1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /*
3  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
4  */
5 #include <rdma/uverbs_ioctl.h>
6 #include <rdma/rdma_user_ioctl.h>
7 #include <linux/bitops.h>
8 #include "rdma_core.h"
9 #include "uverbs.h"
10 
11 static int ib_uverbs_notsupp(struct uverbs_attr_bundle *attrs)
12 {
13 	return -EOPNOTSUPP;
14 }
15 
16 static void *uapi_add_elm(struct uverbs_api *uapi, u32 key, size_t alloc_size)
17 {
18 	void *elm;
19 	int rc;
20 
21 	if (key == UVERBS_API_KEY_ERR)
22 		return ERR_PTR(-EOVERFLOW);
23 
24 	elm = kzalloc(alloc_size, GFP_KERNEL);
25 	if (!elm)
26 		return ERR_PTR(-ENOMEM);
27 	rc = radix_tree_insert(&uapi->radix, key, elm);
28 	if (rc) {
29 		kfree(elm);
30 		return ERR_PTR(rc);
31 	}
32 
33 	return elm;
34 }
35 
36 static void *uapi_add_get_elm(struct uverbs_api *uapi, u32 key,
37 			      size_t alloc_size, bool *exists)
38 {
39 	void *elm;
40 
41 	elm = uapi_add_elm(uapi, key, alloc_size);
42 	if (!IS_ERR(elm)) {
43 		*exists = false;
44 		return elm;
45 	}
46 
47 	if (elm != ERR_PTR(-EEXIST))
48 		return elm;
49 
50 	elm = radix_tree_lookup(&uapi->radix, key);
51 	if (WARN_ON(!elm))
52 		return ERR_PTR(-EINVAL);
53 	*exists = true;
54 	return elm;
55 }
56 
57 static int uapi_create_write(struct uverbs_api *uapi,
58 			     struct ib_device *ibdev,
59 			     const struct uapi_definition *def,
60 			     u32 obj_key,
61 			     u32 *cur_method_key)
62 {
63 	struct uverbs_api_write_method *method_elm;
64 	u32 method_key = obj_key;
65 	bool exists;
66 
67 	if (def->write.is_ex)
68 		method_key |= uapi_key_write_ex_method(def->write.command_num);
69 	else
70 		method_key |= uapi_key_write_method(def->write.command_num);
71 
72 	method_elm = uapi_add_get_elm(uapi, method_key, sizeof(*method_elm),
73 				      &exists);
74 	if (IS_ERR(method_elm))
75 		return PTR_ERR(method_elm);
76 
77 	if (WARN_ON(exists && (def->write.is_ex != method_elm->is_ex)))
78 		return -EINVAL;
79 
80 	method_elm->is_ex = def->write.is_ex;
81 	method_elm->handler = def->func_write;
82 	if (def->write.is_ex)
83 		method_elm->disabled = !(ibdev->uverbs_ex_cmd_mask &
84 					 BIT_ULL(def->write.command_num));
85 	else
86 		method_elm->disabled = !(ibdev->uverbs_cmd_mask &
87 					 BIT_ULL(def->write.command_num));
88 
89 	if (!def->write.is_ex && def->func_write) {
90 		method_elm->has_udata = def->write.has_udata;
91 		method_elm->has_resp = def->write.has_resp;
92 		method_elm->req_size = def->write.req_size;
93 		method_elm->resp_size = def->write.resp_size;
94 	}
95 
96 	*cur_method_key = method_key;
97 	return 0;
98 }
99 
100 static int uapi_merge_method(struct uverbs_api *uapi,
101 			     struct uverbs_api_object *obj_elm, u32 obj_key,
102 			     const struct uverbs_method_def *method,
103 			     bool is_driver)
104 {
105 	u32 method_key = obj_key | uapi_key_ioctl_method(method->id);
106 	struct uverbs_api_ioctl_method *method_elm;
107 	unsigned int i;
108 	bool exists;
109 
