xref: /freebsd/sys/vm/vm_map.c (revision eb1e8a82963684bac34c992a409a5f6ef6ed08c3)
1 /*-
2  * SPDX-License-Identifier: (BSD-3-Clause AND MIT-CMU)
3  *
4  * Copyright (c) 1991, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * The Mach Operating System project at Carnegie-Mellon University.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	from: @(#)vm_map.c	8.3 (Berkeley) 1/12/94
35  *
36  *
37  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
38  * All rights reserved.
39  *
40  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
41  *
42  * Permission to use, copy, modify and distribute this software and
43  * its documentation is hereby granted, provided that both the copyright
44  * notice and this permission notice appear in all copies of the
45  * software, derivative works or modified versions, and any portions
46  * thereof, and that both notices appear in supporting documentation.
47  *
48  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
49  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
50  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
51  *
52  * Carnegie Mellon requests users of this software to return to
53  *
54  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
55  *  School of Computer Science
56  *  Carnegie Mellon University
57  *  Pittsburgh PA 15213-3890
58  *
59  * any improvements or extensions that they make and grant Carnegie the
60  * rights to redistribute these changes.
61  */
62 
63 /*
64  *	Virtual memory mapping module.
65  */
66 
67 #include <sys/cdefs.h>
68 __FBSDID("$FreeBSD$");
69 
70 #include <sys/param.h>
71 #include <sys/systm.h>
72 #include <sys/elf.h>
73 #include <sys/kernel.h>
74 #include <sys/ktr.h>
75 #include <sys/lock.h>
76 #include <sys/mutex.h>
77 #include <sys/proc.h>
78 #include <sys/vmmeter.h>
79 #include <sys/mman.h>
80 #include <sys/vnode.h>
81 #include <sys/racct.h>
82 #include <sys/resourcevar.h>
83 #include <sys/rwlock.h>
84 #include <sys/file.h>
85 #include <sys/sysctl.h>
86 #include <sys/sysent.h>
87 #include <sys/shm.h>
88 
89 #include <vm/vm.h>
90 #include <vm/vm_param.h>
91 #include <vm/pmap.h>
92 #include <vm/vm_map.h>
93 #include <vm/vm_page.h>
94 #include <vm/vm_pageout.h>
95 #include <vm/vm_object.h>
96 #include <vm/vm_pager.h>
97 #include <vm/vm_kern.h>
98 #include <vm/vm_extern.h>
99 #include <vm/vnode_pager.h>
100 #include <vm/swap_pager.h>
101 #include <vm/uma.h>
102 
103 /*
104  *	Virtual memory maps provide for the mapping, protection,
105  *	and sharing of virtual memory objects.  In addition,
106  *	this module provides for an efficient virtual copy of
107  *	memory from one map to another.
108  *
109  *	Synchronization is required prior to most operations.
110  *
111  *	Maps consist of an ordered doubly-linked list of simple
112  *	entries; a self-adjusting binary search tree of these
113  *	entries is used to speed up lookups.
114  *
115  *	Since portions of maps are specified by start/end addresses,
116  *	which may not align with existing map entries, all
117  *	routines merely "clip" entries to these start/end values.
118  *	[That is, an entry is split into two, bordering at a
119  *	start or end value.]  Note that these clippings may not
120  *	always be necessary (as the two resulting entries are then
121  *	not changed); however, the clipping is done for convenience.
122  *
123  *	As mentioned above, virtual copy operations are performed
124  *	by copying VM object references from one map to
125  *	another, and then marking both regions as copy-on-write.
126  */
127 
128 static struct mtx map_sleep_mtx;
129 static uma_zone_t mapentzone;
130 static uma_zone_t kmapentzone;
131 static uma_zone_t vmspace_zone;
132 static int vmspace_zinit(void *mem, int size, int flags);
133 static void _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min,
134     vm_offset_t max);
135 static void vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map);
136 static void vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry);
137 static void vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry);
138 static int vm_map_growstack(vm_map_t map, vm_offset_t addr,
139     vm_map_entry_t gap_entry);
140 static void vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
141     vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags);
142 #ifdef INVARIANTS
143 static void vmspace_zdtor(void *mem, int size, void *arg);
144 #endif
145 static int vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos,
146     vm_size_t max_ssize, vm_size_t growsize, vm_prot_t prot, vm_prot_t max,
147     int cow);
148 static void vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
149     vm_offset_t failed_addr);
150 
151 #define	ENTRY_CHARGED(e) ((e)->cred != NULL || \
152     ((e)->object.vm_object != NULL && (e)->object.vm_object->cred != NULL && \
153      !((e)->eflags & MAP_ENTRY_NEEDS_COPY)))
154 
155 /*
156  * PROC_VMSPACE_{UN,}LOCK() can be a noop as long as vmspaces are type
157  * stable.
158  */
159 #define PROC_VMSPACE_LOCK(p) do { } while (0)
160 #define PROC_VMSPACE_UNLOCK(p) do { } while (0)
161 
162 /*
163  *	VM_MAP_RANGE_CHECK:	[ internal use only ]
164  *
165  *	Asserts that the starting and ending region
166  *	addresses fall within the valid range of the map.
167  */
168 #define	VM_MAP_RANGE_CHECK(map, start, end)		\
169 		{					\
170 		if (start < vm_map_min(map))		\
171 			start = vm_map_min(map);	\
172 		if (end > vm_map_max(map))		\
173 			end = vm_map_max(map);		\
174 		if (start > end)			\
175 			start = end;			\
176 		}
177 
178 #ifndef UMA_MD_SMALL_ALLOC
179 
180 /*
181  * Allocate a new slab for kernel map entries.  The kernel map may be locked or
182  * unlocked, depending on whether the request is coming from the kernel map or a
183  * submap.  This function allocates a virtual address range directly from the
184  * kernel map instead of the kmem_* layer to avoid recursion on the kernel map
185  * lock and also to avoid triggering allocator recursion in the vmem boundary
186  * tag allocator.
187  */
188 static void *
189 kmapent_alloc(uma_zone_t zone, vm_size_t bytes, int domain, uint8_t *pflag,
190     int wait)
191 {
192 	vm_offset_t addr;
193 	int error, locked;
194 
195 	*pflag = UMA_SLAB_PRIV;
196 
197 	if (!(locked = vm_map_locked(kernel_map)))
198 		vm_map_lock(kernel_map);
199 	addr = vm_map_findspace(kernel_map, vm_map_min(kernel_map), bytes);
200 	if (addr + bytes < addr || addr + bytes > vm_map_max(kernel_map))
201 		panic("%s: kernel map is exhausted", __func__);
202 	error = vm_map_insert(kernel_map, NULL, 0, addr, addr + bytes,
203 	    VM_PROT_RW, VM_PROT_RW, MAP_NOFAULT);
204 	if (error != KERN_SUCCESS)
205 		panic("%s: vm_map_insert() failed: %d", __func__, error);
206 	if (!locked)
207 		vm_map_unlock(kernel_map);
208 	error = kmem_back_domain(domain, kernel_object, addr, bytes, M_NOWAIT |
209 	    M_USE_RESERVE | (wait & M_ZERO));
210 	if (error == KERN_SUCCESS) {
211 		return ((void *)addr);
212 	} else {
213 		if (!locked)
214 			vm_map_lock(kernel_map);
215 		vm_map_delete(kernel_map, addr, bytes);
216 		if (!locked)
217 			vm_map_unlock(kernel_map);
218 		return (NULL);
219 	}
220 }
221 
222 static void
223 kmapent_free(void *item, vm_size_t size, uint8_t pflag)
224 {
225 	vm_offset_t addr;
226 	int error;
227 
228 	if ((pflag & UMA_SLAB_PRIV) == 0)
229 		/* XXX leaked */
230 		return;
231 
232 	addr = (vm_offset_t)item;
233 	kmem_unback(kernel_object, addr, size);
234 	error = vm_map_remove(kernel_map, addr, addr + size);
235 	KASSERT(error == KERN_SUCCESS,
236 	    ("%s: vm_map_remove failed: %d", __func__, error));
237 }
238 
239 /*
240  * The worst-case upper bound on the number of kernel map entries that may be
241  * created before the zone must be replenished in _vm_map_unlock().
242  */
243 #define	KMAPENT_RESERVE		1
244 
245 #endif /* !UMD_MD_SMALL_ALLOC */
246 
247 /*
248  *	vm_map_startup:
249  *
250  *	Initialize the vm_map module.  Must be called before any other vm_map
251  *	routines.
252  *
253  *	User map and entry structures are allocated from the general purpose
254  *	memory pool.  Kernel maps are statically defined.  Kernel map entries
255  *	require special handling to avoid recursion; see the comments above
256  *	kmapent_alloc() and in vm_map_entry_create().
257  */
258 void
259 vm_map_startup(void)
260 {
261 	mtx_init(&map_sleep_mtx, "vm map sleep mutex", NULL, MTX_DEF);
262 
263 	/*
264 	 * Disable the use of per-CPU buckets: map entry allocation is
265 	 * serialized by the kernel map lock.
266 	 */
267 	kmapentzone = uma_zcreate("KMAP ENTRY", sizeof(struct vm_map_entry),
268 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR,
269 	    UMA_ZONE_VM | UMA_ZONE_NOBUCKET);
270 #ifndef UMA_MD_SMALL_ALLOC
271 	/* Reserve an extra map entry for use when replenishing the reserve. */
272 	uma_zone_reserve(kmapentzone, KMAPENT_RESERVE + 1);
273 	uma_prealloc(kmapentzone, KMAPENT_RESERVE + 1);
274 	uma_zone_set_allocf(kmapentzone, kmapent_alloc);
275 	uma_zone_set_freef(kmapentzone, kmapent_free);
276 #endif
277 
278 	mapentzone = uma_zcreate("MAP ENTRY", sizeof(struct vm_map_entry),
279 	    NULL, NULL, NULL, NULL, UMA_ALIGN_PTR, 0);
280 	vmspace_zone = uma_zcreate("VMSPACE", sizeof(struct vmspace), NULL,
281 #ifdef INVARIANTS
282 	    vmspace_zdtor,
283 #else
284 	    NULL,
285 #endif
286 	    vmspace_zinit, NULL, UMA_ALIGN_PTR, UMA_ZONE_NOFREE);
287 }
288 
289 static int
290 vmspace_zinit(void *mem, int size, int flags)
291 {
292 	struct vmspace *vm;
293 	vm_map_t map;
294 
295 	vm = (struct vmspace *)mem;
296 	map = &vm->vm_map;
297 
298 	memset(map, 0, sizeof(*map));
299 	mtx_init(&map->system_mtx, "vm map (system)", NULL,
300 	    MTX_DEF | MTX_DUPOK);
301 	sx_init(&map->lock, "vm map (user)");
302 	PMAP_LOCK_INIT(vmspace_pmap(vm));
303 	return (0);
304 }
305 
306 #ifdef INVARIANTS
307 static void
308 vmspace_zdtor(void *mem, int size, void *arg)
309 {
310 	struct vmspace *vm;
311 
312 	vm = (struct vmspace *)mem;
313 	KASSERT(vm->vm_map.nentries == 0,
314 	    ("vmspace %p nentries == %d on free", vm, vm->vm_map.nentries));
315 	KASSERT(vm->vm_map.size == 0,
316 	    ("vmspace %p size == %ju on free", vm, (uintmax_t)vm->vm_map.size));
317 }
318 #endif	/* INVARIANTS */
319 
320 /*
321  * Allocate a vmspace structure, including a vm_map and pmap,
322  * and initialize those structures.  The refcnt is set to 1.
323  */
324 struct vmspace *
325 vmspace_alloc(vm_offset_t min, vm_offset_t max, pmap_pinit_t pinit)
326 {
327 	struct vmspace *vm;
328 
329 	vm = uma_zalloc(vmspace_zone, M_WAITOK);
330 	KASSERT(vm->vm_map.pmap == NULL, ("vm_map.pmap must be NULL"));
331 	if (!pinit(vmspace_pmap(vm))) {
332 		uma_zfree(vmspace_zone, vm);
333 		return (NULL);
334 	}
335 	CTR1(KTR_VM, "vmspace_alloc: %p", vm);
336 	_vm_map_init(&vm->vm_map, vmspace_pmap(vm), min, max);
337 	refcount_init(&vm->vm_refcnt, 1);
338 	vm->vm_shm = NULL;
339 	vm->vm_swrss = 0;
340 	vm->vm_tsize = 0;
341 	vm->vm_dsize = 0;
342 	vm->vm_ssize = 0;
343 	vm->vm_taddr = 0;
344 	vm->vm_daddr = 0;
345 	vm->vm_maxsaddr = 0;
346 	return (vm);
347 }
348 
349 #ifdef RACCT
350 static void
351 vmspace_container_reset(struct proc *p)
352 {
353 
354 	PROC_LOCK(p);
355 	racct_set(p, RACCT_DATA, 0);
356 	racct_set(p, RACCT_STACK, 0);
357 	racct_set(p, RACCT_RSS, 0);
358 	racct_set(p, RACCT_MEMLOCK, 0);
359 	racct_set(p, RACCT_VMEM, 0);
360 	PROC_UNLOCK(p);
361 }
362 #endif
363 
364 static inline void
365 vmspace_dofree(struct vmspace *vm)
366 {
367 
368 	CTR1(KTR_VM, "vmspace_free: %p", vm);
369 
370 	/*
371 	 * Make sure any SysV shm is freed, it might not have been in
372 	 * exit1().
373 	 */
374 	shmexit(vm);
375 
376 	/*
377 	 * Lock the map, to wait out all other references to it.
378 	 * Delete all of the mappings and pages they hold, then call
379 	 * the pmap module to reclaim anything left.
380 	 */
381 	(void)vm_map_remove(&vm->vm_map, vm_map_min(&vm->vm_map),
382 	    vm_map_max(&vm->vm_map));
383 
384 	pmap_release(vmspace_pmap(vm));
385 	vm->vm_map.pmap = NULL;
386 	uma_zfree(vmspace_zone, vm);
387 }
388 
389 void
390 vmspace_free(struct vmspace *vm)
391 {
392 
393 	WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
394 	    "vmspace_free() called");
395 
396 	if (refcount_release(&vm->vm_refcnt))
397 		vmspace_dofree(vm);
398 }
399 
400 void
401 vmspace_exitfree(struct proc *p)
402 {
403 	struct vmspace *vm;
404 
405 	PROC_VMSPACE_LOCK(p);
406 	vm = p->p_vmspace;
407 	p->p_vmspace = NULL;
408 	PROC_VMSPACE_UNLOCK(p);
409 	KASSERT(vm == &vmspace0, ("vmspace_exitfree: wrong vmspace"));
410 	vmspace_free(vm);
411 }
412 
413 void
414 vmspace_exit(struct thread *td)
415 {
416 	struct vmspace *vm;
417 	struct proc *p;
418 	bool released;
419 
420 	p = td->td_proc;
421 	vm = p->p_vmspace;
422 
423 	/*
424 	 * Prepare to release the vmspace reference.  The thread that releases
425 	 * the last reference is responsible for tearing down the vmspace.
426 	 * However, threads not releasing the final reference must switch to the
427 	 * kernel's vmspace0 before the decrement so that the subsequent pmap
428 	 * deactivation does not modify a freed vmspace.
429 	 */
430 	refcount_acquire(&vmspace0.vm_refcnt);
431 	if (!(released = refcount_release_if_last(&vm->vm_refcnt))) {
432 		if (p->p_vmspace != &vmspace0) {
433 			PROC_VMSPACE_LOCK(p);
434 			p->p_vmspace = &vmspace0;
435 			PROC_VMSPACE_UNLOCK(p);
436 			pmap_activate(td);
437 		}
438 		released = refcount_release(&vm->vm_refcnt);
439 	}
440 	if (released) {
441 		/*
442 		 * pmap_remove_pages() expects the pmap to be active, so switch
443 		 * back first if necessary.
444 		 */
445 		if (p->p_vmspace != vm) {
446 			PROC_VMSPACE_LOCK(p);
447 			p->p_vmspace = vm;
448 			PROC_VMSPACE_UNLOCK(p);
449 			pmap_activate(td);
450 		}
451 		pmap_remove_pages(vmspace_pmap(vm));
452 		PROC_VMSPACE_LOCK(p);
453 		p->p_vmspace = &vmspace0;
454 		PROC_VMSPACE_UNLOCK(p);
455 		pmap_activate(td);
456 		vmspace_dofree(vm);
457 	}
458 #ifdef RACCT
459 	if (racct_enable)
460 		vmspace_container_reset(p);
461 #endif
462 }
463 
464 /* Acquire reference to vmspace owned by another process. */
465 
466 struct vmspace *
467 vmspace_acquire_ref(struct proc *p)
468 {
469 	struct vmspace *vm;
470 
471 	PROC_VMSPACE_LOCK(p);
472 	vm = p->p_vmspace;
473 	if (vm == NULL || !refcount_acquire_if_not_zero(&vm->vm_refcnt)) {
474 		PROC_VMSPACE_UNLOCK(p);
475 		return (NULL);
476 	}
477 	if (vm != p->p_vmspace) {
478 		PROC_VMSPACE_UNLOCK(p);
479 		vmspace_free(vm);
480 		return (NULL);
481 	}
482 	PROC_VMSPACE_UNLOCK(p);
483 	return (vm);
484 }
485 
486 /*
487  * Switch between vmspaces in an AIO kernel process.
488  *
489  * The new vmspace is either the vmspace of a user process obtained
490  * from an active AIO request or the initial vmspace of the AIO kernel
491  * process (when it is idling).  Because user processes will block to
492  * drain any active AIO requests before proceeding in exit() or
493  * execve(), the reference count for vmspaces from AIO requests can
494  * never be 0.  Similarly, AIO kernel processes hold an extra
495  * reference on their initial vmspace for the life of the process.  As
496  * a result, the 'newvm' vmspace always has a non-zero reference
497  * count.  This permits an additional reference on 'newvm' to be
498  * acquired via a simple atomic increment rather than the loop in
499  * vmspace_acquire_ref() above.
500  */
501 void
502 vmspace_switch_aio(struct vmspace *newvm)
503 {
504 	struct vmspace *oldvm;
505 
506 	/* XXX: Need some way to assert that this is an aio daemon. */
507 
508 	KASSERT(refcount_load(&newvm->vm_refcnt) > 0,
509 	    ("vmspace_switch_aio: newvm unreferenced"));
510 
511 	oldvm = curproc->p_vmspace;
512 	if (oldvm == newvm)
513 		return;
514 
515 	/*
516 	 * Point to the new address space and refer to it.
517 	 */
518 	curproc->p_vmspace = newvm;
519 	refcount_acquire(&newvm->vm_refcnt);
520 
521 	/* Activate the new mapping. */
522 	pmap_activate(curthread);
523 
524 	vmspace_free(oldvm);
525 }
526 
527 void
528 _vm_map_lock(vm_map_t map, const char *file, int line)
529 {
530 
531 	if (map->system_map)
532 		mtx_lock_flags_(&map->system_mtx, 0, file, line);
533 	else
534 		sx_xlock_(&map->lock, file, line);
535 	map->timestamp++;
536 }
537 
538 void
539 vm_map_entry_set_vnode_text(vm_map_entry_t entry, bool add)
540 {
541 	vm_object_t object;
542 	struct vnode *vp;
543 	bool vp_held;
544 
545 	if ((entry->eflags & MAP_ENTRY_VN_EXEC) == 0)
546 		return;
547 	KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
548 	    ("Submap with execs"));
549 	object = entry->object.vm_object;
550 	KASSERT(object != NULL, ("No object for text, entry %p", entry));
551 	if ((object->flags & OBJ_ANON) != 0)
552 		object = object->handle;
553 	else
554 		KASSERT(object->backing_object == NULL,
555 		    ("non-anon object %p shadows", object));
556 	KASSERT(object != NULL, ("No content object for text, entry %p obj %p",
557 	    entry, entry->object.vm_object));
558 
559 	/*
560 	 * Mostly, we do not lock the backing object.  It is
561 	 * referenced by the entry we are processing, so it cannot go
562 	 * away.
563 	 */
564 	vp = NULL;
565 	vp_held = false;
566 	if (object->type == OBJT_DEAD) {
567 		/*
568 		 * For OBJT_DEAD objects, v_writecount was handled in
569 		 * vnode_pager_dealloc().
570 		 */
571 	} else if (object->type == OBJT_VNODE) {
572 		vp = object->handle;
573 	} else if (object->type == OBJT_SWAP) {
574 		KASSERT((object->flags & OBJ_TMPFS_NODE) != 0,
575 		    ("vm_map_entry_set_vnode_text: swap and !TMPFS "
576 		    "entry %p, object %p, add %d", entry, object, add));
577 		/*
578 		 * Tmpfs VREG node, which was reclaimed, has
579 		 * OBJ_TMPFS_NODE flag set, but not OBJ_TMPFS.  In
580 		 * this case there is no v_writecount to adjust.
581 		 */
582 		VM_OBJECT_RLOCK(object);
583 		if ((object->flags & OBJ_TMPFS) != 0) {
584 			vp = object->un_pager.swp.swp_tmpfs;
585 			if (vp != NULL) {
586 				vhold(vp);
587 				vp_held = true;
588 			}
589 		}
590 		VM_OBJECT_RUNLOCK(object);
591 	} else {
592 		KASSERT(0,
593 		    ("vm_map_entry_set_vnode_text: wrong object type, "
594 		    "entry %p, object %p, add %d", entry, object, add));
595 	}
596 	if (vp != NULL) {
597 		if (add) {
598 			VOP_SET_TEXT_CHECKED(vp);
599 		} else {
600 			vn_lock(vp, LK_SHARED | LK_RETRY);
601 			VOP_UNSET_TEXT_CHECKED(vp);
602 			VOP_UNLOCK(vp);
603 		}
604 		if (vp_held)
605 			vdrop(vp);
606 	}
607 }
608 
609 /*
610  * Use a different name for this vm_map_entry field when it's use
611  * is not consistent with its use as part of an ordered search tree.
612  */
613 #define defer_next right
614 
615 static void
616 vm_map_process_deferred(void)
617 {
618 	struct thread *td;
619 	vm_map_entry_t entry, next;
620 	vm_object_t object;
621 
622 	td = curthread;
623 	entry = td->td_map_def_user;
624 	td->td_map_def_user = NULL;
625 	while (entry != NULL) {
626 		next = entry->defer_next;
627 		MPASS((entry->eflags & (MAP_ENTRY_WRITECNT |
628 		    MAP_ENTRY_VN_EXEC)) != (MAP_ENTRY_WRITECNT |
629 		    MAP_ENTRY_VN_EXEC));
630 		if ((entry->eflags & MAP_ENTRY_WRITECNT) != 0) {
631 			/*
632 			 * Decrement the object's writemappings and
633 			 * possibly the vnode's v_writecount.
634 			 */
635 			KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
636 			    ("Submap with writecount"));
637 			object = entry->object.vm_object;
638 			KASSERT(object != NULL, ("No object for writecount"));
639 			vm_pager_release_writecount(object, entry->start,
640 			    entry->end);
641 		}
642 		vm_map_entry_set_vnode_text(entry, false);
643 		vm_map_entry_deallocate(entry, FALSE);
644 		entry = next;
645 	}
646 }
647 
648 #ifdef INVARIANTS
649 static void
650 _vm_map_assert_locked(vm_map_t map, const char *file, int line)
651 {
652 
653 	if (map->system_map)
654 		mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
655 	else
656 		sx_assert_(&map->lock, SA_XLOCKED, file, line);
657 }
658 
659 #define	VM_MAP_ASSERT_LOCKED(map) \
660     _vm_map_assert_locked(map, LOCK_FILE, LOCK_LINE)
661 
662 enum { VMMAP_CHECK_NONE, VMMAP_CHECK_UNLOCK, VMMAP_CHECK_ALL };
663 #ifdef DIAGNOSTIC
664 static int enable_vmmap_check = VMMAP_CHECK_UNLOCK;
665 #else
666 static int enable_vmmap_check = VMMAP_CHECK_NONE;
667 #endif
668 SYSCTL_INT(_debug, OID_AUTO, vmmap_check, CTLFLAG_RWTUN,
669     &enable_vmmap_check, 0, "Enable vm map consistency checking");
670 
671 static void _vm_map_assert_consistent(vm_map_t map, int check);
672 
673 #define VM_MAP_ASSERT_CONSISTENT(map) \
674     _vm_map_assert_consistent(map, VMMAP_CHECK_ALL)
675 #ifdef DIAGNOSTIC
676 #define VM_MAP_UNLOCK_CONSISTENT(map) do {				\
677 	if (map->nupdates > map->nentries) {				\
678 		_vm_map_assert_consistent(map, VMMAP_CHECK_UNLOCK);	\
679 		map->nupdates = 0;					\
680 	}								\
681 } while (0)
682 #else
683 #define VM_MAP_UNLOCK_CONSISTENT(map)
684 #endif
685 #else
686 #define	VM_MAP_ASSERT_LOCKED(map)
687 #define VM_MAP_ASSERT_CONSISTENT(map)
688 #define VM_MAP_UNLOCK_CONSISTENT(map)
689 #endif /* INVARIANTS */
690 
691 void
692 _vm_map_unlock(vm_map_t map, const char *file, int line)
693 {
694 
695 	VM_MAP_UNLOCK_CONSISTENT(map);
696 	if (map->system_map) {
697 #ifndef UMA_MD_SMALL_ALLOC
698 		if (map == kernel_map && (map->flags & MAP_REPLENISH) != 0) {
699 			uma_prealloc(kmapentzone, 1);
700 			map->flags &= ~MAP_REPLENISH;
701 		}
702 #endif
703 		mtx_unlock_flags_(&map->system_mtx, 0, file, line);
704 	} else {
705 		sx_xunlock_(&map->lock, file, line);
706 		vm_map_process_deferred();
707 	}
708 }
709 
710 void
711 _vm_map_lock_read(vm_map_t map, const char *file, int line)
712 {
713 
714 	if (map->system_map)
715 		mtx_lock_flags_(&map->system_mtx, 0, file, line);
716 	else
717 		sx_slock_(&map->lock, file, line);
718 }
719 
720 void
721 _vm_map_unlock_read(vm_map_t map, const char *file, int line)
722 {
723 
724 	if (map->system_map) {
725 		KASSERT((map->flags & MAP_REPLENISH) == 0,
726 		    ("%s: MAP_REPLENISH leaked", __func__));
727 		mtx_unlock_flags_(&map->system_mtx, 0, file, line);
728 	} else {
729 		sx_sunlock_(&map->lock, file, line);
730 		vm_map_process_deferred();
731 	}
732 }
733 
734 int
735 _vm_map_trylock(vm_map_t map, const char *file, int line)
736 {
737 	int error;
738 
739 	error = map->system_map ?
