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_group_tagged(bundle_alloc_head_hdr, hdr,
40 		struct bundle_alloc_head *next;
41 	);
42 	u8 data[];
43 };
44 
45 struct bundle_priv {
46 	/* Must be first */
47 	struct bundle_alloc_head_hdr alloc_head;
48 	struct bundle_alloc_head *allocated_mem;
49 	size_t internal_avail;
50 	size_t internal_used;
51 
52 	struct radix_tree_root *radix;
53 	const struct uverbs_api_ioctl_method *method_elm;
54 	void __rcu **radix_slots;
55 	unsigned long radix_slots_len;
56 	u32 method_key;
57 
58 	struct ib_uverbs_attr __user *user_attrs;
59 	struct ib_uverbs_attr *uattrs;
60 
61 	DECLARE_BITMAP(uobj_finalize, UVERBS_API_ATTR_BKEY_LEN);
62 	DECLARE_BITMAP(spec_finalize, UVERBS_API_ATTR_BKEY_LEN);
63 	DECLARE_BITMAP(uobj_hw_obj_valid, UVERBS_API_ATTR_BKEY_LEN);
64 
65 	/*
66 	 * Must be last. bundle ends in a flex array which overlaps
67 	 * internal_buffer.
68 	 */
69 	struct uverbs_attr_bundle_hdr bundle;
70 	u64 internal_buffer[32];
71 };
72 
73 /*
74  * Each method has an absolute minimum amount of memory it needs to allocate,
75  * precompute that amount and determine if the onstack memory can be used or
76  * if allocation is need.
77  */
78 void uapi_compute_bundle_size(struct uverbs_api_ioctl_method *method_elm,
79 			      unsigned int num_attrs)
80 {
81 	struct bundle_priv *pbundle;
82 	struct uverbs_attr_bundle *bundle;
83 	size_t bundle_size =
84 		offsetof(struct bundle_priv, internal_buffer) +
85 		sizeof(*bundle->attrs) * method_elm->key_bitmap_len +
86 		sizeof(*pbundle->uattrs) * num_attrs;
87 
88 	method_elm->use_stack = bundle_size <= sizeof(*pbundle);
89 	method_elm->bundle_size =
90 		ALIGN(bundle_size + 256, sizeof(*pbundle->internal_buffer));
91 
92 	/* Do not want order-2 allocations for this. */
93 	WARN_ON_ONCE(method_elm->bundle_size > PAGE_SIZE);
94 }
95 
96 /**
97  * _uverbs_alloc() - Quickly allocate memory for use with a bundle
98  * @bundle: The bundle
99  * @size: Number of bytes to allocate
100  * @flags: Allocator flags
101  *
102  * The bundle allocator is intended for allocations that are connected with
103  * processing the system call related to the bundle. The allocated memory is
104  * always freed once the system call completes, and cannot be freed any other
105  * way.
106  *
107  * This tries to use a small pool of pre-allocated memory for performance.
108  */
109 __malloc void *_uverbs_alloc(struct uverbs_attr_bundle *bundle, size_t size,
110 			     gfp_t flags)
111 {
112 	struct bundle_priv *pbundle =
113 		container_of(&bundle->hdr, struct bundle_priv, bundle);
114 	size_t new_used;
115 	void *res;
116 
117 	if (check_add_overflow(size, pbundle->internal_used, &new_used))
118 		return ERR_PTR(-EOVERFLOW);
119 
120 	if (new_used > pbundle->internal_avail) {
121 		struct bundle_alloc_head *buf;
122 
123 		buf = kvmalloc(struct_size(buf, data, size), flags);
124 		if (!buf)
125 			return ERR_PTR(-ENOMEM);
126 		buf->next = pbundle->allocated_mem;
127 		pbundle->allocated_mem = buf;
128 		return buf->data;
129 	}
130 
131 	res = (void *)pbundle->internal_buffer + pbundle->internal_used;
132 	pbundle->internal_used =
133 		ALIGN(new_used, sizeof(*pbundle->internal_buffer));
134 	if (want_init_on_alloc(flags))
135 		memset(res, 0, size);
136 	return res;
137 }
138 EXPORT_SYMBOL(_uverbs_alloc);
139 
140 static bool uverbs_is_attr_cleared(const struct ib_uverbs_attr *uattr,
