xref: /freebsd/sys/compat/linuxkpi/common/src/linux_compat.c (revision 3a1bf59d195ced99c0f69774969d7090d21f6097)
1 /*-
2  * Copyright (c) 2010 Isilon Systems, Inc.
3  * Copyright (c) 2010 iX Systems, Inc.
4  * Copyright (c) 2010 Panasas, Inc.
5  * Copyright (c) 2013-2021 Mellanox Technologies, Ltd.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice unmodified, this list of conditions, and the following
13  *    disclaimer.
14  * 2. Redistributions in binary form must reproduce the above copyright
15  *    notice, this list of conditions and the following disclaimer in the
16  *    documentation and/or other materials provided with the distribution.
17  *
18  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 #include "opt_global.h"
32 #include "opt_stack.h"
33 
34 #include <sys/param.h>
35 #include <sys/systm.h>
36 #include <sys/malloc.h>
37 #include <sys/kernel.h>
38 #include <sys/sysctl.h>
39 #include <sys/proc.h>
40 #include <sys/sglist.h>
41 #include <sys/sleepqueue.h>
42 #include <sys/refcount.h>
43 #include <sys/lock.h>
44 #include <sys/mutex.h>
45 #include <sys/bus.h>
46 #include <sys/eventhandler.h>
47 #include <sys/fcntl.h>
48 #include <sys/file.h>
49 #include <sys/filio.h>
50 #include <sys/rwlock.h>
51 #include <sys/mman.h>
52 #include <sys/stack.h>
53 #include <sys/stdarg.h>
54 #include <sys/syscall.h>
55 #include <sys/sysent.h>
56 #include <sys/time.h>
57 #include <sys/user.h>
58 
59 #include <vm/vm.h>
60 #include <vm/pmap.h>
61 #include <vm/vm_object.h>
62 #include <vm/vm_page.h>
63 #include <vm/vm_pager.h>
64 #include <vm/vm_radix.h>
65 
66 #if defined(__i386__) || defined(__amd64__)
67 #include <machine/cputypes.h>
68 #include <machine/md_var.h>
69 #endif
70 
71 #include <linux/kobject.h>
72 #include <linux/cpu.h>
73 #include <linux/device.h>
74 #include <linux/slab.h>
75 #include <linux/module.h>
76 #include <linux/moduleparam.h>
77 #include <linux/cdev.h>
78 #include <linux/file.h>
79 #include <linux/fs.h>
80 #include <linux/sysfs.h>
81 #include <linux/mm.h>
82 #include <linux/io.h>
83 #include <linux/vmalloc.h>
84 #include <linux/netdevice.h>
85 #include <linux/timer.h>
86 #include <linux/interrupt.h>
87 #include <linux/uaccess.h>
88 #include <linux/utsname.h>
89 #include <linux/list.h>
90 #include <linux/kthread.h>
91 #include <linux/kernel.h>
92 #include <linux/compat.h>
93 #include <linux/io-mapping.h>
94 #include <linux/poll.h>
95 #include <linux/smp.h>
96 #include <linux/wait_bit.h>
97 #include <linux/rcupdate.h>
98 #include <linux/interval_tree.h>
99 #include <linux/interval_tree_generic.h>
100 #include <linux/printk.h>
101 #include <linux/seq_file.h>
102 #include <linux/uuid.h>
103 
104 #if defined(__i386__) || defined(__amd64__)
105 #include <asm/smp.h>
106 #include <asm/processor.h>
107 #endif
108 
109 #include <xen/xen.h>
110 #ifdef XENHVM
111 #undef xen_pv_domain
112 #undef xen_initial_domain
113 /* xen/xen-os.h redefines __must_check */
114 #undef __must_check
115 #include <xen/xen-os.h>
116 #endif
117 
118 SYSCTL_NODE(_compat, OID_AUTO, linuxkpi, CTLFLAG_RW | CTLFLAG_MPSAFE, 0,
119     "LinuxKPI parameters");
120 
121 int linuxkpi_debug;
122 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, debug, CTLFLAG_RWTUN,
123     &linuxkpi_debug, 0, "Set to enable pr_debug() prints. Clear to disable.");
124 
125 int linuxkpi_rcu_debug;
126 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, rcu_debug, CTLFLAG_RWTUN,
127     &linuxkpi_rcu_debug, 0, "Set to enable RCU warning. Clear to disable.");
128 
129 int linuxkpi_warn_dump_stack = 0;
130 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, warn_dump_stack, CTLFLAG_RWTUN,
131     &linuxkpi_warn_dump_stack, 0,
132     "Set to enable stack traces from WARN_ON(). Clear to disable.");
133 
134 static struct timeval lkpi_net_lastlog;
135 static int lkpi_net_curpps;
136 static int lkpi_net_maxpps = 99;
137 SYSCTL_INT(_compat_linuxkpi, OID_AUTO, net_ratelimit, CTLFLAG_RWTUN,
138     &lkpi_net_maxpps, 0, "Limit number of LinuxKPI net messages per second.");
139 
140 MALLOC_DEFINE(M_KMALLOC, "lkpikmalloc", "Linux kmalloc compat");
141 
142 #include <linux/rbtree.h>
143 /* Undo Linux compat changes. */
144 #undef RB_ROOT
145 #undef file
146 #undef cdev
147 #define	RB_ROOT(head)	(head)->rbh_root
148 
149 static void linux_destroy_dev(struct linux_cdev *);
150 static void linux_cdev_deref(struct linux_cdev *ldev);
151 static struct vm_area_struct *linux_cdev_handle_find(void *handle);
152 
153 cpumask_t cpu_online_mask;
154 static cpumask_t **static_single_cpu_mask;
155 static cpumask_t *static_single_cpu_mask_lcs;
156 struct kobject linux_class_root;
157 struct device linux_root_device;
158 struct class linux_class_misc;
159 struct list_head pci_drivers;
160 struct list_head pci_devices;
161 spinlock_t pci_lock;
162 struct uts_namespace init_uts_ns;
163 
164 unsigned long linux_timer_hz_mask;
165 
166 wait_queue_head_t linux_bit_waitq;
167 wait_queue_head_t linux_var_waitq;
168 
169 const guid_t guid_null;
170 
171 enum system_states system_state = SYSTEM_RUNNING;
172 
173 struct task_struct *
174 __lkpi_current(void)
175 {
176 	struct thread *td;
177 
178 	td = curthread;
179 	linux_set_current(td);
180 	return ((struct task_struct *)td->td_lkpi_task);
181 }
182 
183 int
184 panic_cmp(struct rb_node *one, struct rb_node *two)
185 {
186 	panic("no cmp");
187 }
188 
189 RB_GENERATE(linux_root, rb_node, __entry, panic_cmp);
190 
191 #define	START(node)	((node)->start)
192 #define	LAST(node)	((node)->last)
193 
194 INTERVAL_TREE_DEFINE(struct interval_tree_node, rb, unsigned long,, START,
195     LAST,, lkpi_interval_tree)
196 
197 static void
198 linux_device_release(struct device *dev)
199 {
200 	pr_debug("linux_device_release: %s\n", dev_name(dev));
201 	kfree(dev);
202 }
203 
204 static ssize_t
205 linux_class_show(struct kobject *kobj, struct attribute *attr, char *buf)
206 {
207 	struct class_attribute *dattr;
208 	ssize_t error;
209 
210 	dattr = container_of(attr, struct class_attribute, attr);
211 	error = -EIO;
212 	if (dattr->show)
213 		error = dattr->show(container_of(kobj, struct class, kobj),
214 		    dattr, buf);
215 	return (error);
216 }
217 
218 static ssize_t
219 linux_class_store(struct kobject *kobj, struct attribute *attr, const char *buf,
220     size_t count)
221 {
222 	struct class_attribute *dattr;
223 	ssize_t error;
224 
225 	dattr = container_of(attr, struct class_attribute, attr);
226 	error = -EIO;
227 	if (dattr->store)
228 		error = dattr->store(container_of(kobj, struct class, kobj),
229 		    dattr, buf, count);
230 	return (error);
231 }
232 
233 static void
234 linux_class_release(struct kobject *kobj)
235 {
236 	struct class *class;
237 
238 	class = container_of(kobj, struct class, kobj);
239 	if (class->class_release)
240 		class->class_release(class);
241 }
242 
243 static const struct sysfs_ops linux_class_sysfs = {
244 	.show  = linux_class_show,
245 	.store = linux_class_store,
246 };
247 
248 const struct kobj_type linux_class_ktype = {
249 	.release = linux_class_release,
250 	.sysfs_ops = &linux_class_sysfs
251 };
252 
253 static void
254 linux_dev_release(struct kobject *kobj)
255 {
256 	struct device *dev;
257 
258 	dev = container_of(kobj, struct device, kobj);
259 	/* This is the precedence defined by linux. */
260 	if (dev->release)
261 		dev->release(dev);
262 	else if (dev->class && dev->class->dev_release)
263 		dev->class->dev_release(dev);
264 }
265 
266 static ssize_t
267 linux_dev_show(struct kobject *kobj, struct attribute *attr, char *buf)
268 {
269 	struct device_attribute *dattr;
270 	ssize_t error;
271 
272 	dattr = container_of(attr, struct device_attribute, attr);
273 	error = -EIO;
274 	if (dattr->show)
275 		error = dattr->show(container_of(kobj, struct device, kobj),
276 		    dattr, buf);
277 	return (error);
278 }
279 
280 static ssize_t
281 linux_dev_store(struct kobject *kobj, struct attribute *attr, const char *buf,
282     size_t count)
283 {
284 	struct device_attribute *dattr;
285 	ssize_t error;
286 
287 	dattr = container_of(attr, struct device_attribute, attr);
288 	error = -EIO;
289 	if (dattr->store)
290 		error = dattr->store(container_of(kobj, struct device, kobj),
291 		    dattr, buf, count);
292 	return (error);
293 }
294 
295 static const struct sysfs_ops linux_dev_sysfs = {
296 	.show  = linux_dev_show,
297 	.store = linux_dev_store,
298 };
299 
300 const struct kobj_type linux_dev_ktype = {
301 	.release = linux_dev_release,
302 	.sysfs_ops = &linux_dev_sysfs
303 };
304 
305 struct device *
306 device_create(struct class *class, struct device *parent, dev_t devt,
307     void *drvdata, const char *fmt, ...)
308 {
309 	struct device *dev;
310 	va_list args;
311 
312 	dev = kzalloc(sizeof(*dev), M_WAITOK);
313 	dev->parent = parent;
314 	dev->class = class;
315 	dev->devt = devt;
316 	dev->driver_data = drvdata;
317 	dev->release = linux_device_release;
318 	va_start(args, fmt);
319 	kobject_set_name_vargs(&dev->kobj, fmt, args);
320 	va_end(args);
321 	device_register(dev);
322 
323 	return (dev);
324 }
325 
326 struct device *
327 device_create_groups_vargs(struct class *class, struct device *parent,
328     dev_t devt, void *drvdata, const struct attribute_group **groups,
329     const char *fmt, va_list args)
330 {
331 	struct device *dev = NULL;
332 	int retval = -ENODEV;
333 
334 	if (class == NULL || IS_ERR(class))
335 		goto error;
336 
337 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
338 	if (!dev) {
339 		retval = -ENOMEM;
340 		goto error;
341 	}
342 
343 	dev->devt = devt;
344 	dev->class = class;
345 	dev->parent = parent;
346 	dev->groups = groups;
347 	dev->release = device_create_release;
348 	/* device_initialize() needs the class and parent to be set */
349 	device_initialize(dev);
350 	dev_set_drvdata(dev, drvdata);
351 
352 	retval = kobject_set_name_vargs(&dev->kobj, fmt, args);
353 	if (retval)
354 		goto error;
355 
356 	retval = device_add(dev);
357 	if (retval)
358 		goto error;
359 
360 	return dev;
361 
362 error:
363 	put_device(dev);
364 	return ERR_PTR(retval);
365 }
366 
367 struct class *
368 lkpi_class_create(const char *name)
369 {
370 	struct class *class;
371 	int error;
372 
373 	class = kzalloc(sizeof(*class), M_WAITOK);
374 	class->name = name;
375 	class->class_release = linux_class_kfree;
376 	error = class_register(class);
377 	if (error) {
378 		kfree(class);
379 		return (NULL);
380 	}
381 
382 	return (class);
383 }
384 
385 static void
386 linux_kq_lock(void *arg)
387 {
388 	spinlock_t *s = arg;
389 
390 	spin_lock(s);
391 }
392 static void
393 linux_kq_unlock(void *arg)
394 {
395 	spinlock_t *s = arg;
396 
397 	spin_unlock(s);
398 }
399 
400 static void
401 linux_kq_assert_lock(void *arg, int what)
402 {
403 #ifdef INVARIANTS
404 	spinlock_t *s = arg;
405 
406 	if (what == LA_LOCKED)
407 		mtx_assert(s, MA_OWNED);
408 	else
409 		mtx_assert(s, MA_NOTOWNED);
410 #endif
411 }
412 
413 static void
414 linux_file_kqfilter_poll(struct linux_file *, int);
415 
416 struct linux_file *
417 linux_file_alloc(void)
418 {
419 	struct linux_file *filp;
420 
421 	filp = kzalloc(sizeof(*filp), GFP_KERNEL);
422 
423 	/* set initial refcount */
424 	filp->f_count = 1;
425 
426 	/* setup fields needed by kqueue support */
427 	spin_lock_init(&filp->f_kqlock);
428 	knlist_init(&filp->f_selinfo.si_note, &filp->f_kqlock,
429 	    linux_kq_lock, linux_kq_unlock, linux_kq_assert_lock);
430 
431 	return (filp);
432 }
433 
434 void
435 linux_file_free(struct linux_file *filp)
436 {
437 	if (filp->_file == NULL) {
438 		if (filp->f_op != NULL && filp->f_op->release != NULL)
439 			filp->f_op->release(filp->f_vnode, filp);
440 		if (filp->f_shmem != NULL)
441 			vm_object_deallocate(filp->f_shmem);
442 		kfree_rcu(filp, rcu);
443 	} else {
444 		/*
445 		 * The close method of the character device or file
446 		 * will free the linux_file structure:
447 		 */
448 		_fdrop(filp->_file, curthread);
449 	}
450 }
451 
452 struct linux_cdev *
453 cdev_alloc(void)
454 {
455 	struct linux_cdev *cdev;
456 
457 	cdev = kzalloc(sizeof(struct linux_cdev), M_WAITOK);
458 	kobject_init(&cdev->kobj, &linux_cdev_ktype);
459 	cdev->refs = 1;
460 	return (cdev);
461 }
462 
463 static int
464 linux_cdev_pager_fault(vm_object_t vm_obj, vm_ooffset_t offset, int prot,
465     vm_page_t *mres)
466 {
467 	struct vm_area_struct *vmap;
468 
469 	vmap = linux_cdev_handle_find(vm_obj->handle);
470 
471 	MPASS(vmap != NULL);
472 	MPASS(vmap->vm_private_data == vm_obj->handle);
473 
474 	if (likely(vmap->vm_ops != NULL && offset < vmap->vm_len)) {
475 		vm_paddr_t paddr = IDX_TO_OFF(vmap->vm_pfn) + offset;
476 		vm_page_t page;
477 
478 		if (((*mres)->flags & PG_FICTITIOUS) != 0) {
479 			/*
480 			 * If the passed in result page is a fake
481 			 * page, update it with the new physical
482 			 * address.