110 	if (!method->attrs)
111 		return 0;
112 
113 	method_elm = uapi_add_get_elm(uapi, method_key, sizeof(*method_elm),
114 				      &exists);
115 	if (IS_ERR(method_elm))
116 		return PTR_ERR(method_elm);
117 	if (exists) {
118 		/*
119 		 * This occurs when a driver uses ADD_UVERBS_ATTRIBUTES_SIMPLE
120 		 */
121 		if (WARN_ON(method->handler))
122 			return -EINVAL;
123 	} else {
124 		WARN_ON(!method->handler);
125 		rcu_assign_pointer(method_elm->handler, method->handler);
126 		if (method->handler != uverbs_destroy_def_handler)
127 			method_elm->driver_method = is_driver;
128 	}
129 
130 	for (i = 0; i != method->num_attrs; i++) {
131 		const struct uverbs_attr_def *attr = (*method->attrs)[i];
132 		struct uverbs_api_attr *attr_slot;
133 
134 		if (!attr)
135 			continue;
136 
137 		/*
138 		 * ENUM_IN contains the 'ids' pointer to the driver's .rodata,
139 		 * so if it is specified by a driver then it always makes this
140 		 * into a driver method.
141 		 */
142 		if (attr->attr.type == UVERBS_ATTR_TYPE_ENUM_IN)
143 			method_elm->driver_method |= is_driver;
144 
145 		/*
146 		 * Like other uobject based things we only support a single
147 		 * uobject being NEW'd or DESTROY'd
148 		 */
149 		if (attr->attr.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
150 			u8 access = attr->attr.u2.objs_arr.access;
151 
152 			if (WARN_ON(access == UVERBS_ACCESS_NEW ||
153 				    access == UVERBS_ACCESS_DESTROY))
154 				return -EINVAL;
155 		}
156 
157 		attr_slot =
158 			uapi_add_elm(uapi, method_key | uapi_key_attr(attr->id),
159 				     sizeof(*attr_slot));
160 		/* Attributes are not allowed to be modified by drivers */
161 		if (IS_ERR(attr_slot))
162 			return PTR_ERR(attr_slot);
163 
164 		attr_slot->spec = attr->attr;
165 	}
166 
167 	return 0;
168 }
169 
170 static int uapi_merge_obj_tree(struct uverbs_api *uapi,
171 			       const struct uverbs_object_def *obj,
172 			       bool is_driver)
173 {
174 	struct uverbs_api_object *obj_elm;
175 	unsigned int i;
176 	u32 obj_key;
177 	bool exists;
178 	int rc;
179 
180 	obj_key = uapi_key_obj(obj->id);
181 	obj_elm = uapi_add_get_elm(uapi, obj_key, sizeof(*obj_elm), &exists);
182 	if (IS_ERR(obj_elm))
183 		return PTR_ERR(obj_elm);
184 
185 	if (obj->type_attrs) {
186 		if (WARN_ON(obj_elm->type_attrs))
187 			return -EINVAL;
188 
189 		obj_elm->id = obj->id;
190 		obj_elm->type_attrs = obj->type_attrs;
191 		obj_elm->type_class = obj->type_attrs->type_class;
192 		/*
193 		 * Today drivers are only permitted to use idr_class and
194 		 * fd_class types. We can revoke the IDR types during
195 		 * disassociation, and the FD types require the driver to use
196 		 * struct file_operations.owner to prevent the driver module
197 		 * code from unloading while the file is open. This provides
198 		 * enough safety that uverbs_close_fd() will continue to work.
199 		 * Drivers using FD are responsible to handle disassociation of
200 		 * the device on their own.
