From d71374dafbba7ec3f67371d3b7e9f6310a588808 Mon Sep 17 00:00:00 2001 From: Zhang Yanmin Date: Fri, 2 Jun 2006 12:35:43 +0800 Subject: [PATCH] PCI: fix race with pci_walk_bus and pci_destroy_dev pci_walk_bus has a race with pci_destroy_dev. When cb is called in pci_walk_bus, pci_destroy_dev might unlink the dev pointed by next. Later on in the next loop, pointer next becomes NULL and cause kernel panic. Below patch against 2.6.17-rc4 fixes it by changing pci_bus_lock (spin_lock) to pci_bus_sem (rw_semaphore). Signed-off-by: Zhang Yanmin Signed-off-by: Greg Kroah-Hartman --- drivers/pci/remove.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) (limited to 'drivers/pci/remove.c') diff --git a/drivers/pci/remove.c b/drivers/pci/remove.c index 1a6bf9de166..99ffbd478b2 100644 --- a/drivers/pci/remove.c +++ b/drivers/pci/remove.c @@ -22,18 +22,18 @@ static void pci_destroy_dev(struct pci_dev *dev) pci_proc_detach_device(dev); pci_remove_sysfs_dev_files(dev); device_unregister(&dev->dev); - spin_lock(&pci_bus_lock); + down_write(&pci_bus_sem); list_del(&dev->global_list); dev->global_list.next = dev->global_list.prev = NULL; - spin_unlock(&pci_bus_lock); + up_write(&pci_bus_sem); } /* Remove the device from the device lists, and prevent any further * list accesses from this device */ - spin_lock(&pci_bus_lock); + down_write(&pci_bus_sem); list_del(&dev->bus_list); dev->bus_list.next = dev->bus_list.prev = NULL; - spin_unlock(&pci_bus_lock); + up_write(&pci_bus_sem); pci_free_resources(dev); pci_dev_put(dev); @@ -62,9 +62,9 @@ void pci_remove_bus(struct pci_bus *pci_bus) { pci_proc_detach_bus(pci_bus); - spin_lock(&pci_bus_lock); + down_write(&pci_bus_sem); list_del(&pci_bus->node); - spin_unlock(&pci_bus_lock); + up_write(&pci_bus_sem); pci_remove_legacy_files(pci_bus); class_device_remove_file(&pci_bus->class_dev, &class_device_attr_cpuaffinity); -- cgit v1.2.3