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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0D3ACC433EF for ; Tue, 12 Oct 2021 02:47:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E3879604DC for ; Tue, 12 Oct 2021 02:47:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231982AbhJLCtk (ORCPT ); Mon, 11 Oct 2021 22:49:40 -0400 Received: from szxga03-in.huawei.com ([45.249.212.189]:25174 "EHLO szxga03-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231922AbhJLCtZ (ORCPT ); Mon, 11 Oct 2021 22:49:25 -0400 Received: from dggemv703-chm.china.huawei.com (unknown [172.30.72.53]) by szxga03-in.huawei.com (SkyGuard) with ESMTP id 4HT0RF21Y3z8tVt; Tue, 12 Oct 2021 10:46:17 +0800 (CST) Received: from kwepemm600001.china.huawei.com (7.193.23.3) by dggemv703-chm.china.huawei.com (10.3.19.46) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Tue, 12 Oct 2021 10:47:22 +0800 Received: from [10.174.176.245] (10.174.176.245) by kwepemm600001.china.huawei.com (7.193.23.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2308.8; Tue, 12 Oct 2021 10:47:21 +0800 Subject: Re: [PATCH] PCI/MSI: fix page fault when msi_populate_sysfs() failed To: Barry Song <21cnbao@gmail.com> CC: Bjorn Helgaas , Bjorn Helgaas , Marc Zyngier , Thomas Gleixner , "Barry Song" , Greg Kroah-Hartman , , LKML References: <20211012020959.GA1708781@bhelgaas> From: "wanghai (M)" Message-ID: <49eb8550-f868-a63e-dd54-a6edec8f049f@huawei.com> Date: Tue, 12 Oct 2021 10:47:20 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.245] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemm600001.china.huawei.com (7.193.23.3) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 在 2021/10/12 10:39, Barry Song 写道: > On Tue, Oct 12, 2021 at 3:25 PM wanghai (M) wrote: >> >> 在 2021/10/12 10:09, Bjorn Helgaas 写道: >>> On Tue, Oct 12, 2021 at 09:59:40AM +0800, wanghai (M) wrote: >>>> 在 2021/10/12 1:11, Bjorn Helgaas 写道: >>>>> For v2, please note "git log --oneline drivers/pci/msi.c" and make >>>>> your patch follow the style, including capitalization. >>>>> >>>>> On Mon, Oct 11, 2021 at 05:15:28PM +0800, wanghai (M) wrote: >>>>>> 在 2021/10/11 16:52, Barry Song 写道: >>>>>>> On Mon, Oct 11, 2021 at 9:24 PM Wang Hai wrote: >>>>>>>> I got a page fault report when doing fault injection test: >>>>> When you send v2, can you include information about how you injected >>>>> the fault? If it's easy, others can reproduce the failure that way. >>>> Sorry, the reproduction needs to be based on the fault injection framework >>>> provided by Hulk Robot. I don't know how the framework is implemented. >>>> >>>> The way to reproduce this is to do a fault injection to make >>>> 'msi_attrs = kcalloc() in msi_populate_sysfs()' fail when insmod >>>> 9pnet_virtio.ko. >>>> >>>> I sent v2 yesterday, can you help review it? >>>> https://lore.kernel.org/linux-pci/20211011130837.766323-1-wanghai38@huawei.com/ >>>>>>>> BUG: unable to handle page fault for address: fffffffffffffff4 >>>>>>>> ... >>>>>>>> RIP: 0010:sysfs_remove_groups+0x25/0x60 >>>>>>>> ... >>>>>>>> Call Trace: >>>>>>>> msi_destroy_sysfs+0x30/0xa0 >>>>>>>> free_msi_irqs+0x11d/0x1b0 >>>>>>>> __pci_enable_msix_range+0x67f/0x760 >>>>>>>> pci_alloc_irq_vectors_affinity+0xe7/0x170 >>>>>>>> vp_find_vqs_msix+0x129/0x560 >>>>>>>> vp_find_vqs+0x52/0x230 >>>>>>>> vp_modern_find_vqs+0x47/0xb0 >>>>>>>> p9_virtio_probe+0xa1/0x460 [9pnet_virtio] >>>>>>>> virtio_dev_probe+0x1ed/0x2e0 >>>>>>>> really_probe+0x1c7/0x400 >>>>>>>> __driver_probe_device+0xa4/0x120 >>>>>>>> driver_probe_device+0x32/0xe0 >>>>>>>> __driver_attach+0xbf/0x130 >>>>>>>> bus_for_each_dev+0xbb/0x110 >>>>>>>> driver_attach+0x27/0x30 >>>>>>>> bus_add_driver+0x1d9/0x270 >>>>>>>> driver_register+0xa9/0x180 >>>>>>>> register_virtio_driver+0x31/0x50 >>>>>>>> p9_virtio_init+0x3c/0x1000 [9pnet_virtio] >>>>>>>> do_one_initcall+0x7b/0x380 >>>>>>>> do_init_module+0x5f/0x21e >>>>>>>> load_module+0x265c/0x2c60 >>>>>>>> __do_sys_finit_module+0xb0/0xf0 >>>>>>>> __x64_sys_finit_module+0x1a/0x20 >>>>>>>> do_syscall_64+0x34/0xb0 >>>>>>>> entry_SYSCALL_64_after_hwframe+0x44/0xae >>>>>>>> >>>>>>>> When populating msi_irqs sysfs failed in msi_capability_init() or >>>>>>>> msix_capability_init(), dev->msi_irq_groups will point to ERR_PTR(...). >>>>>>>> This will cause a page fault when destroying the wrong >>>>>>>> dev->msi_irq_groups in free_msi_irqs(). >>>>>>>> >>>>>>>> Fix this by setting dev->msi_irq_groups to NULL when msi_populate_sysfs() >>>>>>>> failed. >>>>>>>> >>>>>>>> Fixes: 2f170814bdd2 ("genirq/msi: Move MSI sysfs handling from PCI to MSI core") >>>>>>>> Reported-by: Hulk Robot >>>>> What exactly was reported by the Hulk Robot? Did it really do the >>>>> fault injection and report the page fault? >>>> Yes, it reported the error and provided a way to reproduce it >>> Great, can you include a link to that report then? >>> . >> Currently hulk robot is still in the process of continuous improvement and >> is not open to the public for the time being, so you can not access our >> links at the moment. We will open it in the future when it is perfected. > hi hai, would you like to put some information in the commit log like > if 'msi_attrs = kcalloc() in msi_populate_sysfs()' fails, blah, blah, blah... > > It seems this can make things a bit clearer to me. Anyway, it doesn't matter > too much. The fix is correct. Okay, I'll refine the commit log and resend a patch >> -- >> Wang Hai >> > Thanks > barry > . > -- Wang Hai