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 (want_init_on_alloc(flags))
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, spec->u2.objs_arr.access,
211 			idr_vals[i], &pbundle->bundle);
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 void uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
224 				   struct uverbs_objs_arr_attr *attr,
225 				   bool commit,
226 				   struct uverbs_attr_bundle *attrs)
227 {
228 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
229 	size_t i;
230 
231 	for (i = 0; i != attr->len; i++)
232 		uverbs_finalize_object(attr->uobjects[i],
233 				       spec->u2.objs_arr.access, commit, attrs);
234 }
235 
236 static int uverbs_process_attr(struct bundle_priv *pbundle,
237 			       const struct uverbs_api_attr *attr_uapi,
238 			       struct ib_uverbs_attr *uattr, u32 attr_bkey)
239 {
240 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
241 	struct uverbs_attr *e = &pbundle->bundle.attrs[attr_bkey];
242 	const struct uverbs_attr_spec *val_spec = spec;
243 	struct uverbs_obj_attr *o_attr;
244 
245 	switch (spec->type) {
246 	case UVERBS_ATTR_TYPE_ENUM_IN:
247 		if (uattr->attr_data.enum_data.elem_id >= spec->u.enum_def.num_elems)
248 			return -EOPNOTSUPP;
249 
250 		if (uattr->attr_data.enum_data.reserved)
251 			return -EINVAL;
252 
253 		val_spec = &spec->u2.enum_def.ids[uattr->attr_data.enum_data.elem_id];
254 
255 		/* Currently we only support PTR_IN based enums */
256 		if (val_spec->type != UVERBS_ATTR_TYPE_PTR_IN)
257 			return -EOPNOTSUPP;
258 
259 		e->ptr_attr.enum_id = uattr->attr_data.enum_data.elem_id;
260 	/* fall through */
261 	case UVERBS_ATTR_TYPE_PTR_IN:
262 		/* Ensure that any data provided by userspace beyond the known
263 		 * struct is zero. Userspace that knows how to use some future
264 		 * longer struct will fail here if used with an old kernel and
265 		 * non-zero content, making ABI compat/discovery simpler.
266 		 */
267 		if (uattr->len > val_spec->u.ptr.len &&
268 		    val_spec->zero_trailing &&
269 		    !uverbs_is_attr_cleared(uattr, val_spec->u.ptr.len))
270 			return -EOPNOTSUPP;
271 
272 	/* fall through */
273 	case UVERBS_ATTR_TYPE_PTR_OUT:
274 		if (uattr->len < val_spec->u.ptr.min_len ||
275 		    (!val_spec->zero_trailing &&
276 		     uattr->len > val_spec->u.ptr.len))
277 			return -EINVAL;
278 
279 		if (spec->type != UVERBS_ATTR_TYPE_ENUM_IN &&
280 		    uattr->attr_data.reserved)
281 			return -EINVAL;
282 
283 		e->ptr_attr.uattr_idx = uattr - pbundle->uattrs;
284 		e->ptr_attr.len = uattr->len;
285 
286 		if (val_spec->alloc_and_copy && !uverbs_attr_ptr_is_inline(e)) {
287 			void *p;
288 
289 			p = uverbs_alloc(&pbundle->bundle, uattr->len);
290 			if (IS_ERR(p))
291 				return PTR_ERR(p);
292 
293 			e->ptr_attr.ptr = p;
294 
295 			if (copy_from_user(p, u64_to_user_ptr(uattr->data),
296 					   uattr->len))
297 				return -EFAULT;
298 		} else {
299 			e->ptr_attr.data = uattr->data;
300 		}
301 		break;
302 
303 	case UVERBS_ATTR_TYPE_IDR:
304 	case UVERBS_ATTR_TYPE_FD:
305 		if (uattr->attr_data.reserved)
306 			return -EINVAL;
307 
308 		if (uattr->len != 0)
309 			return -EINVAL;
310 
311 		o_attr = &e->obj_attr;
312 		o_attr->attr_elm = attr_uapi;
313 
314 		/*
315 		 * The type of uattr->data is u64 for UVERBS_ATTR_TYPE_IDR and
316 		 * s64 for UVERBS_ATTR_TYPE_FD. We can cast the u64 to s64
317 		 * here without caring about truncation as we know that the
318 		 * IDR implementation today rejects negative IDs
319 		 */
320 		o_attr->uobject = uverbs_get_uobject_from_file(
