From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754673AbdKMTXP (ORCPT ); Mon, 13 Nov 2017 14:23:15 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:57166 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754627AbdKMTXL (ORCPT ); Mon, 13 Nov 2017 14:23:11 -0500 Date: Mon, 13 Nov 2017 20:23:17 +0100 From: Greg Kroah-Hartman To: Guenter Roeck Cc: Dmitry Torokhov , Randy Dunlap , LKML , Guenter Roeck , Wei-Ning Huang Subject: Re: drivers/firmware/google/vpd.c: duplicate sysfs file Message-ID: <20171113192317.GA27109@kroah.com> References: <9629c610-26cf-d64d-8351-b90273b09676@infradead.org> <6634ab5b-b21f-120e-2a29-52c824d5dcff@infradead.org> <20171113190400.hayy4iff5wmjy3qt@dtor-ws> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.9.1 (2017-09-22) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 13, 2017 at 11:09:21AM -0800, Guenter Roeck wrote: > On Mon, Nov 13, 2017 at 11:04 AM, Dmitry Torokhov > wrote: > > > > On Mon, Nov 13, 2017 at 10:18:35AM -0800, Randy Dunlap wrote: > > > On 11/13/2017 06:41 AM, Guenter Roeck wrote: > > > > > > > > > > > > On Sun, Nov 12, 2017 at 10:36 PM, Randy Dunlap > wrote: > > > > > > > > sysfs: cannot create duplicate filename '/devices/platform/vpd' > > > > > > > > on the second load of this driver. I.e., > > > > > > > > modprobe vpd-sysfs > > > > rmmod vpd-sysfs > > > > modprobe vpd-sysfs > > > > [boom] > > > > > > > > Neither the platform device nor the platform driver driver are ever unregistered, so this isn't entirely surprising. I'll try to reproduce and send a patch. > > > > > > > > > Seems to be a common theme: > > > > > > google> grep --color=never "platform.*register" *.c > > > coreboot_table-acpi.c: return platform_driver_register(&coreboot_table_acpi_driver); > > > coreboot_table-of.c: return platform_driver_register(&coreboot_table_of_driver); > > > > These are not unloadable (for better or worse) - they do not have > > module_exit() in them. > > > > > > > > gsmi.c: gsmi_dev.pdev = platform_device_register_full(&gsmi_dev_info); > > > gsmi.c: platform_device_unregister(gsmi_dev.pdev); > > > gsmi.c: platform_device_unregister(gsmi_dev.pdev); > > > [looks good] > > > > > > memconsole-coreboot.c: pdev = platform_device_register_simple("memconsole", -1, NULL, 0); > > > memconsole-coreboot.c: platform_driver_register(&memconsole_driver); > > > > Same here: not unloadable. > > > > > > > > vpd.c: pdev = platform_device_register_simple("vpd", -1, NULL, 0); > > > vpd.c: platform_driver_register(&vpd_driver); > > > > Arguably this should not even be a platform driver, there is no hardware > > behind it. I was planning on purring some notifiers into coreboot table > > driver and using notifiers to attach vpd to them. -ENOTIME though. > > > Two options for now: clean it up and make it unloadable, or make it bool > and drop the exit function. Any preference ? > > The problem is easy to reproduce even with the driver is built into > the kernel with a simple unbind/bind sequence. And after the unbind, > it is easy to crash the system since the sysfs attributes are still there. The kernel should not 'crash', just spit out a nasty warning, right? thanks, greg k-h