483 			 */
484 			page = *mres;
485 			vm_page_updatefake(page, paddr, vm_obj->memattr);
486 		} else {
487 			/*
488 			 * Replace the passed in "mres" page with our
489 			 * own fake page and free up the all of the
490 			 * original pages.
491 			 */
492 			VM_OBJECT_WUNLOCK(vm_obj);
493 			page = vm_page_getfake(paddr, vm_obj->memattr);
494 			VM_OBJECT_WLOCK(vm_obj);
495 
496 			vm_page_replace(page, vm_obj, (*mres)->pindex, *mres);
497 			*mres = page;
498 		}
499 		vm_page_valid(page);
500 		return (VM_PAGER_OK);
501 	}
502 	return (VM_PAGER_FAIL);
503 }
504 
505 static int
506 linux_cdev_pager_populate(vm_object_t vm_obj, vm_pindex_t pidx, int fault_type,
507     vm_prot_t max_prot, vm_pindex_t *first, vm_pindex_t *last)
508 {
509 	struct vm_area_struct *vmap;
510 	int err;
511 
512 	/* get VM area structure */
513 	vmap = linux_cdev_handle_find(vm_obj->handle);
514 	MPASS(vmap != NULL);
515 	MPASS(vmap->vm_private_data == vm_obj->handle);
516 
517 	VM_OBJECT_WUNLOCK(vm_obj);
518 
519 	linux_set_current(curthread);
520 
521 	down_write(&vmap->vm_mm->mmap_sem);
522 	if (unlikely(vmap->vm_ops == NULL)) {
523 		err = VM_FAULT_SIGBUS;
524 	} else {
525 		struct vm_fault vmf;
526 
527 		/* fill out VM fault structure */
528 		vmf.virtual_address = (void *)(uintptr_t)IDX_TO_OFF(pidx);
529 		vmf.flags = (fault_type & VM_PROT_WRITE) ? FAULT_FLAG_WRITE : 0;
530 		vmf.pgoff = 0;
531 		vmf.page = NULL;
532 		vmf.vma = vmap;
533 
534 		vmap->vm_pfn_count = 0;
535 		vmap->vm_pfn_pcount = &vmap->vm_pfn_count;
536 		vmap->vm_obj = vm_obj;
537 
538 		err = vmap->vm_ops->fault(&vmf);
539 
540 		while (vmap->vm_pfn_count == 0 && err == VM_FAULT_NOPAGE) {
541 			kern_yield(PRI_USER);
542 			err = vmap->vm_ops->fault(&vmf);
543 		}
544 	}
545 
546 	/* translate return code */
547 	switch (err) {
548 	case VM_FAULT_OOM:
549 		err = VM_PAGER_AGAIN;
550 		break;
551 	case VM_FAULT_SIGBUS:
552 		err = VM_PAGER_BAD;
553 		break;
554 	case VM_FAULT_NOPAGE:
555 		/*
556 		 * By contract the fault handler will return having
557 		 * busied all the pages itself. If pidx is already
558 		 * found in the object, it will simply xbusy the first
559 		 * page and return with vm_pfn_count set to 1.
560 		 */
561 		*first = vmap->vm_pfn_first;
562 		*last = *first + vmap->vm_pfn_count - 1;
563 		err = VM_PAGER_OK;
564 		break;
565 	default:
566 		err = VM_PAGER_ERROR;
567 		break;
568 	}
569 	up_write(&vmap->vm_mm->mmap_sem);
570 	VM_OBJECT_WLOCK(vm_obj);
571 	return (err);
572 }
573 
574 static struct rwlock linux_vma_lock;
575 static TAILQ_HEAD(, vm_area_struct) linux_vma_head =
576     TAILQ_HEAD_INITIALIZER(linux_vma_head);
577 
578 static void
579 linux_cdev_handle_free(struct vm_area_struct *vmap)
580 {
581 	/* Drop reference on vm_file */
582 	if (vmap->vm_file != NULL)
583 		fput(vmap->vm_file);
584 
585 	/* Drop reference on mm_struct */
586 	mmput(vmap->vm_mm);
587 
588 	kfree(vmap);
589 }
590 
591 static void
592 linux_cdev_handle_remove(struct vm_area_struct *vmap)
593 {
594 	rw_wlock(&linux_vma_lock);
595 	TAILQ_REMOVE(&linux_vma_head, vmap, vm_entry);
596 	rw_wunlock(&linux_vma_lock);
597 }
598 
599 static struct vm_area_struct *
600 linux_cdev_handle_find(void *handle)
601 {
602 	struct vm_area_struct *vmap;
603 
604 	rw_rlock(&linux_vma_lock);
605 	TAILQ_FOREACH(vmap, &linux_vma_head, vm_entry) {
606 		if (vmap->vm_private_data == handle)
607 			break;
608 	}
609 	rw_runlock(&linux_vma_lock);
610 	return (vmap);
611 }
612 
613 static int
614 linux_cdev_pager_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
615 		      vm_ooffset_t foff, struct ucred *cred, u_short *color)
616 {
617 
618 	MPASS(linux_cdev_handle_find(handle) != NULL);
619 	*color = 0;
620 	return (0);
621 }
622 
623 static void
624 linux_cdev_pager_dtor(void *handle)
625 {
626 	const struct vm_operations_struct *vm_ops;
627 	struct vm_area_struct *vmap;
628 
629 	vmap = linux_cdev_handle_find(handle);
630 	MPASS(vmap != NULL);
631 
632 	/*
633 	 * Remove handle before calling close operation to prevent
634 	 * other threads from reusing the handle pointer.
635 	 */
636 	linux_cdev_handle_remove(vmap);
637 
638 	down_write(&vmap->vm_mm->mmap_sem);
639 	vm_ops = vmap->vm_ops;
640 	if (likely(vm_ops != NULL))
641 		vm_ops->close(vmap);
642 	up_write(&vmap->vm_mm->mmap_sem);
643 
644 	linux_cdev_handle_free(vmap);
645 }
646 
647 static struct cdev_pager_ops linux_cdev_pager_ops[2] = {
648   {
649 	/* OBJT_MGTDEVICE */
650 	.cdev_pg_populate	= linux_cdev_pager_populate,
651 	.cdev_pg_ctor	= linux_cdev_pager_ctor,
652 	.cdev_pg_dtor	= linux_cdev_pager_dtor
653   },
654   {
655 	/* OBJT_DEVICE */
656 	.cdev_pg_fault	= linux_cdev_pager_fault,
657 	.cdev_pg_ctor	= linux_cdev_pager_ctor,
658 	.cdev_pg_dtor	= linux_cdev_pager_dtor
659   },
660 };
661 
662 int
663 zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
664     unsigned long size)
665 {
666 	struct pctrie_iter pages;
667 	vm_object_t obj;
668 	vm_page_t m;
669 
670 	obj = vma->vm_obj;
671 	if (obj == NULL || (obj->flags & OBJ_UNMANAGED) != 0)
672 		return (-ENOTSUP);
673 	VM_OBJECT_RLOCK(obj);
674 	vm_page_iter_limit_init(&pages, obj, OFF_TO_IDX(address + size));
675 	VM_RADIX_FOREACH_FROM(m, &pages, OFF_TO_IDX(address))
676 		pmap_remove_all(m);
677 	VM_OBJECT_RUNLOCK(obj);
678 	return (0);
679 }
680 
681 void
682 vma_set_file(struct vm_area_struct *vma, struct linux_file *file)
683 {
684 	struct linux_file *tmp;
685 
686 	/* Changing an anonymous vma with this is illegal */
687 	get_file(file);
688 	tmp = vma->vm_file;
689 	vma->vm_file = file;
690 	fput(tmp);
691 }
692 
693 static struct file_operations dummy_ldev_ops = {
694 	/* XXXKIB */
695 };
696 
697 static struct linux_cdev dummy_ldev = {
698 	.ops = &dummy_ldev_ops,
699 };
700 
701 #define	LDEV_SI_DTR	0x0001
702 #define	LDEV_SI_REF	0x0002
703 
704 static void
705 linux_get_fop(struct linux_file *filp, const struct file_operations **fop,
706     struct linux_cdev **dev)
707 {
708 	struct linux_cdev *ldev;
709 	u_int siref;
710 
711 	ldev = filp->f_cdev;
712 	*fop = filp->f_op;
713 	if (ldev != NULL) {
714 		if (ldev->kobj.ktype == &linux_cdev_static_ktype) {
715 			refcount_acquire(&ldev->refs);
716 		} else {
717 			for (siref = ldev->siref;;) {
718 				if ((siref & LDEV_SI_DTR) != 0) {
719 					ldev = &dummy_ldev;
720 					*fop = ldev->ops;
721 					siref = ldev->siref;
722 					MPASS((ldev->siref & LDEV_SI_DTR) == 0);
723 				} else if (atomic_fcmpset_int(&ldev->siref,
724 				    &siref, siref + LDEV_SI_REF)) {
725 					break;
726 				}
727 			}
728 		}
729 	}
730 	*dev = ldev;
731 }
732 
733 static void
734 linux_drop_fop(struct linux_cdev *ldev)
735 {
736 
737 	if (ldev == NULL)
738 		return;
739 	if (ldev->kobj.ktype == &linux_cdev_static_ktype) {
740 		linux_cdev_deref(ldev);
741 	} else {
742 		MPASS(ldev->kobj.ktype == &linux_cdev_ktype);
743 		MPASS((ldev->siref & ~LDEV_SI_DTR) != 0);
744 		atomic_subtract_int(&ldev->siref, LDEV_SI_REF);
745 	}
746 }
747 
748 #define	OPW(fp,td,code) ({			\
749 	struct file *__fpop;			\
750 	__typeof(code) __retval;		\
751 						\
752 	__fpop = (td)->td_fpop;			\
753 	(td)->td_fpop = (fp);			\
754 	__retval = (code);			\
755 	(td)->td_fpop = __fpop;			\
756 	__retval;				\
757 })
758 
759 static int
760 linux_dev_fdopen(struct cdev *dev, int fflags, struct thread *td,
761     struct file *file)
762 {
763 	struct linux_cdev *ldev;
764 	struct linux_file *filp;
765 	const struct file_operations *fop;
766 	int error;
767 
768 	ldev = dev->si_drv1;
769 
770 	filp = linux_file_alloc();
771 	filp->f_dentry = &filp->f_dentry_store;
772 	filp->f_op = ldev->ops;
773 	filp->f_mode = file->f_flag;
774 	filp->f_flags = file->f_flag;
775 	filp->f_vnode = file->f_vnode;
776 	filp->_file = file;
777 	refcount_acquire(&ldev->refs);
778 	filp->f_cdev = ldev;
779 
780 	linux_set_current(td);
781 	linux_get_fop(filp, &fop, &ldev);
782 
783 	if (fop->open != NULL) {
784 		error = -fop->open(file->f_vnode, filp);
785 		if (error != 0) {
786 			linux_drop_fop(ldev);
787 			linux_cdev_deref(filp->f_cdev);
788 			kfree(filp);
789 			return (error);
790 		}
791 	}
792 
793 	/* hold on to the vnode - used for fstat() */
794 	vref(filp->f_vnode);
795 
796 	/* release the file from devfs */
797 	finit(file, filp->f_mode, DTYPE_DEV, filp, &linuxfileops);
798 	linux_drop_fop(ldev);
799 	return (ENXIO);
800 }
801 
802 #define	LINUX_IOCTL_MIN_PTR 0x10000UL
803 #define	LINUX_IOCTL_MAX_PTR (LINUX_IOCTL_MIN_PTR + IOCPARM_MAX)
804 
805 static inline int
806 linux_remap_address(void **uaddr, size_t len)
807 {
808 	uintptr_t uaddr_val = (uintptr_t)(*uaddr);
809 
810 	if (unlikely(uaddr_val >= LINUX_IOCTL_MIN_PTR &&
811 	    uaddr_val < LINUX_IOCTL_MAX_PTR)) {
812 		struct task_struct *pts = current;
813 		if (pts == NULL) {
814 			*uaddr = NULL;
815 			return (1);
816 		}
817 
818 		/* compute data offset */
819 		uaddr_val -= LINUX_IOCTL_MIN_PTR;
820 
821 		/* check that length is within bounds */
822 		if ((len > IOCPARM_MAX) ||
823 		    (uaddr_val + len) > pts->bsd_ioctl_len) {
824 			*uaddr = NULL;
825 			return (1);
826 		}
827 
828 		/* re-add kernel buffer address */
829 		uaddr_val += (uintptr_t)pts->bsd_ioctl_data;
830 
831 		/* update address location */
832 		*uaddr = (void *)uaddr_val;
833 		return (1);
834 	}
835 	return (0);
836 }
837 
838 int
839 linux_copyin(const void *uaddr, void *kaddr, size_t len)
840 {
841 	if (linux_remap_address(__DECONST(void **, &uaddr), len)) {
842 		if (uaddr == NULL)
843 			return (-EFAULT);
844 		memcpy(kaddr, uaddr, len);
845 		return (0);
846 	}
847 	return (-copyin(uaddr, kaddr, len));
848 }
849 
850 int
851 linux_copyout(const void *kaddr, void *uaddr, size_t len)
852 {
853 	if (linux_remap_address(&uaddr, len)) {
854 		if (uaddr == NULL)
855 			return (-EFAULT);
856 		memcpy(uaddr, kaddr, len);
857 		return (0);
858 	}
859 	return (-copyout(kaddr, uaddr, len));
860 }
861 
862 size_t
863 linux_clear_user(void *_uaddr, size_t _len)
864 {
865 	uint8_t *uaddr = _uaddr;
866 	size_t len = _len;
867 
868 	/* make sure uaddr is aligned before going into the fast loop */
869 	while (((uintptr_t)uaddr & 7) != 0 && len > 7) {
870 		if (subyte(uaddr, 0))
871 			return (_len);
872 		uaddr++;
873 		len--;
874 	}
875 
876 	/* zero 8 bytes at a time */
877 	while (len > 7) {
878 #ifdef __LP64__
879 		if (suword64(uaddr, 0))
880 			return (_len);
881 #else
882 		if (suword32(uaddr, 0))
883 			return (_len);
884 		if (suword32(uaddr + 4, 0))
885 			return (_len);
886 #endif
887 		uaddr += 8;
888 		len -= 8;
889 	}
890 
891 	/* zero fill end, if any */
892 	while (len > 0) {
893 		if (subyte(uaddr, 0))
894 			return (_len);
895 		uaddr++;
896 		len--;
897 	}
898 	return (0);
899 }
900 
901 int
902 linux_access_ok(const void *uaddr, size_t len)
903 {
904 	uintptr_t saddr;
905 	uintptr_t eaddr;
906 
907 	/* get start and end address */
908 	saddr = (uintptr_t)uaddr;
909 	eaddr = (uintptr_t)uaddr + len;
910 
911 	/* verify addresses are valid for userspace */
912 	return ((saddr == eaddr) ||
913 	    (eaddr > saddr && eaddr <= VM_MAXUSER_ADDRESS));
914 }
915 
916 /*
917  * This function should return either EINTR or ERESTART depending on
918  * the signal type sent to this thread:
919  */
920 static int
921 linux_get_error(struct task_struct *task, int error)
922 {
923 	/* check for signal type interrupt code */
924 	if (error == EINTR || error == ERESTARTSYS || error == ERESTART) {
925 		error = -linux_schedule_get_interrupt_value(task);
926 		if (error == 0)
927 			error = EINTR;
928 	}
929 	return (error);
930 }
931 
932 static int
933 linux_file_ioctl_sub(struct file *fp, struct linux_file *filp,
934     const struct file_operations *fop, u_long cmd, caddr_t data,
935     struct thread *td)
936 {
937 	struct task_struct *task = current;
938 	unsigned size;
939 	int error;
940 	bool direct;
941 
942 	size = IOCPARM_LEN(cmd);
943 	/* refer to logic in sys_ioctl() */
944 	direct = false;
945 	if (size > 0) {
946 		/*
947 		 * Setup hint for linux_copyin() and linux_copyout().
