Remove upc_{control,register} syscalls and everything that has to do with it.
[dragonfly.git] / sys / vm / vm_map.c
1 /*
2  * (MPSAFE)
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. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by the University of
21  *      California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  *      from: @(#)vm_map.c      8.3 (Berkeley) 1/12/94
39  *
40  *
41  * Copyright (c) 1987, 1990 Carnegie-Mellon University.
42  * All rights reserved.
43  *
44  * Authors: Avadis Tevanian, Jr., Michael Wayne Young
45  *
46  * Permission to use, copy, modify and distribute this software and
47  * its documentation is hereby granted, provided that both the copyright
48  * notice and this permission notice appear in all copies of the
49  * software, derivative works or modified versions, and any portions
50  * thereof, and that both notices appear in supporting documentation.
51  *
52  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
53  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
54  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
55  *
56  * Carnegie Mellon requests users of this software to return to
57  *
58  *  Software Distribution Coordinator  or  Software.Distribution@CS.CMU.EDU
59  *  School of Computer Science
60  *  Carnegie Mellon University
61  *  Pittsburgh PA 15213-3890
62  *
63  * any improvements or extensions that they make and grant Carnegie the
64  * rights to redistribute these changes.
65  *
66  * $FreeBSD: src/sys/vm/vm_map.c,v 1.187.2.19 2003/05/27 00:47:02 alc Exp $
67  */
68
69 /*
70  *      Virtual memory mapping module.
71  */
72
73 #include <sys/param.h>
74 #include <sys/systm.h>
75 #include <sys/kernel.h>
76 #include <sys/proc.h>
77 #include <sys/serialize.h>
78 #include <sys/lock.h>
79 #include <sys/vmmeter.h>
80 #include <sys/mman.h>
81 #include <sys/vnode.h>
82 #include <sys/resourcevar.h>
83 #include <sys/shm.h>
84 #include <sys/tree.h>
85 #include <sys/malloc.h>
86
87 #include <vm/vm.h>
88 #include <vm/vm_param.h>
89 #include <vm/pmap.h>
90 #include <vm/vm_map.h>
91 #include <vm/vm_page.h>
92 #include <vm/vm_object.h>
93 #include <vm/vm_pager.h>
94 #include <vm/vm_kern.h>
95 #include <vm/vm_extern.h>
96 #include <vm/swap_pager.h>
97 #include <vm/vm_zone.h>
98
99 #include <sys/thread2.h>
100 #include <sys/sysref2.h>
101 #include <sys/random.h>
102 #include <sys/sysctl.h>
103
104 /*
105  * Virtual memory maps provide for the mapping, protection, and sharing
106  * of virtual memory objects.  In addition, this module provides for an
107  * efficient virtual copy of 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 entries.
112  * A hint and a RB tree is used to speed-up lookups.
113  *
114  * Callers looking to modify maps specify start/end addresses which cause
115  * the related map entry to be clipped if necessary, and then later
116  * recombined if the pieces remained compatible.
117  *
118  * Virtual copy operations are performed by copying VM object references
119  * from one map to another, and then marking both regions as copy-on-write.
120  */
121 static void vmspace_terminate(struct vmspace *vm);
122 static void vmspace_lock(struct vmspace *vm);
123 static void vmspace_unlock(struct vmspace *vm);
124 static void vmspace_dtor(void *obj, void *private);
125
126 MALLOC_DEFINE(M_VMSPACE, "vmspace", "vmspace objcache backingstore");
127
128 struct sysref_class vmspace_sysref_class = {
129         .name =         "vmspace",
130         .mtype =        M_VMSPACE,
131         .proto =        SYSREF_PROTO_VMSPACE,
132         .offset =       offsetof(struct vmspace, vm_sysref),
133         .objsize =      sizeof(struct vmspace),
134         .nom_cache =    32,
135         .flags = SRC_MANAGEDINIT,
136         .dtor = vmspace_dtor,
137         .ops = {
138                 .terminate = (sysref_terminate_func_t)vmspace_terminate,
139                 .lock = (sysref_lock_func_t)vmspace_lock,
140                 .unlock = (sysref_lock_func_t)vmspace_unlock
141         }
142 };
143
144 /*
145  * per-cpu page table cross mappings are initialized in early boot
146  * and might require a considerable number of vm_map_entry structures.
147  */
148 #define VMEPERCPU       (MAXCPU+1)
149
150 static struct vm_zone mapentzone_store, mapzone_store;
151 static vm_zone_t mapentzone, mapzone;
152 static struct vm_object mapentobj, mapobj;
153
154 static struct vm_map_entry map_entry_init[MAX_MAPENT];
155 static struct vm_map_entry cpu_map_entry_init[MAXCPU][VMEPERCPU];
156 static struct vm_map map_init[MAX_KMAP];
157
158 static int randomize_mmap;
159 SYSCTL_INT(_vm, OID_AUTO, randomize_mmap, CTLFLAG_RW, &randomize_mmap, 0,
160     "Randomize mmap offsets");
161
162 static void vm_map_entry_shadow(vm_map_entry_t entry, int addref);
163 static vm_map_entry_t vm_map_entry_create(vm_map_t map, int *);
164 static void vm_map_entry_dispose (vm_map_t map, vm_map_entry_t entry, int *);
165 static void _vm_map_clip_end (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
166 static void _vm_map_clip_start (vm_map_t, vm_map_entry_t, vm_offset_t, int *);
167 static void vm_map_entry_delete (vm_map_t, vm_map_entry_t, int *);
168 static void vm_map_entry_unwire (vm_map_t, vm_map_entry_t);
169 static void vm_map_copy_entry (vm_map_t, vm_map_t, vm_map_entry_t,
170                 vm_map_entry_t);
171 static void vm_map_unclip_range (vm_map_t map, vm_map_entry_t start_entry, vm_offset_t start, vm_offset_t end, int *count, int flags);
172
173 /*
174  * Initialize the vm_map module.  Must be called before any other vm_map
175  * routines.
176  *
177  * Map and entry structures are allocated from the general purpose
178  * memory pool with some exceptions:
179  *
180  *      - The kernel map is allocated statically.
181  *      - Initial kernel map entries are allocated out of a static pool.
182  *
183  *      These restrictions are necessary since malloc() uses the
184  *      maps and requires map entries.
185  *
186  * Called from the low level boot code only.
187  */
188 void
189 vm_map_startup(void)
190 {
191         mapzone = &mapzone_store;
192         zbootinit(mapzone, "MAP", sizeof (struct vm_map),
193                 map_init, MAX_KMAP);
194         mapentzone = &mapentzone_store;
195         zbootinit(mapentzone, "MAP ENTRY", sizeof (struct vm_map_entry),
196                 map_entry_init, MAX_MAPENT);
197 }
198
199 /*
200  * Called prior to any vmspace allocations.
201  *
202  * Called from the low level boot code only.
203  */
204 void
205 vm_init2(void) 
206 {
207         zinitna(mapentzone, &mapentobj, NULL, 0, 0, 
208                 ZONE_USE_RESERVE | ZONE_SPECIAL, 1);
209         zinitna(mapzone, &mapobj, NULL, 0, 0, 0, 1);
210         pmap_init2();
211         vm_object_init2();
212 }
213
214
215 /*
216  * Red black tree functions
217  *
218  * The caller must hold the related map lock.
219  */
220 static int rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b);
221 RB_GENERATE(vm_map_rb_tree, vm_map_entry, rb_entry, rb_vm_map_compare);
222
223 /* a->start is address, and the only field has to be initialized */
224 static int
225 rb_vm_map_compare(vm_map_entry_t a, vm_map_entry_t b)
226 {
227         if (a->start < b->start)
228                 return(-1);
229         else if (a->start > b->start)
230                 return(1);
231         return(0);
232 }
233
234 /*
235  * Allocate a vmspace structure, including a vm_map and pmap.
236  * Initialize numerous fields.  While the initial allocation is zerod,
237  * subsequence reuse from the objcache leaves elements of the structure
238  * intact (particularly the pmap), so portions must be zerod.
239  *
240  * The structure is not considered activated until we call sysref_activate().
241  *
242  * No requirements.
243  */
244 struct vmspace *
245 vmspace_alloc(vm_offset_t min, vm_offset_t max)
246 {
247         struct vmspace *vm;
248
249         vm = sysref_alloc(&vmspace_sysref_class);
250         bzero(&vm->vm_startcopy,
251               (char *)&vm->vm_endcopy - (char *)&vm->vm_startcopy);
252         vm_map_init(&vm->vm_map, min, max, NULL);       /* initializes token */
253
254         /*
255          * Use a hold to prevent any additional racing hold from terminating
256          * the vmspace before we manage to activate it.  This also acquires
257          * the token for safety.
258          */
259         KKASSERT(vm->vm_holdcount == 0);
260         KKASSERT(vm->vm_exitingcnt == 0);
261         vmspace_hold(vm);
262         pmap_pinit(vmspace_pmap(vm));           /* (some fields reused) */
263         vm->vm_map.pmap = vmspace_pmap(vm);             /* XXX */
264         vm->vm_shm = NULL;
265         vm->vm_flags = 0;
266         cpu_vmspace_alloc(vm);
267         sysref_activate(&vm->vm_sysref);
268         vmspace_drop(vm);
269
270         return (vm);
271 }
272
273 /*
274  * Free a primary reference to a vmspace.  This can trigger a
275  * stage-1 termination.
276  */
277 void
278 vmspace_free(struct vmspace *vm)
279 {
280         /*
281          * We want all finalization to occur via vmspace_drop() so we
282          * need to hold the vm around the put.
283          */
284         vmspace_hold(vm);
285         sysref_put(&vm->vm_sysref);
286         vmspace_drop(vm);
287 }
288
289 void
290 vmspace_ref(struct vmspace *vm)
291 {
292         sysref_get(&vm->vm_sysref);
293 }
294
295 void
296 vmspace_hold(struct vmspace *vm)
297 {
298         refcount_acquire(&vm->vm_holdcount);
299         lwkt_gettoken(&vm->vm_map.token);
300 }
301
302 void
303 vmspace_drop(struct vmspace *vm)
304 {
305         lwkt_reltoken(&vm->vm_map.token);
306         if (refcount_release(&vm->vm_holdcount)) {
307                 if (vm->vm_exitingcnt == 0 &&
308                     sysref_isinactive(&vm->vm_sysref)) {
309                         vmspace_terminate(vm);
310                 }
311         }
312 }
313
314 /*
315  * dtor function - Some elements of the pmap are retained in the
316  * free-cached vmspaces to improve performance.  We have to clean them up
317  * here before returning the vmspace to the memory pool.
318  *
319  * No requirements.
320  */
321 static void
322 vmspace_dtor(void *obj, void *private)
323 {
324         struct vmspace *vm = obj;
325
326         pmap_puninit(vmspace_pmap(vm));
327 }
328
329 /*
330  * Called in three cases:
331  *
332  * (1) When the last sysref is dropped and the vmspace becomes inactive.
333  *     (holdcount will not be 0 because the vmspace is held through the op)
334  *
335  * (2) When exitingcount becomes 0 on the last reap
336  *     (holdcount will not be 0 because the vmspace is held through the op)
337  *
338  * (3) When the holdcount becomes 0 in addition to the above two
339  *
340  * sysref will not scrap the object until we call sysref_put() once more
341  * after the last ref has been dropped.
342  *
343  * VMSPACE_EXIT1 flags the primary deactivation
344  * VMSPACE_EXIT2 flags the last reap
345  */
346 static void
347 vmspace_terminate(struct vmspace *vm)
348 {
349         int count;
350
351         /*
352          *
353          */
354         lwkt_gettoken(&vm->vm_map.token);
355         if ((vm->vm_flags & VMSPACE_EXIT1) == 0) {
356                 vm->vm_flags |= VMSPACE_EXIT1;
357                 shmexit(vm);
358                 pmap_remove_pages(vmspace_pmap(vm), VM_MIN_USER_ADDRESS,
359                                   VM_MAX_USER_ADDRESS);
360                 vm_map_remove(&vm->vm_map, VM_MIN_USER_ADDRESS,
361                               VM_MAX_USER_ADDRESS);
362         }
363         if ((vm->vm_flags & VMSPACE_EXIT2) == 0 && vm->vm_exitingcnt == 0) {
364                 vm->vm_flags |= VMSPACE_EXIT2;
365                 cpu_vmspace_free(vm);
366                 shmexit(vm);
367
368                 /*
369                  * Lock the map, to wait out all other references to it.
370                  * Delete all of the mappings and pages they hold, then call
371                  * the pmap module to reclaim anything left.
372                  */
373                 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
374                 vm_map_lock(&vm->vm_map);
375                 vm_map_delete(&vm->vm_map, vm->vm_map.min_offset,
376                               vm->vm_map.max_offset, &count);
377                 vm_map_unlock(&vm->vm_map);
378                 vm_map_entry_release(count);
379
380                 lwkt_gettoken(&vmspace_pmap(vm)->pm_token);
381                 pmap_release(vmspace_pmap(vm));
382                 lwkt_reltoken(&vmspace_pmap(vm)->pm_token);
383         }
384
385         lwkt_reltoken(&vm->vm_map.token);
386         if (vm->vm_exitingcnt == 0 && vm->vm_holdcount == 0) {
387                 KKASSERT(vm->vm_flags & VMSPACE_EXIT1);
388                 KKASSERT(vm->vm_flags & VMSPACE_EXIT2);
389                 sysref_put(&vm->vm_sysref);
390         }
391 }
392
393 /*
394  * vmspaces are not currently locked.
395  */
396 static void
397 vmspace_lock(struct vmspace *vm __unused)
398 {
399 }
400
401 static void
402 vmspace_unlock(struct vmspace *vm __unused)
403 {
404 }
405
406 /*
407  * This is called during exit indicating that the vmspace is no
408  * longer in used by an exiting process, but the process has not yet
409  * been reaped.
410  *
411  * No requirements.
412  */
413 void
414 vmspace_exitbump(struct vmspace *vm)
415 {
416         vmspace_hold(vm);
417         ++vm->vm_exitingcnt;
418         vmspace_drop(vm);       /* handles termination sequencing */
419 }
420
421 /*
422  * Decrement the exitingcnt and issue the stage-2 termination if it becomes
423  * zero and the stage1 termination has already occured.
424  *
425  * No requirements.
426  */
427 void
428 vmspace_exitfree(struct proc *p)
429 {
430         struct vmspace *vm;
431
432         vm = p->p_vmspace;
433         p->p_vmspace = NULL;
434         vmspace_hold(vm);
435         KKASSERT(vm->vm_exitingcnt > 0);
436         if (--vm->vm_exitingcnt == 0 && sysref_isinactive(&vm->vm_sysref))
437                 vmspace_terminate(vm);
438         vmspace_drop(vm);       /* handles termination sequencing */
439 }
440
441 /*
442  * Swap useage is determined by taking the proportional swap used by
443  * VM objects backing the VM map.  To make up for fractional losses,
444  * if the VM object has any swap use at all the associated map entries
445  * count for at least 1 swap page.
446  *
447  * No requirements.
448  */
449 int
450 vmspace_swap_count(struct vmspace *vm)
451 {
452         vm_map_t map = &vm->vm_map;
453         vm_map_entry_t cur;
454         vm_object_t object;
455         int count = 0;
456         int n;
457
458         vmspace_hold(vm);
459         for (cur = map->header.next; cur != &map->header; cur = cur->next) {
460                 switch(cur->maptype) {
461                 case VM_MAPTYPE_NORMAL:
462                 case VM_MAPTYPE_VPAGETABLE:
463                         if ((object = cur->object.vm_object) == NULL)
464                                 break;
465                         if (object->swblock_count) {
466                                 n = (cur->end - cur->start) / PAGE_SIZE;
467                                 count += object->swblock_count *
468                                     SWAP_META_PAGES * n / object->size + 1;
469                         }
470                         break;
471                 default:
472                         break;
473                 }
474         }
475         vmspace_drop(vm);
476
477         return(count);
478 }
479
480 /*
481  * Calculate the approximate number of anonymous pages in use by
482  * this vmspace.  To make up for fractional losses, we count each
483  * VM object as having at least 1 anonymous page.
484  *
485  * No requirements.
486  */
487 int
488 vmspace_anonymous_count(struct vmspace *vm)
489 {
490         vm_map_t map = &vm->vm_map;
491         vm_map_entry_t cur;
492         vm_object_t object;
493         int count = 0;
494
495         vmspace_hold(vm);
496         for (cur = map->header.next; cur != &map->header; cur = cur->next) {
497                 switch(cur->maptype) {
498                 case VM_MAPTYPE_NORMAL:
499                 case VM_MAPTYPE_VPAGETABLE:
500                         if ((object = cur->object.vm_object) == NULL)
501                                 break;
502                         if (object->type != OBJT_DEFAULT &&
503                             object->type != OBJT_SWAP) {
504                                 break;
505                         }
506                         count += object->resident_page_count;
507                         break;
508                 default:
509                         break;
510                 }
511         }
512         vmspace_drop(vm);
513
514         return(count);
515 }
516
517 /*
518  * Creates and returns a new empty VM map with the given physical map
519  * structure, and having the given lower and upper address bounds.
520  *
521  * No requirements.
522  */
523 vm_map_t
524 vm_map_create(vm_map_t result, pmap_t pmap, vm_offset_t min, vm_offset_t max)
525 {
526         if (result == NULL)
527                 result = zalloc(mapzone);
528         vm_map_init(result, min, max, pmap);
529         return (result);
530 }
531
532 /*
533  * Initialize an existing vm_map structure such as that in the vmspace
534  * structure.  The pmap is initialized elsewhere.
535  *
536  * No requirements.
