FreeBSD/Linux Kernel Cross Reference
sys/uvm/uvm_map.c
1 /* $NetBSD: uvm_map.c,v 1.403 2022/11/23 23:53:53 riastradh Exp $ */
2
3 /*
4 * Copyright (c) 1997 Charles D. Cranor and Washington University.
5 * Copyright (c) 1991, 1993, The Regents of the University of California.
6 *
7 * All rights reserved.
8 *
9 * This code is derived from software contributed to Berkeley by
10 * The Mach Operating System project at Carnegie-Mellon University.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 * notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 * notice, this list of conditions and the following disclaimer in the
19 * documentation and/or other materials provided with the distribution.
20 * 3. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 *
36 * @(#)vm_map.c 8.3 (Berkeley) 1/12/94
37 * from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp
38 *
39 *
40 * Copyright (c) 1987, 1990 Carnegie-Mellon University.
41 * All rights reserved.
42 *
43 * Permission to use, copy, modify and distribute this software and
44 * its documentation is hereby granted, provided that both the copyright
45 * notice and this permission notice appear in all copies of the
46 * software, derivative works or modified versions, and any portions
47 * thereof, and that both notices appear in supporting documentation.
48 *
49 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
50 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
51 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
52 *
53 * Carnegie Mellon requests users of this software to return to
54 *
55 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
56 * School of Computer Science
57 * Carnegie Mellon University
58 * Pittsburgh PA 15213-3890
59 *
60 * any improvements or extensions that they make and grant Carnegie the
61 * rights to redistribute these changes.
62 */
63
64 /*
65 * uvm_map.c: uvm map operations
66 */
67
68 #include <sys/cdefs.h>
69 __KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.403 2022/11/23 23:53:53 riastradh Exp $");
70
71 #include "opt_ddb.h"
72 #include "opt_pax.h"
73 #include "opt_uvmhist.h"
74 #include "opt_uvm.h"
75 #include "opt_sysv.h"
76
77 #include <sys/param.h>
78 #include <sys/systm.h>
79 #include <sys/mman.h>
80 #include <sys/proc.h>
81 #include <sys/pool.h>
82 #include <sys/kernel.h>
83 #include <sys/mount.h>
84 #include <sys/pax.h>
85 #include <sys/vnode.h>
86 #include <sys/filedesc.h>
87 #include <sys/lockdebug.h>
88 #include <sys/atomic.h>
89 #include <sys/sysctl.h>
90 #ifndef __USER_VA0_IS_SAFE
91 #include <sys/kauth.h>
92 #include "opt_user_va0_disable_default.h"
93 #endif
94
95 #include <sys/shm.h>
96
97 #include <uvm/uvm.h>
98 #include <uvm/uvm_readahead.h>
99
100 #if defined(DDB) || defined(DEBUGPRINT)
101 #include <uvm/uvm_ddb.h>
102 #endif
103
104 #ifdef UVMHIST
105 #ifndef UVMHIST_MAPHIST_SIZE
106 #define UVMHIST_MAPHIST_SIZE 100
107 #endif
108 static struct kern_history_ent maphistbuf[UVMHIST_MAPHIST_SIZE];
109 UVMHIST_DEFINE(maphist) = UVMHIST_INITIALIZER(maphist, maphistbuf);
110 #endif
111
112 #if !defined(UVMMAP_COUNTERS)
113
114 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */
115 #define UVMMAP_EVCNT_INCR(ev) /* nothing */
116 #define UVMMAP_EVCNT_DECR(ev) /* nothing */
117
118 #else /* defined(UVMMAP_NOCOUNTERS) */
119
120 #include <sys/evcnt.h>
121 #define UVMMAP_EVCNT_DEFINE(name) \
122 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \
123 "uvmmap", #name); \
124 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name);
125 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++
126 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count--
127
128 #endif /* defined(UVMMAP_NOCOUNTERS) */
129
130 UVMMAP_EVCNT_DEFINE(ubackmerge)
131 UVMMAP_EVCNT_DEFINE(uforwmerge)
132 UVMMAP_EVCNT_DEFINE(ubimerge)
133 UVMMAP_EVCNT_DEFINE(unomerge)
134 UVMMAP_EVCNT_DEFINE(kbackmerge)
135 UVMMAP_EVCNT_DEFINE(kforwmerge)
136 UVMMAP_EVCNT_DEFINE(kbimerge)
137 UVMMAP_EVCNT_DEFINE(knomerge)
138 UVMMAP_EVCNT_DEFINE(map_call)
139 UVMMAP_EVCNT_DEFINE(mlk_call)
140 UVMMAP_EVCNT_DEFINE(mlk_hint)
141 UVMMAP_EVCNT_DEFINE(mlk_tree)
142 UVMMAP_EVCNT_DEFINE(mlk_treeloop)
143
144 const char vmmapbsy[] = "vmmapbsy";
145
146 /*
147 * cache for vmspace structures.
148 */
149
150 static struct pool_cache uvm_vmspace_cache;
151
152 /*
153 * cache for dynamically-allocated map entries.
154 */
155
156 static struct pool_cache uvm_map_entry_cache;
157
158 #ifdef PMAP_GROWKERNEL
159 /*
160 * This global represents the end of the kernel virtual address
161 * space. If we want to exceed this, we must grow the kernel
162 * virtual address space dynamically.
163 *
164 * Note, this variable is locked by kernel_map's lock.
165 */
166 vaddr_t uvm_maxkaddr;
167 #endif
168
169 #ifndef __USER_VA0_IS_SAFE
170 #ifndef __USER_VA0_DISABLE_DEFAULT
171 #define __USER_VA0_DISABLE_DEFAULT 1
172 #endif
173 #ifdef USER_VA0_DISABLE_DEFAULT /* kernel config option overrides */
174 #undef __USER_VA0_DISABLE_DEFAULT
175 #define __USER_VA0_DISABLE_DEFAULT USER_VA0_DISABLE_DEFAULT
176 #endif
177 int user_va0_disable = __USER_VA0_DISABLE_DEFAULT;
178 #endif
179
180 /*
181 * macros
182 */
183
184 /*
185 * uvm_map_align_va: round down or up virtual address
186 */
187 static __inline void
188 uvm_map_align_va(vaddr_t *vap, vsize_t align, int topdown)
189 {
190
191 KASSERT(powerof2(align));
192
193 if (align != 0 && (*vap & (align - 1)) != 0) {
194 if (topdown)
195 *vap = rounddown2(*vap, align);
196 else
197 *vap = roundup2(*vap, align);
198 }
199 }
200
201 /*
202 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging
203 */
204 extern struct vm_map *pager_map;
205
206 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \
207 prot, maxprot, inh, adv, wire) \
208 ((ent)->etype == (type) && \
209 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE)) == 0 && \
210 (ent)->object.uvm_obj == (uobj) && \
211 (ent)->protection == (prot) && \
212 (ent)->max_protection == (maxprot) && \
213 (ent)->inheritance == (inh) && \
214 (ent)->advice == (adv) && \
215 (ent)->wired_count == (wire))
216
217 /*
218 * uvm_map_entry_link: insert entry into a map
219 *
220 * => map must be locked
221 */
222 #define uvm_map_entry_link(map, after_where, entry) do { \
223 uvm_mapent_check(entry); \
224 (map)->nentries++; \
225 (entry)->prev = (after_where); \
226 (entry)->next = (after_where)->next; \
227 (entry)->prev->next = (entry); \
228 (entry)->next->prev = (entry); \
229 uvm_rb_insert((map), (entry)); \
230 } while (/*CONSTCOND*/ 0)
231
232 /*
233 * uvm_map_entry_unlink: remove entry from a map
234 *
235 * => map must be locked
236 */
237 #define uvm_map_entry_unlink(map, entry) do { \
238 KASSERT((entry) != (map)->first_free); \
239 KASSERT((entry) != (map)->hint); \
240 uvm_mapent_check(entry); \
241 (map)->nentries--; \
242 (entry)->next->prev = (entry)->prev; \
243 (entry)->prev->next = (entry)->next; \
244 uvm_rb_remove((map), (entry)); \
245 } while (/*CONSTCOND*/ 0)
246
247 /*
248 * SAVE_HINT: saves the specified entry as the hint for future lookups.
249 *
250 * => map need not be locked.
251 */
252 #define SAVE_HINT(map, check, value) do { \
253 if ((map)->hint == (check)) \
254 (map)->hint = (value); \
255 } while (/*CONSTCOND*/ 0)
256
257 /*
258 * clear_hints: ensure that hints don't point to the entry.
259 *
260 * => map must be write-locked.
261 */
262 static void
263 clear_hints(struct vm_map *map, struct vm_map_entry *ent)
264 {
265
266 SAVE_HINT(map, ent, ent->prev);
267 if (map->first_free == ent) {
268 map->first_free = ent->prev;
269 }
270 }
271
272 /*
273 * VM_MAP_RANGE_CHECK: check and correct range
274 *
275 * => map must at least be read locked
276 */
277
278 #define VM_MAP_RANGE_CHECK(map, start, end) do { \
279 if (start < vm_map_min(map)) \
280 start = vm_map_min(map); \
281 if (end > vm_map_max(map)) \
282 end = vm_map_max(map); \
283 if (start > end) \
284 start = end; \
285 } while (/*CONSTCOND*/ 0)
286
287 /*
288 * local prototypes
289 */
290
291 static struct vm_map_entry *
292 uvm_mapent_alloc(struct vm_map *, int);
293 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *);
294 static void uvm_mapent_free(struct vm_map_entry *);
295 #if defined(DEBUG)
296 static void _uvm_mapent_check(const struct vm_map_entry *, int);
297 #define uvm_mapent_check(map) _uvm_mapent_check(map, __LINE__)
298 #else /* defined(DEBUG) */
299 #define uvm_mapent_check(e) /* nothing */
300 #endif /* defined(DEBUG) */
301
302 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *);
303 static void uvm_map_reference_amap(struct vm_map_entry *, int);
304 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int,
305 int, struct vm_map_entry *);
306 static void uvm_map_unreference_amap(struct vm_map_entry *, int);
307
308 int _uvm_map_sanity(struct vm_map *);
309 int _uvm_tree_sanity(struct vm_map *);
310 static vsize_t uvm_rb_maxgap(const struct vm_map_entry *);
311
312 #define ROOT_ENTRY(map) ((struct vm_map_entry *)(map)->rb_tree.rbt_root)
313 #define LEFT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_left)
314 #define RIGHT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_right)
315 #define PARENT_ENTRY(map, entry) \
316 (ROOT_ENTRY(map) == (entry) \
317 ? NULL : (struct vm_map_entry *)RB_FATHER(&(entry)->rb_node))
318
319 /*
320 * These get filled in if/when SYSVSHM shared memory code is loaded
321 *
322 * We do this with function pointers rather the #ifdef SYSVSHM so the
323 * SYSVSHM code can be loaded and unloaded
324 */
325 void (*uvm_shmexit)(struct vmspace *) = NULL;
326 void (*uvm_shmfork)(struct vmspace *, struct vmspace *) = NULL;
327
328 static int
329 uvm_map_compare_nodes(void *ctx, const void *nparent, const void *nkey)
330 {
331 const struct vm_map_entry *eparent = nparent;
332 const struct vm_map_entry *ekey = nkey;
333
334 KASSERT(eparent->start < ekey->start || eparent->start >= ekey->end);
335 KASSERT(ekey->start < eparent->start || ekey->start >= eparent->end);
336
337 if (eparent->start < ekey->start)
338 return -1;
339 if (eparent->end >= ekey->start)
340 return 1;
341 return 0;
342 }
343
344 static int
345 uvm_map_compare_key(void *ctx, const void *nparent, const void *vkey)
346 {
347 const struct vm_map_entry *eparent = nparent;
348 const vaddr_t va = *(const vaddr_t *) vkey;
349
350 if (eparent->start < va)
351 return -1;
352 if (eparent->end >= va)
353 return 1;
354 return 0;
355 }
356
357 static const rb_tree_ops_t uvm_map_tree_ops = {
358 .rbto_compare_nodes = uvm_map_compare_nodes,
359 .rbto_compare_key = uvm_map_compare_key,
360 .rbto_node_offset = offsetof(struct vm_map_entry, rb_node),
361 .rbto_context = NULL
362 };
363
364 /*
365 * uvm_rb_gap: return the gap size between our entry and next entry.
366 */
367 static inline vsize_t
368 uvm_rb_gap(const struct vm_map_entry *entry)
369 {
370
371 KASSERT(entry->next != NULL);
372 return entry->next->start - entry->end;
373 }
374
375 static vsize_t
376 uvm_rb_maxgap(const struct vm_map_entry *entry)
377 {
378 struct vm_map_entry *child;
379 vsize_t maxgap = entry->gap;
380
381 /*
382 * We need maxgap to be the largest gap of us or any of our
383 * descendents. Since each of our children's maxgap is the
384 * cached value of their largest gap of themselves or their
385 * descendents, we can just use that value and avoid recursing
386 * down the tree to calculate it.
387 */
388 if ((child = LEFT_ENTRY(entry)) != NULL && maxgap < child->maxgap)
389 maxgap = child->maxgap;
390
391 if ((child = RIGHT_ENTRY(entry)) != NULL && maxgap < child->maxgap)
392 maxgap = child->maxgap;
393
394 return maxgap;
395 }
396
397 static void
398 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry)
399 {
400 struct vm_map_entry *parent;
401
402 KASSERT(entry->gap == uvm_rb_gap(entry));
403 entry->maxgap = uvm_rb_maxgap(entry);
404
405 while ((parent = PARENT_ENTRY(map, entry)) != NULL) {
406 struct vm_map_entry *brother;
407 vsize_t maxgap = parent->gap;
408 unsigned int which;
409
410 KDASSERT(parent->gap == uvm_rb_gap(parent));
411 if (maxgap < entry->maxgap)
412 maxgap = entry->maxgap;
413 /*
414 * Since we work towards the root, we know entry's maxgap
415 * value is OK, but its brothers may now be out-of-date due
416 * to rebalancing. So refresh it.
417 */
418 which = RB_POSITION(&entry->rb_node) ^ RB_DIR_OTHER;
419 brother = (struct vm_map_entry *)parent->rb_node.rb_nodes[which];
420 if (brother != NULL) {
421 KDASSERT(brother->gap == uvm_rb_gap(brother));
422 brother->maxgap = uvm_rb_maxgap(brother);
423 if (maxgap < brother->maxgap)
424 maxgap = brother->maxgap;
425 }
426
427 parent->maxgap = maxgap;
428 entry = parent;
429 }
430 }
431
432 static void
433 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry)
434 {
435 struct vm_map_entry *ret __diagused;
436
437 entry->gap = entry->maxgap = uvm_rb_gap(entry);
438 if (entry->prev != &map->header)
439 entry->prev->gap = uvm_rb_gap(entry->prev);
440
441 ret = rb_tree_insert_node(&map->rb_tree, entry);
442 KASSERTMSG(ret == entry,
443 "uvm_rb_insert: map %p: duplicate entry %p", map, ret);
444
445 /*
446 * If the previous entry is not our immediate left child, then it's an
447 * ancestor and will be fixed up on the way to the root. We don't
448 * have to check entry->prev against &map->header since &map->header
449 * will never be in the tree.
450 */
451 uvm_rb_fixup(map,
452 LEFT_ENTRY(entry) == entry->prev ? entry->prev : entry);
453 }
454
455 static void
456 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry)
457 {
458 struct vm_map_entry *prev_parent = NULL, *next_parent = NULL;
459
460 /*
461 * If we are removing an interior node, then an adjacent node will
462 * be used to replace its position in the tree. Therefore we will
463 * need to fixup the tree starting at the parent of the replacement
464 * node. So record their parents for later use.
465 */
466 if (entry->prev != &map->header)
467 prev_parent = PARENT_ENTRY(map, entry->prev);
468 if (entry->next != &map->header)
469 next_parent = PARENT_ENTRY(map, entry->next);
470
471 rb_tree_remove_node(&map->rb_tree, entry);
472
473 /*
474 * If the previous node has a new parent, fixup the tree starting
475 * at the previous node's old parent.
476 */
477 if (entry->prev != &map->header) {
478 /*
479 * Update the previous entry's gap due to our absence.
480 */
481 entry->prev->gap = uvm_rb_gap(entry->prev);
482 uvm_rb_fixup(map, entry->prev);
483 if (prev_parent != NULL
484 && prev_parent != entry
485 && prev_parent != PARENT_ENTRY(map, entry->prev))
486 uvm_rb_fixup(map, prev_parent);
487 }
488
489 /*
490 * If the next node has a new parent, fixup the tree starting
491 * at the next node's old parent.
492 */
493 if (entry->next != &map->header) {
494 uvm_rb_fixup(map, entry->next);
495 if (next_parent != NULL
496 && next_parent != entry
497 && next_parent != PARENT_ENTRY(map, entry->next))
498 uvm_rb_fixup(map, next_parent);
499 }
500 }
501
502 #if defined(DEBUG)
503 int uvm_debug_check_map = 0;
504 int uvm_debug_check_rbtree = 0;
505 #define uvm_map_check(map, name) \
506 _uvm_map_check((map), (name), __FILE__, __LINE__)
507 static void
508 _uvm_map_check(struct vm_map *map, const char *name,
509 const char *file, int line)
510 {
511
512 if ((uvm_debug_check_map && _uvm_map_sanity(map)) ||
513 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) {
514 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)",
515 name, map, file, line);
516 }
517 }
518 #else /* defined(DEBUG) */
519 #define uvm_map_check(map, name) /* nothing */
520 #endif /* defined(DEBUG) */
521
522 #if defined(DEBUG) || defined(DDB)
523 int
524 _uvm_map_sanity(struct vm_map *map)
525 {
526 bool first_free_found = false;
527 bool hint_found = false;
528 const struct vm_map_entry *e;
529 struct vm_map_entry *hint = map->hint;
530
531 e = &map->header;
532 for (;;) {
533 if (map->first_free == e) {
534 first_free_found = true;
535 } else if (!first_free_found && e->next->start > e->end) {
536 printf("first_free %p should be %p\n",
537 map->first_free, e);
538 return -1;
539 }
540 if (hint == e) {
541 hint_found = true;
542 }
543
544 e = e->next;
545 if (e == &map->header) {
546 break;
547 }
548 }
549 if (!first_free_found) {
550 printf("stale first_free\n");
551 return -1;
552 }
553 if (!hint_found) {
554 printf("stale hint\n");
555 return -1;
556 }
557 return 0;
558 }
559
560 int
561 _uvm_tree_sanity(struct vm_map *map)
562 {
563 struct vm_map_entry *tmp, *trtmp;
564 int n = 0, i = 1;
565
566 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) {
567 if (tmp->gap != uvm_rb_gap(tmp)) {
568 printf("%d/%d gap %#lx != %#lx %s\n",
569 n + 1, map->nentries,
570 (ulong)tmp->gap, (ulong)uvm_rb_gap(tmp),
571 tmp->next == &map->header ? "(last)" : "");
572 goto error;
573 }
574 /*
575 * If any entries are out of order, tmp->gap will be unsigned
576 * and will likely exceed the size of the map.
577 */
578 if (tmp->gap >= vm_map_max(map) - vm_map_min(map)) {
579 printf("too large gap %zu\n", (size_t)tmp->gap);
580 goto error;
581 }
582 n++;
583 }
584
585 if (n != map->nentries) {
586 printf("nentries: %d vs %d\n", n, map->nentries);
587 goto error;
588 }
589
590 trtmp = NULL;
591 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) {
592 if (tmp->maxgap != uvm_rb_maxgap(tmp)) {
593 printf("maxgap %#lx != %#lx\n",
594 (ulong)tmp->maxgap,
595 (ulong)uvm_rb_maxgap(tmp));
596 goto error;
597 }
598 if (trtmp != NULL && trtmp->start >= tmp->start) {
599 printf("corrupt: 0x%"PRIxVADDR"x >= 0x%"PRIxVADDR"x\n",
600 trtmp->start, tmp->start);
601 goto error;
602 }
603
604 trtmp = tmp;
605 }
606
607 for (tmp = map->header.next; tmp != &map->header;
608 tmp = tmp->next, i++) {
609 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_LEFT);
610 if (trtmp == NULL)
611 trtmp = &map->header;
612 if (tmp->prev != trtmp) {
613 printf("lookup: %d: %p->prev=%p: %p\n",
614 i, tmp, tmp->prev, trtmp);
615 goto error;
616 }
617 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_RIGHT);
618 if (trtmp == NULL)
619 trtmp = &map->header;
620 if (tmp->next != trtmp) {
621 printf("lookup: %d: %p->next=%p: %p\n",
622 i, tmp, tmp->next, trtmp);
623 goto error;
624 }
625 trtmp = rb_tree_find_node(&map->rb_tree, &tmp->start);
626 if (trtmp != tmp) {
627 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp,
628 PARENT_ENTRY(map, tmp));
629 goto error;
630 }
631 }
632
633 return (0);
634 error:
635 return (-1);
636 }
637 #endif /* defined(DEBUG) || defined(DDB) */
638
639 /*
640 * vm_map_lock: acquire an exclusive (write) lock on a map.
641 *
642 * => The locking protocol provides for guaranteed upgrade from shared ->
643 * exclusive by whichever thread currently has the map marked busy.
644 * See "LOCKING PROTOCOL NOTES" in uvm_map.h. This is horrible; among
645 * other problems, it defeats any fairness guarantees provided by RW
646 * locks.
647 */
648
649 void
650 vm_map_lock(struct vm_map *map)
651 {
652
653 for (;;) {
654 rw_enter(&map->lock, RW_WRITER);
655 if (map->busy == NULL || map->busy == curlwp) {
656 break;
657 }
658 mutex_enter(&map->misc_lock);
659 rw_exit(&map->lock);
660 if (map->busy != NULL) {
661 cv_wait(&map->cv, &map->misc_lock);
662 }
663 mutex_exit(&map->misc_lock);
664 }
665 map->timestamp++;
666 }
667
668 /*
669 * vm_map_lock_try: try to lock a map, failing if it is already locked.
670 */
671
672 bool
673 vm_map_lock_try(struct vm_map *map)
674 {
675
676 if (!rw_tryenter(&map->lock, RW_WRITER)) {
677 return false;
678 }
679 if (map->busy != NULL) {
680 rw_exit(&map->lock);
681 return false;
682 }
683 map->timestamp++;
684 return true;
685 }
686
687 /*
688 * vm_map_unlock: release an exclusive lock on a map.