141 				   u16 len)
142 {
143 	if (uattr->len > sizeof_field(struct ib_uverbs_attr, data))
144 		return ib_is_buffer_cleared(u64_to_user_ptr(uattr->data) + len,
145 					    uattr->len - len);
146 
147 	return !memchr_inv((const void *)&uattr->data + len,
148 			   0, uattr->len - len);
149 }
150 
151 static int uverbs_set_output(const struct uverbs_attr_bundle *bundle,
152 			     const struct uverbs_attr *attr)
153 {
154 	struct bundle_priv *pbundle =
155 		container_of(&bundle->hdr, struct bundle_priv, bundle);
156 	u16 flags;
157 
158 	flags = pbundle->uattrs[attr->ptr_attr.uattr_idx].flags |
159 		UVERBS_ATTR_F_VALID_OUTPUT;
160 	if (put_user(flags,
161 		     &pbundle->user_attrs[attr->ptr_attr.uattr_idx].flags))
162 		return -EFAULT;
163 	return 0;
164 }
165 
166 static int uverbs_process_idrs_array(struct bundle_priv *pbundle,
167 				     const struct uverbs_api_attr *attr_uapi,
168 				     struct uverbs_objs_arr_attr *attr,
169 				     struct ib_uverbs_attr *uattr,
170 				     u32 attr_bkey)
171 {
172 	struct uverbs_attr_bundle *bundle =
173 		container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
174 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
175 	size_t array_len;
176 	u32 *idr_vals;
177 	int ret = 0;
178 	size_t i;
179 
180 	if (uattr->attr_data.reserved)
181 		return -EINVAL;
182 
183 	if (uattr->len % sizeof(u32))
184 		return -EINVAL;
185 
186 	array_len = uattr->len / sizeof(u32);
187 	if (array_len < spec->u2.objs_arr.min_len ||
188 	    array_len > spec->u2.objs_arr.max_len)
189 		return -EINVAL;
190 
191 	attr->uobjects =
192 		uverbs_alloc(bundle,
193 			     array_size(array_len, sizeof(*attr->uobjects)));
194 	if (IS_ERR(attr->uobjects))
195 		return PTR_ERR(attr->uobjects);
196 
197 	/*
198 	 * Since idr is 4B and *uobjects is >= 4B, we can use attr->uobjects
199 	 * to store idrs array and avoid additional memory allocation. The
200 	 * idrs array is offset to the end of the uobjects array so we will be
201 	 * able to read idr and replace with a pointer.
202 	 */
203 	idr_vals = (u32 *)(attr->uobjects + array_len) - array_len;
204 
205 	if (uattr->len > sizeof(uattr->data)) {
206 		ret = copy_from_user(idr_vals, u64_to_user_ptr(uattr->data),
207 				     uattr->len);
208 		if (ret)
209 			return -EFAULT;
210 	} else {
211 		memcpy(idr_vals, &uattr->data, uattr->len);
212 	}
213 
214 	for (i = 0; i != array_len; i++) {
215 		attr->uobjects[i] = uverbs_get_uobject_from_file(
216 			spec->u2.objs_arr.obj_type, spec->u2.objs_arr.access,
217 			idr_vals[i], bundle);
218 		if (IS_ERR(attr->uobjects[i])) {
219 			ret = PTR_ERR(attr->uobjects[i]);
220 			break;
221 		}
222 	}
223 
224 	attr->len = i;
225 	__set_bit(attr_bkey, pbundle->spec_finalize);
226 	return ret;
227 }
228 
229 static void uverbs_free_idrs_array(const struct uverbs_api_attr *attr_uapi,
230 				   struct uverbs_objs_arr_attr *attr,
231 				   bool commit,
232 				   struct uverbs_attr_bundle *attrs)
233 {
234 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
235 	size_t i;
236 
237 	for (i = 0; i != attr->len; i++)
238 		uverbs_finalize_object(attr->uobjects[i],
239 				       spec->u2.objs_arr.access, false, commit,
240 				       attrs);
241 }
242 
243 static int uverbs_process_attr(struct bundle_priv *pbundle,
244 			       const struct uverbs_api_attr *attr_uapi,