740 	    !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
741 	    !sx_try_xlock_(&map->lock, file, line);
742 	if (error == 0)
743 		map->timestamp++;
744 	return (error == 0);
745 }
746 
747 int
748 _vm_map_trylock_read(vm_map_t map, const char *file, int line)
749 {
750 	int error;
751 
752 	error = map->system_map ?
753 	    !mtx_trylock_flags_(&map->system_mtx, 0, file, line) :
754 	    !sx_try_slock_(&map->lock, file, line);
755 	return (error == 0);
756 }
757 
758 /*
759  *	_vm_map_lock_upgrade:	[ internal use only ]
760  *
761  *	Tries to upgrade a read (shared) lock on the specified map to a write
762  *	(exclusive) lock.  Returns the value "0" if the upgrade succeeds and a
763  *	non-zero value if the upgrade fails.  If the upgrade fails, the map is
764  *	returned without a read or write lock held.
765  *
766  *	Requires that the map be read locked.
767  */
768 int
769 _vm_map_lock_upgrade(vm_map_t map, const char *file, int line)
770 {
771 	unsigned int last_timestamp;
772 
773 	if (map->system_map) {
774 		mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
775 	} else {
776 		if (!sx_try_upgrade_(&map->lock, file, line)) {
777 			last_timestamp = map->timestamp;
778 			sx_sunlock_(&map->lock, file, line);
779 			vm_map_process_deferred();
780 			/*
781 			 * If the map's timestamp does not change while the
782 			 * map is unlocked, then the upgrade succeeds.
783 			 */
784 			sx_xlock_(&map->lock, file, line);
785 			if (last_timestamp != map->timestamp) {
786 				sx_xunlock_(&map->lock, file, line);
787 				return (1);
788 			}
789 		}
790 	}
791 	map->timestamp++;
792 	return (0);
793 }
794 
795 void
796 _vm_map_lock_downgrade(vm_map_t map, const char *file, int line)
797 {
798 
799 	if (map->system_map) {
800 		KASSERT((map->flags & MAP_REPLENISH) == 0,
801 		    ("%s: MAP_REPLENISH leaked", __func__));
802 		mtx_assert_(&map->system_mtx, MA_OWNED, file, line);
803 	} else {
804 		VM_MAP_UNLOCK_CONSISTENT(map);
805 		sx_downgrade_(&map->lock, file, line);
806 	}
807 }
808 
809 /*
810  *	vm_map_locked:
811  *
812  *	Returns a non-zero value if the caller holds a write (exclusive) lock
813  *	on the specified map and the value "0" otherwise.
814  */
815 int
816 vm_map_locked(vm_map_t map)
817 {
818 
819 	if (map->system_map)
820 		return (mtx_owned(&map->system_mtx));
821 	else
822 		return (sx_xlocked(&map->lock));
823 }
824 
825 /*
826  *	_vm_map_unlock_and_wait:
827  *
828  *	Atomically releases the lock on the specified map and puts the calling
829  *	thread to sleep.  The calling thread will remain asleep until either
830  *	vm_map_wakeup() is performed on the map or the specified timeout is
831  *	exceeded.
832  *
833  *	WARNING!  This function does not perform deferred deallocations of
834  *	objects and map	entries.  Therefore, the calling thread is expected to
835  *	reacquire the map lock after reawakening and later perform an ordinary
836  *	unlock operation, such as vm_map_unlock(), before completing its
837  *	operation on the map.
838  */
839 int
840 _vm_map_unlock_and_wait(vm_map_t map, int timo, const char *file, int line)
841 {
842 
843 	VM_MAP_UNLOCK_CONSISTENT(map);
844 	mtx_lock(&map_sleep_mtx);
845 	if (map->system_map) {
846 		KASSERT((map->flags & MAP_REPLENISH) == 0,
847 		    ("%s: MAP_REPLENISH leaked", __func__));
848 		mtx_unlock_flags_(&map->system_mtx, 0, file, line);
849 	} else {
850 		sx_xunlock_(&map->lock, file, line);
851 	}
852 	return (msleep(&map->root, &map_sleep_mtx, PDROP | PVM, "vmmaps",
853 	    timo));
854 }
855 
856 /*
857  *	vm_map_wakeup:
858  *
859  *	Awaken any threads that have slept on the map using
860  *	vm_map_unlock_and_wait().
861  */
862 void
863 vm_map_wakeup(vm_map_t map)
864 {
865 
866 	/*
867 	 * Acquire and release map_sleep_mtx to prevent a wakeup()
868 	 * from being performed (and lost) between the map unlock
869 	 * and the msleep() in _vm_map_unlock_and_wait().
870 	 */
871 	mtx_lock(&map_sleep_mtx);
872 	mtx_unlock(&map_sleep_mtx);
873 	wakeup(&map->root);
874 }
875 
876 void
877 vm_map_busy(vm_map_t map)
878 {
879 
880 	VM_MAP_ASSERT_LOCKED(map);
881 	map->busy++;
882 }
883 
884 void
885 vm_map_unbusy(vm_map_t map)
886 {
887 
888 	VM_MAP_ASSERT_LOCKED(map);
889 	KASSERT(map->busy, ("vm_map_unbusy: not busy"));
890 	if (--map->busy == 0 && (map->flags & MAP_BUSY_WAKEUP)) {
891 		vm_map_modflags(map, 0, MAP_BUSY_WAKEUP);
892 		wakeup(&map->busy);
893 	}
894 }
895 
896 void
897 vm_map_wait_busy(vm_map_t map)
898 {
899 
900 	VM_MAP_ASSERT_LOCKED(map);
901 	while (map->busy) {
902 		vm_map_modflags(map, MAP_BUSY_WAKEUP, 0);
903 		if (map->system_map)
904 			msleep(&map->busy, &map->system_mtx, 0, "mbusy", 0);
905 		else
906 			sx_sleep(&map->busy, &map->lock, 0, "mbusy", 0);
907 	}
908 	map->timestamp++;
909 }
910 
911 long
912 vmspace_resident_count(struct vmspace *vmspace)
913 {
914 	return pmap_resident_count(vmspace_pmap(vmspace));
915 }
916 
917 /*
918  * Initialize an existing vm_map structure
919  * such as that in the vmspace structure.
920  */
921 static void
922 _vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
923 {
924 
925 	map->header.eflags = MAP_ENTRY_HEADER;
926 	map->needs_wakeup = FALSE;
927 	map->system_map = 0;
928 	map->pmap = pmap;
929 	map->header.end = min;
930 	map->header.start = max;
931 	map->flags = 0;
932 	map->header.left = map->header.right = &map->header;
933 	map->root = NULL;
934 	map->timestamp = 0;
935 	map->busy = 0;
936 	map->anon_loc = 0;
937 #ifdef DIAGNOSTIC
938 	map->nupdates = 0;
939 #endif
940 }
941 
942 void
943 vm_map_init(vm_map_t map, pmap_t pmap, vm_offset_t min, vm_offset_t max)
944 {
945 
946 	_vm_map_init(map, pmap, min, max);
947 	mtx_init(&map->system_mtx, "vm map (system)", NULL,
948 	    MTX_DEF | MTX_DUPOK);
949 	sx_init(&map->lock, "vm map (user)");
950 }
951 
952 /*
953  *	vm_map_entry_dispose:	[ internal use only ]
954  *
955  *	Inverse of vm_map_entry_create.
956  */
957 static void
958 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry)
959 {
960 	uma_zfree(map->system_map ? kmapentzone : mapentzone, entry);
961 }
962 
963 /*
964  *	vm_map_entry_create:	[ internal use only ]
965  *
966  *	Allocates a VM map entry for insertion.
967  *	No entry fields are filled in.
968  */
969 static vm_map_entry_t
970 vm_map_entry_create(vm_map_t map)
971 {
972 	vm_map_entry_t new_entry;
973 
974 #ifndef UMA_MD_SMALL_ALLOC
975 	if (map == kernel_map) {
976 		VM_MAP_ASSERT_LOCKED(map);
977 
978 		/*
979 		 * A new slab of kernel map entries cannot be allocated at this
980 		 * point because the kernel map has not yet been updated to
981 		 * reflect the caller's request.  Therefore, we allocate a new
982 		 * map entry, dipping into the reserve if necessary, and set a
983 		 * flag indicating that the reserve must be replenished before
984 		 * the map is unlocked.
985 		 */
986 		new_entry = uma_zalloc(kmapentzone, M_NOWAIT | M_NOVM);
987 		if (new_entry == NULL) {
988 			new_entry = uma_zalloc(kmapentzone,
989 			    M_NOWAIT | M_NOVM | M_USE_RESERVE);
990 			kernel_map->flags |= MAP_REPLENISH;
991 		}
992 	} else
993 #endif
994 	if (map->system_map) {
995 		new_entry = uma_zalloc(kmapentzone, M_NOWAIT);
996 	} else {
997 		new_entry = uma_zalloc(mapentzone, M_WAITOK);
998 	}
999 	KASSERT(new_entry != NULL,
1000 	    ("vm_map_entry_create: kernel resources exhausted"));
1001 	return (new_entry);
1002 }
1003 
1004 /*
1005  *	vm_map_entry_set_behavior:
1006  *
1007  *	Set the expected access behavior, either normal, random, or
1008  *	sequential.
1009  */
1010 static inline void
1011 vm_map_entry_set_behavior(vm_map_entry_t entry, u_char behavior)
1012 {
1013 	entry->eflags = (entry->eflags & ~MAP_ENTRY_BEHAV_MASK) |
1014 	    (behavior & MAP_ENTRY_BEHAV_MASK);
1015 }
1016 
1017 /*
1018  *	vm_map_entry_max_free_{left,right}:
1019  *
1020  *	Compute the size of the largest free gap between two entries,
1021  *	one the root of a tree and the other the ancestor of that root
1022  *	that is the least or greatest ancestor found on the search path.
1023  */
1024 static inline vm_size_t
1025 vm_map_entry_max_free_left(vm_map_entry_t root, vm_map_entry_t left_ancestor)
1026 {
1027 
1028 	return (root->left != left_ancestor ?
1029 	    root->left->max_free : root->start - left_ancestor->end);
1030 }
1031 
1032 static inline vm_size_t
1033 vm_map_entry_max_free_right(vm_map_entry_t root, vm_map_entry_t right_ancestor)
1034 {
1035 
1036 	return (root->right != right_ancestor ?
1037 	    root->right->max_free : right_ancestor->start - root->end);
1038 }
1039 
1040 /*
1041  *	vm_map_entry_{pred,succ}:
1042  *
1043  *	Find the {predecessor, successor} of the entry by taking one step
1044  *	in the appropriate direction and backtracking as much as necessary.
1045  *	vm_map_entry_succ is defined in vm_map.h.
1046  */
1047 static inline vm_map_entry_t
1048 vm_map_entry_pred(vm_map_entry_t entry)
1049 {
1050 	vm_map_entry_t prior;
1051 
1052 	prior = entry->left;
1053 	if (prior->right->start < entry->start) {
1054 		do
1055 			prior = prior->right;
1056 		while (prior->right != entry);
1057 	}
1058 	return (prior);
1059 }
1060 
1061 static inline vm_size_t
1062 vm_size_max(vm_size_t a, vm_size_t b)
1063 {
1064 
1065 	return (a > b ? a : b);
1066 }
1067 
1068 #define SPLAY_LEFT_STEP(root, y, llist, rlist, test) do {		\
1069 	vm_map_entry_t z;						\
1070 	vm_size_t max_free;						\
1071 									\
1072 	/*								\
1073 	 * Infer root->right->max_free == root->max_free when		\
1074 	 * y->max_free < root->max_free || root->max_free == 0.		\
1075 	 * Otherwise, look right to find it.				\
1076 	 */								\
1077 	y = root->left;							\
1078 	max_free = root->max_free;					\
1079 	KASSERT(max_free == vm_size_max(				\
1080 	    vm_map_entry_max_free_left(root, llist),			\
1081 	    vm_map_entry_max_free_right(root, rlist)),			\
1082 	    ("%s: max_free invariant fails", __func__));		\
1083 	if (max_free - 1 < vm_map_entry_max_free_left(root, llist))	\
1084 		max_free = vm_map_entry_max_free_right(root, rlist);	\
1085 	if (y != llist && (test)) {					\
1086 		/* Rotate right and make y root. */			\
1087 		z = y->right;						\
1088 		if (z != root) {					\
1089 			root->left = z;					\
1090 			y->right = root;				\
1091 			if (max_free < y->max_free)			\
1092 			    root->max_free = max_free =			\
1093 			    vm_size_max(max_free, z->max_free);		\
1094 		} else if (max_free < y->max_free)			\
1095 			root->max_free = max_free =			\
1096 			    vm_size_max(max_free, root->start - y->end);\
1097 		root = y;						\
1098 		y = root->left;						\
1099 	}								\
1100 	/* Copy right->max_free.  Put root on rlist. */			\
1101 	root->max_free = max_free;					\
1102 	KASSERT(max_free == vm_map_entry_max_free_right(root, rlist),	\
1103 	    ("%s: max_free not copied from right", __func__));		\
1104 	root->left = rlist;						\
1105 	rlist = root;							\
1106 	root = y != llist ? y : NULL;					\
1107 } while (0)
1108 
1109 #define SPLAY_RIGHT_STEP(root, y, llist, rlist, test) do {		\
1110 	vm_map_entry_t z;						\
1111 	vm_size_t max_free;						\
1112 									\
1113 	/*								\
1114 	 * Infer root->left->max_free == root->max_free when		\
1115 	 * y->max_free < root->max_free || root->max_free == 0.		\
1116 	 * Otherwise, look left to find it.				\
1117 	 */								\
1118 	y = root->right;						\
1119 	max_free = root->max_free;					\
1120 	KASSERT(max_free == vm_size_max(				\
1121 	    vm_map_entry_max_free_left(root, llist),			\
1122 	    vm_map_entry_max_free_right(root, rlist)),			\
1123 	    ("%s: max_free invariant fails", __func__));		\
1124 	if (max_free - 1 < vm_map_entry_max_free_right(root, rlist))	\
1125 		max_free = vm_map_entry_max_free_left(root, llist);	\
1126 	if (y != rlist && (test)) {					\
1127 		/* Rotate left and make y root. */			\
1128 		z = y->left;						\
1129 		if (z != root) {					\
1130 			root->right = z;				\
1131 			y->left = root;					\
1132 			if (max_free < y->max_free)			\
1133 			    root->max_free = max_free =			\
1134 			    vm_size_max(max_free, z->max_free);		\
1135 		} else if (max_free < y->max_free)			\
1136 			root->max_free = max_free =			\
1137 			    vm_size_max(max_free, y->start - root->end);\
1138 		root = y;						\
1139 		y = root->right;					\
1140 	}								\
1141 	/* Copy left->max_free.  Put root on llist. */			\
1142 	root->max_free = max_free;					\
1143 	KASSERT(max_free == vm_map_entry_max_free_left(root, llist),	\
1144 	    ("%s: max_free not copied from left", __func__));		\
1145 	root->right = llist;						\
1146 	llist = root;							\
1147 	root = y != rlist ? y : NULL;					\
1148 } while (0)
1149 
1150 /*
1151  * Walk down the tree until we find addr or a gap where addr would go, breaking
1152  * off left and right subtrees of nodes less than, or greater than addr.  Treat
1153  * subtrees with root->max_free < length as empty trees.  llist and rlist are
1154  * the two sides in reverse order (bottom-up), with llist linked by the right
1155  * pointer and rlist linked by the left pointer in the vm_map_entry, and both
1156  * lists terminated by &map->header.  This function, and the subsequent call to
1157  * vm_map_splay_merge_{left,right,pred,succ}, rely on the start and end address
1158  * values in &map->header.
1159  */
1160 static __always_inline vm_map_entry_t
1161 vm_map_splay_split(vm_map_t map, vm_offset_t addr, vm_size_t length,
1162     vm_map_entry_t *llist, vm_map_entry_t *rlist)
1163 {
1164 	vm_map_entry_t left, right, root, y;
1165 
1166 	left = right = &map->header;
1167 	root = map->root;
1168 	while (root != NULL && root->max_free >= length) {
1169 		KASSERT(left->end <= root->start &&
1170 		    root->end <= right->start,
1171 		    ("%s: root not within tree bounds", __func__));
1172 		if (addr < root->start) {
1173 			SPLAY_LEFT_STEP(root, y, left, right,
1174 			    y->max_free >= length && addr < y->start);
1175 		} else if (addr >= root->end) {
1176 			SPLAY_RIGHT_STEP(root, y, left, right,
1177 			    y->max_free >= length && addr >= y->end);
1178 		} else
1179 			break;
1180 	}
1181 	*llist = left;
1182 	*rlist = right;
1183 	return (root);
1184 }
1185 
1186 static __always_inline void
1187 vm_map_splay_findnext(vm_map_entry_t root, vm_map_entry_t *rlist)
1188 {
1189 	vm_map_entry_t hi, right, y;
1190 
1191 	right = *rlist;
1192 	hi = root->right == right ? NULL : root->right;
1193 	if (hi == NULL)
1194 		return;
1195 	do
1196 		SPLAY_LEFT_STEP(hi, y, root, right, true);
1197 	while (hi != NULL);
1198 	*rlist = right;
1199 }
1200 
1201 static __always_inline void
1202 vm_map_splay_findprev(vm_map_entry_t root, vm_map_entry_t *llist)
1203 {
1204 	vm_map_entry_t left, lo, y;
1205 
1206 	left = *llist;
1207 	lo = root->left == left ? NULL : root->left;
1208 	if (lo == NULL)
1209 		return;
1210 	do
1211 		SPLAY_RIGHT_STEP(lo, y, left, root, true);
1212 	while (lo != NULL);
1213 	*llist = left;
1214 }
1215 
1216 static inline void
1217 vm_map_entry_swap(vm_map_entry_t *a, vm_map_entry_t *b)
1218 {
1219 	vm_map_entry_t tmp;
1220 
1221 	tmp = *b;
1222 	*b = *a;
1223 	*a = tmp;
1224 }
1225 
1226 /*
1227  * Walk back up the two spines, flip the pointers and set max_free.  The
1228  * subtrees of the root go at the bottom of llist and rlist.
1229  */
1230 static vm_size_t
1231 vm_map_splay_merge_left_walk(vm_map_entry_t header, vm_map_entry_t root,
1232     vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t llist)
1233 {
1234 	do {
1235 		/*
1236 		 * The max_free values of the children of llist are in
1237 		 * llist->max_free and max_free.  Update with the
1238 		 * max value.
1239 		 */
1240 		llist->max_free = max_free =
1241 		    vm_size_max(llist->max_free, max_free);
1242 		vm_map_entry_swap(&llist->right, &tail);
1243 		vm_map_entry_swap(&tail, &llist);
1244 	} while (llist != header);
1245 	root->left = tail;
1246 	return (max_free);
1247 }
1248 
1249 /*
1250  * When llist is known to be the predecessor of root.
1251  */
1252 static inline vm_size_t
1253 vm_map_splay_merge_pred(vm_map_entry_t header, vm_map_entry_t root,
1254     vm_map_entry_t llist)
1255 {
1256 	vm_size_t max_free;
1257 
1258 	max_free = root->start - llist->end;
1259 	if (llist != header) {
1260 		max_free = vm_map_splay_merge_left_walk(header, root,
1261 		    root, max_free, llist);
1262 	} else {
1263 		root->left = header;
1264 		header->right = root;
1265 	}
1266 	return (max_free);
1267 }
1268 
1269 /*
1270  * When llist may or may not be the predecessor of root.
1271  */
1272 static inline vm_size_t
1273 vm_map_splay_merge_left(vm_map_entry_t header, vm_map_entry_t root,
1274     vm_map_entry_t llist)
1275 {
1276 	vm_size_t max_free;
1277 
1278 	max_free = vm_map_entry_max_free_left(root, llist);
1279 	if (llist != header) {
1280 		max_free = vm_map_splay_merge_left_walk(header, root,
1281 		    root->left == llist ? root : root->left,
1282 		    max_free, llist);
1283 	}
1284 	return (max_free);
1285 }
1286 
1287 static vm_size_t
1288 vm_map_splay_merge_right_walk(vm_map_entry_t header, vm_map_entry_t root,
1289     vm_map_entry_t tail, vm_size_t max_free, vm_map_entry_t rlist)
1290 {
1291 	do {
1292 		/*
1293 		 * The max_free values of the children of rlist are in
1294 		 * rlist->max_free and max_free.  Update with the
1295 		 * max value.
1296 		 */
1297 		rlist->max_free = max_free =
1298 		    vm_size_max(rlist->max_free, max_free);
1299 		vm_map_entry_swap(&rlist->left, &tail);
1300 		vm_map_entry_swap(&tail, &rlist);
1301 	} while (rlist != header);
1302 	root->right = tail;
1303 	return (max_free);
1304 }
1305 
1306 /*
1307  * When rlist is known to be the succecessor of root.
1308  */
1309 static inline vm_size_t
1310 vm_map_splay_merge_succ(vm_map_entry_t header, vm_map_entry_t root,
1311     vm_map_entry_t rlist)
1312 {
1313 	vm_size_t max_free;
1314 
1315 	max_free = rlist->start - root->end;
1316 	if (rlist != header) {
1317 		max_free = vm_map_splay_merge_right_walk(header, root,
1318 		    root, max_free, rlist);
1319 	} else {
1320 		root->right = header;
1321 		header->left = root;
1322 	}
1323 	return (max_free);
1324 }
1325 
1326 /*
1327  * When rlist may or may not be the succecessor of root.
1328  */
1329 static inline vm_size_t
1330 vm_map_splay_merge_right(vm_map_entry_t header, vm_map_entry_t root,
1331     vm_map_entry_t rlist)
1332 {
1333 	vm_size_t max_free;
1334 
1335 	max_free = vm_map_entry_max_free_right(root, rlist);
1336 	if (rlist != header) {
1337 		max_free = vm_map_splay_merge_right_walk(header, root,
1338 		    root->right == rlist ? root : root->right,
1339 		    max_free, rlist);
1340 	}
1341 	return (max_free);
1342 }
1343 
1344 /*
1345  *	vm_map_splay:
1346  *
1347  *	The Sleator and Tarjan top-down splay algorithm with the
1348  *	following variation.  Max_free must be computed bottom-up, so
1349  *	on the downward pass, maintain the left and right spines in
1350  *	reverse order.  Then, make a second pass up each side to fix
1351  *	the pointers and compute max_free.  The time bound is O(log n)
1352  *	amortized.
1353  *
1354  *	The tree is threaded, which means that there are no null pointers.
1355  *	When a node has no left child, its left pointer points to its
1356  *	predecessor, which the last ancestor on the search path from the root
1357  *	where the search branched right.  Likewise, when a node has no right
1358  *	child, its right pointer points to its successor.  The map header node
1359  *	is the predecessor of the first map entry, and the successor of the
1360  *	last.
1361  *
1362  *	The new root is the vm_map_entry containing "addr", or else an
1363  *	adjacent entry (lower if possible) if addr is not in the tree.
1364  *
1365  *	The map must be locked, and leaves it so.
1366  *
1367  *	Returns: the new root.
1368  */
1369 static vm_map_entry_t
1370 vm_map_splay(vm_map_t map, vm_offset_t addr)
1371 {
1372 	vm_map_entry_t header, llist, rlist, root;
1373 	vm_size_t max_free_left, max_free_right;
1374 
1375 	header = &map->header;
1376 	root = vm_map_splay_split(map, addr, 0, &llist, &rlist);
1377 	if (root != NULL) {
1378 		max_free_left = vm_map_splay_merge_left(header, root, llist);
1379 		max_free_right = vm_map_splay_merge_right(header, root, rlist);
1380 	} else if (llist != header) {
1381 		/*
1382 		 * Recover the greatest node in the left
1383 		 * subtree and make it the root.
1384 		 */
1385 		root = llist;
1386 		llist = root->right;
1387 		max_free_left = vm_map_splay_merge_left(header, root, llist);
1388 		max_free_right = vm_map_splay_merge_succ(header, root, rlist);
1389 	} else if (rlist != header) {
1390 		/*
1391 		 * Recover the least node in the right
1392 		 * subtree and make it the root.
1393 		 */
1394 		root = rlist;
1395 		rlist = root->left;
1396 		max_free_left = vm_map_splay_merge_pred(header, root, llist);
1397 		max_free_right = vm_map_splay_merge_right(header, root, rlist);
1398 	} else {
1399 		/* There is no root. */
1400 		return (NULL);
1401 	}
1402 	root->max_free = vm_size_max(max_free_left, max_free_right);
1403 	map->root = root;
1404 	VM_MAP_ASSERT_CONSISTENT(map);
1405 	return (root);
1406 }
1407 
1408 /*
1409  *	vm_map_entry_{un,}link:
1410  *
1411  *	Insert/remove entries from maps.  On linking, if new entry clips
1412  *	existing entry, trim existing entry to avoid overlap, and manage
1413  *	offsets.  On unlinking, merge disappearing entry with neighbor, if
1414  *	called for, and manage offsets.  Callers should not modify fields in
1415  *	entries already mapped.
1416  */
1417 static void
1418 vm_map_entry_link(vm_map_t map, vm_map_entry_t entry)
1419 {
1420 	vm_map_entry_t header, llist, rlist, root;
1421 	vm_size_t max_free_left, max_free_right;
1422 
1423 	CTR3(KTR_VM,
1424 	    "vm_map_entry_link: map %p, nentries %d, entry %p", map,
1425 	    map->nentries, entry);
1426 	VM_MAP_ASSERT_LOCKED(map);
1427 	map->nentries++;
1428 	header = &map->header;
1429 	root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
1430 	if (root == NULL) {
1431 		/*
1432 		 * The new entry does not overlap any existing entry in the
1433 		 * map, so it becomes the new root of the map tree.
1434 		 */
1435 		max_free_left = vm_map_splay_merge_pred(header, entry, llist);
1436 		max_free_right = vm_map_splay_merge_succ(header, entry, rlist);
1437 	} else if (entry->start == root->start) {
1438 		/*
1439 		 * The new entry is a clone of root, with only the end field
1440 		 * changed.  The root entry will be shrunk to abut the new
1441 		 * entry, and will be the right child of the new root entry in
1442 		 * the modified map.