537  */
538 void
539 vm_map_init(struct vm_map *map, vm_offset_t min, vm_offset_t max, pmap_t pmap)
540 {
541         map->header.next = map->header.prev = &map->header;
542         RB_INIT(&map->rb_root);
543         map->nentries = 0;
544         map->size = 0;
545         map->system_map = 0;
546         map->min_offset = min;
547         map->max_offset = max;
548         map->pmap = pmap;
549         map->first_free = &map->header;
550         map->hint = &map->header;
551         map->timestamp = 0;
552         map->flags = 0;
553         lwkt_token_init(&map->token, "vm_map");
554         lockinit(&map->lock, "thrd_sleep", (hz + 9) / 10, 0);
555         TUNABLE_INT("vm.cache_vmspaces", &vmspace_sysref_class.nom_cache);
556 }
557
558 /*
559  * Shadow the vm_map_entry's object.  This typically needs to be done when
560  * a write fault is taken on an entry which had previously been cloned by
561  * fork().  The shared object (which might be NULL) must become private so
562  * we add a shadow layer above it.
563  *
564  * Object allocation for anonymous mappings is defered as long as possible.
565  * When creating a shadow, however, the underlying object must be instantiated
566  * so it can be shared.
567  *
568  * If the map segment is governed by a virtual page table then it is
569  * possible to address offsets beyond the mapped area.  Just allocate
570  * a maximally sized object for this case.
571  *
572  * The vm_map must be exclusively locked.
573  * No other requirements.
574  */
575 static
576 void
577 vm_map_entry_shadow(vm_map_entry_t entry, int addref)
578 {
579         if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
580                 vm_object_shadow(&entry->object.vm_object, &entry->offset,
581                                  0x7FFFFFFF, addref);   /* XXX */
582         } else {
583                 vm_object_shadow(&entry->object.vm_object, &entry->offset,
584                                  atop(entry->end - entry->start), addref);
585         }
586         entry->eflags &= ~MAP_ENTRY_NEEDS_COPY;
587 }
588
589 /*
590  * Allocate an object for a vm_map_entry.
591  *
592  * Object allocation for anonymous mappings is defered as long as possible.
593  * This function is called when we can defer no longer, generally when a map
594  * entry might be split or forked or takes a page fault.
595  *
596  * If the map segment is governed by a virtual page table then it is
597  * possible to address offsets beyond the mapped area.  Just allocate
598  * a maximally sized object for this case.
599  *
600  * The vm_map must be exclusively locked.
601  * No other requirements.
602  */
603 void 
604 vm_map_entry_allocate_object(vm_map_entry_t entry)
605 {
606         vm_object_t obj;
607
608         if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
609                 obj = vm_object_allocate(OBJT_DEFAULT, 0x7FFFFFFF); /* XXX */
610         } else {
611                 obj = vm_object_allocate(OBJT_DEFAULT,
612                                          atop(entry->end - entry->start));
613         }
614         entry->object.vm_object = obj;
615         entry->offset = 0;
616 }
617
618 /*
619  * Set an initial negative count so the first attempt to reserve
620  * space preloads a bunch of vm_map_entry's for this cpu.  Also
621  * pre-allocate 2 vm_map_entries which will be needed by zalloc() to
622  * map a new page for vm_map_entry structures.  SMP systems are
623  * particularly sensitive.
624  *
625  * This routine is called in early boot so we cannot just call
626  * vm_map_entry_reserve().
627  *
628  * Called from the low level boot code only (for each cpu)
629  */
630 void
631 vm_map_entry_reserve_cpu_init(globaldata_t gd)
632 {
633         vm_map_entry_t entry;
634         int i;
635
636         gd->gd_vme_avail -= MAP_RESERVE_COUNT * 2;
637         entry = &cpu_map_entry_init[gd->gd_cpuid][0];
638         for (i = 0; i < VMEPERCPU; ++i, ++entry) {
639                 entry->next = gd->gd_vme_base;
640                 gd->gd_vme_base = entry;
641         }
642 }
643
644 /*
645  * Reserves vm_map_entry structures so code later on can manipulate
646  * map_entry structures within a locked map without blocking trying
647  * to allocate a new vm_map_entry.
648  *
649  * No requirements.
650  */
651 int
652 vm_map_entry_reserve(int count)
653 {
654         struct globaldata *gd = mycpu;
655         vm_map_entry_t entry;
656
657         /*
658          * Make sure we have enough structures in gd_vme_base to handle
659          * the reservation request.
660          *
661          * The critical section protects access to the per-cpu gd.
662          */
663         crit_enter();
664         while (gd->gd_vme_avail < count) {
665                 entry = zalloc(mapentzone);
666                 entry->next = gd->gd_vme_base;
667                 gd->gd_vme_base = entry;
668                 ++gd->gd_vme_avail;
669         }
670         gd->gd_vme_avail -= count;
671         crit_exit();
672
673         return(count);
674 }
675
676 /*
677  * Releases previously reserved vm_map_entry structures that were not
678  * used.  If we have too much junk in our per-cpu cache clean some of
679  * it out.
680  *
681  * No requirements.
682  */
683 void
684 vm_map_entry_release(int count)
685 {
686         struct globaldata *gd = mycpu;
687         vm_map_entry_t entry;
688
689         crit_enter();
690         gd->gd_vme_avail += count;
691         while (gd->gd_vme_avail > MAP_RESERVE_SLOP) {
692                 entry = gd->gd_vme_base;
693                 KKASSERT(entry != NULL);
694                 gd->gd_vme_base = entry->next;
695                 --gd->gd_vme_avail;
696                 crit_exit();
697                 zfree(mapentzone, entry);
698                 crit_enter();
699         }
700         crit_exit();
701 }
702
703 /*
704  * Reserve map entry structures for use in kernel_map itself.  These
705  * entries have *ALREADY* been reserved on a per-cpu basis when the map
706  * was inited.  This function is used by zalloc() to avoid a recursion
707  * when zalloc() itself needs to allocate additional kernel memory.
708  *
709  * This function works like the normal reserve but does not load the
710  * vm_map_entry cache (because that would result in an infinite
711  * recursion).  Note that gd_vme_avail may go negative.  This is expected.
712  *
713  * Any caller of this function must be sure to renormalize after
714  * potentially eating entries to ensure that the reserve supply
715  * remains intact.
716  *
717  * No requirements.
718  */
719 int
720 vm_map_entry_kreserve(int count)
721 {
722         struct globaldata *gd = mycpu;
723
724         crit_enter();
725         gd->gd_vme_avail -= count;
726         crit_exit();
727         KASSERT(gd->gd_vme_base != NULL,
728                 ("no reserved entries left, gd_vme_avail = %d",
729                 gd->gd_vme_avail));
730         return(count);
731 }
732
733 /*
734  * Release previously reserved map entries for kernel_map.  We do not
735  * attempt to clean up like the normal release function as this would
736  * cause an unnecessary (but probably not fatal) deep procedure call.
737  *
738  * No requirements.
739  */
740 void
741 vm_map_entry_krelease(int count)
742 {
743         struct globaldata *gd = mycpu;
744
745         crit_enter();
746         gd->gd_vme_avail += count;
747         crit_exit();
748 }
749
750 /*
751  * Allocates a VM map entry for insertion.  No entry fields are filled in.
752  *
753  * The entries should have previously been reserved.  The reservation count
754  * is tracked in (*countp).
755  *
756  * No requirements.
757  */
758 static vm_map_entry_t
759 vm_map_entry_create(vm_map_t map, int *countp)
760 {
761         struct globaldata *gd = mycpu;
762         vm_map_entry_t entry;
763
764         KKASSERT(*countp > 0);
765         --*countp;
766         crit_enter();
767         entry = gd->gd_vme_base;
768         KASSERT(entry != NULL, ("gd_vme_base NULL! count %d", *countp));
769         gd->gd_vme_base = entry->next;
770         crit_exit();
771
772         return(entry);
773 }
774
775 /*
776  * Dispose of a vm_map_entry that is no longer being referenced.
777  *
778  * No requirements.
779  */
780 static void
781 vm_map_entry_dispose(vm_map_t map, vm_map_entry_t entry, int *countp)
782 {
783         struct globaldata *gd = mycpu;
784
785         KKASSERT(map->hint != entry);
786         KKASSERT(map->first_free != entry);
787
788         ++*countp;
789         crit_enter();
790         entry->next = gd->gd_vme_base;
791         gd->gd_vme_base = entry;
792         crit_exit();
793 }
794
795
796 /*
797  * Insert/remove entries from maps.
798  *
799  * The related map must be exclusively locked.
800  * The caller must hold map->token
801  * No other requirements.
802  */
803 static __inline void
804 vm_map_entry_link(vm_map_t map,
805                   vm_map_entry_t after_where,
806                   vm_map_entry_t entry)
807 {
808         ASSERT_VM_MAP_LOCKED(map);
809
810         map->nentries++;
811         entry->prev = after_where;
812         entry->next = after_where->next;
813         entry->next->prev = entry;
814         after_where->next = entry;
815         if (vm_map_rb_tree_RB_INSERT(&map->rb_root, entry))
816                 panic("vm_map_entry_link: dup addr map %p ent %p", map, entry);
817 }
818
819 static __inline void
820 vm_map_entry_unlink(vm_map_t map,
821                     vm_map_entry_t entry)
822 {
823         vm_map_entry_t prev;
824         vm_map_entry_t next;
825
826         ASSERT_VM_MAP_LOCKED(map);
827
828         if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
829                 panic("vm_map_entry_unlink: attempt to mess with "
830                       "locked entry! %p", entry);
831         }
832         prev = entry->prev;
833         next = entry->next;
834         next->prev = prev;
835         prev->next = next;
836         vm_map_rb_tree_RB_REMOVE(&map->rb_root, entry);
837         map->nentries--;
838 }
839
840 /*
841  * Finds the map entry containing (or immediately preceding) the specified
842  * address in the given map.  The entry is returned in (*entry).
843  *
844  * The boolean result indicates whether the address is actually contained
845  * in the map.
846  *
847  * The related map must be locked.
848  * No other requirements.
849  */
850 boolean_t
851 vm_map_lookup_entry(vm_map_t map, vm_offset_t address, vm_map_entry_t *entry)
852 {
853         vm_map_entry_t tmp;
854         vm_map_entry_t last;
855
856         ASSERT_VM_MAP_LOCKED(map);
857 #if 0
858         /*
859          * XXX TEMPORARILY DISABLED.  For some reason our attempt to revive
860          * the hint code with the red-black lookup meets with system crashes
861          * and lockups.  We do not yet know why.
862          *
863          * It is possible that the problem is related to the setting
864          * of the hint during map_entry deletion, in the code specified
865          * at the GGG comment later on in this file.
866          *
867          * YYY More likely it's because this function can be called with
868          * a shared lock on the map, resulting in map->hint updates possibly
869          * racing.  Fixed now but untested.
870          */
871         /*
872          * Quickly check the cached hint, there's a good chance of a match.
873          */
874         tmp = map->hint;
875         cpu_ccfence();
876         if (tmp != &map->header) {
877                 if (address >= tmp->start && address < tmp->end) {
878                         *entry = tmp;
879                         return(TRUE);
880                 }
881         }
882 #endif
883
884         /*
885          * Locate the record from the top of the tree.  'last' tracks the
886          * closest prior record and is returned if no match is found, which
887          * in binary tree terms means tracking the most recent right-branch
888          * taken.  If there is no prior record, &map->header is returned.
889          */
890         last = &map->header;
891         tmp = RB_ROOT(&map->rb_root);
892
893         while (tmp) {
894                 if (address >= tmp->start) {
895                         if (address < tmp->end) {
896                                 *entry = tmp;
897                                 map->hint = tmp;
898                                 return(TRUE);
899                         }
900                         last = tmp;
901                         tmp = RB_RIGHT(tmp, rb_entry);
902                 } else {
903                         tmp = RB_LEFT(tmp, rb_entry);
904                 }
905         }
906         *entry = last;
907         return (FALSE);
908 }
909
910 /*
911  * Inserts the given whole VM object into the target map at the specified
912  * address range.  The object's size should match that of the address range.
913  *
914  * The map must be exclusively locked.
915  * The object must be held.
916  * The caller must have reserved sufficient vm_map_entry structures.
917  *
918  * If object is non-NULL, ref count must be bumped by caller prior to
919  * making call to account for the new entry.
920  */
921 int
922 vm_map_insert(vm_map_t map, int *countp,
923               vm_object_t object, vm_ooffset_t offset,
924               vm_offset_t start, vm_offset_t end,
925               vm_maptype_t maptype,
926               vm_prot_t prot, vm_prot_t max,
927               int cow)
928 {
929         vm_map_entry_t new_entry;
930         vm_map_entry_t prev_entry;
931         vm_map_entry_t temp_entry;
932         vm_eflags_t protoeflags;
933         int must_drop = 0;
934
935         ASSERT_VM_MAP_LOCKED(map);
936         if (object)
937                 ASSERT_LWKT_TOKEN_HELD(vm_object_token(object));
938
939         /*
940          * Check that the start and end points are not bogus.
941          */
942         if ((start < map->min_offset) || (end > map->max_offset) ||
943             (start >= end))
944                 return (KERN_INVALID_ADDRESS);
945
946         /*
947          * Find the entry prior to the proposed starting address; if it's part
948          * of an existing entry, this range is bogus.
949          */
950         if (vm_map_lookup_entry(map, start, &temp_entry))
951                 return (KERN_NO_SPACE);
952
953         prev_entry = temp_entry;
954
955         /*
956          * Assert that the next entry doesn't overlap the end point.
957          */
958
959         if ((prev_entry->next != &map->header) &&
960             (prev_entry->next->start < end))
961                 return (KERN_NO_SPACE);
962
963         protoeflags = 0;
964
965         if (cow & MAP_COPY_ON_WRITE)
966                 protoeflags |= MAP_ENTRY_COW|MAP_ENTRY_NEEDS_COPY;
967
968         if (cow & MAP_NOFAULT) {
969                 protoeflags |= MAP_ENTRY_NOFAULT;
970
971                 KASSERT(object == NULL,
972                         ("vm_map_insert: paradoxical MAP_NOFAULT request"));
973         }
974         if (cow & MAP_DISABLE_SYNCER)
975                 protoeflags |= MAP_ENTRY_NOSYNC;
976         if (cow & MAP_DISABLE_COREDUMP)
977                 protoeflags |= MAP_ENTRY_NOCOREDUMP;
978         if (cow & MAP_IS_STACK)
979                 protoeflags |= MAP_ENTRY_STACK;
980         if (cow & MAP_IS_KSTACK)
981                 protoeflags |= MAP_ENTRY_KSTACK;
982
983         lwkt_gettoken(&map->token);
984
985         if (object) {
986                 /*
987                  * When object is non-NULL, it could be shared with another
988                  * process.  We have to set or clear OBJ_ONEMAPPING 
989                  * appropriately.
990                  */
991                 if ((object->ref_count > 1) || (object->shadow_count != 0)) {
992                         vm_object_clear_flag(object, OBJ_ONEMAPPING);
993                 }
994         }
995         else if ((prev_entry != &map->header) &&
996                  (prev_entry->eflags == protoeflags) &&
997                  (prev_entry->end == start) &&
998                  (prev_entry->wired_count == 0) &&
999                  prev_entry->maptype == maptype &&
1000                  ((prev_entry->object.vm_object == NULL) ||
1001                   vm_object_coalesce(prev_entry->object.vm_object,
1002                                      OFF_TO_IDX(prev_entry->offset),
1003                                      (vm_size_t)(prev_entry->end - prev_entry->start),
1004                                      (vm_size_t)(end - prev_entry->end)))) {
1005                 /*
1006                  * We were able to extend the object.  Determine if we
1007                  * can extend the previous map entry to include the 
1008                  * new range as well.
1009                  */
1010                 if ((prev_entry->inheritance == VM_INHERIT_DEFAULT) &&
1011                     (prev_entry->protection == prot) &&
1012                     (prev_entry->max_protection == max)) {
1013                         map->size += (end - prev_entry->end);
1014                         prev_entry->end = end;
1015                         vm_map_simplify_entry(map, prev_entry, countp);
1016                         lwkt_reltoken(&map->token);
1017                         return (KERN_SUCCESS);
1018                 }
1019
1020                 /*
1021                  * If we can extend the object but cannot extend the
1022                  * map entry, we have to create a new map entry.  We
1023                  * must bump the ref count on the extended object to
1024                  * account for it.  object may be NULL.
1025                  */
1026                 object = prev_entry->object.vm_object;
1027                 offset = prev_entry->offset +
1028                         (prev_entry->end - prev_entry->start);
1029                 if (object) {
1030                         vm_object_hold(object);
1031                         vm_object_chain_wait(object);
1032                         vm_object_reference_locked(object);
1033                         must_drop = 1;
1034                 }
1035         }
1036
1037         /*
1038          * NOTE: if conditionals fail, object can be NULL here.  This occurs
1039          * in things like the buffer map where we manage kva but do not manage
1040          * backing objects.
1041          */
1042
1043         /*
1044          * Create a new entry
1045          */
1046
1047         new_entry = vm_map_entry_create(map, countp);
1048         new_entry->start = start;
1049         new_entry->end = end;
1050
1051         new_entry->maptype = maptype;
1052         new_entry->eflags = protoeflags;
1053         new_entry->object.vm_object = object;
1054         new_entry->offset = offset;
1055         new_entry->aux.master_pde = 0;
1056
1057         new_entry->inheritance = VM_INHERIT_DEFAULT;
1058         new_entry->protection = prot;
1059         new_entry->max_protection = max;
1060         new_entry->wired_count = 0;
1061
1062         /*
1063          * Insert the new entry into the list
1064          */
1065
1066         vm_map_entry_link(map, prev_entry, new_entry);
1067         map->size += new_entry->end - new_entry->start;
1068
1069         /*
1070          * Update the free space hint.  Entries cannot overlap.
1071          * An exact comparison is needed to avoid matching
1072          * against the map->header.
1073          */
1074         if ((map->first_free == prev_entry) &&
1075             (prev_entry->end == new_entry->start)) {
1076                 map->first_free = new_entry;
1077         }
1078
1079 #if 0
1080         /*
1081          * Temporarily removed to avoid MAP_STACK panic, due to
1082          * MAP_STACK being a huge hack.  Will be added back in
1083          * when MAP_STACK (and the user stack mapping) is fixed.