245 			       struct ib_uverbs_attr *uattr, u32 attr_bkey)
246 {
247 	const struct uverbs_attr_spec *spec = &attr_uapi->spec;
248 	struct uverbs_attr_bundle *bundle =
249 		container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
250 	struct uverbs_attr *e = &bundle->attrs[attr_bkey];
251 	const struct uverbs_attr_spec *val_spec = spec;
252 	struct uverbs_obj_attr *o_attr;
253 
254 	switch (spec->type) {
255 	case UVERBS_ATTR_TYPE_ENUM_IN:
256 		if (uattr->attr_data.enum_data.elem_id >= spec->u.enum_def.num_elems)
257 			return -EOPNOTSUPP;
258 
259 		if (uattr->attr_data.enum_data.reserved)
260 			return -EINVAL;
261 
262 		val_spec = &spec->u2.enum_def.ids[uattr->attr_data.enum_data.elem_id];
263 
264 		/* Currently we only support PTR_IN based enums */
265 		if (val_spec->type != UVERBS_ATTR_TYPE_PTR_IN)
266 			return -EOPNOTSUPP;
267 
268 		e->ptr_attr.enum_id = uattr->attr_data.enum_data.elem_id;
269 		fallthrough;
270 	case UVERBS_ATTR_TYPE_PTR_IN:
271 		/* Ensure that any data provided by userspace beyond the known
272 		 * struct is zero. Userspace that knows how to use some future
273 		 * longer struct will fail here if used with an old kernel and
274 		 * non-zero content, making ABI compat/discovery simpler.
275 		 */
276 		if (uattr->len > val_spec->u.ptr.len &&
277 		    val_spec->zero_trailing &&
278 		    !uverbs_is_attr_cleared(uattr, val_spec->u.ptr.len))
279 			return -EOPNOTSUPP;
280 
281 		fallthrough;
282 	case UVERBS_ATTR_TYPE_PTR_OUT:
283 		if (uattr->len < val_spec->u.ptr.min_len ||
284 		    (!val_spec->zero_trailing &&
285 		     uattr->len > val_spec->u.ptr.len))
286 			return -EINVAL;
287 
288 		if (spec->type != UVERBS_ATTR_TYPE_ENUM_IN &&
289 		    uattr->attr_data.reserved)
290 			return -EINVAL;
291 
292 		e->ptr_attr.uattr_idx = uattr - pbundle->uattrs;
293 		e->ptr_attr.len = uattr->len;
294 
295 		if (val_spec->alloc_and_copy && !uverbs_attr_ptr_is_inline(e)) {
296 			void *p;
297 
298 			p = uverbs_alloc(bundle, uattr->len);
299 			if (IS_ERR(p))
300 				return PTR_ERR(p);
301 
302 			e->ptr_attr.ptr = p;
303 
304 			if (copy_from_user(p, u64_to_user_ptr(uattr->data),
305 					   uattr->len))
306 				return -EFAULT;
307 		} else {
308 			e->ptr_attr.data = uattr->data;
309 		}
310 		break;
311 
312 	case UVERBS_ATTR_TYPE_IDR:
313 	case UVERBS_ATTR_TYPE_FD:
314 		if (uattr->attr_data.reserved)
315 			return -EINVAL;
316 
317 		if (uattr->len != 0)
318 			return -EINVAL;
319 
320 		o_attr = &e->obj_attr;
321 		o_attr->attr_elm = attr_uapi;
322 
323 		/*
324 		 * The type of uattr->data is u64 for UVERBS_ATTR_TYPE_IDR and
325 		 * s64 for UVERBS_ATTR_TYPE_FD. We can cast the u64 to s64
326 		 * here without caring about truncation as we know that the
327 		 * IDR implementation today rejects negative IDs
328 		 */
329 		o_attr->uobject = uverbs_get_uobject_from_file(
330 			spec->u.obj.obj_type, spec->u.obj.access,
331 			uattr->data_s64, bundle);
332 		if (IS_ERR(o_attr->uobject))
333 			return PTR_ERR(o_attr->uobject);
334 		__set_bit(attr_bkey, pbundle->uobj_finalize);
335 
336 		if (spec->u.obj.access == UVERBS_ACCESS_NEW) {
337 			unsigned int uattr_idx = uattr - pbundle->uattrs;
338 			s64 id = o_attr->uobject->id;
339 
340 			/* Copy the allocated id to the user-space */
341 			if (put_user(id, &pbundle->user_attrs[uattr_idx].data))
342 				return -EFAULT;
343 		}
344 
345 		break;