321 			spec->u.obj.obj_type, spec->u.obj.access,
322 			uattr->data_s64, &pbundle->bundle);
323 		if (IS_ERR(o_attr->uobject))
324 			return PTR_ERR(o_attr->uobject);
325 		__set_bit(attr_bkey, pbundle->uobj_finalize);
326 
327 		if (spec->u.obj.access == UVERBS_ACCESS_NEW) {
328 			unsigned int uattr_idx = uattr - pbundle->uattrs;
329 			s64 id = o_attr->uobject->id;
330 
331 			/* Copy the allocated id to the user-space */
332 			if (put_user(id, &pbundle->user_attrs[uattr_idx].data))
333 				return -EFAULT;
334 		}
335 
336 		break;
337 
338 	case UVERBS_ATTR_TYPE_IDRS_ARRAY:
339 		return uverbs_process_idrs_array(pbundle, attr_uapi,
340 						 &e->objs_arr_attr, uattr,
341 						 attr_bkey);
342 	default:
343 		return -EOPNOTSUPP;
344 	}
345 
346 	return 0;
347 }
348 
349 /*
350  * We search the radix tree with the method prefix and now we want to fast
351  * search the suffix bits to get a particular attribute pointer. It is not
352  * totally clear to me if this breaks the radix tree encasulation or not, but
353  * it uses the iter data to determine if the method iter points at the same
354  * chunk that will store the attribute, if so it just derefs it directly. By
355  * construction in most kernel configs the method and attrs will all fit in a
356  * single radix chunk, so in most cases this will have no search. Other cases
357  * this falls back to a full search.
358  */
359 static void __rcu **uapi_get_attr_for_method(struct bundle_priv *pbundle,
360 					     u32 attr_key)
361 {
362 	void __rcu **slot;
363 
364 	if (likely(attr_key < pbundle->radix_slots_len)) {
365 		void *entry;
366 
367 		slot = pbundle->radix_slots + attr_key;
368 		entry = rcu_dereference_raw(*slot);
369 		if (likely(!radix_tree_is_internal_node(entry) && entry))
370 			return slot;
371 	}
372 
373 	return radix_tree_lookup_slot(pbundle->radix,
374 				      pbundle->method_key | attr_key);
375 }
376 
377 static int uverbs_set_attr(struct bundle_priv *pbundle,
378 			   struct ib_uverbs_attr *uattr)
379 {
380 	u32 attr_key = uapi_key_attr(uattr->attr_id);
381 	u32 attr_bkey = uapi_bkey_attr(attr_key);
382 	const struct uverbs_api_attr *attr;
383 	void __rcu **slot;
384 	int ret;
385 
386 	slot = uapi_get_attr_for_method(pbundle, attr_key);
387 	if (!slot) {
388 		/*
389 		 * Kernel does not support the attribute but user-space says it
390 		 * is mandatory
391 		 */
392 		if (uattr->flags & UVERBS_ATTR_F_MANDATORY)
393 			return -EPROTONOSUPPORT;
394 		return 0;
395 	}
396 	attr = rcu_dereference_protected(*slot, true);
397 
398 	/* Reject duplicate attributes from user-space */
399 	if (test_bit(attr_bkey, pbundle->bundle.attr_present))
400 		return -EINVAL;
401 
402 	ret = uverbs_process_attr(pbundle, attr, uattr, attr_bkey);
403 	if (ret)
404 		return ret;
405 
406 	__set_bit(attr_bkey, pbundle->bundle.attr_present);
407 
408 	return 0;
409 }
410 
411 static int ib_uverbs_run_method(struct bundle_priv *pbundle,
412 				unsigned int num_attrs)
413 {
414 	int (*handler)(struct uverbs_attr_bundle *attrs);
415 	size_t uattrs_size = array_size(sizeof(*pbundle->uattrs), num_attrs);
416 	unsigned int destroy_bkey = pbundle->method_elm->destroy_bkey;
417 	unsigned int i;
418 	int ret;
419 
420 	/* See uverbs_disassociate_api() */
421 	handler = srcu_dereference(
422 		pbundle->method_elm->handler,
423 		&pbundle->bundle.ufile->device->disassociate_srcu);
424 	if (!handler)
425 		return -EIO;
426 
427 	pbundle->uattrs = uverbs_alloc(&pbundle->bundle, uattrs_size);
428 	if (IS_ERR(pbundle->uattrs))
