From: Ashish Mhetre <amhetre@nvidia.com>
To: <amhetre@nvidia.com>, <joro@8bytes.org>, <will@kernel.org>,
<robin.murphy@arm.com>, <vdumpa@nvidia.com>
Cc: <iommu@lists.linux-foundation.org>,
<linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>
Subject: [PATCH 1/2] iommu: Fix race condition during default domain allocation
Date: Thu, 10 Jun 2021 09:46:53 +0530 [thread overview]
Message-ID: <1623298614-31755-2-git-send-email-amhetre@nvidia.com> (raw)
In-Reply-To: <1623298614-31755-1-git-send-email-amhetre@nvidia.com>
Domain is getting created more than once during asynchronous multiple
display heads(devices) probe. All the display heads share same SID and
are expected to be in same domain. As iommu_alloc_default_domain() call
is not protected, the group->default_domain and group->domain are ending
up with different domains and leading to subsequent IOMMU faults.
Fix this by protecting iommu_alloc_default_domain() call with group->mutex.
Signed-off-by: Ashish Mhetre <amhetre@nvidia.com>
---
drivers/iommu/iommu.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 808ab70..2700500 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -273,7 +273,9 @@ int iommu_probe_device(struct device *dev)
* support default domains, so the return value is not yet
* checked.
*/
+ mutex_lock(&group->mutex);
iommu_alloc_default_domain(group, dev);
+ mutex_unlock(&group->mutex);
if (group->default_domain) {
ret = __iommu_attach_device(group->default_domain, dev);
--
2.7.4
next prev parent reply other threads:[~2021-06-10 4:17 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-10 4:16 [PATCH 0/2] iommu/arm-smmu: Fix races in iommu domain/group creation Ashish Mhetre
2021-06-10 4:16 ` Ashish Mhetre [this message]
2021-06-11 10:45 ` [PATCH 1/2] iommu: Fix race condition during default domain allocation Will Deacon
2021-06-11 12:49 ` Robin Murphy
2021-06-17 5:51 ` Ashish Mhetre
2021-06-17 17:49 ` Will Deacon
2021-06-11 18:30 ` Krishna Reddy
2021-06-10 4:16 ` [PATCH 2/2] iommu/arm-smmu: Fix race condition during iommu_group creation Ashish Mhetre
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