1 /* $NetBSD: uvm_map.c,v 1.310 2012/01/05 15:19:53 reinoud 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 1.310 2012/01/05 15:19:53 reinoud Exp $"); 70 71 #include "opt_ddb.h" 72 #include "opt_uvmhist.h" 73 #include "opt_uvm.h" 74 #include "opt_sysv.h" 75 76 #include <sys/param.h> 77 #include <sys/systm.h> 78 #include <sys/mman.h> 79 #include <sys/proc.h> 80 #include <sys/malloc.h> 81 #include <sys/pool.h> 82 #include <sys/kernel.h> 83 #include <sys/mount.h> 84 #include <sys/vnode.h> 85 #include <sys/lockdebug.h> 86 #include <sys/atomic.h> 87 #ifndef __USER_VA0_IS_SAFE 88 #include <sys/sysctl.h> 89 #include <sys/kauth.h> 90 #include "opt_user_va0_disable_default.h" 91 #endif 92 93 #ifdef SYSVSHM 94 #include <sys/shm.h> 95 #endif 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 #if !defined(UVMMAP_COUNTERS) 105 106 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */ 107 #define UVMMAP_EVCNT_INCR(ev) /* nothing */ 108 #define UVMMAP_EVCNT_DECR(ev) /* nothing */ 109 110 #else /* defined(UVMMAP_NOCOUNTERS) */ 111 112 #include <sys/evcnt.h> 113 #define UVMMAP_EVCNT_DEFINE(name) \ 114 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \ 115 "uvmmap", #name); \ 116 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name); 117 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++ 118 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count-- 119 120 #endif /* defined(UVMMAP_NOCOUNTERS) */ 121 122 UVMMAP_EVCNT_DEFINE(ubackmerge) 123 UVMMAP_EVCNT_DEFINE(uforwmerge) 124 UVMMAP_EVCNT_DEFINE(ubimerge) 125 UVMMAP_EVCNT_DEFINE(unomerge) 126 UVMMAP_EVCNT_DEFINE(kbackmerge) 127 UVMMAP_EVCNT_DEFINE(kforwmerge) 128 UVMMAP_EVCNT_DEFINE(kbimerge) 129 UVMMAP_EVCNT_DEFINE(knomerge) 130 UVMMAP_EVCNT_DEFINE(map_call) 131 UVMMAP_EVCNT_DEFINE(mlk_call) 132 UVMMAP_EVCNT_DEFINE(mlk_hint) 133 UVMMAP_EVCNT_DEFINE(mlk_list) 134 UVMMAP_EVCNT_DEFINE(mlk_tree) 135 UVMMAP_EVCNT_DEFINE(mlk_treeloop) 136 UVMMAP_EVCNT_DEFINE(mlk_listloop) 137 138 UVMMAP_EVCNT_DEFINE(uke_alloc) 139 UVMMAP_EVCNT_DEFINE(uke_free) 140 UVMMAP_EVCNT_DEFINE(ukh_alloc) 141 UVMMAP_EVCNT_DEFINE(ukh_free) 142 143 const char vmmapbsy[] = "vmmapbsy"; 144 145 /* 146 * cache for vmspace structures. 147 */ 148 149 static struct pool_cache uvm_vmspace_cache; 150 151 /* 152 * cache for dynamically-allocated map entries. 153 */ 154 155 static struct pool_cache uvm_map_entry_cache; 156 157 MALLOC_DEFINE(M_VMMAP, "VM map", "VM map structures"); 158 MALLOC_DEFINE(M_VMPMAP, "VM pmap", "VM pmap"); 159 160 #ifdef PMAP_GROWKERNEL 161 /* 162 * This global represents the end of the kernel virtual address 163 * space. If we want to exceed this, we must grow the kernel 164 * virtual address space dynamically. 165 * 166 * Note, this variable is locked by kernel_map's lock. 167 */ 168 vaddr_t uvm_maxkaddr; 169 #endif 170 171 #ifndef __USER_VA0_IS_SAFE 172 #ifndef __USER_VA0_DISABLE_DEFAULT 173 #define __USER_VA0_DISABLE_DEFAULT 1 174 #endif 175 #ifdef USER_VA0_DISABLE_DEFAULT /* kernel config option overrides */ 176 #undef __USER_VA0_DISABLE_DEFAULT 177 #define __USER_VA0_DISABLE_DEFAULT USER_VA0_DISABLE_DEFAULT 178 #endif 179 static int user_va0_disable = __USER_VA0_DISABLE_DEFAULT; 180 #endif 181 182 /* 183 * macros 184 */ 185 186 /* 187 * VM_MAP_USE_KMAPENT: determine if uvm_kmapent_alloc/free is used 188 * for the vm_map. 189 */ 190 extern struct vm_map *pager_map; /* XXX */ 191 #define VM_MAP_USE_KMAPENT_FLAGS(flags) \ 192 (((flags) & VM_MAP_INTRSAFE) != 0) 193 #define VM_MAP_USE_KMAPENT(map) \ 194 (VM_MAP_USE_KMAPENT_FLAGS((map)->flags) || (map) == kernel_map) 195 196 /* 197 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging 198 */ 199 200 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \ 201 prot, maxprot, inh, adv, wire) \ 202 ((ent)->etype == (type) && \ 203 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE | UVM_MAP_QUANTUM)) \ 204 == 0 && \ 205 (ent)->object.uvm_obj == (uobj) && \ 206 (ent)->protection == (prot) && \ 207 (ent)->max_protection == (maxprot) && \ 208 (ent)->inheritance == (inh) && \ 209 (ent)->advice == (adv) && \ 210 (ent)->wired_count == (wire)) 211 212 /* 213 * uvm_map_entry_link: insert entry into a map 214 * 215 * => map must be locked 216 */ 217 #define uvm_map_entry_link(map, after_where, entry) do { \ 218 uvm_mapent_check(entry); \ 219 (map)->nentries++; \ 220 (entry)->prev = (after_where); \ 221 (entry)->next = (after_where)->next; \ 222 (entry)->prev->next = (entry); \ 223 (entry)->next->prev = (entry); \ 224 uvm_rb_insert((map), (entry)); \ 225 } while (/*CONSTCOND*/ 0) 226 227 /* 228 * uvm_map_entry_unlink: remove entry from a map 229 * 230 * => map must be locked 231 */ 232 #define uvm_map_entry_unlink(map, entry) do { \ 233 KASSERT((entry) != (map)->first_free); \ 234 KASSERT((entry) != (map)->hint); \ 235 uvm_mapent_check(entry); \ 236 (map)->nentries--; \ 237 (entry)->next->prev = (entry)->prev; \ 238 (entry)->prev->next = (entry)->next; \ 239 uvm_rb_remove((map), (entry)); \ 240 } while (/*CONSTCOND*/ 0) 241 242 /* 243 * SAVE_HINT: saves the specified entry as the hint for future lookups. 244 * 245 * => map need not be locked. 246 */ 247 #define SAVE_HINT(map, check, value) do { \ 248 if ((map)->hint == (check)) \ 249 (map)->hint = (value); \ 250 } while (/*CONSTCOND*/ 0) 251 252 /* 253 * clear_hints: ensure that hints don't point to the entry. 254 * 255 * => map must be write-locked. 256 */ 257 static void 258 clear_hints(struct vm_map *map, struct vm_map_entry *ent) 259 { 260 261 SAVE_HINT(map, ent, ent->prev); 262 if (map->first_free == ent) { 263 map->first_free = ent->prev; 264 } 265 } 266 267 /* 268 * VM_MAP_RANGE_CHECK: check and correct range 269 * 270 * => map must at least be read locked 271 */ 272 273 #define VM_MAP_RANGE_CHECK(map, start, end) do { \ 274 if (start < vm_map_min(map)) \ 275 start = vm_map_min(map); \ 276 if (end > vm_map_max(map)) \ 277 end = vm_map_max(map); \ 278 if (start > end) \ 279 start = end; \ 280 } while (/*CONSTCOND*/ 0) 281 282 /* 283 * local prototypes 284 */ 285 286 static struct vm_map_entry * 287 uvm_mapent_alloc(struct vm_map *, int); 288 static struct vm_map_entry * 289 uvm_mapent_alloc_split(struct vm_map *, 290 const struct vm_map_entry *, int, 291 struct uvm_mapent_reservation *); 292 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *); 293 static void uvm_mapent_free(struct vm_map_entry *); 294 #if defined(DEBUG) 295 static void _uvm_mapent_check(const struct vm_map_entry *, const char *, 296 int); 297 #define uvm_mapent_check(map) _uvm_mapent_check(map, __FILE__, __LINE__) 298 #else /* defined(DEBUG) */ 299 #define uvm_mapent_check(e) /* nothing */ 300 #endif /* defined(DEBUG) */ 301 static struct vm_map_entry * 302 uvm_kmapent_alloc(struct vm_map *, int); 303 static void uvm_kmapent_free(struct vm_map_entry *); 304 static vsize_t uvm_kmapent_overhead(vsize_t); 305 306 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *); 307 static void uvm_map_reference_amap(struct vm_map_entry *, int); 308 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int, 309 int, struct vm_map_entry *); 310 static void uvm_map_unreference_amap(struct vm_map_entry *, int); 311 312 int _uvm_map_sanity(struct vm_map *); 313 int _uvm_tree_sanity(struct vm_map *); 314 static vsize_t uvm_rb_maxgap(const struct vm_map_entry *); 315 316 #define ROOT_ENTRY(map) ((struct vm_map_entry *)(map)->rb_tree.rbt_root) 317 #define LEFT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_left) 318 #define RIGHT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_right) 319 #define PARENT_ENTRY(map, entry) \ 320 (ROOT_ENTRY(map) == (entry) \ 321 ? NULL : (struct vm_map_entry *)RB_FATHER(&(entry)->rb_node)) 322 323 static int 324 uvm_map_compare_nodes(void *ctx, const void *nparent, const void *nkey) 325 { 326 const struct vm_map_entry *eparent = nparent; 327 const struct vm_map_entry *ekey = nkey; 328 329 KASSERT(eparent->start < ekey->start || eparent->start >= ekey->end); 330 KASSERT(ekey->start < eparent->start || ekey->start >= eparent->end); 331 332 if (eparent->start < ekey->start) 333 return -1; 334 if (eparent->end >= ekey->start) 335 return 1; 336 return 0; 337 } 338 339 static int 340 uvm_map_compare_key(void *ctx, const void *nparent, const void *vkey) 341 { 342 const struct vm_map_entry *eparent = nparent; 343 const vaddr_t va = *(const vaddr_t *) vkey; 344 345 if (eparent->start < va) 346 return -1; 347 if (eparent->end >= va) 348 return 1; 349 return 0; 350 } 351 352 static const rb_tree_ops_t uvm_map_tree_ops = { 353 .rbto_compare_nodes = uvm_map_compare_nodes, 354 .rbto_compare_key = uvm_map_compare_key, 355 .rbto_node_offset = offsetof(struct vm_map_entry, rb_node), 356 .rbto_context = NULL 357 }; 358 359 /* 360 * uvm_rb_gap: return the gap size between our entry and next entry. 361 */ 362 static inline vsize_t 363 uvm_rb_gap(const struct vm_map_entry *entry) 364 { 365 366 KASSERT(entry->next != NULL); 367 return entry->next->start - entry->end; 368 } 369 370 static vsize_t 371 uvm_rb_maxgap(const struct vm_map_entry *entry) 372 { 373 struct vm_map_entry *child; 374 vsize_t maxgap = entry->gap; 375 376 /* 377 * We need maxgap to be the largest gap of us or any of our 378 * descendents. Since each of our children's maxgap is the 379 * cached value of their largest gap of themselves or their 380 * descendents, we can just use that value and avoid recursing 381 * down the tree to calculate it. 382 */ 383 if ((child = LEFT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 384 maxgap = child->maxgap; 385 386 if ((child = RIGHT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 387 maxgap = child->maxgap; 388 389 return maxgap; 390 } 391 392 static void 393 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry) 394 { 395 struct vm_map_entry *parent; 396 397 KASSERT(entry->gap == uvm_rb_gap(entry)); 398 entry->maxgap = uvm_rb_maxgap(entry); 399 400 while ((parent = PARENT_ENTRY(map, entry)) != NULL) { 401 struct vm_map_entry *brother; 402 vsize_t maxgap = parent->gap; 403 unsigned int which; 404 405 KDASSERT(parent->gap == uvm_rb_gap(parent)); 406 if (maxgap < entry->maxgap) 407 maxgap = entry->maxgap; 408 /* 409 * Since we work towards the root, we know entry's maxgap 410 * value is OK, but its brothers may now be out-of-date due 411 * to rebalancing. So refresh it. 412 */ 413 which = RB_POSITION(&entry->rb_node) ^ RB_DIR_OTHER; 414 brother = (struct vm_map_entry *)parent->rb_node.rb_nodes[which]; 415 if (brother != NULL) { 416 KDASSERT(brother->gap == uvm_rb_gap(brother)); 417 brother->maxgap = uvm_rb_maxgap(brother); 418 if (maxgap < brother->maxgap) 419 maxgap = brother->maxgap; 420 } 421 422 parent->maxgap = maxgap; 423 entry = parent; 424 } 425 } 426 427 static void 428 uvm_rb_insert(struct vm_map *map, struct vm_map_entry *entry) 429 { 430 struct vm_map_entry *ret; 431 432 entry->gap = entry->maxgap = uvm_rb_gap(entry); 433 if (entry->prev != &map->header) 434 entry->prev->gap = uvm_rb_gap(entry->prev); 435 436 ret = rb_tree_insert_node(&map->rb_tree, entry); 437 KASSERTMSG(ret == entry, 438 "uvm_rb_insert: map %p: duplicate entry %p", map, ret); 439 440 /* 441 * If the previous entry is not our immediate left child, then it's an 442 * ancestor and will be fixed up on the way to the root. We don't 443 * have to check entry->prev against &map->header since &map->header 444 * will never be in the tree. 445 */ 446 uvm_rb_fixup(map, 447 LEFT_ENTRY(entry) == entry->prev ? entry->prev : entry); 448 } 449 450 static void 451 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry) 452 { 453 struct vm_map_entry *prev_parent = NULL, *next_parent = NULL; 454 455 /* 456 * If we are removing an interior node, then an adjacent node will 457 * be used to replace its position in the tree. Therefore we will 458 * need to fixup the tree starting at the parent of the replacement 459 * node. So record their parents for later use. 460 */ 461 if (entry->prev != &map->header) 462 prev_parent = PARENT_ENTRY(map, entry->prev); 463 if (entry->next != &map->header) 464 next_parent = PARENT_ENTRY(map, entry->next); 465 466 rb_tree_remove_node(&map->rb_tree, entry); 467 468 /* 469 * If the previous node has a new parent, fixup the tree starting 470 * at the previous node's old parent. 471 */ 472 if (entry->prev != &map->header) { 473 /* 474 * Update the previous entry's gap due to our absence. 475 */ 476 entry->prev->gap = uvm_rb_gap(entry->prev); 477 uvm_rb_fixup(map, entry->prev); 478 if (prev_parent != NULL 479 && prev_parent != entry 480 && prev_parent != PARENT_ENTRY(map, entry->prev)) 481 uvm_rb_fixup(map, prev_parent); 482 } 483 484 /* 485 * If the next node has a new parent, fixup the tree starting 486 * at the next node's old parent. 487 */ 488 if (entry->next != &map->header) { 489 uvm_rb_fixup(map, entry->next); 490 if (next_parent != NULL 491 && next_parent != entry 492 && next_parent != PARENT_ENTRY(map, entry->next)) 493 uvm_rb_fixup(map, next_parent); 494 } 495 } 496 497 #if defined(DEBUG) 498 int uvm_debug_check_map = 0; 499 int uvm_debug_check_rbtree = 0; 500 #define uvm_map_check(map, name) \ 501 _uvm_map_check((map), (name), __FILE__, __LINE__) 502 static void 503 _uvm_map_check(struct vm_map *map, const char *name, 504 const char *file, int line) 505 { 506 507 if ((uvm_debug_check_map && _uvm_map_sanity(map)) || 508 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) { 509 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)", 510 name, map, file, line); 511 } 512 } 513 #else /* defined(DEBUG) */ 514 #define uvm_map_check(map, name) /* nothing */ 515 #endif /* defined(DEBUG) */ 516 517 #if defined(DEBUG) || defined(DDB) 518 int 519 _uvm_map_sanity(struct vm_map *map) 520 { 521 bool first_free_found = false; 522 bool hint_found = false; 523 const struct vm_map_entry *e; 524 struct vm_map_entry *hint = map->hint; 525 526 e = &map->header; 527 for (;;) { 528 if (map->first_free == e) { 529 first_free_found = true; 530 } else if (!first_free_found && e->next->start > e->end) { 531 printf("first_free %p should be %p\n", 532 map->first_free, e); 533 return -1; 534 } 535 if (hint == e) { 536 hint_found = true; 537 } 538 539 e = e->next; 540 if (e == &map->header) { 541 break; 542 } 543 } 544 if (!first_free_found) { 545 printf("stale first_free\n"); 546 return -1; 547 } 548 if (!hint_found) { 549 printf("stale hint\n"); 550 return -1; 551 } 552 return 0; 553 } 554 555 int 556 _uvm_tree_sanity(struct vm_map *map) 557 { 558 struct vm_map_entry *tmp, *trtmp; 559 int n = 0, i = 1; 560 561 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 562 if (tmp->gap != uvm_rb_gap(tmp)) { 563 printf("%d/%d gap %lx != %lx %s\n", 564 n + 1, map->nentries, 565 (ulong)tmp->gap, (ulong)uvm_rb_gap(tmp), 566 tmp->next == &map->header ? "(last)" : ""); 567 goto error; 568 } 569 /* 570 * If any entries are out of order, tmp->gap will be unsigned 571 * and will likely exceed the size of the map. 572 */ 573 if (tmp->gap >= vm_map_max(map) - vm_map_min(map)) { 574 printf("too large gap %zu\n", (size_t)tmp->gap); 575 goto error; 576 } 577 n++; 578 } 579 580 if (n != map->nentries) { 581 printf("nentries: %d vs %d\n", n, map->nentries); 582 goto error; 583 } 584 585 trtmp = NULL; 586 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 587 if (tmp->maxgap != uvm_rb_maxgap(tmp)) { 588 printf("maxgap %lx != %lx\n", 589 (ulong)tmp->maxgap, 590 (ulong)uvm_rb_maxgap(tmp)); 591 goto error; 592 } 593 if (trtmp != NULL && trtmp->start >= tmp->start) { 594 printf("corrupt: 0x%"PRIxVADDR"x >= 0x%"PRIxVADDR"x\n", 595 trtmp->start, tmp->start); 596 goto error; 597 } 598 599 trtmp = tmp; 600 } 601 602 for (tmp = map->header.next; tmp != &map->header; 603 tmp = tmp->next, i++) { 604 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_LEFT); 605 if (trtmp == NULL) 606 trtmp = &map->header; 607 if (tmp->prev != trtmp) { 608 printf("lookup: %d: %p->prev=%p: %p\n", 609 i, tmp, tmp->prev, trtmp); 610 goto error; 611 } 612 trtmp = rb_tree_iterate(&map->rb_tree, tmp, RB_DIR_RIGHT); 613 if (trtmp == NULL) 614 trtmp = &map->header; 615 if (tmp->next != trtmp) { 616 printf("lookup: %d: %p->next=%p: %p\n", 617 i, tmp, tmp->next, trtmp); 618 goto error; 619 } 620 trtmp = rb_tree_find_node(&map->rb_tree, &tmp->start); 621 if (trtmp != tmp) { 622 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp, 623 PARENT_ENTRY(map, tmp)); 624 goto error; 625 } 626 } 627 628 return (0); 629 error: 630 return (-1); 631 } 632 #endif /* defined(DEBUG) || defined(DDB) */ 633 634 #ifdef DIAGNOSTIC 635 static struct vm_map *uvm_kmapent_map(struct vm_map_entry *); 636 #endif 637 638 /* 639 * vm_map_lock: acquire an exclusive (write) lock on a map. 640 * 641 * => Note that "intrsafe" maps use only exclusive, spin locks. 642 * 643 * => The locking protocol provides for guaranteed upgrade from shared -> 644 * exclusive by whichever thread currently has the map marked busy. 645 * See "LOCKING PROTOCOL NOTES" in uvm_map.h. This is horrible; among 646 * other problems, it defeats any fairness guarantees provided by RW 647 * locks. 648 */ 649 650 void 651 vm_map_lock(struct vm_map *map) 652 { 653 654 if ((map->flags & VM_MAP_INTRSAFE) != 0) { 655 mutex_spin_enter(&map->mutex); 656 return; 657 } 658 659 for (;;) { 660 rw_enter(&map->lock, RW_WRITER); 661 if (map->busy == NULL) 662 break; 663 if (map->busy == curlwp) 664 break; 665 mutex_enter(&map->misc_lock); 666 rw_exit(&map->lock); 667 if (map->busy != NULL) 668 cv_wait(&map->cv, &map->misc_lock); 669 mutex_exit(&map->misc_lock); 670 } 671 672 map->timestamp++; 673 } 674 675 /* 676 * vm_map_lock_try: try to lock a map, failing if it is already locked. 