drivers/infiniband/core/uverbs_uapi.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
 /*
  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
  */
 #include <rdma/uverbs_ioctl.h>
 #include <rdma/rdma_user_ioctl.h>
 #include <linux/bitops.h>
 #include "rdma_core.h"
 #include "uverbs.h"

 static void *uapi_add_elm(struct uverbs_api *uapi, u32 key, size_t alloc_size)
 {
 	void *elm;
 	int rc;

 	if (key == UVERBS_API_KEY_ERR)
 		return ERR_PTR(-EOVERFLOW);

 	elm = kzalloc(alloc_size, GFP_KERNEL);
 	rc = radix_tree_insert(&uapi->radix, key, elm);
 	if (rc) {
 		kfree(elm);
 		return ERR_PTR(rc);
 	}

 	return elm;
 }

 static int uapi_merge_method(struct uverbs_api *uapi,
 			     struct uverbs_api_object *obj_elm, u32 obj_key,
 			     const struct uverbs_method_def *method,
 			     bool is_driver)
 {
 	u32 method_key = obj_key | uapi_key_ioctl_method(method->id);
 	struct uverbs_api_ioctl_method *method_elm;
 	unsigned int i;

 	if (!method->attrs)
 		return 0;

 	method_elm = uapi_add_elm(uapi, method_key, sizeof(*method_elm));
 	if (IS_ERR(method_elm)) {
 		if (method_elm != ERR_PTR(-EEXIST))
 			return PTR_ERR(method_elm);

 		/*
 		 * This occurs when a driver uses ADD_UVERBS_ATTRIBUTES_SIMPLE
 		 */
 		if (WARN_ON(method->handler))
 			return -EINVAL;
 		method_elm = radix_tree_lookup(&uapi->radix, method_key);
 		if (WARN_ON(!method_elm))
 			return -EINVAL;
 	} else {
 		WARN_ON(!method->handler);
 		rcu_assign_pointer(method_elm->handler, method->handler);
 		if (method->handler != uverbs_destroy_def_handler)
 			method_elm->driver_method = is_driver;
 	}

 	for (i = 0; i != method->num_attrs; i++) {
 		const struct uverbs_attr_def *attr = (*method->attrs)[i];
 		struct uverbs_api_attr *attr_slot;

 		if (!attr)
 			continue;

 		/*
 		 * ENUM_IN contains the 'ids' pointer to the driver's .rodata,
 		 * so if it is specified by a driver then it always makes this
 		 * into a driver method.
 		 */
 		if (attr->attr.type == UVERBS_ATTR_TYPE_ENUM_IN)
 			method_elm->driver_method |= is_driver;

 		attr_slot =
 			uapi_add_elm(uapi, method_key | uapi_key_attr(attr->id),
 				     sizeof(*attr_slot));
 		/* Attributes are not allowed to be modified by drivers */
 		if (IS_ERR(attr_slot))
 			return PTR_ERR(attr_slot);

 		attr_slot->spec = attr->attr;
 	}

 	return 0;
 }

 static int uapi_merge_tree(struct uverbs_api *uapi,
 			   const struct uverbs_object_tree_def *tree,
 			   bool is_driver)
 {
 	unsigned int i, j;
 	int rc;

 	if (!tree->objects)
 		return 0;

 	for (i = 0; i != tree->num_objects; i++) {
 		const struct uverbs_object_def *obj = (*tree->objects)[i];
 		struct uverbs_api_object *obj_elm;
 		u32 obj_key;

 		if (!obj)
 			continue;

 		obj_key = uapi_key_obj(obj->id);
 		obj_elm = uapi_add_elm(uapi, obj_key, sizeof(*obj_elm));
 		if (IS_ERR(obj_elm)) {
 			if (obj_elm != ERR_PTR(-EEXIST))
 				return PTR_ERR(obj_elm);

