1 /*
2  * Copyright (c) 2017, Mellanox Technologies inc.  All rights reserved.
3  *
4  * This software is available to you under a choice of one of two
5  * licenses.  You may choose to be licensed under the terms of the GNU
6  * General Public License (GPL) Version 2, available from the file
7  * COPYING in the main directory of this source tree, or the
8  * OpenIB.org BSD license below:
9  *
10  *     Redistribution and use in source and binary forms, with or
11  *     without modification, are permitted provided that the following
12  *     conditions are met:
13  *
14  *      - Redistributions of source code must retain the above
15  *        copyright notice, this list of conditions and the following
16  *        disclaimer.
17  *
18  *      - Redistributions in binary form must reproduce the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer in the documentation and/or other materials
21  *        provided with the distribution.
22  *
23  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
24  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
25  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
26  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
27  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
28  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
29  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
30  * SOFTWARE.
31  */
32 
33 #include <rdma/rdma_user_ioctl.h>
34 #include <rdma/uverbs_ioctl.h>
35 #include "rdma_core.h"
36 #include "uverbs.h"
37 
38 struct bundle_alloc_head {
39 	struct bundle_alloc_head *next;
40 	u8 data[];
41 };
42 
43 struct bundle_priv {
44 	/* Must be first */
45 	struct bundle_alloc_head alloc_head;
46 	struct bundle_alloc_head *allocated_mem;
47 	size_t internal_avail;
48 	size_t internal_used;
49 
50 	struct radix_tree_root *radix;
51 	const struct uverbs_api_ioctl_method *method_elm;
52 	void __rcu **radix_slots;
53 	unsigned long radix_slots_len;
54 	u32 method_key;
55 
56 	struct ib_uverbs_attr __user *user_attrs;
57 	struct ib_uverbs_attr *uattrs;
58 
59 	DECLARE_BITMAP(uobj_finalize, UVERBS_API_ATTR_BKEY_LEN);
60 	DECLARE_BITMAP(spec_finalize, UVERBS_API_ATTR_BKEY_LEN);
61 
62 	/*
63 	 * Must be last. bundle ends in a flex array which overlaps
64 	 * internal_buffer.
65 	 */
66 	struct uverbs_attr_bundle bundle;
67 	u64 internal_buffer[32];
68 };
69 
70 /*
71  * Each method has an absolute minimum amount of memory it needs to allocate,
72  * precompute that amount and determine if the onstack memory can be used or
73  * if allocation is need.
74  */
75 void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm,
76 			      unsigned int num_attrs)
77 {
78 	struct bundle_priv *pbundle;
79 	size_t bundle_size =
80 		offsetof(struct bundle_priv, internal_buffer) +
81 		sizeof(*pbundle->bundle.attrs) * method_elm->key_bitmap_len +
82 		sizeof(*pbundle->uattrs) * num_attrs;
83 
84 	method_elm->use_stack = bundle_size <= sizeof(*pbundle);
85 	method_elm->bundle_size =
86 		ALIGN(bundle_size + 256, sizeof(*pbundle->internal_buffer));
87 
88 	/* Do not want order-2 allocations for this. */
89 	WARN_ON_ONCE(method_elm->bundle_size > PAGE_SIZE);
90 }
91 
92 /**
93  * uverbs_alloc() - Quickly allocate memory for use with a bundle
94  * @bundle: The bundle
95  * @size: Number of bytes to allocate
96  * @flags: Allocator flags
97  *
98  * The bundle allocator is intended for allocations that are connected with
99  * processing the system call related to the bundle. The allocated memory is
100  * always freed once the system call completes, and cannot be freed any other
101  * way.
102  *
103  * This tries to use a small pool of pre-allocated memory for performance.
