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=-3.8 required=3.0 tests=BAYES_00, 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 7F768C433E0 for ; Thu, 25 Feb 2021 12:08:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 44A2064F1C for ; Thu, 25 Feb 2021 12:08:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232412AbhBYMIw (ORCPT ); Thu, 25 Feb 2021 07:08:52 -0500 Received: from mx2.suse.de ([195.135.220.15]:51874 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229571AbhBYMIn (ORCPT ); Thu, 25 Feb 2021 07:08:43 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 939BFAC1D; Thu, 25 Feb 2021 12:08:02 +0000 (UTC) Date: Thu, 25 Feb 2021 13:08:02 +0100 Message-ID: From: Takashi Iwai To: Anton Yakovlev Cc: , , , "Michael S. Tsirkin" , Jaroslav Kysela , Takashi Iwai , Jason Wang , Subject: Re: [PATCH v5 2/9] ALSA: virtio: add virtio sound driver In-Reply-To: References: <20210222153444.348390-1-anton.yakovlev@opensynergy.com> <20210222153444.348390-3-anton.yakovlev@opensynergy.com> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/25.3 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 25 Feb 2021 12:51:36 +0100, Anton Yakovlev wrote: > > > Now I'm wondering whether it's safe to do that from this place. > > Basically device_reprobe() unbinds the device that releases the full > > resources once including the devm_* stuff. And this work itself is in > > a part of devm allocated resource, so it'll be released there. That > > said, we might hit use-after-free... This needs to be verified. > > It's safe. Suicide kernel workers are funny but possible things. Since > the kernel itself (AFAIU) assumes such a situation and does not access > the worker structure after the callback function call. Indeed, process_one_work() in workqueue.c assures no access to the work object after the callback. Then this must be fine. Good to know! thanks, Takashi