1443 		 */
1444 		KASSERT(entry->end < root->end,
1445 		    ("%s: clip_start not within entry", __func__));
1446 		vm_map_splay_findprev(root, &llist);
1447 		root->offset += entry->end - root->start;
1448 		root->start = entry->end;
1449 		max_free_left = vm_map_splay_merge_pred(header, entry, llist);
1450 		max_free_right = root->max_free = vm_size_max(
1451 		    vm_map_splay_merge_pred(entry, root, entry),
1452 		    vm_map_splay_merge_right(header, root, rlist));
1453 	} else {
1454 		/*
1455 		 * The new entry is a clone of root, with only the start field
1456 		 * changed.  The root entry will be shrunk to abut the new
1457 		 * entry, and will be the left child of the new root entry in
1458 		 * the modified map.
1459 		 */
1460 		KASSERT(entry->end == root->end,
1461 		    ("%s: clip_start not within entry", __func__));
1462 		vm_map_splay_findnext(root, &rlist);
1463 		entry->offset += entry->start - root->start;
1464 		root->end = entry->start;
1465 		max_free_left = root->max_free = vm_size_max(
1466 		    vm_map_splay_merge_left(header, root, llist),
1467 		    vm_map_splay_merge_succ(entry, root, entry));
1468 		max_free_right = vm_map_splay_merge_succ(header, entry, rlist);
1469 	}
1470 	entry->max_free = vm_size_max(max_free_left, max_free_right);
1471 	map->root = entry;
1472 	VM_MAP_ASSERT_CONSISTENT(map);
1473 }
1474 
1475 enum unlink_merge_type {
1476 	UNLINK_MERGE_NONE,
1477 	UNLINK_MERGE_NEXT
1478 };
1479 
1480 static void
1481 vm_map_entry_unlink(vm_map_t map, vm_map_entry_t entry,
1482     enum unlink_merge_type op)
1483 {
1484 	vm_map_entry_t header, llist, rlist, root;
1485 	vm_size_t max_free_left, max_free_right;
1486 
1487 	VM_MAP_ASSERT_LOCKED(map);
1488 	header = &map->header;
1489 	root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
1490 	KASSERT(root != NULL,
1491 	    ("vm_map_entry_unlink: unlink object not mapped"));
1492 
1493 	vm_map_splay_findprev(root, &llist);
1494 	vm_map_splay_findnext(root, &rlist);
1495 	if (op == UNLINK_MERGE_NEXT) {
1496 		rlist->start = root->start;
1497 		rlist->offset = root->offset;
1498 	}
1499 	if (llist != header) {
1500 		root = llist;
1501 		llist = root->right;
1502 		max_free_left = vm_map_splay_merge_left(header, root, llist);
1503 		max_free_right = vm_map_splay_merge_succ(header, root, rlist);
1504 	} else if (rlist != header) {
1505 		root = rlist;
1506 		rlist = root->left;
1507 		max_free_left = vm_map_splay_merge_pred(header, root, llist);
1508 		max_free_right = vm_map_splay_merge_right(header, root, rlist);
1509 	} else {
1510 		header->left = header->right = header;
1511 		root = NULL;
1512 	}
1513 	if (root != NULL)
1514 		root->max_free = vm_size_max(max_free_left, max_free_right);
1515 	map->root = root;
1516 	VM_MAP_ASSERT_CONSISTENT(map);
1517 	map->nentries--;
1518 	CTR3(KTR_VM, "vm_map_entry_unlink: map %p, nentries %d, entry %p", map,
1519 	    map->nentries, entry);
1520 }
1521 
1522 /*
1523  *	vm_map_entry_resize:
1524  *
1525  *	Resize a vm_map_entry, recompute the amount of free space that
1526  *	follows it and propagate that value up the tree.
1527  *
1528  *	The map must be locked, and leaves it so.
1529  */
1530 static void
1531 vm_map_entry_resize(vm_map_t map, vm_map_entry_t entry, vm_size_t grow_amount)
1532 {
1533 	vm_map_entry_t header, llist, rlist, root;
1534 
1535 	VM_MAP_ASSERT_LOCKED(map);
1536 	header = &map->header;
1537 	root = vm_map_splay_split(map, entry->start, 0, &llist, &rlist);
1538 	KASSERT(root != NULL, ("%s: resize object not mapped", __func__));
1539 	vm_map_splay_findnext(root, &rlist);
1540 	entry->end += grow_amount;
1541 	root->max_free = vm_size_max(
1542 	    vm_map_splay_merge_left(header, root, llist),
1543 	    vm_map_splay_merge_succ(header, root, rlist));
1544 	map->root = root;
1545 	VM_MAP_ASSERT_CONSISTENT(map);
1546 	CTR4(KTR_VM, "%s: map %p, nentries %d, entry %p",
1547 	    __func__, map, map->nentries, entry);
1548 }
1549 
1550 /*
1551  *	vm_map_lookup_entry:	[ internal use only ]
1552  *
1553  *	Finds the map entry containing (or
1554  *	immediately preceding) the specified address
1555  *	in the given map; the entry is returned
1556  *	in the "entry" parameter.  The boolean
1557  *	result indicates whether the address is
1558  *	actually contained in the map.
1559  */
1560 boolean_t
1561 vm_map_lookup_entry(
1562 	vm_map_t map,
1563 	vm_offset_t address,
1564 	vm_map_entry_t *entry)	/* OUT */
1565 {
1566 	vm_map_entry_t cur, header, lbound, ubound;
1567 	boolean_t locked;
1568 
1569 	/*
1570 	 * If the map is empty, then the map entry immediately preceding
1571 	 * "address" is the map's header.
1572 	 */
1573 	header = &map->header;
1574 	cur = map->root;
1575 	if (cur == NULL) {
1576 		*entry = header;
1577 		return (FALSE);
1578 	}
1579 	if (address >= cur->start && cur->end > address) {
1580 		*entry = cur;
1581 		return (TRUE);
1582 	}
1583 	if ((locked = vm_map_locked(map)) ||
1584 	    sx_try_upgrade(&map->lock)) {
1585 		/*
1586 		 * Splay requires a write lock on the map.  However, it only
1587 		 * restructures the binary search tree; it does not otherwise
1588 		 * change the map.  Thus, the map's timestamp need not change
1589 		 * on a temporary upgrade.
1590 		 */
1591 		cur = vm_map_splay(map, address);
1592 		if (!locked) {
1593 			VM_MAP_UNLOCK_CONSISTENT(map);
1594 			sx_downgrade(&map->lock);
1595 		}
1596 
1597 		/*
1598 		 * If "address" is contained within a map entry, the new root
1599 		 * is that map entry.  Otherwise, the new root is a map entry
1600 		 * immediately before or after "address".
1601 		 */
1602 		if (address < cur->start) {
1603 			*entry = header;
1604 			return (FALSE);
1605 		}
1606 		*entry = cur;
1607 		return (address < cur->end);
1608 	}
1609 	/*
1610 	 * Since the map is only locked for read access, perform a
1611 	 * standard binary search tree lookup for "address".
1612 	 */
1613 	lbound = ubound = header;
1614 	for (;;) {
1615 		if (address < cur->start) {
1616 			ubound = cur;
1617 			cur = cur->left;
1618 			if (cur == lbound)
1619 				break;
1620 		} else if (cur->end <= address) {
1621 			lbound = cur;
1622 			cur = cur->right;
1623 			if (cur == ubound)
1624 				break;
1625 		} else {
1626 			*entry = cur;
1627 			return (TRUE);
1628 		}
1629 	}
1630 	*entry = lbound;
1631 	return (FALSE);
1632 }
1633 
1634 /*
1635  *	vm_map_insert:
1636  *
1637  *	Inserts the given whole VM object into the target
1638  *	map at the specified address range.  The object's
1639  *	size should match that of the address range.
1640  *
1641  *	Requires that the map be locked, and leaves it so.
1642  *
1643  *	If object is non-NULL, ref count must be bumped by caller
1644  *	prior to making call to account for the new entry.
1645  */
1646 int
1647 vm_map_insert(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1648     vm_offset_t start, vm_offset_t end, vm_prot_t prot, vm_prot_t max, int cow)
1649 {
1650 	vm_map_entry_t new_entry, next_entry, prev_entry;
1651 	struct ucred *cred;
1652 	vm_eflags_t protoeflags;
1653 	vm_inherit_t inheritance;
1654 	u_long bdry;
1655 	u_int bidx;
1656 
1657 	VM_MAP_ASSERT_LOCKED(map);
1658 	KASSERT(object != kernel_object ||
1659 	    (cow & MAP_COPY_ON_WRITE) == 0,
1660 	    ("vm_map_insert: kernel object and COW"));
1661 	KASSERT(object == NULL || (cow & MAP_NOFAULT) == 0 ||
1662 	    (cow & MAP_SPLIT_BOUNDARY_MASK) != 0,
1663 	    ("vm_map_insert: paradoxical MAP_NOFAULT request, obj %p cow %#x",
1664 	    object, cow));
1665 	KASSERT((prot & ~max) == 0,
1666 	    ("prot %#x is not subset of max_prot %#x", prot, max));
1667 
1668 	/*
1669 	 * Check that the start and end points are not bogus.
1670 	 */
1671 	if (start == end || !vm_map_range_valid(map, start, end))
1672 		return (KERN_INVALID_ADDRESS);
1673 
1674 	/*
1675 	 * Find the entry prior to the proposed starting address; if it's part
1676 	 * of an existing entry, this range is bogus.
1677 	 */
1678 	if (vm_map_lookup_entry(map, start, &prev_entry))
1679 		return (KERN_NO_SPACE);
1680 
1681 	/*
1682 	 * Assert that the next entry doesn't overlap the end point.
1683 	 */
1684 	next_entry = vm_map_entry_succ(prev_entry);
1685 	if (next_entry->start < end)
1686 		return (KERN_NO_SPACE);
1687 
1688 	if ((cow & MAP_CREATE_GUARD) != 0 && (object != NULL ||
1689 	    max != VM_PROT_NONE))
1690 		return (KERN_INVALID_ARGUMENT);
1691 
1692 	protoeflags = 0;
1693 	if (cow & MAP_COPY_ON_WRITE)
1694 		protoeflags |= MAP_ENTRY_COW | MAP_ENTRY_NEEDS_COPY;
1695 	if (cow & MAP_NOFAULT)
1696 		protoeflags |= MAP_ENTRY_NOFAULT;
1697 	if (cow & MAP_DISABLE_SYNCER)
1698 		protoeflags |= MAP_ENTRY_NOSYNC;
1699 	if (cow & MAP_DISABLE_COREDUMP)
1700 		protoeflags |= MAP_ENTRY_NOCOREDUMP;
1701 	if (cow & MAP_STACK_GROWS_DOWN)
1702 		protoeflags |= MAP_ENTRY_GROWS_DOWN;
1703 	if (cow & MAP_STACK_GROWS_UP)
1704 		protoeflags |= MAP_ENTRY_GROWS_UP;
1705 	if (cow & MAP_WRITECOUNT)
1706 		protoeflags |= MAP_ENTRY_WRITECNT;
1707 	if (cow & MAP_VN_EXEC)
1708 		protoeflags |= MAP_ENTRY_VN_EXEC;
1709 	if ((cow & MAP_CREATE_GUARD) != 0)
1710 		protoeflags |= MAP_ENTRY_GUARD;
1711 	if ((cow & MAP_CREATE_STACK_GAP_DN) != 0)
1712 		protoeflags |= MAP_ENTRY_STACK_GAP_DN;
1713 	if ((cow & MAP_CREATE_STACK_GAP_UP) != 0)
1714 		protoeflags |= MAP_ENTRY_STACK_GAP_UP;
1715 	if (cow & MAP_INHERIT_SHARE)
1716 		inheritance = VM_INHERIT_SHARE;
1717 	else
1718 		inheritance = VM_INHERIT_DEFAULT;
1719 	if ((cow & MAP_SPLIT_BOUNDARY_MASK) != 0) {
1720 		/* This magically ignores index 0, for usual page size. */
1721 		bidx = (cow & MAP_SPLIT_BOUNDARY_MASK) >>
1722 		    MAP_SPLIT_BOUNDARY_SHIFT;
1723 		if (bidx >= MAXPAGESIZES)
1724 			return (KERN_INVALID_ARGUMENT);
1725 		bdry = pagesizes[bidx] - 1;
1726 		if ((start & bdry) != 0 || (end & bdry) != 0)
1727 			return (KERN_INVALID_ARGUMENT);
1728 		protoeflags |= bidx << MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
1729 	}
1730 
1731 	cred = NULL;
1732 	if ((cow & (MAP_ACC_NO_CHARGE | MAP_NOFAULT | MAP_CREATE_GUARD)) != 0)
1733 		goto charged;
1734 	if ((cow & MAP_ACC_CHARGED) || ((prot & VM_PROT_WRITE) &&
1735 	    ((protoeflags & MAP_ENTRY_NEEDS_COPY) || object == NULL))) {
1736 		if (!(cow & MAP_ACC_CHARGED) && !swap_reserve(end - start))
1737 			return (KERN_RESOURCE_SHORTAGE);
1738 		KASSERT(object == NULL ||
1739 		    (protoeflags & MAP_ENTRY_NEEDS_COPY) != 0 ||
1740 		    object->cred == NULL,
1741 		    ("overcommit: vm_map_insert o %p", object));
1742 		cred = curthread->td_ucred;
1743 	}
1744 
1745 charged:
1746 	/* Expand the kernel pmap, if necessary. */
1747 	if (map == kernel_map && end > kernel_vm_end)
1748 		pmap_growkernel(end);
1749 	if (object != NULL) {
1750 		/*
1751 		 * OBJ_ONEMAPPING must be cleared unless this mapping
1752 		 * is trivially proven to be the only mapping for any
1753 		 * of the object's pages.  (Object granularity
1754 		 * reference counting is insufficient to recognize
1755 		 * aliases with precision.)
1756 		 */
1757 		if ((object->flags & OBJ_ANON) != 0) {
1758 			VM_OBJECT_WLOCK(object);
1759 			if (object->ref_count > 1 || object->shadow_count != 0)
1760 				vm_object_clear_flag(object, OBJ_ONEMAPPING);
1761 			VM_OBJECT_WUNLOCK(object);
1762 		}
1763 	} else if ((prev_entry->eflags & ~MAP_ENTRY_USER_WIRED) ==
1764 	    protoeflags &&
1765 	    (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP |
1766 	    MAP_VN_EXEC)) == 0 &&
1767 	    prev_entry->end == start && (prev_entry->cred == cred ||
1768 	    (prev_entry->object.vm_object != NULL &&
1769 	    prev_entry->object.vm_object->cred == cred)) &&
1770 	    vm_object_coalesce(prev_entry->object.vm_object,
1771 	    prev_entry->offset,
1772 	    (vm_size_t)(prev_entry->end - prev_entry->start),
1773 	    (vm_size_t)(end - prev_entry->end), cred != NULL &&
1774 	    (protoeflags & MAP_ENTRY_NEEDS_COPY) == 0)) {
1775 		/*
1776 		 * We were able to extend the object.  Determine if we
1777 		 * can extend the previous map entry to include the
1778 		 * new range as well.
1779 		 */
1780 		if (prev_entry->inheritance == inheritance &&
1781 		    prev_entry->protection == prot &&
1782 		    prev_entry->max_protection == max &&
1783 		    prev_entry->wired_count == 0) {
1784 			KASSERT((prev_entry->eflags & MAP_ENTRY_USER_WIRED) ==
1785 			    0, ("prev_entry %p has incoherent wiring",
1786 			    prev_entry));
1787 			if ((prev_entry->eflags & MAP_ENTRY_GUARD) == 0)
1788 				map->size += end - prev_entry->end;
1789 			vm_map_entry_resize(map, prev_entry,
1790 			    end - prev_entry->end);
1791 			vm_map_try_merge_entries(map, prev_entry, next_entry);
1792 			return (KERN_SUCCESS);
1793 		}
1794 
1795 		/*
1796 		 * If we can extend the object but cannot extend the
1797 		 * map entry, we have to create a new map entry.  We
1798 		 * must bump the ref count on the extended object to
1799 		 * account for it.  object may be NULL.
1800 		 */
1801 		object = prev_entry->object.vm_object;
1802 		offset = prev_entry->offset +
1803 		    (prev_entry->end - prev_entry->start);
1804 		vm_object_reference(object);
1805 		if (cred != NULL && object != NULL && object->cred != NULL &&
1806 		    !(prev_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
1807 			/* Object already accounts for this uid. */
1808 			cred = NULL;
1809 		}
1810 	}
1811 	if (cred != NULL)
1812 		crhold(cred);
1813 
1814 	/*
1815 	 * Create a new entry
1816 	 */
1817 	new_entry = vm_map_entry_create(map);
1818 	new_entry->start = start;
1819 	new_entry->end = end;
1820 	new_entry->cred = NULL;
1821 
1822 	new_entry->eflags = protoeflags;
1823 	new_entry->object.vm_object = object;
1824 	new_entry->offset = offset;
1825 
1826 	new_entry->inheritance = inheritance;
1827 	new_entry->protection = prot;
1828 	new_entry->max_protection = max;
1829 	new_entry->wired_count = 0;
1830 	new_entry->wiring_thread = NULL;
1831 	new_entry->read_ahead = VM_FAULT_READ_AHEAD_INIT;
1832 	new_entry->next_read = start;
1833 
1834 	KASSERT(cred == NULL || !ENTRY_CHARGED(new_entry),
1835 	    ("overcommit: vm_map_insert leaks vm_map %p", new_entry));
1836 	new_entry->cred = cred;
1837 
1838 	/*
1839 	 * Insert the new entry into the list
1840 	 */
1841 	vm_map_entry_link(map, new_entry);
1842 	if ((new_entry->eflags & MAP_ENTRY_GUARD) == 0)
1843 		map->size += new_entry->end - new_entry->start;
1844 
1845 	/*
1846 	 * Try to coalesce the new entry with both the previous and next
1847 	 * entries in the list.  Previously, we only attempted to coalesce
1848 	 * with the previous entry when object is NULL.  Here, we handle the
1849 	 * other cases, which are less common.
1850 	 */
1851 	vm_map_try_merge_entries(map, prev_entry, new_entry);
1852 	vm_map_try_merge_entries(map, new_entry, next_entry);
1853 
1854 	if ((cow & (MAP_PREFAULT | MAP_PREFAULT_PARTIAL)) != 0) {
1855 		vm_map_pmap_enter(map, start, prot, object, OFF_TO_IDX(offset),
1856 		    end - start, cow & MAP_PREFAULT_PARTIAL);
1857 	}
1858 
1859 	return (KERN_SUCCESS);
1860 }
1861 
1862 /*
1863  *	vm_map_findspace:
1864  *
1865  *	Find the first fit (lowest VM address) for "length" free bytes
1866  *	beginning at address >= start in the given map.
1867  *
1868  *	In a vm_map_entry, "max_free" is the maximum amount of
1869  *	contiguous free space between an entry in its subtree and a
1870  *	neighbor of that entry.  This allows finding a free region in
1871  *	one path down the tree, so O(log n) amortized with splay
1872  *	trees.
1873  *
1874  *	The map must be locked, and leaves it so.
1875  *
1876  *	Returns: starting address if sufficient space,
1877  *		 vm_map_max(map)-length+1 if insufficient space.
1878  */
1879 vm_offset_t
1880 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length)
1881 {
1882 	vm_map_entry_t header, llist, rlist, root, y;
1883 	vm_size_t left_length, max_free_left, max_free_right;
1884 	vm_offset_t gap_end;
1885 
1886 	VM_MAP_ASSERT_LOCKED(map);
1887 
1888 	/*
1889 	 * Request must fit within min/max VM address and must avoid
1890 	 * address wrap.
1891 	 */
1892 	start = MAX(start, vm_map_min(map));
1893 	if (start >= vm_map_max(map) || length > vm_map_max(map) - start)
1894 		return (vm_map_max(map) - length + 1);
1895 
1896 	/* Empty tree means wide open address space. */
1897 	if (map->root == NULL)
1898 		return (start);
1899 
1900 	/*
1901 	 * After splay_split, if start is within an entry, push it to the start
1902 	 * of the following gap.  If rlist is at the end of the gap containing
1903 	 * start, save the end of that gap in gap_end to see if the gap is big
1904 	 * enough; otherwise set gap_end to start skip gap-checking and move
1905 	 * directly to a search of the right subtree.
1906 	 */
1907 	header = &map->header;
1908 	root = vm_map_splay_split(map, start, length, &llist, &rlist);
1909 	gap_end = rlist->start;
1910 	if (root != NULL) {
1911 		start = root->end;
1912 		if (root->right != rlist)
1913 			gap_end = start;
1914 		max_free_left = vm_map_splay_merge_left(header, root, llist);
1915 		max_free_right = vm_map_splay_merge_right(header, root, rlist);
1916 	} else if (rlist != header) {
1917 		root = rlist;
1918 		rlist = root->left;
1919 		max_free_left = vm_map_splay_merge_pred(header, root, llist);
1920 		max_free_right = vm_map_splay_merge_right(header, root, rlist);
1921 	} else {
1922 		root = llist;
1923 		llist = root->right;
1924 		max_free_left = vm_map_splay_merge_left(header, root, llist);
1925 		max_free_right = vm_map_splay_merge_succ(header, root, rlist);
1926 	}
1927 	root->max_free = vm_size_max(max_free_left, max_free_right);
1928 	map->root = root;
1929 	VM_MAP_ASSERT_CONSISTENT(map);
1930 	if (length <= gap_end - start)
1931 		return (start);
1932 
1933 	/* With max_free, can immediately tell if no solution. */
1934 	if (root->right == header || length > root->right->max_free)
1935 		return (vm_map_max(map) - length + 1);
1936 
1937 	/*
1938 	 * Splay for the least large-enough gap in the right subtree.
1939 	 */
1940 	llist = rlist = header;
1941 	for (left_length = 0;;
1942 	    left_length = vm_map_entry_max_free_left(root, llist)) {
1943 		if (length <= left_length)
1944 			SPLAY_LEFT_STEP(root, y, llist, rlist,
1945 			    length <= vm_map_entry_max_free_left(y, llist));
1946 		else
1947 			SPLAY_RIGHT_STEP(root, y, llist, rlist,
1948 			    length > vm_map_entry_max_free_left(y, root));
1949 		if (root == NULL)
1950 			break;
1951 	}
1952 	root = llist;
1953 	llist = root->right;
1954 	max_free_left = vm_map_splay_merge_left(header, root, llist);
1955 	if (rlist == header) {
1956 		root->max_free = vm_size_max(max_free_left,
1957 		    vm_map_splay_merge_succ(header, root, rlist));
1958 	} else {
1959 		y = rlist;
1960 		rlist = y->left;
1961 		y->max_free = vm_size_max(
1962 		    vm_map_splay_merge_pred(root, y, root),
1963 		    vm_map_splay_merge_right(header, y, rlist));
1964 		root->max_free = vm_size_max(max_free_left, y->max_free);
1965 	}
1966 	map->root = root;
1967 	VM_MAP_ASSERT_CONSISTENT(map);
1968 	return (root->end);
1969 }
1970 
1971 int
1972 vm_map_fixed(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1973     vm_offset_t start, vm_size_t length, vm_prot_t prot,
1974     vm_prot_t max, int cow)
1975 {
1976 	vm_offset_t end;
1977 	int result;
1978 
1979 	end = start + length;
1980 	KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
1981 	    object == NULL,
1982 	    ("vm_map_fixed: non-NULL backing object for stack"));
1983 	vm_map_lock(map);
1984 	VM_MAP_RANGE_CHECK(map, start, end);
1985 	if ((cow & MAP_CHECK_EXCL) == 0) {
1986 		result = vm_map_delete(map, start, end);
1987 		if (result != KERN_SUCCESS)
1988 			goto out;
1989 	}
1990 	if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
1991 		result = vm_map_stack_locked(map, start, length, sgrowsiz,
1992 		    prot, max, cow);
1993 	} else {
1994 		result = vm_map_insert(map, object, offset, start, end,
1995 		    prot, max, cow);
1996 	}
1997 out:
1998 	vm_map_unlock(map);
1999 	return (result);
2000 }
2001 
2002 static const int aslr_pages_rnd_64[2] = {0x1000, 0x10};
2003 static const int aslr_pages_rnd_32[2] = {0x100, 0x4};
2004 
2005 static int cluster_anon = 1;
2006 SYSCTL_INT(_vm, OID_AUTO, cluster_anon, CTLFLAG_RW,
2007     &cluster_anon, 0,
2008     "Cluster anonymous mappings: 0 = no, 1 = yes if no hint, 2 = always");
2009 
2010 static bool
2011 clustering_anon_allowed(vm_offset_t addr)
2012 {
2013 
2014 	switch (cluster_anon) {
2015 	case 0:
2016 		return (false);
2017 	case 1:
2018 		return (addr == 0);
2019 	case 2:
2020 	default:
2021 		return (true);
2022 	}
2023 }
2024 
2025 static long aslr_restarts;
2026 SYSCTL_LONG(_vm, OID_AUTO, aslr_restarts, CTLFLAG_RD,
2027     &aslr_restarts, 0,
2028     "Number of aslr failures");
2029 
2030 /*
2031  * Searches for the specified amount of free space in the given map with the
2032  * specified alignment.  Performs an address-ordered, first-fit search from
2033  * the given address "*addr", with an optional upper bound "max_addr".  If the
2034  * parameter "alignment" is zero, then the alignment is computed from the
2035  * given (object, offset) pair so as to enable the greatest possible use of
2036  * superpage mappings.  Returns KERN_SUCCESS and the address of the free space
2037  * in "*addr" if successful.  Otherwise, returns KERN_NO_SPACE.
2038  *
2039  * The map must be locked.  Initially, there must be at least "length" bytes
2040  * of free space at the given address.
2041  */
2042 static int
2043 vm_map_alignspace(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2044     vm_offset_t *addr, vm_size_t length, vm_offset_t max_addr,
2045     vm_offset_t alignment)
2046 {
2047 	vm_offset_t aligned_addr, free_addr;
2048 
2049 	VM_MAP_ASSERT_LOCKED(map);
2050 	free_addr = *addr;
2051 	KASSERT(free_addr == vm_map_findspace(map, free_addr, length),
2052 	    ("caller failed to provide space %#jx at address %p",
2053 	     (uintmax_t)length, (void *)free_addr));
2054 	for (;;) {
2055 		/*
2056 		 * At the start of every iteration, the free space at address
2057 		 * "*addr" is at least "length" bytes.
