1 /* $NetBSD: uvm_map.c,v 1.292 2010/06/22 18:34:50 rmind 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. All advertising materials mentioning features or use of this software 21 * must display the following acknowledgement: 22 * This product includes software developed by Charles D. Cranor, 23 * Washington University, the University of California, Berkeley and 24 * its contributors. 25 * 4. Neither the name of the University nor the names of its contributors 26 * may be used to endorse or promote products derived from this software 27 * without specific prior written permission. 28 * 29 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 30 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 31 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 32 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 33 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 34 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 35 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 36 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 37 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 38 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 39 * SUCH DAMAGE. 40 * 41 * @(#)vm_map.c 8.3 (Berkeley) 1/12/94 42 * from: Id: uvm_map.c,v 1.1.2.27 1998/02/07 01:16:54 chs Exp 43 * 44 * 45 * Copyright (c) 1987, 1990 Carnegie-Mellon University. 46 * All rights reserved. 47 * 48 * Permission to use, copy, modify and distribute this software and 49 * its documentation is hereby granted, provided that both the copyright 50 * notice and this permission notice appear in all copies of the 51 * software, derivative works or modified versions, and any portions 52 * thereof, and that both notices appear in supporting documentation. 53 * 54 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS" 55 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND 56 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE. 57 * 58 * Carnegie Mellon requests users of this software to return to 59 * 60 * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU 61 * School of Computer Science 62 * Carnegie Mellon University 63 * Pittsburgh PA 15213-3890 64 * 65 * any improvements or extensions that they make and grant Carnegie the 66 * rights to redistribute these changes. 67 */ 68 69 /* 70 * uvm_map.c: uvm map operations 71 */ 72 73 #include <sys/cdefs.h> 74 __KERNEL_RCSID(0, "$NetBSD: uvm_map.c,v 1.292 2010/06/22 18:34:50 rmind Exp $"); 75 76 #include "opt_ddb.h" 77 #include "opt_uvmhist.h" 78 #include "opt_uvm.h" 79 #include "opt_sysv.h" 80 81 #include <sys/param.h> 82 #include <sys/systm.h> 83 #include <sys/mman.h> 84 #include <sys/proc.h> 85 #include <sys/malloc.h> 86 #include <sys/pool.h> 87 #include <sys/kernel.h> 88 #include <sys/mount.h> 89 #include <sys/vnode.h> 90 #include <sys/lockdebug.h> 91 #include <sys/atomic.h> 92 #ifndef __USER_VA0_IS_SAFE 93 #include <sys/sysctl.h> 94 #include <sys/kauth.h> 95 #include "opt_user_va0_disable_default.h" 96 #endif 97 98 #ifdef SYSVSHM 99 #include <sys/shm.h> 100 #endif 101 102 #include <uvm/uvm.h> 103 #include <uvm/uvm_readahead.h> 104 105 #if defined(DDB) || defined(DEBUGPRINT) 106 #include <uvm/uvm_ddb.h> 107 #endif 108 109 #if !defined(UVMMAP_COUNTERS) 110 111 #define UVMMAP_EVCNT_DEFINE(name) /* nothing */ 112 #define UVMMAP_EVCNT_INCR(ev) /* nothing */ 113 #define UVMMAP_EVCNT_DECR(ev) /* nothing */ 114 115 #else /* defined(UVMMAP_NOCOUNTERS) */ 116 117 #include <sys/evcnt.h> 118 #define UVMMAP_EVCNT_DEFINE(name) \ 119 struct evcnt uvmmap_evcnt_##name = EVCNT_INITIALIZER(EVCNT_TYPE_MISC, NULL, \ 120 "uvmmap", #name); \ 121 EVCNT_ATTACH_STATIC(uvmmap_evcnt_##name); 122 #define UVMMAP_EVCNT_INCR(ev) uvmmap_evcnt_##ev.ev_count++ 123 #define UVMMAP_EVCNT_DECR(ev) uvmmap_evcnt_##ev.ev_count-- 124 125 #endif /* defined(UVMMAP_NOCOUNTERS) */ 126 127 UVMMAP_EVCNT_DEFINE(ubackmerge) 128 UVMMAP_EVCNT_DEFINE(uforwmerge) 129 UVMMAP_EVCNT_DEFINE(ubimerge) 130 UVMMAP_EVCNT_DEFINE(unomerge) 131 UVMMAP_EVCNT_DEFINE(kbackmerge) 132 UVMMAP_EVCNT_DEFINE(kforwmerge) 133 UVMMAP_EVCNT_DEFINE(kbimerge) 134 UVMMAP_EVCNT_DEFINE(knomerge) 135 UVMMAP_EVCNT_DEFINE(map_call) 136 UVMMAP_EVCNT_DEFINE(mlk_call) 137 UVMMAP_EVCNT_DEFINE(mlk_hint) 138 UVMMAP_EVCNT_DEFINE(mlk_list) 139 UVMMAP_EVCNT_DEFINE(mlk_tree) 140 UVMMAP_EVCNT_DEFINE(mlk_treeloop) 141 UVMMAP_EVCNT_DEFINE(mlk_listloop) 142 143 UVMMAP_EVCNT_DEFINE(uke_alloc) 144 UVMMAP_EVCNT_DEFINE(uke_free) 145 UVMMAP_EVCNT_DEFINE(ukh_alloc) 146 UVMMAP_EVCNT_DEFINE(ukh_free) 147 148 const char vmmapbsy[] = "vmmapbsy"; 149 150 /* 151 * cache for vmspace structures. 152 */ 153 154 static struct pool_cache uvm_vmspace_cache; 155 156 /* 157 * cache for dynamically-allocated map entries. 158 */ 159 160 static struct pool_cache uvm_map_entry_cache; 161 162 MALLOC_DEFINE(M_VMMAP, "VM map", "VM map structures"); 163 MALLOC_DEFINE(M_VMPMAP, "VM pmap", "VM pmap"); 164 165 #ifdef PMAP_GROWKERNEL 166 /* 167 * This global represents the end of the kernel virtual address 168 * space. If we want to exceed this, we must grow the kernel 169 * virtual address space dynamically. 170 * 171 * Note, this variable is locked by kernel_map's lock. 172 */ 173 vaddr_t uvm_maxkaddr; 174 #endif 175 176 #ifndef __USER_VA0_IS_SAFE 177 #ifndef __USER_VA0_DISABLE_DEFAULT 178 #define __USER_VA0_DISABLE_DEFAULT 1 179 #endif 180 #ifdef USER_VA0_DISABLE_DEFAULT /* kernel config option overrides */ 181 #undef __USER_VA0_DISABLE_DEFAULT 182 #define __USER_VA0_DISABLE_DEFAULT USER_VA0_DISABLE_DEFAULT 183 #endif 184 static int user_va0_disable = __USER_VA0_DISABLE_DEFAULT; 185 #endif 186 187 /* 188 * macros 189 */ 190 191 /* 192 * VM_MAP_USE_KMAPENT: determine if uvm_kmapent_alloc/free is used 193 * for the vm_map. 194 */ 195 extern struct vm_map *pager_map; /* XXX */ 196 #define VM_MAP_USE_KMAPENT_FLAGS(flags) \ 197 (((flags) & VM_MAP_INTRSAFE) != 0) 198 #define VM_MAP_USE_KMAPENT(map) \ 199 (VM_MAP_USE_KMAPENT_FLAGS((map)->flags) || (map) == kernel_map) 200 201 /* 202 * UVM_ET_ISCOMPATIBLE: check some requirements for map entry merging 203 */ 204 205 #define UVM_ET_ISCOMPATIBLE(ent, type, uobj, meflags, \ 206 prot, maxprot, inh, adv, wire) \ 207 ((ent)->etype == (type) && \ 208 (((ent)->flags ^ (meflags)) & (UVM_MAP_NOMERGE | UVM_MAP_QUANTUM)) \ 209 == 0 && \ 210 (ent)->object.uvm_obj == (uobj) && \ 211 (ent)->protection == (prot) && \ 212 (ent)->max_protection == (maxprot) && \ 213 (ent)->inheritance == (inh) && \ 214 (ent)->advice == (adv) && \ 215 (ent)->wired_count == (wire)) 216 217 /* 218 * uvm_map_entry_link: insert entry into a map 219 * 220 * => map must be locked 221 */ 222 #define uvm_map_entry_link(map, after_where, entry) do { \ 223 uvm_mapent_check(entry); \ 224 (map)->nentries++; \ 225 (entry)->prev = (after_where); \ 226 (entry)->next = (after_where)->next; \ 227 (entry)->prev->next = (entry); \ 228 (entry)->next->prev = (entry); \ 229 uvm_rb_insert((map), (entry)); \ 230 } while (/*CONSTCOND*/ 0) 231 232 /* 233 * uvm_map_entry_unlink: remove entry from a map 234 * 235 * => map must be locked 236 */ 237 #define uvm_map_entry_unlink(map, entry) do { \ 238 KASSERT((entry) != (map)->first_free); \ 239 KASSERT((entry) != (map)->hint); \ 240 uvm_mapent_check(entry); \ 241 (map)->nentries--; \ 242 (entry)->next->prev = (entry)->prev; \ 243 (entry)->prev->next = (entry)->next; \ 244 uvm_rb_remove((map), (entry)); \ 245 } while (/*CONSTCOND*/ 0) 246 247 /* 248 * SAVE_HINT: saves the specified entry as the hint for future lookups. 249 * 250 * => map need not be locked. 251 */ 252 #define SAVE_HINT(map, check, value) do { \ 253 if ((map)->hint == (check)) \ 254 (map)->hint = (value); \ 255 } while (/*CONSTCOND*/ 0) 256 257 /* 258 * clear_hints: ensure that hints don't point to the entry. 259 * 260 * => map must be write-locked. 261 */ 262 static void 263 clear_hints(struct vm_map *map, struct vm_map_entry *ent) 264 { 265 266 SAVE_HINT(map, ent, ent->prev); 267 if (map->first_free == ent) { 268 map->first_free = ent->prev; 269 } 270 } 271 272 /* 273 * VM_MAP_RANGE_CHECK: check and correct range 274 * 275 * => map must at least be read locked 276 */ 277 278 #define VM_MAP_RANGE_CHECK(map, start, end) do { \ 279 if (start < vm_map_min(map)) \ 280 start = vm_map_min(map); \ 281 if (end > vm_map_max(map)) \ 282 end = vm_map_max(map); \ 283 if (start > end) \ 284 start = end; \ 285 } while (/*CONSTCOND*/ 0) 286 287 /* 288 * local prototypes 289 */ 290 291 static struct vm_map_entry * 292 uvm_mapent_alloc(struct vm_map *, int); 293 static struct vm_map_entry * 294 uvm_mapent_alloc_split(struct vm_map *, 295 const struct vm_map_entry *, int, 296 struct uvm_mapent_reservation *); 297 static void uvm_mapent_copy(struct vm_map_entry *, struct vm_map_entry *); 298 static void uvm_mapent_free(struct vm_map_entry *); 299 #if defined(DEBUG) 300 static void _uvm_mapent_check(const struct vm_map_entry *, const char *, 301 int); 302 #define uvm_mapent_check(map) _uvm_mapent_check(map, __FILE__, __LINE__) 303 #else /* defined(DEBUG) */ 304 #define uvm_mapent_check(e) /* nothing */ 305 #endif /* defined(DEBUG) */ 306 static struct vm_map_entry * 307 uvm_kmapent_alloc(struct vm_map *, int); 308 static void uvm_kmapent_free(struct vm_map_entry *); 309 static vsize_t uvm_kmapent_overhead(vsize_t); 310 311 static void uvm_map_entry_unwire(struct vm_map *, struct vm_map_entry *); 312 static void uvm_map_reference_amap(struct vm_map_entry *, int); 313 static int uvm_map_space_avail(vaddr_t *, vsize_t, voff_t, vsize_t, int, 314 struct vm_map_entry *); 315 static void uvm_map_unreference_amap(struct vm_map_entry *, int); 316 317 int _uvm_map_sanity(struct vm_map *); 318 int _uvm_tree_sanity(struct vm_map *); 319 static vsize_t uvm_rb_maxgap(const struct vm_map_entry *); 320 321 CTASSERT(offsetof(struct vm_map_entry, rb_node) == 0); 322 #define ROOT_ENTRY(map) ((struct vm_map_entry *)(map)->rb_tree.rbt_root) 323 #define LEFT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_left) 324 #define RIGHT_ENTRY(entry) ((struct vm_map_entry *)(entry)->rb_node.rb_right) 325 #define PARENT_ENTRY(map, entry) \ 326 (ROOT_ENTRY(map) == (entry) \ 327 ? NULL \ 328 : (struct vm_map_entry *)RB_FATHER(&(entry)->rb_node)) 329 330 static int 331 uvm_map_compare_nodes(const struct rb_node *nparent, 332 const struct rb_node *nkey) 333 { 334 const struct vm_map_entry *eparent = (const void *) nparent; 335 const struct vm_map_entry *ekey = (const void *) nkey; 336 337 KASSERT(eparent->start < ekey->start || eparent->start >= ekey->end); 338 KASSERT(ekey->start < eparent->start || ekey->start >= eparent->end); 339 340 if (ekey->start < eparent->start) 341 return -1; 342 if (ekey->start >= eparent->end) 343 return 1; 344 return 0; 345 } 346 347 static int 348 uvm_map_compare_key(const struct rb_node *nparent, const void *vkey) 349 { 350 const struct vm_map_entry *eparent = (const void *) nparent; 351 const vaddr_t va = *(const vaddr_t *) vkey; 352 353 if (va < eparent->start) 354 return -1; 355 if (va >= eparent->end) 356 return 1; 357 return 0; 358 } 359 360 static const struct rb_tree_ops uvm_map_tree_ops = { 361 .rbto_compare_nodes = uvm_map_compare_nodes, 362 .rbto_compare_key = uvm_map_compare_key, 363 }; 364 365 static inline vsize_t 366 uvm_rb_gap(const struct vm_map_entry *entry) 367 { 368 KASSERT(entry->next != NULL); 369 return entry->next->start - entry->end; 370 } 371 372 static vsize_t 373 uvm_rb_maxgap(const struct vm_map_entry *entry) 374 { 375 struct vm_map_entry *child; 376 vsize_t maxgap = entry->gap; 377 378 /* 379 * We need maxgap to be the largest gap of us or any of our 380 * descendents. Since each of our children's maxgap is the 381 * cached value of their largest gap of themselves or their 382 * descendents, we can just use that value and avoid recursing 383 * down the tree to calculate it. 384 */ 385 if ((child = LEFT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 386 maxgap = child->maxgap; 387 388 if ((child = RIGHT_ENTRY(entry)) != NULL && maxgap < child->maxgap) 389 maxgap = child->maxgap; 390 391 return maxgap; 392 } 393 394 static void 395 uvm_rb_fixup(struct vm_map *map, struct vm_map_entry *entry) 396 { 397 struct vm_map_entry *parent; 398 399 KASSERT(entry->gap == uvm_rb_gap(entry)); 400 entry->maxgap = uvm_rb_maxgap(entry); 401 402 while ((parent = PARENT_ENTRY(map, entry)) != NULL) { 403 struct vm_map_entry *brother; 404 vsize_t maxgap = parent->gap; 405 406 KDASSERT(parent->gap == uvm_rb_gap(parent)); 407 if (maxgap < entry->maxgap) 408 maxgap = entry->maxgap; 409 /* 410 * Since we work our towards the root, we know entry's maxgap 411 * value is ok but its brothers may now be out-of-date due 412 * rebalancing. So refresh it. 413 */ 414 brother = (struct vm_map_entry *)parent->rb_node.rb_nodes[RB_POSITION(&entry->rb_node) ^ RB_DIR_OTHER]; 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 entry->gap = entry->maxgap = uvm_rb_gap(entry); 431 if (entry->prev != &map->header) 432 entry->prev->gap = uvm_rb_gap(entry->prev); 433 434 if (!rb_tree_insert_node(&map->rb_tree, &entry->rb_node)) 435 panic("uvm_rb_insert: map %p: duplicate entry?", map); 436 437 /* 438 * If the previous entry is not our immediate left child, then it's an 439 * ancestor and will be fixed up on the way to the root. We don't 440 * have to check entry->prev against &map->header since &map->header 441 * will never be in the tree. 442 */ 443 uvm_rb_fixup(map, 444 LEFT_ENTRY(entry) == entry->prev ? entry->prev : entry); 445 } 446 447 static void 448 uvm_rb_remove(struct vm_map *map, struct vm_map_entry *entry) 449 { 450 struct vm_map_entry *prev_parent = NULL, *next_parent = NULL; 451 452 /* 453 * If we are removing an interior node, then an adjacent node will 454 * be used to replace its position in the tree. Therefore we will 455 * need to fixup the tree starting at the parent of the replacement 456 * node. So record their parents for later use. 457 */ 458 if (entry->prev != &map->header) 459 prev_parent = PARENT_ENTRY(map, entry->prev); 460 if (entry->next != &map->header) 461 next_parent = PARENT_ENTRY(map, entry->next); 462 463 rb_tree_remove_node(&map->rb_tree, &entry->rb_node); 464 465 /* 466 * If the previous node has a new parent, fixup the tree starting 467 * at the previous node's old parent. 468 */ 469 if (entry->prev != &map->header) { 470 /* 471 * Update the previous entry's gap due to our absence. 472 */ 473 entry->prev->gap = uvm_rb_gap(entry->prev); 474 uvm_rb_fixup(map, entry->prev); 475 if (prev_parent != NULL 476 && prev_parent != entry 477 && prev_parent != PARENT_ENTRY(map, entry->prev)) 478 uvm_rb_fixup(map, prev_parent); 479 } 480 481 /* 482 * If the next node has a new parent, fixup the tree starting 483 * at the next node's old parent. 484 */ 485 if (entry->next != &map->header) { 486 uvm_rb_fixup(map, entry->next); 487 if (next_parent != NULL 488 && next_parent != entry 489 && next_parent != PARENT_ENTRY(map, entry->next)) 490 uvm_rb_fixup(map, next_parent); 491 } 492 } 493 494 #if defined(DEBUG) 495 int uvm_debug_check_map = 0; 496 int uvm_debug_check_rbtree = 0; 497 #define uvm_map_check(map, name) \ 498 _uvm_map_check((map), (name), __FILE__, __LINE__) 499 static void 500 _uvm_map_check(struct vm_map *map, const char *name, 501 const char *file, int line) 502 { 503 504 if ((uvm_debug_check_map && _uvm_map_sanity(map)) || 505 (uvm_debug_check_rbtree && _uvm_tree_sanity(map))) { 506 panic("uvm_map_check failed: \"%s\" map=%p (%s:%d)", 507 name, map, file, line); 508 } 509 } 510 #else /* defined(DEBUG) */ 511 #define uvm_map_check(map, name) /* nothing */ 512 #endif /* defined(DEBUG) */ 513 514 #if defined(DEBUG) || defined(DDB) 515 int 516 _uvm_map_sanity(struct vm_map *map) 517 { 518 bool first_free_found = false; 519 bool hint_found = false; 520 const struct vm_map_entry *e; 521 struct vm_map_entry *hint = map->hint; 522 523 e = &map->header; 524 for (;;) { 525 if (map->first_free == e) { 526 first_free_found = true; 527 } else if (!first_free_found && e->next->start > e->end) { 528 printf("first_free %p should be %p\n", 529 map->first_free, e); 530 return -1; 531 } 532 if (hint == e) { 533 hint_found = true; 534 } 535 536 e = e->next; 537 if (e == &map->header) { 538 break; 539 } 540 } 541 if (!first_free_found) { 542 printf("stale first_free\n"); 543 return -1; 544 } 545 if (!hint_found) { 546 printf("stale hint\n"); 547 return -1; 548 } 549 return 0; 550 } 551 552 int 553 _uvm_tree_sanity(struct vm_map *map) 554 { 555 struct vm_map_entry *tmp, *trtmp; 556 int n = 0, i = 1; 557 558 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 559 if (tmp->gap != uvm_rb_gap(tmp)) { 560 printf("%d/%d gap %lx != %lx %s\n", 561 n + 1, map->nentries, 562 (ulong)tmp->gap, (ulong)uvm_rb_gap(tmp), 563 tmp->next == &map->header ? "(last)" : ""); 564 goto error; 565 } 566 /* 567 * If any entries are out of order, tmp->gap will be unsigned 568 * and will likely exceed the size of the map. 569 */ 570 if (tmp->gap >= vm_map_max(map) - vm_map_min(map)) { 571 printf("too large gap %zu\n", (size_t)tmp->gap); 572 goto error; 573 } 574 n++; 575 } 576 577 if (n != map->nentries) { 578 printf("nentries: %d vs %d\n", n, map->nentries); 579 goto error; 580 } 581 582 trtmp = NULL; 583 for (tmp = map->header.next; tmp != &map->header; tmp = tmp->next) { 584 if (tmp->maxgap != uvm_rb_maxgap(tmp)) { 585 printf("maxgap %lx != %lx\n", 586 (ulong)tmp->maxgap, 587 (ulong)uvm_rb_maxgap(tmp)); 588 goto error; 589 } 590 if (trtmp != NULL && trtmp->start >= tmp->start) { 591 printf("corrupt: 0x%"PRIxVADDR"x >= 0x%"PRIxVADDR"x\n", 592 trtmp->start, tmp->start); 593 goto error; 594 } 595 596 trtmp = tmp; 597 } 598 599 for (tmp = map->header.next; tmp != &map->header; 600 tmp = tmp->next, i++) { 601 trtmp = (void *) rb_tree_iterate(&map->rb_tree, &tmp->rb_node, 602 RB_DIR_LEFT); 603 if (trtmp == NULL) 604 trtmp = &map->header; 605 if (tmp->prev != trtmp) { 606 printf("lookup: %d: %p->prev=%p: %p\n", 607 i, tmp, tmp->prev, trtmp); 608 goto error; 609 } 610 trtmp = (void *) rb_tree_iterate(&map->rb_tree, &tmp->rb_node, 611 RB_DIR_RIGHT); 612 if (trtmp == NULL) 613 trtmp = &map->header; 614 if (tmp->next != trtmp) { 615 printf("lookup: %d: %p->next=%p: %p\n", 616 i, tmp, tmp->next, trtmp); 617 goto error; 618 } 619 trtmp = (void *)rb_tree_find_node(&map->rb_tree, &tmp->start); 620 if (trtmp != tmp) { 621 printf("lookup: %d: %p - %p: %p\n", i, tmp, trtmp, 622 PARENT_ENTRY(map, tmp)); 623 goto error; 624 } 625 } 626 627 return (0); 628 error: 629 return (-1); 630 } 631 #endif /* defined(DEBUG) || defined(DDB) */ 632 633 #ifdef DIAGNOSTIC 634 static struct vm_map *uvm_kmapent_map(struct vm_map_entry *); 635 #endif 636 637 /* 638 * vm_map_lock: acquire an exclusive (write) lock on a map. 639 * 640 * => Note that "intrsafe" maps use only exclusive, spin locks. 