201 		 */
202 		if (WARN_ON(is_driver &&
203 			    obj->type_attrs->type_class != &uverbs_idr_class &&
204 			    obj->type_attrs->type_class != &uverbs_fd_class))
205 			return -EINVAL;
206 	}
207 
208 	if (!obj->methods)
209 		return 0;
210 
211 	for (i = 0; i != obj->num_methods; i++) {
212 		const struct uverbs_method_def *method = (*obj->methods)[i];
213 
214 		if (!method)
215 			continue;
216 
217 		rc = uapi_merge_method(uapi, obj_elm, obj_key, method,
218 				       is_driver);
219 		if (rc)
220 			return rc;
221 	}
222 
223 	return 0;
224 }
225 
226 static int uapi_disable_elm(struct uverbs_api *uapi,
227 			    const struct uapi_definition *def,
228 			    u32 obj_key,
229 			    u32 method_key)
230 {
231 	bool exists;
232 
233 	if (def->scope == UAPI_SCOPE_OBJECT) {
234 		struct uverbs_api_object *obj_elm;
235 
236 		obj_elm = uapi_add_get_elm(
237 			uapi, obj_key, sizeof(*obj_elm), &exists);
238 		if (IS_ERR(obj_elm))
239 			return PTR_ERR(obj_elm);
240 		obj_elm->disabled = 1;
241 		return 0;
242 	}
243 
244 	if (def->scope == UAPI_SCOPE_METHOD &&
245 	    uapi_key_is_ioctl_method(method_key)) {
246 		struct uverbs_api_ioctl_method *method_elm;
247 
248 		method_elm = uapi_add_get_elm(uapi, method_key,
249 					      sizeof(*method_elm), &exists);
250 		if (IS_ERR(method_elm))
251 			return PTR_ERR(method_elm);
252 		method_elm->disabled = 1;
253 		return 0;
254 	}
255 
256 	if (def->scope == UAPI_SCOPE_METHOD &&
257 	    (uapi_key_is_write_method(method_key) ||
258 	     uapi_key_is_write_ex_method(method_key))) {
259 		struct uverbs_api_write_method *write_elm;
260 
261 		write_elm = uapi_add_get_elm(uapi, method_key,
262 					     sizeof(*write_elm), &exists);
263 		if (IS_ERR(write_elm))
264 			return PTR_ERR(write_elm);
265 		write_elm->disabled = 1;
266 		return 0;
267 	}
268 
269 	WARN_ON(true);
270 	return -EINVAL;
271 }
272 
273 static int uapi_merge_def(struct uverbs_api *uapi, struct ib_device *ibdev,
274 			  const struct uapi_definition *def_list,
275 			  bool is_driver)
276 {
277 	const struct uapi_definition *def = def_list;
278 	u32 cur_obj_key = UVERBS_API_KEY_ERR;
279 	u32 cur_method_key = UVERBS_API_KEY_ERR;
280 	bool exists;
281 	int rc;
282 
283 	if (!def_list)
284 		return 0;
285 
286 	for (;; def++) {
287 		switch ((enum uapi_definition_kind)def->kind) {
288 		case UAPI_DEF_CHAIN:
289 			rc = uapi_merge_def(uapi, ibdev, def->chain, is_driver);
290 			if (rc)
291 				return rc;
292 			continue;
293 
294 		case UAPI_DEF_CHAIN_OBJ_TREE:
295 			if (WARN_ON(def->object_start.object_id !=
296 				    def->chain_obj_tree->id))
297 				return -EINVAL;
298 