429 		return PTR_ERR(pbundle->uattrs);
430 	if (copy_from_user(pbundle->uattrs, pbundle->user_attrs, uattrs_size))
431 		return -EFAULT;
432 
433 	for (i = 0; i != num_attrs; i++) {
434 		ret = uverbs_set_attr(pbundle, &pbundle->uattrs[i]);
435 		if (unlikely(ret))
436 			return ret;
437 	}
438 
439 	/* User space did not provide all the mandatory attributes */
440 	if (unlikely(!bitmap_subset(pbundle->method_elm->attr_mandatory,
441 				    pbundle->bundle.attr_present,
442 				    pbundle->method_elm->key_bitmap_len)))
443 		return -EINVAL;
444 
445 	if (pbundle->method_elm->has_udata)
446 		uverbs_fill_udata(&pbundle->bundle,
447 				  &pbundle->bundle.driver_udata,
448 				  UVERBS_ATTR_UHW_IN, UVERBS_ATTR_UHW_OUT);
449 	else
450 		pbundle->bundle.driver_udata = (struct ib_udata){};
451 
452 	if (destroy_bkey != UVERBS_API_ATTR_BKEY_LEN) {
453 		struct uverbs_obj_attr *destroy_attr =
454 			&pbundle->bundle.attrs[destroy_bkey].obj_attr;
455 
456 		ret = uobj_destroy(destroy_attr->uobject, &pbundle->bundle);
457 		if (ret)
458 			return ret;
459 		__clear_bit(destroy_bkey, pbundle->uobj_finalize);
460 
461 		ret = handler(&pbundle->bundle);
462 		uobj_put_destroy(destroy_attr->uobject);
463 	} else {
464 		ret = handler(&pbundle->bundle);
465 	}
466 
467 	/*
468 	 * Until the drivers are revised to use the bundle directly we have to
469 	 * assume that the driver wrote to its UHW_OUT and flag userspace
470 	 * appropriately.
471 	 */
472 	if (!ret && pbundle->method_elm->has_udata) {
473 		const struct uverbs_attr *attr =
474 			uverbs_attr_get(&pbundle->bundle, UVERBS_ATTR_UHW_OUT);
475 
476 		if (!IS_ERR(attr))
477 			ret = uverbs_set_output(&pbundle->bundle, attr);
478 	}
479 
480 	/*
481 	 * EPROTONOSUPPORT is ONLY to be returned if the ioctl framework can
482 	 * not invoke the method because the request is not supported.  No
483 	 * other cases should return this code.
484 	 */
485 	if (WARN_ON_ONCE(ret == -EPROTONOSUPPORT))
486 		return -EINVAL;
487 
488 	return ret;
489 }
490 
491 static void bundle_destroy(struct bundle_priv *pbundle, bool commit)
492 {
493 	unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len;
494 	struct bundle_alloc_head *memblock;
495 	unsigned int i;
496 
497 	/* fast path for simple uobjects */
498 	i = -1;
499 	while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
500 				  i + 1)) < key_bitmap_len) {
501 		struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
502 
503 		uverbs_finalize_object(
504 			attr->obj_attr.uobject,
505 			attr->obj_attr.attr_elm->spec.u.obj.access, commit,
506 			&pbundle->bundle);
507 	}
508 
509 	i = -1;
510 	while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len,
511 				  i + 1)) < key_bitmap_len) {
512 		struct uverbs_attr *attr = &pbundle->bundle.attrs[i];
513 		const struct uverbs_api_attr *attr_uapi;
514 		void __rcu **slot;
515 
516 		slot = uapi_get_attr_for_method(
517 			pbundle,
518 			pbundle->method_key | uapi_bkey_to_key_attr(i));
519 		if (WARN_ON(!slot))
520 			continue;
521 
522 		attr_uapi = rcu_dereference_protected(*slot, true);
523 
524 		if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
525 			uverbs_free_idrs_array(attr_uapi, &attr->objs_arr_attr,
526 					       commit, &pbundle->bundle);
527 		}
528 	}
529 
530 	for (memblock = pbundle->allocated_mem; memblock;) {
531 		struct bundle_alloc_head *tmp = memblock;
532 
533 		memblock = memblock->next;
534 		kvfree(tmp);
535 	}
536 }
537 
538 static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