641 * 642 * => The locking protocol provides for guaranteed upgrade from shared -> 643 * exclusive by whichever thread currently has the map marked busy. 644 * See "LOCKING PROTOCOL NOTES" in uvm_map.h. This is horrible; among 645 * other problems, it defeats any fairness guarantees provided by RW 646 * locks. 647 */ 648 649 void 650 vm_map_lock(struct vm_map *map) 651 { 652 653 if ((map->flags & VM_MAP_INTRSAFE) != 0) { 654 mutex_spin_enter(&map->mutex); 655 return; 656 } 657 658 for (;;) { 659 rw_enter(&map->lock, RW_WRITER); 660 if (map->busy == NULL) 661 break; 662 if (map->busy == curlwp) 663 break; 664 mutex_enter(&map->misc_lock); 665 rw_exit(&map->lock); 666 if (map->busy != NULL) 667 cv_wait(&map->cv, &map->misc_lock); 668 mutex_exit(&map->misc_lock); 669 } 670 671 map->timestamp++; 672 } 673 674 /* 675 * vm_map_lock_try: try to lock a map, failing if it is already locked. 676 */ 677 678 bool 679 vm_map_lock_try(struct vm_map *map) 680 { 681 682 if ((map->flags & VM_MAP_INTRSAFE) != 0) 683 return mutex_tryenter(&map->mutex); 684 if (!rw_tryenter(&map->lock, RW_WRITER)) 685 return false; 686 if (map->busy != NULL) { 687 rw_exit(&map->lock); 688 return false; 689 } 690 691 map->timestamp++; 692 return true; 693 } 694 695 /* 696 * vm_map_unlock: release an exclusive lock on a map. 697 */ 698 699 void 700 vm_map_unlock(struct vm_map *map) 701 { 702 703 if ((map->flags & VM_MAP_INTRSAFE) != 0) 704 mutex_spin_exit(&map->mutex); 705 else { 706 KASSERT(rw_write_held(&map->lock)); 707 KASSERT(map->busy == NULL || map->busy == curlwp); 708 rw_exit(&map->lock); 709 } 710 } 711 712 /* 713 * vm_map_unbusy: mark the map as unbusy, and wake any waiters that 714 * want an exclusive lock. 715 */ 716 717 void 718 vm_map_unbusy(struct vm_map *map) 719 { 720 721 KASSERT(map->busy == curlwp); 722 723 /* 724 * Safe to clear 'busy' and 'waiters' with only a read lock held: 725 * 726 * o they can only be set with a write lock held 727 * o writers are blocked out with a read or write hold 728 * o at any time, only one thread owns the set of values 729 */ 730 mutex_enter(&map->misc_lock); 731 map->busy = NULL; 732 cv_broadcast(&map->cv); 733 mutex_exit(&map->misc_lock); 734 } 735 736 /* 737 * vm_map_lock_read: acquire a shared (read) lock on a map. 738 */ 739 740 void 741 vm_map_lock_read(struct vm_map *map) 742 { 743 744 KASSERT((map->flags & VM_MAP_INTRSAFE) == 0); 745 746 rw_enter(&map->lock, RW_READER); 747 } 748 749 /* 750 * vm_map_unlock_read: release a shared lock on a map. 751 */ 752 753 void 754 vm_map_unlock_read(struct vm_map *map) 755 { 756 757 KASSERT((map->flags & VM_MAP_INTRSAFE) == 0); 758 759 rw_exit(&map->lock); 760 } 761 762 /* 763 * vm_map_busy: mark a map as busy. 764 * 765 * => the caller must hold the map write locked 766 */ 767 768 void 769 vm_map_busy(struct vm_map *map) 770 { 771 772 KASSERT(rw_write_held(&map->lock)); 773 KASSERT(map->busy == NULL); 774 775 map->busy = curlwp; 776 } 777 778 /* 779 * vm_map_locked_p: return true if the map is write locked. 780 * 781 * => only for debug purposes like KASSERTs. 782 * => should not be used to verify that a map is not locked. 783 */ 784 785 bool 786 vm_map_locked_p(struct vm_map *map) 787 { 788 789 if ((map->flags & VM_MAP_INTRSAFE) != 0) { 790 return mutex_owned(&map->mutex); 791 } else { 792 return rw_write_held(&map->lock); 793 } 794 } 795 796 /* 797 * uvm_mapent_alloc: allocate a map entry 798 */ 799 800 static struct vm_map_entry * 801 uvm_mapent_alloc(struct vm_map *map, int flags) 802 { 803 struct vm_map_entry *me; 804 int pflags = (flags & UVM_FLAG_NOWAIT) ? PR_NOWAIT : PR_WAITOK; 805 UVMHIST_FUNC("uvm_mapent_alloc"); UVMHIST_CALLED(maphist); 806 807 if (VM_MAP_USE_KMAPENT(map)) { 808 me = uvm_kmapent_alloc(map, flags); 809 } else { 810 me = pool_cache_get(&uvm_map_entry_cache, pflags); 811 if (__predict_false(me == NULL)) 812 return NULL; 813 me->flags = 0; 814 } 815 816 UVMHIST_LOG(maphist, "<- new entry=0x%x [kentry=%d]", me, 817 ((map->flags & VM_MAP_INTRSAFE) != 0 || map == kernel_map), 0, 0); 818 return (me); 819 } 820 821 /* 822 * uvm_mapent_alloc_split: allocate a map entry for clipping. 823 * 824 * => map must be locked by caller if UVM_MAP_QUANTUM is set. 825 */ 826 827 static struct vm_map_entry * 828 uvm_mapent_alloc_split(struct vm_map *map, 829 const struct vm_map_entry *old_entry, int flags, 830 struct uvm_mapent_reservation *umr) 831 { 832 struct vm_map_entry *me; 833 834 KASSERT(!VM_MAP_USE_KMAPENT(map) || 835 (old_entry->flags & UVM_MAP_QUANTUM) || !UMR_EMPTY(umr)); 836 837 if (old_entry->flags & UVM_MAP_QUANTUM) { 838 struct vm_map_kernel *vmk = vm_map_to_kernel(map); 839 840 KASSERT(vm_map_locked_p(map)); 841 me = vmk->vmk_merged_entries; 842 KASSERT(me); 843 vmk->vmk_merged_entries = me->next; 844 KASSERT(me->flags & UVM_MAP_QUANTUM); 845 } else { 846 me = uvm_mapent_alloc(map, flags); 847 } 848 849 return me; 850 } 851 852 /* 853 * uvm_mapent_free: free map entry 854 */ 855 856 static void 857 uvm_mapent_free(struct vm_map_entry *me) 858 { 859 UVMHIST_FUNC("uvm_mapent_free"); UVMHIST_CALLED(maphist); 860 861 UVMHIST_LOG(maphist,"<- freeing map entry=0x%x [flags=%d]", 862 me, me->flags, 0, 0); 863 if (me->flags & UVM_MAP_KERNEL) { 864 uvm_kmapent_free(me); 865 } else { 866 pool_cache_put(&uvm_map_entry_cache, me); 867 } 868 } 869 870 /* 871 * uvm_mapent_free_merged: free merged map entry 872 * 873 * => keep the entry if needed. 874 * => caller shouldn't hold map locked if VM_MAP_USE_KMAPENT(map) is true. 875 * => map should be locked if UVM_MAP_QUANTUM is set. 876 */ 877 878 static void 879 uvm_mapent_free_merged(struct vm_map *map, struct vm_map_entry *me) 880 { 881 882 KASSERT(!(me->flags & UVM_MAP_KERNEL) || uvm_kmapent_map(me) == map); 883 884 if (me->flags & UVM_MAP_QUANTUM) { 885 /* 886 * keep this entry for later splitting. 887 */ 888 struct vm_map_kernel *vmk; 889 890 KASSERT(vm_map_locked_p(map)); 891 KASSERT(VM_MAP_IS_KERNEL(map)); 892 KASSERT(!VM_MAP_USE_KMAPENT(map) || 893 (me->flags & UVM_MAP_KERNEL)); 894 895 vmk = vm_map_to_kernel(map); 896 me->next = vmk->vmk_merged_entries; 897 vmk->vmk_merged_entries = me; 898 } else { 899 uvm_mapent_free(me); 900 } 901 } 902 903 /* 904 * uvm_mapent_copy: copy a map entry, preserving flags 905 */ 906 907 static inline void 908 uvm_mapent_copy(struct vm_map_entry *src, struct vm_map_entry *dst) 909 { 910 911 memcpy(dst, src, ((char *)&src->uvm_map_entry_stop_copy) - 912 ((char *)src)); 913 } 914 915 /* 916 * uvm_mapent_overhead: calculate maximum kva overhead necessary for 917 * map entries. 918 * 919 * => size and flags are the same as uvm_km_suballoc's ones. 920 */ 921 922 vsize_t 923 uvm_mapent_overhead(vsize_t size, int flags) 924 { 925 926 if (VM_MAP_USE_KMAPENT_FLAGS(flags)) { 927 return uvm_kmapent_overhead(size); 928 } 929 return 0; 930 } 931 932 #if defined(DEBUG) 933 static void 934 _uvm_mapent_check(const struct vm_map_entry *entry, const char *file, int line) 935 { 936 937 if (entry->start >= entry->end) { 938 goto bad; 939 } 940 if (UVM_ET_ISOBJ(entry)) { 941 if (entry->object.uvm_obj == NULL) { 942 goto bad; 943 } 944 } else if (UVM_ET_ISSUBMAP(entry)) { 945 if (entry->object.sub_map == NULL) { 946 goto bad; 947 } 948 } else { 949 if (entry->object.uvm_obj != NULL || 950 entry->object.sub_map != NULL) { 951 goto bad; 952 } 953 } 954 if (!UVM_ET_ISOBJ(entry)) { 955 if (entry->offset != 0) { 956 goto bad; 957 } 958 } 959 960 return; 961 962 bad: 963 panic("%s: bad entry %p (%s:%d)", __func__, entry, file, line); 964 } 965 #endif /* defined(DEBUG) */ 966 967 /* 968 * uvm_map_entry_unwire: unwire a map entry 969 * 970 * => map should be locked by caller 971 */ 972 973 static inline void 974 uvm_map_entry_unwire(struct vm_map *map, struct vm_map_entry *entry) 975 { 976 977 entry->wired_count = 0; 978 uvm_fault_unwire_locked(map, entry->start, entry->end); 979 } 980 981 982 /* 983 * wrapper for calling amap_ref() 984 */ 985 static inline void 986 uvm_map_reference_amap(struct vm_map_entry *entry, int flags) 987 { 988 989 amap_ref(entry->aref.ar_amap, entry->aref.ar_pageoff, 990 (entry->end - entry->start) >> PAGE_SHIFT, flags); 991 } 992 993 994 /* 995 * wrapper for calling amap_unref() 996 */ 997 static inline void 998 uvm_map_unreference_amap(struct vm_map_entry *entry, int flags) 999 { 1000 1001 amap_unref(entry->aref.ar_amap, entry->aref.ar_pageoff, 1002 (entry->end - entry->start) >> PAGE_SHIFT, flags); 1003 } 1004 1005 1006 /* 1007 * uvm_map_init: init mapping system at boot time. 1008 */ 1009 1010 void 1011 uvm_map_init(void) 1012 { 1013 #if defined(UVMHIST) 1014 static struct uvm_history_ent maphistbuf[100]; 1015 static struct uvm_history_ent pdhistbuf[100]; 1016 #endif 1017 1018 /* 1019 * first, init logging system. 1020 */ 1021 1022 UVMHIST_FUNC("uvm_map_init"); 1023 UVMHIST_INIT_STATIC(maphist, maphistbuf); 1024 UVMHIST_INIT_STATIC(pdhist, pdhistbuf); 1025 UVMHIST_CALLED(maphist); 1026 UVMHIST_LOG(maphist,"<starting uvm map system>", 0, 0, 0, 0); 1027 1028 /* 1029 * initialize the global lock for kernel map entry. 1030 */ 1031 1032 mutex_init(&uvm_kentry_lock, MUTEX_DRIVER, IPL_VM); 1033 1034 /* 1035 * initialize caches. 1036 */ 1037 1038 pool_cache_bootstrap(&uvm_map_entry_cache, sizeof(struct vm_map_entry), 1039 0, 0, 0, "vmmpepl", NULL, IPL_NONE, NULL, NULL, NULL); 1040 pool_cache_bootstrap(&uvm_vmspace_cache, sizeof(struct vmspace), 1041 0, 0, 0, "vmsppl", NULL, IPL_NONE, NULL, NULL, NULL); 1042 } 1043 1044 /* 1045 * clippers 1046 */ 1047 1048 /* 1049 * uvm_mapent_splitadj: adjust map entries for splitting, after uvm_mapent_copy. 1050 */ 1051 1052 static void 1053 uvm_mapent_splitadj(struct vm_map_entry *entry1, struct vm_map_entry *entry2, 1054 vaddr_t splitat) 1055 { 1056 vaddr_t adj; 1057 1058 KASSERT(entry1->start < splitat); 1059 KASSERT(splitat < entry1->end); 1060 1061 adj = splitat - entry1->start; 1062 entry1->end = entry2->start = splitat; 1063 1064 if (entry1->aref.ar_amap) { 1065 amap_splitref(&entry1->aref, &entry2->aref, adj); 1066 } 1067 if (UVM_ET_ISSUBMAP(entry1)) { 1068 /* ... unlikely to happen, but play it safe */ 1069 uvm_map_reference(entry1->object.sub_map); 1070 } else if (UVM_ET_ISOBJ(entry1)) { 1071 KASSERT(entry1->object.uvm_obj != NULL); /* suppress coverity */ 1072 entry2->offset += adj; 1073 if (entry1->object.uvm_obj->pgops && 1074 entry1->object.uvm_obj->pgops->pgo_reference) 1075 entry1->object.uvm_obj->pgops->pgo_reference( 1076 entry1->object.uvm_obj); 1077 } 1078 } 1079 1080 /* 1081 * uvm_map_clip_start: ensure that the entry begins at or after 1082 * the starting address, if it doesn't we split the entry. 1083 * 1084 * => caller should use UVM_MAP_CLIP_START macro rather than calling 1085 * this directly 1086 * => map must be locked by caller 1087 */ 1088 1089 void 1090 uvm_map_clip_start(struct vm_map *map, struct vm_map_entry *entry, 1091 vaddr_t start, struct uvm_mapent_reservation *umr) 1092 { 1093 struct vm_map_entry *new_entry; 1094 1095 /* uvm_map_simplify_entry(map, entry); */ /* XXX */ 1096 1097 uvm_map_check(map, "clip_start entry"); 1098 uvm_mapent_check(entry); 1099 1100 /* 1101 * Split off the front portion. note that we must insert the new 1102 * entry BEFORE this one, so that this entry has the specified 1103 * starting address. 1104 */ 1105 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr); 1106 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1107 uvm_mapent_splitadj(new_entry, entry, start); 1108 uvm_map_entry_link(map, entry->prev, new_entry); 1109 1110 uvm_map_check(map, "clip_start leave"); 1111 } 1112 1113 /* 1114 * uvm_map_clip_end: ensure that the entry ends at or before 1115 * the ending address, if it does't we split the reference 1116 * 1117 * => caller should use UVM_MAP_CLIP_END macro rather than calling 1118 * this directly 1119 * => map must be locked by caller 1120 */ 1121 1122 void 1123 uvm_map_clip_end(struct vm_map *map, struct vm_map_entry *entry, vaddr_t end, 1124 struct uvm_mapent_reservation *umr) 1125 { 1126 struct vm_map_entry *new_entry; 1127 1128 uvm_map_check(map, "clip_end entry"); 1129 uvm_mapent_check(entry); 1130 1131 /* 1132 * Create a new entry and insert it 1133 * AFTER the specified entry 1134 */ 1135 new_entry = uvm_mapent_alloc_split(map, entry, 0, umr); 1136 uvm_mapent_copy(entry, new_entry); /* entry -> new_entry */ 1137 uvm_mapent_splitadj(entry, new_entry, end); 1138 uvm_map_entry_link(map, entry, new_entry); 1139 1140 uvm_map_check(map, "clip_end leave"); 1141 } 1142 1143 static void 1144 vm_map_drain(struct vm_map *map, uvm_flag_t flags) 1145 { 1146 1147 if (!VM_MAP_IS_KERNEL(map)) { 1148 return; 1149 } 1150 1151 uvm_km_va_drain(map, flags); 1152 } 1153 1154 /* 1155 * M A P - m a i n e n t r y p o i n t 1156 */ 1157 /* 1158 * uvm_map: establish a valid mapping in a map 1159 * 1160 * => assume startp is page aligned. 1161 * => assume size is a multiple of PAGE_SIZE. 1162 * => assume sys_mmap provides enough of a "hint" to have us skip 1163 * over text/data/bss area. 1164 * => map must be unlocked (we will lock it) 1165 * => <uobj,uoffset> value meanings (4 cases): 1166 * [1] <NULL,uoffset> == uoffset is a hint for PMAP_PREFER 1167 * [2] <NULL,UVM_UNKNOWN_OFFSET> == don't PMAP_PREFER 1168 * [3] <uobj,uoffset> == normal mapping 1169 * [4] <uobj,UVM_UNKNOWN_OFFSET> == uvm_map finds offset based on VA 1170 * 1171 * case [4] is for kernel mappings where we don't know the offset until 1172 * we've found a virtual address. note that kernel object offsets are 1173 * always relative to vm_map_min(kernel_map). 1174 * 1175 * => if `align' is non-zero, we align the virtual address to the specified 1176 * alignment. 1177 * this is provided as a mechanism for large pages. 1178 * 1179 * => XXXCDC: need way to map in external amap? 1180 */ 1181 1182 int 1183 uvm_map(struct vm_map *map, vaddr_t *startp /* IN/OUT */, vsize_t size, 1184 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags) 1185 { 1186 struct uvm_map_args args; 1187 struct vm_map_entry *new_entry; 1188 int error; 1189 1190 KASSERT((flags & UVM_FLAG_QUANTUM) == 0 || VM_MAP_IS_KERNEL(map)); 1191 KASSERT((size & PAGE_MASK) == 0); 1192 1193 #ifndef __USER_VA0_IS_SAFE 1194 if ((flags & UVM_FLAG_FIXED) && *startp == 0 && 1195 !VM_MAP_IS_KERNEL(map) && user_va0_disable) 1196 return EACCES; 1197 #endif 1198 1199 /* 1200 * for pager_map, allocate the new entry first to avoid sleeping 1201 * for memory while we have the map locked. 1202 * 1203 * Also, because we allocate entries for in-kernel maps 1204 * a bit differently (cf. uvm_kmapent_alloc/free), we need to 1205 * allocate them before locking the map. 1206 */ 1207 1208 new_entry = NULL; 1209 if (VM_MAP_USE_KMAPENT(map) || (flags & UVM_FLAG_QUANTUM) || 1210 map == pager_map) { 1211 new_entry = uvm_mapent_alloc(map, (flags & UVM_FLAG_NOWAIT)); 1212 if (__predict_false(new_entry == NULL)) 1213 return ENOMEM; 1214 if (flags & UVM_FLAG_QUANTUM) 1215 new_entry->flags |= UVM_MAP_QUANTUM; 1216 } 1217 if (map == pager_map) 1218 flags |= UVM_FLAG_NOMERGE; 1219 1220 error = uvm_map_prepare(map, *startp, size, uobj, uoffset, align, 1221 flags, &args); 1222 if (!error) { 1223 error = uvm_map_enter(map, &args, new_entry); 1224 *startp = args.uma_start; 1225 } else if (new_entry) { 1226 uvm_mapent_free(new_entry); 1227 } 1228 1229 #if defined(DEBUG) 1230 if (!error && VM_MAP_IS_KERNEL(map)) { 1231 uvm_km_check_empty(map, *startp, *startp + size); 1232 } 1233 #endif /* defined(DEBUG) */ 1234 1235 return error; 1236 } 1237 1238 int 1239 uvm_map_prepare(struct vm_map *map, vaddr_t start, vsize_t size, 1240 struct uvm_object *uobj, voff_t uoffset, vsize_t align, uvm_flag_t flags, 1241 struct uvm_map_args *args) 1242 { 1243 struct vm_map_entry *prev_entry; 1244 vm_prot_t prot = UVM_PROTECTION(flags); 1245 vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1246 1247 UVMHIST_FUNC("uvm_map_prepare"); 1248 UVMHIST_CALLED(maphist); 1249 1250 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)", 1251 map, start, size, flags); 1252 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0); 1253 1254 /* 1255 * detect a popular device driver bug. 1256 */ 1257 1258 KASSERT(doing_shutdown || curlwp != NULL || 1259 (map->flags & VM_MAP_INTRSAFE)); 1260 1261 /* 1262 * zero-sized mapping doesn't make any sense. 1263 */ 1264 KASSERT(size > 0); 1265 1266 KASSERT((~flags & (UVM_FLAG_NOWAIT | UVM_FLAG_WAITVA)) != 0); 1267 1268 uvm_map_check(map, "map entry"); 1269 1270 /* 1271 * check sanity of protection code 1272 */ 1273 1274 if ((prot & maxprot) != prot) { 1275 UVMHIST_LOG(maphist, "<- prot. failure: prot=0x%x, max=0x%x", 1276 prot, maxprot,0,0); 1277 return EACCES; 1278 } 1279 1280 /* 1281 * figure out where to put new VM range 1282 */ 1283 1284 retry: 1285 if (vm_map_lock_try(map) == false) { 1286 if ((flags & UVM_FLAG_TRYLOCK) != 0 && 1287 (map->flags & VM_MAP_INTRSAFE) == 0) { 1288 return EAGAIN; 1289 } 1290 vm_map_lock(map); /* could sleep here */ 1291 } 1292 prev_entry = uvm_map_findspace(map, start, size, &start, 1293 uobj, uoffset, align, flags); 1294 if (prev_entry == NULL) { 1295 unsigned int timestamp; 1296 1297 timestamp = map->timestamp; 1298 UVMHIST_LOG(maphist,"waiting va timestamp=0x%x", 1299 timestamp,0,0,0); 1300 map->flags |= VM_MAP_WANTVA; 1301 vm_map_unlock(map); 1302 1303 /* 1304 * try to reclaim kva and wait until someone does unmap. 1305 * fragile locking here, so we awaken every second to 1306 * recheck the condition. 1307 */ 1308 1309 vm_map_drain(map, flags); 1310 1311 mutex_enter(&map->misc_lock); 1312 while ((map->flags & VM_MAP_WANTVA) != 0 && 1313 map->timestamp == timestamp) { 1314 if ((flags & UVM_FLAG_WAITVA) == 0) { 1315 mutex_exit(&map->misc_lock); 1316 UVMHIST_LOG(maphist, 1317 "<- uvm_map_findspace failed!", 0,0,0,0); 1318 return ENOMEM; 1319 } else { 1320 cv_timedwait(&map->cv, &map->misc_lock, hz); 1321 } 1322 } 1323 mutex_exit(&map->misc_lock); 1324 goto retry; 1325 } 1326 1327 #ifdef PMAP_GROWKERNEL 1328 /* 1329 * If the kernel pmap can't map the requested space, 1330 * then allocate more resources for it. 1331 */ 1332 if (map == kernel_map && uvm_maxkaddr < (start + size)) 1333 uvm_maxkaddr = pmap_growkernel(start + size); 1334 #endif 1335 1336 UVMMAP_EVCNT_INCR(map_call); 1337 1338 /* 1339 * if uobj is null, then uoffset is either a VAC hint for PMAP_PREFER 1340 * [typically from uvm_map_reserve] or it is UVM_UNKNOWN_OFFSET. in 1341 * either case we want to zero it before storing it in the map entry 1342 * (because it looks strange and confusing when debugging...) 