104  */
105 __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
106 			     gfp_t flags)
107 {
108 	struct bundle_priv *pbundle =
109 		container_of(bundle, struct bundle_priv, bundle);
110 	size_t new_used;
111 	void *res;
112 
113 	if (check_add_overflow(size, pbundle->internal_used, &new_used))
114 		return ERR_PTR(-EOVERFLOW);
115 
116 	if (new_used > pbundle->internal_avail) {
117 		struct bundle_alloc_head *buf;
118 
119 		buf = kvmalloc(struct_size(buf, data, size), flags);
120 		if (!buf)
121 			return ERR_PTR(-ENOMEM);
122 		buf->next = pbundle->allocated_mem;
123 		pbundle->allocated_mem = buf;
124 		return buf->data;
125 	}
126 
127 	res = (void *)pbundle->internal_buffer + pbundle->internal_used;
128 	pbundle->internal_used =
129 		ALIGN(new_used, sizeof(*pbundle->internal_buffer));
130 	if (flags & __GFP_ZERO)
131 		memset(res, 0, size);
132 	return res;
133 }
134 EXPORT_SYMBOL(_uverbs_alloc);
135 
136 static bool uverbs_is_attr_cleared(const struct ib_uverbs_attr *uattr,
137 				   u16 len)
138 {
139 	if (uattr->len > sizeof(((struct ib_uverbs_attr *)0)->data))
140 		return ib_is_buffer_cleared(u64_to_user_ptr(uattr->data) + len,
141 					    uattr->len - len);
142 
143 	return !memchr_inv((const void *)&uattr->data + len,
144 			   0, uattr->len - len);
145 }
146 
147 static int uverbs_set_output(const struct uverbs_attr_bundle *bundle,
148 			     const struct uverbs_attr *attr)
149 {
150 	struct bundle_priv *pbundle =
151 		container_of(bundle, struct bundle_priv, bundle);
152 	u16 flags;
153 
154 	flags = pbundle->uattrs[attr->ptr_attr.uattr_idx].flags |
155 		UVERBS_ATTR_F_VALID_OUTPUT;
156 	if (put_user(flags,
157 		     &pbundle->user_attrs[attr->ptr_attr.uattr_idx].flags))
158 		return -EFAULT;
159 	return 0;
160 }
161 
162 static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
163 				     const struct uverbs_api_attr *attr_uapi,
164 				     struct uverbs_objs_arr_attr *attr,
165 				     struct ib_uverbs_attr *uattr,
166 				     u32 attr_bkey)
167 {
168 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
169 	size_t array_len;
170 	u32 *idr_vals;
171 	int ret = 0;
172 	size_t i;
173 
174 	if (uattr->attr_data.reserved)
175 		return -EINVAL;
176 
177 	if (uattr->len % sizeof(u32))
178 		return -EINVAL;
179 
180 	array_len = uattr->len / sizeof(u32);
181 	if (array_len < spec->u2.objs_arr.min_len ||
182 	    array_len > spec->u2.objs_arr.max_len)
183 		return -EINVAL;
184 
185 	attr->uobjects =
186 		uverbs_alloc(&pbundle->bundle,
187 			     array_size(array_len, sizeof(*attr->uobjects)));
188 	if (IS_ERR(attr->uobjects))
189 		return PTR_ERR(attr->uobjects);
190 
191 	/*
192 	 * Since idr is 4B and *uobjects is >= 4B, we can use attr->uobjects
193 	 * to store idrs array and avoid additional memory allocation. The
194 	 * idrs array is offset to the end of the uobjects array so we will be
195 	 * able to read idr and replace with a pointer.
196 	 */
197 	idr_vals = (u32 *)(attr->uobjects + array_len) - array_len;
198 
199 	if (uattr->len > sizeof(uattr->data)) {
200 		ret = copy_from_user(idr_vals, u64_to_user_ptr(uattr->data),
201 				     uattr->len);
202 		if (ret)
203 			return -EFAULT;
204 	} else {
205 		memcpy(idr_vals, &uattr->data, uattr->len);
206 	}
207 
208 	for (i = 0; i != array_len; i++) {
209 		attr->uobjects[i] = uverbs_get_uobject_from_file(
210 			spec->u2.objs_arr.obj_type, pbundle->bundle.ufile,
211 			spec->u2.objs_arr.access, idr_vals[i]);
212 		if (IS_ERR(attr->uobjects[i])) {
213 			ret = PTR_ERR(attr->uobjects[i]);
214 			break;
215 		}
216 	}
217 
218 	attr->len = i;
219 	__set_bit(attr_bkey, pbundle->spec_finalize);
220 	return ret;
221 }
222 
223 static int uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
224 				  struct uverbs_objs_arr_attr *attr,
225 				  bool commit)
226 {
227 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
228 	int current_ret;
229 	int ret = 0;
230 	size_t i;
231 
232 	for (i = 0; i != attr->len; i++) {
233 		current_ret = uverbs_finalize_object(
234 			attr->uobjects[i], spec->u2.objs_arr.access, commit);
235 		if (!ret)
236 			ret = current_ret;
237 	}
238 
239 	return ret;
240 }
241 
242 static int uverbs_process_attr(struct bundle_priv *pbundle,