539 			       struct ib_uverbs_ioctl_hdr *hdr,
540 			       struct ib_uverbs_attr __user *user_attrs)
541 {
542 	const struct uverbs_api_ioctl_method *method_elm;
543 	struct uverbs_api *uapi = ufile->device->uapi;
544 	struct radix_tree_iter attrs_iter;
545 	struct bundle_priv *pbundle;
546 	struct bundle_priv onstack;
547 	void __rcu **slot;
548 	int ret;
549 
550 	if (unlikely(hdr->driver_id != uapi->driver_id))
551 		return -EINVAL;
552 
553 	slot = radix_tree_iter_lookup(
554 		&uapi->radix, &attrs_iter,
555 		uapi_key_obj(hdr->object_id) |
556 			uapi_key_ioctl_method(hdr->method_id));
557 	if (unlikely(!slot))
558 		return -EPROTONOSUPPORT;
559 	method_elm = rcu_dereference_protected(*slot, true);
560 
561 	if (!method_elm->use_stack) {
562 		pbundle = kmalloc(method_elm->bundle_size, GFP_KERNEL);
563 		if (!pbundle)
564 			return -ENOMEM;
565 		pbundle->internal_avail =
566 			method_elm->bundle_size -
567 			offsetof(struct bundle_priv, internal_buffer);
568 		pbundle->alloc_head.next = NULL;
569 		pbundle->allocated_mem = &pbundle->alloc_head;
570 	} else {
571 		pbundle = &onstack;
572 		pbundle->internal_avail = sizeof(pbundle->internal_buffer);
573 		pbundle->allocated_mem = NULL;
574 	}
575 
576 	/* Space for the pbundle->bundle.attrs flex array */
577 	pbundle->method_elm = method_elm;
578 	pbundle->method_key = attrs_iter.index;
579 	pbundle->bundle.ufile = ufile;
580 	pbundle->bundle.context = NULL; /* only valid if bundle has uobject */
581 	pbundle->radix = &uapi->radix;
582 	pbundle->radix_slots = slot;
583 	pbundle->radix_slots_len = radix_tree_chunk_size(&attrs_iter);
584 	pbundle->user_attrs = user_attrs;
585 
586 	pbundle->internal_used = ALIGN(pbundle->method_elm->key_bitmap_len *
587 					       sizeof(*pbundle->bundle.attrs),
588 				       sizeof(*pbundle->internal_buffer));
589 	memset(pbundle->bundle.attr_present, 0,
590 	       sizeof(pbundle->bundle.attr_present));
591 	memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize));
592 	memset(pbundle->spec_finalize, 0, sizeof(pbundle->spec_finalize));
593 
594 	ret = ib_uverbs_run_method(pbundle, hdr->num_attrs);
595 	bundle_destroy(pbundle, ret == 0);
596 	return ret;
597 }
598 
599 long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
600 {
601 	struct ib_uverbs_file *file = filp->private_data;
602 	struct ib_uverbs_ioctl_hdr __user *user_hdr =
603 		(struct ib_uverbs_ioctl_hdr __user *)arg;
604 	struct ib_uverbs_ioctl_hdr hdr;
605 	int srcu_key;
606 	int err;
607 
608 	if (unlikely(cmd != RDMA_VERBS_IOCTL))
609 		return -ENOIOCTLCMD;
610 
611 	err = copy_from_user(&hdr, user_hdr, sizeof(hdr));
612 	if (err)
613 		return -EFAULT;
614 
615 	if (hdr.length > PAGE_SIZE ||
616 	    hdr.length != struct_size(&hdr, attrs, hdr.num_attrs))
617 		return -EINVAL;
618 
619 	if (hdr.reserved1 || hdr.reserved2)
620 		return -EPROTONOSUPPORT;
621 
622 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
623 	err = ib_uverbs_cmd_verbs(file, &hdr, user_hdr->attrs);
624 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
625 	return err;
626 }
627 
628 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
629 		       size_t idx, u64 allowed_bits)
630 {
631 	const struct uverbs_attr *attr;
632 	u64 flags;
633 
634 	attr = uverbs_attr_get(attrs_bundle, idx);
635 	/* Missing attribute means 0 flags */
636 	if (IS_ERR(attr)) {
637 		*to = 0;
638 		return 0;
639 	}
640 
641 	/*
642 	 * New userspace code should use 8 bytes to pass flags, but we
643 	 * transparently support old userspaces that were using 4 bytes as
644 	 * well.