689 */
690
691 void
692 vm_map_unlock(struct vm_map *map)
693 {
694
695 KASSERT(rw_write_held(&map->lock));
696 KASSERT(map->busy == NULL || map->busy == curlwp);
697 rw_exit(&map->lock);
698 }
699
700 /*
701 * vm_map_unbusy: mark the map as unbusy, and wake any waiters that
702 * want an exclusive lock.
703 */
704
705 void
706 vm_map_unbusy(struct vm_map *map)
707 {
708
709 KASSERT(map->busy == curlwp);
710
711 /*
712 * Safe to clear 'busy' and 'waiters' with only a read lock held:
713 *
714 * o they can only be set with a write lock held
715 * o writers are blocked out with a read or write hold
716 * o at any time, only one thread owns the set of values
717 */
718 mutex_enter(&map->misc_lock);
719 map->busy = NULL;
720 cv_broadcast(&map->cv);
721 mutex_exit(&map->misc_lock);
722 }
723
724 /*
725 * vm_map_lock_read: acquire a shared (read) lock on a map.
726 */
727
728 void
729 vm_map_lock_read(struct vm_map *map)
730 {
731
732 rw_enter(&map->lock, RW_READER);
733 }
734
735 /*
736 * vm_map_unlock_read: release a shared lock on a map.
737 */
738
739 void
740 vm_map_unlock_read(struct vm_map *map)
741 {
742
743 rw_exit(&map->lock);
744 }
745
746 /*
747 * vm_map_busy: mark a map as busy.
748 *
749 * => the caller must hold the map write locked
750 */
751
752 void
753 vm_map_busy(struct vm_map *map)
754 {
755
756 KASSERT(rw_write_held(&map->lock));
757 KASSERT(map->busy == NULL);
758
759 map->busy = curlwp;
760 }
761
762 /*
763 * vm_map_locked_p: return true if the map is write locked.
764 *
765 * => only for debug purposes like KASSERTs.
766 * => should not be used to verify that a map is not locked.
767 */
768
769 bool
770 vm_map_locked_p(struct vm_map *map)
771 {
772
773 return rw_write_held(&map->lock);
774 }
775
776 /*
777 * uvm_mapent_alloc: allocate a map entry
778 */
779
780 static struct vm_map_entry *
781 uvm_mapent_alloc(struct vm_map *map, int flags)
782 {
783 struct vm_map_entry *me;
784 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK;
785 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
786
787 me = pool_cache_get(&uvm_map_entry_cache, pflags);
788 if (__predict_false(me == NULL)) {
789 return NULL;
790 }
791 me->flags = 0;
792
793 UVMHIST_LOG(maphist, "<- new entry=%#jx [kentry=%jd]", (uintptr_t)me,
794 (map == kernel_map), 0, 0);
795 return me;
796 }
797
798 /*
799 * uvm_mapent_free: free map entry
800 */
801
802 static void
803 uvm_mapent_free(struct vm_map_entry *me)
804 {
805 UVMHIST_FUNC(__func__);
806 UVMHIST_CALLARGS(maphist,"<- freeing map entry=%#jx [flags=%#jx]",
807 (uintptr_t)me, me->flags, 0, 0);
808 pool_cache_put(&uvm_map_entry_cache, me);
809 }
810
811 /*
812 * uvm_mapent_copy: copy a map entry, preserving flags
813 */
814
815 static inline void
816 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst)
817 {
818
819 memcpy(dst, src, sizeof(*dst));
820 dst->flags = 0;
821 }
822
823 #if defined(DEBUG)
824 static void
825 _uvm_mapent_check(const struct vm_map_entry *entry, int line)
826 {
827
828 if (entry->start >= entry->end) {
829 goto bad;
830 }
831 if (UVM_ET_ISOBJ(entry)) {
832 if (entry->object.uvm_obj == NULL) {
833 goto bad;
834 }
835 } else if (UVM_ET_ISSUBMAP(entry)) {
836 if (entry->object.sub_map == NULL) {
837 goto bad;
838 }
839 } else {
840 if (entry->object.uvm_obj != NULL ||
841 entry->object.sub_map != NULL) {
842 goto bad;
843 }
844 }
845 if (!UVM_ET_ISOBJ(entry)) {
846 if (entry->offset != 0) {
847 goto bad;
848 }
849 }
850
851 return;
852
853 bad:
854 panic("%s: bad entry %p, line %d", __func__, entry, line);
855 }
856 #endif /* defined(DEBUG) */
857
858 /*
859 * uvm_map_entry_unwire: unwire a map entry
860 *
861 * => map should be locked by caller
862 */
863
864 static inline void
865 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry)
866 {
867
868 entry->wired_count = 0;
869 uvm_fault_unwire_locked(map, entry->start, entry->end);
870 }
871
872
873 /*
874 * wrapper for calling amap_ref()
875 */
876 static inline void
877 uvm_map_reference_amap(struct vm_map_entry *entry, int flags)
878 {
879
880 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff,
881 (entry->end - entry->start) >> PAGE_SHIFT, flags);
882 }
883
884
885 /*
886 * wrapper for calling amap_unref()
887 */
888 static inline void
889 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags)
890 {
891
892 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff,
893 (entry->end - entry->start) >> PAGE_SHIFT, flags);
894 }
895
896
897 /*
898 * uvm_map_init: init mapping system at boot time.
899 */
900
901 void
902 uvm_map_init(void)
903 {
904 /*
905 * first, init logging system.
906 */
907
908 UVMHIST_FUNC(__func__);
909 UVMHIST_LINK_STATIC(maphist);
910 UVMHIST_LINK_STATIC(pdhist);
911 UVMHIST_CALLED(maphist);
912 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0);
913
914 /*
915 * initialize the global lock for kernel map entry.
916 */
917
918 mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM);
919 }
920
921 /*
922 * uvm_map_init_caches: init mapping system caches.
923 */
924 void
925 uvm_map_init_caches(void)
926 {
927 /*
928 * initialize caches.
929 */
930
931 pool_cache_bootstrap(&uvm_map_entry_cache, sizeof(struct vm_map_entry),
932 coherency_unit, 0, PR_LARGECACHE, "vmmpepl", NULL, IPL_NONE, NULL,
933 NULL, NULL);
934 pool_cache_bootstrap(&uvm_vmspace_cache, sizeof(struct vmspace),
935 0, 0, 0, "vmsppl", NULL, IPL_NONE, NULL, NULL, NULL);
936 }
937
938 /*
939 * clippers
940 */
941
942 /*
943 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy.
944 */
945
946 static void
947 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2,
948 vaddr_t splitat)
949 {
950 vaddr_t adj;
951
952 KASSERT(entry1->start < splitat);
953 KASSERT(splitat < entry1->end);
954
955 adj = splitat - entry1->start;
956 entry1->end = entry2->start = splitat;
957
958 if (entry1->aref.ar_amap) {
959 amap_splitref(&entry1->aref, &entry2->aref, adj);
960 }
961 if (UVM_ET_ISSUBMAP(entry1)) {
962 /* ... unlikely to happen, but play it safe */
963 uvm_map_reference(entry1->object.sub_map);
964 } else if (UVM_ET_ISOBJ(entry1)) {
965 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */
966 entry2->offset += adj;
967 if (entry1->object.uvm_obj->pgops &&
968 entry1->object.uvm_obj->pgops->pgo_reference)
969 entry1->object.uvm_obj->pgops->pgo_reference(
970 entry1->object.uvm_obj);
971 }
972 }
973
974 /*
975 * uvm_map_clip_start: ensure that the entry begins at or after
976 * the starting address, if it doesn't we split the entry.
977 *
978 * => caller should use UVM_MAP_CLIP_START macro rather than calling
979 * this directly
980 * => map must be locked by caller
981 */
982
983 void
984 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry,
985 vaddr_t start)
986 {
987 struct vm_map_entry *new_entry;
988
989 /* uvm_map_simplify_entry(map, entry); */ /* XXX */
990
991 uvm_map_check(map, "clip_start entry");
992 uvm_mapent_check(entry);
993
994 /*
995 * Split off the front portion. note that we must insert the new
996 * entry BEFORE this one, so that this entry has the specified
997 * starting address.
998 */
999 new_entry = uvm_mapent_alloc(map, 0);
1000 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
1001 uvm_mapent_splitadj(new_entry, entry, start);
1002 uvm_map_entry_link(map, entry->prev, new_entry);
1003
1004 uvm_map_check(map, "clip_start leave");
1005 }
1006
1007 /*
1008 * uvm_map_clip_end: ensure that the entry ends at or before
1009 * the ending address, if it does't we split the reference
1010 *
1011 * => caller should use UVM_MAP_CLIP_END macro rather than calling
1012 * this directly
1013 * => map must be locked by caller
1014 */
1015
1016 void
1017 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end)
1018 {
1019 struct vm_map_entry *new_entry;
1020
1021 uvm_map_check(map, "clip_end entry");
1022 uvm_mapent_check(entry);
1023
1024 /*
1025 * Create a new entry and insert it
1026 * AFTER the specified entry
1027 */
1028 new_entry = uvm_mapent_alloc(map, 0);
1029 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */
1030 uvm_mapent_splitadj(entry, new_entry, end);
1031 uvm_map_entry_link(map, entry, new_entry);
1032
1033 uvm_map_check(map, "clip_end leave");
1034 }
1035
1036 /*
1037 * M A P - m a i n e n t r y p o i n t
1038 */
1039 /*
1040 * uvm_map: establish a valid mapping in a map
1041 *
1042 * => assume startp is page aligned.
1043 * => assume size is a multiple of PAGE_SIZE.
1044 * => assume sys_mmap provides enough of a "hint" to have us skip
1045 * over text/data/bss area.
1046 * => map must be unlocked (we will lock it)
1047 * => <uobj,uoffset> value meanings (4 cases):
1048 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER
1049 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER
1050 * [3] <uobj,uoffset> == normal mapping
1051 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA
1052 *
1053 * case [4] is for kernel mappings where we don't know the offset until
1054 * we've found a virtual address. note that kernel object offsets are
1055 * always relative to vm_map_min(kernel_map).
1056 *
1057 * => if `align' is non-zero, we align the virtual address to the specified
1058 * alignment.
1059 * this is provided as a mechanism for large pages.
1060 *
1061 * => XXXCDC: need way to map in external amap?
1062 */
1063
1064 int
1065 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size,
1066 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags)
1067 {
1068 struct uvm_map_args args;
1069 struct vm_map_entry *new_entry;
1070 int error;
1071
1072 KASSERT((size & PAGE_MASK) == 0);
1073 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0);
1074
1075 /*
1076 * for pager_map, allocate the new entry first to avoid sleeping
1077 * for memory while we have the map locked.
1078 */
1079
1080 new_entry = NULL;
1081 if (map == pager_map) {
1082 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT));
1083 if (__predict_false(new_entry == NULL))
1084 return ENOMEM;
1085 }
1086 if (map == pager_map)
1087 flags |= UVM_FLAG_NOMERGE;
1088
1089 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align,
1090 flags, &args);
1091 if (!error) {
1092 error = uvm_map_enter(map, &args, new_entry);
1093 *startp = args.uma_start;
1094 } else if (new_entry) {
1095 uvm_mapent_free(new_entry);
1096 }
1097
1098 #if defined(DEBUG)
1099 if (!error && VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) {
1100 uvm_km_check_empty(map, *startp, *startp + size);
1101 }
1102 #endif /* defined(DEBUG) */
1103
1104 return error;
1105 }
1106
1107 /*
1108 * uvm_map_prepare:
1109 *
1110 * called with map unlocked.
1111 * on success, returns the map locked.
1112 */
1113
1114 int
1115 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size,
1116 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags,
1117 struct uvm_map_args *args)
1118 {
1119 struct vm_map_entry *prev_entry;
1120 vm_prot_t prot = UVM_PROTECTION(flags);
1121 vm_prot_t maxprot = UVM_MAXPROTECTION(flags);
1122
1123 UVMHIST_FUNC(__func__);
1124 UVMHIST_CALLARGS(maphist, "(map=%#jx, start=%#jx, size=%jx, flags=%#jx)",
1125 (uintptr_t)map, start, size, flags);
1126 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj,
1127 uoffset,0,0);
1128
1129 /*
1130 * detect a popular device driver bug.
1131 */
1132
1133 KASSERT(doing_shutdown || curlwp != NULL);
1134
1135 /*
1136 * zero-sized mapping doesn't make any sense.
1137 */
1138 KASSERT(size > 0);
1139
1140 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0);
1141
1142 uvm_map_check(map, "map entry");
1143
1144 /*
1145 * check sanity of protection code
1146 */
1147
1148 if ((prot & maxprot) != prot) {
1149 UVMHIST_LOG(maphist, "<- prot. failure: prot=%#jx, max=%#jx",
1150 prot, maxprot,0,0);
1151 return EACCES;
1152 }
1153
1154 /*
1155 * figure out where to put new VM range
1156 */
1157 retry:
1158 if (vm_map_lock_try(map) == false) {
1159 if ((flags & UVM_FLAG_TRYLOCK) != 0) {
1160 return EAGAIN;
1161 }
1162 vm_map_lock(map); /* could sleep here */
1163 }
1164 if (flags & UVM_FLAG_UNMAP) {
1165 KASSERT(flags & UVM_FLAG_FIXED);
1166 KASSERT((flags & UVM_FLAG_NOWAIT) == 0);
1167
1168 /*
1169 * Set prev_entry to what it will need to be after any existing
1170 * entries are removed later in uvm_map_enter().
1171 */
1172
1173 if (uvm_map_lookup_entry(map, start, &prev_entry)) {
1174 if (start == prev_entry->start)
1175 prev_entry = prev_entry->prev;
1176 else
1177 UVM_MAP_CLIP_END(map, prev_entry, start);
1178 SAVE_HINT(map, map->hint, prev_entry);
1179 }
1180 } else {
1181 prev_entry = uvm_map_findspace(map, start, size, &start,
1182 uobj, uoffset, align, flags);
1183 }
1184 if (prev_entry == NULL) {
1185 unsigned int timestamp;
1186
1187 timestamp = map->timestamp;
1188 UVMHIST_LOG(maphist,"waiting va timestamp=%#jx",
1189 timestamp,0,0,0);
1190 map->flags |= VM_MAP_WANTVA;
1191 vm_map_unlock(map);
1192
1193 /*
1194 * try to reclaim kva and wait until someone does unmap.
1195 * fragile locking here, so we awaken every second to
1196 * recheck the condition.
1197 */
1198
1199 mutex_enter(&map->misc_lock);
1200 while ((map->flags & VM_MAP_WANTVA) != 0 &&
1201 map->timestamp == timestamp) {
1202 if ((flags & UVM_FLAG_WAITVA) == 0) {
1203 mutex_exit(&map->misc_lock);
1204 UVMHIST_LOG(maphist,
1205 "<- uvm_map_findspace failed!", 0,0,0,0);
1206 return ENOMEM;
1207 } else {
1208 cv_timedwait(&map->cv, &map->misc_lock, hz);
1209 }
1210 }
1211 mutex_exit(&map->misc_lock);
1212 goto retry;
1213 }
1214
1215 #ifdef PMAP_GROWKERNEL
1216 /*
1217 * If the kernel pmap can't map the requested space,
1218 * then allocate more resources for it.
1219 */
1220 if (map == kernel_map && uvm_maxkaddr < (start + size))
1221 uvm_maxkaddr = pmap_growkernel(start + size);
1222 #endif
1223
1224 UVMMAP_EVCNT_INCR(map_call);
1225
1226 /*
1227 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER
1228 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in
1229 * either case we want to zero it before storing it in the map entry
1230 * (because it looks strange and confusing when debugging...)
1231 *
1232 * if uobj is not null
1233 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping
1234 * and we do not need to change uoffset.
1235 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset
1236 * now (based on the starting address of the map). this case is
1237 * for kernel object mappings where we don't know the offset until
1238 * the virtual address is found (with uvm_map_findspace). the
1239 * offset is the distance we are from the start of the map.
1240 */
1241
1242 if (uobj == NULL) {
1243 uoffset = 0;
1244 } else {
1245 if (uoffset == UVM_UNKNOWN_OFFSET) {
1246 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj));
1247 uoffset = start - vm_map_min(kernel_map);
1248 }
1249 }
1250
1251 args->uma_flags = flags;
1252 args->uma_prev = prev_entry;
1253 args->uma_start = start;
1254 args->uma_size = size;
1255 args->uma_uobj = uobj;
1256 args->uma_uoffset = uoffset;
1257
1258 UVMHIST_LOG(maphist, "<- done!", 0,0,0,0);
1259 return 0;
1260 }
1261
1262 /*
1263 * uvm_map_enter:
1264 *
1265 * called with map locked.
1266 * unlock the map before returning.
1267 */
1268
1269 int
1270 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args,
1271 struct vm_map_entry *new_entry)
1272 {
1273 struct vm_map_entry *prev_entry = args->uma_prev;
1274 struct vm_map_entry *dead = NULL, *dead_entries = NULL;
1275
1276 const uvm_flag_t flags = args->uma_flags;
1277 const vm_prot_t prot = UVM_PROTECTION(flags);
1278 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags);
1279 const vm_inherit_t inherit = UVM_INHERIT(flags);
1280 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ?
1281 AMAP_EXTEND_NOWAIT : 0;
1282 const int advice = UVM_ADVICE(flags);
1283
1284 vaddr_t start = args->uma_start;
1285 vsize_t size = args->uma_size;
1286 struct uvm_object *uobj = args->uma_uobj;
1287 voff_t uoffset = args->uma_uoffset;
1288
1289 const int kmap = (vm_map_pmap(map) == pmap_kernel());
1290 int merged = 0;
1291 int error;
1292 int newetype;
1293
1294 UVMHIST_FUNC(__func__);
1295 UVMHIST_CALLARGS(maphist, "(map=%#jx, start=%#jx, size=%ju, flags=%#jx)",
1296 (uintptr_t)map, start, size, flags);
1297 UVMHIST_LOG(maphist, " uobj/offset %#jx/%jd", (uintptr_t)uobj,
1298 uoffset,0,0);
1299
1300 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */
1301 KASSERT(vm_map_locked_p(map));
1302 KASSERT((flags & (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP)) !=
1303 (UVM_FLAG_NOWAIT | UVM_FLAG_UNMAP));
1304
1305 if (uobj)
1306 newetype = UVM_ET_OBJ;
1307 else
1308 newetype = 0;
1309
1310 if (flags & UVM_FLAG_COPYONW) {
1311 newetype |= UVM_ET_COPYONWRITE;
1312 if ((flags & UVM_FLAG_OVERLAY) == 0)
1313 newetype |= UVM_ET_NEEDSCOPY;
1314 }
1315
1316 /*
1317 * For mappings with unmap, remove any old entries now. Adding the new
1318 * entry cannot fail because that can only happen if UVM_FLAG_NOWAIT
1319 * is set, and we do not support nowait and unmap together.
1320 */
1321
1322 if (flags & UVM_FLAG_UNMAP) {
1323 KASSERT(flags & UVM_FLAG_FIXED);
1324 uvm_unmap_remove(map, start, start + size, &dead_entries, 0);
1325 #ifdef DEBUG
1326 struct vm_map_entry *tmp_entry __diagused;
1327 bool rv __diagused;
1328
1329 rv = uvm_map_lookup_entry(map, start, &tmp_entry);
1330 KASSERT(!rv);
1331 KASSERTMSG(prev_entry == tmp_entry,
1332 "args %p prev_entry %p tmp_entry %p",
1333 args, prev_entry, tmp_entry);
1334 #endif
1335 SAVE_HINT(map, map->hint, prev_entry);
1336 }
1337
1338 /*
1339 * try and insert in map by extending previous entry, if possible.
1340 * XXX: we don't try and pull back the next entry. might be useful
1341 * for a stack, but we are currently allocating our stack in advance.
1342 */
1343
1344 if (flags & UVM_FLAG_NOMERGE)
1345 goto nomerge;
1346
1347 if (prev_entry->end == start &&
1348 prev_entry != &map->header &&
1349 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, 0,
1350 prot, maxprot, inherit, advice, 0)) {
1351
1352 if (uobj && prev_entry->offset +
1353 (prev_entry->end - prev_entry->start) != uoffset)
1354 goto forwardmerge;
1355
1356 /*
1357 * can't extend a shared amap. note: no need to lock amap to
1358 * look at refs since we don't care about its exact value.
1359 * if it is one (i.e. we have only reference) it will stay there
1360 */
1361
1362 if (prev_entry->aref.ar_amap &&
1363 amap_refs(prev_entry->aref.ar_amap) != 1) {
1364 goto forwardmerge;
1365 }
1366
1367 if (prev_entry->aref.ar_amap) {
1368 error = amap_extend(prev_entry, size,
1369 amapwaitflag | AMAP_EXTEND_FORWARDS);
1370 if (error)
1371 goto nomerge;
1372 }
1373
1374 if (kmap) {
1375 UVMMAP_EVCNT_INCR(kbackmerge);
1376 } else {
1377 UVMMAP_EVCNT_INCR(ubackmerge);
1378 }
1379 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0);
1380
1381 /*
1382 * drop our reference to uobj since we are extending a reference
1383 * that we already have (the ref count can not drop to zero).
1384 */
1385
1386 if (uobj && uobj->pgops->pgo_detach)
1387 uobj->pgops->pgo_detach(uobj);
1388
1389 /*
1390 * Now that we've merged the entries, note that we've grown
1391 * and our gap has shrunk. Then fix the tree.
1392 */
1393 prev_entry->end += size;
1394 prev_entry->gap -= size;
1395 uvm_rb_fixup(map, prev_entry);
1396
1397 uvm_map_check(map, "map backmerged");
1398
1399 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0);
1400 merged++;
1401 }
1402
1403 forwardmerge:
1404 if (prev_entry->next->start == (start + size) &&
1405 prev_entry->next != &map->header &&
1406 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, 0,
1407 prot, maxprot, inherit, advice, 0)) {
1408
1409 if (uobj && prev_entry->next->offset != uoffset + size)
1410 goto nomerge;
1411
1412 /*
1413 * can't extend a shared amap. note: no need to lock amap to
1414 * look at refs since we don't care about its exact value.
1415 * if it is one (i.e. we have only reference) it will stay there.
1416 *
1417 * note that we also can't merge two amaps, so if we
1418 * merged with the previous entry which has an amap,
1419 * and the next entry also has an amap, we give up.