2058 		 */
2059 		if (alignment == 0)
2060 			pmap_align_superpage(object, offset, addr, length);
2061 		else if ((*addr & (alignment - 1)) != 0) {
2062 			*addr &= ~(alignment - 1);
2063 			*addr += alignment;
2064 		}
2065 		aligned_addr = *addr;
2066 		if (aligned_addr == free_addr) {
2067 			/*
2068 			 * Alignment did not change "*addr", so "*addr" must
2069 			 * still provide sufficient free space.
2070 			 */
2071 			return (KERN_SUCCESS);
2072 		}
2073 
2074 		/*
2075 		 * Test for address wrap on "*addr".  A wrapped "*addr" could
2076 		 * be a valid address, in which case vm_map_findspace() cannot
2077 		 * be relied upon to fail.
2078 		 */
2079 		if (aligned_addr < free_addr)
2080 			return (KERN_NO_SPACE);
2081 		*addr = vm_map_findspace(map, aligned_addr, length);
2082 		if (*addr + length > vm_map_max(map) ||
2083 		    (max_addr != 0 && *addr + length > max_addr))
2084 			return (KERN_NO_SPACE);
2085 		free_addr = *addr;
2086 		if (free_addr == aligned_addr) {
2087 			/*
2088 			 * If a successful call to vm_map_findspace() did not
2089 			 * change "*addr", then "*addr" must still be aligned
2090 			 * and provide sufficient free space.
2091 			 */
2092 			return (KERN_SUCCESS);
2093 		}
2094 	}
2095 }
2096 
2097 int
2098 vm_map_find_aligned(vm_map_t map, vm_offset_t *addr, vm_size_t length,
2099     vm_offset_t max_addr, vm_offset_t alignment)
2100 {
2101 	/* XXXKIB ASLR eh ? */
2102 	*addr = vm_map_findspace(map, *addr, length);
2103 	if (*addr + length > vm_map_max(map) ||
2104 	    (max_addr != 0 && *addr + length > max_addr))
2105 		return (KERN_NO_SPACE);
2106 	return (vm_map_alignspace(map, NULL, 0, addr, length, max_addr,
2107 	    alignment));
2108 }
2109 
2110 /*
2111  *	vm_map_find finds an unallocated region in the target address
2112  *	map with the given length.  The search is defined to be
2113  *	first-fit from the specified address; the region found is
2114  *	returned in the same parameter.
2115  *
2116  *	If object is non-NULL, ref count must be bumped by caller
2117  *	prior to making call to account for the new entry.
2118  */
2119 int
2120 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2121 	    vm_offset_t *addr,	/* IN/OUT */
2122 	    vm_size_t length, vm_offset_t max_addr, int find_space,
2123 	    vm_prot_t prot, vm_prot_t max, int cow)
2124 {
2125 	vm_offset_t alignment, curr_min_addr, min_addr;
2126 	int gap, pidx, rv, try;
2127 	bool cluster, en_aslr, update_anon;
2128 
2129 	KASSERT((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0 ||
2130 	    object == NULL,
2131 	    ("vm_map_find: non-NULL backing object for stack"));
2132 	MPASS((cow & MAP_REMAP) == 0 || (find_space == VMFS_NO_SPACE &&
2133 	    (cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) == 0));
2134 	if (find_space == VMFS_OPTIMAL_SPACE && (object == NULL ||
2135 	    (object->flags & OBJ_COLORED) == 0))
2136 		find_space = VMFS_ANY_SPACE;
2137 	if (find_space >> 8 != 0) {
2138 		KASSERT((find_space & 0xff) == 0, ("bad VMFS flags"));
2139 		alignment = (vm_offset_t)1 << (find_space >> 8);
2140 	} else
2141 		alignment = 0;
2142 	en_aslr = (map->flags & MAP_ASLR) != 0;
2143 	update_anon = cluster = clustering_anon_allowed(*addr) &&
2144 	    (map->flags & MAP_IS_SUB_MAP) == 0 && max_addr == 0 &&
2145 	    find_space != VMFS_NO_SPACE && object == NULL &&
2146 	    (cow & (MAP_INHERIT_SHARE | MAP_STACK_GROWS_UP |
2147 	    MAP_STACK_GROWS_DOWN)) == 0 && prot != PROT_NONE;
2148 	curr_min_addr = min_addr = *addr;
2149 	if (en_aslr && min_addr == 0 && !cluster &&
2150 	    find_space != VMFS_NO_SPACE &&
2151 	    (map->flags & MAP_ASLR_IGNSTART) != 0)
2152 		curr_min_addr = min_addr = vm_map_min(map);
2153 	try = 0;
2154 	vm_map_lock(map);
2155 	if (cluster) {
2156 		curr_min_addr = map->anon_loc;
2157 		if (curr_min_addr == 0)
2158 			cluster = false;
2159 	}
2160 	if (find_space != VMFS_NO_SPACE) {
2161 		KASSERT(find_space == VMFS_ANY_SPACE ||
2162 		    find_space == VMFS_OPTIMAL_SPACE ||
2163 		    find_space == VMFS_SUPER_SPACE ||
2164 		    alignment != 0, ("unexpected VMFS flag"));
2165 again:
2166 		/*
2167 		 * When creating an anonymous mapping, try clustering
2168 		 * with an existing anonymous mapping first.
2169 		 *
2170 		 * We make up to two attempts to find address space
2171 		 * for a given find_space value. The first attempt may
2172 		 * apply randomization or may cluster with an existing
2173 		 * anonymous mapping. If this first attempt fails,
2174 		 * perform a first-fit search of the available address
2175 		 * space.
2176 		 *
2177 		 * If all tries failed, and find_space is
2178 		 * VMFS_OPTIMAL_SPACE, fallback to VMFS_ANY_SPACE.
2179 		 * Again enable clustering and randomization.
2180 		 */
2181 		try++;
2182 		MPASS(try <= 2);
2183 
2184 		if (try == 2) {
2185 			/*
2186 			 * Second try: we failed either to find a
2187 			 * suitable region for randomizing the
2188 			 * allocation, or to cluster with an existing
2189 			 * mapping.  Retry with free run.
2190 			 */
2191 			curr_min_addr = (map->flags & MAP_ASLR_IGNSTART) != 0 ?
2192 			    vm_map_min(map) : min_addr;
2193 			atomic_add_long(&aslr_restarts, 1);
2194 		}
2195 
2196 		if (try == 1 && en_aslr && !cluster) {
2197 			/*
2198 			 * Find space for allocation, including
2199 			 * gap needed for later randomization.
2200 			 */
2201 			pidx = MAXPAGESIZES > 1 && pagesizes[1] != 0 &&
2202 			    (find_space == VMFS_SUPER_SPACE || find_space ==
2203 			    VMFS_OPTIMAL_SPACE) ? 1 : 0;
2204 			gap = vm_map_max(map) > MAP_32BIT_MAX_ADDR &&
2205 			    (max_addr == 0 || max_addr > MAP_32BIT_MAX_ADDR) ?
2206 			    aslr_pages_rnd_64[pidx] : aslr_pages_rnd_32[pidx];
2207 			*addr = vm_map_findspace(map, curr_min_addr,
2208 			    length + gap * pagesizes[pidx]);
2209 			if (*addr + length + gap * pagesizes[pidx] >
2210 			    vm_map_max(map))
2211 				goto again;
2212 			/* And randomize the start address. */
2213 			*addr += (arc4random() % gap) * pagesizes[pidx];
2214 			if (max_addr != 0 && *addr + length > max_addr)
2215 				goto again;
2216 		} else {
2217 			*addr = vm_map_findspace(map, curr_min_addr, length);
2218 			if (*addr + length > vm_map_max(map) ||
2219 			    (max_addr != 0 && *addr + length > max_addr)) {
2220 				if (cluster) {
2221 					cluster = false;
2222 					MPASS(try == 1);
2223 					goto again;
2224 				}
2225 				rv = KERN_NO_SPACE;
2226 				goto done;
2227 			}
2228 		}
2229 
2230 		if (find_space != VMFS_ANY_SPACE &&
2231 		    (rv = vm_map_alignspace(map, object, offset, addr, length,
2232 		    max_addr, alignment)) != KERN_SUCCESS) {
2233 			if (find_space == VMFS_OPTIMAL_SPACE) {
2234 				find_space = VMFS_ANY_SPACE;
2235 				curr_min_addr = min_addr;
2236 				cluster = update_anon;
2237 				try = 0;
2238 				goto again;
2239 			}
2240 			goto done;
2241 		}
2242 	} else if ((cow & MAP_REMAP) != 0) {
2243 		if (!vm_map_range_valid(map, *addr, *addr + length)) {
2244 			rv = KERN_INVALID_ADDRESS;
2245 			goto done;
2246 		}
2247 		rv = vm_map_delete(map, *addr, *addr + length);
2248 		if (rv != KERN_SUCCESS)
2249 			goto done;
2250 	}
2251 	if ((cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP)) != 0) {
2252 		rv = vm_map_stack_locked(map, *addr, length, sgrowsiz, prot,
2253 		    max, cow);
2254 	} else {
2255 		rv = vm_map_insert(map, object, offset, *addr, *addr + length,
2256 		    prot, max, cow);
2257 	}
2258 	if (rv == KERN_SUCCESS && update_anon)
2259 		map->anon_loc = *addr + length;
2260 done:
2261 	vm_map_unlock(map);
2262 	return (rv);
2263 }
2264 
2265 /*
2266  *	vm_map_find_min() is a variant of vm_map_find() that takes an
2267  *	additional parameter (min_addr) and treats the given address
2268  *	(*addr) differently.  Specifically, it treats *addr as a hint
2269  *	and not as the minimum address where the mapping is created.
2270  *
2271  *	This function works in two phases.  First, it tries to
2272  *	allocate above the hint.  If that fails and the hint is
2273  *	greater than min_addr, it performs a second pass, replacing
2274  *	the hint with min_addr as the minimum address for the
2275  *	allocation.
2276  */
2277 int
2278 vm_map_find_min(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
2279     vm_offset_t *addr, vm_size_t length, vm_offset_t min_addr,
2280     vm_offset_t max_addr, int find_space, vm_prot_t prot, vm_prot_t max,
2281     int cow)
2282 {
2283 	vm_offset_t hint;
2284 	int rv;
2285 
2286 	hint = *addr;
2287 	for (;;) {
2288 		rv = vm_map_find(map, object, offset, addr, length, max_addr,
2289 		    find_space, prot, max, cow);
2290 		if (rv == KERN_SUCCESS || min_addr >= hint)
2291 			return (rv);
2292 		*addr = hint = min_addr;
2293 	}
2294 }
2295 
2296 /*
2297  * A map entry with any of the following flags set must not be merged with
2298  * another entry.
2299  */
2300 #define	MAP_ENTRY_NOMERGE_MASK	(MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP | \
2301 	    MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_IS_SUB_MAP | MAP_ENTRY_VN_EXEC)
2302 
2303 static bool
2304 vm_map_mergeable_neighbors(vm_map_entry_t prev, vm_map_entry_t entry)
2305 {
2306 
2307 	KASSERT((prev->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 ||
2308 	    (entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0,
2309 	    ("vm_map_mergeable_neighbors: neither %p nor %p are mergeable",
2310 	    prev, entry));
2311 	return (prev->end == entry->start &&
2312 	    prev->object.vm_object == entry->object.vm_object &&
2313 	    (prev->object.vm_object == NULL ||
2314 	    prev->offset + (prev->end - prev->start) == entry->offset) &&
2315 	    prev->eflags == entry->eflags &&
2316 	    prev->protection == entry->protection &&
2317 	    prev->max_protection == entry->max_protection &&
2318 	    prev->inheritance == entry->inheritance &&
2319 	    prev->wired_count == entry->wired_count &&
2320 	    prev->cred == entry->cred);
2321 }
2322 
2323 static void
2324 vm_map_merged_neighbor_dispose(vm_map_t map, vm_map_entry_t entry)
2325 {
2326 
2327 	/*
2328 	 * If the backing object is a vnode object, vm_object_deallocate()
2329 	 * calls vrele().  However, vrele() does not lock the vnode because
2330 	 * the vnode has additional references.  Thus, the map lock can be
2331 	 * kept without causing a lock-order reversal with the vnode lock.
2332 	 *
2333 	 * Since we count the number of virtual page mappings in
2334 	 * object->un_pager.vnp.writemappings, the writemappings value
2335 	 * should not be adjusted when the entry is disposed of.
2336 	 */
2337 	if (entry->object.vm_object != NULL)
2338 		vm_object_deallocate(entry->object.vm_object);
2339 	if (entry->cred != NULL)
2340 		crfree(entry->cred);
2341 	vm_map_entry_dispose(map, entry);
2342 }
2343 
2344 /*
2345  *	vm_map_try_merge_entries:
2346  *
2347  *	Compare the given map entry to its predecessor, and merge its precessor
2348  *	into it if possible.  The entry remains valid, and may be extended.
2349  *	The predecessor may be deleted.
2350  *
2351  *	The map must be locked.
2352  */
2353 void
2354 vm_map_try_merge_entries(vm_map_t map, vm_map_entry_t prev_entry,
2355     vm_map_entry_t entry)
2356 {
2357 
2358 	VM_MAP_ASSERT_LOCKED(map);
2359 	if ((entry->eflags & MAP_ENTRY_NOMERGE_MASK) == 0 &&
2360 	    vm_map_mergeable_neighbors(prev_entry, entry)) {
2361 		vm_map_entry_unlink(map, prev_entry, UNLINK_MERGE_NEXT);
2362 		vm_map_merged_neighbor_dispose(map, prev_entry);
2363 	}
2364 }
2365 
2366 /*
2367  *	vm_map_entry_back:
2368  *
2369  *	Allocate an object to back a map entry.
2370  */
2371 static inline void
2372 vm_map_entry_back(vm_map_entry_t entry)
2373 {
2374 	vm_object_t object;
2375 
2376 	KASSERT(entry->object.vm_object == NULL,
2377 	    ("map entry %p has backing object", entry));
2378 	KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
2379 	    ("map entry %p is a submap", entry));
2380 	object = vm_object_allocate_anon(atop(entry->end - entry->start), NULL,
2381 	    entry->cred, entry->end - entry->start);
2382 	entry->object.vm_object = object;
2383 	entry->offset = 0;
2384 	entry->cred = NULL;
2385 }
2386 
2387 /*
2388  *	vm_map_entry_charge_object
2389  *
2390  *	If there is no object backing this entry, create one.  Otherwise, if
2391  *	the entry has cred, give it to the backing object.
2392  */
2393 static inline void
2394 vm_map_entry_charge_object(vm_map_t map, vm_map_entry_t entry)
2395 {
2396 
2397 	VM_MAP_ASSERT_LOCKED(map);
2398 	KASSERT((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0,
2399 	    ("map entry %p is a submap", entry));
2400 	if (entry->object.vm_object == NULL && !map->system_map &&
2401 	    (entry->eflags & MAP_ENTRY_GUARD) == 0)
2402 		vm_map_entry_back(entry);
2403 	else if (entry->object.vm_object != NULL &&
2404 	    ((entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) &&
2405 	    entry->cred != NULL) {
2406 		VM_OBJECT_WLOCK(entry->object.vm_object);
2407 		KASSERT(entry->object.vm_object->cred == NULL,
2408 		    ("OVERCOMMIT: %s: both cred e %p", __func__, entry));
2409 		entry->object.vm_object->cred = entry->cred;
2410 		entry->object.vm_object->charge = entry->end - entry->start;
2411 		VM_OBJECT_WUNLOCK(entry->object.vm_object);
2412 		entry->cred = NULL;
2413 	}
2414 }
2415 
2416 /*
2417  *	vm_map_entry_clone
2418  *
2419  *	Create a duplicate map entry for clipping.
2420  */
2421 static vm_map_entry_t
2422 vm_map_entry_clone(vm_map_t map, vm_map_entry_t entry)
2423 {
2424 	vm_map_entry_t new_entry;
2425 
2426 	VM_MAP_ASSERT_LOCKED(map);
2427 
2428 	/*
2429 	 * Create a backing object now, if none exists, so that more individual
2430 	 * objects won't be created after the map entry is split.
2431 	 */
2432 	vm_map_entry_charge_object(map, entry);
2433 
2434 	/* Clone the entry. */
2435 	new_entry = vm_map_entry_create(map);
2436 	*new_entry = *entry;
2437 	if (new_entry->cred != NULL)
2438 		crhold(entry->cred);
2439 	if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0) {
2440 		vm_object_reference(new_entry->object.vm_object);
2441 		vm_map_entry_set_vnode_text(new_entry, true);
2442 		/*
2443 		 * The object->un_pager.vnp.writemappings for the object of
2444 		 * MAP_ENTRY_WRITECNT type entry shall be kept as is here.  The
2445 		 * virtual pages are re-distributed among the clipped entries,
2446 		 * so the sum is left the same.
2447 		 */
2448 	}
2449 	return (new_entry);
2450 }
2451 
2452 /*
2453  *	vm_map_clip_start:	[ internal use only ]
2454  *
2455  *	Asserts that the given entry begins at or after
2456  *	the specified address; if necessary,
2457  *	it splits the entry into two.
2458  */
2459 static int
2460 vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t startaddr)
2461 {
2462 	vm_map_entry_t new_entry;
2463 	int bdry_idx;
2464 
2465 	if (!map->system_map)
2466 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2467 		    "%s: map %p entry %p start 0x%jx", __func__, map, entry,
2468 		    (uintmax_t)startaddr);
2469 
2470 	if (startaddr <= entry->start)
2471 		return (KERN_SUCCESS);
2472 
2473 	VM_MAP_ASSERT_LOCKED(map);
2474 	KASSERT(entry->end > startaddr && entry->start < startaddr,
2475 	    ("%s: invalid clip of entry %p", __func__, entry));
2476 
2477 	bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
2478 	    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
2479 	if (bdry_idx != 0) {
2480 		if ((startaddr & (pagesizes[bdry_idx] - 1)) != 0)
2481 			return (KERN_INVALID_ARGUMENT);
2482 	}
2483 
2484 	new_entry = vm_map_entry_clone(map, entry);
2485 
2486 	/*
2487 	 * Split off the front portion.  Insert the new entry BEFORE this one,
2488 	 * so that this entry has the specified starting address.
2489 	 */
2490 	new_entry->end = startaddr;
2491 	vm_map_entry_link(map, new_entry);
2492 	return (KERN_SUCCESS);
2493 }
2494 
2495 /*
2496  *	vm_map_lookup_clip_start:
2497  *
2498  *	Find the entry at or just after 'start', and clip it if 'start' is in
2499  *	the interior of the entry.  Return entry after 'start', and in
2500  *	prev_entry set the entry before 'start'.
2501  */
2502 static int
2503 vm_map_lookup_clip_start(vm_map_t map, vm_offset_t start,
2504     vm_map_entry_t *res_entry, vm_map_entry_t *prev_entry)
2505 {
2506 	vm_map_entry_t entry;
2507 	int rv;
2508 
2509 	if (!map->system_map)
2510 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2511 		    "%s: map %p start 0x%jx prev %p", __func__, map,
2512 		    (uintmax_t)start, prev_entry);
2513 
2514 	if (vm_map_lookup_entry(map, start, prev_entry)) {
2515 		entry = *prev_entry;
2516 		rv = vm_map_clip_start(map, entry, start);
2517 		if (rv != KERN_SUCCESS)
2518 			return (rv);
2519 		*prev_entry = vm_map_entry_pred(entry);
2520 	} else
2521 		entry = vm_map_entry_succ(*prev_entry);
2522 	*res_entry = entry;
2523 	return (KERN_SUCCESS);
2524 }
2525 
2526 /*
2527  *	vm_map_clip_end:	[ internal use only ]
2528  *
2529  *	Asserts that the given entry ends at or before
2530  *	the specified address; if necessary,
2531  *	it splits the entry into two.
2532  */
2533 static int
2534 vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t endaddr)
2535 {
2536 	vm_map_entry_t new_entry;
2537 	int bdry_idx;
2538 
2539 	if (!map->system_map)
2540 		WITNESS_WARN(WARN_GIANTOK | WARN_SLEEPOK, NULL,
2541 		    "%s: map %p entry %p end 0x%jx", __func__, map, entry,
2542 		    (uintmax_t)endaddr);
2543 
2544 	if (endaddr >= entry->end)
2545 		return (KERN_SUCCESS);
2546 
2547 	VM_MAP_ASSERT_LOCKED(map);
2548 	KASSERT(entry->start < endaddr && entry->end > endaddr,
2549 	    ("%s: invalid clip of entry %p", __func__, entry));
2550 
2551 	bdry_idx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
2552 	    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
2553 	if (bdry_idx != 0) {
2554 		if ((endaddr & (pagesizes[bdry_idx] - 1)) != 0)
2555 			return (KERN_INVALID_ARGUMENT);
2556 	}
2557 
2558 	new_entry = vm_map_entry_clone(map, entry);
2559 
2560 	/*
2561 	 * Split off the back portion.  Insert the new entry AFTER this one,
2562 	 * so that this entry has the specified ending address.
2563 	 */
2564 	new_entry->start = endaddr;
2565 	vm_map_entry_link(map, new_entry);
2566 
2567 	return (KERN_SUCCESS);
2568 }
2569 
2570 /*
2571  *	vm_map_submap:		[ kernel use only ]
2572  *
2573  *	Mark the given range as handled by a subordinate map.
2574  *
2575  *	This range must have been created with vm_map_find,
2576  *	and no other operations may have been performed on this
2577  *	range prior to calling vm_map_submap.
2578  *
2579  *	Only a limited number of operations can be performed
2580  *	within this rage after calling vm_map_submap:
2581  *		vm_fault
2582  *	[Don't try vm_map_copy!]
2583  *
2584  *	To remove a submapping, one must first remove the
2585  *	range from the superior map, and then destroy the
2586  *	submap (if desired).  [Better yet, don't try it.]
2587  */
2588 int
2589 vm_map_submap(
2590 	vm_map_t map,
2591 	vm_offset_t start,
2592 	vm_offset_t end,
2593 	vm_map_t submap)
2594 {
2595 	vm_map_entry_t entry;
2596 	int result;
2597 
2598 	result = KERN_INVALID_ARGUMENT;
2599 
2600 	vm_map_lock(submap);
2601 	submap->flags |= MAP_IS_SUB_MAP;
2602 	vm_map_unlock(submap);
2603 
2604 	vm_map_lock(map);
2605 	VM_MAP_RANGE_CHECK(map, start, end);
2606 	if (vm_map_lookup_entry(map, start, &entry) && entry->end >= end &&
2607 	    (entry->eflags & MAP_ENTRY_COW) == 0 &&
2608 	    entry->object.vm_object == NULL) {
2609 		result = vm_map_clip_start(map, entry, start);
2610 		if (result != KERN_SUCCESS)
2611 			goto unlock;
2612 		result = vm_map_clip_end(map, entry, end);
2613 		if (result != KERN_SUCCESS)
2614 			goto unlock;
2615 		entry->object.sub_map = submap;
2616 		entry->eflags |= MAP_ENTRY_IS_SUB_MAP;
2617 		result = KERN_SUCCESS;
2618 	}
2619 unlock:
2620 	vm_map_unlock(map);
2621 
2622 	if (result != KERN_SUCCESS) {
2623 		vm_map_lock(submap);
2624 		submap->flags &= ~MAP_IS_SUB_MAP;
2625 		vm_map_unlock(submap);
2626 	}
2627 	return (result);
2628 }
2629 
2630 /*
2631  * The maximum number of pages to map if MAP_PREFAULT_PARTIAL is specified
2632  */
2633 #define	MAX_INIT_PT	96
2634 
2635 /*
2636  *	vm_map_pmap_enter:
2637  *
2638  *	Preload the specified map's pmap with mappings to the specified
2639  *	object's memory-resident pages.  No further physical pages are
2640  *	allocated, and no further virtual pages are retrieved from secondary
2641  *	storage.  If the specified flags include MAP_PREFAULT_PARTIAL, then a
2642  *	limited number of page mappings are created at the low-end of the
2643  *	specified address range.  (For this purpose, a superpage mapping
2644  *	counts as one page mapping.)  Otherwise, all resident pages within
2645  *	the specified address range are mapped.
2646  */
2647 static void
2648 vm_map_pmap_enter(vm_map_t map, vm_offset_t addr, vm_prot_t prot,
2649     vm_object_t object, vm_pindex_t pindex, vm_size_t size, int flags)
2650 {
2651 	vm_offset_t start;
2652 	vm_page_t p, p_start;
2653 	vm_pindex_t mask, psize, threshold, tmpidx;
2654 
2655 	if ((prot & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0 || object == NULL)
2656 		return;
2657 	if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2658 		VM_OBJECT_WLOCK(object);
2659 		if (object->type == OBJT_DEVICE || object->type == OBJT_SG) {
2660 			pmap_object_init_pt(map->pmap, addr, object, pindex,
2661 			    size);
2662 			VM_OBJECT_WUNLOCK(object);
2663 			return;
2664 		}
2665 		VM_OBJECT_LOCK_DOWNGRADE(object);
2666 	} else
2667 		VM_OBJECT_RLOCK(object);
2668 
2669 	psize = atop(size);
2670 	if (psize + pindex > object->size) {
2671 		if (pindex >= object->size) {
2672 			VM_OBJECT_RUNLOCK(object);
2673 			return;
2674 		}
2675 		psize = object->size - pindex;
2676 	}
2677 
2678 	start = 0;
2679 	p_start = NULL;
2680 	threshold = MAX_INIT_PT;
2681 
2682 	p = vm_page_find_least(object, pindex);
2683 	/*
2684 	 * Assert: the variable p is either (1) the page with the
2685 	 * least pindex greater than or equal to the parameter pindex
2686 	 * or (2) NULL.
2687 	 */
2688 	for (;
2689 	     p != NULL && (tmpidx = p->pindex - pindex) < psize;
2690 	     p = TAILQ_NEXT(p, listq)) {
2691 		/*
2692 		 * don't allow an madvise to blow away our really
2693 		 * free pages allocating pv entries.
