xref: /linux/drivers/infiniband/core/uverbs_main.c (revision 5e3992fe72748ed3892be876f09d4d990548b7af)
1 /*
2  * Copyright (c) 2005 Topspin Communications.  All rights reserved.
3  * Copyright (c) 2005, 2006 Cisco Systems.  All rights reserved.
4  * Copyright (c) 2005 Mellanox Technologies. All rights reserved.
5  * Copyright (c) 2005 Voltaire, Inc. All rights reserved.
6  * Copyright (c) 2005 PathScale, Inc. All rights reserved.
7  *
8  * This software is available to you under a choice of one of two
9  * licenses.  You may choose to be licensed under the terms of the GNU
10  * General Public License (GPL) Version 2, available from the file
11  * COPYING in the main directory of this source tree, or the
12  * OpenIB.org BSD license below:
13  *
14  *     Redistribution and use in source and binary forms, with or
15  *     without modification, are permitted provided that the following
16  *     conditions are met:
17  *
18  *      - Redistributions of source code must retain the above
19  *        copyright notice, this list of conditions and the following
20  *        disclaimer.
21  *
22  *      - Redistributions in binary form must reproduce the above
23  *        copyright notice, this list of conditions and the following
24  *        disclaimer in the documentation and/or other materials
25  *        provided with the distribution.
26  *
27  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
28  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
29  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
30  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
31  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
32  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
33  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
34  * SOFTWARE.
35  */
36 
37 #include <linux/module.h>
38 #include <linux/init.h>
39 #include <linux/device.h>
40 #include <linux/err.h>
41 #include <linux/fs.h>
42 #include <linux/poll.h>
43 #include <linux/sched.h>
44 #include <linux/file.h>
45 #include <linux/cdev.h>
46 #include <linux/anon_inodes.h>
47 #include <linux/slab.h>
48 #include <linux/sched/mm.h>
49 
50 #include <linux/uaccess.h>
51 
52 #include <rdma/ib.h>
53 #include <rdma/uverbs_std_types.h>
54 #include <rdma/rdma_netlink.h>
55 
56 #include "uverbs.h"
57 #include "core_priv.h"
58 #include "rdma_core.h"
59 
60 MODULE_AUTHOR("Roland Dreier");
61 MODULE_DESCRIPTION("InfiniBand userspace verbs access");
62 MODULE_LICENSE("Dual BSD/GPL");
63 
64 enum {
65 	IB_UVERBS_MAJOR       = 231,
66 	IB_UVERBS_BASE_MINOR  = 192,
67 	IB_UVERBS_MAX_DEVICES = RDMA_MAX_PORTS,
68 	IB_UVERBS_NUM_FIXED_MINOR = 32,
69 	IB_UVERBS_NUM_DYNAMIC_MINOR = IB_UVERBS_MAX_DEVICES - IB_UVERBS_NUM_FIXED_MINOR,
70 };
71 
72 #define IB_UVERBS_BASE_DEV	MKDEV(IB_UVERBS_MAJOR, IB_UVERBS_BASE_MINOR)
73 
74 static dev_t dynamic_uverbs_dev;
75 static struct class *uverbs_class;
76 
77 static DEFINE_IDA(uverbs_ida);
78 static int ib_uverbs_add_one(struct ib_device *device);
79 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data);
80 
81 /*
82  * Must be called with the ufile->device->disassociate_srcu held, and the lock
83  * must be held until use of the ucontext is finished.
84  */
85 struct ib_ucontext *ib_uverbs_get_ucontext_file(struct ib_uverbs_file *ufile)
86 {
87 	/*
88 	 * We do not hold the hw_destroy_rwsem lock for this flow, instead
89 	 * srcu is used. It does not matter if someone races this with
90 	 * get_context, we get NULL or valid ucontext.
91 	 */
92 	struct ib_ucontext *ucontext = smp_load_acquire(&ufile->ucontext);
93 
94 	if (!srcu_dereference(ufile->device->ib_dev,
95 			      &ufile->device->disassociate_srcu))
96 		return ERR_PTR(-EIO);
97 
98 	if (!ucontext)
99 		return ERR_PTR(-EINVAL);
100 
101 	return ucontext;
102 }
103 EXPORT_SYMBOL(ib_uverbs_get_ucontext_file);
104 
105 int uverbs_dealloc_mw(struct ib_mw *mw)
106 {
107 	struct ib_pd *pd = mw->pd;
108 	int ret;
109 
110 	ret = mw->device->ops.dealloc_mw(mw);
111 	if (ret)
112 		return ret;
113 
114 	atomic_dec(&pd->usecnt);
115 	kfree(mw);
116 	return ret;
117 }
118 
119 static void ib_uverbs_release_dev(struct device *device)
120 {
121 	struct ib_uverbs_device *dev =
122 			container_of(device, struct ib_uverbs_device, dev);
123 
124 	uverbs_destroy_api(dev->uapi);
125 	cleanup_srcu_struct(&dev->disassociate_srcu);
126 	mutex_destroy(&dev->lists_mutex);
127 	mutex_destroy(&dev->xrcd_tree_mutex);
128 	kfree(dev);
129 }
130 
131 void ib_uverbs_release_ucq(struct ib_uverbs_completion_event_file *ev_file,
132 			   struct ib_ucq_object *uobj)
133 {
134 	struct ib_uverbs_event *evt, *tmp;
135 
136 	if (ev_file) {
137 		spin_lock_irq(&ev_file->ev_queue.lock);
138 		list_for_each_entry_safe(evt, tmp, &uobj->comp_list, obj_list) {
139 			list_del(&evt->list);
140 			kfree(evt);
141 		}
142 		spin_unlock_irq(&ev_file->ev_queue.lock);
143 
144 		uverbs_uobject_put(&ev_file->uobj);
145 	}
146 
147 	ib_uverbs_release_uevent(&uobj->uevent);
148 }
149 
