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=-2.3 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 13648C10F27 for ; Tue, 10 Mar 2020 15:57:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DDC79208E4 for ; Tue, 10 Mar 2020 15:57:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="T0IOSo6R" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726557AbgCJP5V (ORCPT ); Tue, 10 Mar 2020 11:57:21 -0400 Received: from mail-wr1-f65.google.com ([209.85.221.65]:43869 "EHLO mail-wr1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726535AbgCJP5V (ORCPT ); Tue, 10 Mar 2020 11:57:21 -0400 Received: by mail-wr1-f65.google.com with SMTP id v9so16535446wrf.10 for ; Tue, 10 Mar 2020 08:57:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=qqxKcZJOrqeYSSF+8tyd/gsVhc7h6GEjUCuzNcHFAcM=; b=T0IOSo6RAe3cFMhsUTvQi/3XfxYHMQKp60imkGrJQygQ7x8SM9uK0zVfHwStDzocz+ Xu6+o1SVDCx0cONwFl4q7jzXqnUjSDfVZsgV8KAGqm/VE/Yl4xGce5vHkx1XTLxRGNje BM7a2qoc/FWhD45o6m0zGHX0VgAt7RkJYtLFCux8UFiTw2vATVzKf9Swk9EcbxqVOiAH XQA2K2e4WuntGtIRSoFhJN/AJ/wgnUGrnNUSVqcpOOFW/hncl4Y6nam8mwndGsunIJv7 6/sDbM0hsBYM8KSEzgn1utxbnO9TbQfcUEHqEuqx6ZQKrAS7neBmW88/Cm18D1Y1O5Id ptiw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=qqxKcZJOrqeYSSF+8tyd/gsVhc7h6GEjUCuzNcHFAcM=; b=s400Em/u7y11fIDRxA+kyQAnDgYqtFhmE287lnxR4+k+wRpg2eHt9CWAzSFSz+BZzg zzhXwGybr7QdcEpvxWa3odKVtfdkGz1Z8O+vDVi8Rmkqehas4mRss39fOVTD/ju7OulF AEIAY9Y+ePIulLtJIGjoSSPzH3rQfZESBsdvS41lFoapkurCi/LrM4plI+nzv5PVzeWB 82qJ+tHVI9jxAHWud3SsHWm8y5kQz2xh5YXuhid/bq75brHS9JRd76gh4SsSyq9oSEDp dUMRoFoGYismnJru0G02SPPTS+39cwF5EuPLLAPg7yNwpo3VlKllBUzwnstWQM+oTeNu a0rA== X-Gm-Message-State: ANhLgQ0rxqgriAnC6vpLTfby+9w9A53H0lQGBR7GY1mru1HpEXOKLNLJ 1HZoTfqd1E0gERBrt+xwwLQ= X-Google-Smtp-Source: ADFU+vugsoRsjuvoiuX/CEuxMrHQxIhRbKWPA9twtxlRhqEN56ci0XxOcF4+MBvE6gDmZPLUXT036Q== X-Received: by 2002:a5d:5290:: with SMTP id c16mr26828210wrv.235.1583855839436; Tue, 10 Mar 2020 08:57:19 -0700 (PDT) Received: from [10.83.36.153] ([217.173.96.166]) by smtp.gmail.com with ESMTPSA id p16sm3676249wmi.40.2020.03.10.08.57.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 10 Mar 2020 08:57:18 -0700 (PDT) Subject: Re: [PATCH v1 1/4] serial: core: Use string length for SysRq magic sequence To: Andy Shevchenko Cc: Greg Kroah-Hartman , linux-serial@vger.kernel.org References: <20200310132004.86367-1-andriy.shevchenko@linux.intel.com> <64f650b7-8c39-4bef-f1d9-ff2720923c8c@gmail.com> <20200310145706.GQ1922688@smile.fi.intel.com> From: Dmitry Safonov <0x7f454c46@gmail.com> Message-ID: Date: Tue, 10 Mar 2020 15:57:17 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.2 MIME-Version: 1.0 In-Reply-To: <20200310145706.GQ1922688@smile.fi.intel.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-serial-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Hi Andy, On 3/10/20 2:57 PM, Andy Shevchenko wrote: > On Tue, Mar 10, 2020 at 02:38:48PM +0000, Dmitry Safonov wrote: >> On 3/10/20 1:20 PM, Andy Shevchenko wrote: >> [..]> @@ -3209,7 +3209,9 @@ static DECLARE_WORK(sysrq_enable_work, >> uart_sysrq_on); >>> */ >>> static bool uart_try_toggle_sysrq(struct uart_port *port, unsigned int ch) >>> { >>> - if (ARRAY_SIZE(sysrq_toggle_seq) <= 1) >>> + int sysrq_toggle_seq_len = strlen(sysrq_toggle_seq); >>> + >>> + if (!sysrq_toggle_seq_len) >>> return false; >> >> Eh, I wanted to avoid the strlen() call in runtime for every time sysrq >> is pressed. It's not very frequent moment surely, but.. > > I really don't like ARRAY_SIZE() against plain strings. > This will use \0 inclusively and confuse the understanding the code. I still feel a bit awkward that handler will run strlen() for something that could be done compile-time, but I won't insist. Thanks again for looking into warning, Dmitry