2694 		 */
2695 		if (((flags & MAP_PREFAULT_MADVISE) != 0 &&
2696 		    vm_page_count_severe()) ||
2697 		    ((flags & MAP_PREFAULT_PARTIAL) != 0 &&
2698 		    tmpidx >= threshold)) {
2699 			psize = tmpidx;
2700 			break;
2701 		}
2702 		if (vm_page_all_valid(p)) {
2703 			if (p_start == NULL) {
2704 				start = addr + ptoa(tmpidx);
2705 				p_start = p;
2706 			}
2707 			/* Jump ahead if a superpage mapping is possible. */
2708 			if (p->psind > 0 && ((addr + ptoa(tmpidx)) &
2709 			    (pagesizes[p->psind] - 1)) == 0) {
2710 				mask = atop(pagesizes[p->psind]) - 1;
2711 				if (tmpidx + mask < psize &&
2712 				    vm_page_ps_test(p, PS_ALL_VALID, NULL)) {
2713 					p += mask;
2714 					threshold += mask;
2715 				}
2716 			}
2717 		} else if (p_start != NULL) {
2718 			pmap_enter_object(map->pmap, start, addr +
2719 			    ptoa(tmpidx), p_start, prot);
2720 			p_start = NULL;
2721 		}
2722 	}
2723 	if (p_start != NULL)
2724 		pmap_enter_object(map->pmap, start, addr + ptoa(psize),
2725 		    p_start, prot);
2726 	VM_OBJECT_RUNLOCK(object);
2727 }
2728 
2729 /*
2730  *	vm_map_protect:
2731  *
2732  *	Sets the protection of the specified address
2733  *	region in the target map.  If "set_max" is
2734  *	specified, the maximum protection is to be set;
2735  *	otherwise, only the current protection is affected.
2736  */
2737 int
2738 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
2739 	       vm_prot_t new_prot, boolean_t set_max)
2740 {
2741 	vm_map_entry_t entry, first_entry, in_tran, prev_entry;
2742 	vm_object_t obj;
2743 	struct ucred *cred;
2744 	vm_prot_t old_prot;
2745 	int rv;
2746 
2747 	if (start == end)
2748 		return (KERN_SUCCESS);
2749 
2750 again:
2751 	in_tran = NULL;
2752 	vm_map_lock(map);
2753 
2754 	/*
2755 	 * Ensure that we are not concurrently wiring pages.  vm_map_wire() may
2756 	 * need to fault pages into the map and will drop the map lock while
2757 	 * doing so, and the VM object may end up in an inconsistent state if we
2758 	 * update the protection on the map entry in between faults.
2759 	 */
2760 	vm_map_wait_busy(map);
2761 
2762 	VM_MAP_RANGE_CHECK(map, start, end);
2763 
2764 	if (!vm_map_lookup_entry(map, start, &first_entry))
2765 		first_entry = vm_map_entry_succ(first_entry);
2766 
2767 	/*
2768 	 * Make a first pass to check for protection violations.
2769 	 */
2770 	for (entry = first_entry; entry->start < end;
2771 	    entry = vm_map_entry_succ(entry)) {
2772 		if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
2773 			continue;
2774 		if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
2775 			vm_map_unlock(map);
2776 			return (KERN_INVALID_ARGUMENT);
2777 		}
2778 		if ((new_prot & entry->max_protection) != new_prot) {
2779 			vm_map_unlock(map);
2780 			return (KERN_PROTECTION_FAILURE);
2781 		}
2782 		if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0)
2783 			in_tran = entry;
2784 	}
2785 
2786 	/*
2787 	 * Postpone the operation until all in-transition map entries have
2788 	 * stabilized.  An in-transition entry might already have its pages
2789 	 * wired and wired_count incremented, but not yet have its
2790 	 * MAP_ENTRY_USER_WIRED flag set.  In which case, we would fail to call
2791 	 * vm_fault_copy_entry() in the final loop below.
2792 	 */
2793 	if (in_tran != NULL) {
2794 		in_tran->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2795 		vm_map_unlock_and_wait(map, 0);
2796 		goto again;
2797 	}
2798 
2799 	/*
2800 	 * Before changing the protections, try to reserve swap space for any
2801 	 * private (i.e., copy-on-write) mappings that are transitioning from
2802 	 * read-only to read/write access.  If a reservation fails, break out
2803 	 * of this loop early and let the next loop simplify the entries, since
2804 	 * some may now be mergeable.
2805 	 */
2806 	rv = vm_map_clip_start(map, first_entry, start);
2807 	if (rv != KERN_SUCCESS) {
2808 		vm_map_unlock(map);
2809 		return (rv);
2810 	}
2811 	for (entry = first_entry; entry->start < end;
2812 	    entry = vm_map_entry_succ(entry)) {
2813 		rv = vm_map_clip_end(map, entry, end);
2814 		if (rv != KERN_SUCCESS) {
2815 			vm_map_unlock(map);
2816 			return (rv);
2817 		}
2818 
2819 		if (set_max ||
2820 		    ((new_prot & ~entry->protection) & VM_PROT_WRITE) == 0 ||
2821 		    ENTRY_CHARGED(entry) ||
2822 		    (entry->eflags & MAP_ENTRY_GUARD) != 0) {
2823 			continue;
2824 		}
2825 
2826 		cred = curthread->td_ucred;
2827 		obj = entry->object.vm_object;
2828 
2829 		if (obj == NULL ||
2830 		    (entry->eflags & MAP_ENTRY_NEEDS_COPY) != 0) {
2831 			if (!swap_reserve(entry->end - entry->start)) {
2832 				rv = KERN_RESOURCE_SHORTAGE;
2833 				end = entry->end;
2834 				break;
2835 			}
2836 			crhold(cred);
2837 			entry->cred = cred;
2838 			continue;
2839 		}
2840 
2841 		if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP)
2842 			continue;
2843 		VM_OBJECT_WLOCK(obj);
2844 		if (obj->type != OBJT_DEFAULT && obj->type != OBJT_SWAP) {
2845 			VM_OBJECT_WUNLOCK(obj);
2846 			continue;
2847 		}
2848 
2849 		/*
2850 		 * Charge for the whole object allocation now, since
2851 		 * we cannot distinguish between non-charged and
2852 		 * charged clipped mapping of the same object later.
2853 		 */
2854 		KASSERT(obj->charge == 0,
2855 		    ("vm_map_protect: object %p overcharged (entry %p)",
2856 		    obj, entry));
2857 		if (!swap_reserve(ptoa(obj->size))) {
2858 			VM_OBJECT_WUNLOCK(obj);
2859 			rv = KERN_RESOURCE_SHORTAGE;
2860 			end = entry->end;
2861 			break;
2862 		}
2863 
2864 		crhold(cred);
2865 		obj->cred = cred;
2866 		obj->charge = ptoa(obj->size);
2867 		VM_OBJECT_WUNLOCK(obj);
2868 	}
2869 
2870 	/*
2871 	 * If enough swap space was available, go back and fix up protections.
2872 	 * Otherwise, just simplify entries, since some may have been modified.
2873 	 * [Note that clipping is not necessary the second time.]
2874 	 */
2875 	for (prev_entry = vm_map_entry_pred(first_entry), entry = first_entry;
2876 	    entry->start < end;
2877 	    vm_map_try_merge_entries(map, prev_entry, entry),
2878 	    prev_entry = entry, entry = vm_map_entry_succ(entry)) {
2879 		if (rv != KERN_SUCCESS ||
2880 		    (entry->eflags & MAP_ENTRY_GUARD) != 0)
2881 			continue;
2882 
2883 		old_prot = entry->protection;
2884 
2885 		if (set_max)
2886 			entry->protection =
2887 			    (entry->max_protection = new_prot) &
2888 			    old_prot;
2889 		else
2890 			entry->protection = new_prot;
2891 
2892 		/*
2893 		 * For user wired map entries, the normal lazy evaluation of
2894 		 * write access upgrades through soft page faults is
2895 		 * undesirable.  Instead, immediately copy any pages that are
2896 		 * copy-on-write and enable write access in the physical map.
2897 		 */
2898 		if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0 &&
2899 		    (entry->protection & VM_PROT_WRITE) != 0 &&
2900 		    (old_prot & VM_PROT_WRITE) == 0)
2901 			vm_fault_copy_entry(map, map, entry, entry, NULL);
2902 
2903 		/*
2904 		 * When restricting access, update the physical map.  Worry
2905 		 * about copy-on-write here.
2906 		 */
2907 		if ((old_prot & ~entry->protection) != 0) {
2908 #define MASK(entry)	(((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
2909 							VM_PROT_ALL)
2910 			pmap_protect(map->pmap, entry->start,
2911 			    entry->end,
2912 			    entry->protection & MASK(entry));
2913 #undef	MASK
2914 		}
2915 	}
2916 	vm_map_try_merge_entries(map, prev_entry, entry);
2917 	vm_map_unlock(map);
2918 	return (rv);
2919 }
2920 
2921 /*
2922  *	vm_map_madvise:
2923  *
2924  *	This routine traverses a processes map handling the madvise
2925  *	system call.  Advisories are classified as either those effecting
2926  *	the vm_map_entry structure, or those effecting the underlying
2927  *	objects.
2928  */
2929 int
2930 vm_map_madvise(
2931 	vm_map_t map,
2932 	vm_offset_t start,
2933 	vm_offset_t end,
2934 	int behav)
2935 {
2936 	vm_map_entry_t entry, prev_entry;
2937 	int rv;
2938 	bool modify_map;
2939 
2940 	/*
2941 	 * Some madvise calls directly modify the vm_map_entry, in which case
2942 	 * we need to use an exclusive lock on the map and we need to perform
2943 	 * various clipping operations.  Otherwise we only need a read-lock
2944 	 * on the map.
2945 	 */
2946 	switch(behav) {
2947 	case MADV_NORMAL:
2948 	case MADV_SEQUENTIAL:
2949 	case MADV_RANDOM:
2950 	case MADV_NOSYNC:
2951 	case MADV_AUTOSYNC:
2952 	case MADV_NOCORE:
2953 	case MADV_CORE:
2954 		if (start == end)
2955 			return (0);
2956 		modify_map = true;
2957 		vm_map_lock(map);
2958 		break;
2959 	case MADV_WILLNEED:
2960 	case MADV_DONTNEED:
2961 	case MADV_FREE:
2962 		if (start == end)
2963 			return (0);
2964 		modify_map = false;
2965 		vm_map_lock_read(map);
2966 		break;
2967 	default:
2968 		return (EINVAL);
2969 	}
2970 
2971 	/*
2972 	 * Locate starting entry and clip if necessary.
2973 	 */
2974 	VM_MAP_RANGE_CHECK(map, start, end);
2975 
2976 	if (modify_map) {
2977 		/*
2978 		 * madvise behaviors that are implemented in the vm_map_entry.
2979 		 *
2980 		 * We clip the vm_map_entry so that behavioral changes are
2981 		 * limited to the specified address range.
2982 		 */
2983 		rv = vm_map_lookup_clip_start(map, start, &entry, &prev_entry);
2984 		if (rv != KERN_SUCCESS) {
2985 			vm_map_unlock(map);
2986 			return (vm_mmap_to_errno(rv));
2987 		}
2988 
2989 		for (; entry->start < end; prev_entry = entry,
2990 		    entry = vm_map_entry_succ(entry)) {
2991 			if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
2992 				continue;
2993 
2994 			rv = vm_map_clip_end(map, entry, end);
2995 			if (rv != KERN_SUCCESS) {
2996 				vm_map_unlock(map);
2997 				return (vm_mmap_to_errno(rv));
2998 			}
2999 
3000 			switch (behav) {
3001 			case MADV_NORMAL:
3002 				vm_map_entry_set_behavior(entry,
3003 				    MAP_ENTRY_BEHAV_NORMAL);
3004 				break;
3005 			case MADV_SEQUENTIAL:
3006 				vm_map_entry_set_behavior(entry,
3007 				    MAP_ENTRY_BEHAV_SEQUENTIAL);
3008 				break;
3009 			case MADV_RANDOM:
3010 				vm_map_entry_set_behavior(entry,
3011 				    MAP_ENTRY_BEHAV_RANDOM);
3012 				break;
3013 			case MADV_NOSYNC:
3014 				entry->eflags |= MAP_ENTRY_NOSYNC;
3015 				break;
3016 			case MADV_AUTOSYNC:
3017 				entry->eflags &= ~MAP_ENTRY_NOSYNC;
3018 				break;
3019 			case MADV_NOCORE:
3020 				entry->eflags |= MAP_ENTRY_NOCOREDUMP;
3021 				break;
3022 			case MADV_CORE:
3023 				entry->eflags &= ~MAP_ENTRY_NOCOREDUMP;
3024 				break;
3025 			default:
3026 				break;
3027 			}
3028 			vm_map_try_merge_entries(map, prev_entry, entry);
3029 		}
3030 		vm_map_try_merge_entries(map, prev_entry, entry);
3031 		vm_map_unlock(map);
3032 	} else {
3033 		vm_pindex_t pstart, pend;
3034 
3035 		/*
3036 		 * madvise behaviors that are implemented in the underlying
3037 		 * vm_object.
3038 		 *
3039 		 * Since we don't clip the vm_map_entry, we have to clip
3040 		 * the vm_object pindex and count.
3041 		 */
3042 		if (!vm_map_lookup_entry(map, start, &entry))
3043 			entry = vm_map_entry_succ(entry);
3044 		for (; entry->start < end;
3045 		    entry = vm_map_entry_succ(entry)) {
3046 			vm_offset_t useEnd, useStart;
3047 
3048 			if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
3049 				continue;
3050 
3051 			/*
3052 			 * MADV_FREE would otherwise rewind time to
3053 			 * the creation of the shadow object.  Because
3054 			 * we hold the VM map read-locked, neither the
3055 			 * entry's object nor the presence of a
3056 			 * backing object can change.
3057 			 */
3058 			if (behav == MADV_FREE &&
3059 			    entry->object.vm_object != NULL &&
3060 			    entry->object.vm_object->backing_object != NULL)
3061 				continue;
3062 
3063 			pstart = OFF_TO_IDX(entry->offset);
3064 			pend = pstart + atop(entry->end - entry->start);
3065 			useStart = entry->start;
3066 			useEnd = entry->end;
3067 
3068 			if (entry->start < start) {
3069 				pstart += atop(start - entry->start);
3070 				useStart = start;
3071 			}
3072 			if (entry->end > end) {
3073 				pend -= atop(entry->end - end);
3074 				useEnd = end;
3075 			}
3076 
3077 			if (pstart >= pend)
3078 				continue;
3079 
3080 			/*
3081 			 * Perform the pmap_advise() before clearing
3082 			 * PGA_REFERENCED in vm_page_advise().  Otherwise, a
3083 			 * concurrent pmap operation, such as pmap_remove(),
3084 			 * could clear a reference in the pmap and set
3085 			 * PGA_REFERENCED on the page before the pmap_advise()
3086 			 * had completed.  Consequently, the page would appear
3087 			 * referenced based upon an old reference that
3088 			 * occurred before this pmap_advise() ran.
3089 			 */
3090 			if (behav == MADV_DONTNEED || behav == MADV_FREE)
3091 				pmap_advise(map->pmap, useStart, useEnd,
3092 				    behav);
3093 
3094 			vm_object_madvise(entry->object.vm_object, pstart,
3095 			    pend, behav);
3096 
3097 			/*
3098 			 * Pre-populate paging structures in the
3099 			 * WILLNEED case.  For wired entries, the
3100 			 * paging structures are already populated.
3101 			 */
3102 			if (behav == MADV_WILLNEED &&
3103 			    entry->wired_count == 0) {
3104 				vm_map_pmap_enter(map,
3105 				    useStart,
3106 				    entry->protection,
3107 				    entry->object.vm_object,
3108 				    pstart,
3109 				    ptoa(pend - pstart),
3110 				    MAP_PREFAULT_MADVISE
3111 				);
3112 			}
3113 		}
3114 		vm_map_unlock_read(map);
3115 	}
3116 	return (0);
3117 }
3118 
3119 /*
3120  *	vm_map_inherit:
3121  *
3122  *	Sets the inheritance of the specified address
3123  *	range in the target map.  Inheritance
3124  *	affects how the map will be shared with
3125  *	child maps at the time of vmspace_fork.
3126  */
3127 int
3128 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
3129 	       vm_inherit_t new_inheritance)
3130 {
3131 	vm_map_entry_t entry, lentry, prev_entry, start_entry;
3132 	int rv;
3133 
3134 	switch (new_inheritance) {
3135 	case VM_INHERIT_NONE:
3136 	case VM_INHERIT_COPY:
3137 	case VM_INHERIT_SHARE:
3138 	case VM_INHERIT_ZERO:
3139 		break;
3140 	default:
3141 		return (KERN_INVALID_ARGUMENT);
3142 	}
3143 	if (start == end)
3144 		return (KERN_SUCCESS);
3145 	vm_map_lock(map);
3146 	VM_MAP_RANGE_CHECK(map, start, end);
3147 	rv = vm_map_lookup_clip_start(map, start, &start_entry, &prev_entry);
3148 	if (rv != KERN_SUCCESS)
3149 		goto unlock;
3150 	if (vm_map_lookup_entry(map, end - 1, &lentry)) {
3151 		rv = vm_map_clip_end(map, lentry, end);
3152 		if (rv != KERN_SUCCESS)
3153 			goto unlock;
3154 	}
3155 	if (new_inheritance == VM_INHERIT_COPY) {
3156 		for (entry = start_entry; entry->start < end;
3157 		    prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3158 			if ((entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK)
3159 			    != 0) {
3160 				rv = KERN_INVALID_ARGUMENT;
3161 				goto unlock;
3162 			}
3163 		}
3164 	}
3165 	for (entry = start_entry; entry->start < end; prev_entry = entry,
3166 	    entry = vm_map_entry_succ(entry)) {
3167 		KASSERT(entry->end <= end, ("non-clipped entry %p end %jx %jx",
3168 		    entry, (uintmax_t)entry->end, (uintmax_t)end));
3169 		if ((entry->eflags & MAP_ENTRY_GUARD) == 0 ||
3170 		    new_inheritance != VM_INHERIT_ZERO)
3171 			entry->inheritance = new_inheritance;
3172 		vm_map_try_merge_entries(map, prev_entry, entry);
3173 	}
3174 	vm_map_try_merge_entries(map, prev_entry, entry);
3175 unlock:
3176 	vm_map_unlock(map);
3177 	return (rv);
3178 }
3179 
3180 /*
3181  *	vm_map_entry_in_transition:
3182  *
3183  *	Release the map lock, and sleep until the entry is no longer in
3184  *	transition.  Awake and acquire the map lock.  If the map changed while
3185  *	another held the lock, lookup a possibly-changed entry at or after the
3186  *	'start' position of the old entry.
3187  */
3188 static vm_map_entry_t
3189 vm_map_entry_in_transition(vm_map_t map, vm_offset_t in_start,
3190     vm_offset_t *io_end, bool holes_ok, vm_map_entry_t in_entry)
3191 {
3192 	vm_map_entry_t entry;
3193 	vm_offset_t start;
3194 	u_int last_timestamp;
3195 
3196 	VM_MAP_ASSERT_LOCKED(map);
3197 	KASSERT((in_entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3198 	    ("not in-tranition map entry %p", in_entry));
3199 	/*
3200 	 * We have not yet clipped the entry.
3201 	 */
3202 	start = MAX(in_start, in_entry->start);
3203 	in_entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
3204 	last_timestamp = map->timestamp;
3205 	if (vm_map_unlock_and_wait(map, 0)) {
3206 		/*
3207 		 * Allow interruption of user wiring/unwiring?
3208 		 */
3209 	}
3210 	vm_map_lock(map);
3211 	if (last_timestamp + 1 == map->timestamp)
3212 		return (in_entry);
3213 
3214 	/*
3215 	 * Look again for the entry because the map was modified while it was
3216 	 * unlocked.  Specifically, the entry may have been clipped, merged, or
3217 	 * deleted.
3218 	 */
3219 	if (!vm_map_lookup_entry(map, start, &entry)) {
3220 		if (!holes_ok) {
3221 			*io_end = start;
3222 			return (NULL);
3223 		}
3224 		entry = vm_map_entry_succ(entry);
3225 	}
3226 	return (entry);
3227 }
3228 
3229 /*
3230  *	vm_map_unwire:
3231  *
3232  *	Implements both kernel and user unwiring.
3233  */
3234 int
3235 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t end,
3236     int flags)
3237 {
3238 	vm_map_entry_t entry, first_entry, next_entry, prev_entry;
3239 	int rv;
3240 	bool holes_ok, need_wakeup, user_unwire;
3241 
3242 	if (start == end)
3243 		return (KERN_SUCCESS);
3244 	holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
3245 	user_unwire = (flags & VM_MAP_WIRE_USER) != 0;
3246 	vm_map_lock(map);
3247 	VM_MAP_RANGE_CHECK(map, start, end);
3248 	if (!vm_map_lookup_entry(map, start, &first_entry)) {
3249 		if (holes_ok)
3250 			first_entry = vm_map_entry_succ(first_entry);
3251 		else {
3252 			vm_map_unlock(map);
3253 			return (KERN_INVALID_ADDRESS);
3254 		}
3255 	}
3256 	rv = KERN_SUCCESS;
3257 	for (entry = first_entry; entry->start < end; entry = next_entry) {
3258 		if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
3259 			/*
3260 			 * We have not yet clipped the entry.
3261 			 */
3262 			next_entry = vm_map_entry_in_transition(map, start,
3263 			    &end, holes_ok, entry);
3264 			if (next_entry == NULL) {
3265 				if (entry == first_entry) {
3266 					vm_map_unlock(map);
3267 					return (KERN_INVALID_ADDRESS);
3268 				}
3269 				rv = KERN_INVALID_ADDRESS;
3270 				break;
3271 			}
3272 			first_entry = (entry == first_entry) ?
3273 			    next_entry : NULL;
3274 			continue;
3275 		}
3276 		rv = vm_map_clip_start(map, entry, start);
3277 		if (rv != KERN_SUCCESS)
3278 			break;
3279 		rv = vm_map_clip_end(map, entry, end);
3280 		if (rv != KERN_SUCCESS)
3281 			break;
3282 
3283 		/*
3284 		 * Mark the entry in case the map lock is released.  (See
3285 		 * above.)
3286 		 */
3287 		KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
3288 		    entry->wiring_thread == NULL,
3289 		    ("owned map entry %p", entry));
3290 		entry->eflags |= MAP_ENTRY_IN_TRANSITION;
3291 		entry->wiring_thread = curthread;
3292 		next_entry = vm_map_entry_succ(entry);
3293 		/*
3294 		 * Check the map for holes in the specified region.
3295 		 * If holes_ok, skip this check.
3296 		 */
3297 		if (!holes_ok &&
3298 		    entry->end < end && next_entry->start > entry->end) {
3299 			end = entry->end;
3300 			rv = KERN_INVALID_ADDRESS;
3301 			break;
3302 		}
3303 		/*
3304 		 * If system unwiring, require that the entry is system wired.
3305 		 */
3306 		if (!user_unwire &&
3307 		    vm_map_entry_system_wired_count(entry) == 0) {
3308 			end = entry->end;
3309 			rv = KERN_INVALID_ARGUMENT;
3310 			break;
3311 		}
3312 	}
3313 	need_wakeup = false;
3314 	if (first_entry == NULL &&
3315 	    !vm_map_lookup_entry(map, start, &first_entry)) {
3316 		KASSERT(holes_ok, ("vm_map_unwire: lookup failed"));
3317 		prev_entry = first_entry;
3318 		entry = vm_map_entry_succ(first_entry);
3319 	} else {
3320 		prev_entry = vm_map_entry_pred(first_entry);
3321 		entry = first_entry;
3322 	}
3323 	for (; entry->start < end;
3324 	    prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3325 		/*
3326 		 * If holes_ok was specified, an empty
3327 		 * space in the unwired region could have been mapped
3328 		 * while the map lock was dropped for draining
3329 		 * MAP_ENTRY_IN_TRANSITION.  Moreover, another thread
3330 		 * could be simultaneously wiring this new mapping
3331 		 * entry.  Detect these cases and skip any entries
3332 		 * marked as in transition by us.
3333 		 */
3334 		if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
3335 		    entry->wiring_thread != curthread) {
3336 			KASSERT(holes_ok,
3337 			    ("vm_map_unwire: !HOLESOK and new/changed entry"));
3338 			continue;
3339 		}
3340 
3341 		if (rv == KERN_SUCCESS && (!user_unwire ||
3342 		    (entry->eflags & MAP_ENTRY_USER_WIRED))) {
3343 			if (entry->wired_count == 1)
3344 				vm_map_entry_unwire(map, entry);
3345 			else
3346 				entry->wired_count--;
3347 			if (user_unwire)
3348 				entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3349 		}
3350 		KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3351 		    ("vm_map_unwire: in-transition flag missing %p", entry));
3352 		KASSERT(entry->wiring_thread == curthread,
3353 		    ("vm_map_unwire: alien wire %p", entry));
3354 		entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
3355 		entry->wiring_thread = NULL;
3356 		if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
3357 			entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
3358 			need_wakeup = true;
3359 		}
3360 		vm_map_try_merge_entries(map, prev_entry, entry);
3361 	}
3362 	vm_map_try_merge_entries(map, prev_entry, entry);
3363 	vm_map_unlock(map);
3364 	if (need_wakeup)
3365 		vm_map_wakeup(map);
3366 	return (rv);
3367 }
3368 
3369 static void
3370 vm_map_wire_user_count_sub(u_long npages)
3371 {
3372 
3373 	atomic_subtract_long(&vm_user_wire_count, npages);
3374 }
3375 
3376 static bool
3377 vm_map_wire_user_count_add(u_long npages)
3378 {
3379 	u_long wired;
3380 
3381 	wired = vm_user_wire_count;
3382 	do {
3383 		if (npages + wired > vm_page_max_user_wired)
3384 			return (false);
3385 	} while (!atomic_fcmpset_long(&vm_user_wire_count, &wired,
3386 	    npages + wired));
3387 
3388 	return (true);
3389 }
3390 
3391 /*
3392  *	vm_map_wire_entry_failure:
3393  *
3394  *	Handle a wiring failure on the given entry.
3395  *
3396  *	The map should be locked.
3397  */
3398 static void
3399 vm_map_wire_entry_failure(vm_map_t map, vm_map_entry_t entry,
3400     vm_offset_t failed_addr)
3401 {
3402 
3403 	VM_MAP_ASSERT_LOCKED(map);
3404 	KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 &&
3405 	    entry->wired_count == 1,
3406 	    ("vm_map_wire_entry_failure: entry %p isn't being wired", entry));
3407 	KASSERT(failed_addr < entry->end,
3408 	    ("vm_map_wire_entry_failure: entry %p was fully wired", entry));
3409 
3410 	/*
3411 	 * If any pages at the start of this entry were successfully wired,
3412 	 * then unwire them.