346 
347 	case UVERBS_ATTR_TYPE_RAW_FD:
348 		if (uattr->attr_data.reserved || uattr->len != 0 ||
349 		    uattr->data_s64 < INT_MIN || uattr->data_s64 > INT_MAX)
350 			return -EINVAL;
351 		/* _uverbs_get_const_signed() is the accessor */
352 		e->ptr_attr.data = uattr->data_s64;
353 		break;
354 
355 	case UVERBS_ATTR_TYPE_IDRS_ARRAY:
356 		return uverbs_process_idrs_array(pbundle, attr_uapi,
357 						 &e->objs_arr_attr, uattr,
358 						 attr_bkey);
359 	default:
360 		return -EOPNOTSUPP;
361 	}
362 
363 	return 0;
364 }
365 
366 /*
367  * We search the radix tree with the method prefix and now we want to fast
368  * search the suffix bits to get a particular attribute pointer. It is not
369  * totally clear to me if this breaks the radix tree encasulation or not, but
370  * it uses the iter data to determine if the method iter points at the same
371  * chunk that will store the attribute, if so it just derefs it directly. By
372  * construction in most kernel configs the method and attrs will all fit in a
373  * single radix chunk, so in most cases this will have no search. Other cases
374  * this falls back to a full search.
375  */
376 static void __rcu **uapi_get_attr_for_method(struct bundle_priv *pbundle,
377 					     u32 attr_key)
378 {
379 	void __rcu **slot;
380 
381 	if (likely(attr_key < pbundle->radix_slots_len)) {
382 		void *entry;
383 
384 		slot = pbundle->radix_slots + attr_key;
385 		entry = rcu_dereference_raw(*slot);
386 		if (likely(!radix_tree_is_internal_node(entry) && entry))
387 			return slot;
388 	}
389 
390 	return radix_tree_lookup_slot(pbundle->radix,
391 				      pbundle->method_key | attr_key);
392 }
393 
394 static int uverbs_set_attr(struct bundle_priv *pbundle,
395 			   struct ib_uverbs_attr *uattr)
396 {
397 	u32 attr_key = uapi_key_attr(uattr->attr_id);
398 	u32 attr_bkey = uapi_bkey_attr(attr_key);
399 	const struct uverbs_api_attr *attr;
400 	void __rcu **slot;
401 	int ret;
402 
403 	slot = uapi_get_attr_for_method(pbundle, attr_key);
404 	if (!slot) {
405 		/*
406 		 * Kernel does not support the attribute but user-space says it
407 		 * is mandatory
408 		 */
409 		if (uattr->flags & UVERBS_ATTR_F_MANDATORY)
410 			return -EPROTONOSUPPORT;
411 		return 0;
412 	}
413 	attr = rcu_dereference_protected(*slot, true);
414 
415 	/* Reject duplicate attributes from user-space */
416 	if (test_bit(attr_bkey, pbundle->bundle.attr_present))
417 		return -EINVAL;
418 
419 	ret = uverbs_process_attr(pbundle, attr, uattr, attr_bkey);
420 	if (ret)
421 		return ret;
422 
423 	__set_bit(attr_bkey, pbundle->bundle.attr_present);
424 
425 	return 0;
426 }
427 
428 static int ib_uverbs_run_method(struct bundle_priv *pbundle,
429 				unsigned int num_attrs)
430 {
431 	int (*handler)(struct uverbs_attr_bundle *attrs);
432 	struct uverbs_attr_bundle *bundle =
433 		container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
434 	size_t uattrs_size = array_size(sizeof(*pbundle->uattrs), num_attrs);
435 	unsigned int destroy_bkey = pbundle->method_elm->destroy_bkey;
436 	unsigned int i;
437 	int ret;
438 
439 	/* See uverbs_disassociate_api() */
440 	handler = srcu_dereference(
441 		pbundle->method_elm->handler,
442 		&pbundle->bundle.ufile->device->disassociate_srcu);
443 	if (!handler)
444 		return -EIO;
445 
446 	pbundle->uattrs = uverbs_alloc(bundle, uattrs_size);
447 	if (IS_ERR(pbundle->uattrs))
