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=-6.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 CBC6CC433E0 for ; Mon, 8 Mar 2021 14:37:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8BB9D651AF for ; Mon, 8 Mar 2021 14:37:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231202AbhCHOhI (ORCPT ); Mon, 8 Mar 2021 09:37:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:45740 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230051AbhCHOgf (ORCPT ); Mon, 8 Mar 2021 09:36:35 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 83AE9651DC; Mon, 8 Mar 2021 14:36:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1615214194; bh=A0hmv3jMN4wqBTtB8OS7XxKHFgY14vTBrTGYAbFd1AE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QundLkZAHBw7vwUzNjhlWBqcEAAhBwetUmp/vZIOLhOg2eru9Qi/zNP+jbhPJSQw6 RW7YG63jKYTkr56WUVYevwdCiCQbO3BwdlFapU0gyhbFFwSqX5oy+eJsIMN2SyaGNC 5EZkNvPKmrKpKAUPsMJIc23ivHw5l9gNyLSslPwc= Date: Mon, 8 Mar 2021 15:36:31 +0100 From: Greg KH To: Adrian Catangiu Cc: linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, qemu-devel@nongnu.org, kvm@vger.kernel.org, linux-s390@vger.kernel.org, graf@amazon.com, rdunlap@infradead.org, arnd@arndb.de, ebiederm@xmission.com, rppt@kernel.org, 0x7f454c46@gmail.com, borntraeger@de.ibm.com, Jason@zx2c4.com, jannh@google.com, w@1wt.eu, colmmacc@amazon.com, luto@kernel.org, tytso@mit.edu, ebiggers@kernel.org, dwmw@amazon.co.uk, bonzini@gnu.org, sblbir@amazon.com, raduweis@amazon.com, corbet@lwn.net, mst@redhat.com, mhocko@kernel.org, rafael@kernel.org, pavel@ucw.cz, mpe@ellerman.id.au, areber@redhat.com, ovzxemul@gmail.com, avagin@gmail.com, ptikhomirov@virtuozzo.com, gil@azul.com, asmehra@redhat.com, dgunigun@redhat.com, vijaysun@ca.ibm.com, oridgar@gmail.com, ghammer@redhat.com Subject: Re: [PATCH v8] drivers/misc: sysgenid: add system generation id driver Message-ID: References: <1615213083-29869-1-git-send-email-acatan@amazon.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1615213083-29869-1-git-send-email-acatan@amazon.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Mar 08, 2021 at 04:18:03PM +0200, Adrian Catangiu wrote: > +static struct miscdevice sysgenid_misc = { > + .minor = MISC_DYNAMIC_MINOR, > + .name = "sysgenid", > + .fops = &fops, > +}; Much cleaner, but: > +static int __init sysgenid_init(void) > +{ > + int ret; > + > + sysgenid_data.map_buf = get_zeroed_page(GFP_KERNEL); > + if (!sysgenid_data.map_buf) > + return -ENOMEM; > + > + atomic_set(&sysgenid_data.generation_counter, 0); > + atomic_set(&sysgenid_data.outdated_watchers, 0); > + init_waitqueue_head(&sysgenid_data.read_waitq); > + init_waitqueue_head(&sysgenid_data.outdated_waitq); > + spin_lock_init(&sysgenid_data.lock); > + > + ret = misc_register(&sysgenid_misc); > + if (ret < 0) { > + pr_err("misc_register() failed for sysgenid\n"); > + goto err; > + } > + > + return 0; > + > +err: > + free_pages(sysgenid_data.map_buf, 0); > + sysgenid_data.map_buf = 0; > + > + return ret; > +} > + > +static void __exit sysgenid_exit(void) > +{ > + misc_deregister(&sysgenid_misc); > + free_pages(sysgenid_data.map_buf, 0); > + sysgenid_data.map_buf = 0; > +} > + > +module_init(sysgenid_init); > +module_exit(sysgenid_exit); So you do this for any bit of hardware that happens to be out there? Will that really work? You do not have any hwid to trigger off of to know that this is a valid device you can handle? > + > +MODULE_AUTHOR("Adrian Catangiu"); > +MODULE_DESCRIPTION("System Generation ID"); > +MODULE_LICENSE("GPL"); > +MODULE_VERSION("0.1"); MODULE_VERSION() isn't a thing, just drop it please :) thnaks, greg k-h