1420 *
1421 * Interesting cases:
1422 * amap, new, amap -> give up second merge (single fwd extend)
1423 * amap, new, none -> double forward extend (extend again here)
1424 * none, new, amap -> double backward extend (done here)
1425 * uobj, new, amap -> single backward extend (done here)
1426 *
1427 * XXX should we attempt to deal with someone refilling
1428 * the deallocated region between two entries that are
1429 * backed by the same amap (ie, arefs is 2, "prev" and
1430 * "next" refer to it, and adding this allocation will
1431 * close the hole, thus restoring arefs to 1 and
1432 * deallocating the "next" vm_map_entry)? -- @@@
1433 */
1434
1435 if (prev_entry->next->aref.ar_amap &&
1436 (amap_refs(prev_entry->next->aref.ar_amap) != 1 ||
1437 (merged && prev_entry->aref.ar_amap))) {
1438 goto nomerge;
1439 }
1440
1441 if (merged) {
1442 /*
1443 * Try to extend the amap of the previous entry to
1444 * cover the next entry as well. If it doesn't work
1445 * just skip on, don't actually give up, since we've
1446 * already completed the back merge.
1447 */
1448 if (prev_entry->aref.ar_amap) {
1449 if (amap_extend(prev_entry,
1450 prev_entry->next->end -
1451 prev_entry->next->start,
1452 amapwaitflag | AMAP_EXTEND_FORWARDS))
1453 goto nomerge;
1454 }
1455
1456 /*
1457 * Try to extend the amap of the *next* entry
1458 * back to cover the new allocation *and* the
1459 * previous entry as well (the previous merge
1460 * didn't have an amap already otherwise we
1461 * wouldn't be checking here for an amap). If
1462 * it doesn't work just skip on, again, don't
1463 * actually give up, since we've already
1464 * completed the back merge.
1465 */
1466 else if (prev_entry->next->aref.ar_amap) {
1467 if (amap_extend(prev_entry->next,
1468 prev_entry->end -
1469 prev_entry->start,
1470 amapwaitflag | AMAP_EXTEND_BACKWARDS))
1471 goto nomerge;
1472 }
1473 } else {
1474 /*
1475 * Pull the next entry's amap backwards to cover this
1476 * new allocation.
1477 */
1478 if (prev_entry->next->aref.ar_amap) {
1479 error = amap_extend(prev_entry->next, size,
1480 amapwaitflag | AMAP_EXTEND_BACKWARDS);
1481 if (error)
1482 goto nomerge;
1483 }
1484 }
1485
1486 if (merged) {
1487 if (kmap) {
1488 UVMMAP_EVCNT_DECR(kbackmerge);
1489 UVMMAP_EVCNT_INCR(kbimerge);
1490 } else {
1491 UVMMAP_EVCNT_DECR(ubackmerge);
1492 UVMMAP_EVCNT_INCR(ubimerge);
1493 }
1494 } else {
1495 if (kmap) {
1496 UVMMAP_EVCNT_INCR(kforwmerge);
1497 } else {
1498 UVMMAP_EVCNT_INCR(uforwmerge);
1499 }
1500 }
1501 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0);
1502
1503 /*
1504 * drop our reference to uobj since we are extending a reference
1505 * that we already have (the ref count can not drop to zero).
1506 */
1507 if (uobj && uobj->pgops->pgo_detach)
1508 uobj->pgops->pgo_detach(uobj);
1509
1510 if (merged) {
1511 dead = prev_entry->next;
1512 prev_entry->end = dead->end;
1513 uvm_map_entry_unlink(map, dead);
1514 if (dead->aref.ar_amap != NULL) {
1515 prev_entry->aref = dead->aref;
1516 dead->aref.ar_amap = NULL;
1517 }
1518 } else {
1519 prev_entry->next->start -= size;
1520 if (prev_entry != &map->header) {
1521 prev_entry->gap -= size;
1522 KASSERT(prev_entry->gap == uvm_rb_gap(prev_entry));
1523 uvm_rb_fixup(map, prev_entry);
1524 }
1525 if (uobj)
1526 prev_entry->next->offset = uoffset;
1527 }
1528
1529 uvm_map_check(map, "map forwardmerged");
1530
1531 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0);
1532 merged++;
1533 }
1534
1535 nomerge:
1536 if (!merged) {
1537 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0);
1538 if (kmap) {
1539 UVMMAP_EVCNT_INCR(knomerge);
1540 } else {
1541 UVMMAP_EVCNT_INCR(unomerge);
1542 }
1543
1544 /*
1545 * allocate new entry and link it in.
1546 */
1547
1548 if (new_entry == NULL) {
1549 new_entry = uvm_mapent_alloc(map,
1550 (flags & UVM_FLAG_NOWAIT));
1551 if (__predict_false(new_entry == NULL)) {
1552 error = ENOMEM;
1553 goto done;
1554 }
1555 }
1556 new_entry->start = start;
1557 new_entry->end = new_entry->start + size;
1558 new_entry->object.uvm_obj = uobj;
1559 new_entry->offset = uoffset;
1560
1561 new_entry->etype = newetype;
1562
1563 if (flags & UVM_FLAG_NOMERGE) {
1564 new_entry->flags |= UVM_MAP_NOMERGE;
1565 }
1566
1567 new_entry->protection = prot;
1568 new_entry->max_protection = maxprot;
1569 new_entry->inheritance = inherit;
1570 new_entry->wired_count = 0;
1571 new_entry->advice = advice;
1572 if (flags & UVM_FLAG_OVERLAY) {
1573
1574 /*
1575 * to_add: for BSS we overallocate a little since we
1576 * are likely to extend
1577 */
1578
1579 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ?
1580 UVM_AMAP_CHUNK << PAGE_SHIFT : 0;
1581 struct vm_amap *amap = amap_alloc(size, to_add,
1582 (flags & UVM_FLAG_NOWAIT));
1583 if (__predict_false(amap == NULL)) {
1584 error = ENOMEM;
1585 goto done;
1586 }
1587 new_entry->aref.ar_pageoff = 0;
1588 new_entry->aref.ar_amap = amap;
1589 } else {
1590 new_entry->aref.ar_pageoff = 0;
1591 new_entry->aref.ar_amap = NULL;
1592 }
1593 uvm_map_entry_link(map, prev_entry, new_entry);
1594
1595 /*
1596 * Update the free space hint
1597 */
1598
1599 if ((map->first_free == prev_entry) &&
1600 (prev_entry->end >= new_entry->start))
1601 map->first_free = new_entry;
1602
1603 new_entry = NULL;
1604 }
1605
1606 map->size += size;
1607
1608 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
1609
1610 error = 0;
1611
1612 done:
1613 vm_map_unlock(map);
1614
1615 if (new_entry) {
1616 uvm_mapent_free(new_entry);
1617 }
1618 if (dead) {
1619 KDASSERT(merged);
1620 uvm_mapent_free(dead);
1621 }
1622 if (dead_entries)
1623 uvm_unmap_detach(dead_entries, 0);
1624
1625 return error;
1626 }
1627
1628 /*
1629 * uvm_map_lookup_entry_bytree: lookup an entry in tree
1630 */
1631
1632 static inline bool
1633 uvm_map_lookup_entry_bytree(struct vm_map *map, vaddr_t address,
1634 struct vm_map_entry **entry /* OUT */)
1635 {
1636 struct vm_map_entry *prev = &map->header;
1637 struct vm_map_entry *cur = ROOT_ENTRY(map);
1638
1639 while (cur) {
1640 UVMMAP_EVCNT_INCR(mlk_treeloop);
1641 if (address >= cur->start) {
1642 if (address < cur->end) {
1643 *entry = cur;
1644 return true;
1645 }
1646 prev = cur;
1647 cur = RIGHT_ENTRY(cur);
1648 } else
1649 cur = LEFT_ENTRY(cur);
1650 }
1651 *entry = prev;
1652 return false;
1653 }
1654
1655 /*
1656 * uvm_map_lookup_entry: find map entry at or before an address
1657 *
1658 * => map must at least be read-locked by caller
1659 * => entry is returned in "entry"
1660 * => return value is true if address is in the returned entry
1661 */
1662
1663 bool
1664 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address,
1665 struct vm_map_entry **entry /* OUT */)
1666 {
1667 struct vm_map_entry *cur;
1668 UVMHIST_FUNC(__func__);
1669 UVMHIST_CALLARGS(maphist,"(map=%#jx,addr=%#jx,ent=%#jx)",
1670 (uintptr_t)map, address, (uintptr_t)entry, 0);
1671
1672 /*
1673 * make a quick check to see if we are already looking at
1674 * the entry we want (which is usually the case). note also
1675 * that we don't need to save the hint here... it is the
1676 * same hint (unless we are at the header, in which case the
1677 * hint didn't buy us anything anyway).
1678 */
1679
1680 cur = map->hint;
1681 UVMMAP_EVCNT_INCR(mlk_call);
1682 if (cur != &map->header &&
1683 address >= cur->start && cur->end > address) {
1684 UVMMAP_EVCNT_INCR(mlk_hint);
1685 *entry = cur;
1686 UVMHIST_LOG(maphist,"<- got it via hint (%#jx)",
1687 (uintptr_t)cur, 0, 0, 0);
1688 uvm_mapent_check(*entry);
1689 return (true);
1690 }
1691 uvm_map_check(map, __func__);
1692
1693 /*
1694 * lookup in the tree.
1695 */
1696
1697 UVMMAP_EVCNT_INCR(mlk_tree);
1698 if (__predict_true(uvm_map_lookup_entry_bytree(map, address, entry))) {
1699 SAVE_HINT(map, map->hint, *entry);
1700 UVMHIST_LOG(maphist,"<- search got it (%#jx)",
1701 (uintptr_t)cur, 0, 0, 0);
1702 KDASSERT((*entry)->start <= address);
1703 KDASSERT(address < (*entry)->end);
1704 uvm_mapent_check(*entry);
1705 return (true);
1706 }
1707
1708 SAVE_HINT(map, map->hint, *entry);
1709 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0);
1710 KDASSERT((*entry) == &map->header || (*entry)->end <= address);
1711 KDASSERT((*entry)->next == &map->header ||
1712 address < (*entry)->next->start);
1713 return (false);
1714 }
1715
1716 /*
1717 * See if the range between start and start + length fits in the gap
1718 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't
1719 * fit, and -1 address wraps around.
1720 */
1721 static int
1722 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset,
1723 vsize_t align, int flags, int topdown, struct vm_map_entry *entry)
1724 {
1725 vaddr_t end;
1726
1727 #ifdef PMAP_PREFER
1728 /*
1729 * push start address forward as needed to avoid VAC alias problems.
1730 * we only do this if a valid offset is specified.
1731 */
1732
1733 if (uoffset != UVM_UNKNOWN_OFFSET)
1734 PMAP_PREFER(uoffset, start, length, topdown);
1735 #endif
1736 if ((flags & UVM_FLAG_COLORMATCH) != 0) {
1737 KASSERT(align < uvmexp.ncolors);
1738 if (uvmexp.ncolors > 1) {
1739 const u_int colormask = uvmexp.colormask;
1740 const u_int colorsize = colormask + 1;
1741 vaddr_t hint = atop(*start);
1742 const u_int color = hint & colormask;
1743 if (color != align) {
1744 hint -= color; /* adjust to color boundary */
1745 KASSERT((hint & colormask) == 0);
1746 if (topdown) {
1747 if (align > color)
1748 hint -= colorsize;
1749 } else {
1750 if (align < color)
1751 hint += colorsize;
1752 }
1753 *start = ptoa(hint + align); /* adjust to color */
1754 }
1755 }
1756 } else {
1757 KASSERT(powerof2(align));
1758 uvm_map_align_va(start, align, topdown);
1759 /*
1760 * XXX Should we PMAP_PREFER() here again?
1761 * eh...i think we're okay
1762 */
1763 }
1764
1765 /*
1766 * Find the end of the proposed new region. Be sure we didn't
1767 * wrap around the address; if so, we lose. Otherwise, if the
1768 * proposed new region fits before the next entry, we win.
1769 */
1770
1771 end = *start + length;
1772 if (end < *start)
1773 return (-1);
1774
1775 if (entry->next->start >= end && *start >= entry->end)
1776 return (1);
1777
1778 return (0);
1779 }
1780
1781 static void
1782 uvm_findspace_invariants(struct vm_map *map, vaddr_t orig_hint, vaddr_t length,
1783 struct uvm_object *uobj, voff_t uoffset, vsize_t align, int flags,
1784 vaddr_t hint, struct vm_map_entry *entry, int line)
1785 {
1786 const int topdown = map->flags & VM_MAP_TOPDOWN;
1787
1788 KASSERTMSG( topdown || hint >= orig_hint,
1789 "map=%p hint=%#"PRIxVADDR" orig_hint=%#"PRIxVADDR
1790 " length=%#"PRIxVSIZE" uobj=%p uoffset=%#llx align=%"PRIxVSIZE
1791 " flags=%#x entry=%p (uvm_map_findspace line %d)",
1792 map, hint, orig_hint,
1793 length, uobj, (unsigned long long)uoffset, align,
1794 flags, entry, line);
1795 KASSERTMSG(!topdown || hint <= orig_hint,
1796 "map=%p hint=%#"PRIxVADDR" orig_hint=%#"PRIxVADDR
1797 " length=%#"PRIxVSIZE" uobj=%p uoffset=%#llx align=%"PRIxVSIZE
1798 " flags=%#x entry=%p (uvm_map_findspace line %d)",
1799 map, hint, orig_hint,
1800 length, uobj, (unsigned long long)uoffset, align,
1801 flags, entry, line);
1802 }
1803
1804 /*
1805 * uvm_map_findspace: find "length" sized space in "map".
1806 *
1807 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is
1808 * set in "flags" (in which case we insist on using "hint").
1809 * => "result" is VA returned
1810 * => uobj/uoffset are to be used to handle VAC alignment, if required
1811 * => if "align" is non-zero, we attempt to align to that value.
1812 * => caller must at least have read-locked map
1813 * => returns NULL on failure, or pointer to prev. map entry if success
1814 * => note this is a cross between the old vm_map_findspace and vm_map_find
1815 */
1816
1817 struct vm_map_entry *
1818 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length,
1819 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset,
1820 vsize_t align, int flags)
1821 {
1822 #define INVARIANTS() \
1823 uvm_findspace_invariants(map, orig_hint, length, uobj, uoffset, align,\
1824 flags, hint, entry, __LINE__)
1825 struct vm_map_entry *entry = NULL;
1826 struct vm_map_entry *child, *prev, *tmp;
1827 vaddr_t orig_hint __diagused;
1828 const int topdown = map->flags & VM_MAP_TOPDOWN;
1829 int avail;
1830 UVMHIST_FUNC(__func__);
1831 UVMHIST_CALLARGS(maphist, "(map=%#jx, hint=%#jx, len=%ju, flags=%#jx...",
1832 (uintptr_t)map, hint, length, flags);
1833 UVMHIST_LOG(maphist, " uobj=%#jx, uoffset=%#jx, align=%#jx)",
1834 (uintptr_t)uobj, uoffset, align, 0);
1835
1836 KASSERT((flags & UVM_FLAG_COLORMATCH) != 0 || powerof2(align));
1837 KASSERT((flags & UVM_FLAG_COLORMATCH) == 0 || align < uvmexp.ncolors);
1838 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0);
1839
1840 uvm_map_check(map, "map_findspace entry");
1841
1842 /*
1843 * Clamp the hint to the VM map's min/max address, and remmeber
1844 * the clamped original hint. Remember the original hint,
1845 * clamped to the min/max address. If we are aligning, then we
1846 * may have to try again with no alignment constraint if we
1847 * fail the first time.
1848 *
1849 * We use the original hint to verify later that the search has
1850 * been monotonic -- that is, nonincreasing or nondecreasing,
1851 * according to topdown or !topdown respectively. But the
1852 * clamping is not monotonic.
1853 */
1854 if (hint < vm_map_min(map)) { /* check ranges ... */
1855 if (flags & UVM_FLAG_FIXED) {
1856 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0);
1857 return (NULL);
1858 }
1859 hint = vm_map_min(map);
1860 }
1861 if (hint > vm_map_max(map)) {
1862 UVMHIST_LOG(maphist,"<- VA %#jx > range [%#jx->%#jx]",
1863 hint, vm_map_min(map), vm_map_max(map), 0);
1864 return (NULL);
1865 }
1866 orig_hint = hint;
1867 INVARIANTS();
1868
1869 UVMHIST_LOG(maphist,"<- VA %#jx vs range [%#jx->%#jx]",
1870 hint, vm_map_min(map), vm_map_max(map), 0);
1871
1872 /*
1873 * hint may not be aligned properly; we need round up or down it
1874 * before proceeding further.
1875 */
1876 if ((flags & UVM_FLAG_COLORMATCH) == 0) {
1877 uvm_map_align_va(&hint, align, topdown);
1878 INVARIANTS();
1879 }
1880
1881 UVMHIST_LOG(maphist,"<- VA %#jx vs range [%#jx->%#jx]",
1882 hint, vm_map_min(map), vm_map_max(map), 0);
1883 /*
1884 * Look for the first possible address; if there's already
1885 * something at this address, we have to start after it.
1886 */
1887
1888 /*
1889 * @@@: there are four, no, eight cases to consider.
1890 *
1891 * 0: found, fixed, bottom up -> fail
1892 * 1: found, fixed, top down -> fail
1893 * 2: found, not fixed, bottom up -> start after entry->end,
1894 * loop up
1895 * 3: found, not fixed, top down -> start before entry->start,
1896 * loop down
1897 * 4: not found, fixed, bottom up -> check entry->next->start, fail
1898 * 5: not found, fixed, top down -> check entry->next->start, fail
1899 * 6: not found, not fixed, bottom up -> check entry->next->start,
1900 * loop up
1901 * 7: not found, not fixed, top down -> check entry->next->start,
1902 * loop down
1903 *
1904 * as you can see, it reduces to roughly five cases, and that
1905 * adding top down mapping only adds one unique case (without
1906 * it, there would be four cases).
1907 */
1908
1909 if ((flags & UVM_FLAG_FIXED) == 0 &&
1910 hint == (topdown ? vm_map_max(map) : vm_map_min(map))) {
1911 /*
1912 * The uvm_map_findspace algorithm is monotonic -- for
1913 * topdown VM it starts with a high hint and returns a
1914 * lower free address; for !topdown VM it starts with a
1915 * low hint and returns a higher free address. As an
1916 * optimization, start with the first (highest for
1917 * topdown, lowest for !topdown) free address.
1918 *
1919 * XXX This `optimization' probably doesn't actually do
1920 * much in practice unless userland explicitly passes
1921 * the VM map's minimum or maximum address, which
1922 * varies from machine to machine (VM_MAX/MIN_ADDRESS,
1923 * e.g. 0x7fbfdfeff000 on amd64 but 0xfffffffff000 on
1924 * aarch64) and may vary according to other factors
1925 * like sysctl vm.user_va0_disable. In particular, if
1926 * the user specifies 0 as a hint to mmap, then mmap
1927 * will choose a default address which is usually _not_
1928 * VM_MAX/MIN_ADDRESS but something else instead like
1929 * VM_MAX_ADDRESS - stack size - guard page overhead,
1930 * in which case this branch is never hit.
1931 *
1932 * In fact, this branch appears to have been broken for
1933 * two decades between when topdown was introduced in
1934 * ~2003 and when it was adapted to handle the topdown
1935 * case without violating the monotonicity assertion in
1936 * 2022. Maybe Someone^TM should either ditch the
1937 * optimization or find a better way to do it.
1938 */
1939 entry = map->first_free;
1940 } else {
1941 if (uvm_map_lookup_entry(map, hint, &entry)) {
1942 /* "hint" address already in use ... */
1943 if (flags & UVM_FLAG_FIXED) {
1944 UVMHIST_LOG(maphist, "<- fixed & VA in use",
1945 0, 0, 0, 0);
1946 return (NULL);
1947 }
1948 if (topdown)
1949 /* Start from lower gap. */
1950 entry = entry->prev;
1951 } else if (flags & UVM_FLAG_FIXED) {
1952 if (entry->next->start >= hint + length &&
1953 hint + length > hint)
1954 goto found;
1955
1956 /* "hint" address is gap but too small */
1957 UVMHIST_LOG(maphist, "<- fixed mapping failed",
1958 0, 0, 0, 0);
1959 return (NULL); /* only one shot at it ... */
1960 } else {
1961 /*
1962 * See if given hint fits in this gap.
1963 */
1964 avail = uvm_map_space_avail(&hint, length,
1965 uoffset, align, flags, topdown, entry);
1966 INVARIANTS();
1967 switch (avail) {
1968 case 1:
1969 goto found;
1970 case -1:
1971 goto wraparound;
1972 }
1973
1974 if (topdown) {
1975 /*
1976 * Still there is a chance to fit
1977 * if hint > entry->end.
1978 */
1979 } else {
1980 /* Start from higher gap. */
1981 entry = entry->next;
1982 if (entry == &map->header)
1983 goto notfound;
1984 goto nextgap;
1985 }
1986 }
1987 }
1988
1989 /*
1990 * Note that all UVM_FLAGS_FIXED case is already handled.