448 		return PTR_ERR(pbundle->uattrs);
449 	if (copy_from_user(pbundle->uattrs, pbundle->user_attrs, uattrs_size))
450 		return -EFAULT;
451 
452 	for (i = 0; i != num_attrs; i++) {
453 		ret = uverbs_set_attr(pbundle, &pbundle->uattrs[i]);
454 		if (unlikely(ret))
455 			return ret;
456 	}
457 
458 	/* User space did not provide all the mandatory attributes */
459 	if (unlikely(!bitmap_subset(pbundle->method_elm->attr_mandatory,
460 				    pbundle->bundle.attr_present,
461 				    pbundle->method_elm->key_bitmap_len)))
462 		return -EINVAL;
463 
464 	if (pbundle->method_elm->has_udata)
465 		uverbs_fill_udata(bundle, &pbundle->bundle.driver_udata,
466 				  UVERBS_ATTR_UHW_IN, UVERBS_ATTR_UHW_OUT);
467 	else
468 		pbundle->bundle.driver_udata = (struct ib_udata){};
469 
470 	if (destroy_bkey != UVERBS_API_ATTR_BKEY_LEN) {
471 		struct uverbs_obj_attr *destroy_attr = &bundle->attrs[destroy_bkey].obj_attr;
472 
473 		ret = uobj_destroy(destroy_attr->uobject, bundle);
474 		if (ret)
475 			return ret;
476 		__clear_bit(destroy_bkey, pbundle->uobj_finalize);
477 
478 		ret = handler(bundle);
479 		uobj_put_destroy(destroy_attr->uobject);
480 	} else {
481 		ret = handler(bundle);
482 	}
483 
484 	/*
485 	 * Until the drivers are revised to use the bundle directly we have to
486 	 * assume that the driver wrote to its UHW_OUT and flag userspace
487 	 * appropriately.
488 	 */
489 	if (!ret && pbundle->method_elm->has_udata) {
490 		const struct uverbs_attr *attr =
491 			uverbs_attr_get(bundle, UVERBS_ATTR_UHW_OUT);
492 
493 		if (!IS_ERR(attr))
494 			ret = uverbs_set_output(bundle, attr);
495 	}
496 
497 	/*
498 	 * EPROTONOSUPPORT is ONLY to be returned if the ioctl framework can
499 	 * not invoke the method because the request is not supported.  No
500 	 * other cases should return this code.
501 	 */
502 	if (WARN_ON_ONCE(ret == -EPROTONOSUPPORT))
503 		return -EINVAL;
504 
505 	return ret;
506 }
507 
508 static void bundle_destroy(struct bundle_priv *pbundle, bool commit)
509 {
510 	unsigned int key_bitmap_len = pbundle->method_elm->key_bitmap_len;
511 	struct uverbs_attr_bundle *bundle =
512 		container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
513 	struct bundle_alloc_head *memblock;
514 	unsigned int i;
515 
516 	/* fast path for simple uobjects */
517 	i = -1;
518 	while ((i = find_next_bit(pbundle->uobj_finalize, key_bitmap_len,
519 				  i + 1)) < key_bitmap_len) {
520 		struct uverbs_attr *attr = &bundle->attrs[i];
521 
522 		uverbs_finalize_object(
523 			attr->obj_attr.uobject,
524 			attr->obj_attr.attr_elm->spec.u.obj.access,
525 			test_bit(i, pbundle->uobj_hw_obj_valid),
526 			commit, bundle);
527 	}
528 
529 	i = -1;
530 	while ((i = find_next_bit(pbundle->spec_finalize, key_bitmap_len,
531 				  i + 1)) < key_bitmap_len) {
532 		struct uverbs_attr *attr = &bundle->attrs[i];
533 		const struct uverbs_api_attr *attr_uapi;
534 		void __rcu **slot;
535 
536 		slot = uapi_get_attr_for_method(
537 			pbundle,
538 			pbundle->method_key | uapi_bkey_to_key_attr(i));
539 		if (WARN_ON(!slot))
540 			continue;
541 
542 		attr_uapi = rcu_dereference_protected(*slot, true);
543 
544 		if (attr_uapi->spec.type == UVERBS_ATTR_TYPE_IDRS_ARRAY) {
545 			uverbs_free_idrs_array(attr_uapi, &attr->objs_arr_attr,
546 					       commit, bundle);
547 		}
548 	}
549 
