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=-5.5 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 937ABC433E1 for ; Fri, 14 Aug 2020 13:40:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7766A2068E for ; Fri, 14 Aug 2020 13:40:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726596AbgHNNkK (ORCPT ); Fri, 14 Aug 2020 09:40:10 -0400 Received: from lhrrgout.huawei.com ([185.176.76.210]:2607 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726139AbgHNNkK (ORCPT ); Fri, 14 Aug 2020 09:40:10 -0400 Received: from lhreml724-chm.china.huawei.com (unknown [172.18.7.108]) by Forcepoint Email with ESMTP id 7163B571FFE3D7393BC5; Fri, 14 Aug 2020 14:40:08 +0100 (IST) Received: from [127.0.0.1] (10.47.4.107) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.1913.5; Fri, 14 Aug 2020 14:40:07 +0100 Subject: Re: nvme crash - Re: linux-next: Tree for Aug 13 From: John Garry To: Christoph Hellwig CC: linux-nvme , Stephen Rothwell , Linux Next Mailing List , Linux Kernel Mailing List , , Robin Murphy , References: <20200813155009.GA2303@infradead.org> <81e42d30-ede3-d7b0-ad7b-8192bcf27a4c@huawei.com> <20200814120824.GB1872@infradead.org> <895b0c2f-52eb-bd72-7cbf-aa6808c018d2@huawei.com> Message-ID: <4f01dd86-62da-84bd-0ae4-7e31b5484514@huawei.com> Date: Fri, 14 Aug 2020 14:37:52 +0100 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.1.2 MIME-Version: 1.0 In-Reply-To: <895b0c2f-52eb-bd72-7cbf-aa6808c018d2@huawei.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit X-Originating-IP: [10.47.4.107] X-ClientProxiedBy: lhreml726-chm.china.huawei.com (10.201.108.77) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Sender: linux-next-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On 14/08/2020 14:07, John Garry wrote: > > BTW, as for the DMA/sg scatterlist code, it so happens in this case that > we try the dma alloc for size=0 in nvme_alloc_queue() - I know an > allocation for size=0 makes no sense, but couldn't we bit a bit more > robust? it's giving ZERO_SIZE_PTR, which we deference, so ignore me...