677 */ 678 679 bool 680 vm_map_lock_try(struct vm_map *map) 681 { 682 683 if ((map->flags & VM_MAP_INTRSAFE) != 0) 684 return mutex_tryenter(&map->mutex); 685 if (!rw_tryenter(&map->lock, RW_WRITER)) 686 return false; 687 if (map->busy != NULL) { 688 rw_exit(&map->lock); 689 return false; 690 } 691 692 map->timestamp++; 693 return true; 694 } 695 696 /* 697 * vm_map_unlock: release an exclusive lock on a map. 698 */ 699 700 void 701 vm_map_unlock(struct vm_map *map) 702 { 703 704 if ((map->flags & VM_MAP_INTRSAFE) != 0) 705 mutex_spin_exit(&map->mutex); 706 else { 707 KASSERT(rw_write_held(&map->lock)); 708 KASSERT(map->busy == NULL || map->busy == curlwp); 709 rw_exit(&map->lock); 710 } 711 } 712 713 /* 714 * vm_map_unbusy: mark the map as unbusy, and wake any waiters that 715 * want an exclusive lock. 716 */ 717 718 void 719 vm_map_unbusy(struct vm_map *map) 720 { 721 722 KASSERT(map->busy == curlwp); 723 724 /* 725 * Safe to clear 'busy' and 'waiters' with only a read lock held: 726 * 727 * o they can only be set with a write lock held 728 * o writers are blocked out with a read or write hold 729 * o at any time, only one thread owns the set of values 730 */ 731 mutex_enter(&map->misc_lock); 732 map->busy = NULL; 733 cv_broadcast(&map->cv); 734 mutex_exit(&map->misc_lock); 735 } 736 737 /* 738 * vm_map_lock_read: acquire a shared (read) lock on a map. 739 */ 740 741 void 742 vm_map_lock_read(struct vm_map *map) 743 { 744 745 KASSERT((map->flags & VM_MAP_INTRSAFE) == 0); 746 747 rw_enter(&map->lock, RW_READER); 748 } 749 750 /* 751 * vm_map_unlock_read: release a shared lock on a map. 752 */ 753 754 void 755 vm_map_unlock_read(struct vm_map *map) 756 { 757 758 KASSERT((map->flags & VM_MAP_INTRSAFE) == 0); 759 760 rw_exit(&map->lock); 761 } 762 763 /* 764 * vm_map_busy: mark a map as busy. 765 * 766 * => the caller must hold the map write locked 767 */ 768 769 void 770 vm_map_busy(struct vm_map *map) 771 { 772 773 KASSERT(rw_write_held(&map->lock)); 774 KASSERT(map->busy == NULL); 775 776 map->busy = curlwp; 777 } 778 779 /* 780 * vm_map_locked_p: return true if the map is write locked. 781 * 782 * => only for debug purposes like KASSERTs. 783 * => should not be used to verify that a map is not locked. 784 */ 785 786 bool 787 vm_map_locked_p(struct vm_map *map) 788 { 789 790 if ((map->flags & VM_MAP_INTRSAFE) != 0) { 791 return mutex_owned(&map->mutex); 792 } else { 793 return rw_write_held(&map->lock); 794 } 795 } 796 797 /* 798 * uvm_mapent_alloc: allocate a map entry 799 */ 800 801 static struct vm_map_entry * 802 uvm_mapent_alloc(struct vm_map *map, int flags) 803 { 804 struct vm_map_entry *me; 805 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK; 806 UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist); 807 808 if (VM_MAP_USE_KMAPENT(map)) { 809 me = uvm_kmapent_alloc(map, flags); 810 } else { 811 me = pool_cache_get(&uvm_map_entry_cache, pflags); 812 if (__predict_false(me == NULL)) 813 return NULL; 814 me->flags = 0; 815 } 816 817 UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]", me, 818 ((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map), 0, 0); 819 return (me); 820 } 821 822 /* 823 * uvm_mapent_alloc_split: allocate a map entry for clipping. 824 * 825 * => map must be locked by caller if UVM_MAP_QUANTUM is set. 826 */ 827 828 static struct vm_map_entry * 829 uvm_mapent_alloc_split(struct vm_map *map, 830 const struct vm_map_entry *old_entry, int flags, 831 struct uvm_mapent_reservation *umr) 832 { 833 struct vm_map_entry *me; 834 835 KASSERT(!VM_MAP_USE_KMAPENT(map) || 836 (old_entry->flags & UVM_MAP_QUANTUM) || !UMR_EMPTY(umr)); 837 838 if (old_entry->flags & UVM_MAP_QUANTUM) { 839 struct vm_map_kernel *vmk = vm_map_to_kernel(map); 840 841 KASSERT(vm_map_locked_p(map)); 842 me = vmk->vmk_merged_entries; 843 KASSERT(me); 844 vmk->vmk_merged_entries = me->next; 845 KASSERT(me->flags & UVM_MAP_QUANTUM); 846 } else { 847 me = uvm_mapent_alloc(map, flags); 848 } 849 850 return me; 851 } 852 853 /* 854 * uvm_mapent_free: free map entry 855 */ 856 857 static void 858 uvm_mapent_free(struct vm_map_entry *me) 859 { 860 UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist); 861 862 UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]", 863 me, me->flags, 0, 0); 864 if (me->flags & UVM_MAP_KERNEL) { 865 uvm_kmapent_free(me); 866 } else { 867 pool_cache_put(&uvm_map_entry_cache, me); 868 } 869 } 870 871 /* 872 * uvm_mapent_free_merged: free merged map entry 873 * 874 * => keep the entry if needed. 875 * => caller shouldn't hold map locked if VM_MAP_USE_KMAPENT(map) is true. 876 * => map should be locked if UVM_MAP_QUANTUM is set. 877 */ 878 879 static void 880 uvm_mapent_free_merged(struct vm_map *map, struct vm_map_entry *me) 881 { 882 883 KASSERT(!(me->flags & UVM_MAP_KERNEL) || uvm_kmapent_map(me) == map); 884 885 if (me->flags & UVM_MAP_QUANTUM) { 886 /* 887 * keep this entry for later splitting. 888 */ 889 struct vm_map_kernel *vmk; 890 891 KASSERT(vm_map_locked_p(map)); 892 KASSERT(VM_MAP_IS_KERNEL(map)); 893 KASSERT(!VM_MAP_USE_KMAPENT(map) || 894 (me->flags & UVM_MAP_KERNEL)); 895 896 vmk = vm_map_to_kernel(map); 897 me->next = vmk->vmk_merged_entries; 898 vmk->vmk_merged_entries = me; 899 } else { 900 uvm_mapent_free(me); 901 } 902 } 903 904 /* 905 * uvm_mapent_copy: copy a map entry, preserving flags 906 */ 907 908 static inline void 909 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst) 910 { 911 912 memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) - 913 ((char *)src)); 914 } 915 916 /* 917 * uvm_mapent_overhead: calculate maximum kva overhead necessary for 918 * map entries. 919 * 920 * => size and flags are the same as uvm_km_suballoc's ones. 921 */ 922 923 vsize_t 924 uvm_mapent_overhead(vsize_t size, int flags) 925 { 926 927 if (VM_MAP_USE_KMAPENT_FLAGS(flags)) { 928 return uvm_kmapent_overhead(size); 929 } 930 return 0; 931 } 932 933 #if defined(DEBUG) 934 static void 935 _uvm_mapent_check(const struct vm_map_entry *entry, const char *file, int line) 936 { 937 938 if (entry->start >= entry->end) { 939 goto bad; 940 } 941 if (UVM_ET_ISOBJ(entry)) { 942 if (entry->object.uvm_obj == NULL) { 943 goto bad; 944 } 945 } else if (UVM_ET_ISSUBMAP(entry)) { 946 if (entry->object.sub_map == NULL) { 947 goto bad; 948 } 949 } else { 950 if (entry->object.uvm_obj != NULL || 951 entry->object.sub_map != NULL) { 952 goto bad; 953 } 954 } 955 if (!UVM_ET_ISOBJ(entry)) { 956 if (entry->offset != 0) { 957 goto bad; 958 } 959 } 960 961 return; 962 963 bad: 964 panic("%s: bad entry %p (%s:%d)", __func__, entry, file, line); 965 } 966 #endif /* defined(DEBUG) */ 967 968 /* 969 * uvm_map_entry_unwire: unwire a map entry 970 * 971 * => map should be locked by caller 972 */ 973 974 static inline void 975 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry) 976 { 977 978 entry->wired_count = 0; 979 uvm_fault_unwire_locked(map, entry->start, entry->end); 980 } 981 982 983 /* 984 * wrapper for calling amap_ref() 985 */ 986 static inline void 987 uvm_map_reference_amap(struct vm_map_entry *entry, int flags) 988 { 989 990 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff, 991 (entry->end - entry->start) >> PAGE_SHIFT, flags); 992 } 993 994 995 /* 996 * wrapper for calling amap_unref() 997 */ 998 static inline void 999 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags) 1000 { 1001 1002 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff, 1003 (entry->end - entry->start) >> PAGE_SHIFT, flags); 1004 } 1005 1006 1007 /* 1008 * uvm_map_init: init mapping system at boot time. 1009 */ 1010 1011 void 1012 uvm_map_init(void) 1013 { 1014 #if defined(UVMHIST) 1015 static struct kern_history_ent maphistbuf[100]; 1016 static struct kern_history_ent pdhistbuf[100]; 1017 #endif 1018 1019 /* 1020 * first, init logging system. 1021 */ 1022 1023 UVMHIST_FUNC("uvm_map_init"); 1024 UVMHIST_INIT_STATIC(maphist, maphistbuf); 1025 UVMHIST_INIT_STATIC(pdhist, pdhistbuf); 1026 UVMHIST_CALLED(maphist); 1027 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0); 1028 1029 /* 1030 * initialize the global lock for kernel map entry. 1031 */ 1032 1033 mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM); 1034 1035 /* 1036 * initialize caches. 1037 */ 1038 1039 pool_cache_bootstrap(&uvm_map_entry_cache, sizeof(struct vm_map_entry), 1040 0, 0, 0, "vmmpepl", NULL, IPL_NONE, NULL, NULL, NULL); 1041 pool_cache_bootstrap(&uvm_vmspace_cache, sizeof(struct vmspace), 1042 0, 0, 0, "vmsppl", NULL, IPL_NONE, NULL, NULL, NULL); 1043 } 1044 1045 /* 1046 * clippers 1047 */ 1048 1049 /* 1050 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy. 1051 */ 1052 1053 static void 1054 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2, 1055 vaddr_t splitat) 1056 { 1057 vaddr_t adj; 1058 1059 KASSERT(entry1->start < splitat); 1060 KASSERT(splitat < entry1->end); 1061 1062 adj = splitat - entry1->start; 1063 entry1->end = entry2->start = splitat; 1064 1065 if (entry1->aref.ar_amap) { 1066 amap_splitref(&entry1->aref, &entry2->aref, adj); 1067 } 1068 if (UVM_ET_ISSUBMAP(entry1)) { 1069 /* ... unlikely to happen, but play it safe */ 1070 uvm_map_reference(entry1->object.sub_map); 1071 } else if (UVM_ET_ISOBJ(entry1)) { 1072 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */ 1073 entry2->offset += adj; 1074 if (entry1->object.uvm_obj->pgops && 1075 entry1->object.uvm_obj->pgops->pgo_reference) 1076 entry1->object.uvm_obj->pgops->pgo_reference( 1077 entry1->object.uvm_obj); 1078 } 1079 } 1080 1081 /* 1082 * uvm_map_clip_start: ensure that the entry begins at or after 1083 * the starting address, if it doesn't we split the entry. 1084 * 1085 * => caller should use UVM_MAP_CLIP_START macro rather than calling 1086 * this directly 1087 * => map must be locked by caller 1088 */ 1089 1090 void 1091 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry, 1092 vaddr_t start, struct uvm_mapent_reservation *umr) 1093 { 1094 struct vm_map_entry *new_entry; 1095 1096 /* uvm_map_simplify_entry(map, entry); */ /* XXX */ 1097 1098 uvm_map_check(map, "clip_start entry"); 1099 uvm_mapent_check(entry); 1100 1101 /* 1102 * Split off the front portion. note that we must insert the new 1103 * entry BEFORE this one, so that this entry has the specified 1104 * starting address. 1105 */ 1106 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr); 1107 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1108 uvm_mapent_splitadj(new_entry, entry, start); 1109 uvm_map_entry_link(map, entry->prev, new_entry); 1110 1111 uvm_map_check(map, "clip_start leave"); 1112 } 1113 1114 /* 1115 * uvm_map_clip_end: ensure that the entry ends at or before 1116 * the ending address, if it does't we split the reference 1117 * 1118 * => caller should use UVM_MAP_CLIP_END macro rather than calling 1119 * this directly 1120 * => map must be locked by caller 1121 */ 1122 1123 void 1124 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end, 1125 struct uvm_mapent_reservation *umr) 1126 { 1127 struct vm_map_entry *new_entry; 1128 1129 uvm_map_check(map, "clip_end entry"); 1130 uvm_mapent_check(entry); 1131 1132 /* 1133 * Create a new entry and insert it 1134 * AFTER the specified entry 1135 */ 1136 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr); 1137 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1138 uvm_mapent_splitadj(entry, new_entry, end); 1139 uvm_map_entry_link(map, entry, new_entry); 1140 1141 uvm_map_check(map, "clip_end leave"); 1142 } 1143 1144 static void 1145 vm_map_drain(struct vm_map *map, uvm_flag_t flags) 1146 { 1147 1148 if (!VM_MAP_IS_KERNEL(map)) { 1149 return; 1150 } 1151 1152 uvm_km_va_drain(map, flags); 1153 } 1154 1155 /* 1156 * M A P - m a i n e n t r y p o i n t 1157 */ 1158 /* 1159 * uvm_map: establish a valid mapping in a map 1160 * 1161 * => assume startp is page aligned. 1162 * => assume size is a multiple of PAGE_SIZE. 1163 * => assume sys_mmap provides enough of a "hint" to have us skip 1164 * over text/data/bss area. 1165 * => map must be unlocked (we will lock it) 1166 * => <uobj,uoffset> value meanings (4 cases): 1167 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER 1168 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER 1169 * [3] <uobj,uoffset> == normal mapping 1170 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA 1171 * 1172 * case [4] is for kernel mappings where we don't know the offset until 1173 * we've found a virtual address. note that kernel object offsets are 1174 * always relative to vm_map_min(kernel_map). 1175 * 1176 * => if `align' is non-zero, we align the virtual address to the specified 1177 * alignment. 1178 * this is provided as a mechanism for large pages. 1179 * 1180 * => XXXCDC: need way to map in external amap? 1181 */ 1182 1183 int 1184 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size, 1185 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags) 1186 { 1187 struct uvm_map_args args; 1188 struct vm_map_entry *new_entry; 1189 int error; 1190 1191 KASSERT((flags & UVM_FLAG_QUANTUM) == 0 || VM_MAP_IS_KERNEL(map)); 1192 KASSERT((size & PAGE_MASK) == 0); 1193 1194 #ifndef __USER_VA0_IS_SAFE 1195 if ((flags & UVM_FLAG_FIXED) && *startp == 0 && 1196 !VM_MAP_IS_KERNEL(map) && user_va0_disable) 1197 return EACCES; 1198 #endif 1199 1200 /* 1201 * for pager_map, allocate the new entry first to avoid sleeping 1202 * for memory while we have the map locked. 1203 * 1204 * Also, because we allocate entries for in-kernel maps 1205 * a bit differently (cf. uvm_kmapent_alloc/free), we need to 1206 * allocate them before locking the map. 1207 */ 1208 1209 new_entry = NULL; 1210 if (VM_MAP_USE_KMAPENT(map) || (flags & UVM_FLAG_QUANTUM) || 1211 map == pager_map) { 1212 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT)); 1213 if (__predict_false(new_entry == NULL)) 1214 return ENOMEM; 1215 if (flags & UVM_FLAG_QUANTUM) 1216 new_entry->flags |= UVM_MAP_QUANTUM; 1217 } 1218 if (map == pager_map) 1219 flags |= UVM_FLAG_NOMERGE; 1220 1221 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align, 1222 flags, &args); 1223 if (!error) { 1224 error = uvm_map_enter(map, &args, new_entry); 1225 *startp = args.uma_start; 1226 } else if (new_entry) { 1227 uvm_mapent_free(new_entry); 1228 } 1229 1230 #if defined(DEBUG) 1231 if (!error && VM_MAP_IS_KERNEL(map)) { 1232 uvm_km_check_empty(map, *startp, *startp + size); 1233 } 1234 #endif /* defined(DEBUG) */ 1235 1236 return error; 1237 } 1238 1239 /* 1240 * uvm_map_prepare: 1241 * 1242 * called with map unlocked. 1243 * on success, returns the map locked. 1244 */ 1245 1246 int 1247 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size, 1248 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags, 1249 struct uvm_map_args *args) 1250 { 1251 struct vm_map_entry *prev_entry; 1252 vm_prot_t prot = UVM_PROTECTION(flags); 1253 vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1254 1255 UVMHIST_FUNC("uvm_map_prepare"); 1256 UVMHIST_CALLED(maphist); 1257 1258 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)", 1259 map, start, size, flags); 1260 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0); 1261 1262 /* 1263 * detect a popular device driver bug. 1264 */ 1265 1266 KASSERT(doing_shutdown || curlwp != NULL || 1267 (map->flags & VM_MAP_INTRSAFE)); 1268 1269 /* 1270 * zero-sized mapping doesn't make any sense. 1271 */ 1272 KASSERT(size > 0); 1273 1274 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0); 1275 1276 uvm_map_check(map, "map entry"); 1277 1278 /* 1279 * check sanity of protection code 1280 */ 1281 1282 if ((prot & maxprot) != prot) { 1283 UVMHIST_LOG(maphist, "<- prot. failure: prot=0x%x, max=0x%x", 1284 prot, maxprot,0,0); 1285 return EACCES; 1286 } 1287 1288 /* 1289 * figure out where to put new VM range 1290 */ 1291 1292 retry: 1293 if (vm_map_lock_try(map) == false) { 1294 if ((flags & UVM_FLAG_TRYLOCK) != 0 && 1295 (map->flags & VM_MAP_INTRSAFE) == 0) { 1296 return EAGAIN; 1297 } 1298 vm_map_lock(map); /* could sleep here */ 1299 } 1300 prev_entry = uvm_map_findspace(map, start, size, &start, 1301 uobj, uoffset, align, flags); 1302 if (prev_entry == NULL) { 1303 unsigned int timestamp; 1304 1305 timestamp = map->timestamp; 1306 UVMHIST_LOG(maphist,"waiting va timestamp=0x%x", 1307 timestamp,0,0,0); 1308 map->flags |= VM_MAP_WANTVA; 1309 vm_map_unlock(map); 1310 1311 /* 1312 * try to reclaim kva and wait until someone does unmap. 1313 * fragile locking here, so we awaken every second to 1314 * recheck the condition. 1315 */ 1316 1317 vm_map_drain(map, flags); 1318 1319 mutex_enter(&map->misc_lock); 1320 while ((map->flags & VM_MAP_WANTVA) != 0 && 1321 map->timestamp == timestamp) { 1322 if ((flags & UVM_FLAG_WAITVA) == 0) { 1323 mutex_exit(&map->misc_lock); 1324 UVMHIST_LOG(maphist, 1325 "<- uvm_map_findspace failed!", 0,0,0,0); 1326 return ENOMEM; 1327 } else { 1328 cv_timedwait(&map->cv, &map->misc_lock, hz); 1329 } 1330 } 1331 mutex_exit(&map->misc_lock); 1332 goto retry; 1333 } 1334 1335 #ifdef PMAP_GROWKERNEL 1336 /* 1337 * If the kernel pmap can't map the requested space, 1338 * then allocate more resources for it. 1339 */ 1340 if (map == kernel_map && uvm_maxkaddr < (start + size)) 1341 uvm_maxkaddr = pmap_growkernel(start + size); 1342 #endif 1343 1344 UVMMAP_EVCNT_INCR(map_call); 1345 1346 /* 1347 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER 1348 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in 1349 * either case we want to zero it before storing it in the map entry 1350 * (because it looks strange and confusing when debugging...) 1351 * 1352 * if uobj is not null 1353 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping 1354 * and we do not need to change uoffset. 1355 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset 1356 * now (based on the starting address of the map). this case is 1357 * for kernel object mappings where we don't know the offset until 1358 * the virtual address is found (with uvm_map_findspace). the 1359 * offset is the distance we are from the start of the map. 1360 */ 1361 1362 if (uobj == NULL) { 1363 uoffset = 0; 1364 } else { 1365 if (uoffset == UVM_UNKNOWN_OFFSET) { 1366 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj)); 1367 uoffset = start - vm_map_min(kernel_map); 1368 } 1369 } 1370 1371 args->uma_flags = flags; 1372 args->uma_prev = prev_entry; 1373 args->uma_start = start; 1374 args->uma_size = size; 1375 args->uma_uobj = uobj; 1376 args->uma_uoffset = uoffset; 1377 1378 UVMHIST_LOG(maphist, "<- done!", 0,0,0,0); 1379 return 0; 1380 } 1381 1382 /* 1383 * uvm_map_enter: 1384 * 1385 * called with map locked. 1386 * unlock the map before returning. 