550 	for (memblock = pbundle->allocated_mem; memblock;) {
551 		struct bundle_alloc_head *tmp = memblock;
552 
553 		memblock = memblock->next;
554 		kvfree(tmp);
555 	}
556 }
557 
558 static int ib_uverbs_cmd_verbs(struct ib_uverbs_file *ufile,
559 			       struct ib_uverbs_ioctl_hdr *hdr,
560 			       struct ib_uverbs_attr __user *user_attrs)
561 {
562 	const struct uverbs_api_ioctl_method *method_elm;
563 	struct uverbs_api *uapi = ufile->device->uapi;
564 	struct radix_tree_iter attrs_iter;
565 	struct bundle_priv *pbundle;
566 	struct bundle_priv onstack;
567 	void __rcu **slot;
568 	int ret;
569 
570 	if (unlikely(hdr->driver_id != uapi->driver_id))
571 		return -EINVAL;
572 
573 	slot = radix_tree_iter_lookup(
574 		&uapi->radix, &attrs_iter,
575 		uapi_key_obj(hdr->object_id) |
576 			uapi_key_ioctl_method(hdr->method_id));
577 	if (unlikely(!slot))
578 		return -EPROTONOSUPPORT;
579 	method_elm = rcu_dereference_protected(*slot, true);
580 
581 	if (!method_elm->use_stack) {
582 		pbundle = kmalloc(method_elm->bundle_size, GFP_KERNEL);
583 		if (!pbundle)
584 			return -ENOMEM;
585 		pbundle->internal_avail =
586 			method_elm->bundle_size -
587 			offsetof(struct bundle_priv, internal_buffer);
588 		pbundle->alloc_head.next = NULL;
589 		pbundle->allocated_mem = container_of(&pbundle->alloc_head,
590 						struct bundle_alloc_head, hdr);
591 	} else {
592 		pbundle = &onstack;
593 		pbundle->internal_avail = sizeof(pbundle->internal_buffer);
594 		pbundle->allocated_mem = NULL;
595 	}
596 
597 	/* Space for the pbundle->bundle.attrs flex array */
598 	pbundle->method_elm = method_elm;
599 	pbundle->method_key = attrs_iter.index;
600 	pbundle->bundle.ufile = ufile;
601 	pbundle->bundle.context = NULL; /* only valid if bundle has uobject */
602 	pbundle->radix = &uapi->radix;
603 	pbundle->radix_slots = slot;
604 	pbundle->radix_slots_len = radix_tree_chunk_size(&attrs_iter);
605 	pbundle->user_attrs = user_attrs;
606 
607 	pbundle->internal_used = ALIGN(pbundle->method_elm->key_bitmap_len *
608 					       sizeof(*container_of(&pbundle->bundle,
609 							struct uverbs_attr_bundle, hdr)->attrs),
610 					       sizeof(*pbundle->internal_buffer));
611 	memset(pbundle->bundle.attr_present, 0,
612 	       sizeof(pbundle->bundle.attr_present));
613 	memset(pbundle->uobj_finalize, 0, sizeof(pbundle->uobj_finalize));
614 	memset(pbundle->spec_finalize, 0, sizeof(pbundle->spec_finalize));
615 	memset(pbundle->uobj_hw_obj_valid, 0,
616 	       sizeof(pbundle->uobj_hw_obj_valid));
617 
618 	ret = ib_uverbs_run_method(pbundle, hdr->num_attrs);
619 	bundle_destroy(pbundle, ret == 0);
620 	return ret;
621 }
622 
623 long ib_uverbs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
624 {
625 	struct ib_uverbs_file *file = filp->private_data;
626 	struct ib_uverbs_ioctl_hdr __user *user_hdr =
627 		(struct ib_uverbs_ioctl_hdr __user *)arg;
628 	struct ib_uverbs_ioctl_hdr hdr;
629 	int srcu_key;
630 	int err;
631 
632 	if (unlikely(cmd != RDMA_VERBS_IOCTL))
633 		return -ENOIOCTLCMD;
634 
635 	err = copy_from_user(&hdr, user_hdr, sizeof(hdr));
636 	if (err)
637 		return -EFAULT;
638 
639 	if (hdr.length > PAGE_SIZE ||
640 	    hdr.length != struct_size(&hdr, attrs, hdr.num_attrs))
641 		return -EINVAL;
642 
643 	if (hdr.reserved1 || hdr.reserved2)
644 		return -EPROTONOSUPPORT;
645 
646 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
