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 81A26C433EF for ; Tue, 12 Oct 2021 01:59:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B83E60E78 for ; Tue, 12 Oct 2021 01:59:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229978AbhJLCBr (ORCPT ); Mon, 11 Oct 2021 22:01:47 -0400 Received: from szxga02-in.huawei.com ([45.249.212.188]:14331 "EHLO szxga02-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229544AbhJLCBq (ORCPT ); Mon, 11 Oct 2021 22:01:46 -0400 Received: from dggemv711-chm.china.huawei.com (unknown [172.30.72.55]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4HSzHz0NLKz9087; Tue, 12 Oct 2021 09:54:55 +0800 (CST) Received: from kwepemm600001.china.huawei.com (7.193.23.3) by dggemv711-chm.china.huawei.com (10.1.198.66) 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 09:59:41 +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 09:59:40 +0800 Subject: Re: [PATCH] PCI/MSI: fix page fault when msi_populate_sysfs() failed To: Bjorn Helgaas CC: Barry Song <21cnbao@gmail.com>, Bjorn Helgaas , "Marc Zyngier" , Thomas Gleixner , Barry Song , Greg Kroah-Hartman , , LKML References: <20211011171139.GA1662796@bhelgaas> From: "wanghai (M)" Message-ID: <2fc860b4-ec4e-3415-a58b-9099f164b607@huawei.com> Date: Tue, 12 Oct 2021 09:59:40 +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: <20211011171139.GA1662796@bhelgaas> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.174.176.245] X-ClientProxiedBy: dggems706-chm.china.huawei.com (10.3.19.183) To kwepemm600001.china.huawei.com (7.193.23.3) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org 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 >>>> Signed-off-by: Wang Hai >>> Acked-by: Barry Song >>> >>>> --- >>>> drivers/pci/msi.c | 2 ++ >>>> 1 file changed, 2 insertions(+) >>>> >>>> diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c >>>> index 0099a00af361..6f75db9f3be7 100644 >>>> --- a/drivers/pci/msi.c >>>> +++ b/drivers/pci/msi.c >>>> @@ -561,6 +561,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec, >>>> dev->msi_irq_groups = msi_populate_sysfs(&dev->dev); >>>> if (IS_ERR(dev->msi_irq_groups)) { >>>> ret = PTR_ERR(dev->msi_irq_groups); >>>> + dev->msi_irq_groups = NULL; >>>> goto err; >>>> } >>>> >>>> @@ -733,6 +734,7 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries, >>>> dev->msi_irq_groups = msi_populate_sysfs(&dev->dev); >>>> if (IS_ERR(dev->msi_irq_groups)) { >>>> ret = PTR_ERR(dev->msi_irq_groups); >>>> + dev->msi_irq_groups = NULL; >>> Can you define a temp variable and assign it to dev->msi_irq_groups if >>> the temp variable >>> is not PTR_ERR? >> Of course, I will send a v2 patch. >>>> goto out_free; >>>> } >>>> >>>> -- >>>> 2.17.1 >>>> >>> Thanks >>> Barry >>> . >>> >> -- >> Wang Hai >> > . > -- Wang Hai