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=-5.8 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 30C5AC43461 for ; Thu, 8 Apr 2021 08:09:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F081D61164 for ; Thu, 8 Apr 2021 08:09:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229766AbhDHIJp (ORCPT ); Thu, 8 Apr 2021 04:09:45 -0400 Received: from mail.kernel.org ([198.145.29.99]:34548 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229687AbhDHIJn (ORCPT ); Thu, 8 Apr 2021 04:09:43 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 319BC6113D; Thu, 8 Apr 2021 08:09:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617869371; bh=EDBOgrUz8VxB1uH7uiMgZNQY00iTLS1DGawWaDEVVV4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=dhubm0mZjAVfKGnoEMUKJH9bsuP7aQ1qJc1cVA4oG9EPb+nc3utqhekOZTTNkscGZ deKb7EXi6GalWYbQeka1ZPREp27OX8u5JLe8HWDLqHCANUxQH7oVAMhbbXEyCbXcks y2ZuW94O+Nr44DIedN5arz7Ns/UJkjqQyMvNZSK8= Date: Thu, 8 Apr 2021 10:09:29 +0200 From: Greg KH To: Jiri Kosina Cc: Thomas Gleixner , Luis Chamberlain , Minchan Kim , keescook@chromium.org, dhowells@redhat.com, hch@infradead.org, mbenes@suse.com, ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, Jiri Kosina Subject: Re: [PATCH 1/2] zram: fix crashes due to use of cpu hotplug multistate Message-ID: References: <20210319190924.GK4332@42.do-not-panic.com> <20210322204156.GM4332@42.do-not-panic.com> <20210401235925.GR4332@42.do-not-panic.com> <87blap4kum.ffs@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Thu, Apr 08, 2021 at 10:01:23AM +0200, Jiri Kosina wrote: > On Thu, 8 Apr 2021, Greg KH wrote: > > > Removing a module from a system has always been "let's try it and see!" > > type of operation for a very long time. > > Which part of it? > > If there is a driver/subsystem code that can't handle the reverse > operation to modprobe, it clearly can't handle error handling during > modprobe (which, one would hope, is supported), and should be fixed. Huh? No, that's not the issue here, it's the issue of different userspace code paths into the module at the same time that it is trying to be unloaded. That has nothing to do with loading the module the first time as userspace is not touching those apis yet. > If there is a particular issue in kernel dynamic linker that causes crash > on module removal, we'd better off fixing it. Is there one such that makes > you claim module removal unsupported? The linker has nothing to do with this, it's userspace tasks touching code paths. thanks, greg k-h