1084          */
1085         /*
1086          * It may be possible to simplify the entry
1087          */
1088         vm_map_simplify_entry(map, new_entry, countp);
1089 #endif
1090
1091         /*
1092          * Try to pre-populate the page table.  Mappings governed by virtual
1093          * page tables cannot be prepopulated without a lot of work, so
1094          * don't try.
1095          */
1096         if ((cow & (MAP_PREFAULT|MAP_PREFAULT_PARTIAL)) &&
1097             maptype != VM_MAPTYPE_VPAGETABLE) {
1098                 pmap_object_init_pt(map->pmap, start, prot,
1099                                     object, OFF_TO_IDX(offset), end - start,
1100                                     cow & MAP_PREFAULT_PARTIAL);
1101         }
1102         if (must_drop)
1103                 vm_object_drop(object);
1104
1105         lwkt_reltoken(&map->token);
1106         return (KERN_SUCCESS);
1107 }
1108
1109 /*
1110  * Find sufficient space for `length' bytes in the given map, starting at
1111  * `start'.  Returns 0 on success, 1 on no space.
1112  *
1113  * This function will returned an arbitrarily aligned pointer.  If no
1114  * particular alignment is required you should pass align as 1.  Note that
1115  * the map may return PAGE_SIZE aligned pointers if all the lengths used in
1116  * the map are a multiple of PAGE_SIZE, even if you pass a smaller align
1117  * argument.
1118  *
1119  * 'align' should be a power of 2 but is not required to be.
1120  *
1121  * The map must be exclusively locked.
1122  * No other requirements.
1123  */
1124 int
1125 vm_map_findspace(vm_map_t map, vm_offset_t start, vm_size_t length,
1126                  vm_size_t align, int flags, vm_offset_t *addr)
1127 {
1128         vm_map_entry_t entry, next;
1129         vm_offset_t end;
1130         vm_offset_t align_mask;
1131
1132         if (start < map->min_offset)
1133                 start = map->min_offset;
1134         if (start > map->max_offset)
1135                 return (1);
1136
1137         /*
1138          * If the alignment is not a power of 2 we will have to use
1139          * a mod/division, set align_mask to a special value.
1140          */
1141         if ((align | (align - 1)) + 1 != (align << 1))
1142                 align_mask = (vm_offset_t)-1;
1143         else
1144                 align_mask = align - 1;
1145
1146         /*
1147          * Look for the first possible address; if there's already something
1148          * at this address, we have to start after it.
1149          */
1150         if (start == map->min_offset) {
1151                 if ((entry = map->first_free) != &map->header)
1152                         start = entry->end;
1153         } else {
1154                 vm_map_entry_t tmp;
1155
1156                 if (vm_map_lookup_entry(map, start, &tmp))
1157                         start = tmp->end;
1158                 entry = tmp;
1159         }
1160
1161         /*
1162          * Look through the rest of the map, trying to fit a new region in the
1163          * gap between existing regions, or after the very last region.
1164          */
1165         for (;; start = (entry = next)->end) {
1166                 /*
1167                  * Adjust the proposed start by the requested alignment,
1168                  * be sure that we didn't wrap the address.
1169                  */
1170                 if (align_mask == (vm_offset_t)-1)
1171                         end = ((start + align - 1) / align) * align;
1172                 else
1173                         end = (start + align_mask) & ~align_mask;
1174                 if (end < start)
1175                         return (1);
1176                 start = end;
1177                 /*
1178                  * Find the end of the proposed new region.  Be sure we didn't
1179                  * go beyond the end of the map, or wrap around the address.
1180                  * Then check to see if this is the last entry or if the 
1181                  * proposed end fits in the gap between this and the next
1182                  * entry.
1183                  */
1184                 end = start + length;
1185                 if (end > map->max_offset || end < start)
1186                         return (1);
1187                 next = entry->next;
1188
1189                 /*
1190                  * If the next entry's start address is beyond the desired
1191                  * end address we may have found a good entry.
1192                  *
1193                  * If the next entry is a stack mapping we do not map into
1194                  * the stack's reserved space.
1195                  *
1196                  * XXX continue to allow mapping into the stack's reserved
1197                  * space if doing a MAP_STACK mapping inside a MAP_STACK
1198                  * mapping, for backwards compatibility.  But the caller
1199                  * really should use MAP_STACK | MAP_TRYFIXED if they
1200                  * want to do that.
1201                  */
1202                 if (next == &map->header)
1203                         break;
1204                 if (next->start >= end) {
1205                         if ((next->eflags & MAP_ENTRY_STACK) == 0)
1206                                 break;
1207                         if (flags & MAP_STACK)
1208                                 break;
1209                         if (next->start - next->aux.avail_ssize >= end)
1210                                 break;
1211                 }
1212         }
1213         map->hint = entry;
1214
1215         /*
1216          * Grow the kernel_map if necessary.  pmap_growkernel() will panic
1217          * if it fails.  The kernel_map is locked and nothing can steal
1218          * our address space if pmap_growkernel() blocks.
1219          *
1220          * NOTE: This may be unconditionally called for kldload areas on
1221          *       x86_64 because these do not bump kernel_vm_end (which would
1222          *       fill 128G worth of page tables!).  Therefore we must not
1223          *       retry.
1224          */
1225         if (map == &kernel_map) {
1226                 vm_offset_t kstop;
1227
1228                 kstop = round_page(start + length);
1229                 if (kstop > kernel_vm_end)
1230                         pmap_growkernel(start, kstop);
1231         }
1232         *addr = start;
1233         return (0);
1234 }
1235
1236 /*
1237  * vm_map_find finds an unallocated region in the target address map with
1238  * the given length and allocates it.  The search is defined to be first-fit
1239  * from the specified address; the region found is returned in the same
1240  * parameter.
1241  *
1242  * If object is non-NULL, ref count must be bumped by caller
1243  * prior to making call to account for the new entry.
1244  *
1245  * No requirements.  This function will lock the map temporarily.
1246  */
1247 int
1248 vm_map_find(vm_map_t map, vm_object_t object, vm_ooffset_t offset,
1249             vm_offset_t *addr,  vm_size_t length, vm_size_t align,
1250             boolean_t fitit,
1251             vm_maptype_t maptype,
1252             vm_prot_t prot, vm_prot_t max,
1253             int cow)
1254 {
1255         vm_offset_t start;
1256         int result;
1257         int count;
1258
1259         start = *addr;
1260
1261         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1262         vm_map_lock(map);
1263         if (object)
1264                 vm_object_hold(object);
1265         if (fitit) {
1266                 if (vm_map_findspace(map, start, length, align, 0, addr)) {
1267                         if (object)
1268                                 vm_object_drop(object);
1269                         vm_map_unlock(map);
1270                         vm_map_entry_release(count);
1271                         return (KERN_NO_SPACE);
1272                 }
1273                 start = *addr;
1274         }
1275         result = vm_map_insert(map, &count, object, offset,
1276                                start, start + length,
1277                                maptype,
1278                                prot, max,
1279                                cow);
1280         if (object)
1281                 vm_object_drop(object);
1282         vm_map_unlock(map);
1283         vm_map_entry_release(count);
1284
1285         return (result);
1286 }
1287
1288 /*
1289  * Simplify the given map entry by merging with either neighbor.  This
1290  * routine also has the ability to merge with both neighbors.
1291  *
1292  * This routine guarentees that the passed entry remains valid (though
1293  * possibly extended).  When merging, this routine may delete one or
1294  * both neighbors.  No action is taken on entries which have their
1295  * in-transition flag set.
1296  *
1297  * The map must be exclusively locked.
1298  */
1299 void
1300 vm_map_simplify_entry(vm_map_t map, vm_map_entry_t entry, int *countp)
1301 {
1302         vm_map_entry_t next, prev;
1303         vm_size_t prevsize, esize;
1304
1305         if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1306                 ++mycpu->gd_cnt.v_intrans_coll;
1307                 return;
1308         }
1309
1310         if (entry->maptype == VM_MAPTYPE_SUBMAP)
1311                 return;
1312
1313         prev = entry->prev;
1314         if (prev != &map->header) {
1315                 prevsize = prev->end - prev->start;
1316                 if ( (prev->end == entry->start) &&
1317                      (prev->maptype == entry->maptype) &&
1318                      (prev->object.vm_object == entry->object.vm_object) &&
1319                      (!prev->object.vm_object ||
1320                         (prev->offset + prevsize == entry->offset)) &&
1321                      (prev->eflags == entry->eflags) &&
1322                      (prev->protection == entry->protection) &&
1323                      (prev->max_protection == entry->max_protection) &&
1324                      (prev->inheritance == entry->inheritance) &&
1325                      (prev->wired_count == entry->wired_count)) {
1326                         if (map->first_free == prev)
1327                                 map->first_free = entry;
1328                         if (map->hint == prev)
1329                                 map->hint = entry;
1330                         vm_map_entry_unlink(map, prev);
1331                         entry->start = prev->start;
1332                         entry->offset = prev->offset;
1333                         if (prev->object.vm_object)
1334                                 vm_object_deallocate(prev->object.vm_object);
1335                         vm_map_entry_dispose(map, prev, countp);
1336                 }
1337         }
1338
1339         next = entry->next;
1340         if (next != &map->header) {
1341                 esize = entry->end - entry->start;
1342                 if ((entry->end == next->start) &&
1343                     (next->maptype == entry->maptype) &&
1344                     (next->object.vm_object == entry->object.vm_object) &&
1345                      (!entry->object.vm_object ||
1346                         (entry->offset + esize == next->offset)) &&
1347                     (next->eflags == entry->eflags) &&
1348                     (next->protection == entry->protection) &&
1349                     (next->max_protection == entry->max_protection) &&
1350                     (next->inheritance == entry->inheritance) &&
1351                     (next->wired_count == entry->wired_count)) {
1352                         if (map->first_free == next)
1353                                 map->first_free = entry;
1354                         if (map->hint == next)
1355                                 map->hint = entry;
1356                         vm_map_entry_unlink(map, next);
1357                         entry->end = next->end;
1358                         if (next->object.vm_object)
1359                                 vm_object_deallocate(next->object.vm_object);
1360                         vm_map_entry_dispose(map, next, countp);
1361                 }
1362         }
1363 }
1364
1365 /*
1366  * Asserts that the given entry begins at or after the specified address.
1367  * If necessary, it splits the entry into two.
1368  */
1369 #define vm_map_clip_start(map, entry, startaddr, countp)                \
1370 {                                                                       \
1371         if (startaddr > entry->start)                                   \
1372                 _vm_map_clip_start(map, entry, startaddr, countp);      \
1373 }
1374
1375 /*
1376  * This routine is called only when it is known that the entry must be split.
1377  *
1378  * The map must be exclusively locked.
1379  */
1380 static void
1381 _vm_map_clip_start(vm_map_t map, vm_map_entry_t entry, vm_offset_t start,
1382                    int *countp)
1383 {
1384         vm_map_entry_t new_entry;
1385
1386         /*
1387          * Split off the front portion -- note that we must insert the new
1388          * entry BEFORE this one, so that this entry has the specified
1389          * starting address.
1390          */
1391
1392         vm_map_simplify_entry(map, entry, countp);
1393
1394         /*
1395          * If there is no object backing this entry, we might as well create
1396          * one now.  If we defer it, an object can get created after the map
1397          * is clipped, and individual objects will be created for the split-up
1398          * map.  This is a bit of a hack, but is also about the best place to
1399          * put this improvement.
1400          */
1401         if (entry->object.vm_object == NULL && !map->system_map) {
1402                 vm_map_entry_allocate_object(entry);
1403         }
1404
1405         new_entry = vm_map_entry_create(map, countp);
1406         *new_entry = *entry;
1407
1408         new_entry->end = start;
1409         entry->offset += (start - entry->start);
1410         entry->start = start;
1411
1412         vm_map_entry_link(map, entry->prev, new_entry);
1413
1414         switch(entry->maptype) {
1415         case VM_MAPTYPE_NORMAL:
1416         case VM_MAPTYPE_VPAGETABLE:
1417                 if (new_entry->object.vm_object) {
1418                         vm_object_hold(new_entry->object.vm_object);
1419                         vm_object_chain_wait(new_entry->object.vm_object);
1420                         vm_object_reference_locked(new_entry->object.vm_object);
1421                         vm_object_drop(new_entry->object.vm_object);
1422                 }
1423                 break;
1424         default:
1425                 break;
1426         }
1427 }
1428
1429 /*
1430  * Asserts that the given entry ends at or before the specified address.
1431  * If necessary, it splits the entry into two.
1432  *
1433  * The map must be exclusively locked.
1434  */
1435 #define vm_map_clip_end(map, entry, endaddr, countp)            \
1436 {                                                               \
1437         if (endaddr < entry->end)                               \
1438                 _vm_map_clip_end(map, entry, endaddr, countp);  \
1439 }
1440
1441 /*
1442  * This routine is called only when it is known that the entry must be split.
1443  *
1444  * The map must be exclusively locked.
1445  */
1446 static void
1447 _vm_map_clip_end(vm_map_t map, vm_map_entry_t entry, vm_offset_t end,
1448                  int *countp)
1449 {
1450         vm_map_entry_t new_entry;
1451
1452         /*
1453          * If there is no object backing this entry, we might as well create
1454          * one now.  If we defer it, an object can get created after the map
1455          * is clipped, and individual objects will be created for the split-up
1456          * map.  This is a bit of a hack, but is also about the best place to
1457          * put this improvement.
1458          */
1459
1460         if (entry->object.vm_object == NULL && !map->system_map) {
1461                 vm_map_entry_allocate_object(entry);
1462         }
1463
1464         /*
1465          * Create a new entry and insert it AFTER the specified entry
1466          */
1467
1468         new_entry = vm_map_entry_create(map, countp);
1469         *new_entry = *entry;
1470
1471         new_entry->start = entry->end = end;
1472         new_entry->offset += (end - entry->start);
1473
1474         vm_map_entry_link(map, entry, new_entry);
1475
1476         switch(entry->maptype) {
1477         case VM_MAPTYPE_NORMAL:
1478         case VM_MAPTYPE_VPAGETABLE:
1479                 if (new_entry->object.vm_object) {
1480                         vm_object_hold(new_entry->object.vm_object);
1481                         vm_object_chain_wait(new_entry->object.vm_object);
1482                         vm_object_reference_locked(new_entry->object.vm_object);
1483                         vm_object_drop(new_entry->object.vm_object);
1484                 }
1485                 break;
1486         default:
1487                 break;
1488         }
1489 }
1490
1491 /*
1492  * Asserts that the starting and ending region addresses fall within the
1493  * valid range for the map.
1494  */
1495 #define VM_MAP_RANGE_CHECK(map, start, end)     \
1496 {                                               \
1497         if (start < vm_map_min(map))            \
1498                 start = vm_map_min(map);        \
1499         if (end > vm_map_max(map))              \
1500                 end = vm_map_max(map);          \
1501         if (start > end)                        \
1502                 start = end;                    \
1503 }
1504
1505 /*
1506  * Used to block when an in-transition collison occurs.  The map
1507  * is unlocked for the sleep and relocked before the return.
1508  */
1509 void
1510 vm_map_transition_wait(vm_map_t map)
1511 {
1512         tsleep_interlock(map, 0);
1513         vm_map_unlock(map);
1514         tsleep(map, PINTERLOCKED, "vment", 0);
1515         vm_map_lock(map);
1516 }
1517
1518 /*
1519  * When we do blocking operations with the map lock held it is
1520  * possible that a clip might have occured on our in-transit entry,
1521  * requiring an adjustment to the entry in our loop.  These macros
1522  * help the pageable and clip_range code deal with the case.  The
1523  * conditional costs virtually nothing if no clipping has occured.
1524  */
1525
1526 #define CLIP_CHECK_BACK(entry, save_start)              \
1527     do {                                                \
1528             while (entry->start != save_start) {        \
1529                     entry = entry->prev;                \
1530                     KASSERT(entry != &map->header, ("bad entry clip")); \
1531             }                                           \
1532     } while(0)
1533
1534 #define CLIP_CHECK_FWD(entry, save_end)                 \
1535     do {                                                \
1536             while (entry->end != save_end) {            \
1537                     entry = entry->next;                \
1538                     KASSERT(entry != &map->header, ("bad entry clip")); \
1539             }                                           \
1540     } while(0)
1541
1542
1543 /*
1544  * Clip the specified range and return the base entry.  The
1545  * range may cover several entries starting at the returned base
1546  * and the first and last entry in the covering sequence will be
1547  * properly clipped to the requested start and end address.
1548  *
1549  * If no holes are allowed you should pass the MAP_CLIP_NO_HOLES
1550  * flag.
1551  *
1552  * The MAP_ENTRY_IN_TRANSITION flag will be set for the entries
1553  * covered by the requested range.
1554  *
1555  * The map must be exclusively locked on entry and will remain locked
1556  * on return. If no range exists or the range contains holes and you
1557  * specified that no holes were allowed, NULL will be returned.  This
1558  * routine may temporarily unlock the map in order avoid a deadlock when
1559  * sleeping.
1560  */
1561 static
1562 vm_map_entry_t
1563 vm_map_clip_range(vm_map_t map, vm_offset_t start, vm_offset_t end, 
1564                   int *countp, int flags)
1565 {
1566         vm_map_entry_t start_entry;
1567         vm_map_entry_t entry;
1568
1569         /*
1570          * Locate the entry and effect initial clipping.  The in-transition
1571          * case does not occur very often so do not try to optimize it.
1572          */
1573 again:
1574         if (vm_map_lookup_entry(map, start, &start_entry) == FALSE)
1575                 return (NULL);
1576         entry = start_entry;
1577         if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
1578                 entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1579                 ++mycpu->gd_cnt.v_intrans_coll;
1580                 ++mycpu->gd_cnt.v_intrans_wait;
1581                 vm_map_transition_wait(map);
1582                 /*
1583                  * entry and/or start_entry may have been clipped while
1584                  * we slept, or may have gone away entirely.  We have
1585                  * to restart from the lookup.
