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