diff options
Diffstat (limited to 'drivers/infiniband/core/uverbs_uapi.c')
-rw-r--r-- | drivers/infiniband/core/uverbs_uapi.c | 343 |
1 files changed, 343 insertions, 0 deletions
diff --git a/drivers/infiniband/core/uverbs_uapi.c b/drivers/infiniband/core/uverbs_uapi.c new file mode 100644 index 000000000000..21c0de034511 --- /dev/null +++ b/drivers/infiniband/core/uverbs_uapi.c @@ -0,0 +1,343 @@ +// 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 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); + } + + method_elm->key_bitmap_len = max_bkey + 1; + WARN_ON(method_elm->key_bitmap_len > UVERBS_API_ATTR_BKEY_LEN); + + 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; + } + } +} |