1586                  */
1587                 goto again;
1588         }
1589
1590         /*
1591          * Since we hold an exclusive map lock we do not have to restart
1592          * after clipping, even though clipping may block in zalloc.
1593          */
1594         vm_map_clip_start(map, entry, start, countp);
1595         vm_map_clip_end(map, entry, end, countp);
1596         entry->eflags |= MAP_ENTRY_IN_TRANSITION;
1597
1598         /*
1599          * Scan entries covered by the range.  When working on the next
1600          * entry a restart need only re-loop on the current entry which
1601          * we have already locked, since 'next' may have changed.  Also,
1602          * even though entry is safe, it may have been clipped so we
1603          * have to iterate forwards through the clip after sleeping.
1604          */
1605         while (entry->next != &map->header && entry->next->start < end) {
1606                 vm_map_entry_t next = entry->next;
1607
1608                 if (flags & MAP_CLIP_NO_HOLES) {
1609                         if (next->start > entry->end) {
1610                                 vm_map_unclip_range(map, start_entry,
1611                                         start, entry->end, countp, flags);
1612                                 return(NULL);
1613                         }
1614                 }
1615
1616                 if (next->eflags & MAP_ENTRY_IN_TRANSITION) {
1617                         vm_offset_t save_end = entry->end;
1618                         next->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
1619                         ++mycpu->gd_cnt.v_intrans_coll;
1620                         ++mycpu->gd_cnt.v_intrans_wait;
1621                         vm_map_transition_wait(map);
1622
1623                         /*
1624                          * clips might have occured while we blocked.
1625                          */
1626                         CLIP_CHECK_FWD(entry, save_end);
1627                         CLIP_CHECK_BACK(start_entry, start);
1628                         continue;
1629                 }
1630                 /*
1631                  * No restart necessary even though clip_end may block, we
1632                  * are holding the map lock.
1633                  */
1634                 vm_map_clip_end(map, next, end, countp);
1635                 next->eflags |= MAP_ENTRY_IN_TRANSITION;
1636                 entry = next;
1637         }
1638         if (flags & MAP_CLIP_NO_HOLES) {
1639                 if (entry->end != end) {
1640                         vm_map_unclip_range(map, start_entry,
1641                                 start, entry->end, countp, flags);
1642                         return(NULL);
1643                 }
1644         }
1645         return(start_entry);
1646 }
1647
1648 /*
1649  * Undo the effect of vm_map_clip_range().  You should pass the same
1650  * flags and the same range that you passed to vm_map_clip_range().
1651  * This code will clear the in-transition flag on the entries and
1652  * wake up anyone waiting.  This code will also simplify the sequence
1653  * and attempt to merge it with entries before and after the sequence.
1654  *
1655  * The map must be locked on entry and will remain locked on return.
1656  *
1657  * Note that you should also pass the start_entry returned by
1658  * vm_map_clip_range().  However, if you block between the two calls
1659  * with the map unlocked please be aware that the start_entry may
1660  * have been clipped and you may need to scan it backwards to find
1661  * the entry corresponding with the original start address.  You are
1662  * responsible for this, vm_map_unclip_range() expects the correct
1663  * start_entry to be passed to it and will KASSERT otherwise.
1664  */
1665 static
1666 void
1667 vm_map_unclip_range(vm_map_t map, vm_map_entry_t start_entry,
1668                     vm_offset_t start, vm_offset_t end,
1669                     int *countp, int flags)
1670 {
1671         vm_map_entry_t entry;
1672
1673         entry = start_entry;
1674
1675         KASSERT(entry->start == start, ("unclip_range: illegal base entry"));
1676         while (entry != &map->header && entry->start < end) {
1677                 KASSERT(entry->eflags & MAP_ENTRY_IN_TRANSITION,
1678                         ("in-transition flag not set during unclip on: %p",
1679                         entry));
1680                 KASSERT(entry->end <= end,
1681                         ("unclip_range: tail wasn't clipped"));
1682                 entry->eflags &= ~MAP_ENTRY_IN_TRANSITION;
1683                 if (entry->eflags & MAP_ENTRY_NEEDS_WAKEUP) {
1684                         entry->eflags &= ~MAP_ENTRY_NEEDS_WAKEUP;
1685                         wakeup(map);
1686                 }
1687                 entry = entry->next;
1688         }
1689
1690         /*
1691          * Simplification does not block so there is no restart case.
1692          */
1693         entry = start_entry;
1694         while (entry != &map->header && entry->start < end) {
1695                 vm_map_simplify_entry(map, entry, countp);
1696                 entry = entry->next;
1697         }
1698 }
1699
1700 /*
1701  * Mark the given range as handled by a subordinate map.
1702  *
1703  * This range must have been created with vm_map_find(), and no other
1704  * operations may have been performed on this range prior to calling
1705  * vm_map_submap().
1706  *
1707  * Submappings cannot be removed.
1708  *
1709  * No requirements.
1710  */
1711 int
1712 vm_map_submap(vm_map_t map, vm_offset_t start, vm_offset_t end, vm_map_t submap)
1713 {
1714         vm_map_entry_t entry;
1715         int result = KERN_INVALID_ARGUMENT;
1716         int count;
1717
1718         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1719         vm_map_lock(map);
1720
1721         VM_MAP_RANGE_CHECK(map, start, end);
1722
1723         if (vm_map_lookup_entry(map, start, &entry)) {
1724                 vm_map_clip_start(map, entry, start, &count);
1725         } else {
1726                 entry = entry->next;
1727         }
1728
1729         vm_map_clip_end(map, entry, end, &count);
1730
1731         if ((entry->start == start) && (entry->end == end) &&
1732             ((entry->eflags & MAP_ENTRY_COW) == 0) &&
1733             (entry->object.vm_object == NULL)) {
1734                 entry->object.sub_map = submap;
1735                 entry->maptype = VM_MAPTYPE_SUBMAP;
1736                 result = KERN_SUCCESS;
1737         }
1738         vm_map_unlock(map);
1739         vm_map_entry_release(count);
1740
1741         return (result);
1742 }
1743
1744 /*
1745  * Sets the protection of the specified address region in the target map. 
1746  * If "set_max" is specified, the maximum protection is to be set;
1747  * otherwise, only the current protection is affected.
1748  *
1749  * The protection is not applicable to submaps, but is applicable to normal
1750  * maps and maps governed by virtual page tables.  For example, when operating
1751  * on a virtual page table our protection basically controls how COW occurs
1752  * on the backing object, whereas the virtual page table abstraction itself
1753  * is an abstraction for userland.
1754  *
1755  * No requirements.
1756  */
1757 int
1758 vm_map_protect(vm_map_t map, vm_offset_t start, vm_offset_t end,
1759                vm_prot_t new_prot, boolean_t set_max)
1760 {
1761         vm_map_entry_t current;
1762         vm_map_entry_t entry;
1763         int count;
1764
1765         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1766         vm_map_lock(map);
1767
1768         VM_MAP_RANGE_CHECK(map, start, end);
1769
1770         if (vm_map_lookup_entry(map, start, &entry)) {
1771                 vm_map_clip_start(map, entry, start, &count);
1772         } else {
1773                 entry = entry->next;
1774         }
1775
1776         /*
1777          * Make a first pass to check for protection violations.
1778          */
1779         current = entry;
1780         while ((current != &map->header) && (current->start < end)) {
1781                 if (current->maptype == VM_MAPTYPE_SUBMAP) {
1782                         vm_map_unlock(map);
1783                         vm_map_entry_release(count);
1784                         return (KERN_INVALID_ARGUMENT);
1785                 }
1786                 if ((new_prot & current->max_protection) != new_prot) {
1787                         vm_map_unlock(map);
1788                         vm_map_entry_release(count);
1789                         return (KERN_PROTECTION_FAILURE);
1790                 }
1791                 current = current->next;
1792         }
1793
1794         /*
1795          * Go back and fix up protections. [Note that clipping is not
1796          * necessary the second time.]
1797          */
1798         current = entry;
1799
1800         while ((current != &map->header) && (current->start < end)) {
1801                 vm_prot_t old_prot;
1802
1803                 vm_map_clip_end(map, current, end, &count);
1804
1805                 old_prot = current->protection;
1806                 if (set_max) {
1807                         current->protection =
1808                             (current->max_protection = new_prot) &
1809                             old_prot;
1810                 } else {
1811                         current->protection = new_prot;
1812                 }
1813
1814                 /*
1815                  * Update physical map if necessary. Worry about copy-on-write
1816                  * here -- CHECK THIS XXX
1817                  */
1818
1819                 if (current->protection != old_prot) {
1820 #define MASK(entry)     (((entry)->eflags & MAP_ENTRY_COW) ? ~VM_PROT_WRITE : \
1821                                                         VM_PROT_ALL)
1822
1823                         pmap_protect(map->pmap, current->start,
1824                             current->end,
1825                             current->protection & MASK(current));
1826 #undef  MASK
1827                 }
1828
1829                 vm_map_simplify_entry(map, current, &count);
1830
1831                 current = current->next;
1832         }
1833
1834         vm_map_unlock(map);
1835         vm_map_entry_release(count);
1836         return (KERN_SUCCESS);
1837 }
1838
1839 /*
1840  * This routine traverses a processes map handling the madvise
1841  * system call.  Advisories are classified as either those effecting
1842  * the vm_map_entry structure, or those effecting the underlying
1843  * objects.
1844  *
1845  * The <value> argument is used for extended madvise calls.
1846  *
1847  * No requirements.
1848  */
1849 int
1850 vm_map_madvise(vm_map_t map, vm_offset_t start, vm_offset_t end,
1851                int behav, off_t value)
1852 {
1853         vm_map_entry_t current, entry;
1854         int modify_map = 0;
1855         int error = 0;
1856         int count;
1857
1858         /*
1859          * Some madvise calls directly modify the vm_map_entry, in which case
1860          * we need to use an exclusive lock on the map and we need to perform 
1861          * various clipping operations.  Otherwise we only need a read-lock
1862          * on the map.
1863          */
1864
1865         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
1866
1867         switch(behav) {
1868         case MADV_NORMAL:
1869         case MADV_SEQUENTIAL:
1870         case MADV_RANDOM:
1871         case MADV_NOSYNC:
1872         case MADV_AUTOSYNC:
1873         case MADV_NOCORE:
1874         case MADV_CORE:
1875         case MADV_SETMAP:
1876         case MADV_INVAL:
1877                 modify_map = 1;
1878                 vm_map_lock(map);
1879                 break;
1880         case MADV_WILLNEED:
1881         case MADV_DONTNEED:
1882         case MADV_FREE:
1883                 vm_map_lock_read(map);
1884                 break;
1885         default:
1886                 vm_map_entry_release(count);
1887                 return (EINVAL);
1888         }
1889
1890         /*
1891          * Locate starting entry and clip if necessary.
1892          */
1893
1894         VM_MAP_RANGE_CHECK(map, start, end);
1895
1896         if (vm_map_lookup_entry(map, start, &entry)) {
1897                 if (modify_map)
1898                         vm_map_clip_start(map, entry, start, &count);
1899         } else {
1900                 entry = entry->next;
1901         }
1902
1903         if (modify_map) {
1904                 /*
1905                  * madvise behaviors that are implemented in the vm_map_entry.
1906                  *
1907                  * We clip the vm_map_entry so that behavioral changes are
1908                  * limited to the specified address range.
1909                  */
1910                 for (current = entry;
1911                      (current != &map->header) && (current->start < end);
1912                      current = current->next
1913                 ) {
1914                         if (current->maptype == VM_MAPTYPE_SUBMAP)
1915                                 continue;
1916
1917                         vm_map_clip_end(map, current, end, &count);
1918
1919                         switch (behav) {
1920                         case MADV_NORMAL:
1921                                 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_NORMAL);
1922                                 break;
1923                         case MADV_SEQUENTIAL:
1924                                 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_SEQUENTIAL);
1925                                 break;
1926                         case MADV_RANDOM:
1927                                 vm_map_entry_set_behavior(current, MAP_ENTRY_BEHAV_RANDOM);
1928                                 break;
1929                         case MADV_NOSYNC:
1930                                 current->eflags |= MAP_ENTRY_NOSYNC;
1931                                 break;
1932                         case MADV_AUTOSYNC:
1933                                 current->eflags &= ~MAP_ENTRY_NOSYNC;
1934                                 break;
1935                         case MADV_NOCORE:
1936                                 current->eflags |= MAP_ENTRY_NOCOREDUMP;
1937                                 break;
1938                         case MADV_CORE:
1939                                 current->eflags &= ~MAP_ENTRY_NOCOREDUMP;
1940                                 break;
1941                         case MADV_INVAL:
1942                                 /*
1943                                  * Invalidate the related pmap entries, used
1944                                  * to flush portions of the real kernel's
1945                                  * pmap when the caller has removed or
1946                                  * modified existing mappings in a virtual
1947                                  * page table.
1948                                  */
1949                                 pmap_remove(map->pmap,
1950                                             current->start, current->end);
1951                                 break;
1952                         case MADV_SETMAP:
1953                                 /*
1954                                  * Set the page directory page for a map
1955                                  * governed by a virtual page table.  Mark
1956                                  * the entry as being governed by a virtual
1957                                  * page table if it is not.
1958                                  *
1959                                  * XXX the page directory page is stored
1960                                  * in the avail_ssize field if the map_entry.
1961                                  *
1962                                  * XXX the map simplification code does not
1963                                  * compare this field so weird things may
1964                                  * happen if you do not apply this function
1965                                  * to the entire mapping governed by the
1966                                  * virtual page table.
1967                                  */
1968                                 if (current->maptype != VM_MAPTYPE_VPAGETABLE) {
1969                                         error = EINVAL;
1970                                         break;
1971                                 }
1972                                 current->aux.master_pde = value;
1973                                 pmap_remove(map->pmap,
1974                                             current->start, current->end);
1975                                 break;
1976                         default:
1977                                 error = EINVAL;
1978                                 break;
1979                         }
1980                         vm_map_simplify_entry(map, current, &count);
1981                 }
1982                 vm_map_unlock(map);
1983         } else {
1984                 vm_pindex_t pindex;
1985                 int count;
1986
1987                 /*
1988                  * madvise behaviors that are implemented in the underlying
1989                  * vm_object.
1990                  *
1991                  * Since we don't clip the vm_map_entry, we have to clip
1992                  * the vm_object pindex and count.
1993                  *
1994                  * NOTE!  We currently do not support these functions on
1995                  * virtual page tables.
1996                  */
1997                 for (current = entry;
1998                      (current != &map->header) && (current->start < end);
1999                      current = current->next
2000                 ) {
2001                         vm_offset_t useStart;
2002
2003                         if (current->maptype != VM_MAPTYPE_NORMAL)
2004                                 continue;
2005
2006                         pindex = OFF_TO_IDX(current->offset);
2007                         count = atop(current->end - current->start);
2008                         useStart = current->start;
2009
2010                         if (current->start < start) {
2011                                 pindex += atop(start - current->start);
2012                                 count -= atop(start - current->start);
2013                                 useStart = start;
2014                         }
2015                         if (current->end > end)
2016                                 count -= atop(current->end - end);
2017
2018                         if (count <= 0)
2019                                 continue;
2020
2021                         vm_object_madvise(current->object.vm_object,
2022                                           pindex, count, behav);
2023
2024                         /*
2025                          * Try to populate the page table.  Mappings governed
2026                          * by virtual page tables cannot be pre-populated
2027                          * without a lot of work so don't try.
2028                          */
2029                         if (behav == MADV_WILLNEED &&
2030                             current->maptype != VM_MAPTYPE_VPAGETABLE) {
2031                                 pmap_object_init_pt(
2032                                     map->pmap, 
2033                                     useStart,
2034                                     current->protection,
2035                                     current->object.vm_object,
2036                                     pindex, 
2037                                     (count << PAGE_SHIFT),
2038                                     MAP_PREFAULT_MADVISE
2039                                 );
2040                         }
2041                 }
2042                 vm_map_unlock_read(map);
2043         }
2044         vm_map_entry_release(count);
2045         return(error);
2046 }       
2047
2048
2049 /*
2050  * Sets the inheritance of the specified address range in the target map.
2051  * Inheritance affects how the map will be shared with child maps at the
2052  * time of vm_map_fork.
2053  */
2054 int
2055 vm_map_inherit(vm_map_t map, vm_offset_t start, vm_offset_t end,
2056                vm_inherit_t new_inheritance)
2057 {
2058         vm_map_entry_t entry;
2059         vm_map_entry_t temp_entry;
2060         int count;
2061
2062         switch (new_inheritance) {
2063         case VM_INHERIT_NONE:
2064         case VM_INHERIT_COPY:
2065         case VM_INHERIT_SHARE:
2066                 break;
2067         default:
2068                 return (KERN_INVALID_ARGUMENT);
2069         }
2070
2071         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2072         vm_map_lock(map);
2073
2074         VM_MAP_RANGE_CHECK(map, start, end);
2075
2076         if (vm_map_lookup_entry(map, start, &temp_entry)) {
2077                 entry = temp_entry;
2078                 vm_map_clip_start(map, entry, start, &count);
2079         } else
2080                 entry = temp_entry->next;
2081
2082         while ((entry != &map->header) && (entry->start < end)) {
2083                 vm_map_clip_end(map, entry, end, &count);
2084
2085                 entry->inheritance = new_inheritance;
2086
2087                 vm_map_simplify_entry(map, entry, &count);
2088
2089                 entry = entry->next;
2090         }
2091         vm_map_unlock(map);
2092         vm_map_entry_release(count);
2093         return (KERN_SUCCESS);
2094 }
2095
2096 /*
2097  * Implement the semantics of mlock
2098  */
2099 int
2100 vm_map_unwire(vm_map_t map, vm_offset_t start, vm_offset_t real_end,
2101               boolean_t new_pageable)
2102 {
2103         vm_map_entry_t entry;
2104         vm_map_entry_t start_entry;
2105         vm_offset_t end;
2106         int rv = KERN_SUCCESS;
2107         int count;
2108
2109         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2110         vm_map_lock(map);
2111         VM_MAP_RANGE_CHECK(map, start, real_end);
2112         end = real_end;
2113
2114         start_entry = vm_map_clip_range(map, start, end, &count,
2115                                         MAP_CLIP_NO_HOLES);
2116         if (start_entry == NULL) {
2117                 vm_map_unlock(map);
2118                 vm_map_entry_release(count);
2119                 return (KERN_INVALID_ADDRESS);
2120         }
2121
2122         if (new_pageable == 0) {
2123                 entry = start_entry;
2124                 while ((entry != &map->header) && (entry->start < end)) {
2125                         vm_offset_t save_start;
2126                         vm_offset_t save_end;
2127
2128                         /*
2129                          * Already user wired or hard wired (trivial cases)
2130                          */
2131                         if (entry->eflags & MAP_ENTRY_USER_WIRED) {
2132                                 entry = entry->next;
2133                                 continue;
2134                         }
2135                         if (entry->wired_count != 0) {
2136                                 entry->wired_count++;
2137                                 entry->eflags |= MAP_ENTRY_USER_WIRED;
2138                                 entry = entry->next;
2139                                 continue;
2140                         }
2141
2142                         /*
2143                          * A new wiring requires instantiation of appropriate
2144                          * management structures and the faulting in of the
2145                          * page.
