[PATCH v2 2/7] iommufd: Add iommufd_lock_obj() around the auto-domains hwpts

Jason Gunthorpe
2023-02-22T21:02:49Z

A later patch will require this locking - currently under the ioas mutex
the hwpt can not have a 0 reference and be on the list.

Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/iommufd/device.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
index dcfaf6567420e0..0a80ff7b2e0d79 100644
--- a/drivers/iommu/iommufd/device.c
+++ b/drivers/iommu/iommufd/device.c
@@ -282,7 +282,10 @@ static int iommufd_device_auto_get_domain(struct iommufd_device *idev,
if (!hwpt->auto_domain)
continue;

+ if (!iommufd_lock_obj(&hwpt->obj))
+ continue;
rc = iommufd_device_do_attach(idev, hwpt);
+ iommufd_put_object(&hwpt->obj);

/*
* -EINVAL means the domain is incompatible with the device.
--
2.39.1