948 		 *
949 		 * Background: Linux kernel code expects to operate on
950 		 * userspace addresses, but FreeBSD's kern_ioctl()
951 		 * will generally provide a kernel address.  For the
952 		 * native process ABI, where we know how to find the
953 		 * original address, we reach directly into the system
954 		 * call args to get it.  Then, if the Linux driver
955 		 * copied out to that address, we copy the whole block
956 		 * back into the kernel buffer allocated by
957 		 * kern_ioctl() so that kern_ioctl() itself doesn't
958 		 * clobber the driver's data.
959 		 *
960 		 * Otherwise, fall back to the LINUX_IOCTL_MIN_PTR
961 		 * hack.
962 		 */
963 		task->bsd_ioctl_data = data;
964 		task->bsd_ioctl_len = size;
965 		if ((td->td_pflags & TDP_KTHREAD) == 0 &&
966 		    SV_PROC_ABI(td->td_proc) == SV_ABI_FREEBSD &&
967 		    td->td_sa.code == SYS_ioctl) {
968 			direct = true;
969 			data = (void *)(uintptr_t)td->td_sa.args[2];
970 		} else {
971 			data = (void *)LINUX_IOCTL_MIN_PTR;
972 		}
973 	} else {
974 		/* fetch user-space pointer */
975 		data = *(void **)data;
976 	}
977 #ifdef COMPAT_FREEBSD32
978 	if (SV_PROC_FLAG(td->td_proc, SV_ILP32)) {
979 		/* try the compat IOCTL handler first */
980 		if (fop->compat_ioctl != NULL) {
981 			error = -OPW(fp, td, fop->compat_ioctl(filp,
982 			    cmd, (u_long)data));
983 		} else {
984 			error = ENOTTY;
985 		}
986 
987 		/* fallback to the regular IOCTL handler, if any */
988 		if (error == ENOTTY && fop->unlocked_ioctl != NULL) {
989 			error = -OPW(fp, td, fop->unlocked_ioctl(filp,
990 			    cmd, (u_long)data));
991 		}
992 	} else
993 #endif
994 	{
995 		if (fop->unlocked_ioctl != NULL) {
996 			error = -OPW(fp, td, fop->unlocked_ioctl(filp,
997 			    cmd, (u_long)data));
998 		} else {
999 			error = ENOTTY;
1000 		}
1001 	}
1002 	if (error == 0 && size > 0 && (cmd & IOC_OUT) != 0 && direct) {
1003 		void *xdata;
1004 		int error1;
1005 
1006 		/*
1007 		 * Ensure that the copyout in sys_generic.c copies
1008 		 * over the data which is possibly modified by the
1009 		 * driver.  A possible error from the copyin() is
1010 		 * ignored since it is formally possible for the memory
1011 		 * to become unaccessible in the meantime.  Do the copying
1012 		 * through the intermediate buffer instead of copying
1013 		 * directly to bsd_ioctl_data, to ensure atomicity of
1014 		 * the change with respect to the error.
1015 		 */
1016 		xdata = malloc(size, M_TEMP, M_WAITOK);
1017 		error1 = copyin(data, xdata, size);
1018 		if (error1 == 0)
1019 			memcpy(task->bsd_ioctl_data, xdata, size);
1020 		free(xdata, M_TEMP);
1021 	}
1022 	if (size > 0) {
1023 		task->bsd_ioctl_data = NULL;
1024 		task->bsd_ioctl_len = 0;
1025 	}
1026 	if (error == EWOULDBLOCK) {
1027 		/* update kqfilter status, if any */
1028 		linux_file_kqfilter_poll(filp,
1029 		    LINUX_KQ_FLAG_HAS_READ | LINUX_KQ_FLAG_HAS_WRITE);
1030 	} else {
1031 		error = linux_get_error(task, error);
1032 	}
1033 	return (error);
1034 }
1035 
1036 #define	LINUX_POLL_TABLE_NORMAL ((poll_table *)1)
1037 
1038 /*
1039  * This function atomically updates the poll wakeup state and returns
1040  * the previous state at the time of update.
1041  */
1042 static uint8_t
1043 linux_poll_wakeup_state(atomic_t *v, const uint8_t *pstate)
1044 {
1045 	int c, old;
1046 
1047 	c = v->counter;
1048 
1049 	while ((old = atomic_cmpxchg(v, c, pstate[c])) != c)
1050 		c = old;
1051 
1052 	return (c);
1053 }
1054 
1055 static int
1056 linux_poll_wakeup_callback(wait_queue_t *wq, unsigned int wq_state, int flags, void *key)
1057 {
1058 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1059 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_INIT, /* NOP */
1060 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_NOT_READY, /* NOP */
1061 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_READY,
1062 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_READY, /* NOP */
1063 	};
1064 	struct linux_file *filp = container_of(wq, struct linux_file, f_wait_queue.wq);
1065 
1066 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1067 	case LINUX_FWQ_STATE_QUEUED:
1068 		linux_poll_wakeup(filp);
1069 		return (1);
1070 	default:
1071 		return (0);
1072 	}
1073 }
1074 
1075 void
1076 linux_poll_wait(struct linux_file *filp, wait_queue_head_t *wqh, poll_table *p)
1077 {
1078 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1079 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_NOT_READY,
1080 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_NOT_READY, /* NOP */
1081 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_QUEUED, /* NOP */
1082 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_QUEUED,
1083 	};
1084 
1085 	/* check if we are called inside the select system call */
1086 	if (p == LINUX_POLL_TABLE_NORMAL)
1087 		selrecord(curthread, &filp->f_selinfo);
1088 
1089 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1090 	case LINUX_FWQ_STATE_INIT:
1091 		/* NOTE: file handles can only belong to one wait-queue */
1092 		filp->f_wait_queue.wqh = wqh;
1093 		filp->f_wait_queue.wq.func = &linux_poll_wakeup_callback;
1094 		add_wait_queue(wqh, &filp->f_wait_queue.wq);
1095 		atomic_set(&filp->f_wait_queue.state, LINUX_FWQ_STATE_QUEUED);
1096 		break;
1097 	default:
1098 		break;
1099 	}
1100 }
1101 
1102 static void
1103 linux_poll_wait_dequeue(struct linux_file *filp)
1104 {
1105 	static const uint8_t state[LINUX_FWQ_STATE_MAX] = {
1106 		[LINUX_FWQ_STATE_INIT] = LINUX_FWQ_STATE_INIT,	/* NOP */
1107 		[LINUX_FWQ_STATE_NOT_READY] = LINUX_FWQ_STATE_INIT,
1108 		[LINUX_FWQ_STATE_QUEUED] = LINUX_FWQ_STATE_INIT,
1109 		[LINUX_FWQ_STATE_READY] = LINUX_FWQ_STATE_INIT,
1110 	};
1111 
1112 	seldrain(&filp->f_selinfo);
1113 
1114 	switch (linux_poll_wakeup_state(&filp->f_wait_queue.state, state)) {
1115 	case LINUX_FWQ_STATE_NOT_READY:
1116 	case LINUX_FWQ_STATE_QUEUED:
1117 	case LINUX_FWQ_STATE_READY:
1118 		remove_wait_queue(filp->f_wait_queue.wqh, &filp->f_wait_queue.wq);
1119 		break;
1120 	default:
1121 		break;
1122 	}
1123 }
1124 
1125 void
1126 linux_poll_wakeup(struct linux_file *filp)
1127 {
1128 	/* this function should be NULL-safe */
1129 	if (filp == NULL)
1130 		return;
1131 
1132 	selwakeup(&filp->f_selinfo);
1133 
1134 	spin_lock(&filp->f_kqlock);
1135 	filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ |
1136 	    LINUX_KQ_FLAG_NEED_WRITE;
1137 
1138 	/* make sure the "knote" gets woken up */
1139 	KNOTE_LOCKED(&filp->f_selinfo.si_note, 1);
1140 	spin_unlock(&filp->f_kqlock);
1141 }
1142 
1143 static struct linux_file *
1144 __get_file_rcu(struct linux_file **f)
1145 {
1146 	struct linux_file *file1, *file2;
1147 
1148 	file1 = READ_ONCE(*f);
1149 	if (file1 == NULL)
1150 		return (NULL);
1151 
1152 	if (!refcount_acquire_if_not_zero(
1153 	    file1->_file == NULL ? &file1->f_count : &file1->_file->f_count))
1154 		return (ERR_PTR(-EAGAIN));
1155 
1156 	file2 = READ_ONCE(*f);
1157 	if (file2 == file1)
1158 		return (file2);
1159 
1160 	fput(file1);
1161 	return (ERR_PTR(-EAGAIN));
1162 }
1163 
1164 struct linux_file *
1165 linux_get_file_rcu(struct linux_file **f)
1166 {
1167 	struct linux_file *file1;
1168 
1169 	for (;;) {
1170 		file1 = __get_file_rcu(f);
1171 		if (file1 == NULL)
1172 			return (NULL);
1173 
1174 		if (IS_ERR(file1))
1175 			continue;
1176 
1177 		return (file1);
1178 	}
1179 }
1180 
1181 struct linux_file *
1182 get_file_active(struct linux_file **f)
1183 {
1184 	struct linux_file *file1;
1185 
1186 	rcu_read_lock();
1187 	file1 = __get_file_rcu(f);
1188 	rcu_read_unlock();
1189 	if (IS_ERR(file1))
1190 		file1 = NULL;
1191 
1192 	return (file1);
1193 }
1194 
1195 static void
1196 linux_file_kqfilter_detach(struct knote *kn)
1197 {
1198 	struct linux_file *filp = kn->kn_hook;
1199 
1200 	spin_lock(&filp->f_kqlock);
1201 	knlist_remove(&filp->f_selinfo.si_note, kn, 1);
1202 	spin_unlock(&filp->f_kqlock);
1203 }
1204 
1205 static int
1206 linux_file_kqfilter_read_event(struct knote *kn, long hint)
1207 {
1208 	struct linux_file *filp = kn->kn_hook;
1209 
1210 	mtx_assert(&filp->f_kqlock, MA_OWNED);
1211 
1212 	return ((filp->f_kqflags & LINUX_KQ_FLAG_NEED_READ) ? 1 : 0);
1213 }
1214 
1215 static int
1216 linux_file_kqfilter_write_event(struct knote *kn, long hint)
1217 {
1218 	struct linux_file *filp = kn->kn_hook;
1219 
1220 	mtx_assert(&filp->f_kqlock, MA_OWNED);
1221 
1222 	return ((filp->f_kqflags & LINUX_KQ_FLAG_NEED_WRITE) ? 1 : 0);
1223 }
1224 
1225 static const struct filterops linux_dev_kqfiltops_read = {
1226 	.f_isfd = 1,
1227 	.f_detach = linux_file_kqfilter_detach,
1228 	.f_event = linux_file_kqfilter_read_event,
1229 	.f_copy = knote_triv_copy,
1230 };
1231 
1232 static const struct filterops linux_dev_kqfiltops_write = {
1233 	.f_isfd = 1,
1234 	.f_detach = linux_file_kqfilter_detach,
1235 	.f_event = linux_file_kqfilter_write_event,
1236 	.f_copy = knote_triv_copy,
1237 };
1238 
1239 static void
1240 linux_file_kqfilter_poll(struct linux_file *filp, int kqflags)
1241 {
1242 	struct thread *td;
1243 	const struct file_operations *fop;
1244 	struct linux_cdev *ldev;
1245 	int temp;
1246 
1247 	if ((filp->f_kqflags & kqflags) == 0)
1248 		return;
1249 
1250 	td = curthread;
1251 
1252 	linux_get_fop(filp, &fop, &ldev);
1253 	/* get the latest polling state */
1254 	temp = OPW(filp->_file, td, fop->poll(filp, NULL));
1255 	linux_drop_fop(ldev);
1256 
1257 	spin_lock(&filp->f_kqlock);
1258 	/* clear kqflags */
1259 	filp->f_kqflags &= ~(LINUX_KQ_FLAG_NEED_READ |
1260 	    LINUX_KQ_FLAG_NEED_WRITE);
