From 9f8bee9c981f5fe7382a0615d117cc128dd22458 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Thu, 22 Sep 2016 10:45:40 +0200 Subject: [PATCH] xen/pciback: avoid multiple entries in slot list The Xen pciback driver has a list of all pci devices it is ready to seize. There is no check whether a to be added entry already exists. While this might be no problem in the common case it might confuse those which consume the list via sysfs. Modify the handling of this list by not adding an entry which already exists. As this will be needed later split out the list handling into a separate function. Signed-off-by: Juergen Gross Signed-off-by: David Vrabel --- drivers/xen/xen-pciback/pci_stub.c | 39 ++++++++++++++++++++++++------ 1 file changed, 31 insertions(+), 8 deletions(-) diff --git a/drivers/xen/xen-pciback/pci_stub.c b/drivers/xen/xen-pciback/pci_stub.c index 79a9e4d66819..01793332f7e6 100644 --- a/drivers/xen/xen-pciback/pci_stub.c +++ b/drivers/xen/xen-pciback/pci_stub.c @@ -478,6 +478,36 @@ static int __init pcistub_init_devices_late(void) return 0; } +static void pcistub_device_id_add_list(struct pcistub_device_id *new, + int domain, int bus, unsigned int devfn) +{ + struct pcistub_device_id *pci_dev_id; + unsigned long flags; + int found = 0; + + spin_lock_irqsave(&device_ids_lock, flags); + + list_for_each_entry(pci_dev_id, &pcistub_device_ids, slot_list) { + if (pci_dev_id->domain == domain && pci_dev_id->bus == bus && + pci_dev_id->devfn == devfn) { + found = 1; + break; + } + } + + if (!found) { + new->domain = domain; + new->bus = bus; + new->devfn = devfn; + list_add_tail(&new->slot_list, &pcistub_device_ids); + } + + spin_unlock_irqrestore(&device_ids_lock, flags); + + if (found) + kfree(new); +} + static int pcistub_seize(struct pci_dev *dev) { struct pcistub_device *psdev; @@ -1012,7 +1042,6 @@ static inline int str_to_quirk(const char *buf, int *domain, int *bus, int static int pcistub_device_id_add(int domain, int bus, int slot, int func) { struct pcistub_device_id *pci_dev_id; - unsigned long flags; int rc = 0, devfn = PCI_DEVFN(slot, func); if (slot < 0) { @@ -1042,16 +1071,10 @@ static int pcistub_device_id_add(int domain, int bus, int slot, int func) if (!pci_dev_id) return -ENOMEM; - pci_dev_id->domain = domain; - pci_dev_id->bus = bus; - pci_dev_id->devfn = devfn; - pr_debug("wants to seize %04x:%02x:%02x.%d\n", domain, bus, slot, func); - spin_lock_irqsave(&device_ids_lock, flags); - list_add_tail(&pci_dev_id->slot_list, &pcistub_device_ids); - spin_unlock_irqrestore(&device_ids_lock, flags); + pcistub_device_id_add_list(pci_dev_id, domain, bus, devfn); return 0; } -- 2.20.1