243 			       const struct uverbs_api_attr *attr_uapi,
244 			       struct ib_uverbs_attr *uattr, u32 attr_bkey)
245 {
246 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
247 	struct uverbs_attr *e = &pbundle->bundle.attrs[attr_bkey];
248 	const struct uverbs_attr_spec *val_spec = spec;
249 	struct uverbs_obj_attr *o_attr;
250 
251 	switch (spec->type) {
252 	case UVERBS_ATTR_TYPE_ENUM_IN:
253 		if (uattr->attr_data.enum_data.elem_id >= spec->u.enum_def.num_elems)
254 			return -EOPNOTSUPP;
255 
256 		if (uattr->attr_data.enum_data.reserved)
257 			return -EINVAL;
258 
259 		val_spec = &spec->u2.enum_def.ids[uattr->attr_data.enum_data.elem_id];
260 
261 		/* Currently we only support PTR_IN based enums */
262 		if (val_spec->type != UVERBS_ATTR_TYPE_PTR_IN)
263 			return -EOPNOTSUPP;
264 
265 		e->ptr_attr.enum_id = uattr->attr_data.enum_data.elem_id;
266 	/* fall through */
267 	case UVERBS_ATTR_TYPE_PTR_IN:
268 		/* Ensure that any data provided by userspace beyond the known
269 		 * struct is zero. Userspace that knows how to use some future
270 		 * longer struct will fail here if used with an old kernel and
271 		 * non-zero content, making ABI compat/discovery simpler.
272 		 */
273 		if (uattr->len > val_spec->u.ptr.len &&
274 		    val_spec->zero_trailing &&
275 		    !uverbs_is_attr_cleared(uattr, val_spec->u.ptr.len))
276 			return -EOPNOTSUPP;
277 
278 	/* fall through */
279 	case UVERBS_ATTR_TYPE_PTR_OUT:
280 		if (uattr->len < val_spec->u.ptr.min_len ||
281 		    (!val_spec->zero_trailing &&
282 		     uattr->len > val_spec->u.ptr.len))
283 			return -EINVAL;
284 
285 		if (spec->type != UVERBS_ATTR_TYPE_ENUM_IN &&
286 		    uattr->attr_data.reserved)
287 			return -EINVAL;
288 
289 		e->ptr_attr.uattr_idx = uattr - pbundle->uattrs;
290 		e->ptr_attr.len = uattr->len;
291 
292 		if (val_spec->alloc_and_copy && !uverbs_attr_ptr_is_inline(e)) {
293 			void *p;
294 
295 			p = uverbs_alloc(&pbundle->bundle, uattr->len);
296 			if (IS_ERR(p))
297 				return PTR_ERR(p);
298 
299 			e->ptr_attr.ptr = p;
300 
301 			if (copy_from_user(p, u64_to_user_ptr(uattr->data),
302 					   uattr->len))
303 				return -EFAULT;
304 		} else {
305 			e->ptr_attr.data = uattr->data;
306 		}
307 		break;
308 
309 	case UVERBS_ATTR_TYPE_IDR:
310 	case UVERBS_ATTR_TYPE_FD:
311 		if (uattr->attr_data.reserved)
312 			return -EINVAL;
313 
314 		if (uattr->len != 0)
315 			return -EINVAL;
316 
317 		o_attr = &e->obj_attr;
318 		o_attr->attr_elm = attr_uapi;
319 
320 		/*
321 		 * The type of uattr->data is u64 for UVERBS_ATTR_TYPE_IDR and
322 		 * s64 for UVERBS_ATTR_TYPE_FD. We can cast the u64 to s64
323 		 * here without caring about truncation as we know that the
324 		 * IDR implementation today rejects negative IDs
325 		 */
326 		o_attr->uobject = uverbs_get_uobject_from_file(
327 					spec->u.obj.obj_type,
328 					pbundle->bundle.ufile,
329 					spec->u.obj.access,
330 					uattr->data_s64);
331 		if (IS_ERR(o_attr->uobject))
332 			return PTR_ERR(o_attr->uobject);
333 		__set_bit(attr_bkey, pbundle->uobj_finalize);
334 
335 		if (spec->u.obj.access == UVERBS_ACCESS_NEW) {
336 			unsigned int uattr_idx = uattr - pbundle->uattrs;
337 			s64 id = o_attr->uobject->id;
338 
339 			/* Copy the allocated id to the user-space */
340 			if (put_user(id, &pbundle->user_attrs[uattr_idx].data))
341 				return -EFAULT;
342 		}
343 
344 		break;
345 
346 	case UVERBS_ATTR_TYPE_IDRS_ARRAY:
347 		return uverbs_process_idrs_array(pbundle, attr_uapi,
348 						 &e->objs_arr_attr, uattr,
349 						 attr_bkey);
350 	default:
351 		return -EOPNOTSUPP;
352 	}
353 
354 	return 0;
355 }
356 
357 /*
358  * We search the radix tree with the method prefix and now we want to fast
359  * search the suffix bits to get a particular attribute pointer. It is not
360  * totally clear to me if this breaks the radix tree encasulation or not, but
361  * it uses the iter data to determine if the method iter points at the same
362  * chunk that will store the attribute, if so it just derefs it directly. By
363  * construction in most kernel configs the method and attrs will all fit in a
364  * single radix chunk, so in most cases this will have no search. Other cases
365  * this falls back to a full search.