1261 	/* update kqflags */
1262 	if ((temp & (POLLIN | POLLOUT)) != 0) {
1263 		if ((temp & POLLIN) != 0)
1264 			filp->f_kqflags |= LINUX_KQ_FLAG_NEED_READ;
1265 		if ((temp & POLLOUT) != 0)
1266 			filp->f_kqflags |= LINUX_KQ_FLAG_NEED_WRITE;
1267 
1268 		/* make sure the "knote" gets woken up */
1269 		KNOTE_LOCKED(&filp->f_selinfo.si_note, 0);
1270 	}
1271 	spin_unlock(&filp->f_kqlock);
1272 }
1273 
1274 static int
1275 linux_file_kqfilter(struct file *file, struct knote *kn)
1276 {
1277 	struct linux_file *filp;
1278 	struct thread *td;
1279 	int error;
1280 
1281 	td = curthread;
1282 	filp = (struct linux_file *)file->f_data;
1283 	filp->f_flags = file->f_flag;
1284 	if (filp->f_op->poll == NULL)
1285 		return (EINVAL);
1286 
1287 	spin_lock(&filp->f_kqlock);
1288 	switch (kn->kn_filter) {
1289 	case EVFILT_READ:
1290 		filp->f_kqflags |= LINUX_KQ_FLAG_HAS_READ;
1291 		kn->kn_fop = &linux_dev_kqfiltops_read;
1292 		kn->kn_hook = filp;
1293 		knlist_add(&filp->f_selinfo.si_note, kn, 1);
1294 		error = 0;
1295 		break;
1296 	case EVFILT_WRITE:
1297 		filp->f_kqflags |= LINUX_KQ_FLAG_HAS_WRITE;
1298 		kn->kn_fop = &linux_dev_kqfiltops_write;
1299 		kn->kn_hook = filp;
1300 		knlist_add(&filp->f_selinfo.si_note, kn, 1);
1301 		error = 0;
1302 		break;
1303 	default:
1304 		error = EINVAL;
1305 		break;
1306 	}
1307 	spin_unlock(&filp->f_kqlock);
1308 
1309 	if (error == 0) {
1310 		linux_set_current(td);
1311 
1312 		/* update kqfilter status, if any */
1313 		linux_file_kqfilter_poll(filp,
1314 		    LINUX_KQ_FLAG_HAS_READ | LINUX_KQ_FLAG_HAS_WRITE);
1315 	}
1316 	return (error);
1317 }
1318 
1319 static int
1320 linux_file_mmap_single(struct file *fp, const struct file_operations *fop,
1321     vm_ooffset_t *offset, vm_size_t size, struct vm_object **object,
1322     int nprot, bool is_shared, struct thread *td)
1323 {
1324 	struct task_struct *task;
1325 	struct vm_area_struct *vmap;
1326 	struct mm_struct *mm;
1327 	struct linux_file *filp;
1328 	vm_memattr_t attr;
1329 	int error;
1330 
1331 	filp = (struct linux_file *)fp->f_data;
1332 	filp->f_flags = fp->f_flag;
1333 
1334 	if (fop->mmap == NULL)
1335 		return (EOPNOTSUPP);
1336 
1337 	linux_set_current(td);
1338 
1339 	/*
1340 	 * The same VM object might be shared by multiple processes
1341 	 * and the mm_struct is usually freed when a process exits.
1342 	 *
1343 	 * The atomic reference below makes sure the mm_struct is
1344 	 * available as long as the vmap is in the linux_vma_head.
1345 	 */
1346 	task = current;
1347 	mm = task->mm;
1348 	if (atomic_inc_not_zero(&mm->mm_users) == 0)
1349 		return (EINVAL);
1350 
1351 	vmap = kzalloc(sizeof(*vmap), GFP_KERNEL);
1352 	vmap->vm_start = 0;
1353 	vmap->vm_end = size;
1354 	vmap->vm_pgoff = *offset / PAGE_SIZE;
1355 	vmap->vm_pfn = 0;
1356 	vmap->vm_flags = vmap->vm_page_prot = (nprot & VM_PROT_ALL);
1357 	if (is_shared)
1358 		vmap->vm_flags |= VM_SHARED;
1359 	vmap->vm_ops = NULL;
1360 	vmap->vm_file = get_file(filp);
1361 	vmap->vm_mm = mm;
1362 
1363 	if (unlikely(down_write_killable(&vmap->vm_mm->mmap_sem))) {
1364 		error = linux_get_error(task, EINTR);
1365 	} else {
1366 		error = -OPW(fp, td, fop->mmap(filp, vmap));
1367 		error = linux_get_error(task, error);
1368 		up_write(&vmap->vm_mm->mmap_sem);
1369 	}
1370 
1371 	if (error != 0) {
1372 		linux_cdev_handle_free(vmap);
1373 		return (error);
1374 	}
1375 
1376 	attr = pgprot2cachemode(vmap->vm_page_prot);
1377 
1378 	if (vmap->vm_ops != NULL) {
1379 		struct vm_area_struct *ptr;
1380 		void *vm_private_data;
1381 		bool vm_no_fault;
1382 
1383 		if (vmap->vm_ops->open == NULL ||
1384 		    vmap->vm_ops->close == NULL ||
1385 		    vmap->vm_private_data == NULL) {
1386 			/* free allocated VM area struct */
1387 			linux_cdev_handle_free(vmap);
1388 			return (EINVAL);
1389 		}
1390 
1391 		vm_private_data = vmap->vm_private_data;
1392 
1393 		rw_wlock(&linux_vma_lock);
1394 		TAILQ_FOREACH(ptr, &linux_vma_head, vm_entry) {
1395 			if (ptr->vm_private_data == vm_private_data)
1396 				break;
1397 		}
1398 		/* check if there is an existing VM area struct */
1399 		if (ptr != NULL) {
1400 			/* check if the VM area structure is invalid */
1401 			if (ptr->vm_ops == NULL ||
1402 			    ptr->vm_ops->open == NULL ||
1403 			    ptr->vm_ops->close == NULL) {
1404 				error = ESTALE;
1405 				vm_no_fault = 1;
1406 			} else {
1407 				error = EEXIST;
1408 				vm_no_fault = (ptr->vm_ops->fault == NULL);
1409 			}
1410 		} else {
1411 			/* insert VM area structure into list */
1412 			TAILQ_INSERT_TAIL(&linux_vma_head, vmap, vm_entry);
1413 			error = 0;
1414 			vm_no_fault = (vmap->vm_ops->fault == NULL);
1415 		}
1416 		rw_wunlock(&linux_vma_lock);
1417 
1418 		if (error != 0) {
1419 			/* free allocated VM area struct */
1420 			linux_cdev_handle_free(vmap);
1421 			/* check for stale VM area struct */
1422 			if (error != EEXIST)
1423 				return (error);
1424 		}
1425 
1426 		/* check if there is no fault handler */
1427 		if (vm_no_fault) {
1428 			*object = cdev_pager_allocate(vm_private_data, OBJT_DEVICE,
1429 			    &linux_cdev_pager_ops[1], size, nprot, *offset,
1430 			    td->td_ucred);
1431 		} else {
1432 			*object = cdev_pager_allocate(vm_private_data, OBJT_MGTDEVICE,
1433 			    &linux_cdev_pager_ops[0], size, nprot, *offset,
1434 			    td->td_ucred);
1435 		}
1436 
1437 		/* check if allocating the VM object failed */
1438 		if (*object == NULL) {
1439 			if (error == 0) {
1440 				/* remove VM area struct from list */
1441 				linux_cdev_handle_remove(vmap);
1442 				/* free allocated VM area struct */
1443 				linux_cdev_handle_free(vmap);
1444 			}
1445 			return (EINVAL);
1446 		}
1447 	} else {
1448 		struct sglist *sg;
1449 
1450 		sg = sglist_alloc(1, M_WAITOK);
1451 		sglist_append_phys(sg,
1452 		    (vm_paddr_t)vmap->vm_pfn << PAGE_SHIFT, vmap->vm_len);
1453 
1454 		*object = vm_pager_allocate(OBJT_SG, sg, vmap->vm_len,
1455 		    nprot, 0, td->td_ucred);
1456 
1457 		linux_cdev_handle_free(vmap);
1458 
1459 		if (*object == NULL) {
1460 			sglist_free(sg);
1461 			return (EINVAL);
1462 		}
1463 	}
1464 
1465 	if (attr != VM_MEMATTR_DEFAULT) {
1466 		VM_OBJECT_WLOCK(*object);
1467 		vm_object_set_memattr(*object, attr);
1468 		VM_OBJECT_WUNLOCK(*object);
1469 	}
1470 	*offset = 0;
1471 	return (0);
1472 }
1473 
1474 struct cdevsw linuxcdevsw = {
1475 	.d_version = D_VERSION,
1476 	.d_fdopen = linux_dev_fdopen,
1477 	.d_name = "lkpidev",
1478 };
1479 
1480 static int
1481 linux_file_read(struct file *file, struct uio *uio, struct ucred *active_cred,
1482     int flags, struct thread *td)
1483 {
1484 	struct linux_file *filp;
1485 	const struct file_operations *fop;
1486 	struct linux_cdev *ldev;
1487 	ssize_t bytes;
1488 	int error;
1489 
1490 	error = 0;
1491 	filp = (struct linux_file *)file->f_data;
1492 	filp->f_flags = file->f_flag;
1493 	/* XXX no support for I/O vectors currently */
1494 	if (uio->uio_iovcnt != 1)
1495 		return (EOPNOTSUPP);
1496 	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1497 		return (EINVAL);
1498 	linux_set_current(td);
1499 	linux_get_fop(filp, &fop, &ldev);
1500 	if (fop->read != NULL) {
1501 		bytes = OPW(file, td, fop->read(filp,
1502 		    uio->uio_iov->iov_base,
1503 		    uio->uio_iov->iov_len, &uio->uio_offset));
1504 		if (bytes >= 0) {
1505 			uio->uio_iov->iov_base =
1506 			    ((uint8_t *)uio->uio_iov->iov_base) + bytes;
1507 			uio->uio_iov->iov_len -= bytes;
1508 			uio->uio_resid -= bytes;
1509 		} else {
1510 			error = linux_get_error(current, -bytes);
1511 		}
1512 	} else
1513 		error = ENXIO;
1514 
1515 	/* update kqfilter status, if any */
1516 	linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_READ);
1517 	linux_drop_fop(ldev);
1518 
1519 	return (error);
1520 }
1521 
1522 static int
1523 linux_file_write(struct file *file, struct uio *uio, struct ucred *active_cred,
1524     int flags, struct thread *td)
1525 {
1526 	struct linux_file *filp;
1527 	const struct file_operations *fop;
1528 	struct linux_cdev *ldev;
1529 	ssize_t bytes;
1530 	int error;
1531 
1532 	filp = (struct linux_file *)file->f_data;
1533 	filp->f_flags = file->f_flag;
1534 	/* XXX no support for I/O vectors currently */
1535 	if (uio->uio_iovcnt != 1)
1536 		return (EOPNOTSUPP);
1537 	if (uio->uio_resid > DEVFS_IOSIZE_MAX)
1538 		return (EINVAL);
1539 	linux_set_current(td);
1540 	linux_get_fop(filp, &fop, &ldev);
1541 	if (fop->write != NULL) {
1542 		bytes = OPW(file, td, fop->write(filp,
1543 		    uio->uio_iov->iov_base,
1544 		    uio->uio_iov->iov_len, &uio->uio_offset));
1545 		if (bytes >= 0) {
1546 			uio->uio_iov->iov_base =
1547 			    ((uint8_t *)uio->uio_iov->iov_base) + bytes;
1548 			uio->uio_iov->iov_len -= bytes;
1549 			uio->uio_resid -= bytes;
1550 			error = 0;
1551 		} else {
1552 			error = linux_get_error(current, -bytes);
1553 		}
1554 	} else
1555 		error = ENXIO;
1556 
1557 	/* update kqfilter status, if any */
1558 	linux_file_kqfilter_poll(filp, LINUX_KQ_FLAG_HAS_WRITE);
1559 
1560 	linux_drop_fop(ldev);
1561 
1562 	return (error);
1563 }
1564 
1565 static int
1566 linux_file_poll(struct file *file, int events, struct ucred *active_cred,
1567     struct thread *td)
1568 {
1569 	struct linux_file *filp;
1570 	const struct file_operations *fop;
1571 	struct linux_cdev *ldev;
1572 	int revents;
1573 
1574 	filp = (struct linux_file *)file->f_data;
1575 	filp->f_flags = file->f_flag;
1576 	linux_set_current(td);
1577 	linux_get_fop(filp, &fop, &ldev);
1578 	if (fop->poll != NULL) {
