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=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 1E8A5C48BE8 for ; Tue, 15 Jun 2021 05:16:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 024236140F for ; Tue, 15 Jun 2021 05:16:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230334AbhFOFSQ (ORCPT ); Tue, 15 Jun 2021 01:18:16 -0400 Received: from mail.kernel.org ([198.145.29.99]:51792 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229463AbhFOFSQ (ORCPT ); Tue, 15 Jun 2021 01:18:16 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 7EFA66140C; Tue, 15 Jun 2021 05:16:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1623734171; bh=Z00wlTIUpAwaWy8xwiUaTQGWmY0BylPfc2L2hvZ+QA4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XzO4BqfGmAc01uYXz9KRlSIfYofAufPEugrj5xBw07XpsOJdKwMkPD48lw9FwkjbJ UwkVG1u4+JGUrpvF3ZrOKzZ3EW6CO8BVhY7wqok0SYWRu1Htf5oNH/L0Xvu49w78AT KP62aqSUdz4MdZ3D88ffBHHpAxow5RUuKzu3/IwI= Date: Tue, 15 Jun 2021 07:16:07 +0200 From: Greg Kroah-Hartman To: Christoph Hellwig Cc: Jason Gunthorpe , Alex Williamson , Kirti Wankhede , David Airlie , Tony Krowiak , Christian Borntraeger , Cornelia Huck , Jonathan Corbet , Daniel Vetter , dri-devel@lists.freedesktop.org, Vasily Gorbik , Heiko Carstens , intel-gfx@lists.freedesktop.org, Jani Nikula , Jason Herne , Joonas Lahtinen , kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-s390@vger.kernel.org, Halil Pasic , "Rafael J. Wysocki" , Rodrigo Vivi Subject: Re: [PATCH 01/10] driver core: Pull required checks into driver_probe_device() Message-ID: References: <20210614150846.4111871-1-hch@lst.de> <20210614150846.4111871-2-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210614150846.4111871-2-hch@lst.de> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Jun 14, 2021 at 05:08:37PM +0200, Christoph Hellwig wrote: > From: Jason Gunthorpe > > Checking if the dev is dead or if the dev is already bound is a required > precondition to invoking driver_probe_device(). All the call chains > leading here duplicate these checks. > > Add it directly to driver_probe_device() so the precondition is clear and > remove the checks from device_driver_attach() and > __driver_attach_async_helper(). > > The other call chain going through __device_attach_driver() does have > these same checks but they are inlined into logic higher up the call stack > and can't be removed. > > The sysfs uAPI call chain starting at bind_store() is a bit confused > because it reads dev->driver unlocked and returns -ENODEV if it is !NULL, > otherwise it reads it again under lock and returns 0 if it is !NULL. Fix > this to always return -EBUSY and always read dev->driver under its lock. > > Done in preparation for the next patches which will add additional > callers to driver_probe_device() and will need these checks as well. > > Signed-off-by: Jason Gunthorpe > [hch: drop the extra checks in device_driver_attach and bind_store] > Signed-off-by: Christoph Hellwig Reviewed-by: Greg Kroah-Hartman