2146                          */
2147                         if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2148                                 int copyflag = entry->eflags &
2149                                                MAP_ENTRY_NEEDS_COPY;
2150                                 if (copyflag && ((entry->protection &
2151                                                   VM_PROT_WRITE) != 0)) {
2152                                         vm_map_entry_shadow(entry, 0);
2153                                 } else if (entry->object.vm_object == NULL &&
2154                                            !map->system_map) {
2155                                         vm_map_entry_allocate_object(entry);
2156                                 }
2157                         }
2158                         entry->wired_count++;
2159                         entry->eflags |= MAP_ENTRY_USER_WIRED;
2160
2161                         /*
2162                          * Now fault in the area.  Note that vm_fault_wire()
2163                          * may release the map lock temporarily, it will be
2164                          * relocked on return.  The in-transition
2165                          * flag protects the entries. 
2166                          */
2167                         save_start = entry->start;
2168                         save_end = entry->end;
2169                         rv = vm_fault_wire(map, entry, TRUE);
2170                         if (rv) {
2171                                 CLIP_CHECK_BACK(entry, save_start);
2172                                 for (;;) {
2173                                         KASSERT(entry->wired_count == 1, ("bad wired_count on entry"));
2174                                         entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2175                                         entry->wired_count = 0;
2176                                         if (entry->end == save_end)
2177                                                 break;
2178                                         entry = entry->next;
2179                                         KASSERT(entry != &map->header, ("bad entry clip during backout"));
2180                                 }
2181                                 end = save_start;       /* unwire the rest */
2182                                 break;
2183                         }
2184                         /*
2185                          * note that even though the entry might have been
2186                          * clipped, the USER_WIRED flag we set prevents
2187                          * duplication so we do not have to do a 
2188                          * clip check.
2189                          */
2190                         entry = entry->next;
2191                 }
2192
2193                 /*
2194                  * If we failed fall through to the unwiring section to
2195                  * unwire what we had wired so far.  'end' has already
2196                  * been adjusted.
2197                  */
2198                 if (rv)
2199                         new_pageable = 1;
2200
2201                 /*
2202                  * start_entry might have been clipped if we unlocked the
2203                  * map and blocked.  No matter how clipped it has gotten
2204                  * there should be a fragment that is on our start boundary.
2205                  */
2206                 CLIP_CHECK_BACK(start_entry, start);
2207         }
2208
2209         /*
2210          * Deal with the unwiring case.
2211          */
2212         if (new_pageable) {
2213                 /*
2214                  * This is the unwiring case.  We must first ensure that the
2215                  * range to be unwired is really wired down.  We know there
2216                  * are no holes.
2217                  */
2218                 entry = start_entry;
2219                 while ((entry != &map->header) && (entry->start < end)) {
2220                         if ((entry->eflags & MAP_ENTRY_USER_WIRED) == 0) {
2221                                 rv = KERN_INVALID_ARGUMENT;
2222                                 goto done;
2223                         }
2224                         KASSERT(entry->wired_count != 0, ("wired count was 0 with USER_WIRED set! %p", entry));
2225                         entry = entry->next;
2226                 }
2227
2228                 /*
2229                  * Now decrement the wiring count for each region. If a region
2230                  * becomes completely unwired, unwire its physical pages and
2231                  * mappings.
2232                  */
2233                 /*
2234                  * The map entries are processed in a loop, checking to
2235                  * make sure the entry is wired and asserting it has a wired
2236                  * count. However, another loop was inserted more-or-less in
2237                  * the middle of the unwiring path. This loop picks up the
2238                  * "entry" loop variable from the first loop without first
2239                  * setting it to start_entry. Naturally, the secound loop
2240                  * is never entered and the pages backing the entries are
2241                  * never unwired. This can lead to a leak of wired pages.
2242                  */
2243                 entry = start_entry;
2244                 while ((entry != &map->header) && (entry->start < end)) {
2245                         KASSERT(entry->eflags & MAP_ENTRY_USER_WIRED,
2246                                 ("expected USER_WIRED on entry %p", entry));
2247                         entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2248                         entry->wired_count--;
2249                         if (entry->wired_count == 0)
2250                                 vm_fault_unwire(map, entry);
2251                         entry = entry->next;
2252                 }
2253         }
2254 done:
2255         vm_map_unclip_range(map, start_entry, start, real_end, &count,
2256                 MAP_CLIP_NO_HOLES);
2257         map->timestamp++;
2258         vm_map_unlock(map);
2259         vm_map_entry_release(count);
2260         return (rv);
2261 }
2262
2263 /*
2264  * Sets the pageability of the specified address range in the target map.
2265  * Regions specified as not pageable require locked-down physical
2266  * memory and physical page maps.
2267  *
2268  * The map must not be locked, but a reference must remain to the map
2269  * throughout the call.
2270  *
2271  * This function may be called via the zalloc path and must properly
2272  * reserve map entries for kernel_map.
2273  *
2274  * No requirements.
2275  */
2276 int
2277 vm_map_wire(vm_map_t map, vm_offset_t start, vm_offset_t real_end, int kmflags)
2278 {
2279         vm_map_entry_t entry;
2280         vm_map_entry_t start_entry;
2281         vm_offset_t end;
2282         int rv = KERN_SUCCESS;
2283         int count;
2284
2285         if (kmflags & KM_KRESERVE)
2286                 count = vm_map_entry_kreserve(MAP_RESERVE_COUNT);
2287         else
2288                 count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2289         vm_map_lock(map);
2290         VM_MAP_RANGE_CHECK(map, start, real_end);
2291         end = real_end;
2292
2293         start_entry = vm_map_clip_range(map, start, end, &count,
2294                                         MAP_CLIP_NO_HOLES);
2295         if (start_entry == NULL) {
2296                 vm_map_unlock(map);
2297                 rv = KERN_INVALID_ADDRESS;
2298                 goto failure;
2299         }
2300         if ((kmflags & KM_PAGEABLE) == 0) {
2301                 /*
2302                  * Wiring.  
2303                  *
2304                  * 1.  Holding the write lock, we create any shadow or zero-fill
2305                  * objects that need to be created. Then we clip each map
2306                  * entry to the region to be wired and increment its wiring
2307                  * count.  We create objects before clipping the map entries
2308                  * to avoid object proliferation.
2309                  *
2310                  * 2.  We downgrade to a read lock, and call vm_fault_wire to
2311                  * fault in the pages for any newly wired area (wired_count is
2312                  * 1).
2313                  *
2314                  * Downgrading to a read lock for vm_fault_wire avoids a 
2315                  * possible deadlock with another process that may have faulted
2316                  * on one of the pages to be wired (it would mark the page busy,
2317                  * blocking us, then in turn block on the map lock that we
2318                  * hold).  Because of problems in the recursive lock package,
2319                  * we cannot upgrade to a write lock in vm_map_lookup.  Thus,
2320                  * any actions that require the write lock must be done
2321                  * beforehand.  Because we keep the read lock on the map, the
2322                  * copy-on-write status of the entries we modify here cannot
2323                  * change.
2324                  */
2325                 entry = start_entry;
2326                 while ((entry != &map->header) && (entry->start < end)) {
2327                         /*
2328                          * Trivial case if the entry is already wired
2329                          */
2330                         if (entry->wired_count) {
2331                                 entry->wired_count++;
2332                                 entry = entry->next;
2333                                 continue;
2334                         }
2335
2336                         /*
2337                          * The entry is being newly wired, we have to setup
2338                          * appropriate management structures.  A shadow 
2339                          * object is required for a copy-on-write region,
2340                          * or a normal object for a zero-fill region.  We
2341                          * do not have to do this for entries that point to sub
2342                          * maps because we won't hold the lock on the sub map.
2343                          */
2344                         if (entry->maptype != VM_MAPTYPE_SUBMAP) {
2345                                 int copyflag = entry->eflags &
2346                                                MAP_ENTRY_NEEDS_COPY;
2347                                 if (copyflag && ((entry->protection &
2348                                                   VM_PROT_WRITE) != 0)) {
2349                                         vm_map_entry_shadow(entry, 0);
2350                                 } else if (entry->object.vm_object == NULL &&
2351                                            !map->system_map) {
2352                                         vm_map_entry_allocate_object(entry);
2353                                 }
2354                         }
2355
2356                         entry->wired_count++;
2357                         entry = entry->next;
2358                 }
2359
2360                 /*
2361                  * Pass 2.
2362                  */
2363
2364                 /*
2365                  * HACK HACK HACK HACK
2366                  *
2367                  * vm_fault_wire() temporarily unlocks the map to avoid
2368                  * deadlocks.  The in-transition flag from vm_map_clip_range
2369                  * call should protect us from changes while the map is
2370                  * unlocked.  T
2371                  *
2372                  * NOTE: Previously this comment stated that clipping might
2373                  *       still occur while the entry is unlocked, but from
2374                  *       what I can tell it actually cannot.
2375                  *
2376                  *       It is unclear whether the CLIP_CHECK_*() calls
2377                  *       are still needed but we keep them in anyway.
2378                  *
2379                  * HACK HACK HACK HACK
2380                  */
2381
2382                 entry = start_entry;
2383                 while (entry != &map->header && entry->start < end) {
2384                         /*
2385                          * If vm_fault_wire fails for any page we need to undo
2386                          * what has been done.  We decrement the wiring count
2387                          * for those pages which have not yet been wired (now)
2388                          * and unwire those that have (later).
2389                          */
2390                         vm_offset_t save_start = entry->start;
2391                         vm_offset_t save_end = entry->end;
2392
2393                         if (entry->wired_count == 1)
2394                                 rv = vm_fault_wire(map, entry, FALSE);
2395                         if (rv) {
2396                                 CLIP_CHECK_BACK(entry, save_start);
2397                                 for (;;) {
2398                                         KASSERT(entry->wired_count == 1, ("wired_count changed unexpectedly"));
2399                                         entry->wired_count = 0;
2400                                         if (entry->end == save_end)
2401                                                 break;
2402                                         entry = entry->next;
2403                                         KASSERT(entry != &map->header, ("bad entry clip during backout"));
2404                                 }
2405                                 end = save_start;
2406                                 break;
2407                         }
2408                         CLIP_CHECK_FWD(entry, save_end);
2409                         entry = entry->next;
2410                 }
2411
2412                 /*
2413                  * If a failure occured undo everything by falling through
2414                  * to the unwiring code.  'end' has already been adjusted
2415                  * appropriately.
2416                  */
2417                 if (rv)
2418                         kmflags |= KM_PAGEABLE;
2419
2420                 /*
2421                  * start_entry is still IN_TRANSITION but may have been 
2422                  * clipped since vm_fault_wire() unlocks and relocks the
2423                  * map.  No matter how clipped it has gotten there should
2424                  * be a fragment that is on our start boundary.
2425                  */
2426                 CLIP_CHECK_BACK(start_entry, start);
2427         }
2428
2429         if (kmflags & KM_PAGEABLE) {
2430                 /*
2431                  * This is the unwiring case.  We must first ensure that the
2432                  * range to be unwired is really wired down.  We know there
2433                  * are no holes.
2434                  */
2435                 entry = start_entry;
2436                 while ((entry != &map->header) && (entry->start < end)) {
2437                         if (entry->wired_count == 0) {
2438                                 rv = KERN_INVALID_ARGUMENT;
2439                                 goto done;
2440                         }
2441                         entry = entry->next;
2442                 }
2443
2444                 /*
2445                  * Now decrement the wiring count for each region. If a region
2446                  * becomes completely unwired, unwire its physical pages and
2447                  * mappings.
2448                  */
2449                 entry = start_entry;
2450                 while ((entry != &map->header) && (entry->start < end)) {
2451                         entry->wired_count--;
2452                         if (entry->wired_count == 0)
2453                                 vm_fault_unwire(map, entry);
2454                         entry = entry->next;
2455                 }
2456         }
2457 done:
2458         vm_map_unclip_range(map, start_entry, start, real_end,
2459                             &count, MAP_CLIP_NO_HOLES);
2460         map->timestamp++;
2461         vm_map_unlock(map);
2462 failure:
2463         if (kmflags & KM_KRESERVE)
2464                 vm_map_entry_krelease(count);
2465         else
2466                 vm_map_entry_release(count);
2467         return (rv);
2468 }
2469
2470 /*
2471  * Mark a newly allocated address range as wired but do not fault in
2472  * the pages.  The caller is expected to load the pages into the object.
2473  *
2474  * The map must be locked on entry and will remain locked on return.
2475  * No other requirements.
2476  */
2477 void
2478 vm_map_set_wired_quick(vm_map_t map, vm_offset_t addr, vm_size_t size,
2479                        int *countp)
2480 {
2481         vm_map_entry_t scan;
2482         vm_map_entry_t entry;
2483
2484         entry = vm_map_clip_range(map, addr, addr + size,
2485                                   countp, MAP_CLIP_NO_HOLES);
2486         for (scan = entry;
2487              scan != &map->header && scan->start < addr + size;
2488              scan = scan->next) {
2489             KKASSERT(scan->wired_count == 0);
2490             scan->wired_count = 1;
2491         }
2492         vm_map_unclip_range(map, entry, addr, addr + size,
2493                             countp, MAP_CLIP_NO_HOLES);
2494 }
2495
2496 /*
2497  * Push any dirty cached pages in the address range to their pager.
2498  * If syncio is TRUE, dirty pages are written synchronously.
2499  * If invalidate is TRUE, any cached pages are freed as well.
2500  *
2501  * This routine is called by sys_msync()
2502  *
2503  * Returns an error if any part of the specified range is not mapped.
2504  *
2505  * No requirements.
2506  */
2507 int
2508 vm_map_clean(vm_map_t map, vm_offset_t start, vm_offset_t end,
2509              boolean_t syncio, boolean_t invalidate)
2510 {
2511         vm_map_entry_t current;
2512         vm_map_entry_t entry;
2513         vm_size_t size;
2514         vm_object_t object;
2515         vm_object_t tobj;
2516         vm_ooffset_t offset;
2517
2518         vm_map_lock_read(map);
2519         VM_MAP_RANGE_CHECK(map, start, end);
2520         if (!vm_map_lookup_entry(map, start, &entry)) {
2521                 vm_map_unlock_read(map);
2522                 return (KERN_INVALID_ADDRESS);
2523         }
2524         lwkt_gettoken(&map->token);
2525
2526         /*
2527          * Make a first pass to check for holes.
2528          */
2529         for (current = entry; current->start < end; current = current->next) {
2530                 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2531                         lwkt_reltoken(&map->token);
2532                         vm_map_unlock_read(map);
2533                         return (KERN_INVALID_ARGUMENT);
2534                 }
2535                 if (end > current->end &&
2536                     (current->next == &map->header ||
2537                         current->end != current->next->start)) {
2538                         lwkt_reltoken(&map->token);
2539                         vm_map_unlock_read(map);
2540                         return (KERN_INVALID_ADDRESS);
2541                 }
2542         }
2543
2544         if (invalidate)
2545                 pmap_remove(vm_map_pmap(map), start, end);
2546
2547         /*
2548          * Make a second pass, cleaning/uncaching pages from the indicated
2549          * objects as we go.
2550          */
2551         for (current = entry; current->start < end; current = current->next) {
2552                 offset = current->offset + (start - current->start);
2553                 size = (end <= current->end ? end : current->end) - start;
2554                 if (current->maptype == VM_MAPTYPE_SUBMAP) {
2555                         vm_map_t smap;
2556                         vm_map_entry_t tentry;
2557                         vm_size_t tsize;
2558
2559                         smap = current->object.sub_map;
2560                         vm_map_lock_read(smap);
2561                         vm_map_lookup_entry(smap, offset, &tentry);
2562                         tsize = tentry->end - offset;
2563                         if (tsize < size)
2564                                 size = tsize;
2565                         object = tentry->object.vm_object;
2566                         offset = tentry->offset + (offset - tentry->start);
2567                         vm_map_unlock_read(smap);
2568                 } else {
2569                         object = current->object.vm_object;
2570                 }
2571
2572                 if (object)
2573                         vm_object_hold(object);
2574
2575                 /*
2576                  * Note that there is absolutely no sense in writing out
2577                  * anonymous objects, so we track down the vnode object
2578                  * to write out.
2579                  * We invalidate (remove) all pages from the address space
2580                  * anyway, for semantic correctness.
2581                  *
2582                  * note: certain anonymous maps, such as MAP_NOSYNC maps,
2583                  * may start out with a NULL object.