150 void ib_uverbs_release_uevent(struct ib_uevent_object *uobj)
151 {
152 	struct ib_uverbs_async_event_file *async_file = uobj->event_file;
153 	struct ib_uverbs_event *evt, *tmp;
154 
155 	if (!async_file)
156 		return;
157 
158 	spin_lock_irq(&async_file->ev_queue.lock);
159 	list_for_each_entry_safe(evt, tmp, &uobj->event_list, obj_list) {
160 		list_del(&evt->list);
161 		kfree(evt);
162 	}
163 	spin_unlock_irq(&async_file->ev_queue.lock);
164 	uverbs_uobject_put(&async_file->uobj);
165 }
166 
167 void ib_uverbs_detach_umcast(struct ib_qp *qp,
168 			     struct ib_uqp_object *uobj)
169 {
170 	struct ib_uverbs_mcast_entry *mcast, *tmp;
171 
172 	list_for_each_entry_safe(mcast, tmp, &uobj->mcast_list, list) {
173 		ib_detach_mcast(qp, &mcast->gid, mcast->lid);
174 		list_del(&mcast->list);
175 		kfree(mcast);
176 	}
177 }
178 
179 static void ib_uverbs_comp_dev(struct ib_uverbs_device *dev)
180 {
181 	complete(&dev->comp);
182 }
183 
184 void ib_uverbs_release_file(struct kref *ref)
185 {
186 	struct ib_uverbs_file *file =
187 		container_of(ref, struct ib_uverbs_file, ref);
188 	struct ib_device *ib_dev;
189 	int srcu_key;
190 
191 	release_ufile_idr_uobject(file);
192 
193 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
194 	ib_dev = srcu_dereference(file->device->ib_dev,
195 				  &file->device->disassociate_srcu);
196 	if (ib_dev && !ib_dev->ops.disassociate_ucontext)
197 		module_put(ib_dev->ops.owner);
198 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
199 
200 	if (refcount_dec_and_test(&file->device->refcount))
201 		ib_uverbs_comp_dev(file->device);
202 
203 	if (file->default_async_file)
204 		uverbs_uobject_put(&file->default_async_file->uobj);
205 	put_device(&file->device->dev);
206 
207 	if (file->disassociate_page)
208 		__free_pages(file->disassociate_page, 0);
209 	mutex_destroy(&file->umap_lock);
210 	mutex_destroy(&file->ucontext_lock);
211 	kfree(file);
212 }
213 
214 static ssize_t ib_uverbs_event_read(struct ib_uverbs_event_queue *ev_queue,
215 				    struct file *filp, char __user *buf,
216 				    size_t count, loff_t *pos,
217 				    size_t eventsz)
218 {
219 	struct ib_uverbs_event *event;
220 	int ret = 0;
221 
222 	spin_lock_irq(&ev_queue->lock);
223 
224 	while (list_empty(&ev_queue->event_list)) {
225 		spin_unlock_irq(&ev_queue->lock);
226 
227 		if (filp->f_flags & O_NONBLOCK)
228 			return -EAGAIN;
229 
230 		if (wait_event_interruptible(ev_queue->poll_wait,
231 					     (!list_empty(&ev_queue->event_list) ||
232 					      ev_queue->is_closed)))
233 			return -ERESTARTSYS;
234 
235 		spin_lock_irq(&ev_queue->lock);
236 
237 		/* If device was disassociated and no event exists set an error */
238 		if (list_empty(&ev_queue->event_list) && ev_queue->is_closed) {
239 			spin_unlock_irq(&ev_queue->lock);
240 			return -EIO;
241 		}
242 	}
243 
244 	event = list_entry(ev_queue->event_list.next, struct ib_uverbs_event, list);
245 
246 	if (eventsz > count) {
247 		ret   = -EINVAL;
248 		event = NULL;
249 	} else {
250 		list_del(ev_queue->event_list.next);
251 		if (event->counter) {
252 			++(*event->counter);
253 			list_del(&event->obj_list);
254 		}
255 	}
256 
257 	spin_unlock_irq(&ev_queue->lock);
258 
259 	if (event) {
260 		if (copy_to_user(buf, event, eventsz))
261 			ret = -EFAULT;
262 		else
263 			ret = eventsz;
264 	}
265 
266 	kfree(event);
267 
268 	return ret;
269 }
270 
271 static ssize_t ib_uverbs_async_event_read(struct file *filp, char __user *buf,
272 					  size_t count, loff_t *pos)
273 {
274 	struct ib_uverbs_async_event_file *file = filp->private_data;
275 
276 	return ib_uverbs_event_read(&file->ev_queue, filp, buf, count, pos,
277 				    sizeof(struct ib_uverbs_async_event_desc));
278 }
279 
280 static ssize_t ib_uverbs_comp_event_read(struct file *filp, char __user *buf,
281 					 size_t count, loff_t *pos)
282 {
283 	struct ib_uverbs_completion_event_file *comp_ev_file =
284 		filp->private_data;
285 
286 	return ib_uverbs_event_read(&comp_ev_file->ev_queue, filp, buf, count,
287 				    pos,
288 				    sizeof(struct ib_uverbs_comp_event_desc));
289 }
290 
291 static __poll_t ib_uverbs_event_poll(struct ib_uverbs_event_queue *ev_queue,
292 					 struct file *filp,
293 					 struct poll_table_struct *wait)
294 {
295 	__poll_t pollflags = 0;
296 
297 	poll_wait(filp, &ev_queue->poll_wait, wait);
298 
299 	spin_lock_irq(&ev_queue->lock);
300 	if (!list_empty(&ev_queue->event_list))
301 		pollflags = EPOLLIN | EPOLLRDNORM;
302 	else if (ev_queue->is_closed)
303 		pollflags = EPOLLERR;
304 	spin_unlock_irq(&ev_queue->lock);
305 
306 	return pollflags;
307 }
308 
309 static __poll_t ib_uverbs_async_event_poll(struct file *filp,
310 					       struct poll_table_struct *wait)
311 {
312 	struct ib_uverbs_async_event_file *file = filp->private_data;
313 
314 	return ib_uverbs_event_poll(&file->ev_queue, filp, wait);
315 }
316 
317 static __poll_t ib_uverbs_comp_event_poll(struct file *filp,
318 					      struct poll_table_struct *wait)
319 {