647 	err = ib_uverbs_cmd_verbs(file, &hdr, user_hdr->attrs);
648 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
649 	return err;
650 }
651 
652 int uverbs_get_flags64(u64 *to, const struct uverbs_attr_bundle *attrs_bundle,
653 		       size_t idx, u64 allowed_bits)
654 {
655 	const struct uverbs_attr *attr;
656 	u64 flags;
657 
658 	attr = uverbs_attr_get(attrs_bundle, idx);
659 	/* Missing attribute means 0 flags */
660 	if (IS_ERR(attr)) {
661 		*to = 0;
662 		return 0;
663 	}
664 
665 	/*
666 	 * New userspace code should use 8 bytes to pass flags, but we
667 	 * transparently support old userspaces that were using 4 bytes as
668 	 * well.
669 	 */
670 	if (attr->ptr_attr.len == 8)
671 		flags = attr->ptr_attr.data;
672 	else if (attr->ptr_attr.len == 4)
673 		flags = *(u32 *)&attr->ptr_attr.data;
674 	else
675 		return -EINVAL;
676 
677 	if (flags & ~allowed_bits)
678 		return -EINVAL;
679 
680 	*to = flags;
681 	return 0;
682 }
683 EXPORT_SYMBOL(uverbs_get_flags64);
684 
685 int uverbs_get_flags32(u32 *to, const struct uverbs_attr_bundle *attrs_bundle,
686 		       size_t idx, u64 allowed_bits)
687 {
688 	u64 flags;
689 	int ret;
690 
691 	ret = uverbs_get_flags64(&flags, attrs_bundle, idx, allowed_bits);
692 	if (ret)
693 		return ret;
694 
695 	if (flags > U32_MAX)
696 		return -EINVAL;
697 	*to = flags;
698 
699 	return 0;
700 }
701 EXPORT_SYMBOL(uverbs_get_flags32);
702 
703 /*
704  * Fill a ib_udata struct (core or uhw) using the given attribute IDs.
705  * This is primarily used to convert the UVERBS_ATTR_UHW() into the
706  * ib_udata format used by the drivers.
707  */
708 void uverbs_fill_udata(struct uverbs_attr_bundle *bundle,
709 		       struct ib_udata *udata, unsigned int attr_in,
710 		       unsigned int attr_out)
711 {
712 	struct bundle_priv *pbundle =
713 		container_of(&bundle->hdr, struct bundle_priv, bundle);
714 	struct uverbs_attr_bundle *bundle_aux =
715 		container_of(&pbundle->bundle, struct uverbs_attr_bundle, hdr);
716 	const struct uverbs_attr *in =
717 		uverbs_attr_get(bundle_aux, attr_in);
718 	const struct uverbs_attr *out =
719 		uverbs_attr_get(bundle_aux, attr_out);
720 
721 	if (!IS_ERR(in)) {
722 		udata->inlen = in->ptr_attr.len;
723 		if (uverbs_attr_ptr_is_inline(in))
724 			udata->inbuf =
725 				&pbundle->user_attrs[in->ptr_attr.uattr_idx]
726 					 .data;
727 		else
728 			udata->inbuf = u64_to_user_ptr(in->ptr_attr.data);
729 	} else {
730 		udata->inbuf = NULL;
731 		udata->inlen = 0;
732 	}
733 
734 	if (!IS_ERR(out)) {
735 		udata->outbuf = u64_to_user_ptr(out->ptr_attr.data);
736 		udata->outlen = out->ptr_attr.len;
737 	} else {
738 		udata->outbuf = NULL;
739 		udata->outlen = 0;
740 	}
741 }
742 
743 int uverbs_copy_to(const struct uverbs_attr_bundle *bundle, size_t idx,
744 		   const void *from, size_t size)
745 {
746 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
747 	size_t min_size;
748 
749 	if (IS_ERR(attr))
750 		return PTR_ERR(attr);
751 
752 	min_size = min_t(size_t, attr->ptr_attr.len, size);
753 	if (copy_to_user(u64_to_user_ptr(attr->ptr_attr.data), from, min_size))
754 		return -EFAULT;
755 
756 	return uverbs_set_output(bundle, attr);
757 }
758 EXPORT_SYMBOL(uverbs_copy_to);
759 
760 
761 /*
762  * This is only used if the caller has directly used copy_to_use to write the
763  * data.  It signals to user space that the buffer is filled in.