2584                  */
2585                 while (object && (tobj = object->backing_object) != NULL) {
2586                         vm_object_hold(tobj);
2587                         if (tobj == object->backing_object) {
2588                                 vm_object_lock_swap();
2589                                 offset += object->backing_object_offset;
2590                                 vm_object_drop(object);
2591                                 object = tobj;
2592                                 if (object->size < OFF_TO_IDX(offset + size))
2593                                         size = IDX_TO_OFF(object->size) -
2594                                                offset;
2595                                 break;
2596                         }
2597                         vm_object_drop(tobj);
2598                 }
2599                 if (object && (object->type == OBJT_VNODE) && 
2600                     (current->protection & VM_PROT_WRITE) &&
2601                     (object->flags & OBJ_NOMSYNC) == 0) {
2602                         /*
2603                          * Flush pages if writing is allowed, invalidate them
2604                          * if invalidation requested.  Pages undergoing I/O
2605                          * will be ignored by vm_object_page_remove().
2606                          *
2607                          * We cannot lock the vnode and then wait for paging
2608                          * to complete without deadlocking against vm_fault.
2609                          * Instead we simply call vm_object_page_remove() and
2610                          * allow it to block internally on a page-by-page 
2611                          * basis when it encounters pages undergoing async 
2612                          * I/O.
2613                          */
2614                         int flags;
2615
2616                         /* no chain wait needed for vnode objects */
2617                         vm_object_reference_locked(object);
2618                         vn_lock(object->handle, LK_EXCLUSIVE | LK_RETRY);
2619                         flags = (syncio || invalidate) ? OBJPC_SYNC : 0;
2620                         flags |= invalidate ? OBJPC_INVAL : 0;
2621
2622                         /*
2623                          * When operating on a virtual page table just
2624                          * flush the whole object.  XXX we probably ought
2625                          * to 
2626                          */
2627                         switch(current->maptype) {
2628                         case VM_MAPTYPE_NORMAL:
2629                                 vm_object_page_clean(object,
2630                                     OFF_TO_IDX(offset),
2631                                     OFF_TO_IDX(offset + size + PAGE_MASK),
2632                                     flags);
2633                                 break;
2634                         case VM_MAPTYPE_VPAGETABLE:
2635                                 vm_object_page_clean(object, 0, 0, flags);
2636                                 break;
2637                         }
2638                         vn_unlock(((struct vnode *)object->handle));
2639                         vm_object_deallocate_locked(object);
2640                 }
2641                 if (object && invalidate &&
2642                    ((object->type == OBJT_VNODE) ||
2643                     (object->type == OBJT_DEVICE))) {
2644                         int clean_only = 
2645                                 (object->type == OBJT_DEVICE) ? FALSE : TRUE;
2646                         /* no chain wait needed for vnode/device objects */
2647                         vm_object_reference_locked(object);
2648                         switch(current->maptype) {
2649                         case VM_MAPTYPE_NORMAL:
2650                                 vm_object_page_remove(object,
2651                                     OFF_TO_IDX(offset),
2652                                     OFF_TO_IDX(offset + size + PAGE_MASK),
2653                                     clean_only);
2654                                 break;
2655                         case VM_MAPTYPE_VPAGETABLE:
2656                                 vm_object_page_remove(object, 0, 0, clean_only);
2657                                 break;
2658                         }
2659                         vm_object_deallocate_locked(object);
2660                 }
2661                 start += size;
2662                 if (object)
2663                         vm_object_drop(object);
2664         }
2665
2666         lwkt_reltoken(&map->token);
2667         vm_map_unlock_read(map);
2668
2669         return (KERN_SUCCESS);
2670 }
2671
2672 /*
2673  * Make the region specified by this entry pageable.
2674  *
2675  * The vm_map must be exclusively locked.
2676  */
2677 static void 
2678 vm_map_entry_unwire(vm_map_t map, vm_map_entry_t entry)
2679 {
2680         entry->eflags &= ~MAP_ENTRY_USER_WIRED;
2681         entry->wired_count = 0;
2682         vm_fault_unwire(map, entry);
2683 }
2684
2685 /*
2686  * Deallocate the given entry from the target map.
2687  *
2688  * The vm_map must be exclusively locked.
2689  */
2690 static void
2691 vm_map_entry_delete(vm_map_t map, vm_map_entry_t entry, int *countp)
2692 {
2693         vm_map_entry_unlink(map, entry);
2694         map->size -= entry->end - entry->start;
2695
2696         switch(entry->maptype) {
2697         case VM_MAPTYPE_NORMAL:
2698         case VM_MAPTYPE_VPAGETABLE:
2699                 vm_object_deallocate(entry->object.vm_object);
2700                 break;
2701         default:
2702                 break;
2703         }
2704
2705         vm_map_entry_dispose(map, entry, countp);
2706 }
2707
2708 /*
2709  * Deallocates the given address range from the target map.
2710  *
2711  * The vm_map must be exclusively locked.
2712  */
2713 int
2714 vm_map_delete(vm_map_t map, vm_offset_t start, vm_offset_t end, int *countp)
2715 {
2716         vm_object_t object;
2717         vm_map_entry_t entry;
2718         vm_map_entry_t first_entry;
2719
2720         ASSERT_VM_MAP_LOCKED(map);
2721         lwkt_gettoken(&map->token);
2722 again:
2723         /*
2724          * Find the start of the region, and clip it.  Set entry to point
2725          * at the first record containing the requested address or, if no
2726          * such record exists, the next record with a greater address.  The
2727          * loop will run from this point until a record beyond the termination
2728          * address is encountered.
2729          *
2730          * map->hint must be adjusted to not point to anything we delete,
2731          * so set it to the entry prior to the one being deleted.
2732          *
2733          * GGG see other GGG comment.
2734          */
2735         if (vm_map_lookup_entry(map, start, &first_entry)) {
2736                 entry = first_entry;
2737                 vm_map_clip_start(map, entry, start, countp);
2738                 map->hint = entry->prev;        /* possible problem XXX */
2739         } else {
2740                 map->hint = first_entry;        /* possible problem XXX */
2741                 entry = first_entry->next;
2742         }
2743
2744         /*
2745          * If a hole opens up prior to the current first_free then
2746          * adjust first_free.  As with map->hint, map->first_free
2747          * cannot be left set to anything we might delete.
2748          */
2749         if (entry == &map->header) {
2750                 map->first_free = &map->header;
2751         } else if (map->first_free->start >= start) {
2752                 map->first_free = entry->prev;
2753         }
2754
2755         /*
2756          * Step through all entries in this region
2757          */
2758         while ((entry != &map->header) && (entry->start < end)) {
2759                 vm_map_entry_t next;
2760                 vm_offset_t s, e;
2761                 vm_pindex_t offidxstart, offidxend, count;
2762
2763                 /*
2764                  * If we hit an in-transition entry we have to sleep and
2765                  * retry.  It's easier (and not really slower) to just retry
2766                  * since this case occurs so rarely and the hint is already
2767                  * pointing at the right place.  We have to reset the
2768                  * start offset so as not to accidently delete an entry
2769                  * another process just created in vacated space.
2770                  */
2771                 if (entry->eflags & MAP_ENTRY_IN_TRANSITION) {
2772                         entry->eflags |= MAP_ENTRY_NEEDS_WAKEUP;
2773                         start = entry->start;
2774                         ++mycpu->gd_cnt.v_intrans_coll;
2775                         ++mycpu->gd_cnt.v_intrans_wait;
2776                         vm_map_transition_wait(map);
2777                         goto again;
2778                 }
2779                 vm_map_clip_end(map, entry, end, countp);
2780
2781                 s = entry->start;
2782                 e = entry->end;
2783                 next = entry->next;
2784
2785                 offidxstart = OFF_TO_IDX(entry->offset);
2786                 count = OFF_TO_IDX(e - s);
2787                 object = entry->object.vm_object;
2788
2789                 /*
2790                  * Unwire before removing addresses from the pmap; otherwise,
2791                  * unwiring will put the entries back in the pmap.
2792                  */
2793                 if (entry->wired_count != 0)
2794                         vm_map_entry_unwire(map, entry);
2795
2796                 offidxend = offidxstart + count;
2797
2798                 if (object == &kernel_object) {
2799                         vm_object_hold(object);
2800                         vm_object_page_remove(object, offidxstart,
2801                                               offidxend, FALSE);
2802                         vm_object_drop(object);
2803                 } else if (object && object->type != OBJT_DEFAULT &&
2804                            object->type != OBJT_SWAP) {
2805                         /*
2806                          * vnode object routines cannot be chain-locked
2807                          */
2808                         vm_object_hold(object);
2809                         pmap_remove(map->pmap, s, e);
2810                         vm_object_drop(object);
2811                 } else if (object) {
2812                         vm_object_hold(object);
2813                         vm_object_chain_acquire(object);
2814                         pmap_remove(map->pmap, s, e);
2815
2816                         if (object != NULL &&
2817                             object->ref_count != 1 &&
2818                             (object->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) ==
2819                              OBJ_ONEMAPPING &&
2820                             (object->type == OBJT_DEFAULT ||
2821                              object->type == OBJT_SWAP)) {
2822                                 vm_object_collapse(object, NULL);
2823                                 vm_object_page_remove(object, offidxstart,
2824                                                       offidxend, FALSE);
2825                                 if (object->type == OBJT_SWAP) {
2826                                         swap_pager_freespace(object,
2827                                                              offidxstart,
2828                                                              count);
2829                                 }
2830                                 if (offidxend >= object->size &&
2831                                     offidxstart < object->size) {
2832                                         object->size = offidxstart;
2833                                 }
2834                         }
2835                         vm_object_chain_release(object);
2836                         vm_object_drop(object);
2837                 }
2838
2839                 /*
2840                  * Delete the entry (which may delete the object) only after
2841                  * removing all pmap entries pointing to its pages.
2842                  * (Otherwise, its page frames may be reallocated, and any
2843                  * modify bits will be set in the wrong object!)
2844                  */
2845                 vm_map_entry_delete(map, entry, countp);
2846                 entry = next;
2847         }
2848         lwkt_reltoken(&map->token);
2849         return (KERN_SUCCESS);
2850 }
2851
2852 /*
2853  * Remove the given address range from the target map.
2854  * This is the exported form of vm_map_delete.
2855  *
2856  * No requirements.
2857  */
2858 int
2859 vm_map_remove(vm_map_t map, vm_offset_t start, vm_offset_t end)
2860 {
2861         int result;
2862         int count;
2863
2864         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
2865         vm_map_lock(map);
2866         VM_MAP_RANGE_CHECK(map, start, end);
2867         result = vm_map_delete(map, start, end, &count);
2868         vm_map_unlock(map);
2869         vm_map_entry_release(count);
2870
2871         return (result);
2872 }
2873
2874 /*
2875  * Assert that the target map allows the specified privilege on the
2876  * entire address region given.  The entire region must be allocated.
2877  *
2878  * The caller must specify whether the vm_map is already locked or not.
2879  */
2880 boolean_t
2881 vm_map_check_protection(vm_map_t map, vm_offset_t start, vm_offset_t end,
2882                         vm_prot_t protection, boolean_t have_lock)
2883 {
2884         vm_map_entry_t entry;
2885         vm_map_entry_t tmp_entry;
2886         boolean_t result;
2887
2888         if (have_lock == FALSE)
2889                 vm_map_lock_read(map);
2890
2891         if (!vm_map_lookup_entry(map, start, &tmp_entry)) {
2892                 if (have_lock == FALSE)
2893                         vm_map_unlock_read(map);
2894                 return (FALSE);
2895         }
2896         entry = tmp_entry;
2897
2898         result = TRUE;
2899         while (start < end) {
2900                 if (entry == &map->header) {
2901                         result = FALSE;
2902                         break;
2903                 }
2904                 /*
2905                  * No holes allowed!
2906                  */
2907
2908                 if (start < entry->start) {
2909                         result = FALSE;
2910                         break;
2911                 }
2912                 /*
2913                  * Check protection associated with entry.
2914                  */
2915
2916                 if ((entry->protection & protection) != protection) {
2917                         result = FALSE;
2918                         break;
2919                 }
2920                 /* go to next entry */
2921
2922                 start = entry->end;
2923                 entry = entry->next;
2924         }
2925         if (have_lock == FALSE)
2926                 vm_map_unlock_read(map);
2927         return (result);
2928 }
2929
2930 /*
2931  * If appropriate this function shadows the original object with a new object
2932  * and moves the VM pages from the original object to the new object.
2933  * The original object will also be collapsed, if possible.
2934  *
2935  * We can only do this for normal memory objects with a single mapping, and
2936  * it only makes sense to do it if there are 2 or more refs on the original
2937  * object.  i.e. typically a memory object that has been extended into
2938  * multiple vm_map_entry's with non-overlapping ranges.
2939  *
2940  * This makes it easier to remove unused pages and keeps object inheritance
2941  * from being a negative impact on memory usage.
2942  *
2943  * On return the (possibly new) entry->object.vm_object will have an
2944  * additional ref on it for the caller to dispose of (usually by cloning
2945  * the vm_map_entry).  The additional ref had to be done in this routine
2946  * to avoid racing a collapse.  The object's ONEMAPPING flag will also be
2947  * cleared.
2948  *
2949  * The vm_map must be locked and its token held.
2950  */
2951 static void
2952 vm_map_split(vm_map_entry_t entry)
2953 {
2954 #if 0
2955         /* UNOPTIMIZED */
2956         vm_object_t oobject;
2957
2958         oobject = entry->object.vm_object;
2959         vm_object_hold(oobject);
2960         vm_object_chain_wait(oobject);
2961         vm_object_reference_locked(oobject);
2962         vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
2963         vm_object_drop(oobject);
2964 #else
2965         /* OPTIMIZED */
2966         vm_object_t oobject, nobject, bobject;
2967         vm_offset_t s, e;
2968         vm_page_t m;
2969         vm_pindex_t offidxstart, offidxend, idx;
2970         vm_size_t size;
2971         vm_ooffset_t offset;
2972
2973         /*
2974          * Setup.  Chain lock the original object throughout the entire
2975          * routine to prevent new page faults from occuring.
2976          *
2977          * XXX can madvise WILLNEED interfere with us too?
2978          */
2979         oobject = entry->object.vm_object;
2980         vm_object_hold(oobject);
2981         vm_object_chain_acquire(oobject);
2982
2983         /*
2984          * Original object cannot be split?
2985          */
2986         if (oobject->handle == NULL || (oobject->type != OBJT_DEFAULT &&
2987                                         oobject->type != OBJT_SWAP)) {
2988                 vm_object_chain_release(oobject);
2989                 vm_object_reference_locked(oobject);
2990                 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
2991                 vm_object_drop(oobject);
2992                 return;
2993         }
2994
2995         /*
2996          * Collapse original object with its backing store as an
2997          * optimization to reduce chain lengths when possible.
2998          *
2999          * If ref_count <= 1 there aren't other non-overlapping vm_map_entry's
3000          * for oobject, so there's no point collapsing it.
3001          *
3002          * Then re-check whether the object can be split.
3003          */
3004         vm_object_collapse(oobject, NULL);
3005
3006         if (oobject->ref_count <= 1 ||
3007             (oobject->type != OBJT_DEFAULT && oobject->type != OBJT_SWAP) ||
3008             (oobject->flags & (OBJ_NOSPLIT|OBJ_ONEMAPPING)) != OBJ_ONEMAPPING) {
3009                 vm_object_chain_release(oobject);
3010                 vm_object_reference_locked(oobject);
3011                 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3012                 vm_object_drop(oobject);
3013                 return;
3014         }
3015
3016         /*
3017          * Acquire the chain lock on the backing object.
3018          *
3019          * Give bobject an additional ref count for when it will be shadowed
3020          * by nobject.
3021          */
3022         if ((bobject = oobject->backing_object) != NULL) {
3023                 vm_object_hold(bobject);
3024                 vm_object_chain_wait(bobject);
3025                 vm_object_reference_locked(bobject);
3026                 vm_object_chain_acquire(bobject);
3027                 KKASSERT(bobject->backing_object == bobject);
3028                 KKASSERT((bobject->flags & OBJ_DEAD) == 0);
3029         }
3030
3031         /*
3032          * Calculate the object page range and allocate the new object.
3033          */
3034         offset = entry->offset;
3035         s = entry->start;
3036         e = entry->end;
3037
3038         offidxstart = OFF_TO_IDX(offset);
3039         offidxend = offidxstart + OFF_TO_IDX(e - s);
3040         size = offidxend - offidxstart;
3041
3042         switch(oobject->type) {
3043         case OBJT_DEFAULT:
3044                 nobject = default_pager_alloc(NULL, IDX_TO_OFF(size),
3045                                               VM_PROT_ALL, 0);
3046                 break;
3047         case OBJT_SWAP:
3048                 nobject = swap_pager_alloc(NULL, IDX_TO_OFF(size),
3049                                            VM_PROT_ALL, 0);
3050                 break;
3051         default:
3052                 /* not reached */
3053                 nobject = NULL;
3054                 KKASSERT(0);
3055         }
3056
3057         if (nobject == NULL) {
3058                 if (bobject) {
3059                         vm_object_chain_release(bobject);
3060                         vm_object_deallocate(bobject);
3061                         vm_object_drop(bobject);
3062                 }
3063                 vm_object_chain_release(oobject);
3064                 vm_object_reference_locked(oobject);
3065                 vm_object_clear_flag(oobject, OBJ_ONEMAPPING);
3066                 vm_object_drop(oobject);
3067                 return;
3068         }
3069
3070         /*
3071          * The new object will replace entry->object.vm_object so it needs
3072          * a second reference (the caller expects an additional ref).
3073          */
3074         vm_object_hold(nobject);
3075         vm_object_reference_locked(nobject);
3076         vm_object_chain_acquire(nobject);
3077
3078         /*
3079          * nobject shadows bobject (oobject already shadows bobject).