1579 		revents = OPW(file, td, fop->poll(filp,
1580 		    LINUX_POLL_TABLE_NORMAL)) & events;
1581 	} else {
1582 		revents = 0;
1583 	}
1584 	linux_drop_fop(ldev);
1585 	return (revents);
1586 }
1587 
1588 static int
1589 linux_file_close(struct file *file, struct thread *td)
1590 {
1591 	struct linux_file *filp;
1592 	int (*release)(struct inode *, struct linux_file *);
1593 	const struct file_operations *fop;
1594 	struct linux_cdev *ldev;
1595 	int error;
1596 
1597 	filp = (struct linux_file *)file->f_data;
1598 
1599 	KASSERT(file_count(filp) == 0,
1600 	    ("File refcount(%d) is not zero", file_count(filp)));
1601 
1602 	if (td == NULL)
1603 		td = curthread;
1604 
1605 	error = 0;
1606 	filp->f_flags = file->f_flag;
1607 	linux_set_current(td);
1608 	linux_poll_wait_dequeue(filp);
1609 	linux_get_fop(filp, &fop, &ldev);
1610 	/*
1611 	 * Always use the real release function, if any, to avoid
1612 	 * leaking device resources:
1613 	 */
1614 	release = filp->f_op->release;
1615 	if (release != NULL)
1616 		error = -OPW(file, td, release(filp->f_vnode, filp));
1617 	funsetown(&filp->f_sigio);
1618 	if (filp->f_vnode != NULL)
1619 		vrele(filp->f_vnode);
1620 	linux_drop_fop(ldev);
1621 	ldev = filp->f_cdev;
1622 	if (ldev != NULL)
1623 		linux_cdev_deref(ldev);
1624 	linux_synchronize_rcu(RCU_TYPE_REGULAR);
1625 	kfree(filp);
1626 
1627 	return (error);
1628 }
1629 
1630 static int
1631 linux_file_ioctl(struct file *fp, u_long cmd, void *data, struct ucred *cred,
1632     struct thread *td)
1633 {
1634 	struct linux_file *filp;
1635 	const struct file_operations *fop;
1636 	struct linux_cdev *ldev;
1637 	struct fiodgname_arg *fgn;
1638 	const char *p;
1639 	int error, i;
1640 
1641 	error = 0;
1642 	filp = (struct linux_file *)fp->f_data;
1643 	filp->f_flags = fp->f_flag;
1644 	linux_get_fop(filp, &fop, &ldev);
1645 
1646 	linux_set_current(td);
1647 	switch (cmd) {
1648 	case FIONBIO:
1649 		break;
1650 	case FIOASYNC:
1651 		if (fop->fasync == NULL)
1652 			break;
1653 		error = -OPW(fp, td, fop->fasync(0, filp, fp->f_flag & FASYNC));
1654 		break;
1655 	case FIOSETOWN:
1656 		error = fsetown(*(int *)data, &filp->f_sigio);
1657 		if (error == 0) {
1658 			if (fop->fasync == NULL)
1659 				break;
1660 			error = -OPW(fp, td, fop->fasync(0, filp,
1661 			    fp->f_flag & FASYNC));
1662 		}
1663 		break;
1664 	case FIOGETOWN:
1665 		*(int *)data = fgetown(&filp->f_sigio);
1666 		break;
1667 	case FIODGNAME:
1668 #ifdef	COMPAT_FREEBSD32
1669 	case FIODGNAME_32:
1670 #endif
1671 		if (filp->f_cdev == NULL || filp->f_cdev->cdev == NULL) {
1672 			error = ENXIO;
1673 			break;
1674 		}
1675 		fgn = data;
1676 		p = devtoname(filp->f_cdev->cdev);
1677 		i = strlen(p) + 1;
1678 		if (i > fgn->len) {
1679 			error = EINVAL;
1680 			break;
1681 		}
1682 		error = copyout(p, fiodgname_buf_get_ptr(fgn, cmd), i);
1683 		break;
1684 	default:
1685 		error = linux_file_ioctl_sub(fp, filp, fop, cmd, data, td);
1686 		break;
1687 	}
1688 	linux_drop_fop(ldev);
1689 	return (error);
1690 }
1691 
1692 static int
1693 linux_file_mmap_sub(struct thread *td, vm_size_t objsize, vm_prot_t prot,
1694     vm_prot_t maxprot, int flags, struct file *fp,
1695     vm_ooffset_t *foff, const struct file_operations *fop, vm_object_t *objp)
1696 {
1697 	/*
1698 	 * Character devices do not provide private mappings
1699 	 * of any kind:
1700 	 */
1701 	if ((maxprot & VM_PROT_WRITE) == 0 &&
1702 	    (prot & VM_PROT_WRITE) != 0)
1703 		return (EACCES);
1704 	if ((flags & (MAP_PRIVATE | MAP_COPY)) != 0)
1705 		return (EINVAL);
1706 
1707 	return (linux_file_mmap_single(fp, fop, foff, objsize, objp,
1708 	    (int)prot, (flags & MAP_SHARED) ? true : false, td));
1709 }
1710 
1711 static int
1712 linux_file_mmap(struct file *fp, vm_map_t map, vm_offset_t *addr, vm_size_t size,
1713     vm_prot_t prot, vm_prot_t cap_maxprot, int flags, vm_ooffset_t foff,
1714     struct thread *td)
1715 {
1716 	struct linux_file *filp;
1717 	const struct file_operations *fop;
1718 	struct linux_cdev *ldev;
1719 	struct mount *mp;
1720 	struct vnode *vp;
1721 	vm_object_t object;
1722 	vm_prot_t maxprot;
1723 	int error;
1724 
1725 	filp = (struct linux_file *)fp->f_data;
1726 
1727 	vp = filp->f_vnode;
1728 	if (vp == NULL)
1729 		return (EOPNOTSUPP);
1730 
1731 	/*
1732 	 * Ensure that file and memory protections are
1733 	 * compatible.
1734 	 */
1735 	mp = vp->v_mount;
1736 	if (mp != NULL && (mp->mnt_flag & MNT_NOEXEC) != 0) {
1737 		maxprot = VM_PROT_NONE;
1738 		if ((prot & VM_PROT_EXECUTE) != 0)
1739 			return (EACCES);
1740 	} else
1741 		maxprot = VM_PROT_EXECUTE;
1742 	if ((fp->f_flag & FREAD) != 0)
1743 		maxprot |= VM_PROT_READ;
1744 	else if ((prot & VM_PROT_READ) != 0)
1745 		return (EACCES);
1746 
1747 	/*
1748 	 * If we are sharing potential changes via MAP_SHARED and we
1749 	 * are trying to get write permission although we opened it
1750 	 * without asking for it, bail out.
1751 	 *
1752 	 * Note that most character devices always share mappings.
1753 	 *
1754 	 * Rely on linux_file_mmap_sub() to fail invalid MAP_PRIVATE
1755 	 * requests rather than doing it here.
1756 	 */
1757 	if ((flags & MAP_SHARED) != 0) {
1758 		if ((fp->f_flag & FWRITE) != 0)
1759 			maxprot |= VM_PROT_WRITE;
1760 		else if ((prot & VM_PROT_WRITE) != 0)
1761 			return (EACCES);
1762 	}
1763 	maxprot &= cap_maxprot;
1764 
1765 	linux_get_fop(filp, &fop, &ldev);
1766 	error = linux_file_mmap_sub(td, size, prot, maxprot, flags, fp,
1767 	    &foff, fop, &object);
1768 	if (error != 0)
1769 		goto out;
1770 
1771 	error = vm_mmap_object(map, addr, size, prot, maxprot, flags, object,
1772 	    foff, FALSE, td);
1773 	if (error != 0)
1774 		vm_object_deallocate(object);
1775 out:
1776 	linux_drop_fop(ldev);
1777 	return (error);
1778 }
1779 
1780 static int
1781 linux_file_stat(struct file *fp, struct stat *sb, struct ucred *active_cred)
1782 {
1783 	struct linux_file *filp;
1784 	struct vnode *vp;
1785 	int error;
1786 
1787 	filp = (struct linux_file *)fp->f_data;
1788 	if (filp->f_vnode == NULL)
1789 		return (EOPNOTSUPP);
1790 
1791 	vp = filp->f_vnode;
1792 
1793 	vn_lock(vp, LK_SHARED | LK_RETRY);
1794 	error = VOP_STAT(vp, sb, curthread->td_ucred, NOCRED);
1795 	VOP_UNLOCK(vp);
1796 
1797 	return (error);
1798 }
1799 
1800 static int
1801 linux_file_fill_kinfo(struct file *fp, struct kinfo_file *kif,
1802     struct filedesc *fdp)
1803 {
1804 	struct linux_file *filp;
1805 	struct vnode *vp;
1806 	int error;
1807 
1808 	filp = fp->f_data;
1809 	vp = filp->f_vnode;
1810 	if (vp == NULL) {
1811 		error = 0;
1812 		kif->kf_type = KF_TYPE_DEV;
1813 	} else {
1814 		vref(vp);
1815 		FILEDESC_SUNLOCK(fdp);
1816 		error = vn_fill_kinfo_vnode(vp, kif);
1817 		vrele(vp);
1818 		kif->kf_type = KF_TYPE_VNODE;
1819 		FILEDESC_SLOCK(fdp);
1820 	}
1821 	return (error);
1822 }
1823 
1824 unsigned int
1825 linux_iminor(struct inode *inode)
1826 {
1827 	struct linux_cdev *ldev;
1828 
1829 	if (inode == NULL || inode->v_rdev == NULL ||
1830 	    inode->v_rdev->si_devsw != &linuxcdevsw)
1831 		return (-1U);
1832 	ldev = inode->v_rdev->si_drv1;
1833 	if (ldev == NULL)
1834 		return (-1U);
1835 
1836 	return (minor(ldev->dev));
1837 }
1838 
1839 static int
1840 linux_file_kcmp(struct file *fp1, struct file *fp2, struct thread *td)
1841 {
1842 	struct linux_file *filp1, *filp2;
1843 
1844 	if (fp2->f_type != DTYPE_DEV)
1845 		return (3);
1846 
1847 	filp1 = fp1->f_data;
1848 	filp2 = fp2->f_data;
1849 	return (kcmp_cmp((uintptr_t)filp1->f_cdev, (uintptr_t)filp2->f_cdev));
1850 }
1851 
1852 const struct fileops linuxfileops = {
1853 	.fo_read = linux_file_read,
1854 	.fo_write = linux_file_write,
1855 	.fo_truncate = invfo_truncate,
1856 	.fo_kqfilter = linux_file_kqfilter,
1857 	.fo_stat = linux_file_stat,
1858 	.fo_fill_kinfo = linux_file_fill_kinfo,
1859 	.fo_poll = linux_file_poll,
1860 	.fo_close = linux_file_close,
1861 	.fo_ioctl = linux_file_ioctl,
1862 	.fo_mmap = linux_file_mmap,
1863 	.fo_chmod = invfo_chmod,
1864 	.fo_chown = invfo_chown,
1865 	.fo_sendfile = invfo_sendfile,
1866 	.fo_cmp = linux_file_kcmp,
1867 	.fo_flags = DFLAG_PASSABLE,
1868 };
1869 
1870 static char *
1871 devm_kvasprintf(struct device *dev, gfp_t gfp, const char *fmt, va_list ap)
1872 {
1873 	unsigned int len;
1874 	char *p;
1875 	va_list aq;
1876 
1877 	va_copy(aq, ap);
1878 	len = vsnprintf(NULL, 0, fmt, aq);
1879 	va_end(aq);
1880 
1881 	if (dev != NULL)
1882 		p = devm_kmalloc(dev, len + 1, gfp);
1883 	else
1884 		p = kmalloc(len + 1, gfp);
1885 	if (p != NULL)
1886 		vsnprintf(p, len + 1, fmt, ap);
1887 
1888 	return (p);
1889 }
1890 
1891 char *
1892 kvasprintf(gfp_t gfp, const char *fmt, va_list ap)
1893 {
1894 
1895 	return (devm_kvasprintf(NULL, gfp, fmt, ap));
1896 }
1897 
1898 char *
1899 lkpi_devm_kasprintf(struct device *dev, gfp_t gfp, const char *fmt, ...)
1900 {
1901 	va_list ap;
1902 	char *p;
1903 
1904 	va_start(ap, fmt);
1905 	p = devm_kvasprintf(dev, gfp, fmt, ap);
1906 	va_end(ap);
1907 
1908 	return (p);
1909 }
1910 
1911 char *
1912 kasprintf(gfp_t gfp, const char *fmt, ...)
1913 {
1914 	va_list ap;
1915 	char *p;
1916 
1917 	va_start(ap, fmt);
1918 	p = kvasprintf(gfp, fmt, ap);
1919 	va_end(ap);
1920 
1921 	return (p);
1922 }
1923 
1924 int
1925 __lkpi_hexdump_printf(void *arg1 __unused, const char *fmt, ...)
1926 {
1927 	va_list ap;
1928 	int result;
1929 
1930 	va_start(ap, fmt);
1931 	result = vprintf(fmt, ap);
1932 	va_end(ap);
1933 	return (result);
1934 }
1935 
1936 int
1937 __lkpi_hexdump_sbuf_printf(void *arg1, const char *fmt, ...)