 			/* This occurs when a driver uses ADD_UVERBS_METHODS */
 			if (WARN_ON(obj->type_attrs))
 				return -EINVAL;
 			obj_elm = radix_tree_lookup(&uapi->radix, obj_key);
 			if (WARN_ON(!obj_elm))
 				return -EINVAL;
 		} else {
 			obj_elm->type_attrs = obj->type_attrs;
 			if (obj->type_attrs) {
 				obj_elm->type_class =
 					obj->type_attrs->type_class;
 				/*
 				 * Today drivers are only permitted to use
 				 * idr_class types. They cannot use FD types
 				 * because we currently have no way to revoke
 				 * the fops pointer after device
 				 * disassociation.
 				 */
 				if (WARN_ON(is_driver &&
 					    obj->type_attrs->type_class !=
 						    &uverbs_idr_class))
 					return -EINVAL;
 			}
 		}

 		if (!obj->methods)
 			continue;

 		for (j = 0; j != obj->num_methods; j++) {
 			const struct uverbs_method_def *method =
 				(*obj->methods)[j];
 			if (!method)
 				continue;

 			rc = uapi_merge_method(uapi, obj_elm, obj_key, method,
 					       is_driver);
 			if (rc)
 				return rc;
 		}
 	}

 	return 0;
 }

 static int
 uapi_finalize_ioctl_method(struct uverbs_api *uapi,
 			   struct uverbs_api_ioctl_method *method_elm,
 			   u32 method_key)
 {
 	struct radix_tree_iter iter;
 	unsigned int num_attrs = 0;
 	unsigned int max_bkey = 0;
 	bool single_uobj = false;
 	void __rcu **slot;

 	method_elm->destroy_bkey = UVERBS_API_ATTR_BKEY_LEN;
 	radix_tree_for_each_slot (slot, &uapi->radix, &iter,
 				  uapi_key_attrs_start(method_key)) {
 		struct uverbs_api_attr *elm =
 			rcu_dereference_protected(*slot, true);
 		u32 attr_key = iter.index & UVERBS_API_ATTR_KEY_MASK;
 		u32 attr_bkey = uapi_bkey_attr(attr_key);
 		u8 type = elm->spec.type;

 		if (uapi_key_attr_to_method(iter.index) !=
 		    uapi_key_attr_to_method(method_key))
 			break;

 		if (elm->spec.mandatory)
 			__set_bit(attr_bkey, method_elm->attr_mandatory);

 		if (type == UVERBS_ATTR_TYPE_IDR ||
 		    type == UVERBS_ATTR_TYPE_FD) {
 			u8 access = elm->spec.u.obj.access;

 			/*
 			 * Verbs specs may only have one NEW/DESTROY, we don't
 			 * have the infrastructure to abort multiple NEW's or
 			 * cope with multiple DESTROY failure.
 			 */
 			if (access == UVERBS_ACCESS_NEW ||
 			    access == UVERBS_ACCESS_DESTROY) {
 				if (WARN_ON(single_uobj))
 					return -EINVAL;

 				single_uobj = true;
 				if (WARN_ON(!elm->spec.mandatory))
 					return -EINVAL;
 			}

 			if (access == UVERBS_ACCESS_DESTROY)
 				method_elm->destroy_bkey = attr_bkey;
 		}

 		max_bkey = max(max_bkey, attr_bkey);
 		num_attrs++;
 	}

 	method_elm->key_bitmap_len = max_bkey + 1;
 	WARN_ON(method_elm->key_bitmap_len > UVERBS_API_ATTR_BKEY_LEN);

 	uapi_compute_bundle_size(method_elm, num_attrs);
 	return 0;
 }

 static int uapi_finalize(struct uverbs_api *uapi)
 {
 	struct radix_tree_iter iter;
 	void __rcu **slot;
 	int rc;

 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 		struct uverbs_api_ioctl_method *method_elm =
 			rcu_dereference_protected(*slot, true);

 		if (uapi_key_is_ioctl_method(iter.index)) {
 			rc = uapi_finalize_ioctl_method(uapi, method_elm,
 							iter.index);
 			if (rc)
 				return rc;
 		}
 	}

 	return 0;
 }

 void uverbs_destroy_api(struct uverbs_api *uapi)
 {
 	struct radix_tree_iter iter;
 	void __rcu **slot;

 	if (!uapi)
 		return;

 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 		kfree(rcu_dereference_protected(*slot, true));
 		radix_tree_iter_delete(&uapi->radix, &iter, slot);
 	}
 }

 struct uverbs_api *uverbs_alloc_api(
 	const struct uverbs_object_tree_def *const *driver_specs,
 	enum rdma_driver_id driver_id)
 {
 	struct uverbs_api *uapi;
 	int rc;

 	uapi = kzalloc(sizeof(*uapi), GFP_KERNEL);
 	if (!uapi)
 		return ERR_PTR(-ENOMEM);