320 	struct ib_uverbs_completion_event_file *comp_ev_file =
321 		filp->private_data;
322 
323 	return ib_uverbs_event_poll(&comp_ev_file->ev_queue, filp, wait);
324 }
325 
326 static int ib_uverbs_async_event_fasync(int fd, struct file *filp, int on)
327 {
328 	struct ib_uverbs_async_event_file *file = filp->private_data;
329 
330 	return fasync_helper(fd, filp, on, &file->ev_queue.async_queue);
331 }
332 
333 static int ib_uverbs_comp_event_fasync(int fd, struct file *filp, int on)
334 {
335 	struct ib_uverbs_completion_event_file *comp_ev_file =
336 		filp->private_data;
337 
338 	return fasync_helper(fd, filp, on, &comp_ev_file->ev_queue.async_queue);
339 }
340 
341 const struct file_operations uverbs_event_fops = {
342 	.owner	 = THIS_MODULE,
343 	.read	 = ib_uverbs_comp_event_read,
344 	.poll    = ib_uverbs_comp_event_poll,
345 	.release = uverbs_uobject_fd_release,
346 	.fasync  = ib_uverbs_comp_event_fasync,
347 	.llseek	 = no_llseek,
348 };
349 
350 const struct file_operations uverbs_async_event_fops = {
351 	.owner	 = THIS_MODULE,
352 	.read	 = ib_uverbs_async_event_read,
353 	.poll    = ib_uverbs_async_event_poll,
354 	.release = uverbs_async_event_release,
355 	.fasync  = ib_uverbs_async_event_fasync,
356 	.llseek	 = no_llseek,
357 };
358 
359 void ib_uverbs_comp_handler(struct ib_cq *cq, void *cq_context)
360 {
361 	struct ib_uverbs_event_queue   *ev_queue = cq_context;
362 	struct ib_ucq_object	       *uobj;
363 	struct ib_uverbs_event	       *entry;
364 	unsigned long			flags;
365 
366 	if (!ev_queue)
367 		return;
368 
369 	spin_lock_irqsave(&ev_queue->lock, flags);
370 	if (ev_queue->is_closed) {
371 		spin_unlock_irqrestore(&ev_queue->lock, flags);
372 		return;
373 	}
374 
375 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
376 	if (!entry) {
377 		spin_unlock_irqrestore(&ev_queue->lock, flags);
378 		return;
379 	}
380 
381 	uobj = cq->uobject;
382 
383 	entry->desc.comp.cq_handle = cq->uobject->uevent.uobject.user_handle;
384 	entry->counter		   = &uobj->comp_events_reported;
385 
386 	list_add_tail(&entry->list, &ev_queue->event_list);
387 	list_add_tail(&entry->obj_list, &uobj->comp_list);
388 	spin_unlock_irqrestore(&ev_queue->lock, flags);
389 
390 	wake_up_interruptible(&ev_queue->poll_wait);
391 	kill_fasync(&ev_queue->async_queue, SIGIO, POLL_IN);
392 }
393 
394 void ib_uverbs_async_handler(struct ib_uverbs_async_event_file *async_file,
395 			     __u64 element, __u64 event,
396 			     struct list_head *obj_list, u32 *counter)
397 {
398 	struct ib_uverbs_event *entry;
399 	unsigned long flags;
400 
401 	if (!async_file)
402 		return;
403 
404 	spin_lock_irqsave(&async_file->ev_queue.lock, flags);
405 	if (async_file->ev_queue.is_closed) {
406 		spin_unlock_irqrestore(&async_file->ev_queue.lock, flags);
407 		return;
408 	}
409 
410 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
411 	if (!entry) {
412 		spin_unlock_irqrestore(&async_file->ev_queue.lock, flags);
413 		return;
414 	}
415 
416 	entry->desc.async.element = element;
417 	entry->desc.async.event_type = event;
418 	entry->desc.async.reserved = 0;
419 	entry->counter = counter;
420 
421 	list_add_tail(&entry->list, &async_file->ev_queue.event_list);
422 	if (obj_list)
423 		list_add_tail(&entry->obj_list, obj_list);
424 	spin_unlock_irqrestore(&async_file->ev_queue.lock, flags);
425 
426 	wake_up_interruptible(&async_file->ev_queue.poll_wait);
427 	kill_fasync(&async_file->ev_queue.async_queue, SIGIO, POLL_IN);
428 }
429 
430 static void uverbs_uobj_event(struct ib_uevent_object *eobj,
431 			      struct ib_event *event)
432 {
433 	ib_uverbs_async_handler(eobj->event_file,
434 				eobj->uobject.user_handle, event->event,
435 				&eobj->event_list, &eobj->events_reported);
436 }
437 
438 void ib_uverbs_cq_event_handler(struct ib_event *event, void *context_ptr)
439 {
440 	uverbs_uobj_event(&event->element.cq->uobject->uevent, event);
441 }
442 
443 void ib_uverbs_qp_event_handler(struct ib_event *event, void *context_ptr)
444 {
445 	/* for XRC target qp's, check that qp is live */
446 	if (!event->element.qp->uobject)
447 		return;
448 
449 	uverbs_uobj_event(&event->element.qp->uobject->uevent, event);
450 }
451 
452 void ib_uverbs_wq_event_handler(struct ib_event *event, void *context_ptr)
453 {
454 	uverbs_uobj_event(&event->element.wq->uobject->uevent, event);
455 }
456 
457 void ib_uverbs_srq_event_handler(struct ib_event *event, void *context_ptr)
458 {
459 	uverbs_uobj_event(&event->element.srq->uobject->uevent, event);
460 }
461 
462 static void ib_uverbs_event_handler(struct ib_event_handler *handler,
463 				    struct ib_event *event)
464 {
465 	ib_uverbs_async_handler(
466 		container_of(handler, struct ib_uverbs_async_event_file,
467 			     event_handler),
468 		event->element.port_num, event->event, NULL, NULL);
469 }
470 
471 void ib_uverbs_init_event_queue(struct ib_uverbs_event_queue *ev_queue)
472 {
473 	spin_lock_init(&ev_queue->lock);
474 	INIT_LIST_HEAD(&ev_queue->event_list);