1343 * 1344 * if uobj is not null 1345 * if uoffset is not UVM_UNKNOWN_OFFSET then we have a normal mapping 1346 * and we do not need to change uoffset. 1347 * if uoffset is UVM_UNKNOWN_OFFSET then we need to find the offset 1348 * now (based on the starting address of the map). this case is 1349 * for kernel object mappings where we don't know the offset until 1350 * the virtual address is found (with uvm_map_findspace). the 1351 * offset is the distance we are from the start of the map. 1352 */ 1353 1354 if (uobj == NULL) { 1355 uoffset = 0; 1356 } else { 1357 if (uoffset == UVM_UNKNOWN_OFFSET) { 1358 KASSERT(UVM_OBJ_IS_KERN_OBJECT(uobj)); 1359 uoffset = start - vm_map_min(kernel_map); 1360 } 1361 } 1362 1363 args->uma_flags = flags; 1364 args->uma_prev = prev_entry; 1365 args->uma_start = start; 1366 args->uma_size = size; 1367 args->uma_uobj = uobj; 1368 args->uma_uoffset = uoffset; 1369 1370 UVMHIST_LOG(maphist, "<- done!", 0,0,0,0); 1371 return 0; 1372 } 1373 1374 int 1375 uvm_map_enter(struct vm_map *map, const struct uvm_map_args *args, 1376 struct vm_map_entry *new_entry) 1377 { 1378 struct vm_map_entry *prev_entry = args->uma_prev; 1379 struct vm_map_entry *dead = NULL; 1380 1381 const uvm_flag_t flags = args->uma_flags; 1382 const vm_prot_t prot = UVM_PROTECTION(flags); 1383 const vm_prot_t maxprot = UVM_MAXPROTECTION(flags); 1384 const vm_inherit_t inherit = UVM_INHERIT(flags); 1385 const int amapwaitflag = (flags & UVM_FLAG_NOWAIT) ? 1386 AMAP_EXTEND_NOWAIT : 0; 1387 const int advice = UVM_ADVICE(flags); 1388 const int meflagval = (flags & UVM_FLAG_QUANTUM) ? 1389 UVM_MAP_QUANTUM : 0; 1390 1391 vaddr_t start = args->uma_start; 1392 vsize_t size = args->uma_size; 1393 struct uvm_object *uobj = args->uma_uobj; 1394 voff_t uoffset = args->uma_uoffset; 1395 1396 const int kmap = (vm_map_pmap(map) == pmap_kernel()); 1397 int merged = 0; 1398 int error; 1399 int newetype; 1400 1401 UVMHIST_FUNC("uvm_map_enter"); 1402 UVMHIST_CALLED(maphist); 1403 1404 UVMHIST_LOG(maphist, "(map=0x%x, start=0x%x, size=%d, flags=0x%x)", 1405 map, start, size, flags); 1406 UVMHIST_LOG(maphist, " uobj/offset 0x%x/%d", uobj, uoffset,0,0); 1407 1408 KASSERT(map->hint == prev_entry); /* bimerge case assumes this */ 1409 1410 if (flags & UVM_FLAG_QUANTUM) { 1411 KASSERT(new_entry); 1412 KASSERT(new_entry->flags & UVM_MAP_QUANTUM); 1413 } 1414 1415 if (uobj) 1416 newetype = UVM_ET_OBJ; 1417 else 1418 newetype = 0; 1419 1420 if (flags & UVM_FLAG_COPYONW) { 1421 newetype |= UVM_ET_COPYONWRITE; 1422 if ((flags & UVM_FLAG_OVERLAY) == 0) 1423 newetype |= UVM_ET_NEEDSCOPY; 1424 } 1425 1426 /* 1427 * try and insert in map by extending previous entry, if possible. 1428 * XXX: we don't try and pull back the next entry. might be useful 1429 * for a stack, but we are currently allocating our stack in advance. 1430 */ 1431 1432 if (flags & UVM_FLAG_NOMERGE) 1433 goto nomerge; 1434 1435 if (prev_entry->end == start && 1436 prev_entry != &map->header && 1437 UVM_ET_ISCOMPATIBLE(prev_entry, newetype, uobj, meflagval, 1438 prot, maxprot, inherit, advice, 0)) { 1439 1440 if (uobj && prev_entry->offset + 1441 (prev_entry->end - prev_entry->start) != uoffset) 1442 goto forwardmerge; 1443 1444 /* 1445 * can't extend a shared amap. note: no need to lock amap to 1446 * look at refs since we don't care about its exact value. 1447 * if it is one (i.e. we have only reference) it will stay there 1448 */ 1449 1450 if (prev_entry->aref.ar_amap && 1451 amap_refs(prev_entry->aref.ar_amap) != 1) { 1452 goto forwardmerge; 1453 } 1454 1455 if (prev_entry->aref.ar_amap) { 1456 error = amap_extend(prev_entry, size, 1457 amapwaitflag | AMAP_EXTEND_FORWARDS); 1458 if (error) 1459 goto nomerge; 1460 } 1461 1462 if (kmap) { 1463 UVMMAP_EVCNT_INCR(kbackmerge); 1464 } else { 1465 UVMMAP_EVCNT_INCR(ubackmerge); 1466 } 1467 UVMHIST_LOG(maphist," starting back merge", 0, 0, 0, 0); 1468 1469 /* 1470 * drop our reference to uobj since we are extending a reference 1471 * that we already have (the ref count can not drop to zero). 1472 */ 1473 1474 if (uobj && uobj->pgops->pgo_detach) 1475 uobj->pgops->pgo_detach(uobj); 1476 1477 /* 1478 * Now that we've merged the entries, note that we've grown 1479 * and our gap has shrunk. Then fix the tree. 1480 */ 1481 prev_entry->end += size; 1482 prev_entry->gap -= size; 1483 uvm_rb_fixup(map, prev_entry); 1484 1485 uvm_map_check(map, "map backmerged"); 1486 1487 UVMHIST_LOG(maphist,"<- done (via backmerge)!", 0, 0, 0, 0); 1488 merged++; 1489 } 1490 1491 forwardmerge: 1492 if (prev_entry->next->start == (start + size) && 1493 prev_entry->next != &map->header && 1494 UVM_ET_ISCOMPATIBLE(prev_entry->next, newetype, uobj, meflagval, 1495 prot, maxprot, inherit, advice, 0)) { 1496 1497 if (uobj && prev_entry->next->offset != uoffset + size) 1498 goto nomerge; 1499 1500 /* 1501 * can't extend a shared amap. note: no need to lock amap to 1502 * look at refs since we don't care about its exact value. 1503 * if it is one (i.e. we have only reference) it will stay there. 1504 * 1505 * note that we also can't merge two amaps, so if we 1506 * merged with the previous entry which has an amap, 1507 * and the next entry also has an amap, we give up. 1508 * 1509 * Interesting cases: 1510 * amap, new, amap -> give up second merge (single fwd extend) 1511 * amap, new, none -> double forward extend (extend again here) 1512 * none, new, amap -> double backward extend (done here) 1513 * uobj, new, amap -> single backward extend (done here) 1514 * 1515 * XXX should we attempt to deal with someone refilling 1516 * the deallocated region between two entries that are 1517 * backed by the same amap (ie, arefs is 2, "prev" and 1518 * "next" refer to it, and adding this allocation will 1519 * close the hole, thus restoring arefs to 1 and 1520 * deallocating the "next" vm_map_entry)? -- @@@ 1521 */ 1522 1523 if (prev_entry->next->aref.ar_amap && 1524 (amap_refs(prev_entry->next->aref.ar_amap) != 1 || 1525 (merged && prev_entry->aref.ar_amap))) { 1526 goto nomerge; 1527 } 1528 1529 if (merged) { 1530 /* 1531 * Try to extend the amap of the previous entry to 1532 * cover the next entry as well. If it doesn't work 1533 * just skip on, don't actually give up, since we've 1534 * already completed the back merge. 1535 */ 1536 if (prev_entry->aref.ar_amap) { 1537 if (amap_extend(prev_entry, 1538 prev_entry->next->end - 1539 prev_entry->next->start, 1540 amapwaitflag | AMAP_EXTEND_FORWARDS)) 1541 goto nomerge; 1542 } 1543 1544 /* 1545 * Try to extend the amap of the *next* entry 1546 * back to cover the new allocation *and* the 1547 * previous entry as well (the previous merge 1548 * didn't have an amap already otherwise we 1549 * wouldn't be checking here for an amap). If 1550 * it doesn't work just skip on, again, don't 1551 * actually give up, since we've already 1552 * completed the back merge. 1553 */ 1554 else if (prev_entry->next->aref.ar_amap) { 1555 if (amap_extend(prev_entry->next, 1556 prev_entry->end - 1557 prev_entry->start, 1558 amapwaitflag | AMAP_EXTEND_BACKWARDS)) 1559 goto nomerge; 1560 } 1561 } else { 1562 /* 1563 * Pull the next entry's amap backwards to cover this 1564 * new allocation. 1565 */ 1566 if (prev_entry->next->aref.ar_amap) { 1567 error = amap_extend(prev_entry->next, size, 1568 amapwaitflag | AMAP_EXTEND_BACKWARDS); 1569 if (error) 1570 goto nomerge; 1571 } 1572 } 1573 1574 if (merged) { 1575 if (kmap) { 1576 UVMMAP_EVCNT_DECR(kbackmerge); 1577 UVMMAP_EVCNT_INCR(kbimerge); 1578 } else { 1579 UVMMAP_EVCNT_DECR(ubackmerge); 1580 UVMMAP_EVCNT_INCR(ubimerge); 1581 } 1582 } else { 1583 if (kmap) { 1584 UVMMAP_EVCNT_INCR(kforwmerge); 1585 } else { 1586 UVMMAP_EVCNT_INCR(uforwmerge); 1587 } 1588 } 1589 UVMHIST_LOG(maphist," starting forward merge", 0, 0, 0, 0); 1590 1591 /* 1592 * drop our reference to uobj since we are extending a reference 1593 * that we already have (the ref count can not drop to zero). 1594 * (if merged, we've already detached) 1595 */ 1596 if (uobj && uobj->pgops->pgo_detach && !merged) 1597 uobj->pgops->pgo_detach(uobj); 1598 1599 if (merged) { 1600 dead = prev_entry->next; 1601 prev_entry->end = dead->end; 1602 uvm_map_entry_unlink(map, dead); 1603 if (dead->aref.ar_amap != NULL) { 1604 prev_entry->aref = dead->aref; 1605 dead->aref.ar_amap = NULL; 1606 } 1607 } else { 1608 prev_entry->next->start -= size; 1609 if (prev_entry != &map->header) { 1610 prev_entry->gap -= size; 1611 KASSERT(prev_entry->gap == uvm_rb_gap(prev_entry)); 1612 uvm_rb_fixup(map, prev_entry); 1613 } 1614 if (uobj) 1615 prev_entry->next->offset = uoffset; 1616 } 1617 1618 uvm_map_check(map, "map forwardmerged"); 1619 1620 UVMHIST_LOG(maphist,"<- done forwardmerge", 0, 0, 0, 0); 1621 merged++; 1622 } 1623 1624 nomerge: 1625 if (!merged) { 1626 UVMHIST_LOG(maphist," allocating new map entry", 0, 0, 0, 0); 1627 if (kmap) { 1628 UVMMAP_EVCNT_INCR(knomerge); 1629 } else { 1630 UVMMAP_EVCNT_INCR(unomerge); 1631 } 1632 1633 /* 1634 * allocate new entry and link it in. 1635 */ 1636 1637 if (new_entry == NULL) { 1638 new_entry = uvm_mapent_alloc(map, 1639 (flags & UVM_FLAG_NOWAIT)); 1640 if (__predict_false(new_entry == NULL)) { 1641 error = ENOMEM; 1642 goto done; 1643 } 1644 } 1645 new_entry->start = start; 1646 new_entry->end = new_entry->start + size; 1647 new_entry->object.uvm_obj = uobj; 1648 new_entry->offset = uoffset; 1649 1650 new_entry->etype = newetype; 1651 1652 if (flags & UVM_FLAG_NOMERGE) { 1653 new_entry->flags |= UVM_MAP_NOMERGE; 1654 } 1655 1656 new_entry->protection = prot; 1657 new_entry->max_protection = maxprot; 1658 new_entry->inheritance = inherit; 1659 new_entry->wired_count = 0; 1660 new_entry->advice = advice; 1661 if (flags & UVM_FLAG_OVERLAY) { 1662 1663 /* 1664 * to_add: for BSS we overallocate a little since we 1665 * are likely to extend 1666 */ 1667 1668 vaddr_t to_add = (flags & UVM_FLAG_AMAPPAD) ? 1669 UVM_AMAP_CHUNK << PAGE_SHIFT : 0; 1670 struct vm_amap *amap = amap_alloc(size, to_add, 1671 (flags & UVM_FLAG_NOWAIT)); 1672 if (__predict_false(amap == NULL)) { 1673 error = ENOMEM; 1674 goto done; 1675 } 1676 new_entry->aref.ar_pageoff = 0; 1677 new_entry->aref.ar_amap = amap; 1678 } else { 1679 new_entry->aref.ar_pageoff = 0; 1680 new_entry->aref.ar_amap = NULL; 1681 } 1682 uvm_map_entry_link(map, prev_entry, new_entry); 1683 1684 /* 1685 * Update the free space hint 1686 */ 1687 1688 if ((map->first_free == prev_entry) && 1689 (prev_entry->end >= new_entry->start)) 1690 map->first_free = new_entry; 1691 1692 new_entry = NULL; 1693 } 1694 1695 map->size += size; 1696 1697 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 1698 1699 error = 0; 1700 done: 1701 if ((flags & UVM_FLAG_QUANTUM) == 0) { 1702 /* 1703 * vmk_merged_entries is locked by the map's lock. 1704 */ 1705 vm_map_unlock(map); 1706 } 1707 if (new_entry && error == 0) { 1708 KDASSERT(merged); 1709 uvm_mapent_free_merged(map, new_entry); 1710 new_entry = NULL; 1711 } 1712 if (dead) { 1713 KDASSERT(merged); 1714 uvm_mapent_free_merged(map, dead); 1715 } 1716 if ((flags & UVM_FLAG_QUANTUM) != 0) { 1717 vm_map_unlock(map); 1718 } 1719 if (new_entry != NULL) { 1720 uvm_mapent_free(new_entry); 1721 } 1722 return error; 1723 } 1724 1725 /* 1726 * uvm_map_lookup_entry_bytree: lookup an entry in tree 1727 */ 1728 1729 static inline bool 1730 uvm_map_lookup_entry_bytree(struct vm_map *map, vaddr_t address, 1731 struct vm_map_entry **entry /* OUT */) 1732 { 1733 struct vm_map_entry *prev = &map->header; 1734 struct vm_map_entry *cur = ROOT_ENTRY(map); 1735 1736 while (cur) { 1737 UVMMAP_EVCNT_INCR(mlk_treeloop); 1738 if (address >= cur->start) { 1739 if (address < cur->end) { 1740 *entry = cur; 1741 return true; 1742 } 1743 prev = cur; 1744 cur = RIGHT_ENTRY(cur); 1745 } else 1746 cur = LEFT_ENTRY(cur); 1747 } 1748 *entry = prev; 1749 return false; 1750 } 1751 1752 /* 1753 * uvm_map_lookup_entry: find map entry at or before an address 1754 * 1755 * => map must at least be read-locked by caller 1756 * => entry is returned in "entry" 1757 * => return value is true if address is in the returned entry 1758 */ 1759 1760 bool 1761 uvm_map_lookup_entry(struct vm_map *map, vaddr_t address, 1762 struct vm_map_entry **entry /* OUT */) 1763 { 1764 struct vm_map_entry *cur; 1765 bool use_tree = false; 1766 UVMHIST_FUNC("uvm_map_lookup_entry"); 1767 UVMHIST_CALLED(maphist); 1768 1769 UVMHIST_LOG(maphist,"(map=0x%x,addr=0x%x,ent=0x%x)", 1770 map, address, entry, 0); 1771 1772 /* 1773 * start looking either from the head of the 1774 * list, or from the hint. 1775 */ 1776 1777 cur = map->hint; 1778 1779 if (cur == &map->header) 1780 cur = cur->next; 1781 1782 UVMMAP_EVCNT_INCR(mlk_call); 1783 if (address >= cur->start) { 1784 1785 /* 1786 * go from hint to end of list. 1787 * 1788 * but first, make a quick check to see if 1789 * we are already looking at the entry we 1790 * want (which is usually the case). 1791 * note also that we don't need to save the hint 1792 * here... it is the same hint (unless we are 1793 * at the header, in which case the hint didn't 1794 * buy us anything anyway). 1795 */ 1796 1797 if (cur != &map->header && cur->end > address) { 1798 UVMMAP_EVCNT_INCR(mlk_hint); 1799 *entry = cur; 1800 UVMHIST_LOG(maphist,"<- got it via hint (0x%x)", 1801 cur, 0, 0, 0); 1802 uvm_mapent_check(*entry); 1803 return (true); 1804 } 1805 1806 if (map->nentries > 15) 1807 use_tree = true; 1808 } else { 1809 1810 /* 1811 * invalid hint. use tree. 1812 */ 1813 use_tree = true; 1814 } 1815 1816 uvm_map_check(map, __func__); 1817 1818 if (use_tree) { 1819 /* 1820 * Simple lookup in the tree. Happens when the hint is 1821 * invalid, or nentries reach a threshold. 1822 */ 1823 UVMMAP_EVCNT_INCR(mlk_tree); 1824 if (uvm_map_lookup_entry_bytree(map, address, entry)) { 1825 goto got; 1826 } else { 1827 goto failed; 1828 } 1829 } 1830 1831 /* 1832 * search linearly 1833 */ 1834 1835 UVMMAP_EVCNT_INCR(mlk_list); 1836 while (cur != &map->header) { 1837 UVMMAP_EVCNT_INCR(mlk_listloop); 1838 if (cur->end > address) { 1839 if (address >= cur->start) { 1840 /* 1841 * save this lookup for future 1842 * hints, and return 1843 */ 1844 1845 *entry = cur; 1846 got: 1847 SAVE_HINT(map, map->hint, *entry); 1848 UVMHIST_LOG(maphist,"<- search got it (0x%x)", 1849 cur, 0, 0, 0); 1850 KDASSERT((*entry)->start <= address); 1851 KDASSERT(address < (*entry)->end); 1852 uvm_mapent_check(*entry); 1853 return (true); 1854 } 1855 break; 1856 } 1857 cur = cur->next; 1858 } 1859 *entry = cur->prev; 1860 failed: 1861 SAVE_HINT(map, map->hint, *entry); 1862 UVMHIST_LOG(maphist,"<- failed!",0,0,0,0); 1863 KDASSERT((*entry) == &map->header || (*entry)->end <= address); 1864 KDASSERT((*entry)->next == &map->header || 1865 address < (*entry)->next->start); 1866 return (false); 1867 } 1868 1869 /* 1870 * See if the range between start and start + length fits in the gap 1871 * entry->next->start and entry->end. Returns 1 if fits, 0 if doesn't 1872 * fit, and -1 address wraps around. 1873 */ 1874 static int 1875 uvm_map_space_avail(vaddr_t *start, vsize_t length, voff_t uoffset, 1876 vsize_t align, int topdown, struct vm_map_entry *entry) 1877 { 1878 vaddr_t end; 1879 1880 #ifdef PMAP_PREFER 1881 /* 1882 * push start address forward as needed to avoid VAC alias problems. 1883 * we only do this if a valid offset is specified. 1884 */ 1885 1886 if (uoffset != UVM_UNKNOWN_OFFSET) 1887 PMAP_PREFER(uoffset, start, length, topdown); 1888 #endif 1889 if (align != 0) { 1890 if ((*start & (align - 1)) != 0) { 1891 if (topdown) 1892 *start &= ~(align - 1); 1893 else 1894 *start = roundup(*start, align); 1895 } 1896 /* 1897 * XXX Should we PMAP_PREFER() here again? 1898 * eh...i think we're okay 1899 */ 1900 } 1901 1902 /* 1903 * Find the end of the proposed new region. Be sure we didn't 1904 * wrap around the address; if so, we lose. Otherwise, if the 1905 * proposed new region fits before the next entry, we win. 1906 */ 1907 1908 end = *start + length; 1909 if (end < *start) 1910 return (-1); 1911 1912 if (entry->next->start >= end && *start >= entry->end) 1913 return (1); 1914 1915 return (0); 1916 } 1917 1918 /* 1919 * uvm_map_findspace: find "length" sized space in "map". 1920 * 1921 * => "hint" is a hint about where we want it, unless UVM_FLAG_FIXED is 1922 * set in "flags" (in which case we insist on using "hint"). 1923 * => "result" is VA returned 1924 * => uobj/uoffset are to be used to handle VAC alignment, if required 1925 * => if "align" is non-zero, we attempt to align to that value. 1926 * => caller must at least have read-locked map 1927 * => returns NULL on failure, or pointer to prev. map entry if success 1928 * => note this is a cross between the old vm_map_findspace and vm_map_find 1929 */ 1930 1931 struct vm_map_entry * 1932 uvm_map_findspace(struct vm_map *map, vaddr_t hint, vsize_t length, 1933 vaddr_t *result /* OUT */, struct uvm_object *uobj, voff_t uoffset, 1934 vsize_t align, int flags) 1935 { 1936 struct vm_map_entry *entry; 1937 struct vm_map_entry *child, *prev, *tmp; 1938 vaddr_t orig_hint; 1939 const int topdown = map->flags & VM_MAP_TOPDOWN; 1940 UVMHIST_FUNC("uvm_map_findspace"); 1941 UVMHIST_CALLED(maphist); 1942 1943 UVMHIST_LOG(maphist, "(map=0x%x, hint=0x%x, len=%d, flags=0x%x)", 1944 map, hint, length, flags); 1945 KASSERT((align & (align - 1)) == 0); 1946 KASSERT((flags & UVM_FLAG_FIXED) == 0 || align == 0); 1947 1948 uvm_map_check(map, "map_findspace entry"); 1949 1950 /* 1951 * remember the original hint. if we are aligning, then we 1952 * may have to try again with no alignment constraint if 1953 * we fail the first time. 1954 */ 1955 1956 orig_hint = hint; 1957 if (hint < vm_map_min(map)) { /* check ranges ... */ 1958 if (flags & UVM_FLAG_FIXED) { 1959 UVMHIST_LOG(maphist,"<- VA below map range",0,0,0,0); 1960 return (NULL); 1961 } 1962 hint = vm_map_min(map); 1963 } 1964 if (hint > vm_map_max(map)) { 1965 UVMHIST_LOG(maphist,"<- VA 0x%x > range [0x%x->0x%x]", 1966 hint, vm_map_min(map), vm_map_max(map), 0); 1967 return (NULL); 1968 } 1969 1970 /* 1971 * Look for the first possible address; if there's already 1972 * something at this address, we have to start after it. 1973 */ 1974 1975 /* 1976 * @@@: there are four, no, eight cases to consider. 