 	INIT_RADIX_TREE(&uapi->radix, GFP_KERNEL);
 	uapi->driver_id = driver_id;

 	rc = uapi_merge_tree(uapi, uverbs_default_get_objects(), false);
 	if (rc)
 		goto err;

 	for (; driver_specs && *driver_specs; driver_specs++) {
 		rc = uapi_merge_tree(uapi, *driver_specs, true);
 		if (rc)
 			goto err;
 	}

 	rc = uapi_finalize(uapi);
 	if (rc)
 		goto err;

 	return uapi;
 err:
 	if (rc != -ENOMEM)
 		pr_err("Setup of uverbs_api failed, kernel parsing tree description is not valid (%d)??\n",
 		       rc);

 	uverbs_destroy_api(uapi);
 	return ERR_PTR(rc);
 }

 /*
  * The pre version is done before destroying the HW objects, it only blocks
  * off method access. All methods that require the ib_dev or the module data
  * must test one of these assignments prior to continuing.
  */
 void uverbs_disassociate_api_pre(struct ib_uverbs_device *uverbs_dev)
 {
 	struct uverbs_api *uapi = uverbs_dev->uapi;
 	struct radix_tree_iter iter;
 	void __rcu **slot;

 	rcu_assign_pointer(uverbs_dev->ib_dev, NULL);

 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 		if (uapi_key_is_ioctl_method(iter.index)) {
 			struct uverbs_api_ioctl_method *method_elm =
 				rcu_dereference_protected(*slot, true);

 			if (method_elm->driver_method)
 				rcu_assign_pointer(method_elm->handler, NULL);
 		}
 	}

 	synchronize_srcu(&uverbs_dev->disassociate_srcu);
 }

 /*
  * Called when a driver disassociates from the ib_uverbs_device. The
  * assumption is that the driver module will unload after. Replace everything
  * related to the driver with NULL as a safety measure.
  */
 void uverbs_disassociate_api(struct uverbs_api *uapi)
 {
 	struct radix_tree_iter iter;
 	void __rcu **slot;

 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
 		if (uapi_key_is_object(iter.index)) {
 			struct uverbs_api_object *object_elm =
 				rcu_dereference_protected(*slot, true);

 			/*
 			 * Some type_attrs are in the driver module. We don't
 			 * bother to keep track of which since there should be
 			 * no use of this after disassociate.
 			 */
 			object_elm->type_attrs = NULL;
 		} else if (uapi_key_is_attr(iter.index)) {
 			struct uverbs_api_attr *elm =
 				rcu_dereference_protected(*slot, true);

 			if (elm->spec.type == UVERBS_ATTR_TYPE_ENUM_IN)
 				elm->spec.u2.enum_def.ids = NULL;
 		}
 	}
 }
	// SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
	/*
	* Copyright (c) 2017, Mellanox Technologies inc. All rights reserved.
	*/
	#include <rdma/uverbs_ioctl.h>
	#include <rdma/rdma_user_ioctl.h>
	#include <linux/bitops.h>
	#include "rdma_core.h"
	#include "uverbs.h"

	static void uapi_add_elm(struct uverbs_api uapi, u32 key, size_t alloc_size)
	{
	void *elm;
	int rc;

	if (key == UVERBS_API_KEY_ERR)
	return ERR_PTR(-EOVERFLOW);

	elm = kzalloc(alloc_size, GFP_KERNEL);
	rc = radix_tree_insert(&uapi->radix, key, elm);
	if (rc) {
	kfree(elm);
	return ERR_PTR(rc);
	}

	return elm;
	}

	static int uapi_merge_method(struct uverbs_api *uapi,
	struct uverbs_api_object *obj_elm, u32 obj_key,
	const struct uverbs_method_def *method,
	bool is_driver)
	{
	u32 method_key = obj_key \| uapi_key_ioctl_method(method->id);
	struct uverbs_api_ioctl_method *method_elm;
	unsigned int i;

	if (!method->attrs)
	return 0;

	method_elm = uapi_add_elm(uapi, method_key, sizeof(*method_elm));
	if (IS_ERR(method_elm)) {
	if (method_elm != ERR_PTR(-EEXIST))
	return PTR_ERR(method_elm);

	/*
	* This occurs when a driver uses ADD_UVERBS_ATTRIBUTES_SIMPLE
	*/
	if (WARN_ON(method->handler))
	return -EINVAL;
	method_elm = radix_tree_lookup(&uapi->radix, method_key);
	if (WARN_ON(!method_elm))
	return -EINVAL;
	} else {
	WARN_ON(!method->handler);
	rcu_assign_pointer(method_elm->handler, method->handler);
	if (method->handler != uverbs_destroy_def_handler)
	method_elm->driver_method = is_driver;
	}

	for (i = 0; i != method->num_attrs; i++) {
	const struct uverbs_attr_def attr = (method->attrs)[i];
	struct uverbs_api_attr *attr_slot;

	if (!attr)
	continue;