764  */
765 int uverbs_output_written(const struct uverbs_attr_bundle *bundle, size_t idx)
766 {
767 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
768 
769 	if (IS_ERR(attr))
770 		return PTR_ERR(attr);
771 
772 	return uverbs_set_output(bundle, attr);
773 }
774 
775 int _uverbs_get_const_signed(s64 *to,
776 			     const struct uverbs_attr_bundle *attrs_bundle,
777 			     size_t idx, s64 lower_bound, u64 upper_bound,
778 			     s64  *def_val)
779 {
780 	const struct uverbs_attr *attr;
781 
782 	attr = uverbs_attr_get(attrs_bundle, idx);
783 	if (IS_ERR(attr)) {
784 		if ((PTR_ERR(attr) != -ENOENT) || !def_val)
785 			return PTR_ERR(attr);
786 
787 		*to = *def_val;
788 	} else {
789 		*to = attr->ptr_attr.data;
790 	}
791 
792 	if (*to < lower_bound || (*to > 0 && (u64)*to > upper_bound))
793 		return -EINVAL;
794 
795 	return 0;
796 }
797 EXPORT_SYMBOL(_uverbs_get_const_signed);
798 
799 int _uverbs_get_const_unsigned(u64 *to,
800 			       const struct uverbs_attr_bundle *attrs_bundle,
801 			       size_t idx, u64 upper_bound, u64 *def_val)
802 {
803 	const struct uverbs_attr *attr;
804 
805 	attr = uverbs_attr_get(attrs_bundle, idx);
806 	if (IS_ERR(attr)) {
807 		if ((PTR_ERR(attr) != -ENOENT) || !def_val)
808 			return PTR_ERR(attr);
809 
810 		*to = *def_val;
811 	} else {
812 		*to = attr->ptr_attr.data;
813 	}
814 
815 	if (*to > upper_bound)
816 		return -EINVAL;
817 
818 	return 0;
819 }
820 EXPORT_SYMBOL(_uverbs_get_const_unsigned);
821 
822 int uverbs_copy_to_struct_or_zero(const struct uverbs_attr_bundle *bundle,
823 				  size_t idx, const void *from, size_t size)
824 {
825 	const struct uverbs_attr *attr = uverbs_attr_get(bundle, idx);
826 
827 	if (IS_ERR(attr))
828 		return PTR_ERR(attr);
829 
830 	if (size < attr->ptr_attr.len) {
831 		if (clear_user(u64_to_user_ptr(attr->ptr_attr.data) + size,
832 			       attr->ptr_attr.len - size))
833 			return -EFAULT;
834 	}
835 	return uverbs_copy_to(bundle, idx, from, size);
836 }
837 EXPORT_SYMBOL(uverbs_copy_to_struct_or_zero);
838 
839 /* Once called an abort will call through to the type's destroy_hw() */
840 void uverbs_finalize_uobj_create(const struct uverbs_attr_bundle *bundle,
841 				 u16 idx)
842 {
843 	struct bundle_priv *pbundle =
844 		container_of(&bundle->hdr, struct bundle_priv, bundle);
845 
846 	__set_bit(uapi_bkey_attr(uapi_key_attr(idx)),
847 		  pbundle->uobj_hw_obj_valid);
848 }
849 EXPORT_SYMBOL(uverbs_finalize_uobj_create);
850