1977 * 1978 * 0: found, fixed, bottom up -> fail 1979 * 1: found, fixed, top down -> fail 1980 * 2: found, not fixed, bottom up -> start after entry->end, 1981 * loop up 1982 * 3: found, not fixed, top down -> start before entry->start, 1983 * loop down 1984 * 4: not found, fixed, bottom up -> check entry->next->start, fail 1985 * 5: not found, fixed, top down -> check entry->next->start, fail 1986 * 6: not found, not fixed, bottom up -> check entry->next->start, 1987 * loop up 1988 * 7: not found, not fixed, top down -> check entry->next->start, 1989 * loop down 1990 * 1991 * as you can see, it reduces to roughly five cases, and that 1992 * adding top down mapping only adds one unique case (without 1993 * it, there would be four cases). 1994 */ 1995 1996 if ((flags & UVM_FLAG_FIXED) == 0 && hint == vm_map_min(map)) { 1997 entry = map->first_free; 1998 } else { 1999 if (uvm_map_lookup_entry(map, hint, &entry)) { 2000 /* "hint" address already in use ... */ 2001 if (flags & UVM_FLAG_FIXED) { 2002 UVMHIST_LOG(maphist, "<- fixed & VA in use", 2003 0, 0, 0, 0); 2004 return (NULL); 2005 } 2006 if (topdown) 2007 /* Start from lower gap. */ 2008 entry = entry->prev; 2009 } else if (flags & UVM_FLAG_FIXED) { 2010 if (entry->next->start >= hint + length && 2011 hint + length > hint) 2012 goto found; 2013 2014 /* "hint" address is gap but too small */ 2015 UVMHIST_LOG(maphist, "<- fixed mapping failed", 2016 0, 0, 0, 0); 2017 return (NULL); /* only one shot at it ... */ 2018 } else { 2019 /* 2020 * See if given hint fits in this gap. 2021 */ 2022 switch (uvm_map_space_avail(&hint, length, 2023 uoffset, align, topdown, entry)) { 2024 case 1: 2025 goto found; 2026 case -1: 2027 goto wraparound; 2028 } 2029 2030 if (topdown) { 2031 /* 2032 * Still there is a chance to fit 2033 * if hint > entry->end. 2034 */ 2035 } else { 2036 /* Start from higher gap. */ 2037 entry = entry->next; 2038 if (entry == &map->header) 2039 goto notfound; 2040 goto nextgap; 2041 } 2042 } 2043 } 2044 2045 /* 2046 * Note that all UVM_FLAGS_FIXED case is already handled. 2047 */ 2048 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 2049 2050 /* Try to find the space in the red-black tree */ 2051 2052 /* Check slot before any entry */ 2053 hint = topdown ? entry->next->start - length : entry->end; 2054 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2055 topdown, entry)) { 2056 case 1: 2057 goto found; 2058 case -1: 2059 goto wraparound; 2060 } 2061 2062 nextgap: 2063 KDASSERT((flags & UVM_FLAG_FIXED) == 0); 2064 /* If there is not enough space in the whole tree, we fail */ 2065 tmp = ROOT_ENTRY(map); 2066 if (tmp == NULL || tmp->maxgap < length) 2067 goto notfound; 2068 2069 prev = NULL; /* previous candidate */ 2070 2071 /* Find an entry close to hint that has enough space */ 2072 for (; tmp;) { 2073 KASSERT(tmp->next->start == tmp->end + tmp->gap); 2074 if (topdown) { 2075 if (tmp->next->start < hint + length && 2076 (prev == NULL || tmp->end > prev->end)) { 2077 if (tmp->gap >= length) 2078 prev = tmp; 2079 else if ((child = LEFT_ENTRY(tmp)) != NULL 2080 && child->maxgap >= length) 2081 prev = tmp; 2082 } 2083 } else { 2084 if (tmp->end >= hint && 2085 (prev == NULL || tmp->end < prev->end)) { 2086 if (tmp->gap >= length) 2087 prev = tmp; 2088 else if ((child = RIGHT_ENTRY(tmp)) != NULL 2089 && child->maxgap >= length) 2090 prev = tmp; 2091 } 2092 } 2093 if (tmp->next->start < hint + length) 2094 child = RIGHT_ENTRY(tmp); 2095 else if (tmp->end > hint) 2096 child = LEFT_ENTRY(tmp); 2097 else { 2098 if (tmp->gap >= length) 2099 break; 2100 if (topdown) 2101 child = LEFT_ENTRY(tmp); 2102 else 2103 child = RIGHT_ENTRY(tmp); 2104 } 2105 if (child == NULL || child->maxgap < length) 2106 break; 2107 tmp = child; 2108 } 2109 2110 if (tmp != NULL && tmp->start < hint && hint < tmp->next->start) { 2111 /* 2112 * Check if the entry that we found satifies the 2113 * space requirement 2114 */ 2115 if (topdown) { 2116 if (hint > tmp->next->start - length) 2117 hint = tmp->next->start - length; 2118 } else { 2119 if (hint < tmp->end) 2120 hint = tmp->end; 2121 } 2122 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2123 topdown, tmp)) { 2124 case 1: 2125 entry = tmp; 2126 goto found; 2127 case -1: 2128 goto wraparound; 2129 } 2130 if (tmp->gap >= length) 2131 goto listsearch; 2132 } 2133 if (prev == NULL) 2134 goto notfound; 2135 2136 if (topdown) { 2137 KASSERT(orig_hint >= prev->next->start - length || 2138 prev->next->start - length > prev->next->start); 2139 hint = prev->next->start - length; 2140 } else { 2141 KASSERT(orig_hint <= prev->end); 2142 hint = prev->end; 2143 } 2144 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2145 topdown, prev)) { 2146 case 1: 2147 entry = prev; 2148 goto found; 2149 case -1: 2150 goto wraparound; 2151 } 2152 if (prev->gap >= length) 2153 goto listsearch; 2154 2155 if (topdown) 2156 tmp = LEFT_ENTRY(prev); 2157 else 2158 tmp = RIGHT_ENTRY(prev); 2159 for (;;) { 2160 KASSERT(tmp && tmp->maxgap >= length); 2161 if (topdown) 2162 child = RIGHT_ENTRY(tmp); 2163 else 2164 child = LEFT_ENTRY(tmp); 2165 if (child && child->maxgap >= length) { 2166 tmp = child; 2167 continue; 2168 } 2169 if (tmp->gap >= length) 2170 break; 2171 if (topdown) 2172 tmp = LEFT_ENTRY(tmp); 2173 else 2174 tmp = RIGHT_ENTRY(tmp); 2175 } 2176 2177 if (topdown) { 2178 KASSERT(orig_hint >= tmp->next->start - length || 2179 tmp->next->start - length > tmp->next->start); 2180 hint = tmp->next->start - length; 2181 } else { 2182 KASSERT(orig_hint <= tmp->end); 2183 hint = tmp->end; 2184 } 2185 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2186 topdown, tmp)) { 2187 case 1: 2188 entry = tmp; 2189 goto found; 2190 case -1: 2191 goto wraparound; 2192 } 2193 2194 /* 2195 * The tree fails to find an entry because of offset or alignment 2196 * restrictions. Search the list instead. 2197 */ 2198 listsearch: 2199 /* 2200 * Look through the rest of the map, trying to fit a new region in 2201 * the gap between existing regions, or after the very last region. 2202 * note: entry->end = base VA of current gap, 2203 * entry->next->start = VA of end of current gap 2204 */ 2205 2206 for (;;) { 2207 /* Update hint for current gap. */ 2208 hint = topdown ? entry->next->start - length : entry->end; 2209 2210 /* See if it fits. */ 2211 switch (uvm_map_space_avail(&hint, length, uoffset, align, 2212 topdown, entry)) { 2213 case 1: 2214 goto found; 2215 case -1: 2216 goto wraparound; 2217 } 2218 2219 /* Advance to next/previous gap */ 2220 if (topdown) { 2221 if (entry == &map->header) { 2222 UVMHIST_LOG(maphist, "<- failed (off start)", 2223 0,0,0,0); 2224 goto notfound; 2225 } 2226 entry = entry->prev; 2227 } else { 2228 entry = entry->next; 2229 if (entry == &map->header) { 2230 UVMHIST_LOG(maphist, "<- failed (off end)", 2231 0,0,0,0); 2232 goto notfound; 2233 } 2234 } 2235 } 2236 2237 found: 2238 SAVE_HINT(map, map->hint, entry); 2239 *result = hint; 2240 UVMHIST_LOG(maphist,"<- got it! (result=0x%x)", hint, 0,0,0); 2241 KASSERT( topdown || hint >= orig_hint); 2242 KASSERT(!topdown || hint <= orig_hint); 2243 KASSERT(entry->end <= hint); 2244 KASSERT(hint + length <= entry->next->start); 2245 return (entry); 2246 2247 wraparound: 2248 UVMHIST_LOG(maphist, "<- failed (wrap around)", 0,0,0,0); 2249 2250 return (NULL); 2251 2252 notfound: 2253 UVMHIST_LOG(maphist, "<- failed (notfound)", 0,0,0,0); 2254 2255 return (NULL); 2256 } 2257 2258 /* 2259 * U N M A P - m a i n h e l p e r f u n c t i o n s 2260 */ 2261 2262 /* 2263 * uvm_unmap_remove: remove mappings from a vm_map (from "start" up to "stop") 2264 * 2265 * => caller must check alignment and size 2266 * => map must be locked by caller 2267 * => we return a list of map entries that we've remove from the map 2268 * in "entry_list" 2269 */ 2270 2271 void 2272 uvm_unmap_remove(struct vm_map *map, vaddr_t start, vaddr_t end, 2273 struct vm_map_entry **entry_list /* OUT */, 2274 struct uvm_mapent_reservation *umr, int flags) 2275 { 2276 struct vm_map_entry *entry, *first_entry, *next; 2277 vaddr_t len; 2278 UVMHIST_FUNC("uvm_unmap_remove"); UVMHIST_CALLED(maphist); 2279 2280 UVMHIST_LOG(maphist,"(map=0x%x, start=0x%x, end=0x%x)", 2281 map, start, end, 0); 2282 VM_MAP_RANGE_CHECK(map, start, end); 2283 2284 uvm_map_check(map, "unmap_remove entry"); 2285 2286 /* 2287 * find first entry 2288 */ 2289 2290 if (uvm_map_lookup_entry(map, start, &first_entry) == true) { 2291 /* clip and go... */ 2292 entry = first_entry; 2293 UVM_MAP_CLIP_START(map, entry, start, umr); 2294 /* critical! prevents stale hint */ 2295 SAVE_HINT(map, entry, entry->prev); 2296 } else { 2297 entry = first_entry->next; 2298 } 2299 2300 /* 2301 * Save the free space hint 2302 */ 2303 2304 if (map->first_free != &map->header && map->first_free->start >= start) 2305 map->first_free = entry->prev; 2306 2307 /* 2308 * note: we now re-use first_entry for a different task. we remove 2309 * a number of map entries from the map and save them in a linked 2310 * list headed by "first_entry". once we remove them from the map 2311 * the caller should unlock the map and drop the references to the 2312 * backing objects [c.f. uvm_unmap_detach]. the object is to 2313 * separate unmapping from reference dropping. why? 2314 * [1] the map has to be locked for unmapping 2315 * [2] the map need not be locked for reference dropping 2316 * [3] dropping references may trigger pager I/O, and if we hit 2317 * a pager that does synchronous I/O we may have to wait for it. 2318 * [4] we would like all waiting for I/O to occur with maps unlocked 2319 * so that we don't block other threads. 2320 */ 2321 2322 first_entry = NULL; 2323 *entry_list = NULL; 2324 2325 /* 2326 * break up the area into map entry sized regions and unmap. note 2327 * that all mappings have to be removed before we can even consider 2328 * dropping references to amaps or VM objects (otherwise we could end 2329 * up with a mapping to a page on the free list which would be very bad) 2330 */ 2331 2332 while ((entry != &map->header) && (entry->start < end)) { 2333 KASSERT((entry->flags & UVM_MAP_FIRST) == 0); 2334 2335 UVM_MAP_CLIP_END(map, entry, end, umr); 2336 next = entry->next; 2337 len = entry->end - entry->start; 2338 2339 /* 2340 * unwire before removing addresses from the pmap; otherwise 2341 * unwiring will put the entries back into the pmap (XXX). 2342 */ 2343 2344 if (VM_MAPENT_ISWIRED(entry)) { 2345 uvm_map_entry_unwire(map, entry); 2346 } 2347 if (flags & UVM_FLAG_VAONLY) { 2348 2349 /* nothing */ 2350 2351 } else if ((map->flags & VM_MAP_PAGEABLE) == 0) { 2352 2353 /* 2354 * if the map is non-pageable, any pages mapped there 2355 * must be wired and entered with pmap_kenter_pa(), 2356 * and we should free any such pages immediately. 2357 * this is mostly used for kmem_map. 2358 */ 2359 KASSERT(vm_map_pmap(map) == pmap_kernel()); 2360 2361 if ((entry->flags & UVM_MAP_KMAPENT) == 0) { 2362 uvm_km_pgremove_intrsafe(map, entry->start, 2363 entry->end); 2364 pmap_kremove(entry->start, len); 2365 } 2366 } else if (UVM_ET_ISOBJ(entry) && 2367 UVM_OBJ_IS_KERN_OBJECT(entry->object.uvm_obj)) { 2368 KASSERT(vm_map_pmap(map) == pmap_kernel()); 2369 2370 /* 2371 * note: kernel object mappings are currently used in 2372 * two ways: 2373 * [1] "normal" mappings of pages in the kernel object 2374 * [2] uvm_km_valloc'd allocations in which we 2375 * pmap_enter in some non-kernel-object page 2376 * (e.g. vmapbuf). 2377 * 2378 * for case [1], we need to remove the mapping from 2379 * the pmap and then remove the page from the kernel 2380 * object (because, once pages in a kernel object are 2381 * unmapped they are no longer needed, unlike, say, 2382 * a vnode where you might want the data to persist 2383 * until flushed out of a queue). 2384 * 2385 * for case [2], we need to remove the mapping from 2386 * the pmap. there shouldn't be any pages at the 2387 * specified offset in the kernel object [but it 2388 * doesn't hurt to call uvm_km_pgremove just to be 2389 * safe?] 2390 * 2391 * uvm_km_pgremove currently does the following: 2392 * for pages in the kernel object in range: 2393 * - drops the swap slot 2394 * - uvm_pagefree the page 2395 */ 2396 2397 /* 2398 * remove mappings from pmap and drop the pages 2399 * from the object. offsets are always relative 2400 * to vm_map_min(kernel_map). 2401 */ 2402 2403 pmap_remove(pmap_kernel(), entry->start, 2404 entry->start + len); 2405 uvm_km_pgremove(entry->start, entry->end); 2406 2407 /* 2408 * null out kernel_object reference, we've just 2409 * dropped it 2410 */ 2411 2412 entry->etype &= ~UVM_ET_OBJ; 2413 entry->object.uvm_obj = NULL; 2414 } else if (UVM_ET_ISOBJ(entry) || entry->aref.ar_amap) { 2415 2416 /* 2417 * remove mappings the standard way. 2418 */ 2419 2420 pmap_remove(map->pmap, entry->start, entry->end); 2421 } 2422 2423 #if defined(DEBUG) 2424 if ((entry->flags & UVM_MAP_KMAPENT) == 0) { 2425 2426 /* 2427 * check if there's remaining mapping, 2428 * which is a bug in caller. 2429 */ 2430 2431 vaddr_t va; 2432 for (va = entry->start; va < entry->end; 2433 va += PAGE_SIZE) { 2434 if (pmap_extract(vm_map_pmap(map), va, NULL)) { 2435 panic("uvm_unmap_remove: has mapping"); 2436 } 2437 } 2438 2439 if (VM_MAP_IS_KERNEL(map)) { 2440 uvm_km_check_empty(map, entry->start, 2441 entry->end); 2442 } 2443 } 2444 #endif /* defined(DEBUG) */ 2445 2446 /* 2447 * remove entry from map and put it on our list of entries 2448 * that we've nuked. then go to next entry. 2449 */ 2450 2451 UVMHIST_LOG(maphist, " removed map entry 0x%x", entry, 0, 0,0); 2452 2453 /* critical! prevents stale hint */ 2454 SAVE_HINT(map, entry, entry->prev); 2455 2456 uvm_map_entry_unlink(map, entry); 2457 KASSERT(map->size >= len); 2458 map->size -= len; 2459 entry->prev = NULL; 2460 entry->next = first_entry; 2461 first_entry = entry; 2462 entry = next; 2463 } 2464 2465 /* 2466 * Note: if map is dying, leave pmap_update() for pmap_destroy(), 2467 * which will be called later. 2468 */ 2469 if ((map->flags & VM_MAP_DYING) == 0) { 2470 pmap_update(vm_map_pmap(map)); 2471 } else { 2472 KASSERT(vm_map_pmap(map) != pmap_kernel()); 2473 } 2474 2475 uvm_map_check(map, "unmap_remove leave"); 2476 2477 /* 2478 * now we've cleaned up the map and are ready for the caller to drop 2479 * references to the mapped objects. 2480 */ 2481 2482 *entry_list = first_entry; 2483 UVMHIST_LOG(maphist,"<- done!", 0, 0, 0, 0); 2484 2485 if (map->flags & VM_MAP_WANTVA) { 2486 mutex_enter(&map->misc_lock); 2487 map->flags &= ~VM_MAP_WANTVA; 2488 cv_broadcast(&map->cv); 2489 mutex_exit(&map->misc_lock); 2490 } 2491 } 2492 2493 /* 2494 * uvm_unmap_detach: drop references in a chain of map entries 2495 * 2496 * => we will free the map entries as we traverse the list. 2497 */ 2498 2499 void 2500 uvm_unmap_detach(struct vm_map_entry *first_entry, int flags) 2501 { 2502 struct vm_map_entry *next_entry; 2503 UVMHIST_FUNC("uvm_unmap_detach"); UVMHIST_CALLED(maphist); 2504 2505 while (first_entry) { 2506 KASSERT(!VM_MAPENT_ISWIRED(first_entry)); 2507 UVMHIST_LOG(maphist, 2508 " detach 0x%x: amap=0x%x, obj=0x%x, submap?=%d", 2509 first_entry, first_entry->aref.ar_amap, 2510 first_entry->object.uvm_obj, 2511 UVM_ET_ISSUBMAP(first_entry)); 2512 2513 /* 2514 * drop reference to amap, if we've got one 2515 */ 2516 2517 if (first_entry->aref.ar_amap) 2518 uvm_map_unreference_amap(first_entry, flags); 2519 2520 /* 2521 * drop reference to our backing object, if we've got one 2522 */ 2523 2524 KASSERT(!UVM_ET_ISSUBMAP(first_entry)); 2525 if (UVM_ET_ISOBJ(first_entry) && 2526 first_entry->object.uvm_obj->pgops->pgo_detach) { 2527 (*first_entry->object.uvm_obj->pgops->pgo_detach) 2528 (first_entry->object.uvm_obj); 2529 } 2530 next_entry = first_entry->next; 2531 uvm_mapent_free(first_entry); 2532 first_entry = next_entry; 2533 } 2534 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 2535 } 2536 2537 /* 2538 * E X T R A C T I O N F U N C T I O N S 2539 */ 2540 2541 /* 2542 * uvm_map_reserve: reserve space in a vm_map for future use. 2543 * 2544 * => we reserve space in a map by putting a dummy map entry in the 2545 * map (dummy means obj=NULL, amap=NULL, prot=VM_PROT_NONE) 2546 * => map should be unlocked (we will write lock it) 2547 * => we return true if we were able to reserve space 2548 * => XXXCDC: should be inline? 2549 */ 2550 2551 int 2552 uvm_map_reserve(struct vm_map *map, vsize_t size, 2553 vaddr_t offset /* hint for pmap_prefer */, 2554 vsize_t align /* alignment */, 2555 vaddr_t *raddr /* IN:hint, OUT: reserved VA */, 2556 uvm_flag_t flags /* UVM_FLAG_FIXED or 0 */) 2557 { 2558 UVMHIST_FUNC("uvm_map_reserve"); UVMHIST_CALLED(maphist); 2559 2560 UVMHIST_LOG(maphist, "(map=0x%x, size=0x%x, offset=0x%x,addr=0x%x)", 2561 map,size,offset,raddr); 2562 2563 size = round_page(size); 2564 2565 /* 2566 * reserve some virtual space. 2567 */ 2568 2569 if (uvm_map(map, raddr, size, NULL, offset, align, 2570 UVM_MAPFLAG(UVM_PROT_NONE, UVM_PROT_NONE, UVM_INH_NONE, 2571 UVM_ADV_RANDOM, UVM_FLAG_NOMERGE|flags)) != 0) { 2572 UVMHIST_LOG(maphist, "<- done (no VM)", 0,0,0,0); 2573 return (false); 2574 } 2575 2576 UVMHIST_LOG(maphist, "<- done (*raddr=0x%x)", *raddr,0,0,0); 2577 return (true); 2578 } 2579 2580 /* 2581 * uvm_map_replace: replace a reserved (blank) area of memory with 2582 * real mappings. 