From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com ([209.132.183.28]:38259 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760338Ab2EJSzf (ORCPT ); Thu, 10 May 2012 14:55:35 -0400 Date: Thu, 10 May 2012 21:55:17 +0300 From: "Michael S. Tsirkin" To: Jiang Liu Cc: Amos Kong , linux-pci@vger.kernel.org, seabios@seabios.org, qemu-devel@nongnu.org, jbarnes@virtuousgeek.org, alex.williamson@redhat.com, kevin@koconnor.net Subject: Re: [PATCH v3] pci: clean all funcs when hot-removing multifunc device Message-ID: <20120510185516.GI14647@redhat.com> References: <1315976141-6684-1-git-send-email-akong@redhat.com> <20120510154423.11306.85353.stgit@t> <4FABF639.4070205@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <4FABF639.4070205@gmail.com> Sender: linux-pci-owner@vger.kernel.org List-ID: On Fri, May 11, 2012 at 01:09:13AM +0800, Jiang Liu wrote: > On 05/10/2012 11:44 PM, Amos Kong wrote: > > > diff --git a/drivers/pci/hotplug/acpiphp_glue.c b/drivers/pci/hotplug/acpiphp_glue.c > > index 806c44f..a7442d9 100644 > > --- a/drivers/pci/hotplug/acpiphp_glue.c > > +++ b/drivers/pci/hotplug/acpiphp_glue.c > > @@ -885,7 +885,7 @@ static void disable_bridges(struct pci_bus *bus) > > static int disable_device(struct acpiphp_slot *slot) > > { > > struct acpiphp_func *func; > > - struct pci_dev *pdev; > > + struct pci_dev *pdev, *tmp; > > struct pci_bus *bus = slot->bridge->pci_bus; > > > > /* The slot will be enabled when func 0 is added, so check > > @@ -902,9 +902,10 @@ static int disable_device(struct acpiphp_slot *slot) > > func->bridge = NULL; > > } > > > > - pdev = pci_get_slot(slot->bridge->pci_bus, > > - PCI_DEVFN(slot->device, func->function)); > > - if (pdev) { > > + list_for_each_entry_safe(pdev, tmp, &bus->devices, bus_list) { > > + if (PCI_SLOT(pdev->devfn) != slot->device) > > + continue; > > + > The pci_bus_sem lock should be acquired when walking the bus->devices list. > Otherwise it may cause invalid memory access if another thread is modifying > the bus->devices list concurrently. > > BTW, what's the relationship with "[PATCH v3] hotplug: add device per func > in ACPI DSDT tables"? Seems they are both solving the same issue. That's a bios patch. It's needed if you want broken linux to work. This makes linux behave properly on the original bios. > > pci_stop_bus_device(pdev); > > if (pdev->subordinate) { > > disable_bridges(pdev->subordinate); > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at http://vger.kernel.org/majordomo-info.html