645 	 */
646 	if (attr->ptr_attr.len == 8)
647 		flags = attr->ptr_attr.data;
648 	else if (attr->ptr_attr.len == 4)
649 		flags = *(u32 *)&attr->ptr_attr.data;
650 	else
651 		return -EINVAL;
652 
653 	if (flags & ~allowed_bits)
654 		return -EINVAL;
655 
656 	*to = flags;
657 	return 0;
658 }
659 EXPORT_SYMBOL(uverbs_get_flags64);
660 
661 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
662 		       size_t idx, u64 allowed_bits)
663 {
664 	u64 flags;
665 	int ret;
666 
667 	ret = uverbs_get_flags64(&flags, attrs_bundle, idx, allowed_bits);
668 	if (ret)
669 		return ret;
670 
671 	if (flags > U32_MAX)
672 		return -EINVAL;
673 	*to = flags;
674 
675 	return 0;
676 }
677 EXPORT_SYMBOL(uverbs_get_flags32);
678 
679 /*
680  * Fill a ib_udata struct (core or uhw) using the given attribute IDs.
681  * This is primarily used to convert the UVERBS_ATTR_UHW() into the
682  * ib_udata format used by the drivers.
683  */
684 void uverbs_fill_udata(struct uverbs_attr_bundle *bundle,
685 		       struct ib_udata *udata, unsigned int attr_in,
686 		       unsigned int attr_out)
687 {
688 	struct bundle_priv *pbundle =
689 		container_of(bundle, struct bundle_priv, bundle);
690 	const struct uverbs_attr *in =
691 		uverbs_attr_get(&pbundle->bundle, attr_in);
692 	const struct uverbs_attr *out =
693 		uverbs_attr_get(&pbundle->bundle, attr_out);
694 
695 	if (!IS_ERR(in)) {
696 		udata->inlen = in->ptr_attr.len;
697 		if (uverbs_attr_ptr_is_inline(in))
698 			udata->inbuf =
699 				&pbundle->user_attrs[in->ptr_attr.uattr_idx]
700 					 .data;
701 		else
702 			udata->inbuf = u64_to_user_ptr(in->ptr_attr.data);
703 	} else {
704 		udata->inbuf = NULL;
705 		udata->inlen = 0;
706 	}
707 
708 	if (!IS_ERR(out)) {
709 		udata->outbuf = u64_to_user_ptr(out->ptr_attr.data);
710 		udata->outlen = out->ptr_attr.len;
711 	} else {
712 		udata->outbuf = NULL;
713 		udata->outlen = 0;
714 	}
715 }
716 
717 int uverbs_copy_to(const struct uverbs_attr_bundle *bundle, size_t idx,
718 		   const void *from, size_t size)
719 {
720 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
721 	size_t min_size;
722 
723 	if (IS_ERR(attr))
724 		return PTR_ERR(attr);
725 
726 	min_size = min_t(size_t, attr->ptr_attr.len, size);
727 	if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
728 		return -EFAULT;
729 
730 	return uverbs_set_output(bundle, attr);
731 }
732 EXPORT_SYMBOL(uverbs_copy_to);
733 
734 
735 /*
736  * This is only used if the caller has directly used copy_to_use to write the
737  * data.  It signals to user space that the buffer is filled in.
738  */
739 int uverbs_output_written(const struct uverbs_attr_bundle *bundle, size_t idx)
740 {
741 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
742 
743 	if (IS_ERR(attr))
744 		return PTR_ERR(attr);
745 
746 	return uverbs_set_output(bundle, attr);
747 }
748 
749 int _uverbs_get_const(s64 *to, const struct uverbs_attr_bundle *attrs_bundle,
750 		      size_t idx, s64 lower_bound, u64 upper_bound,
751 		      s64  *def_val)
752 {
753 	const struct uverbs_attr *attr;
754 
755 	attr = uverbs_attr_get(attrs_bundle, idx);
756 	if (IS_ERR(attr)) {
757 		if ((PTR_ERR(attr) != -ENOENT) || !def_val)
758 			return PTR_ERR(attr);
759 
760 		*to = *def_val;
761 	} else {
762 		*to = attr->ptr_attr.data;
763 	}
764 
765 	if (*to < lower_bound || (*to > 0 && (u64)*to > upper_bound))
766 		return -EINVAL;
767 
768 	return 0;
769 }
770 EXPORT_SYMBOL(_uverbs_get_const);
771 
772 int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
773 				  size_t idx, const void *from, size_t size)
774 {
775 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
776 
777 	if (IS_ERR(attr))
778 		return PTR_ERR(attr);
779 
780 	if (size < attr->ptr_attr.len) {
781 		if (clear_user(u64_to_user_ptr(attr->ptr_attr.data) + size,
782 			       attr->ptr_attr.len - size))
783 			return -EFAULT;
784 	}
785 	return uverbs_copy_to(bundle, idx, from, size);
786 }
787