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 E0D52CCA47C for ; Thu, 14 Jul 2022 07:47:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237389AbiGNHrD (ORCPT ); Thu, 14 Jul 2022 03:47:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234625AbiGNHq7 (ORCPT ); Thu, 14 Jul 2022 03:46:59 -0400 Received: from out2.migadu.com (out2.migadu.com [188.165.223.204]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BBAD337196; Thu, 14 Jul 2022 00:46:57 -0700 (PDT) Date: Thu, 14 Jul 2022 15:46:45 +0800 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1657784816; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=1TJviPunlwH7RxQV4jVLO1pPXI9F2og9+lwfZ75k6+g=; b=OKMxJzzUX/eSiaPlxOT6jOv1GE3aUntvTUhYa/zLy2CJbOPuL7nAwGJXJ8p5NWffeqB118 YTbQyjLtSsm/NH6anB6VLWIOm/CcVlhhocIHHlNwmTBehCgatSEn1F4yO/M8UNl/aXO16n reyCtQJBf8EZKXDfUHbKAMrUCx3bEwQ= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Tao Zhou To: Daniel Bristot de Oliveira 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, Tao Zhou Subject: Re: [PATCH V5 01/16] rv: Add Runtime Verification (RV) interface Message-ID: References: <442b03c687c298b25c79aa5a16ec7fb2aef0f2c9.1657745645.git.bristot@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <442b03c687c298b25c79aa5a16ec7fb2aef0f2c9.1657745645.git.bristot@kernel.org> X-Migadu-Flow: FLOW_OUT X-Migadu-Auth-User: linux.dev Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org 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'. [...] > +/* > + * 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;` [...] > +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; [...] > +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`. Thanks, Tao > + return -EINVAL; > + > + memset(buff, 0, sizeof(buff)); > + > + retval = simple_write_to_buffer(buff, sizeof(buff) - 1, ppos, user_buf, count); > + if (!retval) > + return -EFAULT; > + > + ptr = strim(buff); > + > + if (ptr[0] == '!') { > + enable = false; > + ptr++; > + } > + > + len = strlen(ptr); > + if (!len) > + return count; > + > + mutex_lock(&rv_interface_lock); > + > + retval = -EINVAL; > + > + list_for_each_entry(mdef, &rv_monitors_list, list) { > + if (strcmp(ptr, mdef->monitor->name) != 0) > + continue; > + > + /* > + * Monitor found! > + */ > + if (enable) > + retval = enable_monitor(mdef); > + else > + retval = disable_monitor(mdef); > + > + if (!retval) > + retval = count; > + > + break; > + } > + > + mutex_unlock(&rv_interface_lock); > + return retval; > +}