299 			cur_obj_key = uapi_key_obj(def->object_start.object_id);
300 			rc = uapi_merge_obj_tree(uapi, def->chain_obj_tree,
301 						 is_driver);
302 			if (rc)
303 				return rc;
304 			continue;
305 
306 		case UAPI_DEF_END:
307 			return 0;
308 
309 		case UAPI_DEF_IS_SUPPORTED_DEV_FN: {
310 			void **ibdev_fn =
311 				(void *)(&ibdev->ops) + def->needs_fn_offset;
312 
313 			if (*ibdev_fn)
314 				continue;
315 			rc = uapi_disable_elm(
316 				uapi, def, cur_obj_key, cur_method_key);
317 			if (rc)
318 				return rc;
319 			continue;
320 		}
321 
322 		case UAPI_DEF_IS_SUPPORTED_FUNC:
323 			if (def->func_is_supported(ibdev))
324 				continue;
325 			rc = uapi_disable_elm(
326 				uapi, def, cur_obj_key, cur_method_key);
327 			if (rc)
328 				return rc;
329 			continue;
330 
331 		case UAPI_DEF_OBJECT_START: {
332 			struct uverbs_api_object *obj_elm;
333 
334 			cur_obj_key = uapi_key_obj(def->object_start.object_id);
335 			obj_elm = uapi_add_get_elm(uapi, cur_obj_key,
336 						   sizeof(*obj_elm), &exists);
337 			if (IS_ERR(obj_elm))
338 				return PTR_ERR(obj_elm);
339 			continue;
340 		}
341 
342 		case UAPI_DEF_WRITE:
343 			rc = uapi_create_write(
344 				uapi, ibdev, def, cur_obj_key, &cur_method_key);
345 			if (rc)
346 				return rc;
347 			continue;
348 		}
349 		WARN_ON(true);
350 		return -EINVAL;
351 	}
352 }
353 
354 static int
355 uapi_finalize_ioctl_method(struct uverbs_api *uapi,
356 			   struct uverbs_api_ioctl_method *method_elm,
357 			   u32 method_key)
358 {
359 	struct radix_tree_iter iter;
360 	unsigned int num_attrs = 0;
361 	unsigned int max_bkey = 0;
362 	bool single_uobj = false;
363 	void __rcu **slot;
364 
365 	method_elm->destroy_bkey = UVERBS_API_ATTR_BKEY_LEN;
366 	radix_tree_for_each_slot (slot, &uapi->radix, &iter,
367 				  uapi_key_attrs_start(method_key)) {
368 		struct uverbs_api_attr *elm =
369 			rcu_dereference_protected(*slot, true);
370 		u32 attr_key = iter.index & UVERBS_API_ATTR_KEY_MASK;
371 		u32 attr_bkey = uapi_bkey_attr(attr_key);
372 		u8 type = elm->spec.type;
373 
374 		if (uapi_key_attr_to_ioctl_method(iter.index) !=
375 		    uapi_key_attr_to_ioctl_method(method_key))
376 			break;
377 
378 		if (elm->spec.mandatory)
379 			__set_bit(attr_bkey, method_elm->attr_mandatory);
380 
381 		if (elm->spec.is_udata)
382 			method_elm->has_udata = true;
383 
384 		if (type == UVERBS_ATTR_TYPE_IDR ||
385 		    type == UVERBS_ATTR_TYPE_FD) {
386 			u8 access = elm->spec.u.obj.access;
387 
388 			/*
389 			 * Verbs specs may only have one NEW/DESTROY, we don't
390 			 * have the infrastructure to abort multiple NEW's or
391 			 * cope with multiple DESTROY failure.