1991 */
1992 KDASSERT((flags & UVM_FLAG_FIXED) == 0);
1993
1994 /* Try to find the space in the red-black tree */
1995
1996 /* Check slot before any entry */
1997 if (topdown) {
1998 KASSERTMSG(entry->next->start >= vm_map_min(map),
1999 "map=%p entry=%p entry->next=%p"
2000 " entry->next->start=0x%"PRIxVADDR" min=0x%"PRIxVADDR,
2001 map, entry, entry->next,
2002 entry->next->start, vm_map_min(map));
2003 if (length > entry->next->start - vm_map_min(map))
2004 hint = vm_map_min(map); /* XXX goto wraparound? */
2005 else
2006 hint = entry->next->start - length;
2007 KASSERT(hint >= vm_map_min(map));
2008 } else {
2009 hint = entry->end;
2010 }
2011 INVARIANTS();
2012 avail = uvm_map_space_avail(&hint, length, uoffset, align, flags,
2013 topdown, entry);
2014 INVARIANTS();
2015 switch (avail) {
2016 case 1:
2017 goto found;
2018 case -1:
2019 goto wraparound;
2020 }
2021
2022 nextgap:
2023 KDASSERT((flags & UVM_FLAG_FIXED) == 0);
2024 /* If there is not enough space in the whole tree, we fail */
2025 tmp = ROOT_ENTRY(map);
2026 if (tmp == NULL || tmp->maxgap < length)
2027 goto notfound;
2028
2029 prev = NULL; /* previous candidate */
2030
2031 /* Find an entry close to hint that has enough space */
2032 for (; tmp;) {
2033 KASSERT(tmp->next->start == tmp->end + tmp->gap);
2034 if (topdown) {
2035 if (tmp->next->start < hint + length &&
2036 (prev == NULL || tmp->end > prev->end)) {
2037 if (tmp->gap >= length)
2038 prev = tmp;
2039 else if ((child = LEFT_ENTRY(tmp)) != NULL
2040 && child->maxgap >= length)
2041 prev = tmp;
2042 }
2043 } else {
2044 if (tmp->end >= hint &&
2045 (prev == NULL || tmp->end < prev->end)) {
2046 if (tmp->gap >= length)
2047 prev = tmp;
2048 else if ((child = RIGHT_ENTRY(tmp)) != NULL
2049 && child->maxgap >= length)
2050 prev = tmp;
2051 }
2052 }
2053 if (tmp->next->start < hint + length)
2054 child = RIGHT_ENTRY(tmp);
2055 else if (tmp->end > hint)
2056 child = LEFT_ENTRY(tmp);
2057 else {
2058 if (tmp->gap >= length)
2059 break;
2060 if (topdown)
2061 child = LEFT_ENTRY(tmp);
2062 else
2063 child = RIGHT_ENTRY(tmp);
2064 }
2065 if (child == NULL || child->maxgap < length)
2066 break;
2067 tmp = child;
2068 }
2069
2070 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) {
2071 /*
2072 * Check if the entry that we found satifies the
2073 * space requirement
2074 */
2075 if (topdown) {
2076 if (hint > tmp->next->start - length)
2077 hint = tmp->next->start - length;
2078 } else {
2079 if (hint < tmp->end)
2080 hint = tmp->end;
2081 }
2082 INVARIANTS();
2083 avail = uvm_map_space_avail(&hint, length, uoffset, align,
2084 flags, topdown, tmp);
2085 INVARIANTS();
2086 switch (avail) {
2087 case 1:
2088 entry = tmp;
2089 goto found;
2090 case -1:
2091 goto wraparound;
2092 }
2093 if (tmp->gap >= length)
2094 goto listsearch;
2095 }
2096 if (prev == NULL)
2097 goto notfound;
2098
2099 if (topdown) {
2100 KASSERT(orig_hint >= prev->next->start - length ||
2101 prev->next->start - length > prev->next->start);
2102 hint = prev->next->start - length;
2103 } else {
2104 KASSERT(orig_hint <= prev->end);
2105 hint = prev->end;
2106 }
2107 INVARIANTS();
2108 avail = uvm_map_space_avail(&hint, length, uoffset, align,
2109 flags, topdown, prev);
2110 INVARIANTS();
2111 switch (avail) {
2112 case 1:
2113 entry = prev;
2114 goto found;
2115 case -1:
2116 goto wraparound;
2117 }
2118 if (prev->gap >= length)
2119 goto listsearch;
2120
2121 if (topdown)
2122 tmp = LEFT_ENTRY(prev);
2123 else
2124 tmp = RIGHT_ENTRY(prev);
2125 for (;;) {
2126 KASSERT(tmp && tmp->maxgap >= length);
2127 if (topdown)
2128 child = RIGHT_ENTRY(tmp);
2129 else
2130 child = LEFT_ENTRY(tmp);
2131 if (child && child->maxgap >= length) {
2132 tmp = child;
2133 continue;
2134 }
2135 if (tmp->gap >= length)
2136 break;
2137 if (topdown)
2138 tmp = LEFT_ENTRY(tmp);
2139 else
2140 tmp = RIGHT_ENTRY(tmp);
2141 }
2142
2143 if (topdown) {
2144 KASSERT(orig_hint >= tmp->next->start - length ||
2145 tmp->next->start - length > tmp->next->start);
2146 hint = tmp->next->start - length;
2147 } else {
2148 KASSERT(orig_hint <= tmp->end);
2149 hint = tmp->end;
2150 }
2151 INVARIANTS();
2152 avail = uvm_map_space_avail(&hint, length, uoffset, align,
2153 flags, topdown, tmp);
2154 INVARIANTS();
2155 switch (avail) {
2156 case 1:
2157 entry = tmp;
2158 goto found;
2159 case -1:
2160 goto wraparound;
2161 }
2162
2163 /*
2164 * The tree fails to find an entry because of offset or alignment
2165 * restrictions. Search the list instead.
2166 */
2167 listsearch:
2168 /*
2169 * Look through the rest of the map, trying to fit a new region in
2170 * the gap between existing regions, or after the very last region.
2171 * note: entry->end = base VA of current gap,
2172 * entry->next->start = VA of end of current gap
2173 */
2174
2175 INVARIANTS();
2176 for (;;) {
2177 /* Update hint for current gap. */
2178 hint = topdown ? entry->next->start - length : entry->end;
2179 INVARIANTS();
2180
2181 /* See if it fits. */
2182 avail = uvm_map_space_avail(&hint, length, uoffset, align,
2183 flags, topdown, entry);
2184 INVARIANTS();
2185 switch (avail) {
2186 case 1:
2187 goto found;
2188 case -1:
2189 goto wraparound;
2190 }
2191
2192 /* Advance to next/previous gap */
2193 if (topdown) {
2194 if (entry == &map->header) {
2195 UVMHIST_LOG(maphist, "<- failed (off start)",
2196 0,0,0,0);
2197 goto notfound;
2198 }
2199 entry = entry->prev;
2200 } else {
2201 entry = entry->next;
2202 if (entry == &map->header) {
2203 UVMHIST_LOG(maphist, "<- failed (off end)",
2204 0,0,0,0);
2205 goto notfound;
2206 }
2207 }
2208 }
2209
2210 found:
2211 SAVE_HINT(map, map->hint, entry);
2212 *result = hint;
2213 UVMHIST_LOG(maphist,"<- got it! (result=%#jx)", hint, 0,0,0);
2214 INVARIANTS();
2215 KASSERT(entry->end <= hint);
2216 KASSERT(hint + length <= entry->next->start);
2217 return (entry);
2218
2219 wraparound:
2220 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0);
2221
2222 return (NULL);
2223
2224 notfound:
2225 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0);
2226
2227 return (NULL);
2228 #undef INVARIANTS
2229 }
2230
2231 /*
2232 * U N M A P - m a i n h e l p e r f u n c t i o n s
2233 */
2234
2235 /*
2236 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop")
2237 *
2238 * => caller must check alignment and size
2239 * => map must be locked by caller
2240 * => we return a list of map entries that we've remove from the map
2241 * in "entry_list"
2242 */
2243
2244 void
2245 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end,
2246 struct vm_map_entry **entry_list /* OUT */, int flags)
2247 {
2248 struct vm_map_entry *entry, *first_entry, *next;
2249 vaddr_t len;
2250 UVMHIST_FUNC(__func__);
2251 UVMHIST_CALLARGS(maphist,"(map=%#jx, start=%#jx, end=%#jx)",
2252 (uintptr_t)map, start, end, 0);
2253 VM_MAP_RANGE_CHECK(map, start, end);
2254
2255 uvm_map_check(map, "unmap_remove entry");
2256
2257 /*
2258 * find first entry
2259 */
2260
2261 if (uvm_map_lookup_entry(map, start, &first_entry) == true) {
2262 /* clip and go... */
2263 entry = first_entry;
2264 UVM_MAP_CLIP_START(map, entry, start);
2265 /* critical! prevents stale hint */
2266 SAVE_HINT(map, entry, entry->prev);
2267 } else {
2268 entry = first_entry->next;
2269 }
2270
2271 /*
2272 * save the free space hint
2273 */
2274
2275 if (map->first_free != &map->header && map->first_free->start >= start)
2276 map->first_free = entry->prev;
2277
2278 /*
2279 * note: we now re-use first_entry for a different task. we remove
2280 * a number of map entries from the map and save them in a linked
2281 * list headed by "first_entry". once we remove them from the map
2282 * the caller should unlock the map and drop the references to the
2283 * backing objects [c.f. uvm_unmap_detach]. the object is to
2284 * separate unmapping from reference dropping. why?
2285 * [1] the map has to be locked for unmapping
2286 * [2] the map need not be locked for reference dropping
2287 * [3] dropping references may trigger pager I/O, and if we hit
2288 * a pager that does synchronous I/O we may have to wait for it.
2289 * [4] we would like all waiting for I/O to occur with maps unlocked
2290 * so that we don't block other threads.
2291 */
2292
2293 first_entry = NULL;
2294 *entry_list = NULL;
2295
2296 /*
2297 * break up the area into map entry sized regions and unmap. note
2298 * that all mappings have to be removed before we can even consider
2299 * dropping references to amaps or VM objects (otherwise we could end
2300 * up with a mapping to a page on the free list which would be very bad)
2301 */
2302
2303 while ((entry != &map->header) && (entry->start < end)) {
2304 KASSERT((entry->flags & UVM_MAP_STATIC) == 0);
2305
2306 UVM_MAP_CLIP_END(map, entry, end);
2307 next = entry->next;
2308 len = entry->end - entry->start;
2309
2310 /*
2311 * unwire before removing addresses from the pmap; otherwise
2312 * unwiring will put the entries back into the pmap (XXX).
2313 */
2314
2315 if (VM_MAPENT_ISWIRED(entry)) {
2316 uvm_map_entry_unwire(map, entry);
2317 }
2318 if (flags & UVM_FLAG_VAONLY) {
2319
2320 /* nothing */
2321
2322 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) {
2323
2324 /*
2325 * if the map is non-pageable, any pages mapped there
2326 * must be wired and entered with pmap_kenter_pa(),
2327 * and we should free any such pages immediately.
2328 * this is mostly used for kmem_map.
2329 */
2330 KASSERT(vm_map_pmap(map) == pmap_kernel());
2331
2332 uvm_km_pgremove_intrsafe(map, entry->start, entry->end);
2333 } else if (UVM_ET_ISOBJ(entry) &&
2334 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) {
2335 panic("%s: kernel object %p %p\n",
2336 __func__, map, entry);
2337 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) {
2338 /*
2339 * remove mappings the standard way. lock object
2340 * and/or amap to ensure vm_page state does not
2341 * change while in pmap_remove().
2342 */
2343
2344 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */
2345 uvm_map_lock_entry(entry, RW_WRITER);
2346 #else
2347 uvm_map_lock_entry(entry, RW_READER);
2348 #endif
2349 pmap_remove(map->pmap, entry->start, entry->end);
2350
2351 /*
2352 * note: if map is dying, leave pmap_update() for
2353 * later. if the map is to be reused (exec) then
2354 * pmap_update() will be called. if the map is
2355 * being disposed of (exit) then pmap_destroy()
2356 * will be called.
2357 */
2358
2359 if ((map->flags & VM_MAP_DYING) == 0) {
2360 pmap_update(vm_map_pmap(map));
2361 } else {
2362 KASSERT(vm_map_pmap(map) != pmap_kernel());
2363 }
2364
2365 uvm_map_unlock_entry(entry);
2366 }
2367
2368 #if defined(UVMDEBUG)
2369 /*
2370 * check if there's remaining mapping,
2371 * which is a bug in caller.
2372 */
2373
2374 vaddr_t va;
2375 for (va = entry->start; va < entry->end;
2376 va += PAGE_SIZE) {
2377 if (pmap_extract(vm_map_pmap(map), va, NULL)) {
2378 panic("%s: %#"PRIxVADDR" has mapping",
2379 __func__, va);
2380 }
2381 }
2382
2383 if (VM_MAP_IS_KERNEL(map) && (flags & UVM_FLAG_NOWAIT) == 0) {
2384 uvm_km_check_empty(map, entry->start,
2385 entry->end);
2386 }
2387 #endif /* defined(UVMDEBUG) */
2388
2389 /*
2390 * remove entry from map and put it on our list of entries
2391 * that we've nuked. then go to next entry.
2392 */
2393
2394 UVMHIST_LOG(maphist, " removed map entry %#jx",
2395 (uintptr_t)entry, 0, 0, 0);
2396
2397 /* critical! prevents stale hint */
2398 SAVE_HINT(map, entry, entry->prev);
2399
2400 uvm_map_entry_unlink(map, entry);
2401 KASSERT(map->size >= len);
2402 map->size -= len;
2403 entry->prev = NULL;
2404 entry->next = first_entry;
2405 first_entry = entry;
2406 entry = next;
2407 }
2408
2409 uvm_map_check(map, "unmap_remove leave");
2410
2411 /*
2412 * now we've cleaned up the map and are ready for the caller to drop
2413 * references to the mapped objects.
2414 */
2415
2416 *entry_list = first_entry;
2417 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0);
2418
2419 if (map->flags & VM_MAP_WANTVA) {
2420 mutex_enter(&map->misc_lock);
2421 map->flags &= ~VM_MAP_WANTVA;
2422 cv_broadcast(&map->cv);
2423 mutex_exit(&map->misc_lock);
2424 }
2425 }
2426
2427 /*
2428 * uvm_unmap_detach: drop references in a chain of map entries
2429 *
2430 * => we will free the map entries as we traverse the list.
2431 */
2432
2433 void
2434 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags)
2435 {
2436 struct vm_map_entry *next_entry;
2437 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
2438
2439 while (first_entry) {
2440 KASSERT(!VM_MAPENT_ISWIRED(first_entry));
2441 UVMHIST_LOG(maphist,
2442 " detach %#jx: amap=%#jx, obj=%#jx, submap?=%jd",
2443 (uintptr_t)first_entry,
2444 (uintptr_t)first_entry->aref.ar_amap,
2445 (uintptr_t)first_entry->object.uvm_obj,
2446 UVM_ET_ISSUBMAP(first_entry));
2447
2448 /*
2449 * drop reference to amap, if we've got one
2450 */
2451
2452 if (first_entry->aref.ar_amap)
2453 uvm_map_unreference_amap(first_entry, flags);
2454
2455 /*
2456 * drop reference to our backing object, if we've got one
2457 */
2458
2459 KASSERT(!UVM_ET_ISSUBMAP(first_entry));
2460 if (UVM_ET_ISOBJ(first_entry) &&
2461 first_entry->object.uvm_obj->pgops->pgo_detach) {
2462 (*first_entry->object.uvm_obj->pgops->pgo_detach)
2463 (first_entry->object.uvm_obj);
2464 }
2465 next_entry = first_entry->next;
2466 uvm_mapent_free(first_entry);
2467 first_entry = next_entry;
2468 }
2469 UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
2470 }
2471
2472 /*
2473 * E X T R A C T I O N F U N C T I O N S
2474 */
2475
2476 /*
2477 * uvm_map_reserve: reserve space in a vm_map for future use.
2478 *
2479 * => we reserve space in a map by putting a dummy map entry in the
2480 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE)
2481 * => map should be unlocked (we will write lock it)
2482 * => we return true if we were able to reserve space
2483 * => XXXCDC: should be inline?
2484 */
2485
2486 int
2487 uvm_map_reserve(struct vm_map *map, vsize_t size,
2488 vaddr_t offset /* hint for pmap_prefer */,
2489 vsize_t align /* alignment */,
2490 vaddr_t *raddr /* IN:hint, OUT: reserved VA */,
2491 uvm_flag_t flags /* UVM_FLAG_FIXED or UVM_FLAG_COLORMATCH or 0 */)
2492 {
2493 UVMHIST_FUNC(__func__);
2494 UVMHIST_CALLARGS(maphist, "(map=%#jx, size=%#jx, offset=%#jx, addr=%#jx)",
2495 (uintptr_t)map, size, offset, (uintptr_t)raddr);
2496
2497 size = round_page(size);
2498
2499 /*
2500 * reserve some virtual space.
2501 */
2502
2503 if (uvm_map(map, raddr, size, NULL, offset, align,
2504 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE,
2505 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) {
2506 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0);
2507 return (false);
2508 }
2509
2510 UVMHIST_LOG(maphist, "<- done (*raddr=%#jx)", *raddr,0,0,0);
2511 return (true);
2512 }
2513
2514 /*
2515 * uvm_map_replace: replace a reserved (blank) area of memory with
2516 * real mappings.
2517 *
2518 * => caller must WRITE-LOCK the map
2519 * => we return true if replacement was a success
2520 * => we expect the newents chain to have nnewents entrys on it and
2521 * we expect newents->prev to point to the last entry on the list
2522 * => note newents is allowed to be NULL
2523 */
2524
2525 static int
2526 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end,
2527 struct vm_map_entry *newents, int nnewents, vsize_t nsize,
2528 struct vm_map_entry **oldentryp)
2529 {
2530 struct vm_map_entry *oldent, *last;
2531
2532 uvm_map_check(map, "map_replace entry");
2533
2534 /*
2535 * first find the blank map entry at the specified address
2536 */
2537
2538 if (!uvm_map_lookup_entry(map, start, &oldent)) {
2539 return (false);
2540 }
2541
2542 /*
2543 * check to make sure we have a proper blank entry
2544 */
2545
2546 if (end < oldent->end) {
2547 UVM_MAP_CLIP_END(map, oldent, end);
2548 }
2549 if (oldent->start != start || oldent->end != end ||
2550 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) {
2551 return (false);
2552 }
2553
2554 #ifdef DIAGNOSTIC
2555
2556 /*
2557 * sanity check the newents chain
2558 */
2559
2560 {
2561 struct vm_map_entry *tmpent = newents;
2562 int nent = 0;
2563 vsize_t sz = 0;
2564 vaddr_t cur = start;
2565
2566 while (tmpent) {
2567 nent++;
2568 sz += tmpent->end - tmpent->start;
2569 if (tmpent->start < cur)
2570 panic("uvm_map_replace1");
2571 if (tmpent->start >= tmpent->end || tmpent->end > end) {
2572 panic("uvm_map_replace2: "
2573 "tmpent->start=%#"PRIxVADDR
2574 ", tmpent->end=%#"PRIxVADDR
2575 ", end=%#"PRIxVADDR,
2576 tmpent->start, tmpent->end, end);
2577 }
2578 cur = tmpent->end;
2579 if (tmpent->next) {
2580 if (tmpent->next->prev != tmpent)
2581 panic("uvm_map_replace3");
2582 } else {
2583 if (newents->prev != tmpent)
2584 panic("uvm_map_replace4");
2585 }
2586 tmpent = tmpent->next;
2587 }
2588 if (nent != nnewents)
2589 panic("uvm_map_replace5");
2590 if (sz != nsize)
2591 panic("uvm_map_replace6");
2592 }
2593 #endif
2594
2595 /*
2596 * map entry is a valid blank! replace it. (this does all the
2597 * work of map entry link/unlink...).
2598 */
2599
2600 if (newents) {
2601 last = newents->prev;
2602
2603 /* critical: flush stale hints out of map */
2604 SAVE_HINT(map, map->hint, newents);
2605 if (map->first_free == oldent)
2606 map->first_free = last;
2607
2608 last->next = oldent->next;
2609 last->next->prev = last;
2610
2611 /* Fix RB tree */
2612 uvm_rb_remove(map, oldent);
2613
2614 newents->prev = oldent->prev;
2615 newents->prev->next = newents;
2616 map->nentries = map->nentries + (nnewents - 1);
2617
2618 /* Fixup the RB tree */
2619 {
2620 int i;
2621 struct vm_map_entry *tmp;
2622
2623 tmp = newents;
2624 for (i = 0; i < nnewents && tmp; i++) {
2625 uvm_rb_insert(map, tmp);
2626 tmp = tmp->next;
2627 }
2628 }
2629 } else {
2630 /* NULL list of new entries: just remove the old one */
2631 clear_hints(map, oldent);
2632 uvm_map_entry_unlink(map, oldent);
2633 }
2634 map->size -= end - start - nsize;
2635
2636 uvm_map_check(map, "map_replace leave");
2637
2638 /*
2639 * now we can free the old blank entry and return.
2640 */
2641
2642 *oldentryp = oldent;
2643 return (true);
2644 }
2645
2646 /*
2647 * uvm_map_extract: extract a mapping from a map and put it somewhere
2648 * (maybe removing the old mapping)
2649 *
2650 * => maps should be unlocked (we will write lock them)
2651 * => returns 0 on success, error code otherwise
2652 * => start must be page aligned
2653 * => len must be page sized
2654 * => flags:
2655 * UVM_EXTRACT_REMOVE: remove mappings from srcmap
2656 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only)
2657 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs
2658 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go
2659 * UVM_EXTRACT_PROT_ALL: set prot to UVM_PROT_ALL as we go
2660 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<<
2661 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only
2662 * be used from within the kernel in a kernel level map <<<
2663 */
2664
2665 int
2666 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len,
2667 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags)
2668 {
2669 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge;
2670 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry,
2671 *deadentry, *oldentry;
2672 struct vm_map_entry *resentry = NULL; /* a dummy reservation entry */
2673 vsize_t elen __unused;
2674 int nchain, error, copy_ok;
2675 vsize_t nsize;
2676 UVMHIST_FUNC(__func__);
2677 UVMHIST_CALLARGS(maphist,"(srcmap=%#jx,start=%#jx, len=%#jx",
2678 (uintptr_t)srcmap, start, len, 0);
2679 UVMHIST_LOG(maphist," ...,dstmap=%#jx, flags=%#jx)",
2680 (uintptr_t)dstmap, flags, 0, 0);
2681
2682 /*
2683 * step 0: sanity check: start must be on a page boundary, length
2684 * must be page sized. can't ask for CONTIG/QREF if you asked for
2685 * REMOVE.
2686 */
2687
2688 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0);
2689 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 ||
2690 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0);
2691
2692 /*
2693 * step 1: reserve space in the target map for the extracted area
2694 */
2695
2696 if ((flags & UVM_EXTRACT_RESERVED) == 0) {
2697 dstaddr = vm_map_min(dstmap);
2698 if (!uvm_map_reserve(dstmap, len, start,
2699 atop(start) & uvmexp.colormask, &dstaddr,
2700 UVM_FLAG_COLORMATCH))
2701 return (ENOMEM);
2702 KASSERT((atop(start ^ dstaddr) & uvmexp.colormask) == 0);
2703 *dstaddrp = dstaddr; /* pass address back to caller */
2704 UVMHIST_LOG(maphist, " dstaddr=%#jx", dstaddr,0,0,0);
2705 } else {
2706 dstaddr = *dstaddrp;
2707 }
2708
2709 /*
2710 * step 2: setup for the extraction process loop by init'ing the
2711 * map entry chain, locking src map, and looking up the first useful
2712 * entry in the map.
2713 */
2714
2715 end = start + len;
2716 newend = dstaddr + len;
2717 chain = endchain = NULL;
2718 nchain = 0;
2719 nsize = 0;
2720 vm_map_lock(srcmap);
2721
2722 if (uvm_map_lookup_entry(srcmap, start, &entry)) {
2723
2724 /* "start" is within an entry */
2725 if (flags & UVM_EXTRACT_QREF) {
2726
2727 /*
2728 * for quick references we don't clip the entry, so
2729 * the entry may map space "before" the starting
2730 * virtual address... this is the "fudge" factor
2731 * (which can be non-zero only the first time
2732 * through the "while" loop in step 3).