475 	init_waitqueue_head(&ev_queue->poll_wait);
476 	ev_queue->is_closed   = 0;
477 	ev_queue->async_queue = NULL;
478 }
479 
480 void ib_uverbs_init_async_event_file(
481 	struct ib_uverbs_async_event_file *async_file)
482 {
483 	struct ib_uverbs_file *uverbs_file = async_file->uobj.ufile;
484 	struct ib_device *ib_dev = async_file->uobj.context->device;
485 
486 	ib_uverbs_init_event_queue(&async_file->ev_queue);
487 
488 	/* The first async_event_file becomes the default one for the file. */
489 	mutex_lock(&uverbs_file->ucontext_lock);
490 	if (!uverbs_file->default_async_file) {
491 		/* Pairs with the put in ib_uverbs_release_file */
492 		uverbs_uobject_get(&async_file->uobj);
493 		smp_store_release(&uverbs_file->default_async_file, async_file);
494 	}
495 	mutex_unlock(&uverbs_file->ucontext_lock);
496 
497 	INIT_IB_EVENT_HANDLER(&async_file->event_handler, ib_dev,
498 			      ib_uverbs_event_handler);
499 	ib_register_event_handler(&async_file->event_handler);
500 }
501 
502 static ssize_t verify_hdr(struct ib_uverbs_cmd_hdr *hdr,
503 			  struct ib_uverbs_ex_cmd_hdr *ex_hdr, size_t count,
504 			  const struct uverbs_api_write_method *method_elm)
505 {
506 	if (method_elm->is_ex) {
507 		count -= sizeof(*hdr) + sizeof(*ex_hdr);
508 
509 		if ((hdr->in_words + ex_hdr->provider_in_words) * 8 != count)
510 			return -EINVAL;
511 
512 		if (hdr->in_words * 8 < method_elm->req_size)
513 			return -ENOSPC;
514 
515 		if (ex_hdr->cmd_hdr_reserved)
516 			return -EINVAL;
517 
518 		if (ex_hdr->response) {
519 			if (!hdr->out_words && !ex_hdr->provider_out_words)
520 				return -EINVAL;
521 
522 			if (hdr->out_words * 8 < method_elm->resp_size)
523 				return -ENOSPC;
524 
525 			if (!access_ok(u64_to_user_ptr(ex_hdr->response),
526 				       (hdr->out_words + ex_hdr->provider_out_words) * 8))
527 				return -EFAULT;
528 		} else {
529 			if (hdr->out_words || ex_hdr->provider_out_words)
530 				return -EINVAL;
531 		}
532 
533 		return 0;
534 	}
535 
536 	/* not extended command */
537 	if (hdr->in_words * 4 != count)
538 		return -EINVAL;
539 
540 	if (count < method_elm->req_size + sizeof(hdr)) {
541 		/*
542 		 * rdma-core v18 and v19 have a bug where they send DESTROY_CQ
543 		 * with a 16 byte write instead of 24. Old kernels didn't
544 		 * check the size so they allowed this. Now that the size is
545 		 * checked provide a compatibility work around to not break
546 		 * those userspaces.
547 		 */
548 		if (hdr->command == IB_USER_VERBS_CMD_DESTROY_CQ &&
549 		    count == 16) {
550 			hdr->in_words = 6;
551 			return 0;
552 		}
553 		return -ENOSPC;
554 	}
555 	if (hdr->out_words * 4 < method_elm->resp_size)
556 		return -ENOSPC;
557 
558 	return 0;
559 }
560 
561 static ssize_t ib_uverbs_write(struct file *filp, const char __user *buf,
562 			     size_t count, loff_t *pos)
563 {
564 	struct ib_uverbs_file *file = filp->private_data;
565 	const struct uverbs_api_write_method *method_elm;
566 	struct uverbs_api *uapi = file->device->uapi;
567 	struct ib_uverbs_ex_cmd_hdr ex_hdr;
568 	struct ib_uverbs_cmd_hdr hdr;
569 	struct uverbs_attr_bundle bundle;
570 	int srcu_key;
571 	ssize_t ret;
572 
573 	if (!ib_safe_file_access(filp)) {
574 		pr_err_once("uverbs_write: process %d (%s) changed security contexts after opening file descriptor, this is not allowed.\n",
575 			    task_tgid_vnr(current), current->comm);
576 		return -EACCES;
577 	}
578 
579 	if (count < sizeof(hdr))
580 		return -EINVAL;
581 
582 	if (copy_from_user(&hdr, buf, sizeof(hdr)))
583 		return -EFAULT;
584 
585 	method_elm = uapi_get_method(uapi, hdr.command);
586 	if (IS_ERR(method_elm))
587 		return PTR_ERR(method_elm);
588 
589 	if (method_elm->is_ex) {
590 		if (count < (sizeof(hdr) + sizeof(ex_hdr)))
591 			return -EINVAL;
592 		if (copy_from_user(&ex_hdr, buf + sizeof(hdr), sizeof(ex_hdr)))
593 			return -EFAULT;
594 	}
595 
596 	ret = verify_hdr(&hdr, &ex_hdr, count, method_elm);
597 	if (ret)
598 		return ret;
599 
600 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
601 
602 	buf += sizeof(hdr);
603 
604 	memset(bundle.attr_present, 0, sizeof(bundle.attr_present));
605 	bundle.ufile = file;
606 	bundle.context = NULL; /* only valid if bundle has uobject */
607 	bundle.uobject = NULL;
608 	if (!method_elm->is_ex) {
609 		size_t in_len = hdr.in_words * 4 - sizeof(hdr);
610 		size_t out_len = hdr.out_words * 4;
611 		u64 response = 0;
612 
613 		if (method_elm->has_udata) {
614 			bundle.driver_udata.inlen =
615 				in_len - method_elm->req_size;
616 			in_len = method_elm->req_size;
617 			if (bundle.driver_udata.inlen)
618 				bundle.driver_udata.inbuf = buf + in_len;
619 			else
620 				bundle.driver_udata.inbuf = NULL;
621 		} else {
622 			memset(&bundle.driver_udata, 0,
623 			       sizeof(bundle.driver_udata));
624 		}
625 
626 		if (method_elm->has_resp) {
627 			/*
628 			 * The macros check that if has_resp is set
629 			 * then the command request structure starts
630 			 * with a '__aligned u64 response' member.