1387 */ 1388 1389 int 1390 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args, 1391 struct vm_map_entry *new_entry) 1392 { 1393 struct vm_map_entry *prev_entry = args->uma_prev; 1394 struct vm_map_entry *dead = NULL; 1395 1396 const uvm_flag_t flags = args->uma_flags; 1397 const vm_prot_t prot = UVM_PROTECTION(flags); 1398 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1399 const vm_inherit_t inherit = UVM_INHERIT(flags); 1400 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ? 1401 AMAP_EXTEND_NOWAIT : 0; 1402 const int advice = UVM_ADVICE(flags); 1403 const int meflagval = (flags & UVM_FLAG_QUANTUM) ? 1404 UVM_MAP_QUANTUM : 0; 1405 1406 vaddr_t start = args->uma_start; 1407 vsize_t size = args->uma_size; 1408 struct uvm_object *uobj = args->uma_uobj; 1409 voff_t uoffset = args->uma_uoffset; 1410 1411 const int kmap = (vm_map_pmap(map) == pmap_kernel()); 1412 int merged = 0; 1413 int error; 1414 int newetype; 1415 1416 UVMHIST_FUNC("uvm_map_enter"); 1417 UVMHIST_CALLED(maphist); 1418 1419 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)", 1420 map, start, size, flags); 1421 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0); 1422 1423 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */ 1424 KASSERT(vm_map_locked_p(map)); 1425 1426 if (flags & UVM_FLAG_QUANTUM) { 1427 KASSERT(new_entry); 1428 KASSERT(new_entry->flags & UVM_MAP_QUANTUM); 1429 } 1430 1431 if (uobj) 1432 newetype = UVM_ET_OBJ; 1433 else 1434 newetype = 0; 1435 1436 if (flags & UVM_FLAG_COPYONW) { 1437 newetype |= UVM_ET_COPYONWRITE; 1438 if ((flags & UVM_FLAG_OVERLAY) == 0) 1439 newetype |= UVM_ET_NEEDSCOPY; 1440 } 1441 1442 /* 1443 * try and insert in map by extending previous entry, if possible. 1444 * XXX: we don't try and pull back the next entry. might be useful 1445 * for a stack, but we are currently allocating our stack in advance. 1446 */ 1447 1448 if (flags & UVM_FLAG_NOMERGE) 1449 goto nomerge; 1450 1451 if (prev_entry->end == start && 1452 prev_entry != &map->header && 1453 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, meflagval, 1454 prot, maxprot, inherit, advice, 0)) { 1455 1456 if (uobj && prev_entry->offset + 1457 (prev_entry->end - prev_entry->start) != uoffset) 1458 goto forwardmerge; 1459 1460 /* 1461 * can't extend a shared amap. note: no need to lock amap to 1462 * look at refs since we don't care about its exact value. 1463 * if it is one (i.e. we have only reference) it will stay there 1464 */ 1465 1466 if (prev_entry->aref.ar_amap && 1467 amap_refs(prev_entry->aref.ar_amap) != 1) { 1468 goto forwardmerge; 1469 } 1470 1471 if (prev_entry->aref.ar_amap) { 1472 error = amap_extend(prev_entry, size, 1473 amapwaitflag | AMAP_EXTEND_FORWARDS); 1474 if (error) 1475 goto nomerge; 1476 } 1477 1478 if (kmap) { 1479 UVMMAP_EVCNT_INCR(kbackmerge); 1480 } else { 1481 UVMMAP_EVCNT_INCR(ubackmerge); 1482 } 1483 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0); 1484 1485 /* 1486 * drop our reference to uobj since we are extending a reference 1487 * that we already have (the ref count can not drop to zero). 1488 */ 1489 1490 if (uobj && uobj->pgops->pgo_detach) 1491 uobj->pgops->pgo_detach(uobj); 1492 1493 /* 1494 * Now that we've merged the entries, note that we've grown 1495 * and our gap has shrunk. Then fix the tree. 1496 */ 1497 prev_entry->end += size; 1498 prev_entry->gap -= size; 1499 uvm_rb_fixup(map, prev_entry); 1500 1501 uvm_map_check(map, "map backmerged"); 1502 1503 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0); 1504 merged++; 1505 } 1506 1507 forwardmerge: 1508 if (prev_entry->next->start == (start + size) && 1509 prev_entry->next != &map->header && 1510 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, meflagval, 1511 prot, maxprot, inherit, advice, 0)) { 1512 1513 if (uobj && prev_entry->next->offset != uoffset + size) 1514 goto nomerge; 1515 1516 /* 1517 * can't extend a shared amap. note: no need to lock amap to 1518 * look at refs since we don't care about its exact value. 1519 * if it is one (i.e. we have only reference) it will stay there. 1520 * 1521 * note that we also can't merge two amaps, so if we 1522 * merged with the previous entry which has an amap, 1523 * and the next entry also has an amap, we give up. 1524 * 1525 * Interesting cases: 1526 * amap, new, amap -> give up second merge (single fwd extend) 1527 * amap, new, none -> double forward extend (extend again here) 1528 * none, new, amap -> double backward extend (done here) 1529 * uobj, new, amap -> single backward extend (done here) 1530 * 1531 * XXX should we attempt to deal with someone refilling 1532 * the deallocated region between two entries that are 1533 * backed by the same amap (ie, arefs is 2, "prev" and 1534 * "next" refer to it, and adding this allocation will 1535 * close the hole, thus restoring arefs to 1 and 1536 * deallocating the "next" vm_map_entry)? -- @@@ 1537 */ 1538 1539 if (prev_entry->next->aref.ar_amap && 1540 (amap_refs(prev_entry->next->aref.ar_amap) != 1 || 1541 (merged && prev_entry->aref.ar_amap))) { 1542 goto nomerge; 1543 } 1544 1545 if (merged) { 1546 /* 1547 * Try to extend the amap of the previous entry to 1548 * cover the next entry as well. If it doesn't work 1549 * just skip on, don't actually give up, since we've 1550 * already completed the back merge. 1551 */ 1552 if (prev_entry->aref.ar_amap) { 1553 if (amap_extend(prev_entry, 1554 prev_entry->next->end - 1555 prev_entry->next->start, 1556 amapwaitflag | AMAP_EXTEND_FORWARDS)) 1557 goto nomerge; 1558 } 1559 1560 /* 1561 * Try to extend the amap of the *next* entry 1562 * back to cover the new allocation *and* the 1563 * previous entry as well (the previous merge 1564 * didn't have an amap already otherwise we 1565 * wouldn't be checking here for an amap). If 1566 * it doesn't work just skip on, again, don't 1567 * actually give up, since we've already 1568 * completed the back merge. 1569 */ 1570 else if (prev_entry->next->aref.ar_amap) { 1571 if (amap_extend(prev_entry->next, 1572 prev_entry->end - 1573 prev_entry->start, 1574 amapwaitflag | AMAP_EXTEND_BACKWARDS)) 1575 goto nomerge; 1576 } 1577 } else { 1578 /* 1579 * Pull the next entry's amap backwards to cover this 1580 * new allocation. 1581 */ 1582 if (prev_entry->next->aref.ar_amap) { 1583 error = amap_extend(prev_entry->next, size, 1584 amapwaitflag | AMAP_EXTEND_BACKWARDS); 1585 if (error) 1586 goto nomerge; 1587 } 1588 } 1589 1590 if (merged) { 1591 if (kmap) { 1592 UVMMAP_EVCNT_DECR(kbackmerge); 1593 UVMMAP_EVCNT_INCR(kbimerge); 1594 } else { 1595 UVMMAP_EVCNT_DECR(ubackmerge); 1596 UVMMAP_EVCNT_INCR(ubimerge); 1597 } 1598 } else { 1599 if (kmap) { 1600 UVMMAP_EVCNT_INCR(kforwmerge); 1601 } else { 1602 UVMMAP_EVCNT_INCR(uforwmerge); 1603 } 1604 } 1605 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0); 1606 1607 /* 1608 * drop our reference to uobj since we are extending a reference 1609 * that we already have (the ref count can not drop to zero). 1610 * (if merged, we've already detached) 1611 */ 1612 if (uobj && uobj->pgops->pgo_detach && !merged) 1613 uobj->pgops->pgo_detach(uobj); 1614 1615 if (merged) { 1616 dead = prev_entry->next; 1617 prev_entry->end = dead->end; 1618 uvm_map_entry_unlink(map, dead); 1619 if (dead->aref.ar_amap != NULL) { 1620 prev_entry->aref = dead->aref; 1621 dead->aref.ar_amap = NULL; 1622 } 1623 } else { 1624 prev_entry->next->start -= size; 1625 if (prev_entry != &map->header) { 1626 prev_entry->gap -= size; 1627 KASSERT(prev_entry->gap == uvm_rb_gap(prev_entry)); 1628 uvm_rb_fixup(map, prev_entry); 1629 } 1630 if (uobj) 1631 prev_entry->next->offset = uoffset; 1632 } 1633 1634 uvm_map_check(map, "map forwardmerged"); 1635 1636 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0); 1637 merged++; 1638 } 1639 1640 nomerge: 1641 if (!merged) { 1642 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0); 1643 if (kmap) { 1644 UVMMAP_EVCNT_INCR(knomerge); 1645 } else { 1646 UVMMAP_EVCNT_INCR(unomerge); 1647 } 1648 1649 /* 1650 * allocate new entry and link it in. 1651 */ 1652 1653 if (new_entry == NULL) { 1654 new_entry = uvm_mapent_alloc(map, 1655 (flags & UVM_FLAG_NOWAIT)); 1656 if (__predict_false(new_entry == NULL)) { 1657 error = ENOMEM; 1658 goto done; 1659 } 1660 } 1661 new_entry->start = start; 1662 new_entry->end = new_entry->start + size; 1663 new_entry->object.uvm_obj = uobj; 1664 new_entry->offset = uoffset; 1665 1666 new_entry->etype = newetype; 1667 1668 if (flags & UVM_FLAG_NOMERGE) { 1669 new_entry->flags |= UVM_MAP_NOMERGE; 1670 } 1671 1672 new_entry->protection = prot; 1673 new_entry->max_protection = maxprot; 1674 new_entry->inheritance = inherit; 1675 new_entry->wired_count = 0; 1676 new_entry->advice = advice; 1677 if (flags & UVM_FLAG_OVERLAY) { 1678 1679 /* 1680 * to_add: for BSS we overallocate a little since we 1681 * are likely to extend 1682 */ 1683 1684 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ? 1685 UVM_AMAP_CHUNK << PAGE_SHIFT : 0; 1686 struct vm_amap *amap = amap_alloc(size, to_add, 1687 (flags & UVM_FLAG_NOWAIT)); 1688 if (__predict_false(amap == NULL)) { 1689 error = ENOMEM; 1690 goto done; 1691 } 1692 new_entry->aref.ar_pageoff = 0; 1693 new_entry->aref.ar_amap = amap; 1694 } else { 1695 new_entry->aref.ar_pageoff = 0; 1696 new_entry->aref.ar_amap = NULL; 1697 } 1698 uvm_map_entry_link(map, prev_entry, new_entry); 1699 1700 /* 1701 * Update the free space hint 1702 */ 1703 1704 if ((map->first_free == prev_entry) && 1705 (prev_entry->end >= new_entry->start)) 1706 map->first_free = new_entry; 1707 1708 new_entry = NULL; 1709 } 1710 1711 map->size += size; 1712 1713 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 1714 1715 error = 0; 1716 done: 1717 if ((flags & UVM_FLAG_QUANTUM) == 0) { 1718 /* 1719 * vmk_merged_entries is locked by the map's lock. 1720 */ 1721 vm_map_unlock(map); 1722 } 1723 if (new_entry && error == 0) { 1724 KDASSERT(merged); 1725 uvm_mapent_free_merged(map, new_entry); 1726 new_entry = NULL; 1727 } 1728 if (dead) { 1729 KDASSERT(merged); 1730 uvm_mapent_free_merged(map, dead); 1731 } 1732 if ((flags & UVM_FLAG_QUANTUM) != 0) { 1733 vm_map_unlock(map); 1734 } 1735 if (new_entry != NULL) { 1736 uvm_mapent_free(new_entry); 1737 } 1738 return error; 1739 } 1740 1741 /* 1742 * uvm_map_lookup_entry_bytree: lookup an entry in tree 1743 */ 1744 1745 static inline bool 1746 uvm_map_lookup_entry_bytree(struct vm_map *map, vaddr_t address, 1747 struct vm_map_entry **entry /* OUT */) 1748 { 1749 struct vm_map_entry *prev = &map->header; 1750 struct vm_map_entry *cur = ROOT_ENTRY(map); 1751 1752 while (cur) { 1753 UVMMAP_EVCNT_INCR(mlk_treeloop); 1754 if (address >= cur->start) { 1755 if (address < cur->end) { 1756 *entry = cur; 1757 return true; 1758 } 1759 prev = cur; 1760 cur = RIGHT_ENTRY(cur); 1761 } else 1762 cur = LEFT_ENTRY(cur); 1763 } 1764 *entry = prev; 1765 return false; 1766 } 1767 1768 /* 1769 * uvm_map_lookup_entry: find map entry at or before an address 1770 * 1771 * => map must at least be read-locked by caller 1772 * => entry is returned in "entry" 1773 * => return value is true if address is in the returned entry 1774 */ 1775 1776 bool 1777 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address, 1778 struct vm_map_entry **entry /* OUT */) 1779 { 1780 struct vm_map_entry *cur; 1781 bool use_tree = false; 1782 UVMHIST_FUNC("uvm_map_lookup_entry"); 1783 UVMHIST_CALLED(maphist); 1784 1785 UVMHIST_LOG(maphist,"(map=0x%x,addr=0x%x,ent=0x%x)", 1786 map, address, entry, 0); 1787 1788 /* 1789 * start looking either from the head of the 1790 * list, or from the hint. 1791 */ 1792 1793 cur = map->hint; 1794 1795 if (cur == &map->header) 1796 cur = cur->next; 1797 1798 UVMMAP_EVCNT_INCR(mlk_call); 1799 if (address >= cur->start) { 1800 1801 /* 1802 * go from hint to end of list. 1803 * 1804 * but first, make a quick check to see if 1805 * we are already looking at the entry we 1806 * want (which is usually the case). 1807 * note also that we don't need to save the hint 1808 * here... it is the same hint (unless we are 1809 * at the header, in which case the hint didn't 1810 * buy us anything anyway). 1811 */ 1812 1813 if (cur != &map->header && cur->end > address) { 1814 UVMMAP_EVCNT_INCR(mlk_hint); 1815 *entry = cur; 1816 UVMHIST_LOG(maphist,"<- got it via hint (0x%x)", 1817 cur, 0, 0, 0); 1818 uvm_mapent_check(*entry); 1819 return (true); 1820 } 1821 1822 if (map->nentries > 15) 1823 use_tree = true; 1824 } else { 1825 1826 /* 1827 * invalid hint. use tree. 1828 */ 1829 use_tree = true; 1830 } 1831 1832 uvm_map_check(map, __func__); 1833 1834 if (use_tree) { 1835 /* 1836 * Simple lookup in the tree. Happens when the hint is 1837 * invalid, or nentries reach a threshold. 1838 */ 1839 UVMMAP_EVCNT_INCR(mlk_tree); 1840 if (uvm_map_lookup_entry_bytree(map, address, entry)) { 1841 goto got; 1842 } else { 1843 goto failed; 1844 } 1845 } 1846 1847 /* 1848 * search linearly 1849 */ 1850 1851 UVMMAP_EVCNT_INCR(mlk_list); 1852 while (cur != &map->header) { 1853 UVMMAP_EVCNT_INCR(mlk_listloop); 1854 if (cur->end > address) { 1855 if (address >= cur->start) { 1856 /* 1857 * save this lookup for future 1858 * hints, and return 1859 */ 1860 1861 *entry = cur; 1862 got: 1863 SAVE_HINT(map, map->hint, *entry); 1864 UVMHIST_LOG(maphist,"<- search got it (0x%x)", 1865 cur, 0, 0, 0); 1866 KDASSERT((*entry)->start <= address); 1867 KDASSERT(address < (*entry)->end); 1868 uvm_mapent_check(*entry); 1869 return (true); 1870 } 1871 break; 1872 } 1873 cur = cur->next; 1874 } 1875 *entry = cur->prev; 1876 failed: 1877 SAVE_HINT(map, map->hint, *entry); 1878 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0); 1879 KDASSERT((*entry) == &map->header || (*entry)->end <= address); 1880 KDASSERT((*entry)->next == &map->header || 1881 address < (*entry)->next->start); 1882 return (false); 1883 } 1884 1885 /* 1886 * See if the range between start and start + length fits in the gap 1887 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't 1888 * fit, and -1 address wraps around. 1889 */ 1890 static int 1891 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset, 1892 vsize_t align, int flags, int topdown, struct vm_map_entry *entry) 1893 { 1894 vaddr_t end; 1895 1896 #ifdef PMAP_PREFER 1897 /* 1898 * push start address forward as needed to avoid VAC alias problems. 1899 * we only do this if a valid offset is specified. 1900 */ 1901 1902 if (uoffset != UVM_UNKNOWN_OFFSET) 1903 PMAP_PREFER(uoffset, start, length, topdown); 1904 #endif 1905 if ((flags & UVM_FLAG_COLORMATCH) != 0) { 1906 KASSERT(align < uvmexp.ncolors); 1907 if (uvmexp.ncolors > 1) { 1908 const u_int colormask = uvmexp.colormask; 1909 const u_int colorsize = colormask + 1; 1910 vaddr_t hint = atop(*start); 1911 const u_int color = hint & colormask; 1912 if (color != align) { 1913 hint -= color; /* adjust to color boundary */ 1914 KASSERT((hint & colormask) == 0); 1915 if (topdown) { 1916 if (align > color) 1917 hint -= colorsize; 1918 } else { 1919 if (align < color) 1920 hint += colorsize; 1921 } 1922 *start = ptoa(hint + align); /* adjust to color */ 1923 } 1924 } 1925 } else if (align != 0) { 1926 if ((*start & (align - 1)) != 0) { 1927 if (topdown) 1928 *start &= ~(align - 1); 1929 else 1930 *start = roundup(*start, align); 1931 } 1932 /* 1933 * XXX Should we PMAP_PREFER() here again? 1934 * eh...i think we're okay 1935 */ 1936 } 1937 1938 /* 1939 * Find the end of the proposed new region. Be sure we didn't 1940 * wrap around the address; if so, we lose. Otherwise, if the 1941 * proposed new region fits before the next entry, we win. 1942 */ 1943 1944 end = *start + length; 1945 if (end < *start) 1946 return (-1); 1947 1948 if (entry->next->start >= end && *start >= entry->end) 1949 return (1); 1950 1951 return (0); 1952 } 1953 1954 /* 1955 * uvm_map_findspace: find "length" sized space in "map". 1956 * 1957 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is 1958 * set in "flags" (in which case we insist on using "hint"). 1959 * => "result" is VA returned 1960 * => uobj/uoffset are to be used to handle VAC alignment, if required 1961 * => if "align" is non-zero, we attempt to align to that value. 1962 * => caller must at least have read-locked map 1963 * => returns NULL on failure, or pointer to prev. map entry if success 1964 * => note this is a cross between the old vm_map_findspace and vm_map_find 1965 */ 1966 1967 struct vm_map_entry * 1968 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length, 1969 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset, 1970 vsize_t align, int flags) 1971 { 1972 struct vm_map_entry *entry; 1973 struct vm_map_entry *child, *prev, *tmp; 1974 vaddr_t orig_hint; 1975 const int topdown = map->flags & VM_MAP_TOPDOWN; 1976 UVMHIST_FUNC("uvm_map_findspace"); 1977 UVMHIST_CALLED(maphist); 1978 1979 UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, flags=0x%x)", 1980 map, hint, length, flags); 1981 KASSERT((flags & UVM_FLAG_COLORMATCH) != 0 || (align & (align - 1)) == 0); 1982 KASSERT((flags & UVM_FLAG_COLORMATCH) == 0 || align < uvmexp.ncolors); 1983 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1984 1985 uvm_map_check(map, "map_findspace entry"); 1986 1987 /* 1988 * remember the original hint. if we are aligning, then we 1989 * may have to try again with no alignment constraint if 1990 * we fail the first time. 1991 */ 1992 1993 orig_hint = hint; 1994 if (hint < vm_map_min(map)) { /* check ranges ... */ 1995 if (flags & UVM_FLAG_FIXED) { 1996 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0); 1997 return (NULL); 1998 } 1999 hint = vm_map_min(map); 2000 } 2001 if (hint > vm_map_max(map)) { 2002 UVMHIST_LOG(maphist,"<- VA 0x%x > range [0x%x->0x%x]", 2003 hint, vm_map_min(map), vm_map_max(map), 0); 2004 return (NULL); 2005 } 2006 2007 /* 2008 * Look for the first possible address; if there's already 2009 * something at this address, we have to start after it. 2010 */ 2011 2012 /* 2013 * @@@: there are four, no, eight cases to consider. 2014 * 2015 * 0: found, fixed, bottom up -> fail 2016 * 1: found, fixed, top down -> fail 2017 * 2: found, not fixed, bottom up -> start after entry->end, 2018 * loop up 2019 * 3: found, not fixed, top down -> start before entry->start, 2020 * loop down 2021 * 4: not found, fixed, bottom up -> check entry->next->start, fail 2022 * 5: not found, fixed, top down -> check entry->next->start, fail 2023 * 6: not found, not fixed, bottom up -> check entry->next->start, 2024 * loop up 2025 * 7: not found, not fixed, top down -> check entry->next->start, 2026 * loop down 2027 * 2028 * as you can see, it reduces to roughly five cases, and that 2029 * adding top down mapping only adds one unique case (without 2030 * it, there would be four cases). 