392 			 */
393 			if (access == UVERBS_ACCESS_NEW ||
394 			    access == UVERBS_ACCESS_DESTROY) {
395 				if (WARN_ON(single_uobj))
396 					return -EINVAL;
397 
398 				single_uobj = true;
399 				if (WARN_ON(!elm->spec.mandatory))
400 					return -EINVAL;
401 			}
402 
403 			if (access == UVERBS_ACCESS_DESTROY)
404 				method_elm->destroy_bkey = attr_bkey;
405 		}
406 
407 		max_bkey = max(max_bkey, attr_bkey);
408 		num_attrs++;
409 	}
410 
411 	method_elm->key_bitmap_len = max_bkey + 1;
412 	WARN_ON(method_elm->key_bitmap_len > UVERBS_API_ATTR_BKEY_LEN);
413 
414 	uapi_compute_bundle_size(method_elm, num_attrs);
415 	return 0;
416 }
417 
418 static int uapi_finalize(struct uverbs_api *uapi)
419 {
420 	const struct uverbs_api_write_method **data;
421 	unsigned long max_write_ex = 0;
422 	unsigned long max_write = 0;
423 	struct radix_tree_iter iter;
424 	void __rcu **slot;
425 	int rc;
426 	int i;
427 
428 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
429 		struct uverbs_api_ioctl_method *method_elm =
430 			rcu_dereference_protected(*slot, true);
431 
432 		if (uapi_key_is_ioctl_method(iter.index)) {
433 			rc = uapi_finalize_ioctl_method(uapi, method_elm,
434 							iter.index);
435 			if (rc)
436 				return rc;
437 		}
438 
439 		if (uapi_key_is_write_method(iter.index))
440 			max_write = max(max_write,
441 					iter.index & UVERBS_API_ATTR_KEY_MASK);
442 		if (uapi_key_is_write_ex_method(iter.index))
443 			max_write_ex =
444 				max(max_write_ex,
445 				    iter.index & UVERBS_API_ATTR_KEY_MASK);
446 	}
447 
448 	uapi->notsupp_method.handler = ib_uverbs_notsupp;
449 	uapi->num_write = max_write + 1;
450 	uapi->num_write_ex = max_write_ex + 1;
451 	data = kmalloc_array(uapi->num_write + uapi->num_write_ex,
452 			     sizeof(*uapi->write_methods), GFP_KERNEL);
453 	for (i = 0; i != uapi->num_write + uapi->num_write_ex; i++)
454 		data[i] = &uapi->notsupp_method;
455 	uapi->write_methods = data;
456 	uapi->write_ex_methods = data + uapi->num_write;
457 
458 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
459 		if (uapi_key_is_write_method(iter.index))
460 			uapi->write_methods[iter.index &
461 					    UVERBS_API_ATTR_KEY_MASK] =
462 				rcu_dereference_protected(*slot, true);
463 		if (uapi_key_is_write_ex_method(iter.index))
464 			uapi->write_ex_methods[iter.index &
465 					       UVERBS_API_ATTR_KEY_MASK] =
466 				rcu_dereference_protected(*slot, true);
467 	}
468 
469 	return 0;
470 }
471 
472 static void uapi_remove_range(struct uverbs_api *uapi, u32 start, u32 last)
473 {
474 	struct radix_tree_iter iter;
475 	void __rcu **slot;
476 
477 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, start) {
478 		if (iter.index > last)
479 			return;
480 		kfree(rcu_dereference_protected(*slot, true));
481 		radix_tree_iter_delete(&uapi->radix, &iter, slot);
482 	}
483 }
484 
485 static void uapi_remove_object(struct uverbs_api *uapi, u32 obj_key)
486 {
487 	uapi_remove_range(uapi, obj_key,
488 			  obj_key | UVERBS_API_METHOD_KEY_MASK |
489 				  UVERBS_API_ATTR_KEY_MASK);
490 }
491 
492 static void uapi_remove_method(struct uverbs_api *uapi, u32 method_key)
493 {
494 	uapi_remove_range(uapi, method_key,
495 			  method_key | UVERBS_API_ATTR_KEY_MASK);
496 }
497 
498 
499 static u32 uapi_get_obj_id(struct uverbs_attr_spec *spec)