	/*
	* ENUM_IN contains the 'ids' pointer to the driver's .rodata,
	* so if it is specified by a driver then it always makes this
	* into a driver method.
	*/
	if (attr->attr.type == UVERBS_ATTR_TYPE_ENUM_IN)
	method_elm->driver_method \|= is_driver;

	attr_slot =
	uapi_add_elm(uapi, method_key \| uapi_key_attr(attr->id),
	sizeof(*attr_slot));
	/* Attributes are not allowed to be modified by drivers */
	if (IS_ERR(attr_slot))
	return PTR_ERR(attr_slot);

	attr_slot->spec = attr->attr;
	}

	return 0;
	}

	static int uapi_merge_tree(struct uverbs_api *uapi,
	const struct uverbs_object_tree_def *tree,
	bool is_driver)
	{
	unsigned int i, j;
	int rc;

	if (!tree->objects)
	return 0;

	for (i = 0; i != tree->num_objects; i++) {
	const struct uverbs_object_def obj = (tree->objects)[i];
	struct uverbs_api_object *obj_elm;
	u32 obj_key;

	if (!obj)
	continue;

	obj_key = uapi_key_obj(obj->id);
	obj_elm = uapi_add_elm(uapi, obj_key, sizeof(*obj_elm));
	if (IS_ERR(obj_elm)) {
	if (obj_elm != ERR_PTR(-EEXIST))
	return PTR_ERR(obj_elm);

	/* This occurs when a driver uses ADD_UVERBS_METHODS */
	if (WARN_ON(obj->type_attrs))
	return -EINVAL;
	obj_elm = radix_tree_lookup(&uapi->radix, obj_key);
	if (WARN_ON(!obj_elm))
	return -EINVAL;
	} else {
	obj_elm->type_attrs = obj->type_attrs;
	if (obj->type_attrs) {
	obj_elm->type_class =
	obj->type_attrs->type_class;
	/*
	* Today drivers are only permitted to use
	* idr_class types. They cannot use FD types
	* because we currently have no way to revoke
	* the fops pointer after device
	* disassociation.
	*/
	if (WARN_ON(is_driver &&
	obj->type_attrs->type_class !=
	&uverbs_idr_class))
	return -EINVAL;
	}
	}

	if (!obj->methods)
	continue;

	for (j = 0; j != obj->num_methods; j++) {
	const struct uverbs_method_def *method =
	(*obj->methods)[j];
	if (!method)
	continue;

	rc = uapi_merge_method(uapi, obj_elm, obj_key, method,
	is_driver);
	if (rc)
	return rc;
	}
	}

	return 0;
	}

	static int
	uapi_finalize_ioctl_method(struct uverbs_api *uapi,
	struct uverbs_api_ioctl_method *method_elm,
	u32 method_key)
	{
	struct radix_tree_iter iter;
	unsigned int num_attrs = 0;
	unsigned int max_bkey = 0;
	bool single_uobj = false;
	void __rcu **slot;

	method_elm->destroy_bkey = UVERBS_API_ATTR_BKEY_LEN;
	radix_tree_for_each_slot (slot, &uapi->radix, &iter,
	uapi_key_attrs_start(method_key)) {
	struct uverbs_api_attr *elm =
	rcu_dereference_protected(*slot, true);
	u32 attr_key = iter.index & UVERBS_API_ATTR_KEY_MASK;
	u32 attr_bkey = uapi_bkey_attr(attr_key);
	u8 type = elm->spec.type;

	if (uapi_key_attr_to_method(iter.index) !=
	uapi_key_attr_to_method(method_key))
	break;

	if (elm->spec.mandatory)
	__set_bit(attr_bkey, method_elm->attr_mandatory);

	if (type == UVERBS_ATTR_TYPE_IDR \|\|
	type == UVERBS_ATTR_TYPE_FD) {
	u8 access = elm->spec.u.obj.access;