3080          */
3081         if (bobject) {
3082                 nobject->backing_object_offset =
3083                     oobject->backing_object_offset + IDX_TO_OFF(offidxstart);
3084                 nobject->backing_object = bobject;
3085                 bobject->shadow_count++;
3086                 bobject->generation++;
3087                 LIST_INSERT_HEAD(&bobject->shadow_head, nobject, shadow_list);
3088                 vm_object_clear_flag(bobject, OBJ_ONEMAPPING); /* XXX? */
3089                 vm_object_chain_release(bobject);
3090                 vm_object_drop(bobject);
3091         }
3092
3093         /*
3094          * Move the VM pages from oobject to nobject
3095          */
3096         for (idx = 0; idx < size; idx++) {
3097                 vm_page_t m;
3098
3099                 m = vm_page_lookup_busy_wait(oobject, offidxstart + idx,
3100                                              TRUE, "vmpg");
3101                 if (m == NULL)
3102                         continue;
3103
3104                 /*
3105                  * We must wait for pending I/O to complete before we can
3106                  * rename the page.
3107                  *
3108                  * We do not have to VM_PROT_NONE the page as mappings should
3109                  * not be changed by this operation.
3110                  *
3111                  * NOTE: The act of renaming a page updates chaingen for both
3112                  *       objects.
3113                  */
3114                 vm_page_rename(m, nobject, idx);
3115                 /* page automatically made dirty by rename and cache handled */
3116                 /* page remains busy */
3117         }
3118
3119         if (oobject->type == OBJT_SWAP) {
3120                 vm_object_pip_add(oobject, 1);
3121                 /*
3122                  * copy oobject pages into nobject and destroy unneeded
3123                  * pages in shadow object.
3124                  */
3125                 swap_pager_copy(oobject, nobject, offidxstart, 0);
3126                 vm_object_pip_wakeup(oobject);
3127         }
3128
3129         /*
3130          * Wakeup the pages we played with.  No spl protection is needed
3131          * for a simple wakeup.
3132          */
3133         for (idx = 0; idx < size; idx++) {
3134                 m = vm_page_lookup(nobject, idx);
3135                 if (m) {
3136                         KKASSERT(m->flags & PG_BUSY);
3137                         vm_page_wakeup(m);
3138                 }
3139         }
3140         entry->object.vm_object = nobject;
3141         entry->offset = 0LL;
3142
3143         /*
3144          * Cleanup
3145          *
3146          * NOTE: There is no need to remove OBJ_ONEMAPPING from oobject, the
3147          *       related pages were moved and are no longer applicable to the
3148          *       original object.
3149          *
3150          * NOTE: Deallocate oobject (due to its entry->object.vm_object being
3151          *       replaced by nobject).
3152          */
3153         vm_object_chain_release(nobject);
3154         vm_object_drop(nobject);
3155         if (bobject) {
3156                 vm_object_chain_release(bobject);
3157                 vm_object_drop(bobject);
3158         }
3159         vm_object_chain_release(oobject);
3160         /*vm_object_clear_flag(oobject, OBJ_ONEMAPPING);*/
3161         vm_object_deallocate_locked(oobject);
3162         vm_object_drop(oobject);
3163 #endif
3164 }
3165
3166 /*
3167  * Copies the contents of the source entry to the destination
3168  * entry.  The entries *must* be aligned properly.
3169  *
3170  * The vm_maps must be exclusively locked.
3171  * The vm_map's token must be held.
3172  *
3173  * Because the maps are locked no faults can be in progress during the
3174  * operation.
3175  */
3176 static void
3177 vm_map_copy_entry(vm_map_t src_map, vm_map_t dst_map,
3178                   vm_map_entry_t src_entry, vm_map_entry_t dst_entry)
3179 {
3180         vm_object_t src_object;
3181
3182         if (dst_entry->maptype == VM_MAPTYPE_SUBMAP)
3183                 return;
3184         if (src_entry->maptype == VM_MAPTYPE_SUBMAP)
3185                 return;
3186
3187         if (src_entry->wired_count == 0) {
3188                 /*
3189                  * If the source entry is marked needs_copy, it is already
3190                  * write-protected.
3191                  */
3192                 if ((src_entry->eflags & MAP_ENTRY_NEEDS_COPY) == 0) {
3193                         pmap_protect(src_map->pmap,
3194                             src_entry->start,
3195                             src_entry->end,
3196                             src_entry->protection & ~VM_PROT_WRITE);
3197                 }
3198
3199                 /*
3200                  * Make a copy of the object.
3201                  *
3202                  * The object must be locked prior to checking the object type
3203                  * and for the call to vm_object_collapse() and vm_map_split().
3204                  * We cannot use *_hold() here because the split code will
3205                  * probably try to destroy the object.  The lock is a pool
3206                  * token and doesn't care.
3207                  *
3208                  * We must bump src_map->timestamp when setting
3209                  * MAP_ENTRY_NEEDS_COPY to force any concurrent fault
3210                  * to retry, otherwise the concurrent fault might improperly
3211                  * install a RW pte when its supposed to be a RO(COW) pte.
3212                  * This race can occur because a vnode-backed fault may have
3213                  * to temporarily release the map lock.
3214                  */
3215                 if (src_entry->object.vm_object != NULL) {
3216                         vm_map_split(src_entry);
3217                         src_object = src_entry->object.vm_object;
3218                         dst_entry->object.vm_object = src_object;
3219                         src_entry->eflags |= (MAP_ENTRY_COW |
3220                                               MAP_ENTRY_NEEDS_COPY);
3221                         dst_entry->eflags |= (MAP_ENTRY_COW |
3222                                               MAP_ENTRY_NEEDS_COPY);
3223                         dst_entry->offset = src_entry->offset;
3224                         ++src_map->timestamp;
3225                 } else {
3226                         dst_entry->object.vm_object = NULL;
3227                         dst_entry->offset = 0;
3228                 }
3229
3230                 pmap_copy(dst_map->pmap, src_map->pmap, dst_entry->start,
3231                     dst_entry->end - dst_entry->start, src_entry->start);
3232         } else {
3233                 /*
3234                  * Of course, wired down pages can't be set copy-on-write.
3235                  * Cause wired pages to be copied into the new map by
3236                  * simulating faults (the new pages are pageable)
3237                  */
3238                 vm_fault_copy_entry(dst_map, src_map, dst_entry, src_entry);
3239         }
3240 }
3241
3242 /*
3243  * vmspace_fork:
3244  * Create a new process vmspace structure and vm_map
3245  * based on those of an existing process.  The new map
3246  * is based on the old map, according to the inheritance
3247  * values on the regions in that map.
3248  *
3249  * The source map must not be locked.
3250  * No requirements.
3251  */
3252 struct vmspace *
3253 vmspace_fork(struct vmspace *vm1)
3254 {
3255         struct vmspace *vm2;
3256         vm_map_t old_map = &vm1->vm_map;
3257         vm_map_t new_map;
3258         vm_map_entry_t old_entry;
3259         vm_map_entry_t new_entry;
3260         vm_object_t object;
3261         int count;
3262
3263         lwkt_gettoken(&vm1->vm_map.token);
3264         vm_map_lock(old_map);
3265
3266         vm2 = vmspace_alloc(old_map->min_offset, old_map->max_offset);
3267         lwkt_gettoken(&vm2->vm_map.token);
3268         bcopy(&vm1->vm_startcopy, &vm2->vm_startcopy,
3269             (caddr_t)&vm1->vm_endcopy - (caddr_t)&vm1->vm_startcopy);
3270         new_map = &vm2->vm_map; /* XXX */
3271         new_map->timestamp = 1;
3272
3273         vm_map_lock(new_map);
3274
3275         count = 0;
3276         old_entry = old_map->header.next;
3277         while (old_entry != &old_map->header) {
3278                 ++count;
3279                 old_entry = old_entry->next;
3280         }
3281
3282         count = vm_map_entry_reserve(count + MAP_RESERVE_COUNT);
3283
3284         old_entry = old_map->header.next;
3285         while (old_entry != &old_map->header) {
3286                 if (old_entry->maptype == VM_MAPTYPE_SUBMAP)
3287                         panic("vm_map_fork: encountered a submap");
3288
3289                 switch (old_entry->inheritance) {
3290                 case VM_INHERIT_NONE:
3291                         break;
3292                 case VM_INHERIT_SHARE:
3293                         /*
3294                          * Clone the entry, creating the shared object if
3295                          * necessary.
3296                          */
3297                         if (old_entry->object.vm_object == NULL)
3298                                 vm_map_entry_allocate_object(old_entry);
3299
3300                         if (old_entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3301                                 /*
3302                                  * Shadow a map_entry which needs a copy,
3303                                  * replacing its object with a new object
3304                                  * that points to the old one.  Ask the
3305                                  * shadow code to automatically add an
3306                                  * additional ref.  We can't do it afterwords
3307                                  * because we might race a collapse.  The call
3308                                  * to vm_map_entry_shadow() will also clear
3309                                  * OBJ_ONEMAPPING.
3310                                  */
3311                                 vm_map_entry_shadow(old_entry, 1);
3312                         } else {
3313                                 /*
3314                                  * We will make a shared copy of the object,
3315                                  * and must clear OBJ_ONEMAPPING.
3316                                  *
3317                                  * XXX assert that object.vm_object != NULL
3318                                  *     since we allocate it above.
3319                                  */
3320                                 if (old_entry->object.vm_object) {
3321                                         object = old_entry->object.vm_object;
3322                                         vm_object_hold(object);
3323                                         vm_object_chain_wait(object);
3324                                         vm_object_reference_locked(object);
3325                                         vm_object_clear_flag(object,
3326                                                              OBJ_ONEMAPPING);
3327                                         vm_object_drop(object);
3328                                 }
3329                         }
3330
3331                         /*
3332                          * Clone the entry.  We've already bumped the ref on
3333                          * any vm_object.
3334                          */
3335                         new_entry = vm_map_entry_create(new_map, &count);
3336                         *new_entry = *old_entry;
3337                         new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3338                         new_entry->wired_count = 0;
3339
3340                         /*
3341                          * Insert the entry into the new map -- we know we're
3342                          * inserting at the end of the new map.
3343                          */
3344
3345                         vm_map_entry_link(new_map, new_map->header.prev,
3346                                           new_entry);
3347
3348                         /*
3349                          * Update the physical map
3350                          */
3351                         pmap_copy(new_map->pmap, old_map->pmap,
3352                             new_entry->start,
3353                             (old_entry->end - old_entry->start),
3354                             old_entry->start);
3355                         break;
3356                 case VM_INHERIT_COPY:
3357                         /*
3358                          * Clone the entry and link into the map.
3359                          */
3360                         new_entry = vm_map_entry_create(new_map, &count);
3361                         *new_entry = *old_entry;
3362                         new_entry->eflags &= ~MAP_ENTRY_USER_WIRED;
3363                         new_entry->wired_count = 0;
3364                         new_entry->object.vm_object = NULL;
3365                         vm_map_entry_link(new_map, new_map->header.prev,
3366                                           new_entry);
3367                         vm_map_copy_entry(old_map, new_map, old_entry,
3368                                           new_entry);
3369                         break;
3370                 }
3371                 old_entry = old_entry->next;
3372         }
3373
3374         new_map->size = old_map->size;
3375         vm_map_unlock(old_map);
3376         vm_map_unlock(new_map);
3377         vm_map_entry_release(count);
3378
3379         lwkt_reltoken(&vm2->vm_map.token);
3380         lwkt_reltoken(&vm1->vm_map.token);
3381
3382         return (vm2);
3383 }
3384
3385 /*
3386  * Create an auto-grow stack entry
3387  *
3388  * No requirements.
3389  */
3390 int
3391 vm_map_stack (vm_map_t map, vm_offset_t addrbos, vm_size_t max_ssize,
3392               int flags, vm_prot_t prot, vm_prot_t max, int cow)
3393 {
3394         vm_map_entry_t  prev_entry;
3395         vm_map_entry_t  new_stack_entry;
3396         vm_size_t       init_ssize;
3397         int             rv;
3398         int             count;
3399         vm_offset_t     tmpaddr;
3400
3401         cow |= MAP_IS_STACK;
3402
3403         if (max_ssize < sgrowsiz)
3404                 init_ssize = max_ssize;
3405         else
3406                 init_ssize = sgrowsiz;
3407
3408         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3409         vm_map_lock(map);
3410
3411         /*
3412          * Find space for the mapping
3413          */
3414         if ((flags & (MAP_FIXED | MAP_TRYFIXED)) == 0) {
3415                 if (vm_map_findspace(map, addrbos, max_ssize, 1,
3416                                      flags, &tmpaddr)) {
3417                         vm_map_unlock(map);
3418                         vm_map_entry_release(count);
3419                         return (KERN_NO_SPACE);
3420                 }
3421                 addrbos = tmpaddr;
3422         }
3423
3424         /* If addr is already mapped, no go */
3425         if (vm_map_lookup_entry(map, addrbos, &prev_entry)) {
3426                 vm_map_unlock(map);
3427                 vm_map_entry_release(count);
3428                 return (KERN_NO_SPACE);
3429         }
3430
3431 #if 0
3432         /* XXX already handled by kern_mmap() */
3433         /* If we would blow our VMEM resource limit, no go */
3434         if (map->size + init_ssize >
3435             curproc->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3436                 vm_map_unlock(map);
3437                 vm_map_entry_release(count);
3438                 return (KERN_NO_SPACE);
3439         }
3440 #endif
3441
3442         /*
3443          * If we can't accomodate max_ssize in the current mapping,
3444          * no go.  However, we need to be aware that subsequent user
3445          * mappings might map into the space we have reserved for
3446          * stack, and currently this space is not protected.  
3447          * 
3448          * Hopefully we will at least detect this condition 
3449          * when we try to grow the stack.
3450          */
3451         if ((prev_entry->next != &map->header) &&
3452             (prev_entry->next->start < addrbos + max_ssize)) {
3453                 vm_map_unlock(map);
3454                 vm_map_entry_release(count);
3455                 return (KERN_NO_SPACE);
3456         }
3457
3458         /*
3459          * We initially map a stack of only init_ssize.  We will
3460          * grow as needed later.  Since this is to be a grow 
3461          * down stack, we map at the top of the range.
3462          *
3463          * Note: we would normally expect prot and max to be
3464          * VM_PROT_ALL, and cow to be 0.  Possibly we should
3465          * eliminate these as input parameters, and just
3466          * pass these values here in the insert call.
3467          */
3468         rv = vm_map_insert(map, &count,
3469                            NULL, 0, addrbos + max_ssize - init_ssize,
3470                            addrbos + max_ssize,
3471                            VM_MAPTYPE_NORMAL,
3472                            prot, max,
3473                            cow);
3474
3475         /* Now set the avail_ssize amount */
3476         if (rv == KERN_SUCCESS) {
3477                 if (prev_entry != &map->header)
3478                         vm_map_clip_end(map, prev_entry, addrbos + max_ssize - init_ssize, &count);
3479                 new_stack_entry = prev_entry->next;
3480                 if (new_stack_entry->end   != addrbos + max_ssize ||
3481                     new_stack_entry->start != addrbos + max_ssize - init_ssize)
3482                         panic ("Bad entry start/end for new stack entry");
3483                 else 
3484                         new_stack_entry->aux.avail_ssize = max_ssize - init_ssize;
3485         }
3486
3487         vm_map_unlock(map);
3488         vm_map_entry_release(count);
3489         return (rv);
3490 }
3491
3492 /*
3493  * Attempts to grow a vm stack entry.  Returns KERN_SUCCESS if the
3494  * desired address is already mapped, or if we successfully grow
3495  * the stack.  Also returns KERN_SUCCESS if addr is outside the
3496  * stack range (this is strange, but preserves compatibility with
3497  * the grow function in vm_machdep.c).
3498  *
3499  * No requirements.
3500  */
3501 int
3502 vm_map_growstack (struct proc *p, vm_offset_t addr)
3503 {
3504         vm_map_entry_t prev_entry;
3505         vm_map_entry_t stack_entry;
3506         vm_map_entry_t new_stack_entry;
3507         struct vmspace *vm = p->p_vmspace;
3508         vm_map_t map = &vm->vm_map;
3509         vm_offset_t    end;
3510         int grow_amount;
3511         int rv = KERN_SUCCESS;
3512         int is_procstack;
3513         int use_read_lock = 1;
3514         int count;
3515
3516         count = vm_map_entry_reserve(MAP_RESERVE_COUNT);
3517 Retry:
3518         if (use_read_lock)
3519                 vm_map_lock_read(map);
3520         else
3521                 vm_map_lock(map);
3522
3523         /* If addr is already in the entry range, no need to grow.*/
3524         if (vm_map_lookup_entry(map, addr, &prev_entry))
3525                 goto done;
3526
3527         if ((stack_entry = prev_entry->next) == &map->header)
3528                 goto done;
3529         if (prev_entry == &map->header) 
3530                 end = stack_entry->start - stack_entry->aux.avail_ssize;
3531         else
3532                 end = prev_entry->end;
3533
3534         /*
3535          * This next test mimics the old grow function in vm_machdep.c.
3536          * It really doesn't quite make sense, but we do it anyway
3537          * for compatibility.
3538          *
3539          * If not growable stack, return success.  This signals the
3540          * caller to proceed as he would normally with normal vm.
3541          */
3542         if (stack_entry->aux.avail_ssize < 1 ||
3543             addr >= stack_entry->start ||
3544             addr <  stack_entry->start - stack_entry->aux.avail_ssize) {
3545                 goto done;
3546         } 
3547         
3548         /* Find the minimum grow amount */
3549         grow_amount = roundup (stack_entry->start - addr, PAGE_SIZE);
3550         if (grow_amount > stack_entry->aux.avail_ssize) {
3551                 rv = KERN_NO_SPACE;
3552                 goto done;
3553         }
3554
3555         /*
3556          * If there is no longer enough space between the entries
3557          * nogo, and adjust the available space.  Note: this 
3558          * should only happen if the user has mapped into the
3559          * stack area after the stack was created, and is
3560          * probably an error.
3561          *
3562          * This also effectively destroys any guard page the user
3563          * might have intended by limiting the stack size.