2583 * 2584 * => caller must WRITE-LOCK the map 2585 * => we return true if replacement was a success 2586 * => we expect the newents chain to have nnewents entrys on it and 2587 * we expect newents->prev to point to the last entry on the list 2588 * => note newents is allowed to be NULL 2589 */ 2590 2591 static int 2592 uvm_map_replace(struct vm_map *map, vaddr_t start, vaddr_t end, 2593 struct vm_map_entry *newents, int nnewents, vsize_t nsize, 2594 struct vm_map_entry **oldentryp) 2595 { 2596 struct vm_map_entry *oldent, *last; 2597 2598 uvm_map_check(map, "map_replace entry"); 2599 2600 /* 2601 * first find the blank map entry at the specified address 2602 */ 2603 2604 if (!uvm_map_lookup_entry(map, start, &oldent)) { 2605 return (false); 2606 } 2607 2608 /* 2609 * check to make sure we have a proper blank entry 2610 */ 2611 2612 if (end < oldent->end && !VM_MAP_USE_KMAPENT(map)) { 2613 UVM_MAP_CLIP_END(map, oldent, end, NULL); 2614 } 2615 if (oldent->start != start || oldent->end != end || 2616 oldent->object.uvm_obj != NULL || oldent->aref.ar_amap != NULL) { 2617 return (false); 2618 } 2619 2620 #ifdef DIAGNOSTIC 2621 2622 /* 2623 * sanity check the newents chain 2624 */ 2625 2626 { 2627 struct vm_map_entry *tmpent = newents; 2628 int nent = 0; 2629 vsize_t sz = 0; 2630 vaddr_t cur = start; 2631 2632 while (tmpent) { 2633 nent++; 2634 sz += tmpent->end - tmpent->start; 2635 if (tmpent->start < cur) 2636 panic("uvm_map_replace1"); 2637 if (tmpent->start >= tmpent->end || tmpent->end > end) { 2638 panic("uvm_map_replace2: " 2639 "tmpent->start=0x%"PRIxVADDR 2640 ", tmpent->end=0x%"PRIxVADDR 2641 ", end=0x%"PRIxVADDR, 2642 tmpent->start, tmpent->end, end); 2643 } 2644 cur = tmpent->end; 2645 if (tmpent->next) { 2646 if (tmpent->next->prev != tmpent) 2647 panic("uvm_map_replace3"); 2648 } else { 2649 if (newents->prev != tmpent) 2650 panic("uvm_map_replace4"); 2651 } 2652 tmpent = tmpent->next; 2653 } 2654 if (nent != nnewents) 2655 panic("uvm_map_replace5"); 2656 if (sz != nsize) 2657 panic("uvm_map_replace6"); 2658 } 2659 #endif 2660 2661 /* 2662 * map entry is a valid blank! replace it. (this does all the 2663 * work of map entry link/unlink...). 2664 */ 2665 2666 if (newents) { 2667 last = newents->prev; 2668 2669 /* critical: flush stale hints out of map */ 2670 SAVE_HINT(map, map->hint, newents); 2671 if (map->first_free == oldent) 2672 map->first_free = last; 2673 2674 last->next = oldent->next; 2675 last->next->prev = last; 2676 2677 /* Fix RB tree */ 2678 uvm_rb_remove(map, oldent); 2679 2680 newents->prev = oldent->prev; 2681 newents->prev->next = newents; 2682 map->nentries = map->nentries + (nnewents - 1); 2683 2684 /* Fixup the RB tree */ 2685 { 2686 int i; 2687 struct vm_map_entry *tmp; 2688 2689 tmp = newents; 2690 for (i = 0; i < nnewents && tmp; i++) { 2691 uvm_rb_insert(map, tmp); 2692 tmp = tmp->next; 2693 } 2694 } 2695 } else { 2696 /* NULL list of new entries: just remove the old one */ 2697 clear_hints(map, oldent); 2698 uvm_map_entry_unlink(map, oldent); 2699 } 2700 map->size -= end - start - nsize; 2701 2702 uvm_map_check(map, "map_replace leave"); 2703 2704 /* 2705 * now we can free the old blank entry and return. 2706 */ 2707 2708 *oldentryp = oldent; 2709 return (true); 2710 } 2711 2712 /* 2713 * uvm_map_extract: extract a mapping from a map and put it somewhere 2714 * (maybe removing the old mapping) 2715 * 2716 * => maps should be unlocked (we will write lock them) 2717 * => returns 0 on success, error code otherwise 2718 * => start must be page aligned 2719 * => len must be page sized 2720 * => flags: 2721 * UVM_EXTRACT_REMOVE: remove mappings from srcmap 2722 * UVM_EXTRACT_CONTIG: abort if unmapped area (advisory only) 2723 * UVM_EXTRACT_QREF: for a temporary extraction do quick obj refs 2724 * UVM_EXTRACT_FIXPROT: set prot to maxprot as we go 2725 * >>>NOTE: if you set REMOVE, you are not allowed to use CONTIG or QREF!<<< 2726 * >>>NOTE: QREF's must be unmapped via the QREF path, thus should only 2727 * be used from within the kernel in a kernel level map <<< 2728 */ 2729 2730 int 2731 uvm_map_extract(struct vm_map *srcmap, vaddr_t start, vsize_t len, 2732 struct vm_map *dstmap, vaddr_t *dstaddrp, int flags) 2733 { 2734 vaddr_t dstaddr, end, newend, oldoffset, fudge, orig_fudge; 2735 struct vm_map_entry *chain, *endchain, *entry, *orig_entry, *newentry, 2736 *deadentry, *oldentry; 2737 struct vm_map_entry *resentry = NULL; /* a dummy reservation entry */ 2738 vsize_t elen; 2739 int nchain, error, copy_ok; 2740 vsize_t nsize; 2741 UVMHIST_FUNC("uvm_map_extract"); UVMHIST_CALLED(maphist); 2742 2743 UVMHIST_LOG(maphist,"(srcmap=0x%x,start=0x%x, len=0x%x", srcmap, start, 2744 len,0); 2745 UVMHIST_LOG(maphist," ...,dstmap=0x%x, flags=0x%x)", dstmap,flags,0,0); 2746 2747 /* 2748 * step 0: sanity check: start must be on a page boundary, length 2749 * must be page sized. can't ask for CONTIG/QREF if you asked for 2750 * REMOVE. 2751 */ 2752 2753 KASSERT((start & PAGE_MASK) == 0 && (len & PAGE_MASK) == 0); 2754 KASSERT((flags & UVM_EXTRACT_REMOVE) == 0 || 2755 (flags & (UVM_EXTRACT_CONTIG|UVM_EXTRACT_QREF)) == 0); 2756 2757 /* 2758 * step 1: reserve space in the target map for the extracted area 2759 */ 2760 2761 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 2762 dstaddr = vm_map_min(dstmap); 2763 if (!uvm_map_reserve(dstmap, len, start, 0, &dstaddr, 0)) 2764 return (ENOMEM); 2765 *dstaddrp = dstaddr; /* pass address back to caller */ 2766 UVMHIST_LOG(maphist, " dstaddr=0x%x", dstaddr,0,0,0); 2767 } else { 2768 dstaddr = *dstaddrp; 2769 } 2770 2771 /* 2772 * step 2: setup for the extraction process loop by init'ing the 2773 * map entry chain, locking src map, and looking up the first useful 2774 * entry in the map. 2775 */ 2776 2777 end = start + len; 2778 newend = dstaddr + len; 2779 chain = endchain = NULL; 2780 nchain = 0; 2781 nsize = 0; 2782 vm_map_lock(srcmap); 2783 2784 if (uvm_map_lookup_entry(srcmap, start, &entry)) { 2785 2786 /* "start" is within an entry */ 2787 if (flags & UVM_EXTRACT_QREF) { 2788 2789 /* 2790 * for quick references we don't clip the entry, so 2791 * the entry may map space "before" the starting 2792 * virtual address... this is the "fudge" factor 2793 * (which can be non-zero only the first time 2794 * through the "while" loop in step 3). 2795 */ 2796 2797 fudge = start - entry->start; 2798 } else { 2799 2800 /* 2801 * normal reference: we clip the map to fit (thus 2802 * fudge is zero) 2803 */ 2804 2805 UVM_MAP_CLIP_START(srcmap, entry, start, NULL); 2806 SAVE_HINT(srcmap, srcmap->hint, entry->prev); 2807 fudge = 0; 2808 } 2809 } else { 2810 2811 /* "start" is not within an entry ... skip to next entry */ 2812 if (flags & UVM_EXTRACT_CONTIG) { 2813 error = EINVAL; 2814 goto bad; /* definite hole here ... */ 2815 } 2816 2817 entry = entry->next; 2818 fudge = 0; 2819 } 2820 2821 /* save values from srcmap for step 6 */ 2822 orig_entry = entry; 2823 orig_fudge = fudge; 2824 2825 /* 2826 * step 3: now start looping through the map entries, extracting 2827 * as we go. 2828 */ 2829 2830 while (entry->start < end && entry != &srcmap->header) { 2831 2832 /* if we are not doing a quick reference, clip it */ 2833 if ((flags & UVM_EXTRACT_QREF) == 0) 2834 UVM_MAP_CLIP_END(srcmap, entry, end, NULL); 2835 2836 /* clear needs_copy (allow chunking) */ 2837 if (UVM_ET_ISNEEDSCOPY(entry)) { 2838 amap_copy(srcmap, entry, 2839 AMAP_COPY_NOWAIT|AMAP_COPY_NOMERGE, start, end); 2840 if (UVM_ET_ISNEEDSCOPY(entry)) { /* failed? */ 2841 error = ENOMEM; 2842 goto bad; 2843 } 2844 2845 /* amap_copy could clip (during chunk)! update fudge */ 2846 if (fudge) { 2847 fudge = start - entry->start; 2848 orig_fudge = fudge; 2849 } 2850 } 2851 2852 /* calculate the offset of this from "start" */ 2853 oldoffset = (entry->start + fudge) - start; 2854 2855 /* allocate a new map entry */ 2856 newentry = uvm_mapent_alloc(dstmap, 0); 2857 if (newentry == NULL) { 2858 error = ENOMEM; 2859 goto bad; 2860 } 2861 2862 /* set up new map entry */ 2863 newentry->next = NULL; 2864 newentry->prev = endchain; 2865 newentry->start = dstaddr + oldoffset; 2866 newentry->end = 2867 newentry->start + (entry->end - (entry->start + fudge)); 2868 if (newentry->end > newend || newentry->end < newentry->start) 2869 newentry->end = newend; 2870 newentry->object.uvm_obj = entry->object.uvm_obj; 2871 if (newentry->object.uvm_obj) { 2872 if (newentry->object.uvm_obj->pgops->pgo_reference) 2873 newentry->object.uvm_obj->pgops-> 2874 pgo_reference(newentry->object.uvm_obj); 2875 newentry->offset = entry->offset + fudge; 2876 } else { 2877 newentry->offset = 0; 2878 } 2879 newentry->etype = entry->etype; 2880 newentry->protection = (flags & UVM_EXTRACT_FIXPROT) ? 2881 entry->max_protection : entry->protection; 2882 newentry->max_protection = entry->max_protection; 2883 newentry->inheritance = entry->inheritance; 2884 newentry->wired_count = 0; 2885 newentry->aref.ar_amap = entry->aref.ar_amap; 2886 if (newentry->aref.ar_amap) { 2887 newentry->aref.ar_pageoff = 2888 entry->aref.ar_pageoff + (fudge >> PAGE_SHIFT); 2889 uvm_map_reference_amap(newentry, AMAP_SHARED | 2890 ((flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0)); 2891 } else { 2892 newentry->aref.ar_pageoff = 0; 2893 } 2894 newentry->advice = entry->advice; 2895 if ((flags & UVM_EXTRACT_QREF) != 0) { 2896 newentry->flags |= UVM_MAP_NOMERGE; 2897 } 2898 2899 /* now link it on the chain */ 2900 nchain++; 2901 nsize += newentry->end - newentry->start; 2902 if (endchain == NULL) { 2903 chain = endchain = newentry; 2904 } else { 2905 endchain->next = newentry; 2906 endchain = newentry; 2907 } 2908 2909 /* end of 'while' loop! */ 2910 if ((flags & UVM_EXTRACT_CONTIG) && entry->end < end && 2911 (entry->next == &srcmap->header || 2912 entry->next->start != entry->end)) { 2913 error = EINVAL; 2914 goto bad; 2915 } 2916 entry = entry->next; 2917 fudge = 0; 2918 } 2919 2920 /* 2921 * step 4: close off chain (in format expected by uvm_map_replace) 2922 */ 2923 2924 if (chain) 2925 chain->prev = endchain; 2926 2927 /* 2928 * step 5: attempt to lock the dest map so we can pmap_copy. 2929 * note usage of copy_ok: 2930 * 1 => dstmap locked, pmap_copy ok, and we "replace" here (step 5) 2931 * 0 => dstmap unlocked, NO pmap_copy, and we will "replace" in step 7 2932 */ 2933 2934 if (srcmap == dstmap || vm_map_lock_try(dstmap) == true) { 2935 copy_ok = 1; 2936 if (!uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 2937 nchain, nsize, &resentry)) { 2938 if (srcmap != dstmap) 2939 vm_map_unlock(dstmap); 2940 error = EIO; 2941 goto bad; 2942 } 2943 } else { 2944 copy_ok = 0; 2945 /* replace defered until step 7 */ 2946 } 2947 2948 /* 2949 * step 6: traverse the srcmap a second time to do the following: 2950 * - if we got a lock on the dstmap do pmap_copy 2951 * - if UVM_EXTRACT_REMOVE remove the entries 2952 * we make use of orig_entry and orig_fudge (saved in step 2) 2953 */ 2954 2955 if (copy_ok || (flags & UVM_EXTRACT_REMOVE)) { 2956 2957 /* purge possible stale hints from srcmap */ 2958 if (flags & UVM_EXTRACT_REMOVE) { 2959 SAVE_HINT(srcmap, srcmap->hint, orig_entry->prev); 2960 if (srcmap->first_free != &srcmap->header && 2961 srcmap->first_free->start >= start) 2962 srcmap->first_free = orig_entry->prev; 2963 } 2964 2965 entry = orig_entry; 2966 fudge = orig_fudge; 2967 deadentry = NULL; /* for UVM_EXTRACT_REMOVE */ 2968 2969 while (entry->start < end && entry != &srcmap->header) { 2970 if (copy_ok) { 2971 oldoffset = (entry->start + fudge) - start; 2972 elen = MIN(end, entry->end) - 2973 (entry->start + fudge); 2974 pmap_copy(dstmap->pmap, srcmap->pmap, 2975 dstaddr + oldoffset, elen, 2976 entry->start + fudge); 2977 } 2978 2979 /* we advance "entry" in the following if statement */ 2980 if (flags & UVM_EXTRACT_REMOVE) { 2981 pmap_remove(srcmap->pmap, entry->start, 2982 entry->end); 2983 oldentry = entry; /* save entry */ 2984 entry = entry->next; /* advance */ 2985 uvm_map_entry_unlink(srcmap, oldentry); 2986 /* add to dead list */ 2987 oldentry->next = deadentry; 2988 deadentry = oldentry; 2989 } else { 2990 entry = entry->next; /* advance */ 2991 } 2992 2993 /* end of 'while' loop */ 2994 fudge = 0; 2995 } 2996 pmap_update(srcmap->pmap); 2997 2998 /* 2999 * unlock dstmap. we will dispose of deadentry in 3000 * step 7 if needed 3001 */ 3002 3003 if (copy_ok && srcmap != dstmap) 3004 vm_map_unlock(dstmap); 3005 3006 } else { 3007 deadentry = NULL; 3008 } 3009 3010 /* 3011 * step 7: we are done with the source map, unlock. if copy_ok 3012 * is 0 then we have not replaced the dummy mapping in dstmap yet 3013 * and we need to do so now. 3014 */ 3015 3016 vm_map_unlock(srcmap); 3017 if ((flags & UVM_EXTRACT_REMOVE) && deadentry) 3018 uvm_unmap_detach(deadentry, 0); /* dispose of old entries */ 3019 3020 /* now do the replacement if we didn't do it in step 5 */ 3021 if (copy_ok == 0) { 3022 vm_map_lock(dstmap); 3023 error = uvm_map_replace(dstmap, dstaddr, dstaddr+len, chain, 3024 nchain, nsize, &resentry); 3025 vm_map_unlock(dstmap); 3026 3027 if (error == false) { 3028 error = EIO; 3029 goto bad2; 3030 } 3031 } 3032 3033 if (resentry != NULL) 3034 uvm_mapent_free(resentry); 3035 3036 return (0); 3037 3038 /* 3039 * bad: failure recovery 3040 */ 3041 bad: 3042 vm_map_unlock(srcmap); 3043 bad2: /* src already unlocked */ 3044 if (chain) 3045 uvm_unmap_detach(chain, 3046 (flags & UVM_EXTRACT_QREF) ? AMAP_REFALL : 0); 3047 3048 if (resentry != NULL) 3049 uvm_mapent_free(resentry); 3050 3051 if ((flags & UVM_EXTRACT_RESERVED) == 0) { 3052 uvm_unmap(dstmap, dstaddr, dstaddr+len); /* ??? */ 3053 } 3054 return (error); 3055 } 3056 3057 /* end of extraction functions */ 3058 3059 /* 3060 * uvm_map_submap: punch down part of a map into a submap 3061 * 3062 * => only the kernel_map is allowed to be submapped 3063 * => the purpose of submapping is to break up the locking granularity 3064 * of a larger map 3065 * => the range specified must have been mapped previously with a uvm_map() 3066 * call [with uobj==NULL] to create a blank map entry in the main map. 3067 * [And it had better still be blank!] 3068 * => maps which contain submaps should never be copied or forked. 3069 * => to remove a submap, use uvm_unmap() on the main map 3070 * and then uvm_map_deallocate() the submap. 3071 * => main map must be unlocked. 3072 * => submap must have been init'd and have a zero reference count. 3073 * [need not be locked as we don't actually reference it] 3074 */ 3075 3076 int 3077 uvm_map_submap(struct vm_map *map, vaddr_t start, vaddr_t end, 3078 struct vm_map *submap) 3079 { 3080 struct vm_map_entry *entry; 3081 struct uvm_mapent_reservation umr; 3082 int error; 3083 3084 uvm_mapent_reserve(map, &umr, 2, 0); 3085 3086 vm_map_lock(map); 3087 VM_MAP_RANGE_CHECK(map, start, end); 3088 3089 if (uvm_map_lookup_entry(map, start, &entry)) { 3090 UVM_MAP_CLIP_START(map, entry, start, &umr); 3091 UVM_MAP_CLIP_END(map, entry, end, &umr); /* to be safe */ 3092 } else { 3093 entry = NULL; 3094 } 3095 3096 if (entry != NULL && 3097 entry->start == start && entry->end == end && 3098 entry->object.uvm_obj == NULL && entry->aref.ar_amap == NULL && 3099 !UVM_ET_ISCOPYONWRITE(entry) && !UVM_ET_ISNEEDSCOPY(entry)) { 3100 entry->etype |= UVM_ET_SUBMAP; 3101 entry->object.sub_map = submap; 3102 entry->offset = 0; 3103 uvm_map_reference(submap); 3104 error = 0; 3105 } else { 3106 error = EINVAL; 3107 } 3108 vm_map_unlock(map); 3109 3110 uvm_mapent_unreserve(map, &umr); 3111 3112 return error; 3113 } 3114 3115 /* 3116 * uvm_map_setup_kernel: init in-kernel map 3117 * 3118 * => map must not be in service yet. 3119 */ 3120 3121 void 3122 uvm_map_setup_kernel(struct vm_map_kernel *map, 3123 vaddr_t vmin, vaddr_t vmax, int flags) 3124 { 3125 3126 uvm_map_setup(&map->vmk_map, vmin, vmax, flags); 3127 callback_head_init(&map->vmk_reclaim_callback, IPL_VM); 3128 LIST_INIT(&map->vmk_kentry_free); 3129 map->vmk_merged_entries = NULL; 3130 } 3131 3132 3133 /* 3134 * uvm_map_protect: change map protection 3135 * 3136 * => set_max means set max_protection. 3137 * => map must be unlocked. 3138 */ 3139 3140 #define MASK(entry) (UVM_ET_ISCOPYONWRITE(entry) ? \ 3141 ~VM_PROT_WRITE : VM_PROT_ALL) 3142 3143 int 3144 uvm_map_protect(struct vm_map *map, vaddr_t start, vaddr_t end, 3145 vm_prot_t new_prot, bool set_max) 3146 { 3147 struct vm_map_entry *current, *entry; 3148 int error = 0; 3149 UVMHIST_FUNC("uvm_map_protect"); UVMHIST_CALLED(maphist); 3150 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_prot=0x%x)", 3151 map, start, end, new_prot); 3152 3153 vm_map_lock(map); 3154 VM_MAP_RANGE_CHECK(map, start, end); 3155 if (uvm_map_lookup_entry(map, start, &entry)) { 3156 UVM_MAP_CLIP_START(map, entry, start, NULL); 3157 } else { 3158 entry = entry->next; 3159 } 3160 3161 /* 3162 * make a first pass to check for protection violations. 3163 */ 3164 3165 current = entry; 3166 while ((current != &map->header) && (current->start < end)) { 3167 if (UVM_ET_ISSUBMAP(current)) { 3168 error = EINVAL; 3169 goto out; 3170 } 3171 if ((new_prot & current->max_protection) != new_prot) { 3172 error = EACCES; 3173 goto out; 3174 } 3175 /* 3176 * Don't allow VM_PROT_EXECUTE to be set on entries that 3177 * point to vnodes that are associated with a NOEXEC file 3178 * system. 3179 */ 3180 if (UVM_ET_ISOBJ(current) && 3181 UVM_OBJ_IS_VNODE(current->object.uvm_obj)) { 3182 struct vnode *vp = 3183 (struct vnode *) current->object.uvm_obj; 3184 3185 if ((new_prot & VM_PROT_EXECUTE) != 0 && 3186 (vp->v_mount->mnt_flag & MNT_NOEXEC) != 0) { 3187 error = EACCES; 3188 goto out; 3189 } 3190 } 3191 3192 current = current->next; 3193 } 3194 3195 /* go back and fix up protections (no need to clip this time). */ 3196 3197 current = entry; 3198 while ((current != &map->header) && (current->start < end)) { 3199 vm_prot_t old_prot; 3200 3201 UVM_MAP_CLIP_END(map, current, end, NULL); 3202 old_prot = current->protection; 3203 if (set_max) 3204 current->protection = 3205 (current->max_protection = new_prot) & old_prot; 3206 else 3207 current->protection = new_prot; 3208 3209 /* 3210 * update physical map if necessary. worry about copy-on-write 3211 * here -- CHECK THIS XXX 3212 */ 3213 3214 if (current->protection != old_prot) { 3215 /* update pmap! */ 3216 pmap_protect(map->pmap, current->start, current->end, 3217 current->protection & MASK(entry)); 3218 3219 /* 3220 * If this entry points at a vnode, and the 3221 * protection includes VM_PROT_EXECUTE, mark 3222 * the vnode as VEXECMAP. 3223 */ 3224 if (UVM_ET_ISOBJ(current)) { 3225 struct uvm_object *uobj = 3226 current->object.uvm_obj; 3227 3228 if (UVM_OBJ_IS_VNODE(uobj) && 3229 (current->protection & VM_PROT_EXECUTE)) { 3230 vn_markexec((struct vnode *) uobj); 3231 } 3232 } 3233 } 3234 3235 /* 3236 * If the map is configured to lock any future mappings, 3237 * wire this entry now if the old protection was VM_PROT_NONE 3238 * and the new protection is not VM_PROT_NONE. 3239 */ 3240 3241 if ((map->flags & VM_MAP_WIREFUTURE) != 0 && 3242 VM_MAPENT_ISWIRED(entry) == 0 && 3243 old_prot == VM_PROT_NONE && 3244 new_prot != VM_PROT_NONE) { 3245 if (uvm_map_pageable(map, entry->start, 3246 entry->end, false, 3247 UVM_LK_ENTER|UVM_LK_EXIT) != 0) { 3248 3249 /* 3250 * If locking the entry fails, remember the 3251 * error if it's the first one. Note we 3252 * still continue setting the protection in 3253 * the map, but will return the error 3254 * condition regardless. 