500 {
501 	if (spec->type == UVERBS_ATTR_TYPE_IDR ||
502 	    spec->type == UVERBS_ATTR_TYPE_FD)
503 		return spec->u.obj.obj_type;
504 	if (spec->type == UVERBS_ATTR_TYPE_IDRS_ARRAY)
505 		return spec->u2.objs_arr.obj_type;
506 	return UVERBS_API_KEY_ERR;
507 }
508 
509 static void uapi_key_okay(u32 key)
510 {
511 	unsigned int count = 0;
512 
513 	if (uapi_key_is_object(key))
514 		count++;
515 	if (uapi_key_is_ioctl_method(key))
516 		count++;
517 	if (uapi_key_is_write_method(key))
518 		count++;
519 	if (uapi_key_is_write_ex_method(key))
520 		count++;
521 	if (uapi_key_is_attr(key))
522 		count++;
523 	WARN(count != 1, "Bad count %d key=%x", count, key);
524 }
525 
526 static void uapi_finalize_disable(struct uverbs_api *uapi)
527 {
528 	struct radix_tree_iter iter;
529 	u32 starting_key = 0;
530 	bool scan_again = false;
531 	void __rcu **slot;
532 
533 again:
534 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, starting_key) {
535 		uapi_key_okay(iter.index);
536 
537 		if (uapi_key_is_object(iter.index)) {
538 			struct uverbs_api_object *obj_elm =
539 				rcu_dereference_protected(*slot, true);
540 
541 			if (obj_elm->disabled) {
542 				/* Have to check all the attrs again */
543 				scan_again = true;
544 				starting_key = iter.index;
545 				uapi_remove_object(uapi, iter.index);
546 				goto again;
547 			}
548 			continue;
549 		}
550 
551 		if (uapi_key_is_ioctl_method(iter.index)) {
552 			struct uverbs_api_ioctl_method *method_elm =
553 				rcu_dereference_protected(*slot, true);
554 
555 			if (method_elm->disabled) {
556 				starting_key = iter.index;
557 				uapi_remove_method(uapi, iter.index);
558 				goto again;
559 			}
560 			continue;
561 		}
562 
563 		if (uapi_key_is_write_method(iter.index) ||
564 		    uapi_key_is_write_ex_method(iter.index)) {
565 			struct uverbs_api_write_method *method_elm =
566 				rcu_dereference_protected(*slot, true);
567 
568 			if (method_elm->disabled) {
569 				kfree(method_elm);
570 				radix_tree_iter_delete(&uapi->radix, &iter, slot);
571 			}
572 			continue;
573 		}
574 
575 		if (uapi_key_is_attr(iter.index)) {
576 			struct uverbs_api_attr *attr_elm =
577 				rcu_dereference_protected(*slot, true);
578 			const struct uverbs_api_object *tmp_obj;
579 			u32 obj_key;
580 
581 			/*
582 			 * If the method has a mandatory object handle
583 			 * attribute which relies on an object which is not
584 			 * present then the entire method is uncallable.
585 			 */
586 			if (!attr_elm->spec.mandatory)
587 				continue;
588 			obj_key = uapi_get_obj_id(&attr_elm->spec);
589 			if (obj_key == UVERBS_API_KEY_ERR)
590 				continue;
591 			tmp_obj = uapi_get_object(uapi, obj_key);
592 			if (IS_ERR(tmp_obj)) {
593 				if (PTR_ERR(tmp_obj) == -ENOMSG)
594 					continue;
595 			} else {
596 				if (!tmp_obj->disabled)
597 					continue;
598 			}
599 
600 			starting_key = iter.index;
601 			uapi_remove_method(
602 				uapi,
603 				iter.index & (UVERBS_API_OBJ_KEY_MASK |
604 					      UVERBS_API_METHOD_KEY_MASK));
605 			goto again;
606 		}
607 
608 		WARN_ON(false);
609 	}
610 
611 	if (!scan_again)
612 		return;
613 	scan_again = false;
614 	starting_key = 0;
615 	goto again;
616 }
617 
618 void uverbs_destroy_api(struct uverbs_api *uapi)
619 {
620 	if (!uapi)
621 		return;
622 