2733 */
2734
2735 fudge = start - entry->start;
2736 } else {
2737
2738 /*
2739 * normal reference: we clip the map to fit (thus
2740 * fudge is zero)
2741 */
2742
2743 UVM_MAP_CLIP_START(srcmap, entry, start);
2744 SAVE_HINT(srcmap, srcmap->hint, entry->prev);
2745 fudge = 0;
2746 }
2747 } else {
2748
2749 /* "start" is not within an entry ... skip to next entry */
2750 if (flags & UVM_EXTRACT_CONTIG) {
2751 error = EINVAL;
2752 goto bad; /* definite hole here ... */
2753 }
2754
2755 entry = entry->next;
2756 fudge = 0;
2757 }
2758
2759 /* save values from srcmap for step 6 */
2760 orig_entry = entry;
2761 orig_fudge = fudge;
2762
2763 /*
2764 * step 3: now start looping through the map entries, extracting
2765 * as we go.
2766 */
2767
2768 while (entry->start < end && entry != &srcmap->header) {
2769
2770 /* if we are not doing a quick reference, clip it */
2771 if ((flags & UVM_EXTRACT_QREF) == 0)
2772 UVM_MAP_CLIP_END(srcmap, entry, end);
2773
2774 /* clear needs_copy (allow chunking) */
2775 if (UVM_ET_ISNEEDSCOPY(entry)) {
2776 amap_copy(srcmap, entry,
2777 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end);
2778 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */
2779 error = ENOMEM;
2780 goto bad;
2781 }
2782
2783 /* amap_copy could clip (during chunk)! update fudge */
2784 if (fudge) {
2785 fudge = start - entry->start;
2786 orig_fudge = fudge;
2787 }
2788 }
2789
2790 /* calculate the offset of this from "start" */
2791 oldoffset = (entry->start + fudge) - start;
2792
2793 /* allocate a new map entry */
2794 newentry = uvm_mapent_alloc(dstmap, 0);
2795 if (newentry == NULL) {
2796 error = ENOMEM;
2797 goto bad;
2798 }
2799
2800 /* set up new map entry */
2801 newentry->next = NULL;
2802 newentry->prev = endchain;
2803 newentry->start = dstaddr + oldoffset;
2804 newentry->end =
2805 newentry->start + (entry->end - (entry->start + fudge));
2806 if (newentry->end > newend || newentry->end < newentry->start)
2807 newentry->end = newend;
2808 newentry->object.uvm_obj = entry->object.uvm_obj;
2809 if (newentry->object.uvm_obj) {
2810 if (newentry->object.uvm_obj->pgops->pgo_reference)
2811 newentry->object.uvm_obj->pgops->
2812 pgo_reference(newentry->object.uvm_obj);
2813 newentry->offset = entry->offset + fudge;
2814 } else {
2815 newentry->offset = 0;
2816 }
2817 newentry->etype = entry->etype;
2818 if (flags & UVM_EXTRACT_PROT_ALL) {
2819 newentry->protection = newentry->max_protection =
2820 UVM_PROT_ALL;
2821 } else {
2822 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ?
2823 entry->max_protection : entry->protection;
2824 newentry->max_protection = entry->max_protection;
2825 }
2826 newentry->inheritance = entry->inheritance;
2827 newentry->wired_count = 0;
2828 newentry->aref.ar_amap = entry->aref.ar_amap;
2829 if (newentry->aref.ar_amap) {
2830 newentry->aref.ar_pageoff =
2831 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT);
2832 uvm_map_reference_amap(newentry, AMAP_SHARED |
2833 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0));
2834 } else {
2835 newentry->aref.ar_pageoff = 0;
2836 }
2837 newentry->advice = entry->advice;
2838 if ((flags & UVM_EXTRACT_QREF) != 0) {
2839 newentry->flags |= UVM_MAP_NOMERGE;
2840 }
2841
2842 /* now link it on the chain */
2843 nchain++;
2844 nsize += newentry->end - newentry->start;
2845 if (endchain == NULL) {
2846 chain = endchain = newentry;
2847 } else {
2848 endchain->next = newentry;
2849 endchain = newentry;
2850 }
2851
2852 /* end of 'while' loop! */
2853 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end &&
2854 (entry->next == &srcmap->header ||
2855 entry->next->start != entry->end)) {
2856 error = EINVAL;
2857 goto bad;
2858 }
2859 entry = entry->next;
2860 fudge = 0;
2861 }
2862
2863 /*
2864 * step 4: close off chain (in format expected by uvm_map_replace)
2865 */
2866
2867 if (chain)
2868 chain->prev = endchain;
2869
2870 /*
2871 * step 5: attempt to lock the dest map so we can pmap_copy.
2872 * note usage of copy_ok:
2873 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5)
2874 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7
2875 */
2876
2877 if (srcmap == dstmap || vm_map_lock_try(dstmap) == true) {
2878 copy_ok = 1;
2879 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
2880 nchain, nsize, &resentry)) {
2881 if (srcmap != dstmap)
2882 vm_map_unlock(dstmap);
2883 error = EIO;
2884 goto bad;
2885 }
2886 } else {
2887 copy_ok = 0;
2888 /* replace defered until step 7 */
2889 }
2890
2891 /*
2892 * step 6: traverse the srcmap a second time to do the following:
2893 * - if we got a lock on the dstmap do pmap_copy
2894 * - if UVM_EXTRACT_REMOVE remove the entries
2895 * we make use of orig_entry and orig_fudge (saved in step 2)
2896 */
2897
2898 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) {
2899
2900 /* purge possible stale hints from srcmap */
2901 if (flags & UVM_EXTRACT_REMOVE) {
2902 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev);
2903 if (srcmap->first_free != &srcmap->header &&
2904 srcmap->first_free->start >= start)
2905 srcmap->first_free = orig_entry->prev;
2906 }
2907
2908 entry = orig_entry;
2909 fudge = orig_fudge;
2910 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */
2911
2912 while (entry->start < end && entry != &srcmap->header) {
2913 if (copy_ok) {
2914 oldoffset = (entry->start + fudge) - start;
2915 elen = MIN(end, entry->end) -
2916 (entry->start + fudge);
2917 pmap_copy(dstmap->pmap, srcmap->pmap,
2918 dstaddr + oldoffset, elen,
2919 entry->start + fudge);
2920 }
2921
2922 /* we advance "entry" in the following if statement */
2923 if (flags & UVM_EXTRACT_REMOVE) {
2924 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */
2925 uvm_map_lock_entry(entry, RW_WRITER);
2926 #else
2927 uvm_map_lock_entry(entry, RW_READER);
2928 #endif
2929 pmap_remove(srcmap->pmap, entry->start,
2930 entry->end);
2931 uvm_map_unlock_entry(entry);
2932 oldentry = entry; /* save entry */
2933 entry = entry->next; /* advance */
2934 uvm_map_entry_unlink(srcmap, oldentry);
2935 /* add to dead list */
2936 oldentry->next = deadentry;
2937 deadentry = oldentry;
2938 } else {
2939 entry = entry->next; /* advance */
2940 }
2941
2942 /* end of 'while' loop */
2943 fudge = 0;
2944 }
2945 pmap_update(srcmap->pmap);
2946
2947 /*
2948 * unlock dstmap. we will dispose of deadentry in
2949 * step 7 if needed
2950 */
2951
2952 if (copy_ok && srcmap != dstmap)
2953 vm_map_unlock(dstmap);
2954
2955 } else {
2956 deadentry = NULL;
2957 }
2958
2959 /*
2960 * step 7: we are done with the source map, unlock. if copy_ok
2961 * is 0 then we have not replaced the dummy mapping in dstmap yet
2962 * and we need to do so now.
2963 */
2964
2965 vm_map_unlock(srcmap);
2966 if ((flags & UVM_EXTRACT_REMOVE) && deadentry)
2967 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */
2968
2969 /* now do the replacement if we didn't do it in step 5 */
2970 if (copy_ok == 0) {
2971 vm_map_lock(dstmap);
2972 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain,
2973 nchain, nsize, &resentry);
2974 vm_map_unlock(dstmap);
2975
2976 if (error == false) {
2977 error = EIO;
2978 goto bad2;
2979 }
2980 }
2981
2982 if (resentry != NULL)
2983 uvm_mapent_free(resentry);
2984
2985 return (0);
2986
2987 /*
2988 * bad: failure recovery
2989 */
2990 bad:
2991 vm_map_unlock(srcmap);
2992 bad2: /* src already unlocked */
2993 if (chain)
2994 uvm_unmap_detach(chain,
2995 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0);
2996
2997 if (resentry != NULL)
2998 uvm_mapent_free(resentry);
2999
3000 if ((flags & UVM_EXTRACT_RESERVED) == 0) {
3001 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */
3002 }
3003 return (error);
3004 }
3005
3006 /* end of extraction functions */
3007
3008 /*
3009 * uvm_map_submap: punch down part of a map into a submap
3010 *
3011 * => only the kernel_map is allowed to be submapped
3012 * => the purpose of submapping is to break up the locking granularity
3013 * of a larger map
3014 * => the range specified must have been mapped previously with a uvm_map()
3015 * call [with uobj==NULL] to create a blank map entry in the main map.
3016 * [And it had better still be blank!]
3017 * => maps which contain submaps should never be copied or forked.
3018 * => to remove a submap, use uvm_unmap() on the main map
3019 * and then uvm_map_deallocate() the submap.
3020 * => main map must be unlocked.
3021 * => submap must have been init'd and have a zero reference count.
3022 * [need not be locked as we don't actually reference it]
3023 */
3024
3025 int
3026 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end,
3027 struct vm_map *submap)
3028 {
3029 struct vm_map_entry *entry;
3030 int error;
3031
3032 vm_map_lock(map);
3033 VM_MAP_RANGE_CHECK(map, start, end);
3034
3035 if (uvm_map_lookup_entry(map, start, &entry)) {
3036 UVM_MAP_CLIP_START(map, entry, start);
3037 UVM_MAP_CLIP_END(map, entry, end); /* to be safe */
3038 } else {
3039 entry = NULL;
3040 }
3041
3042 if (entry != NULL &&
3043 entry->start == start && entry->end == end &&
3044 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL &&
3045 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) {
3046 entry->etype |= UVM_ET_SUBMAP;
3047 entry->object.sub_map = submap;
3048 entry->offset = 0;
3049 uvm_map_reference(submap);
3050 error = 0;
3051 } else {
3052 error = EINVAL;
3053 }
3054 vm_map_unlock(map);
3055
3056 return error;
3057 }
3058
3059 /*
3060 * uvm_map_protect_user: change map protection on behalf of the user.
3061 * Enforces PAX settings as necessary.
3062 */
3063 int
3064 uvm_map_protect_user(struct lwp *l, vaddr_t start, vaddr_t end,
3065 vm_prot_t new_prot)
3066 {
3067 int error;
3068
3069 if ((error = PAX_MPROTECT_VALIDATE(l, new_prot)))
3070 return error;
3071
3072 return uvm_map_protect(&l->l_proc->p_vmspace->vm_map, start, end,
3073 new_prot, false);
3074 }
3075
3076
3077 /*
3078 * uvm_map_protect: change map protection
3079 *
3080 * => set_max means set max_protection.
3081 * => map must be unlocked.
3082 */
3083
3084 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \
3085 ~VM_PROT_WRITE : VM_PROT_ALL)
3086
3087 int
3088 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end,
3089 vm_prot_t new_prot, bool set_max)
3090 {
3091 struct vm_map_entry *current, *entry;
3092 int error = 0;
3093 UVMHIST_FUNC(__func__);
3094 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_prot=%#jx)",
3095 (uintptr_t)map, start, end, new_prot);
3096
3097 vm_map_lock(map);
3098 VM_MAP_RANGE_CHECK(map, start, end);
3099 if (uvm_map_lookup_entry(map, start, &entry)) {
3100 UVM_MAP_CLIP_START(map, entry, start);
3101 } else {
3102 entry = entry->next;
3103 }
3104
3105 /*
3106 * make a first pass to check for protection violations.
3107 */
3108
3109 current = entry;
3110 while ((current != &map->header) && (current->start < end)) {
3111 if (UVM_ET_ISSUBMAP(current)) {
3112 error = EINVAL;
3113 goto out;
3114 }
3115 if ((new_prot & current->max_protection) != new_prot) {
3116 error = EACCES;
3117 goto out;
3118 }
3119 /*
3120 * Don't allow VM_PROT_EXECUTE to be set on entries that
3121 * point to vnodes that are associated with a NOEXEC file
3122 * system.
3123 */
3124 if (UVM_ET_ISOBJ(current) &&
3125 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) {
3126 struct vnode *vp =
3127 (struct vnode *) current->object.uvm_obj;
3128
3129 if ((new_prot & VM_PROT_EXECUTE) != 0 &&
3130 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) {
3131 error = EACCES;
3132 goto out;
3133 }
3134 }
3135
3136 current = current->next;
3137 }
3138
3139 /* go back and fix up protections (no need to clip this time). */
3140
3141 current = entry;
3142 while ((current != &map->header) && (current->start < end)) {
3143 vm_prot_t old_prot;
3144
3145 UVM_MAP_CLIP_END(map, current, end);
3146 old_prot = current->protection;
3147 if (set_max)
3148 current->protection =
3149 (current->max_protection = new_prot) & old_prot;
3150 else
3151 current->protection = new_prot;
3152
3153 /*
3154 * update physical map if necessary. worry about copy-on-write
3155 * here -- CHECK THIS XXX
3156 */
3157
3158 if (current->protection != old_prot) {
3159 /* update pmap! */
3160 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */
3161 uvm_map_lock_entry(current, RW_WRITER);
3162 #else
3163 uvm_map_lock_entry(current, RW_READER);
3164 #endif
3165 pmap_protect(map->pmap, current->start, current->end,
3166 current->protection & MASK(current));
3167 uvm_map_unlock_entry(current);
3168
3169 /*
3170 * If this entry points at a vnode, and the
3171 * protection includes VM_PROT_EXECUTE, mark
3172 * the vnode as VEXECMAP.
3173 */
3174 if (UVM_ET_ISOBJ(current)) {
3175 struct uvm_object *uobj =
3176 current->object.uvm_obj;
3177
3178 if (UVM_OBJ_IS_VNODE(uobj) &&
3179 (current->protection & VM_PROT_EXECUTE)) {
3180 vn_markexec((struct vnode *) uobj);
3181 }
3182 }
3183 }
3184
3185 /*
3186 * If the map is configured to lock any future mappings,
3187 * wire this entry now if the old protection was VM_PROT_NONE
3188 * and the new protection is not VM_PROT_NONE.
3189 */
3190
3191 if ((map->flags & VM_MAP_WIREFUTURE) != 0 &&
3192 VM_MAPENT_ISWIRED(current) == 0 &&
3193 old_prot == VM_PROT_NONE &&
3194 new_prot != VM_PROT_NONE) {
3195
3196 /*
3197 * We must call pmap_update() here because the
3198 * pmap_protect() call above might have removed some
3199 * pmap entries and uvm_map_pageable() might create
3200 * some new pmap entries that rely on the prior
3201 * removals being completely finished.
3202 */
3203
3204 pmap_update(map->pmap);
3205
3206 if (uvm_map_pageable(map, current->start,
3207 current->end, false,
3208 UVM_LK_ENTER|UVM_LK_EXIT) != 0) {
3209
3210 /*
3211 * If locking the entry fails, remember the
3212 * error if it's the first one. Note we
3213 * still continue setting the protection in
3214 * the map, but will return the error
3215 * condition regardless.
3216 *
3217 * XXX Ignore what the actual error is,
3218 * XXX just call it a resource shortage
3219 * XXX so that it doesn't get confused
3220 * XXX what uvm_map_protect() itself would
3221 * XXX normally return.
3222 */
3223
3224 error = ENOMEM;
3225 }
3226 }
3227 current = current->next;
3228 }
3229 pmap_update(map->pmap);
3230
3231 out:
3232 vm_map_unlock(map);
3233
3234 UVMHIST_LOG(maphist, "<- done, error=%jd",error,0,0,0);
3235 return error;
3236 }
3237
3238 #undef MASK
3239
3240 /*
3241 * uvm_map_inherit: set inheritance code for range of addrs in map.
3242 *
3243 * => map must be unlocked
3244 * => note that the inherit code is used during a "fork". see fork
3245 * code for details.
3246 */
3247
3248 int
3249 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end,
3250 vm_inherit_t new_inheritance)
3251 {
3252 struct vm_map_entry *entry, *temp_entry;
3253 UVMHIST_FUNC(__func__);
3254 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_inh=%#jx)",
3255 (uintptr_t)map, start, end, new_inheritance);
3256
3257 switch (new_inheritance) {
3258 case MAP_INHERIT_NONE:
3259 case MAP_INHERIT_COPY:
3260 case MAP_INHERIT_SHARE:
3261 case MAP_INHERIT_ZERO:
3262 break;
3263 default:
3264 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
3265 return EINVAL;
3266 }
3267
3268 vm_map_lock(map);
3269 VM_MAP_RANGE_CHECK(map, start, end);
3270 if (uvm_map_lookup_entry(map, start, &temp_entry)) {
3271 entry = temp_entry;
3272 UVM_MAP_CLIP_START(map, entry, start);
3273 } else {
3274 entry = temp_entry->next;
3275 }
3276 while ((entry != &map->header) && (entry->start < end)) {
3277 UVM_MAP_CLIP_END(map, entry, end);
3278 entry->inheritance = new_inheritance;
3279 entry = entry->next;
3280 }
3281 vm_map_unlock(map);
3282 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
3283 return 0;
3284 }
3285
3286 /*
3287 * uvm_map_advice: set advice code for range of addrs in map.
3288 *
3289 * => map must be unlocked
3290 */
3291
3292 int
3293 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice)
3294 {
3295 struct vm_map_entry *entry, *temp_entry;
3296 UVMHIST_FUNC(__func__);
3297 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_adv=%#jx)",
3298 (uintptr_t)map, start, end, new_advice);
3299
3300 vm_map_lock(map);
3301 VM_MAP_RANGE_CHECK(map, start, end);
3302 if (uvm_map_lookup_entry(map, start, &temp_entry)) {
3303 entry = temp_entry;
3304 UVM_MAP_CLIP_START(map, entry, start);
3305 } else {
3306 entry = temp_entry->next;
3307 }
3308
3309 /*
3310 * XXXJRT: disallow holes?
3311 */
3312
3313 while ((entry != &map->header) && (entry->start < end)) {
3314 UVM_MAP_CLIP_END(map, entry, end);
3315
3316 switch (new_advice) {
3317 case MADV_NORMAL:
3318 case MADV_RANDOM:
3319 case MADV_SEQUENTIAL:
3320 /* nothing special here */
3321 break;
3322
3323 default:
3324 vm_map_unlock(map);
3325 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0);
3326 return EINVAL;
3327 }
3328 entry->advice = new_advice;
3329 entry = entry->next;
3330 }
3331
3332 vm_map_unlock(map);
3333 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
3334 return 0;
3335 }
3336
3337 /*
3338 * uvm_map_willneed: apply MADV_WILLNEED
3339 */
3340
3341 int
3342 uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end)
3343 {
3344 struct vm_map_entry *entry;
3345 UVMHIST_FUNC(__func__);
3346 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx)",
3347 (uintptr_t)map, start, end, 0);
3348
3349 vm_map_lock_read(map);
3350 VM_MAP_RANGE_CHECK(map, start, end);
3351 if (!uvm_map_lookup_entry(map, start, &entry)) {
3352 entry = entry->next;
3353 }
3354 while (entry->start < end) {
3355 struct vm_amap * const amap = entry->aref.ar_amap;
3356 struct uvm_object * const uobj = entry->object.uvm_obj;
3357
3358 KASSERT(entry != &map->header);
3359 KASSERT(start < entry->end);
3360 /*
3361 * For now, we handle only the easy but commonly-requested case.
3362 * ie. start prefetching of backing uobj pages.
3363 *
3364 * XXX It might be useful to pmap_enter() the already-in-core
3365 * pages by inventing a "weak" mode for uvm_fault() which would
3366 * only do the PGO_LOCKED pgo_get().
3367 */
3368 if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) {
3369 off_t offset;
3370 off_t size;
3371
3372 offset = entry->offset;
3373 if (start < entry->start) {
3374 offset += entry->start - start;
3375 }
3376 size = entry->offset + (entry->end - entry->start);
3377 if (entry->end < end) {
3378 size -= end - entry->end;
3379 }
3380 uvm_readahead(uobj, offset, size);
3381 }
3382 entry = entry->next;
3383 }
3384 vm_map_unlock_read(map);
3385 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0);
3386 return 0;
3387 }
3388
3389 /*
3390 * uvm_map_pageable: sets the pageability of a range in a map.
3391 *
3392 * => wires map entries. should not be used for transient page locking.
3393 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()).
3394 * => regions specified as not pageable require lock-down (wired) memory
3395 * and page tables.
3396 * => map must never be read-locked
3397 * => if islocked is true, map is already write-locked
3398 * => we always unlock the map, since we must downgrade to a read-lock
3399 * to call uvm_fault_wire()
3400 * => XXXCDC: check this and try and clean it up.
3401 */
3402
3403 int
3404 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end,
3405 bool new_pageable, int lockflags)
3406 {
3407 struct vm_map_entry *entry, *start_entry, *failed_entry;
3408 int rv;
3409 #ifdef DIAGNOSTIC
3410 u_int timestamp_save;
3411 #endif
3412 UVMHIST_FUNC(__func__);
3413 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,new_pageable=%ju)",
3414 (uintptr_t)map, start, end, new_pageable);
3415 KASSERT(map->flags & VM_MAP_PAGEABLE);
3416
3417 if ((lockflags & UVM_LK_ENTER) == 0)
3418 vm_map_lock(map);
3419 VM_MAP_RANGE_CHECK(map, start, end);
3420
3421 /*
3422 * only one pageability change may take place at one time, since
3423 * uvm_fault_wire assumes it will be called only once for each
3424 * wiring/unwiring. therefore, we have to make sure we're actually
3425 * changing the pageability for the entire region. we do so before
3426 * making any changes.
3427 */
3428
3429 if (uvm_map_lookup_entry(map, start, &start_entry) == false) {
3430 if ((lockflags & UVM_LK_EXIT) == 0)
3431 vm_map_unlock(map);
3432
3433 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0);
3434 return EFAULT;
3435 }
3436 entry = start_entry;
3437
3438 if (start == end) { /* nothing required */
3439 if ((lockflags & UVM_LK_EXIT) == 0)
3440 vm_map_unlock(map);
3441
3442 UVMHIST_LOG(maphist,"<- done (nothing)",0,0,0,0);
3443 return 0;
3444 }
3445
3446 /*
3447 * handle wiring and unwiring separately.