2031 */ 2032 2033 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) { 2034 entry = map->first_free; 2035 } else { 2036 if (uvm_map_lookup_entry(map, hint, &entry)) { 2037 /* "hint" address already in use ... */ 2038 if (flags & UVM_FLAG_FIXED) { 2039 UVMHIST_LOG(maphist, "<- fixed & VA in use", 2040 0, 0, 0, 0); 2041 return (NULL); 2042 } 2043 if (topdown) 2044 /* Start from lower gap. */ 2045 entry = entry->prev; 2046 } else if (flags & UVM_FLAG_FIXED) { 2047 if (entry->next->start >= hint + length && 2048 hint + length > hint) 2049 goto found; 2050 2051 /* "hint" address is gap but too small */ 2052 UVMHIST_LOG(maphist, "<- fixed mapping failed", 2053 0, 0, 0, 0); 2054 return (NULL); /* only one shot at it ... */ 2055 } else { 2056 /* 2057 * See if given hint fits in this gap. 2058 */ 2059 switch (uvm_map_space_avail(&hint, length, 2060 uoffset, align, flags, topdown, entry)) { 2061 case 1: 2062 goto found; 2063 case -1: 2064 goto wraparound; 2065 } 2066 2067 if (topdown) { 2068 /* 2069 * Still there is a chance to fit 2070 * if hint > entry->end. 2071 */ 2072 } else { 2073 /* Start from higher gap. */ 2074 entry = entry->next; 2075 if (entry == &map->header) 2076 goto notfound; 2077 goto nextgap; 2078 } 2079 } 2080 } 2081 2082 /* 2083 * Note that all UVM_FLAGS_FIXED case is already handled. 2084 */ 2085 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 2086 2087 /* Try to find the space in the red-black tree */ 2088 2089 /* Check slot before any entry */ 2090 hint = topdown ? entry->next->start - length : entry->end; 2091 switch (uvm_map_space_avail(&hint, length, uoffset, align, flags, 2092 topdown, entry)) { 2093 case 1: 2094 goto found; 2095 case -1: 2096 goto wraparound; 2097 } 2098 2099 nextgap: 2100 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 2101 /* If there is not enough space in the whole tree, we fail */ 2102 tmp = ROOT_ENTRY(map); 2103 if (tmp == NULL || tmp->maxgap < length) 2104 goto notfound; 2105 2106 prev = NULL; /* previous candidate */ 2107 2108 /* Find an entry close to hint that has enough space */ 2109 for (; tmp;) { 2110 KASSERT(tmp->next->start == tmp->end + tmp->gap); 2111 if (topdown) { 2112 if (tmp->next->start < hint + length && 2113 (prev == NULL || tmp->end > prev->end)) { 2114 if (tmp->gap >= length) 2115 prev = tmp; 2116 else if ((child = LEFT_ENTRY(tmp)) != NULL 2117 && child->maxgap >= length) 2118 prev = tmp; 2119 } 2120 } else { 2121 if (tmp->end >= hint && 2122 (prev == NULL || tmp->end < prev->end)) { 2123 if (tmp->gap >= length) 2124 prev = tmp; 2125 else if ((child = RIGHT_ENTRY(tmp)) != NULL 2126 && child->maxgap >= length) 2127 prev = tmp; 2128 } 2129 } 2130 if (tmp->next->start < hint + length) 2131 child = RIGHT_ENTRY(tmp); 2132 else if (tmp->end > hint) 2133 child = LEFT_ENTRY(tmp); 2134 else { 2135 if (tmp->gap >= length) 2136 break; 2137 if (topdown) 2138 child = LEFT_ENTRY(tmp); 2139 else 2140 child = RIGHT_ENTRY(tmp); 2141 } 2142 if (child == NULL || child->maxgap < length) 2143 break; 2144 tmp = child; 2145 } 2146 2147 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) { 2148 /* 2149 * Check if the entry that we found satifies the 2150 * space requirement 2151 */ 2152 if (topdown) { 2153 if (hint > tmp->next->start - length) 2154 hint = tmp->next->start - length; 2155 } else { 2156 if (hint < tmp->end) 2157 hint = tmp->end; 2158 } 2159 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2160 flags, topdown, tmp)) { 2161 case 1: 2162 entry = tmp; 2163 goto found; 2164 case -1: 2165 goto wraparound; 2166 } 2167 if (tmp->gap >= length) 2168 goto listsearch; 2169 } 2170 if (prev == NULL) 2171 goto notfound; 2172 2173 if (topdown) { 2174 KASSERT(orig_hint >= prev->next->start - length || 2175 prev->next->start - length > prev->next->start); 2176 hint = prev->next->start - length; 2177 } else { 2178 KASSERT(orig_hint <= prev->end); 2179 hint = prev->end; 2180 } 2181 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2182 flags, topdown, prev)) { 2183 case 1: 2184 entry = prev; 2185 goto found; 2186 case -1: 2187 goto wraparound; 2188 } 2189 if (prev->gap >= length) 2190 goto listsearch; 2191 2192 if (topdown) 2193 tmp = LEFT_ENTRY(prev); 2194 else 2195 tmp = RIGHT_ENTRY(prev); 2196 for (;;) { 2197 KASSERT(tmp && tmp->maxgap >= length); 2198 if (topdown) 2199 child = RIGHT_ENTRY(tmp); 2200 else 2201 child = LEFT_ENTRY(tmp); 2202 if (child && child->maxgap >= length) { 2203 tmp = child; 2204 continue; 2205 } 2206 if (tmp->gap >= length) 2207 break; 2208 if (topdown) 2209 tmp = LEFT_ENTRY(tmp); 2210 else 2211 tmp = RIGHT_ENTRY(tmp); 2212 } 2213 2214 if (topdown) { 2215 KASSERT(orig_hint >= tmp->next->start - length || 2216 tmp->next->start - length > tmp->next->start); 2217 hint = tmp->next->start - length; 2218 } else { 2219 KASSERT(orig_hint <= tmp->end); 2220 hint = tmp->end; 2221 } 2222 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2223 flags, topdown, tmp)) { 2224 case 1: 2225 entry = tmp; 2226 goto found; 2227 case -1: 2228 goto wraparound; 2229 } 2230 2231 /* 2232 * The tree fails to find an entry because of offset or alignment 2233 * restrictions. Search the list instead. 2234 */ 2235 listsearch: 2236 /* 2237 * Look through the rest of the map, trying to fit a new region in 2238 * the gap between existing regions, or after the very last region. 2239 * note: entry->end = base VA of current gap, 2240 * entry->next->start = VA of end of current gap 2241 */ 2242 2243 for (;;) { 2244 /* Update hint for current gap. */ 2245 hint = topdown ? entry->next->start - length : entry->end; 2246 2247 /* See if it fits. */ 2248 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2249 flags, topdown, entry)) { 2250 case 1: 2251 goto found; 2252 case -1: 2253 goto wraparound; 2254 } 2255 2256 /* Advance to next/previous gap */ 2257 if (topdown) { 2258 if (entry == &map->header) { 2259 UVMHIST_LOG(maphist, "<- failed (off start)", 2260 0,0,0,0); 2261 goto notfound; 2262 } 2263 entry = entry->prev; 2264 } else { 2265 entry = entry->next; 2266 if (entry == &map->header) { 2267 UVMHIST_LOG(maphist, "<- failed (off end)", 2268 0,0,0,0); 2269 goto notfound; 2270 } 2271 } 2272 } 2273 2274 found: 2275 SAVE_HINT(map, map->hint, entry); 2276 *result = hint; 2277 UVMHIST_LOG(maphist,"<- got it! (result=0x%x)", hint, 0,0,0); 2278 KASSERT( topdown || hint >= orig_hint); 2279 KASSERT(!topdown || hint <= orig_hint); 2280 KASSERT(entry->end <= hint); 2281 KASSERT(hint + length <= entry->next->start); 2282 return (entry); 2283 2284 wraparound: 2285 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0); 2286 2287 return (NULL); 2288 2289 notfound: 2290 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0); 2291 2292 return (NULL); 2293 } 2294 2295 /* 2296 * U N M A P - m a i n h e l p e r f u n c t i o n s 2297 */ 2298 2299 /* 2300 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop") 2301 * 2302 * => caller must check alignment and size 2303 * => map must be locked by caller 2304 * => we return a list of map entries that we've remove from the map 2305 * in "entry_list" 2306 */ 2307 2308 void 2309 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end, 2310 struct vm_map_entry **entry_list /* OUT */, 2311 struct uvm_mapent_reservation *umr, int flags) 2312 { 2313 struct vm_map_entry *entry, *first_entry, *next; 2314 vaddr_t len; 2315 UVMHIST_FUNC("uvm_unmap_remove"); UVMHIST_CALLED(maphist); 2316 2317 UVMHIST_LOG(maphist,"(map=0x%x, start=0x%x, end=0x%x)", 2318 map, start, end, 0); 2319 VM_MAP_RANGE_CHECK(map, start, end); 2320 2321 uvm_map_check(map, "unmap_remove entry"); 2322 2323 /* 2324 * find first entry 2325 */ 2326 2327 if (uvm_map_lookup_entry(map, start, &first_entry) == true) { 2328 /* clip and go... */ 2329 entry = first_entry; 2330 UVM_MAP_CLIP_START(map, entry, start, umr); 2331 /* critical! prevents stale hint */ 2332 SAVE_HINT(map, entry, entry->prev); 2333 } else { 2334 entry = first_entry->next; 2335 } 2336 2337 /* 2338 * Save the free space hint 2339 */ 2340 2341 if (map->first_free != &map->header && map->first_free->start >= start) 2342 map->first_free = entry->prev; 2343 2344 /* 2345 * note: we now re-use first_entry for a different task. we remove 2346 * a number of map entries from the map and save them in a linked 2347 * list headed by "first_entry". once we remove them from the map 2348 * the caller should unlock the map and drop the references to the 2349 * backing objects [c.f. uvm_unmap_detach]. the object is to 2350 * separate unmapping from reference dropping. why? 2351 * [1] the map has to be locked for unmapping 2352 * [2] the map need not be locked for reference dropping 2353 * [3] dropping references may trigger pager I/O, and if we hit 2354 * a pager that does synchronous I/O we may have to wait for it. 2355 * [4] we would like all waiting for I/O to occur with maps unlocked 2356 * so that we don't block other threads. 2357 */ 2358 2359 first_entry = NULL; 2360 *entry_list = NULL; 2361 2362 /* 2363 * break up the area into map entry sized regions and unmap. note 2364 * that all mappings have to be removed before we can even consider 2365 * dropping references to amaps or VM objects (otherwise we could end 2366 * up with a mapping to a page on the free list which would be very bad) 2367 */ 2368 2369 while ((entry != &map->header) && (entry->start < end)) { 2370 KASSERT((entry->flags & UVM_MAP_FIRST) == 0); 2371 2372 UVM_MAP_CLIP_END(map, entry, end, umr); 2373 next = entry->next; 2374 len = entry->end - entry->start; 2375 2376 /* 2377 * unwire before removing addresses from the pmap; otherwise 2378 * unwiring will put the entries back into the pmap (XXX). 2379 */ 2380 2381 if (VM_MAPENT_ISWIRED(entry)) { 2382 uvm_map_entry_unwire(map, entry); 2383 } 2384 if (flags & UVM_FLAG_VAONLY) { 2385 2386 /* nothing */ 2387 2388 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) { 2389 2390 /* 2391 * if the map is non-pageable, any pages mapped there 2392 * must be wired and entered with pmap_kenter_pa(), 2393 * and we should free any such pages immediately. 2394 * this is mostly used for kmem_map. 2395 */ 2396 KASSERT(vm_map_pmap(map) == pmap_kernel()); 2397 2398 if ((entry->flags & UVM_MAP_KMAPENT) == 0) { 2399 uvm_km_pgremove_intrsafe(map, entry->start, 2400 entry->end); 2401 pmap_kremove(entry->start, len); 2402 } 2403 } else if (UVM_ET_ISOBJ(entry) && 2404 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) { 2405 panic("%s: kernel object %p %p\n", 2406 __func__, map, entry); 2407 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) { 2408 /* 2409 * remove mappings the standard way. lock object 2410 * and/or amap to ensure vm_page state does not 2411 * change while in pmap_remove(). 2412 */ 2413 2414 uvm_map_lock_entry(entry); 2415 pmap_remove(map->pmap, entry->start, entry->end); 2416 uvm_map_unlock_entry(entry); 2417 } 2418 2419 #if defined(DEBUG) 2420 if ((entry->flags & UVM_MAP_KMAPENT) == 0) { 2421 2422 /* 2423 * check if there's remaining mapping, 2424 * which is a bug in caller. 2425 */ 2426 2427 vaddr_t va; 2428 for (va = entry->start; va < entry->end; 2429 va += PAGE_SIZE) { 2430 if (pmap_extract(vm_map_pmap(map), va, NULL)) { 2431 panic("%s: %#"PRIxVADDR" has mapping", 2432 __func__, va); 2433 } 2434 } 2435 2436 if (VM_MAP_IS_KERNEL(map)) { 2437 uvm_km_check_empty(map, entry->start, 2438 entry->end); 2439 } 2440 } 2441 #endif /* defined(DEBUG) */ 2442 2443 /* 2444 * remove entry from map and put it on our list of entries 2445 * that we've nuked. then go to next entry. 2446 */ 2447 2448 UVMHIST_LOG(maphist, " removed map entry 0x%x", entry, 0, 0,0); 2449 2450 /* critical! prevents stale hint */ 2451 SAVE_HINT(map, entry, entry->prev); 2452 2453 uvm_map_entry_unlink(map, entry); 2454 KASSERT(map->size >= len); 2455 map->size -= len; 2456 entry->prev = NULL; 2457 entry->next = first_entry; 2458 first_entry = entry; 2459 entry = next; 2460 } 2461 2462 /* 2463 * Note: if map is dying, leave pmap_update() for pmap_destroy(), 2464 * which will be called later. 2465 */ 2466 if ((map->flags & VM_MAP_DYING) == 0) { 2467 pmap_update(vm_map_pmap(map)); 2468 } else { 2469 KASSERT(vm_map_pmap(map) != pmap_kernel()); 2470 } 2471 2472 uvm_map_check(map, "unmap_remove leave"); 2473 2474 /* 2475 * now we've cleaned up the map and are ready for the caller to drop 2476 * references to the mapped objects. 2477 */ 2478 2479 *entry_list = first_entry; 2480 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 2481 2482 if (map->flags & VM_MAP_WANTVA) { 2483 mutex_enter(&map->misc_lock); 2484 map->flags &= ~VM_MAP_WANTVA; 2485 cv_broadcast(&map->cv); 2486 mutex_exit(&map->misc_lock); 2487 } 2488 } 2489 2490 /* 2491 * uvm_unmap_detach: drop references in a chain of map entries 2492 * 2493 * => we will free the map entries as we traverse the list. 2494 */ 2495 2496 void 2497 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags) 2498 { 2499 struct vm_map_entry *next_entry; 2500 UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist); 2501 2502 while (first_entry) { 2503 KASSERT(!VM_MAPENT_ISWIRED(first_entry)); 2504 UVMHIST_LOG(maphist, 2505 " detach 0x%x: amap=0x%x, obj=0x%x, submap?=%d", 2506 first_entry, first_entry->aref.ar_amap, 2507 first_entry->object.uvm_obj, 2508 UVM_ET_ISSUBMAP(first_entry)); 2509 2510 /* 2511 * drop reference to amap, if we've got one 2512 */ 2513 2514 if (first_entry->aref.ar_amap) 2515 uvm_map_unreference_amap(first_entry, flags); 2516 2517 /* 2518 * drop reference to our backing object, if we've got one 2519 */ 2520 2521 KASSERT(!UVM_ET_ISSUBMAP(first_entry)); 2522 if (UVM_ET_ISOBJ(first_entry) && 2523 first_entry->object.uvm_obj->pgops->pgo_detach) { 2524 (*first_entry->object.uvm_obj->pgops->pgo_detach) 2525 (first_entry->object.uvm_obj); 2526 } 2527 next_entry = first_entry->next; 2528 uvm_mapent_free(first_entry); 2529 first_entry = next_entry; 2530 } 2531 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 2532 } 2533 2534 /* 2535 * E X T R A C T I O N F U N C T I O N S 2536 */ 2537 2538 /* 2539 * uvm_map_reserve: reserve space in a vm_map for future use. 2540 * 2541 * => we reserve space in a map by putting a dummy map entry in the 2542 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE) 2543 * => map should be unlocked (we will write lock it) 2544 * => we return true if we were able to reserve space 2545 * => XXXCDC: should be inline? 2546 */ 2547 2548 int 2549 uvm_map_reserve(struct vm_map *map, vsize_t size, 2550 vaddr_t offset /* hint for pmap_prefer */, 2551 vsize_t align /* alignment */, 2552 vaddr_t *raddr /* IN:hint, OUT: reserved VA */, 2553 uvm_flag_t flags /* UVM_FLAG_FIXED or 0 */) 2554 { 2555 UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist); 2556 2557 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x, offset=0x%x,addr=0x%x)", 2558 map,size,offset,raddr); 2559 2560 size = round_page(size); 2561 2562 /* 2563 * reserve some virtual space. 2564 */ 2565 2566 if (uvm_map(map, raddr, size, NULL, offset, align, 2567 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE, 2568 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) { 2569 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 2570 return (false); 2571 } 2572 2573 UVMHIST_LOG(maphist, "<- done (*raddr=0x%x)", *raddr,0,0,0); 2574 return (true); 2575 } 2576 2577 /* 2578 * uvm_map_replace: replace a reserved (blank) area of memory with 2579 * real mappings. 2580 * 2581 * => caller must WRITE-LOCK the map 2582 * => we return true if replacement was a success 2583 * => we expect the newents chain to have nnewents entrys on it and 2584 * we expect newents->prev to point to the last entry on the list 2585 * => note newents is allowed to be NULL 2586 */ 2587 2588 static int 2589 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end, 2590 struct vm_map_entry *newents, int nnewents, vsize_t nsize, 2591 struct vm_map_entry **oldentryp) 2592 { 2593 struct vm_map_entry *oldent, *last; 2594 2595 uvm_map_check(map, "map_replace entry"); 2596 2597 /* 2598 * first find the blank map entry at the specified address 2599 */ 2600 2601 if (!uvm_map_lookup_entry(map, start, &oldent)) { 2602 return (false); 2603 } 2604 2605 /* 2606 * check to make sure we have a proper blank entry 2607 */ 2608 2609 if (end < oldent->end && !VM_MAP_USE_KMAPENT(map)) { 2610 UVM_MAP_CLIP_END(map, oldent, end, NULL); 2611 } 2612 if (oldent->start != start || oldent->end != end || 2613 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) { 2614 return (false); 2615 } 2616 2617 #ifdef DIAGNOSTIC 2618 2619 /* 2620 * sanity check the newents chain 2621 */ 2622 2623 { 2624 struct vm_map_entry *tmpent = newents; 2625 int nent = 0; 2626 vsize_t sz = 0; 2627 vaddr_t cur = start; 2628 2629 while (tmpent) { 2630 nent++; 2631 sz += tmpent->end - tmpent->start; 2632 if (tmpent->start < cur) 2633 panic("uvm_map_replace1"); 2634 if (tmpent->start >= tmpent->end || tmpent->end > end) { 2635 panic("uvm_map_replace2: " 2636 "tmpent->start=0x%"PRIxVADDR 2637 ", tmpent->end=0x%"PRIxVADDR 2638 ", end=0x%"PRIxVADDR, 2639 tmpent->start, tmpent->end, end); 2640 } 2641 cur = tmpent->end; 2642 if (tmpent->next) { 2643 if (tmpent->next->prev != tmpent) 2644 panic("uvm_map_replace3"); 2645 } else { 2646 if (newents->prev != tmpent) 2647 panic("uvm_map_replace4"); 2648 } 2649 tmpent = tmpent->next; 2650 } 2651 if (nent != nnewents) 2652 panic("uvm_map_replace5"); 2653 if (sz != nsize) 2654 panic("uvm_map_replace6"); 2655 } 2656 #endif 2657 2658 /* 2659 * map entry is a valid blank! replace it. (this does all the 2660 * work of map entry link/unlink...). 