3255 * 3256 * XXX Ignore what the actual error is, 3257 * XXX just call it a resource shortage 3258 * XXX so that it doesn't get confused 3259 * XXX what uvm_map_protect() itself would 3260 * XXX normally return. 3261 */ 3262 3263 error = ENOMEM; 3264 } 3265 } 3266 current = current->next; 3267 } 3268 pmap_update(map->pmap); 3269 3270 out: 3271 vm_map_unlock(map); 3272 3273 UVMHIST_LOG(maphist, "<- done, error=%d",error,0,0,0); 3274 return error; 3275 } 3276 3277 #undef MASK 3278 3279 /* 3280 * uvm_map_inherit: set inheritance code for range of addrs in map. 3281 * 3282 * => map must be unlocked 3283 * => note that the inherit code is used during a "fork". see fork 3284 * code for details. 3285 */ 3286 3287 int 3288 uvm_map_inherit(struct vm_map *map, vaddr_t start, vaddr_t end, 3289 vm_inherit_t new_inheritance) 3290 { 3291 struct vm_map_entry *entry, *temp_entry; 3292 UVMHIST_FUNC("uvm_map_inherit"); UVMHIST_CALLED(maphist); 3293 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_inh=0x%x)", 3294 map, start, end, new_inheritance); 3295 3296 switch (new_inheritance) { 3297 case MAP_INHERIT_NONE: 3298 case MAP_INHERIT_COPY: 3299 case MAP_INHERIT_SHARE: 3300 break; 3301 default: 3302 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3303 return EINVAL; 3304 } 3305 3306 vm_map_lock(map); 3307 VM_MAP_RANGE_CHECK(map, start, end); 3308 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3309 entry = temp_entry; 3310 UVM_MAP_CLIP_START(map, entry, start, NULL); 3311 } else { 3312 entry = temp_entry->next; 3313 } 3314 while ((entry != &map->header) && (entry->start < end)) { 3315 UVM_MAP_CLIP_END(map, entry, end, NULL); 3316 entry->inheritance = new_inheritance; 3317 entry = entry->next; 3318 } 3319 vm_map_unlock(map); 3320 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3321 return 0; 3322 } 3323 3324 /* 3325 * uvm_map_advice: set advice code for range of addrs in map. 3326 * 3327 * => map must be unlocked 3328 */ 3329 3330 int 3331 uvm_map_advice(struct vm_map *map, vaddr_t start, vaddr_t end, int new_advice) 3332 { 3333 struct vm_map_entry *entry, *temp_entry; 3334 UVMHIST_FUNC("uvm_map_advice"); UVMHIST_CALLED(maphist); 3335 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_adv=0x%x)", 3336 map, start, end, new_advice); 3337 3338 vm_map_lock(map); 3339 VM_MAP_RANGE_CHECK(map, start, end); 3340 if (uvm_map_lookup_entry(map, start, &temp_entry)) { 3341 entry = temp_entry; 3342 UVM_MAP_CLIP_START(map, entry, start, NULL); 3343 } else { 3344 entry = temp_entry->next; 3345 } 3346 3347 /* 3348 * XXXJRT: disallow holes? 3349 */ 3350 3351 while ((entry != &map->header) && (entry->start < end)) { 3352 UVM_MAP_CLIP_END(map, entry, end, NULL); 3353 3354 switch (new_advice) { 3355 case MADV_NORMAL: 3356 case MADV_RANDOM: 3357 case MADV_SEQUENTIAL: 3358 /* nothing special here */ 3359 break; 3360 3361 default: 3362 vm_map_unlock(map); 3363 UVMHIST_LOG(maphist,"<- done (INVALID ARG)",0,0,0,0); 3364 return EINVAL; 3365 } 3366 entry->advice = new_advice; 3367 entry = entry->next; 3368 } 3369 3370 vm_map_unlock(map); 3371 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3372 return 0; 3373 } 3374 3375 /* 3376 * uvm_map_willneed: apply MADV_WILLNEED 3377 */ 3378 3379 int 3380 uvm_map_willneed(struct vm_map *map, vaddr_t start, vaddr_t end) 3381 { 3382 struct vm_map_entry *entry; 3383 UVMHIST_FUNC("uvm_map_willneed"); UVMHIST_CALLED(maphist); 3384 UVMHIST_LOG(maphist,"(map=0x%lx,start=0x%lx,end=0x%lx)", 3385 map, start, end, 0); 3386 3387 vm_map_lock_read(map); 3388 VM_MAP_RANGE_CHECK(map, start, end); 3389 if (!uvm_map_lookup_entry(map, start, &entry)) { 3390 entry = entry->next; 3391 } 3392 while (entry->start < end) { 3393 struct vm_amap * const amap = entry->aref.ar_amap; 3394 struct uvm_object * const uobj = entry->object.uvm_obj; 3395 3396 KASSERT(entry != &map->header); 3397 KASSERT(start < entry->end); 3398 /* 3399 * XXX IMPLEMENT ME. 3400 * Should invent a "weak" mode for uvm_fault() 3401 * which would only do the PGO_LOCKED pgo_get(). 3402 * 3403 * for now, we handle only the easy but common case. 3404 */ 3405 if (UVM_ET_ISOBJ(entry) && amap == NULL && uobj != NULL) { 3406 off_t offset; 3407 off_t size; 3408 3409 offset = entry->offset; 3410 if (start < entry->start) { 3411 offset += entry->start - start; 3412 } 3413 size = entry->offset + (entry->end - entry->start); 3414 if (entry->end < end) { 3415 size -= end - entry->end; 3416 } 3417 uvm_readahead(uobj, offset, size); 3418 } 3419 entry = entry->next; 3420 } 3421 vm_map_unlock_read(map); 3422 UVMHIST_LOG(maphist,"<- done (OK)",0,0,0,0); 3423 return 0; 3424 } 3425 3426 /* 3427 * uvm_map_pageable: sets the pageability of a range in a map. 3428 * 3429 * => wires map entries. should not be used for transient page locking. 3430 * for that, use uvm_fault_wire()/uvm_fault_unwire() (see uvm_vslock()). 3431 * => regions specified as not pageable require lock-down (wired) memory 3432 * and page tables. 3433 * => map must never be read-locked 3434 * => if islocked is true, map is already write-locked 3435 * => we always unlock the map, since we must downgrade to a read-lock 3436 * to call uvm_fault_wire() 3437 * => XXXCDC: check this and try and clean it up. 3438 */ 3439 3440 int 3441 uvm_map_pageable(struct vm_map *map, vaddr_t start, vaddr_t end, 3442 bool new_pageable, int lockflags) 3443 { 3444 struct vm_map_entry *entry, *start_entry, *failed_entry; 3445 int rv; 3446 #ifdef DIAGNOSTIC 3447 u_int timestamp_save; 3448 #endif 3449 UVMHIST_FUNC("uvm_map_pageable"); UVMHIST_CALLED(maphist); 3450 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,new_pageable=0x%x)", 3451 map, start, end, new_pageable); 3452 KASSERT(map->flags & VM_MAP_PAGEABLE); 3453 3454 if ((lockflags & UVM_LK_ENTER) == 0) 3455 vm_map_lock(map); 3456 VM_MAP_RANGE_CHECK(map, start, end); 3457 3458 /* 3459 * only one pageability change may take place at one time, since 3460 * uvm_fault_wire assumes it will be called only once for each 3461 * wiring/unwiring. therefore, we have to make sure we're actually 3462 * changing the pageability for the entire region. we do so before 3463 * making any changes. 3464 */ 3465 3466 if (uvm_map_lookup_entry(map, start, &start_entry) == false) { 3467 if ((lockflags & UVM_LK_EXIT) == 0) 3468 vm_map_unlock(map); 3469 3470 UVMHIST_LOG(maphist,"<- done (fault)",0,0,0,0); 3471 return EFAULT; 3472 } 3473 entry = start_entry; 3474 3475 /* 3476 * handle wiring and unwiring separately. 3477 */ 3478 3479 if (new_pageable) { /* unwire */ 3480 UVM_MAP_CLIP_START(map, entry, start, NULL); 3481 3482 /* 3483 * unwiring. first ensure that the range to be unwired is 3484 * really wired down and that there are no holes. 3485 */ 3486 3487 while ((entry != &map->header) && (entry->start < end)) { 3488 if (entry->wired_count == 0 || 3489 (entry->end < end && 3490 (entry->next == &map->header || 3491 entry->next->start > entry->end))) { 3492 if ((lockflags & UVM_LK_EXIT) == 0) 3493 vm_map_unlock(map); 3494 UVMHIST_LOG(maphist, "<- done (INVAL)",0,0,0,0); 3495 return EINVAL; 3496 } 3497 entry = entry->next; 3498 } 3499 3500 /* 3501 * POSIX 1003.1b - a single munlock call unlocks a region, 3502 * regardless of the number of mlock calls made on that 3503 * region. 3504 */ 3505 3506 entry = start_entry; 3507 while ((entry != &map->header) && (entry->start < end)) { 3508 UVM_MAP_CLIP_END(map, entry, end, NULL); 3509 if (VM_MAPENT_ISWIRED(entry)) 3510 uvm_map_entry_unwire(map, entry); 3511 entry = entry->next; 3512 } 3513 if ((lockflags & UVM_LK_EXIT) == 0) 3514 vm_map_unlock(map); 3515 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3516 return 0; 3517 } 3518 3519 /* 3520 * wire case: in two passes [XXXCDC: ugly block of code here] 3521 * 3522 * 1: holding the write lock, we create any anonymous maps that need 3523 * to be created. then we clip each map entry to the region to 3524 * be wired and increment its wiring count. 3525 * 3526 * 2: we downgrade to a read lock, and call uvm_fault_wire to fault 3527 * in the pages for any newly wired area (wired_count == 1). 3528 * 3529 * downgrading to a read lock for uvm_fault_wire avoids a possible 3530 * deadlock with another thread that may have faulted on one of 3531 * the pages to be wired (it would mark the page busy, blocking 3532 * us, then in turn block on the map lock that we hold). because 3533 * of problems in the recursive lock package, we cannot upgrade 3534 * to a write lock in vm_map_lookup. thus, any actions that 3535 * require the write lock must be done beforehand. because we 3536 * keep the read lock on the map, the copy-on-write status of the 3537 * entries we modify here cannot change. 3538 */ 3539 3540 while ((entry != &map->header) && (entry->start < end)) { 3541 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3542 3543 /* 3544 * perform actions of vm_map_lookup that need the 3545 * write lock on the map: create an anonymous map 3546 * for a copy-on-write region, or an anonymous map 3547 * for a zero-fill region. (XXXCDC: submap case 3548 * ok?) 3549 */ 3550 3551 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3552 if (UVM_ET_ISNEEDSCOPY(entry) && 3553 ((entry->max_protection & VM_PROT_WRITE) || 3554 (entry->object.uvm_obj == NULL))) { 3555 amap_copy(map, entry, 0, start, end); 3556 /* XXXCDC: wait OK? */ 3557 } 3558 } 3559 } 3560 UVM_MAP_CLIP_START(map, entry, start, NULL); 3561 UVM_MAP_CLIP_END(map, entry, end, NULL); 3562 entry->wired_count++; 3563 3564 /* 3565 * Check for holes 3566 */ 3567 3568 if (entry->protection == VM_PROT_NONE || 3569 (entry->end < end && 3570 (entry->next == &map->header || 3571 entry->next->start > entry->end))) { 3572 3573 /* 3574 * found one. amap creation actions do not need to 3575 * be undone, but the wired counts need to be restored. 3576 */ 3577 3578 while (entry != &map->header && entry->end > start) { 3579 entry->wired_count--; 3580 entry = entry->prev; 3581 } 3582 if ((lockflags & UVM_LK_EXIT) == 0) 3583 vm_map_unlock(map); 3584 UVMHIST_LOG(maphist,"<- done (INVALID WIRE)",0,0,0,0); 3585 return EINVAL; 3586 } 3587 entry = entry->next; 3588 } 3589 3590 /* 3591 * Pass 2. 3592 */ 3593 3594 #ifdef DIAGNOSTIC 3595 timestamp_save = map->timestamp; 3596 #endif 3597 vm_map_busy(map); 3598 vm_map_unlock(map); 3599 3600 rv = 0; 3601 entry = start_entry; 3602 while (entry != &map->header && entry->start < end) { 3603 if (entry->wired_count == 1) { 3604 rv = uvm_fault_wire(map, entry->start, entry->end, 3605 entry->max_protection, 1); 3606 if (rv) { 3607 3608 /* 3609 * wiring failed. break out of the loop. 3610 * we'll clean up the map below, once we 3611 * have a write lock again. 3612 */ 3613 3614 break; 3615 } 3616 } 3617 entry = entry->next; 3618 } 3619 3620 if (rv) { /* failed? */ 3621 3622 /* 3623 * Get back to an exclusive (write) lock. 3624 */ 3625 3626 vm_map_lock(map); 3627 vm_map_unbusy(map); 3628 3629 #ifdef DIAGNOSTIC 3630 if (timestamp_save + 1 != map->timestamp) 3631 panic("uvm_map_pageable: stale map"); 3632 #endif 3633 3634 /* 3635 * first drop the wiring count on all the entries 3636 * which haven't actually been wired yet. 3637 */ 3638 3639 failed_entry = entry; 3640 while (entry != &map->header && entry->start < end) { 3641 entry->wired_count--; 3642 entry = entry->next; 3643 } 3644 3645 /* 3646 * now, unwire all the entries that were successfully 3647 * wired above. 3648 */ 3649 3650 entry = start_entry; 3651 while (entry != failed_entry) { 3652 entry->wired_count--; 3653 if (VM_MAPENT_ISWIRED(entry) == 0) 3654 uvm_map_entry_unwire(map, entry); 3655 entry = entry->next; 3656 } 3657 if ((lockflags & UVM_LK_EXIT) == 0) 3658 vm_map_unlock(map); 3659 UVMHIST_LOG(maphist, "<- done (RV=%d)", rv,0,0,0); 3660 return (rv); 3661 } 3662 3663 if ((lockflags & UVM_LK_EXIT) == 0) { 3664 vm_map_unbusy(map); 3665 } else { 3666 3667 /* 3668 * Get back to an exclusive (write) lock. 3669 */ 3670 3671 vm_map_lock(map); 3672 vm_map_unbusy(map); 3673 } 3674 3675 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3676 return 0; 3677 } 3678 3679 /* 3680 * uvm_map_pageable_all: special case of uvm_map_pageable - affects 3681 * all mapped regions. 3682 * 3683 * => map must not be locked. 3684 * => if no flags are specified, all regions are unwired. 3685 * => XXXJRT: has some of the same problems as uvm_map_pageable() above. 3686 */ 3687 3688 int 3689 uvm_map_pageable_all(struct vm_map *map, int flags, vsize_t limit) 3690 { 3691 struct vm_map_entry *entry, *failed_entry; 3692 vsize_t size; 3693 int rv; 3694 #ifdef DIAGNOSTIC 3695 u_int timestamp_save; 3696 #endif 3697 UVMHIST_FUNC("uvm_map_pageable_all"); UVMHIST_CALLED(maphist); 3698 UVMHIST_LOG(maphist,"(map=0x%x,flags=0x%x)", map, flags, 0, 0); 3699 3700 KASSERT(map->flags & VM_MAP_PAGEABLE); 3701 3702 vm_map_lock(map); 3703 3704 /* 3705 * handle wiring and unwiring separately. 3706 */ 3707 3708 if (flags == 0) { /* unwire */ 3709 3710 /* 3711 * POSIX 1003.1b -- munlockall unlocks all regions, 3712 * regardless of how many times mlockall has been called. 3713 */ 3714 3715 for (entry = map->header.next; entry != &map->header; 3716 entry = entry->next) { 3717 if (VM_MAPENT_ISWIRED(entry)) 3718 uvm_map_entry_unwire(map, entry); 3719 } 3720 map->flags &= ~VM_MAP_WIREFUTURE; 3721 vm_map_unlock(map); 3722 UVMHIST_LOG(maphist,"<- done (OK UNWIRE)",0,0,0,0); 3723 return 0; 3724 } 3725 3726 if (flags & MCL_FUTURE) { 3727 3728 /* 3729 * must wire all future mappings; remember this. 3730 */ 3731 3732 map->flags |= VM_MAP_WIREFUTURE; 3733 } 3734 3735 if ((flags & MCL_CURRENT) == 0) { 3736 3737 /* 3738 * no more work to do! 3739 */ 3740 3741 UVMHIST_LOG(maphist,"<- done (OK no wire)",0,0,0,0); 3742 vm_map_unlock(map); 3743 return 0; 3744 } 3745 3746 /* 3747 * wire case: in three passes [XXXCDC: ugly block of code here] 3748 * 3749 * 1: holding the write lock, count all pages mapped by non-wired 3750 * entries. if this would cause us to go over our limit, we fail. 3751 * 3752 * 2: still holding the write lock, we create any anonymous maps that 3753 * need to be created. then we increment its wiring count. 3754 * 3755 * 3: we downgrade to a read lock, and call uvm_fault_wire to fault 3756 * in the pages for any newly wired area (wired_count == 1). 3757 * 3758 * downgrading to a read lock for uvm_fault_wire avoids a possible 3759 * deadlock with another thread that may have faulted on one of 3760 * the pages to be wired (it would mark the page busy, blocking 3761 * us, then in turn block on the map lock that we hold). because 3762 * of problems in the recursive lock package, we cannot upgrade 3763 * to a write lock in vm_map_lookup. thus, any actions that 3764 * require the write lock must be done beforehand. because we 3765 * keep the read lock on the map, the copy-on-write status of the 3766 * entries we modify here cannot change. 3767 */ 3768 3769 for (size = 0, entry = map->header.next; entry != &map->header; 3770 entry = entry->next) { 3771 if (entry->protection != VM_PROT_NONE && 3772 VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3773 size += entry->end - entry->start; 3774 } 3775 } 3776 3777 if (atop(size) + uvmexp.wired > uvmexp.wiredmax) { 3778 vm_map_unlock(map); 3779 return ENOMEM; 3780 } 3781 3782 if (limit != 0 && 3783 (size + ptoa(pmap_wired_count(vm_map_pmap(map))) > limit)) { 3784 vm_map_unlock(map); 3785 return ENOMEM; 3786 } 3787 3788 /* 3789 * Pass 2. 3790 */ 3791 3792 for (entry = map->header.next; entry != &map->header; 3793 entry = entry->next) { 3794 if (entry->protection == VM_PROT_NONE) 3795 continue; 3796 if (VM_MAPENT_ISWIRED(entry) == 0) { /* not already wired? */ 3797 3798 /* 3799 * perform actions of vm_map_lookup that need the 3800 * write lock on the map: create an anonymous map 3801 * for a copy-on-write region, or an anonymous map 3802 * for a zero-fill region. (XXXCDC: submap case 3803 * ok?) 3804 */ 3805 3806 if (!UVM_ET_ISSUBMAP(entry)) { /* not submap */ 3807 if (UVM_ET_ISNEEDSCOPY(entry) && 3808 ((entry->max_protection & VM_PROT_WRITE) || 3809 (entry->object.uvm_obj == NULL))) { 3810 amap_copy(map, entry, 0, entry->start, 3811 entry->end); 3812 /* XXXCDC: wait OK? */ 3813 } 3814 } 3815 } 3816 entry->wired_count++; 3817 } 3818 3819 /* 3820 * Pass 3. 3821 */ 3822 3823 #ifdef DIAGNOSTIC 3824 timestamp_save = map->timestamp; 3825 #endif 3826 vm_map_busy(map); 3827 vm_map_unlock(map); 3828 3829 rv = 0; 3830 for (entry = map->header.next; entry != &map->header; 3831 entry = entry->next) { 3832 if (entry->wired_count == 1) { 3833 rv = uvm_fault_wire(map, entry->start, entry->end, 3834 entry->max_protection, 1); 3835 if (rv) { 3836 3837 /* 3838 * wiring failed. break out of the loop. 3839 * we'll clean up the map below, once we 3840 * have a write lock again. 3841 */ 3842 3843 break; 3844 } 3845 } 3846 } 3847 3848 if (rv) { 3849 3850 /* 3851 * Get back an exclusive (write) lock. 3852 */ 3853 3854 vm_map_lock(map); 3855 vm_map_unbusy(map); 3856 3857 #ifdef DIAGNOSTIC 3858 if (timestamp_save + 1 != map->timestamp) 3859 panic("uvm_map_pageable_all: stale map"); 3860 #endif 3861 3862 /* 3863 * first drop the wiring count on all the entries 3864 * which haven't actually been wired yet. 3865 * 3866 * Skip VM_PROT_NONE entries like we did above. 3867 */ 3868 3869 failed_entry = entry; 3870 for (/* nothing */; entry != &map->header; 3871 entry = entry->next) { 3872 if (entry->protection == VM_PROT_NONE) 3873 continue; 3874 entry->wired_count--; 3875 } 3876 3877 /* 3878 * now, unwire all the entries that were successfully 3879 * wired above. 3880 * 3881 * Skip VM_PROT_NONE entries like we did above. 