623 	uapi_remove_range(uapi, 0, U32_MAX);
624 	kfree(uapi->write_methods);
625 	kfree(uapi);
626 }
627 
628 static const struct uapi_definition uverbs_core_api[] = {
629 	UAPI_DEF_CHAIN(uverbs_def_obj_counters),
630 	UAPI_DEF_CHAIN(uverbs_def_obj_cq),
631 	UAPI_DEF_CHAIN(uverbs_def_obj_device),
632 	UAPI_DEF_CHAIN(uverbs_def_obj_dm),
633 	UAPI_DEF_CHAIN(uverbs_def_obj_flow_action),
634 	UAPI_DEF_CHAIN(uverbs_def_obj_intf),
635 	UAPI_DEF_CHAIN(uverbs_def_obj_mr),
636 	UAPI_DEF_CHAIN(uverbs_def_write_intf),
637 	{},
638 };
639 
640 struct uverbs_api *uverbs_alloc_api(struct ib_device *ibdev)
641 {
642 	struct uverbs_api *uapi;
643 	int rc;
644 
645 	uapi = kzalloc(sizeof(*uapi), GFP_KERNEL);
646 	if (!uapi)
647 		return ERR_PTR(-ENOMEM);
648 
649 	INIT_RADIX_TREE(&uapi->radix, GFP_KERNEL);
650 	uapi->driver_id = ibdev->ops.driver_id;
651 
652 	rc = uapi_merge_def(uapi, ibdev, uverbs_core_api, false);
653 	if (rc)
654 		goto err;
655 	rc = uapi_merge_def(uapi, ibdev, ibdev->driver_def, true);
656 	if (rc)
657 		goto err;
658 
659 	uapi_finalize_disable(uapi);
660 	rc = uapi_finalize(uapi);
661 	if (rc)
662 		goto err;
663 
664 	return uapi;
665 err:
666 	if (rc != -ENOMEM)
667 		dev_err(&ibdev->dev,
668 			"Setup of uverbs_api failed, kernel parsing tree description is not valid (%d)??\n",
669 			rc);
670 
671 	uverbs_destroy_api(uapi);
672 	return ERR_PTR(rc);
673 }
674 
675 /*
676  * The pre version is done before destroying the HW objects, it only blocks
677  * off method access. All methods that require the ib_dev or the module data
678  * must test one of these assignments prior to continuing.
679  */
680 void uverbs_disassociate_api_pre(struct ib_uverbs_device *uverbs_dev)
681 {
682 	struct uverbs_api *uapi = uverbs_dev->uapi;
683 	struct radix_tree_iter iter;
684 	void __rcu **slot;
685 
686 	rcu_assign_pointer(uverbs_dev->ib_dev, NULL);
687 
688 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
689 		if (uapi_key_is_ioctl_method(iter.index)) {
690 			struct uverbs_api_ioctl_method *method_elm =
691 				rcu_dereference_protected(*slot, true);
692 
693 			if (method_elm->driver_method)
694 				rcu_assign_pointer(method_elm->handler, NULL);
695 		}
696 	}
697 
698 	synchronize_srcu(&uverbs_dev->disassociate_srcu);
699 }
700 
701 /*
702  * Called when a driver disassociates from the ib_uverbs_device. The
703  * assumption is that the driver module will unload after. Replace everything
704  * related to the driver with NULL as a safety measure.
705  */
706 void uverbs_disassociate_api(struct uverbs_api *uapi)
707 {
708 	struct radix_tree_iter iter;
709 	void __rcu **slot;
710 
711 	radix_tree_for_each_slot (slot, &uapi->radix, &iter, 0) {
712 		if (uapi_key_is_object(iter.index)) {
713 			struct uverbs_api_object *object_elm =
714 				rcu_dereference_protected(*slot, true);
715 
716 			/*
717 			 * Some type_attrs are in the driver module. We don't
718 			 * bother to keep track of which since there should be
719 			 * no use of this after disassociate.
720 			 */
721 			object_elm->type_attrs = NULL;
722 		} else if (uapi_key_is_attr(iter.index)) {
723 			struct uverbs_api_attr *elm =
724 				rcu_dereference_protected(*slot, true);
725 
726 			if (elm->spec.type == UVERBS_ATTR_TYPE_ENUM_IN)
727 				elm->spec.u2.enum_def.ids = NULL;
728 		}
729 	}
730 }
731