1938 {
1939 	va_list ap;
1940 	int result;
1941 
1942 	va_start(ap, fmt);
1943 	result = sbuf_vprintf(arg1, fmt, ap);
1944 	va_end(ap);
1945 	return (result);
1946 }
1947 
1948 void
1949 lkpi_hex_dump(int(*_fpf)(void *, const char *, ...), void *arg1,
1950     const char *level, const char *prefix_str,
1951     const int prefix_type, const int rowsize, const int groupsize,
1952     const void *buf, size_t len, const bool ascii, const bool trailing_newline)
1953 {
1954 	typedef const struct { long long value; } __packed *print_64p_t;
1955 	typedef const struct { uint32_t value; } __packed *print_32p_t;
1956 	typedef const struct { uint16_t value; } __packed *print_16p_t;
1957 	const void *buf_old = buf;
1958 	int row, linelen, ret;
1959 
1960 	while (len > 0) {
1961 		linelen = 0;
1962 		if (level != NULL) {
1963 			ret = _fpf(arg1, "%s", level);
1964 			if (ret < 0)
1965 				break;
1966 			linelen += ret;
1967 		}
1968 		if (prefix_str != NULL) {
1969 			ret = _fpf(
1970 			    arg1, "%s%s", linelen ? " " : "", prefix_str);
1971 			if (ret < 0)
1972 				break;
1973 			linelen += ret;
1974 		}
1975 
1976 		switch (prefix_type) {
1977 		case DUMP_PREFIX_ADDRESS:
1978 			ret = _fpf(
1979 			    arg1, "%s[%p]", linelen ? " " : "", buf);
1980 			if (ret < 0)
1981 				return;
1982 			linelen += ret;
1983 			break;
1984 		case DUMP_PREFIX_OFFSET:
1985 			ret = _fpf(
1986 			    arg1, "%s[%#tx]", linelen ? " " : "",
1987 			    ((const char *)buf - (const char *)buf_old));
1988 			if (ret < 0)
1989 				return;
1990 			linelen += ret;
1991 			break;
1992 		default:
1993 			break;
1994 		}
1995 		for (row = 0; row != rowsize; row++) {
1996 			if (groupsize == 8 && len > 7) {
1997 				ret = _fpf(
1998 				    arg1, "%s%016llx", linelen ? " " : "",
1999 				    ((print_64p_t)buf)->value);
2000 				if (ret < 0)
2001 					return;
2002 				linelen += ret;
2003 				buf = (const uint8_t *)buf + 8;
2004 				len -= 8;
2005 			} else if (groupsize == 4 && len > 3) {
2006 				ret = _fpf(
2007 				    arg1, "%s%08x", linelen ? " " : "",
2008 				    ((print_32p_t)buf)->value);
2009 				if (ret < 0)
2010 					return;
2011 				linelen += ret;
2012 				buf = (const uint8_t *)buf + 4;
2013 				len -= 4;
2014 			} else if (groupsize == 2 && len > 1) {
2015 				ret = _fpf(
2016 				    arg1, "%s%04x", linelen ? " " : "",
2017 				    ((print_16p_t)buf)->value);
2018 				if (ret < 0)
2019 					return;
2020 				linelen += ret;
2021 				buf = (const uint8_t *)buf + 2;
2022 				len -= 2;
2023 			} else if (len > 0) {
2024 				ret = _fpf(
2025 				    arg1, "%s%02x", linelen ? " " : "",
2026 				    *(const uint8_t *)buf);
2027 				if (ret < 0)
2028 					return;
2029 				linelen += ret;
2030 				buf = (const uint8_t *)buf + 1;
2031 				len--;
2032 			} else {
2033 				break;
2034 			}
2035 		}
2036 		if (len > 0 && trailing_newline) {
2037 			ret = _fpf(arg1, "\n");
2038 			if (ret < 0)
2039 				break;
2040 		}
2041 	}
2042 }
2043 
2044 struct hdtb_context {
2045 	char	*linebuf;
2046 	size_t	 linebuflen;
2047 	int	 written;
2048 };
2049 
2050 static int
2051 hdtb_cb(void *arg, const char *format, ...)
2052 {
2053 	struct hdtb_context *context;
2054 	int written;
2055 	va_list args;
2056 
2057 	context = arg;
2058 
2059 	va_start(args, format);
2060 	written = vsnprintf(
2061 	    context->linebuf, context->linebuflen, format, args);
2062 	va_end(args);
2063 
2064 	if (written < 0)
2065 		return (written);
2066 
2067 	/*
2068 	 * Linux' hex_dump_to_buffer() function has the same behaviour as
2069 	 * snprintf() basically. Therefore, it returns the number of bytes it
2070 	 * would have written if the destination buffer was large enough.
2071 	 *
2072 	 * If the destination buffer was exhausted, lkpi_hex_dump() will
2073 	 * continue to call this callback but it will only compute the bytes it
2074 	 * would have written but write nothing to that buffer.
2075 	 */
2076 	context->written += written;
2077 
2078 	if (written < context->linebuflen) {
2079 		context->linebuf += written;
2080 		context->linebuflen -= written;
2081 	} else {
2082 		context->linebuf += context->linebuflen;
2083 		context->linebuflen = 0;
2084 	}
2085 
2086 	return (written);
2087 }
2088 
2089 int
2090 lkpi_hex_dump_to_buffer(const void *buf, size_t len, int rowsize,
2091     int groupsize, char *linebuf, size_t linebuflen, bool ascii)
2092 {
2093 	int written;
2094 	struct hdtb_context context;
2095 
2096 	context.linebuf = linebuf;
2097 	context.linebuflen = linebuflen;
2098 	context.written = 0;
2099 
2100 	if (rowsize != 16 && rowsize != 32)
2101 		rowsize = 16;
2102 
2103 	len = min(len, rowsize);
2104 
2105 	lkpi_hex_dump(
2106 	    hdtb_cb, &context, NULL, NULL, DUMP_PREFIX_NONE,
2107 	    rowsize, groupsize, buf, len, ascii, false);
2108 
2109 	written = context.written;
2110 
2111 	return (written);
2112 }
2113 
2114 static void
2115 linux_timer_callback_wrapper(void *context)
2116 {
2117 	struct timer_list *timer;
2118 
2119 	timer = context;
2120 
2121 	/* the timer is about to be shutdown permanently */
2122 	if (timer->function == NULL)
2123 		return;
2124 
2125 	if (linux_set_current_flags(curthread, M_NOWAIT)) {
2126 		/* try again later */
2127 		callout_reset(&timer->callout, 1,
2128 		    &linux_timer_callback_wrapper, timer);
2129 		return;
2130 	}
2131 
2132 	timer->function(timer->data);
2133 }
2134 
2135 static int
2136 linux_timer_jiffies_until(unsigned long expires)
2137 {
2138 	unsigned long delta = expires - jiffies;
2139 
2140 	/*
2141 	 * Guard against already expired values and make sure that the value can
2142 	 * be used as a tick count, rather than a jiffies count.
2143 	 */
2144 	if ((long)delta < 1)
2145 		delta = 1;
2146 	else if (delta > INT_MAX)
2147 		delta = INT_MAX;
2148 	return ((int)delta);
2149 }
2150 
2151 int
2152 mod_timer(struct timer_list *timer, unsigned long expires)
2153 {
2154 	int ret;
2155 
2156 	timer->expires = expires;
2157 	ret = callout_reset(&timer->callout,
2158 	    linux_timer_jiffies_until(expires),
2159 	    &linux_timer_callback_wrapper, timer);
2160 
2161 	MPASS(ret == 0 || ret == 1);
2162 
2163 	return (ret == 1);
2164 }
2165 
2166 void
2167 add_timer(struct timer_list *timer)
2168 {
2169 
2170 	callout_reset(&timer->callout,
2171 	    linux_timer_jiffies_until(timer->expires),
2172 	    &linux_timer_callback_wrapper, timer);
2173 }
2174 
2175 void
2176 add_timer_on(struct timer_list *timer, int cpu)
2177 {
2178 
2179 	callout_reset_on(&timer->callout,
2180 	    linux_timer_jiffies_until(timer->expires),
2181 	    &linux_timer_callback_wrapper, timer, cpu);
2182 }
2183 
2184 int
2185 timer_delete(struct timer_list *timer)
2186 {
2187 
2188 	if (callout_stop(&(timer)->callout) == -1)
2189 		return (0);
2190 	return (1);
2191 }
2192 
2193 int
2194 timer_delete_sync(struct timer_list *timer)
2195 {
2196 
2197 	if (callout_drain(&(timer)->callout) == -1)
2198 		return (0);
2199 	return (1);
2200 }
2201 
2202 int
2203 timer_shutdown_sync(struct timer_list *timer)
2204 {
2205 
2206 	timer->function = NULL;
2207 	return (del_timer_sync(timer));
2208 }
2209 
2210 /* greatest common divisor, Euclid equation */
2211 static uint64_t
2212 lkpi_gcd_64(uint64_t a, uint64_t b)
2213 {
2214 	uint64_t an;
2215 	uint64_t bn;
2216 
2217 	while (b != 0) {
2218 		an = b;
2219 		bn = a % b;
2220 		a = an;
2221 		b = bn;
2222 	}
2223 	return (a);
2224 }
2225 
2226 uint64_t lkpi_nsec2hz_rem;
2227 uint64_t lkpi_nsec2hz_div = 1000000000ULL;
2228 uint64_t lkpi_nsec2hz_max;
2229 
2230 uint64_t lkpi_usec2hz_rem;
2231 uint64_t lkpi_usec2hz_div = 1000000ULL;
2232 uint64_t lkpi_usec2hz_max;
2233 
2234 uint64_t lkpi_msec2hz_rem;
2235 uint64_t lkpi_msec2hz_div = 1000ULL;
2236 uint64_t lkpi_msec2hz_max;
2237 
2238 static void
2239 linux_timer_init(void *arg)
2240 {
2241 	uint64_t gcd;
2242 
2243 	/*
2244 	 * Compute an internal HZ value which can divide 2**32 to
2245 	 * avoid timer rounding problems when the tick value wraps
2246 	 * around 2**32:
2247 	 */
2248 	linux_timer_hz_mask = 1;
2249 	while (linux_timer_hz_mask < (unsigned long)hz)
2250 		linux_timer_hz_mask *= 2;
2251 	linux_timer_hz_mask--;
2252 
2253 	/* compute some internal constants */
2254 
2255 	lkpi_nsec2hz_rem = hz;
2256 	lkpi_usec2hz_rem = hz;
2257 	lkpi_msec2hz_rem = hz;
2258 
2259 	gcd = lkpi_gcd_64(lkpi_nsec2hz_rem, lkpi_nsec2hz_div);
2260 	lkpi_nsec2hz_rem /= gcd;
2261 	lkpi_nsec2hz_div /= gcd;
2262 	lkpi_nsec2hz_max = -1ULL / lkpi_nsec2hz_rem;
2263 
2264 	gcd = lkpi_gcd_64(lkpi_usec2hz_rem, lkpi_usec2hz_div);
2265 	lkpi_usec2hz_rem /= gcd;
2266 	lkpi_usec2hz_div /= gcd;
2267 	lkpi_usec2hz_max = -1ULL / lkpi_usec2hz_rem;
2268 
2269 	gcd = lkpi_gcd_64(lkpi_msec2hz_rem, lkpi_msec2hz_div);
2270 	lkpi_msec2hz_rem /= gcd;
2271 	lkpi_msec2hz_div /= gcd;
2272 	lkpi_msec2hz_max = -1ULL / lkpi_msec2hz_rem;
2273 }
2274 SYSINIT(linux_timer, SI_SUB_DRIVERS, SI_ORDER_FIRST, linux_timer_init, NULL);
2275 
2276 void
2277 linux_complete_common(struct completion *c, int all)
2278 {
2279 	sleepq_lock(c);
2280 	if (all) {
2281 		c->done = UINT_MAX;
2282 		sleepq_broadcast(c, SLEEPQ_SLEEP, 0, 0);
2283 	} else {
2284 		if (c->done != UINT_MAX)
2285 			c->done++;
2286 		sleepq_signal(c, SLEEPQ_SLEEP, 0, 0);
2287 	}
2288 	sleepq_release(c);
2289 }
2290 
2291 /*
2292  * Indefinite wait for done != 0 with or without signals.
2293  */
2294 int
2295 linux_wait_for_common(struct completion *c, int flags)
2296 {
2297 	struct task_struct *task;
2298 	int error;
2299 
2300 	if (SCHEDULER_STOPPED())
2301 		return (0);
2302 
2303 	task = current;
2304 
2305 	if (flags != 0)
2306 		flags = SLEEPQ_INTERRUPTIBLE | SLEEPQ_SLEEP;
2307 	else
2308 		flags = SLEEPQ_SLEEP;
2309 	error = 0;
2310 	for (;;) {
2311 		sleepq_lock(c);
2312 		if (c->done)
2313 			break;
2314 		sleepq_add(c, NULL, "completion", flags, 0);
2315 		if (flags & SLEEPQ_INTERRUPTIBLE) {
2316 			DROP_GIANT();
2317 			error = -sleepq_wait_sig(c, 0);
2318 			PICKUP_GIANT();
2319 			if (error != 0) {
2320 				linux_schedule_save_interrupt_value(task, error);
2321 				error = -ERESTARTSYS;
2322 				goto intr;
2323 			}
2324 		} else {
2325 			DROP_GIANT();
2326 			sleepq_wait(c, 0);
2327 			PICKUP_GIANT();
2328 		}
2329 	}
2330 	if (c->done != UINT_MAX)
2331 		c->done--;
2332 	sleepq_release(c);
2333 
2334 intr:
2335 	return (error);
2336 }
2337 
2338 /*
2339  * Time limited wait for done != 0 with or without signals.