3448 */
3449
3450 if (new_pageable) { /* unwire */
3451 UVM_MAP_CLIP_START(map, entry, start);
3452
3453 /*
3454 * unwiring. first ensure that the range to be unwired is
3455 * really wired down and that there are no holes.
3456 */
3457
3458 while ((entry != &map->header) && (entry->start < end)) {
3459 if (entry->wired_count == 0 ||
3460 (entry->end < end &&
3461 (entry->next == &map->header ||
3462 entry->next->start > entry->end))) {
3463 if ((lockflags & UVM_LK_EXIT) == 0)
3464 vm_map_unlock(map);
3465 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0);
3466 return EINVAL;
3467 }
3468 entry = entry->next;
3469 }
3470
3471 /*
3472 * POSIX 1003.1b - a single munlock call unlocks a region,
3473 * regardless of the number of mlock calls made on that
3474 * region.
3475 */
3476
3477 entry = start_entry;
3478 while ((entry != &map->header) && (entry->start < end)) {
3479 UVM_MAP_CLIP_END(map, entry, end);
3480 if (VM_MAPENT_ISWIRED(entry))
3481 uvm_map_entry_unwire(map, entry);
3482 entry = entry->next;
3483 }
3484 if ((lockflags & UVM_LK_EXIT) == 0)
3485 vm_map_unlock(map);
3486 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0);
3487 return 0;
3488 }
3489
3490 /*
3491 * wire case: in two passes [XXXCDC: ugly block of code here]
3492 *
3493 * 1: holding the write lock, we create any anonymous maps that need
3494 * to be created. then we clip each map entry to the region to
3495 * be wired and increment its wiring count.
3496 *
3497 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault
3498 * in the pages for any newly wired area (wired_count == 1).
3499 *
3500 * downgrading to a read lock for uvm_fault_wire avoids a possible
3501 * deadlock with another thread that may have faulted on one of
3502 * the pages to be wired (it would mark the page busy, blocking
3503 * us, then in turn block on the map lock that we hold). because
3504 * of problems in the recursive lock package, we cannot upgrade
3505 * to a write lock in vm_map_lookup. thus, any actions that
3506 * require the write lock must be done beforehand. because we
3507 * keep the read lock on the map, the copy-on-write status of the
3508 * entries we modify here cannot change.
3509 */
3510
3511 while ((entry != &map->header) && (entry->start < end)) {
3512 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
3513
3514 /*
3515 * perform actions of vm_map_lookup that need the
3516 * write lock on the map: create an anonymous map
3517 * for a copy-on-write region, or an anonymous map
3518 * for a zero-fill region. (XXXCDC: submap case
3519 * ok?)
3520 */
3521
3522 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */
3523 if (UVM_ET_ISNEEDSCOPY(entry) &&
3524 ((entry->max_protection & VM_PROT_WRITE) ||
3525 (entry->object.uvm_obj == NULL))) {
3526 amap_copy(map, entry, 0, start, end);
3527 /* XXXCDC: wait OK? */
3528 }
3529 }
3530 }
3531 UVM_MAP_CLIP_START(map, entry, start);
3532 UVM_MAP_CLIP_END(map, entry, end);
3533 entry->wired_count++;
3534
3535 /*
3536 * Check for holes
3537 */
3538
3539 if (entry->protection == VM_PROT_NONE ||
3540 (entry->end < end &&
3541 (entry->next == &map->header ||
3542 entry->next->start > entry->end))) {
3543
3544 /*
3545 * found one. amap creation actions do not need to
3546 * be undone, but the wired counts need to be restored.
3547 */
3548
3549 while (entry != &map->header && entry->end > start) {
3550 entry->wired_count--;
3551 entry = entry->prev;
3552 }
3553 if ((lockflags & UVM_LK_EXIT) == 0)
3554 vm_map_unlock(map);
3555 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0);
3556 return EINVAL;
3557 }
3558 entry = entry->next;
3559 }
3560
3561 /*
3562 * Pass 2.
3563 */
3564
3565 #ifdef DIAGNOSTIC
3566 timestamp_save = map->timestamp;
3567 #endif
3568 vm_map_busy(map);
3569 vm_map_unlock(map);
3570
3571 rv = 0;
3572 entry = start_entry;
3573 while (entry != &map->header && entry->start < end) {
3574 if (entry->wired_count == 1) {
3575 rv = uvm_fault_wire(map, entry->start, entry->end,
3576 entry->max_protection, 1);
3577 if (rv) {
3578
3579 /*
3580 * wiring failed. break out of the loop.
3581 * we'll clean up the map below, once we
3582 * have a write lock again.
3583 */
3584
3585 break;
3586 }
3587 }
3588 entry = entry->next;
3589 }
3590
3591 if (rv) { /* failed? */
3592
3593 /*
3594 * Get back to an exclusive (write) lock.
3595 */
3596
3597 vm_map_lock(map);
3598 vm_map_unbusy(map);
3599
3600 #ifdef DIAGNOSTIC
3601 if (timestamp_save + 1 != map->timestamp)
3602 panic("uvm_map_pageable: stale map");
3603 #endif
3604
3605 /*
3606 * first drop the wiring count on all the entries
3607 * which haven't actually been wired yet.
3608 */
3609
3610 failed_entry = entry;
3611 while (entry != &map->header && entry->start < end) {
3612 entry->wired_count--;
3613 entry = entry->next;
3614 }
3615
3616 /*
3617 * now, unwire all the entries that were successfully
3618 * wired above.
3619 */
3620
3621 entry = start_entry;
3622 while (entry != failed_entry) {
3623 entry->wired_count--;
3624 if (VM_MAPENT_ISWIRED(entry) == 0)
3625 uvm_map_entry_unwire(map, entry);
3626 entry = entry->next;
3627 }
3628 if ((lockflags & UVM_LK_EXIT) == 0)
3629 vm_map_unlock(map);
3630 UVMHIST_LOG(maphist, "<- done (RV=%jd)", rv,0,0,0);
3631 return (rv);
3632 }
3633
3634 if ((lockflags & UVM_LK_EXIT) == 0) {
3635 vm_map_unbusy(map);
3636 } else {
3637
3638 /*
3639 * Get back to an exclusive (write) lock.
3640 */
3641
3642 vm_map_lock(map);
3643 vm_map_unbusy(map);
3644 }
3645
3646 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0);
3647 return 0;
3648 }
3649
3650 /*
3651 * uvm_map_pageable_all: special case of uvm_map_pageable - affects
3652 * all mapped regions.
3653 *
3654 * => map must not be locked.
3655 * => if no flags are specified, all regions are unwired.
3656 * => XXXJRT: has some of the same problems as uvm_map_pageable() above.
3657 */
3658
3659 int
3660 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit)
3661 {
3662 struct vm_map_entry *entry, *failed_entry;
3663 vsize_t size;
3664 int rv;
3665 #ifdef DIAGNOSTIC
3666 u_int timestamp_save;
3667 #endif
3668 UVMHIST_FUNC(__func__);
3669 UVMHIST_CALLARGS(maphist,"(map=%#jx,flags=%#jx)", (uintptr_t)map, flags,
3670 0, 0);
3671
3672 KASSERT(map->flags & VM_MAP_PAGEABLE);
3673
3674 vm_map_lock(map);
3675
3676 /*
3677 * handle wiring and unwiring separately.
3678 */
3679
3680 if (flags == 0) { /* unwire */
3681
3682 /*
3683 * POSIX 1003.1b -- munlockall unlocks all regions,
3684 * regardless of how many times mlockall has been called.
3685 */
3686
3687 for (entry = map->header.next; entry != &map->header;
3688 entry = entry->next) {
3689 if (VM_MAPENT_ISWIRED(entry))
3690 uvm_map_entry_unwire(map, entry);
3691 }
3692 map->flags &= ~VM_MAP_WIREFUTURE;
3693 vm_map_unlock(map);
3694 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0);
3695 return 0;
3696 }
3697
3698 if (flags & MCL_FUTURE) {
3699
3700 /*
3701 * must wire all future mappings; remember this.
3702 */
3703
3704 map->flags |= VM_MAP_WIREFUTURE;
3705 }
3706
3707 if ((flags & MCL_CURRENT) == 0) {
3708
3709 /*
3710 * no more work to do!
3711 */
3712
3713 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0);
3714 vm_map_unlock(map);
3715 return 0;
3716 }
3717
3718 /*
3719 * wire case: in three passes [XXXCDC: ugly block of code here]
3720 *
3721 * 1: holding the write lock, count all pages mapped by non-wired
3722 * entries. if this would cause us to go over our limit, we fail.
3723 *
3724 * 2: still holding the write lock, we create any anonymous maps that
3725 * need to be created. then we increment its wiring count.
3726 *
3727 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault
3728 * in the pages for any newly wired area (wired_count == 1).
3729 *
3730 * downgrading to a read lock for uvm_fault_wire avoids a possible
3731 * deadlock with another thread that may have faulted on one of
3732 * the pages to be wired (it would mark the page busy, blocking
3733 * us, then in turn block on the map lock that we hold). because
3734 * of problems in the recursive lock package, we cannot upgrade
3735 * to a write lock in vm_map_lookup. thus, any actions that
3736 * require the write lock must be done beforehand. because we
3737 * keep the read lock on the map, the copy-on-write status of the
3738 * entries we modify here cannot change.
3739 */
3740
3741 for (size = 0, entry = map->header.next; entry != &map->header;
3742 entry = entry->next) {
3743 if (entry->protection != VM_PROT_NONE &&
3744 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
3745 size += entry->end - entry->start;
3746 }
3747 }
3748
3749 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) {
3750 vm_map_unlock(map);
3751 return ENOMEM;
3752 }
3753
3754 if (limit != 0 &&
3755 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) {
3756 vm_map_unlock(map);
3757 return ENOMEM;
3758 }
3759
3760 /*
3761 * Pass 2.
3762 */
3763
3764 for (entry = map->header.next; entry != &map->header;
3765 entry = entry->next) {
3766 if (entry->protection == VM_PROT_NONE)
3767 continue;
3768 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */
3769
3770 /*
3771 * perform actions of vm_map_lookup that need the
3772 * write lock on the map: create an anonymous map
3773 * for a copy-on-write region, or an anonymous map
3774 * for a zero-fill region. (XXXCDC: submap case
3775 * ok?)
3776 */
3777
3778 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */
3779 if (UVM_ET_ISNEEDSCOPY(entry) &&
3780 ((entry->max_protection & VM_PROT_WRITE) ||
3781 (entry->object.uvm_obj == NULL))) {
3782 amap_copy(map, entry, 0, entry->start,
3783 entry->end);
3784 /* XXXCDC: wait OK? */
3785 }
3786 }
3787 }
3788 entry->wired_count++;
3789 }
3790
3791 /*
3792 * Pass 3.
3793 */
3794
3795 #ifdef DIAGNOSTIC
3796 timestamp_save = map->timestamp;
3797 #endif
3798 vm_map_busy(map);
3799 vm_map_unlock(map);
3800
3801 rv = 0;
3802 for (entry = map->header.next; entry != &map->header;
3803 entry = entry->next) {
3804 if (entry->wired_count == 1) {
3805 rv = uvm_fault_wire(map, entry->start, entry->end,
3806 entry->max_protection, 1);
3807 if (rv) {
3808
3809 /*
3810 * wiring failed. break out of the loop.
3811 * we'll clean up the map below, once we
3812 * have a write lock again.
3813 */
3814
3815 break;
3816 }
3817 }
3818 }
3819
3820 if (rv) {
3821
3822 /*
3823 * Get back an exclusive (write) lock.
3824 */
3825
3826 vm_map_lock(map);
3827 vm_map_unbusy(map);
3828
3829 #ifdef DIAGNOSTIC
3830 if (timestamp_save + 1 != map->timestamp)
3831 panic("uvm_map_pageable_all: stale map");
3832 #endif
3833
3834 /*
3835 * first drop the wiring count on all the entries
3836 * which haven't actually been wired yet.
3837 *
3838 * Skip VM_PROT_NONE entries like we did above.
3839 */
3840
3841 failed_entry = entry;
3842 for (/* nothing */; entry != &map->header;
3843 entry = entry->next) {
3844 if (entry->protection == VM_PROT_NONE)
3845 continue;
3846 entry->wired_count--;
3847 }
3848
3849 /*
3850 * now, unwire all the entries that were successfully
3851 * wired above.
3852 *
3853 * Skip VM_PROT_NONE entries like we did above.
3854 */
3855
3856 for (entry = map->header.next; entry != failed_entry;
3857 entry = entry->next) {
3858 if (entry->protection == VM_PROT_NONE)
3859 continue;
3860 entry->wired_count--;
3861 if (VM_MAPENT_ISWIRED(entry))
3862 uvm_map_entry_unwire(map, entry);
3863 }
3864 vm_map_unlock(map);
3865 UVMHIST_LOG(maphist,"<- done (RV=%jd)", rv,0,0,0);
3866 return (rv);
3867 }
3868
3869 vm_map_unbusy(map);
3870
3871 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0);
3872 return 0;
3873 }
3874
3875 /*
3876 * uvm_map_clean: clean out a map range
3877 *
3878 * => valid flags:
3879 * if (flags & PGO_CLEANIT): dirty pages are cleaned first
3880 * if (flags & PGO_SYNCIO): dirty pages are written synchronously
3881 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean
3882 * if (flags & PGO_FREE): any cached pages are freed after clean
3883 * => returns an error if any part of the specified range isn't mapped
3884 * => never a need to flush amap layer since the anonymous memory has
3885 * no permanent home, but may deactivate pages there
3886 * => called from sys_msync() and sys_madvise()
3887 * => caller must not write-lock map (read OK).
3888 * => we may sleep while cleaning if SYNCIO [with map read-locked]
3889 */
3890
3891 int
3892 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags)
3893 {
3894 struct vm_map_entry *current, *entry;
3895 struct uvm_object *uobj;
3896 struct vm_amap *amap;
3897 struct vm_anon *anon;
3898 struct vm_page *pg;
3899 vaddr_t offset;
3900 vsize_t size;
3901 voff_t uoff;
3902 int error, refs;
3903 UVMHIST_FUNC(__func__);
3904 UVMHIST_CALLARGS(maphist,"(map=%#jx,start=%#jx,end=%#jx,flags=%#jx)",
3905 (uintptr_t)map, start, end, flags);
3906
3907 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) !=
3908 (PGO_FREE|PGO_DEACTIVATE));
3909
3910 vm_map_lock_read(map);
3911 VM_MAP_RANGE_CHECK(map, start, end);
3912 if (uvm_map_lookup_entry(map, start, &entry) == false) {
3913 vm_map_unlock_read(map);
3914 return EFAULT;
3915 }
3916
3917 /*
3918 * Make a first pass to check for holes and wiring problems.
3919 */
3920
3921 for (current = entry; current->start < end; current = current->next) {
3922 if (UVM_ET_ISSUBMAP(current)) {
3923 vm_map_unlock_read(map);
3924 return EINVAL;
3925 }
3926 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) {
3927 vm_map_unlock_read(map);
3928 return EBUSY;
3929 }
3930 if (end <= current->end) {
3931 break;
3932 }
3933 if (current->end != current->next->start) {
3934 vm_map_unlock_read(map);
3935 return EFAULT;
3936 }
3937 }
3938
3939 error = 0;
3940 for (current = entry; start < end; current = current->next) {
3941 amap = current->aref.ar_amap; /* upper layer */
3942 uobj = current->object.uvm_obj; /* lower layer */
3943 KASSERT(start >= current->start);
3944
3945 /*
3946 * No amap cleaning necessary if:
3947 *
3948 * (1) There's no amap.
3949 *
3950 * (2) We're not deactivating or freeing pages.
3951 */
3952
3953 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0)
3954 goto flush_object;
3955
3956 offset = start - current->start;
3957 size = MIN(end, current->end) - start;
3958
3959 amap_lock(amap, RW_WRITER);
3960 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) {
3961 anon = amap_lookup(¤t->aref, offset);
3962 if (anon == NULL)
3963 continue;
3964
3965 KASSERT(anon->an_lock == amap->am_lock);
3966 pg = anon->an_page;
3967 if (pg == NULL) {
3968 continue;
3969 }
3970 if (pg->flags & PG_BUSY) {
3971 continue;
3972 }
3973
3974 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) {
3975
3976 /*
3977 * In these first 3 cases, we just deactivate the page.
3978 */
3979
3980 case PGO_CLEANIT|PGO_FREE:
3981 case PGO_CLEANIT|PGO_DEACTIVATE:
3982 case PGO_DEACTIVATE:
3983 deactivate_it:
3984 /*
3985 * skip the page if it's loaned or wired,
3986 * since it shouldn't be on a paging queue
3987 * at all in these cases.
3988 */
3989
3990 if (pg->loan_count != 0 ||
3991 pg->wire_count != 0) {
3992 continue;
3993 }
3994 KASSERT(pg->uanon == anon);
3995 uvm_pagelock(pg);
3996 uvm_pagedeactivate(pg);
3997 uvm_pageunlock(pg);
3998 continue;
3999
4000 case PGO_FREE:
4001
4002 /*
4003 * If there are multiple references to
4004 * the amap, just deactivate the page.
4005 */
4006
4007 if (amap_refs(amap) > 1)
4008 goto deactivate_it;
4009
4010 /* skip the page if it's wired */
4011 if (pg->wire_count != 0) {
4012 continue;
4013 }
4014 amap_unadd(¤t->aref, offset);
4015 refs = --anon->an_ref;
4016 if (refs == 0) {
4017 uvm_anfree(anon);
4018 }
4019 continue;
4020 }
4021 }
4022 amap_unlock(amap);
4023
4024 flush_object:
4025 /*
4026 * flush pages if we've got a valid backing object.
4027 * note that we must always clean object pages before
4028 * freeing them since otherwise we could reveal stale
4029 * data from files.
4030 */
4031
4032 uoff = current->offset + (start - current->start);
4033 size = MIN(end, current->end) - start;
4034 if (uobj != NULL) {
4035 rw_enter(uobj->vmobjlock, RW_WRITER);
4036 if (uobj->pgops->pgo_put != NULL)
4037 error = (uobj->pgops->pgo_put)(uobj, uoff,
4038 uoff + size, flags | PGO_CLEANIT);
4039 else
4040 error = 0;
4041 }
4042 start += size;
4043 }
4044 vm_map_unlock_read(map);
4045 return (error);
4046 }
4047
4048
4049 /*
4050 * uvm_map_checkprot: check protection in map
4051 *
4052 * => must allow specified protection in a fully allocated region.
4053 * => map must be read or write locked by caller.
4054 */
4055
4056 bool
4057 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end,
4058 vm_prot_t protection)
4059 {
4060 struct vm_map_entry *entry;
4061 struct vm_map_entry *tmp_entry;
4062
4063 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) {
4064 return (false);
4065 }
4066 entry = tmp_entry;
4067 while (start < end) {
4068 if (entry == &map->header) {
4069 return (false);
4070 }
4071
4072 /*
4073 * no holes allowed
4074 */
4075
4076 if (start < entry->start) {
4077 return (false);
4078 }
4079
4080 /*
4081 * check protection associated with entry
4082 */
4083
4084 if ((entry->protection & protection) != protection) {
4085 return (false);
4086 }
4087 start = entry->end;
4088 entry = entry->next;
4089 }
4090 return (true);
4091 }
4092
4093 /*
4094 * uvmspace_alloc: allocate a vmspace structure.
4095 *
4096 * - structure includes vm_map and pmap
4097 * - XXX: no locking on this structure
4098 * - refcnt set to 1, rest must be init'd by caller
4099 */
4100 struct vmspace *
4101 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax, bool topdown)
4102 {
4103 struct vmspace *vm;
4104 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
4105
4106 vm = pool_cache_get(&uvm_vmspace_cache, PR_WAITOK);
4107 uvmspace_init(vm, NULL, vmin, vmax, topdown);
4108 UVMHIST_LOG(maphist,"<- done (vm=%#jx)", (uintptr_t)vm, 0, 0, 0);
4109 return (vm);
4110 }
4111
4112 /*
4113 * uvmspace_init: initialize a vmspace structure.
4114 *
4115 * - XXX: no locking on this structure
4116 * - refcnt set to 1, rest must be init'd by caller
4117 */
4118 void
4119 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin,
4120 vaddr_t vmax, bool topdown)
4121 {
4122 UVMHIST_FUNC(__func__);
4123 UVMHIST_CALLARGS(maphist, "(vm=%#jx, pmap=%#jx, vmin=%#jx, vmax=%#jx",
4124 (uintptr_t)vm, (uintptr_t)pmap, vmin, vmax);
4125 UVMHIST_LOG(maphist, " topdown=%ju)", topdown, 0, 0, 0);
4126
4127 memset(vm, 0, sizeof(*vm));
4128 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE
4129 | (topdown ? VM_MAP_TOPDOWN : 0)
4130 );
4131 if (pmap)
4132 pmap_reference(pmap);
4133 else
4134 pmap = pmap_create();
4135 vm->vm_map.pmap = pmap;
4136 vm->vm_refcnt = 1;
4137 UVMHIST_LOG(maphist,"<- done",0,0,0,0);
4138 }
4139
4140 /*
4141 * uvmspace_share: share a vmspace between two processes
4142 *
4143 * - used for vfork, threads(?)
4144 */
4145
4146 void
4147 uvmspace_share(struct proc *p1, struct proc *p2)
4148 {
4149
4150 uvmspace_addref(p1->p_vmspace);
4151 p2->p_vmspace = p1->p_vmspace;
4152 }
4153
4154 #if 0
4155
4156 /*
4157 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace
4158 *
4159 * - XXX: no locking on vmspace
4160 */
4161
4162 void
4163 uvmspace_unshare(struct lwp *l)
4164 {
4165 struct proc *p = l->l_proc;
4166 struct vmspace *nvm, *ovm = p->p_vmspace;
4167
4168 if (ovm->vm_refcnt == 1)
4169 /* nothing to do: vmspace isn't shared in the first place */
4170 return;
4171
4172 /* make a new vmspace, still holding old one */
4173 nvm = uvmspace_fork(ovm);
4174
4175 kpreempt_disable();
4176 pmap_deactivate(l); /* unbind old vmspace */
4177 p->p_vmspace = nvm;
4178 pmap_activate(l); /* switch to new vmspace */
4179 kpreempt_enable();
4180
4181 uvmspace_free(ovm); /* drop reference to old vmspace */
4182 }
4183
4184 #endif
4185
4186
4187 /*
4188 * uvmspace_spawn: a new process has been spawned and needs a vmspace
4189 */
4190
4191 void
4192 uvmspace_spawn(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown)
4193 {
4194 struct proc *p = l->l_proc;
4195 struct vmspace *nvm;
4196
4197 #ifdef __HAVE_CPU_VMSPACE_EXEC
4198 cpu_vmspace_exec(l, start, end);
4199 #endif
4200
4201 nvm = uvmspace_alloc(start, end, topdown);
4202 kpreempt_disable();
4203 p->p_vmspace = nvm;
4204 pmap_activate(l);
4205 kpreempt_enable();
4206 }
4207
4208 /*
4209 * uvmspace_exec: the process wants to exec a new program
4210 */
4211
4212 void
4213 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end, bool topdown)
4214 {
4215 struct proc *p = l->l_proc;
4216 struct vmspace *nvm, *ovm = p->p_vmspace;
4217 struct vm_map *map;
4218 int flags;
4219
4220 KASSERT(ovm != NULL);
4221 #ifdef __HAVE_CPU_VMSPACE_EXEC
4222 cpu_vmspace_exec(l, start, end);
4223 #endif
4224
4225 map = &ovm->vm_map;
4226 /*
4227 * see if more than one process is using this vmspace...
