From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752954AbcJDEwC (ORCPT ); Tue, 4 Oct 2016 00:52:02 -0400 Received: from p3plsmtps2ded01.prod.phx3.secureserver.net ([208.109.80.58]:41514 "EHLO p3plsmtps2ded01.prod.phx3.secureserver.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752812AbcJDEwA (ORCPT ); Tue, 4 Oct 2016 00:52:00 -0400 x-originating-ip: 72.167.245.219 From: Long Li To: "K. Y. Srinivasan" , Haiyang Zhang , Bjorn Helgaas Cc: devel@linuxdriverproject.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Long Li Subject: [PATCH 2/2 v3] pci-hyperv: lock pci bus on device eject Date: Mon, 3 Oct 2016 23:43:08 -0700 Message-Id: <1475563388-16547-1-git-send-email-longli@exchange.microsoft.com> X-Mailer: git-send-email 1.7.4.1 X-CMAE-Envelope: MS4wfCqv2V3EeHIujHteNQa/1FyH8CAHOfbWHUm07SV5Q/RZ+scPwEfkDeeXuVoyY1qwKdQpOMWXHmTm9CZj+J9wREsHMXEZBSQk/liGk0dFjf2ar3zTzxAG ZvXxB2Z8B2hcbldQOQUB9T3COMsYGqxMG1DlIgsb6Tu3oyJLaGDju0KL8vac7dPt0Oszfs9ypai6mKkU2onmYPcUemKAw6UZPQZlNqlV1ACmkSMbDWLUgdcD rj46jYrGyw06rLOFew4r/rPXKK0YtL/IUh0uYL0g0LSbBT7+5hvq6XnFb5v5sxqHebitMDJUlzGt3FSsSKKrtQSUAY5Er8wMyQf6HMoGfB9qtSOtK5Ne50Ac +SqZu/x7huCc2YqxA0oN20Z2WCMu/u+DUWR0ImvHLBmjTBposTc= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Long Li A PCI_EJECT message can arrive at the same time we are calling pci_scan_child_bus in the workqueue for the previous PCI_BUS_RELATIONS message or in create_root_hv_pci_bus(), in this case we could potentailly modify the bus from multiple places. Properly lock the bus access. Thanks Dexuan Cui for pointing out the race condition in create_root_hv_pci_bus(). Signed-off-by: Long Li Tested-by: Cathy Avery Reported-by: Xiaofeng Wang --- drivers/pci/host/pci-hyperv.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/pci/host/pci-hyperv.c b/drivers/pci/host/pci-hyperv.c index 4a37598..33c75c9 100644 --- a/drivers/pci/host/pci-hyperv.c +++ b/drivers/pci/host/pci-hyperv.c @@ -1198,9 +1198,11 @@ static int create_root_hv_pci_bus(struct hv_pcibus_device *hbus) hbus->pci_bus->msi = &hbus->msi_chip; hbus->pci_bus->msi->dev = &hbus->hdev->device; + pci_lock_rescan_remove(); pci_scan_child_bus(hbus->pci_bus); pci_bus_assign_resources(hbus->pci_bus); pci_bus_add_devices(hbus->pci_bus); + pci_unlock_rescan_remove(); hbus->state = hv_pcibus_installed; return 0; } @@ -1590,8 +1592,10 @@ static void hv_eject_device_work(struct work_struct *work) pdev = pci_get_domain_bus_and_slot(hpdev->hbus->sysdata.domain, 0, wslot); if (pdev) { + pci_lock_rescan_remove(); pci_stop_and_remove_bus_device(pdev); pci_dev_put(pdev); + pci_unlock_rescan_remove(); } memset(&ctxt, 0, sizeof(ctxt)); -- 1.8.5.6