diff options
| author | Yi Liu <yi.l.liu@intel.com> | 2025-03-21 10:19:23 -0700 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2025-03-25 10:18:30 -0300 |
| commit | ada14b9f1aab5b60d50dec14c17eb84a55c0f682 (patch) | |
| tree | f5688fb6935a94e69ad740d840c33a7e6648c6ea | |
| parent | 06d54f00f3f5a29cbf43410ac93ee2dd89e3b711 (diff) | |
iommu: Require passing new handles to APIs supporting handle
Add kdoc to highligt the caller of iommu_[attach|replace]_group_handle()
and iommu_attach_device_pasid() should always provide a new handle. This
can avoid race with lockless reference to the handle. e.g. the
find_fault_handler() and iommu_report_device_fault() in the PRI path.
Link: https://patch.msgid.link/r/20250321171940.7213-2-yi.l.liu@intel.com
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
| -rw-r--r-- | drivers/iommu/iommu.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c index d96e6fabb4da..34ea7e5e7d00 100644 --- a/drivers/iommu/iommu.c +++ b/drivers/iommu/iommu.c @@ -3365,6 +3365,9 @@ static void __iommu_remove_group_pasid(struct iommu_group *group, * @pasid: the pasid of the device. * @handle: the attach handle. * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle if it intends to pass a valid handle. + * * Return: 0 on success, or an error. */ int iommu_attach_device_pasid(struct iommu_domain *domain, @@ -3525,6 +3528,9 @@ EXPORT_SYMBOL_NS_GPL(iommu_attach_handle_get, "IOMMUFD_INTERNAL"); * This is a variant of iommu_attach_group(). It allows the caller to provide * an attach handle and use it when the domain is attached. This is currently * used by IOMMUFD to deliver the I/O page faults. + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle. */ int iommu_attach_group_handle(struct iommu_domain *domain, struct iommu_group *group, @@ -3594,6 +3600,9 @@ EXPORT_SYMBOL_NS_GPL(iommu_detach_group_handle, "IOMMUFD_INTERNAL"); * * If the currently attached domain is a core domain (e.g. a default_domain), * it will act just like the iommu_attach_group_handle(). + * + * Caller should always provide a new handle to avoid race with the paths + * that have lockless reference to handle. */ int iommu_replace_group_handle(struct iommu_group *group, struct iommu_domain *new_domain, |