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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 93B42C10F13 for ; Thu, 11 Apr 2019 12:13:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 61DA32133D for ; Thu, 11 Apr 2019 12:13:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726595AbfDKMNW (ORCPT ); Thu, 11 Apr 2019 08:13:22 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:38950 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726073AbfDKMNV (ORCPT ); Thu, 11 Apr 2019 08:13:21 -0400 Received: from DGGEMS401-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 8C56641F068B8E92FEB3; Thu, 11 Apr 2019 20:13:18 +0800 (CST) Received: from [127.0.0.1] (10.202.227.238) by DGGEMS401-HUB.china.huawei.com (10.3.19.201) with Microsoft SMTP Server id 14.3.408.0; Thu, 11 Apr 2019 20:13:10 +0800 Subject: Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure To: Robin Murphy , Greg KH References: <1553767685-27077-1-git-send-email-john.garry@huawei.com> <703aca1f-9475-b50d-624a-5f1ceea2c3b2@huawei.com> <20190403081433.GA13222@kroah.com> <3e1f3e2e-a1d3-ecaf-0931-44b4c10faffe@huawei.com> <198058c6-63c6-ac3c-62b7-438e5e3b3f0e@arm.com> CC: , , , , , , , , From: John Garry Message-ID: Date: Thu, 11 Apr 2019 13:13:03 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 MIME-Version: 1.0 In-Reply-To: <198058c6-63c6-ac3c-62b7-438e5e3b3f0e@arm.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.238] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/04/2019 12:01, Robin Murphy wrote: >>>>>>> >>>>>>> The crash occurs for the same reason. >>>>>>> >>>>>>> In this case, on the really_probe() failure path, we are still >>>>>>> clearing >>>>>>> the DMA ops prior to releasing the device's managed memories. >>>>>>> >>>>>>> This patch fixes this issue by reordering the DMA ops teardown >>>>>>> and the >>>>>>> call to devres_release_all() on the failure path. >>>>>>> >>>>>>> Reported-by: Xiang Chen >>>>>>> Tested-by: Xiang Chen >>>>>>> Signed-off-by: John Garry >>>>> >>>>> So does this "fix" 376991db4b64? If so, should this be added to the >>>>> patch and also backported to the stable trees? >>>> >>>> Hi Greg, >>>> >>>> No, I don't think so. I'd say it supplements it. Here I'm trying to fix >>>> up another path in which we tear down the DMA ops prior to releasing >>>> the >>>> device's resources. >>>> >>>> I didn't add a fixes tag as 376991db4b64 didn't have one either. It >>>> will >>>> need to be backported to stable, I figure the same as 376991db4b64. >>> >> >> Hi Greg, >> >> I still think that we should consider merging this patch. > > Bah, sorry, I thought I'd replied to this thread already, but apparently > not :( > > I don't have a particularly strong opinion, but at the moment I am > leaning slightly towards this being a parallel fix for another part of > 09515ef5ddad, rather than a specific fix of the other fix. Either way, > you can have a: I'd say a parallel fix of 09515ef5ddad. > > Reviewed-by: Robin Murphy > cheers Robin > Thanks, > Robin.