366  */
367 static void __rcu **uapi_get_attr_for_method(struct bundle_priv *pbundle,
368 					     u32 attr_key)
369 {
370 	void __rcu **slot;
371 
372 	if (likely(attr_key < pbundle->radix_slots_len)) {
373 		void *entry;
374 
375 		slot = pbundle->radix_slots + attr_key;
376 		entry = rcu_dereference_raw(*slot);
377 		if (likely(!radix_tree_is_internal_node(entry) && entry))
378 			return slot;
379 	}
380 
381 	return radix_tree_lookup_slot(pbundle->radix,
382 				      pbundle->method_key | attr_key);
383 }
384 
385 static int uverbs_set_attr(struct bundle_priv *pbundle,
386 			   struct ib_uverbs_attr *uattr)
387 {
388 	u32 attr_key = uapi_key_attr(uattr->attr_id);
389 	u32 attr_bkey = uapi_bkey_attr(attr_key);
390 	const struct uverbs_api_attr *attr;
391 	void __rcu **slot;
392 	int ret;
393 
394 	slot = uapi_get_attr_for_method(pbundle, attr_key);
395 	if (!slot) {
396 		/*
397 		 * Kernel does not support the attribute but user-space says it
398 		 * is mandatory
399 		 */
400 		if (uattr->flags & UVERBS_ATTR_F_MANDATORY)
401 			return -EPROTONOSUPPORT;
402 		return 0;
403 	}
404 	attr = rcu_dereference_protected(*slot, true);
405 
406 	/* Reject duplicate attributes from user-space */
407 	if (test_bit(attr_bkey, pbundle->bundle.attr_present))
408 		return -EINVAL;
409 
410 	ret = uverbs_process_attr(pbundle, attr, uattr, attr_bkey);
411 	if (ret)
412 		return ret;
413 
414 	__set_bit(attr_bkey, pbundle->bundle.attr_present);
415 
416 	return 0;
417 }
418 
419 static int ib_uverbs_run_method(struct bundle_priv *pbundle,
420 				unsigned int num_attrs)
421 {
422 	int (*handler)(struct uverbs_attr_bundle *attrs);
423 	size_t uattrs_size = array_size(sizeof(*pbundle->uattrs), num_attrs);
424 	unsigned int destroy_bkey = pbundle->method_elm->destroy_bkey;
425 	unsigned int i;
426 	int ret;
427 
428 	/* See uverbs_disassociate_api() */
429 	handler = srcu_dereference(
430 		pbundle->method_elm->handler,
431 		&pbundle->bundle.ufile->device->disassociate_srcu);
432 	if (!handler)
433 		return -EIO;
434 
435 	pbundle->uattrs = uverbs_alloc(&pbundle->bundle, uattrs_size);
436 	if (IS_ERR(pbundle->uattrs))
437 		return PTR_ERR(pbundle->uattrs);
438 	if (copy_from_user(pbundle->uattrs, pbundle->user_attrs, uattrs_size))
439 		return -EFAULT;
440 
441 	for (i = 0; i != num_attrs; i++) {
442 		ret = uverbs_set_attr(pbundle, &pbundle->uattrs[i]);
443 		if (unlikely(ret))
444 			return ret;
445 	}
446 
447 	/* User space did not provide all the mandatory attributes */
448 	if (unlikely(!bitmap_subset(pbundle->method_elm->attr_mandatory,
449 				    pbundle->bundle.attr_present,
450 				    pbundle->method_elm->key_bitmap_len)))
451 		return -EINVAL;
452 
453 	if (pbundle->method_elm->has_udata)
454 		uverbs_fill_udata(&pbundle->bundle,
455 				  &pbundle->bundle.driver_udata,
456 				  UVERBS_ATTR_UHW_IN, UVERBS_ATTR_UHW_OUT);
457 
458 	if (destroy_bkey != UVERBS_API_ATTR_BKEY_LEN) {
459 		struct uverbs_obj_attr *destroy_attr =
460 			&pbundle->bundle.attrs[destroy_bkey].obj_attr;
461 
462 		ret = uobj_destroy(destroy_attr->uobject);
463 		if (ret)
464 			return ret;