2661 */ 2662 2663 if (newents) { 2664 last = newents->prev; 2665 2666 /* critical: flush stale hints out of map */ 2667 SAVE_HINT(map, map->hint, newents); 2668 if (map->first_free == oldent) 2669 map->first_free = last; 2670 2671 last->next = oldent->next; 2672 last->next->prev = last; 2673 2674 /* Fix RB tree */ 2675 uvm_rb_remove(map, oldent); 2676 2677 newents->prev = oldent->prev; 2678 newents->prev->next = newents; 2679 map->nentries = map->nentries + (nnewents - 1); 2680 2681 /* Fixup the RB tree */ 2682 { 2683 int i; 2684 struct vm_map_entry *tmp; 2685 2686 tmp = newents; 2687 for (i = 0; i < nnewents && tmp; i++) { 2688 uvm_rb_insert(map, tmp); 2689 tmp = tmp->next; 2690 } 2691 } 2692 } else { 2693 /* NULL list of new entries: just remove the old one */ 2694 clear_hints(map, oldent); 2695 uvm_map_entry_unlink(map, oldent); 2696 } 2697 map->size -= end - start - nsize; 2698 2699 uvm_map_check(map, "map_replace leave"); 2700 2701 /* 2702 * now we can free the old blank entry and return. 2703 */ 2704 2705 *oldentryp = oldent; 2706 return (true); 2707 } 2708 2709 /* 2710 * uvm_map_extract: extract a mapping from a map and put it somewhere 2711 * (maybe removing the old mapping) 2712 * 2713 * => maps should be unlocked (we will write lock them) 2714 * => returns 0 on success, error code otherwise 2715 * => start must be page aligned 2716 * => len must be page sized 2717 * => flags: 2718 * UVM_EXTRACT_REMOVE: remove mappings from srcmap 2719 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only) 2720 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs 2721 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go 2722 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<< 2723 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only 2724 * be used from within the kernel in a kernel level map <<< 2725 */ 2726 2727 int 2728 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len, 2729 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags) 2730 { 2731 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge; 2732 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry, 2733 *deadentry, *oldentry; 2734 struct vm_map_entry *resentry = NULL; /* a dummy reservation entry */ 2735 vsize_t elen; 2736 int nchain, error, copy_ok; 2737 vsize_t nsize; 2738 UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist); 2739 2740 UVMHIST_LOG(maphist,"(srcmap=0x%x,start=0x%x, len=0x%x", srcmap, start, 2741 len,0); 2742 UVMHIST_LOG(maphist," ...,dstmap=0x%x, flags=0x%x)", dstmap,flags,0,0); 2743 2744 /* 2745 * step 0: sanity check: start must be on a page boundary, length 2746 * must be page sized. can't ask for CONTIG/QREF if you asked for 2747 * REMOVE. 2748 */ 2749 2750 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0); 2751 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 || 2752 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0); 2753 2754 /* 2755 * step 1: reserve space in the target map for the extracted area 2756 */ 2757 2758 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2759 dstaddr = vm_map_min(dstmap); 2760 if (!uvm_map_reserve(dstmap, len, start, 0, &dstaddr, 0)) 2761 return (ENOMEM); 2762 *dstaddrp = dstaddr; /* pass address back to caller */ 2763 UVMHIST_LOG(maphist, " dstaddr=0x%x", dstaddr,0,0,0); 2764 } else { 2765 dstaddr = *dstaddrp; 2766 } 2767 2768 /* 2769 * step 2: setup for the extraction process loop by init'ing the 2770 * map entry chain, locking src map, and looking up the first useful 2771 * entry in the map. 2772 */ 2773 2774 end = start + len; 2775 newend = dstaddr + len; 2776 chain = endchain = NULL; 2777 nchain = 0; 2778 nsize = 0; 2779 vm_map_lock(srcmap); 2780 2781 if (uvm_map_lookup_entry(srcmap, start, &entry)) { 2782 2783 /* "start" is within an entry */ 2784 if (flags & UVM_EXTRACT_QREF) { 2785 2786 /* 2787 * for quick references we don't clip the entry, so 2788 * the entry may map space "before" the starting 2789 * virtual address... this is the "fudge" factor 2790 * (which can be non-zero only the first time 2791 * through the "while" loop in step 3). 2792 */ 2793 2794 fudge = start - entry->start; 2795 } else { 2796 2797 /* 2798 * normal reference: we clip the map to fit (thus 2799 * fudge is zero) 2800 */ 2801 2802 UVM_MAP_CLIP_START(srcmap, entry, start, NULL); 2803 SAVE_HINT(srcmap, srcmap->hint, entry->prev); 2804 fudge = 0; 2805 } 2806 } else { 2807 2808 /* "start" is not within an entry ... skip to next entry */ 2809 if (flags & UVM_EXTRACT_CONTIG) { 2810 error = EINVAL; 2811 goto bad; /* definite hole here ... */ 2812 } 2813 2814 entry = entry->next; 2815 fudge = 0; 2816 } 2817 2818 /* save values from srcmap for step 6 */ 2819 orig_entry = entry; 2820 orig_fudge = fudge; 2821 2822 /* 2823 * step 3: now start looping through the map entries, extracting 2824 * as we go. 2825 */ 2826 2827 while (entry->start < end && entry != &srcmap->header) { 2828 2829 /* if we are not doing a quick reference, clip it */ 2830 if ((flags & UVM_EXTRACT_QREF) == 0) 2831 UVM_MAP_CLIP_END(srcmap, entry, end, NULL); 2832 2833 /* clear needs_copy (allow chunking) */ 2834 if (UVM_ET_ISNEEDSCOPY(entry)) { 2835 amap_copy(srcmap, entry, 2836 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end); 2837 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */ 2838 error = ENOMEM; 2839 goto bad; 2840 } 2841 2842 /* amap_copy could clip (during chunk)! update fudge */ 2843 if (fudge) { 2844 fudge = start - entry->start; 2845 orig_fudge = fudge; 2846 } 2847 } 2848 2849 /* calculate the offset of this from "start" */ 2850 oldoffset = (entry->start + fudge) - start; 2851 2852 /* allocate a new map entry */ 2853 newentry = uvm_mapent_alloc(dstmap, 0); 2854 if (newentry == NULL) { 2855 error = ENOMEM; 2856 goto bad; 2857 } 2858 2859 /* set up new map entry */ 2860 newentry->next = NULL; 2861 newentry->prev = endchain; 2862 newentry->start = dstaddr + oldoffset; 2863 newentry->end = 2864 newentry->start + (entry->end - (entry->start + fudge)); 2865 if (newentry->end > newend || newentry->end < newentry->start) 2866 newentry->end = newend; 2867 newentry->object.uvm_obj = entry->object.uvm_obj; 2868 if (newentry->object.uvm_obj) { 2869 if (newentry->object.uvm_obj->pgops->pgo_reference) 2870 newentry->object.uvm_obj->pgops-> 2871 pgo_reference(newentry->object.uvm_obj); 2872 newentry->offset = entry->offset + fudge; 2873 } else { 2874 newentry->offset = 0; 2875 } 2876 newentry->etype = entry->etype; 2877 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ? 2878 entry->max_protection : entry->protection; 2879 newentry->max_protection = entry->max_protection; 2880 newentry->inheritance = entry->inheritance; 2881 newentry->wired_count = 0; 2882 newentry->aref.ar_amap = entry->aref.ar_amap; 2883 if (newentry->aref.ar_amap) { 2884 newentry->aref.ar_pageoff = 2885 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT); 2886 uvm_map_reference_amap(newentry, AMAP_SHARED | 2887 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0)); 2888 } else { 2889 newentry->aref.ar_pageoff = 0; 2890 } 2891 newentry->advice = entry->advice; 2892 if ((flags & UVM_EXTRACT_QREF) != 0) { 2893 newentry->flags |= UVM_MAP_NOMERGE; 2894 } 2895 2896 /* now link it on the chain */ 2897 nchain++; 2898 nsize += newentry->end - newentry->start; 2899 if (endchain == NULL) { 2900 chain = endchain = newentry; 2901 } else { 2902 endchain->next = newentry; 2903 endchain = newentry; 2904 } 2905 2906 /* end of 'while' loop! */ 2907 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end && 2908 (entry->next == &srcmap->header || 2909 entry->next->start != entry->end)) { 2910 error = EINVAL; 2911 goto bad; 2912 } 2913 entry = entry->next; 2914 fudge = 0; 2915 } 2916 2917 /* 2918 * step 4: close off chain (in format expected by uvm_map_replace) 2919 */ 2920 2921 if (chain) 2922 chain->prev = endchain; 2923 2924 /* 2925 * step 5: attempt to lock the dest map so we can pmap_copy. 2926 * note usage of copy_ok: 2927 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5) 2928 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7 2929 */ 2930 2931 if (srcmap == dstmap || vm_map_lock_try(dstmap) == true) { 2932 copy_ok = 1; 2933 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2934 nchain, nsize, &resentry)) { 2935 if (srcmap != dstmap) 2936 vm_map_unlock(dstmap); 2937 error = EIO; 2938 goto bad; 2939 } 2940 } else { 2941 copy_ok = 0; 2942 /* replace defered until step 7 */ 2943 } 2944 2945 /* 2946 * step 6: traverse the srcmap a second time to do the following: 2947 * - if we got a lock on the dstmap do pmap_copy 2948 * - if UVM_EXTRACT_REMOVE remove the entries 2949 * we make use of orig_entry and orig_fudge (saved in step 2) 2950 */ 2951 2952 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) { 2953 2954 /* purge possible stale hints from srcmap */ 2955 if (flags & UVM_EXTRACT_REMOVE) { 2956 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev); 2957 if (srcmap->first_free != &srcmap->header && 2958 srcmap->first_free->start >= start) 2959 srcmap->first_free = orig_entry->prev; 2960 } 2961 2962 entry = orig_entry; 2963 fudge = orig_fudge; 2964 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */ 2965 2966 while (entry->start < end && entry != &srcmap->header) { 2967 if (copy_ok) { 2968 oldoffset = (entry->start + fudge) - start; 2969 elen = MIN(end, entry->end) - 2970 (entry->start + fudge); 2971 pmap_copy(dstmap->pmap, srcmap->pmap, 2972 dstaddr + oldoffset, elen, 2973 entry->start + fudge); 2974 } 2975 2976 /* we advance "entry" in the following if statement */ 2977 if (flags & UVM_EXTRACT_REMOVE) { 2978 uvm_map_lock_entry(entry); 2979 pmap_remove(srcmap->pmap, entry->start, 2980 entry->end); 2981 uvm_map_unlock_entry(entry); 2982 oldentry = entry; /* save entry */ 2983 entry = entry->next; /* advance */ 2984 uvm_map_entry_unlink(srcmap, oldentry); 2985 /* add to dead list */ 2986 oldentry->next = deadentry; 2987 deadentry = oldentry; 2988 } else { 2989 entry = entry->next; /* advance */ 2990 } 2991 2992 /* end of 'while' loop */ 2993 fudge = 0; 2994 } 2995 pmap_update(srcmap->pmap); 2996 2997 /* 2998 * unlock dstmap. we will dispose of deadentry in 2999 * step 7 if needed 3000 */ 3001 3002 if (copy_ok && srcmap != dstmap) 3003 vm_map_unlock(dstmap); 3004 3005 } else { 3006 deadentry = NULL; 3007 } 3008 3009 /* 3010 * step 7: we are done with the source map, unlock. if copy_ok 3011 * is 0 then we have not replaced the dummy mapping in dstmap yet 3012 * and we need to do so now. 3013 */ 3014 3015 vm_map_unlock(srcmap); 3016 if ((flags & UVM_EXTRACT_REMOVE) && deadentry) 3017 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */ 3018 3019 /* now do the replacement if we didn't do it in step 5 */ 3020 if (copy_ok == 0) { 3021 vm_map_lock(dstmap); 3022 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 3023 nchain, nsize, &resentry); 3024 vm_map_unlock(dstmap); 3025 3026 if (error == false) { 3027 error = EIO; 3028 goto bad2; 3029 } 3030 } 3031 3032 if (resentry != NULL) 3033 uvm_mapent_free(resentry); 3034 3035 return (0); 3036 3037 /* 3038 * bad: failure recovery 3039 */ 3040 bad: 3041 vm_map_unlock(srcmap); 3042 bad2: /* src already unlocked */ 3043 if (chain) 3044 uvm_unmap_detach(chain, 3045 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0); 3046 3047 if (resentry != NULL) 3048 uvm_mapent_free(resentry); 3049 3050 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 3051 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */ 3052 } 3053 return (error); 3054 } 3055 3056 /* end of extraction functions */ 3057 3058 /* 3059 * uvm_map_submap: punch down part of a map into a submap 3060 * 3061 * => only the kernel_map is allowed to be submapped 3062 * => the purpose of submapping is to break up the locking granularity 3063 * of a larger map 3064 * => the range specified must have been mapped previously with a uvm_map() 3065 * call [with uobj==NULL] to create a blank map entry in the main map. 3066 * [And it had better still be blank!] 3067 * => maps which contain submaps should never be copied or forked. 3068 * => to remove a submap, use uvm_unmap() on the main map 3069 * and then uvm_map_deallocate() the submap. 3070 * => main map must be unlocked. 3071 * => submap must have been init'd and have a zero reference count. 3072 * [need not be locked as we don't actually reference it] 3073 */ 3074 3075 int 3076 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end, 3077 struct vm_map *submap) 3078 { 3079 struct vm_map_entry *entry; 3080 struct uvm_mapent_reservation umr; 3081 int error; 3082 3083 uvm_mapent_reserve(map, &umr, 2, 0); 3084 3085 vm_map_lock(map); 3086 VM_MAP_RANGE_CHECK(map, start, end); 3087 3088 if (uvm_map_lookup_entry(map, start, &entry)) { 3089 UVM_MAP_CLIP_START(map, entry, start, &umr); 3090 UVM_MAP_CLIP_END(map, entry, end, &umr); /* to be safe */ 3091 } else { 3092 entry = NULL; 3093 } 3094 3095 if (entry != NULL && 3096 entry->start == start && entry->end == end && 3097 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL && 3098 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) { 3099 entry->etype |= UVM_ET_SUBMAP; 3100 entry->object.sub_map = submap; 3101 entry->offset = 0; 3102 uvm_map_reference(submap); 3103 error = 0; 3104 } else { 3105 error = EINVAL; 3106 } 3107 vm_map_unlock(map); 3108 3109 uvm_mapent_unreserve(map, &umr); 3110 3111 return error; 3112 } 3113 3114 /* 3115 * uvm_map_setup_kernel: init in-kernel map 3116 * 3117 * => map must not be in service yet. 3118 */ 3119 3120 void 3121 uvm_map_setup_kernel(struct vm_map_kernel *map, 3122 vaddr_t vmin, vaddr_t vmax, int flags) 3123 { 3124 3125 uvm_map_setup(&map->vmk_map, vmin, vmax, flags); 3126 callback_head_init(&map->vmk_reclaim_callback, IPL_VM); 3127 LIST_INIT(&map->vmk_kentry_free); 3128 map->vmk_merged_entries = NULL; 3129 } 3130 3131 3132 /* 3133 * uvm_map_protect: change map protection 3134 * 3135 * => set_max means set max_protection. 3136 * => map must be unlocked. 3137 */ 3138 3139 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \ 3140 ~VM_PROT_WRITE : VM_PROT_ALL) 3141 3142 int 3143 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 3144 vm_prot_t new_prot, bool set_max) 3145 { 3146 struct vm_map_entry *current, *entry; 3147 int error = 0; 3148 UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist); 3149 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_prot=0x%x)", 3150 map, start, end, new_prot); 3151 3152 vm_map_lock(map); 3153 VM_MAP_RANGE_CHECK(map, start, end); 3154 if (uvm_map_lookup_entry(map, start, &entry)) { 3155 UVM_MAP_CLIP_START(map, entry, start, NULL); 3156 } else { 3157 entry = entry->next; 3158 } 3159 3160 /* 3161 * make a first pass to check for protection violations. 3162 */ 3163 3164 current = entry; 3165 while ((current != &map->header) && (current->start < end)) { 3166 if (UVM_ET_ISSUBMAP(current)) { 3167 error = EINVAL; 3168 goto out; 3169 } 3170 if ((new_prot & current->max_protection) != new_prot) { 3171 error = EACCES; 3172 goto out; 3173 } 3174 /* 3175 * Don't allow VM_PROT_EXECUTE to be set on entries that 3176 * point to vnodes that are associated with a NOEXEC file 3177 * system. 3178 */ 3179 if (UVM_ET_ISOBJ(current) && 3180 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) { 3181 struct vnode *vp = 3182 (struct vnode *) current->object.uvm_obj; 3183 3184 if ((new_prot & VM_PROT_EXECUTE) != 0 && 3185 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { 3186 error = EACCES; 3187 goto out; 3188 } 3189 } 3190 3191 current = current->next; 3192 } 3193 3194 /* go back and fix up protections (no need to clip this time). */ 3195 3196 current = entry; 3197 while ((current != &map->header) && (current->start < end)) { 3198 vm_prot_t old_prot; 3199 3200 UVM_MAP_CLIP_END(map, current, end, NULL); 3201 old_prot = current->protection; 3202 if (set_max) 3203 current->protection = 3204 (current->max_protection = new_prot) & old_prot; 3205 else 3206 current->protection = new_prot; 3207 3208 /* 3209 * update physical map if necessary. worry about copy-on-write 3210 * here -- CHECK THIS XXX 3211 */ 3212 3213 if (current->protection != old_prot) { 3214 /* update pmap! */ 3215 uvm_map_lock_entry(current); 3216 pmap_protect(map->pmap, current->start, current->end, 3217 current->protection & MASK(entry)); 3218 uvm_map_unlock_entry(current); 3219 3220 /* 3221 * If this entry points at a vnode, and the 3222 * protection includes VM_PROT_EXECUTE, mark 3223 * the vnode as VEXECMAP. 3224 */ 3225 if (UVM_ET_ISOBJ(current)) { 3226 struct uvm_object *uobj = 3227 current->object.uvm_obj; 3228 3229 if (UVM_OBJ_IS_VNODE(uobj) && 3230 (current->protection & VM_PROT_EXECUTE)) { 3231 vn_markexec((struct vnode *) uobj); 3232 } 3233 } 3234 } 3235 3236 /* 3237 * If the map is configured to lock any future mappings, 3238 * wire this entry now if the old protection was VM_PROT_NONE 3239 * and the new protection is not VM_PROT_NONE. 3240 */ 3241 3242 if ((map->flags & VM_MAP_WIREFUTURE) != 0 && 3243 VM_MAPENT_ISWIRED(entry) == 0 && 3244 old_prot == VM_PROT_NONE && 3245 new_prot != VM_PROT_NONE) { 3246 if (uvm_map_pageable(map, entry->start, 3247 entry->end, false, 3248 UVM_LK_ENTER|UVM_LK_EXIT) != 0) { 3249 3250 /* 3251 * If locking the entry fails, remember the 3252 * error if it's the first one. Note we 3253 * still continue setting the protection in 3254 * the map, but will return the error 3255 * condition regardless. 3256 * 3257 * XXX Ignore what the actual error is, 3258 * XXX just call it a resource shortage 3259 * XXX so that it doesn't get confused 3260 * XXX what uvm_map_protect() itself would 3261 * XXX normally return. 3262 */ 3263 3264 error = ENOMEM; 3265 } 3266 } 3267 current = current->next; 3268 } 3269 pmap_update(map->pmap); 3270 3271 out: 3272 vm_map_unlock(map); 3273 3274 UVMHIST_LOG(maphist, "<- done, error=%d",error,0,0,0); 3275 return error; 3276 } 3277 3278 #undef MASK 3279 3280 /* 3281 * uvm_map_inherit: set inheritance code for range of addrs in map. 3282 * 3283 * => map must be unlocked 3284 * => note that the inherit code is used during a "fork". see fork 3285 * code for details. 