	/*
	* Verbs specs may only have one NEW/DESTROY, we don't
	* have the infrastructure to abort multiple NEW's or
	* cope with multiple DESTROY failure.
	*/
	if (access == UVERBS_ACCESS_NEW \|\|
	access == UVERBS_ACCESS_DESTROY) {
	if (WARN_ON(single_uobj))
	return -EINVAL;

	single_uobj = true;
	if (WARN_ON(!elm->spec.mandatory))
	return -EINVAL;
	}

	if (access == UVERBS_ACCESS_DESTROY)
	method_elm->destroy_bkey = attr_bkey;
	}

	max_bkey = max(max_bkey, attr_bkey);
	num_attrs++;
	}

	method_elm->key_bitmap_len = max_bkey + 1;
	WARN_ON(method_elm->key_bitmap_len > UVERBS_API_ATTR_BKEY_LEN);

	uapi_compute_bundle_size(method_elm, num_attrs);
	return 0;
	}

	static int uapi_finalize(struct uverbs_api *uapi)
	{
	struct radix_tree_iter iter;
	void __rcu **slot;
	int rc;

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
	struct uverbs_api_ioctl_method *method_elm =
	rcu_dereference_protected(*slot, true);

	if (uapi_key_is_ioctl_method(iter.index)) {
	rc = uapi_finalize_ioctl_method(uapi, method_elm,
	iter.index);
	if (rc)
	return rc;
	}
	}

	return 0;
	}

	void uverbs_destroy_api(struct uverbs_api *uapi)
	{
	struct radix_tree_iter iter;
	void __rcu **slot;

	if (!uapi)
	return;

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
	kfree(rcu_dereference_protected(*slot, true));
	radix_tree_iter_delete(&uapi->radix, &iter, slot);
	}
	}

	struct uverbs_api *uverbs_alloc_api(
	const struct uverbs_object_tree_def const driver_specs,
	enum rdma_driver_id driver_id)
	{
	struct uverbs_api *uapi;
	int rc;

	uapi = kzalloc(sizeof(*uapi), GFP_KERNEL);
	if (!uapi)
	return ERR_PTR(-ENOMEM);

	INIT_RADIX_TREE(&uapi->radix, GFP_KERNEL);
	uapi->driver_id = driver_id;

	rc = uapi_merge_tree(uapi, uverbs_default_get_objects(), false);
	if (rc)
	goto err;

	for (; driver_specs && *driver_specs; driver_specs++) {
	rc = uapi_merge_tree(uapi, *driver_specs, true);
	if (rc)
	goto err;
	}

	rc = uapi_finalize(uapi);
	if (rc)
	goto err;

	return uapi;
	err:
	if (rc != -ENOMEM)
	pr_err("Setup of uverbs_api failed, kernel parsing tree description is not valid (%d)??\n",
	rc);

	uverbs_destroy_api(uapi);
	return ERR_PTR(rc);
	}

	/*
	* The pre version is done before destroying the HW objects, it only blocks
	* off method access. All methods that require the ib_dev or the module data
	* must test one of these assignments prior to continuing.
	*/
	void uverbs_disassociate_api_pre(struct ib_uverbs_device *uverbs_dev)
	{
	struct uverbs_api *uapi = uverbs_dev->uapi;
	struct radix_tree_iter iter;
	void __rcu **slot;

	rcu_assign_pointer(uverbs_dev->ib_dev, NULL);

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
	if (uapi_key_is_ioctl_method(iter.index)) {
	struct uverbs_api_ioctl_method *method_elm =
	rcu_dereference_protected(*slot, true);

	if (method_elm->driver_method)
	rcu_assign_pointer(method_elm->handler, NULL);
	}
	}

	synchronize_srcu(&uverbs_dev->disassociate_srcu);
	}

	/*
	* Called when a driver disassociates from the ib_uverbs_device. The
	* assumption is that the driver module will unload after. Replace everything
	* related to the driver with NULL as a safety measure.
	*/
	void uverbs_disassociate_api(struct uverbs_api *uapi)
	{
	struct radix_tree_iter iter;
	void __rcu **slot;

	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
	if (uapi_key_is_object(iter.index)) {
	struct uverbs_api_object *object_elm =
	rcu_dereference_protected(*slot, true);

	/*
	* Some type_attrs are in the driver module. We don't
	* bother to keep track of which since there should be
	* no use of this after disassociate.
	*/
	object_elm->type_attrs = NULL;
	} else if (uapi_key_is_attr(iter.index)) {
	struct uverbs_api_attr *elm =
	rcu_dereference_protected(*slot, true);

	if (elm->spec.type == UVERBS_ATTR_TYPE_ENUM_IN)
	elm->spec.u2.enum_def.ids = NULL;
	}
	}
	}