465 		__clear_bit(destroy_bkey, pbundle->uobj_finalize);
466 
467 		ret = handler(&pbundle->bundle);
468 		uobj_put_destroy(destroy_attr->uobject);
469 	} else {
470 		ret = handler(&pbundle->bundle);
471 	}
472 
473 	/*
474 	 * Until the drivers are revised to use the bundle directly we have to
475 	 * assume that the driver wrote to its UHW_OUT and flag userspace
476 	 * appropriately.
477 	 */
478 	if (!ret && pbundle->method_elm->has_udata) {
479 		const struct uverbs_attr *attr =
480 			uverbs_attr_get(&pbundle->bundle, UVERBS_ATTR_UHW_OUT);
481 
482 		if (!IS_ERR(attr))
483 			ret = uverbs_set_output(&pbundle->bundle, attr);
484 	}
485 
486 	/*
487 	 * EPROTONOSUPPORT is ONLY to be returned if the ioctl framework can
488 	 * not invoke the method because the request is not supported.  No
489 	 * other cases should return this code.
490 	 */
491 	if (WARN_ON_ONCE(ret == -EPROTONOSUPPORT))
492 		return -EINVAL;
493 
494 	return ret;
495 }
496 
497 static int bundle_destroy(struct bundle_priv *pbundle, bool commit)
498 {
499 	unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len;
500 	struct bundle_alloc_head *memblock;
501 	unsigned int i;
502 	int ret = 0;
503 
504 	/* fast path for simple uobjects */
505 	i = -1;
506 	while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
507 				  i + 1)) < key_bitmap_len) {
508 		struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
509 		int current_ret;
510 
511 		current_ret = uverbs_finalize_object(
512 			attr->obj_attr.uobject,
513 			attr->obj_attr.attr_elm->spec.u.obj.access, commit);
514 		if (!ret)
515 			ret = current_ret;
516 	}
517 
518 	i = -1;
519 	while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len,
520 				  i + 1)) < key_bitmap_len) {
521 		struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
522 		const struct uverbs_api_attr *attr_uapi;
523 		void __rcu **slot;
524 		int current_ret;
525 
526 		slot = uapi_get_attr_for_method(
527 			pbundle,
528 			pbundle->method_key | uapi_bkey_to_key_attr(i));
529 		if (WARN_ON(!slot))
530 			continue;
531 
532 		attr_uapi = rcu_dereference_protected(*slot, true);
533 
534 		if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
535 			current_ret = uverbs_free_idrs_array(
536 				attr_uapi, &attr->objs_arr_attr, commit);
537 			if (!ret)
538 				ret = current_ret;
539 		}
540 	}
541 
542 	for (memblock = pbundle->allocated_mem; memblock;) {
543 		struct bundle_alloc_head *tmp = memblock;
544 
545 		memblock = memblock->next;
546 		kvfree(tmp);
547 	}
548 
549 	return ret;
550 }
551 
552 static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
553 			       struct ib_uverbs_ioctl_hdr *hdr,
554 			       struct ib_uverbs_attr __user *user_attrs)
555 {
556 	const struct uverbs_api_ioctl_method *method_elm;
557 	struct uverbs_api *uapi = ufile->device->uapi;
558 	struct radix_tree_iter attrs_iter;
559 	struct bundle_priv *pbundle;
560 	struct bundle_priv onstack;
561 	void __rcu **slot;
562 	int destroy_ret;
563 	int ret;
564 
565 	if (unlikely(hdr->driver_id != uapi->driver_id))
566 		return -EINVAL;
567 