3286 */ 3287 3288 int 3289 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end, 3290 vm_inherit_t new_inheritance) 3291 { 3292 struct vm_map_entry *entry, *temp_entry; 3293 UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist); 3294 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_inh=0x%x)", 3295 map, start, end, new_inheritance); 3296 3297 switch (new_inheritance) { 3298 case MAP_INHERIT_NONE: 3299 case MAP_INHERIT_COPY: 3300 case MAP_INHERIT_SHARE: 3301 break; 3302 default: 3303 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3304 return EINVAL; 3305 } 3306 3307 vm_map_lock(map); 3308 VM_MAP_RANGE_CHECK(map, start, end); 3309 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3310 entry = temp_entry; 3311 UVM_MAP_CLIP_START(map, entry, start, NULL); 3312 } else { 3313 entry = temp_entry->next; 3314 } 3315 while ((entry != &map->header) && (entry->start < end)) { 3316 UVM_MAP_CLIP_END(map, entry, end, NULL); 3317 entry->inheritance = new_inheritance; 3318 entry = entry->next; 3319 } 3320 vm_map_unlock(map); 3321 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3322 return 0; 3323 } 3324 3325 /* 3326 * uvm_map_advice: set advice code for range of addrs in map. 3327 * 3328 * => map must be unlocked 3329 */ 3330 3331 int 3332 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice) 3333 { 3334 struct vm_map_entry *entry, *temp_entry; 3335 UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist); 3336 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_adv=0x%x)", 3337 map, start, end, new_advice); 3338 3339 vm_map_lock(map); 3340 VM_MAP_RANGE_CHECK(map, start, end); 3341 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3342 entry = temp_entry; 3343 UVM_MAP_CLIP_START(map, entry, start, NULL); 3344 } else { 3345 entry = temp_entry->next; 3346 } 3347 3348 /* 3349 * XXXJRT: disallow holes? 3350 */ 3351 3352 while ((entry != &map->header) && (entry->start < end)) { 3353 UVM_MAP_CLIP_END(map, entry, end, NULL); 3354 3355 switch (new_advice) { 3356 case MADV_NORMAL: 3357 case MADV_RANDOM: 3358 case MADV_SEQUENTIAL: 3359 /* nothing special here */ 3360 break; 3361 3362 default: 3363 vm_map_unlock(map); 3364 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3365 return EINVAL; 3366 } 3367 entry->advice = new_advice; 3368 entry = entry->next; 3369 } 3370 3371 vm_map_unlock(map); 3372 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3373 return 0; 3374 } 3375 3376 /* 3377 * uvm_map_willneed: apply MADV_WILLNEED 3378 */ 3379 3380 int 3381 uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end) 3382 { 3383 struct vm_map_entry *entry; 3384 UVMHIST_FUNC("uvm_map_willneed"); UVMHIST_CALLED(maphist); 3385 UVMHIST_LOG(maphist,"(map=0x%lx,start=0x%lx,end=0x%lx)", 3386 map, start, end, 0); 3387 3388 vm_map_lock_read(map); 3389 VM_MAP_RANGE_CHECK(map, start, end); 3390 if (!uvm_map_lookup_entry(map, start, &entry)) { 3391 entry = entry->next; 3392 } 3393 while (entry->start < end) { 3394 struct vm_amap * const amap = entry->aref.ar_amap; 3395 struct uvm_object * const uobj = entry->object.uvm_obj; 3396 3397 KASSERT(entry != &map->header); 3398 KASSERT(start < entry->end); 3399 /* 3400 * For now, we handle only the easy but commonly-requested case. 3401 * ie. start prefetching of backing uobj pages. 3402 * 3403 * XXX It might be useful to pmap_enter() the already-in-core 3404 * pages by inventing a "weak" mode for uvm_fault() which would 3405 * only do the PGO_LOCKED pgo_get(). 3406 */ 3407 if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) { 3408 off_t offset; 3409 off_t size; 3410 3411 offset = entry->offset; 3412 if (start < entry->start) { 3413 offset += entry->start - start; 3414 } 3415 size = entry->offset + (entry->end - entry->start); 3416 if (entry->end < end) { 3417 size -= end - entry->end; 3418 } 3419 uvm_readahead(uobj, offset, size); 3420 } 3421 entry = entry->next; 3422 } 3423 vm_map_unlock_read(map); 3424 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3425 return 0; 3426 } 3427 3428 /* 3429 * uvm_map_pageable: sets the pageability of a range in a map. 3430 * 3431 * => wires map entries. should not be used for transient page locking. 3432 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). 3433 * => regions specified as not pageable require lock-down (wired) memory 3434 * and page tables. 3435 * => map must never be read-locked 3436 * => if islocked is true, map is already write-locked 3437 * => we always unlock the map, since we must downgrade to a read-lock 3438 * to call uvm_fault_wire() 3439 * => XXXCDC: check this and try and clean it up. 3440 */ 3441 3442 int 3443 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 3444 bool new_pageable, int lockflags) 3445 { 3446 struct vm_map_entry *entry, *start_entry, *failed_entry; 3447 int rv; 3448 #ifdef DIAGNOSTIC 3449 u_int timestamp_save; 3450 #endif 3451 UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist); 3452 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_pageable=0x%x)", 3453 map, start, end, new_pageable); 3454 KASSERT(map->flags & VM_MAP_PAGEABLE); 3455 3456 if ((lockflags & UVM_LK_ENTER) == 0) 3457 vm_map_lock(map); 3458 VM_MAP_RANGE_CHECK(map, start, end); 3459 3460 /* 3461 * only one pageability change may take place at one time, since 3462 * uvm_fault_wire assumes it will be called only once for each 3463 * wiring/unwiring. therefore, we have to make sure we're actually 3464 * changing the pageability for the entire region. we do so before 3465 * making any changes. 3466 */ 3467 3468 if (uvm_map_lookup_entry(map, start, &start_entry) == false) { 3469 if ((lockflags & UVM_LK_EXIT) == 0) 3470 vm_map_unlock(map); 3471 3472 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0); 3473 return EFAULT; 3474 } 3475 entry = start_entry; 3476 3477 /* 3478 * handle wiring and unwiring separately. 3479 */ 3480 3481 if (new_pageable) { /* unwire */ 3482 UVM_MAP_CLIP_START(map, entry, start, NULL); 3483 3484 /* 3485 * unwiring. first ensure that the range to be unwired is 3486 * really wired down and that there are no holes. 3487 */ 3488 3489 while ((entry != &map->header) && (entry->start < end)) { 3490 if (entry->wired_count == 0 || 3491 (entry->end < end && 3492 (entry->next == &map->header || 3493 entry->next->start > entry->end))) { 3494 if ((lockflags & UVM_LK_EXIT) == 0) 3495 vm_map_unlock(map); 3496 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0); 3497 return EINVAL; 3498 } 3499 entry = entry->next; 3500 } 3501 3502 /* 3503 * POSIX 1003.1b - a single munlock call unlocks a region, 3504 * regardless of the number of mlock calls made on that 3505 * region. 3506 */ 3507 3508 entry = start_entry; 3509 while ((entry != &map->header) && (entry->start < end)) { 3510 UVM_MAP_CLIP_END(map, entry, end, NULL); 3511 if (VM_MAPENT_ISWIRED(entry)) 3512 uvm_map_entry_unwire(map, entry); 3513 entry = entry->next; 3514 } 3515 if ((lockflags & UVM_LK_EXIT) == 0) 3516 vm_map_unlock(map); 3517 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3518 return 0; 3519 } 3520 3521 /* 3522 * wire case: in two passes [XXXCDC: ugly block of code here] 3523 * 3524 * 1: holding the write lock, we create any anonymous maps that need 3525 * to be created. then we clip each map entry to the region to 3526 * be wired and increment its wiring count. 3527 * 3528 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 3529 * in the pages for any newly wired area (wired_count == 1). 3530 * 3531 * downgrading to a read lock for uvm_fault_wire avoids a possible 3532 * deadlock with another thread that may have faulted on one of 3533 * the pages to be wired (it would mark the page busy, blocking 3534 * us, then in turn block on the map lock that we hold). because 3535 * of problems in the recursive lock package, we cannot upgrade 3536 * to a write lock in vm_map_lookup. thus, any actions that 3537 * require the write lock must be done beforehand. because we 3538 * keep the read lock on the map, the copy-on-write status of the 3539 * entries we modify here cannot change. 3540 */ 3541 3542 while ((entry != &map->header) && (entry->start < end)) { 3543 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3544 3545 /* 3546 * perform actions of vm_map_lookup that need the 3547 * write lock on the map: create an anonymous map 3548 * for a copy-on-write region, or an anonymous map 3549 * for a zero-fill region. (XXXCDC: submap case 3550 * ok?) 3551 */ 3552 3553 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3554 if (UVM_ET_ISNEEDSCOPY(entry) && 3555 ((entry->max_protection & VM_PROT_WRITE) || 3556 (entry->object.uvm_obj == NULL))) { 3557 amap_copy(map, entry, 0, start, end); 3558 /* XXXCDC: wait OK? */ 3559 } 3560 } 3561 } 3562 UVM_MAP_CLIP_START(map, entry, start, NULL); 3563 UVM_MAP_CLIP_END(map, entry, end, NULL); 3564 entry->wired_count++; 3565 3566 /* 3567 * Check for holes 3568 */ 3569 3570 if (entry->protection == VM_PROT_NONE || 3571 (entry->end < end && 3572 (entry->next == &map->header || 3573 entry->next->start > entry->end))) { 3574 3575 /* 3576 * found one. amap creation actions do not need to 3577 * be undone, but the wired counts need to be restored. 3578 */ 3579 3580 while (entry != &map->header && entry->end > start) { 3581 entry->wired_count--; 3582 entry = entry->prev; 3583 } 3584 if ((lockflags & UVM_LK_EXIT) == 0) 3585 vm_map_unlock(map); 3586 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); 3587 return EINVAL; 3588 } 3589 entry = entry->next; 3590 } 3591 3592 /* 3593 * Pass 2. 3594 */ 3595 3596 #ifdef DIAGNOSTIC 3597 timestamp_save = map->timestamp; 3598 #endif 3599 vm_map_busy(map); 3600 vm_map_unlock(map); 3601 3602 rv = 0; 3603 entry = start_entry; 3604 while (entry != &map->header && entry->start < end) { 3605 if (entry->wired_count == 1) { 3606 rv = uvm_fault_wire(map, entry->start, entry->end, 3607 entry->max_protection, 1); 3608 if (rv) { 3609 3610 /* 3611 * wiring failed. break out of the loop. 3612 * we'll clean up the map below, once we 3613 * have a write lock again. 3614 */ 3615 3616 break; 3617 } 3618 } 3619 entry = entry->next; 3620 } 3621 3622 if (rv) { /* failed? */ 3623 3624 /* 3625 * Get back to an exclusive (write) lock. 3626 */ 3627 3628 vm_map_lock(map); 3629 vm_map_unbusy(map); 3630 3631 #ifdef DIAGNOSTIC 3632 if (timestamp_save + 1 != map->timestamp) 3633 panic("uvm_map_pageable: stale map"); 3634 #endif 3635 3636 /* 3637 * first drop the wiring count on all the entries 3638 * which haven't actually been wired yet. 3639 */ 3640 3641 failed_entry = entry; 3642 while (entry != &map->header && entry->start < end) { 3643 entry->wired_count--; 3644 entry = entry->next; 3645 } 3646 3647 /* 3648 * now, unwire all the entries that were successfully 3649 * wired above. 3650 */ 3651 3652 entry = start_entry; 3653 while (entry != failed_entry) { 3654 entry->wired_count--; 3655 if (VM_MAPENT_ISWIRED(entry) == 0) 3656 uvm_map_entry_unwire(map, entry); 3657 entry = entry->next; 3658 } 3659 if ((lockflags & UVM_LK_EXIT) == 0) 3660 vm_map_unlock(map); 3661 UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0); 3662 return (rv); 3663 } 3664 3665 if ((lockflags & UVM_LK_EXIT) == 0) { 3666 vm_map_unbusy(map); 3667 } else { 3668 3669 /* 3670 * Get back to an exclusive (write) lock. 3671 */ 3672 3673 vm_map_lock(map); 3674 vm_map_unbusy(map); 3675 } 3676 3677 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3678 return 0; 3679 } 3680 3681 /* 3682 * uvm_map_pageable_all: special case of uvm_map_pageable - affects 3683 * all mapped regions. 3684 * 3685 * => map must not be locked. 3686 * => if no flags are specified, all regions are unwired. 3687 * => XXXJRT: has some of the same problems as uvm_map_pageable() above. 3688 */ 3689 3690 int 3691 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit) 3692 { 3693 struct vm_map_entry *entry, *failed_entry; 3694 vsize_t size; 3695 int rv; 3696 #ifdef DIAGNOSTIC 3697 u_int timestamp_save; 3698 #endif 3699 UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist); 3700 UVMHIST_LOG(maphist,"(map=0x%x,flags=0x%x)", map, flags, 0, 0); 3701 3702 KASSERT(map->flags & VM_MAP_PAGEABLE); 3703 3704 vm_map_lock(map); 3705 3706 /* 3707 * handle wiring and unwiring separately. 3708 */ 3709 3710 if (flags == 0) { /* unwire */ 3711 3712 /* 3713 * POSIX 1003.1b -- munlockall unlocks all regions, 3714 * regardless of how many times mlockall has been called. 3715 */ 3716 3717 for (entry = map->header.next; entry != &map->header; 3718 entry = entry->next) { 3719 if (VM_MAPENT_ISWIRED(entry)) 3720 uvm_map_entry_unwire(map, entry); 3721 } 3722 map->flags &= ~VM_MAP_WIREFUTURE; 3723 vm_map_unlock(map); 3724 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3725 return 0; 3726 } 3727 3728 if (flags & MCL_FUTURE) { 3729 3730 /* 3731 * must wire all future mappings; remember this. 3732 */ 3733 3734 map->flags |= VM_MAP_WIREFUTURE; 3735 } 3736 3737 if ((flags & MCL_CURRENT) == 0) { 3738 3739 /* 3740 * no more work to do! 3741 */ 3742 3743 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); 3744 vm_map_unlock(map); 3745 return 0; 3746 } 3747 3748 /* 3749 * wire case: in three passes [XXXCDC: ugly block of code here] 3750 * 3751 * 1: holding the write lock, count all pages mapped by non-wired 3752 * entries. if this would cause us to go over our limit, we fail. 3753 * 3754 * 2: still holding the write lock, we create any anonymous maps that 3755 * need to be created. then we increment its wiring count. 3756 * 3757 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault 3758 * in the pages for any newly wired area (wired_count == 1). 3759 * 3760 * downgrading to a read lock for uvm_fault_wire avoids a possible 3761 * deadlock with another thread that may have faulted on one of 3762 * the pages to be wired (it would mark the page busy, blocking 3763 * us, then in turn block on the map lock that we hold). because 3764 * of problems in the recursive lock package, we cannot upgrade 3765 * to a write lock in vm_map_lookup. thus, any actions that 3766 * require the write lock must be done beforehand. because we 3767 * keep the read lock on the map, the copy-on-write status of the 3768 * entries we modify here cannot change. 3769 */ 3770 3771 for (size = 0, entry = map->header.next; entry != &map->header; 3772 entry = entry->next) { 3773 if (entry->protection != VM_PROT_NONE && 3774 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3775 size += entry->end - entry->start; 3776 } 3777 } 3778 3779 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { 3780 vm_map_unlock(map); 3781 return ENOMEM; 3782 } 3783 3784 if (limit != 0 && 3785 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { 3786 vm_map_unlock(map); 3787 return ENOMEM; 3788 } 3789 3790 /* 3791 * Pass 2. 3792 */ 3793 3794 for (entry = map->header.next; entry != &map->header; 3795 entry = entry->next) { 3796 if (entry->protection == VM_PROT_NONE) 3797 continue; 3798 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3799 3800 /* 3801 * perform actions of vm_map_lookup that need the 3802 * write lock on the map: create an anonymous map 3803 * for a copy-on-write region, or an anonymous map 3804 * for a zero-fill region. (XXXCDC: submap case 3805 * ok?) 3806 */ 3807 3808 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3809 if (UVM_ET_ISNEEDSCOPY(entry) && 3810 ((entry->max_protection & VM_PROT_WRITE) || 3811 (entry->object.uvm_obj == NULL))) { 3812 amap_copy(map, entry, 0, entry->start, 3813 entry->end); 3814 /* XXXCDC: wait OK? */ 3815 } 3816 } 3817 } 3818 entry->wired_count++; 3819 } 3820 3821 /* 3822 * Pass 3. 3823 */ 3824 3825 #ifdef DIAGNOSTIC 3826 timestamp_save = map->timestamp; 3827 #endif 3828 vm_map_busy(map); 3829 vm_map_unlock(map); 3830 3831 rv = 0; 3832 for (entry = map->header.next; entry != &map->header; 3833 entry = entry->next) { 3834 if (entry->wired_count == 1) { 3835 rv = uvm_fault_wire(map, entry->start, entry->end, 3836 entry->max_protection, 1); 3837 if (rv) { 3838 3839 /* 3840 * wiring failed. break out of the loop. 3841 * we'll clean up the map below, once we 3842 * have a write lock again. 3843 */ 3844 3845 break; 3846 } 3847 } 3848 } 3849 3850 if (rv) { 3851 3852 /* 3853 * Get back an exclusive (write) lock. 3854 */ 3855 3856 vm_map_lock(map); 3857 vm_map_unbusy(map); 3858 3859 #ifdef DIAGNOSTIC 3860 if (timestamp_save + 1 != map->timestamp) 3861 panic("uvm_map_pageable_all: stale map"); 3862 #endif 3863 3864 /* 3865 * first drop the wiring count on all the entries 3866 * which haven't actually been wired yet. 3867 * 3868 * Skip VM_PROT_NONE entries like we did above. 3869 */ 3870 3871 failed_entry = entry; 3872 for (/* nothing */; entry != &map->header; 3873 entry = entry->next) { 3874 if (entry->protection == VM_PROT_NONE) 3875 continue; 3876 entry->wired_count--; 3877 } 3878 3879 /* 3880 * now, unwire all the entries that were successfully 3881 * wired above. 3882 * 3883 * Skip VM_PROT_NONE entries like we did above. 3884 */ 3885 3886 for (entry = map->header.next; entry != failed_entry; 3887 entry = entry->next) { 3888 if (entry->protection == VM_PROT_NONE) 3889 continue; 3890 entry->wired_count--; 3891 if (VM_MAPENT_ISWIRED(entry)) 3892 uvm_map_entry_unwire(map, entry); 3893 } 3894 vm_map_unlock(map); 3895 UVMHIST_LOG(maphist,"<- done (RV=%d)", rv,0,0,0); 3896 return (rv); 3897 } 3898 3899 vm_map_unbusy(map); 3900 3901 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3902 return 0; 3903 } 3904 3905 /* 3906 * uvm_map_clean: clean out a map range 3907 * 3908 * => valid flags: 3909 * if (flags & PGO_CLEANIT): dirty pages are cleaned first 3910 * if (flags & PGO_SYNCIO): dirty pages are written synchronously 3911 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean 3912 * if (flags & PGO_FREE): any cached pages are freed after clean 3913 * => returns an error if any part of the specified range isn't mapped 3914 * => never a need to flush amap layer since the anonymous memory has 3915 * no permanent home, but may deactivate pages there 3916 * => called from sys_msync() and sys_madvise() 3917 * => caller must not write-lock map (read OK). 3918 * => we may sleep while cleaning if SYNCIO [with map read-locked] 3919 */ 3920 3921 int 3922 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 3923 { 3924 struct vm_map_entry *current, *entry; 3925 struct uvm_object *uobj; 3926 struct vm_amap *amap; 3927 struct vm_anon *anon, *anon_tofree; 3928 struct vm_page *pg; 3929 vaddr_t offset; 3930 vsize_t size; 3931 voff_t uoff; 3932 int error, refs; 3933 UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist); 3934 3935 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,flags=0x%x)", 3936 map, start, end, flags); 3937 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) != 3938 (PGO_FREE|PGO_DEACTIVATE)); 3939 3940 vm_map_lock_read(map); 3941 VM_MAP_RANGE_CHECK(map, start, end); 3942 if (uvm_map_lookup_entry(map, start, &entry) == false) { 3943 vm_map_unlock_read(map); 3944 return EFAULT; 3945 } 3946 3947 /* 3948 * Make a first pass to check for holes and wiring problems. 