3564          */
3565         if (grow_amount > stack_entry->start - end) {
3566                 if (use_read_lock && vm_map_lock_upgrade(map)) {
3567                         /* lost lock */
3568                         use_read_lock = 0;
3569                         goto Retry;
3570                 }
3571                 use_read_lock = 0;
3572                 stack_entry->aux.avail_ssize = stack_entry->start - end;
3573                 rv = KERN_NO_SPACE;
3574                 goto done;
3575         }
3576
3577         is_procstack = addr >= (vm_offset_t)vm->vm_maxsaddr;
3578
3579         /* If this is the main process stack, see if we're over the 
3580          * stack limit.
3581          */
3582         if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3583                              p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3584                 rv = KERN_NO_SPACE;
3585                 goto done;
3586         }
3587
3588         /* Round up the grow amount modulo SGROWSIZ */
3589         grow_amount = roundup (grow_amount, sgrowsiz);
3590         if (grow_amount > stack_entry->aux.avail_ssize) {
3591                 grow_amount = stack_entry->aux.avail_ssize;
3592         }
3593         if (is_procstack && (ctob(vm->vm_ssize) + grow_amount >
3594                              p->p_rlimit[RLIMIT_STACK].rlim_cur)) {
3595                 grow_amount = p->p_rlimit[RLIMIT_STACK].rlim_cur -
3596                               ctob(vm->vm_ssize);
3597         }
3598
3599         /* If we would blow our VMEM resource limit, no go */
3600         if (map->size + grow_amount > p->p_rlimit[RLIMIT_VMEM].rlim_cur) {
3601                 rv = KERN_NO_SPACE;
3602                 goto done;
3603         }
3604
3605         if (use_read_lock && vm_map_lock_upgrade(map)) {
3606                 /* lost lock */
3607                 use_read_lock = 0;
3608                 goto Retry;
3609         }
3610         use_read_lock = 0;
3611
3612         /* Get the preliminary new entry start value */
3613         addr = stack_entry->start - grow_amount;
3614
3615         /* If this puts us into the previous entry, cut back our growth
3616          * to the available space.  Also, see the note above.
3617          */
3618         if (addr < end) {
3619                 stack_entry->aux.avail_ssize = stack_entry->start - end;
3620                 addr = end;
3621         }
3622
3623         rv = vm_map_insert(map, &count,
3624                            NULL, 0, addr, stack_entry->start,
3625                            VM_MAPTYPE_NORMAL,
3626                            VM_PROT_ALL, VM_PROT_ALL,
3627                            0);
3628
3629         /* Adjust the available stack space by the amount we grew. */
3630         if (rv == KERN_SUCCESS) {
3631                 if (prev_entry != &map->header)
3632                         vm_map_clip_end(map, prev_entry, addr, &count);
3633                 new_stack_entry = prev_entry->next;
3634                 if (new_stack_entry->end   != stack_entry->start  ||
3635                     new_stack_entry->start != addr)
3636                         panic ("Bad stack grow start/end in new stack entry");
3637                 else {
3638                         new_stack_entry->aux.avail_ssize =
3639                                 stack_entry->aux.avail_ssize -
3640                                 (new_stack_entry->end - new_stack_entry->start);
3641                         if (is_procstack)
3642                                 vm->vm_ssize += btoc(new_stack_entry->end -
3643                                                      new_stack_entry->start);
3644                 }
3645
3646                 if (map->flags & MAP_WIREFUTURE)
3647                         vm_map_unwire(map, new_stack_entry->start,
3648                                       new_stack_entry->end, FALSE);
3649         }
3650
3651 done:
3652         if (use_read_lock)
3653                 vm_map_unlock_read(map);
3654         else
3655                 vm_map_unlock(map);
3656         vm_map_entry_release(count);
3657         return (rv);
3658 }
3659
3660 /*
3661  * Unshare the specified VM space for exec.  If other processes are
3662  * mapped to it, then create a new one.  The new vmspace is null.
3663  *
3664  * No requirements.
3665  */
3666 void
3667 vmspace_exec(struct proc *p, struct vmspace *vmcopy) 
3668 {
3669         struct vmspace *oldvmspace = p->p_vmspace;
3670         struct vmspace *newvmspace;
3671         vm_map_t map = &p->p_vmspace->vm_map;
3672
3673         /*
3674          * If we are execing a resident vmspace we fork it, otherwise
3675          * we create a new vmspace.  Note that exitingcnt is not
3676          * copied to the new vmspace.
3677          */
3678         lwkt_gettoken(&oldvmspace->vm_map.token);
3679         if (vmcopy)  {
3680                 newvmspace = vmspace_fork(vmcopy);
3681                 lwkt_gettoken(&newvmspace->vm_map.token);
3682         } else {
3683                 newvmspace = vmspace_alloc(map->min_offset, map->max_offset);
3684                 lwkt_gettoken(&newvmspace->vm_map.token);
3685                 bcopy(&oldvmspace->vm_startcopy, &newvmspace->vm_startcopy,
3686                       (caddr_t)&oldvmspace->vm_endcopy -
3687                        (caddr_t)&oldvmspace->vm_startcopy);
3688         }
3689
3690         /*
3691          * Finish initializing the vmspace before assigning it
3692          * to the process.  The vmspace will become the current vmspace
3693          * if p == curproc.
3694          */
3695         pmap_pinit2(vmspace_pmap(newvmspace));
3696         pmap_replacevm(p, newvmspace, 0);
3697         lwkt_reltoken(&newvmspace->vm_map.token);
3698         lwkt_reltoken(&oldvmspace->vm_map.token);
3699         vmspace_free(oldvmspace);
3700 }
3701
3702 /*
3703  * Unshare the specified VM space for forcing COW.  This
3704  * is called by rfork, for the (RFMEM|RFPROC) == 0 case.
3705  */
3706 void
3707 vmspace_unshare(struct proc *p) 
3708 {
3709         struct vmspace *oldvmspace = p->p_vmspace;
3710         struct vmspace *newvmspace;
3711
3712         lwkt_gettoken(&oldvmspace->vm_map.token);
3713         if (oldvmspace->vm_sysref.refcnt == 1) {
3714                 lwkt_reltoken(&oldvmspace->vm_map.token);
3715                 return;
3716         }
3717         newvmspace = vmspace_fork(oldvmspace);
3718         lwkt_gettoken(&newvmspace->vm_map.token);
3719         pmap_pinit2(vmspace_pmap(newvmspace));
3720         pmap_replacevm(p, newvmspace, 0);
3721         lwkt_reltoken(&newvmspace->vm_map.token);
3722         lwkt_reltoken(&oldvmspace->vm_map.token);
3723         vmspace_free(oldvmspace);
3724 }
3725
3726 /*
3727  * vm_map_hint: return the beginning of the best area suitable for
3728  * creating a new mapping with "prot" protection.
3729  *
3730  * No requirements.
3731  */
3732 vm_offset_t
3733 vm_map_hint(struct proc *p, vm_offset_t addr, vm_prot_t prot)
3734 {
3735         struct vmspace *vms = p->p_vmspace;
3736
3737         if (!randomize_mmap) {
3738                 /*
3739                  * Set a reasonable start point for the hint if it was
3740                  * not specified or if it falls within the heap space.
3741                  * Hinted mmap()s do not allocate out of the heap space.
3742                  */
3743                 if (addr == 0 ||
3744                     (addr >= round_page((vm_offset_t)vms->vm_taddr) &&
3745                      addr < round_page((vm_offset_t)vms->vm_daddr + maxdsiz))) {
3746                         addr = round_page((vm_offset_t)vms->vm_daddr + maxdsiz);
3747                 }
3748
3749                 return addr;
3750         }
3751
3752         if (addr != 0 && addr >= (vm_offset_t)vms->vm_daddr)
3753                 return addr;
3754
3755 #ifdef notyet
3756 #ifdef __i386__
3757         /*
3758          * If executable skip first two pages, otherwise start
3759          * after data + heap region.
3760          */
3761         if ((prot & VM_PROT_EXECUTE) &&
3762             ((vm_offset_t)vms->vm_daddr >= I386_MAX_EXE_ADDR)) {
3763                 addr = (PAGE_SIZE * 2) +
3764                     (karc4random() & (I386_MAX_EXE_ADDR / 2 - 1));
3765                 return (round_page(addr));
3766         }
3767 #endif /* __i386__ */
3768 #endif /* notyet */
3769
3770         addr = (vm_offset_t)vms->vm_daddr + MAXDSIZ;
3771         addr += karc4random() & (MIN((256 * 1024 * 1024), MAXDSIZ) - 1);
3772
3773         return (round_page(addr));
3774 }
3775
3776 /*
3777  * Finds the VM object, offset, and protection for a given virtual address
3778  * in the specified map, assuming a page fault of the type specified.
3779  *
3780  * Leaves the map in question locked for read; return values are guaranteed
3781  * until a vm_map_lookup_done call is performed.  Note that the map argument
3782  * is in/out; the returned map must be used in the call to vm_map_lookup_done.
3783  *
3784  * A handle (out_entry) is returned for use in vm_map_lookup_done, to make
3785  * that fast.
3786  *
3787  * If a lookup is requested with "write protection" specified, the map may
3788  * be changed to perform virtual copying operations, although the data
3789  * referenced will remain the same.
3790  *
3791  * No requirements.
3792  */
3793 int
3794 vm_map_lookup(vm_map_t *var_map,                /* IN/OUT */
3795               vm_offset_t vaddr,
3796               vm_prot_t fault_typea,
3797               vm_map_entry_t *out_entry,        /* OUT */
3798               vm_object_t *object,              /* OUT */
3799               vm_pindex_t *pindex,              /* OUT */
3800               vm_prot_t *out_prot,              /* OUT */
3801               boolean_t *wired)                 /* OUT */
3802 {
3803         vm_map_entry_t entry;
3804         vm_map_t map = *var_map;
3805         vm_prot_t prot;
3806         vm_prot_t fault_type = fault_typea;
3807         int use_read_lock = 1;
3808         int rv = KERN_SUCCESS;
3809
3810 RetryLookup:
3811         if (use_read_lock)
3812                 vm_map_lock_read(map);
3813         else
3814                 vm_map_lock(map);
3815
3816         /*
3817          * If the map has an interesting hint, try it before calling full
3818          * blown lookup routine.
3819          */
3820         entry = map->hint;
3821         cpu_ccfence();
3822         *out_entry = entry;
3823         *object = NULL;
3824
3825         if ((entry == &map->header) ||
3826             (vaddr < entry->start) || (vaddr >= entry->end)) {
3827                 vm_map_entry_t tmp_entry;
3828
3829                 /*
3830                  * Entry was either not a valid hint, or the vaddr was not
3831                  * contained in the entry, so do a full lookup.
3832                  */
3833                 if (!vm_map_lookup_entry(map, vaddr, &tmp_entry)) {
3834                         rv = KERN_INVALID_ADDRESS;
3835                         goto done;
3836                 }
3837
3838                 entry = tmp_entry;
3839                 *out_entry = entry;
3840         }
3841         
3842         /*
3843          * Handle submaps.
3844          */
3845         if (entry->maptype == VM_MAPTYPE_SUBMAP) {
3846                 vm_map_t old_map = map;
3847
3848                 *var_map = map = entry->object.sub_map;
3849                 if (use_read_lock)
3850                         vm_map_unlock_read(old_map);
3851                 else
3852                         vm_map_unlock(old_map);
3853                 use_read_lock = 1;
3854                 goto RetryLookup;
3855         }
3856
3857         /*
3858          * Check whether this task is allowed to have this page.
3859          * Note the special case for MAP_ENTRY_COW
3860          * pages with an override.  This is to implement a forced
3861          * COW for debuggers.
3862          */
3863
3864         if (fault_type & VM_PROT_OVERRIDE_WRITE)
3865                 prot = entry->max_protection;
3866         else
3867                 prot = entry->protection;
3868
3869         fault_type &= (VM_PROT_READ|VM_PROT_WRITE|VM_PROT_EXECUTE);
3870         if ((fault_type & prot) != fault_type) {
3871                 rv = KERN_PROTECTION_FAILURE;
3872                 goto done;
3873         }
3874
3875         if ((entry->eflags & MAP_ENTRY_USER_WIRED) &&
3876             (entry->eflags & MAP_ENTRY_COW) &&
3877             (fault_type & VM_PROT_WRITE) &&
3878             (fault_typea & VM_PROT_OVERRIDE_WRITE) == 0) {
3879                 rv = KERN_PROTECTION_FAILURE;
3880                 goto done;
3881         }
3882
3883         /*
3884          * If this page is not pageable, we have to get it for all possible
3885          * accesses.
3886          */
3887         *wired = (entry->wired_count != 0);
3888         if (*wired)
3889                 prot = fault_type = entry->protection;
3890
3891         /*
3892          * Virtual page tables may need to update the accessed (A) bit
3893          * in a page table entry.  Upgrade the fault to a write fault for
3894          * that case if the map will support it.  If the map does not support
3895          * it the page table entry simply will not be updated.
3896          */
3897         if (entry->maptype == VM_MAPTYPE_VPAGETABLE) {
3898                 if (prot & VM_PROT_WRITE)
3899                         fault_type |= VM_PROT_WRITE;
3900         }
3901
3902         /*
3903          * If the entry was copy-on-write, we either ...
3904          */
3905         if (entry->eflags & MAP_ENTRY_NEEDS_COPY) {
3906                 /*
3907                  * If we want to write the page, we may as well handle that
3908                  * now since we've got the map locked.
3909                  *
3910                  * If we don't need to write the page, we just demote the
3911                  * permissions allowed.
3912                  */
3913
3914                 if (fault_type & VM_PROT_WRITE) {
3915                         /*
3916                          * Make a new object, and place it in the object
3917                          * chain.  Note that no new references have appeared
3918                          * -- one just moved from the map to the new
3919                          * object.
3920                          */
3921
3922                         if (use_read_lock && vm_map_lock_upgrade(map)) {
3923                                 /* lost lock */
3924                                 use_read_lock = 0;
3925                                 goto RetryLookup;
3926                         }
3927                         use_read_lock = 0;
3928
3929                         vm_map_entry_shadow(entry, 0);
3930                 } else {
3931                         /*
3932                          * We're attempting to read a copy-on-write page --
3933                          * don't allow writes.
3934                          */
3935
3936                         prot &= ~VM_PROT_WRITE;
3937                 }
3938         }
3939
3940         /*
3941          * Create an object if necessary.
3942          */
3943         if (entry->object.vm_object == NULL && !map->system_map) {
3944                 if (use_read_lock && vm_map_lock_upgrade(map))  {
3945                         /* lost lock */
3946                         use_read_lock = 0;
3947                         goto RetryLookup;
3948                 }
3949                 use_read_lock = 0;
3950                 vm_map_entry_allocate_object(entry);
3951         }
3952
3953         /*
3954          * Return the object/offset from this entry.  If the entry was
3955          * copy-on-write or empty, it has been fixed up.
3956          */
3957
3958         *pindex = OFF_TO_IDX((vaddr - entry->start) + entry->offset);
3959         *object = entry->object.vm_object;
3960
3961         /*
3962          * Return whether this is the only map sharing this data.  On
3963          * success we return with a read lock held on the map.  On failure
3964          * we return with the map unlocked.
3965          */
3966         *out_prot = prot;
3967 done:
3968         if (rv == KERN_SUCCESS) {
3969                 if (use_read_lock == 0)
3970                         vm_map_lock_downgrade(map);
3971         } else if (use_read_lock) {
3972                 vm_map_unlock_read(map);
3973         } else {
3974                 vm_map_unlock(map);
3975         }
3976         return (rv);
3977 }
3978
3979 /*
3980  * Releases locks acquired by a vm_map_lookup()
3981  * (according to the handle returned by that lookup).
3982  *
3983  * No other requirements.
3984  */
3985 void
3986 vm_map_lookup_done(vm_map_t map, vm_map_entry_t entry, int count)
3987 {
3988         /*
3989          * Unlock the main-level map
3990          */
3991         vm_map_unlock_read(map);
3992         if (count)
3993                 vm_map_entry_release(count);
3994 }
3995
3996 #include "opt_ddb.h"
3997 #ifdef DDB
3998 #include <sys/kernel.h>
3999
4000 #include <ddb/ddb.h>
4001
4002 /*
4003  * Debugging only
4004  */
4005 DB_SHOW_COMMAND(map, vm_map_print)
4006 {
4007         static int nlines;
4008         /* XXX convert args. */
4009         vm_map_t map = (vm_map_t)addr;
4010         boolean_t full = have_addr;
4011
4012         vm_map_entry_t entry;
4013
4014         db_iprintf("Task map %p: pmap=%p, nentries=%d, version=%u\n",
4015             (void *)map,
4016             (void *)map->pmap, map->nentries, map->timestamp);
4017         nlines++;
4018
4019         if (!full && db_indent)
4020                 return;
4021
4022         db_indent += 2;
4023         for (entry = map->header.next; entry != &map->header;
4024             entry = entry->next) {
4025                 db_iprintf("map entry %p: start=%p, end=%p\n",
4026                     (void *)entry, (void *)entry->start, (void *)entry->end);
4027                 nlines++;
4028                 {
4029                         static char *inheritance_name[4] =
4030                         {"share", "copy", "none", "donate_copy"};
4031
4032                         db_iprintf(" prot=%x/%x/%s",
4033                             entry->protection,
4034                             entry->max_protection,
4035                             inheritance_name[(int)(unsigned char)entry->inheritance]);
4036                         if (entry->wired_count != 0)
4037                                 db_printf(", wired");
4038                 }
4039                 if (entry->maptype == VM_MAPTYPE_SUBMAP) {
4040                         /* XXX no %qd in kernel.  Truncate entry->offset. */
4041                         db_printf(", share=%p, offset=0x%lx\n",
4042                             (void *)entry->object.sub_map,
4043                             (long)entry->offset);
4044                         nlines++;
4045                         if ((entry->prev == &map->header) ||
4046                             (entry->prev->object.sub_map !=
4047                                 entry->object.sub_map)) {
4048