2340  */
2341 unsigned long
2342 linux_wait_for_timeout_common(struct completion *c, unsigned long timeout,
2343     int flags)
2344 {
2345 	struct task_struct *task;
2346 	unsigned long end = jiffies + timeout, error;
2347 
2348 	if (SCHEDULER_STOPPED())
2349 		return (0);
2350 
2351 	task = current;
2352 
2353 	if (flags != 0)
2354 		flags = SLEEPQ_INTERRUPTIBLE | SLEEPQ_SLEEP;
2355 	else
2356 		flags = SLEEPQ_SLEEP;
2357 
2358 	for (;;) {
2359 		sleepq_lock(c);
2360 		if (c->done)
2361 			break;
2362 		sleepq_add(c, NULL, "completion", flags, 0);
2363 		sleepq_set_timeout(c, linux_timer_jiffies_until(end));
2364 
2365 		DROP_GIANT();
2366 		if (flags & SLEEPQ_INTERRUPTIBLE)
2367 			error = -sleepq_timedwait_sig(c, 0);
2368 		else
2369 			error = -sleepq_timedwait(c, 0);
2370 		PICKUP_GIANT();
2371 
2372 		if (error != 0) {
2373 			/* check for timeout */
2374 			if (error == -EWOULDBLOCK) {
2375 				error = 0;	/* timeout */
2376 			} else {
2377 				/* signal happened */
2378 				linux_schedule_save_interrupt_value(task, error);
2379 				error = -ERESTARTSYS;
2380 			}
2381 			goto done;
2382 		}
2383 	}
2384 	if (c->done != UINT_MAX)
2385 		c->done--;
2386 	sleepq_release(c);
2387 
2388 	/* return how many jiffies are left */
2389 	error = linux_timer_jiffies_until(end);
2390 done:
2391 	return (error);
2392 }
2393 
2394 int
2395 linux_try_wait_for_completion(struct completion *c)
2396 {
2397 	int isdone;
2398 
2399 	sleepq_lock(c);
2400 	isdone = (c->done != 0);
2401 	if (c->done != 0 && c->done != UINT_MAX)
2402 		c->done--;
2403 	sleepq_release(c);
2404 	return (isdone);
2405 }
2406 
2407 int
2408 linux_completion_done(struct completion *c)
2409 {
2410 	int isdone;
2411 
2412 	sleepq_lock(c);
2413 	isdone = (c->done != 0);
2414 	sleepq_release(c);
2415 	return (isdone);
2416 }
2417 
2418 static void
2419 linux_cdev_deref(struct linux_cdev *ldev)
2420 {
2421 	if (refcount_release(&ldev->refs) &&
2422 	    ldev->kobj.ktype == &linux_cdev_ktype)
2423 		kfree(ldev);
2424 }
2425 
2426 static void
2427 linux_cdev_release(struct kobject *kobj)
2428 {
2429 	struct linux_cdev *cdev;
2430 	struct kobject *parent;
2431 
2432 	cdev = container_of(kobj, struct linux_cdev, kobj);
2433 	parent = kobj->parent;
2434 	linux_destroy_dev(cdev);
2435 	linux_cdev_deref(cdev);
2436 	kobject_put(parent);
2437 }
2438 
2439 static void
2440 linux_cdev_static_release(struct kobject *kobj)
2441 {
2442 	struct cdev *cdev;
2443 	struct linux_cdev *ldev;
2444 
2445 	ldev = container_of(kobj, struct linux_cdev, kobj);
2446 	cdev = ldev->cdev;
2447 	if (cdev != NULL) {
2448 		destroy_dev(cdev);
2449 		ldev->cdev = NULL;
2450 	}
2451 	kobject_put(kobj->parent);
2452 }
2453 
2454 int
2455 linux_cdev_device_add(struct linux_cdev *ldev, struct device *dev)
2456 {
2457 	int ret;
2458 
2459 	if (dev->devt != 0) {
2460 		/* Set parent kernel object. */
2461 		ldev->kobj.parent = &dev->kobj;
2462 
2463 		/*
2464 		 * Unlike Linux we require the kobject of the
2465 		 * character device structure to have a valid name
2466 		 * before calling this function:
2467 		 */
2468 		if (ldev->kobj.name == NULL)
2469 			return (-EINVAL);
2470 
2471 		ret = cdev_add(ldev, dev->devt, 1);
2472 		if (ret)
2473 			return (ret);
2474 	}
2475 	ret = device_add(dev);
2476 	if (ret != 0 && dev->devt != 0)
2477 		cdev_del(ldev);
2478 	return (ret);
2479 }
2480 
2481 void
2482 linux_cdev_device_del(struct linux_cdev *ldev, struct device *dev)
2483 {
2484 	device_del(dev);
2485 
2486 	if (dev->devt != 0)
2487 		cdev_del(ldev);
2488 }
2489 
2490 static void
2491 linux_destroy_dev(struct linux_cdev *ldev)
2492 {
2493 
2494 	if (ldev->cdev == NULL)
2495 		return;
2496 
2497 	MPASS((ldev->siref & LDEV_SI_DTR) == 0);
2498 	MPASS(ldev->kobj.ktype == &linux_cdev_ktype);
2499 
2500 	atomic_set_int(&ldev->siref, LDEV_SI_DTR);
2501 	while ((atomic_load_int(&ldev->siref) & ~LDEV_SI_DTR) != 0)
2502 		pause("ldevdtr", hz / 4);
2503 
2504 	destroy_dev(ldev->cdev);
2505 	ldev->cdev = NULL;
2506 }
2507 
2508 const struct kobj_type linux_cdev_ktype = {
2509 	.release = linux_cdev_release,
2510 };
2511 
2512 const struct kobj_type linux_cdev_static_ktype = {
2513 	.release = linux_cdev_static_release,
2514 };
2515 
2516 static void
2517 linux_handle_ifnet_link_event(void *arg, struct ifnet *ifp, int linkstate)
2518 {
2519 	struct notifier_block *nb;
2520 	struct netdev_notifier_info ni;
2521 
2522 	nb = arg;
2523 	ni.ifp = ifp;
2524 	ni.dev = (struct net_device *)ifp;
2525 	if (linkstate == LINK_STATE_UP)
2526 		nb->notifier_call(nb, NETDEV_UP, &ni);
2527 	else
2528 		nb->notifier_call(nb, NETDEV_DOWN, &ni);
2529 }
2530 
2531 static void
2532 linux_handle_ifnet_arrival_event(void *arg, struct ifnet *ifp)
2533 {
2534 	struct notifier_block *nb;
2535 	struct netdev_notifier_info ni;
2536 
2537 	nb = arg;
2538 	ni.ifp = ifp;
2539 	ni.dev = (struct net_device *)ifp;
2540 	nb->notifier_call(nb, NETDEV_REGISTER, &ni);
2541 }
2542 
2543 static void
2544 linux_handle_ifnet_departure_event(void *arg, struct ifnet *ifp)
2545 {
2546 	struct notifier_block *nb;
2547 	struct netdev_notifier_info ni;
2548 
2549 	nb = arg;
2550 	ni.ifp = ifp;
2551 	ni.dev = (struct net_device *)ifp;
2552 	nb->notifier_call(nb, NETDEV_UNREGISTER, &ni);
2553 }
2554 
2555 static void
2556 linux_handle_iflladdr_event(void *arg, struct ifnet *ifp)
2557 {
2558 	struct notifier_block *nb;
2559 	struct netdev_notifier_info ni;
2560 
2561 	nb = arg;
2562 	ni.ifp = ifp;
2563 	ni.dev = (struct net_device *)ifp;
2564 	nb->notifier_call(nb, NETDEV_CHANGEADDR, &ni);
2565 }
2566 
2567 static void
2568 linux_handle_ifaddr_event(void *arg, struct ifnet *ifp)
2569 {
2570 	struct notifier_block *nb;
2571 	struct netdev_notifier_info ni;
2572 
2573 	nb = arg;
2574 	ni.ifp = ifp;
2575 	ni.dev = (struct net_device *)ifp;
2576 	nb->notifier_call(nb, NETDEV_CHANGEIFADDR, &ni);
2577 }
2578 
2579 int
2580 register_netdevice_notifier(struct notifier_block *nb)
2581 {
2582 
2583 	nb->tags[NETDEV_UP] = EVENTHANDLER_REGISTER(
2584 	    ifnet_link_event, linux_handle_ifnet_link_event, nb, 0);
2585 	nb->tags[NETDEV_REGISTER] = EVENTHANDLER_REGISTER(
2586 	    ifnet_arrival_event, linux_handle_ifnet_arrival_event, nb, 0);
2587 	nb->tags[NETDEV_UNREGISTER] = EVENTHANDLER_REGISTER(
2588 	    ifnet_departure_event, linux_handle_ifnet_departure_event, nb, 0);
2589 	nb->tags[NETDEV_CHANGEADDR] = EVENTHANDLER_REGISTER(
2590 	    iflladdr_event, linux_handle_iflladdr_event, nb, 0);
2591 
2592 	return (0);
2593 }
2594 
2595 int
2596 register_inetaddr_notifier(struct notifier_block *nb)
2597 {
2598 
2599 	nb->tags[NETDEV_CHANGEIFADDR] = EVENTHANDLER_REGISTER(
2600 	    ifaddr_event, linux_handle_ifaddr_event, nb, 0);
2601 	return (0);
2602 }
2603 
2604 int
2605 unregister_netdevice_notifier(struct notifier_block *nb)
2606 {
2607 
2608 	EVENTHANDLER_DEREGISTER(ifnet_link_event,
2609 	    nb->tags[NETDEV_UP]);
2610 	EVENTHANDLER_DEREGISTER(ifnet_arrival_event,
2611 	    nb->tags[NETDEV_REGISTER]);
2612 	EVENTHANDLER_DEREGISTER(ifnet_departure_event,
2613 	    nb->tags[NETDEV_UNREGISTER]);
2614 	EVENTHANDLER_DEREGISTER(iflladdr_event,
2615 	    nb->tags[NETDEV_CHANGEADDR]);
2616 
2617 	return (0);
2618 }
2619 
2620 int
2621 unregister_inetaddr_notifier(struct notifier_block *nb)
2622 {
2623 
2624 	EVENTHANDLER_DEREGISTER(ifaddr_event,
2625 	    nb->tags[NETDEV_CHANGEIFADDR]);
2626 
2627 	return (0);
2628 }
2629 
2630 struct list_sort_thunk {
2631 	int (*cmp)(void *, struct list_head *, struct list_head *);
2632 	void *priv;
2633 };
2634 
2635 static inline int
2636 linux_le_cmp(const void *d1, const void *d2, void *priv)
2637 {
2638 	struct list_head *le1, *le2;
2639 	struct list_sort_thunk *thunk;
2640 
2641 	thunk = priv;
2642 	le1 = *(__DECONST(struct list_head **, d1));
2643 	le2 = *(__DECONST(struct list_head **, d2));
2644 	return ((thunk->cmp)(thunk->priv, le1, le2));
2645 }
2646 
2647 void
2648 list_sort(void *priv, struct list_head *head, int (*cmp)(void *priv,
2649     struct list_head *a, struct list_head *b))
2650 {
2651 	struct list_sort_thunk thunk;
2652 	struct list_head **ar, *le;
2653 	size_t count, i;
2654 
2655 	count = 0;
2656 	list_for_each(le, head)
2657 		count++;
2658 	ar = malloc(sizeof(struct list_head *) * count, M_KMALLOC, M_WAITOK);
2659 	i = 0;
2660 	list_for_each(le, head)
2661 		ar[i++] = le;
2662 	thunk.cmp = cmp;
2663 	thunk.priv = priv;
2664 	qsort_r(ar, count, sizeof(struct list_head *), linux_le_cmp, &thunk);
2665 	INIT_LIST_HEAD(head);
2666 	for (i = 0; i < count; i++)
2667 		list_add_tail(ar[i], head);
2668 	free(ar, M_KMALLOC);
2669 }
2670 
2671 #if defined(__i386__) || defined(__amd64__)
2672 int
2673 linux_wbinvd_on_all_cpus(void)
2674 {
2675 
2676 	pmap_invalidate_cache();
2677 	return (0);
2678 }
2679 #endif
2680 
2681 int
2682 linux_on_each_cpu(void callback(void *), void *data)
2683 {
2684 
2685 	smp_rendezvous(smp_no_rendezvous_barrier, callback,
2686 	    smp_no_rendezvous_barrier, data);
2687 	return (0);
2688 }
2689 
2690 int
2691 linux_in_atomic(void)
2692 {
2693 
2694 	return ((curthread->td_pflags & TDP_NOFAULTING) != 0);
2695 }
2696 
2697 struct linux_cdev *
2698 linux_find_cdev(const char *name, unsigned major, unsigned minor)
2699 {
2700 	dev_t dev = MKDEV(major, minor);
2701 	struct cdev *cdev;
2702 
2703 	dev_lock();
2704 	LIST_FOREACH(cdev, &linuxcdevsw.d_devs, si_list) {
2705 		struct linux_cdev *ldev = cdev->si_drv1;
2706 		if (ldev->dev == dev &&
2707 		    strcmp(kobject_name(&ldev->kobj), name) == 0) {
2708 			break;
2709 		}
2710 	}
2711 	dev_unlock();
2712 
2713 	return (cdev != NULL ? cdev->si_drv1 : NULL);
2714 }
2715 
2716 int
2717 __register_chrdev(unsigned int major, unsigned int baseminor,
2718     unsigned int count, const char *name,
2719     const struct file_operations *fops)
2720 {
2721 	struct linux_cdev *cdev;
2722 	int ret = 0;
2723 	int i;
2724 
2725 	for (i = baseminor; i < baseminor + count; i++) {
2726 		cdev = cdev_alloc();
2727 		cdev->ops = fops;
2728 		kobject_set_name(&cdev->kobj, name);
2729 
2730 		ret = cdev_add(cdev, makedev(major, i), 1);
2731 		if (ret != 0)
2732 			break;
2733 	}
2734 	return (ret);
2735 }
2736 
2737 int
2738 __register_chrdev_p(unsigned int major, unsigned int baseminor,
2739     unsigned int count, const char *name,
2740     const struct file_operations *fops, uid_t uid,
2741     gid_t gid, int mode)
2742 {
2743 	struct linux_cdev *cdev;
2744 	int ret = 0;
2745 	int i;
2746 
2747 	for (i = baseminor; i < baseminor + count; i++) {
2748 		cdev = cdev_alloc();
2749 		cdev->ops = fops;
2750 		kobject_set_name(&cdev->kobj, name);
2751 
2752 		ret = cdev_add_ext(cdev, makedev(major, i), uid, gid, mode);
2753 		if (ret != 0)
2754 			break;
2755 	}
2756 	return (ret);
2757 }
2758 
2759 void
2760 __unregister_chrdev(unsigned int major, unsigned int baseminor,
2761     unsigned int count, const char *name)
2762 {
2763 	struct linux_cdev *cdevp;
2764 	int i;
2765 
2766 	for (i = baseminor; i < baseminor + count; i++) {
2767 		cdevp = linux_find_cdev(name, major, i);
2768 		if (cdevp != NULL)
2769 			cdev_del(cdevp);
2770 	}
2771 }
2772 
2773 void
2774 linux_dump_stack(void)
2775 {
2776 #ifdef STACK
2777 	struct stack st;
2778 
2779 	stack_save(&st);
2780 	stack_print(&st);
2781 #endif
2782 }
2783 
2784 int
2785 linuxkpi_net_ratelimit(void)
2786 {
2787 
2788 	return (ppsratecheck(&lkpi_net_lastlog, &lkpi_net_curpps,
2789 	   lkpi_net_maxpps));
2790 }
2791 
2792 struct io_mapping *
2793 io_mapping_create_wc(resource_size_t base, unsigned long size)
2794 {
2795 	struct io_mapping *mapping;
2796 
2797 	mapping = kmalloc(sizeof(*mapping), GFP_KERNEL);
2798 	if (mapping == NULL)
2799 		return (NULL);
2800 	return (io_mapping_init_wc(mapping, base, size));
2801 }
2802 
2803 /* We likely want a linuxkpi_device.c at some point. */
2804 bool
2805 device_can_wakeup(struct device *dev)
2806 {
2807 
2808 	if (dev == NULL)
2809 		return (false);
2810 	/*
2811 	 * XXX-BZ iwlwifi queries it as part of enabling WoWLAN.