3949 */ 3950 3951 for (current = entry; current->start < end; current = current->next) { 3952 if (UVM_ET_ISSUBMAP(current)) { 3953 vm_map_unlock_read(map); 3954 return EINVAL; 3955 } 3956 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) { 3957 vm_map_unlock_read(map); 3958 return EBUSY; 3959 } 3960 if (end <= current->end) { 3961 break; 3962 } 3963 if (current->end != current->next->start) { 3964 vm_map_unlock_read(map); 3965 return EFAULT; 3966 } 3967 } 3968 3969 error = 0; 3970 for (current = entry; start < end; current = current->next) { 3971 amap = current->aref.ar_amap; /* upper layer */ 3972 uobj = current->object.uvm_obj; /* lower layer */ 3973 KASSERT(start >= current->start); 3974 3975 /* 3976 * No amap cleaning necessary if: 3977 * 3978 * (1) There's no amap. 3979 * 3980 * (2) We're not deactivating or freeing pages. 3981 */ 3982 3983 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) 3984 goto flush_object; 3985 3986 offset = start - current->start; 3987 size = MIN(end, current->end) - start; 3988 anon_tofree = NULL; 3989 3990 amap_lock(amap); 3991 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { 3992 anon = amap_lookup(¤t->aref, offset); 3993 if (anon == NULL) 3994 continue; 3995 3996 KASSERT(anon->an_lock == amap->am_lock); 3997 pg = anon->an_page; 3998 if (pg == NULL) { 3999 continue; 4000 } 4001 4002 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { 4003 4004 /* 4005 * In these first 3 cases, we just deactivate the page. 4006 */ 4007 4008 case PGO_CLEANIT|PGO_FREE: 4009 case PGO_CLEANIT|PGO_DEACTIVATE: 4010 case PGO_DEACTIVATE: 4011 deactivate_it: 4012 /* 4013 * skip the page if it's loaned or wired, 4014 * since it shouldn't be on a paging queue 4015 * at all in these cases. 4016 */ 4017 4018 mutex_enter(&uvm_pageqlock); 4019 if (pg->loan_count != 0 || 4020 pg->wire_count != 0) { 4021 mutex_exit(&uvm_pageqlock); 4022 continue; 4023 } 4024 KASSERT(pg->uanon == anon); 4025 uvm_pagedeactivate(pg); 4026 mutex_exit(&uvm_pageqlock); 4027 continue; 4028 4029 case PGO_FREE: 4030 4031 /* 4032 * If there are multiple references to 4033 * the amap, just deactivate the page. 4034 */ 4035 4036 if (amap_refs(amap) > 1) 4037 goto deactivate_it; 4038 4039 /* skip the page if it's wired */ 4040 if (pg->wire_count != 0) { 4041 continue; 4042 } 4043 amap_unadd(¤t->aref, offset); 4044 refs = --anon->an_ref; 4045 if (refs == 0) { 4046 anon->an_link = anon_tofree; 4047 anon_tofree = anon; 4048 } 4049 continue; 4050 } 4051 } 4052 uvm_anon_freelst(amap, anon_tofree); 4053 4054 flush_object: 4055 /* 4056 * flush pages if we've got a valid backing object. 4057 * note that we must always clean object pages before 4058 * freeing them since otherwise we could reveal stale 4059 * data from files. 4060 */ 4061 4062 uoff = current->offset + (start - current->start); 4063 size = MIN(end, current->end) - start; 4064 if (uobj != NULL) { 4065 mutex_enter(uobj->vmobjlock); 4066 if (uobj->pgops->pgo_put != NULL) 4067 error = (uobj->pgops->pgo_put)(uobj, uoff, 4068 uoff + size, flags | PGO_CLEANIT); 4069 else 4070 error = 0; 4071 } 4072 start += size; 4073 } 4074 vm_map_unlock_read(map); 4075 return (error); 4076 } 4077 4078 4079 /* 4080 * uvm_map_checkprot: check protection in map 4081 * 4082 * => must allow specified protection in a fully allocated region. 4083 * => map must be read or write locked by caller. 4084 */ 4085 4086 bool 4087 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end, 4088 vm_prot_t protection) 4089 { 4090 struct vm_map_entry *entry; 4091 struct vm_map_entry *tmp_entry; 4092 4093 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) { 4094 return (false); 4095 } 4096 entry = tmp_entry; 4097 while (start < end) { 4098 if (entry == &map->header) { 4099 return (false); 4100 } 4101 4102 /* 4103 * no holes allowed 4104 */ 4105 4106 if (start < entry->start) { 4107 return (false); 4108 } 4109 4110 /* 4111 * check protection associated with entry 4112 */ 4113 4114 if ((entry->protection & protection) != protection) { 4115 return (false); 4116 } 4117 start = entry->end; 4118 entry = entry->next; 4119 } 4120 return (true); 4121 } 4122 4123 /* 4124 * uvmspace_alloc: allocate a vmspace structure. 4125 * 4126 * - structure includes vm_map and pmap 4127 * - XXX: no locking on this structure 4128 * - refcnt set to 1, rest must be init'd by caller 4129 */ 4130 struct vmspace * 4131 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax) 4132 { 4133 struct vmspace *vm; 4134 UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist); 4135 4136 vm = pool_cache_get(&uvm_vmspace_cache, PR_WAITOK); 4137 uvmspace_init(vm, NULL, vmin, vmax); 4138 UVMHIST_LOG(maphist,"<- done (vm=0x%x)", vm,0,0,0); 4139 return (vm); 4140 } 4141 4142 /* 4143 * uvmspace_init: initialize a vmspace structure. 4144 * 4145 * - XXX: no locking on this structure 4146 * - refcnt set to 1, rest must be init'd by caller 4147 */ 4148 void 4149 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, vaddr_t vmax) 4150 { 4151 UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist); 4152 4153 memset(vm, 0, sizeof(*vm)); 4154 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE 4155 #ifdef __USING_TOPDOWN_VM 4156 | VM_MAP_TOPDOWN 4157 #endif 4158 ); 4159 if (pmap) 4160 pmap_reference(pmap); 4161 else 4162 pmap = pmap_create(); 4163 vm->vm_map.pmap = pmap; 4164 vm->vm_refcnt = 1; 4165 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4166 } 4167 4168 /* 4169 * uvmspace_share: share a vmspace between two processes 4170 * 4171 * - used for vfork, threads(?) 4172 */ 4173 4174 void 4175 uvmspace_share(struct proc *p1, struct proc *p2) 4176 { 4177 4178 uvmspace_addref(p1->p_vmspace); 4179 p2->p_vmspace = p1->p_vmspace; 4180 } 4181 4182 #if 0 4183 4184 /* 4185 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace 4186 * 4187 * - XXX: no locking on vmspace 4188 */ 4189 4190 void 4191 uvmspace_unshare(struct lwp *l) 4192 { 4193 struct proc *p = l->l_proc; 4194 struct vmspace *nvm, *ovm = p->p_vmspace; 4195 4196 if (ovm->vm_refcnt == 1) 4197 /* nothing to do: vmspace isn't shared in the first place */ 4198 return; 4199 4200 /* make a new vmspace, still holding old one */ 4201 nvm = uvmspace_fork(ovm); 4202 4203 kpreempt_disable(); 4204 pmap_deactivate(l); /* unbind old vmspace */ 4205 p->p_vmspace = nvm; 4206 pmap_activate(l); /* switch to new vmspace */ 4207 kpreempt_enable(); 4208 4209 uvmspace_free(ovm); /* drop reference to old vmspace */ 4210 } 4211 4212 #endif 4213 4214 /* 4215 * uvmspace_exec: the process wants to exec a new program 4216 */ 4217 4218 void 4219 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end) 4220 { 4221 struct proc *p = l->l_proc; 4222 struct vmspace *nvm, *ovm = p->p_vmspace; 4223 struct vm_map *map; 4224 4225 #ifdef __HAVE_CPU_VMSPACE_EXEC 4226 cpu_vmspace_exec(l, start, end); 4227 #endif 4228 4229 /* 4230 * Special case: no vmspace yet (see posix_spawn) - 4231 * no races possible in this case. 4232 */ 4233 if (ovm == NULL) { 4234 p->p_vmspace = uvmspace_alloc(start, end); 4235 pmap_activate(l); 4236 return; 4237 } 4238 4239 map = &ovm->vm_map; 4240 /* 4241 * see if more than one process is using this vmspace... 4242 */ 4243 4244 if (ovm->vm_refcnt == 1) { 4245 4246 /* 4247 * if p is the only process using its vmspace then we can safely 4248 * recycle that vmspace for the program that is being exec'd. 4249 */ 4250 4251 #ifdef SYSVSHM 4252 /* 4253 * SYSV SHM semantics require us to kill all segments on an exec 4254 */ 4255 4256 if (ovm->vm_shm) 4257 shmexit(ovm); 4258 #endif 4259 4260 /* 4261 * POSIX 1003.1b -- "lock future mappings" is revoked 4262 * when a process execs another program image. 4263 */ 4264 4265 map->flags &= ~VM_MAP_WIREFUTURE; 4266 4267 /* 4268 * now unmap the old program 4269 */ 4270 4271 pmap_remove_all(map->pmap); 4272 uvm_unmap(map, vm_map_min(map), vm_map_max(map)); 4273 KASSERT(map->header.prev == &map->header); 4274 KASSERT(map->nentries == 0); 4275 4276 /* 4277 * resize the map 4278 */ 4279 4280 vm_map_setmin(map, start); 4281 vm_map_setmax(map, end); 4282 } else { 4283 4284 /* 4285 * p's vmspace is being shared, so we can't reuse it for p since 4286 * it is still being used for others. allocate a new vmspace 4287 * for p 4288 */ 4289 4290 nvm = uvmspace_alloc(start, end); 4291 4292 /* 4293 * install new vmspace and drop our ref to the old one. 4294 */ 4295 4296 kpreempt_disable(); 4297 pmap_deactivate(l); 4298 p->p_vmspace = nvm; 4299 pmap_activate(l); 4300 kpreempt_enable(); 4301 4302 uvmspace_free(ovm); 4303 } 4304 } 4305 4306 /* 4307 * uvmspace_addref: add a referece to a vmspace. 4308 */ 4309 4310 void 4311 uvmspace_addref(struct vmspace *vm) 4312 { 4313 struct vm_map *map = &vm->vm_map; 4314 4315 KASSERT((map->flags & VM_MAP_DYING) == 0); 4316 4317 mutex_enter(&map->misc_lock); 4318 KASSERT(vm->vm_refcnt > 0); 4319 vm->vm_refcnt++; 4320 mutex_exit(&map->misc_lock); 4321 } 4322 4323 /* 4324 * uvmspace_free: free a vmspace data structure 4325 */ 4326 4327 void 4328 uvmspace_free(struct vmspace *vm) 4329 { 4330 struct vm_map_entry *dead_entries; 4331 struct vm_map *map = &vm->vm_map; 4332 int n; 4333 4334 UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist); 4335 4336 UVMHIST_LOG(maphist,"(vm=0x%x) ref=%d", vm, vm->vm_refcnt,0,0); 4337 mutex_enter(&map->misc_lock); 4338 n = --vm->vm_refcnt; 4339 mutex_exit(&map->misc_lock); 4340 if (n > 0) 4341 return; 4342 4343 /* 4344 * at this point, there should be no other references to the map. 4345 * delete all of the mappings, then destroy the pmap. 4346 */ 4347 4348 map->flags |= VM_MAP_DYING; 4349 pmap_remove_all(map->pmap); 4350 #ifdef SYSVSHM 4351 /* Get rid of any SYSV shared memory segments. */ 4352 if (vm->vm_shm != NULL) 4353 shmexit(vm); 4354 #endif 4355 if (map->nentries) { 4356 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map), 4357 &dead_entries, NULL, 0); 4358 if (dead_entries != NULL) 4359 uvm_unmap_detach(dead_entries, 0); 4360 } 4361 KASSERT(map->nentries == 0); 4362 KASSERT(map->size == 0); 4363 mutex_destroy(&map->misc_lock); 4364 mutex_destroy(&map->mutex); 4365 rw_destroy(&map->lock); 4366 cv_destroy(&map->cv); 4367 pmap_destroy(map->pmap); 4368 pool_cache_put(&uvm_vmspace_cache, vm); 4369 } 4370 4371 /* 4372 * F O R K - m a i n e n t r y p o i n t 4373 */ 4374 /* 4375 * uvmspace_fork: fork a process' main map 4376 * 4377 * => create a new vmspace for child process from parent. 4378 * => parent's map must not be locked. 4379 */ 4380 4381 struct vmspace * 4382 uvmspace_fork(struct vmspace *vm1) 4383 { 4384 struct vmspace *vm2; 4385 struct vm_map *old_map = &vm1->vm_map; 4386 struct vm_map *new_map; 4387 struct vm_map_entry *old_entry; 4388 struct vm_map_entry *new_entry; 4389 UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist); 4390 4391 vm_map_lock(old_map); 4392 4393 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map)); 4394 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy, 4395 (char *) (vm1 + 1) - (char *) &vm1->vm_startcopy); 4396 new_map = &vm2->vm_map; /* XXX */ 4397 4398 old_entry = old_map->header.next; 4399 new_map->size = old_map->size; 4400 4401 /* 4402 * go entry-by-entry 4403 */ 4404 4405 while (old_entry != &old_map->header) { 4406 4407 /* 4408 * first, some sanity checks on the old entry 4409 */ 4410 4411 KASSERT(!UVM_ET_ISSUBMAP(old_entry)); 4412 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) || 4413 !UVM_ET_ISNEEDSCOPY(old_entry)); 4414 4415 switch (old_entry->inheritance) { 4416 case MAP_INHERIT_NONE: 4417 4418 /* 4419 * drop the mapping, modify size 4420 */ 4421 new_map->size -= old_entry->end - old_entry->start; 4422 break; 4423 4424 case MAP_INHERIT_SHARE: 4425 4426 /* 4427 * share the mapping: this means we want the old and 4428 * new entries to share amaps and backing objects. 4429 */ 4430 /* 4431 * if the old_entry needs a new amap (due to prev fork) 4432 * then we need to allocate it now so that we have 4433 * something we own to share with the new_entry. [in 4434 * other words, we need to clear needs_copy] 4435 */ 4436 4437 if (UVM_ET_ISNEEDSCOPY(old_entry)) { 4438 /* get our own amap, clears needs_copy */ 4439 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK, 4440 0, 0); 4441 /* XXXCDC: WAITOK??? */ 4442 } 4443 4444 new_entry = uvm_mapent_alloc(new_map, 0); 4445 /* old_entry -> new_entry */ 4446 uvm_mapent_copy(old_entry, new_entry); 4447 4448 /* new pmap has nothing wired in it */ 4449 new_entry->wired_count = 0; 4450 4451 /* 4452 * gain reference to object backing the map (can't 4453 * be a submap, already checked this case). 4454 */ 4455 4456 if (new_entry->aref.ar_amap) 4457 uvm_map_reference_amap(new_entry, AMAP_SHARED); 4458 4459 if (new_entry->object.uvm_obj && 4460 new_entry->object.uvm_obj->pgops->pgo_reference) 4461 new_entry->object.uvm_obj-> 4462 pgops->pgo_reference( 4463 new_entry->object.uvm_obj); 4464 4465 /* insert entry at end of new_map's entry list */ 4466 uvm_map_entry_link(new_map, new_map->header.prev, 4467 new_entry); 4468 4469 break; 4470 4471 case MAP_INHERIT_COPY: 4472 4473 /* 4474 * copy-on-write the mapping (using mmap's 4475 * MAP_PRIVATE semantics) 4476 * 4477 * allocate new_entry, adjust reference counts. 4478 * (note that new references are read-only). 4479 */ 4480 4481 new_entry = uvm_mapent_alloc(new_map, 0); 4482 /* old_entry -> new_entry */ 4483 uvm_mapent_copy(old_entry, new_entry); 4484 4485 if (new_entry->aref.ar_amap) 4486 uvm_map_reference_amap(new_entry, 0); 4487 4488 if (new_entry->object.uvm_obj && 4489 new_entry->object.uvm_obj->pgops->pgo_reference) 4490 new_entry->object.uvm_obj->pgops->pgo_reference 4491 (new_entry->object.uvm_obj); 4492 4493 /* new pmap has nothing wired in it */ 4494 new_entry->wired_count = 0; 4495 4496 new_entry->etype |= 4497 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4498 uvm_map_entry_link(new_map, new_map->header.prev, 4499 new_entry); 4500 4501 /* 4502 * the new entry will need an amap. it will either 4503 * need to be copied from the old entry or created 4504 * from scratch (if the old entry does not have an 4505 * amap). can we defer this process until later 4506 * (by setting "needs_copy") or do we need to copy 4507 * the amap now? 4508 * 4509 * we must copy the amap now if any of the following 4510 * conditions hold: 4511 * 1. the old entry has an amap and that amap is 4512 * being shared. this means that the old (parent) 4513 * process is sharing the amap with another 4514 * process. if we do not clear needs_copy here 4515 * we will end up in a situation where both the 4516 * parent and child process are refering to the 4517 * same amap with "needs_copy" set. if the 4518 * parent write-faults, the fault routine will 4519 * clear "needs_copy" in the parent by allocating 4520 * a new amap. this is wrong because the 4521 * parent is supposed to be sharing the old amap 4522 * and the new amap will break that. 4523 * 4524 * 2. if the old entry has an amap and a non-zero 4525 * wire count then we are going to have to call 4526 * amap_cow_now to avoid page faults in the 4527 * parent process. since amap_cow_now requires 4528 * "needs_copy" to be clear we might as well 4529 * clear it here as well. 4530 * 4531 */ 4532 4533 if (old_entry->aref.ar_amap != NULL) { 4534 if ((amap_flags(old_entry->aref.ar_amap) & 4535 AMAP_SHARED) != 0 || 4536 VM_MAPENT_ISWIRED(old_entry)) { 4537 4538 amap_copy(new_map, new_entry, 4539 AMAP_COPY_NOCHUNK, 0, 0); 4540 /* XXXCDC: M_WAITOK ... ok? */ 4541 } 4542 } 4543 4544 /* 4545 * if the parent's entry is wired down, then the 4546 * parent process does not want page faults on 4547 * access to that memory. this means that we 4548 * cannot do copy-on-write because we can't write 4549 * protect the old entry. in this case we 4550 * resolve all copy-on-write faults now, using 4551 * amap_cow_now. note that we have already 4552 * allocated any needed amap (above). 4553 */ 4554 4555 if (VM_MAPENT_ISWIRED(old_entry)) { 4556 4557 /* 4558 * resolve all copy-on-write faults now 4559 * (note that there is nothing to do if 4560 * the old mapping does not have an amap). 4561 */ 4562 if (old_entry->aref.ar_amap) 4563 amap_cow_now(new_map, new_entry); 4564 4565 } else { 4566 4567 /* 4568 * setup mappings to trigger copy-on-write faults 4569 * we must write-protect the parent if it has 4570 * an amap and it is not already "needs_copy"... 4571 * if it is already "needs_copy" then the parent 4572 * has already been write-protected by a previous 4573 * fork operation. 4574 */ 4575 4576 if (old_entry->aref.ar_amap && 4577 !UVM_ET_ISNEEDSCOPY(old_entry)) { 4578 if (old_entry->max_protection & VM_PROT_WRITE) { 4579 pmap_protect(old_map->pmap, 4580 old_entry->start, 4581 old_entry->end, 4582 old_entry->protection & 4583 ~VM_PROT_WRITE); 4584 } 4585 old_entry->etype |= UVM_ET_NEEDSCOPY; 4586 } 4587 } 4588 break; 4589 } /* end of switch statement */ 4590 old_entry = old_entry->next; 4591 } 4592 4593 pmap_update(old_map->pmap); 4594 vm_map_unlock(old_map); 4595 4596 #ifdef SYSVSHM 4597 if (vm1->vm_shm) 4598 shmfork(vm1, vm2); 4599 #endif 4600 4601 #ifdef PMAP_FORK 4602 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap); 4603 #endif 4604 4605 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4606 return (vm2); 4607 } 4608 4609 4610 /* 4611 * in-kernel map entry allocation. 