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 ADEA9C433ED for ; Wed, 7 Apr 2021 15:38:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6E08B6112F for ; Wed, 7 Apr 2021 15:38:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230508AbhDGPij (ORCPT ); Wed, 7 Apr 2021 11:38:39 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:51458 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229965AbhDGPii (ORCPT ); Wed, 7 Apr 2021 11:38:38 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1617809908; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=4jXDVYNZhoFNYiKZYrtZsKuCVb4vwBIdNB0gpCFJ6N8=; b=dZNOmcn5zGPx7ebPr79yv0ft9SJRMr7jf7aLsf53kpD1zxLWqD3SnyL3yyfol8dXVhYI1q +DDoXnaYE7IIMF5n+fFb6XBH7J7wSpoLBMb+7hHow6OnhXY5dIfcXCEYAUuhilsWtqTm6I /Umi3vM1ImDDDcwPNmO+dUy6rNkBQ5o= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-219-51rTN3sKNQOCggXX2cxiZQ-1; Wed, 07 Apr 2021 11:30:39 -0400 X-MC-Unique: 51rTN3sKNQOCggXX2cxiZQ-1 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.phx2.redhat.com [10.5.11.15]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 78CFB9F92C; Wed, 7 Apr 2021 15:30:37 +0000 (UTC) Received: from treble (ovpn-116-68.rdu2.redhat.com [10.10.116.68]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B6C505D6CF; Wed, 7 Apr 2021 15:30:33 +0000 (UTC) Date: Wed, 7 Apr 2021 10:30:31 -0500 From: Josh Poimboeuf To: Peter Zijlstra Cc: Miroslav Benes , Greg KH , Luis Chamberlain , mbenes@suse.com, Minchan Kim , keescook@chromium.org, dhowells@redhat.com, hch@infradead.org, ngupta@vflare.org, sergey.senozhatsky.work@gmail.com, axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, live-patching@vger.kernel.org, Jessica Yu Subject: Re: [PATCH 1/2] zram: fix crashes due to use of cpu hotplug multistate Message-ID: <20210407153031.m4gg3rsgwlr432ba@treble> References: <20210322204156.GM4332@42.do-not-panic.com> <20210401235925.GR4332@42.do-not-panic.com> <20210402183016.GU4332@42.do-not-panic.com> <20210406003152.GZ4332@42.do-not-panic.com> <20210406155423.t7dagp24bupudv3p@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: X-Scanned-By: MIMEDefang 2.79 on 10.5.11.15 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Wed, Apr 07, 2021 at 04:09:44PM +0200, Peter Zijlstra wrote: > On Tue, Apr 06, 2021 at 10:54:23AM -0500, Josh Poimboeuf wrote: > > > Same for Red Hat. Unloading livepatch modules seems to work fine, but > > isn't officially supported. > > > > That said, if rmmod is just considered a development aid, and we're > > going to be ignoring bugs, we should make it official with a new > > TAINT_RMMOD. > > Another option would be to have live-patch modules leak a module > reference by default, except when some debug sysctl is set or something. > Then only those LP modules loaded while the sysctl is set to 'YOLO' can > be unloaded. The issue is broader than just live patching. My suggestion was that if we aren't going to fix bugs in kernel module unloading, then unloading modules shouldn't be supported, and should taint the kernel. -- Josh