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 9C228C4360F for ; Wed, 3 Apr 2019 09:20:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 72A4F20830 for ; Wed, 3 Apr 2019 09:20:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726530AbfDCJUt (ORCPT ); Wed, 3 Apr 2019 05:20:49 -0400 Received: from szxga04-in.huawei.com ([45.249.212.190]:5659 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725907AbfDCJUs (ORCPT ); Wed, 3 Apr 2019 05:20:48 -0400 Received: from DGGEMS408-HUB.china.huawei.com (unknown [10.3.19.208]) by Forcepoint Email with ESMTP id 5741592185FE33C41F48; Wed, 3 Apr 2019 17:20:46 +0800 (CST) Received: from [127.0.0.1] (10.202.227.238) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.408.0; Wed, 3 Apr 2019 17:20:39 +0800 From: John Garry Subject: Re: [PATCH] driver core: Postpone DMA tear-down until after devres release for probe failure To: Greg KH References: <1553767685-27077-1-git-send-email-john.garry@huawei.com> <703aca1f-9475-b50d-624a-5f1ceea2c3b2@huawei.com> <20190403081433.GA13222@kroah.com> CC: , , , , , , , , , Message-ID: <3e1f3e2e-a1d3-ecaf-0931-44b4c10faffe@huawei.com> Date: Wed, 3 Apr 2019 10:20:31 +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: <20190403081433.GA13222@kroah.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.202.227.238] Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/04/2019 09:14, Greg KH wrote: > On Wed, Apr 03, 2019 at 09:02:36AM +0100, John Garry wrote: >> On 28/03/2019 10:08, John Garry wrote: >>> In commit 376991db4b64 ("driver core: Postpone DMA tear-down until after >>> devres release"), we changed the ordering of tearing down the device DMA >>> ops and releasing all the device's resources; this was because the DMA ops >>> should be maintained until we release the device's managed DMA memories. >>> >> >> Hi all, >> >> A friendly reminder on this patch... I didn't see any update. >> >> I thought that it had some importance. >> >> Thanks, >> John >> >>> However, we have seen another crash on an arm64 system when a >>> device driver probe fails: >>> >>> hisi_sas_v3_hw 0000:74:02.0: Adding to iommu group 2 >>> scsi host1: hisi_sas_v3_hw >>> BUG: Bad page state in process swapper/0 pfn:313f5 >>> page:ffff7e0000c4fd40 count:1 mapcount:0 >>> mapping:0000000000000000 index:0x0 >>> flags: 0xfffe00000001000(reserved) >>> raw: 0fffe00000001000 ffff7e0000c4fd48 ffff7e0000c4fd48 >>> 0000000000000000 >>> raw: 0000000000000000 0000000000000000 00000001ffffffff >>> 0000000000000000 >>> page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set >>> bad because of flags: 0x1000(reserved) >>> Modules linked in: >>> CPU: 49 PID: 1 Comm: swapper/0 Not tainted >>> 5.1.0-rc1-43081-g22d97fd-dirty #1433 >>> Hardware name: Huawei D06/D06, BIOS Hisilicon D06 UEFI >>> RC0 - V1.12.01 01/29/2019 >>> Call trace: >>> dump_backtrace+0x0/0x118 >>> show_stack+0x14/0x1c >>> dump_stack+0xa4/0xc8 >>> bad_page+0xe4/0x13c >>> free_pages_check_bad+0x4c/0xc0 >>> __free_pages_ok+0x30c/0x340 >>> __free_pages+0x30/0x44 >>> __dma_direct_free_pages+0x30/0x38 >>> dma_direct_free+0x24/0x38 >>> dma_free_attrs+0x9c/0xd8 >>> dmam_release+0x20/0x28 >>> release_nodes+0x17c/0x220 >>> devres_release_all+0x34/0x54 >>> really_probe+0xc4/0x2c8 >>> driver_probe_device+0x58/0xfc >>> device_driver_attach+0x68/0x70 >>> __driver_attach+0x94/0xdc >>> bus_for_each_dev+0x5c/0xb4 >>> driver_attach+0x20/0x28 >>> bus_add_driver+0x14c/0x200 >>> driver_register+0x6c/0x124 >>> __pci_register_driver+0x48/0x50 >>> sas_v3_pci_driver_init+0x20/0x28 >>> do_one_initcall+0x40/0x25c >>> kernel_init_freeable+0x2b8/0x3c0 >>> kernel_init+0x10/0x100 >>> ret_from_fork+0x10/0x18 >>> Disabling lock debugging due to kernel taint >>> BUG: Bad page state in process swapper/0 pfn:313f6 >>> page:ffff7e0000c4fd80 count:1 mapcount:0 >>> mapping:0000000000000000 index:0x0 >>> [ 89.322983] flags: 0xfffe00000001000(reserved) >>> raw: 0fffe00000001000 ffff7e0000c4fd88 ffff7e0000c4fd88 >>> 0000000000000000 >>> raw: 0000000000000000 0000000000000000 00000001ffffffff >>> 0000000000000000 >>> >>> 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. Thanks, John > > thanks, > > greg k-h > > . >