Commit 00dfff77 authored Jun 14, 2010 by Jiri Slaby Committed by David Woodhouse Jun 15, 2010

intel-iommu: Fix double lock in get_domain_for_dev()



stanse found the following double lock.

In get_domain_for_dev:
  spin_lock_irqsave(&device_domain_lock, flags);
  domain_exit(domain);
    domain_remove_dev_info(domain);
      spin_lock_irqsave(&device_domain_lock, flags);
      spin_unlock_irqrestore(&device_domain_lock, flags);
  spin_unlock_irqrestore(&device_domain_lock, flags);

This happens when the domain is created by another CPU at the same time 
as this function is creating one, and the other CPU wins the race to 
attach it to the device in question, so we have to destroy our own 
newly-created one.

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

parent 25cbff16

drivers/pci/intel-iommu.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1874,15 +1874,16 @@ static struct dmar_domain get_domain_for_dev(struct pci_dev pdev, int gaw)
		}
		}
		if (found) {
		spin_unlock_irqrestore(&device_domain_lock, flags);
		free_devinfo_mem(info);
		domain_exit(domain);
		domain = found;
		} else {
		list_add(&info->link, &domain->devices);
		list_add(&info->global, &device_domain_list);
		}
		spin_unlock_irqrestore(&device_domain_lock, flags);
		}
		}

		found_domain:
		info = alloc_devinfo_mem();