Commit 25f003de authored by Will Deacon's avatar Will Deacon Committed by Joerg Roedel
Browse files

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: default avatarJoerg Roedel <joro@8bytes.org>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
Tested-by: John Garry <john.garry@huawei.com> # smmu v3
Reviewed-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 1a373a78

drivers/iommu/iommu.c

+17 −2
Original line number Diff line number Diff line
@@ -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;

}
@@ -199,8 +211,11 @@ void iommu_release_device(struct device *dev) 
	if (dev->iommu_group)

		ops->remove_device(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,

						 unsigned type);

include/linux/iommu.h

+3 −1
Original line number Diff line number Diff line
@@ -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;

};



/**

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