3882 */ 3883 3884 for (entry = map->header.next; entry != failed_entry; 3885 entry = entry->next) { 3886 if (entry->protection == VM_PROT_NONE) 3887 continue; 3888 entry->wired_count--; 3889 if (VM_MAPENT_ISWIRED(entry)) 3890 uvm_map_entry_unwire(map, entry); 3891 } 3892 vm_map_unlock(map); 3893 UVMHIST_LOG(maphist,"<- done (RV=%d)", rv,0,0,0); 3894 return (rv); 3895 } 3896 3897 vm_map_unbusy(map); 3898 3899 UVMHIST_LOG(maphist,"<- done (OK WIRE)",0,0,0,0); 3900 return 0; 3901 } 3902 3903 /* 3904 * uvm_map_clean: clean out a map range 3905 * 3906 * => valid flags: 3907 * if (flags & PGO_CLEANIT): dirty pages are cleaned first 3908 * if (flags & PGO_SYNCIO): dirty pages are written synchronously 3909 * if (flags & PGO_DEACTIVATE): any cached pages are deactivated after clean 3910 * if (flags & PGO_FREE): any cached pages are freed after clean 3911 * => returns an error if any part of the specified range isn't mapped 3912 * => never a need to flush amap layer since the anonymous memory has 3913 * no permanent home, but may deactivate pages there 3914 * => called from sys_msync() and sys_madvise() 3915 * => caller must not write-lock map (read OK). 3916 * => we may sleep while cleaning if SYNCIO [with map read-locked] 3917 */ 3918 3919 int 3920 uvm_map_clean(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 3921 { 3922 struct vm_map_entry *current, *entry; 3923 struct uvm_object *uobj; 3924 struct vm_amap *amap; 3925 struct vm_anon *anon; 3926 struct vm_page *pg; 3927 vaddr_t offset; 3928 vsize_t size; 3929 voff_t uoff; 3930 int error, refs; 3931 UVMHIST_FUNC("uvm_map_clean"); UVMHIST_CALLED(maphist); 3932 3933 UVMHIST_LOG(maphist,"(map=0x%x,start=0x%x,end=0x%x,flags=0x%x)", 3934 map, start, end, flags); 3935 KASSERT((flags & (PGO_FREE|PGO_DEACTIVATE)) != 3936 (PGO_FREE|PGO_DEACTIVATE)); 3937 3938 vm_map_lock_read(map); 3939 VM_MAP_RANGE_CHECK(map, start, end); 3940 if (uvm_map_lookup_entry(map, start, &entry) == false) { 3941 vm_map_unlock_read(map); 3942 return EFAULT; 3943 } 3944 3945 /* 3946 * Make a first pass to check for holes and wiring problems. 3947 */ 3948 3949 for (current = entry; current->start < end; current = current->next) { 3950 if (UVM_ET_ISSUBMAP(current)) { 3951 vm_map_unlock_read(map); 3952 return EINVAL; 3953 } 3954 if ((flags & PGO_FREE) != 0 && VM_MAPENT_ISWIRED(entry)) { 3955 vm_map_unlock_read(map); 3956 return EBUSY; 3957 } 3958 if (end <= current->end) { 3959 break; 3960 } 3961 if (current->end != current->next->start) { 3962 vm_map_unlock_read(map); 3963 return EFAULT; 3964 } 3965 } 3966 3967 error = 0; 3968 for (current = entry; start < end; current = current->next) { 3969 amap = current->aref.ar_amap; /* upper layer */ 3970 uobj = current->object.uvm_obj; /* lower layer */ 3971 KASSERT(start >= current->start); 3972 3973 /* 3974 * No amap cleaning necessary if: 3975 * 3976 * (1) There's no amap. 3977 * 3978 * (2) We're not deactivating or freeing pages. 3979 */ 3980 3981 if (amap == NULL || (flags & (PGO_DEACTIVATE|PGO_FREE)) == 0) 3982 goto flush_object; 3983 3984 amap_lock(amap); 3985 offset = start - current->start; 3986 size = MIN(end, current->end) - start; 3987 for ( ; size != 0; size -= PAGE_SIZE, offset += PAGE_SIZE) { 3988 anon = amap_lookup(¤t->aref, offset); 3989 if (anon == NULL) 3990 continue; 3991 3992 mutex_enter(&anon->an_lock); 3993 pg = anon->an_page; 3994 if (pg == NULL) { 3995 mutex_exit(&anon->an_lock); 3996 continue; 3997 } 3998 3999 switch (flags & (PGO_CLEANIT|PGO_FREE|PGO_DEACTIVATE)) { 4000 4001 /* 4002 * In these first 3 cases, we just deactivate the page. 4003 */ 4004 4005 case PGO_CLEANIT|PGO_FREE: 4006 case PGO_CLEANIT|PGO_DEACTIVATE: 4007 case PGO_DEACTIVATE: 4008 deactivate_it: 4009 /* 4010 * skip the page if it's loaned or wired, 4011 * since it shouldn't be on a paging queue 4012 * at all in these cases. 4013 */ 4014 4015 mutex_enter(&uvm_pageqlock); 4016 if (pg->loan_count != 0 || 4017 pg->wire_count != 0) { 4018 mutex_exit(&uvm_pageqlock); 4019 mutex_exit(&anon->an_lock); 4020 continue; 4021 } 4022 KASSERT(pg->uanon == anon); 4023 uvm_pagedeactivate(pg); 4024 mutex_exit(&uvm_pageqlock); 4025 mutex_exit(&anon->an_lock); 4026 continue; 4027 4028 case PGO_FREE: 4029 4030 /* 4031 * If there are multiple references to 4032 * the amap, just deactivate the page. 4033 */ 4034 4035 if (amap_refs(amap) > 1) 4036 goto deactivate_it; 4037 4038 /* skip the page if it's wired */ 4039 if (pg->wire_count != 0) { 4040 mutex_exit(&anon->an_lock); 4041 continue; 4042 } 4043 amap_unadd(¤t->aref, offset); 4044 refs = --anon->an_ref; 4045 mutex_exit(&anon->an_lock); 4046 if (refs == 0) 4047 uvm_anfree(anon); 4048 continue; 4049 } 4050 } 4051 amap_unlock(amap); 4052 4053 flush_object: 4054 /* 4055 * flush pages if we've got a valid backing object. 4056 * note that we must always clean object pages before 4057 * freeing them since otherwise we could reveal stale 4058 * data from files. 4059 */ 4060 4061 uoff = current->offset + (start - current->start); 4062 size = MIN(end, current->end) - start; 4063 if (uobj != NULL) { 4064 mutex_enter(&uobj->vmobjlock); 4065 if (uobj->pgops->pgo_put != NULL) 4066 error = (uobj->pgops->pgo_put)(uobj, uoff, 4067 uoff + size, flags | PGO_CLEANIT); 4068 else 4069 error = 0; 4070 } 4071 start += size; 4072 } 4073 vm_map_unlock_read(map); 4074 return (error); 4075 } 4076 4077 4078 /* 4079 * uvm_map_checkprot: check protection in map 4080 * 4081 * => must allow specified protection in a fully allocated region. 4082 * => map must be read or write locked by caller. 4083 */ 4084 4085 bool 4086 uvm_map_checkprot(struct vm_map *map, vaddr_t start, vaddr_t end, 4087 vm_prot_t protection) 4088 { 4089 struct vm_map_entry *entry; 4090 struct vm_map_entry *tmp_entry; 4091 4092 if (!uvm_map_lookup_entry(map, start, &tmp_entry)) { 4093 return (false); 4094 } 4095 entry = tmp_entry; 4096 while (start < end) { 4097 if (entry == &map->header) { 4098 return (false); 4099 } 4100 4101 /* 4102 * no holes allowed 4103 */ 4104 4105 if (start < entry->start) { 4106 return (false); 4107 } 4108 4109 /* 4110 * check protection associated with entry 4111 */ 4112 4113 if ((entry->protection & protection) != protection) { 4114 return (false); 4115 } 4116 start = entry->end; 4117 entry = entry->next; 4118 } 4119 return (true); 4120 } 4121 4122 /* 4123 * uvmspace_alloc: allocate a vmspace structure. 4124 * 4125 * - structure includes vm_map and pmap 4126 * - XXX: no locking on this structure 4127 * - refcnt set to 1, rest must be init'd by caller 4128 */ 4129 struct vmspace * 4130 uvmspace_alloc(vaddr_t vmin, vaddr_t vmax) 4131 { 4132 struct vmspace *vm; 4133 UVMHIST_FUNC("uvmspace_alloc"); UVMHIST_CALLED(maphist); 4134 4135 vm = pool_cache_get(&uvm_vmspace_cache, PR_WAITOK); 4136 uvmspace_init(vm, NULL, vmin, vmax); 4137 UVMHIST_LOG(maphist,"<- done (vm=0x%x)", vm,0,0,0); 4138 return (vm); 4139 } 4140 4141 /* 4142 * uvmspace_init: initialize a vmspace structure. 4143 * 4144 * - XXX: no locking on this structure 4145 * - refcnt set to 1, rest must be init'd by caller 4146 */ 4147 void 4148 uvmspace_init(struct vmspace *vm, struct pmap *pmap, vaddr_t vmin, vaddr_t vmax) 4149 { 4150 UVMHIST_FUNC("uvmspace_init"); UVMHIST_CALLED(maphist); 4151 4152 memset(vm, 0, sizeof(*vm)); 4153 uvm_map_setup(&vm->vm_map, vmin, vmax, VM_MAP_PAGEABLE 4154 #ifdef __USING_TOPDOWN_VM 4155 | VM_MAP_TOPDOWN 4156 #endif 4157 ); 4158 if (pmap) 4159 pmap_reference(pmap); 4160 else 4161 pmap = pmap_create(); 4162 vm->vm_map.pmap = pmap; 4163 vm->vm_refcnt = 1; 4164 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4165 } 4166 4167 /* 4168 * uvmspace_share: share a vmspace between two processes 4169 * 4170 * - used for vfork, threads(?) 4171 */ 4172 4173 void 4174 uvmspace_share(struct proc *p1, struct proc *p2) 4175 { 4176 4177 uvmspace_addref(p1->p_vmspace); 4178 p2->p_vmspace = p1->p_vmspace; 4179 } 4180 4181 #if 0 4182 4183 /* 4184 * uvmspace_unshare: ensure that process "p" has its own, unshared, vmspace 4185 * 4186 * - XXX: no locking on vmspace 4187 */ 4188 4189 void 4190 uvmspace_unshare(struct lwp *l) 4191 { 4192 struct proc *p = l->l_proc; 4193 struct vmspace *nvm, *ovm = p->p_vmspace; 4194 4195 if (ovm->vm_refcnt == 1) 4196 /* nothing to do: vmspace isn't shared in the first place */ 4197 return; 4198 4199 /* make a new vmspace, still holding old one */ 4200 nvm = uvmspace_fork(ovm); 4201 4202 kpreempt_disable(); 4203 pmap_deactivate(l); /* unbind old vmspace */ 4204 p->p_vmspace = nvm; 4205 pmap_activate(l); /* switch to new vmspace */ 4206 kpreempt_enable(); 4207 4208 uvmspace_free(ovm); /* drop reference to old vmspace */ 4209 } 4210 4211 #endif 4212 4213 /* 4214 * uvmspace_exec: the process wants to exec a new program 4215 */ 4216 4217 void 4218 uvmspace_exec(struct lwp *l, vaddr_t start, vaddr_t end) 4219 { 4220 struct proc *p = l->l_proc; 4221 struct vmspace *nvm, *ovm = p->p_vmspace; 4222 struct vm_map *map = &ovm->vm_map; 4223 4224 #ifdef __sparc__ 4225 /* XXX cgd 960926: the sparc #ifdef should be a MD hook */ 4226 kill_user_windows(l); /* before stack addresses go away */ 4227 #endif 4228 4229 /* 4230 * see if more than one process is using this vmspace... 4231 */ 4232 4233 if (ovm->vm_refcnt == 1) { 4234 4235 /* 4236 * if p is the only process using its vmspace then we can safely 4237 * recycle that vmspace for the program that is being exec'd. 4238 */ 4239 4240 #ifdef SYSVSHM 4241 /* 4242 * SYSV SHM semantics require us to kill all segments on an exec 4243 */ 4244 4245 if (ovm->vm_shm) 4246 shmexit(ovm); 4247 #endif 4248 4249 /* 4250 * POSIX 1003.1b -- "lock future mappings" is revoked 4251 * when a process execs another program image. 4252 */ 4253 4254 map->flags &= ~VM_MAP_WIREFUTURE; 4255 4256 /* 4257 * now unmap the old program 4258 */ 4259 4260 pmap_remove_all(map->pmap); 4261 uvm_unmap(map, vm_map_min(map), vm_map_max(map)); 4262 KASSERT(map->header.prev == &map->header); 4263 KASSERT(map->nentries == 0); 4264 4265 /* 4266 * resize the map 4267 */ 4268 4269 vm_map_setmin(map, start); 4270 vm_map_setmax(map, end); 4271 } else { 4272 4273 /* 4274 * p's vmspace is being shared, so we can't reuse it for p since 4275 * it is still being used for others. allocate a new vmspace 4276 * for p 4277 */ 4278 4279 nvm = uvmspace_alloc(start, end); 4280 4281 /* 4282 * install new vmspace and drop our ref to the old one. 4283 */ 4284 4285 kpreempt_disable(); 4286 pmap_deactivate(l); 4287 p->p_vmspace = nvm; 4288 pmap_activate(l); 4289 kpreempt_enable(); 4290 4291 uvmspace_free(ovm); 4292 } 4293 } 4294 4295 /* 4296 * uvmspace_addref: add a referece to a vmspace. 4297 */ 4298 4299 void 4300 uvmspace_addref(struct vmspace *vm) 4301 { 4302 struct vm_map *map = &vm->vm_map; 4303 4304 KASSERT((map->flags & VM_MAP_DYING) == 0); 4305 4306 mutex_enter(&map->misc_lock); 4307 KASSERT(vm->vm_refcnt > 0); 4308 vm->vm_refcnt++; 4309 mutex_exit(&map->misc_lock); 4310 } 4311 4312 /* 4313 * uvmspace_free: free a vmspace data structure 4314 */ 4315 4316 void 4317 uvmspace_free(struct vmspace *vm) 4318 { 4319 struct vm_map_entry *dead_entries; 4320 struct vm_map *map = &vm->vm_map; 4321 int n; 4322 4323 UVMHIST_FUNC("uvmspace_free"); UVMHIST_CALLED(maphist); 4324 4325 UVMHIST_LOG(maphist,"(vm=0x%x) ref=%d", vm, vm->vm_refcnt,0,0); 4326 mutex_enter(&map->misc_lock); 4327 n = --vm->vm_refcnt; 4328 mutex_exit(&map->misc_lock); 4329 if (n > 0) 4330 return; 4331 4332 /* 4333 * at this point, there should be no other references to the map. 4334 * delete all of the mappings, then destroy the pmap. 4335 */ 4336 4337 map->flags |= VM_MAP_DYING; 4338 pmap_remove_all(map->pmap); 4339 #ifdef SYSVSHM 4340 /* Get rid of any SYSV shared memory segments. */ 4341 if (vm->vm_shm != NULL) 4342 shmexit(vm); 4343 #endif 4344 if (map->nentries) { 4345 uvm_unmap_remove(map, vm_map_min(map), vm_map_max(map), 4346 &dead_entries, NULL, 0); 4347 if (dead_entries != NULL) 4348 uvm_unmap_detach(dead_entries, 0); 4349 } 4350 KASSERT(map->nentries == 0); 4351 KASSERT(map->size == 0); 4352 mutex_destroy(&map->misc_lock); 4353 mutex_destroy(&map->mutex); 4354 rw_destroy(&map->lock); 4355 cv_destroy(&map->cv); 4356 pmap_destroy(map->pmap); 4357 pool_cache_put(&uvm_vmspace_cache, vm); 4358 } 4359 4360 /* 4361 * F O R K - m a i n e n t r y p o i n t 4362 */ 4363 /* 4364 * uvmspace_fork: fork a process' main map 4365 * 4366 * => create a new vmspace for child process from parent. 4367 * => parent's map must not be locked. 4368 */ 4369 4370 struct vmspace * 4371 uvmspace_fork(struct vmspace *vm1) 4372 { 4373 struct vmspace *vm2; 4374 struct vm_map *old_map = &vm1->vm_map; 4375 struct vm_map *new_map; 4376 struct vm_map_entry *old_entry; 4377 struct vm_map_entry *new_entry; 4378 UVMHIST_FUNC("uvmspace_fork"); UVMHIST_CALLED(maphist); 4379 4380 vm_map_lock(old_map); 4381 4382 vm2 = uvmspace_alloc(vm_map_min(old_map), vm_map_max(old_map)); 4383 memcpy(&vm2->vm_startcopy, &vm1->vm_startcopy, 4384 (char *) (vm1 + 1) - (char *) &vm1->vm_startcopy); 4385 new_map = &vm2->vm_map; /* XXX */ 4386 4387 old_entry = old_map->header.next; 4388 new_map->size = old_map->size; 4389 4390 /* 4391 * go entry-by-entry 4392 */ 4393 4394 while (old_entry != &old_map->header) { 4395 4396 /* 4397 * first, some sanity checks on the old entry 4398 */ 4399 4400 KASSERT(!UVM_ET_ISSUBMAP(old_entry)); 4401 KASSERT(UVM_ET_ISCOPYONWRITE(old_entry) || 4402 !UVM_ET_ISNEEDSCOPY(old_entry)); 4403 4404 switch (old_entry->inheritance) { 4405 case MAP_INHERIT_NONE: 4406 4407 /* 4408 * drop the mapping, modify size 4409 */ 4410 new_map->size -= old_entry->end - old_entry->start; 4411 break; 4412 4413 case MAP_INHERIT_SHARE: 4414 4415 /* 4416 * share the mapping: this means we want the old and 4417 * new entries to share amaps and backing objects. 4418 */ 4419 /* 4420 * if the old_entry needs a new amap (due to prev fork) 4421 * then we need to allocate it now so that we have 4422 * something we own to share with the new_entry. [in 4423 * other words, we need to clear needs_copy] 4424 */ 4425 4426 if (UVM_ET_ISNEEDSCOPY(old_entry)) { 4427 /* get our own amap, clears needs_copy */ 4428 amap_copy(old_map, old_entry, AMAP_COPY_NOCHUNK, 4429 0, 0); 4430 /* XXXCDC: WAITOK??? */ 4431 } 4432 4433 new_entry = uvm_mapent_alloc(new_map, 0); 4434 /* old_entry -> new_entry */ 4435 uvm_mapent_copy(old_entry, new_entry); 4436 4437 /* new pmap has nothing wired in it */ 4438 new_entry->wired_count = 0; 4439 4440 /* 4441 * gain reference to object backing the map (can't 4442 * be a submap, already checked this case). 4443 */ 4444 4445 if (new_entry->aref.ar_amap) 4446 uvm_map_reference_amap(new_entry, AMAP_SHARED); 4447 4448 if (new_entry->object.uvm_obj && 4449 new_entry->object.uvm_obj->pgops->pgo_reference) 4450 new_entry->object.uvm_obj-> 4451 pgops->pgo_reference( 4452 new_entry->object.uvm_obj); 4453 4454 /* insert entry at end of new_map's entry list */ 4455 uvm_map_entry_link(new_map, new_map->header.prev, 4456 new_entry); 4457 4458 break; 4459 4460 case MAP_INHERIT_COPY: 4461 4462 /* 4463 * copy-on-write the mapping (using mmap's 4464 * MAP_PRIVATE semantics) 4465 * 4466 * allocate new_entry, adjust reference counts. 4467 * (note that new references are read-only). 4468 */ 4469 4470 new_entry = uvm_mapent_alloc(new_map, 0); 4471 /* old_entry -> new_entry */ 4472 uvm_mapent_copy(old_entry, new_entry); 4473 4474 if (new_entry->aref.ar_amap) 4475 uvm_map_reference_amap(new_entry, 0); 4476 4477 if (new_entry->object.uvm_obj && 4478 new_entry->object.uvm_obj->pgops->pgo_reference) 4479 new_entry->object.uvm_obj->pgops->pgo_reference 4480 (new_entry->object.uvm_obj); 4481 4482 /* new pmap has nothing wired in it */ 4483 new_entry->wired_count = 0; 4484 4485 new_entry->etype |= 4486 (UVM_ET_COPYONWRITE|UVM_ET_NEEDSCOPY); 4487 uvm_map_entry_link(new_map, new_map->header.prev, 4488 new_entry); 4489 4490 /* 4491 * the new entry will need an amap. it will either 4492 * need to be copied from the old entry or created 4493 * from scratch (if the old entry does not have an 4494 * amap). can we defer this process until later 4495 * (by setting "needs_copy") or do we need to copy 4496 * the amap now? 4497 * 4498 * we must copy the amap now if any of the following 4499 * conditions hold: 4500 * 1. the old entry has an amap and that amap is 4501 * being shared. this means that the old (parent) 4502 * process is sharing the amap with another 4503 * process. if we do not clear needs_copy here 4504 * we will end up in a situation where both the 4505 * parent and child process are refering to the 4506 * same amap with "needs_copy" set. if the 4507 * parent write-faults, the fault routine will 4508 * clear "needs_copy" in the parent by allocating 4509 * a new amap. this is wrong because the 4510 * parent is supposed to be sharing the old amap 4511 * and the new amap will break that. 4512 * 4513 * 2. if the old entry has an amap and a non-zero 4514 * wire count then we are going to have to call 4515 * amap_cow_now to avoid page faults in the 4516 * parent process. since amap_cow_now requires 4517 * "needs_copy" to be clear we might as well 4518 * clear it here as well. 4519 * 4520 */ 4521 4522 if (old_entry->aref.ar_amap != NULL) { 4523 if ((amap_flags(old_entry->aref.ar_amap) & 4524 AMAP_SHARED) != 0 || 4525 VM_MAPENT_ISWIRED(old_entry)) { 4526 4527 amap_copy(new_map, new_entry, 4528 AMAP_COPY_NOCHUNK, 0, 0); 4529 /* XXXCDC: M_WAITOK ... ok? */ 4530 } 4531 } 4532 4533 /* 4534 * if the parent's entry is wired down, then the 4535 * parent process does not want page faults on 4536 * access to that memory. this means that we 4537 * cannot do copy-on-write because we can't write 4538 * protect the old entry. in this case we 4539 * resolve all copy-on-write faults now, using 4540 * amap_cow_now. note that we have already 4541 * allocated any needed amap (above). 4542 */ 4543 4544 if (VM_MAPENT_ISWIRED(old_entry)) { 4545 4546 /* 4547 * resolve all copy-on-write faults now 4548 * (note that there is nothing to do if 4549 * the old mapping does not have an amap). 4550 */ 4551 if (old_entry->aref.ar_amap) 4552 amap_cow_now(new_map, new_entry); 4553 4554 } else { 4555 4556 /* 4557 * setup mappings to trigger copy-on-write faults 4558 * we must write-protect the parent if it has 4559 * an amap and it is not already "needs_copy"... 4560 * if it is already "needs_copy" then the parent 4561 * has already been write-protected by a previous 4562 * fork operation. 4563 */ 4564 4565 if (old_entry->aref.ar_amap && 4566 !UVM_ET_ISNEEDSCOPY(old_entry)) { 4567 if (old_entry->max_protection & VM_PROT_WRITE) { 4568 pmap_protect(old_map->pmap, 4569 old_entry->start, 4570 old_entry->end, 4571 old_entry->protection & 4572 ~VM_PROT_WRITE); 4573 } 4574 old_entry->etype |= UVM_ET_NEEDSCOPY; 4575 } 4576 } 4577 break; 4578 } /* end of switch statement */ 4579 old_entry = old_entry->next; 4580 } 4581 4582 pmap_update(old_map->pmap); 4583 vm_map_unlock(old_map); 4584 4585 #ifdef SYSVSHM 4586 if (vm1->vm_shm) 4587 shmfork(vm1, vm2); 4588 #endif 4589 4590 #ifdef PMAP_FORK 4591 pmap_fork(vm1->vm_map.pmap, vm2->vm_map.pmap); 4592 #endif 4593 4594 UVMHIST_LOG(maphist,"<- done",0,0,0,0); 4595 return (vm2); 4596 } 4597 4598 4599 /* 4600 * in-kernel map entry allocation. 