drivers/iommu: Take a ref to the IOMMU driver prior to ->add_device()

To avoid accidental removal of an active IOMMU driver module, take a
reference to the driver module in 'iommu_probe_device()' immediately
prior to invoking the '->add_device()' callback and hold it until the
after the device has been removed by '->remove_device()'.

Suggested-by: Joerg Roedel <joro@8bytes.org>
Signed-off-by: Will Deacon <will@kernel.org>
Tested-by: John Garry <john.garry@huawei.com> # smmu v3
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
This commit is contained in:
Will Deacon 2019-12-19 12:03:41 +00:00 committed by Joerg Roedel
parent 1a373a78b8
commit 25f003de98
2 changed files with 20 additions and 3 deletions

View File

@ -22,6 +22,7 @@
#include <linux/bitops.h>
#include <linux/property.h>
#include <linux/fsl/mc.h>
#include <linux/module.h>
#include <trace/events/iommu.h>
static struct kset *iommu_group_kset;
@ -185,10 +186,21 @@ int iommu_probe_device(struct device *dev)
if (!iommu_get_dev_param(dev))
return -ENOMEM;
if (!try_module_get(ops->owner)) {
ret = -EINVAL;
goto err_free_dev_param;
}
ret = ops->add_device(dev);
if (ret)
iommu_free_dev_param(dev);
goto err_module_put;
return 0;
err_module_put:
module_put(ops->owner);
err_free_dev_param:
iommu_free_dev_param(dev);
return ret;
}
@ -199,7 +211,10 @@ void iommu_release_device(struct device *dev)
if (dev->iommu_group)
ops->remove_device(dev);
iommu_free_dev_param(dev);
if (dev->iommu_param) {
module_put(ops->owner);
iommu_free_dev_param(dev);
}
}
static struct iommu_domain *__iommu_domain_alloc(struct bus_type *bus,

View File

@ -246,9 +246,10 @@ struct iommu_iotlb_gather {
* @sva_get_pasid: Get PASID associated to a SVA handle
* @page_response: handle page request response
* @cache_invalidate: invalidate translation caches
* @pgsize_bitmap: bitmap of all possible supported page sizes
* @sva_bind_gpasid: bind guest pasid and mm
* @sva_unbind_gpasid: unbind guest pasid and mm
* @pgsize_bitmap: bitmap of all possible supported page sizes
* @owner: Driver module providing these ops
*/
struct iommu_ops {
bool (*capable)(enum iommu_cap);
@ -318,6 +319,7 @@ struct iommu_ops {
int (*sva_unbind_gpasid)(struct device *dev, int pasid);
unsigned long pgsize_bitmap;
struct module *owner;
};
/**