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iommu: Don't call .probe_finalize() under group->mutex 

The .probe_finalize() call-back of some IOMMU drivers calls into
arm_iommu_attach_device(). This function will call back into the
IOMMU core code, where it tries to take group->mutex again, resulting
in a deadlock.

As there is no reason why .probe_finalize() needs to be called under
that mutex, move it after the lock has been released to fix the
deadlock.

Fixes: deac0b3bed ("iommu: Split off default domain allocation from group assignment")
Reported-by: Yong Wu <yong.wu@mediatek.com>
Tested-by: Yong Wu <yong.wu@mediatek.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Cc: Yong Wu <yong.wu@mediatek.com>
Link: https://lore.kernel.org/r/20200519132824.15163-1-joro@8bytes.org
This commit is contained in:
Joerg Roedel 2020-05-19 15:28:24 +02:00
parent 2bc61fbcc1
commit 70b8170e55
1 changed files with 18 additions and 10 deletions
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28
drivers/iommu/iommu.c
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@ -1674,17 +1674,8 @@ static void probe_alloc_default_domain(struct bus_type *bus,
static int iommu_group_do_dma_attach(struct device *dev, void *data)
{
struct iommu_domain *domain = data;
const struct iommu_ops *ops;
int ret;
ret = __iommu_attach_device(domain, dev);
ops = domain->ops;
if (ret == 0 && ops->probe_finalize)
ops->probe_finalize(dev);
return ret;
return __iommu_attach_device(domain, dev);
}
static int __iommu_group_dma_attach(struct iommu_group *group)
@ -1693,6 +1684,21 @@ static int __iommu_group_dma_attach(struct iommu_group *group)
iommu_group_do_dma_attach);
}
static int iommu_group_do_probe_finalize(struct device *dev, void *data)
{
struct iommu_domain *domain = data;
if (domain->ops->probe_finalize)
domain->ops->probe_finalize(dev);
return 0;
}
static void __iommu_group_dma_finalize(struct iommu_group *group)
{
__iommu_group_for_each_dev(group, group->default_domain,
iommu_group_do_probe_finalize);
}
static int iommu_do_create_direct_mappings(struct device *dev, void *data)
{
struct iommu_group *group = data;
@ -1745,6 +1751,8 @@ int bus_iommu_probe(struct bus_type *bus)
if (ret)
break;
__iommu_group_dma_finalize(group);
}
return ret;