4228 */
4229
4230 if (ovm->vm_refcnt == 1
4231 && topdown == ((ovm->vm_map.flags & VM_MAP_TOPDOWN) != 0)) {
4232
4233 /*
4234 * if p is the only process using its vmspace then we can safely
4235 * recycle that vmspace for the program that is being exec'd.
4236 * But only if TOPDOWN matches the requested value for the new
4237 * vm space!
4238 */
4239
4240 /*
4241 * SYSV SHM semantics require us to kill all segments on an exec
4242 */
4243 if (uvm_shmexit && ovm->vm_shm)
4244 (*uvm_shmexit)(ovm);
4245
4246 /*
4247 * POSIX 1003.1b -- "lock future mappings" is revoked
4248 * when a process execs another program image.
4249 */
4250
4251 map->flags &= ~VM_MAP_WIREFUTURE;
4252
4253 /*
4254 * now unmap the old program.
4255 *
4256 * XXX set VM_MAP_DYING for the duration, so pmap_update()
4257 * is not called until the pmap has been totally cleared out
4258 * after pmap_remove_all(), or it can confuse some pmap
4259 * implementations. it would be nice to handle this by
4260 * deferring the pmap_update() while it is known the address
4261 * space is not visible to any user LWP other than curlwp,
4262 * but there isn't an elegant way of inferring that right
4263 * now.
4264 */
4265
4266 flags = pmap_remove_all(map->pmap) ? UVM_FLAG_VAONLY : 0;
4267 map->flags |= VM_MAP_DYING;
4268 uvm_unmap1(map, vm_map_min(map), vm_map_max(map), flags);
4269 map->flags &= ~VM_MAP_DYING;
4270 pmap_update(map->pmap);
4271 KASSERT(map->header.prev == &map->header);
4272 KASSERT(map->nentries == 0);
4273
4274 /*
4275 * resize the map
4276 */
4277
4278 vm_map_setmin(map, start);
4279 vm_map_setmax(map, end);
4280 } else {
4281
4282 /*
4283 * p's vmspace is being shared, so we can't reuse it for p since
4284 * it is still being used for others. allocate a new vmspace
4285 * for p
4286 */
4287
4288 nvm = uvmspace_alloc(start, end, topdown);
4289
4290 /*
4291 * install new vmspace and drop our ref to the old one.
4292 */
4293
4294 kpreempt_disable();
4295 pmap_deactivate(l);
4296 p->p_vmspace = nvm;
4297 pmap_activate(l);
4298 kpreempt_enable();
4299
4300 uvmspace_free(ovm);
4301 }
4302 }
4303
4304 /*
4305 * uvmspace_addref: add a reference to a vmspace.
4306 */
4307
4308 void
4309 uvmspace_addref(struct vmspace *vm)
4310 {
4311
4312 KASSERT((vm->vm_map.flags & VM_MAP_DYING) == 0);
4313 KASSERT(vm->vm_refcnt > 0);
4314 atomic_inc_uint(&vm->vm_refcnt);
4315 }
4316
4317 /*
4318 * uvmspace_free: free a vmspace data structure
4319 */
4320
4321 void
4322 uvmspace_free(struct vmspace *vm)
4323 {
4324 struct vm_map_entry *dead_entries;
4325 struct vm_map *map = &vm->vm_map;
4326 int flags;
4327
4328 UVMHIST_FUNC(__func__);
4329 UVMHIST_CALLARGS(maphist,"(vm=%#jx) ref=%jd", (uintptr_t)vm,
4330 vm->vm_refcnt, 0, 0);
4331
4332 membar_release();
4333 if (atomic_dec_uint_nv(&vm->vm_refcnt) > 0)
4334 return;
4335 membar_acquire();
4336
4337 /*
4338 * at this point, there should be no other references to the map.
4339 * delete all of the mappings, then destroy the pmap.
4340 */
4341
4342 map->flags |= VM_MAP_DYING;
4343 flags = pmap_remove_all(map->pmap) ? UVM_FLAG_VAONLY : 0;
4344
4345 /* Get rid of any SYSV shared memory segments. */
4346 if (uvm_shmexit && vm->vm_shm != NULL)
4347 (*uvm_shmexit)(vm);
4348
4349 if (map->nentries) {
4350 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map),
4351 &dead_entries, flags);
4352 if (dead_entries != NULL)
4353 uvm_unmap_detach(dead_entries, 0);
4354 }
4355 KASSERT(map->nentries == 0);
4356 KASSERT(map->size == 0);
4357
4358 mutex_destroy(&map->misc_lock);
4359 rw_destroy(&map->lock);
4360 cv_destroy(&map->cv);
4361 pmap_destroy(map->pmap);
4362 pool_cache_put(&uvm_vmspace_cache, vm);
4363 }
4364
4365 static struct vm_map_entry *
4366 uvm_mapent_clone(struct vm_map *new_map, struct vm_map_entry *old_entry,
4367 int flags)
4368 {
4369 struct vm_map_entry *new_entry;
4370
4371 new_entry = uvm_mapent_alloc(new_map, 0);
4372 /* old_entry -> new_entry */
4373 uvm_mapent_copy(old_entry, new_entry);
4374
4375 /* new pmap has nothing wired in it */
4376 new_entry->wired_count = 0;
4377
4378 /*
4379 * gain reference to object backing the map (can't
4380 * be a submap, already checked this case).
4381 */
4382
4383 if (new_entry->aref.ar_amap)
4384 uvm_map_reference_amap(new_entry, flags);
4385
4386 if (new_entry->object.uvm_obj &&
4387 new_entry->object.uvm_obj->pgops->pgo_reference)
4388 new_entry->object.uvm_obj->pgops->pgo_reference(
4389 new_entry->object.uvm_obj);
4390
4391 /* insert entry at end of new_map's entry list */
4392 uvm_map_entry_link(new_map, new_map->header.prev,
4393 new_entry);
4394
4395 return new_entry;
4396 }
4397
4398 /*
4399 * share the mapping: this means we want the old and
4400 * new entries to share amaps and backing objects.
4401 */
4402 static void
4403 uvm_mapent_forkshared(struct vm_map *new_map, struct vm_map *old_map,
4404 struct vm_map_entry *old_entry)
4405 {
4406 /*
4407 * if the old_entry needs a new amap (due to prev fork)
4408 * then we need to allocate it now so that we have
4409 * something we own to share with the new_entry. [in
4410 * other words, we need to clear needs_copy]
4411 */
4412
4413 if (UVM_ET_ISNEEDSCOPY(old_entry)) {
4414 /* get our own amap, clears needs_copy */
4415 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK,
4416 0, 0);
4417 /* XXXCDC: WAITOK??? */
4418 }
4419
4420 uvm_mapent_clone(new_map, old_entry, AMAP_SHARED);
4421 }
4422
4423
4424 static void
4425 uvm_mapent_forkcopy(struct vm_map *new_map, struct vm_map *old_map,
4426 struct vm_map_entry *old_entry)
4427 {
4428 struct vm_map_entry *new_entry;
4429
4430 /*
4431 * copy-on-write the mapping (using mmap's
4432 * MAP_PRIVATE semantics)
4433 *
4434 * allocate new_entry, adjust reference counts.
4435 * (note that new references are read-only).
4436 */
4437
4438 new_entry = uvm_mapent_clone(new_map, old_entry, 0);
4439
4440 new_entry->etype |=
4441 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY);
4442
4443 /*
4444 * the new entry will need an amap. it will either
4445 * need to be copied from the old entry or created
4446 * from scratch (if the old entry does not have an
4447 * amap). can we defer this process until later
4448 * (by setting "needs_copy") or do we need to copy
4449 * the amap now?
4450 *
4451 * we must copy the amap now if any of the following
4452 * conditions hold:
4453 * 1. the old entry has an amap and that amap is
4454 * being shared. this means that the old (parent)
4455 * process is sharing the amap with another
4456 * process. if we do not clear needs_copy here
4457 * we will end up in a situation where both the
4458 * parent and child process are referring to the
4459 * same amap with "needs_copy" set. if the
4460 * parent write-faults, the fault routine will
4461 * clear "needs_copy" in the parent by allocating
4462 * a new amap. this is wrong because the
4463 * parent is supposed to be sharing the old amap
4464 * and the new amap will break that.
4465 *
4466 * 2. if the old entry has an amap and a non-zero
4467 * wire count then we are going to have to call
4468 * amap_cow_now to avoid page faults in the
4469 * parent process. since amap_cow_now requires
4470 * "needs_copy" to be clear we might as well
4471 * clear it here as well.
4472 *
4473 */
4474
4475 if (old_entry->aref.ar_amap != NULL) {
4476 if ((amap_flags(old_entry->aref.ar_amap) & AMAP_SHARED) != 0 ||
4477 VM_MAPENT_ISWIRED(old_entry)) {
4478
4479 amap_copy(new_map, new_entry,
4480 AMAP_COPY_NOCHUNK, 0, 0);
4481 /* XXXCDC: M_WAITOK ... ok? */
4482 }
4483 }
4484
4485 /*
4486 * if the parent's entry is wired down, then the
4487 * parent process does not want page faults on
4488 * access to that memory. this means that we
4489 * cannot do copy-on-write because we can't write
4490 * protect the old entry. in this case we
4491 * resolve all copy-on-write faults now, using
4492 * amap_cow_now. note that we have already
4493 * allocated any needed amap (above).
4494 */
4495
4496 if (VM_MAPENT_ISWIRED(old_entry)) {
4497
4498 /*
4499 * resolve all copy-on-write faults now
4500 * (note that there is nothing to do if
4501 * the old mapping does not have an amap).
4502 */
4503 if (old_entry->aref.ar_amap)
4504 amap_cow_now(new_map, new_entry);
4505
4506 } else {
4507 /*
4508 * setup mappings to trigger copy-on-write faults
4509 * we must write-protect the parent if it has
4510 * an amap and it is not already "needs_copy"...
4511 * if it is already "needs_copy" then the parent
4512 * has already been write-protected by a previous
4513 * fork operation.
4514 */
4515 if (old_entry->aref.ar_amap &&
4516 !UVM_ET_ISNEEDSCOPY(old_entry)) {
4517 if (old_entry->max_protection & VM_PROT_WRITE) {
4518 #ifdef __HAVE_UNLOCKED_PMAP /* XXX temporary */
4519 uvm_map_lock_entry(old_entry, RW_WRITER);
4520 #else
4521 uvm_map_lock_entry(old_entry, RW_READER);
4522 #endif
4523 pmap_protect(old_map->pmap,
4524 old_entry->start, old_entry->end,
4525 old_entry->protection & ~VM_PROT_WRITE);
4526 uvm_map_unlock_entry(old_entry);
4527 }
4528 old_entry->etype |= UVM_ET_NEEDSCOPY;
4529 }
4530 }
4531 }
4532
4533 /*
4534 * zero the mapping: the new entry will be zero initialized
4535 */
4536 static void
4537 uvm_mapent_forkzero(struct vm_map *new_map, struct vm_map *old_map,
4538 struct vm_map_entry *old_entry)
4539 {
4540 struct vm_map_entry *new_entry;
4541
4542 new_entry = uvm_mapent_clone(new_map, old_entry, 0);
4543
4544 new_entry->etype |=
4545 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY);
4546
4547 if (new_entry->aref.ar_amap) {
4548 uvm_map_unreference_amap(new_entry, 0);
4549 new_entry->aref.ar_pageoff = 0;
4550 new_entry->aref.ar_amap = NULL;
4551 }
4552
4553 if (UVM_ET_ISOBJ(new_entry)) {
4554 if (new_entry->object.uvm_obj->pgops->pgo_detach)
4555 new_entry->object.uvm_obj->pgops->pgo_detach(
4556 new_entry->object.uvm_obj);
4557 new_entry->object.uvm_obj = NULL;
4558 new_entry->offset = 0;
4559 new_entry->etype &= ~UVM_ET_OBJ;
4560 }
4561 }
4562
4563 /*
4564 * F O R K - m a i n e n t r y p o i n t
4565 */
4566 /*
4567 * uvmspace_fork: fork a process' main map
4568 *
4569 * => create a new vmspace for child process from parent.
4570 * => parent's map must not be locked.
4571 */
4572
4573 struct vmspace *
4574 uvmspace_fork(struct vmspace *vm1)
4575 {
4576 struct vmspace *vm2;
4577 struct vm_map *old_map = &vm1->vm_map;
4578 struct vm_map *new_map;
4579 struct vm_map_entry *old_entry;
4580 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
4581
4582 vm_map_lock(old_map);
4583
4584 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map),
4585 vm1->vm_map.flags & VM_MAP_TOPDOWN);
4586 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy,
4587 (char *) (vm1 + 1) - (char *) &vm1->vm_startcopy);
4588 new_map = &vm2->vm_map; /* XXX */
4589
4590 old_entry = old_map->header.next;
4591 new_map->size = old_map->size;
4592
4593 /*
4594 * go entry-by-entry
4595 */
4596
4597 while (old_entry != &old_map->header) {
4598
4599 /*
4600 * first, some sanity checks on the old entry
4601 */
4602
4603 KASSERT(!UVM_ET_ISSUBMAP(old_entry));
4604 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) ||
4605 !UVM_ET_ISNEEDSCOPY(old_entry));
4606
4607 switch (old_entry->inheritance) {
4608 case MAP_INHERIT_NONE:
4609 /*
4610 * drop the mapping, modify size
4611 */
4612 new_map->size -= old_entry->end - old_entry->start;
4613 break;
4614
4615 case MAP_INHERIT_SHARE:
4616 uvm_mapent_forkshared(new_map, old_map, old_entry);
4617 break;
4618
4619 case MAP_INHERIT_COPY:
4620 uvm_mapent_forkcopy(new_map, old_map, old_entry);
4621 break;
4622
4623 case MAP_INHERIT_ZERO:
4624 uvm_mapent_forkzero(new_map, old_map, old_entry);
4625 break;
4626 default:
4627 KASSERT(0);
4628 break;
4629 }
4630 old_entry = old_entry->next;
4631 }
4632
4633 pmap_update(old_map->pmap);
4634 vm_map_unlock(old_map);
4635
4636 if (uvm_shmfork && vm1->vm_shm)
4637 (*uvm_shmfork)(vm1, vm2);
4638
4639 #ifdef PMAP_FORK
4640 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap);
4641 #endif
4642
4643 UVMHIST_LOG(maphist,"<- done",0,0,0,0);
4644 return (vm2);
4645 }
4646
4647
4648 /*
4649 * uvm_mapent_trymerge: try to merge an entry with its neighbors.
4650 *
4651 * => called with map locked.
4652 * => return non zero if successfully merged.
4653 */
4654
4655 int
4656 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags)
4657 {
4658 struct uvm_object *uobj;
4659 struct vm_map_entry *next;
4660 struct vm_map_entry *prev;
4661 vsize_t size;
4662 int merged = 0;
4663 bool copying;
4664 int newetype;
4665
4666 if (entry->aref.ar_amap != NULL) {
4667 return 0;
4668 }
4669 if ((entry->flags & UVM_MAP_NOMERGE) != 0) {
4670 return 0;
4671 }
4672
4673 uobj = entry->object.uvm_obj;
4674 size = entry->end - entry->start;
4675 copying = (flags & UVM_MERGE_COPYING) != 0;
4676 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype;
4677
4678 next = entry->next;
4679 if (next != &map->header &&
4680 next->start == entry->end &&
4681 ((copying && next->aref.ar_amap != NULL &&
4682 amap_refs(next->aref.ar_amap) == 1) ||
4683 (!copying && next->aref.ar_amap == NULL)) &&
4684 UVM_ET_ISCOMPATIBLE(next, newetype,
4685 uobj, entry->flags, entry->protection,
4686 entry->max_protection, entry->inheritance, entry->advice,
4687 entry->wired_count) &&
4688 (uobj == NULL || entry->offset + size == next->offset)) {
4689 int error;
4690
4691 if (copying) {
4692 error = amap_extend(next, size,
4693 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS);
4694 } else {
4695 error = 0;
4696 }
4697 if (error == 0) {
4698 if (uobj) {
4699 if (uobj->pgops->pgo_detach) {
4700 uobj->pgops->pgo_detach(uobj);
4701 }
4702 }
4703
4704 entry->end = next->end;
4705 clear_hints(map, next);
4706 uvm_map_entry_unlink(map, next);
4707 if (copying) {
4708 entry->aref = next->aref;
4709 entry->etype &= ~UVM_ET_NEEDSCOPY;
4710 }
4711 uvm_map_check(map, "trymerge forwardmerge");
4712 uvm_mapent_free(next);
4713 merged++;
4714 }
4715 }
4716
4717 prev = entry->prev;
4718 if (prev != &map->header &&
4719 prev->end == entry->start &&
4720 ((copying && !merged && prev->aref.ar_amap != NULL &&
4721 amap_refs(prev->aref.ar_amap) == 1) ||
4722 (!copying && prev->aref.ar_amap == NULL)) &&
4723 UVM_ET_ISCOMPATIBLE(prev, newetype,
4724 uobj, entry->flags, entry->protection,
4725 entry->max_protection, entry->inheritance, entry->advice,
4726 entry->wired_count) &&
4727 (uobj == NULL ||
4728 prev->offset + prev->end - prev->start == entry->offset)) {
4729 int error;
4730
4731 if (copying) {
4732 error = amap_extend(prev, size,
4733 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS);
4734 } else {
4735 error = 0;
4736 }
4737 if (error == 0) {
4738 if (uobj) {
4739 if (uobj->pgops->pgo_detach) {
4740 uobj->pgops->pgo_detach(uobj);
4741 }
4742 entry->offset = prev->offset;
4743 }
4744
4745 entry->start = prev->start;
4746 clear_hints(map, prev);
4747 uvm_map_entry_unlink(map, prev);
4748 if (copying) {
4749 entry->aref = prev->aref;
4750 entry->etype &= ~UVM_ET_NEEDSCOPY;
4751 }
4752 uvm_map_check(map, "trymerge backmerge");
4753 uvm_mapent_free(prev);
4754 merged++;
4755 }
4756 }
4757
4758 return merged;
4759 }
4760
4761 /*
4762 * uvm_map_setup: init map
4763 *
4764 * => map must not be in service yet.
4765 */
4766
4767 void
4768 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags)
4769 {
4770
4771 rb_tree_init(&map->rb_tree, &uvm_map_tree_ops);
4772 map->header.next = map->header.prev = &map->header;
4773 map->nentries = 0;
4774 map->size = 0;
4775 map->ref_count = 1;
4776 vm_map_setmin(map, vmin);
4777 vm_map_setmax(map, vmax);
4778 map->flags = flags;
4779 map->first_free = &map->header;
4780 map->hint = &map->header;
4781 map->timestamp = 0;
4782 map->busy = NULL;
4783
4784 rw_init(&map->lock);
4785 cv_init(&map->cv, "vm_map");
4786 mutex_init(&map->misc_lock, MUTEX_DRIVER, IPL_NONE);
4787 }
4788
4789 /*
4790 * U N M A P - m a i n e n t r y p o i n t
4791 */
4792
4793 /*
4794 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop")
4795 *
4796 * => caller must check alignment and size
4797 * => map must be unlocked (we will lock it)
4798 * => flags is UVM_FLAG_QUANTUM or 0.
4799 */
4800
4801 void
4802 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags)
4803 {
4804 struct vm_map_entry *dead_entries;
4805 UVMHIST_FUNC(__func__);
4806 UVMHIST_CALLARGS(maphist, " (map=%#jx, start=%#jx, end=%#jx)",
4807 (uintptr_t)map, start, end, 0);
4808
4809 KASSERTMSG(start < end,
4810 "%s: map %p: start %#jx < end %#jx", __func__, map,
4811 (uintmax_t)start, (uintmax_t)end);
4812 if (map == kernel_map) {
4813 LOCKDEBUG_MEM_CHECK((void *)start, end - start);
4814 }
4815
4816 /*
4817 * work now done by helper functions. wipe the pmap's and then
4818 * detach from the dead entries...