568 	slot = radix_tree_iter_lookup(
569 		&uapi->radix, &attrs_iter,
570 		uapi_key_obj(hdr->object_id) |
571 			uapi_key_ioctl_method(hdr->method_id));
572 	if (unlikely(!slot))
573 		return -EPROTONOSUPPORT;
574 	method_elm = rcu_dereference_protected(*slot, true);
575 
576 	if (!method_elm->use_stack) {
577 		pbundle = kmalloc(method_elm->bundle_size, GFP_KERNEL);
578 		if (!pbundle)
579 			return -ENOMEM;
580 		pbundle->internal_avail =
581 			method_elm->bundle_size -
582 			offsetof(struct bundle_priv, internal_buffer);
583 		pbundle->alloc_head.next = NULL;
584 		pbundle->allocated_mem = &pbundle->alloc_head;
585 	} else {
586 		pbundle = &onstack;
587 		pbundle->internal_avail = sizeof(pbundle->internal_buffer);
588 		pbundle->allocated_mem = NULL;
589 	}
590 
591 	/* Space for the pbundle->bundle.attrs flex array */
592 	pbundle->method_elm = method_elm;
593 	pbundle->method_key = attrs_iter.index;
594 	pbundle->bundle.ufile = ufile;
595 	pbundle->radix = &uapi->radix;
596 	pbundle->radix_slots = slot;
597 	pbundle->radix_slots_len = radix_tree_chunk_size(&attrs_iter);
598 	pbundle->user_attrs = user_attrs;
599 
600 	pbundle->internal_used = ALIGN(pbundle->method_elm->key_bitmap_len *
601 					       sizeof(*pbundle->bundle.attrs),
602 				       sizeof(*pbundle->internal_buffer));
603 	memset(pbundle->bundle.attr_present, 0,
604 	       sizeof(pbundle->bundle.attr_present));
605 	memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize));
606 	memset(pbundle->spec_finalize, 0, sizeof(pbundle->spec_finalize));
607 
608 	ret = ib_uverbs_run_method(pbundle, hdr->num_attrs);
609 	destroy_ret = bundle_destroy(pbundle, ret == 0);
610 	if (unlikely(destroy_ret && !ret))
611 		return destroy_ret;
612 
613 	return ret;
614 }
615 
616 long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
617 {
618 	struct ib_uverbs_file *file = filp->private_data;
619 	struct ib_uverbs_ioctl_hdr __user *user_hdr =
620 		(struct ib_uverbs_ioctl_hdr __user *)arg;
621 	struct ib_uverbs_ioctl_hdr hdr;
622 	int srcu_key;
623 	int err;
624 
625 	if (unlikely(cmd != RDMA_VERBS_IOCTL))
626 		return -ENOIOCTLCMD;
627 
628 	err = copy_from_user(&hdr, user_hdr, sizeof(hdr));
629 	if (err)
630 		return -EFAULT;
631 
632 	if (hdr.length > PAGE_SIZE ||
633 	    hdr.length != struct_size(&hdr, attrs, hdr.num_attrs))
634 		return -EINVAL;
635 
636 	if (hdr.reserved1 || hdr.reserved2)
637 		return -EPROTONOSUPPORT;
638 
639 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
640 	err = ib_uverbs_cmd_verbs(file, &hdr, user_hdr->attrs);
641 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
642 	return err;
643 }
644 
645 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
646 		       size_t idx, u64 allowed_bits)
647 {
648 	const struct uverbs_attr *attr;
649 	u64 flags;
650 
651 	attr = uverbs_attr_get(attrs_bundle, idx);
652 	/* Missing attribute means 0 flags */
653 	if (IS_ERR(attr)) {
654 		*to = 0;
655 		return 0;
656 	}
657 
658 	/*
659 	 * New userspace code should use 8 bytes to pass flags, but we
660 	 * transparently support old userspaces that were using 4 bytes as
661 	 * well.