3413 	 */
3414 	if (failed_addr > entry->start) {
3415 		pmap_unwire(map->pmap, entry->start, failed_addr);
3416 		vm_object_unwire(entry->object.vm_object, entry->offset,
3417 		    failed_addr - entry->start, PQ_ACTIVE);
3418 	}
3419 
3420 	/*
3421 	 * Assign an out-of-range value to represent the failure to wire this
3422 	 * entry.
3423 	 */
3424 	entry->wired_count = -1;
3425 }
3426 
3427 int
3428 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
3429 {
3430 	int rv;
3431 
3432 	vm_map_lock(map);
3433 	rv = vm_map_wire_locked(map, start, end, flags);
3434 	vm_map_unlock(map);
3435 	return (rv);
3436 }
3437 
3438 /*
3439  *	vm_map_wire_locked:
3440  *
3441  *	Implements both kernel and user wiring.  Returns with the map locked,
3442  *	the map lock may be dropped.
3443  */
3444 int
3445 vm_map_wire_locked(vm_map_t map, vm_offset_t start, vm_offset_t end, int flags)
3446 {
3447 	vm_map_entry_t entry, first_entry, next_entry, prev_entry;
3448 	vm_offset_t faddr, saved_end, saved_start;
3449 	u_long incr, npages;
3450 	u_int bidx, last_timestamp;
3451 	int rv;
3452 	bool holes_ok, need_wakeup, user_wire;
3453 	vm_prot_t prot;
3454 
3455 	VM_MAP_ASSERT_LOCKED(map);
3456 
3457 	if (start == end)
3458 		return (KERN_SUCCESS);
3459 	prot = 0;
3460 	if (flags & VM_MAP_WIRE_WRITE)
3461 		prot |= VM_PROT_WRITE;
3462 	holes_ok = (flags & VM_MAP_WIRE_HOLESOK) != 0;
3463 	user_wire = (flags & VM_MAP_WIRE_USER) != 0;
3464 	VM_MAP_RANGE_CHECK(map, start, end);
3465 	if (!vm_map_lookup_entry(map, start, &first_entry)) {
3466 		if (holes_ok)
3467 			first_entry = vm_map_entry_succ(first_entry);
3468 		else
3469 			return (KERN_INVALID_ADDRESS);
3470 	}
3471 	for (entry = first_entry; entry->start < end; entry = next_entry) {
3472 		if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
3473 			/*
3474 			 * We have not yet clipped the entry.
3475 			 */
3476 			next_entry = vm_map_entry_in_transition(map, start,
3477 			    &end, holes_ok, entry);
3478 			if (next_entry == NULL) {
3479 				if (entry == first_entry)
3480 					return (KERN_INVALID_ADDRESS);
3481 				rv = KERN_INVALID_ADDRESS;
3482 				goto done;
3483 			}
3484 			first_entry = (entry == first_entry) ?
3485 			    next_entry : NULL;
3486 			continue;
3487 		}
3488 		rv = vm_map_clip_start(map, entry, start);
3489 		if (rv != KERN_SUCCESS)
3490 			goto done;
3491 		rv = vm_map_clip_end(map, entry, end);
3492 		if (rv != KERN_SUCCESS)
3493 			goto done;
3494 
3495 		/*
3496 		 * Mark the entry in case the map lock is released.  (See
3497 		 * above.)
3498 		 */
3499 		KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 &&
3500 		    entry->wiring_thread == NULL,
3501 		    ("owned map entry %p", entry));
3502 		entry->eflags |= MAP_ENTRY_IN_TRANSITION;
3503 		entry->wiring_thread = curthread;
3504 		if ((entry->protection & (VM_PROT_READ | VM_PROT_EXECUTE)) == 0
3505 		    || (entry->protection & prot) != prot) {
3506 			entry->eflags |= MAP_ENTRY_WIRE_SKIPPED;
3507 			if (!holes_ok) {
3508 				end = entry->end;
3509 				rv = KERN_INVALID_ADDRESS;
3510 				goto done;
3511 			}
3512 		} else if (entry->wired_count == 0) {
3513 			entry->wired_count++;
3514 
3515 			npages = atop(entry->end - entry->start);
3516 			if (user_wire && !vm_map_wire_user_count_add(npages)) {
3517 				vm_map_wire_entry_failure(map, entry,
3518 				    entry->start);
3519 				end = entry->end;
3520 				rv = KERN_RESOURCE_SHORTAGE;
3521 				goto done;
3522 			}
3523 
3524 			/*
3525 			 * Release the map lock, relying on the in-transition
3526 			 * mark.  Mark the map busy for fork.
3527 			 */
3528 			saved_start = entry->start;
3529 			saved_end = entry->end;
3530 			last_timestamp = map->timestamp;
3531 			bidx = (entry->eflags & MAP_ENTRY_SPLIT_BOUNDARY_MASK)
3532 			    >> MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
3533 			incr =  pagesizes[bidx];
3534 			vm_map_busy(map);
3535 			vm_map_unlock(map);
3536 
3537 			for (faddr = saved_start; faddr < saved_end;
3538 			    faddr += incr) {
3539 				/*
3540 				 * Simulate a fault to get the page and enter
3541 				 * it into the physical map.
3542 				 */
3543 				rv = vm_fault(map, faddr, VM_PROT_NONE,
3544 				    VM_FAULT_WIRE, NULL);
3545 				if (rv != KERN_SUCCESS)
3546 					break;
3547 			}
3548 			vm_map_lock(map);
3549 			vm_map_unbusy(map);
3550 			if (last_timestamp + 1 != map->timestamp) {
3551 				/*
3552 				 * Look again for the entry because the map was
3553 				 * modified while it was unlocked.  The entry
3554 				 * may have been clipped, but NOT merged or
3555 				 * deleted.
3556 				 */
3557 				if (!vm_map_lookup_entry(map, saved_start,
3558 				    &next_entry))
3559 					KASSERT(false,
3560 					    ("vm_map_wire: lookup failed"));
3561 				first_entry = (entry == first_entry) ?
3562 				    next_entry : NULL;
3563 				for (entry = next_entry; entry->end < saved_end;
3564 				    entry = vm_map_entry_succ(entry)) {
3565 					/*
3566 					 * In case of failure, handle entries
3567 					 * that were not fully wired here;
3568 					 * fully wired entries are handled
3569 					 * later.
3570 					 */
3571 					if (rv != KERN_SUCCESS &&
3572 					    faddr < entry->end)
3573 						vm_map_wire_entry_failure(map,
3574 						    entry, faddr);
3575 				}
3576 			}
3577 			if (rv != KERN_SUCCESS) {
3578 				vm_map_wire_entry_failure(map, entry, faddr);
3579 				if (user_wire)
3580 					vm_map_wire_user_count_sub(npages);
3581 				end = entry->end;
3582 				goto done;
3583 			}
3584 		} else if (!user_wire ||
3585 			   (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
3586 			entry->wired_count++;
3587 		}
3588 		/*
3589 		 * Check the map for holes in the specified region.
3590 		 * If holes_ok was specified, skip this check.
3591 		 */
3592 		next_entry = vm_map_entry_succ(entry);
3593 		if (!holes_ok &&
3594 		    entry->end < end && next_entry->start > entry->end) {
3595 			end = entry->end;
3596 			rv = KERN_INVALID_ADDRESS;
3597 			goto done;
3598 		}
3599 	}
3600 	rv = KERN_SUCCESS;
3601 done:
3602 	need_wakeup = false;
3603 	if (first_entry == NULL &&
3604 	    !vm_map_lookup_entry(map, start, &first_entry)) {
3605 		KASSERT(holes_ok, ("vm_map_wire: lookup failed"));
3606 		prev_entry = first_entry;
3607 		entry = vm_map_entry_succ(first_entry);
3608 	} else {
3609 		prev_entry = vm_map_entry_pred(first_entry);
3610 		entry = first_entry;
3611 	}
3612 	for (; entry->start < end;
3613 	    prev_entry = entry, entry = vm_map_entry_succ(entry)) {
3614 		/*
3615 		 * If holes_ok was specified, an empty
3616 		 * space in the unwired region could have been mapped
3617 		 * while the map lock was dropped for faulting in the
3618 		 * pages or draining MAP_ENTRY_IN_TRANSITION.
3619 		 * Moreover, another thread could be simultaneously
3620 		 * wiring this new mapping entry.  Detect these cases
3621 		 * and skip any entries marked as in transition not by us.
3622 		 *
3623 		 * Another way to get an entry not marked with
3624 		 * MAP_ENTRY_IN_TRANSITION is after failed clipping,
3625 		 * which set rv to KERN_INVALID_ARGUMENT.
3626 		 */
3627 		if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) == 0 ||
3628 		    entry->wiring_thread != curthread) {
3629 			KASSERT(holes_ok || rv == KERN_INVALID_ARGUMENT,
3630 			    ("vm_map_wire: !HOLESOK and new/changed entry"));
3631 			continue;
3632 		}
3633 
3634 		if ((entry->eflags & MAP_ENTRY_WIRE_SKIPPED) != 0) {
3635 			/* do nothing */
3636 		} else if (rv == KERN_SUCCESS) {
3637 			if (user_wire)
3638 				entry->eflags |= MAP_ENTRY_USER_WIRED;
3639 		} else if (entry->wired_count == -1) {
3640 			/*
3641 			 * Wiring failed on this entry.  Thus, unwiring is
3642 			 * unnecessary.
3643 			 */
3644 			entry->wired_count = 0;
3645 		} else if (!user_wire ||
3646 		    (entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
3647 			/*
3648 			 * Undo the wiring.  Wiring succeeded on this entry
3649 			 * but failed on a later entry.
3650 			 */
3651 			if (entry->wired_count == 1) {
3652 				vm_map_entry_unwire(map, entry);
3653 				if (user_wire)
3654 					vm_map_wire_user_count_sub(
3655 					    atop(entry->end - entry->start));
3656 			} else
3657 				entry->wired_count--;
3658 		}
3659 		KASSERT((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0,
3660 		    ("vm_map_wire: in-transition flag missing %p", entry));
3661 		KASSERT(entry->wiring_thread == curthread,
3662 		    ("vm_map_wire: alien wire %p", entry));
3663 		entry->eflags &= ~(MAP_ENTRY_IN_TRANSITION |
3664 		    MAP_ENTRY_WIRE_SKIPPED);
3665 		entry->wiring_thread = NULL;
3666 		if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
3667 			entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
3668 			need_wakeup = true;
3669 		}
3670 		vm_map_try_merge_entries(map, prev_entry, entry);
3671 	}
3672 	vm_map_try_merge_entries(map, prev_entry, entry);
3673 	if (need_wakeup)
3674 		vm_map_wakeup(map);
3675 	return (rv);
3676 }
3677 
3678 /*
3679  * vm_map_sync
3680  *
3681  * Push any dirty cached pages in the address range to their pager.
3682  * If syncio is TRUE, dirty pages are written synchronously.
3683  * If invalidate is TRUE, any cached pages are freed as well.
3684  *
3685  * If the size of the region from start to end is zero, we are
3686  * supposed to flush all modified pages within the region containing
3687  * start.  Unfortunately, a region can be split or coalesced with
3688  * neighboring regions, making it difficult to determine what the
3689  * original region was.  Therefore, we approximate this requirement by
3690  * flushing the current region containing start.
3691  *
3692  * Returns an error if any part of the specified range is not mapped.
3693  */
3694 int
3695 vm_map_sync(
3696 	vm_map_t map,
3697 	vm_offset_t start,
3698 	vm_offset_t end,
3699 	boolean_t syncio,
3700 	boolean_t invalidate)
3701 {
3702 	vm_map_entry_t entry, first_entry, next_entry;
3703 	vm_size_t size;
3704 	vm_object_t object;
3705 	vm_ooffset_t offset;
3706 	unsigned int last_timestamp;
3707 	int bdry_idx;
3708 	boolean_t failed;
3709 
3710 	vm_map_lock_read(map);
3711 	VM_MAP_RANGE_CHECK(map, start, end);
3712 	if (!vm_map_lookup_entry(map, start, &first_entry)) {
3713 		vm_map_unlock_read(map);
3714 		return (KERN_INVALID_ADDRESS);
3715 	} else if (start == end) {
3716 		start = first_entry->start;
3717 		end = first_entry->end;
3718 	}
3719 
3720 	/*
3721 	 * Make a first pass to check for user-wired memory, holes,
3722 	 * and partial invalidation of largepage mappings.
3723 	 */
3724 	for (entry = first_entry; entry->start < end; entry = next_entry) {
3725 		if (invalidate) {
3726 			if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0) {
3727 				vm_map_unlock_read(map);
3728 				return (KERN_INVALID_ARGUMENT);
3729 			}
3730 			bdry_idx = (entry->eflags &
3731 			    MAP_ENTRY_SPLIT_BOUNDARY_MASK) >>
3732 			    MAP_ENTRY_SPLIT_BOUNDARY_SHIFT;
3733 			if (bdry_idx != 0 &&
3734 			    ((start & (pagesizes[bdry_idx] - 1)) != 0 ||
3735 			    (end & (pagesizes[bdry_idx] - 1)) != 0)) {
3736 				vm_map_unlock_read(map);
3737 				return (KERN_INVALID_ARGUMENT);
3738 			}
3739 		}
3740 		next_entry = vm_map_entry_succ(entry);
3741 		if (end > entry->end &&
3742 		    entry->end != next_entry->start) {
3743 			vm_map_unlock_read(map);
3744 			return (KERN_INVALID_ADDRESS);
3745 		}
3746 	}
3747 
3748 	if (invalidate)
3749 		pmap_remove(map->pmap, start, end);
3750 	failed = FALSE;
3751 
3752 	/*
3753 	 * Make a second pass, cleaning/uncaching pages from the indicated
3754 	 * objects as we go.
3755 	 */
3756 	for (entry = first_entry; entry->start < end;) {
3757 		offset = entry->offset + (start - entry->start);
3758 		size = (end <= entry->end ? end : entry->end) - start;
3759 		if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0) {
3760 			vm_map_t smap;
3761 			vm_map_entry_t tentry;
3762 			vm_size_t tsize;
3763 
3764 			smap = entry->object.sub_map;
3765 			vm_map_lock_read(smap);
3766 			(void) vm_map_lookup_entry(smap, offset, &tentry);
3767 			tsize = tentry->end - offset;
3768 			if (tsize < size)
3769 				size = tsize;
3770 			object = tentry->object.vm_object;
3771 			offset = tentry->offset + (offset - tentry->start);
3772 			vm_map_unlock_read(smap);
3773 		} else {
3774 			object = entry->object.vm_object;
3775 		}
3776 		vm_object_reference(object);
3777 		last_timestamp = map->timestamp;
3778 		vm_map_unlock_read(map);
3779 		if (!vm_object_sync(object, offset, size, syncio, invalidate))
3780 			failed = TRUE;
3781 		start += size;
3782 		vm_object_deallocate(object);
3783 		vm_map_lock_read(map);
3784 		if (last_timestamp == map->timestamp ||
3785 		    !vm_map_lookup_entry(map, start, &entry))
3786 			entry = vm_map_entry_succ(entry);
3787 	}
3788 
3789 	vm_map_unlock_read(map);
3790 	return (failed ? KERN_FAILURE : KERN_SUCCESS);
3791 }
3792 
3793 /*
3794  *	vm_map_entry_unwire:	[ internal use only ]
3795  *
3796  *	Make the region specified by this entry pageable.
3797  *
3798  *	The map in question should be locked.
3799  *	[This is the reason for this routine's existence.]
3800  */
3801 static void
3802 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
3803 {
3804 	vm_size_t size;
3805 
3806 	VM_MAP_ASSERT_LOCKED(map);
3807 	KASSERT(entry->wired_count > 0,
3808 	    ("vm_map_entry_unwire: entry %p isn't wired", entry));
3809 
3810 	size = entry->end - entry->start;
3811 	if ((entry->eflags & MAP_ENTRY_USER_WIRED) != 0)
3812 		vm_map_wire_user_count_sub(atop(size));
3813 	pmap_unwire(map->pmap, entry->start, entry->end);
3814 	vm_object_unwire(entry->object.vm_object, entry->offset, size,
3815 	    PQ_ACTIVE);
3816 	entry->wired_count = 0;
3817 }
3818 
3819 static void
3820 vm_map_entry_deallocate(vm_map_entry_t entry, boolean_t system_map)
3821 {
3822 
3823 	if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0)
3824 		vm_object_deallocate(entry->object.vm_object);
3825 	uma_zfree(system_map ? kmapentzone : mapentzone, entry);
3826 }
3827 
3828 /*
3829  *	vm_map_entry_delete:	[ internal use only ]
3830  *
3831  *	Deallocate the given entry from the target map.
3832  */
3833 static void
3834 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry)
3835 {
3836 	vm_object_t object;
3837 	vm_pindex_t offidxstart, offidxend, size1;
3838 	vm_size_t size;
3839 
3840 	vm_map_entry_unlink(map, entry, UNLINK_MERGE_NONE);
3841 	object = entry->object.vm_object;
3842 
3843 	if ((entry->eflags & MAP_ENTRY_GUARD) != 0) {
3844 		MPASS(entry->cred == NULL);
3845 		MPASS((entry->eflags & MAP_ENTRY_IS_SUB_MAP) == 0);
3846 		MPASS(object == NULL);
3847 		vm_map_entry_deallocate(entry, map->system_map);
3848 		return;
3849 	}
3850 
3851 	size = entry->end - entry->start;
3852 	map->size -= size;
3853 
3854 	if (entry->cred != NULL) {
3855 		swap_release_by_cred(size, entry->cred);
3856 		crfree(entry->cred);
3857 	}
3858 
3859 	if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 || object == NULL) {
3860 		entry->object.vm_object = NULL;
3861 	} else if ((object->flags & OBJ_ANON) != 0 ||
3862 	    object == kernel_object) {
3863 		KASSERT(entry->cred == NULL || object->cred == NULL ||
3864 		    (entry->eflags & MAP_ENTRY_NEEDS_COPY),
3865 		    ("OVERCOMMIT vm_map_entry_delete: both cred %p", entry));
3866 		offidxstart = OFF_TO_IDX(entry->offset);
3867 		offidxend = offidxstart + atop(size);
3868 		VM_OBJECT_WLOCK(object);
3869 		if (object->ref_count != 1 &&
3870 		    ((object->flags & OBJ_ONEMAPPING) != 0 ||
3871 		    object == kernel_object)) {
3872 			vm_object_collapse(object);
3873 
3874 			/*
3875 			 * The option OBJPR_NOTMAPPED can be passed here
3876 			 * because vm_map_delete() already performed
3877 			 * pmap_remove() on the only mapping to this range
3878 			 * of pages.
3879 			 */
3880 			vm_object_page_remove(object, offidxstart, offidxend,
3881 			    OBJPR_NOTMAPPED);
3882 			if (offidxend >= object->size &&
3883 			    offidxstart < object->size) {
3884 				size1 = object->size;
3885 				object->size = offidxstart;
3886 				if (object->cred != NULL) {
3887 					size1 -= object->size;
3888 					KASSERT(object->charge >= ptoa(size1),
3889 					    ("object %p charge < 0", object));
3890 					swap_release_by_cred(ptoa(size1),
3891 					    object->cred);
3892 					object->charge -= ptoa(size1);
3893 				}
3894 			}
3895 		}
3896 		VM_OBJECT_WUNLOCK(object);
3897 	}
3898 	if (map->system_map)
3899 		vm_map_entry_deallocate(entry, TRUE);
3900 	else {
3901 		entry->defer_next = curthread->td_map_def_user;
3902 		curthread->td_map_def_user = entry;
3903 	}
3904 }
3905 
3906 /*
3907  *	vm_map_delete:	[ internal use only ]
3908  *
3909  *	Deallocates the given address range from the target
3910  *	map.
3911  */
3912 int
3913 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end)
3914 {
3915 	vm_map_entry_t entry, next_entry, scratch_entry;
3916 	int rv;
3917 
3918 	VM_MAP_ASSERT_LOCKED(map);
3919 
3920 	if (start == end)
3921 		return (KERN_SUCCESS);
3922 
3923 	/*
3924 	 * Find the start of the region, and clip it.
3925 	 * Step through all entries in this region.
3926 	 */
3927 	rv = vm_map_lookup_clip_start(map, start, &entry, &scratch_entry);
3928 	if (rv != KERN_SUCCESS)
3929 		return (rv);
3930 	for (; entry->start < end; entry = next_entry) {
3931 		/*
3932 		 * Wait for wiring or unwiring of an entry to complete.
3933 		 * Also wait for any system wirings to disappear on
3934 		 * user maps.
3935 		 */
3936 		if ((entry->eflags & MAP_ENTRY_IN_TRANSITION) != 0 ||
3937 		    (vm_map_pmap(map) != kernel_pmap &&
3938 		    vm_map_entry_system_wired_count(entry) != 0)) {
3939 			unsigned int last_timestamp;
3940 			vm_offset_t saved_start;
3941 
3942 			saved_start = entry->start;
3943 			entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
3944 			last_timestamp = map->timestamp;
3945 			(void) vm_map_unlock_and_wait(map, 0);
3946 			vm_map_lock(map);
3947 			if (last_timestamp + 1 != map->timestamp) {
3948 				/*
3949 				 * Look again for the entry because the map was
3950 				 * modified while it was unlocked.
3951 				 * Specifically, the entry may have been
3952 				 * clipped, merged, or deleted.
3953 				 */
3954 				rv = vm_map_lookup_clip_start(map, saved_start,
3955 				    &next_entry, &scratch_entry);
3956 				if (rv != KERN_SUCCESS)
3957 					break;
3958 			} else
3959 				next_entry = entry;
3960 			continue;
3961 		}
3962 
3963 		/* XXXKIB or delete to the upper superpage boundary ? */
3964 		rv = vm_map_clip_end(map, entry, end);
3965 		if (rv != KERN_SUCCESS)
3966 			break;
3967 		next_entry = vm_map_entry_succ(entry);
3968 
3969 		/*
3970 		 * Unwire before removing addresses from the pmap; otherwise,
3971 		 * unwiring will put the entries back in the pmap.
3972 		 */
3973 		if (entry->wired_count != 0)
3974 			vm_map_entry_unwire(map, entry);
3975 
3976 		/*
3977 		 * Remove mappings for the pages, but only if the
3978 		 * mappings could exist.  For instance, it does not
3979 		 * make sense to call pmap_remove() for guard entries.
3980 		 */
3981 		if ((entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0 ||
3982 		    entry->object.vm_object != NULL)
3983 			pmap_remove(map->pmap, entry->start, entry->end);
3984 
3985 		if (entry->end == map->anon_loc)
3986 			map->anon_loc = entry->start;
3987 
3988 		/*
3989 		 * Delete the entry only after removing all pmap
3990 		 * entries pointing to its pages.  (Otherwise, its
3991 		 * page frames may be reallocated, and any modify bits
3992 		 * will be set in the wrong object!)
3993 		 */
3994 		vm_map_entry_delete(map, entry);
3995 	}
3996 	return (rv);
3997 }
3998 
3999 /*
4000  *	vm_map_remove:
4001  *
4002  *	Remove the given address range from the target map.
4003  *	This is the exported form of vm_map_delete.
4004  */
4005 int
4006 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
4007 {
4008 	int result;
4009 
4010 	vm_map_lock(map);
4011 	VM_MAP_RANGE_CHECK(map, start, end);
4012 	result = vm_map_delete(map, start, end);
4013 	vm_map_unlock(map);
4014 	return (result);
4015 }
4016 
4017 /*
4018  *	vm_map_check_protection:
4019  *
4020  *	Assert that the target map allows the specified privilege on the
4021  *	entire address region given.  The entire region must be allocated.
4022  *
4023  *	WARNING!  This code does not and should not check whether the
4024  *	contents of the region is accessible.  For example a smaller file
4025  *	might be mapped into a larger address space.
4026  *
4027  *	NOTE!  This code is also called by munmap().
4028  *
4029  *	The map must be locked.  A read lock is sufficient.
4030  */
4031 boolean_t
4032 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
4033 			vm_prot_t protection)
4034 {
4035 	vm_map_entry_t entry;
4036 	vm_map_entry_t tmp_entry;
4037 
4038 	if (!vm_map_lookup_entry(map, start, &tmp_entry))
4039 		return (FALSE);
4040 	entry = tmp_entry;
4041 
4042 	while (start < end) {
4043 		/*
4044 		 * No holes allowed!
4045 		 */
4046 		if (start < entry->start)
4047 			return (FALSE);
4048 		/*
4049 		 * Check protection associated with entry.
4050 		 */
4051 		if ((entry->protection & protection) != protection)
4052 			return (FALSE);
4053 		/* go to next entry */
4054 		start = entry->end;
4055 		entry = vm_map_entry_succ(entry);
4056 	}
4057 	return (TRUE);
4058 }
4059 
4060 /*
4061  *
4062  *	vm_map_copy_swap_object:
4063  *
4064  *	Copies a swap-backed object from an existing map entry to a
4065  *	new one.  Carries forward the swap charge.  May change the
4066  *	src object on return.
4067  */
4068 static void
4069 vm_map_copy_swap_object(vm_map_entry_t src_entry, vm_map_entry_t dst_entry,
4070     vm_offset_t size, vm_ooffset_t *fork_charge)
4071 {
4072 	vm_object_t src_object;
4073 	struct ucred *cred;
4074 	int charged;
4075 
4076 	src_object = src_entry->object.vm_object;
4077 	charged = ENTRY_CHARGED(src_entry);
4078 	if ((src_object->flags & OBJ_ANON) != 0) {
4079 		VM_OBJECT_WLOCK(src_object);
4080 		vm_object_collapse(src_object);
4081 		if ((src_object->flags & OBJ_ONEMAPPING) != 0) {
4082 			vm_object_split(src_entry);
4083 			src_object = src_entry->object.vm_object;
4084 		}
4085 		vm_object_reference_locked(src_object);
4086 		vm_object_clear_flag(src_object, OBJ_ONEMAPPING);
4087 		VM_OBJECT_WUNLOCK(src_object);
4088 	} else
4089 		vm_object_reference(src_object);
4090 	if (src_entry->cred != NULL &&
4091 	    !(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
4092 		KASSERT(src_object->cred == NULL,
4093 		    ("OVERCOMMIT: vm_map_copy_anon_entry: cred %p",
4094 		     src_object));
4095 		src_object->cred = src_entry->cred;
4096 		src_object->charge = size;
4097 	}
4098 	dst_entry->object.vm_object = src_object;
4099 	if (charged) {
4100 		cred = curthread->td_ucred;
4101 		crhold(cred);
4102 		dst_entry->cred = cred;
4103 		*fork_charge += size;
4104 		if (!(src_entry->eflags & MAP_ENTRY_NEEDS_COPY)) {
4105 			crhold(cred);
4106 			src_entry->cred = cred;
4107 			*fork_charge += size;
4108 		}
4109 	}
4110 }
4111 
4112 /*
4113  *	vm_map_copy_entry:
4114  *
4115  *	Copies the contents of the source entry to the destination
4116  *	entry.  The entries *must* be aligned properly.
