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Commit bea64033 authored by Joerg Roedel's avatar Joerg Roedel
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iommu/vt-d: Fix dead-locks in disable_dmar_iommu() path 



It turns out that the disable_dmar_iommu() code-path tried
to get the device_domain_lock recursivly, which will
dead-lock when this code runs on dmar removal. Fix both
code-paths that could lead to the dead-lock.

Fixes: 55d94043 ('iommu/vt-d: Get rid of domain->iommu_lock')
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 8c82d6ec

drivers/iommu/intel-iommu.c

+12 −2
Original line number Diff line number Diff line
@@ -1711,6 +1711,7 @@ static void disable_dmar_iommu(struct intel_iommu *iommu) 
	if (!iommu->domains || !iommu->domain_ids)

		return;



again:

	spin_lock_irqsave(&device_domain_lock, flags);

	list_for_each_entry_safe(info, tmp, &device_domain_list, global) {

		struct dmar_domain *domain;
@@ -1723,10 +1724,19 @@ static void disable_dmar_iommu(struct intel_iommu *iommu) 


		domain = info->domain;



		dmar_remove_one_dev_info(domain, info->dev);

		__dmar_remove_one_dev_info(info);



		if (!domain_type_is_vm_or_si(domain))

		if (!domain_type_is_vm_or_si(domain)) {

			/*

			 * The domain_exit() function  can't be called under

			 * device_domain_lock, as it takes this lock itself.

			 * So release the lock here and re-run the loop

			 * afterwards.

			 */

			spin_unlock_irqrestore(&device_domain_lock, flags);

			domain_exit(domain);

			goto again;

		}

	}

	spin_unlock_irqrestore(&device_domain_lock, flags);