4612 */ 4613 4614 struct uvm_kmapent_hdr { 4615 LIST_ENTRY(uvm_kmapent_hdr) ukh_listq; 4616 int ukh_nused; 4617 struct vm_map_entry *ukh_freelist; 4618 struct vm_map *ukh_map; 4619 struct vm_map_entry ukh_entries[0]; 4620 }; 4621 4622 #define UVM_KMAPENT_CHUNK \ 4623 ((PAGE_SIZE - sizeof(struct uvm_kmapent_hdr)) \ 4624 / sizeof(struct vm_map_entry)) 4625 4626 #define UVM_KHDR_FIND(entry) \ 4627 ((struct uvm_kmapent_hdr *)(((vaddr_t)entry) & ~PAGE_MASK)) 4628 4629 4630 #ifdef DIAGNOSTIC 4631 static struct vm_map * 4632 uvm_kmapent_map(struct vm_map_entry *entry) 4633 { 4634 const struct uvm_kmapent_hdr *ukh; 4635 4636 ukh = UVM_KHDR_FIND(entry); 4637 return ukh->ukh_map; 4638 } 4639 #endif 4640 4641 static inline struct vm_map_entry * 4642 uvm_kmapent_get(struct uvm_kmapent_hdr *ukh) 4643 { 4644 struct vm_map_entry *entry; 4645 4646 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4647 KASSERT(ukh->ukh_nused >= 0); 4648 4649 entry = ukh->ukh_freelist; 4650 if (entry) { 4651 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT)) 4652 == UVM_MAP_KERNEL); 4653 ukh->ukh_freelist = entry->next; 4654 ukh->ukh_nused++; 4655 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4656 } else { 4657 KASSERT(ukh->ukh_nused == UVM_KMAPENT_CHUNK); 4658 } 4659 4660 return entry; 4661 } 4662 4663 static inline void 4664 uvm_kmapent_put(struct uvm_kmapent_hdr *ukh, struct vm_map_entry *entry) 4665 { 4666 4667 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT)) 4668 == UVM_MAP_KERNEL); 4669 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4670 KASSERT(ukh->ukh_nused > 0); 4671 KASSERT(ukh->ukh_freelist != NULL || 4672 ukh->ukh_nused == UVM_KMAPENT_CHUNK); 4673 KASSERT(ukh->ukh_freelist == NULL || 4674 ukh->ukh_nused < UVM_KMAPENT_CHUNK); 4675 4676 ukh->ukh_nused--; 4677 entry->next = ukh->ukh_freelist; 4678 ukh->ukh_freelist = entry; 4679 } 4680 4681 /* 4682 * uvm_kmapent_alloc: allocate a map entry for in-kernel map 4683 */ 4684 4685 static struct vm_map_entry * 4686 uvm_kmapent_alloc(struct vm_map *map, int flags) 4687 { 4688 struct vm_page *pg; 4689 struct uvm_kmapent_hdr *ukh; 4690 struct vm_map_entry *entry; 4691 #ifndef PMAP_MAP_POOLPAGE 4692 struct uvm_map_args args; 4693 uvm_flag_t mapflags = UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 4694 UVM_INH_NONE, UVM_ADV_RANDOM, flags | UVM_FLAG_NOMERGE); 4695 int error; 4696 #endif 4697 vaddr_t va; 4698 int i; 4699 4700 KDASSERT(UVM_KMAPENT_CHUNK > 2); 4701 KDASSERT(kernel_map != NULL); 4702 KASSERT(vm_map_pmap(map) == pmap_kernel()); 4703 4704 UVMMAP_EVCNT_INCR(uke_alloc); 4705 entry = NULL; 4706 again: 4707 /* 4708 * try to grab an entry from freelist. 4709 */ 4710 mutex_spin_enter(&uvm_kentry_lock); 4711 ukh = LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free); 4712 if (ukh) { 4713 entry = uvm_kmapent_get(ukh); 4714 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK) 4715 LIST_REMOVE(ukh, ukh_listq); 4716 } 4717 mutex_spin_exit(&uvm_kentry_lock); 4718 4719 if (entry) 4720 return entry; 4721 4722 /* 4723 * there's no free entry for this vm_map. 4724 * now we need to allocate some vm_map_entry. 4725 * for simplicity, always allocate one page chunk of them at once. 4726 */ 4727 4728 #ifdef PMAP_ALLOC_POOLPAGE 4729 pg = PMAP_ALLOC_POOLPAGE( 4730 (flags & UVM_KMF_NOWAIT) != 0 ? UVM_PGA_USERESERVE : 0); 4731 #else 4732 pg = uvm_pagealloc(NULL, 0, NULL, 4733 (flags & UVM_KMF_NOWAIT) != 0 ? UVM_PGA_USERESERVE : 0); 4734 #endif 4735 if (__predict_false(pg == NULL)) { 4736 if (flags & UVM_FLAG_NOWAIT) 4737 return NULL; 4738 uvm_wait("kme_alloc"); 4739 goto again; 4740 } 4741 4742 #ifdef PMAP_MAP_POOLPAGE 4743 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 4744 KASSERT(va != 0); 4745 #else 4746 error = uvm_map_prepare(map, 0, PAGE_SIZE, NULL, UVM_UNKNOWN_OFFSET, 4747 VM_PGCOLOR_BUCKET(pg), mapflags | UVM_FLAG_COLORMATCH, &args); 4748 if (error) { 4749 uvm_pagefree(pg); 4750 return NULL; 4751 } 4752 4753 va = args.uma_start; 4754 4755 pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), 4756 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); 4757 pmap_update(vm_map_pmap(map)); 4758 4759 #endif 4760 ukh = (void *)va; 4761 4762 /* 4763 * use the last entry for ukh itsself. 4764 */ 4765 4766 i = UVM_KMAPENT_CHUNK - 1; 4767 #ifndef PMAP_MAP_POOLPAGE 4768 entry = &ukh->ukh_entries[i--]; 4769 entry->flags = UVM_MAP_KERNEL | UVM_MAP_KMAPENT; 4770 error = uvm_map_enter(map, &args, entry); 4771 KASSERT(error == 0); 4772 #endif 4773 4774 ukh->ukh_nused = UVM_KMAPENT_CHUNK; 4775 ukh->ukh_map = map; 4776 ukh->ukh_freelist = NULL; 4777 for (; i >= 1; i--) { 4778 struct vm_map_entry *xentry = &ukh->ukh_entries[i]; 4779 4780 xentry->flags = UVM_MAP_KERNEL; 4781 uvm_kmapent_put(ukh, xentry); 4782 } 4783 #ifdef PMAP_MAP_POOLPAGE 4784 KASSERT(ukh->ukh_nused == 1); 4785 #else 4786 KASSERT(ukh->ukh_nused == 2); 4787 #endif 4788 4789 mutex_spin_enter(&uvm_kentry_lock); 4790 LIST_INSERT_HEAD(&vm_map_to_kernel(map)->vmk_kentry_free, 4791 ukh, ukh_listq); 4792 mutex_spin_exit(&uvm_kentry_lock); 4793 4794 /* 4795 * return first entry. 4796 */ 4797 4798 entry = &ukh->ukh_entries[0]; 4799 entry->flags = UVM_MAP_KERNEL; 4800 UVMMAP_EVCNT_INCR(ukh_alloc); 4801 4802 return entry; 4803 } 4804 4805 /* 4806 * uvm_mapent_free: free map entry for in-kernel map 4807 */ 4808 4809 static void 4810 uvm_kmapent_free(struct vm_map_entry *entry) 4811 { 4812 struct uvm_kmapent_hdr *ukh; 4813 struct vm_page *pg; 4814 struct vm_map *map; 4815 #ifndef PMAP_UNMAP_POOLPAGE 4816 struct pmap *pmap; 4817 struct vm_map_entry *deadentry; 4818 #endif 4819 vaddr_t va; 4820 paddr_t pa; 4821 4822 UVMMAP_EVCNT_INCR(uke_free); 4823 ukh = UVM_KHDR_FIND(entry); 4824 map = ukh->ukh_map; 4825 4826 mutex_spin_enter(&uvm_kentry_lock); 4827 uvm_kmapent_put(ukh, entry); 4828 #ifdef PMAP_UNMAP_POOLPAGE 4829 if (ukh->ukh_nused > 0) { 4830 #else 4831 if (ukh->ukh_nused > 1) { 4832 #endif 4833 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK - 1) 4834 LIST_INSERT_HEAD( 4835 &vm_map_to_kernel(map)->vmk_kentry_free, 4836 ukh, ukh_listq); 4837 mutex_spin_exit(&uvm_kentry_lock); 4838 return; 4839 } 4840 4841 /* 4842 * now we can free this ukh. 4843 * 4844 * however, keep an empty ukh to avoid ping-pong. 4845 */ 4846 4847 if (LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free) == ukh && 4848 LIST_NEXT(ukh, ukh_listq) == NULL) { 4849 mutex_spin_exit(&uvm_kentry_lock); 4850 return; 4851 } 4852 LIST_REMOVE(ukh, ukh_listq); 4853 mutex_spin_exit(&uvm_kentry_lock); 4854 4855 va = (vaddr_t)ukh; 4856 4857 #ifdef PMAP_UNMAP_POOLPAGE 4858 KASSERT(ukh->ukh_nused == 0); 4859 pa = PMAP_UNMAP_POOLPAGE(va); 4860 KASSERT(pa != 0); 4861 #else 4862 KASSERT(ukh->ukh_nused == 1); 4863 4864 /* 4865 * remove map entry for ukh itsself. 4866 */ 4867 4868 KASSERT((va & PAGE_MASK) == 0); 4869 vm_map_lock(map); 4870 uvm_unmap_remove(map, va, va + PAGE_SIZE, &deadentry, NULL, 0); 4871 KASSERT(deadentry->flags & UVM_MAP_KERNEL); 4872 KASSERT(deadentry->flags & UVM_MAP_KMAPENT); 4873 KASSERT(deadentry->next == NULL); 4874 KASSERT(deadentry == &ukh->ukh_entries[UVM_KMAPENT_CHUNK - 1]); 4875 4876 /* 4877 * unmap the page from pmap and free it. 4878 */ 4879 4880 pmap = vm_map_pmap(map); 4881 KASSERT(pmap == pmap_kernel()); 4882 if (!pmap_extract(pmap, va, &pa)) 4883 panic("%s: no mapping", __func__); 4884 pmap_kremove(va, PAGE_SIZE); 4885 pmap_update(vm_map_pmap(map)); 4886 vm_map_unlock(map); 4887 #endif /* !PMAP_UNMAP_POOLPAGE */ 4888 pg = PHYS_TO_VM_PAGE(pa); 4889 uvm_pagefree(pg); 4890 UVMMAP_EVCNT_INCR(ukh_free); 4891 } 4892 4893 static vsize_t 4894 uvm_kmapent_overhead(vsize_t size) 4895 { 4896 4897 /* 4898 * - the max number of unmerged entries is howmany(size, PAGE_SIZE) 4899 * as the min allocation unit is PAGE_SIZE. 4900 * - UVM_KMAPENT_CHUNK "kmapent"s are allocated from a page. 4901 * one of them are used to map the page itself. 4902 */ 4903 4904 return howmany(howmany(size, PAGE_SIZE), (UVM_KMAPENT_CHUNK - 1)) * 4905 PAGE_SIZE; 4906 } 4907 4908 /* 4909 * map entry reservation 4910 */ 4911 4912 /* 4913 * uvm_mapent_reserve: reserve map entries for clipping before locking map. 4914 * 4915 * => needed when unmapping entries allocated without UVM_FLAG_QUANTUM. 4916 * => caller shouldn't hold map locked. 4917 */ 4918 int 4919 uvm_mapent_reserve(struct vm_map *map, struct uvm_mapent_reservation *umr, 4920 int nentries, int flags) 4921 { 4922 4923 umr->umr_nentries = 0; 4924 4925 if ((flags & UVM_FLAG_QUANTUM) != 0) 4926 return 0; 4927 4928 if (!VM_MAP_USE_KMAPENT(map)) 4929 return 0; 4930 4931 while (nentries--) { 4932 struct vm_map_entry *ent; 4933 ent = uvm_kmapent_alloc(map, flags); 4934 if (!ent) { 4935 uvm_mapent_unreserve(map, umr); 4936 return ENOMEM; 4937 } 4938 UMR_PUTENTRY(umr, ent); 4939 } 4940 4941 return 0; 4942 } 4943 4944 /* 4945 * uvm_mapent_unreserve: 4946 * 4947 * => caller shouldn't hold map locked. 4948 * => never fail or sleep. 4949 */ 4950 void 4951 uvm_mapent_unreserve(struct vm_map *map, struct uvm_mapent_reservation *umr) 4952 { 4953 4954 while (!UMR_EMPTY(umr)) 4955 uvm_kmapent_free(UMR_GETENTRY(umr)); 4956 } 4957 4958 /* 4959 * uvm_mapent_trymerge: try to merge an entry with its neighbors. 4960 * 4961 * => called with map locked. 4962 * => return non zero if successfully merged. 4963 */ 4964 4965 int 4966 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags) 4967 { 4968 struct uvm_object *uobj; 4969 struct vm_map_entry *next; 4970 struct vm_map_entry *prev; 4971 vsize_t size; 4972 int merged = 0; 4973 bool copying; 4974 int newetype; 4975 4976 KASSERT(vm_map_locked_p(map)); 4977 if (VM_MAP_USE_KMAPENT(map)) { 4978 return 0; 4979 } 4980 if (entry->aref.ar_amap != NULL) { 4981 return 0; 4982 } 4983 if ((entry->flags & UVM_MAP_NOMERGE) != 0) { 4984 return 0; 4985 } 4986 4987 uobj = entry->object.uvm_obj; 4988 size = entry->end - entry->start; 4989 copying = (flags & UVM_MERGE_COPYING) != 0; 4990 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype; 4991 4992 next = entry->next; 4993 if (next != &map->header && 4994 next->start == entry->end && 4995 ((copying && next->aref.ar_amap != NULL && 4996 amap_refs(next->aref.ar_amap) == 1) || 4997 (!copying && next->aref.ar_amap == NULL)) && 4998 UVM_ET_ISCOMPATIBLE(next, newetype, 4999 uobj, entry->flags, entry->protection, 5000 entry->max_protection, entry->inheritance, entry->advice, 5001 entry->wired_count) && 5002 (uobj == NULL || entry->offset + size == next->offset)) { 5003 int error; 5004 5005 if (copying) { 5006 error = amap_extend(next, size, 5007 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS); 5008 } else { 5009 error = 0; 5010 } 5011 if (error == 0) { 5012 if (uobj) { 5013 if (uobj->pgops->pgo_detach) { 5014 uobj->pgops->pgo_detach(uobj); 5015 } 5016 } 5017 5018 entry->end = next->end; 5019 clear_hints(map, next); 5020 uvm_map_entry_unlink(map, next); 5021 if (copying) { 5022 entry->aref = next->aref; 5023 entry->etype &= ~UVM_ET_NEEDSCOPY; 5024 } 5025 uvm_map_check(map, "trymerge forwardmerge"); 5026 uvm_mapent_free_merged(map, next); 5027 merged++; 5028 } 5029 } 5030 5031 prev = entry->prev; 5032 if (prev != &map->header && 5033 prev->end == entry->start && 5034 ((copying && !merged && prev->aref.ar_amap != NULL && 5035 amap_refs(prev->aref.ar_amap) == 1) || 5036 (!copying && prev->aref.ar_amap == NULL)) && 5037 UVM_ET_ISCOMPATIBLE(prev, newetype, 5038 uobj, entry->flags, entry->protection, 5039 entry->max_protection, entry->inheritance, entry->advice, 5040 entry->wired_count) && 5041 (uobj == NULL || 5042 prev->offset + prev->end - prev->start == entry->offset)) { 5043 int error; 5044 5045 if (copying) { 5046 error = amap_extend(prev, size, 5047 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS); 5048 } else { 5049 error = 0; 5050 } 5051 if (error == 0) { 5052 if (uobj) { 5053 if (uobj->pgops->pgo_detach) { 5054 uobj->pgops->pgo_detach(uobj); 5055 } 5056 entry->offset = prev->offset; 5057 } 5058 5059 entry->start = prev->start; 5060 clear_hints(map, prev); 5061 uvm_map_entry_unlink(map, prev); 5062 if (copying) { 5063 entry->aref = prev->aref; 5064 entry->etype &= ~UVM_ET_NEEDSCOPY; 5065 } 5066 uvm_map_check(map, "trymerge backmerge"); 5067 uvm_mapent_free_merged(map, prev); 5068 merged++; 5069 } 5070 } 5071 5072 return merged; 5073 } 5074 5075 /* 5076 * uvm_map_create: create map 5077 */ 5078 5079 struct vm_map * 5080 uvm_map_create(pmap_t pmap, vaddr_t vmin, vaddr_t vmax, int flags) 5081 { 5082 struct vm_map *result; 5083 5084 result = malloc(sizeof(struct vm_map), M_VMMAP, M_WAITOK); 5085 uvm_map_setup(result, vmin, vmax, flags); 5086 result->pmap = pmap; 5087 return(result); 5088 } 5089 5090 /* 5091 * uvm_map_setup: init map 5092 * 5093 * => map must not be in service yet. 5094 */ 5095 5096 void 5097 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags) 5098 { 5099 int ipl; 5100 5101 rb_tree_init(&map->rb_tree, &uvm_map_tree_ops); 5102 map->header.next = map->header.prev = &map->header; 5103 map->nentries = 0; 5104 map->size = 0; 5105 map->ref_count = 1; 5106 vm_map_setmin(map, vmin); 5107 vm_map_setmax(map, vmax); 5108 map->flags = flags; 5109 map->first_free = &map->header; 5110 map->hint = &map->header; 5111 map->timestamp = 0; 5112 map->busy = NULL; 5113 5114 if ((flags & VM_MAP_INTRSAFE) != 0) { 5115 ipl = IPL_VM; 5116 } else { 5117 ipl = IPL_NONE; 5118 } 5119 5120 rw_init(&map->lock); 5121 cv_init(&map->cv, "vm_map"); 5122 mutex_init(&map->misc_lock, MUTEX_DRIVER, ipl); 5123 mutex_init(&map->mutex, MUTEX_DRIVER, ipl); 5124 } 5125 5126 5127 /* 5128 * U N M A P - m a i n e n t r y p o i n t 5129 */ 5130 5131 /* 5132 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop") 5133 * 5134 * => caller must check alignment and size 5135 * => map must be unlocked (we will lock it) 5136 * => flags is UVM_FLAG_QUANTUM or 0. 5137 */ 5138 5139 void 5140 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 5141 { 5142 struct vm_map_entry *dead_entries; 5143 struct uvm_mapent_reservation umr; 5144 UVMHIST_FUNC("uvm_unmap"); UVMHIST_CALLED(maphist); 5145 5146 UVMHIST_LOG(maphist, " (map=0x%x, start=0x%x, end=0x%x)", 5147 map, start, end, 0); 5148 if (map == kernel_map) { 5149 LOCKDEBUG_MEM_CHECK((void *)start, end - start); 5150 } 5151 /* 5152 * work now done by helper functions. wipe the pmap's and then 5153 * detach from the dead entries... 5154 */ 5155 uvm_mapent_reserve(map, &umr, 2, flags); 5156 vm_map_lock(map); 5157 uvm_unmap_remove(map, start, end, &dead_entries, &umr, flags); 5158 vm_map_unlock(map); 5159 uvm_mapent_unreserve(map, &umr); 5160 5161 if (dead_entries != NULL) 5162 uvm_unmap_detach(dead_entries, 0); 5163 5164 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 5165 } 5166 5167 5168 /* 5169 * uvm_map_reference: add reference to a map 5170 * 5171 * => map need not be locked (we use misc_lock). 5172 */ 5173 5174 void 5175 uvm_map_reference(struct vm_map *map) 5176 { 5177 mutex_enter(&map->misc_lock); 5178 map->ref_count++; 5179 mutex_exit(&map->misc_lock); 5180 } 5181 5182 struct vm_map_kernel * 5183 vm_map_to_kernel(struct vm_map *map) 5184 { 5185 5186 KASSERT(VM_MAP_IS_KERNEL(map)); 5187 5188 return (struct vm_map_kernel *)map; 5189 } 5190 5191 bool 5192 vm_map_starved_p(struct vm_map *map) 5193 { 5194 5195 if ((map->flags & VM_MAP_WANTVA) != 0) { 5196 return true; 5197 } 5198 /* XXX */ 5199 if ((vm_map_max(map) - vm_map_min(map)) / 16 * 15 < map->size) { 5200 return true; 5201 } 5202 return false; 5203 } 5204 5205 void 5206 uvm_map_lock_entry(struct vm_map_entry *entry) 5207 { 5208 5209 if (entry->aref.ar_amap != NULL) { 5210 amap_lock(entry->aref.ar_amap); 5211 } 5212 if (UVM_ET_ISOBJ(entry)) { 5213 mutex_enter(entry->object.uvm_obj->vmobjlock); 5214 } 5215 } 5216 5217 void 5218 uvm_map_unlock_entry(struct vm_map_entry *entry) 5219 { 5220 5221 if (UVM_ET_ISOBJ(entry)) { 5222 mutex_exit(entry->object.uvm_obj->vmobjlock); 5223 } 5224 if (entry->aref.ar_amap != NULL) { 5225 amap_unlock(entry->aref.ar_amap); 5226 } 5227 } 5228 5229 #if defined(DDB) || defined(DEBUGPRINT) 5230 5231 /* 5232 * uvm_map_printit: actually prints the map 5233 */ 5234 5235 void 5236 uvm_map_printit(struct vm_map *map, bool full, 5237 void (*pr)(const char *, ...)) 5238 { 5239 struct vm_map_entry *entry; 5240 5241 (*pr)("MAP %p: [0x%lx->0x%lx]\n", map, vm_map_min(map), 5242 vm_map_max(map)); 5243 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=0x%x\n", 5244 map->nentries, map->size, map->ref_count, map->timestamp, 5245 map->flags); 5246 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap, 5247 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap)); 5248 if (!full) 5249 return; 5250 for (entry = map->header.next; entry != &map->header; 5251 entry = entry->next) { 5252 (*pr)(" - %p: 0x%lx->0x%lx: obj=%p/0x%llx, amap=%p/%d\n", 5253 entry, entry->start, entry->end, entry->object.uvm_obj, 5254 (long long)entry->offset, entry->aref.ar_amap, 5255 entry->aref.ar_pageoff); 5256 (*pr)( 5257 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, " 5258 "wc=%d, adv=%d\n", 5259 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F', 5260 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F', 5261 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F', 5262 entry->protection, entry->max_protection, 5263 entry->inheritance, entry->wired_count, entry->advice); 5264 } 5265 } 5266 5267 void 5268 uvm_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 5269 { 5270 struct vm_map *map; 5271 5272 for (map = kernel_map;;) { 5273 struct vm_map_entry *entry; 5274 5275 if (!uvm_map_lookup_entry_bytree(map, (vaddr_t)addr, &entry)) { 5276 break; 5277 } 5278 (*pr)("%p is %p+%zu from VMMAP %p\n", 5279 (void *)addr, (void *)entry->start, 5280 (size_t)(addr - (uintptr_t)entry->start), map); 5281 if (!UVM_ET_ISSUBMAP(entry)) { 5282 break; 5283 } 5284 map = entry->object.sub_map; 5285 } 5286 } 5287 5288 #endif /* DDB || DEBUGPRINT */ 5289 5290 #ifndef __USER_VA0_IS_SAFE 5291 static int 5292 sysctl_user_va0_disable(SYSCTLFN_ARGS) 5293 { 5294 struct sysctlnode node; 5295 int t, error; 5296 5297 node = *rnode; 5298 node.sysctl_data = &t; 5299 t = user_va0_disable; 5300 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 5301 if (error || newp == NULL) 5302 return (error); 5303 5304 /* lower only at securelevel < 1 */ 5305 if (!t && user_va0_disable && 5306 kauth_authorize_system(l->l_cred, 5307 KAUTH_SYSTEM_CHSYSFLAGS /* XXX */, 0, 5308 NULL, NULL, NULL)) 5309 return EPERM; 5310 5311 user_va0_disable = !!t; 5312 return 0; 5313 } 5314 5315 SYSCTL_SETUP(sysctl_uvmmap_setup, "sysctl uvmmap setup") 5316 { 5317 5318 sysctl_createv(clog, 0, NULL, NULL, 5319 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 5320 CTLTYPE_INT, "user_va0_disable", 5321 SYSCTL_DESCR("Disable VA 0"), 5322 sysctl_user_va0_disable, 0, &user_va0_disable, 0, 5323 CTL_VM, CTL_CREATE, CTL_EOL); 5324 } 5325 #endif 5326