2812 	 * Normally this would be based on a bool in dev->power.XXX.
2813 	 * Check such as PCI PCIM_PCAP_*PME.  We have no way to enable this yet.
2814 	 * We may get away by directly calling into bsddev for as long as
2815 	 * we can assume PCI only avoiding changing struct device breaking KBI.
2816 	 */
2817 	pr_debug("%s:%d: not enabled; see comment.\n", __func__, __LINE__);
2818 	return (false);
2819 }
2820 
2821 static void
2822 devm_device_group_remove(struct device *dev, void *p)
2823 {
2824 	const struct attribute_group **dr = p;
2825 	const struct attribute_group *group = *dr;
2826 
2827 	sysfs_remove_group(&dev->kobj, group);
2828 }
2829 
2830 int
2831 lkpi_devm_device_add_group(struct device *dev,
2832     const struct attribute_group *group)
2833 {
2834 	const struct attribute_group **dr;
2835 	int ret;
2836 
2837 	dr = devres_alloc(devm_device_group_remove, sizeof(*dr), GFP_KERNEL);
2838 	if (dr == NULL)
2839 		return (-ENOMEM);
2840 
2841 	ret = sysfs_create_group(&dev->kobj, group);
2842 	if (ret == 0) {
2843 		*dr = group;
2844 		devres_add(dev, dr);
2845 	} else
2846 		devres_free(dr);
2847 
2848 	return (ret);
2849 }
2850 
2851 #if defined(__i386__) || defined(__amd64__)
2852 bool linux_cpu_has_clflush;
2853 struct cpuinfo_x86 boot_cpu_data;
2854 struct cpuinfo_x86 *__cpu_data;
2855 #endif
2856 
2857 cpumask_t *
2858 lkpi_get_static_single_cpu_mask(int cpuid)
2859 {
2860 
2861 	KASSERT((cpuid >= 0 && cpuid <= mp_maxid), ("%s: invalid cpuid %d\n",
2862 	    __func__, cpuid));
2863 	KASSERT(!CPU_ABSENT(cpuid), ("%s: cpu with cpuid %d is absent\n",
2864 	    __func__, cpuid));
2865 
2866 	return (static_single_cpu_mask[cpuid]);
2867 }
2868 
2869 bool
2870 lkpi_xen_initial_domain(void)
2871 {
2872 #ifdef XENHVM
2873 	return (xen_initial_domain());
2874 #else
2875 	return (false);
2876 #endif
2877 }
2878 
2879 bool
2880 lkpi_xen_pv_domain(void)
2881 {
2882 #ifdef XENHVM
2883 	return (xen_pv_domain());
2884 #else
2885 	return (false);
2886 #endif
2887 }
2888 
2889 static void
2890 linux_compat_init(void *arg)
2891 {
2892 	struct sysctl_oid *rootoid;
2893 	int i;
2894 
2895 #if defined(__i386__) || defined(__amd64__)
2896 	static const uint32_t x86_vendors[X86_VENDOR_NUM] = {
2897 		[X86_VENDOR_INTEL] = CPU_VENDOR_INTEL,
2898 		[X86_VENDOR_CYRIX] = CPU_VENDOR_CYRIX,
2899 		[X86_VENDOR_AMD] = CPU_VENDOR_AMD,
2900 		[X86_VENDOR_UMC] = CPU_VENDOR_UMC,
2901 		[X86_VENDOR_CENTAUR] = CPU_VENDOR_CENTAUR,
2902 		[X86_VENDOR_TRANSMETA] = CPU_VENDOR_TRANSMETA,
2903 		[X86_VENDOR_NSC] = CPU_VENDOR_NSC,
2904 		[X86_VENDOR_HYGON] = CPU_VENDOR_HYGON,
2905 	};
2906 	uint8_t x86_vendor = X86_VENDOR_UNKNOWN;
2907 
2908 	for (i = 0; i < X86_VENDOR_NUM; i++) {
2909 		if (cpu_vendor_id != 0 && cpu_vendor_id == x86_vendors[i]) {
2910 			x86_vendor = i;
2911 			break;
2912 		}
2913 	}
2914 	linux_cpu_has_clflush = (cpu_feature & CPUID_CLFSH);
2915 	boot_cpu_data.x86_clflush_size = cpu_clflush_line_size;
2916 	boot_cpu_data.x86_max_cores = mp_ncpus;
2917 	boot_cpu_data.x86 = CPUID_TO_FAMILY(cpu_id);
2918 	boot_cpu_data.x86_model = CPUID_TO_MODEL(cpu_id);
2919 	boot_cpu_data.x86_vendor = x86_vendor;
2920 	boot_cpu_data.x86_stepping = CPUID_TO_STEPPING(cpu_id);
2921 
2922 	__cpu_data = kmalloc_array(mp_maxid + 1,
2923 	    sizeof(*__cpu_data), M_WAITOK | M_ZERO);
2924 	CPU_FOREACH(i) {
2925 		__cpu_data[i].x86_clflush_size = cpu_clflush_line_size;
2926 		__cpu_data[i].x86_max_cores = mp_ncpus;
2927 		__cpu_data[i].x86 = CPUID_TO_FAMILY(cpu_id);
2928 		__cpu_data[i].x86_model = CPUID_TO_MODEL(cpu_id);
2929 		__cpu_data[i].x86_vendor = x86_vendor;
2930 	}
2931 #endif
2932 	rw_init(&linux_vma_lock, "lkpi-vma-lock");
2933 
2934 	rootoid = SYSCTL_ADD_ROOT_NODE(NULL,
2935 	    OID_AUTO, "sys", CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, "sys");
2936 	kobject_init(&linux_class_root, &linux_class_ktype);
2937 	kobject_set_name(&linux_class_root, "class");
2938 	linux_class_root.oidp = SYSCTL_ADD_NODE(NULL, SYSCTL_CHILDREN(rootoid),
2939 	    OID_AUTO, "class", CTLFLAG_RD|CTLFLAG_MPSAFE, NULL, "class");
2940 	kobject_init(&linux_root_device.kobj, &linux_dev_ktype);
2941 	kobject_set_name(&linux_root_device.kobj, "device");
2942 	linux_root_device.kobj.oidp = SYSCTL_ADD_NODE(NULL,
2943 	    SYSCTL_CHILDREN(rootoid), OID_AUTO, "device",
2944 	    CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "device");
2945 	linux_root_device.bsddev = root_bus;
2946 	linux_class_misc.name = "misc";
2947 	class_register(&linux_class_misc);
2948 	INIT_LIST_HEAD(&pci_drivers);
2949 	INIT_LIST_HEAD(&pci_devices);
2950 	spin_lock_init(&pci_lock);
2951 	init_waitqueue_head(&linux_bit_waitq);
2952 	init_waitqueue_head(&linux_var_waitq);
2953 
2954 	CPU_COPY(&all_cpus, &cpu_online_mask);
2955 	/*
2956 	 * Generate a single-CPU cpumask_t for each CPU (possibly) in the system.
2957 	 * CPUs are indexed from 0..(mp_maxid).  The entry for cpuid 0 will only
2958 	 * have itself in the cpumask, cupid 1 only itself on entry 1, and so on.
2959 	 * This is used by cpumask_of() (and possibly others in the future) for,
2960 	 * e.g., drivers to pass hints to irq_set_affinity_hint().
2961 	 */
2962 	static_single_cpu_mask = kmalloc_array(mp_maxid + 1,
2963 	    sizeof(static_single_cpu_mask), M_WAITOK | M_ZERO);
2964 
2965 	/*
2966 	 * When the number of CPUs reach a threshold, we start to save memory
2967 	 * given the sets are static by overlapping those having their single
2968 	 * bit set at same position in a bitset word.  Asymptotically, this
2969 	 * regular scheme is in O(n²) whereas the overlapping one is in O(n)
2970 	 * only with n being the maximum number of CPUs, so the gain will become
2971 	 * huge quite quickly.  The threshold for 64-bit architectures is 128
2972 	 * CPUs.
2973 	 */
2974 	if (mp_ncpus < (2 * _BITSET_BITS)) {
2975 		cpumask_t *sscm_ptr;
2976 
2977 		/*
2978 		 * This represents 'mp_ncpus * __bitset_words(CPU_SETSIZE) *
2979 		 * (_BITSET_BITS / 8)' bytes (for comparison with the
2980 		 * overlapping scheme).
2981 		 */
2982 		static_single_cpu_mask_lcs = kmalloc_array(mp_ncpus,
2983 		    sizeof(*static_single_cpu_mask_lcs),
2984 		    M_WAITOK | M_ZERO);
2985 
2986 		sscm_ptr = static_single_cpu_mask_lcs;
2987 		CPU_FOREACH(i) {
2988 			static_single_cpu_mask[i] = sscm_ptr++;
2989 			CPU_SET(i, static_single_cpu_mask[i]);
2990 		}
2991 	} else {
2992 		/* Pointer to a bitset word. */
2993 		__typeof(((cpuset_t *)NULL)->__bits[0]) *bwp;
2994 
2995 		/*
2996 		 * Allocate memory for (static) spans of 'cpumask_t' ('cpuset_t'
2997 		 * really) with a single bit set that can be reused for all
2998 		 * single CPU masks by making them start at different offsets.
2999 		 * We need '__bitset_words(CPU_SETSIZE) - 1' bitset words before
3000 		 * the word having its single bit set, and the same amount
3001 		 * after.
3002 		 */
3003 		static_single_cpu_mask_lcs = mallocarray(_BITSET_BITS,
3004 		    (2 * __bitset_words(CPU_SETSIZE) - 1) * (_BITSET_BITS / 8),
3005 		    M_KMALLOC, M_WAITOK | M_ZERO);
3006 
3007 		/*
3008 		 * We rely below on cpuset_t and the bitset generic
3009 		 * implementation assigning words in the '__bits' array in the
3010 		 * same order of bits (i.e., little-endian ordering, not to be
3011 		 * confused with machine endianness, which concerns bits in
3012 		 * words and other integers).  This is an imperfect test, but it
3013 		 * will detect a change to big-endian ordering.
3014 		 */
3015 		_Static_assert(
3016 		    __bitset_word(_BITSET_BITS + 1, _BITSET_BITS) == 1,
3017 		    "Assumes a bitset implementation that is little-endian "
3018 		    "on its words");
3019 
3020 		/* Initialize the single bit of each static span. */
3021 		bwp = (__typeof(bwp))static_single_cpu_mask_lcs +
3022 		    (__bitset_words(CPU_SETSIZE) - 1);
3023 		for (i = 0; i < _BITSET_BITS; i++) {
3024 			CPU_SET(i, (cpuset_t *)bwp);
3025 			bwp += (2 * __bitset_words(CPU_SETSIZE) - 1);
3026 		}
3027 
3028 		/*
3029 		 * Finally set all CPU masks to the proper word in their
3030 		 * relevant span.
3031 		 */
3032 		CPU_FOREACH(i) {
3033 			bwp = (__typeof(bwp))static_single_cpu_mask_lcs;
3034 			/* Find the non-zero word of the relevant span. */
3035 			bwp += (2 * __bitset_words(CPU_SETSIZE) - 1) *
3036 			    (i % _BITSET_BITS) +
3037 			    __bitset_words(CPU_SETSIZE) - 1;
3038 			/* Shift to find the CPU mask start. */
3039 			bwp -= (i / _BITSET_BITS);
3040 			static_single_cpu_mask[i] = (cpuset_t *)bwp;
3041 		}
3042 	}
3043 
3044 	strlcpy(init_uts_ns.name.release, osrelease, sizeof(init_uts_ns.name.release));
3045 }
3046 SYSINIT(linux_compat, SI_SUB_DRIVERS, SI_ORDER_SECOND, linux_compat_init, NULL);
3047 
3048 static void
3049 linux_compat_uninit(void *arg)
3050 {
3051 	linux_kobject_kfree_name(&linux_class_root);
3052 	linux_kobject_kfree_name(&linux_root_device.kobj);
3053 	linux_kobject_kfree_name(&linux_class_misc.kobj);
3054 
3055 	free(static_single_cpu_mask_lcs, M_KMALLOC);
3056 	free(static_single_cpu_mask, M_KMALLOC);
3057 #if defined(__i386__) || defined(__amd64__)
3058 	free(__cpu_data, M_KMALLOC);
3059 #endif
3060 
3061 	spin_lock_destroy(&pci_lock);
3062 	rw_destroy(&linux_vma_lock);
3063 }
3064 SYSUNINIT(linux_compat, SI_SUB_DRIVERS, SI_ORDER_SECOND, linux_compat_uninit, NULL);
3065 
3066 /*
3067  * NOTE: Linux frequently uses "unsigned long" for pointer to integer
3068  * conversion and vice versa, where in FreeBSD "uintptr_t" would be
3069  * used. Assert these types have the same size, else some parts of the
3070  * LinuxKPI may not work like expected:
3071  */
3072 CTASSERT(sizeof(unsigned long) == sizeof(uintptr_t));
3073