4601 */ 4602 4603 struct uvm_kmapent_hdr { 4604 LIST_ENTRY(uvm_kmapent_hdr) ukh_listq; 4605 int ukh_nused; 4606 struct vm_map_entry *ukh_freelist; 4607 struct vm_map *ukh_map; 4608 struct vm_map_entry ukh_entries[0]; 4609 }; 4610 4611 #define UVM_KMAPENT_CHUNK \ 4612 ((PAGE_SIZE - sizeof(struct uvm_kmapent_hdr)) \ 4613 / sizeof(struct vm_map_entry)) 4614 4615 #define UVM_KHDR_FIND(entry) \ 4616 ((struct uvm_kmapent_hdr *)(((vaddr_t)entry) & ~PAGE_MASK)) 4617 4618 4619 #ifdef DIAGNOSTIC 4620 static struct vm_map * 4621 uvm_kmapent_map(struct vm_map_entry *entry) 4622 { 4623 const struct uvm_kmapent_hdr *ukh; 4624 4625 ukh = UVM_KHDR_FIND(entry); 4626 return ukh->ukh_map; 4627 } 4628 #endif 4629 4630 static inline struct vm_map_entry * 4631 uvm_kmapent_get(struct uvm_kmapent_hdr *ukh) 4632 { 4633 struct vm_map_entry *entry; 4634 4635 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4636 KASSERT(ukh->ukh_nused >= 0); 4637 4638 entry = ukh->ukh_freelist; 4639 if (entry) { 4640 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT)) 4641 == UVM_MAP_KERNEL); 4642 ukh->ukh_freelist = entry->next; 4643 ukh->ukh_nused++; 4644 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4645 } else { 4646 KASSERT(ukh->ukh_nused == UVM_KMAPENT_CHUNK); 4647 } 4648 4649 return entry; 4650 } 4651 4652 static inline void 4653 uvm_kmapent_put(struct uvm_kmapent_hdr *ukh, struct vm_map_entry *entry) 4654 { 4655 4656 KASSERT((entry->flags & (UVM_MAP_KERNEL | UVM_MAP_KMAPENT)) 4657 == UVM_MAP_KERNEL); 4658 KASSERT(ukh->ukh_nused <= UVM_KMAPENT_CHUNK); 4659 KASSERT(ukh->ukh_nused > 0); 4660 KASSERT(ukh->ukh_freelist != NULL || 4661 ukh->ukh_nused == UVM_KMAPENT_CHUNK); 4662 KASSERT(ukh->ukh_freelist == NULL || 4663 ukh->ukh_nused < UVM_KMAPENT_CHUNK); 4664 4665 ukh->ukh_nused--; 4666 entry->next = ukh->ukh_freelist; 4667 ukh->ukh_freelist = entry; 4668 } 4669 4670 /* 4671 * uvm_kmapent_alloc: allocate a map entry for in-kernel map 4672 */ 4673 4674 static struct vm_map_entry * 4675 uvm_kmapent_alloc(struct vm_map *map, int flags) 4676 { 4677 struct vm_page *pg; 4678 struct uvm_kmapent_hdr *ukh; 4679 struct vm_map_entry *entry; 4680 #ifndef PMAP_MAP_POOLPAGE 4681 struct uvm_map_args args; 4682 uvm_flag_t mapflags = UVM_MAPFLAG(UVM_PROT_ALL, UVM_PROT_ALL, 4683 UVM_INH_NONE, UVM_ADV_RANDOM, flags | UVM_FLAG_NOMERGE); 4684 int error; 4685 #endif 4686 vaddr_t va; 4687 int i; 4688 4689 KDASSERT(UVM_KMAPENT_CHUNK > 2); 4690 KDASSERT(kernel_map != NULL); 4691 KASSERT(vm_map_pmap(map) == pmap_kernel()); 4692 4693 UVMMAP_EVCNT_INCR(uke_alloc); 4694 entry = NULL; 4695 again: 4696 /* 4697 * try to grab an entry from freelist. 4698 */ 4699 mutex_spin_enter(&uvm_kentry_lock); 4700 ukh = LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free); 4701 if (ukh) { 4702 entry = uvm_kmapent_get(ukh); 4703 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK) 4704 LIST_REMOVE(ukh, ukh_listq); 4705 } 4706 mutex_spin_exit(&uvm_kentry_lock); 4707 4708 if (entry) 4709 return entry; 4710 4711 /* 4712 * there's no free entry for this vm_map. 4713 * now we need to allocate some vm_map_entry. 4714 * for simplicity, always allocate one page chunk of them at once. 4715 */ 4716 4717 pg = uvm_pagealloc(NULL, 0, NULL, 4718 (flags & UVM_KMF_NOWAIT) != 0 ? UVM_PGA_USERESERVE : 0); 4719 if (__predict_false(pg == NULL)) { 4720 if (flags & UVM_FLAG_NOWAIT) 4721 return NULL; 4722 uvm_wait("kme_alloc"); 4723 goto again; 4724 } 4725 4726 #ifdef PMAP_MAP_POOLPAGE 4727 va = PMAP_MAP_POOLPAGE(VM_PAGE_TO_PHYS(pg)); 4728 KASSERT(va != 0); 4729 #else 4730 error = uvm_map_prepare(map, 0, PAGE_SIZE, NULL, UVM_UNKNOWN_OFFSET, 4731 0, mapflags, &args); 4732 if (error) { 4733 uvm_pagefree(pg); 4734 return NULL; 4735 } 4736 4737 va = args.uma_start; 4738 4739 pmap_kenter_pa(va, VM_PAGE_TO_PHYS(pg), 4740 VM_PROT_READ|VM_PROT_WRITE, PMAP_KMPAGE); 4741 pmap_update(vm_map_pmap(map)); 4742 4743 #endif 4744 ukh = (void *)va; 4745 4746 /* 4747 * use the last entry for ukh itsself. 4748 */ 4749 4750 i = UVM_KMAPENT_CHUNK - 1; 4751 #ifndef PMAP_MAP_POOLPAGE 4752 entry = &ukh->ukh_entries[i--]; 4753 entry->flags = UVM_MAP_KERNEL | UVM_MAP_KMAPENT; 4754 error = uvm_map_enter(map, &args, entry); 4755 KASSERT(error == 0); 4756 #endif 4757 4758 ukh->ukh_nused = UVM_KMAPENT_CHUNK; 4759 ukh->ukh_map = map; 4760 ukh->ukh_freelist = NULL; 4761 for (; i >= 1; i--) { 4762 struct vm_map_entry *xentry = &ukh->ukh_entries[i]; 4763 4764 xentry->flags = UVM_MAP_KERNEL; 4765 uvm_kmapent_put(ukh, xentry); 4766 } 4767 #ifdef PMAP_MAP_POOLPAGE 4768 KASSERT(ukh->ukh_nused == 1); 4769 #else 4770 KASSERT(ukh->ukh_nused == 2); 4771 #endif 4772 4773 mutex_spin_enter(&uvm_kentry_lock); 4774 LIST_INSERT_HEAD(&vm_map_to_kernel(map)->vmk_kentry_free, 4775 ukh, ukh_listq); 4776 mutex_spin_exit(&uvm_kentry_lock); 4777 4778 /* 4779 * return first entry. 4780 */ 4781 4782 entry = &ukh->ukh_entries[0]; 4783 entry->flags = UVM_MAP_KERNEL; 4784 UVMMAP_EVCNT_INCR(ukh_alloc); 4785 4786 return entry; 4787 } 4788 4789 /* 4790 * uvm_mapent_free: free map entry for in-kernel map 4791 */ 4792 4793 static void 4794 uvm_kmapent_free(struct vm_map_entry *entry) 4795 { 4796 struct uvm_kmapent_hdr *ukh; 4797 struct vm_page *pg; 4798 struct vm_map *map; 4799 #ifndef PMAP_UNMAP_POOLPAGE 4800 struct pmap *pmap; 4801 struct vm_map_entry *deadentry; 4802 #endif 4803 vaddr_t va; 4804 paddr_t pa; 4805 4806 UVMMAP_EVCNT_INCR(uke_free); 4807 ukh = UVM_KHDR_FIND(entry); 4808 map = ukh->ukh_map; 4809 4810 mutex_spin_enter(&uvm_kentry_lock); 4811 uvm_kmapent_put(ukh, entry); 4812 #ifdef PMAP_UNMAP_POOLPAGE 4813 if (ukh->ukh_nused > 0) { 4814 #else 4815 if (ukh->ukh_nused > 1) { 4816 #endif 4817 if (ukh->ukh_nused == UVM_KMAPENT_CHUNK - 1) 4818 LIST_INSERT_HEAD( 4819 &vm_map_to_kernel(map)->vmk_kentry_free, 4820 ukh, ukh_listq); 4821 mutex_spin_exit(&uvm_kentry_lock); 4822 return; 4823 } 4824 4825 /* 4826 * now we can free this ukh. 4827 * 4828 * however, keep an empty ukh to avoid ping-pong. 4829 */ 4830 4831 if (LIST_FIRST(&vm_map_to_kernel(map)->vmk_kentry_free) == ukh && 4832 LIST_NEXT(ukh, ukh_listq) == NULL) { 4833 mutex_spin_exit(&uvm_kentry_lock); 4834 return; 4835 } 4836 LIST_REMOVE(ukh, ukh_listq); 4837 mutex_spin_exit(&uvm_kentry_lock); 4838 4839 va = (vaddr_t)ukh; 4840 4841 #ifdef PMAP_UNMAP_POOLPAGE 4842 KASSERT(ukh->ukh_nused == 0); 4843 pa = PMAP_UNMAP_POOLPAGE(va); 4844 KASSERT(pa != 0); 4845 #else 4846 KASSERT(ukh->ukh_nused == 1); 4847 4848 /* 4849 * remove map entry for ukh itsself. 4850 */ 4851 4852 KASSERT((va & PAGE_MASK) == 0); 4853 vm_map_lock(map); 4854 uvm_unmap_remove(map, va, va + PAGE_SIZE, &deadentry, NULL, 0); 4855 KASSERT(deadentry->flags & UVM_MAP_KERNEL); 4856 KASSERT(deadentry->flags & UVM_MAP_KMAPENT); 4857 KASSERT(deadentry->next == NULL); 4858 KASSERT(deadentry == &ukh->ukh_entries[UVM_KMAPENT_CHUNK - 1]); 4859 4860 /* 4861 * unmap the page from pmap and free it. 4862 */ 4863 4864 pmap = vm_map_pmap(map); 4865 KASSERT(pmap == pmap_kernel()); 4866 if (!pmap_extract(pmap, va, &pa)) 4867 panic("%s: no mapping", __func__); 4868 pmap_kremove(va, PAGE_SIZE); 4869 pmap_update(vm_map_pmap(map)); 4870 vm_map_unlock(map); 4871 #endif /* !PMAP_UNMAP_POOLPAGE */ 4872 pg = PHYS_TO_VM_PAGE(pa); 4873 uvm_pagefree(pg); 4874 UVMMAP_EVCNT_INCR(ukh_free); 4875 } 4876 4877 static vsize_t 4878 uvm_kmapent_overhead(vsize_t size) 4879 { 4880 4881 /* 4882 * - the max number of unmerged entries is howmany(size, PAGE_SIZE) 4883 * as the min allocation unit is PAGE_SIZE. 4884 * - UVM_KMAPENT_CHUNK "kmapent"s are allocated from a page. 4885 * one of them are used to map the page itself. 4886 */ 4887 4888 return howmany(howmany(size, PAGE_SIZE), (UVM_KMAPENT_CHUNK - 1)) * 4889 PAGE_SIZE; 4890 } 4891 4892 /* 4893 * map entry reservation 4894 */ 4895 4896 /* 4897 * uvm_mapent_reserve: reserve map entries for clipping before locking map. 4898 * 4899 * => needed when unmapping entries allocated without UVM_FLAG_QUANTUM. 4900 * => caller shouldn't hold map locked. 4901 */ 4902 int 4903 uvm_mapent_reserve(struct vm_map *map, struct uvm_mapent_reservation *umr, 4904 int nentries, int flags) 4905 { 4906 4907 umr->umr_nentries = 0; 4908 4909 if ((flags & UVM_FLAG_QUANTUM) != 0) 4910 return 0; 4911 4912 if (!VM_MAP_USE_KMAPENT(map)) 4913 return 0; 4914 4915 while (nentries--) { 4916 struct vm_map_entry *ent; 4917 ent = uvm_kmapent_alloc(map, flags); 4918 if (!ent) { 4919 uvm_mapent_unreserve(map, umr); 4920 return ENOMEM; 4921 } 4922 UMR_PUTENTRY(umr, ent); 4923 } 4924 4925 return 0; 4926 } 4927 4928 /* 4929 * uvm_mapent_unreserve: 4930 * 4931 * => caller shouldn't hold map locked. 4932 * => never fail or sleep. 4933 */ 4934 void 4935 uvm_mapent_unreserve(struct vm_map *map, struct uvm_mapent_reservation *umr) 4936 { 4937 4938 while (!UMR_EMPTY(umr)) 4939 uvm_kmapent_free(UMR_GETENTRY(umr)); 4940 } 4941 4942 /* 4943 * uvm_mapent_trymerge: try to merge an entry with its neighbors. 4944 * 4945 * => called with map locked. 4946 * => return non zero if successfully merged. 4947 */ 4948 4949 int 4950 uvm_mapent_trymerge(struct vm_map *map, struct vm_map_entry *entry, int flags) 4951 { 4952 struct uvm_object *uobj; 4953 struct vm_map_entry *next; 4954 struct vm_map_entry *prev; 4955 vsize_t size; 4956 int merged = 0; 4957 bool copying; 4958 int newetype; 4959 4960 if (VM_MAP_USE_KMAPENT(map)) { 4961 return 0; 4962 } 4963 if (entry->aref.ar_amap != NULL) { 4964 return 0; 4965 } 4966 if ((entry->flags & UVM_MAP_NOMERGE) != 0) { 4967 return 0; 4968 } 4969 4970 uobj = entry->object.uvm_obj; 4971 size = entry->end - entry->start; 4972 copying = (flags & UVM_MERGE_COPYING) != 0; 4973 newetype = copying ? (entry->etype & ~UVM_ET_NEEDSCOPY) : entry->etype; 4974 4975 next = entry->next; 4976 if (next != &map->header && 4977 next->start == entry->end && 4978 ((copying && next->aref.ar_amap != NULL && 4979 amap_refs(next->aref.ar_amap) == 1) || 4980 (!copying && next->aref.ar_amap == NULL)) && 4981 UVM_ET_ISCOMPATIBLE(next, newetype, 4982 uobj, entry->flags, entry->protection, 4983 entry->max_protection, entry->inheritance, entry->advice, 4984 entry->wired_count) && 4985 (uobj == NULL || entry->offset + size == next->offset)) { 4986 int error; 4987 4988 if (copying) { 4989 error = amap_extend(next, size, 4990 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_BACKWARDS); 4991 } else { 4992 error = 0; 4993 } 4994 if (error == 0) { 4995 if (uobj) { 4996 if (uobj->pgops->pgo_detach) { 4997 uobj->pgops->pgo_detach(uobj); 4998 } 4999 } 5000 5001 entry->end = next->end; 5002 clear_hints(map, next); 5003 uvm_map_entry_unlink(map, next); 5004 if (copying) { 5005 entry->aref = next->aref; 5006 entry->etype &= ~UVM_ET_NEEDSCOPY; 5007 } 5008 uvm_map_check(map, "trymerge forwardmerge"); 5009 uvm_mapent_free_merged(map, next); 5010 merged++; 5011 } 5012 } 5013 5014 prev = entry->prev; 5015 if (prev != &map->header && 5016 prev->end == entry->start && 5017 ((copying && !merged && prev->aref.ar_amap != NULL && 5018 amap_refs(prev->aref.ar_amap) == 1) || 5019 (!copying && prev->aref.ar_amap == NULL)) && 5020 UVM_ET_ISCOMPATIBLE(prev, newetype, 5021 uobj, entry->flags, entry->protection, 5022 entry->max_protection, entry->inheritance, entry->advice, 5023 entry->wired_count) && 5024 (uobj == NULL || 5025 prev->offset + prev->end - prev->start == entry->offset)) { 5026 int error; 5027 5028 if (copying) { 5029 error = amap_extend(prev, size, 5030 AMAP_EXTEND_NOWAIT|AMAP_EXTEND_FORWARDS); 5031 } else { 5032 error = 0; 5033 } 5034 if (error == 0) { 5035 if (uobj) { 5036 if (uobj->pgops->pgo_detach) { 5037 uobj->pgops->pgo_detach(uobj); 5038 } 5039 entry->offset = prev->offset; 5040 } 5041 5042 entry->start = prev->start; 5043 clear_hints(map, prev); 5044 uvm_map_entry_unlink(map, prev); 5045 if (copying) { 5046 entry->aref = prev->aref; 5047 entry->etype &= ~UVM_ET_NEEDSCOPY; 5048 } 5049 uvm_map_check(map, "trymerge backmerge"); 5050 uvm_mapent_free_merged(map, prev); 5051 merged++; 5052 } 5053 } 5054 5055 return merged; 5056 } 5057 5058 /* 5059 * uvm_map_create: create map 5060 */ 5061 5062 struct vm_map * 5063 uvm_map_create(pmap_t pmap, vaddr_t vmin, vaddr_t vmax, int flags) 5064 { 5065 struct vm_map *result; 5066 5067 result = malloc(sizeof(struct vm_map), M_VMMAP, M_WAITOK); 5068 uvm_map_setup(result, vmin, vmax, flags); 5069 result->pmap = pmap; 5070 return(result); 5071 } 5072 5073 /* 5074 * uvm_map_setup: init map 5075 * 5076 * => map must not be in service yet. 5077 */ 5078 5079 void 5080 uvm_map_setup(struct vm_map *map, vaddr_t vmin, vaddr_t vmax, int flags) 5081 { 5082 int ipl; 5083 5084 rb_tree_init(&map->rb_tree, &uvm_map_tree_ops); 5085 map->header.next = map->header.prev = &map->header; 5086 map->nentries = 0; 5087 map->size = 0; 5088 map->ref_count = 1; 5089 vm_map_setmin(map, vmin); 5090 vm_map_setmax(map, vmax); 5091 map->flags = flags; 5092 map->first_free = &map->header; 5093 map->hint = &map->header; 5094 map->timestamp = 0; 5095 map->busy = NULL; 5096 5097 if ((flags & VM_MAP_INTRSAFE) != 0) { 5098 ipl = IPL_VM; 5099 } else { 5100 ipl = IPL_NONE; 5101 } 5102 5103 rw_init(&map->lock); 5104 cv_init(&map->cv, "vm_map"); 5105 mutex_init(&map->misc_lock, MUTEX_DRIVER, ipl); 5106 mutex_init(&map->mutex, MUTEX_DRIVER, ipl); 5107 } 5108 5109 5110 /* 5111 * U N M A P - m a i n e n t r y p o i n t 5112 */ 5113 5114 /* 5115 * uvm_unmap1: remove mappings from a vm_map (from "start" up to "stop") 5116 * 5117 * => caller must check alignment and size 5118 * => map must be unlocked (we will lock it) 5119 * => flags is UVM_FLAG_QUANTUM or 0. 5120 */ 5121 5122 void 5123 uvm_unmap1(struct vm_map *map, vaddr_t start, vaddr_t end, int flags) 5124 { 5125 struct vm_map_entry *dead_entries; 5126 struct uvm_mapent_reservation umr; 5127 UVMHIST_FUNC("uvm_unmap"); UVMHIST_CALLED(maphist); 5128 5129 UVMHIST_LOG(maphist, " (map=0x%x, start=0x%x, end=0x%x)", 5130 map, start, end, 0); 5131 if (map == kernel_map) { 5132 LOCKDEBUG_MEM_CHECK((void *)start, end - start); 5133 } 5134 /* 5135 * work now done by helper functions. wipe the pmap's and then 5136 * detach from the dead entries... 5137 */ 5138 uvm_mapent_reserve(map, &umr, 2, flags); 5139 vm_map_lock(map); 5140 uvm_unmap_remove(map, start, end, &dead_entries, &umr, flags); 5141 vm_map_unlock(map); 5142 uvm_mapent_unreserve(map, &umr); 5143 5144 if (dead_entries != NULL) 5145 uvm_unmap_detach(dead_entries, 0); 5146 5147 UVMHIST_LOG(maphist, "<- done", 0,0,0,0); 5148 } 5149 5150 5151 /* 5152 * uvm_map_reference: add reference to a map 5153 * 5154 * => map need not be locked (we use misc_lock). 5155 */ 5156 5157 void 5158 uvm_map_reference(struct vm_map *map) 5159 { 5160 mutex_enter(&map->misc_lock); 5161 map->ref_count++; 5162 mutex_exit(&map->misc_lock); 5163 } 5164 5165 struct vm_map_kernel * 5166 vm_map_to_kernel(struct vm_map *map) 5167 { 5168 5169 KASSERT(VM_MAP_IS_KERNEL(map)); 5170 5171 return (struct vm_map_kernel *)map; 5172 } 5173 5174 bool 5175 vm_map_starved_p(struct vm_map *map) 5176 { 5177 5178 if ((map->flags & VM_MAP_WANTVA) != 0) { 5179 return true; 5180 } 5181 /* XXX */ 5182 if ((vm_map_max(map) - vm_map_min(map)) / 16 * 15 < map->size) { 5183 return true; 5184 } 5185 return false; 5186 } 5187 5188 #if defined(DDB) || defined(DEBUGPRINT) 5189 5190 /* 5191 * uvm_map_printit: actually prints the map 5192 */ 5193 5194 void 5195 uvm_map_printit(struct vm_map *map, bool full, 5196 void (*pr)(const char *, ...)) 5197 { 5198 struct vm_map_entry *entry; 5199 5200 (*pr)("MAP %p: [0x%lx->0x%lx]\n", map, vm_map_min(map), 5201 vm_map_max(map)); 5202 (*pr)("\t#ent=%d, sz=%d, ref=%d, version=%d, flags=0x%x\n", 5203 map->nentries, map->size, map->ref_count, map->timestamp, 5204 map->flags); 5205 (*pr)("\tpmap=%p(resident=%ld, wired=%ld)\n", map->pmap, 5206 pmap_resident_count(map->pmap), pmap_wired_count(map->pmap)); 5207 if (!full) 5208 return; 5209 for (entry = map->header.next; entry != &map->header; 5210 entry = entry->next) { 5211 (*pr)(" - %p: 0x%lx->0x%lx: obj=%p/0x%llx, amap=%p/%d\n", 5212 entry, entry->start, entry->end, entry->object.uvm_obj, 5213 (long long)entry->offset, entry->aref.ar_amap, 5214 entry->aref.ar_pageoff); 5215 (*pr)( 5216 "\tsubmap=%c, cow=%c, nc=%c, prot(max)=%d/%d, inh=%d, " 5217 "wc=%d, adv=%d\n", 5218 (entry->etype & UVM_ET_SUBMAP) ? 'T' : 'F', 5219 (entry->etype & UVM_ET_COPYONWRITE) ? 'T' : 'F', 5220 (entry->etype & UVM_ET_NEEDSCOPY) ? 'T' : 'F', 5221 entry->protection, entry->max_protection, 5222 entry->inheritance, entry->wired_count, entry->advice); 5223 } 5224 } 5225 5226 void 5227 uvm_whatis(uintptr_t addr, void (*pr)(const char *, ...)) 5228 { 5229 struct vm_map *map; 5230 5231 for (map = kernel_map;;) { 5232 struct vm_map_entry *entry; 5233 5234 if (!uvm_map_lookup_entry_bytree(map, (vaddr_t)addr, &entry)) { 5235 break; 5236 } 5237 (*pr)("%p is %p+%zu from VMMAP %p\n", 5238 (void *)addr, (void *)entry->start, 5239 (size_t)(addr - (uintptr_t)entry->start), map); 5240 if (!UVM_ET_ISSUBMAP(entry)) { 5241 break; 5242 } 5243 map = entry->object.sub_map; 5244 } 5245 } 5246 5247 #endif /* DDB || DEBUGPRINT */ 5248 5249 #ifndef __USER_VA0_IS_SAFE 5250 static int 5251 sysctl_user_va0_disable(SYSCTLFN_ARGS) 5252 { 5253 struct sysctlnode node; 5254 int t, error; 5255 5256 node = *rnode; 5257 node.sysctl_data = &t; 5258 t = user_va0_disable; 5259 error = sysctl_lookup(SYSCTLFN_CALL(&node)); 5260 if (error || newp == NULL) 5261 return (error); 5262 5263 /* lower only at securelevel < 1 */ 5264 if (!t && user_va0_disable && 5265 kauth_authorize_system(l->l_cred, 5266 KAUTH_SYSTEM_CHSYSFLAGS /* XXX */, 0, 5267 NULL, NULL, NULL)) 5268 return EPERM; 5269 5270 user_va0_disable = !!t; 5271 return 0; 5272 } 5273 5274 SYSCTL_SETUP(sysctl_uvmmap_setup, "sysctl uvmmap setup") 5275 { 5276 5277 sysctl_createv(clog, 0, NULL, NULL, 5278 CTLFLAG_PERMANENT|CTLFLAG_READWRITE, 5279 CTLTYPE_INT, "user_va0_disable", 5280 SYSCTL_DESCR("Disable VA 0"), 5281 sysctl_user_va0_disable, 0, &user_va0_disable, 0, 5282 CTL_VM, CTL_CREATE, CTL_EOL); 5283 } 5284 #endif 5285