631 			 */
632 			ret = get_user(response, (const u64 __user *)buf);
633 			if (ret)
634 				goto out_unlock;
635 
636 			if (method_elm->has_udata) {
637 				bundle.driver_udata.outlen =
638 					out_len - method_elm->resp_size;
639 				out_len = method_elm->resp_size;
640 				if (bundle.driver_udata.outlen)
641 					bundle.driver_udata.outbuf =
642 						u64_to_user_ptr(response +
643 								out_len);
644 				else
645 					bundle.driver_udata.outbuf = NULL;
646 			}
647 		} else {
648 			bundle.driver_udata.outlen = 0;
649 			bundle.driver_udata.outbuf = NULL;
650 		}
651 
652 		ib_uverbs_init_udata_buf_or_null(
653 			&bundle.ucore, buf, u64_to_user_ptr(response),
654 			in_len, out_len);
655 	} else {
656 		buf += sizeof(ex_hdr);
657 
658 		ib_uverbs_init_udata_buf_or_null(&bundle.ucore, buf,
659 					u64_to_user_ptr(ex_hdr.response),
660 					hdr.in_words * 8, hdr.out_words * 8);
661 
662 		ib_uverbs_init_udata_buf_or_null(
663 			&bundle.driver_udata, buf + bundle.ucore.inlen,
664 			u64_to_user_ptr(ex_hdr.response) + bundle.ucore.outlen,
665 			ex_hdr.provider_in_words * 8,
666 			ex_hdr.provider_out_words * 8);
667 
668 	}
669 
670 	ret = method_elm->handler(&bundle);
671 	if (bundle.uobject)
672 		uverbs_finalize_object(bundle.uobject, UVERBS_ACCESS_NEW, true,
673 				       !ret, &bundle);
674 out_unlock:
675 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
676 	return (ret) ? : count;
677 }
678 
679 static const struct vm_operations_struct rdma_umap_ops;
680 
681 static int ib_uverbs_mmap(struct file *filp, struct vm_area_struct *vma)
682 {
683 	struct ib_uverbs_file *file = filp->private_data;
684 	struct ib_ucontext *ucontext;
685 	int ret = 0;
686 	int srcu_key;
687 
688 	srcu_key = srcu_read_lock(&file->device->disassociate_srcu);
689 	ucontext = ib_uverbs_get_ucontext_file(file);
690 	if (IS_ERR(ucontext)) {
691 		ret = PTR_ERR(ucontext);
692 		goto out;
693 	}
694 	vma->vm_ops = &rdma_umap_ops;
695 	ret = ucontext->device->ops.mmap(ucontext, vma);
696 out:
697 	srcu_read_unlock(&file->device->disassociate_srcu, srcu_key);
698 	return ret;
699 }
700 
701 /*
702  * The VMA has been dup'd, initialize the vm_private_data with a new tracking
703  * struct
704  */
705 static void rdma_umap_open(struct vm_area_struct *vma)
706 {
707 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
708 	struct rdma_umap_priv *opriv = vma->vm_private_data;
709 	struct rdma_umap_priv *priv;
710 
711 	if (!opriv)
712 		return;
713 
714 	/* We are racing with disassociation */
715 	if (!down_read_trylock(&ufile->hw_destroy_rwsem))
716 		goto out_zap;
717 	/*
718 	 * Disassociation already completed, the VMA should already be zapped.
719 	 */
720 	if (!ufile->ucontext)
721 		goto out_unlock;
722 
723 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
724 	if (!priv)
725 		goto out_unlock;
726 	rdma_umap_priv_init(priv, vma, opriv->entry);
727 
728 	up_read(&ufile->hw_destroy_rwsem);
729 	return;
730 
731 out_unlock:
732 	up_read(&ufile->hw_destroy_rwsem);
733 out_zap:
734 	/*
735 	 * We can't allow the VMA to be created with the actual IO pages, that
736 	 * would break our API contract, and it can't be stopped at this
737 	 * point, so zap it.
738 	 */
739 	vma->vm_private_data = NULL;
740 	zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
741 }
742 
743 static void rdma_umap_close(struct vm_area_struct *vma)
744 {
745 	struct ib_uverbs_file *ufile = vma->vm_file->private_data;
746 	struct rdma_umap_priv *priv = vma->vm_private_data;
747 
748 	if (!priv)
749 		return;
750 
751 	/*
752 	 * The vma holds a reference on the struct file that created it, which
753 	 * in turn means that the ib_uverbs_file is guaranteed to exist at
754 	 * this point.
755 	 */
756 	mutex_lock(&ufile->umap_lock);
757 	if (priv->entry)
758 		rdma_user_mmap_entry_put(priv->entry);
759 
760 	list_del(&priv->list);
761 	mutex_unlock(&ufile->umap_lock);
762 	kfree(priv);
763 }
764 
765 /*
766  * Once the zap_vma_ptes has been called touches to the VMA will come here and
767  * we return a dummy writable zero page for all the pfns.
768  */
769 static vm_fault_t rdma_umap_fault(struct vm_fault *vmf)
770 {
771 	struct ib_uverbs_file *ufile = vmf->vma->vm_file->private_data;
772 	struct rdma_umap_priv *priv = vmf->vma->vm_private_data;
773 	vm_fault_t ret = 0;
774 
775 	if (!priv)
776 		return VM_FAULT_SIGBUS;
777 
778 	/* Read only pages can just use the system zero page. */
779 	if (!(vmf->vma->vm_flags & (VM_WRITE | VM_MAYWRITE))) {
780 		vmf->page = ZERO_PAGE(vmf->address);
781 		get_page(vmf->page);
782 		return 0;
783 	}
784 
785 	mutex_lock(&ufile->umap_lock);
786 	if (!ufile->disassociate_page)
787 		ufile->disassociate_page =
788 			alloc_pages(vmf->gfp_mask | __GFP_ZERO, 0);
789 
790 	if (ufile->disassociate_page) {
791 		/*
792 		 * This VMA is forced to always be shared so this doesn't have
793 		 * to worry about COW.
794 		 */
795 		vmf->page = ufile->disassociate_page;
796 		get_page(vmf->page);
797 	} else {
798 		ret = VM_FAULT_SIGBUS;
799 	}
800 	mutex_unlock(&ufile->umap_lock);
801 
802 	return ret;
803 }
804 
805 static const struct vm_operations_struct rdma_umap_ops = {
806 	.open = rdma_umap_open,
807 	.close = rdma_umap_close,
808 	.fault = rdma_umap_fault,
809 };
810 
811 void uverbs_user_mmap_disassociate(struct ib_uverbs_file *ufile)
812 {
813 	struct rdma_umap_priv *priv, *next_priv;
814 
815 	lockdep_assert_held(&ufile->hw_destroy_rwsem);
816 
817 	while (1) {
818 		struct mm_struct *mm = NULL;
819 
820 		/* Get an arbitrary mm pointer that hasn't been cleaned yet */
821 		mutex_lock(&ufile->umap_lock);
822 		while (!list_empty(&ufile->umaps)) {
823 			int ret;
824 
825 			priv = list_first_entry(&ufile->umaps,
826 						struct rdma_umap_priv, list);
827 			mm = priv->vma->vm_mm;
828 			ret = mmget_not_zero(mm);
829 			if (!ret) {
830 				list_del_init(&priv->list);
831 				if (priv->entry) {
832 					rdma_user_mmap_entry_put(priv->entry);
833 					priv->entry = NULL;
834 				}
835 				mm = NULL;
836 				continue;
837 			}
838 			break;
839 		}
840 		mutex_unlock(&ufile->umap_lock);
841 		if (!mm)
842 			return;
843 
844 		/*
845 		 * The umap_lock is nested under mmap_lock since it used within
846 		 * the vma_ops callbacks, so we have to clean the list one mm
847 		 * at a time to get the lock ordering right. Typically there
848 		 * will only be one mm, so no big deal.
