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[PATCH] PCI: fix race with pci_walk_bus and pci_destroy_dev

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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 <yanmin.zhang@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Zhang Yanmin
2006-06-02 12:35:43 +08:00
committed by Greg Kroah-Hartman
parent 733a7fe122
commit d71374dafb
5 changed files with 41 additions and 43 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
drivers/pci/remove.c
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@@ -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);