From: Joerg Roedel <joro@8bytes.org>
To: iommu@lists.linux-foundation.org
Cc: Joerg Roedel <jroedel@suse.de>,
linux-kernel@vger.kernel.org, linux-mediatek@lists.infradead.org,
Matthias Brugger <matthias.bgg@gmail.com>,
linux-arm-kernel@lists.infradead.org
Subject: [PATCH] iommu: Don't call .probe_finalize() under group->mutex
Date: Tue, 19 May 2020 15:28:24 +0200 [thread overview]
Message-ID: <20200519132824.15163-1-joro@8bytes.org> (raw)
From: Joerg Roedel <jroedel@suse.de>
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.
Cc: Yong Wu <yong.wu@mediatek.com>
Reported-by: Yong Wu <yong.wu@mediatek.com>
Fixes: deac0b3bed26 ("iommu: Split off default domain allocation from group assignment")
Signed-off-by: Joerg Roedel <jroedel@suse.de>
---
drivers/iommu/iommu.c | 28 ++++++++++++++++++----------
1 file changed, 18 insertions(+), 10 deletions(-)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 629d209b8e88..d5d9fcbc9714 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1683,17 +1683,8 @@ 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)
@@ -1702,6 +1693,21 @@ 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;
@@ -1754,6 +1760,8 @@ int bus_iommu_probe(struct bus_type *bus)
if (ret)
break;
+
+ __iommu_group_dma_finalize(group);
}
return ret;
--
2.25.1
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next reply other threads:[~2020-05-19 13:28 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-19 13:28 Joerg Roedel [this message]
2020-05-20 6:53 ` [PATCH] iommu: Don't call .probe_finalize() under group->mutex Yong Wu
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