849 		 */
850 		mmap_read_lock(mm);
851 		mutex_lock(&ufile->umap_lock);
852 		list_for_each_entry_safe (priv, next_priv, &ufile->umaps,
853 					  list) {
854 			struct vm_area_struct *vma = priv->vma;
855 
856 			if (vma->vm_mm != mm)
857 				continue;
858 			list_del_init(&priv->list);
859 
860 			zap_vma_ptes(vma, vma->vm_start,
861 				     vma->vm_end - vma->vm_start);
862 
863 			if (priv->entry) {
864 				rdma_user_mmap_entry_put(priv->entry);
865 				priv->entry = NULL;
866 			}
867 		}
868 		mutex_unlock(&ufile->umap_lock);
869 		mmap_read_unlock(mm);
870 		mmput(mm);
871 	}
872 }
873 
874 /*
875  * ib_uverbs_open() does not need the BKL:
876  *
877  *  - the ib_uverbs_device structures are properly reference counted and
878  *    everything else is purely local to the file being created, so
879  *    races against other open calls are not a problem;
880  *  - there is no ioctl method to race against;
881  *  - the open method will either immediately run -ENXIO, or all
882  *    required initialization will be done.
883  */
884 static int ib_uverbs_open(struct inode *inode, struct file *filp)
885 {
886 	struct ib_uverbs_device *dev;
887 	struct ib_uverbs_file *file;
888 	struct ib_device *ib_dev;
889 	int ret;
890 	int module_dependent;
891 	int srcu_key;
892 
893 	dev = container_of(inode->i_cdev, struct ib_uverbs_device, cdev);
894 	if (!refcount_inc_not_zero(&dev->refcount))
895 		return -ENXIO;
896 
897 	get_device(&dev->dev);
898 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
899 	mutex_lock(&dev->lists_mutex);
900 	ib_dev = srcu_dereference(dev->ib_dev,
901 				  &dev->disassociate_srcu);
902 	if (!ib_dev) {
903 		ret = -EIO;
904 		goto err;
905 	}
906 
907 	if (!rdma_dev_access_netns(ib_dev, current->nsproxy->net_ns)) {
908 		ret = -EPERM;
909 		goto err;
910 	}
911 
912 	/* In case IB device supports disassociate ucontext, there is no hard
913 	 * dependency between uverbs device and its low level device.
914 	 */
915 	module_dependent = !(ib_dev->ops.disassociate_ucontext);
916 
917 	if (module_dependent) {
918 		if (!try_module_get(ib_dev->ops.owner)) {
919 			ret = -ENODEV;
920 			goto err;
921 		}
922 	}
923 
924 	file = kzalloc(sizeof(*file), GFP_KERNEL);
925 	if (!file) {
926 		ret = -ENOMEM;
927 		if (module_dependent)
928 			goto err_module;
929 
930 		goto err;
931 	}
932 
933 	file->device	 = dev;
934 	kref_init(&file->ref);
935 	mutex_init(&file->ucontext_lock);
936 
937 	spin_lock_init(&file->uobjects_lock);
938 	INIT_LIST_HEAD(&file->uobjects);
939 	init_rwsem(&file->hw_destroy_rwsem);
940 	mutex_init(&file->umap_lock);
941 	INIT_LIST_HEAD(&file->umaps);
942 
943 	filp->private_data = file;
944 	list_add_tail(&file->list, &dev->uverbs_file_list);
945 	mutex_unlock(&dev->lists_mutex);
946 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
947 
948 	setup_ufile_idr_uobject(file);
949 
950 	return stream_open(inode, filp);
951 
952 err_module:
953 	module_put(ib_dev->ops.owner);
954 
955 err:
956 	mutex_unlock(&dev->lists_mutex);
957 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
958 	if (refcount_dec_and_test(&dev->refcount))
959 		ib_uverbs_comp_dev(dev);
960 
961 	put_device(&dev->dev);
962 	return ret;
963 }
964 
965 static int ib_uverbs_close(struct inode *inode, struct file *filp)
966 {
967 	struct ib_uverbs_file *file = filp->private_data;
968 
969 	uverbs_destroy_ufile_hw(file, RDMA_REMOVE_CLOSE);
970 
971 	mutex_lock(&file->device->lists_mutex);
972 	list_del_init(&file->list);
973 	mutex_unlock(&file->device->lists_mutex);
974 
975 	kref_put(&file->ref, ib_uverbs_release_file);
976 
977 	return 0;
978 }
979 
980 static const struct file_operations uverbs_fops = {
981 	.owner	 = THIS_MODULE,
982 	.write	 = ib_uverbs_write,
983 	.open	 = ib_uverbs_open,
984 	.release = ib_uverbs_close,
985 	.llseek	 = no_llseek,
986 	.unlocked_ioctl = ib_uverbs_ioctl,
987 	.compat_ioctl = compat_ptr_ioctl,
988 };
989 
990 static const struct file_operations uverbs_mmap_fops = {
991 	.owner	 = THIS_MODULE,
992 	.write	 = ib_uverbs_write,
993 	.mmap    = ib_uverbs_mmap,
994 	.open	 = ib_uverbs_open,
995 	.release = ib_uverbs_close,
996 	.llseek	 = no_llseek,
997 	.unlocked_ioctl = ib_uverbs_ioctl,
998 	.compat_ioctl = compat_ptr_ioctl,
999 };
1000 
1001 static int ib_uverbs_get_nl_info(struct ib_device *ibdev, void *client_data,
1002 				 struct ib_client_nl_info *res)
1003 {
1004 	struct ib_uverbs_device *uverbs_dev = client_data;
1005 	int ret;
1006 
1007 	if (res->port != -1)
1008 		return -EINVAL;
1009 
1010 	res->abi = ibdev->ops.uverbs_abi_ver;
1011 	res->cdev = &uverbs_dev->dev;
1012 
1013 	/*
1014 	 * To support DRIVER_ID binding in userspace some of the driver need
1015 	 * upgrading to expose their PCI dependent revision information
1016 	 * through get_context instead of relying on modalias matching. When
1017 	 * the drivers are fixed they can drop this flag.