4117  */
4118 static void
4119 vm_map_copy_entry(
4120 	vm_map_t src_map,
4121 	vm_map_t dst_map,
4122 	vm_map_entry_t src_entry,
4123 	vm_map_entry_t dst_entry,
4124 	vm_ooffset_t *fork_charge)
4125 {
4126 	vm_object_t src_object;
4127 	vm_map_entry_t fake_entry;
4128 	vm_offset_t size;
4129 
4130 	VM_MAP_ASSERT_LOCKED(dst_map);
4131 
4132 	if ((dst_entry->eflags|src_entry->eflags) & MAP_ENTRY_IS_SUB_MAP)
4133 		return;
4134 
4135 	if (src_entry->wired_count == 0 ||
4136 	    (src_entry->protection & VM_PROT_WRITE) == 0) {
4137 		/*
4138 		 * If the source entry is marked needs_copy, it is already
4139 		 * write-protected.
4140 		 */
4141 		if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0 &&
4142 		    (src_entry->protection & VM_PROT_WRITE) != 0) {
4143 			pmap_protect(src_map->pmap,
4144 			    src_entry->start,
4145 			    src_entry->end,
4146 			    src_entry->protection & ~VM_PROT_WRITE);
4147 		}
4148 
4149 		/*
4150 		 * Make a copy of the object.
4151 		 */
4152 		size = src_entry->end - src_entry->start;
4153 		if ((src_object = src_entry->object.vm_object) != NULL) {
4154 			if (src_object->type == OBJT_DEFAULT ||
4155 			    src_object->type == OBJT_SWAP) {
4156 				vm_map_copy_swap_object(src_entry, dst_entry,
4157 				    size, fork_charge);
4158 				/* May have split/collapsed, reload obj. */
4159 				src_object = src_entry->object.vm_object;
4160 			} else {
4161 				vm_object_reference(src_object);
4162 				dst_entry->object.vm_object = src_object;
4163 			}
4164 			src_entry->eflags |= MAP_ENTRY_COW |
4165 			    MAP_ENTRY_NEEDS_COPY;
4166 			dst_entry->eflags |= MAP_ENTRY_COW |
4167 			    MAP_ENTRY_NEEDS_COPY;
4168 			dst_entry->offset = src_entry->offset;
4169 			if (src_entry->eflags & MAP_ENTRY_WRITECNT) {
4170 				/*
4171 				 * MAP_ENTRY_WRITECNT cannot
4172 				 * indicate write reference from
4173 				 * src_entry, since the entry is
4174 				 * marked as needs copy.  Allocate a
4175 				 * fake entry that is used to
4176 				 * decrement object->un_pager writecount
4177 				 * at the appropriate time.  Attach
4178 				 * fake_entry to the deferred list.
4179 				 */
4180 				fake_entry = vm_map_entry_create(dst_map);
4181 				fake_entry->eflags = MAP_ENTRY_WRITECNT;
4182 				src_entry->eflags &= ~MAP_ENTRY_WRITECNT;
4183 				vm_object_reference(src_object);
4184 				fake_entry->object.vm_object = src_object;
4185 				fake_entry->start = src_entry->start;
4186 				fake_entry->end = src_entry->end;
4187 				fake_entry->defer_next =
4188 				    curthread->td_map_def_user;
4189 				curthread->td_map_def_user = fake_entry;
4190 			}
4191 
4192 			pmap_copy(dst_map->pmap, src_map->pmap,
4193 			    dst_entry->start, dst_entry->end - dst_entry->start,
4194 			    src_entry->start);
4195 		} else {
4196 			dst_entry->object.vm_object = NULL;
4197 			dst_entry->offset = 0;
4198 			if (src_entry->cred != NULL) {
4199 				dst_entry->cred = curthread->td_ucred;
4200 				crhold(dst_entry->cred);
4201 				*fork_charge += size;
4202 			}
4203 		}
4204 	} else {
4205 		/*
4206 		 * We don't want to make writeable wired pages copy-on-write.
4207 		 * Immediately copy these pages into the new map by simulating
4208 		 * page faults.  The new pages are pageable.
4209 		 */
4210 		vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry,
4211 		    fork_charge);
4212 	}
4213 }
4214 
4215 /*
4216  * vmspace_map_entry_forked:
4217  * Update the newly-forked vmspace each time a map entry is inherited
4218  * or copied.  The values for vm_dsize and vm_tsize are approximate
4219  * (and mostly-obsolete ideas in the face of mmap(2) et al.)
4220  */
4221 static void
4222 vmspace_map_entry_forked(const struct vmspace *vm1, struct vmspace *vm2,
4223     vm_map_entry_t entry)
4224 {
4225 	vm_size_t entrysize;
4226 	vm_offset_t newend;
4227 
4228 	if ((entry->eflags & MAP_ENTRY_GUARD) != 0)
4229 		return;
4230 	entrysize = entry->end - entry->start;
4231 	vm2->vm_map.size += entrysize;
4232 	if (entry->eflags & (MAP_ENTRY_GROWS_DOWN | MAP_ENTRY_GROWS_UP)) {
4233 		vm2->vm_ssize += btoc(entrysize);
4234 	} else if (entry->start >= (vm_offset_t)vm1->vm_daddr &&
4235 	    entry->start < (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize)) {
4236 		newend = MIN(entry->end,
4237 		    (vm_offset_t)vm1->vm_daddr + ctob(vm1->vm_dsize));
4238 		vm2->vm_dsize += btoc(newend - entry->start);
4239 	} else if (entry->start >= (vm_offset_t)vm1->vm_taddr &&
4240 	    entry->start < (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize)) {
4241 		newend = MIN(entry->end,
4242 		    (vm_offset_t)vm1->vm_taddr + ctob(vm1->vm_tsize));
4243 		vm2->vm_tsize += btoc(newend - entry->start);
4244 	}
4245 }
4246 
4247 /*
4248  * vmspace_fork:
4249  * Create a new process vmspace structure and vm_map
4250  * based on those of an existing process.  The new map
4251  * is based on the old map, according to the inheritance
4252  * values on the regions in that map.
4253  *
4254  * XXX It might be worth coalescing the entries added to the new vmspace.
4255  *
4256  * The source map must not be locked.
4257  */
4258 struct vmspace *
4259 vmspace_fork(struct vmspace *vm1, vm_ooffset_t *fork_charge)
4260 {
4261 	struct vmspace *vm2;
4262 	vm_map_t new_map, old_map;
4263 	vm_map_entry_t new_entry, old_entry;
4264 	vm_object_t object;
4265 	int error, locked;
4266 	vm_inherit_t inh;
4267 
4268 	old_map = &vm1->vm_map;
4269 	/* Copy immutable fields of vm1 to vm2. */
4270 	vm2 = vmspace_alloc(vm_map_min(old_map), vm_map_max(old_map),
4271 	    pmap_pinit);
4272 	if (vm2 == NULL)
4273 		return (NULL);
4274 
4275 	vm2->vm_taddr = vm1->vm_taddr;
4276 	vm2->vm_daddr = vm1->vm_daddr;
4277 	vm2->vm_maxsaddr = vm1->vm_maxsaddr;
4278 	vm_map_lock(old_map);
4279 	if (old_map->busy)
4280 		vm_map_wait_busy(old_map);
4281 	new_map = &vm2->vm_map;
4282 	locked = vm_map_trylock(new_map); /* trylock to silence WITNESS */
4283 	KASSERT(locked, ("vmspace_fork: lock failed"));
4284 
4285 	error = pmap_vmspace_copy(new_map->pmap, old_map->pmap);
4286 	if (error != 0) {
4287 		sx_xunlock(&old_map->lock);
4288 		sx_xunlock(&new_map->lock);
4289 		vm_map_process_deferred();
4290 		vmspace_free(vm2);
4291 		return (NULL);
4292 	}
4293 
4294 	new_map->anon_loc = old_map->anon_loc;
4295 	new_map->flags |= old_map->flags & (MAP_ASLR | MAP_ASLR_IGNSTART);
4296 
4297 	VM_MAP_ENTRY_FOREACH(old_entry, old_map) {
4298 		if ((old_entry->eflags & MAP_ENTRY_IS_SUB_MAP) != 0)
4299 			panic("vm_map_fork: encountered a submap");
4300 
4301 		inh = old_entry->inheritance;
4302 		if ((old_entry->eflags & MAP_ENTRY_GUARD) != 0 &&
4303 		    inh != VM_INHERIT_NONE)
4304 			inh = VM_INHERIT_COPY;
4305 
4306 		switch (inh) {
4307 		case VM_INHERIT_NONE:
4308 			break;
4309 
4310 		case VM_INHERIT_SHARE:
4311 			/*
4312 			 * Clone the entry, creating the shared object if
4313 			 * necessary.
4314 			 */
4315 			object = old_entry->object.vm_object;
4316 			if (object == NULL) {
4317 				vm_map_entry_back(old_entry);
4318 				object = old_entry->object.vm_object;
4319 			}
4320 
4321 			/*
4322 			 * Add the reference before calling vm_object_shadow
4323 			 * to insure that a shadow object is created.
4324 			 */
4325 			vm_object_reference(object);
4326 			if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
4327 				vm_object_shadow(&old_entry->object.vm_object,
4328 				    &old_entry->offset,
4329 				    old_entry->end - old_entry->start,
4330 				    old_entry->cred,
4331 				    /* Transfer the second reference too. */
4332 				    true);
4333 				old_entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
4334 				old_entry->cred = NULL;
4335 
4336 				/*
4337 				 * As in vm_map_merged_neighbor_dispose(),
4338 				 * the vnode lock will not be acquired in
4339 				 * this call to vm_object_deallocate().
4340 				 */
4341 				vm_object_deallocate(object);
4342 				object = old_entry->object.vm_object;
4343 			} else {
4344 				VM_OBJECT_WLOCK(object);
4345 				vm_object_clear_flag(object, OBJ_ONEMAPPING);
4346 				if (old_entry->cred != NULL) {
4347 					KASSERT(object->cred == NULL,
4348 					    ("vmspace_fork both cred"));
4349 					object->cred = old_entry->cred;
4350 					object->charge = old_entry->end -
4351 					    old_entry->start;
4352 					old_entry->cred = NULL;
4353 				}
4354 
4355 				/*
4356 				 * Assert the correct state of the vnode
4357 				 * v_writecount while the object is locked, to
4358 				 * not relock it later for the assertion
4359 				 * correctness.
4360 				 */
4361 				if (old_entry->eflags & MAP_ENTRY_WRITECNT &&
4362 				    object->type == OBJT_VNODE) {
4363 					KASSERT(((struct vnode *)object->
4364 					    handle)->v_writecount > 0,
4365 					    ("vmspace_fork: v_writecount %p",
4366 					    object));
4367 					KASSERT(object->un_pager.vnp.
4368 					    writemappings > 0,
4369 					    ("vmspace_fork: vnp.writecount %p",
4370 					    object));
4371 				}
4372 				VM_OBJECT_WUNLOCK(object);
4373 			}
4374 
4375 			/*
4376 			 * Clone the entry, referencing the shared object.
4377 			 */
4378 			new_entry = vm_map_entry_create(new_map);
4379 			*new_entry = *old_entry;
4380 			new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
4381 			    MAP_ENTRY_IN_TRANSITION);
4382 			new_entry->wiring_thread = NULL;
4383 			new_entry->wired_count = 0;
4384 			if (new_entry->eflags & MAP_ENTRY_WRITECNT) {
4385 				vm_pager_update_writecount(object,
4386 				    new_entry->start, new_entry->end);
4387 			}
4388 			vm_map_entry_set_vnode_text(new_entry, true);
4389 
4390 			/*
4391 			 * Insert the entry into the new map -- we know we're
4392 			 * inserting at the end of the new map.
4393 			 */
4394 			vm_map_entry_link(new_map, new_entry);
4395 			vmspace_map_entry_forked(vm1, vm2, new_entry);
4396 
4397 			/*
4398 			 * Update the physical map
4399 			 */
4400 			pmap_copy(new_map->pmap, old_map->pmap,
4401 			    new_entry->start,
4402 			    (old_entry->end - old_entry->start),
4403 			    old_entry->start);
4404 			break;
4405 
4406 		case VM_INHERIT_COPY:
4407 			/*
4408 			 * Clone the entry and link into the map.
4409 			 */
4410 			new_entry = vm_map_entry_create(new_map);
4411 			*new_entry = *old_entry;
4412 			/*
4413 			 * Copied entry is COW over the old object.
4414 			 */
4415 			new_entry->eflags &= ~(MAP_ENTRY_USER_WIRED |
4416 			    MAP_ENTRY_IN_TRANSITION | MAP_ENTRY_WRITECNT);
4417 			new_entry->wiring_thread = NULL;
4418 			new_entry->wired_count = 0;
4419 			new_entry->object.vm_object = NULL;
4420 			new_entry->cred = NULL;
4421 			vm_map_entry_link(new_map, new_entry);
4422 			vmspace_map_entry_forked(vm1, vm2, new_entry);
4423 			vm_map_copy_entry(old_map, new_map, old_entry,
4424 			    new_entry, fork_charge);
4425 			vm_map_entry_set_vnode_text(new_entry, true);
4426 			break;
4427 
4428 		case VM_INHERIT_ZERO:
4429 			/*
4430 			 * Create a new anonymous mapping entry modelled from
4431 			 * the old one.
4432 			 */
4433 			new_entry = vm_map_entry_create(new_map);
4434 			memset(new_entry, 0, sizeof(*new_entry));
4435 
4436 			new_entry->start = old_entry->start;
4437 			new_entry->end = old_entry->end;
4438 			new_entry->eflags = old_entry->eflags &
4439 			    ~(MAP_ENTRY_USER_WIRED | MAP_ENTRY_IN_TRANSITION |
4440 			    MAP_ENTRY_WRITECNT | MAP_ENTRY_VN_EXEC |
4441 			    MAP_ENTRY_SPLIT_BOUNDARY_MASK);
4442 			new_entry->protection = old_entry->protection;
4443 			new_entry->max_protection = old_entry->max_protection;
4444 			new_entry->inheritance = VM_INHERIT_ZERO;
4445 
4446 			vm_map_entry_link(new_map, new_entry);
4447 			vmspace_map_entry_forked(vm1, vm2, new_entry);
4448 
4449 			new_entry->cred = curthread->td_ucred;
4450 			crhold(new_entry->cred);
4451 			*fork_charge += (new_entry->end - new_entry->start);
4452 
4453 			break;
4454 		}
4455 	}
4456 	/*
4457 	 * Use inlined vm_map_unlock() to postpone handling the deferred
4458 	 * map entries, which cannot be done until both old_map and
4459 	 * new_map locks are released.
4460 	 */
4461 	sx_xunlock(&old_map->lock);
4462 	sx_xunlock(&new_map->lock);
4463 	vm_map_process_deferred();
4464 
4465 	return (vm2);
4466 }
4467 
4468 /*
4469  * Create a process's stack for exec_new_vmspace().  This function is never
4470  * asked to wire the newly created stack.
4471  */
4472 int
4473 vm_map_stack(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
4474     vm_prot_t prot, vm_prot_t max, int cow)
4475 {
4476 	vm_size_t growsize, init_ssize;
4477 	rlim_t vmemlim;
4478 	int rv;
4479 
4480 	MPASS((map->flags & MAP_WIREFUTURE) == 0);
4481 	growsize = sgrowsiz;
4482 	init_ssize = (max_ssize < growsize) ? max_ssize : growsize;
4483 	vm_map_lock(map);
4484 	vmemlim = lim_cur(curthread, RLIMIT_VMEM);
4485 	/* If we would blow our VMEM resource limit, no go */
4486 	if (map->size + init_ssize > vmemlim) {
4487 		rv = KERN_NO_SPACE;
4488 		goto out;
4489 	}
4490 	rv = vm_map_stack_locked(map, addrbos, max_ssize, growsize, prot,
4491 	    max, cow);
4492 out:
4493 	vm_map_unlock(map);
4494 	return (rv);
4495 }
4496 
4497 static int stack_guard_page = 1;
4498 SYSCTL_INT(_security_bsd, OID_AUTO, stack_guard_page, CTLFLAG_RWTUN,
4499     &stack_guard_page, 0,
4500     "Specifies the number of guard pages for a stack that grows");
4501 
4502 static int
4503 vm_map_stack_locked(vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
4504     vm_size_t growsize, vm_prot_t prot, vm_prot_t max, int cow)
4505 {
4506 	vm_map_entry_t new_entry, prev_entry;
4507 	vm_offset_t bot, gap_bot, gap_top, top;
4508 	vm_size_t init_ssize, sgp;
4509 	int orient, rv;
4510 
4511 	/*
4512 	 * The stack orientation is piggybacked with the cow argument.
4513 	 * Extract it into orient and mask the cow argument so that we
4514 	 * don't pass it around further.
4515 	 */
4516 	orient = cow & (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP);
4517 	KASSERT(orient != 0, ("No stack grow direction"));
4518 	KASSERT(orient != (MAP_STACK_GROWS_DOWN | MAP_STACK_GROWS_UP),
4519 	    ("bi-dir stack"));
4520 
4521 	if (max_ssize == 0 ||
4522 	    !vm_map_range_valid(map, addrbos, addrbos + max_ssize))
4523 		return (KERN_INVALID_ADDRESS);
4524 	sgp = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
4525 	    (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
4526 	    (vm_size_t)stack_guard_page * PAGE_SIZE;
4527 	if (sgp >= max_ssize)
4528 		return (KERN_INVALID_ARGUMENT);
4529 
4530 	init_ssize = growsize;
4531 	if (max_ssize < init_ssize + sgp)
4532 		init_ssize = max_ssize - sgp;
4533 
4534 	/* If addr is already mapped, no go */
4535 	if (vm_map_lookup_entry(map, addrbos, &prev_entry))
4536 		return (KERN_NO_SPACE);
4537 
4538 	/*
4539 	 * If we can't accommodate max_ssize in the current mapping, no go.
4540 	 */
4541 	if (vm_map_entry_succ(prev_entry)->start < addrbos + max_ssize)
4542 		return (KERN_NO_SPACE);
4543 
4544 	/*
4545 	 * We initially map a stack of only init_ssize.  We will grow as
4546 	 * needed later.  Depending on the orientation of the stack (i.e.
4547 	 * the grow direction) we either map at the top of the range, the
4548 	 * bottom of the range or in the middle.
4549 	 *
4550 	 * Note: we would normally expect prot and max to be VM_PROT_ALL,
4551 	 * and cow to be 0.  Possibly we should eliminate these as input
4552 	 * parameters, and just pass these values here in the insert call.
4553 	 */
4554 	if (orient == MAP_STACK_GROWS_DOWN) {
4555 		bot = addrbos + max_ssize - init_ssize;
4556 		top = bot + init_ssize;
4557 		gap_bot = addrbos;
4558 		gap_top = bot;
4559 	} else /* if (orient == MAP_STACK_GROWS_UP) */ {
4560 		bot = addrbos;
4561 		top = bot + init_ssize;
4562 		gap_bot = top;
4563 		gap_top = addrbos + max_ssize;
4564 	}
4565 	rv = vm_map_insert(map, NULL, 0, bot, top, prot, max, cow);
4566 	if (rv != KERN_SUCCESS)
4567 		return (rv);
4568 	new_entry = vm_map_entry_succ(prev_entry);
4569 	KASSERT(new_entry->end == top || new_entry->start == bot,
4570 	    ("Bad entry start/end for new stack entry"));
4571 	KASSERT((orient & MAP_STACK_GROWS_DOWN) == 0 ||
4572 	    (new_entry->eflags & MAP_ENTRY_GROWS_DOWN) != 0,
4573 	    ("new entry lacks MAP_ENTRY_GROWS_DOWN"));
4574 	KASSERT((orient & MAP_STACK_GROWS_UP) == 0 ||
4575 	    (new_entry->eflags & MAP_ENTRY_GROWS_UP) != 0,
4576 	    ("new entry lacks MAP_ENTRY_GROWS_UP"));
4577 	if (gap_bot == gap_top)
4578 		return (KERN_SUCCESS);
4579 	rv = vm_map_insert(map, NULL, 0, gap_bot, gap_top, VM_PROT_NONE,
4580 	    VM_PROT_NONE, MAP_CREATE_GUARD | (orient == MAP_STACK_GROWS_DOWN ?
4581 	    MAP_CREATE_STACK_GAP_DN : MAP_CREATE_STACK_GAP_UP));
4582 	if (rv == KERN_SUCCESS) {
4583 		/*
4584 		 * Gap can never successfully handle a fault, so
4585 		 * read-ahead logic is never used for it.  Re-use
4586 		 * next_read of the gap entry to store
4587 		 * stack_guard_page for vm_map_growstack().
4588 		 */
4589 		if (orient == MAP_STACK_GROWS_DOWN)
4590 			vm_map_entry_pred(new_entry)->next_read = sgp;
4591 		else
4592 			vm_map_entry_succ(new_entry)->next_read = sgp;
4593 	} else {
4594 		(void)vm_map_delete(map, bot, top);
4595 	}
4596 	return (rv);
4597 }
4598 
4599 /*
4600  * Attempts to grow a vm stack entry.  Returns KERN_SUCCESS if we
4601  * successfully grow the stack.
4602  */
4603 static int
4604 vm_map_growstack(vm_map_t map, vm_offset_t addr, vm_map_entry_t gap_entry)
4605 {
4606 	vm_map_entry_t stack_entry;
4607 	struct proc *p;
4608 	struct vmspace *vm;
4609 	struct ucred *cred;
4610 	vm_offset_t gap_end, gap_start, grow_start;
4611 	vm_size_t grow_amount, guard, max_grow;
4612 	rlim_t lmemlim, stacklim, vmemlim;
4613 	int rv, rv1;
4614 	bool gap_deleted, grow_down, is_procstack;
4615 #ifdef notyet
4616 	uint64_t limit;
4617 #endif
4618 #ifdef RACCT
4619 	int error;
4620 #endif
4621 
4622 	p = curproc;
4623 	vm = p->p_vmspace;
4624 
4625 	/*
4626 	 * Disallow stack growth when the access is performed by a
4627 	 * debugger or AIO daemon.  The reason is that the wrong
4628 	 * resource limits are applied.
4629 	 */
4630 	if (p != initproc && (map != &p->p_vmspace->vm_map ||
4631 	    p->p_textvp == NULL))
4632 		return (KERN_FAILURE);
4633 
4634 	MPASS(!map->system_map);
4635 
4636 	lmemlim = lim_cur(curthread, RLIMIT_MEMLOCK);
4637 	stacklim = lim_cur(curthread, RLIMIT_STACK);
4638 	vmemlim = lim_cur(curthread, RLIMIT_VMEM);
4639 retry:
4640 	/* If addr is not in a hole for a stack grow area, no need to grow. */
4641 	if (gap_entry == NULL && !vm_map_lookup_entry(map, addr, &gap_entry))
4642 		return (KERN_FAILURE);
4643 	if ((gap_entry->eflags & MAP_ENTRY_GUARD) == 0)
4644 		return (KERN_SUCCESS);
4645 	if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_DN) != 0) {
4646 		stack_entry = vm_map_entry_succ(gap_entry);
4647 		if ((stack_entry->eflags & MAP_ENTRY_GROWS_DOWN) == 0 ||
4648 		    stack_entry->start != gap_entry->end)
4649 			return (KERN_FAILURE);
4650 		grow_amount = round_page(stack_entry->start - addr);
4651 		grow_down = true;
4652 	} else if ((gap_entry->eflags & MAP_ENTRY_STACK_GAP_UP) != 0) {
4653 		stack_entry = vm_map_entry_pred(gap_entry);
4654 		if ((stack_entry->eflags & MAP_ENTRY_GROWS_UP) == 0 ||
4655 		    stack_entry->end != gap_entry->start)
4656 			return (KERN_FAILURE);
4657 		grow_amount = round_page(addr + 1 - stack_entry->end);
4658 		grow_down = false;
4659 	} else {
4660 		return (KERN_FAILURE);
4661 	}
4662 	guard = ((curproc->p_flag2 & P2_STKGAP_DISABLE) != 0 ||
4663 	    (curproc->p_fctl0 & NT_FREEBSD_FCTL_STKGAP_DISABLE) != 0) ? 0 :
4664 	    gap_entry->next_read;
4665 	max_grow = gap_entry->end - gap_entry->start;
4666 	if (guard > max_grow)
4667 		return (KERN_NO_SPACE);
4668 	max_grow -= guard;
4669 	if (grow_amount > max_grow)
4670 		return (KERN_NO_SPACE);
4671 
4672 	/*
4673 	 * If this is the main process stack, see if we're over the stack
4674 	 * limit.
