From 00dfff77e7184140dc45724c7232e99302f6bf97 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 14 Jun 2010 17:17:32 +0200 Subject: [PATCH] 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 --- drivers/pci/intel-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c index 3bd3055..bf8fd91 100644 --- a/drivers/pci/intel-iommu.c +++ b/drivers/pci/intel-iommu.c @@ -1874,14 +1874,15 @@ 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); } - spin_unlock_irqrestore(&device_domain_lock, flags); } found_domain: -- 2.7.4