1018 	 */
1019 	if (!ibdev->ops.uverbs_no_driver_id_binding) {
1020 		ret = nla_put_u32(res->nl_msg, RDMA_NLDEV_ATTR_UVERBS_DRIVER_ID,
1021 				  ibdev->ops.driver_id);
1022 		if (ret)
1023 			return ret;
1024 	}
1025 	return 0;
1026 }
1027 
1028 static struct ib_client uverbs_client = {
1029 	.name   = "uverbs",
1030 	.no_kverbs_req = true,
1031 	.add    = ib_uverbs_add_one,
1032 	.remove = ib_uverbs_remove_one,
1033 	.get_nl_info = ib_uverbs_get_nl_info,
1034 };
1035 MODULE_ALIAS_RDMA_CLIENT("uverbs");
1036 
1037 static ssize_t ibdev_show(struct device *device, struct device_attribute *attr,
1038 			  char *buf)
1039 {
1040 	struct ib_uverbs_device *dev =
1041 			container_of(device, struct ib_uverbs_device, dev);
1042 	int ret = -ENODEV;
1043 	int srcu_key;
1044 	struct ib_device *ib_dev;
1045 
1046 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1047 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1048 	if (ib_dev)
1049 		ret = sysfs_emit(buf, "%s\n", dev_name(&ib_dev->dev));
1050 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1051 
1052 	return ret;
1053 }
1054 static DEVICE_ATTR_RO(ibdev);
1055 
1056 static ssize_t abi_version_show(struct device *device,
1057 				struct device_attribute *attr, char *buf)
1058 {
1059 	struct ib_uverbs_device *dev =
1060 			container_of(device, struct ib_uverbs_device, dev);
1061 	int ret = -ENODEV;
1062 	int srcu_key;
1063 	struct ib_device *ib_dev;
1064 
1065 	srcu_key = srcu_read_lock(&dev->disassociate_srcu);
1066 	ib_dev = srcu_dereference(dev->ib_dev, &dev->disassociate_srcu);
1067 	if (ib_dev)
1068 		ret = sysfs_emit(buf, "%u\n", ib_dev->ops.uverbs_abi_ver);
1069 	srcu_read_unlock(&dev->disassociate_srcu, srcu_key);
1070 
1071 	return ret;
1072 }
1073 static DEVICE_ATTR_RO(abi_version);
1074 
1075 static struct attribute *ib_dev_attrs[] = {
1076 	&dev_attr_abi_version.attr,
1077 	&dev_attr_ibdev.attr,
1078 	NULL,
1079 };
1080 
1081 static const struct attribute_group dev_attr_group = {
1082 	.attrs = ib_dev_attrs,
1083 };
1084 
1085 static CLASS_ATTR_STRING(abi_version, S_IRUGO,
1086 			 __stringify(IB_USER_VERBS_ABI_VERSION));
1087 
1088 static int ib_uverbs_create_uapi(struct ib_device *device,
1089 				 struct ib_uverbs_device *uverbs_dev)
1090 {
1091 	struct uverbs_api *uapi;
1092 
1093 	uapi = uverbs_alloc_api(device);
1094 	if (IS_ERR(uapi))
1095 		return PTR_ERR(uapi);
1096 
1097 	uverbs_dev->uapi = uapi;
1098 	return 0;
1099 }
1100 
1101 static int ib_uverbs_add_one(struct ib_device *device)
1102 {
1103 	int devnum;
1104 	dev_t base;
1105 	struct ib_uverbs_device *uverbs_dev;
1106 	int ret;
1107 
1108 	if (!device->ops.alloc_ucontext)
1109 		return -EOPNOTSUPP;
1110 
1111 	uverbs_dev = kzalloc(sizeof(*uverbs_dev), GFP_KERNEL);
1112 	if (!uverbs_dev)
1113 		return -ENOMEM;
1114 
1115 	ret = init_srcu_struct(&uverbs_dev->disassociate_srcu);
1116 	if (ret) {
1117 		kfree(uverbs_dev);
1118 		return -ENOMEM;
1119 	}
1120 
1121 	device_initialize(&uverbs_dev->dev);
1122 	uverbs_dev->dev.class = uverbs_class;
1123 	uverbs_dev->dev.parent = device->dev.parent;
1124 	uverbs_dev->dev.release = ib_uverbs_release_dev;
1125 	uverbs_dev->groups[0] = &dev_attr_group;
1126 	uverbs_dev->dev.groups = uverbs_dev->groups;
1127 	refcount_set(&uverbs_dev->refcount, 1);
1128 	init_completion(&uverbs_dev->comp);
1129 	uverbs_dev->xrcd_tree = RB_ROOT;
1130 	mutex_init(&uverbs_dev->xrcd_tree_mutex);
1131 	mutex_init(&uverbs_dev->lists_mutex);
1132 	INIT_LIST_HEAD(&uverbs_dev->uverbs_file_list);
1133 	rcu_assign_pointer(uverbs_dev->ib_dev, device);
1134 	uverbs_dev->num_comp_vectors = device->num_comp_vectors;
1135 
1136 	devnum = ida_alloc_max(&uverbs_ida, IB_UVERBS_MAX_DEVICES - 1,
1137 			       GFP_KERNEL);
1138 	if (devnum < 0) {
1139 		ret = -ENOMEM;
1140 		goto err;
1141 	}
1142 	uverbs_dev->devnum = devnum;
1143 	if (devnum >= IB_UVERBS_NUM_FIXED_MINOR)
1144 		base = dynamic_uverbs_dev + devnum - IB_UVERBS_NUM_FIXED_MINOR;
1145 	else
1146 		base = IB_UVERBS_BASE_DEV + devnum;
1147 
1148 	ret = ib_uverbs_create_uapi(device, uverbs_dev);
1149 	if (ret)
1150 		goto err_uapi;
1151 
1152 	uverbs_dev->dev.devt = base;
1153 	dev_set_name(&uverbs_dev->dev, "uverbs%d", uverbs_dev->devnum);
1154 
1155 	cdev_init(&uverbs_dev->cdev,
1156 		  device->ops.mmap ? &uverbs_mmap_fops : &uverbs_fops);
1157 	uverbs_dev->cdev.owner = THIS_MODULE;
1158 
1159 	ret = cdev_device_add(&uverbs_dev->cdev, &uverbs_dev->dev);
1160 	if (ret)
1161 		goto err_uapi;
1162 
1163 	ib_set_client_data(device, &uverbs_client, uverbs_dev);
1164 	return 0;
1165 
1166 err_uapi:
1167 	ida_free(&uverbs_ida, devnum);
1168 err:
1169 	if (refcount_dec_and_test(&uverbs_dev->refcount))
1170 		ib_uverbs_comp_dev(uverbs_dev);
1171 	wait_for_completion(&uverbs_dev->comp);
1172 	put_device(&uverbs_dev->dev);
1173 	return ret;
1174 }
1175 
1176 static void ib_uverbs_free_hw_resources(struct ib_uverbs_device *uverbs_dev,
1177 					struct ib_device *ib_dev)
1178 {
1179 	struct ib_uverbs_file *file;
1180 
1181 	/* Pending running commands to terminate */
1182 	uverbs_disassociate_api_pre(uverbs_dev);
1183 
1184 	mutex_lock(&uverbs_dev->lists_mutex);
1185 	while (!list_empty(&uverbs_dev->uverbs_file_list)) {
1186 		file = list_first_entry(&uverbs_dev->uverbs_file_list,
1187 					struct ib_uverbs_file, list);
1188 		list_del_init(&file->list);
1189 		kref_get(&file->ref);
1190 
1191 		/* We must release the mutex before going ahead and calling
1192 		 * uverbs_cleanup_ufile, as it might end up indirectly calling
1193 		 * uverbs_close, for example due to freeing the resources (e.g
1194 		 * mmput).
