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