4819 */
4820 vm_map_lock(map);
4821 uvm_unmap_remove(map, start, end, &dead_entries, flags);
4822 vm_map_unlock(map);
4823
4824 if (dead_entries != NULL)
4825 uvm_unmap_detach(dead_entries, 0);
4826
4827 UVMHIST_LOG(maphist, "<- done", 0,0,0,0);
4828 }
4829
4830
4831 /*
4832 * uvm_map_reference: add reference to a map
4833 *
4834 * => map need not be locked
4835 */
4836
4837 void
4838 uvm_map_reference(struct vm_map *map)
4839 {
4840
4841 atomic_inc_uint(&map->ref_count);
4842 }
4843
4844 void
4845 uvm_map_lock_entry(struct vm_map_entry *entry, krw_t op)
4846 {
4847
4848 if (entry->aref.ar_amap != NULL) {
4849 amap_lock(entry->aref.ar_amap, op);
4850 }
4851 if (UVM_ET_ISOBJ(entry)) {
4852 rw_enter(entry->object.uvm_obj->vmobjlock, op);
4853 }
4854 }
4855
4856 void
4857 uvm_map_unlock_entry(struct vm_map_entry *entry)
4858 {
4859
4860 if (UVM_ET_ISOBJ(entry)) {
4861 rw_exit(entry->object.uvm_obj->vmobjlock);
4862 }
4863 if (entry->aref.ar_amap != NULL) {
4864 amap_unlock(entry->aref.ar_amap);
4865 }
4866 }
4867
4868 #define UVM_VOADDR_TYPE_MASK 0x3UL
4869 #define UVM_VOADDR_TYPE_UOBJ 0x1UL
4870 #define UVM_VOADDR_TYPE_ANON 0x2UL
4871 #define UVM_VOADDR_OBJECT_MASK ~UVM_VOADDR_TYPE_MASK
4872
4873 #define UVM_VOADDR_GET_TYPE(voa) \
4874 ((voa)->object & UVM_VOADDR_TYPE_MASK)
4875 #define UVM_VOADDR_GET_OBJECT(voa) \
4876 ((voa)->object & UVM_VOADDR_OBJECT_MASK)
4877 #define UVM_VOADDR_SET_OBJECT(voa, obj, type) \
4878 do { \
4879 KASSERT(((uintptr_t)(obj) & UVM_VOADDR_TYPE_MASK) == 0); \
4880 (voa)->object = ((uintptr_t)(obj)) | (type); \
4881 } while (/*CONSTCOND*/0)
4882
4883 #define UVM_VOADDR_GET_UOBJ(voa) \
4884 ((struct uvm_object *)UVM_VOADDR_GET_OBJECT(voa))
4885 #define UVM_VOADDR_SET_UOBJ(voa, uobj) \
4886 UVM_VOADDR_SET_OBJECT(voa, uobj, UVM_VOADDR_TYPE_UOBJ)
4887
4888 #define UVM_VOADDR_GET_ANON(voa) \
4889 ((struct vm_anon *)UVM_VOADDR_GET_OBJECT(voa))
4890 #define UVM_VOADDR_SET_ANON(voa, anon) \
4891 UVM_VOADDR_SET_OBJECT(voa, anon, UVM_VOADDR_TYPE_ANON)
4892
4893 /*
4894 * uvm_voaddr_acquire: returns the virtual object address corresponding
4895 * to the specified virtual address.
4896 *
4897 * => resolves COW so the true page identity is tracked.
4898 *
4899 * => acquires a reference on the page's owner (uvm_object or vm_anon)
4900 */
4901 bool
4902 uvm_voaddr_acquire(struct vm_map * const map, vaddr_t const va,
4903 struct uvm_voaddr * const voaddr)
4904 {
4905 struct vm_map_entry *entry;
4906 struct vm_anon *anon = NULL;
4907 bool result = false;
4908 bool exclusive = false;
4909 void (*unlock_fn)(struct vm_map *);
4910
4911 UVMHIST_FUNC(__func__); UVMHIST_CALLED(maphist);
4912 UVMHIST_LOG(maphist,"(map=%#jx,va=%#jx)", (uintptr_t)map, va, 0, 0);
4913
4914 const vaddr_t start = trunc_page(va);
4915 const vaddr_t end = round_page(va+1);
4916
4917 lookup_again:
4918 if (__predict_false(exclusive)) {
4919 vm_map_lock(map);
4920 unlock_fn = vm_map_unlock;
4921 } else {
4922 vm_map_lock_read(map);
4923 unlock_fn = vm_map_unlock_read;
4924 }
4925
4926 if (__predict_false(!uvm_map_lookup_entry(map, start, &entry))) {
4927 unlock_fn(map);
4928 UVMHIST_LOG(maphist,"<- done (no entry)",0,0,0,0);
4929 return false;
4930 }
4931
4932 if (__predict_false(entry->protection == VM_PROT_NONE)) {
4933 unlock_fn(map);
4934 UVMHIST_LOG(maphist,"<- done (PROT_NONE)",0,0,0,0);
4935 return false;
4936 }
4937
4938 /*
4939 * We have a fast path for the common case of "no COW resolution
4940 * needed" whereby we have taken a read lock on the map and if
4941 * we don't encounter any need to create a vm_anon then great!
4942 * But if we do, we loop around again, instead taking an exclusive
4943 * lock so that we can perform the fault.
4944 *
4945 * In the event that we have to resolve the fault, we do nearly the
4946 * same work as uvm_map_pageable() does:
4947 *
4948 * 1: holding the write lock, we create any anonymous maps that need
4949 * to be created. however, we do NOT need to clip the map entries
4950 * in this case.
4951 *
4952 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault
4953 * in the page (assuming the entry is not already wired). this
4954 * is done because we need the vm_anon to be present.
4955 */
4956 if (__predict_true(!VM_MAPENT_ISWIRED(entry))) {
4957
4958 bool need_fault = false;
4959
4960 /*
4961 * perform the action of vm_map_lookup that need the
4962 * write lock on the map: create an anonymous map for
4963 * a copy-on-write region, or an anonymous map for
4964 * a zero-fill region.
4965 */
4966 if (__predict_false(UVM_ET_ISSUBMAP(entry))) {
4967 unlock_fn(map);
4968 UVMHIST_LOG(maphist,"<- done (submap)",0,0,0,0);
4969 return false;
4970 }
4971 if (__predict_false(UVM_ET_ISNEEDSCOPY(entry) &&
4972 ((entry->max_protection & VM_PROT_WRITE) ||
4973 (entry->object.uvm_obj == NULL)))) {
4974 if (!exclusive) {
4975 /* need to take the slow path */
4976 KASSERT(unlock_fn == vm_map_unlock_read);
4977 vm_map_unlock_read(map);
4978 exclusive = true;
4979 goto lookup_again;
4980 }
4981 need_fault = true;
4982 amap_copy(map, entry, 0, start, end);
4983 /* XXXCDC: wait OK? */
4984 }
4985
4986 /*
4987 * do a quick check to see if the fault has already
4988 * been resolved to the upper layer.
4989 */
4990 if (__predict_true(entry->aref.ar_amap != NULL &&
4991 need_fault == false)) {
4992 amap_lock(entry->aref.ar_amap, RW_WRITER);
4993 anon = amap_lookup(&entry->aref, start - entry->start);
4994 if (__predict_true(anon != NULL)) {
4995 /* amap unlocked below */
4996 goto found_anon;
4997 }
4998 amap_unlock(entry->aref.ar_amap);
4999 need_fault = true;
5000 }
5001
5002 /*
5003 * we predict this test as false because if we reach
5004 * this point, then we are likely dealing with a
5005 * shared memory region backed by a uvm_object, in
5006 * which case a fault to create the vm_anon is not
5007 * necessary.
5008 */
5009 if (__predict_false(need_fault)) {
5010 if (exclusive) {
5011 vm_map_busy(map);
5012 vm_map_unlock(map);
5013 unlock_fn = vm_map_unbusy;
5014 }
5015
5016 if (uvm_fault_wire(map, start, end,
5017 entry->max_protection, 1)) {
5018 /* wiring failed */
5019 unlock_fn(map);
5020 UVMHIST_LOG(maphist,"<- done (wire failed)",
5021 0,0,0,0);
5022 return false;
5023 }
5024
5025 /*
5026 * now that we have resolved the fault, we can unwire
5027 * the page.
5028 */
5029 if (exclusive) {
5030 vm_map_lock(map);
5031 vm_map_unbusy(map);
5032 unlock_fn = vm_map_unlock;
5033 }
5034
5035 uvm_fault_unwire_locked(map, start, end);
5036 }
5037 }
5038
5039 /* check the upper layer */
5040 if (entry->aref.ar_amap) {
5041 amap_lock(entry->aref.ar_amap, RW_WRITER);
5042 anon = amap_lookup(&entry->aref, start - entry->start);
5043 if (anon) {
5044 found_anon: KASSERT(anon->an_lock == entry->aref.ar_amap->am_lock);
5045 anon->an_ref++;
5046 rw_obj_hold(anon->an_lock);
5047 KASSERT(anon->an_ref != 0);
5048 UVM_VOADDR_SET_ANON(voaddr, anon);
5049 voaddr->offset = va & PAGE_MASK;
5050 result = true;
5051 }
5052 amap_unlock(entry->aref.ar_amap);
5053 }
5054
5055 /* check the lower layer */
5056 if (!result && UVM_ET_ISOBJ(entry)) {
5057 struct uvm_object *uobj = entry->object.uvm_obj;
5058
5059 KASSERT(uobj != NULL);
5060 (*uobj->pgops->pgo_reference)(uobj);
5061 UVM_VOADDR_SET_UOBJ(voaddr, uobj);
5062 voaddr->offset = entry->offset + (va - entry->start);
5063 result = true;
5064 }
5065
5066 unlock_fn(map);
5067
5068 if (result) {
5069 UVMHIST_LOG(maphist,
5070 "<- done OK (type=%jd,owner=%#jx,offset=%#jx)",
5071 UVM_VOADDR_GET_TYPE(voaddr),
5072 UVM_VOADDR_GET_OBJECT(voaddr),
5073 voaddr->offset, 0);
5074 } else {
5075 UVMHIST_LOG(maphist,"<- done (failed)",0,0,0,0);
5076 }
5077
5078 return result;
5079 }
5080
5081 /*
5082 * uvm_voaddr_release: release the references held by the
5083 * vitual object address.
5084 */
5085 void
5086 uvm_voaddr_release(struct uvm_voaddr * const voaddr)
5087 {
5088
5089 switch (UVM_VOADDR_GET_TYPE(voaddr)) {
5090 case UVM_VOADDR_TYPE_UOBJ: {
5091 struct uvm_object * const uobj = UVM_VOADDR_GET_UOBJ(voaddr);
5092
5093 KASSERT(uobj != NULL);
5094 KASSERT(uobj->pgops->pgo_detach != NULL);
5095 (*uobj->pgops->pgo_detach)(uobj);
5096 break;
5097 }
5098 case UVM_VOADDR_TYPE_ANON: {
5099 struct vm_anon * const anon = UVM_VOADDR_GET_ANON(voaddr);
5100 krwlock_t *lock;
5101
5102 KASSERT(anon != NULL);
5103 rw_enter((lock = anon->an_lock), RW_WRITER);
5104 KASSERT(anon->an_ref > 0);
5105 if (--anon->an_ref == 0) {
5106 uvm_anfree(anon);
5107 }
5108 rw_exit(lock);
5109 rw_obj_free(lock);
5110 break;
5111 }
5112 default:
5113 panic("uvm_voaddr_release: bad type");
5114 }
5115 memset(voaddr, 0, sizeof(*voaddr));
5116 }
5117
5118 /*
5119 * uvm_voaddr_compare: compare two uvm_voaddr objects.
5120 *
5121 * => memcmp() semantics
5122 */
5123 int
5124 uvm_voaddr_compare(const struct uvm_voaddr * const voaddr1,
5125 const struct uvm_voaddr * const voaddr2)
5126 {
5127 const uintptr_t type1 = UVM_VOADDR_GET_TYPE(voaddr1);
5128 const uintptr_t type2 = UVM_VOADDR_GET_TYPE(voaddr2);
5129
5130 KASSERT(type1 == UVM_VOADDR_TYPE_UOBJ ||
5131 type1 == UVM_VOADDR_TYPE_ANON);
5132
5133 KASSERT(type2 == UVM_VOADDR_TYPE_UOBJ ||
5134 type2 == UVM_VOADDR_TYPE_ANON);
5135
5136 if (type1 < type2)
5137 return -1;
5138 if (type1 > type2)
5139 return 1;
5140
5141 const uintptr_t addr1 = UVM_VOADDR_GET_OBJECT(voaddr1);
5142 const uintptr_t addr2 = UVM_VOADDR_GET_OBJECT(voaddr2);
5143
5144 if (addr1 < addr2)
5145 return -1;
5146 if (addr1 > addr2)
5147 return 1;
5148
5149 if (voaddr1->offset < voaddr2->offset)
5150 return -1;
5151 if (voaddr1->offset > voaddr2->offset)
5152 return 1;
5153
5154 return 0;
5155 }
5156
5157 #if defined(DDB) || defined(DEBUGPRINT)
5158
5159 /*
5160 * uvm_map_printit: actually prints the map
5161 */
5162
5163 void
5164 uvm_map_printit(struct vm_map *map, bool full,
5165 void (*pr)(const char *, ...))
5166 {
5167 struct vm_map_entry *entry;
5168
5169 (*pr)("MAP %p: [%#lx->%#lx]\n", map, vm_map_min(map),
5170 vm_map_max(map));
5171 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=%#x\n",
5172 map->nentries, map->size, map->ref_count, map->timestamp,
5173 map->flags);
5174 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap,
5175 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap));
5176 if (!full)
5177 return;
5178 for (entry = map->header.next; entry != &map->header;
5179 entry = entry->next) {
5180 (*pr)(" - %p: %#lx->%#lx: obj=%p/%#llx, amap=%p/%d\n",
5181 entry, entry->start, entry->end, entry->object.uvm_obj,
5182 (long long)entry->offset, entry->aref.ar_amap,
5183 entry->aref.ar_pageoff);
5184 (*pr)(
5185 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, "
5186 "wc=%d, adv=%d%s\n",
5187 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F',
5188 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F',
5189 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F',
5190 entry->protection, entry->max_protection,
5191 entry->inheritance, entry->wired_count, entry->advice,
5192 entry == map->first_free ? " (first_free)" : "");
5193 }
5194 }
5195
5196 void
5197 uvm_whatis(uintptr_t addr, void (*pr)(const char *, ...))
5198 {
5199 struct vm_map *map;
5200
5201 for (map = kernel_map;;) {
5202 struct vm_map_entry *entry;
5203
5204 if (!uvm_map_lookup_entry_bytree(map, (vaddr_t)addr, &entry)) {
5205 break;
5206 }
5207 (*pr)("%p is %p+%zu from VMMAP %p\n",
5208 (void *)addr, (void *)entry->start,
5209 (size_t)(addr - (uintptr_t)entry->start), map);
5210 if (!UVM_ET_ISSUBMAP(entry)) {
5211 break;
5212 }
5213 map = entry->object.sub_map;
5214 }
5215 }
5216
5217 #endif /* DDB || DEBUGPRINT */
5218
5219 #ifndef __USER_VA0_IS_SAFE
5220 static int
5221 sysctl_user_va0_disable(SYSCTLFN_ARGS)
5222 {
5223 struct sysctlnode node;
5224 int t, error;
5225
5226 node = *rnode;
5227 node.sysctl_data = &t;
5228 t = user_va0_disable;
5229 error = sysctl_lookup(SYSCTLFN_CALL(&node));
5230 if (error || newp == NULL)
5231 return (error);
5232
5233 if (!t && user_va0_disable &&
5234 kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MAP_VA_ZERO, 0,
5235 NULL, NULL, NULL))
5236 return EPERM;
5237
5238 user_va0_disable = !!t;
5239 return 0;
5240 }
5241 #endif
5242
5243 static int
5244 fill_vmentry(struct lwp *l, struct proc *p, struct kinfo_vmentry *kve,
5245 struct vm_map *m, struct vm_map_entry *e)
5246 {
5247 #ifndef _RUMPKERNEL
5248 int error;
5249
5250 memset(kve, 0, sizeof(*kve));
5251 KASSERT(e != NULL);
5252 if (UVM_ET_ISOBJ(e)) {
5253 struct uvm_object *uobj = e->object.uvm_obj;
5254 KASSERT(uobj != NULL);
5255 kve->kve_ref_count = uobj->uo_refs;
5256 kve->kve_count = uobj->uo_npages;
5257 if (UVM_OBJ_IS_VNODE(uobj)) {
5258 struct vattr va;
5259 struct vnode *vp = (struct vnode *)uobj;
5260 vn_lock(vp, LK_SHARED | LK_RETRY);
5261 error = VOP_GETATTR(vp, &va, l->l_cred);
5262 VOP_UNLOCK(vp);
5263 kve->kve_type = KVME_TYPE_VNODE;
5264 if (error == 0) {
5265 kve->kve_vn_size = vp->v_size;
5266 kve->kve_vn_type = (int)vp->v_type;
5267 kve->kve_vn_mode = va.va_mode;
5268 kve->kve_vn_rdev = va.va_rdev;
5269 kve->kve_vn_fileid = va.va_fileid;
5270 kve->kve_vn_fsid = va.va_fsid;
5271 error = vnode_to_path(kve->kve_path,
5272 sizeof(kve->kve_path) / 2, vp, l, p);
5273 }
5274 } else if (UVM_OBJ_IS_KERN_OBJECT(uobj)) {
5275 kve->kve_type = KVME_TYPE_KERN;
5276 } else if (UVM_OBJ_IS_DEVICE(uobj)) {
5277 kve->kve_type = KVME_TYPE_DEVICE;
5278 } else if (UVM_OBJ_IS_AOBJ(uobj)) {
5279 kve->kve_type = KVME_TYPE_ANON;
5280 } else {
5281 kve->kve_type = KVME_TYPE_OBJECT;
5282 }
5283 } else if (UVM_ET_ISSUBMAP(e)) {
5284 struct vm_map *map = e->object.sub_map;
5285 KASSERT(map != NULL);
5286 kve->kve_ref_count = map->ref_count;
5287 kve->kve_count = map->nentries;
5288 kve->kve_type = KVME_TYPE_SUBMAP;
5289 } else
5290 kve->kve_type = KVME_TYPE_UNKNOWN;
5291
5292 kve->kve_start = e->start;
5293 kve->kve_end = e->end;
5294 kve->kve_offset = e->offset;
5295 kve->kve_wired_count = e->wired_count;
5296 kve->kve_inheritance = e->inheritance;
5297 kve->kve_attributes = 0; /* unused */
5298 kve->kve_advice = e->advice;
5299 #define PROT(p) (((p) & VM_PROT_READ) ? KVME_PROT_READ : 0) | \
5300 (((p) & VM_PROT_WRITE) ? KVME_PROT_WRITE : 0) | \
5301 (((p) & VM_PROT_EXECUTE) ? KVME_PROT_EXEC : 0)
5302 kve->kve_protection = PROT(e->protection);
5303 kve->kve_max_protection = PROT(e->max_protection);
5304 kve->kve_flags |= (e->etype & UVM_ET_COPYONWRITE)
5305 ? KVME_FLAG_COW : 0;
5306 kve->kve_flags |= (e->etype & UVM_ET_NEEDSCOPY)
5307 ? KVME_FLAG_NEEDS_COPY : 0;
5308 kve->kve_flags |= (m->flags & VM_MAP_TOPDOWN)
5309 ? KVME_FLAG_GROWS_DOWN : KVME_FLAG_GROWS_UP;
5310 kve->kve_flags |= (m->flags & VM_MAP_PAGEABLE)
5311 ? KVME_FLAG_PAGEABLE : 0;
5312 #endif
5313 return 0;
5314 }
5315
5316 static int
5317 fill_vmentries(struct lwp *l, pid_t pid, u_int elem_size, void *oldp,
5318 size_t *oldlenp)
5319 {
5320 int error;
5321 struct proc *p;
5322 struct kinfo_vmentry *vme;
5323 struct vmspace *vm;
5324 struct vm_map *map;
5325 struct vm_map_entry *entry;
5326 char *dp;
5327 size_t count, vmesize;
5328
5329 if (elem_size == 0 || elem_size > 2 * sizeof(*vme))
5330 return EINVAL;
5331
5332 if (oldp) {
5333 if (*oldlenp > 10UL * 1024UL * 1024UL)
5334 return E2BIG;
5335 count = *oldlenp / elem_size;
5336 if (count == 0)
5337 return ENOMEM;
5338 vmesize = count * sizeof(*vme);
5339 } else
5340 vmesize = 0;
5341
5342 if ((error = proc_find_locked(l, &p, pid)) != 0)
5343 return error;
5344
5345 vme = NULL;
5346 count = 0;
5347
5348 if ((error = proc_vmspace_getref(p, &vm)) != 0)
5349 goto out;
5350
5351 map = &vm->vm_map;
5352 vm_map_lock_read(map);
5353
5354 dp = oldp;
5355 if (oldp)
5356 vme = kmem_alloc(vmesize, KM_SLEEP);
5357 for (entry = map->header.next; entry != &map->header;
5358 entry = entry->next) {
5359 if (oldp && (dp - (char *)oldp) < vmesize) {
5360 error = fill_vmentry(l, p, &vme[count], map, entry);
5361 if (error)
5362 goto out;
5363 dp += elem_size;
5364 }
5365 count++;
5366 }
5367 vm_map_unlock_read(map);
5368 uvmspace_free(vm);
5369
5370 out:
5371 if (pid != -1)
5372 mutex_exit(p->p_lock);
5373 if (error == 0) {
5374 const u_int esize = uimin(sizeof(*vme), elem_size);
5375 dp = oldp;
5376 for (size_t i = 0; i < count; i++) {
5377 if (oldp && (dp - (char *)oldp) < vmesize) {
5378 error = sysctl_copyout(l, &vme[i], dp, esize);
5379 if (error)
5380 break;
5381 dp += elem_size;
5382 } else
5383 break;
5384 }
5385 count *= elem_size;
5386 if (oldp != NULL && *oldlenp < count)
5387 error = ENOSPC;
5388 *oldlenp = count;
5389 }
5390 if (vme)
5391 kmem_free(vme, vmesize);
5392 return error;
5393 }
5394
5395 static int
5396 sysctl_vmproc(SYSCTLFN_ARGS)
5397 {
5398 int error;
5399
5400 if (namelen == 1 && name[0] == CTL_QUERY)
5401 return (sysctl_query(SYSCTLFN_CALL(rnode)));
5402
5403 if (namelen == 0)
5404 return EINVAL;
5405
5406 switch (name[0]) {
5407 case VM_PROC_MAP:
5408 if (namelen != 3)
5409 return EINVAL;
5410 sysctl_unlock();
5411 error = fill_vmentries(l, name[1], name[2], oldp, oldlenp);
5412 sysctl_relock();
5413 return error;
5414 default:
5415 return EINVAL;
5416 }
5417 }
5418
5419 SYSCTL_SETUP(sysctl_uvmmap_setup, "sysctl uvmmap setup")
5420 {
5421
5422 sysctl_createv(clog, 0, NULL, NULL,
5423 CTLFLAG_PERMANENT,
5424 CTLTYPE_STRUCT, "proc",
5425 SYSCTL_DESCR("Process vm information"),
5426 sysctl_vmproc, 0, NULL, 0,
5427 CTL_VM, VM_PROC, CTL_EOL);
5428 #ifndef __USER_VA0_IS_SAFE
5429 sysctl_createv(clog, 0, NULL, NULL,
5430 CTLFLAG_PERMANENT|CTLFLAG_READWRITE,
5431 CTLTYPE_INT, "user_va0_disable",
5432 SYSCTL_DESCR("Disable VA 0"),
5433 sysctl_user_va0_disable, 0, &user_va0_disable, 0,
5434 CTL_VM, CTL_CREATE, CTL_EOL);
5435 #endif
5436 }
Cache object: ae0606ffdcf4d9dd38a74cb3a6460d89
|