...] see kernel/trace/trace_events.c:s_start... >> +static ssize_t >> +enabled_monitors_write(struct file *filp, const char __user *user_buf, >> + size_t count, loff_t *ppos) >> +{ >> + char buff[MAX_RV_MONITOR_NAME_SIZE + 2]; >> + struct rv_monitor_def *mdef; >> + int retval = -EINVAL; >> + bool enable = true; >> + char *ptr = buff; >> + int len; >> + >> + if (count < 1 || count > MAX_RV_MONITOR_NAME_SIZE + 2) > > @count would not include '\0'. That the max val of @count is > MAX_RV_MONITOR_NAME_SIZE+1. So the up bound check of @count is > `count > MAX_RV_MONITOR_NAME_SIZE + 1`. Fixed for v6... -- Daniel