1195 		 */
1196 		mutex_unlock(&uverbs_dev->lists_mutex);
1197 
1198 		uverbs_destroy_ufile_hw(file, RDMA_REMOVE_DRIVER_REMOVE);
1199 		kref_put(&file->ref, ib_uverbs_release_file);
1200 
1201 		mutex_lock(&uverbs_dev->lists_mutex);
1202 	}
1203 	mutex_unlock(&uverbs_dev->lists_mutex);
1204 
1205 	uverbs_disassociate_api(uverbs_dev->uapi);
1206 }
1207 
1208 static void ib_uverbs_remove_one(struct ib_device *device, void *client_data)
1209 {
1210 	struct ib_uverbs_device *uverbs_dev = client_data;
1211 	int wait_clients = 1;
1212 
1213 	cdev_device_del(&uverbs_dev->cdev, &uverbs_dev->dev);
1214 	ida_free(&uverbs_ida, uverbs_dev->devnum);
1215 
1216 	if (device->ops.disassociate_ucontext) {
1217 		/* We disassociate HW resources and immediately return.
1218 		 * Userspace will see a EIO errno for all future access.
1219 		 * Upon returning, ib_device may be freed internally and is not
1220 		 * valid any more.
1221 		 * uverbs_device is still available until all clients close
1222 		 * their files, then the uverbs device ref count will be zero
1223 		 * and its resources will be freed.
1224 		 * Note: At this point no more files can be opened since the
1225 		 * cdev was deleted, however active clients can still issue
1226 		 * commands and close their open files.
1227 		 */
1228 		ib_uverbs_free_hw_resources(uverbs_dev, device);
1229 		wait_clients = 0;
1230 	}
1231 
1232 	if (refcount_dec_and_test(&uverbs_dev->refcount))
1233 		ib_uverbs_comp_dev(uverbs_dev);
1234 	if (wait_clients)
1235 		wait_for_completion(&uverbs_dev->comp);
1236 
1237 	put_device(&uverbs_dev->dev);
1238 }
1239 
1240 static char *uverbs_devnode(const struct device *dev, umode_t *mode)
1241 {
1242 	if (mode)
1243 		*mode = 0666;
1244 	return kasprintf(GFP_KERNEL, "infiniband/%s", dev_name(dev));
1245 }
1246 
1247 static int __init ib_uverbs_init(void)
1248 {
1249 	int ret;
1250 
1251 	ret = register_chrdev_region(IB_UVERBS_BASE_DEV,
1252 				     IB_UVERBS_NUM_FIXED_MINOR,
1253 				     "infiniband_verbs");
1254 	if (ret) {
1255 		pr_err("user_verbs: couldn't register device number\n");
1256 		goto out;
1257 	}
1258 
1259 	ret = alloc_chrdev_region(&dynamic_uverbs_dev, 0,
1260 				  IB_UVERBS_NUM_DYNAMIC_MINOR,
1261 				  "infiniband_verbs");
1262 	if (ret) {
1263 		pr_err("couldn't register dynamic device number\n");
1264 		goto out_alloc;
1265 	}
1266 
1267 	uverbs_class = class_create("infiniband_verbs");
1268 	if (IS_ERR(uverbs_class)) {
1269 		ret = PTR_ERR(uverbs_class);
1270 		pr_err("user_verbs: couldn't create class infiniband_verbs\n");
1271 		goto out_chrdev;
1272 	}
1273 
1274 	uverbs_class->devnode = uverbs_devnode;
1275 
1276 	ret = class_create_file(uverbs_class, &class_attr_abi_version.attr);
1277 	if (ret) {
1278 		pr_err("user_verbs: couldn't create abi_version attribute\n");
1279 		goto out_class;
1280 	}
1281 
1282 	ret = ib_register_client(&uverbs_client);
1283 	if (ret) {
1284 		pr_err("user_verbs: couldn't register client\n");
1285 		goto out_class;
1286 	}
1287 
1288 	return 0;
1289 
1290 out_class:
1291 	class_destroy(uverbs_class);
1292 
1293 out_chrdev:
1294 	unregister_chrdev_region(dynamic_uverbs_dev,
1295 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1296 
1297 out_alloc:
1298 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1299 				 IB_UVERBS_NUM_FIXED_MINOR);
1300 
1301 out:
1302 	return ret;
1303 }
1304 
1305 static void __exit ib_uverbs_cleanup(void)
1306 {
1307 	ib_unregister_client(&uverbs_client);
1308 	class_destroy(uverbs_class);
1309 	unregister_chrdev_region(IB_UVERBS_BASE_DEV,
1310 				 IB_UVERBS_NUM_FIXED_MINOR);
1311 	unregister_chrdev_region(dynamic_uverbs_dev,
1312 				 IB_UVERBS_NUM_DYNAMIC_MINOR);
1313 	mmu_notifier_synchronize();
1314 }
1315 
1316 module_init(ib_uverbs_init);
1317 module_exit(ib_uverbs_cleanup);
1318