662 	 */
663 	if (attr->ptr_attr.len == 8)
664 		flags = attr->ptr_attr.data;
665 	else if (attr->ptr_attr.len == 4)
666 		flags = *(u32 *)&attr->ptr_attr.data;
667 	else
668 		return -EINVAL;
669 
670 	if (flags & ~allowed_bits)
671 		return -EINVAL;
672 
673 	*to = flags;
674 	return 0;
675 }
676 EXPORT_SYMBOL(uverbs_get_flags64);
677 
678 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
679 		       size_t idx, u64 allowed_bits)
680 {
681 	u64 flags;
682 	int ret;
683 
684 	ret = uverbs_get_flags64(&flags, attrs_bundle, idx, allowed_bits);
685 	if (ret)
686 		return ret;
687 
688 	if (flags > U32_MAX)
689 		return -EINVAL;
690 	*to = flags;
691 
692 	return 0;
693 }
694 EXPORT_SYMBOL(uverbs_get_flags32);
695 
696 /*
697  * Fill a ib_udata struct (core or uhw) using the given attribute IDs.
698  * This is primarily used to convert the UVERBS_ATTR_UHW() into the
699  * ib_udata format used by the drivers.
700  */
701 void uverbs_fill_udata(struct uverbs_attr_bundle *bundle,
702 		       struct ib_udata *udata, unsigned int attr_in,
703 		       unsigned int attr_out)
704 {
705 	struct bundle_priv *pbundle =
706 		container_of(bundle, struct bundle_priv, bundle);
707 	const struct uverbs_attr *in =
708 		uverbs_attr_get(&pbundle->bundle, attr_in);
709 	const struct uverbs_attr *out =
710 		uverbs_attr_get(&pbundle->bundle, attr_out);
711 
712 	if (!IS_ERR(in)) {
713 		udata->inlen = in->ptr_attr.len;
714 		if (uverbs_attr_ptr_is_inline(in))
715 			udata->inbuf =
716 				&pbundle->user_attrs[in->ptr_attr.uattr_idx]
717 					 .data;
718 		else
719 			udata->inbuf = u64_to_user_ptr(in->ptr_attr.data);
720 	} else {
721 		udata->inbuf = NULL;
722 		udata->inlen = 0;
723 	}
724 
725 	if (!IS_ERR(out)) {
726 		udata->outbuf = u64_to_user_ptr(out->ptr_attr.data);
727 		udata->outlen = out->ptr_attr.len;
728 	} else {
729 		udata->outbuf = NULL;
730 		udata->outlen = 0;
731 	}
732 }
733 
734 int uverbs_copy_to(const struct uverbs_attr_bundle *bundle, size_t idx,
735 		   const void *from, size_t size)
736 {
737 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
738 	size_t min_size;
739 
740 	if (IS_ERR(attr))
741 		return PTR_ERR(attr);
742 
743 	min_size = min_t(size_t, attr->ptr_attr.len, size);
744 	if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
745 		return -EFAULT;
746 
747 	return uverbs_set_output(bundle, attr);
748 }
749 EXPORT_SYMBOL(uverbs_copy_to);
750 
751 
752 /*
753  * This is only used if the caller has directly used copy_to_use to write the
754  * data.  It signals to user space that the buffer is filled in.
755  */
756 int uverbs_output_written(const struct uverbs_attr_bundle *bundle, size_t idx)
757 {
758 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
759 
760 	if (IS_ERR(attr))
761 		return PTR_ERR(attr);
762 
763 	return uverbs_set_output(bundle, attr);
764 }
765 
766 int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
767 		      size_t idx, s64 lower_bound, u64 upper_bound,
768 		      s64  *def_val)
769 {
770 	const struct uverbs_attr *attr;
771 
772 	attr = uverbs_attr_get(attrs_bundle, idx);
773 	if (IS_ERR(attr)) {
774 		if ((PTR_ERR(attr) != -ENOENT) || !def_val)
775 			return PTR_ERR(attr);
776 
777 		*to = *def_val;
778 	} else {
779 		*to = attr->ptr_attr.data;
780 	}
781 
782 	if (*to < lower_bound || (*to > 0 && (u64)*to > upper_bound))
783 		return -EINVAL;
784 
785 	return 0;
786 }
787 EXPORT_SYMBOL(_uverbs_get_const);
788 
789 int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
790 				  size_t idx, const void *from, size_t size)
791 {
792 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
793 
794 	if (size < attr->ptr_attr.len) {
795 		if (clear_user(u64_to_user_ptr(attr->ptr_attr.data) + size,
796 			       attr->ptr_attr.len - size))
797 			return -EFAULT;
798 	}
799 	return uverbs_copy_to(bundle, idx, from, size);
800 }
801