4675 	 */
4676 	is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr &&
4677 	    addr < (vm_offset_t)p->p_sysent->sv_usrstack;
4678 	if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim))
4679 		return (KERN_NO_SPACE);
4680 
4681 #ifdef RACCT
4682 	if (racct_enable) {
4683 		PROC_LOCK(p);
4684 		if (is_procstack && racct_set(p, RACCT_STACK,
4685 		    ctob(vm->vm_ssize) + grow_amount)) {
4686 			PROC_UNLOCK(p);
4687 			return (KERN_NO_SPACE);
4688 		}
4689 		PROC_UNLOCK(p);
4690 	}
4691 #endif
4692 
4693 	grow_amount = roundup(grow_amount, sgrowsiz);
4694 	if (grow_amount > max_grow)
4695 		grow_amount = max_grow;
4696 	if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > stacklim)) {
4697 		grow_amount = trunc_page((vm_size_t)stacklim) -
4698 		    ctob(vm->vm_ssize);
4699 	}
4700 
4701 #ifdef notyet
4702 	PROC_LOCK(p);
4703 	limit = racct_get_available(p, RACCT_STACK);
4704 	PROC_UNLOCK(p);
4705 	if (is_procstack && (ctob(vm->vm_ssize) + grow_amount > limit))
4706 		grow_amount = limit - ctob(vm->vm_ssize);
4707 #endif
4708 
4709 	if (!old_mlock && (map->flags & MAP_WIREFUTURE) != 0) {
4710 		if (ptoa(pmap_wired_count(map->pmap)) + grow_amount > lmemlim) {
4711 			rv = KERN_NO_SPACE;
4712 			goto out;
4713 		}
4714 #ifdef RACCT
4715 		if (racct_enable) {
4716 			PROC_LOCK(p);
4717 			if (racct_set(p, RACCT_MEMLOCK,
4718 			    ptoa(pmap_wired_count(map->pmap)) + grow_amount)) {
4719 				PROC_UNLOCK(p);
4720 				rv = KERN_NO_SPACE;
4721 				goto out;
4722 			}
4723 			PROC_UNLOCK(p);
4724 		}
4725 #endif
4726 	}
4727 
4728 	/* If we would blow our VMEM resource limit, no go */
4729 	if (map->size + grow_amount > vmemlim) {
4730 		rv = KERN_NO_SPACE;
4731 		goto out;
4732 	}
4733 #ifdef RACCT
4734 	if (racct_enable) {
4735 		PROC_LOCK(p);
4736 		if (racct_set(p, RACCT_VMEM, map->size + grow_amount)) {
4737 			PROC_UNLOCK(p);
4738 			rv = KERN_NO_SPACE;
4739 			goto out;
4740 		}
4741 		PROC_UNLOCK(p);
4742 	}
4743 #endif
4744 
4745 	if (vm_map_lock_upgrade(map)) {
4746 		gap_entry = NULL;
4747 		vm_map_lock_read(map);
4748 		goto retry;
4749 	}
4750 
4751 	if (grow_down) {
4752 		grow_start = gap_entry->end - grow_amount;
4753 		if (gap_entry->start + grow_amount == gap_entry->end) {
4754 			gap_start = gap_entry->start;
4755 			gap_end = gap_entry->end;
4756 			vm_map_entry_delete(map, gap_entry);
4757 			gap_deleted = true;
4758 		} else {
4759 			MPASS(gap_entry->start < gap_entry->end - grow_amount);
4760 			vm_map_entry_resize(map, gap_entry, -grow_amount);
4761 			gap_deleted = false;
4762 		}
4763 		rv = vm_map_insert(map, NULL, 0, grow_start,
4764 		    grow_start + grow_amount,
4765 		    stack_entry->protection, stack_entry->max_protection,
4766 		    MAP_STACK_GROWS_DOWN);
4767 		if (rv != KERN_SUCCESS) {
4768 			if (gap_deleted) {
4769 				rv1 = vm_map_insert(map, NULL, 0, gap_start,
4770 				    gap_end, VM_PROT_NONE, VM_PROT_NONE,
4771 				    MAP_CREATE_GUARD | MAP_CREATE_STACK_GAP_DN);
4772 				MPASS(rv1 == KERN_SUCCESS);
4773 			} else
4774 				vm_map_entry_resize(map, gap_entry,
4775 				    grow_amount);
4776 		}
4777 	} else {
4778 		grow_start = stack_entry->end;
4779 		cred = stack_entry->cred;
4780 		if (cred == NULL && stack_entry->object.vm_object != NULL)
4781 			cred = stack_entry->object.vm_object->cred;
4782 		if (cred != NULL && !swap_reserve_by_cred(grow_amount, cred))
4783 			rv = KERN_NO_SPACE;
4784 		/* Grow the underlying object if applicable. */
4785 		else if (stack_entry->object.vm_object == NULL ||
4786 		    vm_object_coalesce(stack_entry->object.vm_object,
4787 		    stack_entry->offset,
4788 		    (vm_size_t)(stack_entry->end - stack_entry->start),
4789 		    grow_amount, cred != NULL)) {
4790 			if (gap_entry->start + grow_amount == gap_entry->end) {
4791 				vm_map_entry_delete(map, gap_entry);
4792 				vm_map_entry_resize(map, stack_entry,
4793 				    grow_amount);
4794 			} else {
4795 				gap_entry->start += grow_amount;
4796 				stack_entry->end += grow_amount;
4797 			}
4798 			map->size += grow_amount;
4799 			rv = KERN_SUCCESS;
4800 		} else
4801 			rv = KERN_FAILURE;
4802 	}
4803 	if (rv == KERN_SUCCESS && is_procstack)
4804 		vm->vm_ssize += btoc(grow_amount);
4805 
4806 	/*
4807 	 * Heed the MAP_WIREFUTURE flag if it was set for this process.
4808 	 */
4809 	if (rv == KERN_SUCCESS && (map->flags & MAP_WIREFUTURE) != 0) {
4810 		rv = vm_map_wire_locked(map, grow_start,
4811 		    grow_start + grow_amount,
4812 		    VM_MAP_WIRE_USER | VM_MAP_WIRE_NOHOLES);
4813 	}
4814 	vm_map_lock_downgrade(map);
4815 
4816 out:
4817 #ifdef RACCT
4818 	if (racct_enable && rv != KERN_SUCCESS) {
4819 		PROC_LOCK(p);
4820 		error = racct_set(p, RACCT_VMEM, map->size);
4821 		KASSERT(error == 0, ("decreasing RACCT_VMEM failed"));
4822 		if (!old_mlock) {
4823 			error = racct_set(p, RACCT_MEMLOCK,
4824 			    ptoa(pmap_wired_count(map->pmap)));
4825 			KASSERT(error == 0, ("decreasing RACCT_MEMLOCK failed"));
4826 		}
4827 	    	error = racct_set(p, RACCT_STACK, ctob(vm->vm_ssize));
4828 		KASSERT(error == 0, ("decreasing RACCT_STACK failed"));
4829 		PROC_UNLOCK(p);
4830 	}
4831 #endif
4832 
4833 	return (rv);
4834 }
4835 
4836 /*
4837  * Unshare the specified VM space for exec.  If other processes are
4838  * mapped to it, then create a new one.  The new vmspace is null.
4839  */
4840 int
4841 vmspace_exec(struct proc *p, vm_offset_t minuser, vm_offset_t maxuser)
4842 {
4843 	struct vmspace *oldvmspace = p->p_vmspace;
4844 	struct vmspace *newvmspace;
4845 
4846 	KASSERT((curthread->td_pflags & TDP_EXECVMSPC) == 0,
4847 	    ("vmspace_exec recursed"));
4848 	newvmspace = vmspace_alloc(minuser, maxuser, pmap_pinit);
4849 	if (newvmspace == NULL)
4850 		return (ENOMEM);
4851 	newvmspace->vm_swrss = oldvmspace->vm_swrss;
4852 	/*
4853 	 * This code is written like this for prototype purposes.  The
4854 	 * goal is to avoid running down the vmspace here, but let the
4855 	 * other process's that are still using the vmspace to finally
4856 	 * run it down.  Even though there is little or no chance of blocking
4857 	 * here, it is a good idea to keep this form for future mods.
4858 	 */
4859 	PROC_VMSPACE_LOCK(p);
4860 	p->p_vmspace = newvmspace;
4861 	PROC_VMSPACE_UNLOCK(p);
4862 	if (p == curthread->td_proc)
4863 		pmap_activate(curthread);
4864 	curthread->td_pflags |= TDP_EXECVMSPC;
4865 	return (0);
4866 }
4867 
4868 /*
4869  * Unshare the specified VM space for forcing COW.  This
4870  * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
4871  */
4872 int
4873 vmspace_unshare(struct proc *p)
4874 {
4875 	struct vmspace *oldvmspace = p->p_vmspace;
4876 	struct vmspace *newvmspace;
4877 	vm_ooffset_t fork_charge;
4878 
4879 	if (refcount_load(&oldvmspace->vm_refcnt) == 1)
4880 		return (0);
4881 	fork_charge = 0;
4882 	newvmspace = vmspace_fork(oldvmspace, &fork_charge);
4883 	if (newvmspace == NULL)
4884 		return (ENOMEM);
4885 	if (!swap_reserve_by_cred(fork_charge, p->p_ucred)) {
4886 		vmspace_free(newvmspace);
4887 		return (ENOMEM);
4888 	}
4889 	PROC_VMSPACE_LOCK(p);
4890 	p->p_vmspace = newvmspace;
4891 	PROC_VMSPACE_UNLOCK(p);
4892 	if (p == curthread->td_proc)
4893 		pmap_activate(curthread);
4894 	vmspace_free(oldvmspace);
4895 	return (0);
4896 }
4897 
4898 /*
4899  *	vm_map_lookup:
4900  *
4901  *	Finds the VM object, offset, and
4902  *	protection for a given virtual address in the
4903  *	specified map, assuming a page fault of the
4904  *	type specified.
4905  *
4906  *	Leaves the map in question locked for read; return
4907  *	values are guaranteed until a vm_map_lookup_done
4908  *	call is performed.  Note that the map argument
4909  *	is in/out; the returned map must be used in
4910  *	the call to vm_map_lookup_done.
4911  *
4912  *	A handle (out_entry) is returned for use in
4913  *	vm_map_lookup_done, to make that fast.
4914  *
4915  *	If a lookup is requested with "write protection"
4916  *	specified, the map may be changed to perform virtual
4917  *	copying operations, although the data referenced will
4918  *	remain the same.
4919  */
4920 int
4921 vm_map_lookup(vm_map_t *var_map,		/* IN/OUT */
4922 	      vm_offset_t vaddr,
4923 	      vm_prot_t fault_typea,
4924 	      vm_map_entry_t *out_entry,	/* OUT */
4925 	      vm_object_t *object,		/* OUT */
4926 	      vm_pindex_t *pindex,		/* OUT */
4927 	      vm_prot_t *out_prot,		/* OUT */
4928 	      boolean_t *wired)			/* OUT */
4929 {
4930 	vm_map_entry_t entry;
4931 	vm_map_t map = *var_map;
4932 	vm_prot_t prot;
4933 	vm_prot_t fault_type;
4934 	vm_object_t eobject;
4935 	vm_size_t size;
4936 	struct ucred *cred;
4937 
4938 RetryLookup:
4939 
4940 	vm_map_lock_read(map);
4941 
4942 RetryLookupLocked:
4943 	/*
4944 	 * Lookup the faulting address.
4945 	 */
4946 	if (!vm_map_lookup_entry(map, vaddr, out_entry)) {
4947 		vm_map_unlock_read(map);
4948 		return (KERN_INVALID_ADDRESS);
4949 	}
4950 
4951 	entry = *out_entry;
4952 
4953 	/*
4954 	 * Handle submaps.
4955 	 */
4956 	if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
4957 		vm_map_t old_map = map;
4958 
4959 		*var_map = map = entry->object.sub_map;
4960 		vm_map_unlock_read(old_map);
4961 		goto RetryLookup;
4962 	}
4963 
4964 	/*
4965 	 * Check whether this task is allowed to have this page.
4966 	 */
4967 	prot = entry->protection;
4968 	if ((fault_typea & VM_PROT_FAULT_LOOKUP) != 0) {
4969 		fault_typea &= ~VM_PROT_FAULT_LOOKUP;
4970 		if (prot == VM_PROT_NONE && map != kernel_map &&
4971 		    (entry->eflags & MAP_ENTRY_GUARD) != 0 &&
4972 		    (entry->eflags & (MAP_ENTRY_STACK_GAP_DN |
4973 		    MAP_ENTRY_STACK_GAP_UP)) != 0 &&
4974 		    vm_map_growstack(map, vaddr, entry) == KERN_SUCCESS)
4975 			goto RetryLookupLocked;
4976 	}
4977 	fault_type = fault_typea & VM_PROT_ALL;
4978 	if ((fault_type & prot) != fault_type || prot == VM_PROT_NONE) {
4979 		vm_map_unlock_read(map);
4980 		return (KERN_PROTECTION_FAILURE);
4981 	}
4982 	KASSERT((prot & VM_PROT_WRITE) == 0 || (entry->eflags &
4983 	    (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY)) !=
4984 	    (MAP_ENTRY_USER_WIRED | MAP_ENTRY_NEEDS_COPY),
4985 	    ("entry %p flags %x", entry, entry->eflags));
4986 	if ((fault_typea & VM_PROT_COPY) != 0 &&
4987 	    (entry->max_protection & VM_PROT_WRITE) == 0 &&
4988 	    (entry->eflags & MAP_ENTRY_COW) == 0) {
4989 		vm_map_unlock_read(map);
4990 		return (KERN_PROTECTION_FAILURE);
4991 	}
4992 
4993 	/*
4994 	 * If this page is not pageable, we have to get it for all possible
4995 	 * accesses.
4996 	 */
4997 	*wired = (entry->wired_count != 0);
4998 	if (*wired)
4999 		fault_type = entry->protection;
5000 	size = entry->end - entry->start;
5001 
5002 	/*
5003 	 * If the entry was copy-on-write, we either ...
5004 	 */
5005 	if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
5006 		/*
5007 		 * If we want to write the page, we may as well handle that
5008 		 * now since we've got the map locked.
5009 		 *
5010 		 * If we don't need to write the page, we just demote the
5011 		 * permissions allowed.
5012 		 */
5013 		if ((fault_type & VM_PROT_WRITE) != 0 ||
5014 		    (fault_typea & VM_PROT_COPY) != 0) {
5015 			/*
5016 			 * Make a new object, and place it in the object
5017 			 * chain.  Note that no new references have appeared
5018 			 * -- one just moved from the map to the new
5019 			 * object.
5020 			 */
5021 			if (vm_map_lock_upgrade(map))
5022 				goto RetryLookup;
5023 
5024 			if (entry->cred == NULL) {
5025 				/*
5026 				 * The debugger owner is charged for
5027 				 * the memory.
5028 				 */
5029 				cred = curthread->td_ucred;
5030 				crhold(cred);
5031 				if (!swap_reserve_by_cred(size, cred)) {
5032 					crfree(cred);
5033 					vm_map_unlock(map);
5034 					return (KERN_RESOURCE_SHORTAGE);
5035 				}
5036 				entry->cred = cred;
5037 			}
5038 			eobject = entry->object.vm_object;
5039 			vm_object_shadow(&entry->object.vm_object,
5040 			    &entry->offset, size, entry->cred, false);
5041 			if (eobject == entry->object.vm_object) {
5042 				/*
5043 				 * The object was not shadowed.
5044 				 */
5045 				swap_release_by_cred(size, entry->cred);
5046 				crfree(entry->cred);
5047 			}
5048 			entry->cred = NULL;
5049 			entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
5050 
5051 			vm_map_lock_downgrade(map);
5052 		} else {
5053 			/*
5054 			 * We're attempting to read a copy-on-write page --
5055 			 * don't allow writes.
5056 			 */
5057 			prot &= ~VM_PROT_WRITE;
5058 		}
5059 	}
5060 
5061 	/*
5062 	 * Create an object if necessary.
5063 	 */
5064 	if (entry->object.vm_object == NULL && !map->system_map) {
5065 		if (vm_map_lock_upgrade(map))
5066 			goto RetryLookup;
5067 		entry->object.vm_object = vm_object_allocate_anon(atop(size),
5068 		    NULL, entry->cred, entry->cred != NULL ? size : 0);
5069 		entry->offset = 0;
5070 		entry->cred = NULL;
5071 		vm_map_lock_downgrade(map);
5072 	}
5073 
5074 	/*
5075 	 * Return the object/offset from this entry.  If the entry was
5076 	 * copy-on-write or empty, it has been fixed up.
5077 	 */
5078 	*pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
5079 	*object = entry->object.vm_object;
5080 
5081 	*out_prot = prot;
5082 	return (KERN_SUCCESS);
5083 }
5084 
5085 /*
5086  *	vm_map_lookup_locked:
5087  *
5088  *	Lookup the faulting address.  A version of vm_map_lookup that returns
5089  *      KERN_FAILURE instead of blocking on map lock or memory allocation.
5090  */
5091 int
5092 vm_map_lookup_locked(vm_map_t *var_map,		/* IN/OUT */
5093 		     vm_offset_t vaddr,
5094 		     vm_prot_t fault_typea,
5095 		     vm_map_entry_t *out_entry,	/* OUT */
5096 		     vm_object_t *object,	/* OUT */
5097 		     vm_pindex_t *pindex,	/* OUT */
5098 		     vm_prot_t *out_prot,	/* OUT */
5099 		     boolean_t *wired)		/* OUT */
5100 {
5101 	vm_map_entry_t entry;
5102 	vm_map_t map = *var_map;
5103 	vm_prot_t prot;
5104 	vm_prot_t fault_type = fault_typea;
5105 
5106 	/*
5107 	 * Lookup the faulting address.
5108 	 */
5109 	if (!vm_map_lookup_entry(map, vaddr, out_entry))
5110 		return (KERN_INVALID_ADDRESS);
5111 
5112 	entry = *out_entry;
5113 
5114 	/*
5115 	 * Fail if the entry refers to a submap.
5116 	 */
5117 	if (entry->eflags & MAP_ENTRY_IS_SUB_MAP)
5118 		return (KERN_FAILURE);
5119 
5120 	/*
5121 	 * Check whether this task is allowed to have this page.
5122 	 */
5123 	prot = entry->protection;
5124 	fault_type &= VM_PROT_READ | VM_PROT_WRITE | VM_PROT_EXECUTE;
5125 	if ((fault_type & prot) != fault_type)
5126 		return (KERN_PROTECTION_FAILURE);
5127 
5128 	/*
5129 	 * If this page is not pageable, we have to get it for all possible
5130 	 * accesses.
5131 	 */
5132 	*wired = (entry->wired_count != 0);
5133 	if (*wired)
5134 		fault_type = entry->protection;
5135 
5136 	if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
5137 		/*
5138 		 * Fail if the entry was copy-on-write for a write fault.
5139 		 */
5140 		if (fault_type & VM_PROT_WRITE)
5141 			return (KERN_FAILURE);
5142 		/*
5143 		 * We're attempting to read a copy-on-write page --
5144 		 * don't allow writes.
5145 		 */
5146 		prot &= ~VM_PROT_WRITE;
5147 	}
5148 
5149 	/*
5150 	 * Fail if an object should be created.
5151 	 */
5152 	if (entry->object.vm_object == NULL && !map->system_map)
5153 		return (KERN_FAILURE);
5154 
5155 	/*
5156 	 * Return the object/offset from this entry.  If the entry was
5157 	 * copy-on-write or empty, it has been fixed up.
5158 	 */
5159 	*pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
5160 	*object = entry->object.vm_object;
5161 
5162 	*out_prot = prot;
5163 	return (KERN_SUCCESS);
5164 }
5165 
5166 /*
5167  *	vm_map_lookup_done:
5168  *
5169  *	Releases locks acquired by a vm_map_lookup
5170  *	(according to the handle returned by that lookup).
5171  */
5172 void
5173 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry)
5174 {
5175 	/*
5176 	 * Unlock the main-level map
5177 	 */
5178 	vm_map_unlock_read(map);
5179 }
5180 
5181 vm_offset_t
5182 vm_map_max_KBI(const struct vm_map *map)
5183 {
5184 
5185 	return (vm_map_max(map));
5186 }
5187 
5188 vm_offset_t
5189 vm_map_min_KBI(const struct vm_map *map)
5190 {
5191 
5192 	return (vm_map_min(map));
5193 }
5194 
5195 pmap_t
5196 vm_map_pmap_KBI(vm_map_t map)
5197 {
5198 
5199 	return (map->pmap);
5200 }
5201 
5202 bool
5203 vm_map_range_valid_KBI(vm_map_t map, vm_offset_t start, vm_offset_t end)
5204 {
5205 
5206 	return (vm_map_range_valid(map, start, end));
5207 }
5208 
5209 #ifdef INVARIANTS
5210 static void
5211 _vm_map_assert_consistent(vm_map_t map, int check)
5212 {
5213 	vm_map_entry_t entry, prev;
5214 	vm_map_entry_t cur, header, lbound, ubound;
5215 	vm_size_t max_left, max_right;
5216 
5217 #ifdef DIAGNOSTIC
5218 	++map->nupdates;
5219 #endif
5220 	if (enable_vmmap_check != check)
5221 		return;
5222 
5223 	header = prev = &map->header;
5224 	VM_MAP_ENTRY_FOREACH(entry, map) {
5225 		KASSERT(prev->end <= entry->start,
5226 		    ("map %p prev->end = %jx, start = %jx", map,
5227 		    (uintmax_t)prev->end, (uintmax_t)entry->start));
5228 		KASSERT(entry->start < entry->end,
5229 		    ("map %p start = %jx, end = %jx", map,
5230 		    (uintmax_t)entry->start, (uintmax_t)entry->end));
5231 		KASSERT(entry->left == header ||
5232 		    entry->left->start < entry->start,
5233 		    ("map %p left->start = %jx, start = %jx", map,
5234 		    (uintmax_t)entry->left->start, (uintmax_t)entry->start));
5235 		KASSERT(entry->right == header ||
5236 		    entry->start < entry->right->start,
5237 		    ("map %p start = %jx, right->start = %jx", map,
5238 		    (uintmax_t)entry->start, (uintmax_t)entry->right->start));
5239 		cur = map->root;
5240 		lbound = ubound = header;
5241 		for (;;) {
5242 			if (entry->start < cur->start) {
5243 				ubound = cur;
5244 				cur = cur->left;
5245 				KASSERT(cur != lbound,
5246 				    ("map %p cannot find %jx",
5247 				    map, (uintmax_t)entry->start));
5248 			} else if (cur->end <= entry->start) {
5249 				lbound = cur;
5250 				cur = cur->right;
5251 				KASSERT(cur != ubound,
5252 				    ("map %p cannot find %jx",
5253 				    map, (uintmax_t)entry->start));
5254 			} else {
5255 				KASSERT(cur == entry,
5256 				    ("map %p cannot find %jx",
5257 				    map, (uintmax_t)entry->start));
5258 				break;
5259 			}
5260 		}
5261 		max_left = vm_map_entry_max_free_left(entry, lbound);
5262 		max_right = vm_map_entry_max_free_right(entry, ubound);
5263 		KASSERT(entry->max_free == vm_size_max(max_left, max_right),
5264 		    ("map %p max = %jx, max_left = %jx, max_right = %jx", map,
5265 		    (uintmax_t)entry->max_free,
5266 		    (uintmax_t)max_left, (uintmax_t)max_right));
5267 		prev = entry;
5268 	}
5269 	KASSERT(prev->end <= entry->start,
5270 	    ("map %p prev->end = %jx, start = %jx", map,
5271 	    (uintmax_t)prev->end, (uintmax_t)entry->start));
5272 }
5273 #endif
5274 
5275 #include "opt_ddb.h"
5276 #ifdef DDB
5277 #include <sys/kernel.h>
5278 
5279 #include <ddb/ddb.h>
5280 
5281 static void
5282 vm_map_print(vm_map_t map)
5283 {
5284 	vm_map_entry_t entry, prev;
5285 
5286 	db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
5287 	    (void *)map,
5288 	    (void *)map->pmap, map->nentries, map->timestamp);
5289 
5290 	db_indent += 2;
5291 	prev = &map->header;
5292 	VM_MAP_ENTRY_FOREACH(entry, map) {
5293 		db_iprintf("map entry %p: start=%p, end=%p, eflags=%#x, \n",
5294 		    (void *)entry, (void *)entry->start, (void *)entry->end,
5295 		    entry->eflags);
5296 		{
5297 			static const char * const inheritance_name[4] =
5298 			{"share", "copy", "none", "donate_copy"};
5299 
5300 			db_iprintf(" prot=%x/%x/%s",
5301 			    entry->protection,
5302 			    entry->max_protection,
5303 			    inheritance_name[(int)(unsigned char)
5304 			    entry->inheritance]);
5305 			if (entry->wired_count != 0)
5306 				db_printf(", wired");
5307 		}
5308 		if (entry->eflags & MAP_ENTRY_IS_SUB_MAP) {
5309 			db_printf(", share=%p, offset=0x%jx\n",
5310 			    (void *)entry->object.sub_map,
5311 			    (uintmax_t)entry->offset);
5312 			if (prev == &map->header ||
5313 			    prev->object.sub_map !=
5314 				entry->object.sub_map) {
5315 				db_indent += 2;
5316 				vm_map_print((vm_map_t)entry->object.sub_map);
5317 				db_indent -= 2;
5318 			}
5319 		} else {
5320 			if (entry->cred != NULL)
5321 				db_printf(", ruid %d", entry->cred->cr_ruid);
5322 			db_printf(", object=%p, offset=0x%jx",
5323 			    (void *)entry->object.vm_object,
5324 			    (uintmax_t)entry->offset);
5325 			if (entry->object.vm_object && entry->object.vm_object->cred)
5326 				db_printf(", obj ruid %d charge %jx",
5327 				    entry->object.vm_object->cred->cr_ruid,
5328 				    (uintmax_t)entry->object.vm_object->charge);
5329 			if (entry->eflags & MAP_ENTRY_COW)
5330 				db_printf(", copy (%s)",
5331 				    (entry->eflags & MAP_ENTRY_NEEDS_COPY) ? "needed" : "done");
5332 			db_printf("\n");
5333 
5334 			if (prev == &map->header ||
5335 			    prev->object.vm_object !=
5336 				entry->object.vm_object) {
5337 				db_indent += 2;
5338 				vm_object_print((db_expr_t)(intptr_t)
5339 						entry->object.vm_object,
5340 						0, 0, (char *)0);
5341 				db_indent -= 2;
5342 			}
5343 		}
5344 		prev = entry;
5345 	}
5346 	db_indent -= 2;
5347 }
5348 
5349 DB_SHOW_COMMAND(map, map)
5350 {
5351 
5352 	if (!have_addr) {
5353 		db_printf("usage: show map <addr>\n");
5354 		return;
5355 	}
5356 	vm_map_print((vm_map_t)addr);
5357 }
5358 
5359 DB_SHOW_COMMAND(procvm, procvm)
5360 {
5361 	struct proc *p;
5362 
5363 	if (have_addr) {
5364 		p = db_lookup_proc(addr);
5365 	} else {
5366 		p = curproc;
5367 	}
5368 
5369 	db_printf("p = %p, vmspace = %p, map = %p, pmap = %p\n",
5370 	    (void *)p, (void *)p->p_vmspace, (void *)&p->p_vmspace->vm_map,
5371 	    (void *)vmspace_pmap(p->p_vmspace));
5372 
5373 	vm_map_print((vm_map_t)&p->p_vmspace->vm_map);
5374 }
5375 
5376 #endif /* DDB */
5377