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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 CCC85C35671 for ; Sun, 23 Feb 2020 11:26:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8AA8C20656 for ; Sun, 23 Feb 2020 11:26:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=arista.com header.i=@arista.com header.b="L4zCbEHE" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726023AbgBWLWB (ORCPT ); Sun, 23 Feb 2020 06:22:01 -0500 Received: from mail-ed1-f65.google.com ([209.85.208.65]:34153 "EHLO mail-ed1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726236AbgBWLWB (ORCPT ); Sun, 23 Feb 2020 06:22:01 -0500 Received: by mail-ed1-f65.google.com with SMTP id r18so8365121edl.1 for ; Sun, 23 Feb 2020 03:22:00 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arista.com; s=googlenew; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=I7rQJgBtj2WD56CuhDDY5luHd0dpn2aSY0uftQht5ZY=; b=L4zCbEHEPzVE43pBLR7WjtzcS3JDvt5WjCIe2+iDIf92RrrcWY75h+Vn/ZR+naVONz Fcm5D3OfF3aM7CMksqiP2I+71HuT6iHUs3nsiFj6opaJgJ1vDw9YR0pYZJU8PedHfQA6 wBD7ISEfBuhjerMlqm11ycAWFmES2smKg9wM+jqewCAztKimeFXNmkXa4IZstD4c/A1T 6NC8zAAtl71g1htXbl8fxs2pznxDL4EXhIPCwUx62wyZamIJr99eT5Xwxg1Z4U/NQPx3 Tjx1COuUUmV7AhWJcwyA4atKE/yYfeMIyE2vQWSzM2E6hmRq6ZxfZarJbGXmTwU4qgUB vHoQ== 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=I7rQJgBtj2WD56CuhDDY5luHd0dpn2aSY0uftQht5ZY=; b=MgIZU7HcCvtavChQaP0RobLPv2xEseBrAGwpu0SHnzxRtvJVEW6X3XRotcwyjs5CH+ 3mAOx3StSR53vDkWlmYxH2ugyf7FTGM1Do93W67IMGU3VFMW/sxyA2LUJNlV6cLir+AP Gu20sQabF0eOMnmxhFtBJ4bzz8lAB+GWev3pwrB4weV5BHwqpP/SSruNvFikAk3gH6BT gEmHwrF03VzwCI3zBWJvKbIfl7uzCAiB9dOoeBh3EEMvUHi5+TgO4Bs3BWPrgqrw0y/k ocK8y4WDkQnpu41shS0xF5ahE3iJ12gHl2mEmmdAA2jwXkJeMG6abMseKLV+huDrvkkT uAnA== X-Gm-Message-State: APjAAAWXdQbzuGIf9YUV5VwP4/zJmYA+yBBgjDHPJL8kEPtRa2HE/K3m qX/en0XkQKXraLaGevqn91wMjw== X-Google-Smtp-Source: APXvYqyD2OOCxUukSbGgSCpuRxlrUzuSY/iqLh1Bk/5C1CX3LGqG3cxQPjzRF8TdhBraa6MyX457BQ== X-Received: by 2002:aa7:df09:: with SMTP id c9mr41891593edy.133.1582456919461; Sun, 23 Feb 2020 03:21:59 -0800 (PST) Received: from ?IPv6:2a02:8084:e84:2480:228:f8ff:fe6f:83a8? ([2a02:8084:e84:2480:228:f8ff:fe6f:83a8]) by smtp.gmail.com with ESMTPSA id b9sm762595edm.60.2020.02.23.03.21.58 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 23 Feb 2020 03:21:58 -0800 (PST) Subject: Re: [PATCHv2] watchdog: Add stop_on_reboot parameter to control reboot policy To: Guenter Roeck Cc: linux-kernel@vger.kernel.org, Dmitry Safonov <0x7f454c46@gmail.com>, Wim Van Sebroeck , linux-watchdog@vger.kernel.org References: <20200214162209.129107-1-dima@arista.com> <20200222160639.GA12925@roeck-us.net> From: Dmitry Safonov Message-ID: Date: Sun, 23 Feb 2020 11:21:59 +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: <20200222160639.GA12925@roeck-us.net> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Hi Guenter, On 2/22/20 4:06 PM, Guenter Roeck wrote: > On Fri, Feb 14, 2020 at 04:22:09PM +0000, Dmitry Safonov wrote: [..] >> +static int stop_on_reboot = -1; >> +module_param(stop_on_reboot, int, 0644); >> +MODULE_PARM_DESC(stop_on_reboot, "Stop watchdogs on reboot (0=keep watching, 1=stop)"); >> + > > My major concern is that this is writeable at runtime. > Changing the value won't change the behavior of already loaded > drivers. Unloading and reloading the driver will change its behavior > after the value was changed. This would be confusing, and it is hard > to imagine for anyone to expect such a behavior. Does this have to be > writeable ? No, it wasn't. I've messed it up by thinking about fours in 0644, but for some reason failed to recognize that it allows root writes. I'll follow up with v3, sorry for simple-minded typo. Thanks, Dmitry